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How Interactions Between the Inflation Reduction Act and Existing Policies Facilitate a Just Energy Transition
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A Hyperbolic Relaxation Solver for Numerical Relativity
Get PDFNumerical relativity (NR) simulations are essential for self-consistently modeling compact binary mergers, whose observations form the heart of gravitational-wave science. Stable NR simulations are the result of mathematical and computational breakthroughs spanning several decades: early attempts to numerically solve the two-body problem in General Relativity (GR) date back to the 1960s, while the first successful black-hole binary merger simulations were performed in 2005 with the generalized harmonic coordinates, and in 2006 using the moving-puncture gauge.
Today, NR continues to drive progress in gravity research, with ongoing efforts focused on increasing physical realism in simulations containing matter, exploring alternative theories of gravity, optimizing numerical algorithms, and fully leveraging the power of modern computer hardware.
Stable numerical evolutions require splitting the governing partial differential equations (PDEs) into two distinct groups: constraint equations, the elliptic PDEs that are solved to generate the initial data, and evolution equations, the hyperbolic PDEs that are integrated forward in time to simulate dynamical spacetimes. Solving elliptic and hyperbolic PDEs requires different numerical techniques, and specialized NR codes have been developed to handle each type of equation. This typically results in an overspecialization in the field of NR, with individual researchers focusing on a single kind of PDE solver.
In this thesis, I introduce NRPyElliptic, a new hyperbolic relaxation solver for elliptic equations developed within the NRPy framework. The hyperbolic relaxation method transforms elliptic PDEs into hyperbolic PDEs, which are then evolved using a combination of damping and wave propagation. The system is evolved until it reaches a steady state, at which point the solution to the hyperbolic PDEs coincides with that of the original elliptic equations. By using standard wave-equation techniques to solve the constraint equations, we can leverage existing expertise and code infrastructure from evolution solvers, allowing development efforts to focus on new physical applications.
NRPyElliptic has been applied to solve different elliptic systems. In its first application, we have generated binary black-hole (BBH) initial data using the conformal flatness approximation. The solution was validated against TwoPunctures, a widely used NR initial data solver, showing excellent agreement. Since conformally flat initial data can only model BBHs with dimensionless spin parameters up to chi=0.93, we drop this assumption in the second application and implement the full coupled elliptic system of Hamiltonian and momentum constraints in conformally curved spacetimes. Extensive validation and convergence tests for single black-hole initial data in conformally curved spacetimes are presented, along with a proof-of-principle solution for the binary case. As high-resolution conformally curved BBH initial data requires a multi-patch numerical domain, the code has been designed with the ability to integrate into such a framework. Finally, as an example of its flexibility, NRPyElliptic is extended to generate static binary solutions for scalar field configurations in k-essence theory
Laser Deposition Additive Manufacturing of Multi-Material and Metal-Ceramic Composite Structures
No full textThe increasing performance requirements of modern industrial systems, coupled with the imperative for decarbonization, necessitate a fundamental rethinking of metallic component design and manufacturing. Traditional materials, with their inherent limitations in property optimization, susceptibility to degradation, and weight constraints, are proving insufficient. Multi-material joining offers a potential solution, enabling designers to strategically integrate diverse materials with specific, tailored properties into single component. Functionally graded materials (FGMs) and oxide dispersion strengthened (ODS) materials are prime examples of this approach, delivering substantial improvements in wear resistance, thermal regulation, high-temperature resilience, and overall weight efficiency. However, conventional manufacturing approaches further exacerbate the limitations of single-material systems, typically leading to residual stresses, porosity, and difficulties when joining materials with dissimilar properties, resulting in interfacial defects and bonding inconsistencies.
Laser powder feed–directed energy deposition (L-DED), a promising additive manufacturing technology, facilitates multi-material fabrication through rapid melting and solidification, creating strong metallurgical bonds with minimal stress and distortion. This research leverages L-DED technology to pioneer two transformative pathways in multi-material engineering.
