Heat pumps; Synergy of high efficiency and low carbon electricity

Energy Technology Data Exchange (ETDEWEB)

Koike, Akio

2010-09-15

Heat pump is attracting wide attention for its high efficiency to utilize inexhaustible and renewable ambient heat in the environment. With its rapid innovation and efficiency improvement, this technology has a huge potential to reduce CO2 emissions by replacing currently widespread fossil fuel combustion systems to meet various heat demands from the residential, commercial and industrial sectors. Barriers to deployment such as low public awareness and a relatively long pay-back period do exist, so it is strongly recommended that each country implement policies to promote heat pumps as a renewable energy option and an effective method to combat global warming.

Fossil fuel-fired power generation. Case studies of recently constructed coal- and gas-fired plants

Energy Technology Data Exchange (ETDEWEB)

Henderson, C. [IEA Clean Coal Centre, London (United Kingdom)

2007-10-23

To meet future energy demand growth and replace older or inefficient units, a large number of fossil fuel-fired plants will be required to be built worldwide in the next decade. Yet CO{sub 2} emissions from fossil-fired power generation are a major contributor to climate change. As a result, new plants must be designed and operated at highest efficiency both to reduce CO{sub 2} emissions and to facilitate deployment of CO{sub 2} capture and storage in the future. The series of case studies in this report, which respond to a request to the IEA from the G8 Summit in July 2005, were conducted to illustrate what efficiency is achieved now in modern plants in different parts of the world using different grades of fossil fuels. The plants were selected from different geographical areas, because local factors influence attainable efficiency. The case studies include pulverized coal combustion (PCC) with both subcritical and supercritical (very high pressure and temperature) steam turbine cycles, a review of current and future applications of coal-fuelled integrated gasification combined cycle plants (IGCC), and a case study of a natural gas fired combined cycle plant to facilitate comparisons. The results of these analyses show that the technologies for high efficiency (low CO{sub 2} emission) and very low conventional pollutant emissions (particulates, SO{sub 2}, NOx) from fossil fuel-fired power generation are available now through PCC, IGCC or NGCC at commercially acceptable cost. This report contains comprehensive technical and indicative cost information for modern fossil fuel-fired plants that was previously unavailable. It serves as a valuable sourcebook for policy makers and technical decision makers contemplating decisions to build new fossil fuel-fired power generation plants.

A Bayesian stochastic frontier analysis of Chinese fossil-fuel electricity generation companies

International Nuclear Information System (INIS)

Chen, Zhongfei; Barros, Carlos Pestana; Borges, Maria Rosa

2015-01-01

This paper analyses the technical efficiency of Chinese fossil-fuel electricity generation companies from 1999 to 2011, using a Bayesian stochastic frontier model. The results reveal that efficiency varies among the fossil-fuel electricity generation companies that were analysed. We also focus on the factors of size, location, government ownership and mixed sources of electricity generation for the fossil-fuel electricity generation companies, and also examine their effects on the efficiency of these companies. Policy implications are derived. - Highlights: • We analyze the efficiency of 27 quoted Chinese fossil-fuel electricity generation companies during 1999–2011. • We adopt a Bayesian stochastic frontier model taking into consideration the identified heterogeneity. • With reform background in Chinese energy industry, we propose four hypotheses and check their influence on efficiency. • Big size, coastal location, government control and hydro energy sources all have increased costs

New fossil fuel combustion technologies

International Nuclear Information System (INIS)

Minghetti, E.; Palazzi, G.

1995-01-01

The aim of the present article is to supply general information concerning fossil fuels that represent, today and for the near future, the main energy source of our Planet. New fossil fuel technologies are in continual development with two principal goals: to decrease environmental impact and increase transformation process efficiency. Examples of this efforts are: 1) gas-steam combined cycles integrated with coal gasification plants, or with pressurized-fluidized-bed combustors; 2) new cycles with humid air or coal direct fired turbine, now under development. In the first part of this article the international and national energy situations and trends are shown. After some brief notes on environmental problems and alternative fuels, such as bio masses and municipal wastes, technological aspects, mainly relevant to increase fossil-fueled power plant performances, are examined in greater depth. Finally the research and technological development activities of ENEA (Italian Agency for New Technologies, Energy and Environment) Engineering Branch, in order to improve fossil fuels energy and environmental use are presented

Proceedings of the eleventh annual conference on fossil energy materials

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R. [comp.

1997-12-01

The objective of the Advanced Research and Technology Development (AR and TD) Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. These proceedings contain 34 papers organized under the following topical sections: Ceramic composites and functional materials; Ceramics, new alloys, and functional materials; and New alloys. Also included is a summary of a workshop on materials issues in low emission boilers and in high efficiency coal-fired cycles. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Energy and the transport sector. [For countries with no fossil fuels

Energy Technology Data Exchange (ETDEWEB)

Olson, P E

1979-01-01

This article describes the current energy situation from both the global viewpoint and the viewpoint of countries with no indigenous sources of fossil fuels. The lack of fossil fuels necessitates a substitution with indigenous sources of energy, where feasible. Long-distance railway transport is a self-evident element in the expanding transport sector. In view of the proven high energy efficiency of electric railway systems, there is every incentive for a more active investment policy in railway electrification. This applies to both medium-distance transportation of freight and passengers and different electric mass transit systems.

Wood anatomy reveals high theoretical hydraulic conductivity and low resistance to vessel implosion in a Cretaceous fossil forest from northern Mexico.

Science.gov (United States)

Martínez-Cabrera, Hugo I; Estrada-Ruiz, Emilio

2014-01-01

The Olmos Formation (upper Campanian), with over 60 angiosperm leaf morphotypes, is Mexico's richest Cretaceous flora. Paleoclimate leaf physiognomy estimates indicate that the Olmos paleoforest grew under wet and warm conditions, similar to those present in modern tropical rainforests. Leaf surface area, tree size and climate reconstructions suggest that this was a highly productive system. Efficient carbon fixation requires hydraulic efficiency to meet the evaporative demands of the photosynthetic surface, but it comes at the expense of increased risk of drought-induced cavitation. Here we tested the hypothesis that the Olmos paleoforest had high hydraulic efficiency, but was prone to cavitation. We characterized the hydraulic properties of the Olmos paleoforest using theoretical conductivity (Ks), vessel composition (S) and vessel fraction (F), and measured drought resistance using vessel implosion resistance (t/b)h(2) and the water potential at which there is 50% loss of hydraulic conductivity (P50). We found that the Olmos paleoforest had high hydraulic efficiency, similar to that present in several extant tropical-wet or semi-deciduous forest communities. Remarkably, the fossil flora had the lowest (t/b)h(2), which, together with low median P50 (-1.9 MPa), indicate that the Olmos paleoforest species were extremely vulnerable to drought-induced cavitation. Our findings support paleoclimate inferences from leaf physiognomy and paleoclimatic models suggesting it represented a highly productive wet tropical rainforest. Our results also indicate that the Olmos Formation plants had a large range of water conduction strategies, but more restricted variation in cavitation resistance. These straightforward methods for measuring hydraulic properties, used herein for the first time, can provide useful information on the ecological strategies of paleofloras and on temporal shifts in ecological function of fossil forests chronosequences.

Amorphizing of Cu Nanoparticles toward Highly Efficient and Robust Electrocatalyst for CO2 Reduction to Liquid Fuels with High Faradaic Efficiencies.

Science.gov (United States)

Duan, Yan-Xin; Meng, Fan-Lu; Liu, Kai-Hua; Yi, Sha-Sha; Li, Si-Jia; Yan, Jun-Min; Jiang, Qing

2018-04-01

Conversion of carbon dioxide (CO 2 ) into valuable chemicals, especially liquid fuels, through electrochemical reduction driven by sustainable energy sources, is a promising way to get rid of dependence on fossil fuels, wherein developing of highly efficient catalyst is still of paramount importance. In this study, as a proof-of-concept experiment, first a facile while very effective protocol is proposed to synthesize amorphous Cu NPs. Unexpectedly, superior electrochemical performances, including high catalytic activity and selectivity of CO 2 reduction to liquid fuels are achieved, that is, a total Faradaic efficiency of liquid fuels can sum up to the maximum value of 59% at -1.4 V, with formic acid (HCOOH) and ethanol (C 2 H 6 O) account for 37% and 22%, respectively, as well as a desirable long-term stability even up to 12 h. More importantly, this work opens a new avenue for improved electroreduction of CO 2 based on amorphous metal catalysts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

International Nuclear Information System (INIS)

Brown, L.C.; Funk, J.F.; Showalter, S.K.

1999-01-01

OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study

Developments in fossil fuel electricity generation

International Nuclear Information System (INIS)

Williams, A.; Argiri, M.

1993-01-01

A major part of the world's electricity is generated by the combustion of fossil fuels, and there is a significant environmental impact due to the production of fossil fuels and their combustion. Coal is responsible for 63% of the electricity generated from fossil fuels; natural gas accounts for about 20% and fuel oils for 17%. Because of developments in supply and improvements in generating efficiencies there is apparently a considerable shift towards a greater use of natural gas, and by the year 2000 it could provide 25% of the world electricity output. At the same time the amount of fuel oil burned will have decreased. The means to minimize the environmental impact of the use of fossil fuels, particularly coal, in electricity production are considered, together with the methods of emission control. Cleaner coal technologies, which include fluidized bed combustion and an integrated gasification combined cycle (IGCC), can reduce the emissions of NO x , SO 2 and CO 2 . (author)

Next generation of high-efficient waste incinerators. Final report

Energy Technology Data Exchange (ETDEWEB)

Jappe Frandsen, F.

2010-11-15

Modern society produces increasing amounts of combustible waste which may be utilized for heat and power production, at a lower emission of CO{sub 2}, e.g. by substituting a certain fraction of energy from fossil fuel-fired power stations. In 2007, 20.4 % of the district heating and 4.5 % of the power produced in Denmark came from thermal conversion of waste, and waste is a very important part of a future sustainable, and independent, Danish energy supply [Frandsen et al., 2009; Groen Energi, 2010]. In Denmark, approx 3.3 Mtons of waste was produced in 2005, an amount predicted to increase to 4.4 Mtons by the year 2030. According to Affald Danmark, 25 % of the current WtE plant capacity in Denmark is older than 20 years, which is usually considered as the technical and economical lifetime of WtE plants. Thus, there is a need for installation of a significant fraction of new waste incineration capacity, preferentially with an increased electrical efficiency, within the next few years. Compared to fossil fuels, waste is difficult to handle in terms of pre-treatment, combustion, and generation of reusable solid residues. In particular, the content of inorganic species (S, Cl, K, Na, etc.) is problematic, due to enhanced deposition and corrosion - especially at higher temperatures. This puts severe constraints on the electrical efficiency of grate-fired units utilizing waste, which seldom exceeds 26-27%, campared to 46-48 % for coal combustion in suspension. The key parameters when targeting higher electrical efficiency are the pressure and temperature in the steam cycle, which are limited by high-temperature corrosion, boiler- and combustion-technology. This report reviews some of the means that can be applied in order to increase the electrical efficiency in plants firing waste on a grate. (Author)

Advanced Nanomaterials for High-Efficiency Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Chen, Junhong [University of Wisconsin-Milwaukee

2013-11-29

Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these

Fossil energy biotechnology: A research needs assessment. Final report

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

The Office of Program Analysis of the US Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation`s fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and, (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

Highly-Efficient Thermoelectronic Conversion of Heat and Solar Radiation to Electric Power

OpenAIRE

Meir, Stefan

2013-01-01

Thermionic energy conversion has long been a candidate to convert solar radiation and the combustion heat of fossil fuels into electricity at high efficiencies. However, the formation of electron space charges has prevented the widespread use of the principle since its was first suggested in 1915. In this work, a novel mechanism to suppress the effects of the space charge was investigated: the acceleration of electrons in a special configuration of electric and magnetic fields. This work d...

Development of the ultra high efficiency thermal power generation facility

Energy Technology Data Exchange (ETDEWEB)

Sano, Toshihiro

2010-09-15

In order to prevent global warming, attention is focused on nuclear power generation and renewable energy such as wind and solar power generation. The electric power suppliers of Japan are aiming to increase the amount of nuclear and non-fossil fuel power generation over 50% of the total power generation by 2020. But this means that the remaining half will still be of thermal power generation using fossil fuel and will still play an important role. Under such circumstances, further efficiency improvement of the thermal power generation and its aggressive implementation is ongoing in Japan.

The effects of variable renewable electricity on energy efficiency and full load hours of fossil-fired power plants in the European Union

NARCIS (Netherlands)

de Groot, Mats; Crijns-Graus, Wina; Harmsen, Robert

2017-01-01

This study focused on the effects of variable renewable electricity (VRE) on full load hours and energy efficiency of fossil-fired power generation in the European Union from 1990-2014. Member states were aggregated into three groups based on the level of VRE penetration. Average full load hours are

Fossil fuel usage and the environment

International Nuclear Information System (INIS)

Klass, D.L.

1991-01-01

The Greenhouse Effect and global warming, ozone formation in the troposphere, ozone destruction in the stratosphere, and acid rain are important environmental issues. The relationship of fossil fuel usage to some of these issues is discussed. Data on fossil fuel consumption and the sources and sinks of carbon dioxide, carbon monoxide, methane, nitrogen and sulfur oxides, and ozone indicate that natural gas provides lower emissions of carbon dioxide, carbon monoxide, and nitrogen and sulfur oxides than other fossil fuels. Global emissions of methane from the gas industry are significantly less than those from other anthropogenic activities and natural sources, and methane plays an important role along with carbon monoxide and nitric oxide in tropospheric ozone formation. Reductions in any or all of these air pollutants would reduce ozone in the lower atmosphere. Several remedial measures have been or are being implemented in certain countries to reduce fossil fuel emissions. These include removal of emissions from the atmosphere by new biomass growth, fuel substitution by use of cleaner burning fuels for stationary and mobile sources, and fossil fuel combustion at higher efficiencies. It is unlikely that concerted environmental action by all governments of the world will occur soon, but much progress has been made to achieve clean air

Hydrogen as a renewable and sustainable solution in reducing global fossil fuel consumption

International Nuclear Information System (INIS)

Midilli, Adnan; Dincer, Ibrahim

2008-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for reducing global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions are derived depending primarily upon the exergetic utilization ratios of fossil fuels and hydrogen: the fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency, fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator. These relations incorporate predicted exergetic utilization ratios for hydrogen energy from non-fossil fuel resources such as water, etc., and are used to investigate whether or not exergetic utilization of hydrogen can significantly reduce the fossil fuel based global irreversibility coefficient (ranging from 1 to +∞) indicating the fossil fuel consumption and contribute to increase the hydrogen based global exergetic indicator (ranging from 0 to 1) indicating the hydrogen utilization at a certain ratio of fossil fuel utilization. In order to verify all these exergetic expressions, the actual fossil fuel consumption and production data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. For the verification of these parameters, the variations of fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator as the functions of fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency and exergetic utilization of hydrogen from non-fossil fuels are analyzed and discussed in detail. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases

Carbon dioxide from fossil fuels: adapting to uncertainty

Energy Technology Data Exchange (ETDEWEB)

Chen, K; Winter, R C; Bergman, M K

1980-12-01

If present scientific information is reasonable, the world is likely to experience noticeable global warming by the beginning of the next century if high annual growth rates of fossil-fuel energy use continue. Only with optimistic assumptions and low growth rates will carbon-dioxide-induced temperature increases be held below 2/sup 0/C or so over the next century. Conservation, flexible energy choices, and control options could lessen the potential effects of carbon dioxide. Though perhaps impractical from the standpoint of costs and efficiency losses, large coastal centralized facilities would be the most amenable to carbon dioxide control and disposal. Yet no country can control carbon dioxide levels unilaterally. The USA, however, which currently contributes over a quarter of all fossil-fuel carbon dioxide emissions and possesses a quarter of the world's coal resources, could provide a much needed role in leadership, research and education. 70 references.

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER FINAL RECHNICAL REPORT FOR THE PERIOD AUGUST 1, 1999 THROUGH SEPTEMBER 30, 2002 REV. 1

Energy Technology Data Exchange (ETDEWEB)

BROWN,LC; BESENBRUCH,GE; LENTSCH, RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-12-01

OAK-B135 Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy [1-1,1-2]. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties [1-3,1-4]. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily

The Inefficiencies of Energy Efficiency : Reviewing the Strategic Role of Energy Efficiency and its Effectiveness in Alleviating Climate Change

NARCIS (Netherlands)

Read, S.A.; Lindhult, Erik; Mashayekhi, A.

2016-01-01

Our present economy is high-energy and demand-intensive, demand met through the use of high energy yield fossil fuels. Energy efficiency and renewable energy sources are proposed as the solution and named the ‘twin pillars’ of sustainable energy policy. Increasing energy efficiencies are expected to

Energy efficiency of milkmaid systems in Uruguay

International Nuclear Information System (INIS)

LLanos, E.; Astigarraga, L.; Jacques, R.; Picasso, V.

2013-01-01

Reducing fossil fuel consumption and increasing energy efficiency of agricultural systems may result in environmental and economic benefits. The aim of this study was to analyze dairy production systems from an energy perspective, to identify the main variables affecting energy efficiency and fossil energy consumption, through a model of inputs and outputs. The model included as inputs energy costs of food, labor, electricity, agrochemicals, fuels and machinery, and as outputs dairy and meat production. We analyzed a database of 30 dairy farms from southern Uruguay, from the Cooperative Nacional de Product ores de Leche (Conaprole), organized in three strata based on their dairy productivity per hectare. The fossil energy use was 2.40, 3.63 y 3.80 MJ.l-1 for productivity strata low, medium and high respectively (P<0.01). Energy efficiency averages were 1.40, 0.90 y 0.86 for the same strata (P<0.01). Fossil energy of agrochemicals and fuel accounted for more than 80% of the energy consumed in the three strata. The greater the percentage of concentrate in the diet, the lower energy efficiency (P<0.01). These results suggest the existence of a negative relationship between the intensification of dairy production and energy efficiency

Bayesian phylogenetic estimation of fossil ages.

Science.gov (United States)

Drummond, Alexei J; Stadler, Tanja

2016-07-19

Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth-death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the 'morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses.This article is part of the themed issue 'Dating species divergences using

Program energy research and energy technologies. Annual report 1987. Fossil energy carriers, renewable energy sources, efficient use of energy. Programm Energieforschung und Energietechnologien. Jahresbericht 1987. Fossile Energietraeger, erneuerbare Energiequellen, rationelle Energieverwendung

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

After a general introduction and a short overview of financial contributions in 1987 there is a description of the projects sponsored. The main section contains project descriptions of the partial programmes Fossil Energy Carriers, Renewable Energy Sources and Efficient Use of Energy. The ordering of the wide-ranging material is carried out essentially via two indices: the index of project numbers and the index of companies. Then an overview is given of final reports published in 1987. A list of 1987 patents forms the final section.

Evaluation of hard fossil fuel

International Nuclear Information System (INIS)

Zivkovic, S.; Nuic, J.

1999-01-01

Because of its inexhaustible supplies hard fossil fuel will represent the pillar of the power systems of the 21st century. Only high-calorie fossil fuels have the market value and participate in the world trade. Low-calorie fossil fuels ((brown coal and lignite) are fuels spent on the spot and their value is indirectly expressed through manufactured kWh. For the purpose of determining the real value of a tonne of low-calorie coal, the criteria that help in establishing the value of a tonne of hard coal have to be corrected and thus evaluated and assessed at the market. (author)

Fossil Explorers

Science.gov (United States)

Moran, Sean; McLaughlin, Cheryl; MacFadden, Bruce; Jacobbe, Elizabeth; Poole, Michael

2015-01-01

Many young learners are fascinated with fossils, particularly charismatic forms such as dinosaurs and giant sharks. Fossils provide tangible, objective evidence of life that lived millions of years ago. They also provide a timescale of evolution not typically appreciated by young learners. Fossils and the science of paleontology can, therefore,…

Financial subsidies to the Australian fossil fuel industry

International Nuclear Information System (INIS)

Riedy, Chris; Diesendorf, Mark

2003-01-01

A common claim during international greenhouse gas reduction negotiations has been that domestic emissions cuts will harm national economies. This argument fails to consider the distorting effect of existing financial subsidies and associated incentives to fossil fuel production and consumption provided by governments in most developed countries. These subsidies support a fossil fuel energy sector that is the major contributor to global greenhouse gas emissions and conflict with attempts to expand the role of sustainable energy technologies. Reform of these types of subsidies has the potential to provide substantial gains in economic efficiency as well as reductions in carbon dioxide emissions--a 'no regrets' outcome for the economy and the environment. This paper examines financial subsidies to fossil fuel production and consumption in Australia and estimates the magnitude of the subsidies. Subsidies and associated incentives to fossil fuel production and consumption in Australia are similar to those in the United States and the other countries that have pushed for increased 'flexibility' during international negotiations

Radioactivity in fossils at the Hagerman Fossil Beds National Monument.

Science.gov (United States)

Farmer, C Neal; Kathren, Ronald L; Christensen, Craig

2008-08-01

Since 1996, higher than background levels of naturally occurring radioactivity have been documented in both fossil and mineral deposits at Hagerman Fossil Beds National Monument in south-central Idaho. Radioactive fossil sites occur primarily within an elevation zone of 900-1000 m above sea level and are most commonly found associated with ancient river channels filled with sand. Fossils found in clay rich deposits do not exhibit discernable levels of radioactivity. Out of 300 randomly selected fossils, approximately three-fourths exhibit detectable levels of natural radioactivity ranging from 1 to 2 orders of magnitude above ambient background levels when surveyed with a portable hand held Geiger-Muller survey instrument. Mineral deposits in geologic strata also show above ambient background levels of radioactivity. Radiochemical lab analysis has documented the presence of numerous natural radioactive isotopes. It is postulated that ancient groundwater transported radioactive elements through sand bodies containing fossils which precipitated out of solution during the fossilization process. The elevated levels of natural radioactivity in fossils may require special precautions to ensure that exposures to personnel from stored or displayed items are kept as low as reasonably achievable (ALARA).

Fossil energy and food security

International Nuclear Information System (INIS)

Folke, G.

2001-01-01

To fulfil the basic goal of delivering food for the tables of the citizens, modern Western agriculture is extremely dependent on supporting material flows, infrastructure, and fossil energy. According to several observers, fossil fuel production is about to peak, i.e., oil extraction is no longer capable of keeping pace with the increasing demand. This situation may trigger an unprecedented increase in fossil energy prices, which may make the current highly energy dependent food production-distribution system highly vulnerable. The paper starts with a survey of this vulnerability. Also, the supply of phosphorus, a key factor in agriculture, may be at stake under such circumstances. The paper analyses this situation and discusses settlement structures integrated with agriculture that might increase food security by reducing energy demands. In the proposed ideal societal structure, agriculture is integrated with settlements and most of the food needed by the population is produced locally, and the nutrients for food production are recycled from households and animals by means of biological processes demanding considerably less mechanical investment and fossil support energy than the conventional type of agriculture. The vulnerability of this structure would be considerably lower, than that of the current system. (author)

Sustainability of Fossil Fuels

Science.gov (United States)

Lackner, K. S.

2002-05-01

For a sustainable world economy, energy is a bottleneck. Energy is at the basis of a modern, technological society, but unlike materials it cannot be recycled. Energy or more precisely "negentropy" (the opposite of entropy) is always consumed. Thus, one either accepts the use of large but finite resources or must stay within the limits imposed by dilute but self-renewing resources like sunlight. The challenge of sustainable energy is exacerbated by likely growth in world energy demand due to increased population and increased wealth. Most of the world still has to undergo the transition to a wealthy, stable society with the near zero population growth that characterizes a modern industrial society. This represents a huge unmet demand. If ten billion people were to consume energy like North Americans do today, world energy demand would be ten times higher. In addition, technological advances while often improving energy efficiency tend to raise energy demand by offering more opportunity for consumption. Energy consumption still increases at close to the 2.3% per year that would lead to a tenfold increase over the course of the next century. Meeting future energy demands while phasing out fossil fuels appears extremely difficult. Instead, the world needs sustainable or nearly sustainable fossil fuels. I propose the following definition of sustainable under which fossil fuels would well qualify: The use of a technology or resource is sustainable if the intended and unintended consequences will not force its abandonment within a reasonable planning horizon. Of course sustainable technologies must not be limited by resource depletion but this is only one of many concerns. Environmental impacts, excessive land use, and other constraints can equally limit the use of a technology and thus render it unsustainable. In the foreseeable future, fossil fuels are not limited by resource depletion. However, environmental concerns based on climate change and other environmental

Traversing the mountaintop: world fossil fuel production to 2050.

Science.gov (United States)

Nehring, Richard

2009-10-27

During the past century, fossil fuels--petroleum liquids, natural gas and coal--were the dominant source of world energy production. From 1950 to 2005, fossil fuels provided 85-93% of all energy production. All fossil fuels grew substantially during this period, their combined growth exceeding the increase in world population. This growth, however, was irregular, providing for rapidly growing per capita production from 1950 to 1980, stable per capita production from 1980 to 2000 and rising per capita production again after 2000. During the past half century, growth in fossil fuel production was essentially limited by energy demand. During the next half century, fossil fuel production will be limited primarily by the amount and characteristics of remaining fossil fuel resources. Three possible scenarios--low, medium and high--are developed for the production of each of the fossil fuels to 2050. These scenarios differ primarily by the amount of ultimate resources estimated for each fossil fuel. Total fossil fuel production will continue to grow, but only slowly for the next 15-30 years. The subsequent peak plateau will last for 10-15 years. These production peaks are robust; none of the fossil fuels, even with highly optimistic resource estimates, is projected to keep growing beyond 2050. World fossil fuel production per capita will thus begin an irreversible decline between 2020 and 2030.

Management of fossil natural resources: the impossible challenge?

International Nuclear Information System (INIS)

Loubens, Audrey

2013-10-01

A set of articles addresses various issues related to fossil energies and resources. A first set addresses the general context of fossil resources: the forced wedding between fossil energies and the environment (discussion of an annual report by the IEA on coal reserves), the availability of fossil fuels (discussion about the high share of fossil fuel in an always more renewable world). A second set addresses how to transform resources into reserves: discussion of the annual IEA report on conventional oil and gas reserves, on unconventional oil and gas reserves, and on coal reserves. The next set is a prospective one, and addresses the question of a scenario by 2040: the extremely high tension between fossil resources and geopolitical reality, and the question of the possibility of a world energy transition (discussions of the World Energy Outlook published by the IEA). Other issues are addressed by the last set of articles: the abundance of fossil energies obscures the potential of renewable energies, the evolution of the chemical industry towards alternative solutions in order to limit the use of hydrocarbons, and the territorial claims by Russia in the Arctic region

Fossil Crinoids

Science.gov (United States)

Hess, Hans; Ausich, William I.; Brett, Carlton E.; Simms, Michael J.

2003-01-01

Crinoids have graced the oceans for more than 500 million years. Among the most attractive fossils, crinoids had a key role in the ecology of marine communities through much of the fossil record, and their remains are prominent rock forming constituents of many limestones. This is the first comprehensive volume to bring together their form and function, classification, evolutionary history, occurrence, preservation and ecology. The main part of the book is devoted to assemblages of intact fossil crinoids, which are described in their geological setting in twenty-three chapters ranging from the Ordovician to the Tertiary. The final chapter deals with living sea lilies and feather stars. The volume is exquisitely illustrated with abundant photographs and line drawings of crinoids from sites around the world. This authoritative account recreates a fascinating picture of fossil crinoids for paleontologists, geologists, evolutionary and marine biologists, ecologists and amateur fossil collectors.

Economic value of U.S. fossil fuel electricity health impacts.

Science.gov (United States)

Machol, Ben; Rizk, Sarah

2013-02-01

Fossil fuel energy has several externalities not accounted for in the retail price, including associated adverse human health impacts, future costs from climate change, and other environmental damages. Here, we quantify the economic value of health impacts associated with PM(2.5) and PM(2.5) precursors (NO(x) and SO(2)) on a per kilowatt hour basis. We provide figures based on state electricity profiles, national averages and fossil fuel type. We find that the economic value of improved human health associated with avoiding emissions from fossil fuel electricity in the United States ranges from a low of $0.005-$0.013/kWh in California to a high of $0.41-$1.01/kWh in Maryland. When accounting for the adverse health impacts of imported electricity, the California figure increases to $0.03-$0.07/kWh. Nationally, the average economic value of health impacts associated with fossil fuel usage is $0.14-$0.35/kWh. For coal, oil, and natural gas, respectively, associated economic values of health impacts are $0.19-$0.45/kWh, $0.08-$0.19/kWh, and $0.01-$0.02/kWh. For coal and oil, these costs are larger than the typical retail price of electricity, demonstrating the magnitude of the externality. When the economic value of health impacts resulting from air emissions is considered, our analysis suggests that on average, U.S. consumers of electricity should be willing to pay $0.24-$0.45/kWh for alternatives such as energy efficiency investments or emission-free renewable sources that avoid fossil fuel combustion. The economic value of health impacts is approximately an order of magnitude larger than estimates of the social cost of carbon for fossil fuel electricity. In total, we estimate that the economic value of health impacts from fossil fuel electricity in the United States is $361.7-886.5 billion annually, representing 2.5-6.0% of the national GDP. Published by Elsevier Ltd.

Finding fossils in new ways: an artificial neural network approach to predicting the location of productive fossil localities.

Science.gov (United States)

Anemone, Robert; Emerson, Charles; Conroy, Glenn

2011-01-01

Chance and serendipity have long played a role in the location of productive fossil localities by vertebrate paleontologists and paleoanthropologists. We offer an alternative approach, informed by methods borrowed from the geographic information sciences and using recent advances in computer science, to more efficiently predict where fossil localities might be found. Our model uses an artificial neural network (ANN) that is trained to recognize the spectral characteristics of known productive localities and other land cover classes, such as forest, wetlands, and scrubland, within a study area based on the analysis of remotely sensed (RS) imagery. Using these spectral signatures, the model then classifies other pixels throughout the study area. The results of the neural network classification can be examined and further manipulated within a geographic information systems (GIS) software package. While we have developed and tested this model on fossil mammal localities in deposits of Paleocene and Eocene age in the Great Divide Basin of southwestern Wyoming, a similar analytical approach can be easily applied to fossil-bearing sedimentary deposits of any age in any part of the world. We suggest that new analytical tools and methods of the geographic sciences, including remote sensing and geographic information systems, are poised to greatly enrich paleoanthropological investigations, and that these new methods should be embraced by field workers in the search for, and geospatial analysis of, fossil primates and hominins. Copyright © 2011 Wiley-Liss, Inc.

Organic preservation of fossil musculature with ultracellular detail.

Science.gov (United States)

McNamara, Maria; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver-Mollá, Enrique

2010-02-07

The very labile (decay-prone), non-biomineralized, tissues of organisms are rarely fossilized. Occurrences thereof are invaluable supplements to a body fossil record dominated by biomineralized tissues, which alone are extremely unrepresentative of diversity in modern and ancient ecosystems. Fossil examples of extremely labile tissues (e.g. muscle) that exhibit a high degree of morphological fidelity are almost invariably replicated by inorganic compounds such as calcium phosphate. There is no consensus as to whether such tissues can be preserved with similar morphological fidelity as organic remains, except when enclosed inside amber. Here, we report fossilized musculature from an approximately 18 Myr old salamander from lacustrine sediments of Ribesalbes, Spain. The muscle is preserved organically, in three dimensions, and with the highest fidelity of morphological preservation yet documented from the fossil record. Preserved ultrastructural details include myofilaments, endomysium, layering within the sarcolemma, and endomysial circulatory vessels infilled with blood. Slight differences between the fossil tissues and their counterparts in extant amphibians reflect limited degradation during fossilization. Our results provide unequivocal evidence that high-fidelity organic preservation of extremely labile tissues is not only feasible, but likely to be common. This is supported by the discovery of similarly preserved tissues in the Eocene Grube Messel biota.

Fossil energy savings potential of sugar cane bio-energy systems

DEFF Research Database (Denmark)

Nguyen, Thu Lan T; Hermansen, John Erik; Sagisaka, Masayuki

2009-01-01

One important rationale for bio-energy systems is their potential to save fossil energy. Converting a conventional sugar mill into a bio-energy process plant would contribute to fossil energy savings via the extraction of renewable electricity and ethanol substituting for fossil electricity...... and gasoline, respectively. This paper takes a closer look at the Thai sugar industry and examines two practical approaches that will enhance fossil energy savings. The first one addresses an efficient extraction of energy in the form of electricity from the excess bagasse and cane trash. The second while...... proposing to convert molasses or sugar cane to ethanol stresses the use of bagasse as well as distillery spent wash to replace coal in meeting ethanol plants' energy needs. The savings potential achieved with extracting ethanol from surplus sugar versus current practice in sugar industry in Thailand amounts...

75 FR 66008 - Fossil Fuel-Generated Energy Consumption Reduction for New Federal Buildings and Major...

Science.gov (United States)

2010-10-27

... Fossil Fuel-Generated Energy Consumption Reduction for New Federal Buildings and Major Renovations of Federal Buildings; Correction AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... the fossil fuel- generated energy consumption [[Page 66009

The Fossile Episode

OpenAIRE

Hassler, John; Sinn, Hans-Werner

2012-01-01

We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an inital pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form expr...

The Fossil Episode

OpenAIRE

John Hassler; Hans-Werner Sinn

2012-01-01

We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an initial pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form exp...

Carbon-doped SnS2 nanostructure as a high-efficiency solar fuel catalyst under visible light.

Science.gov (United States)

Shown, Indrajit; Samireddi, Satyanarayana; Chang, Yu-Chung; Putikam, Raghunath; Chang, Po-Han; Sabbah, Amr; Fu, Fang-Yu; Chen, Wei-Fu; Wu, Chih-I; Yu, Tsyr-Yan; Chung, Po-Wen; Lin, M C; Chen, Li-Chyong; Chen, Kuei-Hsien

2018-01-12

Photocatalytic formation of hydrocarbons using solar energy via artificial photosynthesis is a highly desirable renewable-energy source for replacing conventional fossil fuels. Using an L-cysteine-based hydrothermal process, here we synthesize a carbon-doped SnS 2 (SnS 2 -C) metal dichalcogenide nanostructure, which exhibits a highly active and selective photocatalytic conversion of CO 2 to hydrocarbons under visible-light. The interstitial carbon doping induced microstrain in the SnS 2 lattice, resulting in different photophysical properties as compared with undoped SnS 2 . This SnS 2 -C photocatalyst significantly enhances the CO 2 reduction activity under visible light, attaining a photochemical quantum efficiency of above 0.7%. The SnS 2 -C photocatalyst represents an important contribution towards high quantum efficiency artificial photosynthesis based on gas phase photocatalytic CO 2 reduction under visible light, where the in situ carbon-doped SnS 2 nanostructure improves the stability and the light harvesting and charge separation efficiency, and significantly enhances the photocatalytic activity.

Uranium concentration in fossils

International Nuclear Information System (INIS)

Okano, J.; Uyeda, C.

1988-01-01

Recently it is known that fossil bones tend to accumulate uranium. The uranium concentration, C u in fossils has been measured so far by γ ray spectroscopy or by fission track method. The authors applied secondary ion mass spectrometry, SIMS, to detect the uranium in fossil samples. The purpose of this work is to investigate the possibility of semi-quantitative analyses of uranium in fossils, and to study the correlation between C u and the age of fossil bones. The further purpose of this work is to apply SIMS to measure the distribution of C u in fossil teeth

Modes of fossil preservation

Science.gov (United States)

Schopf, J.M.

1975-01-01

The processes of geologic preservation are important for understanding the organisms represented by fossils. Some fossil differences are due to basic differences in organization of animals and plants, but the interpretation of fossils has also tended to be influenced by modes of preservation. Four modes of preservation generally can be distinguished: (1) Cellular permineralization ("petrifaction") preserves anatomical detail, and, occasionally, even cytologic structures. (2) Coalified compression, best illustrated by structures from coal but characteristic of many plant fossils in shale, preserves anatomical details in distorted form and produces surface replicas (impressions) on enclosing matrix. (3) Authigenic preservation replicates surface form or outline (molds and casts) prior to distortion by compression and, depending on cementation and timing, may intergrade with fossils that have been subject to compression. (4) Duripartic (hard part) preservation is characteristic of fossil skeletal remains, predominantly animal. Molds, pseudomorphs, or casts may form as bulk replacements following dissolution of the original fossil material, usually by leaching. Classification of the kinds of preservation in fossils will aid in identifying the processes responsible for modifying the fossil remains of both animals and plants. ?? 1975.

Fossil fuel power generation within the European Research Area

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-12-10

The report is the first in a series of three produced by the PowerClean Thematic Network that looks at and defines future requirements for research and development of fossil fuel power generation in the European Union. It makes the case for fossil fuel R & D with emphasis on the need for clean coal technologies (to increased efficiency and other CO{sub 2} capture and storage) For satisfying future energy demands of the enlarged European Union between now and 2030. The report concludes that affirmative R, D and D action is needed to support the EU power industry, working together on a Europe-wide basis, to establish the use of coal and other fossil fuels in near-zero emissions power plant. The role model would be the European Research Area, as in the Sixth Framework Programme (FP6), but with a more comprehensive range of technical objectives recognising the importance of fossil fuels. Section headings are: introduction; current energy use; future needs and requirements; the future for clean fossil fuel energy in Europe; comparison with approaches adopted elsewhere (USA Vision 21 and FutureGen programmes, Japan); and responsibilities for EU coal R, D & D. 14 refs., 9 figs., 4 tabs.

Spatiotemporal patterns of the fossil-fuel CO2 signal in central Europe: results from a high-resolution atmospheric transport model

Science.gov (United States)

Liu, Yu; Gruber, Nicolas; Brunner, Dominik

2017-11-01

The emission of CO2 from the burning of fossil fuel is a prime determinant of variations in atmospheric CO2. Here, we simulate this fossil-fuel signal together with the natural and background components with a regional high-resolution atmospheric transport model for central and southern Europe considering separately the emissions from different sectors and countries on the basis of emission inventories and hourly emission time functions. The simulated variations in atmospheric CO2 agree very well with observation-based estimates, although the observed variance is slightly underestimated, particularly for the fossil-fuel component. Despite relatively rapid atmospheric mixing, the simulated fossil-fuel signal reveals distinct annual mean structures deep into the troposphere, reflecting the spatially dense aggregation of most emissions. The fossil-fuel signal accounts for more than half of the total (fossil fuel + biospheric + background) temporal variations in atmospheric CO2 in most areas of northern and western central Europe, with the largest variations occurring on diurnal timescales owing to the combination of diurnal variations in emissions and atmospheric mixing and transport out of the surface layer. The covariance of the fossil-fuel emissions and atmospheric transport on diurnal timescales leads to a diurnal fossil-fuel rectifier effect of up to 9 ppm compared to a case with time-constant emissions. The spatial pattern of CO2 from the different sectors largely reflects the distribution and relative magnitude of the corresponding emissions, with power plant emissions leaving the most distinguished mark. An exception is southern and western Europe, where the emissions from the transportation sector dominate the fossil-fuel signal. Most of the fossil-fuel CO2 remains within the country responsible for the emission, although in smaller countries up to 80 % of the fossil-fuel signal can come from abroad. A fossil-fuel emission reduction of 30 % is clearly

An early Oligocene fossil demonstrates treeshrews are slowly evolving "living fossils".

