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Ohl 106, no. 7 – Forged inscription on the lid of a sarcophagus, with the partial sculpture of a boy astride a dolphin, undatable forgery
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Numerical Analysis of the Impact of Debris Protection on Hydrokinetic Rotor
Get PDFGlobal energy consumption is rising each year, and with an increase in energy consumption comes an increase in the reliance in renewable energy. Currently, hydropower is one of the most prominent forms of renewable energy used across the globe. However, the implementation of hydropower facilities is expensive, time consuming, and comes with a litany of environmental issues. An alternative to hydropower is hydrokinetic energy; hydrokinetic energy harnesses kinetic energy from moving streams of water rather than relying on the potential energy difference between water bodies. The purpose of this research is to validate a hydrokinetic turbine using Computational Fluid Dynamics (CFD). Previously the turbine was analyzed using Blade Element Momentum theory (BEM). However, this is a simple approach that does not account for turbulence created by the blades. StarCCM+ is utilized to construct the CFD model, which is then validated against BEM-derived flow parameters for maximum power efficiency. Validation of the BEM results using CFD is crucial because it facilitates further testing of additional geometrical features necessary for real world implementation. Additionally, this study investigates the impact of cylindrical rods placed upstream to act as a grid to block debris. Determining the grids optimal positioning based on their effect on the turbine’s power efficiency.No embargoAcademic Major: Mechanical Engineerin
Low-Speed CFD Simulations of High-Speed Wing Configurations for a Highly Maneuverable UAV
Get PDFIn the past few decades, unmanned aerial vehicles have become increasingly present in the skies above. This can be attributed to key advancements in control systems, navigation systems, communications hardware, and other key systems that were not readily available before. The use of unmanned aerial vehicles by the military is growing rapidly as their potential to fulfill various missions has been revealed through recent conflicts. One role of particular interest is the air-to-air combat role, which could be fulfilled by an uninhabited combat aerial vehicle (UCAV). To achieve this goal the use of a high-speed wing configuration, such as the delta wing, would be necessary. The delta wing performs favorably in the supersonic flow regime but underperforms in the subsonic flow regime. The purpose of this research was to investigate the low-speed aerodynamics of high-speed wing configurations for a highly maneuverable UAV using Computational Fluid Dynamics (CFD). Computational analysis was done using Ansys FLUENT to develop a full aircraft model that characterized important flow features of the delta wing at various angles of attack. Simulations were conducted at standard day conditions and a Reynolds Number of 5×10^5. Model results were verified using pressure, velocity, and streamline contours. The model was validated by comparing the lift and drag coefficient results with experimental and theoretical data. It was revealed that at low speeds and high angles of attack leading edge vortices form, which aid the delta wing in generating additional lift in the subsonic flow regime. As the angle of attack increases, the vortices grow spanwise and begin to break down resulting in a loss of lift. This research demonstrates CFD’s ability to play a vital role in the aircraft design process. The results from this research will complement existing wind tunnel results and aid in future design improvements by the Flight Vehicle Design & Testing Group to the experimental UAV. Furthermore, results from this research will help those in industry and the Department of Defense (DOD) in designing unmanned aerial vehicles.No embargoAcademic Major: Mechanical Engineerin
Impact of Abrupt Mammary Gland Involution on Visceral Fat and its Connection to Increased Risk of Breast Cancer
No full textPre-menopausal African American women have higher rates and mortality from triple negative breast cancer (TNBC) than Caucasian women. Lack or short-term breastfeeding and visceral adiposity are two independent risk factors of TNBC. Following pregnancy and lactation, the mammary gland undergoes involution, the process of reverting to a near pre-pregnancy state. Prolonged breastfeeding leads to gradual involution (GI) while abrupt weaning to abrupt involution (AI). At 120 days postpartum, we observed an increase of perigonadal visceral adipose in a mouse model of abrupt involution. Epidemiological studies of women who did not breastfeed reported similar observation. Visceral adiposity is associated with systemic inflammation, metabolic syndrome, and hormonal dysregulation elevating breast cancer risk. We hypothesize that AI but not GI leads to qualitative and quantitative alteration in adipocytes of visceral depot and systemic inflammation and enhances risk for breast cancer. Our objective is to investigate and compare histological and molecular differences in visceral adipose tissue between involution groups.A one-year embargo was granted for this item.Academic Major: Biolog
Parenting together vs. individually: Do mothers and fathers differ?
