Modeling fuel consumption and emissions by taxis in Tabriz, Iran: uncertainty and sensitivity analyses.

Taxis pose a higher threat to global climate change and human health through air emissions. However, the evidence on this topic is scarce, especially, in developing countries. Therefore, this study conducted estimation of fuel consumption (FC) and emission inventories on Tabriz taxi fleet (TTF), Iran. A structured questionnaire to obtain operational data of TTF, municipality organizations, and literature review were used as data sources. Then modeling was used to estimate fuel consumption ratio (FCR), emission factors (EFs), annual FC, and emissions of TTF using uncertainty analysis. Also, the impact of COVID-19 pandemic period was considered on the studied parameters. The results showed that TTF have high FCRs of 18.68 L/100 km (95% CI=17.67-19.69 L/100 km), which are not affected by age or mileage of taxis, significantly. The estimated EFs for TTF are higher than Euro standards, but the differences are not significant. However, it is critical as can be an indication of inefficiency of periodic regulatory technical inspection tests for TTF. COVID-19 pandemic caused significant decrease in annual total FC and emissions (9.03-15.6%), but significant increase in EFs of per-passenger-kilometer traveled (47.9-57.3%). Annual vehicle-kilometer-traveled by TTF and the estimated EFs for gasoline-compressed natural gas bi-fueled TTF are the main influential parameters in the variability of annual FC and emission levels. More studies on sustainable FC and emissions mitigation strategies are needed for TTF.

Fossil fuels subsidy removal and the EU carbon neutrality policy

The complexity of the EU carbon neutrality policy is addressed by evaluating the impacts of the interaction among different policy instruments. An energy-economic dynamic CGE model based on GTAP utilities is developed for simulating different policy scenarios starting from a business as usual case where the economic impacts related to the COVID-19 pandemic and recovery measures are included. The instruments tested as part of the EU climate strategy are the removal of fossil-fuel consumption subsidies, a carbon pricing mechanism and the public support to clean energy technologies. The modelling approach is based on a revenue recycling mechanism to finance clean energy technologies. We find that the simultaneous implementation of all instruments under the EU climate strategy including the removal of subsidies to fossil fuels and the reuse of revenues to foster the technological transition of the energy system is a win-win solution for a sustainable and decarbonised EU economy. © 2023 The Author(s)

Arrival flight efficiency in pre- and post-Covid-19 pandemics

Covid-19 pandemic affected aviation severely, resulting in unprecedented reduction of air traffic. While aviation is slowly re-gaining traffic volumes, we use the opportunity to study the arrival performance in the Terminal Maneuvering Area (TMA) in non-congested scenarios. Applying flight efficiency and environmental performance indicators (PIs) to the historical data of arrivals to Stockholm Arlanda and Gothenburg Landvetter airports, we discover noticeable inefficiencies, despite significant reduction of traffic intensity. We analyze the impact of such factors as weather and traffic intensity on arrival efficiency in isolated scenarios when only one factor dominates: isolated scenario with low traffic and isolated scenario with good weather conditions. Our analysis uncovers that weather has a stronger influence than traffic intensity on the vertical efficiency, while traffic intensity has stronger effect on the lateral efficiency. Impact of traffic intensity on the lateral efficiency might be explained by frequent hold-on patterns and flight trajectory extensions due to vectoring in high traffic conditions. Further investigation is needed to explain weather and vertical/lateral efficiency correlations, the conclusions might be country-specific.

