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Migration rate of a discoherent martensitic phase boundary
No full textInterfaces are a vital topic to research for a complete understanding of materials and their properties. Grain and phase boundaries particularly have importance, as they play integral roles in a multitude of mechanical behaviors. This project explores an aspect of phase boundaries by quantifying their movement in relation to an applied driving force. Specifically, the phase boundary encountered in martensite steel between HCP and BCC phase crystals and the strain energy produced by deformation.
The interface of HCP and BCC phases is not inherently coherent. The crystal orientations must undergo an affine transformation with a rotation and shift for coincident site atoms to align. Even with the transformation, an additional non-affine deformation is necessary to fully generate the coherency. Dislocations, termed discohesions, are formed for these atoms to be correctly position in the interface. These discohesions facilitate the construction of a coherent interface termed discoherent. This type of interface and the introduced discohesions are hypothesized to contribute to the ease of mobility of the phase boundary.
Research into this interface was primarily accomplished using molecular dynamics simulation via LAMMPS. A strain is applied in a specified ratio between the two phases to function as the driving force to control the migration of the interface. This varying ratio of strain is applied to both phases over simulation iterations to obtain a relationship between the difference in energy across the interface and the velocity of the boundary. For each iteration, a phase boundary velocity and strain energy delta were calculated and analyzed.
Results from the analysis show that the boundary was more easily able to migrate to facilitate the growth of the BCC phase versus the HCP phase. With the highest velocity magnitude being 0.3192 m/s when the HCP phase grew, while the BCC grew with a maximum magnitude of 0.4700 m/s. Overall, the phase boundary is capable of moving easily to minimize the energy difference across the interface. Which is potentially facilitated by the introduction of the discohesions in the interface.M.S.Includes bibliographical reference
A disease conceptual model of KCNT1-related epilepsy
No full textPotassium sodium-activated channel subfamily T member 1 (KCNT1) related epilepsy is a rare genetic neurodevelopmental disorder characterized by two distinct phenotypes, sleep-related hypermotor epilepsy (SHE) and epilepsy of infancy with migrating focal seizures (EIMFS). The impacts of the disorder on the person with KCNT1-relateded epilepsy and their caregivers are not well understood for either phenotype. Disease concept models (DCMs) are formal frameworks which highlight the lived experiences of these individuals and their primary caregivers. To further understand these impacts, we conducted twelve semi-structured open-ended interviews with primary caregivers of individuals with this condition. Of the twelve total participants, nine were caregivers of patients with EIMFS and three were caregivers of patients with SHE. Three categories of domains were used as the framework for coding and data analysis: symptoms, symptom impacts on the individual, and caregiver impacts. Symptoms reported by all caregivers of both EIMFS and SHE participants included communication, neurological and sleep symptoms. Though both phenotypes present with intellectual disability, caregivers of more severely affected individuals placed emphasis on motor issues (EIMFS participants (n=9), and the less severely affected described concerns about cognitive disabilities (SHE participants (n=3)). Inconsolable crying was described in 5 of the 9 EIMFS participants which was previously underreported in the medical literature. Of note, delayed puberty was described in one male SHE participant which, to our knowledge, is a novel concept. Commonly reported impacts of KCNT1 mutation on the individual were reported in the domains of schooling (n=10), socialization (n=8), hospitalizations (n=9), self-care and daily living tasks (n=12), and surgical interventions (n=6). The most common domains of caregiver impacts include general caregiver requirements (n=12), emotional impacts (n=12), financial impact (n=11), need for formal support (n=7), overall health impacts (n=10), and social impacts (n=12). The conceptual model of KCNT1-related epilepsy herein described expands the description of the disorder known from public medical literature.M.S.Includes bibliographical reference
Individual preferences in sanction policy: a multi-level study of EU sanction preferences against Russia
