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Title: UNDERSTANDING THE ROLES OF INTERKINGDOM MICROBIAL INTERACTIONS, MICROBIAL TRAITS, AND HOST FACTORS IN THE ASSEMBLY OF PLANT MICROBIOMES
Creator: Liber, Julian Aaron
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The community of organisms that associate with plants are vital to both the survival of the host plant but also the diseases which may kill it. The processes by which this community, called the microbiome, assemble and function can contribute to the traits of the host, including plants that humans rely on for food, resources, and ecosystems services. This thesis focuses on understanding the assembly of microbiomes at the scale of microbe-microbe interactions and traits of individual microbes,...
Show moreThe community of organisms that associate with plants are vital to both the survival of the host plant but also the diseases which may kill it. The processes by which this community, called the microbiome, assemble and function can contribute to the traits of the host, including plants that humans rely on for food, resources, and ecosystems services. This thesis focuses on understanding the assembly of microbiomes at the scale of microbe-microbe interactions and traits of individual microbes, as well as how characters of the host may change this process. I first address this by examining the in vitro and in planta interactions within small synthetic communities of root-inhabiting bacteria and fungi and with the plant host and viral disease of the host. While intermicrobial interactions in vitro were not predictive of in planta interactions, adding host disease or additional organisms to the system altered the assembly process. I then show the development and applications of the CONSTAX2 classifier, a taxonomic assignment tool for metabarcoding studies, which offers improved accuracy and ease of use for conducting metabarcoding studies exploring the diversity and structure of microbial communities. Last, I present a study testing which factors affected the composition of forest fungal communities to understand the ecology of litter-inhabiting fungi and improve methodologies for sampling leaf-associated fungal communities. The factors affecting the assembly of plant microbiomes are complex and varied but connecting individual interactions to community composition and ultimately function may improve our abilities to predict and manage microbiome processes.
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Title: Environments Effect on Mood : A Comparative Analysis of Environments on Mood Enhancement
Creator: Hayes, Jonah
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Mental health is an issue that millions of people are suffering and struggling with, reconnecting with natural environments could be part of the solution to this problem. Although research demonstrated the significance of the healing properties of natural environments, little research compared natural environments to each other. This research explores which aspects of different natural environments have a positive impact on mood. Using survey questionnaires, two environments were tested. The...
Show moreMental health is an issue that millions of people are suffering and struggling with, reconnecting with natural environments could be part of the solution to this problem. Although research demonstrated the significance of the healing properties of natural environments, little research compared natural environments to each other. This research explores which aspects of different natural environments have a positive impact on mood. Using survey questionnaires, two environments were tested. The first being natural environments, where participant exposure to man-made or urban elements is limited and they are surrounded by natural elements. The second environment, urban environments, are spaces such as parks that are not separated from the urban environment. While in the urban environments’ participants were still able to perceive the urban elements that surrounds the space, such as cars, buildings, and roads. Participants were surveyed before and after using the spaces to allow the measuring and analysis of the change the participants experienced. Both the change in mental restoration, but also of the perceived variables of the space. Statistical analysis of the survey responses showed that a greater amount of change to the perceived variables, and mental restoration happened in natural environments, but both environments were restorative. This supports the idea that accessibility to a diverse set of environments and recreational elements will increase mental restoration. Therefore, policy practitioners, and designers should work to increase park space accessibility to a diverse set of environments and recreation amenities.
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Title: EPIDEMIC MODELS UNDER MOBILITY ON MULTI-LAYER NETWORKS
Creator: Abhishek, Vishal
Date: 2021
Collection: Electronic Theses & Dissertations
Description: We study epidemic spreading models namely, SIS and SIR models, under mobility on multilayer networks. In particular, we consider a patchy environment in which each patch comprises individuals belonging the different classes, e.g., individuals in different socio-economic strata. We model the mobility of individuals of each class across different patches through an associated Continuous Time Markov Chain (CTMC). The topology of these multiple CTMCs constitute the multi-layer network of mobility...
