Plug-In Electric Vehicles: A Case Study of Seven Markets

At the current stage of plug-in electric vehicle (PEV) market development, sales rates vary dramatically across different countries and regions. For policy-makers and other stakeholders it is useful to understand the major social, economic, and policy drivers of vehicle adoption. This paper provides insights into the developing PEV markets in Norway, Netherlands, California, United States, France, Japan, and Germany. This is accomplished by applying a Technological Innovation System (TIS) approach that systematically identifies the role of different factors in promulgating new markets. Our comparison between markets shows that in all studied regions, sales of PEVs are supported through various types of government incentives, government resources, and other legitimation activities. However, regions with relatively strong PEV markets have a greater focus on market formation activities and relatively higher costs savings associated with operating an electric vehicle as compared to a conventional vehicle. To determine whether these factors are the primary determinants of PEV market shares, further research should be undertaken that also incorporates analysis related to the presence and government support for entrepreneurial activities related to electric vehicle innovation

Internal Combustion Engine Bans and Global Oil Use

Automotive transport represents one of the highest contributing sources of oil use, local air pollution, and greenhouse gas emissions. Several countries, notably including several European countries and China, have proposed bans on the sale of automotive internal combustion engine (ICE) vehicles as a means to abate these negative effects from the sector. Some cities and regions have already instituted restrictions on ICE vehicles. Larger, national bans have been discussed as a policy to begin in 2040. We consider the literature on proposed policies to ban ICE vehicles and develop scenarios to estimate the potential impacts of these proposed bans, to contribute to a peaking in oil demand and eventual reductions in CO2 emissions. We find that national level ICE car bans in key markets such as China and Europe in 2040 could reduce oil use by five million barrels a day (b/d) by 2050, under five percent of projected global oil use. A global ban would eliminate three times that level of oil use but would likely take several decades for its full impact is realized. Our findings suggest that other supporting policies beyond the bans alone might be necessary to trigger more rapid changes in markets and purchase behavior

Technology and Fuel Transition Scenarios to Low Greenhouse Gas Futures for Cars and Trucks in California

This study examines potential changes in car and truck powertrain technology and fuel mix that could enable a transition to low carbon futures, out to 2050, in California. We consider combinations of battery-electric and plug-in hybrid electric vehicles, hydrogen fuel cells, and advanced biofuels, including ethanol, diesel biofuels, and renewable natural gas, for internal combustion engines that could lead to 80% GHG reductions compared to 1990. We consider two main low-carbon scenarios—a high ZEV adoption case (ZEV) and a mixed (ZEV and Biofuel) adoption case (ZEV+B)—both relative to a business-as-usual (BAU) case. We find that achieving an 80% reduction in CO2 from cars and trucks (separately and together) appears feasible at relatively low cumulative cost, and with eventual likely net savings (as fuel savings exceed vehicle cost, mostly after 2030). However, the required rates of increase in sales of ZEV cars and trucks, and production volumes of advanced, low-carbon biofuels, will be quite challenging. Regarding ZEVs, we expect the greatest challenge to be for long-haul trucks, and we reduce the rate of sales increase for these as a result. In the ZEV scenario, all vehicle types reach 100% ZEV sales shares by 2050 (except long-haul trucks, which reach 80%). In the ZEV+B scenario, these targets are lower, but a strong ramp-up in advanced biofuel use is needed to achieve the 80% target, with commercial scale cellulosic production of ethanol and renewable diesel dominant by 2050. The net costs or savings of the scenarios are relatively low—on the order of ±$10-50 billion over the next 30 years—in relation to$4 trillion total spending in the BAU scenario. However, the additional costs of vehicle purchase run as high as $110 billion in the ZEV scenario, which will likely require substantial purchase incentives to overcome. Future research should examine how costs translate into policy needs (including generalized cost factors such as driving range) and the potential role, sourcing, and cost of advanced biofuels

