2,552 research outputs found
Vacancy Reassessed
Since 1950, Philadelphia's population has been declining dramatically, by more than 30 percent. This rapid depopulation has led to the vacancy and abandonment of a large number of unmanaged residential lots and buildings. The future of Philadelphia rests on its ability to manage this decline, and in 1999, efforts were fragmented. This report highlights the barriers that many faced in trying to access vacant property and provides recommendations for a more strategic vision so that the city can create a significant and lasting impact
Wear-Resistant Boride Nanocomposite coating Exhibits Low Friction
Many components experience sliding or rotating contact with other parts or with their environments. Their performance often degrades during service because their dimensions are altered by wear. Furthermore, the friction at the contact surface wastes energy. To mitigate these problems, hard coatings may be applied to contact surfaces to increase their wear resistance, and surfaces are often covered with a lubricant to reduce friction. At Ames National Laboratory, a nanocomposite boron-aluminum-magnesium ceramic alloy coating (AlMgB14 + TiB2) has been developed that provides a superhard, wear-resistant surface that also has an exceptionally low coefficient of friction. Tests show that these boride coatings offer a combination of wear resistance and low friction unmatched by other hard mate - rials (e.g., tungsten carbide, cubic boron nitride, or diamondlike carbon)
Is there any Evidence for Regional Atmospheric 14C Offsets in the Southern Hemisphere?
Center for Accelerator Mass Spectrometry (CAMS) Tasmanian huon pine (Lagarostrobos franklinii) decadal measurements for the interval AD 745–855 suggest a mean interhemispheric radiocarbon offset (20 ± 5 yr), which is considerably lower than the previously reported mean interhemispheric offset for the last 2 millennia (44 ± 17 yr). However, comparable University of Waikato (Wk) New Zealand kauri (Agathis australis) measurements show significantly higher values (56 ± 6 yr), suggesting the possibility of a temporary geographic (intrahemispheric) offset between Tasmania, Australia, and Northland, New Zealand, during at least 1 common time interval. Here, we report 9 new Wk Tasmanian huon pine measurements from the decades showing the largest huon/kauri difference. We show statistically indistinguishable Wk huon and Wk kauri 14C ages, thus dispelling the suggestion of a 14C geographic offset between Tasmania and Northland
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Governance in niche development for a transition to a new mobility regime
Urban mobility is a difficult sustainability challenge; measures to reduce transport impacts produce only marginal reductions in overall energy use and CO2 emissions. Even fuel switch to electric vehicles and measures to manage traffic produce insufficient improvements. Seeking transport sustainability within the existing socio-technical regime involves policy approaches for dense cities to provide high-capacity, corridor-based public transport, expecting people to arrange their lives around such transport systems. Yet this socio-technical regime ill-fits modern mobility needs.
The reluctance to use public transport stems much from this 150 year old regime configuration. The social-technical landscape has shifted significantly: travel patterns are increasingly dispersed in space and time – not funnelled into traditional corridor peak-hour movements. The key is not getting people to return to travel patterns of 100 years ago, but in a transition to a socio-technical transport regime that delivers sustainability compatible with the 21st century social-technical landscape.
An opportunity may be emerging for socio-technical configurations in niche environments to effect transitions to alternate mobility futures. Autonomous vehicles are rapidly approaching market application. Since 2011, small autonomous pods have operated on segregated tracks at Heathrow Airport. In 2014 a similar system opened at the Suncheon Bay tourist area in South Korea.
Since 2011 there have been public street trials of autonomous vehicles in the USA and in 2015 they became street legal in the UK. The Milton Keynes (MK) ‘Pathfinder’ project focuses on two-seat pods which do not need segregated tracks, but will run on cycleways and footpaths, mixing with cyclists and pedestrians. Trials will start in 2015, on short distance links from the railway station to destinations in Central Milton Keynes. This project forms part of the wider Milton Keynes Future Cities Programme and Open University-led MK:Smart project.
This paper draws on these trials in MK to show through case study research how autonomous vehicles applications are moving beyond protected niches and, along with other developments, hold the potential to stimulate a major transition in public transport systems. The vehicles are small and each journey is individual to the passenger(s). Services do not run along corridor routes, like buses and trams, but are based on alternate rule-sets to the existing regime with individual journeys customised for each user. Such developments may therefore stimulate transition to totally different sorts of public transport systems and ultimately, socio-technical mobility regimes, by offering much more to users than any corridor system can provide. Rather than people adjusting their behaviour to bus routes, schedules and operating times, they travel directly, whenever they want, on services running 24/7. Thus these new regimes could be more compatible with lifestyle and economic trends that comprise 21st century socio-technical landscapes. As such, they provide credible alternatives to the private car, and so hold potential to deliver major sustainability gains.