Show moreWe study epidemic spreading models namely, SIS and SIR models, under mobility on multilayer networks. In particular, we consider a patchy environment in which each patch comprises individuals belonging the different classes, e.g., individuals in different socio-economic strata. We model the mobility of individuals of each class across different patches through an associated Continuous Time Markov Chain (CTMC). The topology of these multiple CTMCs constitute the multi-layer network of mobility. At each time, individuals in the multi-layer network of spatially-distributed patches move according to their CTMC and subsequently interact with the local individuals in the patch according to SIS or SIR models. We establish the existence of various equilibria under different parameter regimes and establish their (almost) global asymptotic stability using Lyapunov techniques. We also derive simple conditions that highlight the influence of the multi layer network on the stability of these equilibria. We numerically illustrate that the derived model provides a good approximation to the stochastic model with a finite population and also demonstrate the influence of the multi-layer network structure.Next, we extend some of the results to the case of weakly connected networks. Here, we use the notion of strongly connected components and input to state stability to study the stability of equilibria. Finally, we consider a resource allocation problem to maximize the rate of convergence to an equilibrium. We show that under certain assumptions the problem can be formulated as a geometric program. We provide numerical illustrations to corroborate the results.
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Title: Keeping the Tradition Alive : Irish Traditional Music Sessions During COVID-19
Creator: Bobker, Andrew
Date: 2021
Collection: Electronic Theses & Dissertations
Description: In the spring of 2020, performers of traditional Irish music responded to pandemicinducedsocial distancing by creating a new variant of an old tradition: the virtual Irish session. Unlike conventional pub sessions, virtual sessions occur entirely in virtual space, facilitated by conferencing applications like Zoom or YouTube livestreaming. The move to virtual sessions presents numerous challenges to the traditional structure and norms of Irish traditional music. This thesis will explore the...
Show moreIn the spring of 2020, performers of traditional Irish music responded to pandemicinducedsocial distancing by creating a new variant of an old tradition: the virtual Irish session. Unlike conventional pub sessions, virtual sessions occur entirely in virtual space, facilitated by conferencing applications like Zoom or YouTube livestreaming. The move to virtual sessions presents numerous challenges to the traditional structure and norms of Irish traditional music. This thesis will explore the strategies and motivations of Irish musicians as they have adapted to the conditions of COVID-19 and isolation. Maintaining an authentic practice within the auspices of technological innovation involves the negotiation of geography, ethnicity, and selective tradition in a complex social space. This work is based in large part on ethnographic research conducted between March and December of 2020, including both in-person interviews and Internet ethnography. Interviews were conducted with musicians in Austin, Texas; Portland, Maine; Seattle, Washington; and Boston, Massachusetts.
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Title: A RISK BASED USER TOOL TO BUILD USER CENTERED LABELS FOR MEDICAL DEVICES
Creator: Estrada, Eric Joseph
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Herein we develop a user-driven, risk-based tool to inform the design of a standardized label for use with medical devices. Researchers identified 11 labeling inputs found on commercial labels and organized the inputs into a “Device Facts” box at 3 risk levels: high, medium, and low. mock labels and commercial labels were objectively compared by healthcare practitioners using a forced choice methodology where accuracy and response time served as dependent variables. Results suggested that...
Show moreHerein we develop a user-driven, risk-based tool to inform the design of a standardized label for use with medical devices. Researchers identified 11 labeling inputs found on commercial labels and organized the inputs into a “Device Facts” box at 3 risk levels: high, medium, and low. mock labels and commercial labels were objectively compared by healthcare practitioners using a forced choice methodology where accuracy and response time served as dependent variables. Results suggested that pairwise comparisons between labels (mock vs commercial) within a given risk category (e.g. high) yielded statistically significant differences at a confidence level of 95% for time to correct response. For both medium (p=0.0016) and high risk information (p<0.0001), the mock labels yielded a quicker correct response than their commercial counterparts. Only for low risk information were the commercial labels faster (p<0.0001). The gains in speed made in high/moderate risk information were not attributable trade-off. Mock labels were at least as accurate as their commercial counterparts; low and high risk yielded no sign of significant difference when mock and commercial were compared and participants were significantly more accurate with questions requiring medium risk information for the mock labels.