Science.gov (United States)

Li, Qiang; Ni, Xijun

2016-01-14

Treeshrews are widely considered a "living model" of an ancestral primate, and have long been called "living fossils". Actual fossils of treeshrews, however, are extremely rare. We report a new fossil species of Ptilocercus treeshrew recovered from the early Oligocene (~34 Ma) of China that represents the oldest definitive fossil record of the crown group of treeshrews and nearly doubles the temporal length of their fossil record. The fossil species is strikingly similar to the living Ptilocercus lowii, a species generally recognized as the most plesiomorphic extant treeshrew. It demonstrates that Ptilocercus treeshrews have undergone little evolutionary change in their morphology since the early Oligocene. Morphological comparisons and phylogenetic analysis support the long-standing idea that Ptilocercus treeshrews are morphologically conservative and have probably retained many characters present in the common stock that gave rise to archontans, which include primates, flying lemurs, plesiadapiforms and treeshrews. This discovery provides an exceptional example of slow morphological evolution in a mammalian group over a period of 34 million years. The persistent and stable tropical environment in Southeast Asia through the Cenozoic likely played a critical role in the survival of such a morphologically conservative lineage.

FOSSIL2 energy policy model documentation: FOSSIL2 documentation

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume II provides the model equations with each of their variables defined, while Volume III lists the equations, and a one line definition for equations, in a shorter, more readable format.

Screening potential social impacts of fossil fuels and biofuels for vehicles

International Nuclear Information System (INIS)

Ekener-Petersen, Elisabeth; Höglund, Jonas; Finnveden, Göran

2014-01-01

The generic social and socioeconomic impacts of various biofuels and fossil fuels were screened by applying Social Life Cycle Assessment methodology. Data were taken from the Social Hotspots Database on all categories for all the related themes and all indicators available. To limit the amount of data, only high and very high risk indicators were considered for each combination. The risks identified per life cycle phase were listed for each fuel assessed and the results were then aggregated by counting the number of high and very high risk indicators for that fuel. All the fossil fuels and biofuels analysed were found to display high or very high risks of negative impacts. Country of origin seemed to be of greater importance for risks than fuel type, as the most risk-related and least risk-related product systems referred to the same type of fuel, fossil oil from Russia/Nigeria and fossil oil from Norway, respectively. These results suggest that in developing policy, strict procurement requirements on social performance should be set for both fossil fuel and biofuel. However, the results must be interpreted with care owing to some limitations in the assessment, such as simplifications to life cycles, method used and data collection. - Highlights: • Both fossil and biofuels displayed high or very high risks of negative social impacts. • Social procurement requirements should be applied on all vehicle fuels. • Applying social criteria only on biofuels may be unfairly benefiting fossil fuels. • Social LCA can identify severe social impacts and influence policies accordingly. • Schemes can be adapted to include relevant criteria for specific fuels and/or origins

Fossil Fuels.

Science.gov (United States)

Crank, Ron

This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

Science.gov (United States)

Ulevicius, Vidmantas; Byčenkienė, Steigvilė; Bozzetti, Carlo; Vlachou, Athanasia; Plauškaitė, Kristina; Mordas, Genrik; Dudoitis, Vadimas; Abbaszade, Gülcin; Remeikis, Vidmantas; Garbaras, Andrius; Masalaite, Agne; Blees, Jan; Fröhlich, Roman; Dällenbach, Kaspar R.; Canonaco, Francesco; Slowik, Jay G.; Dommen, Josef; Zimmermann, Ralf; Schnelle-Kreis, Jürgen; Salazar, Gary A.; Agrios, Konstantinos; Szidat, Sönke; El Haddad, Imad; Prévôt, André S. H.

2016-05-01

In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m-3 and black carbon (BC) up to 17 µg m-3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26-44 % and 13-23 % to the total carbon (TC), respectively. 5-8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4-13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13-24 and 7-13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

Developing fossil fuel based technologies

International Nuclear Information System (INIS)

Manzoori, A.R.; Lindner, E.R.

1991-01-01

Some of the undesirable effects of burning fossil fuels in the conventional power generating systems have resulted in increasing demand for alternative technologies for power generation. This paper describes a number of new technologies and their potential to reduce the level of atmospheric emissions associated with coal based power generation, such as atmospheric and pressurized fluid bed combustion systems and fuel cells. The status of their development is given and their efficiency is compared with that of conventional pc fired power plants. 1 tab., 7 figs

Fossil plants from Romanian deposits of Bacles, Dolj District, Romania

Directory of Open Access Journals (Sweden)

Nicolae T̡icleanu

2001-09-01

Full Text Available From the Middle Romanian lacustrine deposits of the Oltenia province, the authors describe the youngest fossil flora known until now in Oltenia. The inventory of the fossil flora includes the following taxa: Taxodium dubium, ?Platanus platanifolia, Ulmus laevis, Quercus roburoides, Q. cf. muehlenbergii, Carya serraefolia, Acer cf. tricuspidatum and Salix sp. In the Bâcleş fossil flora, Glyptostrobus europaeus, which is a thermophilous and shows a high frequency in all Oltenia area till the XV-th coal seam, is absent. Consequently, having in view the high frequency of Taxodium dubium, which indicate temperate climate conditions, the other consider that the fossil flora from Bâcleş is much more younger and marks an important cooling. From palaeofloristic point of view, the study of Bâcleş fossil flora is indicative for river meadow forest and, probably, flat plain forest environments.

Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

Science.gov (United States)

Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

2018-04-01

Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

Clean fossil-fuelled power generation

International Nuclear Information System (INIS)

Oliver, Tony

2008-01-01

Using fossil fuels is likely to remain the dominant means of producing electricity in 2030 and even 2050, partly because power stations have long lives. There are two main ways of reducing CO 2 emissions from fossil-fuelled power plants. These are carbon capture and storage (CCS), which can produce near-zero CO 2 emissions, and increases in plant efficiency, which can give rise to significant reductions in CO 2 emissions and to reduced costs. If a typical UK coal-fired plant was replaced by today's best available technology, it would lead to reductions of around 25% in emissions of CO 2 per MW h of electricity produced. Future technologies are targeting even larger reductions in emissions, as well as providing a route, with CCS, to zero emissions. These two routes are linked and they are both essential activities on the pathway to zero emissions. This paper focuses on the second route and also covers an additional third route for reducing emissions, the use of biomass. It discusses the current status of the science and technologies for fossil-fuelled power generation and outlines likely future technologies, development targets and timescales. This is followed by a description of the scientific and technological developments that are needed to meet these challenges. Once built, a power plant can last for over 40 years, so the ability to upgrade and retrofit a plant during its lifetime is important

Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

Directory of Open Access Journals (Sweden)

V. Ulevicius

2016-05-01

Full Text Available In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1 was measured by an Aerodyne aerosol chemical speciation monitor (ACSM and a source apportionment with the multilinear engine (ME-2 running the positive matrix factorization (PMF model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m−3 and black carbon (BC up to 17 µg m−3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C measurements of the elemental (EC and organic (OC carbon fractions. Non-fossil organic carbon (OCnf was the dominant fraction of PM1, with the primary (POCnf and secondary (SOCnf fractions contributing 26–44 % and 13–23 % to the total carbon (TC, respectively. 5–8 % of the TC had a primary fossil origin (POCf, whereas the contribution of fossil secondary organic carbon (SOCf was 4–13 %. Non-fossil EC (ECnf and fossil EC (ECf ranged from 13–24 and 7–13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

A comparative study among fossil fuel power plants in PJM and California ISO by DEA environmental assessment

International Nuclear Information System (INIS)

Sueyoshi, Toshiyuki; Goto, Mika

2013-01-01

This study compares among fossil fuel power plants in PJM and California ISO by their unified (operational and environmental) performance. DEA (Data Envelopment Analysis) is used as a methodology. For comparative analysis, DEA incorporates strategic concepts such as natural and managerial disposability into the computational process. This study explores both how to measure Returns to Scale (RTS) under natural disposability and how to measure Damages to Scale (DTS) under managerial disposability. This empirical study obtains two implications on US energy policy. One of the two policy implications is that California ISO outperforms PJM in terms of the three unified efficiency measures. The result implies that strict regulation on undesirable outputs, as found in California, is important in enhancing the performance of US fossil fuel power plants. Thus, it is necessary for federal and local governments to regulate the fossil fuel power plants under the strict implementation of environmental protection. Under such a policy direction, it is possible for US fossil fuel power plants to attain economic prosperity (by enhancing their operational efficiencies) and to satisfy environmental regulation (by enhancing their environmental efficiencies). The other policy implication is that coal-fired and gas-fired power plants in PJM and California ISO need to reduce their operational sizes or introduce technology innovation on desirable and undesirable outputs and/or new management for environmental protection within their operations. Meanwhile, oil-fired power plants may increase their operational sizes if they can introduce technology innovation and new management on undesirable outputs. - Highlights: • This study compares fossil fuel power plants in PJM and California ISO. • California ISO outperforms PJM in terms of their unified efficiency measures. • Regulation by Clean Air Act is important for environmental protection. • Fossil fuel power plants need technology

Synergistic energy conversion process using nuclear energy and fossil fuels

International Nuclear Information System (INIS)

Hori, Masao

2007-01-01

Because primary energies such as fossil fuels, nuclear energy and renewable energy are limited in quantity of supply, it is necessary to use available energies effectively for the increase of energy demand that is inevitable this century while keeping environment in good condition. For this purpose, an efficient synergistic energy conversion process using nuclear energy and fossil fuels together converted to energy carriers such are electricity, hydrogen, and synthetic fuels seems to be effective. Synergistic energy conversion processes containing nuclear energy were surveyed and effects of these processes on resource saving and the CO 2 emission reduction were discussed. (T.T.)

Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

Science.gov (United States)

Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

2007-01-01

The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

Methods for efficient usage of energy and materials in high temperature metallurgical processes; Methoden zur Energie- und Stoffeffizienz in der metallurgischen Hochtemperaturtechnik

Energy Technology Data Exchange (ETDEWEB)

Scholz, Reinhard; Stuermer, Thomas [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik

2012-07-15

Metallurgy belongs to the most energy intensive industries where the chain of processes, from materials production to materials recycling, proceeds typically at high temperatures. The higher the process temperature, the more valuable is energy recovery. In parallel with the current trends of improving energy efficiencies, one observes an increase of energy conversion costs in conversion processes of both fossil fuels and renewable energy sources. The paper is concerned with methods of improving energy efficiencies, as well as, with establishing their maximum values determined by the thermodynamics of the metallurgical processes considered. In a number of processes, for example in the blast furnace process of pig iron production, these thermodynamic limits have been reached. Then, if the prices of raw materials and/or energy (electricity produced either from fossil fuels or from renewables) are on the rise, the industry does not have any other option but increasing the final product prices which obviously affect competitiveness. (orig.)

High efficiency bio-hydrogen production from glucose revealed in an inoculum of heat-pretreated landfill leachate sludge

International Nuclear Information System (INIS)

Wong, Y.M.; Juan, J.C.; Ting, Adeline; Wu, T.Y.

2014-01-01

Bio-hydrogen is a promising sustainable energy to replace fossil fuels. This study investigated bio-H 2 production from the inoculum of heat-pretreated landfill leachate sludge using glucose as model substrate. The seed sludge pretreated at 65 °C showed the highest amount of H 2 at the optimum condition of pH 6 and 37 °C. The maximum H 2 yield estimated by the modified Gompertz model was 6.43 mol H 2 /mol glucose. The high efficient of H 2 production is thermodynamically feasible with the Gibbs free energy of −34 kJ/mol. This study reveals that pretreated landfill leachate sludge has considerable potential for H 2 production. - Highlights: • Heat retreated landfill leachate sludge revealed high efficient H 2 production. • High efficient H 2 yield, 6.4 mol H 2 /mol glucose. • The synergisms between H 2 -producing bacteria may responsible for the high H 2 yield. • High H 2 yield is thermodynamically feasible with Gibbs free energy of −34 kJ/mol

Fossil energy. Program report, 1 October 1977-30 September 1978. [US DOE

Energy Technology Data Exchange (ETDEWEB)

None

1979-12-01

The Fossil Energy program is now in its second year under the Department of Energy. This document describes the Fossil Energy-supported contract and project activity for FY 1978. The primary thrust of the Program is on coal - especially direct coal combustion and what can be done to increase the environmental acceptability of coal. We are concerned with developing cleaner technologies, and we are working on precombustion cleanup, fluidized-bed combustion, and post-combustion cleanup. Longer range technologies are being developed to use coal more efficiently; for example, magnetohydrodynamics, fuel cells, and high-temperature turbine utilization. Another Fossil Energy priority is the development of a capability to produce synthetic fuels from coal. We are also engaged in a coal mining research and development program that focuses on increased mine productivity and workers' safety through the development of improved technologies. Our activity in the petroleum and gas research areas is intended to complement efforts in the private sector, which are to be further stimulated by new pricing or Federal incentives. Our present enhanced oil recovery efforts represent a shift in emphasis toward longer range, high-technology development projects instead of numerous field demonstrations and tests. The enhanced gas program emphasis activities to increase our knowledge of the size and economic productivity of the unconventional gas resources. We are also involved in oil shale development. We are continually assessing our program. Total annual funding has increased from $58 million in FY 1973 to $881 million in FY 1979.Fossil Energy is working closely with all parts of the Department of Energy, other appropriate Federal agencies, industry, and universities to insure that we maintain a balanced, aggressive, and responsive program suited to our national needs.

Synergistic production of hydrogen using fossil fuels and nuclear energy application of nuclear-heated membrane reformer

International Nuclear Information System (INIS)

Hori, M.; Matsui, K.; Tashimo, M.; Yasuda, I.

2004-01-01

Processes and technologies to produce hydrogen synergistically by the steam reforming reaction using fossil fuels and nuclear heat are reviewed. Formulas of chemical reactions, required heats for reactions, saving of fuel consumption or reduction of carbon dioxide emission, possible processes and other prospects are examined for such fossil fuels as natural gas, petroleum and coal. The 'membrane reformer' steam reforming with recirculation of reaction products in a closed loop configuration is considered to be the most advantageous among various synergistic hydrogen production methods. Typical merits of this method are: nuclear heat supply at medium temperature below 600 deg. C, compact plant size and membrane area for hydrogen production, efficient conversion of feed fuel, appreciable reduction of carbon dioxide emission, high purity hydrogen without any additional process, and ease of separating carbon dioxide for future sequestration requirements. With all these benefits, the synergistic production of hydrogen by membrane reformer using fossil fuels and nuclear energy can be an effective solution in this century for the world which has to use. fossil fuels any way to some extent while reducing carbon dioxide emission. For both the fossil fuels industry and the nuclear industry, which are under constraint of resource, environment and economy, this production method will be a viable symbiosis strategy for the coming hydrogen economy era. (author)

A revisit of fossil-fuel subsidies in China: Challenges and opportunities for energy price reform

International Nuclear Information System (INIS)

Lin, Boqiang; Ouyang, Xiaoling

2014-01-01

Highlights: • We measure fossil-fuel subsidies and effects of subsidy removal in a systematic fashion during 2006–2010. • Fossil-fuel subsidies scale of China was CNY 881.94 billion in 2010, equivalent to 2.59% of GDP. • Impacts of removing subsidies on macroeconomic variables are examined by the CGE model. • Future policy should focus on designing transparent, targeted and efficient energy subsidies. - Abstract: Fossil-fuel subsidies contribute to the extensive growth of energy demand and the related carbon dioxide emissions in China. However, the process of energy price reform is slow, even though China faces increasing problems of energy scarcity and environmental deterioration. This paper focuses on analyzing fossil fuel subsidies in China by estimating subsidies scale and the implications for future reform. We begin by measuring fossil-fuel subsidies and the effects of subsidy removal in a systematic fashion during 2006–2010 using a price-gap approach. Results indicate that the oil price reform in 2009 significantly reduced China’s fossil-fuel subsidies and modified the subsidy structure. Fossil-fuel subsidies scale in China was 881.94 billion CNY in 2010, which was lower than the amount in 2006, equivalent to 2.59% of the GDP. The macro-economic impacts of removing fossil-fuel subsidies are then evaluated by the computable general equilibrium (CGE) model. Results demonstrate that the economic growth and employment will be negatively affected as well as energy demand, carbon dioxide and sulfur dioxide emissions. Finally, policy implications are suggested: first, risks of government pricing of energy are far from negligible; second, an acceptable macroeconomic impact is a criterion for energy price reform in China; third, the future energy policy should focus on designing transparent, targeted and efficient energy subsidies

FUTURE FOSSIL FUEL PRICE IMPACTS ON NDC ACHIEVEMENT; ESTIMATION OF GHG EMISSIONS AND MITIGATION COSTS

Directory of Open Access Journals (Sweden)

Yosuke Arino

2017-12-01

Full Text Available The Shale Revolution in the US, a supply-side innovation in oil and gas production, has been dramatically changing the world’s fossil fuel energy markets – leading to a decrease in oil, gas and coal prices. Some projections suggest that low fossil fuel prices might continue at least over the next few decades. Uncertainty in fossil fuel prices might affect the levels of emission reductions expected from submitted nationally determined contributions (NDCs and/or influence the difficulty of achieving the NDCs. This paper evaluated the impact of different (high, medium, and low fossil fuel prices, sustained through to 2050, on worldwide GHG emissions reductions and associated costs (mainly marginal abatement costs (MACs. Total global GHG emissions were estimated to be 57.5-61.5 GtCO2eq by 2030, with the range shown reflecting uncertainties about fossil fuel prices and the target levels of several NDCs (i.e., whether their upper or lower targets were adopted. It was found that lower fuel prices not only diminished the environmental effectiveness of global NDCs but also widened regional differences of marginal and total abatement costs, thereby generating more room for carbon leakage. One possible policy direction in terms of abatement efficiency, fairness and environmental effectiveness would be to require countries with low marginal and total abatement costs but having a major influence on global GHG emissions (such as China and India to increase their mitigation efforts, especially in a low-fuelprice world.

Croatian non-fossil energy programme (NFE Program); Program nefosilnih energenata u Hrvatskoj (Program NFE)

Energy Technology Data Exchange (ETDEWEB)

Kamenski, M; Potocnik, V [Zagreb (Croatia)

1997-12-31

Proposed NFE Program (rational energy use and renewable energy) takes into account European Union experience and the facts of scarce fossil fuel reserves and relatively low energy efficiency in Croatia. Implementation of the NFE Program is expected to reduce fossil fuels import growth and environmental pollution, to improve import-export trade balance and to contribute to the new local jobs. (author). 4 figs., 11 refs.

Fossil energy savings potential of sugar cane bio-energy systems

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thu Lan T. [Department of Agroecology, Aarhus University, Tjele (Denmark); The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Hermansen, John E. [Department of Agroecology, Aarhus University, Tjele (Denmark); Sagisaka, Masayuki [Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

2009-11-15

One important rationale for bio-energy systems is their potential to save fossil energy. Converting a conventional sugar mill into a bio-energy process plant would contribute to fossil energy savings via the extraction of renewable electricity and ethanol substituting for fossil electricity and gasoline, respectively. This paper takes a closer look at the Thai sugar industry and examines two practical approaches that will enhance fossil energy savings. The first one addresses an efficient extraction of energy in the form of electricity from the excess bagasse and cane trash. The second while proposing to convert molasses or sugar cane to ethanol stresses the use of bagasse as well as distillery spent wash to replace coal in meeting ethanol plants' energy needs. The savings potential achieved with extracting ethanol from surplus sugar versus current practice in sugar industry in Thailand amounts to 15 million barrels of oil a year. Whether the saving benefits could be fully realized, however, depends on how well the potential land use change resulting from an expansion of ethanol production is managed. The results presented serve as a useful guidance to formulate strategies that enable optimum utilization of biomass as an energy source. (author)

Status of fossil fuel reserves; Etat des reserves des combustibles fossiles

Energy Technology Data Exchange (ETDEWEB)

Laherrere, J

2005-07-01

Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)

Emissions Scenarios and Fossil-fuel Peaking

Science.gov (United States)

Brecha, R.

2008-12-01

Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some

Development of Nano-crystalline Doped-Ceramic Enabled Fiber Sensors for High Temperature In-Situ Monitoring of Fossil Fuel Gases

Energy Technology Data Exchange (ETDEWEB)

Xiao, Hai [Missouri Univ. of Science and Technology, Rolla, MO (United States); Dong, Junhang [Univ. of Cincinnati, OH (United States); Lin, Jerry [Arizona State Univ., Tempe, AZ (United States); Romero, Van [New Mexico Institute of Mining and Technology, Socorro, NM (United States)

2012-03-01

This is a final technical report for the first project year from July 1, 2005 to Jan 31, 2012 for DoE/NETL funded project DE-FC26-05NT42439: Development of Nanocrystalline Doped-Ceramic Enabled Fiber Sensors for High Temperature In-Situ Monitoring of Fossil Fuel Gases. This report summarizes the technical progresses and achievements towards the development of novel nanocrystalline doped ceramic material-enabled optical fiber sensors for in situ and real time monitoring the gas composition of flue or hot gas streams involved in fossil-fuel based power generation and hydrogen production.

Children's Ideas about Fossils and Foundational Concepts Related to Fossils

Science.gov (United States)

Borgerding, Lisa A.; Raven, Sara

2018-01-01

Many standards documents and learning progressions recommend evolution learning in elementary grades. Given young children's interest in dinosaurs and other fossils, fossil investigations can provide a rich entry into evolutionary biology for young learners. Educational psychology literature has addressed children's reasoning about foundational…

Co-firing biomass and fossil fuels

International Nuclear Information System (INIS)

Junge, D.C.

1991-01-01

In June 1989, the Alaska Energy Authority and the University of Alaska Anchorage published a monograph summarizing the technology of co-firing biomass and fossil fuels. The title of the 180 page monograph is 'Use of Mixed Fuels in Direct Combustion Systems'. Highlights from the monograph are presented in this paper with emphasis on the following areas: (1) Equipment design and operational experience co-firing fuels; (2) The impact of co-firing on efficiency; (3) Environmental considerations associated with co-firing; (4) Economic considerations in co-firing; and (5) Decision making criteria for co-firing

Right-handed fossil humans.

Science.gov (United States)

Lozano, Marina; Estalrrich, Almudena; Bondioli, Luca; Fiore, Ivana; Bermúdez de Castro, José-Maria; Arsuaga, Juan Luis; Carbonell, Eudald; Rosas, Antonio; Frayer, David W

2017-11-01

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right- to 1 left-hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right-handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right-handed fossils come from Europe, but a single maxilla from a Homo habilis, OH-65, shows a predominance of right oblique scratches, thus extending right-handedness into the early Pleistocene of Africa. Other studies show right-handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non-European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right-handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens. © 2017 Wiley Periodicals, Inc.

Evaluation of a flue gas driven open absorption system for heat and water recovery from fossil fuel boilers

International Nuclear Information System (INIS)

Wang, Zhenying; Zhang, Xiaoyue; Li, Zhen

2016-01-01

Highlights: • Flue gas driven open absorption system that efficiently recovers total heat. • Efficient heat and water recovery for various kinds of fossil fuel boilers. • Heat and water recovery efficiencies increase with moisture content of flue gas. • Temperature requirements for district heat supply and domestic hot water were met. • Experimental system surpasses conventional condensing system in total heat recovery. - Abstract: This paper presents an open absorption system for total heat recovery from fossil fuel boilers using the high temperature flue gas as the regeneration heat source. In this system, liquid desiccant serves as the recycling medium, which absorbs waste heat and moisture contained in the low temperature flue gas in the packed tower and then regenerates in the regenerator by the high temperature flue gas. Water vapor generated in the regenerator gets condensed after releasing heat to the heating water system and the condensing water also gets recycled. The return water collects heat from the solution water heat exchanger, the flue gas water heat exchanger and the condenser respectively and is then used for district heating. Driven by the vapor pressure difference between high humidity flue gas and the liquid desiccant, the heat recovery efficiency of the system is not limited by the dew point of the flue gas, enabling a warmer water to be heated up than the conventional condensing boiler. The performance of this system was analyzed theoretically and experimentally and the results showed that the system operated well for both district heat supply and domestic hot water supply. The system efficiency increased with the moisture content of flue gas and the total heat recovery was about 8.5%, 17.2%, 21.2%, and 9.2% higher than the conventional condensing system in the case of coal fired boiler, fuel oil boiler, natural gas boiler, and coke oven gas boiler, respectively.

Efficient technique for computational design of thermoelectric materials

Science.gov (United States)

Núñez-Valdez, Maribel; Allahyari, Zahed; Fan, Tao; Oganov, Artem R.

2018-01-01

Efficient thermoelectric materials are highly desirable, and the quest for finding them has intensified as they could be promising alternatives to fossil energy sources. Here we present a general first-principles approach to predict, in multicomponent systems, efficient thermoelectric compounds. The method combines a robust evolutionary algorithm, a Pareto multiobjective optimization, density functional theory and a Boltzmann semi-classical calculation of thermoelectric efficiency. To test the performance and reliability of our overall framework, we use the well-known system Bi2Te3-Sb2Te3.

High-Performance Rh ₂ P Electrocatalyst for Efficient Water Splitting

Energy Technology Data Exchange (ETDEWEB)

Duan, Haohong; Li, Dongguo; Tang, Yan; He, Yang; Ji, Shufang; Wang, Rongyue; Lv, Haifeng; Lopes, Pietro P.; Paulikas, Arvydas P.; Li, Haoyi; Mao, Scott X.; Wang, Chongmin; Markovic, Nenad M.; Li, Jun; Stamenkovic, Vojislav R.; Li, Yadong

2017-04-05

Search for active, stable and cost-efficient electrocatalysts for hydrogen production via water splitting could make substantial impact to the energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high surface area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C NCs exhibit remarkable performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) compared to Rh/C and Pt/C catalysts. The atomic structure of the rhodium phosphide nanocubes was directly observed by annular dark-field scanning transmission electron microscopy (ADF-STEM), which revealed phosphorous-rich outermost atomic layer. Combined experimental and computational studies suggest that surface phosphorous plays crucial role in determining the robust catalyst properties.

High-Performance Rh ₂ P Electrocatalyst for Efficient Water Splitting

Energy Technology Data Exchange (ETDEWEB)

Duan, Haohong [Department; Chemistry; Li, Dongguo [Materials; Tang, Yan [Department; amp, Molecular; He, Yang [Department; Ji, Shufang [Department; Wang, Rongyue [Materials; Lv, Haifeng [Materials; Lopes, Pietro P. [Materials; Paulikas, Arvydas P. [Materials; Li, Haoyi [Department; amp, Molecular; Mao, Scott X. [Department; Wang, Chongmin [Environmental; Markovic, Nenad M. [Materials; Li, Jun [Department; amp, Molecular; Stamenkovic, Vojislav R. [Materials; Li, Yadong [Department

2017-04-05

The search for active, stable, and cost-efficient electrocatalysts for hydrogen production via water splitting could make a substantial impact on energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high-surface-area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C NCs exhibit remarkable performance for hydrogen evolution reaction and oxygen evolution reaction compared to Rh/C and Pt/C catalysts. The atomic structure of the Rh2P NCs was directly observed by annular dark-field scanning transmission electron microscopy, which revealed a phosphorus-rich outermost atomic layer. Combined experimental and computational studies suggest that surface phosphorus plays a crucial role in determining the robust catalyst properties.

The Ecological Rise of Whales Chronicled by the Fossil Record.

Science.gov (United States)

Pyenson, Nicholas D

2017-06-05

The evolution of cetaceans is one of the best examples of macroevolution documented from the fossil record. While ecological transitions dominate each phase of cetacean history, this context is rarely stated explicitly. The first major ecological phase involves a transition from riverine and deltaic environments to marine ones, concomitant with dramatic evolutionary transformations documented in their early fossil record. The second major phase involves ecological shifts associated with evolutionary innovations: echolocation (facilitating hunting prey at depth) and filter-feeding (enhancing foraging efficiency on small prey). This latter phase involves body size shifts, attributable to changes in foraging depth and environmental forcing, as well as re-invasions of freshwater systems on continental basins by multiple lineages. Modern phenomena driving cetacean ecology, such as trophic dynamics and arms races, have an evolutionary basis that remains mostly unexamined. The fossil record of cetaceans provides an historical basis for understanding current ecological mechanisms and consequences, especially as global climate change rapidly alters ocean and river ecosystems at rates and scales comparable to those over geologic time. Published by Elsevier Ltd.

The original colours of fossil beetles.

Science.gov (United States)

McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Noh, Heeso; Cao, Hui

2012-03-22

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.

Conceptual design of a hydrogen production system by DME steam reforming and high-efficiency nuclear reactor technology

International Nuclear Information System (INIS)

Fukushima, Kimichika; Ogawa, Takashi

2003-01-01

Hydrogen is a potential alternative energy source and produced commercially by methane (natural gas) or LPG steam reforming, a process that requires high temperatures, which are produced by burning fossil fuels. However, since this process emits large amounts of CO 2 , replacement of the combustion heat source with a nuclear heat source for 773-1173 K processes has been proposed in order to eliminate these CO 2 emissions. This paper proposes a novel method of low-temperature nuclear hydrogen production by reforming dimethyl ether (DME) with steam produced by a low-temperature nuclear reactor at about 573 K. The authors identified conditions that provide high hydrogen production fraction at low pressure and temperatures of about 523-573 K. By setting this low-temperature hydrogen production process at about 573K upstream from a turbine, it was found theoretically that the total energy utilization efficiency is about 50% and very high. By setting a turbine upstream of the hydrogen production plant, an overall efficiency of is 75% for an FBR and 76% for a supercritical-water cooled power reactor (SCPR). (author)

China's INDC and non-fossil energy development

Directory of Open Access Journals (Sweden)

Jian-Kun He

2015-09-01

Full Text Available Global climate change promotes the energy system reform. Achieving a high proportion of renewable energy becomes the major countries' energy strategy. As proposed in its Intended Nationally Determined Contributions (INDC, China intends to raise the proportion of non-fossil energy in primary energy consumption to about 20% by 2030. That ambitious goal means the non-fossil energy supplies by 2030 will be 7–8 times that of 2005, and the annual increase rate is more than 8% within the 25 years. Besides, the capacity of wind power, solar power, hydropower and nuclear power reaches 400 GW, 350 GW, 450 GW, and 150 GW respectively, and China's non-fossil power capacity is even greater than the U.S.'s total power capacity. In addition, the scale of natural gas increases. Consequently, by 2030, the proportion of coal falls from the current 70% to below 50%, and the CO2 intensity of energy consumption decreases by 20% compared with the level of 2005, which play important roles in significantly reducing the CO2 intensity of GDP. Since China has confirmed to achieve the CO2 emissions peak around 2030, at that time, the newly added energy demand will be satisfied by non-fossil energy, and the consumption of fossil fuel will stop growing. By 2030, non-fossil energy accounts for 20%, and the large scale and sound momentum of new and renewable energy industry will support the growth of total energy demand, which plays a key role in CO2 emissions peaking and beginning to decline, and lays the foundation for establishing a new energy system dominated by new and renewable energy in the second half of the 21st century as well as finally achieving the CO2 zero-emission.

The legacy of fossil fuels.

Science.gov (United States)

Armaroli, Nicola; Balzani, Vincenzo

2011-03-01

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The legacy of fossil fuels

Energy Technology Data Exchange (ETDEWEB)

Armaroli, N.; Balzani, V. [CNR, Bologna (Italy)

2011-03-01

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production.

Influence of fossil energy applications on environmental pollution

Energy Technology Data Exchange (ETDEWEB)

Balat, M.; Ayar, G.; Oguzhan, C.; Uluduz, H.; Faiz, U. [University of Mahallesi, Trabzon (Turkey)

2007-07-01

The aim of this work is to investigate influence of fossil energy applications on the environmental pollution. Turkey's high rate of economic growth experienced during much of the 1990s, besides resulting in booming industrial production, also led to higher levels of energy consumption, imports, air and water pollution, and greater risks to the country's environment. Air pollution is a major problem in Turkey, with key pollutants including sulfur dioxide, suspended particulates, nitrogen oxides, and carbon dioxide. In Turkey, carbon dioxide emissions from fossil fuels totaled about 50.07 million tons in 2001. However, fuel share of carbon emissions in 2001 was oil 44.2%, coal 38.8%, and natural gas 16.9%. Total carbon dioxide emissions from fossil fuels are expected to be 104 million tons in 2025.

Reducing the CO2 emissions from fossil fuel power plans by exhaust gas treatment

International Nuclear Information System (INIS)

David, Elena

2007-01-01

The emission of carbon dioxide (CO 2 ) and other pollutants which result from burning fossil fuels has been identified as the major contributor to global warming and climate change. However, for the short term, at least for the next 10-20 years, the world will continue to rely on fossil fuels as the source of primary energy. The challenge for the fossil the fuel industry is to find cost-effective solutions that will reduce the release of CO 2 and other pollutants into the atmosphere. The focus of this paper is on the ability to treat the exhaust gas from fossil fuel power plants in order to capture and store the CO 2 and remove the other pollutants such as SO x and NO x which are released into the atmosphere. In summary, capture/separation costs represent the largest financial impediment for this type of plants. Hence, efficient, cost-effective capture/separation technologies need to be developed to allow their large-scale use. (author)

Climate policy and the optimal extraction of high- and low-carbon fossil fuels

International Nuclear Information System (INIS)

Smulders, S.; Van der Werf, E.

2005-01-01

We study how restricting CO2 emissions affects resource prices and depletion over time. We use a Hotelling-style model with two non- renewable fossil fuels that differ in their carbon content (e.g. coal and natural gas) and that are imperfect substitutes in final good production. We study both an unexpected constraint and an anticipated constraint. Both shocks induce intertemporal substitution of resource use. When emissions are unexpectedly restricted, it is cost-effective to use high-carbon resources relatively more (less) intensively on impact if this resource is relatively scarce (abundant). If the emission constraint is anticipated, it is cost-effective to use relatively more (less) of the low-carbon input before the constraint becomes binding, in order to conserve relatively more (less) of the high-carbon input for the period when climate policy is active in case the high-carbon resource is relatively scarce (abundant)

Soft-Bodied Fossils Are Not Simply Rotten Carcasses - Toward a Holistic Understanding of Exceptional Fossil Preservation: Exceptional Fossil Preservation Is Complex and Involves the Interplay of Numerous Biological and Geological Processes.

Science.gov (United States)

Parry, Luke A; Smithwick, Fiann; Nordén, Klara K; Saitta, Evan T; Lozano-Fernandez, Jesus; Tanner, Alastair R; Caron, Jean-Bernard; Edgecombe, Gregory D; Briggs, Derek E G; Vinther, Jakob

2018-01-01

Exceptionally preserved fossils are the product of complex interplays of biological and geological processes including burial, autolysis and microbial decay, authigenic mineralization, diagenesis, metamorphism, and finally weathering and exhumation. Determining which tissues are preserved and how biases affect their preservation pathways is important for interpreting fossils in phylogenetic, ecological, and evolutionary frameworks. Although laboratory decay experiments reveal important aspects of fossilization, applying the results directly to the interpretation of exceptionally preserved fossils may overlook the impact of other key processes that remove or preserve morphological information. Investigations of fossils preserving non-biomineralized tissues suggest that certain structures that are decay resistant (e.g., the notochord) are rarely preserved (even where carbonaceous components survive), and decay-prone structures (e.g., nervous systems) can fossilize, albeit rarely. As we review here, decay resistance is an imperfect indicator of fossilization potential, and a suite of biological and geological processes account for the features preserved in exceptional fossils. © 2017 The Authors. BioEssays Published by WILEY Periodicals, Inc.

Uranium concentrations in fossils measured by SIMS

International Nuclear Information System (INIS)

Uyeda, Chiaki; Okano, Jun

1988-01-01

Semiquantitative analyses of uranium in fossil bones and teeth were carried out by SIMS. The results show a tendency that uranium concentrations in the fossils increase with the ages of the fossils. It is noticed that fossil bones and teeth having uranium concentration of more than several hundred ppm are not rare. (author)

Fossil fuel subsidies and the new EU Climate and Energy Governance Mechanism

International Nuclear Information System (INIS)

Sartor, Oliver; Spencer, Thomas

2016-07-01

There is currently no dedicated process to track the extent of fossil fuel subsidies, nor to ensure that Member States phase them out. This situation is inconsistent with the European Union's stated decarbonization and energy efficiency dimensions under the Energy Union. The EU is therefore in need of an alternative process for tracking and ensuring the phase-out of fossil fuel subsidies by the Member States. The new Energy Union governance mechanism presents an opportunity for creating this alternative. Providing the right price signals is essential part of the policy mix that is needed to achieve Europe's climate policy goals. Phasing out fossil fuel subsidies in the EU is an important part of aligning energy prices with the EU's climate and energy goals. Depending on how they are measured, combined fossil fuel subsidies in the EU range from 39 to over euro 200 billion per annum (European Commission, 2014). They therefore constitute a significant source of incoherence between the EU's climate mitigation and fiscal policies for energy. However, there has recently been mixed progress in addressing fossil fuel subsidies in Europe. For instance, under the Europe 2020 Strategy, Member States had committed to begin developing plans for phasing out fossil fuel subsidies by 2020. Progress on implementing these plans was supposed to be monitored under the European Semester. However, the decision was taken to remove the focus on energy and fossil fuel subsidies from the European Semester in 2015. As yet, no new system for governing the phase-out of fossil fuel subsidies has been advanced, leaving the question of fossil fuel subsidy reform in limbo. The advent of the EU's Energy Union project creates an opportunity for putting the phase-out of fossil fuel subsidies back on track in Europe. This could be done by including requirements for national goal setting on specific kinds of fossil fuel subsidies in a dedicated sub-section of the National Climate and Energy Plans

Water Use of Fossil Energy Production and Supply in China

Directory of Open Access Journals (Sweden)

Gang Lin

2017-07-01

Full Text Available Fossil energy and water resources are both important for economic and social development in China, and they are tightly interlinked. Fossil energy production consumes large amounts of water, and it is essential to investigate the water footprint of fossil energy production (WFEP in China. In addition, fossil energy is supplied to consumers in China by both domestic and foreign producers, and understanding the water footprint of fossil energy supply (WFES is also highly significant for water and energy development programs in the long-term. The objectives of this paper were to provide an estimation of the blue component of WFEP and WFES in China for the period from 2001 to 2014, and to evaluate the impact on water resources from energy production, the contribution of internal and external WFES, and water-energy related issues of the international energy trade by applying water footprint analysis based on the bottom-up approach. The results indicate that generally, the WFEP and WFES in China both maintained steady growth before 2013, with the WFEP increasing from approximately 3900 million m3/year to 10,400 million m3/year, while the WFES grew from 3900 million m3/year to 11,600 million m3/year. The fossil energy production caps of the 13th Five Year Plan can bring the water consumed for fossil energy production back to a sustainable level. Over the long-term, China’s energy trade plan should also consider the water and energy resources of the countries from which fossil energy is imported.

Recent developments in biodesulfurization of fossil fuels.

Science.gov (United States)

Xu, Ping; Feng, Jinhui; Yu, Bo; Li, Fuli; Ma, Cuiqing

2009-01-01

The emission of sulfur oxides can have adverse effects on the environment. Biodesulfurization of fossil fuels is attracting more and more attention because such a bioprocess is environmentally friendly. Some techniques of desulfurization have been used or studied to meet the stricter limitation on sulfur content in China. Recent advances have demonstrated the mechanism and developments for biodesulfurization of gasoline, diesel and crude oils by free cells or immobilized cells. Genetic technology was also used to improve sulfur removal efficiencies. In this review, we summarize recent progress mainly in China on petroleum biodesulfurization.

Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

DEFF Research Database (Denmark)

Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

2007-01-01

Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken....... This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other corrosion mechanisms...... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

High-resolution leaf-fossil record spanning the Cretaceous/Tertiary boundary

Science.gov (United States)

Johnson, K.R.; Nichols, D.J.; Attrep, M.; Orth, C.J.

