Galactic Archaeology and Minimum Spanning Trees

Chemical tagging of stellar debris from disrupted open clusters and associations underpins the science cases for next-generation multi-object spectroscopic surveys. As part of the Galactic Archaeology project TraCD (Tracking Cluster Debris), a preliminary attempt at reconstructing the birth clouds of now phase-mixed thin disk debris is undertaken using a parametric minimum spanning tree (MST) approach. Empirically-motivated chemical abundance pattern uncertainties (for a 10-dimensional chemistry-space) are applied to NBODY6-realised stellar associations dissolved into a background sea of field stars, all evolving in a Milky Way potential. We demonstrate that significant population reconstruction degeneracies appear when the abundance uncertainties approach 0.1 dex and the parameterised MST approach is employed; more sophisticated methodologies will be required to ameliorate these degeneracies

Relationship between corn stalk strength and southwestern corn borer penetration

Studies were conducted to determine if corn stalk strength had an effect on southwestern corn borer (Diatraea grandiosella Dyar) survival during different growth stages. In 2006 southwestern corn borer larvae were placed on corn during the tassel stage near the ear and base of the plant. Survival was higher near the ear than near the base of the plant. In 2007, five varieties of corn were planted at three locations in Mississippi. Plants were infested with five 3rd instar larvae at the ear zone during tassel, dough and dent development stages. After five days stalk strength and borer survival were measured. Survival decreased as the corn progressed from tassel to dent stage. Survival varied among corn varieties. The relationship between stalk strength and borer survival was not consistent, indicating that there are likely factors more directly limiting borer survival than physical stalk strength

Simple and accurate modelling of the gravitational potential produced by thick and thin exponential discs

We present accurate models of the gravitational potential produced by a radially exponential disc mass distribution. The models are produced by combining three separate Miyamoto–Nagai discs. Such models have been used previously to model the disc of the Milky Way, but here we extend this framework to allow its application to discs of any mass, scalelength, and a wide range of thickness from infinitely thin to near spherical (ellipticities from 0 to 0.9). The models have the advantage of simplicity of implementation, and we expect faster run speeds over a double exponential disc treatment. The potentials are fully analytical, and differentiable at all points. The mass distribution of our models deviates from the radial mass distribution of a pure exponential disc by <0.4 per cent out to 4 disc scalelengths, and <1.9 per cent out to 10 disc scalelengths. We tabulate fitting parameters which facilitate construction of exponential discs for any scalelength, and a wide range of disc thickness (a user-friendly, web-based interface is also available). Our recipe is well suited for numerical modelling of the tidal effects of a giant disc galaxy on star clusters or dwarf galaxies. We consider three worked examples; the Milky Way thin and thick disc, and a discy dwarf galaxy

A mixed methods evaluation of a digital intervention to improve sedentary behaviour across multiple workplace settings

Background: Prolonged sedentary behaviour (SB) is associated with risk of chronic diseases. Digital interventions in SB require mixed method evaluations to understand potential for impact in real-world settings. In this study, the RE-AIM QuEST evaluation framework will be used to understand the potential of a digital health promotion application which targets reducing and breaking up SB across multiple workplace settings. Methods: Four companies and 80 employees were recruited to use a digital application. Questionnaires were used to measure SB, and additional health and work-related outcomes at baseline, one month, three month and six month follow-up. Qualitative data was collected through focus groups with employees and interviews with stakeholders. Questionnaire data was analysed using Wilcoxon Sign Rank tests and qualitative data was thematically analysed. Results: The digital application significantly increased standing time at one month for the total group and transitions per hour in one of the companies. Facilitators and barriers were identified across RE-AIM. Conclusions: Addressing the barriers which have been identified, while maintaining the positive attributes will be critical to producing an effective digital application which also has the potential for impact in the real world

