Middle Tennessee State University
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DESIGN, SIMULATION AND ANALYSIS OF A NOVEL ROTARY VALVE FOR IMPROVEMENT IN THE EFFICIENCY OF AN INTERNAL COMBUSTION ENGINE
No full textNumerous studies have concentrated on enhancing the efficiency of internal combustion engines through various means, including refined design, superior materials, and regenerative technologies. Toyota recently reported a 40% gasoline engine efficiency with their Prius model in 2016. However, further research is warranted for improvement towards reaching the theoretical value of 73% efficiency as outlined by the Carnot Theorem.
The first section of this dissertation gives an in-depth introduction of internal combustion engine from aspects including the history and the popular modern design as well as the history of the inventions of rotary valve engines.
In the second section, the concept of using rotary valve instead of the conventional poppet valve for internal combustion engine is proposed. The study lists major drawbacks of the conventional poppet valve and explains the advantages of the rotary valve in general. A novel vertical positioned, servo motor driven, bell shape rotary valve is proposed to potentially improve the efficiency of a known conventional valve designed engine. The data of the new design is compared to the conventional poppet valve design with respect to several parameters to discuss its working principle and advantages over the conventional valve mechanism. Modeling is performed using Python programming to predict the valve opening mechanism. The experimental design is setup to control and tune different parameters accordingly within the reasonable range of engine speed viz. 1000-6000 RPM to simulate various working conditions. The maximum opening area for the rotary valve is calculated to be 0.795 sq.in which is smaller than the poppet valve’s area of 1.315 sq.in. However, under an example of 2900 RPM, the rotary valve was able to remain fully opened with constant efficiency of about 54% from 40 to 160 degrees of the crankshaft angle, while the poppet valve achieves 88% efficiency at 90 degree of the crankshaft angle and the efficiency significantly drops on either side of the maximum. Calculation shows that the proposed rotary valve can gain better performance with engine speed below 4400 RPM which is acceptable for real world use.
Building on these findings, the third section develops and improves the rotary valve mechanism and the engine design. With key parameters such as displacement, cylinder bore, stroke, and compression ratio remaining the same, a transvers positioned, servo motor driven, spherical shape rotary valve is introduced. Instead of retrofitting the existing engine head with the bell-shaped valve, a new engine head design is developed, aiming to minimize the overall number of components required.
A new spindle port shape is proposed, accompanied by a comparative calculation with the traditional circular shape. The valve flow coefficient prediction and in-cylinder pressure prediction are performed followed by volumetric efficiency prediction.
An engine simulation based on the ideal Otto cycle is conducted with adequate predictions and parameter settings. The results reveal that the spherical shape rotary valve achieves a valve opening area comparable to that of the conventional poppet valve. Additionally, the spindle valve opening port shape delivers a volumetric efficiency gain of up to 3% compared to the circular shape at the same crankshaft angle. This improvement in volumetric efficiency is attributed to the engine's kinematics and mechanical engineering principles. The rapid creation of valve opening area by the rotary valve during the intake process results in very low negative work, as depicted in the P-V diagram from the engine simulation.
