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Constraining the Properties and Formation Pathways of Low Mass X-ray Binaries in Early-Type Galaxies
No full textIn this dissertation, we explore how low-mass X-ray binaries (LMXBs) form and evolve in nearby early-type galaxies. We investigate X-ray binary (XRB) luminosity function (XLF) scaling relations for Chandra-detected populations of LMXBs within the footprints of 24 early-type galaxies. Our sample includes Chandra and Hubble Space Telescope observed galaxies at D ≲ 25Mpc that have estimates of the globular cluster (GC) specific frequency (SN) reported in the literature. As such, we are able to directly classify X-ray-detected sources as being coincident with unrelated background/foreground objects, GCs, or sources that are within the fields of the galaxy targets. We model the GC and field LMXB popu- lation XLFs for all galaxies separately and then construct global models characterizing how the LMXB XLFs vary with galaxy stellar mass and SN . We find that our field LMXB XLF models require a component that scales with SN and has a shape consistent with that found for the GC LMXB XLF. We take this to indicate that GCs are “seeding” the galactic field LMXB population, through the ejection of GC LMXBs and/or the diffusion of the GCs in the galactic fields themselves. However, we also find that an important LMXB XLF com- ponent is required for all galaxies that scales with stellar mass, implying that a substantial population of LMXBs are formed “in situ,” which dominates the LMXB population emission for galaxies with SN ≲ 2. For the first time, we provide a framework quantifying how directly associated GC LMXBs, GC-seeded LMXBs, and in situ LMXBs contribute to LMXB XLFs in the broader early-type galaxy population. We further analyze the host GC properties of LMXBs and find statistically significant trends in host cluster mass and color, consistent with theoretical expectations that metal-rich and massive clusters are more efficient at retaining and forming LMXBs. Finally, in a new case study, we present a broadband X-ray spec- tral energy distribution (SED) for Maffei 1, a nearby elliptical galaxy. Using Chandra and NuSTAR data, we construct a 0.5–20 keV spectral model and fit an absorbed broken power law plus hot gas component. Our results suggest the hard X-ray emission is background- dominated, and that the XRB population is consistent with a mixture of neutron star and black hole binaries. Scaling relations suggest the adopted distance to Maffei 1 may be un- derestimated. Together, these results offer new insights into the formation pathways and emission properties of LMXBs across ETGs, both in population-level scaling and detailed spectral behavior
Field experience and production challenges in Australia and New Zealand
No full textVariability management represents the primary technical challenge facing the Australian and New Zealand (ANZ) broiler industry\u27s vertically integrated operations. This analysis examines systematic approaches to controlling seasonal performance fluctuations, raw material quality variations, emerging disease pressures, and evolving welfare demands. Key variability sources include climatic extremes, season to season raw material quality and nutrient value variability and intermittent [mostly enteric] disease challenges, particularly in no antibiotics ever (NAE) production systems. Solutions require a scientific, data-driven approach with insights from field experience for causation identification and a collaborative approach within business functional units, and across industry collaborators such as suppliers and researchers to maintain profitable broiler production despite the unique blend of challenges experienced in ANZ
Ab initio studies on mechanical properties of freestanding ferroic monolayers
No full textThis thesis explores the role of mechanical properties and elastic couplings in freestanding paradigmatic ferroic monolayers within the framework of density functional theory. This dissertation is comprised of three interconnected published studies: (i) establishing the elastic behavior across a temperature-driven phase transition in SnSe monolayers; (ii) thermally-driven phase transitions in graphene-like silicene, germanene, and stanene, examining the structural stability and band gap occlusion; and (iii) magnetoelastic coupling in an Ising-like CrSiTe3 monolayer, focused on assessing magnetic contributions to the material stiffness by establishing a proper non-magnetic reference
Employee Engagement in the Manufacturing Industry
No full textThe primary objective of this paper is to analyze employee engagement in the manufacturing industry while explaining the implementation processes for putting engagement initiatives in place. Employee engagement has shown to have an impact on overall business performance and this paper examines the original introduction of engagement in a workplace setting, theories relating to employee engagement, the need for engagement in the manufacturing industry, the key drivers of employee engagement, and human resource practices. This paper also walks through my 10-week internship with Klein Tools, and the processes I took to implementing employee engagement methods at Klein Tools’ manufacturing plant and distribution center
Low protein diet strategy
No full textReduced crude protein (CP) diets can lower nitrogen excretion and improve litter quality, but their effectiveness varies depending on the grain type, with wheat-based diets often showing poorer broiler performance compared to maize or sorghum. The digestive dynamics and synchrony between NBAA and protein-bound amino acids, along with starch-to-protein ratios, influence feed efficiency and fat deposition, which remains a challenge in reduced CP diets. Optimizing amino acid supplementation and exploring alternative protein-rich ingredients may help improve outcomes, especially in regions with limited access to soybean meal
Don’t miss our latest research from our current issue, featuring: Genotypic Variation and Wilting Speed Affect Soybean (Glycine max) Germination and Growth by Adriana Peissel, Jessica Ayala, and Rupesh Kariyat
No full textAdriana Peissel waters young soybean plants in the greenhouse.https://scholarworks.uark.edu/discovery_images/1063/thumbnail.jp