Systematic Overview of Newly Available Technologies in the Green Maritime Sector

The application of newly available technologies in the green maritime sector is difficult due to conflicting requirements and the inter-relation of different ecological, technological and economical parameters. The governments incentivize radical reductions in harmful emissions as an overall priority. If the politics do not change, the continuous implementation of stricter government regulations for reducing emissions will eventually result in the mandatory use of, what we currently consider, alternative fuels. Immediate application of radically different strategies would significantly increase the economic costs of maritime transport, thus jeopardizing its greatest benefit: the transport of massive quantities of freight at the lowest cost. Increased maritime transport costs would immediately disrupt the global economy, as seen recently during the COVID-19 pandemic. For this reason, the industry has shifted towards a gradual decrease in emissions through the implementation of "better" transitional solutions until alternative fuels eventually become low-cost fuels. Since this topic is very broad and interdisciplinary, our systematic overview gives insight into the state-of-the-art available technologies in green maritime transport with a focus on the following subjects: (i) alternative fuels;(ii) hybrid propulsion systems and hydrogen technologies;(iii) the benefits of digitalization in the maritime sector aimed at increasing vessel efficiency;(iv) hull drag reduction technologies;and (v) carbon capture technologies. This paper outlines the challenges, advantages and disadvantages of their implementation. The results of this analysis elucidate the current technologies' readiness levels and their expected development over the coming years.

Fossil fuels subsidy removal and the EU carbon neutrality policy

The complexity of the EU carbon neutrality policy is addressed by evaluating the impacts of the interaction among different policy instruments. An energy-economic dynamic CGE model based on GTAP utilities is developed for simulating different policy scenarios starting from a business as usual case where the economic impacts related to the COVID-19 pandemic and recovery measures are included. The instruments tested as part of the EU climate strategy are the removal of fossil-fuel consumption subsidies, a carbon pricing mechanism and the public support to clean energy technologies. The modelling approach is based on a revenue recycling mechanism to finance clean energy technologies. We find that the simultaneous implementation of all instruments under the EU climate strategy including the removal of subsidies to fossil fuels and the reuse of revenues to foster the technological transition of the energy system is a win-win solution for a sustainable and decarbonised EU economy.

Economic Features of the Use of Electric Vehicles in Delivery Services in Estonia

The article is devoted to substantiating the prospects and advantages of developing a small business specializing in the delivery of lightweight cargo in Tallinn during the COVID-19 pandemic. It was justified why such a business should not only be cost effective but also comply with the general principles of sustainable development and be socially responsible. Particular attention in the article is paid to identifying possible alternative strategies for forming the vehicle park of such a company. Analytically (based on the latest data from the auto producer;car, energy and fuel markets, as well as a company specializing in the construction of turnkey solar power plants), it has been proven that a mixed park, which is consists of gasoline cars and plug-in hybrids is the most a flexible solution requiring an investment exclusively in moving property. At the same time, it was shown that if a company has territorial capabilities to accommodate a sufficient number of solar panels and is ready to organize a business with a smaller park of cars, then the choice of electric ones becomes obvious. © 2022, Econjournals. All rights reserved.

Arrival flight efficiency in pre- and post-Covid-19 pandemics

Covid-19 pandemic affected aviation severely, resulting in unprecedented reduction of air traffic. While aviation is slowly re-gaining traffic volumes, we use the opportunity to study the arrival performance in the Terminal Maneuvering Area (TMA) in non-congested scenarios. Applying flight efficiency and environmental performance indicators (PIs) to the historical data of arrivals to Stockholm Arlanda and Gothenburg Landvetter airports, we discover noticeable inefficiencies, despite significant reduction of traffic intensity. We analyze the impact of such factors as weather and traffic intensity on arrival efficiency in isolated scenarios when only one factor dominates: isolated scenario with low traffic and isolated scenario with good weather conditions. Our analysis uncovers that weather has a stronger influence than traffic intensity on the vertical efficiency, while traffic intensity has stronger effect on the lateral efficiency. Impact of traffic intensity on the lateral efficiency might be explained by frequent hold-on patterns and flight trajectory extensions due to vectoring in high traffic conditions. Further investigation is needed to explain weather and vertical/lateral efficiency correlations, the conclusions might be country-specific.

