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- Title
- FIBER-OPTIC SILICON FABRY-PEROT INTERFEROMETERS FOR HIGH-SPEED ANEMOMETER AND HIGH-SENSITIVITY BOLOMETER APPLICATIONS
- Creator
- Uddin, Nezam
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
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Fiber-optic silicon Fabry-Perot interferometric temperature sensor offers the advantage of high-speed and high-resolution to characterize the ocean turbulence in oceanographic research. Compared to silica, the material that makes the optical fiber, silicon has a thermo-optic coefficient ten times higher and a thermal conductivity sixty time higher. Silicon is highly transparent in the infrared wavelength range and can be easily processed with the mature microfabrication technology. All of...
Show moreFiber-optic silicon Fabry-Perot interferometric temperature sensor offers the advantage of high-speed and high-resolution to characterize the ocean turbulence in oceanographic research. Compared to silica, the material that makes the optical fiber, silicon has a thermo-optic coefficient ten times higher and a thermal conductivity sixty time higher. Silicon is highly transparent in the infrared wavelength range and can be easily processed with the mature microfabrication technology. All of these make silicon a very attractive material for high-speed and high-resolution turbulence measurement. We attached a small silicon pillar to the end of an optical fiber to make fiber-optic Fabry-Perot interferometric sensor demodulated by a white light system for fast turbulence measurement. We studied the two modes of fiber-optic hot wire anemometer operation for turbulence measurement theoretically and experimentally. The constant temperature operation of the fiber-optic hot wire anemometer was introduced for the first time to reduce the time constant significantly. The anemometer used for demonstration is based on a silicon low-finesse Fabry-Perot interferometer (FPI) attached to the tip of a single mode fiber. Turbulent flow measurement method based on constant temperature operation offers high measuring speed, because the wire temperature is kept constant, the effect of thermal inertia of the wire is suppressed. We also investigated a new sensor structure experimentally and theoretically for the measurement of water flow with reduced directivity. This sensor consists of a laser heated silicon FPI embedded in a metal microsphere. Herein, the spherical shape of the outside metal shell gives a symmetric response to water flow direction; thus, the directivity is reduced greatly. Moreover, the water flow measurement by the hot wire fiber-optic water flow sensor based on laser heated silicon FPI need to compensate the effect of water temperature variation. We reported a technique to compensate the effect of water temperature change in the flow measurement by using another sensor which will track the temperature of the water. By using the information of the water temperature change, baseline can be defined which will provide unique wavelength change for the flow. Finally, the wavelength change corresponding to the flow speed were calibrated using the sensor pair after compensating the effect of water temperature variation. We expanded the use of silicon Fabry-Perot interferometric sensor in the measurement of plasma radiation by modifying the structure with gold coated silicon and multimode graded index fiber between the single mode fiber (SMF) and silicon. We reported the design, fabrication, and characterization of a fiber-optic bolometer (FOB) with improved noise equivalent power density (NEPD) performance and increased absorption to high energy photons by engineering the absorber of the FOB. We also have developed a multichannel fiberoptic bolometry system with five bolometers connected to each channel of the coarse wavelength division multiplexer (CWDM), a single light source of super luminescent LED (SLED) and a single I-MON 512 OEM spectrometer. Easy sensor fabrication, significantly enhanced measurement range compared to the previous high-finesse FPI bolometer system for measuring radiation are some of the advantages. Moreover, utilization of the FOB in the vacuum for radiation measurement with reduced time constant was also studied which is practically required in the fusion devices. This was done by adding a heat sink with the current FOB structure and using the deconvolution method to get better temporal resolution. Finally, the FOB with the heat sink was tested in the vacuum condition to measure the radiation using the deconvolution method. Experimental results are presented to support the idea of heat sink and deconvolution method for plasma radiation measurement.
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- Title
- KNOWLEDGE SPILLOVERS AND SAFE DRINKING WATER ACT COMPLIANCE
- Creator
- Redican, Kyle James
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
-
In the wake of the 2014 Flint Water Crisis, researchers, regulators, and utility professionals have given increased attention to understanding drivers of (CWS) Safe Drinking Water Act (SDWA) compliance by community water systems (CWSs). Most of this research has only explored system traits while ignoring the vital role of human capital, especially the operator. The status of CWS operators can vary widely between different systems. More critically, scholars have not investigated how effective...