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Title: Thermal Characterization and Crystal Growth of the Germanium Telluride-Tin Telluride System
Creator: Levental, Gill
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Thermoelectric materials, which can create an electrical current from a temperature gradient within the material, are an important means of generating electrical power in very remote and harsh environments. However, their deployment in terrestrial environments has been limited, due to two primary factors: the high cost of thermoelectric materials and their low energy conversion efficiency- too low for economic use in almost all applications. One method by which thermoelectric material energy...
Show moreThermoelectric materials, which can create an electrical current from a temperature gradient within the material, are an important means of generating electrical power in very remote and harsh environments. However, their deployment in terrestrial environments has been limited, due to two primary factors: the high cost of thermoelectric materials and their low energy conversion efficiency- too low for economic use in almost all applications. One method by which thermoelectric material energy conversion efficiency may be increased is by reducing material lattice thermal conductivity, or a material’s ability to conduct heat through the vibrations of its crystalline atomic lattice, which are called phonons. In support of that objective, this work presents a characterization of fundamental material properties that influence the lattice thermal conductivity of the germanium telluride-tin telluride (Ge1-xSnxTe) system, a promising thermoelectric material. The properties characterized include composition-dependent coefficients of thermal expansion, speeds of sound within the material, and elastic moduli. These were characterized using high-temperature X-ray diffraction, resonant ultrasound spectroscopy, and high-pressure X-ray diffraction, respectively. This work also presents an account of the synthesis of bulk single-crystal ingots of several compositions within the Ge1-xSnxTe system, which will be used for an in-depth investigation of Ge1-xSnxTe phonon characteristics by collaborators using inelastic neutron scattering.
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Title: Cross-Cultural Comparison of Public Attitudes and Adverse Impact of Stuttering
Creator: Wozniak, Angelica
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Purpose: The purpose of this study was to explore potential links between public perceptions ofstuttering and the adverse impact of these perceptions on the experiences of individuals who stutter. This was completed by analyzing data from a demographic survey, the Public Opinion Survey of Human Attributes (POSHA), the Overall Assessment of the Speaker's Experience of Stuttering (OASES), and the Stuttering Perception Scale (4S). Data was collected from the United States and Australia. Methods:...
Show morePurpose: The purpose of this study was to explore potential links between public perceptions ofstuttering and the adverse impact of these perceptions on the experiences of individuals who stutter. This was completed by analyzing data from a demographic survey, the Public Opinion Survey of Human Attributes (POSHA), the Overall Assessment of the Speaker's Experience of Stuttering (OASES), and the Stuttering Perception Scale (4S). Data was collected from the United States and Australia. Methods: This was a qualitative study that involved 24 people who stutter from the United States and 22 people who stutter from Australia, as well as 45 people who do not stutter from the United States and 48 people who do not stutter from Australia (aged 18+) who were recruited via research registries, personal contacts, stuttering associations, and by word of mouth. A descriptive analysis was completed using the student’s t-test, the Chi Square test, and percentage ‘yes’ to determine the presence of significant differences in the data. Results: No significant differences were found regarding adverse impact and self-stigma between respondents from the United States and Australia. No significant differences were also found regarding public perceptions of stuttering between respondents from the United States and Australia. Conclusions: The following results can be interpreted as indicating that there are minimal differences cross-culturally for adverse impact and self-stigma in respondents who stutter, as well as minimal differences cross-culturally for public perceptions of stuttering in respondents who do not stutter.
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Title: Grouping Patterns and Decisions for School-Age Children Who Stutter
Creator: Zukowski, Danielle
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Background. In the United States, the school system is one of the most common settings for stuttering intervention, yet adults who stutter report significant dissatisfaction with their prior school-based therapy experiences. In the schools, group therapy is the predominant service-delivery model for all students, but limited research is available regarding grouping practices, grouping decisions, or the impact of service-delivery models and group composition on students who stutter. Method....