1989-01-01

THEORIES that explain the extinctions characterizing the Cretaceous/Tertiary (K/T) boundary1-3 need to be tested by analyses of thoroughly sampled biotas. Palynological studies are the primary means for stratigraphic placement of the terrestrial boundary and for estimates of plant extinction4-12, but have not been combined with quantitative analyses of fossil leaves (megaflora). Megafloral studies complement palynology by representing local floras with assemblages capable of high taxonomic resolution13, but have previously lacked the sample size and stratigraphic spacing needed to resolve latest Cretaceous floral history5,14-18. We have now combined megafloral data from a 100-m-thick composite K/T boundary section in North Dakota with detailed palynological analysis. Here the boundary is marked by a 30% palynofloral extinction coincident with iridium and shocked-mineral anomalies and lies ???2 m above the highest dinosaur remains. The megaflora undergoes a 79% turnover across the boundary, and smaller changes 17- and 25-m below it. This pattern is consistent with latest Cretaceous climatic warming preceding a bolide impact. ?? 1989 Nature Publishing Group.

X-ray computed tomography datasets for forensic analysis of vertebrate fossils

Science.gov (United States)

Rowe, Timothy B.; Luo, Zhe-Xi; Ketcham, Richard A.; Maisano, Jessica A.; Colbert, Matthew W.

2016-01-01

We describe X-ray computed tomography (CT) datasets from three specimens recovered from Early Cretaceous lakebeds of China that illustrate the forensic interpretation of CT imagery for paleontology. Fossil vertebrates from thinly bedded sediments often shatter upon discovery and are commonly repaired as amalgamated mosaics grouted to a solid backing slab of rock or plaster. Such methods are prone to inadvertent error and willful forgery, and once required potentially destructive methods to identify mistakes in reconstruction. CT is an efficient, nondestructive alternative that can disclose many clues about how a specimen was handled and repaired. These annotated datasets illustrate the power of CT in documenting specimen integrity and are intended as a reference in applying CT more broadly to evaluating the authenticity of comparable fossils. PMID:27272251

Testing the molecular clock using mechanistic models of fossil preservation and molecular evolution.

Science.gov (United States)

Warnock, Rachel C M; Yang, Ziheng; Donoghue, Philip C J

2017-06-28

Molecular sequence data provide information about relative times only, and fossil-based age constraints are the ultimate source of information about absolute times in molecular clock dating analyses. Thus, fossil calibrations are critical to molecular clock dating, but competing methods are difficult to evaluate empirically because the true evolutionary time scale is never known. Here, we combine mechanistic models of fossil preservation and sequence evolution in simulations to evaluate different approaches to constructing fossil calibrations and their impact on Bayesian molecular clock dating, and the relative impact of fossil versus molecular sampling. We show that divergence time estimation is impacted by the model of fossil preservation, sampling intensity and tree shape. The addition of sequence data may improve molecular clock estimates, but accuracy and precision is dominated by the quality of the fossil calibrations. Posterior means and medians are poor representatives of true divergence times; posterior intervals provide a much more accurate estimate of divergence times, though they may be wide and often do not have high coverage probability. Our results highlight the importance of increased fossil sampling and improved statistical approaches to generating calibrations, which should incorporate the non-uniform nature of ecological and temporal fossil species distributions. © 2017 The Authors.

Progress in ESR dating of fossils

International Nuclear Information System (INIS)

Ikeya, M.

1983-01-01

In this review the progress of ESR dating is briefly described together with its historical development. Examples of fossil dating include shells and corals in geological sediments, fossil bones and teeth in anthropology and fossil woods in geology. The total dose of natural radiation (TD) equivalent to the archaeological dose in TL dating was obtained by the additive dose method. Initially, the TDs were plotted against the known ages; using the apparent annual dose-rate thus obtained gives the ESR age within a factor of 2 or 3 for a fossil. Precise assessment of the radiation environment was made later taking the disequilibrium of uranium series disintegration into account. ESR ages of corals agreed well with those obtained by radiocarbon and uranium-thorium methods. The time-independent accumulation rate or a linear accumulation or uranium was adopted as a first sensible model for the opensystem fossil bones: the relation between the TD and the age explains the ages of anthropologically important bones. Lastly, geological assessment of fossil woods was made by ESR based on the organic radicals and electron traps in the silicified part. (author)

Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

DEFF Research Database (Denmark)

Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

2008-01-01

Over the past few years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore, to combat chloride corrosion problems cofiring of biomass with a fossil fuel has been...... undertaken. This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other...... corrosion mechanisms appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 h using 0–20% straw co-firing with coal, the plant now runs with a fuel mix of 10% strawþcoal. Based on results from a 3 years exposure...

From Fossil Parasitoids to Vectors: Insects as Parasites and Hosts.

Science.gov (United States)

Nagler, Christina; Haug, Joachim T

2015-01-01

Within Metazoa, it has been proposed that as many as two-thirds of all species are parasitic. This propensity towards parasitism is also reflected within insects, where several lineages independently evolved a parasitic lifestyle. Parasitic behaviour ranges from parasitic habits in the strict sense, but also includes parasitoid, phoretic or kleptoparasitic behaviour. Numerous insects are also the host for other parasitic insects or metazoans. Insects can also serve as vectors for numerous metazoan, protistan, bacterial and viral diseases. The fossil record can report this behaviour with direct (parasite associated with its host) or indirect evidence (insect with parasitic larva, isolated parasitic insect, pathological changes of host). The high abundance of parasitism in the fossil record of insects can reveal important aspects of parasitic lifestyles in various evolutionary lineages. For a comprehensive view on fossil parasitic insects, we discuss here different aspects, including phylogenetic systematics, functional morphology and a direct comparison of fossil and extant species. Copyright © 2015 Elsevier Ltd. All rights reserved.

The fossil history of pseudoscorpions (Arachnida: Pseudoscorpiones

Directory of Open Access Journals (Sweden)

D. Harms

2017-08-01

Full Text Available Pseudoscorpions, given their resemblance to scorpions, have attracted human attention since the time of Aristotle, although they are much smaller and lack the sting and elongated tail. These arachnids have a long evolutionary history but their origins and phylogenetic affinities are still being debated. Here, we summarise their fossil record based on a comprehensive review of the literature and data contained in other sources. Pseudoscorpions are one of the oldest colonisers of the land, with fossils known since the Middle Devonian (ca. 390 Ma. The only arachnid orders with an older fossil record are scorpions, harvestmen and acariform mites, plus two extinct groups. Pseudoscorpions do not fossilise easily, and records from the Mesozoic and Cenozoic consist almost exclusively of amber inclusions. Most Mesozoic fossils come from Archingeay and Burmese ambers (Late Cretaceous and those from the Cenozoic are primarily from Eocene Baltic amber, although additional fossils from, for example, Miocene Dominican and Mexican ambers, are known. Overall, 16 of the 26 families of living pseudoscorpions have been documented from fossils and 49 currently valid species are recognised in the literature. Pseudoscorpions represent a case of morphological stasis and even the Devonian fossils look rather modern. Indeed, most amber fossils are comparable to Recent groups despite a major gap in the fossil record of almost 250 Myr. Baltic amber inclusions indicate palaeofauna inhabiting much warmer climates than today and point to climatic shifts in central Europe since the Eocene. They also indicate that some groups (e.g. Feaellidae and Pseudogarypidae had much wider Eocene distributions. Their present-day occurrence is relictual and highlights past extinction events. Faunas from younger tropical amber deposits (e.g. Dominican and Mexican amber are comparable to Recent ones. Generally, there is a strong bias in the amber record towards groups that live under tree

Radioactive dinosaur fossil bones of Balasinor area, Kheda district, Gujarat, India

International Nuclear Information System (INIS)

Maithani, P.B.; Rathaiah, Y.V.; Dwivedy, K.K.

1993-01-01

High-thorium (upto 0.4% ThO 2 ) bearing Dinosaur fossil remains are reported from the Infratrappeans of Balasinor area, Kheda district, Gujarat. The thorium enrichment in these fossils is confined to the osseous matter which could be attributed to either isomorphic substitution for Ca 2+ or adsorption and colloidal precipitation on the bone surfaces. (author). 5 refs., 1 fig

API focuses on cleanliness, economics of fossil fuels

International Nuclear Information System (INIS)

Anon.

1993-01-01

Fossil fuels, consumed in free markets, are playing positive economic and environmental roles as the world economy becomes integrated, industry leader said last week. Environmental zealots threaten to force conversion from gasoline as a motor fuel in the U.S. and oppose the growing integration of the world economy. Fossil fuels, free markets, human creativity, and entrepreneurial spirit--not government intervention--are the keys to a clean environment, said API pres. Charles J. DiBona and outgoing Chairman C.J. (Pete) Silas, chairman and chief executive officer of Phillips Petroleum Co. DiBona said proponents of the BTU tax defeated earlier this year used erroneous assumptions to make a case against oil use in an effort to replace the efficiency of the marketplace with the inefficiency of bureaucracy. The government's role is to set tough standards and avoid dictating the way environmental standards are met, they said. Other speakers warned that voluntary measures put forward by the Clinton administration of address global climate change issues likely will fall short

Estimating Age-Dependent Extinction: Contrasting Evidence from Fossils and Phylogenies.

Science.gov (United States)

Hagen, Oskar; Andermann, Tobias; Quental, Tiago B; Antonelli, Alexandre; Silvestro, Daniele

2018-05-01

The estimation of diversification rates is one of the most vividly debated topics in modern systematics, with considerable controversy surrounding the power of phylogenetic and fossil-based approaches in estimating extinction. Van Valen's seminal work from 1973 proposed the "Law of constant extinction," which states that the probability of extinction of taxa is not dependent on their age. This assumption of age-independent extinction has prevailed for decades with its assessment based on survivorship curves, which, however, do not directly account for the incompleteness of the fossil record, and have rarely been applied at the species level. Here, we present a Bayesian framework to estimate extinction rates from the fossil record accounting for age-dependent extinction (ADE). Our approach, unlike previous implementations, explicitly models unobserved species and accounts for the effects of fossil preservation on the observed longevity of sampled lineages. We assess the performance and robustness of our method through extensive simulations and apply it to a fossil data set of terrestrial Carnivora spanning the past 40 myr. We find strong evidence of ADE, as we detect the extinction rate to be highest in young species and declining with increasing species age. For comparison, we apply a recently developed analogous ADE model to a dated phylogeny of extant Carnivora. Although the phylogeny-based analysis also infers ADE, it indicates that the extinction rate, instead, increases with increasing taxon age. The estimated mean species longevity also differs substantially, with the fossil-based analyses estimating 2.0 myr, in contrast to 9.8 myr derived from the phylogeny-based inference. Scrutinizing these discrepancies, we find that both fossil and phylogeny-based ADE models are prone to high error rates when speciation and extinction rates increase or decrease through time. However, analyses of simulated and empirical data show that fossil-based inferences are more

Status of fossil fuel reserves

International Nuclear Information System (INIS)

Laherrere, J.

2005-01-01

Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)

Overview of Ecological Agriculture with High Efficiency

OpenAIRE

Huang, Guo-qin; Zhao, Qi-guo; Gong, Shao-lin; Shi, Qing-hua

2012-01-01

From the presentation, connotation, characteristics, principles, pattern, and technologies of ecological agriculture with high efficiency, we conduct comprehensive and systematic analysis and discussion of the theoretical and practical progress of ecological agriculture with high efficiency. (i) Ecological agriculture with high efficiency was first advanced in China in 1991. (ii) Ecological agriculture with high efficiency highlights "high efficiency", "ecology", and "combination". (iii) Ecol...

The importance of fossil-fired power plants for the future energy supply

International Nuclear Information System (INIS)

Czychon, K.H.

2013-01-01

In response to the nuclear disaster in Fukushima and the phasing out of nuclear energy in Germany which is planned up to the year 2022, in addition to the already decommissioned nuclear power plants, a further outage capacity of approximately 13 MW will result. Against the background of the unresolved storage problem, regardless of further expansion of the use of renewable energy sources, the need arises for additional fossil-fueled power plants, i.e. gas and coal power plants. The development of gas prices shows that a further expansion of the gas turbine power plants is limited for economic reasons. This leads to the consequence that the future coal-fired power plants are needed to produce electricity. To meet the requirements for a reduction of CO 2 emissions laws, new power plants must be built with increased efficiency compared to previous systems. In order to meet the challenges of future fossil fuel power plant generations, the Grosskraftwerk Mannheim (Large-scale Power Plant Mannheim) is involved in numerous research projects to increase efficiency, reduce harmful emissions and economic implementation of ambitious technologies.

Fossil Microorganisms in Archaean

Science.gov (United States)

Astafleva, Marina; Hoover, Richard; Rozanov, Alexei; Vrevskiy, A.

2006-01-01

Ancient Archean and Proterozoic rocks are the model objects for investigation of rocks comprising astromaterials. The first of Archean fossil microorganisms from Baltic shield have been reported at the last SPIE Conference in 2005. Since this confeence biomorphic structures have been revealed in Archean rocks of Karelia. It was determined that there are 3 types of such bion structures: 1. structures found in situ, in other words microorganisms even-aged with rock matrix, that is real Archean fossils biomorphic structures, that is to say forms inhabited early formed rocks, and 3. younger than Archean-Protherozoic minerali microorganisms, that is later contamination. We made attempt to differentiate these 3 types of findings and tried to understand of burial of microorganisms. The structures belongs (from our point of view) to the first type, or real Archean, forms were under examination. Practical investigation of ancient microorganisms from Green-Stone-Belt of Northern Karelia turns to be very perspective. It shows that even in such ancient time as Archean ancient diverse world existed. Moreover probably such relatively highly organized cyanobacteria and perhaps eukaryotic formes existed in Archean world.

First fossil insectivores from Flores

NARCIS (Netherlands)

Hoek Ostende, van den L.W.; Berch, van der G.; Awe Due, R.

2006-01-01

The hominid bearing strata from the Liang Bua cave on Flores have yielded a large amount of microvertebrate remains. Among these are three mandibles of shrews, the first record of fossil insectivores from the island. The fossils, representing two different species, are not referable to any of the

Free Switzerland from fossil energy sources - Clear proposals for the building, transportation and electrical power sectors

International Nuclear Information System (INIS)

Nordmann, R.

2010-10-01

A comprehensive review of the current situation of energy resources and consumption and of the prevailing framework like climate change is given, with a focus on Switzerland. The author, a member of the Lower House of the Swiss Parliament, presents facts and figures in a simple language, illustrated by tables and diagrams, in a well structured, easy-to-read book, with detailed indications of his data sources. Starting from the limited character of fossil energy sources, 'peak-oil' and the necessary reduction of greenhouse gas emissions, the author states that nuclear energy is not the solution. Action is absolutely needed, but which policy should be adopted? A global strategy is required that includes the stabilization of the world population as a key factor. An international agreement signed by as many states as possible should create stringent commitments. The developed countries have to demonstrate that prosperity and high life standard are compatible with an economy based on renewable energy sources. This will give to the most ambitious countries a significant advantage on new markets created by renewable energy use and energy efficiency. The author goes on by describing the current status of the technologies needed. What regards the particular case of Switzerland, this country is strongly dependent on energy import - mainly fossil - and CO 2 emissions arise mainly from the building and transportation sectors. A 50% efficiency improvement until 2030 is needed in fossil energy use. Electricity use has to become more efficient as well. Electricity generation - today about 60% renewable - shall move towards 100% renewable. The next chapters discuss clear realistic proposals on how to achieve these goals in the transportation sector ('Intelligent mobility'), the building sector ('Retrofitting the buildings to get them up-to-date') and the electrical power sector ('Entirely renewable electricity'). The title of the conclusion chapter: 'Focus again on the general

Uranium in fossil bones

International Nuclear Information System (INIS)

Koul, S.L.

1978-01-01

An attempt has been made to determine the uranium content and thus the age of certain fossil bones Haritalyangarh (Himachal Pradesh), India. The results indicate that bones rich in apatite are also rich in uranium, and that the radioactivity is due to radionuclides in the uranium series. The larger animals apparently have a higher concentration of uranium than the small. The dating of a fossil jaw (elephant) places it in the Pleistocene. (Auth.)

Efficient power generating portfolio in Brazil: Conciliating cost, emissions and risk

International Nuclear Information System (INIS)

Losekann, Luciano; Marrero, Gustavo A.; Ramos-Real, Francisco J.; Fagundes de Almeida, Edmar Luiz

2013-01-01

The main purpose of this paper is to assess efficiency of the Brazilian electricity generation mix proposed in the 2020 Decennial Plan for Energy Expansion (DPEE 2020). It evaluates estimated costs, risks and CO 2 emissions following the mean–variance portfolio theory. The efficiency frontier is estimated for three CO 2 prices scenarios: no CO 2 prices, low CO 2 price and high CO 2 price. The planned portfolio in Brazil presented in the DPEE 2020 is relatively close to the efficient frontier, however there is still room for risk mitigation by diversifying the energy portfolio. As there is currently no CO 2 price in Brazil, the tendency is that diversification increases fossil fuel share in the energy mix, but the introduction of a CO 2 price can be an option to promote renewables. This type of large general market framework can contribute to reduce market uncertainties by reducing the level of government′s discretionary activism. -- Highlights: •We use portfolio theory to evaluate Brazilian generation mix expansion. •The Brazilian expansion plan is evaluated in three CO 2 price scenarios. •It is room to efficiency gains through portfolio diversification. •When CO 2 is not priced, fossil fuel increases it shares in the efficient portfolio. •High CO 2 prices increase the share of wind and biomass in the mix

Heat planning for fossil-fuel-free district heating areas with extensive end-use heat savings

DEFF Research Database (Denmark)

Harrestrup, Maria; Svendsen, S.

2014-01-01

is a theoretical investigation of the district heating system in the Copenhagen area, in which heat conservation is related to the heat supply in buildings from an economic perspective. Supplying the existing building stock from low-temperature energy resources, e.g. geothermal heat, might lead to oversized......The Danish government plans to make the Danish energy system to be completely free of fossil fuels by 2050 and that by 2035 the energy supply for buildings and electricity should be entirely based on renewable energy sources. To become independent from fossil fuels, it is necessary to reduce...... the energy consumption of the existing building stock, increase energy efficiency, and convert the present heat supply from fossil fuels to renewable energy sources. District heating is a sustainable way of providing space heating and domestic hot water to buildings in densely populated areas. This paper...

The energy efficiency of onboard hydrogen storage

DEFF Research Database (Denmark)

Jensen, Jens Oluf; Li, Qingfeng; Bjerrum, Niels

2010-01-01

Global warming resulting from the use of fossil fuels is threatening the environment and energy efficiency is one of the most important ways to reduce this threat. Industry, transport and buildings are all high energy-using sectors in the world and even in the most technologically optimistic...... perspectives energy use is projected to increase in the next 50 years. How and when energy is used determines society's ability to create long-term sustainable energy systems. This is why this book, focusing on energy efficiency in these sectors and from different perspectives, is sharp and also important...

Fossil Groups as Cosmological Labs

Science.gov (United States)

D'Onghia, Elena

Optical and X-ray measurements of fossil groups (FGs) suggest that they are old and relaxed systems. If FGs are assembled at higher redshift, there is enough time for intermediate-luminosity galaxies to merge, resulting in the formation of the brightest group galaxy (BGG). We carry out the first, systematic study of a large sample of FGs, the "FOssil Group Origins'' (FOGO) based on an International Time Project at the Roque de los Muchachos Observatory. For ten FOGO FGs we have been awarded time at SUZAKU Telescope to measure the temperature of the hot intragroup gas (IGM). For these systems we plan to evaluate and correlate their X-ray luminosity and X-ray temperature, Lx-Tx, optical luminosity and X-ray temperature, Lopt-Tx, and group velocity dispersion with their X-ray temperature, sigma V-Tx, as compared to the non fossil systems. By combining these observations with state-of-art cosmological hydrodynamical simulations we will open a new window into the study of the IGM and the nature of fossil systems. Our proposed work will be of direct relevance for the understanding and interpretation of data from several NASA science missions. Specifically, the scaling relations obtained from these data combined with our predictions obtained using state-of-the-art hydrodynamical simulation numerical adopting a new hydrodynamical scheme will motivate new proposal on CHANDRA X-ray telescope for fossil groups and clusters. We will additionally create a public Online Planetarium Show. This will be an educational site, containing an interactive program called: "A Voyage to our Universe''. In the show we will provide observed images of fossil groups and similar images and movies obtained from the numerical simulations showing their evolution. The online planetarium show will be a useful reference and an interactive educational tool for both students and the public.

THE GB/3D Fossil Types Online Database

Science.gov (United States)

Howe, M. P.; McCormick, T.

2012-12-01

The ICZN and the International Code of Nomenclature for algae, fungi and plants require that every species or subspecies of organism (living & fossil), should have a type or reference specimen to define its characteristic features. These specimens are held in collections around the world and must be available for study. Over time, type specimens can deteriorate or become lost. The British Geological Survey, the National Museum of Wales, the Sedgwick Museum Cambridge and the Oxford Museum of Natural History are working together to create an online database of the type fossils they hold. The web portal provides data about each specimen, searchable on taxonomic, stratigraphic and spatial criteria. For each specimen it is possible to view and download high resolution photographs, and for many of them, 'anaglyph' stereo pairs and 3D scans are available. The portal also provides educational resources (OERs). The rise to prominence of the Web has transformed expectations in accessing information and the Web is now usually the first port of call. However, while many geological museums are providing web-searchable text catalogues, few have undertaken a large-scale program of providing images and 3D models. This project has tackled the issues of merging four distinct data holdings, and setting up workflows to image and scan large numbers of disparate fossils, ranging from small invertebrate macrofossils to large vertebrate skeletal elements. There are three advantages in providing such resources: (1) All users can exploit the collections more efficiently. End-users can view specimens remotely and assess their nature, preservation quality and completeness - in some cases this may be sufficient. It will reduce the need for institutions to send specimens (which are often fragile and always irreplaceable) to researchers by post, or for researchers to make possibly long, expensive and environmentally damaging journeys. (2) A public outreach and education dividend - the ability to

The phylogeny of fossil whip spiders.

Science.gov (United States)

Garwood, Russell J; Dunlop, Jason A; Knecht, Brian J; Hegna, Thomas A

2017-04-21

Arachnids are a highly successful group of land-dwelling arthropods. They are major contributors to modern terrestrial ecosystems, and have a deep evolutionary history. Whip spiders (Arachnida, Amblypygi), are one of the smaller arachnid orders with ca. 190 living species. Here we restudy one of the oldest fossil representatives of the group, Graeophonus anglicus Pocock, 1911 from the Late Carboniferous (Duckmantian, ca. 315 Ma) British Middle Coal Measures of the West Midlands, UK. Using X-ray microtomography, our principal aim was to resolve details of the limbs and mouthparts which would allow us to test whether this fossil belongs in the extant, relict family Paracharontidae; represented today by a single, blind species Paracharon caecus Hansen, 1921. Tomography reveals several novel and significant character states for G. anglicus; most notably in the chelicerae, pedipalps and walking legs. These allowed it to be scored into a phylogenetic analysis together with the recently described Paracharonopsis cambayensis Engel & Grimaldi, 2014 from the Eocene (ca. 52 Ma) Cambay amber, and Kronocharon prendinii Engel & Grimaldi, 2014 from Cretaceous (ca. 99 Ma) Burmese amber. We recovered relationships of the form ((Graeophonus (Paracharonopsis + Paracharon)) + (Charinus (Stygophrynus (Kronocharon (Charon (Musicodamon + Paraphrynus)))))). This tree largely reflects Peter Weygoldt's 1996 classification with its basic split into Paleoamblypygi and Euamblypygi lineages; we were able to score several of his characters for the first time in fossils. Our analysis draws into question the monophyly of the family Charontidae. Our data suggest that Graeophonus is a crown group amblypygid, and falls within a monophyletic Paleoamblypgi clade, but outside the family Paracharontidae (= Paracharonopsis + Paracharon). Our results also suggest a new placement for the Burmese amber genus Kronocharon, a node further down from its original position. Overall, we offer a

Oldest record of Metrosideros (Myrtaceae): Fossil flowers, fruits, and leaves from Australia.

Science.gov (United States)

Tarran, Myall; Wilson, Peter G; Hill, Robert S

2016-04-01

Myrtaceous fossil capsular fruits and flowers from the northwest of Tasmania, in the Early Oligocene-aged Little Rapid River (LRR) deposit, are described. The reproductive organs are found in association with Myrtaceous leaves previously thought to belong to a fleshy-fruited genus, Xanthomyrtus at both LRR, and an Eocene Tasmanian site at Hasties, which are reassessed with fresh morphological evidence. Standard Light Microscopy (LM) and Scanning Electron Microscopy (SEM) were used to investigate cuticular characters and an auto-montage camera system was used to take high-resolution images of fossil and extant fruits. Fossils are identified using a nearest living relative (NLR) approach. The fossil fruits and flowers share a number of characters with genera of capsular-fruited Myrtaceae, in particular sharing several synapomorphies with species of Metrosideros subg. Metrosideros (tribe: Metrosidereae). The fossil is here described, and named Metrosideros leunigii, sp. nov. This research establishes the presence of Metrosideros (aff. subg. Metrosideros) in the Eocene-Oligocene (∼40-30 mya) of Tasmania, Australia. This is the first fossil record of Metrosideros in Australia, as well as the oldest conclusive fossil record, and may provide evidence for an Australian origin of the genus. It is also yet another example of extinction in the Tertiary of a group of plants on the Australian mainland that is only found today on nearby Pacific landmasses. © 2016 Botanical Society of America.

Fossil and non-fossil sources of organic carbon (OC and elemental carbon (EC in Göteborg, Sweden

Directory of Open Access Journals (Sweden)

S. Szidat

2009-03-01

Full Text Available Particulate matter was collected at an urban site in Göteborg (Sweden in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC concentrations were 2.1–3.6 μg m⁻³, 1.8–1.9 μg m⁻³, and 2.2–3.0 μg m⁻³ for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC, organic carbon (OC, water-insoluble OC (WINSOC, and water-soluble OC (WSOC were analyzed for ¹⁴C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and ¹⁴C analysis and combined using Latin-hypercube sampling (LHS. For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter.

Environmental costs of fossil fuel energy production

International Nuclear Information System (INIS)

Riva, A.; Trebeschi, C.

1997-01-01

The costs of environmental impacts caused by fossil fuel energy production are external to the energy economy and normally they are not reflected in energy prices. To determine the environmental costs associated with an energy source a detailed analysis of all environmental impacts of the complete energy cycle is required. The economic evaluation of environmental damages is presented caused by atmospheric emissions produced by fossil fuel combustion for different uses. Considering the emission factors of sulphur oxides, nitrogen oxides, dust and carbon dioxide and the economic evaluation of their environmental damages reported in literature, a range of environmental costs associated with different fossil fuels and technologies is presented. A comparison of environmental costs resulting from atmospheric emissions produced by fossil-fuel combustion for energy production shows that natural gas has a significantly higher environmental value than other fossil fuels. (R.P.)

Eocene Antarctic seasonality inferred from high-resolution stable isotope profiles of fossil bivalves and driftwood

Science.gov (United States)

Judd, E. J.; Ivany, L. C.; Miklus, N. M.; Uveges, B. T.; Junium, C. K.

2017-12-01

The Eocene Epoch was a time of large-scale global climate change, experiencing both the warmest temperatures of the Cenozoic and the onset of southern hemisphere glaciation. The record of average global temperatures throughout this transition is reasonably well constrained, however considerably less is known about the accompanying changes in seasonality. Seasonally resolved temperature data provide a wealth of information not readily available from mean annual temperature data alone. These data are particularly important in the climatically sensitive high latitudes, as they can elucidate the means by which climate changes and the conditions necessary for the growth of ice sheets. Several recent studies, however, have suggested the potential for monsoonal precipitation regimes in the early-middle Eocene high latitudes, which complicates interpretation of seasonally resolved oxygen isotope records in shallow nearshore marine settings. Seasonal precipitation and runoff could create a brackish, isotopically depleted lens in these environments, depleting summertime δ18Ocarb and thereby inflating the inferred mean and range of isotope-derived temperatures. Here, we assess intra-annual variations in temperature in shallow nearshore Antarctic waters during the middle and late Eocene, inferred from high-resolution oxygen isotope profiles from accretionary bivalves of the La Meseta Formation, Seymour Island, Antarctica. To address concerns related to precipitation and runoff, we also subsample exceptionally preserved fossil driftwood from within the formation and use seasonal differences in δ13Corg values to estimate the ratio of summertime to wintertime precipitation. Late Eocene oxygen isotope profiles exhibit strongly attenuated seasonal amplitudes and more enriched mean annual values in comparison with data from the middle Eocene. Preliminary fossil wood data are not indicative of a strongly seasonal precipitation regime, implying that intra-annual variation in oxygen

A long-term view of fossil-fuelled power generation in Europe

International Nuclear Information System (INIS)

Tzimas, Evangelos; Georgakaki, Aliki

2010-01-01

The paper presents a view into the long term future of fossil-fuelled power generation in the European Union, based on a number of alternative scenarios for the development of the coal, natural gas and CO 2 markets, and the penetration of renewable and nuclear technologies. The new fossil fuelled capacity needed and the likely technology mix are estimated using a cost optimisation model based on the screening curve method, taking into consideration the rate of retirement of the current power plant fleet, the capacity already planned or under construction and the role of carbon capture and storage technologies. This analysis shows that measures to increase both non-fossil-fuel-based power generation and the price of CO 2 are necessary to drive the composition of the European power generation capacity so that the European policy goal of reducing greenhouse gas emissions is achieved. Meeting this goal will however require a high capital investment for the creation of an optimal fossil fuel power plant technology mix.

Vanadium contents in Kazakhstan fossils hydrocarbons by data of nuclear-physical analysis methods

International Nuclear Information System (INIS)

Nadirov, N.K.; Solodukhin, V.P.

1998-01-01

Investigation of nuclear physical methods possibilities of vanadium determination analysis in organic fossils and an application of these methods for solution of scientific and practical tasks are presented. Vanadium contents in high viscous petroleums and petroleum bituminous rock of different deposits of Western Kazakhstan and carbonaceous shales of Dzhangariya are studied. Presented data evidence that organic fossils of numerous deposits of Kazakhstan have industrial interest because of high vanadium concentration in its contents

Let your fingers do the walking: A simple spectral signature model for "remote" fossil prospecting.

Science.gov (United States)

Conroy, Glenn C; Emerson, Charles W; Anemone, Robert L; Townsend, K E Beth

2012-07-01

Even with the most meticulous planning, and utilizing the most experienced fossil-hunters, fossil prospecting in remote and/or extensive areas can be time-consuming, expensive, logistically challenging, and often hit or miss. While nothing can predict or guarantee with 100% assurance that fossils will be found in any particular location, any procedures or techniques that might increase the odds of success would be a major benefit to the field. Here we describe, and test, one such technique that we feel has great potential for increasing the probability of finding fossiliferous sediments - a relatively simple spectral signature model using the spatial analysis and image classification functions of ArcGIS(®)10 that creates interactive thematic land cover maps that can be used for "remote" fossil prospecting. Our test case is the extensive Eocene sediments of the Uinta Basin, Utah - a fossil prospecting area encompassing ∼1200 square kilometers. Using Landsat 7 ETM+ satellite imagery, we "trained" the spatial analysis and image classification algorithms using the spectral signatures of known fossil localities discovered in the Uinta Basin prior to 2005 and then created interactive probability models highlighting other regions in the Basin having a high probability of containing fossiliferous sediments based on their spectral signatures. A fortuitous "post-hoc" validation of our model presented itself. Our model identified several paleontological "hotspots", regions that, while not producing any fossil localities prior to 2005, had high probabilities of being fossiliferous based on the similarities of their spectral signatures to those of previously known fossil localities. Subsequent fieldwork found fossils in all the regions predicted by the model. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fossil fuel support mechanisms in Finland

Energy Technology Data Exchange (ETDEWEB)

Lampinen, Ari

2013-10-15

Fossil fuel subsidies and other state support for fossil fuels are forbidden by the Kyoto Protocol and other international treaties. However, they are still commonly used. This publication presents and analyses diverse state support mechanisms for fossil fuels in Finland in 2003-2010. Total of 38 support mechanisms are covered in quantitative analysis and some other mechanisms are mentioned qualitatively only. For some mechanisms the study includes a longer historical perspective. This is the case for tax subsidies for crude oil based traffic fuels that have been maintained in Finland since 1965.

Fossil power plant automation

International Nuclear Information System (INIS)

Divakaruni, S.M.; Touchton, G.

1991-01-01

This paper elaborates on issues facing the utilities industry and seeks to address how new computer-based control and automation technologies resulting from recent microprocessor evolution, can improve fossil plant operations and maintenance. This in turn can assist utilities to emerge stronger from the challenges ahead. Many presentations at the first ISA/EPRI co-sponsored conference are targeted towards improving the use of computer and control systems in the fossil and nuclear power plants and we believe this to be the right forum to share our ideas

Towards a fossil free energy future. The next energy transition

Energy Technology Data Exchange (ETDEWEB)

Lazarus, M.; Greber, L.; Hall, J.; Bartels, C.; Bernow, S.; Hansen, E.; Raskin, P.; Von Hippel, D. (Stockholm Environment Institute, Boston, MA (United States))

1993-04-01

The report provides technical analysis and documentation as input to the Greenpeace project 'Towards a fossil free energy future'. It presents a main scenario and several variants for reducing greenhouse gas emissions, and the technical methods and assumptions used to develop them. The goal is to investigate the technical, economic and policy feasibility to phasing out fossil fuels over the next century as part of a strategy to avert unacceptably high levels or rates of global warming. 209 refs., 42 figs., 27 tabs.

Implications of a fossil stickleback assemblage for Darwinian gradualism.

Science.gov (United States)

Bell, M A

2009-11-01

Darwin postulated that a complete fossil record would contain numerous gradual transitions between ancestral and descendant species, but 150 years after publication of The Origin of Species, few such transitions have materialized. The fossil stickleback Gasterosteus doryssus and the deposit in which it occurs provide excellent conditions to detect such transitions. Abundant, well-preserved fossils occur in a stratigraphic setting with fine temporal resolution. The paleoecology of G. doryssus resembles the ecology of modern lakes that harbour the phenotypically similar three-spined stickleback Gasterosteus aculeatus. Gasterosteus aculeatus are primitively highly armoured, but G. doryssus comprised two contemporaneous biological species with relatively weak armour, including a near-shore, benthic feeder (benthic) and an offshore planktivore (limnetic). The benthic species expanded its range into the limnetic zone of the lake, where it apparently switched to planktivory and evolved reduced armour within c. 5000 years in response to directional selection. Although gradual evolution of mean phenotypes occurred, a single major gene caused much of evolutionary change of the pelvic skeleton. Thus, Darwin's expectation that transitions between species in the fossil record would be gradual was met at a fine time scale, but for pelvic structure, a well-studied trait, his expectation that gradual change would depend entirely on numerous, small, heritable differences among individuals was incorrect.

Progress of OLED devices with high efficiency at high luminance

Science.gov (United States)

Nguyen, Carmen; Ingram, Grayson; Lu, Zhenghong

2014-03-01

Organic light emitting diodes (OLEDs) have progressed significantly over the last two decades. For years, OLEDs have been promoted as the next generation technology for flat panel displays and solid-state lighting due to their potential for high energy efficiency and dynamic range of colors. Although high efficiency can readily be obtained at low brightness levels, a significant decline at high brightness is commonly observed. In this report, we will review various strategies for achieving highly efficient phosphorescent OLED devices at high luminance. Specifically, we will provide details regarding the performance and general working principles behind each strategy. We will conclude by looking at how some of these strategies can be combined to produce high efficiency white OLEDs at high brightness.

Progress of fossil fuel science

Energy Technology Data Exchange (ETDEWEB)

Demirbas, M.F.

2007-07-01

Coal is the most abundant and widely distributed fossil fuel. More than 45% of the world's electricity is generated from coal, and it is the major fuel for generating electricity worldwide. The known coal reserves in the world are enough for more than 215 years of consumption, while the known oil reserves are only about 39 times of the world's consumption and the known natural gas reserves are about 63 times of the world's consumption level in 1998. In recent years, there have been effective scientific investigations on Turkish fossil fuels, which are considerable focused on coal resources. Coal is a major fossil fuel source for Turkey. Turkish coal consumption has been stable over the past decade and currently accounts for about 24% of the country's total energy consumption. Lignite coal has had the biggest share in total fossil fuel production, at 43%, in Turkey. Turkish researchers may investigate ten broad pathways of coal species upgrading, such as desulfurization and oxydesulfurization, pyrolysis and hydropyrolysis, liquefaction and hydroliquefaction, extraction and supercritical fluid extraction, gasification, oxidation, briquetting, flotation, and structure identification.

High-power, high-efficiency FELs

International Nuclear Information System (INIS)

Sessler, A.M.

1989-04-01

High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs

Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

Energy Technology Data Exchange (ETDEWEB)

Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

1993-12-01

This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

Supply of fossil heating and motor fuels

International Nuclear Information System (INIS)

Kaegi, W.; Siegrist, S.; Schaefli, M.; Eichenberger, U.

2003-01-01

This comprehensive study made for the Swiss Federal Office of Energy (SFOE) within the framework of the Energy Economics Fundamentals research programme examines if it can be guaranteed that Swiss industry can be supplied with fossil fuels for heating and transport purposes over the next few decades. The results of a comprehensive survey of literature on the subject are presented, with a major focus being placed on oil. The study examines both pessimistic and optimistic views and also presents an overview of fossil energy carriers and the possibilities of substituting them. Scenarios and prognoses on the availability of fossil fuels and their reserves for the future are presented. Also, new technologies for exploration and the extraction of fossil fuels are discussed, as are international interdependencies that influence supply. Market and price scenarios are presented that take account of a possible increasing scarcity of fossil fuels. The implications for industry and investment planning are examined

Fossil evidence of the zygomycetous fungi

NARCIS (Netherlands)

Krings, M.; Taylor, T.N.; Dotzler, N.

2013-01-01

Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved

Combining phylogenomics and fossils in higher-level squamate reptile phylogeny: molecular data change the placement of fossil taxa.

Science.gov (United States)

Wiens, John J; Kuczynski, Caitlin A; Townsend, Ted; Reeder, Tod W; Mulcahy, Daniel G; Sites, Jack W

2010-12-01

Molecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa. We find several intriguing results. First, some fossil taxa undergo major changes in their phylogenetic position when molecular data are added. Second, most fossil taxa are placed with strong support in the expected clades by the combined data Bayesian analyses, despite each having >98% missing cells and despite recent suggestions that extensive missing data are problematic for Bayesian phylogenetics. Third, morphological data can change the placement of living taxa in combined analyses, even when there is an overwhelming majority of molecular characters. Finally, we find strong but apparently misleading signal in the morphological data, seemingly associated with a burrowing lifestyle in snakes, amphisbaenians, and dibamids. Overall, our results suggest promise for an integrated and comprehensive Tree of Life by combining molecular and morphological data for living and fossil taxa.

Primate diversification inferred from phylogenies and fossils.

Science.gov (United States)

Herrera, James P

2017-12-01

Biodiversity arises from the balance between speciation and extinction. Fossils record the origins and disappearance of organisms, and the branching patterns of molecular phylogenies allow estimation of speciation and extinction rates, but the patterns of diversification are frequently incongruent between these two data sources. I tested two hypotheses about the diversification of primates based on ∼600 fossil species and 90% complete phylogenies of living species: (1) diversification rates increased through time; (2) a significant extinction event occurred in the Oligocene. Consistent with the first hypothesis, analyses of phylogenies supported increasing speciation rates and negligible extinction rates. In contrast, fossils showed that while speciation rates increased, speciation and extinction rates tended to be nearly equal, resulting in zero net diversification. Partially supporting the second hypothesis, the fossil data recorded a clear pattern of diversity decline in the Oligocene, although diversification rates were near zero. The phylogeny supported increased extinction ∼34 Ma, but also elevated extinction ∼10 Ma, coinciding with diversity declines in some fossil clades. The results demonstrated that estimates of speciation and extinction ignoring fossils are insufficient to infer diversification and information on extinct lineages should be incorporated into phylogenetic analyses. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Three dimensional reconstruction of fossils with X-ray CT and computer graphics

Energy Technology Data Exchange (ETDEWEB)

Hamada, Takashi; Tateno, Satoko (Tokyo Univ. (Japan). Coll. of Arts and Sciences); Suzuki, Naoki

1991-12-01

We have developed a method for three dimensional (3D) visualization of fossils such as trilobites and ammonites by non-destructive measurement and computer graphics. The imaging techniques in the medical sciences are applied for fossils by us to have quantitative data analyses on the structural and functional features of some extinct creatures. These methods are composed of a high resolutional X-ray computed tomography (X-ray CT) and computer graphics. We are able to observe not only outer shape but also inner structure of fossils as a 3D image by this method. Consequently, the shape and volume are measurable on these 3D image quantitatively. In addition to that, it is able to reconstruct an ideal figure from the deformed fossils by graphical treatments of the data. Such a 3D reconstruction method is useful to obtain a new information from the paleontological standpoint. (author).

