4,053 research outputs found

    Transport: Introduction

    Get PDF
    Space transportation requirements for the NASA baseline scenario for future space missions are discussed. Spacecraft/propulsion technologies required for surface-to-orbit, orbit-to-orbit, and surface (lunar) transportation are addressed

    Methodology development for evaluation of selective-fidelity rotorcraft simulation

    Get PDF
    This paper addressed the initial step toward the goal of establishing performance and handling qualities acceptance criteria for realtime rotorcraft simulators through a planned research effort to quantify the system capabilities of 'selective fidelity' simulators. Within this framework the simulator is then classified based on the required task. The simulator is evaluated by separating the various subsystems (visual, motion, etc.) and applying corresponding fidelity constants based on the specific task. This methodology not only provides an assessment technique, but also provides a technique to determine the required levels of subsystem fidelity for a specific task

    Observations of Hierarchical Solar-Type Multiple Star Systems

    Get PDF
    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color-magnitude diagram and discuss each multiple system individually.Comment: Accepted to Astronomical Journa

    Perceptions of Diabetes Distress and Counseling During the Pandemic - Rural Provider Perspectives

    Get PDF
    Introduction West Virginia is an Appalachian rural state that ranks highest in the nation in the prevalence of diabetes (16.2%). The COVID-19 pandemic impacted routine diabetes care. As a result, individuals experienced diabetes distress over the physical and psychological burdens of diabetes management. In rural and medically underserved counties (71%), diabetes care is often provided by primary care physicians. However, healthcare providers’ perspectives on diabetes distress and related counseling to address them are unclear. This cross-sectional study’s objective was to explore healthcare providers’ (HCP) perspectives regarding their patient’s diabetes distress and how it guided their counseling for diabetes self-care during clinic visits. Methods Participants included 72 West Virginia Practice-Based Research Network members who completed an online survey in June 2021. However, only HCPs (physicians and advanced practice professionals, N=59) were included in the analysis. Data was collected using validated measures of diabetes distress, health literacy, and counseling for diabetes self-care. Results HCPs frequently evaluated their patients’ diabetes distress and health literacy levels to guide their conversations. Furthermore, HCPs perceived high diabetes distress (58.5%) in their patients during the pandemic and provided optimal counseling, especially for healthier diets and improved physical activity (98%). Multivariable logistic regression showed a significant reduction in diabetes distress with diabetes counseling. Results also showed HCPs were less likely (65%) to counsel for diet and 4.2 times more likely to counsel for exercise for patients with high diabetes distress. Conclusion Formal training of providers on the importance of assessing diabetes distress and tailoring their counseling can further improve diabetes management

    Cuprate addition to a 6-substituted pentafulvene: preparation of sec-alkyl substituted titanocene dichlorides and their biological activity

    Get PDF
    The copper-catalysed (10 mol-% CuBr·SMe2, CuCN·LiCl or CuI/PPh3) addition of RMgBr to the pentafulvene 1-(cyclopenta-2,4-dien-1-ylidenemethyl)-2-methoxybenzene allows the formation of cyclopentadienyl derivatives with α-CHR(2-MeOPh) sidechains (R = Me, Et, nBu, iBu, allyl, Ph) without H– transfer. The deprotonation of these sec-alkyl-substituted cyclopentadienyls followed by the addition of TiCl4 allows the isolation of TiCl2{η5-C5H4CHR(2-OMePh)} as rac/meso mixtures that show activity against human colon, breast and pancreatic cell lines (GI50 2.3–42.4 μM)

    Know the Star, Know the Planet. III. Discovery of Late-Type Companions to Two Exoplanet Host Stars

    Get PDF
    We discuss two multiple star systems that host known exoplanets: HD 2638 and 30 Ari B. Adaptive optics imagery revealed an additional stellar companion to both stars. We collected multi-epoch images of the systems with Robo-AO and the PALM-3000 adaptive optics systems at Palomar Observatory and provide relative photometry and astrometry. The astrometry indicates that the companions share common proper motion with their respective primaries. Both of the new companions have projected separations less than 30 AU from the exoplanet host star. Using the projected separations to compute orbital periods of the new stellar companions, HD 2638 has a period of 130 yrs and 30 Ari B has a period of 80 years. Previous studies have shown that the true period is most likely within a factor of three of these estimated values. The additional component to the 30 Ari makes it the second confirmed quadruple system known to host an exoplanet. HD 2638 hosts a hot Jupiter and the discovery of a new companion strengthens the connection between hot Jupiters and binary stars. We place the systems on a color-magnitude diagram and derive masses for the companions which turn out to be roughly 0.5 solar mass stars.Comment: Accepted to Astronomical Journal, 16 pages, 5 Figure

    The Role of an Urban Tallgrass Prairie Remnant in Conservation: A Case Study in Central Iowa (USA)

    Get PDF
    Although more than 85% of Iowa (USA) was covered by tallgrass prairie at the time of settlement by Europeans in the early 19th century, less than 0.1% remains. The Richard W. Pohl State Preserve at Ames (IA) High School, surrounded on three sides by structures, roads, and other development, protects 4 ha of tallgrass prairie. The preserve, commonly referred to as Ames High Prairie (AHP), was grazed but never plowed under private ownership until its acquisition by the Ames School District in 1959. Although considered for development as a parking lot or football field in the 1960s, the residents of Ames voted in 1970 to award The Nature Conservancy (TNC) a 49-year lease to the property (until 2019). This preserve, almost completely open in the 1930s, has been subject to numerous threats, including encroachment by woody plants, entry of non-native and invasive plant species associated with human activity, and erosion associated with storm water runoff, sewer line repair, foot and bike traffic, and major flood events. Recent management activities at AHP, conducted by volunteer land stewards, high school and college students, TNC summer interns, and private contractors, has consisted of controlled burns, cutting and herbicide treatment of encroaching woody plants, manual removal and herbicide treatment of invasive herbaceous plants, and sowing of seeds (collected on site) into reopened areas. Three vascular plant inventories of the 8.9 ha preserve (1966, 1995, current study) have documented the occurrence of 465 taxa (329 native) at AHP, including 5 Iowa special concern species. This flora includes 147 native prairie plant taxa, which ranks 8th in comparison with the 26 other (and mostly larger) prairies protected as state preserves in Iowa. As a vegetation remnant, AHP protects tallgrass prairie taxa and their gene pools, maintains an example of historically abundant (but now scarce) tallgrass prairie vegetation, and provides citizens an opportunity to experience prairie
    • …
    corecore