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Title: PRETERM DELIVERY AND ITS ASSOCIATION WITH FALSE POSITIVE, AUDITORY BRAINSTEM RESPONSE (ABR)-BASED NEWBORN HEARING SCREENING FINDINGS
Creator: Rathore, Mandavni
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Newborn hearing screening failure can occur in infants without hearing loss; these false-positive (FP) results have been speculated to reflect neurodevelopmental disorder risk. Preterm birth (PTB), a known neurodevelopmental risk factor, has been associated with FP at initial screening. We aim to further characterize this association by stratifying PTB by gestational age and delivery circumstance. To do this, we analyzed birth certificate and Early Hearing Detection & Intervention data from...
Show moreNewborn hearing screening failure can occur in infants without hearing loss; these false-positive (FP) results have been speculated to reflect neurodevelopmental disorder risk. Preterm birth (PTB), a known neurodevelopmental risk factor, has been associated with FP at initial screening. We aim to further characterize this association by stratifying PTB by gestational age and delivery circumstance. To do this, we analyzed birth certificate and Early Hearing Detection & Intervention data from the Michigan Dept. of Health & Human Services (2007–2015; n = 919,363). We restricted our analysis to singleton live births with available ABR-based hearing screening data and obstetric estimates of gestational age (n = 655,079). We then used logistic regression to evaluate the association of PTB defined by gestational age (extreme: < 28 weeks; moderate: 28–34 weeks; late: 34–36 weeks) and delivery circumstance (spontaneous, medically indicated) with FP, using full-term birth (≥ 37 weeks) as the referent group. Approximately 4% of infants had FP findings. All gestational age categories were associated with this phenomenon (extreme: OR = 4.2, 95% CI 3.7, 4.7; moderate: OR = 1.2, 95% CI 1.1, 1.3; late: 1.6, 95% CI 1.5, 1.7). Spontaneous and medically indicated PTB were also associated with FP (OR = 1.7, 95% CI 1.6, 1.8; OR = 1.4, 95% CI 1.3, 1.5, respectively). All results persisted following adjustment for socio-demographic and antepartum factors except for moderate PTB (OR = 1.0, 95% CI 0.9, 1.1), though sensitivity analyses suggested marked heterogeneity within this group. Further research is needed to investigate factors underlying these differences and whether they correlate with neurodevelopmental disorder diagnoses.
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Title: Improving the Efficiency of Residential Buildings in Rural Alaska : An Analysis of Existing Infrastructure and Its Importance in Creating Energy-Efficient Homes
Creator: Milan, Maria
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Rural communities in Alaska, many of which have a high Alaska Native population, currently face significant housing challenges. In a climate that can become extremely cold, houses are generally lacking in energy efficiency. Residents pay high rates for both oil and electricity to heat and operate their homes. Their homes are much smaller and with higher occupancy in comparison to typical U.S. homes. In addition, as the winter season brings sub-zero temperatures, windows remain shut with...
Show moreRural communities in Alaska, many of which have a high Alaska Native population, currently face significant housing challenges. In a climate that can become extremely cold, houses are generally lacking in energy efficiency. Residents pay high rates for both oil and electricity to heat and operate their homes. Their homes are much smaller and with higher occupancy in comparison to typical U.S. homes. In addition, as the winter season brings sub-zero temperatures, windows remain shut with limited mechanical or natural ventilation, also creating indoor air quality concerns. To date there has been limited studies of rural Alaskan communities’ housing, to better understand and quantify such housing challenges. This research focuses on a detailed study of the rural Alaskan community of Unalakleet. Located on the western shore of Alaska, this coastal community of approximately 765 people faces many housing challenges, similar to other rural Alaskan communities. Through collaboration with the housing authority in Unalakleet, this research conducted home energy assessments and resident interviews in the summer of 2021, including 27 energy assessments and 22 interviews. The purpose of the energy assessments was to collect information on typical building features and data, as well as to identify housing challenges. The interviews were generally completed for homes that also had an energy assessment and were used to better understand residents’ perspectives on energy and housing challenges beyond what was observed in the assessments. Blower door tests suggest that homes are usually small and tight, with leakiness around areas like the windows, where mold frequently was observed. Short-term indoor air quality monitoring suggests that some homes, especially those less than 46 m2 , had high CO2 concentrations, relative to others. Some homes had significant mold growth, and others had many areas of damage. Still, interviews with community members suggest that they were grateful for their housing and the ability to live in Unalakleet. The overall purpose of this research is to provide evidence to quantify the typical housing characteristics presence in rural Alaskan communities, as well as to provide results that motivate and support opportunities for new, more efficient housing. The introduction discusses major housing challenges, from high energy bills to the history of inefficient infrastructure in rural Alaska. Physical characteristics of assessed homes, followed by indoor air quality and air flow, are discussed in Chapters 2 and 3, respectively. Finally, Chapter 4 uses data collected from the 27 housing assessments to create a building energy model, where energy usage in existing housing is modeled to represent a ‘typical’ rural Alaskan home. The results of this model show where the largest improvements in efficiency can be made, especially in adding higher R-value insulation. The conclusion provides a brief overview of research contribution, limitations, and future work.