No full textDeterminants of public sanction preferences in sender countries are understudied, not incorporating variation in individual- and country-level costs that arise from the restriction in trade. By applying the trade policy preference framework on the recent EU economic sanctions against Russia, this paper tests whether sociotropic, ideational or economic self-interest variables and measures of country-level costs and benefits determine sanction approval among EU citizens. Two multi-level models find that with increasing economic repercussions, individuals are more likely to rely on their perceptions of personal economic costs while notions of ideational foreign policy preferences remain consistently important for sanction preference formation. Absent of experienced severe costs, individuals seem to be ignorant of economic consequences of sanction policy regardless of their educational attainment. By applying the trade policy preference framework to another type of foreign policy, this thesis highlights the versatility and shortcomings of the framework and contributes towards the identified research gap regarding the role of economic costs of sanctions within the sender country.M.A.Includes bibliographical reference
Investigations into the multielectron reactivity of cobalt complexes with redox-active o-phenylenediamide ligands
No full textChapter 1.The development of new organometallic complexes and (electro)catalysts based on earth-abundant, non-previous metals that are capable of multielectron reactivity is a pressing research field for improving the sustainability of many organic transformations. The introduction of redox-active ligands into transition metal complexes can lead to novel redox behavior due to the propensity of these ligands to serve as electron reservoirs. This prospect is especially attractive at first-row transition metal systems that traditionally favor one-electron redox processes and radical reactivity over the two-electron redox cycles typically observed at the noble metals. The redox flexibility afforded by redox-active ligands may enable substrate activation and/or bond forming and breaking processes that would otherwise not be accessible at first-row metal centers with traditional redox innocent ligands. Herein, key examples of substrate activation and organic transformations that are facilitated by ligand-promoted multielectron reactivity will be discussed. We highlight the electrochemical properties of these metal complexes in relation to their substrate reactivity, where, in several cases, these systems are limited by well-separated, sequential redox events at two redox-active ligands. This discussion sets the stage for the subsequent chapters of this thesis, in which we describe a family of novel cobalt complexes bearing a single-redox active ligand that are capable of multielectron redox behavior and multielectron substrate activation.
Chapter 2. Achieving multielectron activity at first-row transition metal complexes has important implications for homogeneous catalysis using earth-abundant metals. In this chapter, we report a family of cobalt-phenylenediamide complexes that undergo reversible 2e− oxidation regardless of the ligand substituents, enabling unprecedented multielectron redox tuning over 0.5 V and, in each case, affording the dicationic CoIII-benzoquinonediimine species. The neutral complexes are best described as delocalized systems with π-bonding in the metallocycle, consistent with a closed-shell singlet ground-state predicted by density functional theory (DFT) calculations. Our DFT results also predict an ECE pathway for 2e− oxidation (ECE = electrochemical step, chemical step, electrochemical step), where the first 1e− step involves redox-induced electron transfer to yield a CoII intermediate. Disruption of the metallocycle bonding in this state enables a change in the coordination geometry through association of an addition ligand, which is critical for accessing the potential inversion. The electronic properties of the phenylenediamide ligand govern whether the second electron is lost from the ligand or metal, providing a remarkable example of tunable 2e− behavior at first-row systems.
Chapter 3. The reactivity of an electron-rich cobalt complex bearing an o-phenylenediamide ligand with electrophilic trifluoromethyl and electrophilic fluorine sources is reported. These reactions lead to rapid generation of the CoIII−CF3 or CoIII−F complex, respectively, promoted by redox-active ligand-to-substrate two-electron transfer. The rate of trifluoromethyl addition at the cobalt center is found to correlate with the potential difference between the cobalt complex and the trifluoromethyl reagent. In this chapter, we also present initial demonstrations of radical trifluoromethylation and nucleophilic fluorination of organic substrates, setting the stage for the development of electrocatalytic pathways for these bond-forming reactions.