Get PDFThis study investigated the similarities and differences in mothers’ and fathers’ parenting behaviors when parenting their child individually (dyadic) or together (triadic). In addition, this study examined whether the quality of the coparenting relationship between parents is related to differences in parenting behavior across dyadic and triadic contexts. The sample consisted of 153 dual-earner couples from the New Parent Project and their 9-month-old infant. Parents were observed interacting separately with their infants for 5 minutes and together with their infants for 10 minutes. The interactions were coded for the quality of their parenting behavior (i.e., sensitivity, intrusiveness, detachment, positive regard, and negative regard). Both mothers and fathers also completed the Coparenting Relationship Scale to assess the quality of the interparental relationship. Paired t-tests indicated that mothers’ and fathers’ behavior significantly decreased when parenting together (except for mothers’ sensitivity). Differences were also found between mothers’ and fathers’ parenting behaviors when parenting individually versus together. Correlations revealed various associations between coparenting domains and parenting behavior when together versus individually. The most notable: mothers who reported more support from fathers demonstrated more intrusiveness when parenting together versus individually. In addition, mothers who endorsed their partner's parenting showed lower sensitivity and higher intrusiveness when parenting together versus individually. Taken together, these findings suggest that the coparenting relationship may influence mothers’ parenting behaviors more in dual-earner families.Undergraduate Research Apprenticeship ProgramUndergraduate Research ScholarshipNo embargoAcademic Major: Psycholog
VARIATION IN NOBLE GAS ISOTOPES FROM VOLCÁN PACAYA SINCE 1961
Get PDFVolcán de Pacaya is a volcanic complex that lies within the Central American Volcano Arc, formed by the subduction of the Cocos plate beneath the Caribbean Plate. In 1961, it began erupting following a 76-year dormancy. The dominant lithology of the lavas erupted during this time has been olivine-bearing basalt. Noble gas isotope ratios can provide chemical signatures for the source of magma, whether it be a subducting plate causing flux melting or mantle upwelling and decompression melting caused by crustal thinning. The 3He/4He ratio from this study indicated that mantle input has been occurring into Pacaya’s magma system since at least 1961. Helium isotope signatures of back-arc volcanism and midocean ridge basalts occur within these lavas. The argon isotopes indicate that the magma has been enriched with mantle material and that the magma did not fractionate before eruption. Lastly, the neon isotopes indicate that some crustal material is present within Pacaya’s magma, but it is dominated by a mantle signal.The Friends of Orton Hall FundNo embargoAcademic Major: Earth Science
Avian Malaria and Altitude
Get PDFAvian malaria is a mosquito-borne disease in birds caused by Plasmodium parasites. The disease has contributed to the decline and extinction of several forest birds. Furthermore, avian species play a significant role as a reservoir for many pathogens and zoonotic diseases. Although zoonotic transmission of non-human malaria parasites is deemed unlikely for most Plasmodium species, climate change and rapid urbanization have put ecological pressures on parasites that may change the mode of transmission and Avian malaria is a mosquito-borne disease in birds caused by Plasmodium parasites. The disease has contributed to the decline and extinction of several forest birds. Furthermore, avian species play a significant role as a reservoir for many pathogens and zoonotic diseases. Although zoonotic transmission of non-human malaria parasites is deemed unlikely for most Plasmodium species, climate change and rapid urbanization have put ecological pressures on parasites that may change the mode of transmission and host-seeking behavior rendering human populations at risk. Altitude and weather are one such ecological pressure. High elevation is not a favorable habitat for Plasmodium because of its associated low temperatures. However, increasing temperatures may lead to a shift to higher elevations for Plasmodium populations.
The current study investigated the relationship between elevation and avian malaria, a relatively new research area lacking adequate attention. Using secondary sources from the Dryad Repository, data on avian infection rates in three bird communities from lowland forests in Cameroon, highland forests in East Africa, and fynbos in South Africa were collected. The association between infection rates and altitude was analyzed and hot spots were mapped using geospatial information systems. The results showed an inverse trend between altitude and infection rates with higher altitude being correlated with lower infection rates, although this was not statistically significant. Analyses also revealed outliers within our small sample. Future research would benefit from larger-scale studies to confirm the observed trend and as well as collect temperature and parasitic load over a longer time period. This study underlines the importance of understanding the ecological conditions of avian malaria transmission for avian welfare with important implications for human health.Department of Evolution, Ecology, & Organismal BiologyAcademic Major: Biolog
Postnatal Development of Vasculature in the Hippocampal Neural Stem Cell Niche
Get PDFAdult neurogenesis is the continued process of generating new neurons throughout life. In the mammalian brain, adult neurogenesis occurs in both the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus (DG) of the hippocampus. Adult neurogenesis in the DG of the hippocampus is thought to play a role in memory and learning systems. The radial glial like neural stem cells (RGL-NSCs) and their progeny intermediate progenitor cells (IPCs) involved in adult hippocampal neurogenesis are surrounded by a microenvironment called the neurogenic niche, a major feature of which is local blood vessels. The vasculature within the niche provides neural stem and progenitor cells (NSPCs) access to oxygen and circulating support molecules such as growth factors. Additionally, blood vessels can act as scaffolding for neuroblasts and progenitors to migrate tangentially. Past research has validated that inside the DG of mice, during adulthood, the vasculature is especially dense and the NSCs, reside in close proximity to local blood vessels. Though the proximity of NSCs to vessels in adulthood has been well established, little is known about when it develops. To characterize the developmental time course of NSPCs proximity to blood vessels, I quantified RGL-NSC and IPC association with blood vessels in wildtype mice at 2, 3, 5, and 9 weeks of age. I used immunofluorescent phenotypic markers to identify RGL-NSCs, IPCs and endothelial cells in fixed tissue sections. I found that there was a progressive reduction in the distance between RGL-NSC bodies and the nearest blood vessel from 2 to 9 weeks of age. These results were similarly true for the distance between IPC bodies and the nearest blood vessel. These results suggest that the association of NSPCs with vasculature is not a preserved feature from early development, but rather one that arises de novo during postnatal maturation. Further, these results imply that the DG neurogenic vascular niche continues to develop postnatally and is not complete until adulthood. To further characterize the development of the vasculature niche, I am currently using a transcardially perfused dye coupled with postmortem tissue clearing of thick brain slices to create 3D rendered images of the DG vasculature network in mice at 2, 3, and 9 weeks of age. These future studies investigating the changing vascular niche alongside the development of the NSCs will provide insight into the unique relationship between NSPCs and vasculature that may aid in the preservation of neurogenesis in the adult DG.No embargoAcademic Major: Neuroscienc
