3,612 research outputs found
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European perspectives on a new fiscal framework for transport
This chapter presents an overview of changes in transport taxation in European countries to promote more sustainable transport. A number of changes in the framework of car taxation have resulted in some useful environmental gains. However, these changes are limited because the transport tax system has been designed to produce a substantial income from internal-combustion-engine vehicles in an easily administered form. A major restructuring of transport taxation is required to fully address a different goal – that of stimulating improvements to environmental performance. A generalised road user charging-based system could be the way forward. Such a system is now seen by several European countries and some USA states as the transport taxation regime for the 21st century.
Tax regime change is emerging onto the transport policy agenda as a vital long-term strategy. Largely by default, transport policy-makers are coming to realise that road taxation regime change is inevitable if traffic and congestion management is to be a reality. The way we taxed vehicles and fuel in the 20th century is simply not appropriate for the transport challenges we face today
Can a light technipion be discovered at the Tevatron if it decays to two gluons?
In multiscale and topcolor-assisted models of walking technicolor, light,
spin-one technihadrons can exist with masses of a few hundred GeV; they are
expected to decay as rho_T -> W pi_T. For technirho masses ~200 GeV and
technipion masses ~100 GeV, the process pbar p -> rho_T -> W pi_T has a cross
section of about a picobarn at the Tevatron. We demonstrate the detectability
of this process with simulations appropriate to Run II conditions, for the
challenging case where the technipion decays dominantly into two gluons.Comment: 11 pages, LaTeX, including figure
Flexibility – Designing for Optionality on Warehouse Modernization Projects
The Department of Defense relies upon a vast network logistics facilities and capabilities across the planet. Assets are largely sourced from the Defense Logistics Agency, which is considering a modernization project for their Eastern Distribution Center (EDC). It handles 25% of all materials that DLA supplies, and the facility is antiquated. In order to maximize their investment, flexible options for the modernization should be considered. This research was conducted as a case study of the EDC in order to develop a framework of flexibility for DoD decision makers going forward. This case study gathers subject matter expert knowledge from government and commercial decision makers to develop a framework for DoD managers moving forward into the future
Examining the Relationship Between Principal Leadership and School Climate
The purpose of this quantitative study was to explore the relationship between transformative school principal leadership and school climate. The population of this study consisted of two middle schools with grades ranging from six through eight and one high school with grades ranging from nine through twelve. These schools are within the state of Texas. Quantitative data were obtained by using two instruments, the Principal Leadership Questionnaire (Jantzi & Leithwood, 1996) and the School Climate Assessment Instrument (Alliance for the Study of School Climate, 2014), and evaluated to determine if (a) correlations exist between the factors of transformational leadership and school climate, (b) if any predictive linear relationships exist between the factors of transformational leadership and school climate, and (c) if the individual school site, employment role, and tenure influence school climate in the tested Texas schools.
This study found that there was: (a) a statistically significant relationship between the six factors of transformational leadership and the leadership decisions factor of school climate, and (b) that the factors of transformational leadership influenced the factors of school climate, and (c) that the school site was the most significant predictor of school climate
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Taxation Futures for Sustainable Mobility: final report to the ESRC
The existing transport tax and charging regime has stimulated limited behavioural change and has been politically problematic (as demonstrated by the September 2000 fuel duty protests). This project synthesised a range of research that has explored ways in which road user charging could replace the present regime based on taxing fuels and car ownership. In 2002, when this project was proposed, this was a fringe transport policy issue. Throughout 2003 the subject achieved a sudden prominence, with a government working party being established to explore the possibility of long-term area-wide road user charging.
A tax regime change towards a car road user charge for cars has occurred, or is being considered, in societies as contrasting as Oregon State in the USA, the Netherlands, Switzerland and the UK, reflecting a range of policy considerations. For the UK, these include: the ongoing failure of transport policy measures to achieve adequate cuts in congestion and emissions; the success of the London Congestion Charge; the rise in the cost of transport policy interventions; the reduction in Treasury income of eco-reforms to the current tax regime; and the difficulties of, and equity issues relating to, taxing fuel in a future multi-fuel transport sector.
The project developed tax change scenarios in conjunction with the project's user group (including policymakers, NGOs and researchers). Five scenarios were modelled using an adaptation of the Dutch Mobility Explorer program. An 'opt-in' transitional policy mechanism involved replacing VED with a small flat-rate kilometre charge for cars of 0.77 p/km. The model suggested it would have little policy impact, but could be used to familiarise car drivers with the concept of a distance charge. A fiscally neutral scenario involved the replacement of VED and Fuel Duty with a banded kilometre charge for cars of between 2.3 and 8.5 p/km (varied by the environmental performance of the vehicle type). This induced little behaviour change, reducing car driver mobility by only 4%. A further scenario, restored the tax revenues lost from post-2000 tax changes, generating an additional £3 billion or £6b per annum. These reduced car driver mobility by 9% - 14%, and total CO2 emissions were predicted to drop by 6% - 9% by 2015, compared to the base scenario.
The type of change involved in the revenue-raising scenarios is significant. There would be only a small increase in the use of public transport, with the predominant response being the better utilisation of cars with higher occupancy and more linking of trips to cut distances driven.
