A Darío Torrenti I Todo el viaje fue un error. Para ir a encontrarte necesitaba ropa gruesa, lo más abrigada posible. Pero si decidía no ir nada de eso era necesario. Le voy a decir que me caí, que ...me quebré una pierna y que no puedo ir, pensé. Le voy a decir que me desmayé y que desperté en un hospital y que no puedo ir, pensé. Comíamos lentejas, queso, olivas. Concentrado y sin hablar sacabas pequeñas piedras negras que ponías aparte y con las que yo jugaba a formar figuras sobre el mantel. Al principio era como un juego, como ir caminando solos, pero no. Traté de concentrarme en esos detalles, en mis pies cada vez más fríos y húmedos.
This fascinating and informative book looks at the Tilling Group of bus companies during the 1960s. These operated approximately half of the inter-urban and rural bus services in England and Wales, ...and were nationalised by Clement Attlee's Labour Government in 1948 under the control of the British Transport Commission. Ownership passed to the Transport Holding Company Ltd in 1963, though the fleets remained under Tilling Group control. During the period covered by this book, the operators within the group had very standardised fleets, with the vast majority of their buses and coaches having Bristol chassis and Eastern Coachworks (ECW) bodywork.
Over the past decade, system-on-chip (SoC) designs have evolved to address the ever increasing complexity of applications, fueled by the era of digital convergence. Improvements in process technology ...have effectively shrunk board-level components so they can be integrated on a single chip. New on-chip communication architectures have been designed to support all inter-component communication in a SoC design. These communication architecture fabrics have a critical impact on the power consumption, performance, cost and design cycle time of modern SoC designs. As application complexity strains the communication backbone of SoC designs, academic and industrial R&D efforts and dollars are increasingly focused on communication architecture design. This book is a comprehensive reference on concepts, research and trends in on-chip communication architecture design. It will provide practitioners, researchers, software developers and students with a comprehensive survey, not available elsewhere, of all current standards for on-chip communication architectures.
Switching from diesel-powered to battery-powered buses has been a global tendency. Traditional approaches rely on standard driving cycles or fuel economy data for energy consumption on a limited ...number of buses; thus, expanding to large bus fleets at the city level has become challenging. This study uses high-resolution GPS and smart card transaction data to generate each bus driving profile and weight dynamics in a large-scale transit network. Two vehicle activity-based energy consumption models are adopted and calibrated for diesel bus (DB) and electric bus by using the field data of 630 bus routes in Beijing. The average energy consumptions of DBs and electric buses are 43.5 and 14.1 L/100 km, respectively. A gradient boosting regression tree algorithm is presented to examine and rank distinct influential factors on the energy consumption of DBs and electric buses. Heterogenous behaviors are identified: the leading attributes affecting the energy consumption of electric buses and DBs are route characteristics and operational condition, respectively. After computing, the total energy conservation of electrifying all bus fleets is equivalent to 0.87% of daily electricity demand in Beijing. These findings set a good base for further studies on bus fleet replacement, charging infrastructure deployment, and electrified route prioritization.
•Activity-based energy consumption models are adopted for diesel and electric buses.•Models are well calibrated using GPS and smart card data of 630 routes in Beijing.•Route characteristics are identified as the leading influential factors for electric buses.•Operational condition is the leading influential factor for diesel buses.•The energy saving of electrifying all bus fleets in Beijing is around 2.5GWH per day.
The transportation sector holds significant importance within a nation, constituting a considerable share of its total energy consumption. In developing nations, the predominant use of non-renewable ...energy sources like natural gas and petroleum-based fuels is notably observed in the transportation domain. Both public and private vehicles predominantly operate on fossil fuels, giving rise to concerns such as depleting national energy resources and escalating environmental impacts. Consequently, addressing these challenges calls for a shift towards cleaner and more sustainable transportation options. Therefore, the purpose of this research is to conduct a comprehensive ex-ante social cost-benefit analysis of various types of buses for public transportation. Specifically, the types of buses considered include: (i) solar buses, (ii) electric buses, (iii) hydrogen buses, and (iv) diesel buses. This study investigates the feasibility of each type of bus by determining its overall benefits and costs. The economic, environmental, and social impacts are determined and monetized which are used to calculate the net present values (NPV). The solar bus was found to have a comparatively higher NPV of 79.46 Million PKR which demonstrates that the associated overall benefits are higher as compared to the costs. On the contrary, the hydrogen bus was found to have a comparatively lower NPV of −5.87 Million PKR which depicted that considerably higher costs surpassed its benefits. Finally, an exhaustive sensitivity analysis was performed to investigate the impacts of critical system parameters on the feasibility of the examined buses.
•Strategic insight into transitioning to sustainable public transportation.•SCBA emphasizes the significance of cleaner bus options for long-term benefits.•Solar buses demonstrate superior net present values, highlighting economic benefits.•Global roadmap for cleaner, economic and environmentally viable transportation.
