The Anomalous Temporal Behaviour of Broadband Lyα\alpha Emission During Solar Flares From SDO/EVE

Despite being the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Ly$\alpha$ emission during solar flares in recent years. However, the few examples that do exist have shown Ly$\alpha$ emission to be a substantial radiator of the total energy budget of solar flares (on the order of 10%). It is also a known driver of fluctuations in earth's ionosphere. The EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory now provides broadband, photometric Ly$\alpha$ data at 10 s cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H$\alpha$, Ly$\beta$, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission, rather than during the impulsive phase when energy deposition in the chromosphere - often assumed to be in the form of nonthermal electrons - is greatest. Given that spectrally-resolved Ly$\alpha$ observations during flares from SORCE/SOLSTICE peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines and/or continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting broadband Ly$\alpha$ observations of solar flares. Comparisons have also been made with other broadband Ly$\alpha$ photometers such as PROBA2/LYRA and GOES/EUVS-E.Comment: Submitted to A&A Research Notes, 5 pages 4 figure

Decay Phase Cooling and Inferred Heating of M- and X-class Solar Flares

In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared to the predictions of an analytical 0-D hydrodynamic model. It is found that the model does not fit the observations well, but does provide a well defined lower limit on a flare's total cooling time. The discrepancy between observations and the model is then assumed to be primarily due to heating during the decay phase. The decay phase heating necessary to account for the discrepancy is quantified and found be ~50% of the total thermally radiated energy as calculated with GOES. This decay phase heating is found to scale with the observed peak thermal energy. It is predicted that approximating the total thermal energy from the peak is minimally affected by the decay phase heating in small flares. However, in the most energetic flares the decay phase heating inferred from the model can be several times greater than the peak thermal energy.Comment: Published in the Astrophysical Journal, 201

Lithographic patterning of polymeric media for biotechnology applications

Lithographic patterning has heavily utilized in the semiconductor industry for its ability to pattern vast numbers of complex shapes down to the nanometer scale. However, only recently has this technology been employed in the biotechnology field despite the fact that most of that the most important biological components such as cells, antibodies, DNA and proteins operate at this level. This work is an exploration of the use of lithographic printing methods in two areas deeply-entrenched in biotechnology: self assembly and microarray-based manipulation of biological media. It was inspired by the natural self assembly which occurs in nature and in our bodies at all scales. The majority of this work dealt with the patterning of bioreactive copolymers into different three-dimensional microshapes which could be functionalized with single strands of DNA for subsequent sequence-specific particle assembly. This type of technology, where very small-scale matter can be directed to self assembly into programmed macrostructures in a highly-specific manner has the capability to be adapted for many next-generation applications in drug delivery, nanofabrication, biosensing, and microelectronics. A secondary technology was explored in this work involving the paired sequencing of antibody gene sequences with the aid of lithographically-patterned microarrays. This methodology represents a bridging of bottom-up fabrication methods of DNA and proteins with top-down optical fabrication techniques which is already finding increasing utility in applications such as vaccine discovery, diagnostics, and autoimmune research. Because of the versatile nature of the components of this research, it is the hope of the author that the techniques discovered and explored here provide support and inspiration for future research in the biotechnology field as well as in other fields which may benefit as well.Chemical Engineerin

Late Holocene Spit Evolution on Centennial Timescales in the Southeast Delaware Bay, USA

The relationship between barrier spit growth and longshore drift is well established. However, the role of storm activity in spit evolution on an intermediate (centennial) timescale is more of a mystery due to a knowledge gap between decadal-scale shoreline processes and millennial-scale stratigraphic data. Recent studies in the northwestern Atlantic basin using ground-penetrating radar (GPR) and optically-stimulated luminescence (OSL) are providing the opportunity to study centennial-scale shoreline evolution and examine similar age storm activity. Cape Henlopen, Delaware exhibits preserved remnants of a long-term northward-growing spit coastline that evolved from a recurved spit complex, to a cuspate spit, to the present-day simple spit. This location provides ideal late-Holocene spit features on which to collect GPR and OSL data. Within Cape Henlopen State Park, approximately 10 trackline-km of GPR data were collected from the southernmost relict recurved spits to the more northern simple spit for the purpose of revealing the internal architecture and growth patterns of the spits, as well as evidence of storm influence. A total of 8 OSL samples were obtained to find coincidences among the ages of the spit deposits and periods of increased storm activity. GPR analysis exhibits 5 major sedimentary facies: shallow marine, spit platform, spit beach and dune, overwash fan foreset deposits, and modern dunes. OSL ages indicate that spit development began around 2.4 ka, followed by phases of major growth of recurved spits during CE 100 to 500 (1.9-1.5 ka) and then converting to a cuspate foreland around CE 1500 (0.5 ka). Analysis of the OSL dates reveals concurrences between the ages of the spit features and periods of increased storm frequency during CE 0 to 700 (2.0-1.3 ka) and CE 1300 to 1800(0.7-0.2 ka) in the North Atlantic basin which produces evidence that storm activity may have a significant influence on barrier spit evolution on centennial timescales. The results of this study provide both an increased understanding of how barrier spits evolve as well as centennial-scale data to be used for coastal change and hazard management modeling

