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Fuel Efficiency (fuel + efficiency)

Distribution by Scientific Domains

Engineering	37%
Business, Economics, Finance and Accounting	37%
Chemistry	12%

Selected Abstracts

Constructing a cognition map of alternative fuel vehicles using the DEMATEL method

JOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 1-2 2009
Cheng-Wei Lin
Abstract Environmental protection has taken serious notice of global warming. The Intergovernmental Panel on Climate Change (IPCC) has proved that CO2 is one of the factors for global warming. Furthermore, the majority of this emission comes from the vehicles using petroleum fuels. For this reason, alternative fuels become a very popular issue. There are many automakers and researchers endeavoring to develop alternative fuel vehicles (AFVs). There already have been many types of alternative fuels used in vehicles, such as electric vehicles (EVs), hybrid electric vehicles (HEVs), fuel cell (hydrogen) vehicles, natural gas vehicles (CNG), methanol vehicles, ethanol vehicles, and bio-diesel vehicles, etc. Different types of the alternative fuels have different characteristics to which attention should be paid. It is difficult for users to identify which one is the best choice for them to use. This problem concerns the characteristics of each alternative fuel. A lot of criteria and aspects related to the alternative fuels should be considered at the same time. In this study, we try to apply the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method to deal with the importance and causal relationships among the evaluation factors of AFVs. Results show the top three critical evaluation criteria are ,new car cost', ,cruising range', and ,fuel efficiency'; ,air pollution' is the key cause factor influencing others; and ,cruising range' is the key effect factor influenced by others. It is no accident that cost is the most critical factor for users. Consequently, it is suggested to automakers and researchers to carefully analyze the characteristics of each alternative fuel. Fuel efficiency is not only focused on by users, but also it will affect the cruising range. Air pollution is what users care about, so even zero-emission vehicles (ZEVs), which cost more but have lower emission and higher fuel efficiency, could be accepted. There seems to be no perfect AFV, but to endeavor on ZEVs will reduce some disadvantages. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Energy efficiency improvement strategies for a diesel engine in low-temperature combustion

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2009
Ming Zheng
Abstract The lowered combustion temperature in diesel engines is capable of reducing nitrogen oxides and soot simultaneously, which can be implemented by the heavy use of exhaust gas recirculation (EGR) or the homogeneous charge compression ignition (HCCI) type of combustion. However, the fuel efficiency of the low-temperature combustion (LTC) cycles is commonly compromised by the high levels of hydrocarbon and carbon monoxide emissions. More seriously, the scheduling of fuel delivery in HCCI engines has lesser leverage on the exact timing of auto-ignition that may even occur before the compression stroke is completed, which may cause excessive efficiency reduction and combustion roughness. New LTC control strategies have been explored experimentally to achieve ultralow emissions under independently controlled EGR, intake boost, exhaust backpressure, and multi-event fuel-injection events. Empirical comparisons have been made between the fuel efficiencies of LTC and conventional diesel cycles. Preliminary adaptive control strategies based on cylinder pressure characteristics have been implemented to enable and stabilize the LTC when heavy EGR is applied. The impact of heat-release phasing, duration, shaping, and splitting on the thermal efficiency has also been analyzed with engine cycle simulations. This research intends to identify the major parameters that affect diesel LTC engine thermal efficiency. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Prospects for Alkaline Anion-Exchange Membranes in Low Temperature Fuel Cells,

FUEL CELLS, Issue 2 2005
J. R. Varcoe
Abstract This article introduces the radical approach of applying alkaline anion-exchange membranes (AAEMs) to meet the current challenges with regards to direct methanol fuel cells (DMFCs). A review of the literature is presented with regards to the testing of fuel cells with alkaline membranes (fuelled with hydrogen or methanol) and also to candidate alkaline anion-exchange membranes for such an application. A brief review of the directly related patent literature is also included. Current and future research challenges are identified along with potential strategies to overcome them. Finally, the advantages and challenges with the direct electrochemical oxidation of alternative fuels are discussed, along with how the application of alkaline membranes in such fuel cells may assist in improving performance and fuel efficiency. [source]

Energy efficiency improvement strategies for a diesel engine in low-temperature combustion