Three dimensional reconstruction of fossils with X-ray CT and computer graphics

International Nuclear Information System (INIS)

Hamada, Takashi; Tateno, Satoko; Suzuki, Naoki.

1991-01-01

We have developed a method for three dimensional (3D) visualization of fossils such as trilobites and ammonites by non-destructive measurement and computer graphics. The imaging techniques in the medical sciences are applied for fossils by us to have quantitative data analyses on the structural and functional features of some extinct creatures. These methods are composed of a high resolutional X-ray computed tomography (X-ray CT) and computer graphics. We are able to observe not only outer shape but also inner structure of fossils as a 3D image by this method. Consequently, the shape and volume are measurable on these 3D image quantitatively. In addition to that, it is able to reconstruct an ideal figure from the deformed fossils by graphical treatments of the data. Such a 3D reconstruction method is useful to obtain a new information from the paleontological standpoint. (author)

Quantification of fossil organic matter in contaminated sediments from an industrial watershed: Validation of the quantitative multimolecular approach by radiocarbon analysis

International Nuclear Information System (INIS)

Jeanneau, Laurent; Faure, Pierre

2010-01-01

The quantitative multimolecular approach (QMA) based on an exhaustive identification and quantification of molecules from the extractable organic matter (EOM) has been recently developed in order to investigate organic contamination in sediments by a more complete method than the restrictive quantification of target contaminants. Such an approach allows (i) the comparison between natural and anthropogenic inputs, (ii) between modern and fossil organic matter and (iii) the differentiation between several anthropogenic sources. However QMA is based on the quantification of molecules recovered by organic solvent and then analyzed by gas chromatography-mass spectrometry, which represent a small fraction of sedimentary organic matter (SOM). In order to extend the conclusions of QMA to SOM, radiocarbon analyses have been performed on organic extracts and decarbonated sediments. This analysis allows (i) the differentiation between modern biomass (contemporary 14 C) and fossil organic matter ( 14 C-free) and (ii) the calculation of the modern carbon percentage (PMC). At the confluence between Fensch and Moselle Rivers, a catchment highly contaminated by both industrial activities and urbanization, PMC values in decarbonated sediments are well correlated with the percentage of natural molecular markers determined by QMA. It highlights that, for this type of contamination by fossil organic matter inputs, the conclusions of QMA can be scaled up to SOM. QMA is an efficient environmental diagnostic tool that leads to a more realistic quantification of fossil organic matter in sediments.

Environmental, economic and exergetic sustainability assessment of power generation from fossil and renewable energy sources

NARCIS (Netherlands)

Stougie, L.; Giustozzi, N.; van der Kooi, H.J.; Stoppato, Anna

2018-01-01

Energy conversion systems have assumed a crucial role in current society. The threat of climate change, fossil fuel depletion and the growing world energy demand ask for a more sustainable way of electricity production, eg, by using renewable energy sources, by improving the conversion efficiency

Technological research and development of fossil fuels; Ricerca e sviluppo tecnologico per lo sfruttamento ottimale dei combustibili fossili

Energy Technology Data Exchange (ETDEWEB)

Minghetti, E; Palazzi, G [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Energia

1995-05-01

The aim of the present document is to supply general information concerning fossil fuels that represent, today and for the near future, the main energy source of our planet. New fossil fuel technologies are in continual development with two principal goals: to decrease environmental impact and increase transformation process efficiency. Examples of this effort are: (1) gas-steam combined cycles integrated with coal gasification plants, or with pressurized-fluidized-bed combustors; (2) new cycles with humid air or coal direct fired turbine, now under development. In the first part of this document the international and national energy situations and trends are shown. After some brief notes on environment problems and alternative fuels, such as biomasses and municipal wastes, technological aspects, mainly relevant to increasing fossil-fueled power plant performances, are examined in greater depth. Finally the research and technological development activities of ENEA (National Agency for New technologies, Energy and the Environment) Engineering Branch in order to improve fossil fuels energy and environmental use are presented.

Fossil wood flora from the Siwalik Group of Arunachal Pradesh, India and its climatic and phytogeographic significance

Science.gov (United States)

Srivastava, Gaurav; Mehrotra, R. C.; Srikarni, C.

2018-02-01

The plant fossil records from the Siwalik Group of Arunachal Pradesh, India are far from satisfactory due to remoteness and dense vegetation of the area. We report seven fossil woods of which three belong to the Middle Siwalik (Subansiri Formation), while the rest are from the Upper Siwalik (Kimin Formation). The modern analogues of the fossils from the Middle Siwalik are Lophopetalum littorale (Celastraceae), Afzelia-Intsia and Sindora siamensis (Fabaceae) and from the Upper Siwalik are Miliusa velutina (Annonaceae), Calophyllum tomentosum and Kayea (Calophyllaceae) and Diospyros melanoxylon (Ebenaceae). The dominance of diffuse porosity in the fossil woods indicates a tropical climate with low seasonality (little variation) in temperature, while a high proportion of large vessels and simple perforation plates in the assemblage infer high precipitation during the deposition of the sediments. The aforesaid inference is in strong agreement with the previous quantitative reconstruction based on fossil leaves. Several modern analogues of the fossil taxa are now growing in low latitudes possibly due to an increase in seasonality (increased variation) in temperature caused by the rising Himalaya.

OKLO: fossil reactors

International Nuclear Information System (INIS)

Naudet, R.

Events leading up to the discovery during the summer of 1972 of the Oklo fossil reactor in Gabon and its subsequent exploration are reviewed. Results of studies are summarized; future investigations are outlined

Energy Analysis of the Danish Food Production System: Food-EROI and Fossil Fuel Dependency

DEFF Research Database (Denmark)

Markussen, Mads Ville; Østergård, Hanne

2013-01-01

Modern food production depends on limited natural resources for providing energy and fertilisers. We assess the fossil fuel dependency for the Danish food production system by means of Food Energy Returned on fossil Energy Invested (Food-EROI) and by the use of energy intensive nutrients from....... Furthermore, nutrients in commercial fertiliser and imported feed account for 84%, 90% and 90% of total supply of N, P and K, respectively. We conclude that the system is unsustainable because it is embedded in a highly fossil fuel dependent system based on a non-circular flow of nutrients. As energy and thus...... imported livestock feed and commercial fertilisers. The analysis shows that the system requires 221 PJ of fossil energy per year and that for each joule of fossil energy invested in farming, processing and transportation, 0.25 J of food energy is produced; 0.28 when crediting for produced bioenergy...

Recovery of value-added fossil resin from El-Maghara coal

Energy Technology Data Exchange (ETDEWEB)

Ibrahim, S.S.; Mostafa, S.I. [Central Metallurgical R and D Inst., Cairo (Egypt)

2003-06-01

El-Maghara coal was confirmed to contain a substantial amount of fossil resin intimately associated with its macerals. Macroscopic identification as well as physical diagnosis of solvent refined resinite material proved its particular significance and sufficient value to justify a fossil resin industry in Egypt. This resin has thermosetting properties superior to most synthetics resins available from petrochemicals. It could compete in the market as a chemical commodity in high-speed printing and high-performance adhesive applications. It could have also special values as a feedstock for high-density jet fuel after proper hydrogenation. The froth flotation technique was applied to recover this valuable material from El-Maghara ground coal. The solvent extraction method using commercial solvents was used to refine the resinite fraction collected as flotation concentrate. The variables affecting the flotation technique were studied. Characterization of refined resin was applied. (orig.)

Climate Policy and the Optimal Extraction of High- and Low-Carbon Fossil Fuels

NARCIS (Netherlands)

Smulders, J.A.; van der Werf, E.H.

2005-01-01

We study how restricting CO2 emissions affcts resource prices and depletion over time.We use a Hotelling-style model with two nonrenewable fossil fuels that differ in their carbon content (e.g. coal and natural gas) and that are imperfect substitutes in final good production.We study both an

New Mesozoic and Cenozoic fossils from Ecuador: Invertebrates, vertebrates, plants, and microfossils

Science.gov (United States)

Cadena, Edwin A.; Mejia-Molina, Alejandra; Brito, Carla M.; Peñafiel, Sofia; Sanmartin, Kleber J.; Sarmiento, Luis B.

2018-04-01

Ecuador is well known for its extensive extant biodiversity, however, its paleobiodiversity is still poorly explored. Here we report seven new Mesozoic and Cenozoic fossil localities from the Pacific coast, inter-Andean depression and Napo basin of Ecuador, including vertebrates, invertebrates, plants, and microfossils. The first of these localities is called El Refugio, located near the small town of Chota, Imbabura Province, from where we report several morphotypes of fossil leaves and a mycetopodid freshwater mussel of the Upper Miocene Chota Formation. A second site is also located near the town of Chota, corresponding to potentially Pleistocene to Holocene lake deposits from which we report the occurrence of leaves and fossil diatoms. A third locality is at the Pacific coast of the country, near Rocafuerte, a town in Esmeraldas Province, from which we report a late Miocene palm leaf. We also report the first partially articulated skull with teeth from a Miocene scombridid (Mackerels) fish from El Cruce locality, and completely preserved seeds from La Pila locality, both sites from Manabí Province. Two late Cretaceous fossil sites from the Napo Province, one near Puerto Napo showing a good record of fossil shrimps and a second near the town of Loreto shows the occurrence of granular amber and small gymnosperms seeds and cuticles. All these new sites and fossils show the high potential of the sedimentary sequences and basins of Ecuador for paleontological studies and for a better understanding of the fossil record of the country and northern South America.

Inefficiency and Bias of Search Engines in Retrieving References Containing Scientific Names of Fossil Amphibians

Science.gov (United States)

Brown, Lauren E.; Dubois, Alain; Shepard, Donald B.

2008-01-01

Retrieval efficiencies of paper-based references in journals and other serials containing 10 scientific names of fossil amphibians were determined for seven major search engines. Retrievals were compared to the number of references obtained covering the period 1895-2006 by a Comprehensive Search. The latter was primarily a traditional…

Reconstructing Carotenoid-Based and Structural Coloration in Fossil Skin.

Science.gov (United States)

McNamara, Maria E; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver, Enrique

2016-04-25

Evidence of original coloration in fossils provides insights into the visual communication strategies used by ancient animals and the functional evolution of coloration over time [1-7]. Hitherto, all reconstructions of the colors of reptile integument and the plumage of fossil birds and feathered dinosaurs have been of melanin-based coloration [1-6]. Extant animals also use other mechanisms for producing color [8], but these have not been identified in fossils. Here we report the first examples of carotenoid-based coloration in the fossil record, and of structural coloration in fossil integument. The fossil skin, from a 10 million-year-old colubrid snake from the Late Miocene Libros Lagerstätte (Teruel, Spain) [9, 10], preserves dermal pigment cells (chromatophores)-xanthophores, iridophores, and melanophores-in calcium phosphate. Comparison with chromatophore abundance and position in extant reptiles [11-15] indicates that the fossil snake was pale-colored in ventral regions; dorsal and lateral regions were green with brown-black and yellow-green transverse blotches. Such coloration most likely functioned in substrate matching and intraspecific signaling. Skin replicated in authigenic minerals is not uncommon in exceptionally preserved fossils [16, 17], and dermal pigment cells generate coloration in numerous reptile, amphibian, and fish taxa today [18]. Our discovery thus represents a new means by which to reconstruct the original coloration of exceptionally preserved fossil vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-efficiency airfoil rudders applied to submarines

Directory of Open Access Journals (Sweden)

ZHOU Yimei

2017-03-01

Full Text Available Modern submarine design puts forward higher and higher requirements for control surfaces, and this creates a requirement for designers to constantly innovate new types of rudder so as to improve the efficiency of control surfaces. Adopting the high-efficiency airfoil rudder is one of the most effective measures for improving the efficiency of control surfaces. In this paper, we put forward an optimization method for a high-efficiency airfoil rudder on the basis of a comparative analysis of the various strengths and weaknesses of the airfoil, and the numerical calculation method is adopted to analyze the influence rule of the hydrodynamic characteristics and wake field by using the high-efficiency airfoil rudder and the conventional NACA rudder comparatively; at the same time, a model load test in a towing tank was carried out, and the test results and simulation calculation obtained good consistency:the error between them was less than 10%. The experimental results show that the steerage of a high-efficiency airfoil rudder is increased by more than 40% when compared with the conventional rudder, but the total resistance is close:the error is no more than 4%. Adopting a high-efficiency airfoil rudder brings much greater lifting efficiency than the total resistance of the boat. The results show that high-efficiency airfoil rudder has obvious advantages for improving the efficiency of control, giving it good application prospects.

Taxing fossil fuels under speculative storage

International Nuclear Information System (INIS)

Tumen, Semih; Unalmis, Deren; Unalmis, Ibrahim; Unsal, D. Filiz

2016-01-01

Long-term environmental consequences of taxing fossil fuel usage have been extensively studied in the literature. However, these taxes may also impose several short-run macroeconomic policy challenges, the nature of which remains underexplored. This paper investigates the mechanisms through which environmental taxes on fossil fuel usage can affect the main macroeconomic variables in the short-run. We concentrate on a particular mechanism: speculative storage. Formulating and using a dynamic stochastic general equilibrium (DSGE) model, calibrated for the United States, with an explicit storage facility and nominal rigidities, we show that in designing environmental tax policies it is crucial to account for the fact that fossil fuel prices are subject to speculation. The existence of forward-looking speculators in the model improves the effectiveness of tax policies in reducing fossil fuel usage. Improved policy effectiveness, however, is costly: it drives inflation and interest rates up, while impeding output. Based on this tradeoff, we seek an answer to the question how monetary policy should interact with environmental tax policies in our DSGE model of fossil fuel storage. We show that, in an environment with no speculative storers, monetary policy should respond to output along with CPI inflation in order to minimize the welfare losses brought by taxes. However, when the storage facility is activated, responding to output in the monetary policy rule becomes less desirable.

Trace elemental imaging of rare earth elements discriminates tissues at microscale in flat fossils.

Science.gov (United States)

Gueriau, Pierre; Mocuta, Cristian; Dutheil, Didier B; Cohen, Serge X; Thiaudière, Dominique; Charbonnier, Sylvain; Clément, Gaël; Bertrand, Loïc

2014-01-01

The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies.

Investments in Fossil Energy Technology: How the Government's Fossil Energy R&D Program Has Made a Difference

Science.gov (United States)

1997-03-01

America has the technological capacity to change its energy future. There is no reason, for example, why our nation must continue following a path of rising oil imports when billions of barrels of crude oil remain in domestic oil fields. There is no reason why we cannot continue to use our abundant supplies of high-value, low-cost coal when we have the scientific know-how to remove virtually all of its pollutants and reduce greenhouse gas emissions. There is no reason why we cannot turn increasingly to clean-burning natural gas and tap the huge supplies we know exist within our borders. We remain a nation rich in the fuels that have powered economic growth. Today 85 percent of the energy we use to heat our homes and businesses, generate our electricity, and fuel our vehicles comes from coal, petroleum and natural gas. As we move toward a new century, the contributions of these fuels will grow. By 2015, the United States is likely to require nearly 20 percent more energy than it uses today, and fossil fuels are projected to supply almost 88 percent of the energy Americans will consume. We have the scientific know-how to continue using our fossil fuel wealth without fear of environmental damage or skyrocketing costs. The key is technology - developing cutting edge concepts that are beyond the private sector's current capabilities. Some of the most important innovations in America's energy industry are the results of investments in the Federal government's fossil energy research and development programs. Today, our air and water are cleaner, our economy is stronger, and our industries are more competitive in the global market because these programs have produced results. This booklet summarizes many of these achievements. It is not a comprehensive list by any means. Still, it provides solid evidence that the taxpayers' investment in government fossil energy research has paid real and measurable dividends.

[Characteristics of phosphorus uptake and use efficiency of rice with high yield and high phosphorus use efficiency].

Science.gov (United States)

Li, Li; Zhang, Xi-Zhou; Li, Tinx-Xuan; Yu, Hai-Ying; Ji, Lin; Chen, Guang-Deng

2014-07-01

A total of twenty seven middle maturing rice varieties as parent materials were divided into four types based on P use efficiency for grain yield in 2011 by field experiment with normal phosphorus (P) application. The rice variety with high yield and high P efficiency was identified by pot experiment with normal and low P applications, and the contribution rates of various P efficiencies to yield were investigated in 2012. There were significant genotype differences in yield and P efficiency of the test materials. GRLu17/AiTTP//Lu17_2 (QR20) was identified as a variety with high yield and high P efficiency, and its yields at the low and normal rates of P application were 1.96 and 1.92 times of that of Yuxiang B, respectively. The contribution rate of P accumulation to yield was greater than that of P grain production efficiency and P harvest index across field and pot experiments. The contribution rates of P accumulation and P grain production efficiency to yield were not significantly different under the normal P condition, whereas obvious differences were observed under the low P condition (66.5% and 26.6%). The minimal contribution to yield was P harvest index (11.8%). Under the normal P condition, the contribution rates of P accumulation to yield and P harvest index were the highest at the jointing-heading stage, which were 93.4% and 85.7%, respectively. In addition, the contribution rate of P accumulation to grain production efficiency was 41.8%. Under the low P condition, the maximal contribution rates of P accumulation to yield and grain production efficiency were observed at the tillering-jointing stage, which were 56.9% and 20.1% respectively. Furthermore, the contribution rate of P accumulation to P harvest index was 16.0%. The yield, P accumulation, and P harvest index of QR20 significantly increased under the normal P condition by 20.6%, 18.1% and 18.2% respectively compared with that in the low P condition. The rank of the contribution rates of P

High-Temperature High-Efficiency Solar Thermoelectric Generators

Energy Technology Data Exchange (ETDEWEB)

Baranowski, LL; Warren, EL; Toberer, ES

2014-03-01

Inspired by recent high-efficiency thermoelectric modules, we consider thermoelectrics for terrestrial applications in concentrated solar thermoelectric generators (STEGs). The STEG is modeled as two subsystems: a TEG, and a solar absorber that efficiently captures the concentrated sunlight and limits radiative losses from the system. The TEG subsystem is modeled using thermoelectric compatibility theory; this model does not constrain the material properties to be constant with temperature. Considering a three-stage TEG based on current record modules, this model suggests that 18% efficiency could be experimentally expected with a temperature gradient of 1000A degrees C to 100A degrees C. Achieving 15% overall STEG efficiency thus requires an absorber efficiency above 85%, and we consider two methods to achieve this: solar-selective absorbers and thermally insulating cavities. When the TEG and absorber subsystem models are combined, we expect that the STEG modeled here could achieve 15% efficiency with optical concentration between 250 and 300 suns.

Extant-only comparative methods fail to recover the disparity preserved in the bird fossil record.

Science.gov (United States)

Mitchell, Jonathan S

2015-09-01

Most extant species are in clades with poor fossil records, and recent studies of comparative methods show they have low power to infer even highly simplified models of trait evolution without fossil data. Birds are a well-studied radiation, yet their early evolutionary patterns are still contentious. The fossil record suggests that birds underwent a rapid ecological radiation after the end-Cretaceous mass extinction, and several smaller, subsequent radiations. This hypothesized series of repeated radiations from fossil data is difficult to test using extant data alone. By uniting morphological and phylogenetic data on 604 extant genera of birds with morphological data on 58 species of extinct birds from 50 million years ago, the "halfway point" of avian evolution, I have been able to test how well extant-only methods predict the diversity of fossil forms. All extant-only methods underestimate the disparity, although the ratio of within- to between-clade disparity does suggest high early rates. The failure of standard models to predict high early disparity suggests that recent radiations are obscuring deep time patterns in the evolution of birds. Metrics from different models can be used in conjunction to provide more valuable insights than simply finding the model with the highest relative fit. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Divergence time estimates of mammals from molecular clocks and fossils: relevance of new fossil finds from India.

Science.gov (United States)

Prasad, G V R

2009-11-01

This paper presents a brief review of recent advances in the classification of mammals at higher levels using fossils and molecular clocks. It also discusses latest fossil discoveries from the Cretaceous - Eocene (66-55 m.y.) rocks of India and their relevance to our current understanding of placental mammal origins and diversifications.

Series-Tuned High Efficiency RF-Power Amplifiers

DEFF Research Database (Denmark)

Vidkjær, Jens

2008-01-01

An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits.......An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits....

Trace-fossil assemblages with a new ichnogenus in "spotted"

Science.gov (United States)

Šimo, Vladimír; Tomašových, Adam

2013-10-01

Highly-bioturbated "spotted" limestones and marls (Fleckenmergel-Fleckenkalk facies) of the Early Jurassic, which were deposited in broad and recurrent deep-shelf habitats of the Northern Tethys, are characterized by rare benthic carbonate-producing macroinvertebrates. To address this paradox, we analyse trace-fossil assemblages in a ~85 m-thick succession of Pliensbachian spotted deposits (Zliechov Basin, Western Carpathians). They are dominated by infaunal and semi-infaunal deposit-feeders, with 9 ichnogenera and pyritized tubes of the semi-infaunal foraminifer Bathysiphon, being dominated by Chondrites, Lamellaeichnus (new ichnogenus), and Teichichnus. Lamellaeichnus, represented by a horizontal basal cylindrical burrow and an upper row of stacked convex-up gutters, was produced by a mobile deposit-feeder inhabiting shallow tiers because it is crossed by most other trace fossils. We show that the spotty appearance of the deposits is generated by a mixture of (1) dark, organic-rich shallow- and deep-tier traces (TOC = 0.16-0.36), and (2) light grey, organic-poor mottled or structurless sediment (TOC = 0.09-0.22). The higher TOC in shallow-tier burrows of Lamellaeichnus demonstrates that uppermost sediment layers were affected by poor redox cycling. Such conditions imply a limited mixed-layer depth and inefficient nutrient recycling conditioned by hypoxic bottom-waters, allowed by poor circulation and high sedimentation rates in depocenters of the Zliechov Basin. Hypoxic conditions are further supported by (1) dominance of trace-fossils produced by infaunal deposit feeders, (2) high abundance of hypoxiatolerant agglutinated foraminifer Bathysiphon, and (3) high abundance of Chondrites with ~0.5 mm-sized branches. Oxygen-deficient bottom-conditions can thus simultaneously explain the rarity of benthic carbonate-producing macroinvertebrates and high standing abundance of tolerant soft-shell and agglutinated organisms in spotted deposits.

Dental development in living and fossil orangutans.

Science.gov (United States)

Smith, Tanya M

2016-05-01

Numerous studies have investigated molar development in extant and fossil hominoids, yet relatively little is known about orangutans, the only great ape with an extensive fossil record. This study characterizes aspects of dental development, including cuspal enamel daily secretion rate, long-period line periodicities, cusp-specific molar crown formation times and extension rates, and initiation and completion ages in living and fossil orangutan postcanine teeth. Daily secretion rate and periodicities in living orangutans are similar to previous reports, while crown formation times often exceed published values, although direct comparisons are limited. One wild Bornean individual died at 4.5 years of age with fully erupted first molars (M1s), while a captive individual and a wild Sumatran individual likely erupted their M1s around five or six years of age. These data underscore the need for additional samples of orangutans of known sex, species, and developmental environment to explore potential sources of variation in molar emergence and their relationship to life history variables. Fossil orangutans possess larger crowns than living orangutans, show similarities in periodicities, and have faster daily secretion rate, longer crown formation times, and slower extension rates. Molar crown formation times exceed reported values for other fossil apes, including Gigantopithecus blacki. When compared to African apes, both living and fossil orangutans show greater cuspal enamel thickness values and periodicities, resulting in longer crown formation times and slower extension rates. Several of these variables are similar to modern humans, representing examples of convergent evolution. Molar crown formation does not appear to be equivalent among extant great apes or consistent within living and fossil members of Pongo or Homo. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

D Central Line Extraction of Fossil Oyster Shells

Science.gov (United States)

Djuricic, A.; Puttonen, E.; Harzhauser, M.; Mandic, O.; Székely, B.; Pfeifer, N.

2016-06-01

Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils. This saves manpower in relation to current documentation practice and makes the fragile specimens more available for paleontological analysis and public education. In this study, high resolution orthophoto (0.5 mm) and digital surface models (1 mm) are used to define fossil boundaries that are then used as an input to automatically extract fossil length information via central lines. In general, central lines are widely used in geosciences as they ease observation, monitoring and evaluation of object dimensions. Here, the 3D central lines are used in a novel paleontological context to study fossilized oyster shells with photogrammetric and LiDAR-obtained 3D point cloud data. 3D central lines of 1121 Crassostrea gryphoides oysters of various shapes and sizes were computed in the study. Central line calculation included: i) Delaunay triangulation between the fossil shell boundary points and formation of the Voronoi diagram; ii) extraction of Voronoi vertices and construction of a connected graph tree from them; iii) reduction of the graph to the longest possible central line via Dijkstra's algorithm; iv) extension of longest central line to the shell boundary and smoothing by an adjustment of cubic spline curve; and v) integration of the central line into the corresponding 3D point cloud. The resulting longest path estimate for the 3D central line is a size parameter that can be applied in oyster shell age determination both in paleontological and biological applications. Our investigation evaluates ability and performance of the central line method to measure shell sizes accurately by comparing automatically extracted central lines with manually collected reference data used in paleontological analysis. Our results show that the automatically obtained central line length overestimated the manually collected reference by 1.5% in the test set, which is deemed

Security of supply: a neglected fossil fuel externality

International Nuclear Information System (INIS)

Cavallo, A.J.

1995-01-01

Various groups have attempted to set a monetary value on the externalities of fossil fuel usage based on damages caused by emissions of particulates, sulfur dioxide, and oxides of nitrogen and carbon. One externality that has been neglected in this type of analysis, however, is the cost of maintaining a secure supply of fossil fuels. Military expenditures for this purpose are relatively easy to quantify based on US Department of Defense and Office of Management and Budget figures, and amount to between $1 and more than $3 per million Btu, based on total fossil fuel consumption in the US. Open acknowledgment of such expenses would, at the very least, have a profound effect on the perceived competitiveness of all non-fossil fuel technologies. It should also provide a simple and easily comprehended rationale for an energy content (Btu) charge on all fossil fuels. (Author)

High efficiency, long life terrestrial solar panel

Science.gov (United States)

Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

1977-01-01

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

Non-Renewable Energy and Macroeconomic Efficiency of Seven Major Oil Producing Economies in Africa

Directory of Open Access Journals (Sweden)

Awodumi Olabanji Benjamin

2016-05-01

Full Text Available This study adopted two-stage DEA to estimate the technical efficiency scores and assess the impact of the two most important components of fossil fuel associated with oil production on macroeconomic efficiency of Seven oil producing African countries during 2005-2012. Our results showed that increasing the consumption of natural gas would improve technical efficiency. Furthermore, increasing the share of fossil fuel in total energy consumption has negative effect on the efficiency of the economies of the top African oil producers. Also, we found that increasing the consumption of primary energy improves efficiency in these economies. We therefore, recommend that governments and other stakeholders in the energy industry should adopt inclusive strategies that will promote the use of natural gas in the short term. However, in the long-run, efforts should be geared towards increasing the use of primary energy, thereby reducing the percentage share of fossil fuel in total energy consumption.

Fossil energy and GHG saving potentials of pig farming in the EU

International Nuclear Information System (INIS)

Nguyen, Thu Lan T.; Hermansen, John E.; Mogensen, Lisbeth

2010-01-01

In Europe, the highly developed livestock industry places a high burden on resource use and environmental quality. This paper examines pig meat production in North-West Europe as a base case and runs different scenarios to investigate how improvements in terms of energy and greenhouse gas (GHG) savings can be feasibly achieved. As shown in the results of the analysis, pig farming in the EU has a high potential to reduce fossil energy use and GHG emissions by taking improvement measures in three aspects: (i) feed use; (ii) manure management; and (iii) manure utilization. In particular, a combination of improvements in all mentioned aspects offers the highest savings potential of up to 61% fossil energy and 49% GHG emissions. In weighing these three aspects, manure utilization for energy production is found to be the most important factor in reducing fossil energy use and GHG emissions. However, when GHG implications of land use change and land opportunity cost associated with the production of feed crops (e.g. soy meal, cereals) are considered, reducing feed use becomes the main factor in improving GHG performance of EU pork.

Fossil energy and GHG saving potentials of pig farming in the EU

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thu Lan T.; Hermansen, John E.; Mogensen, Lisbeth [Department of Agroecology and Environment, Aarhus University, Tjele (Denmark)

2010-05-15

In Europe, the highly developed livestock industry places a high burden on resource use and environmental quality. This paper examines pig meat production in North-West Europe as a base case and runs different scenarios to investigate how improvements in terms of energy and greenhouse gas (GHG) savings can be feasibly achieved. As shown in the results of the analysis, pig farming in the EU has a high potential to reduce fossil energy use and GHG emissions by taking improvement measures in three aspects: (i) feed use; (2) manure management; and (3) manure utilization. In particular, a combination of improvements in all mentioned aspects offers the highest savings potential of up to 61% fossil energy and 49% GHG emissions. In weighing these three aspects, manure utilization for energy production is found to be the most important factor in reducing fossil energy use and GHG emissions. However, when GHG implications of land use change and land opportunity cost associated with the production of feed crops (e.g. soy meal, cereals) are considered, reducing feed use becomes the main factor in improving GHG performance of EU pork. (author)

Fossil energy: From laboratory to marketplace

International Nuclear Information System (INIS)

1992-03-01

The purpose of this work is to provide a summary description of the role of advanced research in the overall Fossil Energy R ampersand D program successes. It presents the specific Fossil Energy advanced research products that have been adopted commercially or fed into other R ampersand D programs as part of the crosscutting enabling technology base upon which advanced systems are based

Trace elemental imaging of rare earth elements discriminates tissues at microscale in flat fossils.

Directory of Open Access Journals (Sweden)

Pierre Gueriau

Full Text Available The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies.

Lessons learned from fossil FAC assessments

Energy Technology Data Exchange (ETDEWEB)

Dooley, R. Barry; Shields, Kevin J. [Structural Integrity Associates, Inc., Oakville, ON (Canada); Shulder, Stephen J. [Structural Integrity Associates, Inc., Annapolis, MD (United States)

2010-09-15

In their work the authors have noted great diversity in the Flow-Accelerated Corrosion (FAC) Programs used at conventional fossil power plants. The results and findings of FAC Program assessments conducted at 22 conventional plants are summarized and discussed. By comparing the FAC Program characteristics and relevant unit features with damage and failure experiences, a number of common factors requiring attention from fossil utility organizations have been identified. The assessment experiences have also provided a picture of trends in specific FAC activities and general awareness within the conventional fossil fleet. One of the most important aspects of these studies is that while a few new locations of FAC have been found, there is some consolidation of the most frequently found locations. (orig.)

Energy Efficiency instead of CO2 levy

International Nuclear Information System (INIS)

Uetz, R.

2005-01-01

This article takes a look at ways of avoiding a future, planned Swiss CO 2 levy by improving the efficiency of energy use. The political situation concerning the reduction of CO 2 emissions in Switzerland is reviewed and the likeliness of the introduction of a CO 2 levy is discussed. Strategies for the reduction of fossil fuel consumption and therefore of CO 2 emissions are looked at, including process optimisation. Recommendations are made on how to approach this work systematically - data collection, assessment of the potential for reduction and the planning of measures to be taken are looked at. The high economic efficiency of immediate action is stressed and typical middle and long-term measures are listed

Otoliths as an integral part in fossil fish taxonomy

Directory of Open Access Journals (Sweden)

Christoph Gierl

2015-11-01

Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

Electrical discharge phenomena application for solid fossil fuels in-situ conversion

International Nuclear Information System (INIS)

Bukharkin, A A; Lopatin, V V; Martemyanov, S M; Koryashov, I A

2014-01-01

The application of high voltage to oil shale initiates partial discharges (PDs) with the following treeing like in insulating dielectrics. Critical PDs and treeing with a high propagation rate occur under the low electrical intensity ∼10 2 V/cm due to oil shale's high porosity, heterogeneity and anisotropy. The completed discharge occurs as a result of these phenomena. Carbonization is initiated around a plasma channel at the treeing stage and extended during electromagnetic action time. Carbonized rock electrical resistance decreases by 8÷10 degrees to 10 ohm·cm, and shale and coal could be heated by Joule heat in carbonized volume and discharge plasma. A high-current supply is necessary for this heating stage. Also, a high- voltage supply with steep-grade characteristics can be used for PDs and treeing initiating and heating the carbonized rock with low resistance. Thus, these phenomena allow in-situ processing in order to produce a flammable gas and synthetic oil from inferior solid fossil fuels by pyrolytic conversion. Computations show that the ratio between energy derived from gas flaming and energy for shale conversion is more than fifty. Therefore, oil shale conversion with the help of electrical discharge phenomena application can be very efficient, as it needs little energy

FOSSIL SYSTEMS IN THE 400d CLUSTER CATALOG

International Nuclear Information System (INIS)

Voevodkin, Alexey; Borozdin, Konstantin; Heitmann, Katrin; Habib, Salman; Vikhlinin, Alexey; Mescheryakov, Alexander; Burenin, Rodion; Hornstrup, Allan

2010-01-01

We report the discovery of seven new fossil systems in the 400d cluster survey. Our search targets nearby, z ≤ 0.2, and X-ray bright, L X ≥ 10 43 erg s -1 , clusters of galaxies. Where available, we measure the optical luminosities from Sloan Digital Sky Survey images, thereby obtaining uniform sets of both X-ray and optical data. Our selection criteria identify 12 fossil systems, out of which five are known from previous studies. While in general agreement with earlier results, our larger sample size allows us to put tighter constraints on the number density of fossil clusters. It has been previously reported that fossil groups are more X-ray bright than other X-ray groups of galaxies for the same optical luminosity. We find, however, that the X-ray brightness of massive fossil systems is consistent with that of the general population of galaxy clusters and follows the same L X -L opt scaling relation.

Fossil Fuels, Backstop Technologies, and Imperfect Substitution

NARCIS (Netherlands)

van der Meijden, G.C.; Pittel, Karen; van der Ploeg, Frederick; Withagen, Cees

2014-01-01

This chapter studies the transition from fossil fuels to backstop technologies in a general equilibrium model in which growth is driven by research and development. The analysis generalizes the existing literature by allowing for imperfect substitution between fossil fuels and the new energy

The GB/3D Type Fossils Online Web Portal

Science.gov (United States)

McCormick, T.; Howe, M. P.

2013-12-01

Fossils are the remains of once-living organisms that existed and played out their lives in 3-dimensional environments. The information content provided by a 3d representation of a fossil is much greater than that provided by a traditional photograph, and can grab the attention and imagination of the younger and older general public alike. The British Geological Survey has been leading a consortium of UK natural history museums including the Oxford University Museum of Natural History, the Sedgwick Museum Cambridge, the National Museum of Wales Cardiff, and a number of smaller regional British museums to construct a web portal giving access to metadata, high resolution images and interactive 3d models of type fossils from the UK. The web portal at www.3d-fossils.ac.uk was officially launched in August 2013. It can be used to discover metadata describing the provenance, taxonomy, and stratigraphy of the specimens. Zoom-able high resolution digital photographs are available, including for many specimens ';anaglyph' stereo images that can be viewed in 3d using red-cyan stereo spectacles. For many of the specimens interactive 3d models were generated by scanning with portable ';NextEngine 3D HD' 3d scanners. These models can be downloaded in zipped .OBJ and .PLY format from the web portal, or may be viewed and manipulated directly in certain web browsers. The images and scans may be freely downloaded subject to a Creative Commons Attribution ShareAlike Non-Commercial license. There is a simple application programming interface (API) allowing metadata to be downloaded, with links to the images and models, in a standardised format for use in data mash-ups and third party applications. The web portal also hosts ';open educational resources' explaining the process of fossilization and the importance of type specimens in taxonomy, as well as providing introductions to the most important fossil groups. We have experimented with using a 3d printer to create replicas of the

Fossil Energy Materials Program conference proceedings

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R. (comp.)

1987-08-01

The US Department of Energy Office of Fossil Energy has recognized the need for materials research and development to assure the adequacy of materials of construction for advanced fossil energy systems. The principal responsibility for identifying needed materials research and for establishing a program to address these needs resides within the Office of Technical Coordination. That office has established the Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program to fulfill that responsibility. In addition to the AR and TD Materials Program, which is designed to address in a generic way the materials needs of fossil energy systems, specific materials support activities are also sponsored by the various line organizations such as the Office of Coal Gasification. A conference was held at Oak Ridge, Tennessee on May 19-21, 1987, to present and discuss the results of program activities during the past year. The conference program was organized in accordance with the research thrust areas we have established. These research thrust areas include structural ceramics (particularly fiber-reinforced ceramic composites), corrosion and erosion, and alloy development and mechanical properties. Eighty-six people attended the conference. Papers have been entered individually into EDB and ERA. (LTN)

Biofuel: an alternative to fossil fuel for alleviating world energy and economic crises.

Science.gov (United States)

Bhattarai, Keshav; Stalick, Wayne M; McKay, Scott; Geme, Gija; Bhattarai, Nimisha

2011-01-01

The time has come when it is desirable to look for alternative energy resources to confront the global energy crisis. Consideration of the increasing environmental problems and the possible crisis of fossil fuel availability at record high prices dictate that some changes will need to occur sooner rather than later. The recent oil spill in the Gulf of Mexico is just another example of the environmental threats that fossil fuels pose. This paper is an attempt to explore various bio-resources such as corn, barley, oat, rice, wheat, sorghum, sugar, safflower, and coniferous and non-coniferous species for the production of biofuels (ethanol and biodiesel). In order to assess the potential production of biofuel, in this paper, countries are organized into three groups based on: (a) geographic areas; (b) economic development; and(c) lending types, as classified by the World Bank. First, the total fossil fuel energy consumption and supply and possible carbon emission from burning fossil fuel is projected for these three groups of countries. Second, the possibility of production of biofuel from grains and vegetative product is projected. Third, a comparison of fossil fuel and biofuel is done to examine energy sustainability issues.

Fossil Energy Program semiannual progress report for October 1991--March 1992

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.

1992-11-01

This report covers progress made during the period October 1, 1991, through March 31, 1992, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development. The Fossil Energy Program organization chart is shown in the appendix. Topics discussed are under the following projects: materials research and developments; environmental analysis support; coal conversion development; coal combustion research; and fossil fuels supplies modeling and research.

Fossiler i Grønland. 2. del

DEFF Research Database (Denmark)

Harper, David Alexander Taylor; Lindow, Bent Erik Kramer

2009-01-01

Dette er anden og sidste del af POST Greenlands serie om fossiler i Grønland med tre frimærker, der beretter om de mange og spændende fossilfund fra Grønland. Mærkerne fortsætter vores rejse gennem nogle af nøglebegivenhederne i livets historie, smukt illustreret af endnu flere unikke fossiler....... Disse tre fossiler, en plante, et bløddyr og et hvirveldyr, er fra de yngre aflejringer i Grønland med aldre spændende fra for 200 millioner og indtil kun 8.000 år siden....

Fossil evidence for evolution of the shape and color of penguin feathers.

