The analysis of vehicle cold start emissions has become an issue of utmost importance since the cold phase occurs mainly in urban context, where most of the population lives. In this sense, this ...research work analyzes and quantifies the impacts of cold start in urban context using naturalistic driving data. Furthermore, an assessment of the influence of ambient temperature on the percentage of time spent on cold start was also performed.
Regarding the impacts of ambient temperature on cold start duration, a higher percentage of time spent on cold start was found for lower ambient temperatures (80% of the time for 0°C and ~50% for 29°C). Results showed that, during cold start, energy consumption is >110% higher than during hot conditions while emissions are up to 910% higher. Moreover, a higher increase on both energy consumption and emissions was found for gasoline vehicles than for diesel vehicles. When assessing the impacts on a city perspective, results revealed that the impacts of cold start increase for more local streets.
The main finding of this study is to provide evidence that a higher increase on emissions occurs on more local streets, where most of the population lives. This kind of knowledge is of particular relevance to urban planners in order to perform an informed definition of public policies and regulations to be implemented in the future, to achieve a cleaner and healthier urban environment.
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•Extensive real world data collection to evaluate vehicle cold start running.•Assess the impacts of cold start running on the city perspective.•Lower average ambient temperatures increases the cold start running duration.•Increase of 110% on energy consumption and up to 910% on emissions for cold start.•The impact of cold start is higher on more densely populated areas.
•Cost-benefit analysis to a carsharing system.•Different vehicle technology in the carsharing fleet.•System configuration with and without vehicle relocations.•Environmental analysis of the ...carsharing system.
In this study we propose a cost-benefit analysis method to assess the performance of carsharing systems with conventional and alternative vehicles, taking into account the different stakeholders’ financial costs as well as the environmental benefits. The method was applied to simulated mobility data for the case study of Lisbon, Portugal.
Regarding operators’ annual profit, only diesel vehicles promised a profit of 544 thousand euros per year without vehicle relocations, and 646 thousand with relocations. Electric vehicles would lead to estimated losses of 1.1 million euros per year without vehicle relocations, which could go down to 890 thousand euros of financial losses with relocations. Fleets using two-seater gasoline vehicles can also achieve positive profit if they implement relocations.
When analyzing the performance of carsharing systems with no relocations, only electric vehicles showed positive environmental impacts. However, when vehicles are relocated, the environmental benefit decreases because of the added kilometers. Additional scenarios for carsharing with electric vehicles were performed: free parking charges; duty-free costs; and depreciation costs similar to those of diesel vehicles. All the analyses showed positive annual net profits for the operator, indicating that policies might promote the use of cleaner vehicles.
From the travellers’ perspective, the overall balance is always negative because the price paid for the carsharing system is not offset by the savings of not using a private car or public transport. This happened even if we add the more subjective benefit of the added utility of an extra transport option to the current mode choice.
•Assess the impacts of road grade and driving aggressiveness on fuel consumption.•Extensive real world driving data from a sample of 47 drivers.•Road grade and aggressive driving impact fuel ...consumption rates significantly.•Driving aggressiveness correlates with fuel consumption differently across road grades.•The impact of driving aggressiveness tends to be higher on urban streets.
The transportation sector contributes significantly to energy consumption with inherent consequences in terms of emission of local pollutants, which is associated with air quality deterioration. Considering that driving behavior significantly influences fuel consumption, this work goal was to assess how driving aggressiveness is influenced by the type of road and by the road grade, and consequently their impacts on fuel consumption. For that purpose, 47 drivers were monitored in the Lisbon Metropolitan Area during 6 months, allowing building an extensive 1 Hz real world driving database (∼33,000 trips, totalizing 28.9 million seconds). This database provided distinctive and representative data, allowing assessing the impacts on fuel consumption rates. Results showed that both road context and aggressive driving behavior impact fuel consumption rates significantly. However, for non-aggressive driving behavior fuel consumption rates increased more with road grade increments (up to 3 times) than for aggressive driving behavior (up to 2.3 times). Furthermore, this study results demonstrated that aggressiveness influences fuel consumption differently across road grades. Aggressiveness impacts are higher for lower road grades, with increased fuel consumption rates by up to 255%. The key findings associated to this research work are that aggressiveness on roads with lower grades tends to correlate with higher percent increase on fuel consumption for all speed ranges. Moreover, aggressiveness seems to correlate with higher fuel consumption on urban streets. Consequently, a reduction in driving under these conditions can offer significant savings in fuel consumption.
•We report background levels of heavy metals in the sediments of Parnaíba River Delta.•The measured values were compared with sediment quality standards.•The Delta is characterized by the presence of ...low levels of heavy metals in sediments.•The metal concentrations suggest a low probability of adverse effects to the local aquatic biota.