In this paper, we propose a vehicle-scheduling model for electric transit buses with either battery swapping or fast charging at a battery station, and a vehicle-scheduling model with the maximum ...route distance constraint for compressed natural gas, diesel, or hybrid-diesel buses. Both of these scheduling models are NP-hard. We develop column-generation-based algorithms to solve the scheduling problems. We conduct extensive case studies based on real-world instances and instances randomly generated in a practical setting. Our computational experiments show that our algorithms demonstrate very good computational performances. We also use real-world transit data to systematically analyze the number of buses needed, the total operational costs, and the vehicle emissions generated when compressed natural gas, diesel, hybrid, or electric buses are used in service.
Background: Commuters are exposed to high concentrations of air pollutants, but little quantitative information is currently available on differences in exposure between different modes of transport, ...routes, and fuel types. Objectives: The aim of our study was to assess differences in commuters' exposure to traffic-related air pollution related to transport mode, route, and fuel type. Methods: We measured particle number counts (PNCs) and concentrations of PM₂.₅ (particulate matter ≤ 2.5 um in aerodynamic diameter), PM₁₀, and soot between June 2007 and June 2008 on 47 weekdays, from 0800 to 1000 hours, in diesel and electric buses, gasoline-and diesel-fueled cars, and along two bicycle routes with different traffic intensities in Arnhem, the Netherlands. In addition, each-day measurements were taken at an urban background location. Results: We found that median PNC exposures were highest in diesel buses (38,500 particles/cm³) and for cyclists along the high-traffic intensity route (46,600 particles/cm 3 ) and lowest in electric buses (29,200 particles/cm³). Median PM₁₀ exposure was highest from diesel buses (47 μg/m³) and lowest along the high-and low-traffic bicycle routes (39 and 37 μg/m³). The median soot exposure was highest in gasoline-fueled cars (9.0 х 10⁻⁵/m), diesel cars (7.9 х 10⁻⁵/m), and diesel buses (7.4 х 10⁻⁵/m) and lowest along the low-traffic bicycle route (4.9 х 10⁻⁵/m). Because the minute ventilation (volume of air per minute) of cyclists, which we estimated from measured heart rates, was twice the minute ventilation of car and bus passengers, we calculated that the inhaled air pollution doses were highest for cyclists. With the exception of PM₁₀, we found that inhaled air pollution doses were lowest for electric bus passengers. Conclusions: Commuters' rush hour exposures were significantly influenced by mode of transport, route, and fuel type.
This paper shows the results of an in-depth techno-economic analysis of the public transport sector in a small to midsize city and its surrounding area. Public battery-electric and hydrogen fuel cell ...buses are comparatively evaluated by means of a total cost of ownership (TCO) model building on historical data and a projection of market prices. Additionally, a structural analysis of the public transport system of a specific city is performed, assessing best fitting bus lines for the use of electric or hydrogen busses, which is supported by a brief acceptance evaluation of the local citizens. The TCO results for electric buses show a strong cost decrease until the year 2030, reaching 23.5% lower TCOs compared to the conventional diesel bus. The optimal electric bus charging system will be the opportunity (pantograph) charging infrastructure. However, the opportunity charging method is applicable under the assumption that several buses share the same station and there is a “hotspot” where as many as possible bus lines converge. In the case of electric buses for the year 2020, the parameter which influenced the most on the TCO was the battery cost, opposite to the year 2030 in where the bus body cost and fuel cost parameters are the ones that dominate the TCO, due to the learning rate of the batteries. For H2 buses, finding a hotspot is not crucial because they have a similar range to the diesel ones as well as a similar refueling time. H2 buses until 2030 still have 15.4% higher TCO than the diesel bus system. Considering the benefits of a hypothetical scaling-up effect of hydrogen infrastructures in the region, the hydrogen cost could drop to 5 €/kg. In this case, the overall TCO of the hydrogen solution would drop to a slightly lower TCO than the diesel solution in 2030. Therefore, hydrogen buses can be competitive in small to midsize cities, even with limited routes. For hydrogen buses, the bus body and fuel cost make up a large part of the TCO. Reducing the fuel cost will be an important aspect to reduce the total TCO of the hydrogen bus.
Nearly two-thirds of the emissions that cause smog come from road transport. In April 2019, the European Parliament adopted new regulations on public procurement to encourage investment in clean ...buses—electric, hydrogen, or gas. Directive 2009/33/EC is to apply from the second half of 2021. The aim of this article is to make an attempt to simulate the number of zero-emission buses (ZEB) in European Union (EU) member countries in two time horizons: 2025 and 2030, and to forecast the number of clean vehicles in the precise time horizons, including before and after 2050. Research questions are as follows: (1) what will be the number of ZEBs in individual EU countries over the next few years; (2) which of the EU countries will reach by 2030 the level of 95% share of ZEBs in all buses, which are a fleet of public transport buses; and (3) in which year will which EU countries reach the level of 95% share of zero-emission buses. The method used is a Bass model. The conducted analyses demonstrate that, by 2050, only four of the EU members will be able to reach 95% level of share of clean buses in the city bus transport fleets. It is likely that other countries may not achieve this even by 2050.
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