Overall, these findings underscore the potential of the spherical shape rotary valve and spindle valve opening port shape to enhance engine performance and efficiency, offering valuable insights for further advancements in internal combustion engine design.Ph.D
Revolutionizing Cooking with Induction Heating Stovetops: Unveiling the Benefits, Design Considerations and Nationwide Integration Strategy
No full textStudies have been surfacing over the detrimental effect gas stovetops have on the environment and consumers. An alternative stovetop technology is needed to counteract the growing energy consumption in the United States. This thesis is an in-depth evaluation of how to best implement induction for use in stovetops and formulation of a process toward the adoption of induction cooking nationwide. Conducting a thorough analysis of the optimal design and materials for induction cooking, combined with a comprehensive evaluation of the advantages of induction stovetops over alternative cooking surfaces, can effectively persuade the public to embrace induction heating. A well-informed understanding of the most effective implementation of induction heating stovetops is crucial for a seamless transition towards a clean and efficient future in cooking. Government interventions, such as tax breaks, can further contribute to convincing individuals to adopt a more environmentally friendly stovetop solution
The Effects of Antibiotic-Oxytocin Interactions on Social and Motivational Behavior
No full textOxytocin is a neuropeptide that plays a role in many parts of the body; and is well known for its role in social behaviors. Antibiotics are a staple in the modern world, with nearly 50 million yearly prescriptions given to people under the age of 20 (Center for Disease Control, 2024). To date, no studies have examined the drug interaction of oxytocin and antibiotics and its effect on social motivation. Mice were used as model organisms to study these behavioral effects. The experimental groups included both sexes and four drug groups: saline (control), oxytocin, antibiotics, and oxytocin with antibiotics. After 14 days of drug administration, 3 behavioral assays were conducted to examine social motivation effects. The results of this study found that the oxytocin-antibiotics group had lower social avoidance than the other groups. No sex effects were found in any social behavior analysis and no social approach differences were found between groups
DSI Assessment 2023-2024
No full textDigital Scholarship Initiatives, an extension of the mission of the Walker Library as an active partner in the scholarly communication process, supports the educational mission of the university by providing access to information. Walker Library has invested resources to establish the necessary and supportive infrastructure used in the creation and dissemination of digital resources. Learn more at http://dsi.mtsu.edu. To print as brochure, use the following printer settings: double-sided, flip on short edge as 99% scale.A Digital Scholarship Center Assessment. Digital Scholarship Initiatives began at Walker Library several years ago as a way to build out the library’s collections digitally. More recently, other initiatives have been added including library publishing through JEWLScholar and Journal Hosting services; the creation of a collaborative Digital Partners group; and a Digital Scholarship Lab (DSL) dedicated to faculty and advanced students who enhance research by using digital tools and methodologies learned in workshops, collaborating on digital projects, and disseminating research through digital platforms. What follows is an assessment of the past year's development
Where language and content intersect: Implementing a system of supports for middle school content area classroom teachers who also serve ESL students.
No full textEnglish as a second language students continue to make up the fastest-growing group among students in public schools today (Garcia, 2012). Teachers are not adequately prepared to teach both content and language acquisition simultaneously, but this is the reality in many classrooms. The purpose of this design-based qualitative research study was to develop a robust intervention with a collaborative team, that will identify and define the characteristics of a system of supports that can be put in place for content area teachers of ESL learners. The questions guiding this study are: (1.) What does instruction currently look like for ESL students in general education content area classrooms at Skylark Middle School and what changes are needed for improvement in instructional practices? (2.) What are the characteristics of a system of supports that are needed for classroom teachers, at the middle school level, who serve English as a Second Language students in general education mainstream content area classrooms?
This study is set in a large suburban middle school in Middle Tennessee. While ESL students are distal actors in this research, the primary participants are mainstream middle school academic content area teachers, and a collaborative team called the EDIT. The findings suggest that in our context there were inconsistencies in student scheduling that needed to be addressed as well as understanding the various levels of background knowledge and English language acquisition that ESL students have. Based on this finding, the support systems for teachers will address scheduling and various forms of ongoing professional development to increase levels of content knowledge and pedagogy specific to ESL student needs.Ed.D
BURY YOUR BLONDES: THE LIFE, DEATH, AND ONGOING OBSESSION WITH MARILYN MONROE AND ANNA NICOLE SMITH
No full textThis thesis explores why the media and the public were – and continue to be – so