This study establishes regional background levels and upper thresholds (geochemical baseline) for Zn, Cu, Pb, Cr, Mn, and Fe from surface samples and profiles taken in 16 sedimentary environments of the Parnaíba River Delta estuary, NE–Brazil. Three approaches were applied to evaluate metal contamination: normalization to Fe, statistical analysis and sediment quality guidelines or environmental assessment criteria (TEL–PEL). Metal concentrations in sediments ranged from 2.4 to 31mgZnkg−1, 1.5 to 48mgCukg−1, 1.3 to 28mgPbkg−1, 1.5 to 38mgCrkg−1; 145 to 1,356mgMnkg−1, and 0.3% to 2.5% for Fe. All metals showed positive correlations with the <0.63μm sediment fraction, indicating a significant association with rich lithogenic sources of iron oxide–hydroxides. Results suggest a low probability of adverse effects to the local aquatic biota. The background values of the area were lower than those reported for other areas of the northeastern coast of Brazil.
Considering the role of behavioral and environmental factors on road accidents and traffic intensities, the characterization of vehicle use and driver behavior opens new opportunities for safety ...improvements and energy savings. Thus, the objective of this work was to identify driving behavior patterns for several driving environments (based on street level and weather conditions) from real-world driving data and to analyze how these driving environments influenced driving behavior. The case study for this work was Lisbon, Portugal, where driving data from 47 drivers were collected with on-board data loggers for at least 6 months. The results show that both street level and weather conditions impact driving behavior significantly. However, while for rainy conditions, the results provide evidence that drivers tend to drive more calmly (average speed is 22% lower for heavy rain than without rain, while positive and negative accelerations decrease by 8% and 11%, respectively), when considering the influence of street level more local streets (level 2, 3 and 4 streets) are the ones that present more aggressive driving patterns in terms of acceleration (30–40% increase from level 1 to level 4 streets). This work contribution regards the quantification of the impacts of driving environment on driving behavior, providing evidence that rain conditions significantly affect driving behavior, leading drivers to adjust their driving behavior to the driving environment. However, regarding street level, the differences found in driving behavior seem to be more a consequence of the infrastructure characteristics than an adjustment of driving behavior.
•Development of methodology to assess economic feasibility of EV parking spaces.•NPV break-even is more “easily” reached for higher parking prices.•Reductions of up to 14% with increasing occupancy ...rates were observed.•52–86% Reductions in WTW energy and environmental impacts were obtained.
The transportation sector faces increasing challenges related to energy consumption and local and global emissions profiles. Thus, alternative vehicle technologies and energy pathways are being considered in order to overturn this trend and electric mobility is considered one adequate possibility towards a more sustainable transportation sector.
In this sense, this research work consisted on the development of a methodology to assess the economic feasibility of deploying EV charging stations (Park-EV) by quantifying the tradeoff between economic and energy/environmental impacts for EV parking spaces deployment. This methodology was applied to 4 different cities (Lisbon, Madrid, Minneapolis and Manhattan), by evaluating the influence of parking premium, infrastructure cost and occupancy rates on the investment Net Present Value (NPV). The main findings are that the maximization of the premium and the minimization of the equipment cost lead to higher NPV results. The NPV break-even for the cities considered is more “easily” reached for higher parking prices, namely in the case of Manhattan with the higher parking price profile. In terms of evaluating occupancy rates of the EV parking spaces, shifting from a low usage (LU) to a high usage (HU) scenario represented a reduction in the premium to obtain a NPV=0 of approximately 14% for a 2500€ equipment cost, and, in the case of a zero equipment cost (e.g. financed by the city), a NPV=0 was obtained with approximately a 2% reduction in the parking premium. Moreover, due to the use of electric mobility instead of the average conventional technologies, Well-to-Wheel (WTW) gains for Lisbon, Madrid, Minneapolis and Manhattan were estimated in 58%, 53%, 52% and 75% for energy consumption and 66%, 75%, 62% and 86% for CO2 emissions, respectively.
This research confirms that the success of deploying an EV charging stations infrastructure will be highly dependent on the price the user will have to pay, on the cost of the infrastructure deployed and on the adhesion of the EV users to this kind of infrastructure. These variables are not independent and, consequently, the coordination of public policies and private interest must be promoted in order to reach an optimal solution that does not result in prohibitive costs for the users.