Show moreBackground. In the United States, the school system is one of the most common settings for stuttering intervention, yet adults who stutter report significant dissatisfaction with their prior school-based therapy experiences. In the schools, group therapy is the predominant service-delivery model for all students, but limited research is available regarding grouping practices, grouping decisions, or the impact of service-delivery models and group composition on students who stutter. Method. The current study collected data on the factors clinicians consider when determining whether to use groups and how to form groups in therapy. The method involved the distribution of a questionnaire to speech-language pathologists (SLPs) working in public schools. Results. Analyses indicated that the choice of service-delivery model and group composition were influenced by student factors, such as stuttering characteristics, progress in therapy, and social dynamics, and clinician/workplace factors, including caseload size, workload, and scheduling restrictions. Discussion. Excess job expectations and limited time impact clinicians’ ability to implement individualized decision-making when choosing whether to use and how to form groups for students who stutter. By reducing barriers, school SLPs will be better able to align their clinical judgment with their grouping practices and more adequately meet the needs of students.
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Title: Exploring the potential of the biological control agent Hypena opulenta (Christoph) (Lepidoptera : Erebidae) at controlling invasive swallow-wort vines in Michigan and its indirect effects on monarch butterflies
Creator: Alred, Brianna Joy
Date: 2021
Collection: Electronic Theses & Dissertations
Description: This thesis focuses on swallow-wort, an invasive vine related to milkweeds, and the potential of Hypena opulenta for providing biological control in Michigan, as well as the indirect effects that the introduction of H. opulenta may have on the monarch butterfly. The first chapter covers the background of swallow-wort in its invasive range and outlines previous research done with H. opulenta in the United States and Canada.In the second chapter, the impact and the phenology of H. opulenta on...
Show moreThis thesis focuses on swallow-wort, an invasive vine related to milkweeds, and the potential of Hypena opulenta for providing biological control in Michigan, as well as the indirect effects that the introduction of H. opulenta may have on the monarch butterfly. The first chapter covers the background of swallow-wort in its invasive range and outlines previous research done with H. opulenta in the United States and Canada.In the second chapter, the impact and the phenology of H. opulenta on black swallow-worts in Michigan is examined in common garden experiments. Swallow-wort survival and reproductive output are measured and compared when different adult densities are released in one study. The second study assessed the phenology of H. opulenta when releases took place at different dates either in sunny or shaded sites. In southern Michigan, H. opulenta is found to produce two generations per season, though overwintering could not be confirmed. Damage caused by larval feeding was higher in the shade but was not enough to reduce plant fitness regardless of release size or light availability. Swallow-worts can serve as oviposition sinks for monarchs, however, the presence of H. opulenta larvae may serve as an oviposition deterrent. Examination of the indirect effects of H. opulenta on monarch butterflies in the third chapter found no evidence that H. opulenta deters monarch oviposition. In addition, the utilization of swallow-wort by wild monarch butterflies as an oviposition host in Michigan was confirmed.
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Title: ADDITIVE MANUFACTURING FOR RAPID PROTOTYPING OF MM-WAVE CIRCUITS
Creator: Crump, Cameron Austin
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Additive manufacturing (AM) has recently attracted significant interest to meet the need of nextgeneration of wireless systems, and the growing demand for customization and rapid prototyping of electronic systems. In addition, AM is being investigated to supplement and in some cases replace traditional microelectronic fabrication techniques. This is to lessen the ecological impact of electronics manufacturing as well as to reduce cleanroom facility costs. This research work focuses on the use...
Show moreAdditive manufacturing (AM) has recently attracted significant interest to meet the need of nextgeneration of wireless systems, and the growing demand for customization and rapid prototyping of electronic systems. In addition, AM is being investigated to supplement and in some cases replace traditional microelectronic fabrication techniques. This is to lessen the ecological impact of electronics manufacturing as well as to reduce cleanroom facility costs. This research work focuses on the use of AM for the design and fabrication of microwave and millimeter wave components and systems, leading to heterogeneous integration. For systems integration, two major challenges to tackle are: (1) rapid printing of conductive regions with high precision and high conductivity; (2) selective deposition of dielectrics with varying geometries surrounding active and passive components. In this work, printing of both conductors and dielectrics was carried out using aerosol jet printing (AJP). AJP allows for high resolution printing (~10 μm) at a large standoff distance (~10 mm). Silver (Ag) based inks were investigated to achieve high conductivity and polymers (benzocyclobutene, BCB and Polyimide, PI) as low-loss dielectric materials.
