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Impact of physiological and environmental variation on the behavioral response of the two biological control agents of the emerald ash borer to host-associated odors
No full textEmerald ash borer (Agrilus planipennis Fairmaire; EAB) is an invasive pest that threatens ash trees (Fraxinus spp.) throughout North America and Europe. Since its introduction to North America, EAB has killed hundreds of millions of trees, resulting in severe ecological and economic damage exceeding 10 billion US dollars. Classical biological control involves the introduction of natural enemies from the native range of pests to manage their populations. Specialist parasitoid wasps have been released to reduce the populations of EAB. Detection and response to long-range attractants associated with EAB is critical for the location and parasitism by classical biological control agents. The ash foliage has been shown to be an important cue for the two species of Spathius wasps. The physiological state of parasitoids may vary across environmental conditions and has been predicted to alter host-location behaviors and biological control success. However, the impact of physiological differences on parasitoids’ ability to detect and respond to host-associated cues is crucial to understanding their foraging behavior. I evaluated how adult feeding influences the survival and number of mature eggs of two species of Spathius wasps to optimize parasitoid release strategies. The response of wasps to attractants was tested in a four-arm olfactometer under varying physiological conditions. Wasps were fed or starved before bioassays. I validated the response of Spathius agrili Yang to a known attractant (green ash foliage) in a behavioral arena that had not been previously used with this species (a four-arm olfactometer). Additionally, I demonstrated that Spathius galinae Belokobylskij is also attracted to the foliage of green ash. Both species of Spathius can detect and respond to foliage from young and old green ash trees. I described the reproductive systems of S. agrili and S. galinae morphologically for the first time using fluorescent microscopy. Nutritional stress shifts their preference toward younger trees, reduces survivorship, and decreases the number of mature eggs available for oviposition. These studies contribute to classical biological control by connecting natural enemy physiology to establishment and parasitism rates across environmental gradients, making predictions about differences in the success of biological control of EAB in southeastern ecosystems, with an emphasis on subtropical Louisiana
UNDERSTANDING ROCK-BRINE GEOCHEMICAL INTERACTIONS FOR UNDERGROUND HYDROGEN STORAGE
No full textUnderground hydrogen storage (UHS) is a promising approach for large scale, long duration energy storage, but limited information exists on how hydrogen interacts with subsurface rocks and fluids. This study examines hydrogen, brine, and rock interactions under conditions representative of potential storage sites in Louisiana. Batch experiments were performed using sandstone and shale samples, synthetic formation brine, and mixed hydrogen and nitrogen gas at ambient and elevated temperatures (70 °C). Nitrogen was used as a control to distinguish hydrogen related effects. Chemical and mineralogical analyses of the fluid and solid phases were conducted using ICP-OES, TGA, and gas composition monitoring.
Results indicate that rock type and mineral composition play a dominant role in hydrogen reactivity. Sandstone, composed mainly of quartz, showed little chemical or mineral alteration, suggesting geochemical stability under the tested conditions. Shale, in contrast, exhibited increases in dissolved iron, manganese, and sulfur, indicating minor reduction and dissolution of Fe(III) minerals such as chlorite or hematite, as well as slight carbonate loss and formation of amorphous material. These patterns suggest that shale can act as a weakly reactive barrier where limited redox and hydrogen uptake processes occur.
