Matching Items (5)
Filtering by
- Member of: Theses and Dissertations
Description
A model has been developed to modify Euler-Bernoulli beam theory for wooden beams, using visible properties of wood knot-defects. Treating knots in a beam as a system of two ellipses that change the local bending stiffness has been shown to improve the fit of a theoretical beam displacement function to edge-line deflection data extracted from digital imagery of experimentally loaded beams. In addition, an Ellipse Logistic Model (ELM) has been proposed, using L1-regularized logistic regression, to predict the impact of a knot on the displacement of a beam. By classifying a knot as severely positive or negative, vs. mildly positive or negative, ELM can classify knots that lead to large changes to beam deflection, while not over-emphasizing knots that may not be a problem. Using ELM with a regression-fit Young's Modulus on three-point bending of Douglass Fir, it is possible estimate the effects a knot will have on the shape of the resulting displacement curve.
ContributorsSexton, Thurston Bryant (Author) / Takahashi, Timothy (Thesis director) / Jones, Donald (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2015-05
Description
The purpose of this cookbook was to provide students that live in the Barrett dorms with easily accessible nutritious meals that prevent total reliance on the dorm's dining hall throughout the year. Limitations of this research included staying within budget, the availability of near-by grocery stores, meal preparation time, and the types of appliances which can be used in dorms. While living in dorms many students may find that dining halls have a large variety of food offerings that are consistently available. Although there are many options, they are not necessarily the healthiest choices. In addition to health these options rarely change. For safety reasons students are limited to dorm room appliance options that include a mini-fridge and a microwave. There is not a lot of cooking you can do with just a microwave, but with the proper knowledge it is surprisingly enough to make a great meal. In addition to appliances students can utilize cutting boards, plates, and plastic utensils, but if students are not educated about cooking diverse meals it is easy to venture toward unhealthy meal choices. Attending college can be costly. Expenses of tuition, books, supplies and living fees can add up quickly. Students are always in need of healthy meal options that are also healthy for their bank accounts. This cookbook contains affordable, healthy, and quick to make recipes. Virtually everyone who has ever been a student usually has a weekly/monthly budgetary amount to spend and cooking their own meals in the dorms will turn out to be much cheaper alternative to having dining hall meals every day. It was interesting to create a week full of meal preps for breakfast, lunch and dinner- including snacks with various alternatives. Not every student has a vehicle in which they can get necessary ingredients for cooking; Therefore, this cookbook has a grocery store map that includes address and store hours to aid students in choosing closer more convenient locations. In college, the journey to a healthy lifestyle is not easy. There are many ways to keep on track and follow the routine which works for both the body and the mind. Following the easy recipes within this cook book will minimize the risk of freshman 15 weight gain and decrease the time spent on both cooking and coming up with healthy meal ideas. These meals are uncomplicated, affordable, and take little to no effort. Barrett CookBook for Dorms main mission was to provide students with a foundation for a nutritional, flexible, and stress-free dining environment without the added stress of constantly thinking about what goes into their bodies.
ContributorsCherkaskykh, Alisa A. (Author) / Grgich, Traci (Thesis director) / Johnston, Carol (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
For this creative project, the student's overarching objective was to establish a signature dish and to learn how to cook. She acquired a cookbook fit for novice cooks, "Eat What You Love" by Marlene Koch, which focused on healthy eating through the reduction of sugar and fat. The student completed thirty recipes including two appetizers, five breakfast entrees, five lunch entrees, twelve dinner entrees, and six desserts. Her culinary ventures were then detailed through a blog site the student had created. Blog posts included a brief description primarily of the portion size, a nutritional analysis of the recipe, enjoyable aspects of the dish, whether something went wrong, what was learned from creating the dish, as well as a photograph of the prepared dish. A large element of this project focused upon food photography and obtaining images that made the created dish look appealing. It was found that the best images were taken in natural lighting with good compositions and pops of color. In order to gain readership, the student developed an Instagram account where she would post images of the food and provide links to her blog entries and recipes. Through this means, she was able to obtain over 100 followers to her blog. In addition to learning how to cook, the student sought out to understand components of a healthy diet and how each nutrient contributes to an individual health. This objective is detailed throughout the course of the paper as well as several other objectives. The student also studied how social media has impacted the way in which we share food and our knowledge of food. Additionally in this paper, the student evaluated the evolution of the USDA Dietary Guidelines and their effectiveness over time. From this project, the student walked away with new knowledge about nutritional eating and lifestyle habits that she will retain for years to come. She hopes that this project will encourage other students to take on their own culinary adventure.
