5,610 research outputs found

    Rotary solenoid shutter drive assembly and rotary inertia damper and stop plate assembly

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    A camera shutter assembly composed of a pair of superposed opaque planar shutter blades, each having an aperture and being arranged for reciprocal linear movement is disclosed. A pair of rotary solenoids, each connected to one of the blades by a linkage and arranged to be actuated separately at a predetermined interval is provided. An inertia damper and stop plate is built into each solenoid to prevent rebound

    Dissecting the Functions of Conserved Prolines within Transmembrane Helices of the D2 Dopamine Receptor

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    G protein-coupled receptors (GPCRs) contain a number of conserved proline residues in their transmembrane helices, and it is generally assumed these play important functional and/or structural roles. Here we use unnatural amino acid mutagenesis, employing α-hydroxy acids and proline analogues, to examine the functional roles of five proline residues in the transmembrane helices of the D2 dopamine receptor. The well-known tendency of proline to disrupt helical structure is important at all sites, while we find no evidence for a functional role for backbone amide cis–trans isomerization, another feature associated with proline. At most proline sites, the loss of the backbone NH is sufficient to explain the role of the proline. However, at one site, P210^(5.50), a substituent on the backbone N appears to be essential for proper function. Interestingly, the pattern in functional consequences that we see is mirrored in the pattern of structural distortions seen in recent GPCR crystal structures

    Burnout And Job Satisfaction Of Behavior Technicians Working In Public Schools: A Quantitative Correlational Study

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    The purpose of this quantitative correlational study was to determine if the characteristics of burnout predict job satisfaction of behavior technicians in public schools. There was a need to examine if the high levels of burnout and low job satisfaction experienced by teachers and paraprofessionals that have resulted in high rates of attrition also impact behavior technicians in public school settings (Madigan & Kim, 2021; NCES, 2022; Sims, 2020; Skaalvik & Skaalvik, 2020). An online survey was created using REDCap consisting of the Maslach Burnout Inventory-Educators Survey (Maslach et al., 1996), the Minnesota Satisfaction Questionnaire short form (Weiss et al., 19a 77), and a demographic questionnaire. Recruitment occurred via social media and 78 behavior technicians participated in the study. Using multiple linear regression, the first finding of this study expanded the literature by suggesting that the characteristics of burnout are significantly impacted by overall job satisfaction. The second finding of this study was that behavior technicians in public schools did not meet all the requirements of burnout. Although, the results of this study did align with the research on behavior technicians in private settings, which found that high levels of depersonalization were not expected (Novack & Dixon, 2019). The third finding of this study indicated that intrinsic satisfaction significantly impacted personal accomplishment. School districts can utilize this study’s findings and future research to increase job satisfaction and decrease burnout experienced by behavior technicians who play such a valuable role in schools

    Vibration isolation for line of sight performance improvement

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    Diagrams of the Reaction Wheel Assembly (RWA) are presented along with charts and graphs illustrating jitter error model, induced vibration tests, radial displacement transfer function, and axial displacement power spectra density. The RWA isolator specification requirements are listed

    The Utility of Trouble: Maximizing the Value of Our Human Services Dollars

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    Outlines recommendations to standardize service delivery areas and consolidate area offices of the state's seven largest human services agencies, as well as to close antiquated institutions. Projects benefits such as improved accessibility and savings

    Experimental Persistence Probability for Fluctuating Steps

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    The persistence behavior for fluctuating steps on the Si(111)Si(111) (3×3)R300Al(\sqrt3 \times \sqrt3)R30^{0} - Al surface was determined by analyzing time-dependent STM images for temperatures between 770 and 970K. The measured persistence probability follows a power law decay with an exponent of θ=0.77±0.03\theta=0.77 \pm 0.03. This is consistent with the value of θ=3/4\theta= 3/4 predicted for attachment/detachment limited step kinetics. If the persistence analysis is carried out in terms of return to a fixed reference position, the measured persistence probability decays exponentially. Numerical studies of the Langevin equation used to model step motion corroborate the experimental observations.Comment: LaTeX, 11 pages, 4 figures, minor changes in References sectio

    Quasiperpendicular high Mach number Shocks

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    Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\tau}c, where {\tau}c is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA, a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.Comment: Accepted and Published in Physical Review Letters (2015
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