Evaluating the Impact of COVID-19 on Transportation Infrastructure Funding in the United States

The coronavirus disease 2019 (COVID-19) pandemic has caused a reduction in business and routine activity and resulted in less motor fuel consumption. Thus, the gas tax revenue is reduced, which is the major funding resource supporting the rehabilitation and maintenance of transportation infrastructure systems. The focus of this study is to evaluate the impact of the COVID-19 pandemic on transportation infrastructure funds in the United States through analyzing the motor fuel consumption data. Machine learning models were developed by integrating COVID-19 scenarios, fuel consumptions, and demographic data. The best model achieves an R2-score of more than 95% and captures the fluctuations of fuel consumption during the pandemic. Using the developed model, we project future motor gas consumption for each state. For some states, the gas tax revenues are going to be 10%-15% lower than the pre-pandemic level for at least one or two years. © 2022 International Conference on Transportation and Development

Feed outlook: special article: ethanol markets in 2020

U.S. Ethanol Market Faced Shock in 2020: The US. ethanol market faced pandemic-related shocks in 2020, as COVID-19 reduced driving miles and demand for transportation fuel. These shocks ultimately impacted U.S. feed-grains markets, particularly corn. Since the creation of the Renewable Fuel Standard (RFS) in 2005, and the subsequent passage of RFSZ in 2007, the use of corn for ethanol fuel has created a link between US. feed grain markets and transportation fuel use. As a result of this linkage, the sudden change in social and economic behaviors caused by COVID-19 led to changes in US. com markets. The following is a broad summary of the pre-pandemic state of the ethanol market, the 2020 ethanol market, and the identification of certain market factors that are expected to be important for the outlook of the US. ethanol market. Ethanol Market Trends and Conditions Prior to COVID-19: For the 4 years spanning 2016-2019, the US. motor gasoline product supplied was quite stable. According to US. Energy Information Administration data (EIA), monthly gasoline product supplied averaged about 11.9 billion gallons between 2016-2019. Deviations generally followed seasonal patterns. Gasoline supply levels began 2020 up slightly from their 2016-2019 averages: 11.4 billion gallons in January, compared to an average January-supply level of 11.3 billion gallons and 10.9 billion gallons in February, compared to an average of 10.7 billion gallons.

Optimization of Aircraft Taxiing Strategies to Reduce the Impacts of Landing and Take-Off Cycle at Airports

The increasing attention of opinion towards climate change has prompted public authorities to provide plans for the containment of emissions to reduce the environmental impact of human activities. The transport sector is one of the main ones responsible for greenhouse emissions and is under investigation to counter its burdens. Therefore, it is essential to identify a strategy that allows for reducing the environmental impact produced by aircraft on the landing and take-off cycle and its operating costs. In this study, four different taxiing strategies are implemented in an existing Italian airport. The results show advantageous scenarios through single-engine taxiing, reduced taxi time through improved surface traffic management, and onboard systems. On the other hand, operating towing solutions with internal combustion cause excessive production of pollutants, especially HC, CO, NOX, and particulate matter. Finally, towing with an electrically powered external vehicle provides good results for pollutants and the maximum reduction in fuel consumption, but it implies externalities on taxiing time. Compared to the current conditions, the best solutions ensure significant reductions in pollutants throughout the landing and take-off cycle (−3.2% for NOx and −44.2% for HC) and economic savings (−13.4% of fuel consumption).

Induction of a Consumption Pattern for Ethanol and Gasoline in Brazil

Historically, carbon dioxide emissions from transport have been a globally discussed and analyzed problem. The adoption of flex fuel vehicles designed to run ethanol–gasoline blends is important to mitigate these emissions. The main purpose of this paper is to analyze the impact of the ethanol–gasoline price ratio on different vehicle models, and discuss the opportunities to increase ethanol consumption from this perspective. Our analysis shows that the use of a unique fuel economy ratio for all flex–fuel vehicles in the country significantly reduces the opportunity of some customers to purchase hydrous ethanol. The paper also discusses possible actions to provide adequate information that may increase the possibility of fuelling vehicles with a high-level ethanol blend.