Determinantal representations of hyperbolic plane curves: An elementary approach

If a real symmetric matrix of linear forms is positive definite at some point, then its determinant is a hyperbolic hypersurface. In 2007, Helton and Vinnikov proved a converse in three variables, namely that every hyperbolic plane curve has a definite real symmetric determinantal representation. The goal of this paper is to give a more concrete proof of a slightly weaker statement. Here we show that every hyperbolic plane curve has a definite determinantal representation with Hermitian matrices. We do this by relating the definiteness of a matrix to the real topology of its minors and extending a construction of Dixon from 1902. Like Helton and Vinnikov's theorem, this implies that every hyperbolic region in the plane is defined by a linear matrix inequality.Comment: 15 pages, 4 figures, minor revision

Constraints on the Atmospheric Circulation and Variability of the Eccentric Hot Jupiter XO-3b

We report secondary eclipse photometry of the hot Jupiter XO-3b in the 4.5~$\mu$m band taken with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We measure individual eclipse depths and center of eclipse times for a total of twelve secondary eclipses. We fit these data simultaneously with two transits observed in the same band in order to obtain a global best-fit secondary eclipse depth of $0.1580\pm 0.0036\%$ and a center of eclipse phase of $0.67004\pm 0.00013$. We assess the relative magnitude of variations in the dayside brightness of the planet by measuring the size of the residuals during ingress and egress from fitting the combined eclipse light curve with a uniform disk model and place an upper limit of 0.05$\%$. The new secondary eclipse observations extend the total baseline from one and a half years to nearly three years, allowing us to place an upper limit on the periastron precession rate of $2.9\times 10^{-3}$ degrees/day the tightest constraint to date on the periastron precession rate of a hot Jupiter. We use the new transit observations to calculate improved estimates for the system properties, including an updated orbital ephemeris. We also use the large number of secondary eclipses to obtain the most stringent limits to date on the orbit-to-orbit variability of an eccentric hot Jupiter and demonstrate the consistency of multiple-epoch Spitzer observations.Comment: 14 pages, 11 figures, published by Ap

Toric Degenerations of Fano Threefolds Giving Weak Landau-Ginzburg Models

We show that every rank one smooth Fano threefold has a weak Landau-Ginzburg model coming from a toric degeneration. The fibers of these Landau-Ginzburg models can be compactified to K3 surfaces with Picard lattice of rank 19. We also show that any smooth Fano variety of arbitrary dimension which is a complete intersection of Cartier divisors in weighted projective space has a very weak Landau-Ginzburg model coming from a toric degeneration.Comment: v3: minor corrections for final versio

Perception of academic learning environments and perceived impact on articulation of employability; a mixed methods study

This study reports on the findings of a mixed methods study that was undertaken to establish student perceptions of academic learning environments and the perceived impact of these on their articulation of employability skills. This was so student perspectives on employability could be used to inform reflection on pedagogic practices for their educators in higher education. Using a purposive sample of 250 students based in a recently modernised Sciences Complex Building in a Higher Education Institution (HEI), the study was cross sectional and descriptive by design. The social learning spaces researched were perceived by participants to provide optimal academic learning environments for their development of knowledge, skills and professionalism through certain signature pedagogies as they progressed through their programmes of study. Students also expressed the view that their acquisition of functional skills were significantly more important than any personal attributes/characteristics that they brought to programmes. What also mattered was whether the importance of certain graduate skills to the workplace had been made explicit to them so that they could see the relevance of their studies to practice. In defining ‘graduateness’, in employability terms the research Hayes et al. Perception of academic learning environments and perceived impact on articulation of employability skills Journal of Learning Development in Higher Education, Issue 10: November 2016 2 concluded that it was necessary to consider how it was shaped by the context of delivery of subject disciplines, stages of academic progression, and the use of social learning spaces, as they all had a significant impact on the perceptions students held about their potential employability upon completion of their academic programmes. Keywords: learning environments; employability; signature pedagogies; situated cognition; problem based learning

3.6 and 4.5 μ\mum Spitzer{\it Spitzer} Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b