The first pathway explores a steep or bimetallic FGM manipulation to enhance thermo-electrical and wear resistance properties of L-DED as-deposited Inconel 718 (IN718), a nickel-based superalloy. A selective alloy coating is deposited through optimized process parameters to create strong, defect-free interfacial bonds aided by Marangoni convection effects. For thermal-cooling and electro-magnetic resistance applications, a copper alloy (CuSn10) is deposited onto IN718 via interlayer machining, functionalizing its performance for aerospace, power-generation and marine applications. Additionally, a cobalt alloy is integrated to IN718’s thermal-fatigue and wear resistance, enabling its application for high-temperature and multiphase flow characteristic of demanding industrial systems. The resulting FGM’s interfacial bonding region properties were characterized by assessing its thermo-electrical, and mechanical responses in conjunction with detailed microstructural and phase characterization studies, benchmarked against those of the original alloys.
The second pathway investigates a cutting-edge powder processing technique called mechano-chemical bonding (MCB) for embedding nano-oxides uniformly into SS316L (stainless steel alloy), producing ODS materials. Renowned for their high-temperature strength, resistance to void swelling, and durability against neutron irradiation, ODS materials serve critical roles in Gen-IV reactors’ infrastructure. Through varied Y₂O₃ concentrations, this study assessed their effects on microstructure stability, mechanical properties, and phase transformations in as-deposited ODS SS 316L and SS316L at constant energy density, tailoring the material for demanding applications.
By refining interfacial bonding characteristics through a comprehensive understanding of DED-induced microstructure evolution, phase transformations, as well as metallurgical properties, this research unlocks the full potential of multi-material systems. The findings pave the way for a sustainable, high-performance industrial future with robust, reliable components that meet the ever-evolving demands of the modern world
Using TouchMath® as an Intervention for Students with Disabilities at a Public Montessori School
No full textStudents with high-incidence disabilities enrolled in public Montessori elementary schools do not always make adequate growth in mathematics using traditional Montessori materials and instruction. While direct instruction methods are not typically used in a Montessori setting, such teaching practices have been proven to be successful when teaching students with disabilities.
This study analyzed the effects of an evidence-based math intervention, TouchMath®, on the addition fact fluency and acquisition of double-digit addition skills of elementary students with disabilities who receive small-group special education instruction in a public Montessori school. The students’ confidence levels before and after receiving the intervention was assessed to determine student perceptions of the impact of TouchMath® intervention on their mathematics skill development. Results from this study may extend the literature for use of the TouchMath® program by special education teachers in Montessori schools as a means to support the math skill development of students with high-incidence disabilities
Measures of feed efficiency in beef cattle: Biological basis and effect on response to dietary supplementation
Get PDFDuring the feedlot receiving period, newly weaned beef cattle face various stressors, including weaning, transportation, vaccination, and exposure to pathogens. Additionally, changes in diet and low dry matter intake contribute to nutrient deficiencies, heightening susceptibility to disease and performance declines. Therefore, we examined the effects of dietary supplementation with a multicomponent blend of prebiotics and probiotics on the health, immune status, metabolism, and performance of newly weaned beef steers during a 35-day receiving period. Our results showed that compared to the control group, the supplemental additive (SYNB) increased average daily gain (ADG), dry matter intake, and meal events during the first 7 days. Over the entire 35-day receiving period, beef steers fed supplemental SYNB had greater ADG and feed efficiency and a lower percentage (35% vs. 50%) of animals treated for Bovine Respiratory Disease (BRD). Whole blood expression of pro-inflammatory genes was downregulated while that of anti-inflammatory genes was upregulated in beef steers fed supplemental SYNB. Six nutrient metabolic pathways associated with health benefits were enriched in beef steers fed supplemental SYNB. This study demonstrated that dietary supplementation of SYNB during the first 21 days of arrival reduced BRD morbidity, improved the performance, immune, and metabolic status of beef steers over a 35-day receiving period, thereby extending the SYNB effect by a further 14-day post-supplementation. However, due to inconsistent responses to supplemental microbial products and the development of new direct-fed microbial strains, there is a need for more research studies to provide insight into their mechanisms of action and the physiological factors affecting these responses. Therefore, in the second chapter of this dissertation, we employed a range of omics approaches to focus on elucidating the biological mechanisms associated with the divergent