Reconstructing Poverty Discourse: Poverty and Reagan’s Narrative Rationality

This thesis examines President Ronald Reagan’s poverty discourse during his first term. Using the work of Walter Fisher, this study examines Reagan’s narrative rationality in constructing images of welfare recipients and the welfare system in the justification of his policies. By identifying links between Reagan’s rhetoric and the rhetoric of debates leading to the passage of the 1996 Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA), this thesis supports Asen’s (2002) claim that Reagan created a discursive context that made passage of PRWORA possible. Moreover, the study suggests the utility of using Skowronek’s (1997) Recurrent Structure of Presidential Authority in understanding United States Presidential Discourse

Impact of Crop Rotations and Winter Cover Crops on Vegetative Cover, Aboveground Biomass, and Soil Organic Matter under No-Till in Western Tennessee

We investigated, under long-term no-till in western Tennessee, the effects of rotating the low-input crops cotton and soybeans with the high-input crop corn, compared to continuous monocultures of cotton and soybeans, and of using the winter cover crops (WCCs) winter wheat and hairy vetch, compared to winter fallow, on key indicators of soil health concerning vegetative cover and labile SOM. The line-transect method was used to measure percent vegetative cover. Dry weight of surface crop residue and aboveground living plant biomass (WCCs and winter weeds) was obtained. The living plant biomass was analyzed for carbon (C) and nitrogen (N) by dry combustion to determine C/N ratios. The sand-sized POM-C fraction at 0 to 5 and 5 to 15 cm was physically fractionated and analyzed for C by dry combustion. The inclusion of corn in rotation with cotton significantly increased aboveground crop residue quantity, aboveground winter weed biomass quantity, total aboveground biomass quantity, percent vegetative cover, and POM-C at 0 to 5 cm. The inclusion of corn in rotation with soybeans significantly increased aboveground crop residue quantity and POM-C at 0 to 5 cm, but significantly decreased aboveground winter wheat biomass quantity, total aboveground biomass quantity under winter wheat, aboveground winter weed biomass C/N ratio, and POM-C at 5 to 15 cm. The use of WCCs did not significantly increase total aboveground biomass quantity under most cropping sequences, and significantly reduced aboveground crop residue quantity, aboveground winter weed biomass quantity, and percent vegetative cover. The WCCs generally did not affect POM-C at either depth, though they significantly increased POM-C at 5 to 15 cm under continuous soybeans. Compared to winter wheat, hairy vetch significantly increased aboveground winter weed biomass quantity and percent vegetative cover. Our results demonstrate that the inclusion of corn in rotation with cotton is highly effective, while inclusion of corn in rotation with soybeans and the use of WCCs are ineffective in improving soil quality by increasing vegetative cover and the labile pool of SOM under these conditions

The Evolution of Electronic Surveillance: Balancing National Security and Civil Liberties

This paper examines the history of electronic surveillance for national security purposes within the United States and relates the statutory and constitutional law to the current, post September 11th practices. An extensive examination of the Foreign Intelligence Surveillance Court and the recently leaked, classified Terrorist Surveillance Program shows that the FISA Court, within its narrow jurisdiction, adequately accounts for constitutional standards, yet the TSP—including recent reforms—is in clear violation of constitutional and statutory law

The Role of Psychological Flexibility in Eating Disorders in a Residential Treatment Sample

Eating disorders have a dramatic effect on the lives of people who struggle with them, including cardiovascular and gastrointestinal problems, and death. Individuals with these diagnoses are also often struggling with comorbid diagnoses such as depression, anxiety, and substance abuse/dependence. Building on a conceptualization of eating disorders as a means to dysfunctionally regulate negative affect and escape unwanted thoughts, psychological flexibility, the ability of a person to contact unwanted thoughts or feelings and behave without escape or avoidance, is investigated as a tool for treatment. Additionally, because quantitative analysis of the construct of psychological flexibility has often employed the use of college samples, this study employed a sample of participants drawn from a residential treatment facility dedicated to the treatment of eating disorders. Through regression and modeling, psychological flexibility demonstrates its utility in the treatment of eating disorders through its relationship with body dissatisfaction and quality of life

Effect of radiation damage on organic phase change materials thermal storage properties

This work discusses the effects of radiation damage on organic phase change materials for use in nuclear reactor containments and space craft. The effects of radiation on the latent heat of polyethylene wax (PEW) and a eutectic of methyl palmitate and lauric acid (EMPaLA) are evaluated. These PCMs were irradiated in three locations: the Missouri University of Science and Technology research reactor (MSTR), the University of Missouri research reactor (MURR) and cyclotron (MUC) up to a total dose of 2826, 2895 and 662 Gy, respectively. The samples irradiated at the MSTR showed latent heat changes up to 15.5% lower than the starting values however the error bars are so close that the there is no conclusive evidence for a statistically significant change. The MUC irradiation did not yield any statistically significant change in the latent heat. The irradiation at MURR showed a drop of 18.8% which could indicate a dose rate effect. Raman spectra were also taken of the irradiated samples. PEW was found to have a a new peak at about 150 cm-1 when irradiated at MUC but no other observable changes were found. A statistical model was developed to calculate chain length distribution after irradiation by utilizing a displacements per atom (DPA) approach. This model was intended to extrapolate the change in latent heat from the change in molecular chain length. The current model only accounts for scissions and neglects any crosslinking that could occur. The model was found to have an absolute error of under 0.15 at the starting chain length when compared to a similar model developed by Charlesby. It was found that the current model predicts that there will be minimal change in the starting chain lengths which indicates no significant change in the latent heat. This agrees with the data found --Abstract, page iv