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Title: SOLIDARITY & RESISTANCE : WOMEN’S PERSPECTIVES ON EMPOWERMENT THROUGH SELF HELP GROUPS
Creator: Mishra, Manasi
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Development interventions mostly aim to ‘empower’ rural women by increasing their income and livelihood but rarely consider the voices of their beneficiaries. I study the meanings and experiences of empowerment or nari shakti as understood and described by rural women who lead self-help groups (SHGs) engaged in savings, micro-credit and income generation. I conducted the research in the central Himalayan region of rural India in Uttarakhand State using in-depth interviews with 11 SHG leaders....
Show moreDevelopment interventions mostly aim to ‘empower’ rural women by increasing their income and livelihood but rarely consider the voices of their beneficiaries. I study the meanings and experiences of empowerment or nari shakti as understood and described by rural women who lead self-help groups (SHGs) engaged in savings, micro-credit and income generation. I conducted the research in the central Himalayan region of rural India in Uttarakhand State using in-depth interviews with 11 SHG leaders. The findings indicate that the participants experience empowerment as solidarity and collective power that manifest in the form of self-reliance, courage, and independence. The participants associate their self-reliance with courage and inner strength which they have built as a means to survive the pain and struggle. Their stories of nari shakti are also stories of pain and struggle.This research implies the need to examine perspectives of feminists on empowerment related interventions. Further research is needed on how micro-credit SHGs help build collective action that can challenge patriarchal power structures and bring about social change. Such research can help provide solutions on how non-profits can utilize feminist strategies of consciousness raising while still meeting donor expectations for the SHG programs.
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Title: THE VALUE OF HABITAT DATA FOR CONSERVING STREAMS WITH CHANGING CLIMATE : PROMOTING GREATER USE FOR MORE EFFECTIVE MANAGEMENT
Creator: Betances, Samantha J.
Date: 2021
Collection: Electronic Theses & Dissertations
Description: North America’s rivers and streams support a diversity of fish species that provide significant ecological, socioeconomic, cultural, and spiritual benefits, and the quality and quantity of habitat in streams directly supports fish diversity. Because rivers are products of the landscapes they drain, features of the landscape like land use, geology, and climate control habitat. Based on these relationships, it stands that anticipated changes in climate will lead to changes in stream fishes...
Show moreNorth America’s rivers and streams support a diversity of fish species that provide significant ecological, socioeconomic, cultural, and spiritual benefits, and the quality and quantity of habitat in streams directly supports fish diversity. Because rivers are products of the landscapes they drain, features of the landscape like land use, geology, and climate control habitat. Based on these relationships, it stands that anticipated changes in climate will lead to changes in stream fishes through changes in habitat. While natural resource management agencies collect habitat data to help conserve streams into the future, stream habitat data are not always used as intended, in part because some managers may have an incomplete understanding of interactions between rivers and the landscapes they drain. To fully address the impacts of climate change on stream fishes, managers must better understand how climate affects stream habitat and incorporate these concepts into management decision-making processes. This thesis addresses that need. In Chapter 1, we identify ways to increase use of stream habitat data by natural resource management agencies to better conserve fishes from current and future stressors. In Chapter 2, we investigate influences of multiple landscape factors on physical stream habitat, including climate factors. Collectively, outcomes of this research offer managers information and strategies for using stream habitat data to conserve stream habitats and the fishes they support with changing climate.
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Title: CHARACTERIZING THE SOCIAL GAP IN UTILITY-SCALE SOLAR ENERGY
Creator: Crawford, Jessica Alex
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Many consider utility-scale photovoltaic solar power to be an essential component of decarbonizing the United States power sector and mitigating climate change. This technology is well accepted by the public in general surveys, yet often faces local resistance during project siting. This phenomenon is known as the “social gap.” Using social gap theory from the wind energy literature as a foundation, this study examines the causes of and offers recommendations for addressing the solar social...