A Dynamic Integrated Analysis of Truck Tires in Western Europe

JOURNAL OF INDUSTRIAL ECOLOGY, Issue 2 2000
Pieter J. H. van Beukering
Summary By evaluating tires from a perspective of industrial metabolism, potential novel and practical ways to reduce their environmental impact can be found. This may be achieved by focusing on technological issues such as choosing materials, designing products, and recovering materials, or by looking at institutional and social barriers and incentives such as opening waste markets or changing consumer behavior. A model is presented for the life cycle of truck tires in Western Europe that is dynamic in nature and values both environmental and economic consequences. Various scenarios are simulated including longer tire lifetimes, better maintenance of tire pressure, increased use of less-expensive Asian tires, and increased use of fuel efficiency-enhancing tires ("eco-tires"). Tentative results indicate that, among other things, more than 95% of the overall environmental impact during the life of a tire occurs during the use of the tire, due to the impact of tires on automotive fuel efficiency. Better maintenance of tire pressure and use of eco-tires produce greater environmental and economics benefits than more-durable and/or less-expensive (Asian) tires. These results imply that the emphasis in environmental policies related to tires should shift from the production and the waste stages to the consumption stage. It also suggests that the focus on materials throughput and associated improvements through factor 4 or factor 10 advances in reduction in mass are less important than the quality of the tires and their management. [source]

Statistical study of organomolybdenum compounds in an engine oil formulation and the results of engine testing

LUBRICATION SCIENCE, Issue 1 2001
M. S. Saini
Abstract Organomolybdenum compounds are versatile lubricant additives of interest in the design of engine oils to meet the new ILSAC (International Lubricant Standardization and Approval Committee) GF-3 performance standard, especially for fuel efficiency. In this work, organomolybdenum and 13 other components were studied by experimental design and statistical analysis to determine their effects on friction, wear, and oxidation properties. The resulting linear model was used to construct a trial engine oil formulation. Engine test results, including some new tests required for ILSAC GF-3, confirmed some of the strengths of organomolybdenum compounds, as well as their sensitivity to other additives in the formulation. [source]

Maximising the fuel efficiency of engine oils: The role of tribology

LUBRICATION SCIENCE, Issue 3 2001
Stefan Korcek
Abstract Improvement of engine fuel efficiency is one of the most important goals of current automotive development. Maximising the contribution of engine oils to fuel efficiency is a very important part of this process. Engine friction modelling, based on fundamental tribological considerations, has shown that further engine friction improvements are possible through engine oil reformulation. This reformulation should minimise friction under hydrodynamic conditions through modification of the rheological properties of oils, and also minimise friction under mixed and boundary lubrication conditions through changes in the chemical composition of the oils. These improvements can be achieved by appropriate selection of a base oil as well as by the use of effective friction-reducing additive systems. A very important consideration in formulating these highly fuel-efficient oils is their ability to retain their fuel efficiency during the entire oil service interval. This paper describes the role of tribological research in the development and introduction of advanced fuel-efficient engine oils. [source]

Aviation fuel demand modelling in OECD and developing countries: impacts of fuel efficiency

OPEC ENERGY REVIEW, Issue 1 2009
Mohammad Mazraati
On the quest for reducing the fuel consumption per passenger per flight for economical and environmental reasons, commercial aircraft manufacturers are implementing new strategies for optimising aircraft performance by using new lighter and stronger materials and enhancing engines' efficiencies in terms of fuel consumption and maintenance requirements. With the rising and falling of economies, whether in the Organization for Economic Cooperation and Development (OECD) countries or other developing countries, the aviation industry has been affected by multiple factors such as passenger traffic, freight traffic, airport capacities and oil prices. Aircraft manufacturers have worked on improving the engine efficiency of their newly built airplanes (e.g. Airbus's A-380 and Boeing's B-787), and many airports in the world have increased the number of their runways to face the increasing demand for air traffic in the world. Aviation efficiency can also be achieved through better load management, which in return enables airliners to cope with higher oil prices or rising costs. Aviation fuel demand is modelled in OECD North America, Europe and Pacific regions and some selected developing countries. Price elasticities of fuel demand in all regions are low, while income elasticities are high. The elasticity of aviation fuel demand on passenger kilometre performed (PKP) is considerably low. One per cent increase in PKP leads to less than half a per cent increase in aviation fuel demand, confirming an ongoing fuel efficiency in aviation industry. [source]

Oil demand in transportation sector in Iran: an efficiency and income asymmetric modelling approach