Overall, hydrogen and rock reactions were slow and mild under low temperature and near atmospheric conditions. The results demonstrate that mineralogy, particularly the amount of iron and carbonate minerals, exerts greater control on reactivity than temperature. This work provides experimental data that support geochemical risk assessment and enhance understanding of hydrogen stability, retention, and migration within potential geological storage formations
The Frequency Shift and Q of Disordered Superconducting RF Cavities
No full textNiobium superconducting radio-frequency (SRF) cavities for high-energy accelerator applications have been greatly improved in terms of the quality factor Q by techniques such as Nitrogen doping. However, the mechanisms leading to improvement in Q are still not fully understood. Quite recently the SRF group at Fermilab measured anomalies in the frequency shift of N-doped SRF Niobium cavities near the transition temperature. Here we report our theoretical analysis of these results based on the microscopic theory of superconductivity that incorporates anisotropy of the superconducting gap and inhomogeneous disorder in the screening region of the SRF cavities. We are able to account for frequency shift anomalies very close to Tc on the order of fractions of 1 kHz. Our results for the frequency shift and Q are in good agreement with the experimental data reported for all four N-doped Nb SRF cavities by Bafia et al. We also compare our theory with an earlier report on a Nb sample measured at 60 GHz. In addition, we show that the quality factor calculated theoretically has a peak of upper convexity with the largest Q at intermediate levels of disorder. For strong disorder, i.e. the dirty limit, pair breaking in the presence of disorder and screening currents limits the Q
Hydrogen and deuterium tunneling in niobium
No full textWe use density functional methods to identify the atomic configurations of H and D atoms trapped by O impurities embedded in bulk Nb. The O atoms are located at the octahedral position in the Nb body-centered cubic (BCC) lattice, and H (D) atoms tunnel between two degenerate tetrahedral sites separated by a mirror plane. Using nudged elastic band (NEB) methods, we calculate the double-well potential for O-H and O-D impurities and the wave functions and tunnel splittings for H and D atoms. Our results agree with those obtained from analysis of heat capacity and neutron scattering measurements on Nb with low concentrations of O-H and O-D
On Unavoidable Infinite Hypergraphs
Full text linkRamsey\u27s Theorem states that every infinite graph contains either K∞ or as an induced subgraph. For this reason, K∞ and are often referred to as the unavoidable infinite graphs. Many similar results have characterized the unavoidable members for various classes of infinite graphs; perhaps the most notable of these is König\u27s Infinity Lemma, which states that every infinite, connected, locally finite graph contains a ray as an induced subgraph. From these findings, one can easily deduce that every infinite, connected graph contains an infinite clique, star, or ray as an induced subgraph; the goal of this dissertation is to obtain analogous results for hypergraphs.
This work is split into two main chapters. First, we focus on hypergraphs that contain a vertex of infinite degree, and find that the unavoidable members are obtained from a finite hypergraph by a specific method of replicating and extending edges; this turns out to be a novel class of hypergraphs, which we call recurrent hypergraphs. We subsequently shift our focus to connected, locally finite hypergraphs, and find that every such hypergraph contains a generalization of a ray as an induced subhypergraph; we call such hypergraphs quasirays. We also provide versions of our results that pertain to finite hypergraphs
Exploring Pedagogical Approaches and Discussion for Young Beginner Double Bass Players
Full text linkIn recent years, early childhood education for the double bass has gained increasing attention and plays a crucial role in shaping the future development of the instrument. However, compared to other instruments, research on early childhood education for the double bass remains relatively underdeveloped, with a lack of written materials on the subject. This thesis introduces the formation of early childhood teaching concepts and explains why parents play an irreplaceable role in a child’s initial exposure to music learning. By collecting and analyzing traditional double bass teaching methods and integrating common principles from other string instrument teaching approaches, this study provides a detailed breakdown of each step in the teaching sequence, along with the reasoning behind it. It emphasizes the philosophy of deconstructing all movements into smaller, manageable learning tasks, ensuring that children focus on mastering one new element at a time through a progressive teaching strategy. Additionally, due to its large size and physical challenges, the double bass is more difficult to handle and less accessible compared to other instruments, making its promotion more challenging. There are still many aspects worthy of further exploration in the future, offering opportunities for continued research and development
The Influence of Selected Demographic and Academic Factors on the Persistence to Degree Completion of Military Veterans at a Research University in the South