Show moreMany consider utility-scale photovoltaic solar power to be an essential component of decarbonizing the United States power sector and mitigating climate change. This technology is well accepted by the public in general surveys, yet often faces local resistance during project siting. This phenomenon is known as the “social gap.” Using social gap theory from the wind energy literature as a foundation, this study examines the causes of and offers recommendations for addressing the solar social gap in Michigan. The study relied on 33 semi-structured interviews with citizens, government officials, and developers across four Michigan communities, each facing a prospective utility-scale solar project. Through thematic analysis, I show that the solar social gap can be attributed to both a vocal minority that dominated community sentiment and project proposals that failed to meet the community’s standards for acceptable development. The gap was exacerbated by the presence of organized opposition groups as well as decision-makers relying on ineffective public processes to engage citizens. This research makes it clear that government officials and developers need to adopt practices that enhance community representation, process transparency, and decision-influence. Though decision-making strategies are not the only factor that affects community acceptance, implementing improved procedures could help close the solar social gap.
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Title: PRECISION DIAGNOSTICS AND INNOVATIONS FOR PLANT BREEDING RESEARCH
Creator: Hugghis, Eli
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Major technological advances are necessary to reach the goal of feeding our world’s growing population. To do this, there is an increasing demand within the agricultural field for rapid diagnostic tools to improve the efficiency of current methods in plant disease and DNA identification. The use of gold nanoparticles has emerged as a promising technology for a range of applications from smart agrochemical delivery systems to pathogen detection. In addition to this, advances in image...
Show moreMajor technological advances are necessary to reach the goal of feeding our world’s growing population. To do this, there is an increasing demand within the agricultural field for rapid diagnostic tools to improve the efficiency of current methods in plant disease and DNA identification. The use of gold nanoparticles has emerged as a promising technology for a range of applications from smart agrochemical delivery systems to pathogen detection. In addition to this, advances in image classification analyses have allowed machine learning approaches to become more accessible to the agricultural field. Here we present the use of gold nanoparticles (AuNPs) for the detection of transgenic gene sequences in maize and the use of machine learning algorithms for the identification and classification of Fusarium spp. infected wheat seed. AuNPs show promise in their ability to diagnose the presence of transgenic insertions in DNA samples within 10 minutes through colorimetric response. Image-based analysis with the utilization of logistic regression, support vector machines, and k-nearest neighbors were able to accurately identify and differentiate healthy and diseased wheat kernels within the testing set at an accuracy of 95-98.8%. These technologies act as rapid tools to be used by plant breeders and pathologists to improve their ability to make selection decisions efficiently and objectively.
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Title: DEVELOPING A DECISION SUPPORT SYSTEM FOR PACKAGING POSTPONEMENT
Creator: Yuan, Tingyu
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Postponement refers to a strategy which intentionally delays supply chain activities until the demand is known. Postponement decreases safety stock and the holding cost, while also incurring some additional costs. The main focus of this study is packaging postponement which is recommended if only the packaging of products destined at multiple retailers are different. This thesis summarizes research that exclusively studied packaging postponement and presents a decision support system that...
Show morePostponement refers to a strategy which intentionally delays supply chain activities until the demand is known. Postponement decreases safety stock and the holding cost, while also incurring some additional costs. The main focus of this study is packaging postponement which is recommended if only the packaging of products destined at multiple retailers are different. This thesis summarizes research that exclusively studied packaging postponement and presents a decision support system that determines which postponement strategy, i.e., full, partial (tailored), or no postponement, is optimal. The decision support system is a mixed-integer nonlinear programming model with the objective of minimizing total costs, including the holding cost and the additional cost, and is constrained by the limited capacity of packaging production at a distribution center and the integrity of variables. In this research, the impact of various factors on optimal packaging postponement strategy is also analyzed. To sum up, this research provides a collection of research papers that exclusively studied packaging postponement and presents a decision support model for packaging postponement.