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Title: Harnessing Machine Learning Techniques for Large-Scale Mapping of Inland Aquaculture Waterbodies in Bangladesh
Creator: Ferriby, Hannah
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Aquaculture in Bangladesh has grown dramatically in an unplanned manner in the past few decades, becoming a major contributor to the rural economy in many parts of the country. National systems for the collection of statistics have been unable to keep pace with these rapid changes, and more accurate, up to date information is needed to inform policymakers. Using Sentinel-2 Top of Atmosphere Reflectance images within Google Earth Engine and ArcGIS platforms, we proposed six strategies for...
Show moreAquaculture in Bangladesh has grown dramatically in an unplanned manner in the past few decades, becoming a major contributor to the rural economy in many parts of the country. National systems for the collection of statistics have been unable to keep pace with these rapid changes, and more accurate, up to date information is needed to inform policymakers. Using Sentinel-2 Top of Atmosphere Reflectance images within Google Earth Engine and ArcGIS platforms, we proposed six strategies for improving fishpond detection as the existing techniques seem unreliable. The study area is comprised of seven districts in south-west and south-central Bangladesh. The tested strategies include: 1) identification of the best period for image collection, 2) testing the buffer size for threshold optimization, 3) determining the best combination of image reducer and water-identifying indices, 4) introduction of a convolution filter to enhance edge-detection, 5) evaluating the impact of ground-truthing data on machine learning algorithm training, and 6) identifying the best machine learning classifier. Each enhancement builds on the previous one to develop a comprehensive improvement strategy called the Enhanced Method for fishpond detection. We compared the results of each improvement strategy to the known ground-truthing fishponds as the metric of success. We compared the precision, recall, and F1 score for machine learning classifiers to determine the quality of results. Among the studied methods, the Classification and Regression Trees performed the best. Overall, the proposed strategies enhanced fishpond area detection in all districts within the study area.
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Title: HOW CAREGIVERS OF CHILDREN IN EARLY INTERVENTION FEEL ABOUT SIMPLIFIED LANGUAGE INPUT : A SURVEY STUDY
Creator: Nylund, Megan
Date: 2022
Collection: Electronic Theses & Dissertations
Description: There is some disagreement regarding how adults should simplify their utterances when speaking to young children with language delays. One type of simplification that has come into question is telegraphic input, a style of speaking that involves removing grammatical aspects of phrases, such as function words and grammatical markers (e.g., All done snack, Cookie yummy). In the current study, we utilized survey data collected by Andary (2020) surveying caregivers of children in early...
Show moreThere is some disagreement regarding how adults should simplify their utterances when speaking to young children with language delays. One type of simplification that has come into question is telegraphic input, a style of speaking that involves removing grammatical aspects of phrases, such as function words and grammatical markers (e.g., All done snack, Cookie yummy). In the current study, we utilized survey data collected by Andary (2020) surveying caregivers of children in early intervention about their views on different types of simplified language. Specifically, we asked: How do caregivers’ beliefs about telegraphic input relate to how comfortable they are producing different types of simplified utterances? Results were also analyzed for correlations between demographics and beliefs of simplification. Additionally, the survey provided space for caregivers to share recommendations they gained through Early On resources. Results show caregivers with a positive view of telegraphic input felt significantly less comfortable producing full, grammatical utterances than caregivers with a negative or neutral view of telegraphic input. Demographic analysis revealed caregivers with higher education levels preferred more grammatical utterances. These findings emphasize the importance of understanding caregiver perspectives in caregiver-mediated intervention approaches.
