Emissions of greenhouse gases from the use of transportation fuels and electricity. Volume 1, Main text

This report presents estimates of full fuel-cycle emissions of greenhouse gases from using transportation fuels and electricity. The data cover emissions of carbon dioxide (CO{sub 2}), methane, carbon monoxide, nitrous oxide, nitrogen oxides, and nonmethane organic compounds resulting from the end use of fuels, compression or liquefaction of gaseous transportation fuels, fuel distribution, fuel production, feedstock transport, feedstock recovery, manufacture of motor vehicles, maintenance of transportation systems, manufacture of materials used in major energy facilities, and changes in land use that result from using biomass-derived fuels. The results for electricity use are in grams of CO{sub 2}-equivalent emissions per kilowatt-hour of electricity delivered to end users and cover generating plants powered by coal, oil, natural gas, methanol, biomass, and nuclear energy. The transportation analysis compares CO{sub 2}-equivalent emissions, in grams per mile, from base-case gasoline and diesel fuel cycles with emissions from these alternative- fuel cycles: methanol from coal, natural gas, or wood; compressed or liquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefied petroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity from coal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electric vehicles; and hydrogen and methanol used in fuel-cell vehicles

Comparison between transfer path analysis methods on an electric vehicle

A comparison between transfer path analysis and operational path analysis methods using an electric vehicle is presented in this study. Structure-borne noise paths to the cabin from different engine and suspension points have been considered. To realise these methods, two types of test have been performed; operational tests on a rolling road and hammer tests in static conditions. The main aim of this work is assessing the critical paths which are transmitting the structure-borne vibrations from the electric vehicle?s vibration sources to the driver?s ear. This assessment includes the analysis of the noise contribution of each path depending on the frequency and vehicle speed range and moreover, the assessment of the path noise impact for harmonic orders which arise due to the physical components of the electric vehicle. Furthermore, the applicability of these methods to electric vehicles is assessed as these techniques have been extensively used for vehicles powered with internal combustion engines.The authors would like to acknowledge the COST ACTION TU1105 for supporting this research

HLA-Driven Convergence of HIV-1 Viral Subtypes B and F Toward the Adaptation to Immune Responses in Human Populations

BACKGROUND: Cytotoxic T-Lymphocyte (CTL) response drives the evolution of HIV-1 at a host-level by selecting HLA-restricted escape mutations. Dissecting the dynamics of these escape mutations at a population-level would help to understand how HLA-mediated selection drives the evolution of HIV-1. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a study of the dynamics of HIV-1 CTL-escape mutations by analyzing through statistical approaches and phylogenetic methods the viral gene gag sequenced in plasma samples collected between the years 1987 and 2006 from 302 drug-naive HIV-positive patients. By applying logistic regression models and after performing correction for multiple test, we identified 22 potential CTL-escape mutations (p-value<0.05; q-value<0.2); 10 of these associations were confirmed in samples biologically independent by a Bayesian Markov Chain Monte-Carlo method. Analyzing their prevalence back in time we found that escape mutations that are the consensus residue in samples collected after 2003 have actually significantly increased in time in one of either B or F subtype until becoming the most frequent residue, while dominating the other viral subtype. Their estimated prevalence in the viral subtype they did not dominate was lower than 30% for the majority of samples collected at the end of the 80's. In addition, when screening the entire viral region, we found that the 75% of positions significantly changing in time (p<0.05) were located within known CTL epitopes. CONCLUSIONS: Across HIV Gag protein, the rise of polymorphisms from independent origin during the last twenty years of epidemic in our setting was related to an association with an HLA allele. The fact that these mutations accumulated in one of either B or F subtypes have also dominated the other subtype shows how this selection might be causing a convergence of viral subtypes to variants which are more likely to evade the immune response of the population where they circulate

Alternative Transportation Energy

Transportation energy issues are moving to the forefront of the public consciousness in the U.S. and particularly California, and gaining increasing attention from legislators and regulators. The three principal concerns motivating interest in transportation energy are urban air quality, oil dependence, and the threat of global warming. Transportation fuels are a principal contributor to each of these. The transportation sector, mostly motor vehicles, contributes roughly half the urban air pollutants, almost one-third of the carbon dioxide, and consumes over 60% of all petroleum

Addendum to Emissions of greenhouse gases from the use of transportation fuels and electricity. Effect of 1992 revision of global warming potential (GWP) by the Intergovernmental Panel on Climate Change (IPCC).

