997 research outputs found

    Feedbacks between ice cover, ocean stratification, and heat content in Ryder Bay, western Antarctic Peninsula

    Get PDF
    A multi-year, all-season time series of water column physical properties and sea ice conditions in Ryder Bay, at the western Antarctic Peninsula (WAP), is used to assess the effects on the ocean of varying ice cover. Reduced ice cover leads to increased mixing and heat loss in the winter. The reduction in stratification persists into the following summer, preconditioning the water column to a greater vertical extent of surface-driven mixing. This leads to an increased amount of heat from insolation being mixed down, affecting approximately the top 100m. The increased heat uptake in summer exceeds the heat lost the preceding winter, giving the initially counter-intuitive effect that enhanced winter cooling generates warmer temperatures in the following summer and autumn. This process is therefore a positive feedback on sea ice, as reduced sea ice leads to increased heat content in the ocean the following autumn. It also causes increased winter atmospheric temperatures due to the increased winter heat loss from the ocean. In the deeper part of the water column, heat and carbon stored in the Circumpolar Deep Water (CDW) layer are released by deep mixing events. At these depths, conditions are restored by advection and vertical mixing on multi-year timescales. In recent years, stronger deep mixing events in winter have led to a persistent reduction in CDW temperatures at the study site. Ocean glider data demonstrate the representativeness of these results across the wider region of Marguerite Bay, within which Ryder Bay is situated

    A New Method to Describe Image Theory for an Imperfect Conductor

    Get PDF
    Problem statement: Modify the equations associated with image theory in order to account for perfect and imperfect conductors. Approach: A novel approach for describing the application of image theory for an imperfect conductive surface was presented. The method presented here purposely downplays the physics of how image theory was employed to account for a charge which is in the presence of an imperfect conductive surface. In turn, it adopted an approach which focused on the geometry that existed between the charged particle and surface ground. In doing so, the proposed method formulated a solution that had minimized the complexity of the original problem while providing an approximation founded upon a geometric relationship. Results: The equations derived had elicited the concept of using plane geometry to augment image theory. Conclusion: A method for evaluating image theory for the imperfect conductor had been presented. As the results had shown, the equations derived had provided an augmented approach to account for surfaces which were both perfect and imperfect

    The Horizontal Electric Field Induced by a Lightning Return Stroke

    Get PDF
    Problem statement: Develop a new formula which describes the horizontal electric field induced by a lightning return stroke in contact with an imperfect conductive surface. Approach: A new method for describing the horizontal electric field induced by a lightning return stroke will be presented. The method presented here had utilized an approach which purposely downplayed the physics of how image theory was employed in the presence of an imperfect conductive surface. It did so by adopting a technique which had focused on the geometry that existed between the lightning channel and surface ground. In doing so, new expressions for surface currents had been derived. This study presented the derivation of these currents along with the horizontal electric field which transpired as a result of their usage. Results: The equation derived had elicited the concept that the channel\u27s image varies with surface conductivity. Conclusion: A method for deriving the horizontal electric field induced by a lightning return stroke had been presented. As the results had shown, once the surface conductivity began to decrease, the horizontal electric field played an increasingly more significant role

    The Magnetic Field Induced by a Lightning Strikes Indirect Effect Double Exponential Current Waveform

    Get PDF
    Problem statement: Develop a new formula which describes the magnetic field induced by a lightning strike\u27s indirect effect double exponential current waveform. Approach: A novel approach for developing a closed-form solution for the magnetic field from the indirect effect double exponential current waveform will be presented. In the literature, models typically employ the pulse waveform to derive the corresponding electromagnetic fields. However, given the Department of Defense (DoD) has incorporated the double exponential current waveform as part of their Electromagnetic Environmental Effects Requirements For Systems , we felt it important to develop a solution for the magnetic field which utilized this waveform. In order to facilitate the integration required for deriving the field, Taylor series expansion was used for all variable dependent exponential terms. In many publications, the dipole and monopole techniques have been used when solving for the magnetic field. However, for this study the dipole technique was deemed the preferred method for evaluating the field. A derivation of the magnetic field will be presented along with a graphical illustration of the field\u27s distribution over time. Results: The equation presented utilized Taylor series to augment the integration required to solve for the magnetic field. Conclusion: A new method for deriving the magnetic field induced by a lightning strike\u27s indirect effect double exponential has been presented. By approximating the variable dependent exponential terms, we were able to minimize the complexity of the mathematics required to solve for the magnetic field in closed-form