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Title: AGGREGATE PLANNING IN MANUFACTURING OF REUSABLE CONTAINERS
Creator: Tao, Jinli
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Aggregate production planning (APP) is a method to make several decisions simultaneously on production, inventory, and workforce levels over a finite time horizon, aiming to maximize the profit or minimize the cost while meeting fluctuating demands. Building mathematical models that reflect real-world problems is often difficult, as the constraints are usually intricate and may interact with each other. Decomposing the interconnected system into a number of independent phases could simplify...
Show moreAggregate production planning (APP) is a method to make several decisions simultaneously on production, inventory, and workforce levels over a finite time horizon, aiming to maximize the profit or minimize the cost while meeting fluctuating demands. Building mathematical models that reflect real-world problems is often difficult, as the constraints are usually intricate and may interact with each other. Decomposing the interconnected system into a number of independent phases could simplify the problem; however, it may not guarantee the optimality of the best solutions due to the missed constraints between stages. In this study, two mixed integer programming models for the manufacturing of reusable plastic containers are presented. One is based on the flow of the material and the other is based on the level of the workforce at each period. The proposed models are able to (i) deal with varying demand, (ii) reflect various regulations and restrictions of public and private warehouses for storing materials, and (iii) identify the importance of subcontracting when demand increases dramatically. Both mathematical models are implemented in the case of packaging manufacturing. A comprehensive sensitivity analysis has been conducted on different parameters of the problem to test the effect of parameter changes. To sum up, the general framework of the mathematical models not only can be used for reusable container manufacturing but also the manufacturing of any type of product with a similar supply chain network.
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Title: EFFECT OF ALUMINUM OXIDE ON THE FUNCTIONAL PROPERTIES OF CHITOSAN FILMS
Creator: Konda, Akhil Sai
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Chitosan is the one of the most abundant naturally occurring polymer in the world and has applications in a lot of different fields, including flexible packaging films. Aluminum oxide in the form of nanoparticle have good mechanical strength, barrier, thermal and antimicrobial properties which, when added to a polymer, can improve its properties significantly and increase its applications considerably. This research attempts to develop a biodegradable film with chitosan added with aluminum...
Show moreChitosan is the one of the most abundant naturally occurring polymer in the world and has applications in a lot of different fields, including flexible packaging films. Aluminum oxide in the form of nanoparticle have good mechanical strength, barrier, thermal and antimicrobial properties which, when added to a polymer, can improve its properties significantly and increase its applications considerably. This research attempts to develop a biodegradable film with chitosan added with aluminum oxide and study its effect on the functional properties of the chitosan film. The functional properties taken into consideration were tensile strength, % elongation at break, water vapor permeability (WVP), oxygen permeability (OP), antimicrobial and thermal properties. There can be potential novel applications in packaging if these composite films have improved requisite properties. The oxygen permeability of the films was not affected after adding aluminum oxide and decreased only by 6% after adding 2% Al2O3. On other hand, the water vapor permeability values increased significantly (p<0.05) by around 30% after adding 2% Al2O3, which is not desired. The tensile strength decreased from 40 MPa to 36 MPa and the % elongation at break reduced significantly (p<0.05) from 98% to 83%. There was no change observed in the thermal properties of the films, and there was no inhibition zone seen when tested for its antimicrobial properties after the addition of aluminum oxide. These results suggest that the properties of this composite material formed using chitosan with aluminum oxide were not affected in some aspects such as tensile strength and oxygen barrier property; and additional work is required to conclude the hypothesis of generating a composite chitosan film with aluminum oxide as nanoparticles for improved properties.
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Title: Analysis of Positional Bias Within Multiple Stimulus Without Replacement Preference Assessments
Creator: Miranda, David Ray Gutierrez
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Positional bias is a pattern of responding to a specific location that can be influenced by response effort and/or prior learning history. Within the contexts of preference assessments, positional bias create additional variables that make ascertaining true preferences within a preference assessment more difficult. Prior research on positional bias within preference assessments have focused primarily on its use in paired stimulus assessments due to the complex nature of the multiple-stimulus...