Chapter 4. In this chapter, the synthesis and characterization of [CoIII–CF3] complexes in three oxidation states are presented. Each species is isolable and has been fully characterized by various methods. The Co–CF3 bond formation occurs between [CpCp(tBuUreaopda)] and an electrophilic trifluoromethyl source, which proceeds without a change in the formal oxidation state of the cobalt center; instead, the redox-active phenylenediamide ligand serves as a 2e– reservoir, generating [CpCp(tBuUreabqdi)(CF3)]+. Electrochemical studies of the monocationic species [Co–CF3]+ reveal two reversible 1e– reductions that are assigned as ligand-based processes. Chemical reduction with 1 or 2 equiv. reducing agent enables isolation of the neutral and anionic complexes, respectively, where the [CoIII–CF3] bond remains intact. Analysis of the crystal structures of these three species show systematic changes to the N–Cphenlyene and C–C bond lengths, consistent with reduction of the ligand from [opda]2– to [s-bqdi]•– to [bqdi]0. In principle, these [Co–CF3]n+ complexes may enable formal umpolung of the CF3 group if the CF3– moiety can be released from [Co–CF3]– and used for organic trifluoromethylation reactions. In contrast, the reaction of [CpCo(tBuUreaopda)] and alkyl triflates results in ligand-centered alkylation of the ureayl substituents instead of the desired Co–alkyl bond formation, suggesting less favorable bond formation at cobalt and greater nucleophilic accessibility of the ureayl groups compared to the metal center.
Chapter 5. The o-phenylenediamine (opdaH2) ligand in half-sandwich cobalt complexes [CpCo(opdaH2)(MeCN)]2+ or [Cp*Co(opdaH2)(MeCN)]2+ can react with ligand-centered hydrogen atom transfer. In this chapter, we show that these complexes transfer two hydrogen atoms to molecular oxygen (O2) or the tBu3PhO• radical, with concomitant formation of [Co-bqdi]2+ in which the ligand exists in the diimine form. The reactivity of [Co-opdaH2]2+ and O2 (or air) was monitored by UV-vis and NMR spectroscopy, which revealed the apparent direct conversion of [Co-opdaH2]2+ to [Co-bqdi]2+ without the presence of other intermediates. DFT calculations suggest consecutive hydrogen atom transfer from [Co-opdaH2]2+ in which the BDFE value for the first N–H bond is greater than that of the second N–H bond. The calculated average BDFE value of the N–H bonds (70.8 kcal/mol) is very close to our experimentally determined value (74.1 kcal/mol). Combined with our measurements of the N–H bond acidity, we have fully characterized the thermodynamic parameters of this system, which enables construction of a double square scheme to depict the overall 2e−, 2H+ or 2H• transfer from [Co-opdaH2]2+.Ph.D.Includes bibliographical reference
"And now I have male privilege": transgender accounts of the precarity of privilege
No full textThis common and current conceptualization of male privilege implies that men are privileged as a result of being men and that women are disadvantaged as a result of being women, and that this binary classification is absolute. This is largely true- there are gender-based advantages that women (and those perceived as women) simply do not benefit from. However, what happens when the privileges associated with masculinity conflict with the disadvantages associated with Blackness, with queerness, with neurodivergence, and even with height? Is male privilege about the personal, the biological, or the social, and does the answer to that question leave room for women and other genders to also have male privilege? Through in-depth interviews with transgender people who have experience being perceived on both sides of the gender binary I draw patterns across who has access to male privilege, whether privilege is fixed or dynamic, and the sociomental and intersubjective process of assigning privilege, particularly when there are socially incompatible characteristics. I find that male privilege can be gained, lost, and maintained, that the degree of male privilege one benefits from is dependent on visible or assumable characteristics that conflict with Western hegemonic masculinity, and that domination works both internally (men having privilege relative to other men) and externally (men having privilege relative to other genders).Ph.D.Includes bibliographical reference
"Obesity isn’t 'good health' it immediately means bad health": uses, transformations, and consequences of the diagnosis of obesity