Residual Body Weight Gain (RADG) phenotype in beef cattle. Through ruminal and plasma metabolomics, as well as 16S rRNA gene sequencing, this dissertation aimed to identify differences in host metabolome, rumen metabolome, and microbial community in beef steers with positive or negative RADG phenotype. Our microbiome results revealed greater relative abundance of Bacteroidetes_vadinHA17 and Anaerovibrio in beef steers with positive RADG compared to the negative RADG group. Additionally, pathway enrichment analysis of the metabolome data revealed the enrichment of five metabolic pathways including steroid hormone biosynthesis, thiamine metabolism, and propanoate metabolism in the plasma of steers with positive RADG. Overall, our results showed that selection for divergent feed efficiency phenotype is associated with differences in rumen microbiome and overall animal metabolism, notably amino acid metabolism-related pathways, and therefore may be an important animal-related factor that can affect the response of beef cattle to nutritional interventions such as rumen bypass protein supplement. Feeding rumen-bypass protein to cattle has demonstrated positive impacts on weight gain and feed efficiency, especially in rapidly growing young calves. However, the increasing costs of feeding protein and the challenges of excessive nitrogen (N) discharge into the environment underscore the need for sustainable protein supplementation in ruminant diets. Although past research has aimed at enhancing amino acid utilization efficiency and/or reducing nitrogen excretion in ruminants by minimizing dietary protein content, there\u27s a gap: no study has assessed how factors intrinsic to the animal, like feed efficiency status, might influence the response of ruminants to dietary protein supplements. In our follow-up study, we investigated the effects of a rumen-bypass protein (RBP) supplement on growth performance, plasma and urinary N concentration, hepatic mitochondrial protein complexes, and mRNA expression of immune genes in crossbred beef steers with divergent negative or positive residual feed intake (RFI) phenotype, another measure of feed efficiency. We assessed the impact of rumen by-pass protein (RBP) supplementation on feed efficiency in beef steers. Forty steers (BW: 492 ± 36 kg) underwent a 42-day trial in a 2 × 2 factorial arrangement, considering RFI classification and RBP supplementation. Liver tissue samples collected on day 42 were analyzed for mRNA expression of immune genes and mitochondrial protein complexes I - V. Regardless of RFI status, RBP increased blood urea nitrogen (BUN) (P = 0.01), with lower BUN in low-RFI steers. Interactions of RBP and RFI were observed (P ≤ 0.05) for mitochondrial activities of complexes IV, V, and mRNA expressions of immune genes (TLR2, TLR3, IL23A). While RBP did not impact growth performance, its effects on immune gene expression and mitochondrial protein complexes varied with RFI status, highlighting the importance of considering feed efficiency status in future studies investigating the effects of dietary protein supplements effects in beef cattle
A Balancing Act: MicroRNA Mediated Insect-Bacterial Homeostasis and the Tsetse Fly
No full textMicrobial symbioses are ubiquitous across all kingdoms of life with broad and diverse impacts on the evolution of species. The sum of all microbes living in, on, or otherwise in close association with a host form the microbiota. In some cases, the development of a stable microbial association seems to have been necessary for the specialization of diet, as can be observed in numerous insect species, especially wood-eating, sap-feeding, and blood-feeding organisms. For the medically and economically tsetse fly (family Glossinidae), the mutualistic bacteria Wigglesworthia glossinidia is required for proper reproduction and supplementation of nutrients that the fly does not receive from its strict blood-feeding diet. This symbiosis is ancient, dating back at least 50 million years, with extreme genome reduction occurring in Wigglesworthia, whose ~0.7 kb genome is specifically adapted to survival in the host environment. Unlike other hematophagous Dipterans such as mosquitoes, tsetse flies feed solely on blood, a diet low in essential B-vitamins such as thiamine (B1), pyridoxine (B6), and folate (B9), which Wigglesworthia retains the capacity to synthesize and can be supplemented to symbiont-free flies for partial phenotypic recovery. This essential nature of the Wigglesworthia-tsetse symbiosis to the survival and reproduction of the fly has necessitated extensive evolutionary change in the tsetse fly to promote the survival and perfect vertical transfer of the bacteria. This includes the evolution of adenotrophic viviparity, a metabolically costly reproductive strategy in which the flies give birth to a single, well-developed larvae per gonotrophic cycle that is sustained by specialized milk glands in utero. These milk secretions serve to infect the progeny with Wigglesworthia, which colonizes the milk glands as free-living organisms, while another population resides in a specialized region of the gut known as the bacteriome. The bacteriome contains specialized bacteriocyte cells that host an intracellular Wigglesworthia population responsible for nutrient provisioning. While these physiological adaptations for the symbiosis are well understood, the dynamics of a fly’s lifecycle