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Title: WE DON’T NEED TO KNOW WHAT WE SEE : MODEST MEDIATION OF BISTABLE PERCEPTION BY KNOWLEDGE
Creator: Zhang, Bobicheng
Date: 2022
Collection: Electronic Theses & Dissertations
Description: When faced with ambiguous visual input, an observer may have various perceptual interpre- tations even when the input remains unchanged. Indeed, such ambiguous displays can cause the observer to experience distinct perceptual interpretations in turn, unpredictably switching between them over time. Theories of such so-called multistable perception broadly fall into two categories: top-down theories that hold that perception in these cases depends strongly on higher-level cogni- tive factors...
Show moreWhen faced with ambiguous visual input, an observer may have various perceptual interpre- tations even when the input remains unchanged. Indeed, such ambiguous displays can cause the observer to experience distinct perceptual interpretations in turn, unpredictably switching between them over time. Theories of such so-called multistable perception broadly fall into two categories: top-down theories that hold that perception in these cases depends strongly on higher-level cogni- tive factors such as knowledge, and bottom-up theories which suggests more vital involvement of aspects of lower-order information processing such as local adaptation in the visual system. We evaluated whether the occurrence of perceptual reversals in the face of ambiguous input is related to the observer’s knowledge that the input is, indeed, ambiguous. We used an ambiguous animation that was designed such that subjects could report perceptual reversals without realizing the ambigu- ity. Subjects observed the animation, reported their perception, and filled out a questionnaire that assessed their knowledge of the animation’s ambiguity. We found that informed subjects reported slightly more perceptual switches than the other subjects, but that this between-group difference was very small compared to the lack of variability within each group between subjects who were aware of the ambiguity and those who were not. These findings suggests that knowledge of ambiguity can influence perception of ambiguous stimuli, but that this influence is relatively minor. This discrepancy between current findings and past work is discussed.
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Title: BLAME JUDGEMENTS FOR PAST ACTIONS OF GROUPS
Creator: Vallabha, Shree
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Historically, groups have committed innumerable atrocities, including genocide and slavery. I tested if people blame current groups for the actions of their past members and what underlies this blame. Current models of blame overlook the dimension of time and therefore have difficulty explaining this phenomenon. I hypothesized that perceiving higher (a) connectedness between past and present perpetrator groups, (b) unfulfilled obligations of perpetrator groups, (c) continued privilege of...
Show moreHistorically, groups have committed innumerable atrocities, including genocide and slavery. I tested if people blame current groups for the actions of their past members and what underlies this blame. Current models of blame overlook the dimension of time and therefore have difficulty explaining this phenomenon. I hypothesized that perceiving higher (a) connectedness between past and present perpetrator groups, (b) unfulfilled obligations of perpetrator groups, (c) continued privilege of perpetrator groups, and (d) continued harm of victim groups would facilitate higher blame judgements against current groups for the past. In a survey (N=518) using real events, I find results consistent with all the four hypotheses and some preliminary evidence for group differences in these relationships. I find that factors that link the present group to the past explain why groups are blamed for their past actions. These findings bring to light the deficiencies in existing theories of blame – calling into question its assumptions and incomplete criterion of judgement.
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Title: Evaluation of Operational Performance and Environmental Impact of a Commercial Scale Anaerobic Digester Utilizing Multiple Feedstocks
Creator: Dwilaksono, Fahmi
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Food waste and livestock manure become some of major sources that contribute to greenhouse gas (GHG) emissions in the U.S. Utilizing manure and food wastes as biogas feedstocks through anaerobic digestion (AD) process can improve renewable energy production while reducing the impact of climate change due to GHG emission from untreated organic wastes. This study evaluated the operational performance of Michigan State University’s commercial South Campus Anaerobic Digester (SCAD) as well as the...