No full textOver the past three decades, obesity has emerged as a central problem of individual and public health. At the same time, however, social scientists have established that obesity is not necessarily a natural health issue but is instead a socially constructed problem that originated in nonscientific white supremacist constructions of black bodies. In this dissertation, I address a gap in this literature by approaching obesity as a specific type of socially constructed problem: a diagnosis. Diagnoses are social categories and social processes that serve as a nexus for a number of phenomena (medical authority, social values, the management of uncertainty, etc.) and are put to use both within and outside of medicine. Through three studies of different aspects of obesity as diagnosis, I address a broader set of questions: How does the diagnosis of obesity operate? For whom is it useful and in what ways? I examine the following aspects of obesity as a diagnosis: 1. Physicians’ professional definitions of and organization around obesity via (de)medicalization; 2. The consequences of being labeled obese in the context of care utilization; and 3. Lay public deployments and transformations of obesity during the COVID-19 pandemic. I show that obesity is a malleable category that can be altered to serve the needs of medical professionals and lay people alike, as well as a category that has uneven and negative consequences for those who bear its label. Obesity can be deployed as a site for professional organization or a tool to resolve uncertainty; at the same time, it can serve as a barrier to healthcare and a means to deny fat people’s humanity. While obesity is central to Western understandings of health, this dissertation demonstrates that it is an unstable, exploitable category that can justify or produce harm against those to whom it is applied.Ph.D.Includes bibliographical reference
High dimensional time series data mining in automatic fire monitoring and automotive quality management
No full textTime series data is increasingly being generated in many domains around the world. Monitoring an event using multiple variables gathered over time forms a high-dimensional time series when the number of variables is high. High-dimensional time series are being widely applied across many areas. Thus, the need to develop more efficient and effective approaches to analyze and monitor high-dimensional time series data has become more critical. For instance, within the realm of fire disaster management, the advancement of fire detection systems has garnered research interest aimed at safeguarding human lives and property against devastating fire incidents. Nonetheless, the task of monitoring indoor fires presents complexities attributed to the distinct attributes of fire sensor signals (namely, high-dimensional time series), including the presence of time-based dependencies and varied signal patterns across different types of fires, such as those from flaming, heating, and smoldering sources.
In the field of automobile quality management, minimizing internal vehicle noise is crucial for enhancing both customer satisfaction and the overall quality of the vehicle. Windshield wipers are significant contributors to such noise, and defective wipers can adversely impact the driving perception of passengers. Therefore, detecting wiper defects during production can lead to an improved driving experience, enhanced vehicle and road safety, and decreased driver distraction. Currently, the process for detecting noise from windshield wipers is manual, subjective, and requires considerable time.
This dissertation presents several novel time series monitoring and anomaly detection approaches in two domains: 1) fire disaster management and 2) automotive quality management. The proposed approaches effectively address the limitations of traditional and existing systems and enhance human safety while reducing human and economic losses.
In the fire disaster management domain, we first propose two fire detection systems using dynamic time warping (DTW) distance measure. The first fire detection system is based on DTW and the nearest neighbor (NN) classifier (NN-DTW). The second fire detection system utilizes a support vector machine with DTW kernel function (SVM-DTWK) to improve classification accuracy by utilizing SVM capability to obtain nonlinear decision boundaries. Using the DTW distance measure, both fire detection systems retain the temporal dynamics in the sensor signals of different fire types. Additionally, the suggested systems dynamically identify the essential sensors for early fire detection through the newly developed k-out-of-P fire voting rule. This rule integrates decision-making processes from P multichannel sensor signals effectively. To validate the efficiency of these systems, a case study was conducted using a real-world fire dataset from the National Institute of Standards and Technology.
Secondly, we introduce a real-time, wavelet-based fire detection algorithm that leverages the multi-resolution capability of wavelet transformation. This approach differs from traditional fire detection methods by capturing the temporal dynamics of chemical sensor signals for different fire scenarios, including flaming, heating, and smoldering fires. A novel feature selection method tailored to fire types is employed to identify optimal features for distinguishing between normal conditions and various fire situations. Subsequently, a real-time detection algorithm incorporating a multi-model framework is developed to efficiently apply these chosen features, creating multiple fire detection models adept at identifying different fire types without pre-existing knowledge. Testing with publicly available fire data indicates that our algorithm surpasses conventional methods in terms of early detection capabilities, maintaining a low rate of false alarms across all fire categories.