OPEC ENERGY REVIEW, Issue 4 2007
Mohammad Mazraati
The transportation sector in Iran consumed about 52 per cent of oil demand in 2005. This high consumption rate of oil in the sector is fuelled by many factors including fiscal policies structural, as well as infrastructural factors. The vehicle ownership (intensity), efficiency of vehicles, public transportation, transport infrastructure, per capita income, cost of vehicle use, and fuel prices are among the factors which are shaping the trend of oil demand in this very important sector. Energy in Iran is heavily subsidized and in the transportation sector, the subsidy amounted to $3.59 billion in 1996, rising to $12.43 billion in 2005. Logistic model of vehicle ownership is estimated as a function of real per capita income, length of roads and other explanatory variables. Per capita income is a cumulative non-declining variable incorporating the idea of income asymmetric. Oil demand is estimated as a function of fuel efficiency, age of car fleet, per capita income and vehicle ownership per 1,000 inhabitants. Oil demand elasticities of vehicle ownership and fuel efficiency are 1.29 and 1.11, respectively, confirming that these variables have major impacts on oil demand in the transportation sector. It is concluded that rationing of fuel or upward price adjustment merely cannot curb the fast growth of oil demand in the sector. A policy package including mandatory fuel efficiency standards, scraping of old vehicles, upward fuel price, and development of public transportation could lead to better management of fuel consumption in this sector. [source]

Fuel demand and car ownership modelling in India

OPEC ENERGY REVIEW, Issue 1 2007
Taoufik Bouachera
Motorisation in Asia is soaring with rapid growth in incomes non-lin-early. Even though car ownership per 1,000 population is still low in countries like China, India or Indonesia, escalating number of cars is affected by GDP growth among other infrastructural factors in a non-linear manner. This quick growth in car ownership may represent a significant implication on road transport fuel demand. This paper forecasts the demand for road transport fuel in India. For this purpose, econometric models, based on time series data, are constructed as for a major factor affecting fuel demand in road transportation i.e. car ownership. Firstly the econometric car ownership model was attempted in this study, for projecting future car stock in India based on cross section time series technique. The car stock is modelled by using three functional forms, which are the logistic, quasi-logistic and Gompertz curves. However, to take into consideration countries with different income levels in that part of the world, these models were estimated by using pooled data of seven Asian countries (Japan, China, South Korea, Thailand, Indonesia, Malaysia and India). Then, a set of fuel consumption scenarios were developed in order to make forecast until 2030. These scenarios were generated by taking into consideration car stock, fuel efficiency and the average distance travelled in India. [source]

Climate Change and Emergency Medicine: Impacts and Opportunities

ACADEMIC EMERGENCY MEDICINE, Issue 8 2009
Jeremy J. Hess MD
Abstract There is scientific consensus that the climate is changing, that human activity plays a major role, and that the changes will continue through this century. Expert consensus holds that significant health effects are very likely. Public health and health care systems must understand these impacts to properly pursue preparedness and prevention activities. All of medicine will very likely be affected, and certain medical specialties are likely to be more significantly burdened based on their clinical activity, ease of public access, public health roles, and energy use profiles. These specialties have been called on to consider the likely impacts on their patients and practice and to prepare their practitioners. Emergency medicine (EM), with its focus on urgent and emergent ambulatory care, role as a safety-net provider, urban concentration, and broad-based clinical mission, will very likely experience a significant rise in demand for its services over and above current annual increases. Clinically, EM will see amplification of weather-related disease patterns and shifts in disease distribution. In EM's prehospital care and disaster response activities, both emergency medical services (EMS) activity and disaster medical assistance team (DMAT) deployment activities will likely increase. EM's public health roles, including disaster preparedness, emergency department (ED)-based surveillance, and safety-net care, are likely to face increasing demands, along with pressures to improve fuel efficiency and reduce greenhouse gas emissions. Finally, EM's roles in ED and hospital management, particularly related to building and purchasing, are likely to be impacted by efforts to reduce greenhouse gas emissions and enhance energy efficiency. Climate change thus presents multiple clinical and public health challenges to EM, but also creates numerous opportunities for research, education, and leadership on an emerging health issue of global scope. [source]

Simulating the Heat Transfer Process of Horizontal Anode Baking Furnace

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3-4 2004
Liqi Zhang
A transient two-dimensional mathematical model of a horizontal baking furnace is presented. The model combines complicated thermal phenomena in the baking process such as air infiltration, evolution and combustion of volatile matter; combustion of packing coke, and heat losses. The predicted results are in good agreement with measured data. Furthermore, the processes are simulated under different operating conditions such as firing cycle time, airflow and air infiltration. The simulated results indicate that the fuel consumption decreases as the firing cycle time decreases, it is also found that reducing the airflow and air infiltration will assist fuel efficiency. The model has proved to be a useful tool in the process optimization of the baking furnace in the aluminum industry. [source]