Show moreFood waste and livestock manure become some of major sources that contribute to greenhouse gas (GHG) emissions in the U.S. Utilizing manure and food wastes as biogas feedstocks through anaerobic digestion (AD) process can improve renewable energy production while reducing the impact of climate change due to GHG emission from untreated organic wastes. This study evaluated the operational performance of Michigan State University’s commercial South Campus Anaerobic Digester (SCAD) as well as the environmental impact during its operation in 2014-2020. Evaluation of feedstock supplies quantity and output parameters of SCAD was conducted to understand the operational performance of the digester. A life cycle assessment (LCA) was done to know the environmental impact of SCAD by comparing it to the conventional waste management methods. Technoeconomic analysis was conducted to know the financial feasibility of SCAD as a commercial digester. The result shows that during its operation from 2014 to 2020, SCAD has processed 159,145 metric tons of feedstock from 18 different organic wastes to produce 15,165,156 kWh of electricity for MSU community. LCA results show that AD system possesses fewer environmental burdens in both global warming potential (GWP) and water eutrophication potential (WEP) compared to the conventional system. Technoeconomic analysis reveals that SCAD needs 21.5 years to accomplish its payback time, which is considered quite economically competitive.
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Title: Evaluation of potential therapeutics for non-small cell lung cancer using 3D tumor spheroid models
Creator: Stoub, Hayden Eric
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The development of novel and improved therapies for cancers requires robust means of investigation that both effectively recapitulate tumor biology while also utilizing resources efficiently. 3D tissue culture methods, namely spheroids and organoids, have emerged as an effective bridge between conventional in vitro methods and in vivo animal models in cancer research. This thesis provides background into lung cancer and the current landscape of 3D in vitro models of cancer, as well as...
Show moreThe development of novel and improved therapies for cancers requires robust means of investigation that both effectively recapitulate tumor biology while also utilizing resources efficiently. 3D tissue culture methods, namely spheroids and organoids, have emerged as an effective bridge between conventional in vitro methods and in vivo animal models in cancer research. This thesis provides background into lung cancer and the current landscape of 3D in vitro models of cancer, as well as detailing two studies in which multicellular tumor spheroids were used to investigate the therapeutic potential of candidate compounds. The first study uses an NCI-H358 multicellular tumor spheroid to investigate three compounds: Apigenin, a plant derived flavonoid; MSU42011, a novel retinoid x receptor (RXR) agonist; and CEP-1347, a mixed lineage kinase (MLK) inhibitor. It was found that Apigenin alone decreased the viability of spheroids, and that the combination of Apigenin and CEP-1347 synergistically decreased viability and increased cell death within the spheroids.The second study uses a murine lung adenocarcinoma tumor spheroid model to investigate the effects of MSU-71, a novel inhibitor of the nuclear factor erythroid 2-related factor (NRF2) pathway, on macrophage-induced invasion and migration. This compound blocked both migration in conventional experiments along with spheroid invasion, indicating its potential efficacy in preventing LUAD progression. This study also adapted the spheroid invasion model for use in multiple human LUAD cell lines and THP-1 conditioned medium. The findings presented herein demonstrate the versatility and value of 3D tumor spheroid models in the cancer drug development field.
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Title: A descriptive analysis of beginning specialty crop farmer training programs in Michigan
Creator: Comer, Donald M.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Michigan's diverse agricultural landscape provides multiple perspectives when considering the need for beginning farmer training. One perspective is a $104 billion industrial agricultural industry, with an ageing and decreasing farming population, and consolidation of land (MDARD, 2019). Another perspective is a growing movement of smaller-scale, regenerative farms with an emphasis on direct marketing, minimizing external inputs and improving ecosystem services. In the middle is an emerging...
Show moreMichigan's diverse agricultural landscape provides multiple perspectives when considering the need for beginning farmer training. One perspective is a $104 billion industrial agricultural industry, with an ageing and decreasing farming population, and consolidation of land (MDARD, 2019). Another perspective is a growing movement of smaller-scale, regenerative farms with an emphasis on direct marketing, minimizing external inputs and improving ecosystem services. In the middle is an emerging population of passionate and inexperienced growers that need training to get started, and farmer training organizations with their own challenges to meet farmers' needs. The purpose of this descriptive study was to survey Michigan's beginning specialty crop farmer training organizations in order to inform educators, policy makers, and beginning farmers. The research provides a description of existing training programs, the types of farmers participating in those programs, and current collaborations among the organizations. The results showed that Michigan has a diverse number of training options, but most operate independently of each other and lack resources to provide the best possible services. Recommendations include developing a state-wide systems approach to training and developing a central body or network that will aid in collaboration, resource allocation, and policy development. With this research as a foundation, it will be possible to complete a more comprehensive analysis, and to begin building a network that will provide future farmers to meet Michigan's agricultural challenges.