    Differences in Relationship and Sexual Satisfaction and Social Support Between Only Lesbian, Mostly Lesbian, and Bisexual Women

    Get PDF
    Research suggests relationship and sexual satisfaction and social support are correlated with components of well-being such as anxiety, depression, and physical health. Differences in relationship and sexual satisfaction and social support have been identified between sexual minority women (SMW; i.e., lesbian and bisexual) and heterosexual women. However, classifying SMW into a single group may mask important differences. Further research is needed to better understand the differences in relationship and sexual satisfaction and social support between subgroups of SMW. Thus, the purpose of the present study was to examine differences in these constructs between women who identify as only lesbian, mostly lesbian, and bisexual. Participants were 427 partnered sexual minority women (Mage = 24.66; 84.8% White; 46.8% only lesbian; 34.2% mostly lesbian; 19% bisexual) recruited from social media to complete an online survey consisting of measures of relationship, health, and related factors as part of a larger study. A one-way ANOVA revealed statistically significant differences between only lesbian, mostly lesbian, and bisexual women in relationship satisfaction (p=.021), sexual satisfaction (p=.049), and social support (p=.034). Post-hoc pairwise comparisons revealed women who identified as only lesbian reported better relationship satisfaction (p=.007), sexual satisfaction (p=.015), and social support (p=.010) than women who identified as mostly lesbian. There were no differences between bisexual women and women who identified as either only lesbian or mostly lesbian. These findings identified important differences between subgroups of SMW, with women who identify as mostly lesbian reporting the lowest relationship and sexual satisfaction and social support. This study provides further evidence that collapsing across identities within the broad category of SMW may mask meaningful subgroup differences. Additional research is needed to further explore disparities in well-being among subsections of SMW. Findings may help identify important protective factors for mental and physical health and well-being specific to SMW of different identities.https://digitalcommons.odu.edu/gradposters2023_sciences/1007/thumbnail.jp

    A systematic review of educational resources for teaching patient handover skills to residents

    Get PDF
    Background: As physicians reduce their work hours, transfer of patient care becomes more common; this is a time of heightened risk to patients. Training in patient handover skills may reduce this risk. The objective of this study was to systematically review the literature regarding education models available to teach handovers skills to healthcare professionals. Methods: A systematic review was conducted to identify published educational resources on patient handover skills. Two investigators independently reviewed publications for inclusion/exclusion. A third reviewer resolved any disagreement. Included papers contained an educational resource for teaching handover skills to any health profession in any patient population. Papers were rated on a previously described 4 point scale for quality. Results: 1746 papers were identified, of which twelve met the inclusion criteria These studies presented information on educational curricula, simulation technologies and didactic sessions. The most common educational method was simulation or role-playing, which is better received by learners than didactic sessions. Teaching handover practices makes residents feel more confident in their handover, and residents receiving adequate handover are more comfortable with their duties.Conclusions: Although  data are limited, effective training models for handover skills have been described in the literature. Residents and other healthcare practitioners should receive training in handover to improve practitioner comfort and patient care.

    Columbus State University Honors College: Senior Theses, Fall 2019

    Get PDF
    This is a collection of senior theses written by honors students at Columbus State University in 2019.https://csuepress.columbusstate.edu/honors_theses/1000/thumbnail.jp
    corecore