Science.gov (United States)

Clarke, Julia A; Ksepka, Daniel T; Salas-Gismondi, Rodolfo; Altamirano, Ali J; Shawkey, Matthew D; D'Alba, Liliana; Vinther, Jakob; DeVries, Thomas J; Baby, Patrice

2010-11-12

Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight.

Sun, Ocean, Nuclear Bombs, and Fossil Fuels: Radiocarbon Variations and Implications for High-Resolution Dating

Science.gov (United States)

Dutta, Koushik

2016-06-01

Radiocarbon, or 14C, is a radiometric dating method ideally suited for providing a chronological framework in archaeology and geosciences for timescales spanning the last 50,000 years. 14C is easily detectable in most common natural organic materials and has a half-life (5,730±40 years) relevant to these timescales. 14C produced from large-scale detonations of nuclear bombs between the 1950s and the early 1960s can be used for dating modern organic materials formed after the 1950s. Often these studies demand high-resolution chronology to resolve ages within a few decades to less than a few years. Despite developments in modern, high-precision 14C analytical methods, the applicability of 14C in high-resolution chronology is limited by short-term variations in atmospheric 14C in the past. This article reviews the roles of the principal natural drivers (e.g., solar magnetic activity and ocean circulation) and the anthropogenic perturbations (e.g., fossil fuel CO2 and 14C from nuclear and thermonuclear bombs) that are responsible for short-term 14C variations in the environment. Methods and challenges of high-resolution 14C dating are discussed.

New highly efficient piezoceramic materials

International Nuclear Information System (INIS)

Dantsiger, A.Ya.; Razumovskaya, O.N.; Reznichenko, L.A.; Grineva, L.D.; Devlikanova, R.U.; Dudkina, S.I.; Gavrilyachenko, S.V.; Dergunova, N.V.

1993-01-01

New high efficient piezoceramic materials with various combination of parameters inclusing high Curie point for high-temperature transducers using in atomic power engineering are worked. They can be used in systems for heated matters nondestructive testing, controllers for varied industrial power plants and other high-temperature equipment

Exploring the Relationship of Organizational Culture and Implicit Leadership Theory to Performance Differences in the Nuclear and Fossil Energy Industry

Science.gov (United States)

Cravey, Kristopher J.

Notable performance differences exist between nuclear and fossil power generation plants in areas such as safety, outage duration efficiency, and capacity factor. This study explored the relationship of organizational culture and implicit leadership theory to these performance differences. A mixed methods approach consisting of quantitative instruments, namely the Organizational Culture Assessment Instrument and the GLOBE Leadership Scales, and qualitative interviews were used in this study. Subjects were operations middle managers in a U.S. energy company that serves nuclear or fossil power plants. Results from the quantitative instruments revealed no differences between nuclear and fossil groups in regards to organizational culture types and implicit leadership theories. However, the qualitative results did reveal divergence between the two groups in regards to what is valued in the organization and how that drives behaviors and decision making. These organizational phenomenological differences seem to explain why performance differences exist between nuclear and fossil plants because, ultimately, they affect how the organization functions.

Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

International Nuclear Information System (INIS)

Guo, P.; Wang, J.; Li, X.; Zhu, J.; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T.

2000-01-01

Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd 3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores (<10 μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation

In place chemical cleaning of Will County Unit 4 high pressure turbine for efficiency recovery

International Nuclear Information System (INIS)

Cloffi, S.J.

1989-01-01

Due to the proliferation of nuclear units and the economic penalties associated with nuclear unit's following load, the fossil industry has had to switch gears in their mode of operation. A fossil unit must be able to cycle on and off if it is to remain useful to system power supply. Furthermore, a fossil unit is indispensable if it can go to a low load at night and ramp up during the day to meet load demand. Despite the cautions, warnings, and lack of information from turbine and boiler manufactures, Will County Unit 4 achieved such minimum load operation in November 1987. Within the year, Unit 4 experienced numerous cycle chemistry upsets and a steady decline in turbine capability. In depth turbine testing coupled with the chemistry characteristics reveal the cause to be copper deposits on the second and third stages of the high pressure turbine. This paper details the investigation, remedial action, and possible solutions to this turbine capability problem

Fossil avian eggshell preserves ancient DNA

DEFF Research Database (Denmark)

Oskam, Charlotte L; Haile, James Seymour; McLay, Emma

2010-01-01

Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful...... isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids......, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has...

The fossil record of the sixth extinction.

Science.gov (United States)

Plotnick, Roy E; Smith, Felisa A; Lyons, S Kathleen

2016-05-01

Comparing the magnitude of the current biodiversity crisis with those in the fossil record is difficult without an understanding of differential preservation. Integrating data from palaeontological databases with information on IUCN status, ecology and life history characteristics of contemporary mammals, we demonstrate that only a small and biased fraction of threatened species (fossil record, compared with 20% of non-threatened species. We find strong taphonomic biases related to body size and geographic range. Modern species with a fossil record tend to be large and widespread and were described in the 19(th) century. The expected magnitude of the current extinction based only on species with a fossil record is about half of that of one based on all modern species; values for genera are similar. The record of ancient extinctions may be similarly biased, with many species having originated and gone extinct without leaving a tangible record. © 2016 John Wiley & Sons Ltd/CNRS.

Proceedings of the Seventh Annual Conference on Fossil Energy Materials. Fossil Energy AR and TD Materials Program

Energy Technology Data Exchange (ETDEWEB)

Cole, N.C.; Judkins, R.R. [comps.

1993-07-01

Objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The 37 papers are arranged into 3 sessions: ceramics, new alloys/intermetallics, and new alloys/advanced austenitics. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Fossil hominin radii from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain).

Science.gov (United States)

Rodríguez, Laura; Carretero, José Miguel; García-González, Rebeca; Lorenzo, Carlos; Gómez-Olivencia, Asier; Quam, Rolf; Martínez, Ignacio; Gracia-Téllez, Ana; Arsuaga, Juan Luis

2016-01-01

Complete radii in the fossil record preceding recent humans and Neandertals are very scarce. Here we introduce the radial remains recovered from the Sima de los Huesos (SH) site in the Sierra de Atapuerca between 1976 and 2011 and which have been dated in excess of 430 ky (thousands of years) ago. The sample comprises 89 specimens, 49 of which are attributed to adults representing a minimum of seven individuals. All elements are described anatomically and metrically, and compared with other fossil hominins and recent humans in order to examine the phylogenetic polarity of certain radial features. Radial remains from SH have some traits that differentiate them from those of recent humans and make them more similar to Neandertals, including strongly curved shafts, anteroposterior expanded radial heads and both absolutely and relatively long necks. In contrast, the SH sample differs from Neandertals in showing a high overall gracility as well as a high frequency (80%) of an anteriorly oriented radial tuberosity. Thus, like the cranial and dental remains from the SH site, characteristic Neandertal radial morphology is not present fully in the SH radii. We also analyzed the cross-sectional properties of the SH radial sample at two different levels: mid-shaft and at the midpoint of the neck length. When standardized by shaft length, no difference in the mid-shaft cross-sectional properties were found between the SH hominins, Neandertals and recent humans. Nevertheless, due to their long neck length, the SH hominins show a higher lever efficiency than either Neandertals or recent humans. Functionally, the SH radial morphology is consistent with more efficient pronation-supination and flexion-extension movements. The particular trait composition in the SH sample and Neandertals resembles more closely morphology evident in recent human males. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coastal Microstructure: From Active Overturn to Fossil Turbulence

Science.gov (United States)

Tau Leung, Pak

2011-11-01

The Remote Anthropogenic Sensing Program was a five year effort (2001- 2005) to examine subsurface phenomena related to a sewage outfall off the coast of Oahu, Hawaii. This research has implications for basic ocean hydrodynamics, particularly for a greatly improved understanding of the evolution of turbulent patches. It was the first time a microstructure measurement was used to study such a buoyancy-driven turbulence generated by a sea-floor diffuser. In 2004, two stations were selected to represent the near field and ambient conditions. They have nearly identical bathymetrical and hydrographical features and provide an ideal environment for a control experiment. Repeated vertical microstructure measurements were performed at both stations for 20 days. A time series of physical parameters was collected and used for statistical analysis. After comparing the data from both stations, it can be concluded that the turbulent mixing generated by the diffuser contributes to the elevated dissipation rate observed in the pycnocline and bottom boundary layer. To further understand the mixing processes in both regions, data were plotted on a Hydrodynamic Phase Diagram. The overturning stages of the turbulent patches are identified by Hydrodynamic Phase Diagram. This technique provides detailed information on the evolution of the turbulent patches from active overturns to fossilized scalar microstructures in the water column. Results from this study offer new evidence to support the fossil turbulence theory. This study concluded that: 1. Field Data collected near a sea-floor outfall diffuser show that turbulent patches evolve from active (overturning) to fossil (buoyancy-inhibited) stages, consistent with the process of turbulent patch evolution proposed by fossil turbulence theory. 2. The data show that active (overturning) and fossil (buoyancy-inhibited) patches have smaller length scales than the active+fossil (intermediate) stage of patch evolution, consistent with fossil

Contemporaneous trace and body fossils from a late Pleistocene Lakebed in Victoria, Australia, allow assessment of bias in the fossil record.

Science.gov (United States)

Camens, Aaron Bruce; Carey, Stephen Paul

2013-01-01

The co-occurrence of vertebrate trace and body fossils within a single geological formation is rare and the probability of these parallel records being contemporaneous (i.e. on or near the same bedding plane) is extremely low. We report here a late Pleistocene locality from the Victorian Volcanic Plains in south-eastern Australia in which demonstrably contemporaneous, but independently accumulated vertebrate trace and body fossils occur. Bite marks from a variety of taxa are also present on the bones. This site provides a unique opportunity to examine the biases of these divergent fossil records (skeletal, footprints and bite marks) that sampled a single fauna. The skeletal record produced the most complete fauna, with the footprint record indicating a markedly different faunal composition with less diversity and the feeding traces suggesting the presence, amongst others, of a predator not represented by either the skeletal or footprint records. We found that the large extinct marsupial predator Thylacoleo was the only taxon apparently represented by all three records, suggesting that the behavioral characteristics of large carnivores may increase the likelihood of their presence being detected within a fossil fauna. In contrast, Diprotodon (the largest-ever marsupial) was represented only by trace fossils at this site and was absent from the site's skeletal record, despite its being a common and easily detected presence in late Pleistocene skeletal fossil faunas elsewhere in Australia. Small mammals absent from the footprint record for the site were represented by skeletal fossils and bite marks on bones.

High-efficiency cavity-dumped micro-chip Yb:YAG laser

Science.gov (United States)

Nishio, M.; Maruko, A.; Inoue, M.; Takama, M.; Matsubara, S.; Okunishi, H.; Kato, K.; Kyomoto, K.; Yoshida, T.; Shimabayashi, K.; Morioka, M.; Inayoshi, S.; Yamagata, S.; Kawato, S.

2014-09-01

High-efficiency cavity-dumped ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser was developed. Although the high quantum efficiency of ytterbium-doped laser materials is appropriate for high-efficiency laser oscillation, the efficiency is decreased by their quasi-three/four laser natures. High gain operation by high intensity pumping is suitable for high efficiency oscillation on the quasi-three/four lasers without extremely low temperature cooling. In our group, highest efficiency oscillations for continuous wave, nanosecond to picosecond pulse lasers were achieved at room temperature by the high gain operation in which pump intensities were beyond 100 kW/cm2.

The first evidence of trace fossils and pseudo-fossils in the continental interlava volcaniclastic sediments on the Faroe Islands

Czech Academy of Sciences Publication Activity Database

Pokorný, R.; Krmíček, Lukáš; Árting, U. E.

2015-01-01

Roč. 63, č. 1 (2015), s. 45-57 ISSN 2245-7070 Institutional support: RVO:67985831 Keywords : Faroe Islands * trace fossils * pseudo- fossils * volcaniclastic sediments Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.889, year: 2015 http://2dgf.dk/xpdf/bull63-45-57.pdf

Microbial biocatalyst developments to upgrade fossil fuels.

Science.gov (United States)

Kilbane, John J

2006-06-01

Steady increases in the average sulfur content of petroleum and stricter environmental regulations concerning the sulfur content have promoted studies of bioprocessing to upgrade fossil fuels. Bioprocesses can potentially provide a solution to the need for improved and expanded fuel upgrading worldwide, because bioprocesses for fuel upgrading do not require hydrogen and produce far less carbon dioxide than thermochemical processes. Recent advances have demonstrated that biodesulfurization is capable of removing sulfur from hydrotreated diesel to yield a product with an ultra-low sulfur concentration that meets current environmental regulations. However, the technology has not yet progressed beyond laboratory-scale testing, as more efficient biocatalysts are needed. Genetic studies to obtain improved biocatalysts for the selective removal of sulfur and nitrogen from petroleum provide the focus of current research efforts.

Two fossil species of Metrosideros (Myrtaceae) from the Oligo-Miocene Golden Fleece locality in Tasmania, Australia.

Science.gov (United States)

Tarran, Myall; Wilson, Peter G; Macphail, Michael K; Jordan, Greg J; Hill, Robert S

2017-06-01

The capsular-fruited genus Metrosideros (Myrtaceae) is one of the most widely distributed flowering plant genera in the Pacific but is extinct in Australia today. The center of geographic origin for the genus and the reason for and timing of its extinction in Australia remain uncertain. We identify fossil Metrosideros fruits from the newly discovered Golden Fleece fossil flora in the Oligo-Miocene of Tasmania, Australia, shedding further light on these problems. Standard paleopalynological techniques were used to date the fossil-bearing sediments. Scanning electron microscopy and an auto-montage camera system were used to take high-resolution images of fossil and extant fruits taken from herbarium specimens. Fossils are identified using a nearest-living-relative approach. The fossil-bearing sediments are palynostratigraphically dated as being Proteacidites tuberculatus Zone Equivalent (ca. 33-16 Ma) in age and provide a confident Oligo-Miocene age for the macrofossils. Two new fossil species of Metrosideros are described and are here named Metrosideros dawsonii sp. nov. and Metrosideros wrightii sp. nov. These newly described fossil species of Metrosideros provide a second record of the genus in the Cenozoic of Australia, placing them in the late Early Oligocene to late Early Miocene. It is now apparent not only that Metrosideros was present in Australia, where the genus is now extinct, but that at least several Metrosideros species were present during the Cenozoic. These fossils further strengthen the case for an Australian origin of the genus. © 2017 Botanical Society of America.

Fossil Energy Program semiannual progress report for April 1992-- September 1992

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.

1992-12-01

This report covers progress made during the period April 1, 1992, through September 30, 1992, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Office of Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development.

Constraints of fossil fuels depletion on global warming projections

International Nuclear Information System (INIS)

Chiari, Luca; Zecca, Antonio

2011-01-01

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO 2 concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO 2 emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO 2 concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: → CO 2 and global temperature are projected under fossil fuels exhaustion scenarios. → Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. → Temperature projections are possibly lower than the IPCC ones. → Fossil fuels exhaustion will not avoid dangerous global warming.

Constraints of fossil fuels depletion on global warming projections

Energy Technology Data Exchange (ETDEWEB)

Chiari, Luca, E-mail: chiari@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy); Zecca, Antonio, E-mail: zecca@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy)

2011-09-15

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO{sub 2} concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO{sub 2} emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO{sub 2} concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: > CO{sub 2} and global temperature are projected under fossil fuels exhaustion scenarios. > Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. > Temperature projections are possibly lower than the IPCC ones. > Fossil fuels exhaustion will not avoid dangerous global warming.

Energy properties of solid fossil fuels and solid biofuels

International Nuclear Information System (INIS)

Holubcik, Michal; Jandacka, Jozef; Kolkova, Zuzana

2016-01-01

The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

The strategic value of fossil fuels: challenges and responses

International Nuclear Information System (INIS)

1996-01-01

Several speeches of the conference concerning the strategic value of fossil fuels that was held on May 8 to 11, 1995 in Houston, Texas are presented. The current and future importance of fossil fuels in energy consumption throughout the world is highlighted. The role of developing countries in the fossil fuels market is increasing, and these countries need some assistance from developed countries to develop. International and regional cooperation seems to be a good way to ensure economic growth. The importance of fossil fuels is shown by the growth of international coal and natural gas trade. (TEC)

Energy properties of solid fossil fuels and solid biofuels

Energy Technology Data Exchange (ETDEWEB)

Holubcik, Michal, E-mail: michal.holubcik@fstroj.uniza.sk; Jandacka, Jozef, E-mail: jozef.jandacka@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 8215/1, 010 26 Žilina (Slovakia); Kolkova, Zuzana, E-mail: zuzana.kolkova@rc.uniza.sk [Research centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina (Slovakia)

2016-06-30

The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

Microelements in fossil bones and the estimation of age

International Nuclear Information System (INIS)

Besliu, C.; Olariu, A.; Popescu, I.; Badica, Th.

1993-01-01

Neutron activation analysis was used to determine microelements fossil bones and the correlation was found between some elements and the C-14 estimated age of the bones. Fluorine, uranium and manganese content in the bones structure increases with the time elapsed, during fossilization. This means that measurable concentrations of these elements and known environmental conditions could provide a relative dating tool of bones beyond the 70 ky radiocarbon limit, for paleolithic archaeology. Sodium, scandium, iron, and zinc have been also determined in fossil bones, but a relation with the increasing antiquity of the fossil has been observed. (Author)

Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

International Nuclear Information System (INIS)

Conklin, Jim; Forsberg, Charles W.

2007-01-01

A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high-temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR

Global exergetic dimension of hydrogen use in reducing fossil fuel consumption

International Nuclear Information System (INIS)

Adnan Midilli; Ibrahim Dincer

2009-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for minimizing the fossil fuel based-global irreversibility coefficient of global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions such as global waste exergy factor, global irreversibility coefficient and hydrogen based-global exergetic indicator. In order to investigate the role of hydrogen use at minimizing the fossil fuel based global irreversibility, the actual fossil fuel consumption data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases, the fossil fuel based-global irreversibility coefficient will decrease. (author)

Development of Inexpensive, Efficient and Non-Toxic Thermoelectric Materials

Science.gov (United States)

Gali, Anand Pratik

In the wake of the impending climate change challenges, it is highly necessary to reevaluate our energy utilization technologies and ensure their efficient operation. Fossil fuel powered power-plants account for the majority of the energy production in the United States. With an average efficiency not exceeding 40%, these fossil fuel power plants dissipate exorbitant amounts of wasted heat. One of the ways of making such energy conversion processes more efficient is by incorporating technologies that can harvest this scavenge heat. One of the ways of achieving this is by the use of thermoelectric (TE) materials, which utilize the Seebeck effect to convert thermal gradient into potential difference. Therefore, our research project focusses on development of TE materials, which are inexpensive, efficient, and non-toxic. Fe0.50V0.25Al0.25 is a narrow band-gap semiconductor, ideal for TE applications. Unlike the current market leader Bi0.4Te0.6, Fe0.50V0.25 Al0.25 contains earth abundant and non-toxic constituents making it viable for commercial production. Nevertheless, the TE efficiency, ZT, of Fe0.50V0.25Al0.25 is limited by its high thermal conductivity. Therefore, the goal of the current research is two-fold. Firstly, to design and fabricate apparatus for performing TE characterization on bulk materials. For this purpose, two sets of apparatus were designed and fabricated for measuring high temperature Seebeck coefficient and electrical resistivity. Secondly, to study the influence of doping on TE properties of Fe0.50V0.25Al0.25 alloy. In order to achieve this, vanadium in Fe0.50V0.25Al0.25 was substituted with dopants like Ti, Cr, Zr, W, Nb, Ta. This led to a 20 times improvement in ZT, from the baseline Fe0.50V0.25Al0.25, by effectively reducing the thermal conductivity and increasing the Seebeck coefficient.

Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 4: Energy from fossil fuels

Science.gov (United States)

Williams, J. R.

1974-01-01

The conversion of fossil-fired power plants now burning oil or gas to burn coal is discussed along with the relaxation of air quality standards and the development of coal gasification processes to insure a continued supply of gas from coal. The location of oil fields, refining areas, natural gas fields, and pipelines in the U.S. is shown. The technologies of modern fossil-fired boilers and gas turbines are defined along with the new technologies of fluid-bed boilers and MHD generators.

The first fossil cyphophthalmid harvestman from Baltic amber

Directory of Open Access Journals (Sweden)

Dunlop, Jason A.

2011-01-01

Full Text Available The first fossil cyphophthalmid harvestman (Opiliones: Cyphophthalmi from Palaeogene (Eocene Baltic amber is described. This is only the third fossil example of this basal harvestman lineage; the others being from the probably slightly younger Bitterfeld amber and the much older, early Cretaceous, Myanmar (Burmese amber. Although incomplete and lacking most of the appendages, the new Baltic amber fossil can be identified as a female. The somatic characters preserved, especially spiracle morphology and the coxo-genital region, allow it to be assigned with some confidence to the extant genus Siro Latreille, 1796 (Sironidae. This fossil is formally described here as Siro balticus sp. nov. It resembles modern North American Siro species more than modern European ones, and can be distinguished principally on its relatively large size and the outline form of the body.

Magnetohydrodynamic dynamos in the presence of fossil magnetic fields

International Nuclear Information System (INIS)

Boyer, D.W.

1982-01-01

A fossil magnetic field embedded in the radiative core of the Sun has been thought possible for some time now. However, such a fossil magnetic field has, a priori, not been considered a visible phenomenon due to the effects of turbulence in the solar convection zone. Since a well developed theory (referred to herein as magnetohydrodynamic dynamo theory) exists for describing the regeneration of magnetic fields in astrophysical objects like the Sun, it is possible to quantitatively evaluate the interaction of a fossil magnetic field with the magnetohydrodynamic dynamo operating in the solar convection zone. In this work, after a brief description of the basic dynamo equations, a spherical model calculation of the solar dynamo is introduced. First, the interaction of a fossil magnetic field with a dynamo in which the regeneration mechanisms of cyclonic convection and large-scale, nonuniform rotation are confined to spherical shells is calculated. It is argued that the amount of amplification or suppression of a fossil magnetic field will be smallest for a uniform distribution of cyclonic convection and nonuniform rotation, as expected in the Sun. Secondly, the interaction of a fossil magnetic field with a dynamo having a uniform distribution of cyclonic convection and large-scale, nonuniform rotation is calculated. It is found that the dipole or quadrupole moments of a fossil magnetic field are suppressed by factors of -0.35 and -0.37, respectively

Danmarks Største Fossiler

DEFF Research Database (Denmark)

Lindow, Bent Erik Kramer; Cuny, Gilles Guy Roger

2008-01-01

For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram.......For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram....

Proceedings of the sixth annual conference on fossil energy materials. Fossil Energy AR and TD Mateials Program

Energy Technology Data Exchange (ETDEWEB)

Cole, N.C.; Judkins, R.R. [comps.

1992-07-01

The Sixth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on May 12--14, 1992. The meeting was sponsored by the US Department of Energy`s Office of Fossil Energy through the Advanced Research and Technology Development (AR&TD) Materials Program, and ASM International. The objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The management of the Program has been decentralized to the DOE Field Office, Oak Ridge with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by a substantial number of researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) ceramics, (2) development and corrosion resistance of iron aluminide, advanced austenitic and chromium-niobium alloys, and (3) technology assessment and technology transfer. This conference is held each year to review the work on all of the projects of the Program. The agenda for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B. ASM International cosponsored the conference, for which we are especially grateful.

Advanced fission and fossil plant economics-implications for fusion

International Nuclear Information System (INIS)

Delene, J.G.

1994-01-01

In order for fusion energy to be a viable option for electric power generation, it must either directly compete with future alternatives or serve as a reasonable backup if the alternatives become unacceptable. This paper discusses projected costs for the most likely competitors with fusion power for baseload electric capacity and what these costs imply for fusion economics. The competitors examined include advanced nuclear fission and advanced fossil-fired plants. The projected costs and their basis are discussed. The estimates for these technologies are compared with cost estimates for magnetic and inertial confinement fusion plants. The conclusion of the analysis is that fusion faces formidable economic competition. Although the cost level for fusion appears greater than that for fission or fossil, the costs are not so high as to preclude fusion's potential competitiveness

Effects of New Fossil Fuel Developments on the Possibilities of Meeting 2C Scenarios

Energy Technology Data Exchange (ETDEWEB)

Meindertsma, W.; Blok, K.

2012-12-15

Recent years have seen an increasing activity in developing new fossil fuel production capacity. This includes unconventional fossil fuels, such as tar sands and shale gas, fossil fuels from remote locations, and fossil fuels with a very large increase in production in the near future. In this report, the impact of such developments on our ability to mitigate climate change is investigated. Our inventory shows that the new fossil fuel developments currently underway consist of 29,400 billion cubic meters of natural gas, 260,000 million barrels of oil and 49,600 million tonnes of coal. The development of these new fossil fuels would result in emissions of 300 billion tonnes of CO2 -equivalent (CO2e) from 2012 until 2050. Until 2050, a 'carbon budget' of 1550 billion tonnes CO2e is still available if we want to of keep global warming below 2C with a 50% probability. For a 75% probability to stay below 2C this budget is only 1050 billion tonnes CO2e. So, the new fossil fuel developments identified in this report consume 20-33% of the remaining carbon budget until 2050. In a scenario where the new fossil fuels are developed, we need to embark on a rapid emission reductions pathway at the latest in 2019 in order to meet the 50% probability carbon budget. Avoiding the development of new fossil fuels will give us until 2025 to start further rapid emission reductions. These calculations are based on the assumption that the maximum emission reduction rate is 4% per year and that the maximum change in emission trend is 0.5 percentage point per year. The starting year for rapid emission reductions depends on the choice of these parameters. A sensitivity analysis shows that, in all cases, refraining from new fossil fuel development allows for a delay of 5 to 8 years before we should embark on a rapid emission reduction pathway. The high investments required for developing new fossil fuels lead to a lock in effect; once developed, these fossil fuels need to be

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

Giving the early fossil record of sponges a squeeze.

Science.gov (United States)

Antcliffe, Jonathan B; Callow, Richard H T; Brasier, Martin D

2014-11-01

Twenty candidate fossils with claim to be the oldest representative of the Phylum Porifera have been re-analysed. Three criteria are used to assess each candidate: (i) the diagnostic criteria needed to categorize sponges in the fossil record; (ii) the presence, or absence, of such diagnostic features in the putative poriferan fossils; and (iii) the age constraints for the candidate fossils. All three criteria are critical to the correct interpretation of any fossil and its placement within an evolutionary context. Our analysis shows that no Precambrian fossil candidate yet satisfies all three of these criteria to be a reliable sponge fossil. The oldest widely accepted candidate, Mongolian silica hexacts from c. 545 million years ago (Ma), are here shown to be cruciform arsenopyrite crystals. The oldest reliable sponge remains are siliceous spicules from the basal Cambrian (Protohertzina anabarica Zone) Soltanieh Formation, Iran, which are described and analysed here in detail for the first time. Extensive archaeocyathan sponge reefs emerge and radiate as late as the middle of the Fortunian Stage of the Cambrian and demonstrate a gradual assembly of their skeletal structure through this time coincident with the evolution of other metazoan groups. Since the Porifera are basal in the Metazoa, their presence within the late Proterozoic has been widely anticipated. Molecular clock calibration for the earliest Porifera and Metazoa should now be based on the Iranian hexactinellid material dated to c. 535 Ma. The earliest convincing fossil sponge remains appeared at around the time of the Precambrian-Cambrian boundary, associated with the great radiation events of that interval. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

3D CENTRAL LINE EXTRACTION OF FOSSIL OYSTER SHELLS

Directory of Open Access Journals (Sweden)

A. Djuricic

2016-06-01

Full Text Available Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils. This saves manpower in relation to current documentation practice and makes the fragile specimens more available for paleontological analysis and public education. In this study, high resolution orthophoto (0.5 mm and digital surface models (1 mm are used to define fossil boundaries that are then used as an input to automatically extract fossil length information via central lines. In general, central lines are widely used in geosciences as they ease observation, monitoring and evaluation of object dimensions. Here, the 3D central lines are used in a novel paleontological context to study fossilized oyster shells with photogrammetric and LiDAR-obtained 3D point cloud data. 3D central lines of 1121 Crassostrea gryphoides oysters of various shapes and sizes were computed in the study. Central line calculation included: i Delaunay triangulation between the fossil shell boundary points and formation of the Voronoi diagram; ii extraction of Voronoi vertices and construction of a connected graph tree from them; iii reduction of the graph to the longest possible central line via Dijkstra’s algorithm; iv extension of longest central line to the shell boundary and smoothing by an adjustment of cubic spline curve; and v integration of the central line into the corresponding 3D point cloud. The resulting longest path estimate for the 3D central line is a size parameter that can be applied in oyster shell age determination both in paleontological and biological applications. Our investigation evaluates ability and performance of the central line method to measure shell sizes accurately by comparing automatically extracted central lines with manually collected reference data used in paleontological analysis. Our results show that the automatically obtained central line length overestimated the manually collected reference by 1.5% in the test set, which

Multiple Threats to Child Health from Fossil Fuel Combustion: Impacts of Air Pollution and Climate Change.

Science.gov (United States)

Perera, Frederica P

2017-02-01

Approaches to estimating and addressing the risk to children from fossil fuel combustion have been fragmented, tending to focus either on the toxic air emissions or on climate change. Yet developing children, and especially poor children, now bear a disproportionate burden of disease from both environmental pollution and climate change due to fossil fuel combustion. This commentary summarizes the robust scientific evidence regarding the multiple current and projected health impacts of fossil fuel combustion on the young to make the case for a holistic, child-centered energy and climate policy that addresses the full array of physical and psychosocial stressors resulting from fossil fuel pollution. The data summarized here show that by sharply reducing our dependence on fossil fuels we would achieve highly significant health and economic benefits for our children and their future. These benefits would occur immediately and also play out over the life course and potentially across generations. Going beyond the powerful scientific and economic arguments for urgent action to reduce the burning of fossil fuels is the strong moral imperative to protect our most vulnerable populations. Citation: Perera FP. 2017. Multiple threats to child health from fossil fuel combustion: impacts of air pollution and climate change. Environ Health Perspect 125:141-148; http://dx.doi.org/10.1289/EHP299.

Fossil Energy Advanced Research and Technology Development (AR&TD) Materials Program semiannual progress report for the period ending September 30, 1991. Fossil Energy Program

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.; Cole, N.C. [comps.

1992-04-01

The objective of the Fossil Energy Advanced Research and Technology Development Materials Program is to conduct research and development on materials for fossil energy applications with a focus on the longer-term and generic needs of the various fossil fuel technologies. The Program includes research aimed toward a better understanding of materials behavior in fossil energy environments and the development of new materials capable of substantial enhancement of plant operations and reliability. Research is outlined in four areas: Ceramics, New Alloys, Corrosion and Erosion Research, and Technology Development and Transfer. (VC)

DETERMINING THE COMPOSITION OF HIGH TEMPERATURE COMBUSTION PRODUCTS OF FOSSIL FUEL BASED ON VARIATIONAL PRINCIPLES AND GEOMETRIC PROGRAMMING

Directory of Open Access Journals (Sweden)

Velibor V Vujović

2011-01-01

Full Text Available This paper presents the algorithm and results of a computer program for calculation of complex equilibrium composition for the high temperature fossil fuel combustion products. The method of determining the composition of high temperatures combustion products at the temperatures appearing in the open cycle MHD power generation is given. The determination of combustion product composition is based on minimization of the Gibbs free energy. The number of equations to be solved is reduced by using variational principles and a method of geometric programming and is equal to the sum of the numbers of elements and phases. A short description of the computer program for the calculation of the composition and an example of the results are also given.

Implications for global energy markets: implications for non-fossil energy sources

International Nuclear Information System (INIS)

Grubb, Michael

1998-01-01

This paper highlights the recent developments concerning non-fossil energy and examines the impact of the Kyoto Protocol on non-fossil energy sources, and the implications for non-fossil sources in the implementation of the Kyoto Protocol. The current contributions of fossil and non-fossil fuels to electricity production, prospects for expansion of the established non-fossil sources, new renewables in Europe to date, renewables in Europe to 2010, and policy integration in the EU are discussed. Charts illustrating the generating capacity of renewable energy plant in Britain (1992-1966), wind energy capacity in Europe (1990-2000), and projected renewable energy contributions in the EU (wind, small hydro, photovoltaic, biomass and geothermal) are provided. (UK)

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography.

Science.gov (United States)

Dunlop, Jason A; Wirth, Stefan; Penney, David; McNeil, Andrew; Bradley, Robert S; Withers, Philip J; Preziosi, Richard F

2012-06-23

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44-49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers.

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography

Science.gov (United States)

Dunlop, Jason A.; Wirth, Stefan; Penney, David; McNeil, Andrew; Bradley, Robert S.; Withers, Philip J.; Preziosi, Richard F.

2012-01-01

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44–49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers. PMID:22072283

The Fossil Calibration Database-A New Resource for Divergence Dating.

Science.gov (United States)

Ksepka, Daniel T; Parham, James F; Allman, James F; Benton, Michael J; Carrano, Matthew T; Cranston, Karen A; Donoghue, Philip C J; Head, Jason J; Hermsen, Elizabeth J; Irmis, Randall B; Joyce, Walter G; Kohli, Manpreet; Lamm, Kristin D; Leehr, Dan; Patané, Josés L; Polly, P David; Phillips, Matthew J; Smith, N Adam; Smith, Nathan D; Van Tuinen, Marcel; Ware, Jessica L; Warnock, Rachel C M

2015-09-01

Fossils provide the principal basis for temporal calibrations, which are critical to the accuracy of divergence dating analyses. Translating fossil data into minimum and maximum bounds for calibrations is the most important-often least appreciated-step of divergence dating. Properly justified calibrations require the synthesis of phylogenetic, paleontological, and geological evidence and can be difficult for nonspecialists to formulate. The dynamic nature of the fossil record (e.g., new discoveries, taxonomic revisions, updates of global or local stratigraphy) requires that calibration data be updated continually lest they become obsolete. Here, we announce the Fossil Calibration Database (http://fossilcalibrations.org), a new open-access resource providing vetted fossil calibrations to the scientific community. Calibrations accessioned into this database are based on individual fossil specimens and follow best practices for phylogenetic justification and geochronological constraint. The associated Fossil Calibration Series, a calibration-themed publication series at Palaeontologia Electronica, will serve as a key pipeline for peer-reviewed calibrations to enter the database. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Highly Efficient Segmented p-type Thermoelectric Leg

Science.gov (United States)

Sadia, Yatir; Ben-Yehuda, Ohad; Gelbstein, Yaniv

In the past years, energy demands in the entire world have been constantly increasing. This fact, coupled with the requirement for decreasing the world's dependence on fossil fuels, has given rise to the need for alternative energy sources. While no single alternative energy source can solely replace the traditional fossil fuels, the combination of several alternative power sources can greatly decrease their usage. Thermoelectricity is one way to produce such energy via the harvesting of waste heat into electricity. One common example is the automobile industry which in the past few years had been looking into the option of harvesting the waste heat created by the engine, around the exhaust pipe and in the catalytic converter. Thermoelectricity is ideal for such application since it can convert the energy directly into electric current without any moving parts, thereby extending the life cycle of the operation.

The energy challenge of a post-fossil world: Seasonal energy storage

International Nuclear Information System (INIS)

Forsberg, C.

2009-01-01

Fossil fuels are an energy source and an energy storage system. The demand for electricity and heat varies daily, weekly, and seasonally with seasonal variations often varying by a factor of two or more. The variable demand is met by fossil fuels because 1) fossil fuels are inexpensive to store in coal piles, oil tanks, and underground natural gas storage facilities and 2) the capital cost of the equipment to burn fossil fuels and convert the energy to heat or electricity is small relative to the cost of the fossil fuels. Concerns about climate change may limit the conventional use of fossil fuels. The alternative low-carbon energy production systems (nuclear, fossil fuels with carbon dioxide sequestration, wind, and solar) are capital-intensive energy sources with low operating costs. To obtain favorable economics these technologies must operate at full capacity; but, their output does not match energy demand. We have energy alternatives to fossil fuels but no replacements for the energy storage capabilities or fossil fuels. Proposed strategies and technologies to address the grand storage challenge (including seasonal storage of electricity) are described. The options suggest a nuclear-renewable future to address seasonal energy storage needs in a low-carbon world.

When will fossil fuel reserves be diminished?

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2009-01-01

Crude oil, coal and gas are the main resources for world energy supply. The size of fossil fuel reserves and the dilemma that 'when non-renewable energy will be diminished' is a fundamental and doubtful question that needs to be answered. This paper presents a new formula for calculating when fossil fuel reserves are likely to be depleted and develops an econometrics model to demonstrate the relationship between fossil fuel reserves and some main variables. The new formula is modified from the Klass model and thus assumes a continuous compound rate and computes fossil fuel reserve depletion times for oil, coal and gas of approximately 35, 107 and 37 years, respectively. This means that coal reserves are available up to 2112, and will be the only fossil fuel remaining after 2042. In the Econometrics model, the main exogenous variables affecting oil, coal and gas reserve trends are their consumption and respective prices between 1980 and 2006. The models for oil and gas reserves unexpectedly show a positive and significant relationship with consumption, while presenting a negative and significant relationship with price. The econometrics model for coal reserves, however, expectedly illustrates a negative and significant relationship with consumption and a positive and significant relationship with price. Consequently, huge reserves of coal and low-level coal prices in comparison to oil and gas make coal one of the main energy substitutions for oil and gas in the future, under the assumption of coal as a clean energy source

Market power in the market for greenhouse gas emission permits - the interplay with the fossil fuel markets

International Nuclear Information System (INIS)

Hagem, Cathrine; Maestad, Ottar

2002-01-01

Implementation of the Kyoto Protocol is likely to leave Russia and other Eastern European countries with market power in the market for emission permits. Ceteris paribus, this will raise the permit price above the competitive permit price. However, Russia is also a large exporter of fossil fuels. A high price on emission permits may lower the producer price on fossil fuels. Thus, if Russia co-ordinates its permit market and fossil fuel market policies, market power will not necessarily lead to a higher permit price. Fossil fuel producers may also exert market power in the permit market, provided they conceive the permit price to be influenced by their production volumes. If higher volumes drive up the permit price Russian fuel producers may become more aggressive relative to their competitors in the fuel markets. If the sale of fuels is co-ordinated with the sale of permits. The result is reversed if high fuel production drives the permit price down. (Author)

Market power in the market for greenhouse gas emission permits - the interplay with the fossil fuel markets

Energy Technology Data Exchange (ETDEWEB)

Hagem, Cathrine; Maestad, Ottar

2002-07-01

Implementation of the Kyoto Protocol is likely to leave Russia and other Eastern European countries with market power in the market for emission permits. Ceteris paribus, this will raise the permit price above the competitive permit price. However, Russia is also a large exporter of fossil fuels. A high price on emission permits may lower the producer price on fossil fuels. Thus, if Russia co-ordinates its permit market and fossil fuel market policies, market power will not necessarily lead to a higher permit price. Fossil fuel producers may also exert market power in the permit market, provided they conceive the permit price to be influenced by their production volumes. If higher volumes drive up the permit price Russian fuel producers may become more aggressive relative to their competitors in the fuel markets. If the sale of fuels is co-ordinated with the sale of permits. The result is reversed if high fuel production drives the permit price down. (Author)

Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment.