This addendum contains 2 important messages. (1) This document supersedes all previous versions of this work. Please do not use any older versions any more. (2) The atmospheric-science community now believes that it cannot estimate confidently the ''Global Warming Potentials'' (GWPs) of the indirect effects of greenhouse gases. A GWP is a number that converts a mass-unit emission of a greenhouse gas other than CO{sub 2} into the mass amount of CO{sub 2} that has an equivalent warming effect over a given period of time. This report refers to GWPs as ''CO{sub 2}-equivalency factors.'' For example, a forthcoming report by the Intergovernmental Panel on Climate Change disavows many of the GWPs estimated in an earlier IPCC report, and states that GWPs for the indirect effects of the non-CO{sub 2} greenhouse gases cannot be estimated accurately yet. However, this does not mean that in principle there are no GWPs for the non-CO{sub 2} greenhouse gases; rather, it means that some of the GWPs are uncertain, and that the earlier IPCC estimates of the GWPs may or may not turn out to be right (albeit, in at lease one case, discussed in this paper, the earlier estimates almost certainly will be wrong). In this report the author used the IPCC's 1990 estimates of the GWPs for 20-, 100-, and 500-year time horizons, and expressed the bottom-line results for each of these three time horizons. However, the recent uncertainty about the GWPs affects how you should interpret the results. Because the IPCC has disclaimed some of its GWPs, the GWPs as a group no longer are the best estimates of the warming effects over 20, 100, and 500 years. Instead, they are just a collection of possible values for the GWPs--in short, scenarios. Therefore, you should interpret the ''20-, 100-, and 500-year time horizons'' as three general GWP scenarios--say, scenarios, A, B, and C.--and not as time-period scenarios. For example, you should not think that the results shown here under the ''100-year time horizon'' actually embody the scientific community's best estimates of the relative warming potentials of the various greenhouse gases over a 100-year period. Instead, you should understand the results to be the outcome of making a particular set of assumptions about what the GWPs might be. The ''time horizons'' no longer necessarily represent time horizons, but rather general scenarios for, or assumptions about, the GWPs

Solar-Hydrogen Fuel-Cell Vehicles

Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powered electric vehicles (BPEVS) -- zero emissions, high efficiency, quiet operation and long life -- with the long range and fast refueling time of internal-combustion-engine vehicles (ICEVs). If fuel-cell technology develops as hoped, then hydrogen FCEVs will be a significant advance over both hydrogen ICEVs and solar BPEVs: they will be cleaner and more efficient than hydrogen ICEVs, have a much shorter refueling time than BPEVs and have a lower life-cycle cost than both. Solar-hydrogen fuel-cell vehicles would be general-purpose zero-emission vehicles, and could be an important component of a strategy for reducing dependence on imported oil, mitigating global warming and improving urban air quality, at an acceptable cost

Solar-hydrogen fuel-cell vehicles

Hydrogen is an especially attractive transportation fuel. It is the least populating fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powered electric vehicles (BPEVS)-zero emissions, high efficiency, quiet operation and long life-with the long range and fast refueling time of internal-combustion-engine vehicles (ICEVs). If fuel-cell technology develops as hoped, then hydrogen FCEVs will be a significant advance over both hydrogen ICEVs and solar BPEVs: they will be cleaner and more efficient than hydrogen ICEVs, have a much shorter refueling time than BPEVs and have a lower life-cycle cost than both. Solar-hydrogen fuel-cell vehicles would be general-purpose zero-emission vehicles, and could be an important component of a strategy for reducing dependence on imported oil, mitigating global warming and improving urban air quality, at an acceptable cost.

Development of an ELISA for measuring the activity of tetanus toxoid in vaccines and comparison with the toxin neutralization test in mice

An enzyme-linked immunosorbent assay (ELISA) has been developed to measure anti-tetanus toxoid antibody levels in immunized guinea-pig sera as a useful alternative to the currently used toxin neutralization test (TNT) in determining the activity of the tetanus toxoid in vaccines. The ELISA was found to measure antibody levels as low as 5.8 x 10(-5) IU/ml. Furthermore, a comparison of the results from ELISA and TNT involving 132 different commercial vaccines showed a very good correlation (r = 0.94, p < 0.001) between antibody levels measured by both methods. The results suggest that the proposed ELISA is a reliable, simple and economical alternative to the TNT in mice for assessing the activity of tetanus toxoids in vaccines