Show moreIn the wake of the 2014 Flint Water Crisis, researchers, regulators, and utility professionals have given increased attention to understanding drivers of (CWS) Safe Drinking Water Act (SDWA) compliance by community water systems (CWSs). Most of this research has only explored system traits while ignoring the vital role of human capital, especially the operator. The status of CWS operators can vary widely between different systems. More critically, scholars have not investigated how effective external linkages between CWS operators have impacted SDWA compliance. Drawing from the theories of Organizational Learning’s inter-organizational learning, Innovation Systems’ knowledge transfers, and Agglomeration Economics’ knowledge spillovers, I hypothesized that increased interactions between CWS operators, facilitated in part by geographic proximity, would lead to more information sharing, increased CWS performance, and fewer SDWA violations. Remarkably little is known about the drivers of inter-operator interactions or whether such interactions improve SDWA compliance, and this research helped fill the data gap through a large-sample survey of CWS operators in Michigan to capture the frequency of interactions along with a range of operator and system characteristics which may explain why some operators participate in more inter-operator interactions than others. With this novel dataset, along with publicly available system and community data, this research first investigated what endogenous operator characteristics were associated with more reported inter-operator interactions. Through multiple methods on reported operator interactions, the Utility and Contract operators and operators with memberships in professional organizations appear more likely to report more interactions than Non-Affiliated operators and all operators who were not members of professional organizations. Second, based on Tobler’s first law of geography, there should be some spatial autocorrelation in the number of reported interactions, and this was tested using variogram modeling. Observed spatial autocorrelation indicated location-based differences in the number of reported interactions. Third, we used multiple methods to explore the primary research question to identify endogenous and spatial drivers of reported inter-operator interactions. Multiple models found that rural districts had a higher probability of fewer SDWA violations with increased interactions, while the urban districts had the inverse relationship. Fourth, the research incorporated CWS-specific and operator-specific variables, as the operator-specific data were not independent of the CWS observations (since some operators run multiple CWSs). I used a Generalized Linear Mixed-Model to estimate these relationships accounted for the multiple levels and found that more interactions increased the probability of SDWA compliance for certain types of operators. The broader implications of this research encourage stakeholders to pursue more inter-operator interactions as a low-cost mechanism to increase SDWA compliance. Seven avenues to increase interactions are outlined, ranging from open operator contact lists to operator focus groups to identify common problems and solutions to creating a state-level operator mentorship program to support new operators.
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- Title
- BUILDING STATE WILDLIFE AGENCY CAPACITY FOR EFFECTIVE PARTNERSHIPS
- Creator
- Cross, Megan M
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
-
State wildlife agencies (SWAs) partner with organizations of various types, on projects of various types, at what is anticipated to be an increasing rate. Inclusion of multiple and diverse stakeholders and partners is postulated to improve effectiveness of wildlife management (Anderson & Loomis, 2007; Jacobson et al., 2010). Through partnerships, actors from private, civil, and public sectors work together to reduce negative impacts from wildlife and improve access to and benefits of wildlife...
Show moreState wildlife agencies (SWAs) partner with organizations of various types, on projects of various types, at what is anticipated to be an increasing rate. Inclusion of multiple and diverse stakeholders and partners is postulated to improve effectiveness of wildlife management (Anderson & Loomis, 2007; Jacobson et al., 2010). Through partnerships, actors from private, civil, and public sectors work together to reduce negative impacts from wildlife and improve access to and benefits of wildlife resources. Although partnerships can improve the ability of SWAs to address these issues, little is known about how the perspectives of internal employees and external partners and stakeholders differ regarding factors affecting perceived success of partnerships in wildlife conservation.This dissertation addresses SWA partnerships through an examination of one prototypical SWA’s partnership arrangements. I propose a typology for categorization of SWA partnerships and apply a theory of collaborative capacity to the assessment of them. I surveyed all employees of the Michigan SWA and asked them to identify the three partners they consider most key to their work and found gaps in the frequencies of partners considered key to the work of SWA employees based on their locations in the defined typology. Additionally, the model of collaborative capacity tested varied in performance when applied to SWA employees and SWA partners. This research has implications for transparency regarding how state power is shared and considers how the disparate prevalence of various partnership arrangements may affect wildlife governance. Furthermore, my research findings may be used to improve SWA partnership arrangements and improve their alignment with governance and management-relate goals, as well as increase awareness of differences in views regarding partnership success as defined by SWA employees and partners.