Science.gov (United States)

Llorens, Laura; Osborne, Colin P; Beerling, David J

2009-07-01

During the Mesozoic, the polar regions supported coniferous forests that experienced warm climates, a CO(2)-rich atmosphere and extreme seasonal variations in daylight. How the interaction between the last two factors might have influenced water use of these conifers was investigated. An experimental approach was used to test the following hypotheses: (1) the expected beneficial effects of elevated [CO(2)] on water-use efficiency (WUE) are reduced or lost during the 24-h light of the high-latitude summer; and (2) elevated [CO(2)] reduces plant water use over the growing season. Measurements of leaf and whole-plant gas exchange, and leaf-stable carbon isotope composition were made on one evergreen (Sequoia sempervirens) and two deciduous (Metasequoia glyptostroboides and Taxodium distichum) 'living fossil' coniferous species after 3 years' growth in controlled-environment simulated Cretaceous Arctic (69 degrees N) conditions at either ambient (400 micromol mol(-1)) or elevated (800 micromol mol(-1)) [CO(2)]. Stimulation of whole-plant WUE (WUE(P)) by CO(2) enrichment was maintained over the growing season for the three studied species but this pattern was not reflected in patterns of WUE inferred from leaf-scale gas exchange measurements (iWUE(L)) and delta(13)C of foliage (tWUE(L)). This response was driven largely by increased rates of carbon uptake, because there was no overall CO(2) effect on daily whole-plant transpiration or whole-plant water loss integrated over the study period. Seasonal patterns of tWUE(L) differed from those measured for iWUE(L). The results suggest caution against over simplistic interpretations of WUE(P) based on leaf isotopic composition. The data suggest that the efficiency of whole-tree water use may be improved by CO(2) enrichment in a simulated high-latitude environment, but that transpiration is relatively insensitive to atmospheric CO(2) in the living fossil species investigated.

High Efficiency Room Air Conditioner

Energy Technology Data Exchange (ETDEWEB)

Bansal, Pradeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

Theory and practice. Possible ways of putting fossil fuels to more efficient use in thermal power stations

Energy Technology Data Exchange (ETDEWEB)

Peter, F

1986-02-01

In the past decade, the development of fuel and investment costs as it occurred has not given any crucial incentive for a necessary change in thermal efficiency. This can be partly attributed to the high level of technology, but also to the fact that the money spent on efficiency-improving measures increases exponentially for the most part. In any case, it should always be borne in mind in planning a new power station plant that the economic efficiency not only of the plant as a whole must be optimized, but also each individual component and system involved. All efforts to improve economic efficiency in systems and components should be harmonised to fit in with one another.

Pulse Combustor Driven Pressure Gain Combustion for High Efficiency Gas Turbine Engines

KAUST Repository

Lisanti, Joel

2017-02-01

The gas turbine engine is an essential component of the global energy infrastructure which accounts for a significant portion of the total fossil fuel consumption in transportation and electric power generation sectors. For this reason there is significant interest in further increasing the efficiency and reducing the pollutant emissions of these devices. Conventional approaches to this goal, which include increasing the compression ratio, turbine inlet temperature, and turbine/compressor efficiency, have brought modern gas turbine engines near the limits of what may be achieved with the conventionally applied Brayton cycle. If a significant future step increase in gas turbine efficiency is to be realized some deviation from this convention is necessary. The pressure gain gas turbine concept is a well established new combustion technology that promises to provide a dramatic increase in gas turbine efficiency by replacing the isobaric heat addition process found in conventional technology with an isochoric process. The thermodynamic benefit of even a small increase in stagnation pressure across a gas turbine combustor translates to a significant increase in cycle efficiency. To date there have been a variety of methods proposed for achieving stagnation pressure gains across a gas turbine combustor and these concepts have seen a broad spectrum of levels of success. The following chapter provides an introduction to one of the proposed pressure gain methods that may be most easily realized in a practical application. This approach, known as pulse combustor driven pressure gain combustion, utilizes an acoustically resonant pulse combustor to approximate isochoric heat release and thus produce a rise in stagnation pressure.

Efficient thermal desalination technologies with renewable energy systems: A state-of-the-art review

Energy Technology Data Exchange (ETDEWEB)

Esfahani, Iman Janghorban; Rashidi, Jouan; Ifaei, Pouya; Yoo, ChangKyoo [Center for Environmental Studies, Kyung Hee University, Yongin (Korea, Republic of)

2016-02-15

Due to the current fossil fuel crisis and associated adverse environmental impacts, renewable energy sources (RES) have drawn interest as alternatives to fossil fuels for powering water desalination systems. Over the last few decades the utility of renewable energy sources such as solar, geothermal, and wind to run desalination processes has been explored. However, the expansion of these technologies to larger scales is hampered by techno-economic and thermo-economic challenges. This paper reviews the state-of-the-art in the field of renewable energy-powered thermal desalination systems (RE-PTD) to compare their productivity and efficiency through thermodynamic, economic, and environmental analyses. We performed a comparative study using published data to classify RE-PTD systems technologies on the basis of the energy collection systems that they use. Among RE-PTD systems, solar energy powered-thermal desalination systems demonstrate high thermo-environ-economic efficiency to produce fresh water to meet various scales of demand.

Efficient thermal desalination technologies with renewable energy systems: A state-of-the-art review

International Nuclear Information System (INIS)

Esfahani, Iman Janghorban; Rashidi, Jouan; Ifaei, Pouya; Yoo, ChangKyoo

2016-01-01

Due to the current fossil fuel crisis and associated adverse environmental impacts, renewable energy sources (RES) have drawn interest as alternatives to fossil fuels for powering water desalination systems. Over the last few decades the utility of renewable energy sources such as solar, geothermal, and wind to run desalination processes has been explored. However, the expansion of these technologies to larger scales is hampered by techno-economic and thermo-economic challenges. This paper reviews the state-of-the-art in the field of renewable energy-powered thermal desalination systems (RE-PTD) to compare their productivity and efficiency through thermodynamic, economic, and environmental analyses. We performed a comparative study using published data to classify RE-PTD systems technologies on the basis of the energy collection systems that they use. Among RE-PTD systems, solar energy powered-thermal desalination systems demonstrate high thermo-environ-economic efficiency to produce fresh water to meet various scales of demand.

A long-term view of worldwide fossil fuel prices

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2010-01-01

This paper reviews a long-term trend of worldwide fossil fuel prices in the future by introducing a new method to forecast oil, natural gas and coal prices. The first section of this study analyses the global fossil fuel market and the historical trend of real and nominal fossil fuel prices from 1950 to 2008. Historical fossil fuel price analysis shows that coal prices are decreasing, while natural gas prices are increasing. The second section reviews previously available price modelling techniques and proposes a new comprehensive version of the long-term trend reverting jump and dip diffusion model. The third section uses the new model to forecast fossil fuel prices in nominal and real terms from 2009 to 2018. The new model follows the extrapolation of the historical sinusoidal trend of nominal and real fossil fuel prices. The historical trends show an increase in nominal/real oil and natural gas prices plus nominal coal prices, as well as a decrease in real coal prices. Furthermore, the new model forecasts that oil, natural gas and coal will stay in jump for the next couple of years and after that they will revert back to the long-term trend until 2018. (author)

Do forests best mitigate CO2 emissions to the atmosphere by setting them aside for maximization of carbon storage or by management for fossil fuel substitution?

DEFF Research Database (Denmark)

Taeroe, Anders; Fayez Mustapha, Walid; Stupak, Inge

2017-01-01

fossil fuels and fossil fuel intensive materials. We defined a modelling framework for calculation of the carbon pools and fluxes along the forest energy and wood product supply chains over 200 years for three forest management alternatives (FMA): 1) a traditionally managed European beech forest...... the lowest CCE when using coal as the reference fossil fuel. With natural gas as the reference fossil fuel, the CCE of the business-as-usual and the energy poplar was nearly equal, with the unmanaged forest having the highest CCE after 40 years. CPTs ranged from 0 to 156 years, depending on the applied model...... assumptions. CCE and CPT were especially sensitive to the reference fossil fuel, material alternatives to wood, forest growth rates for the three FMAs, and energy conversion efficiencies. Assumptions about the long-term steady-state levels of carbon stored in the unmanaged forest had a limited effect on CCE...

Electric buses - An energy efficient urban transportation means

Energy Technology Data Exchange (ETDEWEB)

Kuehne, Reinhart [German Aerospace Center (DLR), Transportation Studies, Rutherfordstr. 2, 12489 Berlin (Germany)

2010-12-15

Bus transit systems with electric traction are an important contribution to the post fossil fuel mobility. Most renewable energy sources provide energy in the form of electricity. Electric motors thus have promise in the development of the way ''beyond oil''. The reactivation of trolley bus systems - grid bounded but also catenary free for short distances - paves this way. The design of modern trolley bus operations overcomes the existing disadvantages of conventional buses using fossil fuel. Germany has an efficient industry in this field, that offers braking energy recovery and energy storage in modern supercapacitors as well as technical and organisational innovations for a local emission free and a low noise transit system. Gentle but powerful when starting and braking, the trolley bus is cost effective and easy to integrate into an existing infrastructure. Such an electric bus system is ecological, customer-friendly and suitable for cities. It has a high economic efficiency and it also expands the traffic planning field towards an ecological future technology. This paper shows examples at home and abroad how electric buses achieve an energy solving modern urban traffic. It gives insights into technical developments of electric vehicle equipment, cateneries with fast driving handling characteristics and the use of plain electric and hybrid powertrains. (author)

Depletion of fossil fuels and anthropogenic climate change—A review

International Nuclear Information System (INIS)

Höök, Mikael; Tang, Xu

2013-01-01

Future scenarios with significant anthropogenic climate change also display large increases in world production of fossil fuels, the principal CO 2 emission source. Meanwhile, fossil fuel depletion has also been identified as a future challenge. This chapter reviews the connection between these two issues and concludes that limits to availability of fossil fuels will set a limit for mankind's ability to affect the climate. However, this limit is unclear as various studies have reached quite different conclusions regarding future atmospheric CO 2 concentrations caused by fossil fuel limitations. It is concluded that the current set of emission scenarios used by the IPCC and others is perforated by optimistic expectations on future fossil fuel production that are improbable or even unrealistic. The current situation, where climate models largely rely on emission scenarios detached from the reality of supply and its inherent problems are problematic. In fact, it may even mislead planners and politicians into making decisions that mitigate one problem but make the other one worse. It is important to understand that the fossil energy problem and the anthropogenic climate change problem are tightly connected and need to be treated as two interwoven challenges necessitating a holistic solution. - Highlights: ► Review of the development of emission scenarios. ► Survey of future fossil fuel trajectories used by the IPCC emission scenarios. ► Discussions on energy transitions in the light of oil depletion. ► Review of earlier studies of future climate change and fossil fuel limitations.

Renewables vs fossil fuels

Energy Technology Data Exchange (ETDEWEB)

Adams, K. (Energy Research and Development Corporation (Australia))

1992-01-01

The paper examines some of the factors which will influence the future mix of energy from fossil fuels and renewable sources in Australia. Aspects covered include: the present energy situation; impact of environmental issues; potential for renewable energy; motivators for change; and research and development. It is concluded that the future for fossil fuels and renewable energy is dependent on a number of complex factors, many of which are currently unknown. The key factor is economic viability and that will be influenced by a range of factors such as policies of the Australian and overseas governments in relation to pollution and environment protection (reflected in the cost of meeting such requirements), exploration and production costs (also influenced by government policies), availability of supply, rate of technological development and the size of export markets. 8 refs., 2 figs., 1 tab.

Financing Energy Efficient Homes

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

Existing buildings require over 40% of the world's total final energy consumption, and account for 24% of world CO2 emissions (IEA, 2006). Much of this consumption could be avoided through improved efficiency of building energy systems (IEA, 2006) using current, commercially-viable technology. In most cases, these technologies make economic sense on a life-cycle cost analysis (IEA, 2006b). Moreover, to the extent that they reduce dependence on risk-prone fossil energy sources, energy efficient technologies also address concerns of energy security.

Financing Energy Efficient Homes

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

Existing buildings require over 40% of the world's total final energy consumption, and account for 24% of world CO2 emissions (IEA, 2006). Much of this consumption could be avoided through improved efficiency of building energy systems (IEA, 2006) using current, commercially-viable technology. In most cases, these technologies make economic sense on a life-cycle cost analysis (IEA, 2006b). Moreover, to the extent that they reduce dependence on risk-prone fossil energy sources, energy efficient technologies also address concerns of energy security.

CH50% - A Switzerland with a consumption of fossil energy split in half

International Nuclear Information System (INIS)

1999-06-01

The Swiss Academy of Engineering Sciences has investigated the possibilities and the consequences of a consumption reduction by 50 % of fossil energy agents within a time frame of 20 to 40 years. A working group of the Academy has made a study on the subject of if and when it would be possible to reduce the consumption of fossil energy in Switzerland by 50 % compared to 1990. The working group came to the conclusion that a reduction of well over 40 % would be feasible by the year 2020, principally due to an improvement in efficiency. This takes into account the substitution potential by renewable energy alternatives. A reduction by 50% will be possible in the second quarter of the 21st century under the condition that both today's known technologies are indeed exploited and that energy prices are increased. For Switzerland's economy and society no unacceptable impacts will thereby result. (author) [de

The financial impact of divestment from fossil fuels

NARCIS (Netherlands)

Plantinga, Auke; Scholtens, Bert

2016-01-01

Divesting from fossil companies has been put forward as a means to address climate change. We study the impact of such divesting on investment portfolio performance. To this extent, we systematically investigate the investment performance of portfolios with and without fossil fuel company stocks. We

Compression map, functional groups and fossilization: A chemometric approach (Pennsylvanian neuropteroid foliage, Canada)

Science.gov (United States)

D'Angelo, J. A.; Zodrow, E.L.; Mastalerz, Maria

2012-01-01

Nearly all of the spectrochemical studies involving Carboniferous foliage of seed-ferns are based on a limited number of pinnules, mainly compressions. In contrast, in this paper we illustrate working with a larger pinnate segment, i.e., a 22-cm long neuropteroid specimen, compression-preserved with cuticle, the compression map. The objective is to study preservation variability on a larger scale, where observation of transparency/opacity of constituent pinnules is used as a first approximation for assessing the degree of pinnule coalification/fossilization. Spectrochemical methods by Fourier transform infrared spectrometry furnish semi-quantitative data for principal component analysis.The compression map shows a high degree of preservation variability, which ranges from comparatively more coalified pinnules to less coalified pinnules that resemble fossilized-cuticles, noting that the pinnule midveins are preserved more like fossilized-cuticles. A general overall trend of coalified pinnules towards fossilized-cuticles, i.e., variable chemistry, is inferred from the semi-quantitative FTIR data as higher contents of aromatic compounds occur in the visually more opaque upper location of the compression map. The latter also shows a higher condensation of the aromatic nuclei along with some variation in both ring size and degree of aromatic substitution. From principal component analysis we infer correspondence between transparency/opacity observation and chemical information which correlate with varying degree to fossilization/coalification among pinnules. ?? 2011 Elsevier B.V.

Methane emissions and climate compatibility of fossil fuels

International Nuclear Information System (INIS)

Meier, B.

1992-01-01

Methane contributes directly and indirectly to the additional greenhouse effect caused by human activities. The vast majority of the anthropogenic methane release occurs worldwide in non-fossil sources such as rice cultivation, livestock operations, sanitary landfills and combustion of bio-mass. Methane emissions also occur during production, distribution and utilisation of fossil fuels. Also when considering the methane release and CO 2 -emissions of processes upstream of combustion, the ranking of environmental compatibility of natural gas, fuel oil and cool remains unchanged. Of all fossil fuels, natural gas contributes the least to the greenhouse effect. (orig.) [de

Problems related to fossil fuels utilization

International Nuclear Information System (INIS)

Rota, R.

1999-01-01

Fossil fuels still present the main energy source in the world since about 90% of the energy produced comes from combustion. This paper, based on the lectures given at the conference of Energy and Environment hold at the Accademia dei Lincei in 1998, presents a short review of some of the problems related to the utilization of fossil fuels, such as their availability in the medium period, the effect of pollutant dispersion in the atmosphere as well as the available technologies to deal with such problems [it

Multiple Threats to Child Health from Fossil Fuel Combustion: Impacts of Air Pollution and Climate Change

Science.gov (United States)

Perera, Frederica P.

2016-01-01

Background: Approaches to estimating and addressing the risk to children from fossil fuel combustion have been fragmented, tending to focus either on the toxic air emissions or on climate change. Yet developing children, and especially poor children, now bear a disproportionate burden of disease from both environmental pollution and climate change due to fossil fuel combustion. Objective: This commentary summarizes the robust scientific evidence regarding the multiple current and projected health impacts of fossil fuel combustion on the young to make the case for a holistic, child-centered energy and climate policy that addresses the full array of physical and psychosocial stressors resulting from fossil fuel pollution. Discussion: The data summarized here show that by sharply reducing our dependence on fossil fuels we would achieve highly significant health and economic benefits for our children and their future. These benefits would occur immediately and also play out over the life course and potentially across generations. Conclusion: Going beyond the powerful scientific and economic arguments for urgent action to reduce the burning of fossil fuels is the strong moral imperative to protect our most vulnerable populations. Citation: Perera FP. 2017. Multiple threats to child health from fossil fuel combustion: impacts of air pollution and climate change. Environ Health Perspect 125:141–148; http://dx.doi.org/10.1289/EHP299 PMID:27323709

Iron-doped nickel oxide nanocrystals as highly efficient electrocatalysts for alkaline water splitting.

Science.gov (United States)

Fominykh, Ksenia; Chernev, Petko; Zaharieva, Ivelina; Sicklinger, Johannes; Stefanic, Goran; Döblinger, Markus; Müller, Alexander; Pokharel, Aneil; Böcklein, Sebastian; Scheu, Christina; Bein, Thomas; Fattakhova-Rohlfing, Dina

2015-05-26

Efficient electrochemical water splitting to hydrogen and oxygen is considered a promising technology to overcome our dependency on fossil fuels. Searching for novel catalytic materials for electrochemical oxygen generation is essential for improving the total efficiency of water splitting processes. We report the synthesis, structural characterization, and electrochemical performance in the oxygen evolution reaction of Fe-doped NiO nanocrystals. The facile solvothermal synthesis in tert-butanol leads to the formation of ultrasmall crystalline and highly dispersible FexNi1-xO nanoparticles with dopant concentrations of up to 20%. The increase in Fe content is accompanied by a decrease in particle size, resulting in nonagglomerated nanocrystals of 1.5-3.8 nm in size. The Fe content and composition of the nanoparticles are determined by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy measurements, while Mössbauer and extended X-ray absorption fine structure analyses reveal a substitutional incorporation of Fe(III) into the NiO rock salt structure. The excellent dispersibility of the nanoparticles in ethanol allows for the preparation of homogeneous ca. 8 nm thin films with a smooth surface on various substrates. The turnover frequencies (TOF) of these films could be precisely calculated using a quartz crystal microbalance. Fe0.1Ni0.9O was found to have the highest electrocatalytic water oxidation activity in basic media with a TOF of 1.9 s(-1) at the overpotential of 300 mV. The current density of 10 mA cm(-2) is reached at an overpotential of 297 mV with a Tafel slope of 37 mV dec(-1). The extremely high catalytic activity, facile preparation, and low cost of the single crystalline FexNi1-xO nanoparticles make them very promising catalysts for the oxygen evolution reaction.

40 CFR 761.71 - High efficiency boilers.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the following...

The environmental dilemma of fossil fuels

International Nuclear Information System (INIS)

MacCracken, M.C.

1992-04-01

The increasing atmospheric concentration of carbon dioxide poses an environmental dilemma for fossil fuel energy generation that, unlike other related emissions, cannot be resolved by control technologies alone. Although fossil fuels presently provide the most cost-effective global energy source, and model projections suggest that their use is initiating climatic changes which, while quite uncertain, may induce significant, counter-balancing impacts to water resources, coastal resources, ecological systems, and possibly agricultural production. The climate model indicate that the warming should have begun, and there is some evidence for this occurring, but at a less rapid and more uneven rate than projected. In addition, different climate models are not yet in agreement in their latitudinal or regional predictions, and it will likely require a decade or more for such agreement to develop as high performance computers become available for addressing this ''grand challenge'' problem. Thus, in addition to the prospect for climatic change, the uncertainties of the changes and associated impacts contribute to the dilemma of dealing with the issue. Further, the problem is pervasive and international scope, with different countries and peoples having differing perspectives of technology, development, and environmental responsibility. Dealing with this issue will thus require creativity, commitment, and flexibility

Unconventional, High-Efficiency Propulsors

DEFF Research Database (Denmark)

Andersen, Poul

1996-01-01

The development of ship propellers has generally been characterized by search for propellers with as high efficiency as possible and at the same time low noise and vibration levels and little or no cavitation. This search has lead to unconventional propulsors, like vane-wheel propulsors, contra-r...

New record of a fossil haplotilapiine cichlid from Central Kenya

Directory of Open Access Journals (Sweden)

Stefanie B. R. Penk

2015-11-01

Full Text Available African freshwater cichlids (Cichlidae: Pseudocrenilabrinae are well known for their exceptionally great diversity and their capability of rapid speciation as well as diverse adaptations. The extant Pseudocrenilabrinae can be grouped into 27 tribes, with more than 2000 species harbored in the Great Lakes and surrounding water bodies of the East African Rift System. However, this unique diversity is not reflected in the fossil record because fossil cichlids were predominantly reported based on isolated teeth and bones. Moreover, the few articulated specimens that are known have not been analyzed sufficiently with regard to their systematic position due to lack of comparative material. Here we present a new extraordinarily well-preserved cichlid fish fossil from the Middle Miocene (c. 12.5 Ma Lagerstaette Kabchore, which was recovered during recent fieldwork in the Tugen Hills (Baringo County, Central Kenya Rift. Based on the evidence of tricuspid teeth, the Kabchore fossil can be assigned to the subclade of the Haplotilapiines within the Pseudocrenilabrinae. The multivariate analysis of a large meristic data set, derived from 1014 extant specimens (encompassing all main lineages of Haplotilapiines and usage of available osteological data suggest that this fossil is most likely related to one of the three haplotilapiine tribes Tilapiini, Haplochromini or Oreochromini. Moreover, the fossil specimen closely resembles the extinct cichlid Oreochromis martyni (Van Couvering, 1982, previously described as species of Sarotherodon from the Middle Miocene alkaline Kapkiamu Lake in the Tugen Hills. The analysis of the greatly preserved fossil fish specimen from Kabchore definitely supplements the fragmentary fossil record of Africa’s Cichlidae and will afford new insights into its evolutionary history. We also expect that this fossil will be useful as calibration point for new divergence-time estimates.

Long time management of fossil fuel resources to limit global warming and avoid ice age onsets

Science.gov (United States)

Shaffer, Gary

2009-02-01

There are about 5000 billion tons of fossil fuel carbon in accessible reserves. Combustion of all this carbon within the next few centuries would force high atmospheric CO2 content and extreme global warming. On the other hand, low atmospheric CO2 content favors the onset of an ice age when changes in the Earth's orbit lead to low summer insolation at high northern latitudes. Here I present Earth System Model projections showing that typical reduction targets for fossil fuel use in the present century could limit ongoing global warming to less than one degree Celcius above present. Furthermore, the projections show that combustion pulses of remaining fossil fuel reserves could then be tailored to raise atmospheric CO2 content high and long enough to parry forcing of ice age onsets by summer insolation minima far into the future. Our present interglacial period could be extended by about 500,000 years in this way.

Fossil-Fuel C02 Emissions Database and Exploration System

Science.gov (United States)

Krassovski, M.; Boden, T.

2012-04-01

Fossil-Fuel C02 Emissions Database and Exploration System Misha Krassovski and Tom Boden Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) quantifies the release of carbon from fossil-fuel use and cement production each year at global, regional, and national spatial scales. These estimates are vital to climate change research given the strong evidence suggesting fossil-fuel emissions are responsible for unprecedented levels of carbon dioxide (CO2) in the atmosphere. The CDIAC fossil-fuel emissions time series are based largely on annual energy statistics published for all nations by the United Nations (UN). Publications containing historical energy statistics make it possible to estimate fossil-fuel CO2 emissions back to 1751 before the Industrial Revolution. From these core fossil-fuel CO2 emission time series, CDIAC has developed a number of additional data products to satisfy modeling needs and to address other questions aimed at improving our understanding of the global carbon cycle budget. For example, CDIAC also produces a time series of gridded fossil-fuel CO2 emission estimates and isotopic (e.g., C13) emissions estimates. The gridded data are generated using the methodology described in Andres et al. (2011) and provide monthly and annual estimates for 1751-2008 at 1° latitude by 1° longitude resolution. These gridded emission estimates are being used in the latest IPCC Scientific Assessment (AR4). Isotopic estimates are possible thanks to detailed information for individual nations regarding the carbon content of select fuels (e.g., the carbon signature of natural gas from Russia). CDIAC has recently developed a relational database to house these baseline emissions estimates and associated derived products and a web-based interface to help users worldwide query these data holdings. Users can identify, explore and download desired CDIAC

Mapping Global Flows of Chemicals: From Fossil Fuel Feedstocks to Chemical Products.

Science.gov (United States)

Levi, Peter G; Cullen, Jonathan M

2018-02-20

Chemical products are ubiquitous in modern society. The chemical sector is the largest industrial energy consumer and the third largest industrial emitter of carbon dioxide. The current portfolio of mitigation options for the chemical sector emphasizes upstream "supply side" solutions, whereas downstream mitigation options, such as material efficiency, are given comparatively short shrift. Key reasons for this are the scarcity of data on the sector's material flows, and the highly intertwined nature of its complex supply chains. We provide the most up to date, comprehensive and transparent data set available publicly, on virgin production routes in the chemical sector: from fossil fuel feedstocks to chemical products. We map global mass flows for the year 2013 through a complex network of transformation processes, and by taking account of secondary reactants and by-products, we maintain a full mass balance throughout. The resulting data set partially addresses the dearth of publicly available information on the chemical sector's supply chain, and can be used to prioritise downstream mitigation options.

Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia during the last decade.

Science.gov (United States)

O'Sullivan, Michael; Rap, Alex; Reddington, Carly; Spracklen, Dominick; Buermann, Wolfgang

2016-04-01

The global terrestrial carbon sink has increased since the start of this century at a time of rapidly growing carbon dioxide emissions from fossil fuel burning. Here we test the hypothesis that increases in atmospheric aerosols from fossil fuel burning have increased the diffuse fraction of incoming solar radiation and the efficiency of photosynthesis leading to increased plant carbon uptake. Using a combination of atmospheric and biospheric models, we find that changes in diffuse light associated with fossil fuel aerosol emission accounts for only 2.8% of the increase in global net primary production (1.221 PgC/yr) over the study period 1998 to 2007. This relatively small global signal is however a result of large regional compensations. Over East Asia, the strong increase in fossil fuel emissions contributed nearly 70% of the increased plant carbon uptake (21 TgC/yr), whereas the declining fossil fuel aerosol emissions in Europe and North America contributed negatively (-16% and -54%, respectively) to increased plant carbon uptake. At global scale, we also find the CO2 fertilization effect on photosynthesis to be the dominant driver of increased plant carbon uptake, in line with previous studies. These results suggest that further research into alternative mechanisms by which fossil fuel emissions could increase carbon uptake, such as nitrogen deposition and carbon-nitrogen interactions, is required to better understand a potential link between the recent changes in fossil fuel emissions and terrestrial carbon uptake.

Research & Implementation of AC - DC Converter with High Power Factor & High Efficiency

Directory of Open Access Journals (Sweden)

Hsiou-Hsian Nien

2014-05-01

Full Text Available In this paper, we design and develop a high power factor, high efficiency two-stage AC - DC power converter. This paper proposes a two-stage AC - DC power converter. The first stage is boost active power factor correction circuit. The latter stage is near constant frequency LLC resonant converter. In addition to traditional LLC high efficiency advantages, light-load conversion efficiency of this power converter can be improved. And it possesses high power factor and near constant frequency operating characteristics, can significantly reduce the electromagnetic interference. This paper first discusses the main structure and control manner of power factor correction circuit. And then by the LLC resonant converter equivalent model proceed to circuit analysis to determine the important parameters of the converter circuit elements. Then design a variable frequency resonant tank. The resonant frequency can change automatically on the basis of the load to reach near constant frequency operation and a purpose of high efficiency. Finally, actually design and produce an AC – DC power converter with output of 190W to verify the characteristics and feasibility of this converter. The experimental results show that in a very light load (9.5 W the efficiency is as high as 81%, the highest efficiency of 88% (90 W. Full load efficiency is 87%. At 19 W ~ 190 W power changes, the operating frequency change is only 0.4 kHz (AC 110 V and 0.3 kHz (AC 220 V.

Efficiency of poly-generating high temperature fuel cells

Energy Technology Data Exchange (ETDEWEB)

Margalef, Pere; Brown, Tim; Brouwer, Jacob; Samuelsen, Scott [National Fuel Cell Research Center (NFCRC), University of California, Irvine, CA 92697-3550 (United States)

2011-02-15

High temperature fuel cells can be designed and operated to poly-generate electricity, heat, and useful chemicals (e.g., hydrogen) in a variety of configurations. The highly integrated and synergistic nature of poly-generating high temperature fuel cells, however, precludes a simple definition of efficiency for analysis and comparison of performance to traditional methods. There is a need to develop and define a methodology to calculate each of the co-product efficiencies that is useful for comparative analyses. Methodologies for calculating poly-generation efficiencies are defined and discussed. The methodologies are applied to analysis of a Hydrogen Energy Station (H{sub 2}ES) showing that high conversion efficiency can be achieved for poly-generation of electricity and hydrogen. (author)

News technology utilization fossil fuel

Directory of Open Access Journals (Sweden)

Blišanová Monika

2004-09-01

Full Text Available Fossil fuel – “alternative energy“ is coal, petroleum, natural gas. Petroleum and natural gas are scarce resources, but they are delimited. Reserves petroleum will be depleted after 39 years and reserves natural gas after 60 years.World reserves coal are good for another 240 years. Coal is the most abundant fossil fuel. It is the least expensive energy source for generating electricity. Many environmental problems associated with use of coal:in coal production, mining creates environmental problems.On Slovakia representative coal only important internal fuel – power of source and coal is produced in 5 locality. Nowadays, oneself invest to new technology on utilization coal. Perspective solution onself shows UCG, IGCC.

Fossils and decapod phylogeny

NARCIS (Netherlands)

Schram, Frederick R.; Dixon, Christopher

2003-01-01

An expanded series of morphological characters developed for a cladistic analysis of extant decapods has yielded a new hypothesis for the phylogeny of the group. Application of this database to selected fossil genera produces some interesting results and demonstrates the feasibility of treating

High efficiency, variable geometry, centrifugal cryogenic pump

International Nuclear Information System (INIS)

Forsha, M.D.; Nichols, K.E.; Beale, C.A.

1994-01-01

A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions

Fossil resource trade balances. Emerging trends for the UK

International Nuclear Information System (INIS)

Papathanasopoulou, Eleni; Jackson, Tim

2008-01-01

The aim of this paper is to examine the extent to which the UK can be classified as a net importer of fossil resources and a creator of pollution havens abroad between 1968 and 2000. Using input-output techniques and a derived Resource Flow Classification System, both the physical trade balance (PTB) and pollution trade balance (UTB) associated with fossil resource use are computed. The PTB shows that between 1968 and the early 1980's the UK is presented as a net importer of direct fossil resource flows. Between 1984 and 2000, the UK is identified as a net exporter of direct fossil resources. These trends are primarily explained by the UK's discovery and commercial production of North Sea oil and gas fields in the late 1970s. On the other hand, the UTB shows that over the whole period the indirect used flows attributable to the UK's exports are higher than those attributable to its imports. These findings suggest that the UK did not create pollution havens abroad from the use of fossil resources between 1968 and 2000. However, it is noticeable in both cases that from 1995 the UK's position as a net exporter has been decreasing considerably. Maturing North Sea oil and gas fields set against increasing demands for fossil fuels and imported goods is signalling a return to the UK's pre-1984 dependence on direct imported fossil resources and the possible creation of pollution havens abroad. Knowledge of these trends contributes to the evidence base for the UK's changing import and export structure and the potential environmental repercussions at home and abroad. (author)

Fossil resource trade balances. Emerging trends for the UK

Energy Technology Data Exchange (ETDEWEB)

Papathanasopoulou, Eleni; Jackson, Tim [Centre for Environmental Strategy, University of Surrey, Guildford, Surrey, GU2 7TH (United Kingdom)

2008-06-15

The aim of this paper is to examine the extent to which the UK can be classified as a net importer of fossil resources and a creator of pollution havens abroad between 1968 and 2000. Using input-output techniques and a derived Resource Flow Classification System, both the physical trade balance (PTB) and pollution trade balance (UTB) associated with fossil resource use are computed. The PTB shows that between 1968 and the early 1980's the UK is presented as a net importer of direct fossil resource flows. Between 1984 and 2000, the UK is identified as a net exporter of direct fossil resources. These trends are primarily explained by the UK's discovery and commercial production of North Sea oil and gas fields in the late 1970s. On the other hand, the UTB shows that over the whole period the indirect used flows attributable to the UK's exports are higher than those attributable to its imports. These findings suggest that the UK did not create pollution havens abroad from the use of fossil resources between 1968 and 2000. However, it is noticeable in both cases that from 1995 the UK's position as a net exporter has been decreasing considerably. Maturing North Sea oil and gas fields set against increasing demands for fossil fuels and imported goods is signalling a return to the UK's pre-1984 dependence on direct imported fossil resources and the possible creation of pollution havens abroad. Knowledge of these trends contributes to the evidence base for the UK's changing import and export structure and the potential environmental repercussions at home and abroad. (author)

Analysis of radiation level on dinosaur fossil in Zigong

International Nuclear Information System (INIS)

Yang Changshu; Liang Shuzhi; Fan Zhengnian.

1995-01-01

Study on radiation level of dinosaur fossil and environment in conservation zone in Zigong, Sichuan has been done. The results showed that the γ radiation dose and radioactivity strength of 232 Th and 40 K in dinosaur fossil, soil and rock in the conservation zone were within the limits of radioactive background value in Zigong. Radioactivity strength of 238 U, 226 Ra in dinosaur fossil were 26.6 and 29.2 times higher than the rock of same layer respectively

Total-Evidence Dating under the Fossilized Birth-Death Process.

Science.gov (United States)

Zhang, Chi; Stadler, Tanja; Klopfstein, Seraina; Heath, Tracy A; Ronquist, Fredrik

2016-03-01

Bayesian total-evidence dating involves the simultaneous analysis of morphological data from the fossil record and morphological and sequence data from recent organisms, and it accommodates the uncertainty in the placement of fossils while dating the phylogenetic tree. Due to the flexibility of the Bayesian approach, total-evidence dating can also incorporate additional sources of information. Here, we take advantage of this and expand the analysis to include information about fossilization and sampling processes. Our work is based on the recently described fossilized birth-death (FBD) process, which has been used to model speciation, extinction, and fossilization rates that can vary over time in a piecewise manner. So far, sampling of extant and fossil taxa has been assumed to be either complete or uniformly at random, an assumption which is only valid for a minority of data sets. We therefore extend the FBD process to accommodate diversified sampling of extant taxa, which is standard practice in studies of higher-level taxa. We verify the implementation using simulations and apply it to the early radiation of Hymenoptera (wasps, ants, and bees). Previous total-evidence dating analyses of this data set were based on a simple uniform tree prior and dated the initial radiation of extant Hymenoptera to the late Carboniferous (309 Ma). The analyses using the FBD prior under diversified sampling, however, date the radiation to the Triassic and Permian (252 Ma), slightly older than the age of the oldest hymenopteran fossils. By exploring a variety of FBD model assumptions, we show that it is mainly the accommodation of diversified sampling that causes the push toward more recent divergence times. Accounting for diversified sampling thus has the potential to close the long-discussed gap between rocks and clocks. We conclude that the explicit modeling of fossilization and sampling processes can improve divergence time estimates, but only if all important model aspects

Caught in the act: the first record of copulating fossil vertebrates.

Science.gov (United States)

Joyce, Walter G; Micklich, Norbert; Schaal, Stephan F K; Scheyer, Torsten M

2012-10-23

The behaviour of fossil organisms can typically be inferred only indirectly, but rare fossil finds can provide surprising insights. Here, we report from the Eocene Messel Pit Fossil Site between Darmstadt and Frankfurt, Germany numerous pairs of the fossil carettochelyid turtle Allaeochelys crassesculpta that represent for the first time among fossil vertebrates couples that perished during copulation. Females of this taxon can be distinguished from males by their relatively shorter tails and development of plastral kinesis. The preservation of mating pairs has important taphonomic implications for the Messel Pit Fossil Site, as it is unlikely that the turtles would mate in poisonous surface waters. Instead, the turtles initiated copulation in habitable surface waters, but perished when their skin absorbed poisons while sinking into toxic layers. The mating pairs from Messel are therefore more consistent with a stratified, volcanic maar lake with inhabitable surface waters and a deadly abyss.

Diagnosing Homo sapiens in the fossil record.

Science.gov (United States)

Stringer, Christopher Brian; Buck, Laura Tabitha

2014-01-01

Diagnosing Homo sapiens is a critical question in the study of human evolution. Although what constitutes living members of our own species is straightforward, in the fossil record this is still a matter of much debate. The issue is complicated by questions of species diagnoses and ideas about the mode by which a new species is born, by the arguments surrounding the behavioural and cognitive separateness of the species, by the increasing appreciation of variation in the early African H. sapiens record and by new DNA evidence of hybridization with extinct species. This study synthesizes thinking on the fossils, archaeology and underlying evolutionary models of the last several decades with recent DNA results from both H. sapiens and fossil species. It is concluded that, although it may not be possible or even desirable to cleanly partition out a homogenous morphological description of recent H. sapiens in the fossil record, there are key, distinguishing morphological traits in the cranium, dentition and pelvis that can be usefully employed to diagnose the H. sapiens lineage. Increasing advances in retrieving and understanding relevant genetic data provide a complementary and perhaps potentially even more fruitful means of characterizing the differences between H. sapiens and its close relatives.

Reforming fossil fuel prices in India: Dilemma of a developing economy

International Nuclear Information System (INIS)

Anand, Mukesh Kumar

2016-01-01

Over the period between 1990–1 and 2012–3, fossil fuel use on farms has risen and its indirect use in farming, particularly for non-energy purposes, is also growing. Consequently, both energy intensity and fossil fuel intensity are rising for Indian agriculture. But, these are declining for the aggregate Indian economy. Thus, revision of fossil fuel prices acquires greater significance for Indian agriculture than for rest of the economy. There are significant differences across crops. The crop-level analysis is supplemented by an alternative approach that utilizes a three-sector input–output (I–O) model for the Indian economy representing farming, fossil fuels, and rest of economy. Fossil fuels sector is assessed to portray, in general, strong forward linkages. The increase in total cost of farming, for a given change in fossil fuel prices, is estimated as a multiple of increase in direct input cost of fossil fuels in farming. From the three-sector aggregated economy this multiple was estimated at 3.99 for 1998–9. But it grew to 6.7 in 2007–8. The findings have stronger ramifications than commonly recognized, for inflation and cost of implementing the policy on food security. - Highlights: •Fossil fuels’ contribution in primary energy supply has risen from 55 to 75 per cent. •Energy intensity halved for aggregate GDP, but doubled for agricultural GDP. •Impact of fossil fuel price increase on farming costs mimics a widening spiral. •Total cost of farming may increase 6.7 times the increase in direct fuel input cost.

THE XMM CLUSTER SURVEY: THE STELLAR MASS ASSEMBLY OF FOSSIL GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Harrison, Craig D.; Miller, Christopher J. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Richards, Joseph W.; Deadman, Paul-James [Center for Time Domain Informatics, University of California, Berkeley, CA 94720 (United States); Lloyd-Davies, E. J.; Kathy Romer, A.; Mehrtens, Nicola; Liddle, Andrew R. [Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Hoyle, Ben [Institute of Sciences of the Cosmos (ICCUB) and IEEC, Physics Department, University of Barcelona, Barcelona 08024 (Spain); Hilton, Matt [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa); Stott, John P.; Capozzi, Diego; Collins, Chris A. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Sahlen, Martin [Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Stanford, S. Adam [Physics Department, University of California, Davis, CA 95616 (United States); Viana, Pedro T. P., E-mail: craigha@umich.edu [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2012-06-10

This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and stellar populations of their fossil galaxies. In total, 17 groups and clusters are identified at z < 0.25 with large magnitude gaps between the first and fourth brightest galaxies. All the information necessary to classify these systems as fossils is provided. For both groups and clusters, the total and fractional luminosity of the brightest galaxy is positively correlated with the magnitude gap. The brightest galaxies in FSs (called fossil galaxies) have stellar populations and star formation histories which are similar to normal brightest cluster galaxies (BCGs). However, at fixed group/cluster mass, the stellar masses of the fossil galaxies are larger compared to normal BCGs, a fact that holds true over a wide range of group/cluster masses. Moreover, the fossil galaxies are found to contain a significant fraction of the total optical luminosity of the group/cluster within 0.5 R{sub 200}, as much as 85%, compared to the non-fossils, which can have as little as 10%. Our results suggest that FSs formed early and in the highest density regions of the universe and that fossil galaxies represent the end products of galaxy mergers in groups and clusters.