obsessed with Marilyn Monroe and Anna Nicole Smith. Qualitative textual analysis is
utilized to analyze coverage of both women within the New York Times both during their
lives and after their deaths. The dialogue used to discuss Monroe and Smith within these
articles is examined to show the Times articles perpetuating common themes such as a
preoccupation with their personal lives, a dismissal of their professional abilities, and an
obsession with reporting every detail of their health struggles. In perpetuating these
themes, the Times helped construct and firmly establish the “tragic blonde” archetype that
is so strongly associated with Monroe and Smith.M.S
Exploring the Connection Between Game-Based Learning, Social and Emotional Learning, and Critical Thinking through Tabletop Role-Playing Games
No full textThe purpose of this thesis is to explore the potential of tabletop role-playing games (TTRPGs) as educational tools for developing critical thinking and social-emotional learning (SEL) competencies. This study focuses on identifying the key elements that make TTRPGs effective in cultivating these competencies and developing a rubric to assess their presence in TTRPGs. A comprehensive literature review is conducted to synthesize findings from various studies on game-based learning, critical thinking, and SEL. From this review, categories for examination are formulated, including problem-solving tasks, decision-making scenarios, reflective activities, and information analysis and evaluation. Data is collected and categorized according to these themes. From these data, educators may learn how to effectively implement TTRPGs in educational settings to foster critical thinking and SEL competencies. A rubric is developed to assess the presence of these elements in TTRPGs, considering factors such as game mechanics, gameplay rules, facilitation, and narrative elements. That rubric is then applied to a small sample of TTRPGs to demonstrate how to use the rubric
Teacher Perceptions of Instructional Coach Support
No full textThis action research investigates the perceptions of teachers regarding the supports provided by instructional coaches within the context of Dan Alko Middle School. Recognizing that effective instructional coaching is crucial for teacher development, the study explores the challenges coaches face, including teacher resistance to change, scheduling conflicts, misalignments between coaching styles and teachers’ learning preferences, trust issues, and inconsistent implementation of coaching strategies. The research emphasizes the importance of individualized, context-specific support, drawing on teacher learning theories and the effectiveness of Jim Knight’s Impact Cycle. Through qualitative methods—interviews, coaching cycles, and surveys—the study examines the impact these supports on teacher preparedness and instructional practices. Findings reveal distinct experiences among participating teachers, with one demonstrating growth through collaborative engagement, while the other exhibited reluctance to fully embrace the coaching process. The study underscores the necessity for adaptive coaching strategies and ongoing support to foster productive teacher-coach relationships, ultimately contributing to enhanced instructional effectiveness and professional growth. The insights gained aim to inform future practices in instructional coaching, promoting a culture of continuous improvement within educational settings.Ed.D
Growing Freshwater Sponge Gemmules into Adulthood for Preliminary Utilization as Gray Water Filters.
No full textFreshwater sponges are multicellular sessile heterotrophs, extracting their
nutrients from their surrounding water environment through a process called filter
feeding. As the river current flows through their internal canals, they collect essential
minerals and ions to grow such as magnesium, potassium, sodium, and nitrogen. During
unfavorable environmental conditions, these sponges produce gemmules within their
adult tissue to survive these adverse conditions. When conditions become favorable for
growth, gemmules will then release totipotent archeocytes, which will differentiate into
specialized cells needed for growth to produce another adult sponge. Locally collected
sponge gemmules were subjected to three treatments to stimulate hatching and measure
their growth in vitro. Overall, these results provide the first records of hatching
conditions for Tennessee sponges. The sponge Ephydatia fluviatilis proved to be the most
robust species, hatching in a wide variety of in vitro conditions. The three other species
used in this study showed more mixed results. Strekal’s medium in larger petri dishes
were the optimal conditions for sponge hatching and growth in these experiments. The
results of sponge feeding trials were not determinant of an optimal treatment, and further
research is needed in this area. The foundational knowledge generated in this study will
serve as a steppingstone for future research to potentially use sponges as a living filter for
gray water reduction
A Brief History of the Preventorium: Architectural and Other Challenges of Preserving the Children’s Preventorium
No full textBeginning in the 1970s, with assessments increasing in number in the 1980s and 1990s, historic preservationists have studied sanitoriums, small and large, across the United States. Almost no attention has been given to preventoriums, which were institutions that housed those with latent or bone and joint tuberculosis. These institutions represent a significant period of American medicine and understanding this resource’s significance was the primary purpose of the thesis. It combines both architectural survey and primary resources to make the case for the future preservation and interpretation of preventoriums.M.L.A