Using GREET to analyze natural gas usage in municipal fleets

GREET was used to calculate energy consumption and pollutants emitted from specific fuel/vehicle types when given a specific set of parameters. In this case, the parameters were the type of fuel mix from TVA, the selected vehicle year of 2015, the vehicle weight specified in the heavy-duty vehicle range, and type of simulation technique, which was the Hammersely Sequence Sampling. These inputs, along with seventeen fuel/vehicles mixes, specific pollutants, and cost considerations, were used to investigate the environmental impact of the transition from petrol diesel to natural gas in the municipal fleets of Chattanooga, Tennessee. The energy consumption included coal, petroleum, natural gas, and other power generating sources like electricity and biomass/bio-diesel. The pollutants investigated included greenhouse gases (GHGs), carbon monoxide (CO), nitrous oxides (NOx), sulfur oxides (SOx), and particulate matter (PM2.5). The pollutant of particular importance to the city of Chattanooga is PM2.5 since the city is designated a Nonattainment Area by the EPA and is looking to be redesignated as a Maintenance Area. Natural gas vehicles emitted the lowest amount of GHGs, NOx , and PM2.5, only receiving competition from the standard electric vehicle with slightly lower emissions. Overall, Well-topump emissions were the lowest for vehicles that used pure natural gas. To summarize, compressed natural gas seems like the best option for a fuel because it is cheap, fueling the vehicle is easy, there is an unlimited hold time for the fuel, GHG and PM2.5 emissions are lower, compressed natural gas prices fluctuate less in the current market, and the engine for the vehicle is quieter, especially when compared to diesel trucks

High-resolution infrared spectroscopy in pursuit of C60 and other astrochemical targets

This work is primarily concerned with the development of a mid-infrared cavity ringdown spectrometer with the intent of observing rotationally-resolved vibrational spectra of C60 and other astronomically relevant molecules, including the polyoxymethylene 1,3,5-trioxane. C60 was first discovered during experiments intended to simulate the conditions found in carbon stars, and has since been observed via emission spectroscopy in several planetary nebulae as well as the inerstellar medium. Due to its low ionization potential, much of the C60 in interstellar space is expected to be ionized to C60+, which has long been suspected as one of the carriers of the diffuse interstellar bands; recent work supports this assignment, further increasing interest in the astrochemistry of C60. While these observations through emission spectroscopy have had a significant impact, emission spectroscopy is not an effective approach in cold regions of space with low ultraviolet flux - as such, obtaining a high-resolution absorption spectrum remains an important goal. This is an extension of previous development work and attempts to observe the spectrum of C60 - as the principle shortfall of those previous attempts was the the inability to vibrationally cool C60 produced via thermal vaporization, much of this following will focus on the development and validation of an alternative vaporization method involving the expansion of supercritical fluids containing the target molecules. This should allow vapor to be produced at much lower temperatures, allowing more C60 to reach the ground state in spite of inefficient supersonic cooling. The first generation source has been constructed and tested, with the results informing the design of a second-generation source that has been constructed and is currently being evaluated. In addition to the development of an improved source for cold C60, we have also implemented a new external-cavity quantum cascade laser as the light source in our instrument. This new laser has significantly improved spectral coverage when compared to the previous light source, in addition to considerably easier and more reliable frequency tuning. However, the addition of a vibration-sensitive grating as a wavelength selective element introduced an unacceptable jitter in the lasing frequency. To address this, we developed a novel laser locking system based on side-of-fringe locking to a solid germanium etalon; in order to maintain continuous wavelength tuning, the free spectral range of the etalon is tuned by stepping its angle with respect to the incident laser. This has allowed us to stabilize the laser to acceptable levels while maintaining the ability to tune its lasing frequency very precisely. Finally, we recorded, simulated, and assigned the rotationally-resolved absorption spectrum of the v16 vibrational band of 1,3,5-trioxane. In addition to the importance of trioxane to understanding formaldehyde chemistry in comets, trioxane was chosen as a means of testing the various improvements made to the spectrometer. The spectrum described in this work was obtained using the new external-cavity quantum cascade laser and locking system; efforts to evaluate the second-generation supercritical fluid expansion source will use trioxane spectroscopy to estimate the efficiency of rotational and vibrational cooling

A mixed methods evaluation of a digital intervention to improve sedentary behaviour across multiple workplace settings

Background: Prolonged sedentary behaviour (SB) is associated with risk of chronic diseases. Digital interventions in SB require mixed method evaluations to understand potential for impact in real-world settings. In this study, the RE-AIM QuEST evaluation framework will be used to understand the potential of a digital health promotion application which targets reducing and breaking up SB across multiple workplace settings. Methods: Four companies and 80 employees were recruited to use a digital application. Questionnaires were used to measure SB, and additional health and work-related outcomes at baseline, one month, three month and six month follow-up. Qualitative data was collected through focus groups with employees and interviews with stakeholders. Questionnaire data was analysed using Wilcoxon Sign Rank tests and qualitative data was thematically analysed. Results: The digital application significantly increased standing time at one month for the total group and transitions per hour in one of the companies. Facilitators and barriers were identified across RE-AIM. Conclusions: Addressing the barriers which have been identified, while maintaining the positive attributes will be critical to producing an effective digital application which also has the potential for impact in the real world

