618 research outputs found
Conclusion: Popular Criminology Revisited
The concluding chapter discusses the significance of popular criminology, revisiting the key issues addressed in the different chapters of the book. It highlights the diversity of contemporary crime-and-deviance-related popular culture and provides an outlook for future research in the field
The development of structural adhesive systems suitable for use with liquid oxygen Annual summary report, 1 Jul. 1964 - 30 Jun. 1965
Preparation and testing of adhesive polyurethanes, polycarbonates, and other highy halogenated polymers for liquid oxygen compatibilit
Spatially-Resolved Spectra of the "Teacup" AGN: Tracing the History of a Dying Quasar
The Sloan Digital Sky Survey (SDSS) Galaxy Zoo project has revealed a number
of spectacular galaxies possessing Extended Emission-Line Regions (EELRs), the
most famous being Hanny's Voorwerp galaxy. We present another EELR object
discovered in the SDSS endeavor: the Teacup Active Galactic Nucleus (AGN),
nicknamed for its EELR, which has a handle like structure protruding 15 kpc
into the northeast quadrant of the galaxy. We analyze physical conditions of
this galaxy with long-slit ground based spectroscopy from Lowell, Lick, and
KPNO observatories. With the Lowell 1.8m Perkin's telescope we took multiple
observations at different offset positions, allowing us to recover spatially
resolved spectra across the galaxy. Line diagnostics indicate the ionized gas
is photoionized primarily by the AGN. Additionally we are able to derive the
hydrogen density from the [S II] 6716/6731 ratio. We generated two-component
photoionization models for each spatially resolved Lowell spectrum. These
models allow us to calculate the AGN bolometric luminosity seen by the gas at
different radii from the nuclear center of the Teacup. Our results show a drop
in bolometric luminosity by more than two orders of magnitude from the EELR to
the nucleus, suggesting that the AGN has decreased in luminosity by this amount
in a continuous fashion over 46,000 years, supporting the case for a dying AGN
in this galaxy independent of any IR based evidence. We demonstrate that
spatially resolved photoionization modeling could be applied to EELRs to
investigate long time scale variability.Comment: 38 pages, 11 figures, accepted for publication in the Astrophysical
Journa
A Hybrid Traffic Responsive Intersection Control Algorithm Using Global Positioning System and Inductive Loop Data
This paper compares the performance of a traffic responsive intersection controller which combines vehicle Global Positioning System (GPS) data and inductive loop information, to fixed-time, inductive loop, and GPS based controllers. The INRIX Global Traffic Scorecard reports that vehicles spent up to 42% of their travel time in congested traffic in 2016. Inefficient signal timing choices by isolated intersection controllers contribute to traffic delays, causing severe negative impacts on the economy and environment. Signal timings can be improved using vehicles’ GPS information combined with vehicle flow information from inductive loops to overcome the control action deficit at isolated intersections. This proposed new signal control algorithm is beneficial for traffic engineers and governmental agencies, as optimised traffic flow can reduce fuel consumption and emissions. The proposed traffic responsive Hybrid Vehicle Actuation (HVA) algorithm uses position and heading data from vehicle status broadcasts, and inferred velocity information to determine vehicle queue lengths and detect vehicles passing through the intersection to actuate intersection signal timings. When vehicle broadcast data are unavailable, HVA uses inductive loop data. Microscopic simulations comparing HVA to fixed-time control, inductive Loop Based Vehicle Actuation (Loop-VA) and GPS Based Vehicle Actuation (GPS-VA) on four urban road networks were carried out to see how the proposed HVA algorithm performs compared to existing control strategies. The results show that HVA is an effective alternative to traditional intersection control strategies, offering delay reductions of up to 32% over Loop-VA, for networks with 0−100% connected vehicle presence
Traffic Responsive Intersection Control Algorithm Using GPS Data
This paper reports on the performance of signalised intersection control using vehicle GPS information compared to fixed-time and inductive loop based control. Traffic congestion forecasts estimate an increase of about 60% in 2030. At present, poor choice of signal timings by isolated intersection controllers cause traffic delays that have enormous negative impacts on the economy and environment. Signal timings can be improved by using vehicles' GPS information to overcome the control action deficit at isolated intersections. This new signal control algorithm is beneficial for traffic engineers and governmental agencies, as traffic flow can be optimised and, hence, fuel consumption and emissions decreased. Under the open European Telecommunication Standards Institute (ETSI) Cooperative Awareness Message (CAM) framework, a traffic responsive GPS based vehicle actuation algorithm (GPS-VA) is proposed. GPS-VA uses position and heading data from vehicle status broadcasts, and inferred velocity information to determine vehicle queue lengths and detect vehicles passing through the intersection. The gathered information is then used to actuate intersection signal timings. Microscopic simulations comparing GPS-VA to fixed-time control and inductive loop based vehicle actuation (Loop-VA) on four urban road networks were performed to see how the proposed GPS-VA algorithm performs compared to existing control strategies. The results show that GPS-VA is an effective alternative to traditional intersection control strategies, offering delay reductions of up to 50% for connected vehicle fleet penetrations above 30%
A Multi-Wavelength Study of the Nature of Type 1.8/1.9 Seyfert Galaxies
We focus on determining the underlying physical cause of a Seyfert galaxy's
appearance as type a 1.8 or 1.9. Are these "intermediate" Seyfert types typical
Seyfert 1 nuclei with reddened broad-line regions? Or are they objects with
intrinsically weak continua and broad emission lines? We compare measurements
of the optical reddening of the narrow and broad-line regions with each other
and with the X-ray column derived from XMM-Newton 0.5-10 keV spectra to
determine the presence and location of dust in the line of sight. We also
searched the literature to see if the objects showed evidence for broad-line
variability, and determined if the changes were consistent with a change in
reddening or a change in the intrinsic ionizing continuum flux. We find that 10
of 19 objects previously classified as Seyfert 1.8/1.9s received this
designation due to their low continuum flux. In four objects the classification
was due to BLR reddening, either by the torus or dust structures in the
vicinity of the NLR; in the remaining five objects there is not sufficient
evidence to favor one scenario over the other. These findings imply that, in
general, samples of 1.8/1.9s are not suitable for use in studies of the gas and
dust in the central torus.Comment: 85 pages, accepted by Ap
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