Thirdly, we introduce an innovative fire detection system designed for monitoring a range of indoor fire types. Unlike traditional research, which tends to separate the development of fire sensing and detection algorithms, our system seamlessly integrates these phases. This integration allows for the effective real-time utilization of varied sensor signals to identify fire outbreaks at their inception. Our system collects data from multiple types of sensors, each sensitive to different fire-emitted components. This data then feeds into a similarity matching-based detection algorithm that identifies distinct pattern shapes within the sensor signals across various fire conditions, enabling early detection of fires with minimal false alarms. The efficacy of this system is demonstrated through the use of real sensor data and experimental results, underscoring the system’s ability to accurately detect fires at an early stage.
Lastly, in the automotive quality management domain, we introduce an innovative automated system for detecting faults in windshield wipers. Initially, we apply a new binarization technique to transform spectrograms of the sound produced by windshield wipers, isolating noisy regions. Following this, we propose a novel matrix factorization technique, termed orthogonal binary singular value decomposition, to break down these binarized mel spectrograms into uncorrelated binary eigenimages. This process enables the extraction of significant features for identifying defective wipers. Utilizing the k-NN classifier, these features are then categorized into normal or faulty wipers. The system’s efficiency was validated using real-world datasets of windshield wiper reversal and squeal noises, demonstrating superior performance over existing methodologies.
The proposed approaches excel in detecting complex temporal patterns in high-dimensional time series data, with wide applicability across healthcare, environmental monitoring, and manufacturing for tasks like vital signs monitoring, climate and pollution tracking, and machinery maintenance. Additionally, the OBSVD technique, producing binary, uncorrelated eigenimages for unique information capture, broadens its use to medical imaging for anomaly detection, security for facial recognition, quality control for defect detection, document processing, and environmental analysis via satellite imagery. This versatility highlights the research's significant potential across machine learning and signal processing, improving efficiency and accuracy in time series data analysis.Ph.D.Includes bibliographical reference
Assessing the trend of China’s rise (1979-2022): an analysis based on the classical geopolitics
No full textIn the recent decade (2010-2022), several geopolitical events have been closely related to China’s rise, such as ‘the Pivot to Asia’ and ‘the Indo-Pacific Strategy.’ Meanwhile, there were enormous discussions globally regarding China’s rise, primarily focusing on whether China’s rise will be peaceful or not. After analyzing discourses related to China’s rise from perspectives of international relations and geopolitics, this study adopts qualitative and quantitative research methods to develop an analytical framework for assessing the trend of China’s rise. The analytical framework provides a ternary worldview that the world is divided into three parts: the part of the Eurasia continent, the part of the sea, and the part of the outer/insular crescent. China is one of the actors in the part of the Eurasia continent. Then, this research adopts three case studies at three different levels (domestic, regional, and global) and reaches three points: one, China’s rise is peace-oriented; two, China’s rise was generally peaceful between 1979 and 2022: first, 1979-2010: China’s rise was peaceful; second, 2010-2022: China’s rise was less peaceful than that of 1979-2010; third, in the future, China’s peaceful rise is more likely to be interrupted by the outside world or halted by China itself; three, although none of the major theoretical schools offer a flawless explanation for China’s rise, China’s rise is closer to the liberal perspective regarding economic interdependence than the realist perspective. Then, to assess the trend of China’s rise, this research revisits three case studies from the perspective of the analytical framework and reaches two conclusions: first, the classical geopolitical theories still have significant value for understanding contemporary international relations in the 21st century; second, China’s rise and return to the world’s No.1 in terms of GDP is expected to occur within the coming decades, and it is also a symbol of an actor in the part of the Eurasia continent, for the first-time overcoming actors in