and various events such as feeding or mating, are likely to significantly impact the symbiosis, necessitating the evolution of complex mechanisms for preventing dysbiosis, the disruption of the microbiota’s homeostasis. One factor that has been demonstrated to play a role in similar nutritional symbioses of other insects is host-generated microRNAs (miRNAs). By binding to mRNAs, primarily at the 3’ UTR of the host organism, these small, noncoding, RNAs prevent the translation of mRNAs to proteins which may be essential to the symbiosis. My dissertation sought to uncover the potential of microRNAs to contribute to tsetse-Wigglesworthia symbiosis. In Chapter 1, significant background information is provided in host-microbe symbiosis, the tsetse fly and its symbionts, and miRNAs in general, in comparison to small interfering RNAs (siRNAs), and in symbiosis. In Chapter 2, RNAseq data from two evolutionary distant species (G. morsitans and G. brevipalpis) of tsetse flies is explored. Aposymbiotic crop and proventriculus tissues were compared to the symbiont containing bacteriome organs, and genes showing conserved differential expression between species and tissues identified by known homology and functional characterization based on clusters of orthologous groups (COGs) and phylogenetic reconstruction. A small number of genes were differentially expressed between aposymbiotic and bacteriome tissues and found to have consistent expression patterns between both species, of which a subset shows different expression between mated and virgin flies of G. morsitans and was targeted by miRNAs found to have a comparable level of expression in both species. A single miRNA::mRNA interaction (miR-31a::fatty acyl-CoA reductase) within bacteriomes was identified as being of further interest after further phylogenetic analysis. Finally, the fatty acyl-CoA reductase gene family in Glossina is characterized with a prediction for a role in the structural maintenance of the bacteriome. Ultimately, no impact on the host could be determined by the disruption of the fatty acyl-CoA reductase, however, disruption of the functionally identical miR-31 with antagomirs showed an impact on bacteriome development suggesting other targets may be essential to the symbiosis
A Self-Supervised Knowledge Distillation Approach to Anomaly Detection in X-ray Imagery
Get PDFMany cargo containers enter the United States every day by truck, rail, and sea. As a result of the large number of cargo containers entering the United States, not all of them can be thoroughly inspected. Most of these containers contain properly documented and legal cargo, but some people take advantage of this situation by hiding illicit items in the cargo containers such as drugs. To more efficiently and thoroughly inspect cargo containers, Customs and Border Protection (CBP) uses X-ray imaging machines to obtain images that reveal the interior of cargo containers. These X-ray images must be inspected to ensure that there are no illicit items in the cargo containers. An algorithm that inspects these images will make the detection of illicit items more reliable and more efficient. This work proposes a self-supervised, knowledge distillation, patch-based algorithm to address this problem. When knowledge distillation is applied to anomaly detection, there is a teacher network that generates an output and a student network that aims to replicate the output of the teacher network for normal images. The proposed method has two teachers, one pretrained and one adapted for the target dataset, one student, and a segmentation network. The teachers and student are used to create multi-level anomaly maps and the segmentation network is used to combine these anomaly maps. Additionally, pseudo anomalies are used to create a self-supervision task for the model. This model was evaluated using the CargoX [30] dataset, which is a dataset that contains X-ray images of cargo containers with synthetic anomalies
Static Response of FRP Structural Systems – Piles, Platforms, and Poles
Get PDFThis study addresses the static response of three Fiber Reinforced Polymer (FRP) structural systems (piles, platforms, and poles) under static loads. This research aims to improve safety and sustainability in modern infrastructure by bridging the knowledge gap currently that exists between the experimental behavior and theoretical predictions.
FRP round piles (18-inch in diameter) were tested under axial compression, shear, four-point bending and fatigue. Both the load-deflection and stress-strain responses were analyzed. Coupon tests were conducted and related to the outcomes of full-scale test data. Two major differences were observed in the response of the bending test specimens with modulus of elasticity in compression being greater than that in tension and failure stress of full-size specimens being nearly half of the coupon specimens. A comprehensive analytical study was carried out by accounting for local effects and principal stress to address these discrepancies. Round piles exhibited conventional performance under compressive and shear loads but demonstrated complex bending response. Local effects had significant impact on the bending response and principal stresses calculated by combining bending, local axial compression, local shear, and global shear bridged the gap between bending stress responses of coupons and those of full-size specimens.