HIGH EFFICIENCY TURBINE

OpenAIRE

VARMA, VIJAYA KRUSHNA

2012-01-01

Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufac...

Instrumentation and control for fossil-energy processes

Energy Technology Data Exchange (ETDEWEB)

1982-09-01

The 1982 symposium on instrumentation and control for fossil energy processes was held June 7 through 9, 1982, at Adam's Mark Hotel, Houston, Texas. It was sponsored by the US Department of Energy, Office of Fossil Energy; Argonne National Laboratory; and the Society for Control and Instrumentation of Energy Processes. Fifty-two papers have been entered individually into EDB and ERA; eleven papers had been entered previously from other sources. (LTN)

Reconstruction of deglacial sea surface temperature in the tropical Pacific from selective analysis of a fossil coral

Energy Technology Data Exchange (ETDEWEB)

Allison, N.; Finch, A.A.; Tudhope, A.W.; Newville, M.; Sutton, S.R.; Ellam, R.M. (St Andrews); (Edinburgh); (Scottish); (UC); (St Andrews)

2010-07-13

The Sr/Ca of coral skeletons demonstrates potential as an indicator of sea surface temperatures (SSTs). However, the glacial-interglacial SST ranges predicted from Sr/Ca of fossil corals are usually higher than from other marine proxies. We observed infilling of secondary aragonite, characterized by high Sr/Ca ratios, along intraskeletal pores of a fossil coral from Papua New Guinea that grew during the penultimate deglaciation (130 {+-} 2 ka). Selective microanalysis of unaltered areas of the fossil coral indicates that SSTs at {approx}130 ka were {le} 1 C cooler than at present in contrast with bulk measurements (combining infilled and unaltered areas) which indicate a difference of 6-7 C. The analysis of unaltered areas of fossil skeletons by microprobe techniques may offer a route to more accurate reconstruction of past SSTs.

A WELL PRESERVED SKELETON OF THE FOSSIL SHARK COSMOPOLITODUS HASTALIS FROM THE LATE MIOCENE OF PERU, FEATURING FISH REMAINS AS FOSSILIZED STOMACH CONTENTS

Directory of Open Access Journals (Sweden)

ALBERTO COLLARETA

2017-01-01

Full Text Available Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru. Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus. Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation.

Fossil gaps inferred from phylogenies alter the apparent nature of diversification in dragonflies and their relatives

Directory of Open Access Journals (Sweden)

Nicholson David B

2011-09-01

Full Text Available Abstract Background The fossil record has suggested that clade growth may differ in marine and terrestrial taxa, supporting equilibrial models in the former and expansionist models in the latter. However, incomplete sampling may bias findings based on fossil data alone. To attempt to correct for such bias, we assemble phylogenetic supertrees on one of the oldest clades of insects, the Odonatoidea (dragonflies, damselflies and their extinct relatives, using MRP and MRC. We use the trees to determine when, and in what clades, changes in taxonomic richness have occurred. We then test whether equilibrial or expansionist models are supported by fossil data alone, and whether findings differ when phylogenetic information is used to infer gaps in the fossil record. Results There is broad agreement in family-level relationships between both supertrees, though with some uncertainty along the backbone of the tree regarding dragonflies (Anisoptera. "Anisozygoptera" are shown to be paraphyletic when fossil information is taken into account. In both trees, decreases in net diversification are associated with species-poor extant families (Neopetaliidae, Hemiphlebiidae, and an upshift is associated with Calopterygidae + Polythoridae. When ghost ranges are inferred from the fossil record, many families are shown to have much earlier origination dates. In a phylogenetic context, the number of family-level lineages is shown to be up to twice as high as the fossil record alone suggests through the Cretaceous and Cenozoic, and a logistic increase in richness is detected in contrast to an exponential increase indicated by fossils alone. Conclusions Our analysis supports the notion that taxa, which appear to have diversified exponentially using fossil data, may in fact have diversified more logistically. This in turn suggests that one of the major apparent differences between the marine and terrestrial fossil record may simply be an artifact of incomplete sampling

A new commelinid monocot seed fossil from the early Eocene previously identified as Solanaceae.

Science.gov (United States)

Särkinen, Tiina; Kottner, Sören; Stuppy, Wolfgang; Ahmed, Farah; Knapp, Sandra

2018-01-01

Fossils provide minimum age estimates for extant lineages. Here we critically evaluate Cantisolanum daturoides Reid & Chandler and two other early putative seed fossils of Solanaceae, an economically important plant family in the Asteridae. Three earliest seed fossil taxa of Solanaceae from the London Clay Formation (Cantisolanum daturoides) and the Poole and Branksome Sand Formations (Solanum arnense Chandler and Solanispermum reniforme Chandler) were studied using x-ray microcomputed tomography (MCT) and scanning electron microscopy (SEM). The MCT scans of Cantisolanum daturoides revealed a high level of pyrite preservation at the cellular level. Cantisolanum daturoides can be clearly excluded from Solanaceae and has more affinities to the commelinid monocots based on a straight longitudinal axis, a prominent single layer of relatively thin-walled cells in the testa, and a clearly differentiated micropyle surrounded by radially elongated and inwardly curved testal cells. While the MCT scans show no internal preservation in Solanum arnense and Solanispermum reniforme, SEM images show the presence of several characteristics that allow the placement of these taxa at the stem node of Solanaceae. Cantisolanum daturoides is likely a member of commelinid monocots and not Solanaceae as previously suggested. The earliest fossil record of Solanaceae is revised to consist of fruit fossil with inflated calyces from the early Eocene of Patagonia (52 Ma) and fossilized seeds from the early to mid-Eocene of Europe (48-46 Ma). The new identity for Cantisolanum daturoides does not alter a late Cretaceous minimum age for commelinids. © 2018 Botanical Society of America.

Improved Fossil/Industrial CO2 Emissions Modeling for the North American Carbon Program

Science.gov (United States)

Gurney, K. R.; Seib, B.; Mendoza, D.; Knox, S.; Fischer, M.; Murtishaw, S.

2006-12-01

The quantification of fossil fuel CO2 emissions has implications for a wide variety of scientific and policy- related questions. Improvement in inverse-estimated carbon fluxes, country-level carbon budgeting, analysis of regional emissions trading systems, and targeting of observational systems are all important applications better served by improvements in understanding where and when fossil fuel/industrial CO2 is emitted. Traditional approaches to quantifying fossil/industrial CO2 emissions have relied on national sales/consumption of fossil fuels with secondary spatial footprints performed via proxies such as population. This approach has provided global spatiotemporal resolution of one degree/monthly. In recent years the need has arisen for emission estimates that not only achieve higher spatiotemporal scales but include a process- level component. This latter attribute provides dynamic linkages between energy policy/decisionmaking and emissions for use in projecting changes to energy systems and the implications these changes may have on climate change. We have embarked on a NASA-funded research strategy to construct a process-level fossil/industrial CO2 emissions model/database for North America that will resolve fossil/industrial CO2 emissions hourly and at 36 km. This project is a critical component of the North American Carbon Program. Our approach builds off of many decades of air quality monitoring for regulated pollutants such as NOx, VOCs and CO that has been performed by regional air quality managers, states, and the Environmental Protection Agency in the United States. By using the highly resolved monitoring data supplied to the EPA, we have computed CO2 emissions for residential, commercial/industrial, transportation, and biogenic sources. This effort employs a new emissions modeling system (CONCEPT) that spatially and temporally distributes the monitored emissions across the US. We will provide a description of the methodology we have employed, the

Sanitary effects of fossil fuels; Effets sanitaires des combustibles fossiles

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H. [Centre National de la Recherche Scientifique (IN2P3/CNRS), 38 - Grenoble (France)

2006-07-01

In this compilation are studied the sanitary effects of fossil fuels, behavioral and environmental sanitary risks. The risks in connection with the production, the transport and the distribution(casting) are also approached for the oil(petroleum), the gas and the coal. Accidents in the home are evoked. The risks due to the atmospheric pollution are seen through the components of the atmospheric pollution as well as the sanitary effects of this pollution. (N.C.)

Fossil human remains from Bolomor Cave (Valencia, Spain).

Science.gov (United States)

Arsuaga, Juan Luis; Fernández Peris, Josep; Gracia-Téllez, Ana; Quam, Rolf; Carretero, José Miguel; Barciela González, Virginia; Blasco, Ruth; Cuartero, Felipe; Sañudo, Pablo

2012-05-01

Systematic excavations carried out since 1989 at Bolomor Cave have led to the recovery of four Pleistocene human fossil remains, consisting of a fibular fragment, two isolated teeth, and a nearly complete adult parietal bone. All of these specimens date to the late Middle and early Late Pleistocene (MIS 7-5e). The fibular fragment shows thick cortical bone, an archaic feature found in non-modern (i.e. non-Homo sapiens) members of the genus Homo. Among the dental remains, the lack of a midtrigonid crest in the M(1) represents a departure from the morphology reported for the majority of Neandertal specimens, while the large dimensions and pronounced shoveling of the marginal ridges in the C(1) are similar to other European Middle and late Pleistocene fossils. The parietal bone is very thick, with dimensions that generally fall above Neandertal fossils and resemble more closely the Middle Pleistocene Atapuerca (SH) adult specimens. Based on the presence of archaic features, all the fossils from Bolomor are attributed to the Neandertal evolutionary lineage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Gamma-ray spectrometer system with high efficiency and high resolution

International Nuclear Information System (INIS)

Moss, C.E.; Bernard, W.; Dowdy, E.J.; Garcia, C.; Lucas, M.C.; Pratt, J.C.

1983-01-01

Our gamma-ray spectrometer system, designed for field use, offers high efficiency and high resolution for safeguards applications. The system consists of three 40% high-purity germanium detectors and a LeCroy 3500 data acquisition system that calculates a composite spectrum for the three detectors. The LeCroy 3500 mainframe can be operated remotely from the detector array with control exercised through modems and the telephone system. System performance with a mixed source of 125 Sb, 154 Eu, and 155 Eu confirms the expected efficiency of 120% with the overall resolution showing little degradation over that of the worst detector

High voltage generator circuit with low power and high efficiency applied in EEPROM

International Nuclear Information System (INIS)

Liu Yan; Zhang Shilin; Zhao Yiqiang

2012-01-01

This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (V th ) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation. (semiconductor integrated circuits)

Natural product terpenoids in Eocene and Miocene conifer fossils.

Science.gov (United States)

Otto, Angelika; White, James D; Simoneit, Bernd R T

2002-08-30

Numerous saturated and aromatic hydrocarbons, but not polar compounds, originating from plants and microorganisms (biomarkers) have been reported in sediments, coals, and petroleum. Here we describe natural product terpenoids found in two fossil conifers, Taxodium balticum (Eocene) and Glyptostrobus oregonensis (Miocene). A similar terpenoid pattern is also observed in extant Taxodium distichum. The preservation of characteristic terpenoids (unaltered natural products) in the fossil conifers supports their systematic assignment to the Cypress family (Cupressaceae sensu lato). The results also show that fossil conifers can contain polar terpenoids, which are valuable markers for (paleo)chemosystematics and phylogeny.

ESR dating studies on fossil of elaphurus davidianus horn

International Nuclear Information System (INIS)

Chen Shiming; Wang Hong; Tang Jingjuan; Yan Xiaomin; Guo Shiqing

1991-01-01

On the basis of studies on elephant tooth fossil, ESR dating of elaphurus davidianus horn fossil found in Anhui Province was reported. The sample examined by TEM electron spectrum is composed of hydroxyapatite. ESR experiments showed that the solid bone sample can be chosen as dating material. According to the contents of U, Th and K in the sample determined by ICP, the annual dose of radiation was calculated by using the linear uranium accumulation model and disequilibrium decay. The age of this fossil was determined to be 2.5 x 10 4 years

Microbial Biotechnology 2020; microbiology of fossil fuel resources.

Science.gov (United States)

Head, Ian M; Gray, Neil D

2016-09-01

This roadmap examines the future of microbiology research and technology in fossil fuel energy recovery. Globally, the human population will be reliant on fossil fuels for energy and chemical feedstocks for at least the medium term. Microbiology is already important in many areas relevant to both upstream and downstream activities in the oil industry. However, the discipline has struggled for recognition in a world dominated by geophysicists and engineers despite widely known but still poorly understood microbially mediated processes e.g. reservoir biodegradation, reservoir souring and control, microbial enhanced oil recovery. The role of microbiology is even less understood in developing industries such as shale gas recovery by fracking or carbon capture by geological storage. In the future, innovative biotechnologies may offer new routes to reduced emissions pathways especially when applied to the vast unconventional heavy oil resources formed, paradoxically, from microbial activities in the geological past. However, despite this potential, recent low oil prices may make industry funding hard to come by and recruitment of microbiologists by the oil and gas industry may not be a high priority. With regards to public funded research and the imperative for cheap secure energy for economic growth in a growing world population, there are signs of inherent conflicts between policies aimed at a low carbon future using renewable technologies and policies which encourage technologies which maximize recovery from our conventional and unconventional fossil fuel assets. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Fossil Energy Program annual progress report for April 1994 through March 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

This report covers progress made during the period April 1, 1994, through March 31, 1995, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, and DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Bartlesville Project Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve. The following research areas are covered in this report: Materials research and development; Environmental analysis support; Bioprocessing research; Coal combustion research; and Fossil fuels supplies modeling and research. Selected papers have been processed separately for inclusion in the Energy Science an Technology database.

The Fossil Fuel Divestment Movement: An Ethical Dilemma for the Geosciences?

Science.gov (United States)

Greene, C. H.; Kammen, D. M.

2014-12-01

For over 200 years, fossil fuels have been the basis for an industrial revolution that has delivered a level of prosperity to modern society unimaginable during the previous 5000 years of human civilization. However, society's dependence on fossil fuels is coming to an end for two reasons. The first reason is because our fossil fuel reserves are running out, oil in this century, natural gas during the next century, and coal a few centuries later. The second reason is because fossil fuels are having a devastating impact on the habitability of our planet, disrupting our climate system and acidifying our oceans. So the question is not whether we will discontinue using fossil fuels, but rather whether we will stop using them before they do irreparable damage to the Earth's life-support systems. Within our geoscience community, climate scientists have determined that a majority of existing fossil fuel reserves must remain unburned if dangerous climate change and ocean acidification are to be avoided. In contrast, Exxon-Mobil, Shell, and other members of the fossil fuel industry are pursuing a business model that assumes all of their reserves will be burned and will not become stranded assets. Since the geosciences have had a long and mutually beneficial relationship with the fossil fuel industry, this inherent conflict between climate science and industrial interests presents an ethical dilemma for many geoscientists. This conflict is further heightened by the fossil fuel divestment movement, which is underway at over 400 college and university campuses around the world. This presentation will explore some of the ethical and financial issues being raised by the divestment movement from a geoscientist's perspective.

Fossils and palaeontological distributions of Macaranga and Mallotus (Euphorbiaceae)

NARCIS (Netherlands)

Nucete, M.; van Konijnenburg-van Cittert, J.H.A.; van Welzen, P.C.

2012-01-01

The correct identification of described plant fossils from the sister genera Macaranga and Mallotus (Euphorbiaceae) needs to be confirmed in order to correctly date their phylogeny and map their palaeontological distributions. Previous identifications of fossil specimens often appear to be

Proceedings of the fourth annual conference on fossil energy materials

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.; Braski, D.N. (comps.)

1990-08-01

The Fourth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on may 15--17, 1990. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. Individual projects are processed separately for the data bases.

Switching from fossil fuel to renewables in residential heating systems: An empirical study of homeowners' decisions in Germany

International Nuclear Information System (INIS)

Michelsen, Carl Christian; Madlener, Reinhard

2016-01-01

The replacement of outdated and inefficient fossil fuel residential heating systems (RHS) by more efficient and less CO_2-intensive appliances primarily based on renewable energy sources is an important pillar for the transition to a cleaner and more sustainable energy system. This paper empirically investigates drivers and barriers behind homeowners' decisions to switch from a fossil fuel to a renewable RHS in Germany. For this purpose, we draw on data from a 2010 questionnaire survey among owners of existing single-family and duplex houses in Germany that had received a financial grant to install an RHS (i.e. condensing boiler with solar thermal support, heat pump or wood pellet boiler). We show that environmental protection, a lower dependency on fossil fuels, and a higher degree of RHS-related knowledge are key drivers. In contrast, the perceived difficulty of getting used to the system and a misunderstanding of its principal functioning are obstacles for the heat pump. For the wood pellet boiler, perceived barriers include the low usability, the labor-intensive operation, and the systems' fault liability. Hence, a higher replacement rate requires the willingness to relinquish old habits and perceptions of how an RHS works and operates. - Highlights: • Homeowners' decisions to switch from a fossil fuel to a renewable RHS. • Data from a questionnaire survey among owners of existing homes in Germany. • Environmental protection, lower dependency on fossil fuels, and knowledge as drivers. • Old habits and perceptions of how an RHS works and operates as principal barriers.

Energy Efficiency and Air Quality Repairs at Lyonsdale Biomass

Energy Technology Data Exchange (ETDEWEB)

Brower, Michael R; Morrison, James A; Spomer, Eric; Thimot, Carol A

2012-07-31

This project enabled Lyonsdale Biomass, LLC to effect analyses, repairs and upgrades for its biomass cogeneration facility located in Lewis County, New York and close by the Adirondack Park to reduce air emissions by improving combustion technique and through the overall reduction of biomass throughput by increasing the system's thermodynamic efficiency for its steam-electrical generating cycle. Project outcomes result in significant local, New York State, Northeast U.S. and national benefits including improved renewable energy operational surety, enhanced renewable energy efficiency and more freedom from foreign fossil fuel source dependence. Specifically, the reliability of the Lyonsdale Biomass 20MWe woody biomass combined-heat and power (CHP) was and is now directly enhanced. The New York State and Lewis County benefits are equally substantial since the facility sustains 26 full-time equivalency (FTE) jobs at the facility and as many as 125 FTE jobs in the biomass logistics supply chain. Additionally, the project sustains essential local and state payment in lieu of taxes revenues. This project helps meet several USDOE milestones and contributes directly to the following sustainability goals:  Climate: Reduces greenhouse gas emissions associated with bio-power production, conversion and use, in comparison to fossil fuels. Efficiency and Productivity: Enhances efficient use of renewable resources and maximizes conversion efficiency and productivity. Profitability: Lowers production costs. Rural Development: Enhances economic welfare and rural development through job creation and income generation. Standards: Develop standards and corresponding metrics for ensuring sustainable biopower production. Energy Diversification and Security: Reduces dependence on foreign oil and increases energy supply diversity. Net Energy Balance: Ensures positive net energy balance for all alternatives to fossil fuels.

Development and characterization of high-efficiency, high-specific impulse xenon Hall thrusters

Science.gov (United States)

Hofer, Richard Robert

This dissertation presents research aimed at extending the efficient operation of 1600 s specific impulse Hall thruster technology to the 2000--3000 s range. While recent studies of commercially developed Hall thrusters demonstrated greater than 4000 s specific impulse, maximum efficiency occurred at less than 3000 s. It was hypothesized that the efficiency maximum resulted as a consequence of modern magnetic field designs, optimized for 1600 s, which were unsuitable at high-specific impulse. Motivated by the industry efforts and mission studies, the aim of this research was to develop and characterize xenon Hall thrusters capable of both high-specific impulse and high-efficiency operation. The research divided into development and characterization phases. During the development phase, the laboratory-model NASA-173M Hall thrusters were designed with plasma lens magnetic field topographies and their performance and plasma characteristics were evaluated. Experiments with the NASA-173M version 1 (v1) validated the plasma lens design by showing how changing the magnetic field topography at high-specific impulse improved efficiency. Experiments with the NASA-173M version 2 (v2) showed there was a minimum current density and optimum magnetic field topography at which efficiency monotonically increased with voltage. Between 300--1000 V, total specific impulse and total efficiency of the NASA-173Mv2 operating at 10 mg/s ranged from 1600--3400 s and 51--61%, respectively. Comparison of the thrusters showed that efficiency can be optimized for specific impulse by varying the plasma lens design. During the characterization phase, additional plasma properties of the NASA-173Mv2 were measured and a performance model was derived accounting for a multiply-charged, partially-ionized plasma. Results from the model based on experimental data showed how efficient operation at high-specific impulse was enabled through regulation of the electron current with the magnetic field. The

An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

International Nuclear Information System (INIS)

Roberts, D.E.; Plessis, A. du; Steyn, J.; Botha, L.R.; Pityana, S.; Berger, L.R.

2012-01-01

Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus. - Highlights: ► LIBS used to discriminate fossils from rock as potential processing control mechanism. ► 2 million year old fossils from Malapa hominin site found to be high in phosphorus. ► Rock spectral lines from silicon, iron and manganese, but no phosphorus. ► Holds great promise for process control in laser preparation of fossils. ► Also promising for accurate identification of fossils at excavation sites.

Sweden's primary production and supplies of food - Possible consequences of a lack of fossil energy; Sveriges primaerproduktion och foersoerjning av livsmedel - Moejliga konsekvenser vid en brist paa fossil energi

Energy Technology Data Exchange (ETDEWEB)

Baky, Andras; Widerberg, Anna; Landquist, Birgit; Norberg, Ida; Berlin, Johanna; Engstroem, Jonas; Svanaeng, Karin; Lorentzon, Katarina; Cronholm, Lars-Aake; Pettersson, Ola

2013-07-01

This report provides an insight into what may be the consequences for Sweden's food supply if the ability to import sufficient quantities of fossil energy decreases. The situation described is an imaginary situation that arose quickly and unexpectedly by political unrest or natural disaster. There has thus been no preparation for the situation. The length of the crisis is set to a period of 3-5 years. During that time, there is assumed no technological development or other structural change, that will change conditions compared to the current situation. If the crisis becomes more prolonged it will however gradually force major changes. Today's food supply in Sweden and much of the world depends on a constant supply of fossil energy. In the production of food is used, for example, large amounts of diesel, heating oil and mineral fertilizers. This applies to primary production of vegetables and animal breeding but also to a high degree of for user-industries , which ensures that the raw materials become finished food products for consumers. Between the different stages there are transport's in many directions that depend on fossil energy. Three different scenarios are termed low deprivation, lack of resources and high deprivation. They represent different failure scenarios where the availability of fossil energy is assumed to decrease. The three levels are tentatively set as a decrease of 25%, 50% and 75% compared with current levels. These percentages are set as initial discussion-levels from which calculations have been made of how the different stages of production will be affected.

A fossils detector

International Nuclear Information System (INIS)

Buffetaut, E.

1998-01-01

Because fossil bones are often rich in uraninite they can be detected using a portable gamma-ray detector run over the prospected site. Zones with higher radioactivity are possible accumulations of bones or skeletons. This method invented by R. Jones from the University of Utah (Salt Lake City, USA) has been successfully used in the field and led to the discovery of new dinosaur skeletons. Short paper. (J.S.)

New methods reveal oldest known fossil epiphyllous moss: Bryiidites utahensis gen. et sp. nov. (Bryidae).

Science.gov (United States)

Barclay, Richard S; McElwain, Jennifer C; Duckett, Jeffrey G; van Es, Maarten H; Mostaert, Anika S; Pressel, Silvia; Sageman, Bradley B

2013-12-01

Epiphyllous bryophytes are a highly characteristic feature of many humid tropical forest ecosystems. In contrast to the extensive fossil record for the leaves of their host plants, the record is virtually nonexistent for the epiphylls themselves, despite a fossil record for mosses that begins in the Middle Carboniferous Period, 330 million years ago. Epifluorescence optical microscopy, scanning electron microscopy, and atomic force microscopy were employed to investigate an intimate association between a newly discovered epiphyllous moss and a Lauraceae plant host from the middle Cretaceous. We describe the oldest fossil specimen of an epiphyllous moss, Bryiidites utahensis gen. et sp. nov., identified from an individual specimen only 450 µm long, situated on an approximately one millimeter square fossil leaf fragment. The moss epiphyll is exquisitely preserved as germinating spores and short-celled protonemata with transverse and oblique cross-walls closely matching those of extant epiphyllous mosses on the surface of the plant-leaf hosts. The extension of the epiphyll record back to the middle Cretaceous provides fossil evidence for the appearance of epiphyllous mosses during the diversification of flowering plants, at least 95 million years ago. It also provides substantive evidence for a tropical maritime climate in central North America during the middle Cretaceous.

Fossil nutlets of Boraginaceae from the continental Eocene of Hamada of Méridja (southwestern Algeria): The first fossil of the Borage family in Africa.

Science.gov (United States)

Hammouda, Sid Ahmed; Weigend, Maximilian; Mebrouk, Fateh; Chacón, Juliana; Bensalah, Mustapha; Ensikat, Hans-Jürgen; Adaci, Mohammed

2015-12-01

The Paleogene deposits of the Hamada of Méridja, southwestern Algeria, are currently dated as lower-to-middle Eocene in age based on fossil gastropods and charophytes. Here we report the presence of fruits that can be assigned to the Boraginaceae s.str., apparently representing the first fossil record for this family in Africa, shedding new light on the historical biogeography of this group. Microscopic studies of the fossil nutlets were carried out and compared to extant Boraginaceae nutlets, and to types reported in the literature for this family. The fossils are strikingly similar in general size and morphology, particularly in the finer details of the attachment scar and ornamentation, to nutlets of extant representatives of the Boraginaceae tribe Echiochileae, and especially the genus Ogastemma. We believe that these nutlets represent an extinct member of this lineage. The Ogastemma-like fossils indicate that the Echiochileae, which are most diverse in northern Africa and southwestern Asia, have a long history in this region, dating back to the Eocene. This tribe corresponds to the basal-most clade in Boraginaceae s.str., and the fossils described here agree well with an assumed African origin of the family and the Boraginales I, providing an important additional calibration point for dating the phylogenies of this clade. © 2015 Botanical Society of America.

JMorph: Software for performing rapid morphometric measurements on digital images of fossil assemblages

Science.gov (United States)

Lelièvre, Peter G.; Grey, Melissa

2017-08-01

Quantitative morphometric analyses of form are widely used in palaeontology, especially for taxonomic and evolutionary research. These analyses can involve several measurements performed on hundreds or even thousands of samples. Performing measurements of size and shape on large assemblages of macro- or microfossil samples is generally infeasible or impossible with traditional instruments such as vernier calipers. Instead, digital image processing software is required to perform measurements via suitable digital images of samples. Many software packages exist for morphometric analyses but there is not much available for the integral stage of data collection, particularly for the measurement of the outlines of samples. Some software exists to automatically detect the outline of a fossil sample from a digital image. However, automatic outline detection methods may perform inadequately when samples have incomplete outlines or images contain poor contrast between the sample and staging background. Hence, a manual digitization approach may be the only option. We are not aware of any software packages that are designed specifically for efficient digital measurement of fossil assemblages with numerous samples, especially for the purposes of manual outline analysis. Throughout several previous studies, we have developed a new software tool, JMorph, that is custom-built for that task. JMorph provides the means to perform many different types of measurements, which we describe in this manuscript. We focus on JMorph's ability to rapidly and accurately digitize the outlines of fossils. JMorph is freely available from the authors.

RX J1548.9+0851, a fossil cluster?

Science.gov (United States)

Eigenthaler, P.; Zeilinger, W. W.

2012-04-01

Context. Fossil galaxy groups are spatially extended X-ray sources with X-ray luminosities above L{X, bol ≥ 1042 h50-2} erg s-1 and a central elliptical galaxy dominating the optical, the second-brightest galaxy being at least 2 mag fainter in the R band. Whether these systems are a distinct class of objects resulting from exceptional formation and evolution histories is still unclear, mainly due to the small number of objects studied so far, mostly lacking spectroscopy of group members for group membership confirmation and a detailed kinematical analysis. Aims: To complement the scarce sample of spectroscopically studied fossils down to their faint galaxy populations, the fossil candidate RX J1548.9+0851 (z = 0.072) is studied in this work. Our results are compared with existing data from fossils in the literature. Methods: We use ESO VLT VIMOS multi-object spectroscopy to determine redshifts of the faint galaxy population and study the luminosity-weighted dynamics and luminosity function of the system. The full-spectrum fitting package ULySS is used to determine ages and metallicities of group members. VIMOS imaging data are used to study the morphology of the central elliptical. Results: We identify 40 group members spectroscopically within the central 300 kpc of the system and find 31 additional redshifts from the literature, resulting in a total number of 54 spectroscopically confirmed group members within 1 Mpc. RX J1548.9+0851 is made up of two bright ellipticals in the central region with a magnitude gap of Δm1,2 = 1.34 in the SDSS r' band leaving the definition of RX J1548.9+0851 being a fossil to the assumption of the virial radius. We find a luminosity-weighted velocity dispersion of 568 km s-1 and a mass of 2.5 × 1014 M⊙ for the system confirming previous studies that revealed fossils to be massive. An average mass-to-light ratio of M/L 400 M⊙/L⊙ is derived from the SDSS g', r', and i' bands. The central elliptical is well-fitted by a pure de

High-efficiency white OLEDs based on small molecules

Science.gov (United States)

Hatwar, Tukaram K.; Spindler, Jeffrey P.; Ricks, M. L.; Young, Ralph H.; Hamada, Yuuhiko; Saito, N.; Mameno, Kazunobu; Nishikawa, Ryuji; Takahashi, Hisakazu; Rajeswaran, G.

2004-02-01

Eastman Kodak Company and SANYO Electric Co., Ltd. recently demonstrated a 15" full-color, organic light-emitting diode display (OLED) using a high-efficiency white emitter combined with a color-filter array. Although useful for display applications, white emission from organic structures is also under consideration for other applications, such as solid-state lighting, where high efficiency and good color rendition are important. By incorporating adjacent blue and orange emitting layers in a multi-layer structure, highly efficient, stable white emission has been attained. With suitable host and dopant combinations, a luminance yield of 20 cd/A and efficiency of 8 lm/W have been achieved at a drive voltage of less than 8 volts and luminance level of 1000 cd/m2. The estimated external efficiency of this device is 6.3% and a high level of operational stability is observed. To our knowledge, this is the highest performance reported so far for white organic electroluminescent devices. We will review white OLED technology and discuss the fabrication and operating characteristics of these devices.

Approaches to achieve high grain yield and high resource use efficiency in rice

Directory of Open Access Journals (Sweden)

Jianchang YANG

2015-06-01

Full Text Available This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

Clustering fossils in solid inflation

Energy Technology Data Exchange (ETDEWEB)

Akhshik, Mohammad, E-mail: m.akhshik@ipm.ir [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2015-05-01

In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tenor perturbation induces observable clustering fossils in the form of quadrupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar bispectrum for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with the Planck constraints. Specializing to this allowed range of model parameter we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of the scalar perturbations. We argue that the imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

The eco-efficiency of tourism

Energy Technology Data Exchange (ETDEWEB)

Goessling, Stefan [Department of Service Management, Lund University, Box 882, 251 08 Helsingborg (Sweden); Peeters, Paul [NHTV Breda University, Centre for Sustainable Tourism and Transport, P.O. Box 3917, 4800 DX Breda (Netherlands); Ceron, Jean-Paul [Centre de Recherche en Droit de l' Environnement, de l' Amenagement et de l' Urbanisme (CRIDEAU), Universite de Limoges, 34 Rue Dupleix, 87000 Limoges (France); Dubois, Ghislain [Tourisme Environnement Consultants (TEC), 89 Rue de la Republique, 13002 Marseille (France); Patterson, Trista [University of Siena, Department of Science and Technology for Physical Chemistry in Biosystems, Via Della Diana 2A, 53100 Siena (Italy); Richardson, Robert B. [1024 Philip Street, New Orleans, LA 70130 (United States)

2005-09-15

The use of fossil energy is one of the major environmental problems associated with tourism and travel. Consequently, the need to limit fossil energy use has been highlighted as a precondition for achieving sustainable tourism development. However, tourism is also one of the most important sectors of the world economy, and fears have thus been expressed by the tourist industry and its organisations that increasing energy prices (for example, as a result of eco-taxes) could substantially decrease the economic welfare of countries and destinations. In this article, the interplay of environmental damage and economic gains is thus analysed within the context of tourism. Carbon dioxide-equivalent emissions are assessed in relation to the revenues generated, allowing for conclusions about the eco-efficiency of tourism.

The eco-efficiency of tourism

International Nuclear Information System (INIS)

Goessling, Stefan; Peeters, Paul; Ceron, Jean-Paul; Dubois, Ghislain; Patterson, Trista; Richardson, Robert B.

2005-01-01

The use of fossil energy is one of the major environmental problems associated with tourism and travel. Consequently, the need to limit fossil energy use has been highlighted as a precondition for achieving sustainable tourism development. However, tourism is also one of the most important sectors of the world economy, and fears have thus been expressed by the tourist industry and its organisations that increasing energy prices (for example, as a result of eco-taxes) could substantially decrease the economic welfare of countries and destinations. In this article, the interplay of environmental damage and economic gains is thus analysed within the context of tourism. Carbon dioxide-equivalent emissions are assessed in relation to the revenues generated, allowing for conclusions about the eco-efficiency of tourism

Fossil fuels in the 21st century.

Science.gov (United States)

Lincoln, Stephen F

2005-12-01

An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.

Development of concepts for a zero-fossil-energy greenhouse

NARCIS (Netherlands)

Ooster, A. van 't; Henten, E.J. van; Janssen, E.G.O.N.; Bot, G.P.A.; Dekker, E.

2008-01-01

Dutch government and greenhouse horticultural practice aim for strongly reduced fossil energy use and of environmental loads in 2010 and energy neutral greenhouses in 2020. This research aims to design a greenhouse concept with minimal use of fossil energy and independent of nearby greenhouses. The

New insights on equid locomotor evolution from the lumbar region of fossil horses.

Science.gov (United States)

Jones, Katrina Elizabeth

2016-04-27

The specialization of equid limbs for cursoriality is a classic case of adaptive evolution, but the role of the axial skeleton in this famous transition is not well understood. Extant horses are extremely fast and efficient runners, which use a stiff-backed gallop with reduced bending of the lumbar region relative to other mammals. This study tests the hypothesis that stiff-backed running in horses evolved in response to evolutionary increases in body size by examining lumbar joint shape from a broad sample of fossil equids in a phylogenetic context. Lumbar joint shape scaling suggests that stability of the lumbar region does correlate with size through equid evolution. However, scaling effects were dampened in the posterior lumbar region, near the sacrum, which suggests strong selection for sagittal mobility in association with locomotor-respiratory coupling near the lumbosacral joint. I hypothesize that small-bodied fossil horses may have used a speed-dependent running gait, switching between stiff-backed and flex-backed galloping as speed increased. © 2016 The Author(s).

Efficiency and Loading Evaluation of High Efficiency Mist Eliminators (HEME) - 12003

Energy Technology Data Exchange (ETDEWEB)

Giffin, Paxton K.; Parsons, Michael S.; Waggoner, Charles A. [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)

2012-07-01

High efficiency mist eliminators (HEME) are filters primarily used to remove moisture and/or liquid aerosols from an air stream. HEME elements are designed to reduce aerosol and particulate load on primary High Efficiency Particulate Air (HEPA) filters and to have a liquid particle removal efficiency of approximately 99.5% for aerosols down to sub-micron size particulates. The investigation presented here evaluates the loading capacity of the element in the absence of a water spray cleaning system. The theory is that without the cleaning system, the HEME element will suffer rapid buildup of solid aerosols, greatly reducing the particle loading capacity. Evaluation consists of challenging the element with a waste surrogate dry aerosol and di-octyl phthalate (DOP) at varying intervals of differential pressure to examine the filtering efficiency of three different element designs at three different media velocities. Also, the elements are challenged with a liquid waste surrogate using Laskin nozzles and large dispersion nozzles. These tests allow the loading capacity of the unit to be determined and the effectiveness of washing down the interior of the elements to be evaluated. (authors)

Material flow analysis of fossil fuels in China during 2000-2010.

Science.gov (United States)

Wang, Sheng; Dai, Jing; Su, Meirong

2012-01-01

Since the relationship between the supply and demand of fossil fuels is on edge in the long run, the contradiction between the economic growth and limited resources will hinder the sustainable development of the Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000-2010 via the material flow analysis (MFA) that takes hidden flows into account. With coal, oil, and natural gas quantified by MFA, three indexes, consumption and supply ratio (C/S ratio), resource consumption intensity (RCI), and fossil fuels productivity (FFP), are proposed to reflect the interactions between population, GDP, and fossil fuels. The results indicated that in the past 11 years, China's requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to a single energy consumption structure as well as excessive dependence on the domestic exploitation. It is advisable to control the fossil fuels consumption by energy recycling and new energy facilities' popularization in order to lead a sustainable access to nonrenewable resources and decrease the soaring carbon emissions.

Integrated production of sugarcane ethanol and soybean biodiesel: Environmental and economic implications of fossil diesel displacement

International Nuclear Information System (INIS)

Souza, Simone P.; Seabra, Joaquim E.A.

2014-01-01

Highlights: • Sugarcane sector is responsible for around 4% of the diesel consumption in Brazil. • Soybean biodiesel can reduce the fossil diesel demand in the sugarcane sector. • The local use of biodiesel could reduce logistic problems and environmental burdens. • The sugarcane–soybean integration is likely to improve ethanol life cycle performance. • Fiscal incentives could reduce the economic uncertainties of the integration. - Abstract: The sugarcane industry in Brazil has been considered promising for the production of advanced fuels and bio-based products. However, the sugarcane crop requires high volumes of fossil fuel for cultivation and transport. The use of biodiesel as a diesel substitute could reduce the environmental burdens associated with this high consumption. This work performed a stochastic evaluation of the environmental and economic implications of the integrated production of sugarcane bioethanol and soybean biodiesel, in comparison with the traditional sugarcane-to-ethanol process. The analysis was focused on the states of Goiás, Mato Grosso and São Paulo, where this integration would be particularly attractive. The environmental aspects addressed were the fossil energy use and the GHG emissions in a cradle-to-gate approach. The economic analysis comprised the evaluation of the net present value of an incremental cash flow generated by the soybean production and by the adjacent plants of oil extraction and biodiesel. Results indicate that the integrated system is likely to improve the ethanol environmental performance, especially with regard to the fossil energy use. The integration is economically feasible but highly uncertain; however, it could be significantly improved through fiscal incentives to biodiesel producers, founded on the reduction of fossil energy use and on improvements in logistics. In addition, the proposed model may also assist in the design of other integrated systems applied to the sugarcane sector in Brazil

Fossil isotope records of seasonal climate and ecology: Straight from the horse's mouth

Science.gov (United States)

Sharp, Z. D.; Cerling, T. E.