Environmental Benefits and Energy Savings from Gas Radiant Heaters’ Flue-Gas Heat Recovery

This paper demonstrates the need and potential for using waste heat recovery (WHR) systems from infrared gas radiant heaters, which are typical heat sources in large halls, due to the increasing energy-saving requirements for buildings in the EU and the powerful and wide-spread development of the e-commerce market. The types of gas radiant heaters are discussed and the classification of WHR systems from these devices is performed. The article also presents for the first time our innovative solution, not yet available on the market, for the recovery of heat from the exhaust gases of ceramic infrared heaters. The energy analysis for an industrial hall shows that this solution allows for environmental benefits at different levels, depending on the gas infrared heater efficiency, by reducing the amount of fuel and emissions for domestic hot water (DHW) preparation (36.8%, 15.4% and 5.4%, respectively, in the case of low-, standard- and high-efficiency infrared heaters). These reductions, considering both DHW preparation and hall heating, are 16.1%, 7.6% and 3.0%, respectively. The key conclusion is that the innovative solution can spectacularly improve the environmental effect and achieve the highest level of fuel savings in existing buildings that are heated with radiant heaters with the lowest radiant efficiency.

Effect of Al2O3 Nanoparticles on Performance and Emission Characteristics of Diesel Engine Fuelled with Diesel–Neem Biodiesel Blends

Indagation in the sphere of nanoparticle utilisation has provided commendatory upshots in discrete areas of application varying from medicinal use to environmental degradation alleviation. This study incorporates alumina nanoparticles as additives to diesel and biodiesel blends. The prime objective of the present study was the scrutinisation of the denouement of Al2O3 nanoparticle incorporation in diesel–biodiesel blends on a diesel engine’s performance and emission characteristics. Test fuel samples were prepared by blending different proportions of biodiesel and dispersing two concentrations of alumina nanoparticles (25 and 50 ppm) in the diesel. Dispersion was made without the use of a nanoparticle stabiliser to meet real-world feasibility. High-speed shearing was employed to blend the biodiesel and diesel, while nanoparticles were dispersed in the blends by ultrasonication. The blends so devised were tested using a single-cylinder diesel engine at fixed RPM and applied load for three compression ratios. Upshots of brake-specific fuel consumption (BSFC) and brake thermal efficiency (BTE) for fuel samples were measured with LabView-based software, whereas CO emissions and unburnt hydrocarbon (UBHC) emissions were computed using an external gas analyser attached to the exhaust vent of the engine. Investigation revealed that the inclusion of Al2O3 nanoparticles culminates in the amelioration of engine performance along with the alleviation of deleterious exhaust from engine. Furthermore, the incorporation of alumina nanoparticles assisted in the amelioration of dwindled performance attributed to biodiesel blending. More favourable results of nanoparticle inclusion were obtained at higher compression ratios compared to lower ones. Reckoning evinced that the Al2O3 nanoparticle is a lucrative introduction for fuels to boost the performance and dwindle the deleterious exhaust of diesel engines.

Experimental Investigation and neural network modelling of diesel engine using hexanol blended ternary waste cooking oil biodiesel with moderate preheating

The depleting fossil fuel reserves, rising air pollution, technology transformation threat, and most recently, global economic slowdown by the COVID-19 pandemic, led the internal combustion engine-based automotive industries in a critical condition. The development of improved biofuels to meet stringent emission norms is a promising solution. Higher alcohols possess the fuel properties better than lower alcohols to blend with diesel and biodiesel. The miscibility and higher viscosity is the issue. Preheating can help the vaporization and atomization of fuel. The present study investigates the engine characteristics of moderately preheated ternary fuel using 20 to 40% blends of 1-hexanol, waste cooking oil biodiesel, and diesel. The study found that moderately preheated ternary fuel blends showed a drop in brake-specific fuel consumption, HC, CO, and smoke emissions with improvement in peak cylinder pressure, heat release rate, and brake thermal efficiency. A multi-layer neural network model is developed to prognosticate the engine characteristics. Backpropagation algorithm-based neural network with single hidden layers using Levenberg–Marquardt training function gave the best results. The mean square error of the network was 0.00028517 and the correlation coefficient was 0.99944, 0.99945, and 0.99923 for training, validation, and testing respectively. The mean absolute percentage error was found below 4%. © 2022 Elsevier Ltd