Show morePositional bias is a pattern of responding to a specific location that can be influenced by response effort and/or prior learning history. Within the contexts of preference assessments, positional bias create additional variables that make ascertaining true preferences within a preference assessment more difficult. Prior research on positional bias within preference assessments have focused primarily on its use in paired stimulus assessments due to the complex nature of the multiple-stimulus without replacement preference assessment. The present study is a secondary analysis that utilized four different methods to measure side bias and center bias for 19 young children with autism spectrum disorders. Results indicate that participants had varying degrees of biased responding but collectively engaged in little biased responding. Present study includes discussion of general patterns of responding, an analysis of the four methodologies, and general recommendations for the application of these methodologies.
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Title: TEACHING STAFF TO IMPLEMENT MAND TRAINING WITH CHILDREN WITH ASD THROUGH TELEHEALTH
Creator: Rosalik, Shelby R.
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Telehealth services have increased substantially in the field of applied behavior analysis (ABA) since the start of the COVID-19 pandemic, though little research exists to empirically evaluate the efficacy of direct ABA telehealth treatment or more specifically, how behavior technicians can be trained to implement such treatment. The present investigation utilized a nonconcurrent multiple baseline design across participants to evaluate the use of an online behavioral skills training (BST)...
Show moreTelehealth services have increased substantially in the field of applied behavior analysis (ABA) since the start of the COVID-19 pandemic, though little research exists to empirically evaluate the efficacy of direct ABA telehealth treatment or more specifically, how behavior technicians can be trained to implement such treatment. The present investigation utilized a nonconcurrent multiple baseline design across participants to evaluate the use of an online behavioral skills training (BST) approach to teach behavior technicians to implement 20-min mand training sessions via telehealth with children diagnosed with autism spectrum disorder (ASD). The training phase of the study consisted of both role-play with feedback as well as feedback during sessions with the child participant. Results showed increases in behavior technician’s percentage of accurate implementation and rate of fully correct trials implemented following the training. Child participants also showed increased rates of independent mands following the BST implementation. Thus, BST may be an effective approach to teach behavior technicians to deliver mand training via telehealth.
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Title: EXPLORING THE IMPACT OF BIOGAS QUANTITY AND QUALITY IN DIFFERENT DIGESTER TYPES WITH VARIATIONS IN TEMPERATURE
Creator: Barrios Arosemena, Maria Ines
Date: 2021
Collection: Electronic Theses & Dissertations
Description: The energy sector in the U.S. has been pushing for policies such as the Renewable Portfolio Standard (RPS) to mitigate the impacts of GHG emissions. Biogas from anaerobic digesters is a viable form of renewable energy, due to its CH4 composition, it can be used as a replacement for power and heat generation or upgraded and sold as biomethane. This study analyzed the effects of temperature in biogas quality and quantity of dairy cow manure in order to compare two main systems, a CSTR and a...
Show moreThe energy sector in the U.S. has been pushing for policies such as the Renewable Portfolio Standard (RPS) to mitigate the impacts of GHG emissions. Biogas from anaerobic digesters is a viable form of renewable energy, due to its CH4 composition, it can be used as a replacement for power and heat generation or upgraded and sold as biomethane. This study analyzed the effects of temperature in biogas quality and quantity of dairy cow manure in order to compare two main systems, a CSTR and a covered lagoon. A biochemical methane potential (BMP) test was performed to determine material biodegradability of dairy cow manure with respect to temperature. The results show that all samples are anaerobically biodegradable with samples yielding 86, 168, 440, 475 and 448 L biogas per kg initial VS for 15°C, non-mixed; 20°C, non-mixed; 30°C, non-mixed; 39°C, non-mixed; and 39°C, mixed, respectively. The BMP results demonstrated so significant difference between 30°C, non-mixed; 39°C, non-mixed; and 39°C, mixed, respectively. In addition, the effects of psychrophilic, unregulated, and mesophilic conditions were tested in small scale lab pilot digesters. Results show that mesophilic condition yielded the highest cumulative biogas production, while the psychrophilic and unregulated conditions presented higher methane yield. A life cycle analysis was performed to compare two popular anaerobic digestion systems, a CTSR and a covered lagoon, versus current manure management systems for dairy cow manure. The LCA revealed that both systems have less environmental burdens when compared to current waste management systems and a CSTR has less environmental burdens than a covered lagoon.
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