Wheaton College (MA) Digital Repository
Not a member yet
3441 research outputs found
Sort by
Lack of Effects of Methylmercuric Chloride on the Velocity of Mitochondria within Glial Cells of the Domestic Chicken, Gallus gallus.
No full text12 pages; color illustrations.Includes bibliographical references
Magnetohydrodynamics modeling in Python : simulating magnetic fluids.
No full texti, 101 leaves : color illustrations.Includes bibliographical references.The purpose of this work is to present a gentle first introduction to numerical magnetohydrodynamics at the advanced undergraduate level. We first present the necessary background physics, building up the magnetohydrodynamics equations piece by piece. Then, we present numerical methods to discretize the equations. In addition to the traditional finite difference method, we present stable and nonstandard discretization methods employed in THE.ARGO, a minimalist magnetohydrodynamics code written in Python by this author. A backtracking scheme is used to discretize advection and diffusion and is guaranteed to be stable. Our nonstandard discretization is an atypical use of Fast Fourier Transforms to find the fluid pressure. Last, we present test problems validating the physical accuracy of THE.ARGO's unusual methods. We hope this work will provide students with some foundation before delving into the nasty traditional codes written in C and Fortran. Additionally, we hope the scientific community may benefit from our presentation of the nonstandard techniques we used to discretize the magnetohydrodynamics equation. Unlike common methods, our schemes guarantee stability, allowing larger time steps than the Courant conditions permits.The physics of ideal MHD -- Introduction -- What is a fluid? -- The fluid equations --The MHD equations -- Looking to the future -- Discretizing the MHD equations -- The Hollywood way of life -- Finite differencing -- Backtracking methods for advection and diffusion -- Eliminating velocity divergence by relaxing the pressure -- Fourier transform method -- Discretization methods summary -- Simulations testing THE.ARGO -- Simulation parameters -- Advection -- Advection plus diffusion in 1D -- Advection plus diffusion in 2D -- Lid-driven cavity flow -- Double vortex -- The orszag-tang vortex
Kinematics and muscle activity during punting in freshwater stingrays.
No full texti, 41 leaves : illustrations.Includes bibliographical references: leaves 38-41.Many, benthic batoids (skates and rays) locomote by use of the water's substrate (Wilga and Lauder, 2004, Macesic and Kajiura, 2010). They perform what is known as augmented punting in which the thrust from pelvic fins are assisted by oscillations of the pectoral fins (Macesic and Kajiura 2010). The goal of my thesis is to better understand gait transitions, or changes in movement patterns while transitioning from one speed to another (Vogel, 2003a), in freshwater stingray punting. Specifically, I want to know how pectoral fins and the pelvic fins contribute to increasing punting speeds. I used five freshwater stingrays (Potamotrygon hystrix), and tested them each in a flume, recording electromyography (EMG) and video kinematics while speeds were increased. Nested ANOVAs were performed for both EMG and kinematic data. I found that none of the variables for each muscle change significantly with speed. For kinematics, the normalized pectoral fin amplitude significantly change with increased speed, but pectoral fin wave frequency (Hz) and punt frequency (Hz) do not significantly increase with increasing speeds. Previous research indicates that in stingray swimming, pectoral frequency increases and pectoral fin amplitude remains constant across different speeds (Blevins and Lauder, 2012; Rosenberger and Westnest, 1999). These differences suggest that punting and swimming undergo different kinematic strategies which may help reduce the cost of energy for each mode of locomotion
Finding success : the role of social support in the lives of American teen mothers.
No full texti, 91 leaves : illustrations.Includes bibliographical references: leaves 88-91.This study was designed to determine the influences of various types of social support on the life trajectories of teen mothers. In this study, I conducted semi-structured interviews with ten teen mothers regarding their support networks and the types of support they received. I particularly focused on emotional support, cognitive support, material support (both monetary and goods and services), and social network support. Framed by social reproduction theory, the concept of capital, and the importance of transformative assets, I determined that certain types of support, such as monetary material support, are more transformative for the future of a teen mother than others. These types of support tend to be offered by the families of middle-class teen mothers rather than lower-working class teen mothers, resulting in the disparity of outcomes. While other types of social support, such as emotional support, are also crucial to the daily life of a teen mother, they will not break the cycle of inequality as an experience such as attending college would
Effect of lithium on axon brightness in Gallus gallus neurons.
No full text14 pages; colored illustrations.Includes bibliographical references
Notorious crimes & high misdemeanors : New England women in court 1620-1690.
No full texti, 140 leaves.Includes bibliography: leaves 137-140.Notorious Crimes & High Misdemeanors argues that the experiences of women in court in seventeenth-century New England were shaped not only by the circumstances of their crimes and established legal and cultural attitudes towards women, but also by the attempts of colony leaders to maintain the hierarchical structure of their communities, especially in times of religious, political, and social crisis. It looks at the actions of magistrates to assert control through five chapters organized by crime—crimes of unorthodoxy, speech and apparel offenses, liquor and theft, murder and witchcraft, and fornication, adultery, and divorce.Heterodox women -- Crimes of expression -- Tavern keepers, common drunkards, and thieves -- Taking lives and making covenants with the devil -- The regulation of marriage
Method development for detecting metals in human nails and hair using an indigo-spiropyran sensor.
No full texti, 50 leaves : illustrations (some color)Includes bibliographical references.The main goal of this study was to design a nitrospiropyran-indigo based sensor for detecting metal concentration in human samples. The dye indigo and its derivatives form a complex with different metal ions such as Cu²⁺ and Pb²⁺ in carbonate buffer solution at pH 10. UV-Vis absorption and fluorescence emission spectra of these complexes reacting with 1,2-hydroxyethyl-3,3-dimethylindoline-6-nitrobensopyrylospiran (SPOH) were investigated in aqueous media. Solutions comprised of two dyes, spiropyran and indigo or indigo derivatives, and varying concentrations of metal ions were analyzed by UV-Vis absorption and fluorescence emission spectrophotometric methods, resulting in calibration curves that are useful for the detection and determination of the concentration of copper and lead ions in human samples. Different pH conditions were tested to determine the pH range in which this metal cation sensor is most effective. Results show that neutral and buffered media gave the most useful results. This research may contribute to the development of cost-effective detection methods for metals in human body samples, such as hair and nails. Furthermore, results from tests could be used for early metal ion deficiency prevention and the study of interrelations between human diseases and essential metal cations (M²⁺)