Full text linkA large number of veterans leave the military each year, hoping to reacclimate successfully to civilian society while utilizing the knowledge and skills they acquired in the military to assist in their pursuit of gainful employment. Many wish to enhance this process by earning a college degree. Unfortunately, various barriers and other random personal hurdles can impede the progress of the now-veteran student toward degree completion. The lack of knowledge about these barriers and the factors that support a veteran student’s persistence to complete a college degree has created the need for this investigation. The primary purpose of this study was to determine the influence of selected personal demographic characteristics and academic factors on the persistence to degree completion of both military veteran and non-veteran students at a research university in the South. A quantitative methodology was employed to design a correlational, exploratory research study. Analysis of an archived, extant, and sanitized data set from 2014 to 2020 (pre-COVID) included select personal demographic and academic information. A secure, computerized instrument was developed and approved by the Institutional Review Board (IRB), and the necessary data were obtained from the University\u27s Office of the Registrar. A multiple discriminant analysis (MDA) was the primary statistical technique used in the study. The research results indicated four substantive and significant findings from the MDA model regarding the non-veteran student sample, as both first- and second-semester earned credit hours and grade point averages were the most influential academic factors leading to degree completion for that group. The researcher also concluded that all fifty-two veteran student participants persisted to degree completion status and graduated within the six-year timeline provided by the study. The researcher recommended replicating this study under the same guidelines at other Tier 1 universities in the South to investigate the potential of a veteran student anomaly while also reinforcing the findings regarding non-veteran students
Evaluating feedback frequency preference and its relation to task performance
No full textMany researchers have evaluated how characteristics of feedback may influence trainee performance, but relatively little attention has been allocated to directly assessing trainee preference for feedback characteristics and its relation to performance. Thus, the primary purpose of this study was to use a within-subject experimental design to directly assess trainee preference for the frequency of feedback and its relation to task performance. A secondary objective was to evaluate how trainee preferences varied across specific task components based on component complexity. Thirty-five undergraduate students completed two arbitrary tasks and were given the opportunity to request feedback after each component of the task. For 85.71% of our participants, an inverse relation was observed between preference for feedback frequency and task performance. Participants requested feedback less often as performance improved. Feedback preferences also varied with the complexity of each component of the task. Implications for training, supervision, and feedback practices are discussed
THE LEGACY OF AUGUSTE FRANCHOMME: PEDAGOGICAL ANALYSIS AND PERFORMANCE PRACTICE FOR THE “TWELVE CAPRICES OPUS 7 FOR CELLO SOLO”
Full text linkThis written document focuses on a personal pedagogical analysis of the Twelve Caprices composed by the French cellist and pedagogue, Auguste Franchomme. His works have served as significant cello studies for young cellists, comparable in importance to the Twelve Caprices by Carlo Alfredo Piatti and the High School of Cello Playing by David Popper. Each of these caprices is written in different key signatures, tempi, include a variety of bowing styles and techniques, express melodies over a wide range of the cello register, and present unique and ubiquitous issues that cellists may encounter in the canon of cello literature.
In addition, the development of cello technique in the past differed significantly from that of the present day. This project also aims to provide alternative solutions for overcoming technical challenges faced by cellists with petite builds or smaller hand sizes such as myself, especially since these studies are usually tackled by younger musicians with small hands.
I endeavor to present an in-depth analysis of Auguste Franchomme’s Twelve Caprices enabling cellists to develop a better understanding of how to utilize their body’s strength effectively, locate foreign and new positions, create sounds (both connected and disconnected) in the hope that ultimately my suggestions may foster self-reliance when addressing potential technical challenges in future learning
Community-Aware Reliability Metrics for Strategic Battery Storage Placement in Distribution Systems
No full textTraditional power system reliability metrics, such as energy not supplied (ENS), are predominantly utility-centric, focusing on system-wide performance while overlooking the disproportionate impacts of power outages on low-income households. Although the classical ENS metric provides significant insight for grid reliability analysis, it does not address socioeconomic disparities. This paper introduces a community-aware reliability metric that incorporates community hardships into the reliability assessment of power distribution systems. Through a preliminary survey study, three socioeconomic factors, including income, education, and homeownership, are identified to measure community hardships caused by power failures. These factors are combined to create a hardship index for each community zone, which is then integrated with ENS to develop a combined community-utility reliability index. As proof of concept, this reliability index has been applied to the placement of battery storage to establish a community-aware decision-making framework. This framework considers both utility and community needs in storage placement. Simulation results on a 13-bus power distribution system demonstrate that community-aware placement reduces hardship-weighted ENS in low-income households by 43.9 %, significantly addressing socioeconomic inequities while maintaining acceptable system-wide reliability that meets both technical and social objectives