When the Curiosity Mars rover encounters a serious fault, it enters a configuration called safe mode. Curiosity's autonomous safe mode behavior must keep the rover communicative and stable until the ...operations team can triage the issue and send recovery commands. In safe mode, Curiosity follows a preset schedule of windows that specify the antenna, telemetry for transmission, and solar time of each communication opportunity. The timing of these windows, called system fault protection (SFP) windows, is crucial for Curiosity to maintain both communication and power-positivity, or generating more energy that consumed. Not only do SFP windows dictate when Curiosity attempts to communicate over its ultra-high frequency and X-band radios, they also largely control the rover's power consumption by dictating when its primary computer powers on and off, known as awake and sleep states. Because Curiosity is power-negative when awake, sleep time is necessary to charge its batteries to a higher state of charge than the previous sol, or Martian day.During Curiosity's prime mission, fault protection engineers regularly updated SFP windows to accommodate changing Mars relay orbits and relative geometry of Earth and Mars. The initial SFP windows at landing directed Curiosity to stay awake for nine Martian hours of communication each sol. This design allowed enough sleep time for Curiosity to increase the state of charge of its batteries by 22% over a single sol in safe mode. But as the mission progressed, updates to SFP windows were additionally driven by Curiosity's aging power source, which continuously requires increased sleep time to maintain power-positivity. As of 2023, 6.6 hours of safe mode communication per sol will only increase the battery state of charge by 5.5%. Secondary factors that were not present during Curiosity's prime mission-including changing uplink strategies and Mars relay infrastructure-have introduced new challenges to updating SFP windows. The process of selecting SFP window times has evolved into an iterative analysis that must consider several dynamic operational factors to achieve a balance of communication time and power consumption. By using this analysis to converge on a design that satisfies energy requirements and desired communication opportunities, fault protection engineers ensure Curiosity's safe mode configuration in its extended mission remains truly safe. This paper discusses how Curiosity uses SFP windows to communicate in safe mode, the factors that influence how SFP windows are designed, and how both the design process and the windows themselves have changed over ten years of surface operations.
Abstract
Disclosure: J. Brown: None. M. Dewan: None. J. Courter: None. A. Spooner: None. J. Treasure: None. K. Kaplan: None. N.A. Crimmins: None.
Unnecessary testing may lead to patient harm, ...inappropriate treatments, and/or increased cost. Per the Endocrine Society, in conjunction with Choosing Wisely, 1,25-dihydroxyvitamin D (1,25-OH D) should not be measured unless a patient has hypercalcemia or decreased kidney function. This study sought to evaluate overutilization of 1,25-OH D at Cincinnati Children's Hospital Medical Center. We queried EPIC for all 1,25 OH vitamin D tests drawn in all patients (inpatient and outpatient) between 01/01/2021 and 12/31/2021. We then cross-referenced each test with all patient ICD10 codes associated with each patient’s chart. Appropriate ordering was defined as the patient having an ICD10 code related to calcium disorders or renal disease (531 codes included, data not shown). Out of a total of 1,057 1,25-OH D tests ordered, we found that only 19.4 percent were in patients whose chart contained a code that clinically would indicate testing. Further analysis showed most of these tests were obtained by psychiatry (22.7%) and community general pediatricians (14.6%) and not by endocrinology (12.5%) or nephrology (2.2%) providers. We will use this as baseline data to design quality improvement interventions to reduce unnecessary ordering of 1,25 OH vitamin D, including an ordering pathway in Epic to provide point of care education and guidance regarding appropriate Vitamin D test selection. In summary, inappropriate ordering of 1,25 vitamin D is common, likely due to misunderstanding of the best test to determine vitamin D sufficiency.
Presentation: Thursday, June 15, 2023
We present the survey design, data reduction, and spectral fitting pipeline for the VIRUS-P Exploration of Nearby Galaxies (VENGA). VENGA is an integral field spectroscopic survey, which maps the ...disks of 30 nearby spiral galaxies. Targets span a wide range in Hubble type, star formation activity, morphology, and inclination. The VENGA data cubes have 5"6 FWHM spatial resolution, ~5 A FWHM spectral resolution, sample the 3600 A-6800 A range, and cover large areas typically sampling galaxies out to ~0.7 R sub(25). These data cubes can be used to produce two-dimensional maps of the star formation rate, dust extinction, electron density, stellar population parameters, the kinematics and chemical abundances of both stars and ionized gas, and other physical quantities derived from the fitting of the stellar spectrum and the measurement of nebular emission lines. To exemplify our methods and the quality of the data, we present the VENGA data cube on the face-on Sc galaxy NGC 628 (a.k.a. M 74). The VENGA observations of NGC 628 are described, as well as the construction of the data cube, our spectral fitting method, and the fitting of the stellar and ionized gas velocity fields. We also propose a new method to measure the inclination of nearly face-on systems based on the matching of the stellar and gas rotation curves using asymmetric drift corrections. VENGA will measure relevant physical parameters across different environments within these galaxies, allowing a series of studies on star formation, structure assembly, stellar populations, chemical evolution, galactic feedback, nuclear activity, and the properties of the interstellar medium in massive disk galaxies.
