The third term denotes the effect of the vascular network on the growth of cells [ 18 ]. As above, we use a no-flux boundary condition and an initial conditionwhere defines the initial spatial distribution of tumor cells assumed to be a Gaussian distribution.
Reprinted with permission; copyrightMassachusetts Institute of Technology. Regulation of Transportation Air Quality Emissions The past four decades have seen a substantial national effort to regulate the emissions from transportation, starting with light-duty vehicles in the s, and moving to heavy-duty on-road vehicle, and most recently to a range of other Consequences of spatial distribution and consumption sources, including construction and agricultural equipment, locomotives, boats, and ships NRC c.
These efforts have been driven in part by even stricter standards adopted by California, which have in turn been adopted by a number of states. The result has been substantial reductions in emissions and ambient levels of a number of pollutants, even as vehicle miles have increased.
For example, there have been substantial reductions of ambient levels of carbon monoxide COin most cases to levels below 2 the current National Ambient Air Quality Standards NRC b.
Page Share Cite Suggested Citation: Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use. The National Academies Press. Substantial requirements have also been enacted this decade that require enhanced use of biofuels more details provided later in chapter.
Improving Vehicle Efficiency In addition to regulation to reduce emissions in the transportation sector, the United States has seen substantial efforts, beginning in the s and renewed recently, to improve vehicle efficiency NRC c.
That report notes that energy usage in transportation has grown rapidly in the United States over the past decades except for brief pauses during economic recessions in,and The present economic decline, along with the spike in petroleum prices, is also likely to slow the demand for transportation fuels.
Globally, the major drivers for energy efficiency are the price of fuel influenced by taxesregulations, personal choice, and the personal environmental values movement.
In Europe, where high fuel and vehicle taxes raise owner costs and where diesel fuel is taxed less than gasoline, new-vehicle fuel economy is approaching 40 miles per gallon mpg. InJapan revised its fuel economy standard to 47 mpg by Ann et al. In the United States, technological efficiency improvements are available at fairly modest costs.
However, rather than reducing their fuel expenses as a result of these improvements, most U. So in spite of technological improvements in the efficiency of vehicle components, the fuel demand has continued to rise, and the U.
Recently, California adopted so-called GHG emission standards that would require substantial reductions in GHG emissions, primarily through enhancements in fuel economy, by ; 13 additional states indicated that they would adopt the standards once the U.
This action is expected to result in the achievement of the former A wide variety of technologies are available to improve fuel economy, in particular those to improve drive-train efficiency, vehicle aerodynamics, rolling resistance, and weight reduction NRC b. Many of these will be widely deployed bybut further gains will be possible.
A shift to these technologies, coupled with other improvements, could result in a new-vehicle fleet with substantially improved fuel efficiency. Therefore, the committee attempted to place transportation energy uses in order of importance on the basis of two key factors: In applying these criteria and assessing the degree to which the data would support quantitative analysis, the committee focused on two key areas: A quantitative analysis of current and energy use, emissions, and externalities for highway transportation for both petroleum-based fuels and conventional biofuels for example, corn ethanol using the GREET Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model for primary analysis tied to the APEEP Air Pollution Emission Experiments and Policy model to estimate physical effects and monetary damages.
Transportation Life-Cycle Analysis Our goal is to develop and apply an LCA framework that can provide more detailed quantitative assessments of the comparative health and environmental benefits, risks, and costs of existing fossil fuels petroleumas well as future mixes of transportation technologies and fuels.
One can take either a top-down or bottom-up approach when allocating health and environmental costs to transportation technologies. The top-down approach considers morbidity and mortality statistics for a specific population, such as the inhabitants of a country or of a large urban region, and attempts to allocate these impacts to a specific source, such as transportation emissions or power-plant emissions.
The bottom-up approach provides a list of hazard sources such as pollutant releases and tracks these hazards from the source to exposure and damage.
Top-down assessments for air pollution have been carried out for many regions, making it possible to provide a disease-burden estimate for air pollution.
However, allocation to specific energy systems cannot be resolved because the top-down approach lacks the spatial and temporal resolution needed to track impacts to specific technologies. In contrast, the impact pathway assessment used in the ExternE study ECp. The life cycle of effects associated with using energy for transportation includes upstream effects, such as extracting and processing the fuels, building the infrastructure needed to use transportation systems for example, roadsbuilding the infrastructure needed to deliver energy for vehicles for example, pipelines and tankersand manufacturing the vehicles.
With respect to the categories of interest in this study, the committee summarized some of the key pathways by which energy sources for transportation lead to impacts.
In general, most of the emissions occur as a result of burning fossil fuels in the life cycle of transportation fuels.
Such energy use occurs across the supply chain, including fuel use for drilling oil wells or farming biomass fields, to transporting feedstocks and fuels to and from refineries, the refining process, transporting fuel to and from consumers, and the use of the fuels by consumers. The movement of feedstocks and fuels in the supply chain of transportation fuels is different from that of electricity.
Petroleum and petroleum products for example, gasoline or diesel fuel are generally transported by pipeline or truck; whereas coal, the primary energy source for electricity, is predominantly transported by rail.
A significant share of the petroleum used to make fuels is from foreign sources where it is extracted and delivered to the U. Various studies have been conducted of externalities of energy use in transportation. The term fuel cycle was intended to represent the entire cycle of effects associated with using fuels.
In general, these terms all refer to the holistic study of impacts from extraction through combustion of the fuel for transportation.
We also provide a unique and comprehensive estimate for the comparison of spatial distribution of the seals’ foraging effort, total and detailed prey consumption at the colony level, and fisheries landings for the same prey species, during the same period and at the same geographical scale. the spatial distribution of foragers within that patch feed back to inﬂuence the population dynamics of the central-place forager and the species richness of the associated recipient community. Based on the spatial distribution characteristics of the stable light, the saturation light of the electric power supply area of Japan was corrected using a cubic regression equation. The regression between the correction calculations by the cubic regression equation and the statistical electric power consumption data was applied in Japan and.
Prior studies around the world have assessed the relative contribution of environmental burdens from producing and using fuels for transportation for example, DelucchiMacLean and Lave a,b, Ogden et al.In this study, “scenario” is defined as the “spatial distribution of population and urban land use,” and “compact district” is defined as the “district which urban land use is concentrated.” “Urban land use” is mainly land use with artificial facilities: residential, industrial, commercial, public facilities and roads.
Quantification of spatial patterns like aggregation and adjacency in land uses within different landscape units found along the basin, shows correlations be-tween the dispersion of agricultural areas and the management techniques (Mouri et al.
, Salman et al. ). This determines the incidence of crop spatial distribution in river pollution. production and consumption of coal (World Coal Association ). Coal is the country's primary energy source as shown in Figure 1 (US Energy and Information Administration ).
"Disentangling spillover effects of antibiotic consumption: a spatial panel approach," Applied Economics, Taylor & Francis Journals, vol.
45(8), pages , March. Laura GonzÃ¡lez & . The Global Spatial Distribution of – Food declines as a share of the consumption basket – Falling transport costs reduce the benefit of living in a food‐producing area.
consumption choices in order to match the distribution of predicted restaurant choices made by the remainder of the population. Despite the magnitude of the estimated spatial and.