The omnidirectional runway with infinite heading as a futuristic runway concept for future free route airspace operations

Purpose>The purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations.Design/methodology/approach>This paper researches and analyses the new generated runway concept with the fast time simulation method. Fuel consumption and environmental effect of the new runway system are calculated based on simulation results.Findings>According to different traffic density analyses the Omnidirectional Runway with Infinite Heading (ORIH) reduced fuel consumption and CO2 emissions up to 46.97%. Also the total emissions of the ORIH concept, for the hydro carbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) pollutants were lower than the total emissions with the conventional runway up to 83.13, 74.36 and 51.49%, respectively.Practical implications>Free route airspaces bring many advantages to air traffic management and airline operations. Direct routes become available from airport to airport thanks to free route airspace concept. However, conventional single runway structure does not allow aircraft operations for every direction. The landing and take-off operations of a conventional airport with a single runway must be executed with only two heading direction. This limitation brings a bottleneck direct approach and departure route usage as convenient with free route airspace concept. This paper suggests and analyzes the omnidirectional runway with infinite heading (ORIH) as a solution for free route airspace.Originality/value>This paper suggests a new and futuristic runway design and operation for the free route operations. This paper has its originality from the suggested and newly created runway system.

A statistical analysis to compare results of different on-road vehicle performance testing

Assessing the energy performances of a vehicle on the road requires collecting large data samples to ensure repeatability of the measurements despite the many variables which influence them. This paper proposes a method to dimension the campaign and compares various campaigns despite differences in the influencing variables through statistical analysis. This methodology has been applied to the Italian testing campaign of Toyota Yaris Hybrid 2020. The results are compared to those collected in a similar campaign for the previous model. The pandemic of COVID-19 forced the acquisitions to be made in months in which the weather and the traffic weredifferent,and the reduced mobility lowered the traffic intensity. The proposed method was able to make the campaigns comparable besides the differences. It can also be applied to design future campaigns to reduce the quantity of collected data while maintaining the same statistical significance. The newest model of Toyota Yaris Hybrid performs better than the previous one, and it was analysed how.

Study on Aviation Fuel Efficiency Evaluation System Based on QAR Data Analysis

Recently, airlines mainly rely on QAR (Quick access Record) data to evaluate the combustion efficiency. Due to the multi-level relation of combustion efficiency, the index system is complicated. Meanwhile, some uncontrollable factors could greatly affect the fuel combustion evaluation, such as, payload changes of airplane. It is urgent to establish a relatively intuitive, simplified and reasonable combustion efficiency evaluation system based on the QAR data, to reflect the management ability of energy conservation and emission reduction of airlines. This paper focuses on the superiority of total combustion index use. By the method of correction payload comparison analysis, it could avoid the abnormally jump of combustion efficiency in the airlines operation and contribute to establish the relative combustion evaluation system. Due to the data accuracy, it could reflect the refinement and volatility process of the fuel cost of the airlines in the COVID-19 period. There is significant reference for the airlines' cost evaluation and control in the future. © 2021 IEEE

Review of Top-Down Method to Determine Atmospheric Emissions in Port. Case of Study: Port of Veracruz, Mexico

