Analysis of the potential of sustainable forest-based bioenergy for climate change mitigation

Current climate mitigation policies are likely to become a strong driver of increased demand for renewable energy sources and particularly for bioenergy. Therefore, it is becoming more and more important to assess the potential amount of biomass that will be available for future energy production and the costs, in terms of greenhouse gas (GHG) emissions, connected to extraction of these potentials. The estimate of emissions produced by different bioenergy sources is important for evaluating the advantages of biomass-based energy compared to fossil fuel use. This allows promotion of energy sources that are the most advantageous for climate mitigation

The long-term price-earnings ratio

price-earnings ratio;value premium;arbitrage trading rule;UK stock returns;contrarian investment Abstract:  The price-earnings effect has been thoroughly documented and is the subject of numerous academic studies. However, in existing research it has almost exclusively been calculated on the basis of the previous year's earnings. We show that the power of the effect has until now been seriously underestimated due to taking too short-term a view of earnings. Looking at all UK companies since 1975, using the traditional P/E ratio we find the difference in average annual returns between the value and glamour deciles to be 6%. This is similar to other authors' findings. We are able to almost double the value premium by calculating the P/E ratio using earnings averaged over the previous eight years

Effects of a nanoscopic filler on the structure and dynamics of a simulated polymer melt and the relationship to ultra-thin films

We perform molecular dynamics simulations of an idealized polymer melt surrounding a nanoscopic filler particle to probe the effects of a filler on the local melt structure and dynamics. We show that the glass transition temperature $T_g$ of the melt can be shifted to either higher or lower temperatures by appropriately tuning the interactions between polymer and filler. A gradual change of the polymer dynamics approaching the filler surface causes the change in the glass transition. We also find that while the bulk structure of the polymers changes little, the polymers close to the surface tend to be elongated and flattened, independent of the type of interaction we study. Consequently, the dynamics appear strongly influenced by the interactions, while the melt structure is only altered by the geometric constraints imposed by the presence of the filler. Our findings show a strong similarity to those obtained for ultra-thin polymer films (thickness $\lesssim 100$ nm) suggesting that both ultra-thin films and filled-polymer systems might be understood in the same context

Initial State Interactions for K−K^--Proton Radiative Capture

The effects of the initial state interactions on the $K^--p$ radiative capture branching ratios are examined and found to be quite sizable. A general coupled-channel formalism for both strong and electromagnetic channels using a particle basis is presented, and applied to all the low energy $K^--p$ data with the exception of the {\it 1s} atomic level shift. Satisfactory fits are obtained using vertex coupling constants for the electromagnetic channels that are close to their expected SU(3) values.Comment: 16 pages, uses revte

Probing mSUGRA via the Extreme Universe Space Observatory

An analysis is carried out within mSUGRA of the estimated number of events originating from upward moving ultra-high energy neutralinos that could be detected by the Extreme Universe Space Observatory (EUSO). The analysis exploits a recently proposed technique that differentiates ultra-high energy neutralinos from ultra-high energy neutrinos using their different absorption lengths in the Earth's crust. It is shown that for a significant part of the parameter space, where the neutralino is mostly a Bino and with squark mass $\sim 1$ TeV, EUSO could see ultra-high energy neutralino events with essentially no background. In the energy range 10^9 GeV < E < 10^11 GeV, the unprecedented aperture of EUSO makes the telescope sensitive to neutralino fluxes as low as 1.1 \times 10^{-6} (E/GeV)^{-1.3} GeV^{-1} cm^{-2} yr^{-1} sr^{-1}, at the 95% CL. Such a hard spectrum is characteristic of supermassive particles' $N$-body hadronic decay. The case in which the flux of ultra-high energy neutralinos is produced via decay of metastable heavy particles with uniform distribution throughout the universe is analyzed in detail. The normalization of the ratio of the relics' density to their lifetime has been fixed so that the baryon flux produced in the supermassive particle decays contributes to about 1/3 of the events reported by the AGASA Collaboration below 10^{11} GeV, and hence the associated GeV gamma-ray flux is in complete agreement with EGRET data. For this particular case, EUSO will collect between 4 and 5 neutralino events (with 0.3 of background) in ~ 3 yr of running. NASA's planned mission, the Orbiting Wide-angle Light-collectors (OWL), is also briefly discussed in this context.Comment: Some discussion added, final version to be published in Physical Review

Improved methods for carbon accounting for bioenergy: descriptions and evaluations

