Modeling White Dwarf Binary Systems - A Hubble Space Telescope Project

White dwarfs are the final stage of stellar evolution for most stars–those less than about eight times the mass of the Sun. In these cases the star has ejected its outer layers, leaving a superheated core behind to cool. White dwarfs that are part of a binary system, or have a companion star, lead to many interesting astrophysical situations, and so are important objects to understand. In this study, we look specifically at binary white dwarf systems where the second object is a main sequence star. After the discovery of a binary system, it is necessary to create a working model to better understand the physical characteristics of the system. This is accomplished using data about the changing brightness of the system and measures of the speed of the stars toward and away from us as they orbit one another. We built preliminary models for two white dwarf binary systems–WD1136+667 and Gaia-DR2-3150–which we describe in this presentation. Both of these systems are part of a larger Hubble Space Telescope program studying very hot white dwarfs

Shacklefords Commercial Development Analysis

King and Queen County believes that economic development is crucial to ensuring a stable economy and high quality of life for residents of the county. With an out-commuting rate of 71% for the entire Middle Peninsula region, residents and businesses are spending their money outside of the region due to a lack of job opportunities and commercial development. However, the intersection of Route 33 and The Trail at Shacklefords within King and Queen County provides a major economic development opportunity for King and Queen County and the Middle Peninsula region. Through a one-semester research project, students in a VCU Commercial Revitalization course were invited by King and Queen County Administrator, Thomas Swartzwelder, to complete research on King and Queen County’s opportunity to attract the commuting traffic passing Shacklefords each day, as well as meet the desires of the community and the existing plans for this site. A VDOT Smart Scale funded development, currently in the design phase, will create a telecommuting center at the Shacklefords site, and relocate the offices of the Middle Peninsula Planning District Commission (PDC) to the same development. On a separate site at the same intersection, a privately established craft brewery site represents a convergence of new development that could spur additional commercial opportunities

The Shape of LITTLE THINGS Dwarf Galaxies DDO 46 and DDO 168: Understanding the stellar and gas kinematics

We present the stellar and gas kinematics of DDO 46 and DDO 168 from the LITTLE THINGS survey and determine their respective Vmax/sigma_z,0 values. We used the KPNO's 4-meter telescope with the Echelle spectrograph as a long-slit spectrograph. We acquired spectra of DDO 168 along four position angles by placing the slit over the morphological major and minor axes and two intermediate position angles. However, due to poor weather conditions during our observing run for DDO 46, we were able to extract only one useful data point from the morphological major axis. We determined a central stellar velocity dispersion perpendicular to the disk, sigma_z,0, of 13.5+/-8 km/s for DDO 46 and of 10.7+/-2.9 km/s for DDO 168. We then derived the maximum rotation speed in both galaxies using the LITTLE THINGS HI data. We separated bulk motions from non-circular motions using a double Gaussian decomposition technique and applied a tilted-ring model to the bulk velocity field. We corrected the observed HI rotation speeds for asymmetric drift and found a maximum velocity, Vmax, of 77.4 +/- 3.7 and 67.4 +/- 4.0 km/s for DDO 46 and DDO 168, respectively. Thus, we derived a kinematic measure, Vmax/sigma_z,0, of 5.7 +/- 0.6 for DDO 46 and 6.3 +/- 0.3 for DDO 168. Comparing these values to ones determined for spiral galaxies, we find that DDO 46 and DDO 168 have Vmax/sigma_z,0 values indicative of thin disks, which is in contrast to minor-to-major axis ratio studies

Student experiences and perceptions of compulsory research projects: a veterinary perspective

Background Although research underpins clinical work, many students training to be clinicians are not inherently interested in developing research skills. Aim To characterise and understand veterinary student experiences and perceptions of compulsory research projects. Methods This was an explanatory sequential mixed-methods study, with a questionnaire survey of an entire cohort informing purposive selection for focus group discussions. Student views were triangulated with staff questionnaire data. Results About a third of the cohort felt that the project had not been worthwhile or had not fostered useful skills. Focus group data analysis identified fragility of motivation and lack of clear schemata for the research process as key themes. Students were easily demotivated by typical research challenges and lack of schemata contributed to a poor understanding of the rationale for the project, encouraging highly extrinsic forms of motivation. Triangulation with staff questionnaire data indicated that staff understood students’ challenges, but were more likely than students to consider it to be a valuable learning experience. Conclusions Findings support ongoing curriculum development and emphasise that, to optimise motivation, engagement and learning, students training to be clinicians need a clear rationale for research, based on development of critical inquiry skills as a core clinical competency

The kinematics of molecular clumps surrounding hot cores in G29.96-0.02 and G31.41+0.31

