550 research outputs found

    Homelessness and De-Institutionalization

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    The nation faces a social problem caused by the discharge of chronic mentally ill patients to the community through a process known as deinstitutionalization. Frequently hcmeless, these individuals require many community supports and have aroused public sentiment. A review of current literature is used to validate these observations. The University of Connecticut has initiated a practicn training project to educate case managers in serving the hcmeless mentally ill. From an historical perspective, this study outlines the evolution of deinstitutionalization and the identification of treatment models applied to this process

    Identification of Resonant Frequencies in LIGO-like Suspension with Finite-Element Modeling

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    Following the upgrades to Advanced LIGO (aLIGO), measurements were made of the detector suspensions' frequency response characteristics. While most resonant frequencies could be identified with simple mechanical models, such as the fiber vibration modes, some were unexplained. Using a finite element model of the quadruple pendulum suspension, we search for and identify lines from unknown sources. The present work focuses on two resonant lines observed in the Upper Intermediate Mass as examples of this technique. Our simulations suggest a common source for these lines, which could be accounted for in a redesign. By modeling these response frequencies, we can examine the motion of individual components, and suggest methods to reduce their amplitude, alter their frequency, or eliminate them in future gravitational wave detector designs

    Miniature Optical Communications Transceiver (MOCT)

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    This project will advance the technology readiness of the Miniature Optical Communications Transceiver (MOCT) from TRL 3 to TRL 4. MOCT consists of a novel software-defined pulse modulator (SDPM),integrated laser system, and avalanche photodetection system, and is designed for optical communications between small spacecraft, including CubeSats, using a pulse position modulation (PPM) scheme. PPM encodes data in the timing of optical pulses with respect to a set of timing windows known as slots. The MOCT design focuses on power-efficiency making it particularly interesting for small satellites. We have demonstrated in the laboratory that this technology can generate shorter than 1 nanosecond-wide 1550 nanometer (nm) optical pulses with better than 50 picosecond (ps) timing accuracy. The timing resolution of this system is roughly a factor of four better than previously flown systems, meaning that it can transmit more bits of data with each optical pulse. Because this technology can both generate and time stamp the arrival of short optical pulses with 50 ps precision, it simultaneously provides power efficient communications and relative ranging between small spacecraft at the centimeter (cm) level

    Astro2020 White Paper: A Direct Measure of Cosmic Acceleration

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    Nearly a century after the discovery that we live in an expanding Universe, and two decades after the discovery of accelerating cosmic expansion, there remains no direct detection of this acceleration via redshift drift - a change in the cosmological expansion velocity versus time. Because cosmological redshift drift directly determines the Hubble parameter H(z), it is arguably the cleanest possible measurement of the expansion history, and has the potential to constrain dark energy models (e.g. Kim et al. 2015). The challenge is that the signal is small - the best observational constraint presently has an uncertainty several orders of magnitude larger than the expected signal (Darling 2012). Nonetheless, direct detection of redshift drift is becoming feasible, with upcoming facilities such as the ESO-ELT and SKA projecting possible detection within two to three decades. This timescale is uncomfortably long given the potential of this cosmological test. With dedicated experiments it should be possible to rapidly accelerate progress and detect redshift drift with only a five-year observational baseline. Such a facility would also be ideal for precision radial velocity measurements of exoplanets, which could be obtained as a byproduct of the ongoing calibration measurements for the experiment.Comment: White paper submitted to the Astro2020 Decadal Survey. 6 page
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