The project results suggest that road user charging may deliver more revenue stability than fuel taxation. However, clarity is needed over the policy goals – congestion reduction, emission reduction, revenue stability – for a national road user charge, because the goals are not necessarily complementary. It should also be emphasised that a change of tax regime would not remove the need the hard political decisions in this area
A revision of North American Cryphalini (Scolytidae, Coleoptera)
The Oryphalin1 are cosmopolitan in distribution~
Although the great majority of genera and species occur in the tropics. Procryphalus is confined to the coniferous forests of Canada and the high mountains of the western United States; Cryphalus has a similar North American distribution,but also occupies the same habitat in Eurasia. Cryphalomorphus, Hypocryphalus, and Cryptocarenus are tropical genera and reach only to the subtropical southern tip of Florida and possibly of Texas
An analytical model for gas overpressure in slug-driven explosions:insights into Strombolian volcanic eruptions
Strombolian eruptions, common at basaltic volcanoes, are mildly explosive events that are driven by a large bubble of magmatic gas (a slug) rising up the conduit and bursting at the surface. Gas overpressure within the bursting slug governs explosion dynamics and vigor and is the main factor controlling associated acoustic and seismic signals. We present a theoretical investigation of slug overpressure based on magma-static and geometric considerations and develop a set of equations that can be used to calculate the overpressure in a slug when it bursts, slug length at burst, and the depth at which the burst process begins. We find that burst overpressure is controlled by two dimensionless parameters: V', which represents the amount of gas in the slug, and A', which represents the thickness of the film of magma that falls around the rising slug. Burst overpressure increases nonlinearly as V' and A' increase. We consider two eruptive scenarios: (1) the "standard model," in which magma remains confined to the vent during slug expansion, and (2) the " overflow model," in which slug expansion is associated with lava effusion, as occasionally observed in the field. We find that slug overpressure is higher for the overflow model by a factor of 1.2-2.4. Applying our model to typical Strombolian eruptions at Stromboli, we find that the transition from passive degassing to explosive bursting occurs for slugs with volume >24-230 m(3), depending on magma viscosity and conduit diameter, and that at burst, a typical Strombolian slug (with a volume of 100-1000 m(3)) has an internal gas pressure of 1-5 bars and a length of 13-120 m. We compare model predictions with field data from Stromboli for low-energy " puffers," mildly explosive Strombolian eruptions, and the violently explosive 5 April 2003 paroxysm. We find that model predictions are consistent with field observations across this broad spectrum of eruptive styles, suggesting a common slug-driven mechanism; we propose that paroxysms are driven by unusually large slugs (large V')
A Quillen model structure for Gray-categories
A Quillen model structure on the category Gray-Cat of Gray-categories is
described, for which the weak equivalences are the triequivalences. It is shown
to restrict to the full subcategory Gray-Gpd of Gray-groupoids. This is used to
provide a functorial and model-theoretic proof of the unpublished theorem of
Joyal and Tierney that Gray-groupoids model homotopy 3-types. The model
structure on Gray-Cat is conjectured to be Quillen equivalent to a model
structure on the category Tricat of tricategories and strict homomorphisms of
tricategories.Comment: v2: fuller discussion of relationship with work of Berger;
localizations are done directly with simplicial set
Rheology contrast in the shallow conduit and eruption dynamics at Stromboli:insights from analogue experiments
Strombolian eruptions result from the bursting of large individual gas pockets (slugs) in a low-viscosity magma. Scaled experimental investigations of the processes involved have generally been carried out in single Newtonian liquids, and have explored the dynamics of slug expansion, burst and their control on the generation of geophysical signals. Such studies provide a thorough first order investigation of the mechanisms involved, but little attention has been given so far to the processes of slug expansion and burst in more complex fluids. Observations at Stromboli show that obstructions in the conduit (due to, e.g., partial wall collapse or fall back in the vent of ejecta) can generate a viscous impedance within the upper portion of magma, leading to more violent eruptions. Petrological and textural data also suggest the presence of different magma rheologies due to degassing driven crystallisation. Here we use laboratory experiments to investigate the role of a vertical contrast in magma rheology on the dynamics of slug expansion and burst, and the resulting geophysical signals. The analogue materials used are silicon oil ( = 0.1 Pa*s) capped with castor oil ( = 1 Pa*s) to give a viscosity contrast of 10. Vertical pressure gradient is scaled by reducing the pressure at the top of the experimental apparatus with a vacuum pump. Pressure variations are measured at the top and bottom of the apparatus and correlated with high-speed imagery of the experiments and the results compared with control experiments using single liquid. The thickness of the viscous plug was varied along with the gas volumes and the gas pressure at the liquid surface (1 kPa, 3 kPa and 300 Pa). Our results show that the thickness of the viscous plug strongly controls slug expansion and systematically changes the magnitude of the associated pressure transients, favouring a more impulsive and energetic pressure release compared with the control experiments. The intrusion of slugs in the viscous plug leads to complex flow configurations: small slugs can enter the viscous plug either partly or wholly before bursting. Large slugs lead to complex interaction between the two liquids: the intrusion of the low-viscosity liquid into the high-viscosity one provides a preferential pathway for the slugs. The viscous plug generates an annulus of variable thickness acting as a narrowing of the tube. Furthermore, higher gas volumes can induce both instabilities in the falling film and the disruption of the viscous annulus, clots of which are brought to the top by the slug
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