ROTATIONALLY-RESOLVED INFRARED SPECTROSCOPY OF THE _16 BAND OF 1,3,5-TRIOXANE

1,3,5-trioxane is the simplest cyclic form of polyoxymethylene (POM), a class of formaldehyde polymers that has been proposed as the origin of distributed formaldehyde formation in comet comae and a potential source of formaldehyde in prebiotic chemistry. Although claimed POM detections have since been proven to be inconclusive, laboratory simulations of cometary conditions have yielded trioxane and other POMsfootnote{Cottin, H., Bﾎnilan, Y., Gazeau, M-C., and Raulin, F. Origin of Cometary Extended Sources from Degradation of Refractory Organics on Grains: Polyoxymethylene as Formaldehyde Parent Molecule. textit{Icarus} textbf{167} (2004), 397-416.}. While the microwave spectrum of 1,3,5-trioxane has been studied extensivelyfootnote{Oka, T., Tsuchiya, K., Iwata, S., and Morino, Y. Microwave Spectrum of s-Trioxane. textit{Bull. Chem. Soc. Jpn.} textbf{37} (1964), 4-7.}, to date only one rotationally-resolved ro-vibrational spectrum has been publishedfootnote{Henninot, J-F., Bolvin, H., Demaison, J., and Lemoine, B. The Infrared Spectrum of Trioxane in a Supersonic Slit Jet. textit{J. Mol. Spect.} textbf{152} (1992), 62-68.}. Here, we present our studies of the nub{16} band of gas-phase trioxane centered at 1177 wn. Trioxane was entrained in a supersonic expansion of argon and characterized by continuous-wave cavity ringdown spectroscopy using an etalon-stabilized external-cavity quantum cascade laserfootnote{Gibson, B.M. and McCall, B.J., contribution TJ08, presented at the 69$^{th}$ International Symposium on Molecular Spectroscopy, Urbana, IL, USA, 2014.}. Rotationally resolved spectra were obtained with less than 15 MHz resolution

Beyond the Toolpath: Site-Specific Melt Pool Size Control Enables Printing of Extra-Toolpath Geometry in Laser Wire-Based Directed Energy Deposition

A variety of techniques have been utilized in metal additive manufacturing (AM) for melt pool size management, including modeling and feed-forward approaches. In a few cases, closed-loop control has been demonstrated. In this research, closed-loop melt pool size control for large-scale, laser wire-based directed energy deposition is demonstrated with a novel modification, i.e., site-specific changes to the controller setpoint were commanded at trigger points, the locations of which were generated by the projection of a secondary geometry onto the primary three-dimensional (3D) printed component geometry. The present work shows that, through this technique, it is possible to print a specific geometry that occurs beyond the actual toolpath of the print head. This is denoted as extra-toolpath geometry and is fundamentally different from other methods of generating component features in metal AM. A proof-of-principle experiment is presented in which a complex oak leaf geometry was embossed on an otherwise ordinary double-bead wall made from Ti-6Al-4V. The process is introduced and characterized primarily from a controls perspective with reports on the performance of the control system, the melt pool size response, and the resulting geometry. The implications of this capability, which extend beyond localized control of bead geometry to the potential mitigations of defects and functional grading of component properties, are discussed

Surveying Public Research 2 University Libraries’ Programs Supporting Digital Scholarship: A Report

Librarians at Ball State University designed and distributed a survey to libraries personnel at all public R2 research universities to assess the nature of university libraries’ engagement with digital scholarship, digital humanities, or digital research. Project researchers received 36 usable responses to the survey from individuals at 26 institutions, for an individual response rate of 12% and an institutional response rate of 35%. This report communicates core data and findings as a result of the survey project. Included is data regarding services and expertise offered by the libraries, the nature of libraries’ collaborations with researchers, technology infrastructure to support digital scholarship/digital research/digital humanities, and the nature of libraries’ participation in scholarship and public presentation regarding digital scholarship/digital research/digital humanities