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- Title
- THE ROLE OF PREZYGOTIC SELF-COMPATIBILITY IN FACILITATING INTERSPECIFIC COMPATIBILITY IN SOLANUM SECTION PETOTA
- Creator
- Behling, William
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
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Domesticated potato (Solanum tuberosum L.) is the fourth most important food crop worldwide and critical food security crop. The high significance of this crop coupled with high production losses place potato at a high priority for genetic improvement, especially in the face of climate change. Potato breeding is undergoing a seismic shift from a tetraploid outcrossing crop towards a F1 hybrid system using diploid inbred lines as parents. This transformation has also changed how potato...
Show moreDomesticated potato (Solanum tuberosum L.) is the fourth most important food crop worldwide and critical food security crop. The high significance of this crop coupled with high production losses place potato at a high priority for genetic improvement, especially in the face of climate change. Potato breeding is undergoing a seismic shift from a tetraploid outcrossing crop towards a F1 hybrid system using diploid inbred lines as parents. This transformation has also changed how potato breeders access important traits from wild species. Pre- and post-zygotic barriers, such as self-incompatibility (SI) and endosperm failure, inhibit and complicate the use of the more valuable wild species in conventional and diploid breeding schemes. Traditionally plant breeders have employed the SC x SI rule, using self-compatibility (SC) to increase the success of interspecific crosses. In order to evaluate the potential of several different SC factors in facilitating broad interspecific compatibility: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 knockout (KO) lines of S-RNase, HT-B and HT-B + S-RNase in S. tuberosum were evaluated along with the self-compatible species S. verrucosum, and S-locus inhibitor gene (Sli) from S. chacoense. Findings confirm the central role of S-RNase in interspecific pollination barriers and the inconsequential role of HT-B alone. Sli had no effect on interspecific barriers despite its prominent role as a source of SC. Finally, S. verrucosum styles displayed an absence of prezygotic barriers. Further analysis of the role of HT-A, as well as other mechanisms that potentially underlie the SC phenotype in S. verrucosum will further clarify the role of specific genetic factors that regulate interspecific compatibility in Solanum section Petota
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- Title
- Life Cycle Monitoring of Reversible Adhesive Bonded Joints using Guided Waves
- Creator
- Palanisamy, Rajendra Prasath
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
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Recent advancements in automotive, aerospace, civil and wind-energy industries have resulted in an ever-increasing demand for lightweight, cost-effective, rapidly manufactured and recyclable/reusable of structural components. Adopting composite materials is a popular solution to achieve light-weighting, however it requires complex joining methods compared to traditional mechanical fasteners. Electromagnetic targeted heating of nano-Fe3O4 reinforced thermoplastic adhesives (Reversible-Adhesive...