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Title: Modeling inactivation of Salmonella during spray drying of soy protein isolate
Creator: Steinbrunner, Philip
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Foodborne illness outbreaks linked to spray dried foods like infant formula and protein powders demonstrate a need for greater understanding of bacterial inactivation kinetics during spray drying. However, despite extensive research regarding the mechanisms of the spray drying process, the survival of bacteria during spray drying is not well understood. Therefore, the objectives were to: (1) measure the inactivation rates of Salmonella within a spray drying droplet, (2) develop a model that...
Show more"Foodborne illness outbreaks linked to spray dried foods like infant formula and protein powders demonstrate a need for greater understanding of bacterial inactivation kinetics during spray drying. However, despite extensive research regarding the mechanisms of the spray drying process, the survival of bacteria during spray drying is not well understood. Therefore, the objectives were to: (1) measure the inactivation rates of Salmonella within a spray drying droplet, (2) develop a model that relates droplet drying kinetics to Salmonella inactivation rate, and (3) assess the survivability of Salmonella and Enterococcus faecium throughout a pilot-scale spray dryer. In the first study, a thin layer of soy protein slurry inoculated with Salmonella was dried in a convection oven using actual spray drying conditions to measure the inactivation rate of Salmonella within droplets. Thereafter, a heat-mass coupled droplet drying model and secondary bacterial inactivation models using droplet temperature and moisture content were developed. Lastly, the survival and spatial distribution of Salmonella and Enterococcus faecium throughout a pilot-scale spray dryer were evaluated at various process temperatures. Bacterial inactivation rate was successfully modeled, with the best fitting secondary model including parameters for both droplet temperature and moisture content, which were coupled with the droplet drying model and validated. Although the spray drying process was able to reduce both organisms, survivors were found both in the final powder as well as the interior dryer surfaces, which indicates a potential health risk if the spray dryer is contaminated."--Page ii.
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Title: Biomass production potential, theoretical ethanol yield, environmental sustainability of miscanthus x giganteus and nitrogen fertilizer effect on quantity and quality in five lignocellulosic biomass crops in North-Central US
Creator: Wang, Sichao
Date: 2017
Collection: Electronic Theses & Dissertations
Description: ABSTRACTBIOMASS PRODUCTION POTENTIAL, THEORETICAL ETHANOL YIELD, ENVIRONMENTAL SUSTAINABILITY OF MISCANTHUS x GIGANTEUS AND NITROGEN FERTILIZER EFFECT ON QUANTITY AND QUALITY IN FIVE LIGNOCELLULOSIC BIOMASS CROPS IN NORTH-CENTRAL US BYSichao WangIncreasing concerns on climate change and energy security leads to growing emphasis has been placed on lignocellulosic ethanol industry in the U.S. Among many lignocellulosic feedstock crops, little information about long-term production and quality...
Show moreABSTRACTBIOMASS PRODUCTION POTENTIAL, THEORETICAL ETHANOL YIELD, ENVIRONMENTAL SUSTAINABILITY OF MISCANTHUS x GIGANTEUS AND NITROGEN FERTILIZER EFFECT ON QUANTITY AND QUALITY IN FIVE LIGNOCELLULOSIC BIOMASS CROPS IN NORTH-CENTRAL US BYSichao WangIncreasing concerns on climate change and energy security leads to growing emphasis has been placed on lignocellulosic ethanol industry in the U.S. Among many lignocellulosic feedstock crops, little information about long-term production and quality of giant miscanthus (Miscanthus × giganteus) is available in U.S. This study evaluated yield and quality parameters of giant miscanthus in southwest Michigan (KBS) and southcentral Wisconsin (ARL). An attributional life cycle assessment was also performed on giant miscanthus and switchgrass production phases by using empirical data. Nitrogen responses on yield and quality parameters were examined for five perennial bioenergy cropping systems: 1) switchgrass (Panicum virgatum L.); 2) giant miscanthus (Miscanthus × giganteus); 3) a native grass mixture (5 species); 4) an early successional field; and, 5) a restored prairie (18 species). The highest yield of miscanthus reached 22.81 ± 1.023 Mg ha-1 at KBS and 15.7 ± 0.898 Mg ha-1 at ARL. Giant miscanthus exhibited a positive yield response to nitrogen fertilization at both KBS and ARL and had the highest nitrogen fertilizer use efficiency among five cropping systems evaluated in this study. Compared to switchgrass cropping system, the giant miscanthus cropping system is more favorable in GHG emissions reduction when taking gasoline displacement credits into account. Due to higher yield, giant miscanthus had higher energy return on investment than switchgrass at both KBS and ARL.