Indicators of environmental policies in force in Mexico, fossil fuels will continue to be used in industrial sectors, especially marine fuels, such as marine diesel oil, in port systems for some time. Considering this, we have evaluated several methods corresponding to a top-down system for determining fuel consumption and sulfur dioxide atmospheric emissions for the port of Veracruz in 2020 by type of ship on a daily resolution, considering a sulfur content of 0.5% mass by mass in marine fuel. After analyzing seven methods for determining sulfur dioxide atmospheric emission levels, Goldsworthy’s method was found to be the best option to characterize this port. The port system has two maritime zones, one of which is in expansion, which represented 55.66% of fuel consumption and 23.05% of atmospheric emissions according to the typology of vessels. We found that higher fuel consumption corresponded to container vessels, and tanker vessels represented higher atmospheric emission levels in the berthing position. The main differences that we found in the analysis of the seven methods of the top-down system corresponded to the load factor parameter, main and auxiliary engine power, and estimation of fuel consumption by type of vessel.

Carbon Emissions from the Transportation Sector during the Covid-19 Pandemic in the Special Region of Yogyakarta, Indonesia

Government policies to curb the Covid-19 pandemic have drastically changed the pattern of energy demand worldwide. Closed borders and international travel bans have changed consumption patterns and reduced transport use, thus significantly lowering carbon emissions in several countries, particularly urban areas in the Southeast Asia region. Based on these conditions, the study aimed to analyze carbon dioxide emissions generated by the transportation sector in the Special Region of Yogyakarta during the pandemic. The required data, serving as research objects, included fuel consumption, fuel sales, transportation sector activities, road sections, and road density derived from the Transportation Department’s traffic cameras and BPS-Statistics Indonesia. Google Form was also used to collect information for fuel consumption pattern analysis. The Covid-19 - Google Global Mobility Report was used to map trends of change in the respondents’ activity and mobility. The results showed that, from 2019 to 2020, the fuel consumption decreased by 74 kL/year and the CO2 emissions by 169,865 tons/year. Government policies, including the large-scale social activity restrictions implemented for the first time in the region, have influenced community mobility trends across different categories of places.

Transformation of urban mobility during COVID-19 pandemic - Lessons for transportation planning.

INTRODUCTION: The coronavirus disease (COVID-19) pandemic is a global threat that started in Wuhan, China, in 2019 and spread rapidly to the globe. To reduce the spread of the COVID-19, different non-pharmacological control measures have been conducted in different countries, which include social distancing, distance working, and stay-at-home mandates. These control measures had affected global transportation and mobility significantly. This study investigated the short-term changes in urban mobility, tropospheric air pollution, and fuel consumption in two major cities of Saudi Arabia, namely, Riyadh and Jeddah. METHODS: In this study, the dynamics of the number of trips and trip purposes in different provinces of the country were analyzed, focusing on the pandemic period and the lockdown program. These changes impacted fuel consumption and, consequently, air pollutants. The quantity of fuel consumption and its trend was projected considering a few possible fuel consumption and emission scenarios. It is also expected that fuel price plays a role in fuel consumption. The spatial and temporal distributions of the remote sensed tropospheric Nitrogen Dioxide (NO2) levels in different provinces were presented to depict the short 19 and long-term impact on the air quality due to the changes in mobility. RESULTS: The significant reduction in urban mobility has been observed since the beginning of the first partial curfew in March 2020 compared to that in 2019. The air pollutant levels (such as NO2) in 2020 after the pandemic were generally less than those of 2019. The fuel consumption has been following a decreasing trend in 2020 starting from January due to dynamic fuel price and the additional influence of pandemic. Based on the current online shopping pattern, it is argued that there will be some permanent behavioral changes in urban mobility, which will decrease some shopping trips at least immediately after the recovery from the pandemic. CONCLUSIONS: This study concluded that the availability of global urban mobility data, remote sensed based tropospheric air pollution data, and global fuel consumption database are important sources of information to investigate the impact of COVID pandemic, especially for the developing countries which suffer from scarcity of pertinent urban mobility information. It seems that, at least in the study area, the spread of COVID-19 is a complex phenomenon in which several exogenous factors, in addition to the curfew protocols, affect the spread of the virus.