We present high angular resolution interferometric observations of the 3 and 1.3mm continuum emission, and HCO+(1-0) and SiO(2-1)v=0 lines, obtained with the Owens Valley Radio Observatory millimeter-wave array, toward two hot cores (HCs) associated with two well known ultracompact (UC) HII regions: G29.96-0.02 and G31.41+0.31. These HCs are believed to host young forming massive stars which have been suggested to be surrounded by massive rotating accretion disks. The aim of these new observations is to study the structure and kinematics of the molecular clumps surrounding the HCs and nearby UCHII regions at moderately high angular resolution. Our observations reveal that the clumps within which the HCs and UCHII regions are embedded have a complex kinematical structure. The total mass of the clumps is estimated to be in the range 1000-3000 Msun, consistent with previous findings. Our observations also show compelling evidence that the clump in G29.96-0.02 is contracting onto the HC position, suggesting that the accretion process onto the massive young stellar object embedded in the HC is still ongoing. In these objects the kinematical structure that we observe is also compatible with the presence of a massive rotating disk within the HC, even though we cannot prove this suggestion with our data. The case of G31.41+0.31 is more complicated, and our data, although consistent with the presence of an inner disk and an infalling envelope around it, do not have the required spatial resolution to resolve the different structures.Comment: 13 pages, 15 figs, A&A in pres

Extensive Bilateral Extraluminal Perivascular Pulmonary Haemorrhage Associated with Stanford Type A Aortic Dissection

We present the case of an 80-year old man with a Stanford Type A dissecting thoracic aortic aneurysm plus the unusual CT finding of extramural haemorrhage along the pulmonary vessels. The clinical and radiological picture has an extremely high mortalit

Development of large scale inland flood scenarios for disaster response planning based on spatial/temporal conditional probability analysis

Extreme event scenarios are useful for civil emergency services to help in developing contingency plans for responding effectively to major flooding incidents. In the UK, the official national risk register includes a scenario for inland flooding (from rivers and other sources), which is described in terms of a probability of occurrence over a five year period of between 1 in 200 and 1 in 20. This scenario was previously based on recent extreme floods, in conjunction with maps produced to aid in development planning on floodplains. At the time it was constructed, it was not feasible to assess scientifically the combined probability of a nationally-significant flood event of this type, therefore the scenario probability assessment was ambiguous. Recent developments in multivariate extreme value statistics now allow the probability of large scale flood events to be assessed with reference to hydrological summary statistics or impact metrics. Building on theory and pilot studies by Heffernan and Tawn [1], Lamb et al. [2] and Keef et al. [3], we describe the development of a set of national-scale scenarios based on a high-dimensional (ca. 1,100 locations) conditional probability analysis of extreme river flows and rainfall. The methodology provides a theoretically justified basis for extrapolation into the joint tail of the distribution of these variables, which is then used to simulate extreme events with associated probabilities. The probabilistic events are compared with current understanding of meteorological scenarios associated with significant, large-scale flooding in the UK, and with historical flooding, in order to identify plausible events that can inform national risk scenarios. Additionally, we combined scenarios of inland and coastal extremes that have been considered by linking the analysis discussed in this paper with methods presented in a companion paper by Wyncoll et al

Lexmark Paper Redirector

Several of Lexmark’s current models employ a paper path that is concentrated within the front section of the printers in order to provide easy access for internal paper jams. However, this construction introduces complications associated with the accompanying output tray, as it necessitates a backward-facing paper feed which ejects sheets away from the user. This presents an inconvenience to the consumer if there are any obstructions above the paper tray. For example, if the printer is placed inside a cubby, on a shelf, or utilizes one of Lexmark’s attachment devices, access to the printed sheets becomes greatly restricted. As such, the task presented to the design team was to devise a mechanism which could circumvent this issue. Particularly, the client requested an attachment which could be added to existing printers or future models which would provide the consumer with a redirected output. The resultant output would bring the printed sheets forward, providing users with much easier access to the paper output in any situation

Increasing Access to Food: A Comprehensive Report on Food Supply Options

Access to food is one of the most important aspects of a healthy, sustainable community. Grocery stores and other suppliers can serve as an economic anchor to provide social benefits to communities. Unfortunately, many communities do not have convenient and/or affordable access to grocery items, particularly fresh produce. As part of Virginia Commonwealth University\u27s Fall 2019 graduate course on Urban Commercial Revitalization, class members researched 13 retail and other food access options, which are described in this report. Each chapter covers a food access option and provides basic information that will be useful to individuals, organizations, or government agencies that wish to attract and/or develop grocery operations in their communities