We analyze full-orbit phase curve observations of the transiting hot Jupiters WASP-19b and HAT-P-7b at 3.6 and 4.5 $\mu$m obtained using the Spitzer Space Telescope. For WASP-19b, we measure secondary eclipse depths of $0.485\%\pm 0.024\%$ and $0.584\%\pm 0.029\%$ at 3.6 and 4.5 $\mu$m, which are consistent with a single blackbody with effective temperature $2372 \pm 60$ K. The measured 3.6 and 4.5 $\mu$m secondary eclipse depths for HAT-P-7b are $0.156\%\pm 0.009\%$ and $0.190\%\pm 0.006\%$, which are well-described by a single blackbody with effective temperature $2667\pm 57$ K. Comparing the phase curves to the predictions of one-dimensional and three-dimensional atmospheric models, we find that WASP-19b's dayside emission is consistent with a model atmosphere with no dayside thermal inversion and moderately efficient day-night circulation. We also detect an eastward-shifted hotspot, suggesting the presence of a superrotating equatorial jet. In contrast, HAT-P-7b's dayside emission suggests a dayside thermal inversion and relatively inefficient day-night circulation; no hotspot shift is detected. For both planets, these same models do not agree with the measured nightside emission. The discrepancies in the model-data comparisons for WASP-19b might be explained by high-altitude silicate clouds on the nightside and/or high atmospheric metallicity, while the very low 3.6 $\mu$m nightside planetary brightness for HAT-P-7b may be indicative of an enhanced global C/O ratio. We compute Bond albedos of 0 ($<0.08$ at $1\sigma$) and $0.38\pm 0.06$ for WASP-19b and HAT-P-7b, respectively. In the context of other planets with thermal phase curve measurements, we show that WASP-19b and HAT-P-7b fit the general trend of decreasing day-night heat recirculation with increasing irradiation.Comment: 22 pages, 29 figures, accepted by Ap

Climate and transportation policy sequencing in California and Quebec

We compare flexible low-carbon regulations in the transportation sector and their interaction and sequencing with greenhouse gas emissions trading systems in California and Quebec. As momentum builds for greater climate action, it is necessary to better understand how carbon markets and other low-carbon transportation policies influence one another. First, we demonstrate that emissions trading between California and Quebec has been asymmetric, with linking having little influence on carbon prices from California\u27s perspective but leading to a considerable cost reduction from the point of view of Quebec. Second, we present evidence that Quebec has replicated many of California\u27s low-carbon transportation policies that promote increased electric vehicle use, where Quebec has an advantage, while deferring to the Canadian federal government with regard to policies that incentivize the production of other low-carbon transportation fuels. Third, we demonstrate that while the stringency of the policy mix of carbon pricing and flexible transportation regulations has increased over time in both jurisdictions, the stringency of flexible regulations has been more aggressively ratcheted up and is expected to continue to dominate. Overall, our findings suggest that the policy sequence observed in California and Quebec can be attributed to the political economy benefits that the selected instruments confer to governments seeking to move from the middle towards the bottom of the clean technology experience curve. We discuss a number of important research questions and associated hypotheses emanating from our findings, which provide the basis for more in-depth studies involving a larger universe of cases and economic sectors

Spitzer Secondary Eclipse Observations of Five Cool Gas Giant Planets and Empirical Trends in Cool Planet Emission Spectra

In this work we present Spitzer 3.6 and 4.5 micron secondary eclipse observations of five new cool (<1200 K) transiting gas giant planets: HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured eclipse depths to the predictions of a suite of atmosphere models and to eclipse depths for planets with previously published observations in order to constrain the temperature- and mass-dependent properties of gas giant planet atmospheres. We find that the dayside emission spectra of planets less massive than Jupiter require models with efficient circulation of energy to the night side and/or increased albedos, while those with masses greater than that of Jupiter are consistently best-matched by models with inefficient circulation and low albedos. At these relatively low temperatures we expect the atmospheric methane to CO ratio to vary as a function of metallicity, and we therefore use our observations of these planets to constrain their atmospheric metallicities. We find that the most massive planets have dayside emission spectra that are best-matched by solar metallicity atmosphere models, but we are not able to place strong constraints on metallicities of the smaller planets in our sample. Interestingly, we find that the ratio of the 3.6 and 4.5 micron brightness temperatures for these cool transiting planets is independent of planet temperature, and instead exhibits a tentative correlation with planet mass. If this trend can be confirmed, it would suggest that the shape of these planets' emission spectra depends primarily on their masses, consistent with the hypothesis that lower-mass planets are more likely to have metal-rich atmospheres.Comment: 16 pages, 14 figures, accepted for publication in Ap