This study presents a methodology to develop scenarios of evolution from 2010 to 2050, for energy consumption and emissions (CO2, HC, CO, NOx, PM) of the road transportation sector (light-duty and ...heavy-duty vehicles). The methodology is applied to Portugal and results are analyzed in a life-cycle perspective. A BAU trend and 5 additional scenarios are explored: Policy-based (Portuguese political targets considered); Liquid fuels-based (dependency on liquid fuels and no deployment of alternative refueling infrastructure); Diversified (introduction of a wide diversity of alternative vehicle technology/energy sources); Electricity vision (deployment of a wide spread electricity recharging infrastructure); Hydrogen pathway (a broad hydrogen refueling infrastructure is deployed). Total life-cycle energy consumption could decrease between 2 and 66% in 2050 relatively to 2010, while CO2 emissions will decrease between 7 and 73% in 2050 relatively to 2010. In 2050 the BAU scenario remains 30% above the 1990 level for energy consumption and CO2 emissions; the other considered scenarios lead to 4 to 29% reductions for energy consumption and 10 to 33% for CO2 emissions in 2050 compared to the BAU. Therefore, alternative vehicle technologies are required in the long-term, but changes in taxation and alternative transportation modes policies are crucial for achieving short-term impacts.
► Assess future energy consumption and emissions scenarios for road transportation. ► LCA energy consumption could decrease 2 to 66% in 2050 relatively to 2010. ► Alternative vehicle technologies can help to lower the BAU scenario impacts. ► Different deployments of alternative technologies can lead to similar impacts.
Diabetes mellitus (DM) is one of the most common and serious chronic diseases in the world. Here, we investigated the effects of mouse dental pulp stem cell (mDPSC) transplantation in a ...streptozotocin (STZ)-induced diabetes type 1 model. C57BL/6 mice were treated intraperitoneally with 80 mg/kg of STZ and transplanted with 1 × 106 mDPSCs or injected with saline, by an endovenous route, after diabetes onset. Blood and urine glucose levels were reduced in hyperglycemic mice treated with mDPSCs when compared to saline-treated controls. This correlated with an increase in pancreatic islets and insulin production 30 days after mDPSC therapy. Moreover, urea and proteinuria levels normalized after mDPSC transplantation in diabetic mice, indicating an improvement of renal function. This was confirmed by a histopathological analysis of kidney sections. We observed the loss of the epithelial brush border and proximal tubule dilatation only in saline-treated diabetic mice, which is indicative of acute renal lesion. STZ-induced thermal hyperalgesia was also reduced after cell therapy. Three days after transplantation, mDPSC-treated diabetic mice exhibited nociceptive thresholds similar to that of nondiabetic mice, an effect maintained throughout the 90-day evaluation period. Immunofluorescence analyses of the pancreas revealed the presence of GFP+ cells in, or surrounding, pancreatic islets. Our results demonstrate that mDPSCs may contribute to pancreatic β-cell renewal, prevent renal damage in diabetic animals, and produce a powerful and long-lasting antinociceptive effect on behavioral neuropathic pain. Our results suggest stem cell therapy as an option for the control of diabetes complications such as intractable diabetic neuropathic pain.
► The paper compares the urban accessibility provided in different urban neighborhoods. ► A methodology is developed to define accessibility indicators in a local scale. ► An evaluation of urban ...accessibility based on internal and external environmental cost. ► Results of an integrated accessibility indicators ranking of neighborhood.
This paper estimates urban accessibility considering types of transport and destinations, taking into account the internal travel time costs, and the ensuing external environmental impacts. Based on online and local surveys, an accessibility function is developed to allow for the construction of an accessibility curve for each transport mode that decreases with distance to represent decaying accessibility. An external environmental impact is associated with the accessibility indicators, taking into account the influence of the cold-start emissions that are particularly relevant for short-distance trips. The methodology is applied to neighborhoods in Lisbon, Portugal, with significant differences in their urban planning, mobility patterns, concentration of services and availability of public transportation.
•Extensive real world data collection to evaluate aggressive driving behavior.•Assess the impacts of aggressive driving at a city perspective.•Aggressive driving increases energy consumption by 200% ...and emissions by 330%.•Avoiding aggressive driving can save up to 52.5 k€ on a daily basis.•Higher impacts of aggressive driving occur in more local streets.
This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving compared to non-aggressive driving (in MJ/km and in g/km, respectively). This increment was found to be even higher for diesel vehicles than for gasoline vehicles. On the contrary, gasoline vehicles showed higher percentages of increase for most emissions (CO, NOx and NO). Results also revealed that aggressive driving impacts are higher for local streets when examining the city level. Moreover, the economic analysis showed that significant cost reductions may be achieved by avoiding aggressive driving, reaching up to 52.5 k€ on a daily basis. In conclusion, this study is of particular relevance to policy makers and urban planners, enabling to obtain a comprehensive overview of the impacts of aggressive driving behaviors at a city level and providing new insights to perform further developments and to assess the feasibility of the implementation of policy measures.
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