The ability to control crystal form is essential for the development of materials with desired properties. The rational design of heterosurfaces to control nucleation is one such approach. ...Heterosurfaces are commonly selected based on their chemistry and/or crystallography and/or morphology. However, the heterosurface is almost always considered to be in equilibrium with the crystallization medium during nucleation. This may lead to an inaccurate description of the epitaxial mechanisms responsible for controlling nucleation. Herein, we discuss controlling the surface equilibria of sparingly soluble crystals to control heterogeneous nucleation and crystal form. The heterogeneous crystallization of 3-aminobenzensulfonic acid (3-ABSA) on seeds of 1,5-diaminonaphthalene (DAN) was investigated. The DAN crystal faces were determined to be in a nonequilibrium state upon suspension in an aqueous solution of 3-ABSA, resulting in significant changes in surface morphology. Controlling the kinetics of surface equilibration resulted in DAN seeds with differing surface morphologies. Seeding with these different surface morphologies led to the nucleation of different crystal forms of 3-ABSA, including the so-called “disappeared” polymorph, Form I. Utilizing surface equilibria to control heterogeneous nucleation represents a highly novel approach to controlling the crystal form.
IGRINS Slit-viewing Camera Software Lee, Hye-In; Pak, Soojong; Mace, Gregory N. ...
Publications of the Astronomical Society of the Pacific,
04/2020, Volume:
132, Issue:
1010
Journal Article
Peer reviewed
We have developed observation control software for the Immersion GRating INfrared Spectrometer (IGRINS) slit-viewing camera module, which maintains the position of an astronomical target on the ...spectroscopic slit. It is composed of several packages that monitor and control the system, acquire the images, and compensate for the tracking error by sending tracking feedback information to the telescope control system. For efficient development and maintenance of each software package, we have applied software engineering methods, i.e., a spiral software development with model-based design. It is not trivial to define the shape and center of astronomical object point spread functions (PSFs), which do not have symmetric Gaussian profiles in short exposure (<4 s) guiding images. Efforts to determine the PSF centroid are additionally complicated by the core saturation of bright guide stars. We have applied both a two-dimensional Gaussian fitting algorithm (2DGA) and center balancing algorithm (CBA) to identify an appropriate method for IGRINS in the near-infrared K-band. The CBA derives the expected center position along the slit-width by referencing the spillover flux ratio of the PSF wings on both sides of the slit. In this research, we have compared the accuracy and reliability of the CBA to the 2DGA by using data from IGRINS commissioning observations at McDonald Observatory. We find that the performance of each algorithm depends on the brightness of the targets and the seeing conditions, with the CBA performing better in typical observing scenarios. The algorithms and test results we present can be utilized with future spectroscopic slit observations in various observing conditions and for a variety of spectrograph designs.
The Perseverance rover has completed a very successful 2.5 years on Mars. It has filled 24 of the 43 sample tubes it brought to Mars and completed the Three Forks Sample Depot on January 28, 2023, ...where it deposited 10 of these samples on the surface of Mars. Each deposited sample was sealed within a Returnable Sample Tube Assembly (RSTA) and attached glove assembly (RGA). Creation of this sample depot has satisfied all of the prime mission requirements. The Mars Sample Return mission aims to bring some of the samples that Perseverance collects from Mars to Earth, either via direct delivery from the Perseverance rover to the Sample Retrieval Lander (SRL), or by deploying Sample Recovery Helicopters (SRH) to fly to the samples and collect them. This paper describes the strategic planning and tactical execution of the mobility, robotic arm, sampling and imaging activities that led to the very successful depot creation. A number of factors had to be considered including SRH access, communication obstructions, view for imaging, and contingency handling. It discusses how the strategic planning arrived at the plan for alternating two main types of sols: drop and image, and drive and photoshoot. Drop and image choreographed moves between the Perseverance external robotic arm and the Adaptive Caching Assembly (ACA) inside the rover, which has a second robotic arm - the Sample Handling Arm - to image the sample before and after depositing it on the surface. Drive and photoshoot consists of backing up and taking mid-drive images of the dropped sample. During the 42 Martian days (sols) that it took to create and document the Three Forks depot, the rover drove 207.93 meters, dropped 10 sample RGAs, and took 4000 images. Completion of this sample depot ensures that there will be samples for the Mars Sample Return mission to transport back to Earth for the first time.
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ∼10 cm s−1 ...sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm s−1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments.
This dissertation presents an archival study of Hans Werner Henze and his work with an international roster of associates between 1955 and 1961 to broadly ask: how does artistic collaboration ...engender intimate relationships that challenge the strictures of social norms? Whereas previous scholarship seeks to identify how homosexual artists like Henze represented their dissident sexual identities in music, this project demonstrates that focusing on individual expression ignores the collaborative ethos documented in correspondence and other sources. Drawing from intensive archival research, I explain how Henze’s claims of finding compositional and personal freedom were contingent on his affiliation with artists who favored the conventions of the nineteenth century over high modernist aesthetics. These relationships are reconstructed in chapters on chamber music written for tenor Peter Pears and based on Hölderlin’s poetry; an orchestral song with poetry by Ingeborg Bachmann for the soprano Gloria Davy; ballets directed by Luchino Visconti and Frederick Ashton; and Henze’s first operatic venture with W. H. Auden and Chester Kallman. I argue that these works did not proffer a naïve withdrawal into the past, but rather staged the postwar crisis of artistic intelligibility within the domain of interpersonal attachment. To develop this argument, I place Henze’s collaborative works into conversation with philosopher Theodor W. Adorno’s contemporaneous writings on aesthetics to consider how intimate relationships offer both forms of creative inspiration as well as social exclusion.