the part of the outer/insular crescent in terms of GDP in the recent 200 years in human history. However, whether China could realize a peaceful rise in the future depends not only on China but also on the outside world, especially the United States (U.S.), which is currently the world’s existed key global hegemon and superpower. As China’s maritime capabilities grow rapidly and close to those of the U.S., the U.S. will see China’s rise as a vast and urgent threat to the foundation of U.S. global hegemony. In the meantime, conflicts, disputes, and frictions between China and the U.S. are likely to intensify near the point of equilibrium. This is the stage of China’s rise now and for some time to come. Keywords: China’s Rise, Classical Geopolitics, Global Development, International Security, Economic InterdependencePh.D.Includes bibliographical reference
Inoculation with root-associated fungus Mollisia panicicola to enhance establishment of switchgrass (Panicum virgatum)
No full textThis study investigates the conditions under which New Jersey Pine Barrens (NJPB) microbes applied to switchgrass seeds at planting can improve early growth and stand establishment. Switchgrass, with its large, perennial yield of fermentable leaves and stems, has great potential as a sustainable bioethanol feedstock, especially considering its hardiness in agriculturally marginal areas. Switchgrass has been found to associate with a varied microbiome, containing numerous culturable strains with the potential to benefit their plant host. Two microbes isolated from wild switchgrass in the acidic, nutrient-poor NJ Pine Barrens ecosystem, one bacterial (Pseudomonas sp.) and one fungal (Mollisia panicicola), were selected for inoculation of switchgrass seeds in a field planting at two farm sites. Plots of the upland switchgrass variety ‘Carthage’ and lowland variety ‘Kanlow’ inoculated with one, both, or neither of the microbes were observed for two years, to evaluate their germination, height, and biomass yield, as indicators of successful establishment and plant health. Over the two years of this study, ‘Kanlow’ across locations benefited from the M. panicicola inoculation, producing larger plants over two years when the fungus was present. This study demonstrates one method for inoculating switchgrass symbiotic fungus in the field, and suggests that microbial benefits such as these may be specific to only sensitive switchgrass varieties.M.S.Includes bibliographical reference
Prognostic performance of combined hematopoietic cell transplantation – comorbidity index, age and socioeconomic status in recipients of allogeneic hematopoietic cell transplants for patients with acute myeloid leukemia and myelodysplastic syndromes
No full textMedical prognostication models based on both clinical and non-clinical characteristics are used to estimate the risk of outcomes in individuals undergoing hematopoietic cell transplant for acute myeloid leukemia and myelodysplastic syndrome. It is imperative that clinical decision makers have accurate tools for pre-transplant risk-benefit assessment that would allow for optimal stratification of patients to determine suitability of hematopoietic cell transplants (HCT), maximize the benefits of HCT to the patients and aid transplant centers optimize their resources. Using educational level, occupation status and income level as factors of socioeconomic status (SES) index, this study combines SES with hematopoietic cell transplantation comorbidity index (HCT-CI) and age before transplant to develop a new prognostic tool for overall survival and non-relapse mortality outcomes for patients with acute myeloid leukemia and myelodysplastic syndromes at Memorial Sloan Kettering Cancer Center (MSKCC). The predictive capabilities of the new HCT-CI/Age/SES for this single center cohort were compared to the HCT-CI and HCT-CI/Age. At 95% Confidence Interval, estimates of adjusted c-statistic for overall survival were 0.673 and 0.676 for HCT-CI and HCT-CI/Age, respectively, while it was 0.652 for HCT-CI/Age/SES index. The predictive capability of the latter suggests that the new tool can be a valuable prognostic assessment for overall survival outcome. Delineating the relative importance of SES and each of the individual factors, the SES index did not significantly predict either overall survival or non-relapse mortality at 2 years post HCT in this patient cohort. Advances in research, novel therapies, treatment expertise and optimal follow-up protocols at MSKCC may have contributed to ameliorate the impact of low SES; suggesting that with access to the same expert care, lower SES individuals can achieve similar treatment outcomes as those at higher SES levels.Ph.D.Includes bibliographical reference