Show moreRecent advancements in automotive, aerospace, civil and wind-energy industries have resulted in an ever-increasing demand for lightweight, cost-effective, rapidly manufactured and recyclable/reusable of structural components. Adopting composite materials is a popular solution to achieve light-weighting, however it requires complex joining methods compared to traditional mechanical fasteners. Electromagnetic targeted heating of nano-Fe3O4 reinforced thermoplastic adhesives (Reversible-Adhesive) is an emerging technique for rapid assembly, dis-assembly, and re-assembly of bonded composite parts. Alternate magnetic field applied to the dispersed ferromagnetic nanoparticles (FMNP) within a thermoplastic adhesive results in these particles acting as nano-heaters and rapidly heating the surrounding material resulting in melting and flow of the adhesive, which upon cooling forms a structural bond. This process can be repeated and hence termed reversible adhesive. Reversible-adhesive bonded composite structures (RBCS) offer a greater advantage over thermosets or mechanical joints such as rapid processing, easy repair, quick disassembly, and possible re-usability of components. However, it is essential to accurately measure the temperature of the adhesive during processing and repair, since overheating may cause chemical degradation and underheating may introduce improper bonds. Adhesively bonded composite structures provide a more uniform stress distribution in the bond-line than riveted joints resulting in higher fatigue life. However, modeling the physics behind crack initiation and propagation inside bonded regions is challenging especially under fatigue loading. As a result, real-time in-service bond monitoring is required to ensure structural safety. In addition to monitoring the damage state, prediction of damage area and remaining useful life of the component is imperative. Thus, this research work focusses on developing a life cycle monitoring solution for RBCS using the guided wave (GW) technique. Ultrasonic guided waves were made to propagate across the bond-line of the joint by exciting and sensing them using miniature piezoelectric wafers. Analysis of dispersion relations and dynamic wave propagation were performed using finite element modeling (FEM). Fundamental longitudinal mode L_0 at 35 kHz was found optimal for bond process monitoring. Mapping between the FE-simulated transmission coefficient of L_0 and actual temperature of the thermoplastic adhesive was established using the DMA test data. Real-time guided wave measurements were used as feedback in the discrete control of the induction heater so as to provide optimal bonding and prevent adhesive degradation. The developed ultrasonic technique was successfully validated by fiber-optic temperature sensing. Results indicate that the bondlines processed with GW control offer better ultimate strength compared to uncontrolled processing.Guided wave modal and frequency sensitivity analysis for fatigue damage was performed. Based on the analysis, symmetric mode at 85 kHz was found optimal for fatigue damage detection. Further, a damage propagation model based on Paris law was developed to estimate remaining useful life in terms of the GW signal features. Finally, the remaining useful life of the lap-joint was predicted and validated experimentally. One of the major advantages of reversible adhesive is its ability to repair/heal the damage. The controlled processing technique developed earlier was used for controlled healing of fatigue damaged joints. Experimental investigation proves the healed-bond line have returned to its original strength. A holistic approach of a complete lifecycle monitoring of bonded joints was aimed at increasing the confidence in the use of bonded joints relative to mechanical fasteners, and can be easily extended to other structural applications.
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- Title
- High-precision and Personalized Wearable Sensing Systems for Healthcare Applications
- Creator
- Tu, Linlin
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
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The cyber-physical system (CPS) has been discussed and studied extensively since 2010. It provides various solutions for monitoring the user's physical and psychological health states, enhancing the user's experience, and improving the lifestyle. A variety of mobile internet devices with built-in sensors, such as accelerators, cameras, PPG sensors, pressure sensors, and the microphone, can be leveraged to build mobile cyber-physical applications that collected sensing data from the real world...
Show moreThe cyber-physical system (CPS) has been discussed and studied extensively since 2010. It provides various solutions for monitoring the user's physical and psychological health states, enhancing the user's experience, and improving the lifestyle. A variety of mobile internet devices with built-in sensors, such as accelerators, cameras, PPG sensors, pressure sensors, and the microphone, can be leveraged to build mobile cyber-physical applications that collected sensing data from the real world, had data processed, communicated to the internet services and transformed into behavioral and physiological models. The detected results can be used as feedback to help the user understand his/her behavior, improve the lifestyle, or avoid danger. They can also be delivered to therapists to facilitate their diagnose. Designing CPS for health monitoring is challenging due to multiple factors. First of all, high estimation accuracy is necessary for health monitoring. However, some systems suffer irregular noise. For example, PPG sensors for cardiac health state monitoring are extremely vulnerable to motion noise. Second, to include human in the loop, health monitoring systems are required to be user-friendly. However, some systems involve cumbersome equipment for a long time of data collection, which is not feasible for daily monitoring. Most importantly, large-scale high-level health-related monitoring systems, such as the systems for human activity recognition, require high accuracy and communication efficiency. However, with users' raw data uploading to the server, centralized learning fails to protect users' private information and is communication-inefficient. The research introduced in this dissertation addressed the above three significant challenges in developing health-related monitoring systems. We build a lightweight system for accurate heart rate measurement during exercise, design a smart in-home breathing training system with bio-Feedback via virtual reality (VR) game, and propose federated learning via dynamic layer sharing for human activity recognition.
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