But such transitions face major challenges from entrenched actors within the existing regime. Taxis, minicabs and bus operators would be threatened. If the Uber cab app is being blocked by incumbent actors, they look likely to be powerful opponents of autonomous vehicle based cab services. However, MK provides an interesting innovation context where there are several overlapping smart transport niches in different stages of development. As well as autonomous pods, demand responsive minibuses are planned and inductive changed electric buses are in service. If these projects build links to each other (niche accumulation), demonstrate economic value and reproduced beyond their original experimental spaces (niche proliferation), there is potential for them to overcome incumbent resistance. In Milton Keynes, these processes could be getting close to reaching critical mass, opening up the possibility of moving closer to radical regime transitions
The Willingness to Pay for Mortality Risk Reductions: A Comparison of the United States and Canada
We present results for two contingent valuation surveys conducted in Hamilton, Canada and the US to elicit WTP for mortality risk reductions. We find similar Value of Statistical Life estimates across the two studies, ranging from USD 930,000 to USD 4.8 million (2000 US dollars). WTP increases with risk reduction size, but varies little with respondent age: individuals aged over 70 years hold WTP values approximately one-third lower than other respondents. Respondent health status has limited effect on WTP. These results provide little or no evidence for adjusting VSL estimates used in policy analyses for the affected population’s age or health status.value of a statistical life, mortality risks, benefit-cost analysis
Evidence for suppressed mid-Holocene northeastern Australian monsoon variability from coral luminescence
Summer monsoon rainfall in northeastern (NE) Australia exhibits substantial interannual variability resulting in highly variable river flows. The occurrence and magnitude of these seasonal river flows are reliably recorded in modern inshore corals as luminescent lines. Here we present reconstructed annual river flows for two ~120 year mid-Holocene windows based on luminescence measurements from five cores obtained from three separate coral colonies. We were able to cross-date the luminescence signatures in four cores from two of the colonies, providing confidence in the derived reconstruction. Present-day NE Australian rainfall and river flow are sensitive to El Niño–Southern Oscillation (ENSO) variability, with La Niña (El Niño) events typically associated with wetter (drier) monsoon seasons. Thus, our replicated and annually resolved coral records provide valuable insights into the northern Australian summer monsoon and ENSO variability at a key period (6 ka) when greenhouse gas levels and ice sheet cover were comparable to the preindustrial period but orbital forcing was different. Average modern and mid-Holocene growth characteristics were very similar, suggesting that sea surface temperatures off NE Australia at 6 kyr were also close to present values. The reconstructed river flow record suggests, however, that the mid-Holocene Australian summer monsoon was weaker, less variable from year to year (possibly indicative of reduced ENSO variability), and characterized by more within-season flood pulses than present. In contrast to today, the delivery of moisture appears to have been dominated by eastward propagating convective coupled waves associated with the Madden-Julian Oscillation
Oxidation Kinetics of Nicrofer-6025HT for Use in Elevated Temperature Electrochemical Devices
Recent advances in high temperature electrochemical devices have prompted research into potential materials for component fabrication
The willingness to pay for mortality risk reductions: A comparison of the United States and Canada
We present the results of two contingent valuation surveys conducted in Hamilton, Canada and nation-wide in the US to elicit WTP for reductions in one's risk of death. We find that the Values of a Statistical Life implied by WTP are very similar across the two studies, and range from 4.8 million (2000 US dollars). WTP increases with the size of the risk reduction, but varies little with the age of the respondents: people older than 70 years of age hold WTP values that are about one-third lower than those of other respondents. This effect is significant in Canada but not in the US. Health status of the respondent has limited effect on WTP. In general, these results provide only little or no evidence that VSL used in environmental policy analyses should be adjusted for the age or health status of people whose lives are saved by environmental policies
The Willingness to Pay for Mortality Risk Reductions: A Comparison of the United States and Canada
We present results for two contingent valuation surveys conducted in Hamilton, Canada and the US to elicit WTP for mortality risk reductions. We find similar Value of Statistical Life estimates across the two studies, ranging from USD 930,000 to USD 4.8 million (2000 US dollars). WTP increases with risk reduction size, but varies little with respondent age: individuals aged over 70 years hold WTP values approximately one-third lower than other respondents. Respondent health status has limited effect on WTP. These results provide little or no evidence for adjusting VSL estimates used in policy analyses for the affected population's age or health status
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