3,967 research outputs found

    Determination of absorption length of CO2 and high power diode laser radiation for ordinary Portland cement

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    The laser beam absorption lengths of CO2 and a high power diode laser (HPDL) radiation for the ordinary Portland cement (OPC) surface of concrete have been determined. By employing Beer-Lambert’s law the absorption lengths for concrete of CO2 and a HPDL radiation were 470±22 μm and 177±15 μm respectively

    Let\u27s Get Free: Family Policing, Prison Industrial Complex Abolition, and Transcendent Love

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    My objective is to illuminate the painful, discriminatory, and avoidable effects of family separation underneath the American child welfare system and tradition of family policing. In this bureaucratically sprawling and interconnected system comprising of prisons, courts, social workers, and doctors, individual blame is assigned to parents, families, and communities facing long-running systemic problems. Family policing and the child welfare system have long been excluded from conventional discussions surrounding the harms of police and prisons. The everyday violence Black, Latinx, and low-income families face at the threat of/implementation of family separation - an immensely traumatic and agonizing process - must be understood through the lens of the US’ genocidal practices toward Indigenous and Black communities, and the prioritization of economic growth over general well-being. Like the logic of prisons, the child welfare system addresses only the effects and not root causes of harm. Policing and family policing are one and the same, operating through the same cruel, destructive, and discriminatory apparatuses and logics

    Dynamic Wireless QoS Analysis for Real-Time Control in URLLC

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    One of the major goals of ultra-reliable and low-latency communication (URLLC) is to enable real-time wireless control systems. However, it is challenging to use URLLC throughout the control process since a huge amount of wireless resource is needed to maintain the rigorous quality-of-service (QoS) in URLLC, i.e, ultra reliability and low latency. In this paper, our goal is to discuss that whether the extreme high QoS in URLLC leads to better control performance than low QoS during the control process. This is expected to provide a guideline on the usage of the URLLC throughout the control process dynamically. Specifically, we first investigate the relationship between the URLLC QoS and control performance. Then, we discuss the effect of different communication QoS on the control performance. Our results show that the rigorous QoS in URLLC and a low QoS can be used dynamically throughout the control process with high system performance

    Gamma-ray upper limits on magnetars with 6 years of Fermi-LAT observations

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    We report on the search for gamma-ray emission from 20 magnetars using 6 years of Fermi, Large Area Telescope (LAT) observations. No significant evidence for gamma-ray emission from any of the currently-known magnetars is found. We derived the most stringent upper limits to date on the 0.1--10 GeV emission of Galactic magnetars, which are estimated between ∼10−12−10−11\sim10^{-12}-10^{-11} erg s−1^{-1} cm−2^{-2}. Gamma-ray pulsations were searched for the four magnetars having reliable ephemerides over the observing period, but none were detected. On the other hand, we also studied the gamma-ray morphology and spectra of seven Supernova Remnants associated or adjacent to the magnetars.Comment: 22 pages, 4 figures, 2 tables, submitted to Ap

    Gamma-ray emission from PSR J0007+7303 using 7 years of Fermi Large Area Telescope observations

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    Based on more than seven years of Fermi Large Area Telescope (LAT) Pass 8 data, we report on a detailed analysis of the bright gamma-ray pulsar (PSR) J0007+7303. We confirm that PSR J0007+7303 is significantly detected as a point source also during the off-peak phases with a TS value of 262 (∼\sim 16 σ\sigma). In the description of PSR J0007+7303 off-peak spectrum, a power law with an exponential cutoff at 2.7±\pm1.2±\pm1.3 GeV (the first/second uncertainties correspond to statistical/systematic errors) is preferred over a single power law at a level of 3.5 σ\sigma. The possible existence of a cutoff hints at a magnetospheric origin of the emission. In addition, no extended gamma-ray emission is detected compatible with either the supernova remnant (CTA 1) or the very high energy (> 100 GeV) pulsar wind nebula. A flux upper limit of 6.5×\times10−12^{-12} erg cm−2^{-2} s−1^{-1} in the 10-300 GeV energy range is reported, for an extended source assuming the morphology of the VERITAS detection. During on-peak phases, a sub-exponential cutoff is significantly preferred (∼\sim11 σ\sigma) for representing the spectral energy distribution, both in the phase-averaged and in the phase-resolved spectra. Three glitches are detected during the observation period and we found no flux variability at the time of the glitches or in the long-term behavior. We also report the discovery of a previously unknown gamma-ray source in the vicinity of PSR J0007+7303, Fermi J0020+7328, which we associate with the z = 1.781 quasar S5 0016+73. A concurrent analysis of this source is needed to correctly characterize the behavior of CTA 1 and it is also presented in the paper.Comment: 26 pages, 10 figures, 4 tables; Accepted for publication in Ap
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