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Title: Barriers and enablers to climate and health adaptation planning in rural, coastal counties in Michigan
Creator: Cangelosi, Elena Jean
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Authorities have declared that the implementation of adaptation strategies is necessary to protect current and future generations from the public health impacts of climate change (IPCC, 2018; US EPA, 2018; USGCRP, 2018). Yet not all communities have begun to plan for climate change, nor implement adaptation (Rosina Bierbaum et al., 2013a). Current adaptation literature focuses heavily on urban areas, developing countries, and agricultural practices. Nonagricultural-dependent rural areas,...
Show more"Authorities have declared that the implementation of adaptation strategies is necessary to protect current and future generations from the public health impacts of climate change (IPCC, 2018; US EPA, 2018; USGCRP, 2018). Yet not all communities have begun to plan for climate change, nor implement adaptation (Rosina Bierbaum et al., 2013a). Current adaptation literature focuses heavily on urban areas, developing countries, and agricultural practices. Nonagricultural-dependent rural areas, accounting for over 80% of the nonmetro counties in the United States (USDA ERS, 2015), are largely unexplored. Through a qualitative, exploratory, mixed-methods approach, surveys and interviews are used in this study to examine the barriers and enablers to climate and health adaptation in nonagricultural-based rural, coastal Marquette County in Michigan. Relatively advanced in climate adaptation planning, the study area represents a rural county actively addressing climate and health concerns. The findings support other researchers while identifying barriers and enablers unique to nonagricultural-based rural, coastal areas. This study broadens the current understanding of the challenges and opportunities faced in approaching adaptation, in hopes of ultimately better preparing communities for the negative health impacts of climate change."--Page ii.
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Title: Intra-household human capital measures and child and maternal health : evidence from Zambia
Creator: Faas, Simone Margaret
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Zambia has one of the highest rates of childhood stunting in the world. Traditional health production functions model that good health quality for young children is dependent on the necessary inputs of parental influences, including parental health, parental education, and household wealth. Using data from a Feed the Future survey from rural Zambia and the Women's Empowerment in Agriculture Index, I examine the relationship between several measures of spousal human capital and the health...
Show moreZambia has one of the highest rates of childhood stunting in the world. Traditional health production functions model that good health quality for young children is dependent on the necessary inputs of parental influences, including parental health, parental education, and household wealth. Using data from a Feed the Future survey from rural Zambia and the Women's Empowerment in Agriculture Index, I examine the relationship between several measures of spousal human capital and the health outcomes of young children and women of child-bearing age. I find the ability to read and write of both spouses is highly correlated with positive changes in children's and women's health outcomes. Literacy and education campaigns which target both boys and girls should be heavily emphasized among rural and disadvantaged communities in southern Africa, as men's literacy and education as well as women's literacy are both important to improving future health outcomes for children and adults.
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Title: BIOLOGICAL CONTROL OF THE INVASIVE BROWN MARMORATED STINK BUG (HALYOMORPHA HALYS) (HEMIPTERA : PENTATOMIDAE) IN MICHIGAN BY INTRODUCED AND NATIVE PARASTIOIDS IN A CHANGING CLIMATE
Creator: Simaz, Olivia Claire
Date: 2020
Collection: Electronic Theses & Dissertations
Description: This thesis focuses on evaluating the potential of native natural enemies and an exotic parasitoid to provide biological control of an invasive pest, the brown marmorated stink bug (Halyomorpha halys Stål) in Michigan and explores the consequences climate change might have both on the pest and its natural enemies. The first chapter provides background on the invasion of H. halys and reviews research on the native parasitoid community and their potential to provide biological control for this...