FRP platforms were assessed for lateral load resistance for modular industrial construction. Three sizes of the platforms (3ft x 3ft, 3ft x 6ft, and 3ft x 9ft) were analyzed. Four different bottom connections that included 3/8” angle, ½” angle, 2” x 2” square tube, stiffened bottom with plate were used. Bolt torque levels were varied (0ft-lb, 20ft-lb, and 40ft-lb) to establish joint rigidity and find joint failure under different bolt torques and corresponding load-strain and deflection response are plotted. ETABS (FE) modelling was carried out to compare the experimental data. The joint capacity was also determined following the principles of FRP connection design referring ASCE 74-23. The experimental results revealed that torque level impacts the platform’s stability, with 40 ft-lb torque providing the best performance. Load-deflection responses showed that joint stiffened configurations at the footer level consistently minimized deflection, demonstrating superior stiffness. Notably, platform orientation influenced performance, with platforms loaded along shorter directions exhibiting higher resistance and lower deflection than those loaded along longer directions. Grating also significantly enhanced stiffness through a diaphragm effect.
Finally, cantilever loading response was investigated on carbon fiber cantilever poles. Large deflections were observed on the poles and possible geometrically nonlinear response was investigated. The Euler-Bernoulli nonlinear deflection equation was used and compared with experimental load-deflection response. The experimental data closely matched the theoretical prediction.
In summary, all three FRP configurations highlighted the advantages of FRP\u27s strength, stiffness, and lightweight properties, making them ideal for applications that require weight reduction without sacrificing load-bearing capacity. Furthermore, each configuration emphasized the importance of design considerations—such as connection design, load distribution, and deflection response—that are critical for optimizing FRP performance in a variety of applications. These shared characteristics reinforce FRP\u27s suitability in industries that prioritize safety, sustainability, and structural resilience
Advancing GFRP Column Design: Strength, Effective Lengths, and Failure Modes
Get PDFGlass fiber reinforced polymer (GFRP) composites have become an increasingly popular choice in construction industry due to their higher strength-to-weight ratio, ease of manufacture including lower Embodied Carbon Factor, and better durability in harsh environmental conditions than conventional structural construction materials. Currently, GFRP composite column design lacks well-established design standards due to the material\u27s unique properties such as lower bending and shear stiffness than steel, differing compressive and tensile moduli, which leads to complexities in computing buckling capacities under local effects such as flange or web buckling and even torsional buckling under off-centered compression loading. Therefore, GFRP columns will behave differently under axial load than traditional steel and concrete materials. Therefore, AISC/ACI/ASCE’s effective length design guidelines and equations may not accurately predict failure modes and loads in GFRP members under compression.
This study consisted of testing 18-inch diameter GFRP piles through three testing methods to assess failure modes and loads. A lateral crush test was conducted on eight Samples to evaluate resistance to local transverse loading. A local compression washer test was conducted to assess the local crushing capacity. A pin test was performed on four Samples, two Samples tested in the longitudinal and two in the transverse direction, to analyze the bearing load capacity.
Additionally, 48 GFRP box columns were tested under axial compression with six replications for each column length. The columns were categorized by lengths in feet as follows: 1, 2, 4, 6, 8, 10, 15, and 20. All columns had the same cross-sectional dimensions of 3.5” x 3.5” x 0.36”. Half of these Samples were tested using fixed-fixed end conditions and the other half were tested with pin-pin end conditions. Furthermore, an effective length-dependent failure model was developed at the West Virginia University Constructed Facilities Center (WVU-CFC) to help develop standardized effective length recommendations for GFRP columns. In addition to the failure analyses, the degree of fixity provided by the end conditions was analyzed to assess its influence on column behavior by collecting strain gauge data near the support fixture and at the center of each test specimen. The experiments were conducted with due considerations to minimize crushing at the ends by providing column plugs and wraps at the ends and measuring column crookedness due to manufacturing anomalies. Also, extensive number of strain gages were mounted to measure stress concentration at corners of flanges, so that a draft testing procedure can be developed for ASTM standards.
Finally, the mathematical models and the corresponding failure load results were compared with both the prior and current experimental data to verify their accuracy and consistenc