Under the United Nations Framework Convention on Climate Change, carbon dioxide emissions from bioenergy are counted as carbon stock losses in the land use sector rather than in the energy sector. This method omits many emissions since many nations that source biomass for bioenergy do not have greenhouse gas obligations. Accounting systems have been proposed to address this omission. This working paper describes and classifies these accounting systems into three basic types. Type 1 counts carbon dioxide emissions from bioenergy combustion unaccounted for in the energy sector. Type 2 counts bioenergy combustion emission accounted for in the energy sector. Type 3 counts all other emissions along the supply chain, which are the responsibility of end users. The accounting systems are evaluated against three criteria: comprehensiveness, simplicity and scale independence. They are also evaluated again three key stakeholder goals: stimulation of rural economies and food security, greenhouse gas emission reductions and preservation of forests. The paper describes four key conclusions. First, Type 2 approaches incorporate more emissions than Type 1 in the real-world situation. Second, a Type 2 system that includes carbon dioxide uptake by vegetation in the land use sector ranks highly if stimulation of rural economies and food security is a priority. However, it may not preserve forests or stimulate bioenergy development. Third, policies can make Type 1 approaches effective. However, this may be of limited value if many countries remain outside the accounting system. Fourth, a Type 3 approach supports greenhouse gas emission reductions and preservation of forests but is less simple, and stimulation of the rural economy depends on the structure of the cap-and-trade system

Zero, one, or in between: Evaluation of alternative national and entity-level accounting for bioenergy

Accounting for bioenergy's carbon dioxide (CO2) emissions, as done under the Kyoto Protocol (KP) and European Union (EU) Emissions Trading Scheme, fails to capture the full extent of these emissions. As a consequence, other approaches have been suggested. Both the EU and United States already use value-chain approaches to determine emissions due to biofuels – an approach quite different from that of the KP. Further, both the EU and United States are engaged in consultation processes to determine how emissions connected with use of biomass for heat and power will be handled under regulatory systems. The United States is considering whether CO2 emissions from biomass should be handled like fossil fuels. In this context, this article reviews and evaluates the three basic bioenergy accounting options.* CO2 emissions from bioenergy are not counted at the point of combustion. Instead emissions due to use of biomass are accounted for in the land-use sector as carbon stock losses – a combustion factor (CoF) = 0 approach; * CO2 emissions from bioenergy are accounted for in the energy sector – a CoF = 1 approach; and * End users account for all or a specified subset of CO2 emissions, regardless of where geographically these emissions occur – 0 < CoF < 1. Following short descriptions of the basic options, this article discusses variations to these options and uses numerical examples to illustrate the impacts of approaches at a local and international level. Finally, the alternative accounting systems are evaluated against general criteria and for impacts on selected stakeholder goals. General criteria considered are: (a) comprehensiveness, (b) simplicity, and (c) scale independence. Stakeholder goals reviewed are: (a) stimulation of rural economies, (b) food security, (c) GHG reductions, and (d) preservation of forests

Review of existing methods for carbon accounting

Forests are sources of biomass that can be used to create forest-based bioenergy, whether directly by establishing energy plantations on non-forestland, by using existing forest resources or by using residues from harvesting for nonbioenergy purposes. If created in a sustainable manner, this bioenergy can have significant positive greenhouse gas benefits. However, past experience provides strong reason to believe that significant bioenergy development will come at the expense of natural forests, either through direct conversion of forests to non-forestland or through indirect competition between land uses. Bioenergy development may increase the demand for agricultural land, which may be sourced from tropical forests. In this case, the net carbon balance would be highly negative. This paper first reviews existing methods for carbon accounting for forest-based bioenergy development.The review examines methodologies from: 1. the IPCC Good Practice Guidance for Land Use, Land-Use Change and Forestry (GPGLULUCF) and the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2006 IPCC Guidelines); and 2. Directive 2009/28/EC of the European Parliament and of the Council (EU Renewable Energy Directive)

Technologies to produce liquid biofuels for transportation: An overview

This report provides an overview of the state of the art of first and second generation biofuel production pathways. Information is provided on primary feedstocks, typical feedstock yields, available conversion technologies, biofuel production costs and market opportunities. In this report, a pathway element is considered first generation if it is deployed at commercial scale. Thus corn, sugarcane, oil palm, and soya are first generation feedstocks, whereas jatropha is a second generation feedstock. Conversion technologies are similarly divided into first and second generation according to their level of deployment. Preferred feedstock production systems depend on country or regional circumstances. Factors such as climate and soils, marketing opportunities, traditional crop and land uses, and local production costs determine preferred biofuel production pathways. Currently the primary feedstocks for ethanol are corn and sugarcane, whereas soya, rapeseed and oil palm are the primary feedstocks used for biodiesel production. The easiest and lowest greenhouse gas (GHG) production path to ethanol is fermentation of sugarcane. Converting corn or similar starches into ethanol is more complex, because the raw material has to be converted to sugar prior fermentation. These pathways also tend to result in higher GHG emissions. Conversion of plant oils to biodiesel is primarily done via transesterification. Conversion of lignocellulosic materials (woodchips, straw, algae etc.) to ethanol or biodiesel requires second generation conversion technologies. Thermochemical processes can be used to convert these feedstocks into biodiesel (e.g., via Fischer-Tropsch processes), or enzymatic hydrolysis can be used to produce bioethanol. Currently ethanol from sugarcane is the only biofuel that is cost-competitive with fossil-based transportation fuels. Both biodiesel via transesterification and biofuels produced via second generation conversion processes have high production costs and need subsidies or higher fossil fuel prices to be competitive. Although export of biofuels could be a source of income for developing countries, trade in biofuels is expected to remain a small fraction of total biofuel production