Show moreThis thesis focuses on evaluating the potential of native natural enemies and an exotic parasitoid to provide biological control of an invasive pest, the brown marmorated stink bug (Halyomorpha halys Stål) in Michigan and explores the consequences climate change might have both on the pest and its natural enemies. The first chapter provides background on the invasion of H. halys and reviews research on the native parasitoid community and their potential to provide biological control for this pest. The second chapter focuses on augmentative releases of the biological control agent, Trissolcus japonicus (Ashmead), which is an exotic parasitoid, discovered in Michigan in 2018. The importance of release size and of release frequency were tested during two years of augmentative releases and the native parasitoid community was surveyed. Overwintering success and reproduction of Tr. japonicus were confirmed but population growth was found slow. Parasitism by native parasitoids was below 5%, which is too low to provide control of H. halys. In the third chapter the effects of heat waves were evaluated on H. halys and Tr. japonicus. Eggs of H. halys were found to be more sensitive to heat waves than larval stages of Tr. japonicus. While heat waves did not reduce parasitism rates, Tr. japonicus adult mortality increased and their development was delayed with intensifying heat waves. These results suggest that Tr. japonicus could maintain its biocontrol potential even in the face of climate change.
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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: Use of Recycled Aggregate Materials Characteristics in Pavement Design Analyses
Creator: Gheibi, Ida
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Use of recycled materials promotes sustainability in roadway construction by reducing consumption of energy and emission of greenhouse gases associated with mining and the production of natural aggregates. Recycled asphalt pavements (RAP) and recycled concrete aggregates (RCA) have comparable characteristics to natural aggregates that are currently used in roadway base course applications. This study has developed a database for RAP and RCA materials’ characteristics including resilient...
Show moreUse of recycled materials promotes sustainability in roadway construction by reducing consumption of energy and emission of greenhouse gases associated with mining and the production of natural aggregates. Recycled asphalt pavements (RAP) and recycled concrete aggregates (RCA) have comparable characteristics to natural aggregates that are currently used in roadway base course applications. This study has developed a database for RAP and RCA materials’ characteristics including resilient modulus (Mr), California bearing ratio (CBR), gradations along with construction specifications. RAP and RCA relationships with different engineering and index properties were investigated and some trends were proposed such as higher RAP content reveals higher summary of resilient modulus (SMr), higher RCA content causes higher optimum moisture content (OMC) and lower maximum dry unit (MDU).In addition, pavement mechanistic-empirical (ME) analyses have been conducted with the material inputs collected for the database to determine whether different values of different characteristics of RCA and RAP can be used in flexible or rigid pavement designs. Results showed that Mr parameter had the highest impact on pavement distress predictions among gradations and hydraulic conductivity.
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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: 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: 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: The use of waste from orange juicing for food packaging applications
Creator: Fehlberg, Jack Alan
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Utilization of orange juicing waste (OP) as a filler material within a polymer matrix can add value to this agricultural waste and reduce dependency on non-renewable resources. This study aims to study the impact of OP filler's physical characteristics including size, loading, and retention or removal of zest on the properties of linear low density polyethylene (LLDPE) and to produce LLDPE/OP films by blown-film extrusion. LLDPE/OP sheets with zest exhibited decreased thermal stability,...
Show moreUtilization of orange juicing waste (OP) as a filler material within a polymer matrix can add value to this agricultural waste and reduce dependency on non-renewable resources. This study aims to study the impact of OP filler's physical characteristics including size, loading, and retention or removal of zest on the properties of linear low density polyethylene (LLDPE) and to produce LLDPE/OP films by blown-film extrusion. LLDPE/OP sheets with zest exhibited decreased thermal stability, larger OP agglomerates, worsened dispersion, and darker yellower colors and can act as UV- and light-absorbers. Larger OP particles increased air bubble formation, decreased mechanical properties, worsen dispersion, and produced darker yellower composites. Higher OP loadings resulted in LLDPE/OP composite sheets that have darker yellower color, decreased mechanical properties, and increased the size of OP agglomerates, as well as improved distribution and worsened dispersion. LLDPE/OP sheets that had properties most like neat LLDPE were sheets containing OP without zest and smaller particles sizes. This OP was used to determine maximum OP loading for LLDPE/OP films produced by blown-film extrusion. The LLDPE/OP films were subject to a sensory similarity triangle test and a comparison of package acceptance when different OP loading was used. This study found no difference in sensory qualities of bread when packaged in LLDPE/OP to neat LLDPE films. OP loading did not influence consumer perceptions of overall liking, appearance, surface roughness, color, or smell when LLDPE/OP films with 5 and 11.5% OP loadings were compared. This study demonstrates that OP waste can be converted and physically modified into a usable filler for plastic films for food packaging applications without altering the quality of the food product.
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