ContributorsMarley, Allison Marie (Author) / Levinson, Simin (Thesis director) / Martinelli, Sarah (Committee member) / Harrington Bioengineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
In materials science, developing GeSn alloys is major current research interest concerning the production of efficient Group-IV photonics. These alloys are particularly interesting because the development of next-generation semiconductors for ultrafast (terahertz) optoelectronic communication devices could be accomplished through integrating these novel alloys with industry-standard silicon technology. Unfortunately, incorporating a maximal amount of Sn into a Ge lattice has been difficult to achieve experimentally. At ambient conditions, pure Ge and Sn adopt cubic (α) and tetragonal (β) structures, respectively, however, to date the relative stability and structure of α and β phase GeSn alloys versus percent composition Sn has not been thoroughly studied. In this research project, computational tools were used to perform state-of-the-art predictive quantum simulations to study the structural, bonding and energetic trends in GeSn alloys in detail over a range of experimentally accessible compositions. Since recent X-Ray and vibrational studies have raised some controversy about the nanostructure of GeSn alloys, the investigation was conducted with ordered, random and clustered alloy models.
By means of optimized geometry analysis, pure Ge and Sn were found to adopt the alpha and beta structures, respectively, as observed experimentally. For all theoretical alloys, the corresponding αphase structure was found to have the lowest energy, for Sn percent compositions up to 90%. However at 50% Sn, the correspondingβ alloy energies are predicted to be only ~70 meV higher. The formation energy of α-phase alloys was found to be positive for all compositions, whereas only two beta formation energies were negative. Bond length distributions were analyzed and dependence on Sn incorporation was found, perhaps surprisingly, not to be directly correlated with cell volume. It is anticipated that the data collected in this project may help to elucidate observed complex vibrational properties in these systems.
By means of optimized geometry analysis, pure Ge and Sn were found to adopt the alpha and beta structures, respectively, as observed experimentally. For all theoretical alloys, the corresponding αphase structure was found to have the lowest energy, for Sn percent compositions up to 90%. However at 50% Sn, the correspondingβ alloy energies are predicted to be only ~70 meV higher. The formation energy of α-phase alloys was found to be positive for all compositions, whereas only two beta formation energies were negative. Bond length distributions were analyzed and dependence on Sn incorporation was found, perhaps surprisingly, not to be directly correlated with cell volume. It is anticipated that the data collected in this project may help to elucidate observed complex vibrational properties in these systems.
ContributorsLiberman-Martin, Zoe Elise (Author) / Chizmeshya, Andrew (Thesis director) / Sayres, Scott (Committee member) / Wolf, George (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Non-Destructive Testing (NDT) is integral to preserving the structural health of materials. Techniques that fall under the NDT category are able to evaluate integrity and condition of a material without permanently altering any property of the material. Additionally, they can typically be used while the material is in active use instead of needing downtime for inspection.
The two general categories of structural health monitoring (SHM) systems include passive and active monitoring. Active SHM systems utilize an input of energy to monitor the health of a structure (such as sound waves in ultrasonics), while passive systems do not. As such, passive SHM tends to be more desirable. A system could be permanently fixed to a critical location, passively accepting signals until it records a damage event, then localize and characterize the damage. This is the goal of acoustic emissions testing.
When certain types of damage occur, such as matrix cracking or delamination in composites, the corresponding release of energy creates sound waves, or acoustic emissions, that propagate through the material. Audio sensors fixed to the surface can pick up data from both the time and frequency domains of the wave. With proper data analysis, a time of arrival (TOA) can be calculated for each sensor allowing for localization of the damage event. The frequency data can be used to characterize the damage.
In traditional acoustic emissions testing, the TOA combined with wave velocity and information about signal attenuation in the material is used to localize events. However, in instances of complex geometries or anisotropic materials (such as carbon fibre composites), velocity and attenuation can vary wildly based on the direction of interest. In these cases, localization can be based off of the time of arrival distances for each sensor pair. This technique is called Delta T mapping, and is the main focus of this study.
The two general categories of structural health monitoring (SHM) systems include passive and active monitoring. Active SHM systems utilize an input of energy to monitor the health of a structure (such as sound waves in ultrasonics), while passive systems do not. As such, passive SHM tends to be more desirable. A system could be permanently fixed to a critical location, passively accepting signals until it records a damage event, then localize and characterize the damage. This is the goal of acoustic emissions testing.
When certain types of damage occur, such as matrix cracking or delamination in composites, the corresponding release of energy creates sound waves, or acoustic emissions, that propagate through the material. Audio sensors fixed to the surface can pick up data from both the time and frequency domains of the wave. With proper data analysis, a time of arrival (TOA) can be calculated for each sensor allowing for localization of the damage event. The frequency data can be used to characterize the damage.
In traditional acoustic emissions testing, the TOA combined with wave velocity and information about signal attenuation in the material is used to localize events. However, in instances of complex geometries or anisotropic materials (such as carbon fibre composites), velocity and attenuation can vary wildly based on the direction of interest. In these cases, localization can be based off of the time of arrival distances for each sensor pair. This technique is called Delta T mapping, and is the main focus of this study.
ContributorsBriggs, Nathaniel (Author) / Chattopadhyay, Aditi (Thesis director) / Papandreou-Suppappola, Antonia (Committee member) / Skinner, Travis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05