1998-03-01

Isotope analysis of a bulk fossil tooth gives a “snapshot” impression of paleoclimatic conditions—a single point in time. However, hypsodont teeth grow over a period of a year or more, so that stable carbon and oxygen isotope variations along their length are a “tape recorder” of short-term seasonal variations from the distant past. We have used a new in situ micro-laser sampling method to determine submillimeter carbon and oxygen isotope variations in the enamel of individual fossil horse teeth to assess ancient annual meteoric water variations and feeding patterns. The δ18O values from a 6.8 Ma fossil horse tooth (Astrohippus ansae) from Texas vary cyclically along the 6 cm length of the tooth with a smoothed amplitude of >4‰, similar to the monthly averaged amplitude measured in modern meteoric waters from the region. The seasonal δ18O values are ˜3‰ to 4‰ higher than those calculated from modern meteoric water data, suggesting either a higher local meteoric water value in the Miocene of Texas, or that the animal received a high proportion of its dietary water from plants or highly evaporated water. A Holocene horse tooth from the shores of Glacial Lake Agassiz, North Dakota (Equus sp.), also has isotopic variations with the same 35 mm periodicity, but a smoothed amplitude of only 2‰. This horse most likely had a buffered drinking supply. The calculated δ18O of the water in equilibrium with this tooth is the same as the modern measured annual average. The variations within a single tooth can be as large as those generally observed in entire stratigraphic sections of fossil teeth analyzed by bulk methods. The new method provides an important technique for evaluating fossil diagenesis; conventional bulk analyses of teeth fragments may not be representative of the whole tooth, thus explaining analytical scatter that has been previously attributed to diagenesis.

An econometrics view of worldwide fossil fuel consumption and the role of US

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2008-01-01

Crude oil, coal and gas, known as fossil fuels, play a crucial role in the global economy. This paper proposes new econometrics modelling to demonstrate the trend of fossil fuels consumption. The main variables affecting consumption trends are: world reserves, the price of fossil fuels, US production and US net imports. All variables have been analysed individually for more than half a century. The research found that while the consumption of fossil fuels worldwide has increased trends in the US production and net imports have been dependent on the type of fossil fuels. Most of the US coal and gas production has been for domestic use, which is why it does not have a strong influence on worldwide fossil fuel prices. Moreover, the reserves of fossil fuels have not shown any diminution during the last couple of decades and predictions that they were about to run out are not substantiated. The nominal and real price of fossil fuels was found to change depending on the type. Finally, estimates of three econometric models for the consumption of fossil fuels from 1949 to 2006 are presented which identify the effects of significant variables

Partially incorrect fossil data augment analyses of discrete trait evolution in living species.

Science.gov (United States)

Puttick, Mark N

2016-08-01

Ancestral state reconstruction of discrete character traits is often vital when attempting to understand the origins and homology of traits in living species. The addition of fossils has been shown to alter our understanding of trait evolution in extant taxa, but researchers may avoid using fossils alongside extant species if only few are known, or if the designation of the trait of interest is uncertain. Here, I investigate the impacts of fossils and incorrectly coded fossils in the ancestral state reconstruction of discrete morphological characters under a likelihood model. Under simulated phylogenies and data, likelihood-based models are generally accurate when estimating ancestral node values. Analyses with combined fossil and extant data always outperform analyses with extant species alone, even when around one quarter of the fossil information is incorrect. These results are especially pronounced when model assumptions are violated, such as when there is a trend away from the root value. Fossil data are of particular importance when attempting to estimate the root node character state. Attempts should be made to include fossils in analysis of discrete traits under likelihood, even if there is uncertainty in the fossil trait data. © 2016 The Authors.

Critical study of high efficiency deep grinding

OpenAIRE

Johnstone, lain

2002-01-01

The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experim...

Mineralogy of Non-Silicified Fossil Wood

Directory of Open Access Journals (Sweden)

George E. Mustoe

2018-03-01

Full Text Available The best-known and most-studied petrified wood specimens are those that are mineralized with polymorphs of silica: opal-A, opal-C, chalcedony, and quartz. Less familiar are fossil woods preserved with non-silica minerals. This report reviews discoveries of woods mineralized with calcium carbonate, calcium phosphate, various iron and copper minerals, manganese oxide, fluorite, barite, natrolite, and smectite clay. Regardless of composition, the processes of mineralization involve the same factors: availability of dissolved elements, pH, Eh, and burial temperature. Permeability of the wood and anatomical features also plays important roles in determining mineralization. When precipitation occurs in several episodes, fossil wood may have complex mineralogy.

Combustion phasing for maximum efficiency for conventional and high efficiency engines

International Nuclear Information System (INIS)

Caton, Jerald A.

2014-01-01

Highlights: • Combustion phasing for max efficiency is a function of engine parameters. • Combustion phasing is most affected by heat transfer, compression ratio, burn duration. • Combustion phasing is less affected by speed, load, equivalence ratio and EGR. • Combustion phasing for a high efficiency engine was more advanced. • Exergy destruction during combustion as functions of combustion phasing is reported. - Abstract: The importance of the phasing of the combustion event for internal-combustion engines is well appreciated, but quantitative details are sparse. The objective of the current work was to examine the optimum combustion phasing (based on maximum bmep) as functions of engine design and operating variables. A thermodynamic, engine cycle simulation was used to complete this assessment. As metrics for the combustion phasing, both the crank angle for 50% fuel mass burned (CA 50 ) and the crank angle for peak pressure (CA pp ) are reported as functions of the engine variables. In contrast to common statements in the literature, the optimum CA 50 and CA pp vary depending on the design and operating variables. Optimum, as used in this paper, refers to the combustion timing that provides the maximum bmep and brake thermal efficiency (MBT timing). For this work, the variables with the greatest influence on the optimum CA 50 and CA pp were the heat transfer level, the burn duration and the compression ratio. Other variables such as equivalence ratio, EGR level, engine speed and engine load had a much smaller impact on the optimum CA 50 and CA pp . For the conventional engine, for the conditions examined, the optimum CA 50 varied between about 5 and 11°aTDC, and the optimum CA pp varied between about 9 and 16°aTDC. For a high efficiency engine (high dilution, high compression ratio), the optimum CA 50 was 2.5°aTDC, and the optimum CA pp was 7.8°aTDC. These more advanced values for the optimum CA 50 and CA pp for the high efficiency engine were

CAUSAL RELATIONSHIP BETWEEN FOSSIL FUEL CONSUMPTION AND ECONOMIC GROWTH IN JAPAN: A MULTIVARIATE APPROACH

Directory of Open Access Journals (Sweden)

Hazuki Ishida

2013-01-01

Full Text Available This paper explores whether Japanese economy can continue to grow without extensive dependence on fossil fuels. The paper conducts time series analysis using a multivariate model of fossil fuels, non-fossil energy, labor, stock and GDP to investigate the relationship between fossil fuel consumption and economic growth in Japan. The results of cointegration tests indicate long-run relationships among the variables. Using a vector error-correction model, the study reveals bidirectional causality between fossil fuels and GDP. The results also show that there is no causal relationship between non-fossil energy and GDP. The results of cointegration analysis, Granger causality tests, and variance decomposition analysis imply that non-fossil energy may not necessarily be able to play the role of fossil fuels. Japan cannot seem to realize both continuous economic growth and the departure from dependence on fossil fuels. Hence, growth-oriented macroeconomic policies should be re-examined.

Do fossil vertebrate biominerals hold the key to the Palaeozoic climate?

Science.gov (United States)

Žigaitė, Ž.

2012-04-01

Fossil vertebrate hard tissues - teeth and dermoskeleton - are considered among the most geochemically stable biominerals, and therefore are widely used for palaeoenvironmental and palaeoclimatic reconstructions. Elemental and isotopic compositions of fossil dental tissues may provide unique palaeoenvironmental information, ranging from the diet and trophic positions on a food chain, to the palaeosalinity and water temperatures of ancient seas. However, the post-mortem alteration and re-crystallisation of fossil hard tissues may hamper these interpretations. Chemical composition and isotopic equilibrium of the biomineral change readily at any time from the earliest diagenesis to the final laboratory acid treatment during the fossil preparation. This is why particular attention shall be given to the preservation of fossil tissues, evaluating carefully the level of possible alteration in the primary geochemical composition. Pre-evaluation of fossil preservation can be made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections using Energy Dispersive X-ray Spectroscopy (EDS), and help to preview the chemical composition of biomineral. The Electron Backscatter Diffractometry (EBSD) is useful to examine the cristallinity and possible structural alterations. In addition, rare earth element (REE) abundances can be measured in situ within the fine fossil tissues (such as enamel) using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS), giving evidence on the selective geochemical resilience between separate vertebrate hard tissues. Therefore, in order to decipher the geochemical signal correctly, the evaluation of preservation is a necessary starting point to any further studies of fossil biomineral geochemistry.

Microalgal and terrestrial transport biofuels to displace fossil fuels

NARCIS (Netherlands)

Reijnders, L.

2009-01-01

Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn,

Synchrotron μ-XRF determination of element distribution in fossilized sauropod bones

International Nuclear Information System (INIS)

Zoeger, N.; Wobrauschek, P.; Streli, C.; Jokubonis, C.; Pepponi, G.; FalKEXnberg, G.; Sander, P.M.; Ferreyro, R.; Pyzalla, A.R.

2005-01-01

Full text: Sauropod dinosaurs were typically one magnitude larger than any other living or extinct terrestrial animal. This sheer size of the sauropod leads to scale effects in their biology and physiology that still are only inadequately understood. The primary remnants of the sauropods are their fossilized bones. These fossilized bones have sustained burial for some hundred million years and thus may have experienced significant diagenetic changes which are not affecting bone preservation at the histological level, but lead to significant alterations of the bone microstructure at the sub histological level. We investigated the influence of diagenesis on the microstructure of fossilized sauropod bones using bone cross sections of Brachiosaurus brancai and Barosaurus africanus long bones (femura and humeri) that were excavated from the Tendaguru beds in Tanzania. The change in chemical composition due to interactions between bone and sediments was characterized by synchrotron micro-X-ray fluorescence analysis (SR l'-XRF) in confocal geometry. Measurements have been carried out at the micro-focus end-station at HASYLAB beamline L using a monochromatic synchrotron beam from a bending magnet at 17.2 KEXV. The high spatial resolution achievable using this variant of SR l'-XRF revealed two-dimensional element maps of U, Sr, Pb, Fe, Cu, Mn, V, Cr, Co in the fluorapatite of the fossilized bone and in the calcite filling of the bone cavities. The results show distinct differences in the spatial distribution of these elements. The inhomogeneities of the element distribution observed in the dinosaur bone thus give some indications about the interdiffusion between the bone and its environment. (author)

Synchrotron {mu}-XRF determination of element distribution in fossilized sauropod bones

Energy Technology Data Exchange (ETDEWEB)

Zoeger, N; Wobrauschek, P; Streli, C; Jokubonis, C [TU Wien, Atominstitiut der Oesterreichischen Universitaeten, Stadionallee 2, A-1020 Wien (Austria); Pepponi, G [ITC-irst, Centro per la Ricerca Scientifica e Tecnologica, via Sommarive 18, 38050 Povo, Trento (Italy); FalKEXnberg, G [Hamburger Synchrotronstrahlungslabor HASYLAB am Deutschen Elektronen-Synchrotron, NotKEXstr. 85, 22603 Hamburg (Germany); Sander, P M [Institute for Paleontology, University of Bonn, Nussallee 8, D-53115 Bonn (Germany); Ferreyro, R; Pyzalla, A R [TU Wien, Institute of Material Science and Technology, Karlsplatz 13-308, A-1040 Wien (Austria)

2005-07-01

Full text: Sauropod dinosaurs were typically one magnitude larger than any other living or extinct terrestrial animal. This sheer size of the sauropod leads to scale effects in their biology and physiology that still are only inadequately understood. The primary remnants of the sauropods are their fossilized bones. These fossilized bones have sustained burial for some hundred million years and thus may have experienced significant diagenetic changes which are not affecting bone preservation at the histological level, but lead to significant alterations of the bone microstructure at the sub histological level. We investigated the influence of diagenesis on the microstructure of fossilized sauropod bones using bone cross sections of Brachiosaurus brancai and Barosaurus africanus long bones (femura and humeri) that were excavated from the Tendaguru beds in Tanzania. The change in chemical composition due to interactions between bone and sediments was characterized by synchrotron micro-X-ray fluorescence analysis (SR l'-XRF) in confocal geometry. Measurements have been carried out at the micro-focus end-station at HASYLAB beamline L using a monochromatic synchrotron beam from a bending magnet at 17.2 KEXV. The high spatial resolution achievable using this variant of SR l'-XRF revealed two-dimensional element maps of U, Sr, Pb, Fe, Cu, Mn, V, Cr, Co in the fluorapatite of the fossilized bone and in the calcite filling of the bone cavities. The results show distinct differences in the spatial distribution of these elements. The inhomogeneities of the element distribution observed in the dinosaur bone thus give some indications about the interdiffusion between the bone and its environment. (author)

Innovative fossil fuel fired vitrification technology for soil remediation

International Nuclear Information System (INIS)

1993-08-01

Vortex has successfully completed Phase 1 of the ''Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation'' program with the Department of Energy (DOE) Morgantown Energy Technology Center (METC). The Combustion and Melting System (CMS) has processed 7000 pounds of material representative of contaminated soil that is found at DOE sites. The soil was spiked with Resource Conversation and Recovery Act (RCRA) metals surrogates, an organic contaminant, and a surrogate radionuclide. The samples taken during the tests confirmed that virtually all of the radionuclide was retained in the glass and that it did not leach to the environment. The organic contaminant, anthracene, was destroyed during the test with a Destruction and Removal Efficiency (DRE) of at least 99.99%. RCRA metal surrogates, that were in the vitrified product, were retained and will not leach to the environment--as confirmed by the TCLP testing. Semi-volatile RCRA metal surrogates were captured by the Air Pollution Control (APC) system, and data on the amount of metal oxide particulate and the chemical composition of the particulate were established for use in the Phase 2 APC system design. This topical report will present a summary of the activities conducted during Phase 1 of the ''Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation'' program. The report includes the detail technical data generated during the experimental program and the design and cost data for the preliminary Phase 2 plant

Prospects of nuclear power in fossil fuel saving

International Nuclear Information System (INIS)

Chernavskij, S.Ya.

1984-01-01

Economic aspects of the World energy situation are considered. The growth in the world prices for energy and energy resources has demanded to reconstruct the structure of both consumers and primary energy resources. The nuclear power development is one of the most important aspects of this reconstruction. In connection with its development the acceptability of nuclear power technology and possible spheres of its application in different fields of power engineering are considered. When discussing these problems one pays the main attention to the psychological effect and potential measures for its compensation. A forecast estimate is given of specific capital investments in and expenditures on electric energy production for NPPs and conventional power stations for the considered period of 30 years. The estimates are differentiated for the European and Asian parts of the country. The problems of developing nuclear central heating-and-power plants and nuclear thermal stations are discussed. It is pointed out that presently no sufficient experience has been gained in their commerical operation to discuss for sure the prospects of their wide-scale utilization. Results of calculations are presented showing that in the range of high-temperature processes the use of electric energy based on the nuclear power development is more efficient than direct combustion of fossil fuel as estimated with respect to its export at the world market prices

Highly efficient red electrophosphorescent devices at high current densities

International Nuclear Information System (INIS)

Wu Youzhi; Zhu Wenqing; Zheng Xinyou; Sun, Runguang; Jiang Xueyin; Zhang Zhilin; Xu Shaohong

2007-01-01

Efficiency decrease at high current densities in red electrophosphorescent devices is drastically restrained compared with that from conventional electrophosphorescent devices by using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker. Ir complex, bis(2-(2'-benzo[4,5-α]thienyl) pyridinato-N,C 3' ) iridium (acetyl-acetonate) is used as an emitter, maximum external quantum efficiency (QE) of 7.0% and luminance of 10000cd/m 2 are obtained. The QE is still as high as 4.1% at higher current density J=100mA/cm 2 . CIE-1931 co-ordinates are 0.672, 0.321. A carrier trapping mechanism is revealed to dominate in the process of electroluminescence

Testing New Proxies for Photosymbiosis in the Fossil Record

Science.gov (United States)

Tornabene, C.; Martindale, R. C.; Schaller, M. F.

2015-12-01

Photosymbiosis is a mutualistic relationship that many corals have developed with dinoflagellates called zooxanthellae. The dinoflagellates, of the genus Symbiodinium, photosynthesize and provide corals with most of their energy, while in turn coral hosts live in waters where zooxanthellae have optimal exposure to sunlight. Thanks to this relationship, symbiotic corals calcify faster than non-symbiotic corals. Photosymbiosis is therefore considered the evolutionary innovation that allowed corals to become major reef-builders through geological time.This relationship is extremely difficult to study. Zooxanthellae, which are housed in the coral tissue, are not preserved in fossil coral skeletons, thus determining whether corals had symbionts requires a robust proxy. In order to address this critical question, the goal of this research is to test new proxies for ancient photosymbiosis. Currently the project is focused on assessing the nitrogen (δ15N) isotopes of corals' organic matrices, sensu Muscatine et al. (2005), as well as carbon and oxygen (δ13C, δ18O) isotopes of fossil coral skeletons. Samples from Modern, Pleistocene, Oligocene and Triassic coral skeletons were analyzed to test the validity of these proxies. Coral samples comprise both (interpreted) symbiotic and non-symbiotic fossil corals from the Oligocene and Triassic as well as symbiotic fossil corals from the Modern and Pleistocene to corroborate our findings with the results of Muscatine et al. (2005). Samples were tested for diagenesis through petrographic and scanning electron microscope (SEM) analyses to avoid contamination. Additionally, a novel technique that has not yet been applied to the fossil record was tested. The technique aims to recognize dinosterol, a dinoflagellate biomarker, in both modern and fossil coral samples. The premise of this proxy is that symbiotic corals should contain the dinoflagellate biomarker, whereas those lacking symbionts should lack dinosterol. Results from this

Environmental damage caused by fossil fuels consumption

International Nuclear Information System (INIS)

Barbir, F.; Veziroglu, T.N.

1991-01-01

This paper reports that the objectives of this study is to identify the negative effects of the fossil fuels use and to evaluate their economic significance. An economic value of the damage for each of the analyzed effects has been estimated in US dollars per unit energy of the fuel used ($/GJ). This external costs of fossil fuel use should be added to their existing market price, and such real costs should be compared with the real costs of other, environmentally acceptable, energy alternatives, such as hydrogen

Divesting from Fossil Fuels Makes Sense Morally… and Financially

Science.gov (United States)

Cleveland, Cutler J.; Reibstein, Richard

2015-01-01

Should university endowments divest from fossil fuels? A public discussion of this question has seen some university presidents issuing statements that they would not divest--that investments should not be used for "political action." Many universities hold large endowments that have significant positions in fossil fuel companies or…

High Efficiency, Low Emission Refrigeration System

Energy Technology Data Exchange (ETDEWEB)

Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

2016-08-01

Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

Fundamentals of electromagnetic levitation engineering sustainability through efficiency

CERN Document Server

Sangster, Alan J

2012-01-01

This book aims to make aspiring and existing electrical engineers aware of the efficiency implications of frictionless machines and how important this may be in a post fossil-fuel world in which the energy available from renewable sources is strictly limited.

Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea).

Science.gov (United States)

Jong, Rienk DE

2017-05-25

Fossil butterflies are extremely rare. Yet, they are the only direct evidence of the first appearance of particular characters and as such, they are crucial for calibrating a molecular clock, from which divergence ages are estimated. In turn, these estimates, in combination with paleogeographic information, are most important in paleobiogeographic considerations. The key issue here is the correct allocation of fossils on the phylogenetic tree from which the molecular clock is calibrated.The allocation of a fossil on a tree should be based on an apomorphic character found in a tree based on extant species, similar to the allocation of a new extant species. In practice, the latter is not done, at least not explicitly, on the basis of apomorphy, but rather on overall similarity or on a phylogenetic analysis, which is not possible for most butterfly fossils since they usually are very fragmentary. Characters most often preserved are in the venation of the wings. Therefore, special attention is given to possible apomorphies in venational characters in extant butterflies. For estimation of divergence times, not only the correct allocation of the fossil on the tree is important, but also the tree itself influences the outcome as well as the correct determination of the age of the fossil. These three aspects are discussed.        All known butterfly fossils, consisting of 49 taxa, are critically reviewed and their relationship to extant taxa is discussed as an aid for correctly calibrating a molecular clock for papilionoid Lepidoptera. In this context some aspects of age estimation and biogeographic conclusions are briefly mentioned in review. Specific information has been summarized in four appendices.

Bioenergy from Low-Intensity Agricultural Systems: An Energy Efficiency Analysis

Directory of Open Access Journals (Sweden)

Oludunsin Arodudu

2016-12-01

Full Text Available In light of possible future restrictions on the use of fossil fuel, due to climate change obligations and continuous depletion of global fossil fuel reserves, the search for alternative renewable energy sources is expected to be an issue of great concern for policy stakeholders. This study assessed the feasibility of bioenergy production under relatively low-intensity conservative, eco-agricultural settings (as opposed to those produced under high-intensity, fossil fuel based industrialized agriculture. Estimates of the net energy gain (NEG and the energy return on energy invested (EROEI obtained from a life cycle inventory of the energy inputs and outputs involved reveal that the energy efficiency of bioenergy produced in low-intensity eco-agricultural systems could be as much as much as 448.5–488.3 GJ·ha−1 of NEG and an EROEI of 5.4–5.9 for maize ethanol production systems, and as much as 155.0–283.9 GJ·ha−1 of NEG and an EROEI of 14.7–22.4 for maize biogas production systems. This is substantially higher than for industrialized agriculture with a NEG of 2.8–52.5 GJ·ha−1 and an EROEI of 1.2–1.7 for maize ethanol production systems, as well as a NEG of 59.3–188.7 GJ·ha−1 and an EROEI of 2.2–10.2 for maize biogas production systems. Bioenergy produced in low-intensity eco-agricultural systems could therefore be an important source of energy with immense net benefits for local and regional end-users, provided a more efficient use of the co-products is ensured.

High quality ceramic coatings sprayed by high efficiency hypersonic plasma spraying gun

International Nuclear Information System (INIS)

Zhu Sheng; Xu Binshi; Yao JiuKun

2005-01-01

This paper introduced the structure of the high efficiency hypersonic plasma spraying gun and the effects of hypersonic plasma jet on the sprayed particles. The optimised spraying process parameters for several ceramic powders such as Al 2 O 3 , Cr 2 O 3 , ZrO 2 , Cr 3 C 2 and Co-WC were listed. The properties and microstructure of the sprayed ceramic coatings were investigated. Nano Al 2 O 3 -TiO 2 ceramic coating sprayed by using the high efficiency hypersonic plasma spraying was also studied. Compared with the conventional air plasma spraying, high efficiency hypersonic plasma spraying improves greatly the ceramic coatings quality but at low cost. (orig.)

Fossil energy research meeting

Energy Technology Data Exchange (ETDEWEB)

Kropschot, R. H.; Phillips, G. C.

1977-12-01

U.S. ERDA's research programs in fossil energy are reviewed with brief descriptions, budgets, etc. Of general interest are discussions related to the capabilities for such research of national laboratories, universities, energy centers, etc. Of necessity many items are treated briefly, but a general overview of the whole program is provided. (LTN)

Displacement efficiency of alternative energy and trans-provincial imported electricity in China

Science.gov (United States)

Hu, Yuanan; Cheng, Hefa

2017-02-01

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ~0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ~10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

Energy Technology Data Exchange (ETDEWEB)

Roberts, D.E., E-mail: troberts@csir.co.za [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Plessis, A. du [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); University of Stellenbosch, Private Bag X1, Matieland, Stellenbosch (South Africa); Steyn, J.; Botha, L.R.; Pityana, S. [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Berger, L.R. [Institute for Human Evolution, School of GeoSciences, University of Witwatersrand, Private Bag 3, Wits 2050 (South Africa)

2012-07-15

Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus. - Highlights: Black-Right-Pointing-Pointer LIBS used to discriminate fossils from rock as potential processing control mechanism. Black-Right-Pointing-Pointer 2 million year old fossils from Malapa hominin site found to be high in phosphorus. Black-Right-Pointing-Pointer Rock spectral lines from silicon, iron and manganese, but no phosphorus. Black-Right-Pointing-Pointer Holds great promise for process control in laser preparation of fossils. Black-Right-Pointing-Pointer Also promising for accurate identification of fossils at excavation sites.

Simple Motor Control Concept Results High Efficiency at High Velocities

Science.gov (United States)

Starin, Scott; Engel, Chris

2013-09-01

The need for high velocity motors in space applications for reaction wheels and detectors has stressed the limits of Brushless Permanent Magnet Motors (BPMM). Due to inherent hysteresis core losses, conventional BPMMs try to balance the need for torque verses hysteresis losses. Cong-less motors have significantly less hysteresis losses but suffer from lower efficiencies. Additionally, the inherent low inductance in cog-less motors result in high ripple currents or high switching frequencies, which lowers overall efficiency and increases performance demands on the control electronics.However, using a somewhat forgotten but fully qualified technology of Isotropic Magnet Motors (IMM), extremely high velocities may be achieved at low power input using conventional drive electronics. This paper will discuss the trade study efforts and empirical test data on a 34,000 RPM IMM.

High efficiency nebulization for helium inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

2006-01-01

A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

A synthesis of carbon dioxide emissions from fossil-fuel combustion

DEFF Research Database (Denmark)

Andres, R.J.; Boden, T.A.; Bréon, F.-M.

2012-01-01

This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms......; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions......, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossilfuel carbon dioxide emissions are known to within 10% uncertainty (95% confidence interval). Uncertainty on individual national total fossil-fuel carbon...

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

Is energy efficiency environmentally friendly?

Energy Technology Data Exchange (ETDEWEB)

Herring, H. [Open University, Milton Keynes (United Kingdom). Energy and Environment Research Unit

2000-07-01

The paper challenges the view that improving the efficiency of energy use will lead to a reduction in national energy consumption, and hence is an effective policy for reducing CO{sub 2} emissions. It argues that improving energy efficiency lowers the implicit price of energy and hence makes its use more affordable, thus leading to greater use. The paper presents the views of economists, as well as green critics of 'efficiency' and the 'dematerialization' thesis. It argues that a more effective CO{sub 2} policy is to concentrate on shifting to non-fossil fuel, like renewables, subsidized through a carbon tax. Ultimately what is needed, to limit energy consumption is energy conservation not energy efficiency. 44 refs.

Gas separation membranes for zero-emission fossil power plants: MEM-BRAIN

NARCIS (Netherlands)

Czyperek, M.; Zapp, P.; Bouwmeester, Henricus J.M.; Modigell, M.; Ebert, K.; Voigt, I.; Meulenberg, W.A.; Singheiser, L.; Stöver, D.

2010-01-01

The objective of the “MEM-BRAIN” project is the development and integration of ceramic and polymeric gas separation membranes for zero-emission fossil power plants. This will be achieved using membranes with a high permeability and selectivity for either CO2, O2 or H2, for the three CO2 capture

The late Middle Pleistocene hominin fossil record of eastern Asia: synthesis and review.

Science.gov (United States)

Bae, Christopher J

2010-01-01

Traditionally, Middle Pleistocene hominin fossils that cannot be allocated to Homo erectus sensu lato or modern H. sapiens have been assigned to different specific taxa. For example, in eastern Asia, these hominin fossils have been classified as archaic, early, or premodern H. sapiens. An increasing number of Middle Pleistocene hominin fossils are currently being assigned to H. heidelbergensis. This is particularly the case for the African and European Middle Pleistocene hominin fossil record. There have been suggestions that perhaps the eastern Asian late Middle Pleistocene hominins can also be allocated to the H. heidelbergensis hypodigm. In this article, I review the current state of the late Middle Pleistocene hominin fossil record from eastern Asia and examine the various arguments for assigning these hominins to the different specific taxa. The two primary conclusions drawn from this review are as follows: 1) little evidence currently exists in the eastern Asian Middle Pleistocene hominin fossil record to support their assignment to H. heidelbergensis; and 2) rather than add to the growing list of hominin fossil taxa by using taxonomic names like H. daliensis for northeast Asian fossils and H. mabaensis for Southeast Asian fossils, it is better to err on the side of caution and continue to use the term archaic H. sapiens to represent all of these hominin fossils. What should be evident from this review is the need for an increase in the quality and quantity of the eastern Asian hominin fossil data set. Fortunately, with the increasing number of large-scale multidisciplinary paleoanthropological field and laboratory research projects in eastern Asia, the record is quickly becoming better understood. Copyright © 2010 Wiley-Liss, Inc.

High Current Planar Transformer for Very High Efficiency Isolated Boost DC-DC Converters

DEFF Research Database (Denmark)

Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

2014-01-01

This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac-resistance a......This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac......-resistance and transformer leakage inductance. Design and optimization procedures are validated based on an experimental prototype of a 6 kW dcdc isolated full bridge boost converter developed on fully planar magnetics. The prototype is rated at 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side...... with a peak efficiency of 97.8% at 80 V 3.5 kW. Results highlights that thick copper windings can provide good performance at low switching frequencies due to the high transformer filling factor. PCB windings can also provide very high efficiency if stacked in parallel utilizing the transformer winding window...

Improving large-scale groundwater models by considering fossil gradients

Science.gov (United States)

Schulz, Stephan; Walther, Marc; Michelsen, Nils; Rausch, Randolf; Dirks, Heiko; Al-Saud, Mohammed; Merz, Ralf; Kolditz, Olaf; Schüth, Christoph

2017-05-01

Due to limited availability of surface water, many arid to semi-arid countries rely on their groundwater resources. Despite the quasi-absence of present day replenishment, some of these groundwater bodies contain large amounts of water, which was recharged during pluvial periods of the Late Pleistocene to Early Holocene. These mostly fossil, non-renewable resources require different management schemes compared to those which are usually applied in renewable systems. Fossil groundwater is a finite resource and its withdrawal implies mining of aquifer storage reserves. Although they receive almost no recharge, some of them show notable hydraulic gradients and a flow towards their discharge areas, even without pumping. As a result, these systems have more discharge than recharge and hence are not in steady state, which makes their modelling, in particular the calibration, very challenging. In this study, we introduce a new calibration approach, composed of four steps: (i) estimating the fossil discharge component, (ii) determining the origin of fossil discharge, (iii) fitting the hydraulic conductivity with a pseudo steady-state model, and (iv) fitting the storage capacity with a transient model by reconstructing head drawdown induced by pumping activities. Finally, we test the relevance of our approach and evaluated the effect of considering or ignoring fossil gradients on aquifer parameterization for the Upper Mega Aquifer (UMA) on the Arabian Peninsula.

High-efficiency silicon solar cells for low-illumination applications

OpenAIRE

Glunz, S.W.; Dicker, J.; Esterle, M.; Hermle, M.; Isenberg, J.; Kamerewerd, F.; Knobloch, J.; Kray, D.; Leimenstoll, A.; Lutz, F.; Oßwald, D.; Preu, R.; Rein, S.; Schäffer, E.; Schetter, C.

2002-01-01

At Fraunhofer ISE the fabrication of high-efficiency solar cells was extended from a laboratory scale to a small pilot-line production. Primarily, the fabricated cells are used in small high-efficiency modules integrated in prototypes of solar-powered portable electronic devices such as cellular phones, handheld computers etc. Compared to other applications of high-efficiency cells such as solar cars and planes, the illumination densities found in these mainly indoor applications are signific...

Macro fossils vegetable in Palmar formation (later pleistocene) in Entre Rios - Argentina

International Nuclear Information System (INIS)

Ramos, R.; Brea, M.; Krohling, D.

2012-01-01

This work is about the macro fossil knowledge preserved like wood fossils in the El Palmar Formation (Late Pleistocene) from a systematic - anatomical as well as paleoecological and paleoclimate point of view.The paleo Flora comes from various fossil located in the province of Entre Rios - Argentina

High Efficiency Colloidal Quantum Dot Phosphors

Energy Technology Data Exchange (ETDEWEB)

Kahen, Keith

2013-12-31

The project showed that non-Cd containing, InP-based nanocrystals (semiconductor materials with dimensions of ~6 nm) have high potential for enabling next-generation, nanocrystal-based, on chip phosphors for solid state lighting. Typical nanocrystals fall short of the requirements for on chip phosphors due to their loss of quantum efficiency under the operating conditions of LEDs, such as, high temperature (up to 150 °C) and high optical flux (up to 200 W/cm2). The InP-based nanocrystals invented during this project maintain high quantum efficiency (>80%) in polymer-based films under these operating conditions for emission wavelengths ranging from ~530 to 620 nm. These nanocrystals also show other desirable attributes, such as, lack of blinking (a common problem with nanocrystals which limits their performance) and no increase in the emission spectral width from room to 150 °C (emitters with narrower spectral widths enable higher efficiency LEDs). Prior to these nanocrystals, no nanocrystal system (regardless of nanocrystal type) showed this collection of properties; in fact, other nanocrystal systems are typically limited to showing only one desirable trait (such as high temperature stability) but being deficient in other properties (such as high flux stability). The project showed that one can reproducibly obtain these properties by generating a novel compositional structure inside of the nanomaterials; in addition, the project formulated an initial theoretical framework linking the compositional structure to the list of high performance optical properties. Over the course of the project, the synthetic methodology for producing the novel composition was evolved to enable the synthesis of these nanomaterials at a cost approximately equal to that required for forming typical conventional nanocrystals. Given the above results, the last major remaining step prior to scale up of the nanomaterials is to limit the oxidation of these materials during the tens of

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya

OpenAIRE

Joordens , Josephine ,; Dupont-Nivet , Guillaume; Feibel , Craig ,; Spoor , Fred; Sier , Mark ,; Van Der Lubbe , Jeroen ,; Nielsen , Trine; Knul , Monika ,; Davies , Gareth ,; Vonhof , Hubert ,

2013-01-01

International audience; To address questions regarding the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place the occurrence of hominin fossils in a high-resolution chronological framework. The period around 2 Ma (millions of years ago) in eastern Africa is of particular interest as it is at this time that a more substantial fossil record of the genus Homo is first found. Here we combine magnetostratigraphy and strontium (Sr) isotope stratigraphy...

Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

KAUST Repository

Wu, Hongjun

2017-07-13

Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

Science.gov (United States)

Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

2017-09-01

Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

An extraordinary gobioid fish fossil from Southern France.

Directory of Open Access Journals (Sweden)

Christoph Gierl

Full Text Available BACKGROUND: The classification of gobioid fishes is still under discussion. Several lineages, including the Eleotridae and Butidae, remain difficult to characterize because synapomorphies are rare (Eleotridae or have not yet been determined (Butidae. Moreover, the fossil record of these groups is scarce. RESULTS: Exceptionally well-preserved fish fossils with otoliths in situ from uppermost Oligocene sediments (≈23-24 Mio. y. ago in Southern France provide the most in-depth description of a fossil gobioid to date. The species was initially described as Cottus aries Agassiz, then transferred to †Lepidocottus Sauvage, and subsequently assigned to Gobius. Based on a comparative analysis of meristic, osteological and otolith data, this species most likely is a member of the family Butidae. This discovery is important because it represents the first record of a fossil butid fish based on articulated skeletons from Europe. SIGNIFICANCE: The Butidae and Eleotridae are currently distributed in W-Africa, Madagascar, Asia and Australia, but they do not appear in Europe and also not in the Mediterranean Sea. The new results indicate that several species of the Butidae thrived in Europe during the Oligocene and Early Miocene. Similar to the recent Butidae and Eleotridae, these fishes were adapted to a wide range of salinities and thrived in freshwater, brackish and marginal marine habitats. The fossil Butidae disappeared from Europe and the Mediterranean and Paratethys areas during the Early Miocene, due probably to their lack of competitiveness compared to other Gobioidei that radiated during this period of time. In addition, this study documents the great value of otoliths for gobioid systematics.

A synthesis of carbon dioxide emissions from fossil-fuel combustion

Directory of Open Access Journals (Sweden)

R. J. Andres

2012-05-01

Full Text Available This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e., maps; how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10 % uncertainty (95 % confidence interval. Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. This manuscript concludes that carbon dioxide emissions from fossil-fuel combustion continue to increase with time and that while much is known about the overall characteristics of these emissions, much is still to be learned about the detailed characteristics of these emissions.

Fossilized Mammalian Erythrocytes Associated With a Tick Reveal Ancient Piroplasms.

Science.gov (United States)

Poinar, George

2017-07-01

Ticks transmit a variety of pathogenic organisms to vertebrates, especially mammals. The fossil record of such associations is extremely rare. An engorged nymphal tick of the genus Ambylomma in Dominican amber was surrounded by erythrocytes from its mammalian host. Some of the exposed erythrocytes contained developmental stages of a hemoprotozoan resembling members of the Order Piroplasmida. The fossil piroplasm is described, its stages compared with those of extant piroplasms, and reasons provided why the mammalian host could have been a primate. The parasites were also found in the gut epithelial cells and body cavity of the fossil tick. Aside from providing the first fossil mammalian red blood cells and the first fossil intraerythrocytic hemoparasites, the present discovery shows that tick-piroplasm associations were already well established in the Tertiary. This discovery provides a timescale that can be used in future studies on the evolution of the Piroplasmida. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online March 20, 2017 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

Highly efficient fully transparent inverted OLEDs

Science.gov (United States)

Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

2007-09-01

One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

High efficiency lithium-thionyl chloride cell

Science.gov (United States)

Doddapaneni, N.

1982-08-01

The polarization characteristics and the specific cathode capacity of Teflon bonded carbon electrodes in the Li/SOCl2 system have been evaluated. Doping of electrocatalysts such as cobalt and iron phthalocyanine complexes improved both cell voltage and cell rate capability. High efficiency Li/SOCl2 cells were thus achieved with catalyzed cathodes. The electrochemical reduction of SOCl2 seems to undergo modification at catalyzed cathode. For example, the reduction of SOCl2 at FePc catalyzed cathode involves 2-1/2 e-/mole of SOCl2. Furthermore, the reduction mechanism is simplified and unwanted chemical species are eliminated by the catalyst. Thus a potentially safer high efficiency Li/SOCl2 can be anticipated.

Refining of fossil resin flotation concentrate from western coal. Final report

Energy Technology Data Exchange (ETDEWEB)

Jensen, G.F.; Miller, J.D.

1995-02-16

During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

The global environment effects of fossil and nuclear fuels

International Nuclear Information System (INIS)

Kemeny, L.G.

1981-01-01

The relative risks and environmental impacts of coal and uranium fueled power plants are dicussed. Fossil-fuel power plants are associated with a build-up of carbon dioxide levels and consequent climatic changes, release of sulphur dioxide and resultant acid rains and radioactive emissions. In comparing the discharges per megawatt year of sulphur dioxide, nitrogen dioxide and radioactive Ra-226 and Ra-225 in fly ash from coal and other fossil plants with Kr-85 and I-131 from nuclear plants, the fossil plants have a much poorer performance. Estimates indicate that nuclear energy can be adopted on a large scale as an alternative to coal without any increase in hazards and with a probability of a substantial reduction

Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

Science.gov (United States)

Herwartz, Daniel; Münker, Carsten; Tütken, Thomas; Hoffmann, J. Elis; Wittke, Andreas; Barbier, Bruno

2013-01-01

Reliable methods for direct dating of biogenic apatite from pre-Pleistocene fossils are currently not available, and recent attempts using the Lu-Hf decay system yielded highly inaccurate ages for both bones and teeth. The geological processes accounting for this poor accuracy of Lu-Hf chronometry are not yet understood. Here we explore Lu-Hf systematics in fossil bones and teeth in detail, by applying five different sample digestion techniques that are tested on bones and composites of bone and sediment. Our current dataset implies that dissolution methods only slightly affect the resulting Lu-Hf ages, while clear differences between the individual digestion techniques became apparent for element concentrations. By analysing the insoluble leftovers from incomplete sample dissolution, four main reservoirs of Hf in fossil bones were identified: (1) a radiogenic end-member associated with apatite; (2) an unradiogenic end-member represented by the authigenic minerals or the embedding sediment; (3) a highly unradiogenic end-member that can be attributed to detrital zircon; and (4) a moderately soluble phase (probably a Zr(Hf)-phosphate) that yielded very low Lu/Hf but a highly radiogenic Hf isotope composition at the same time. This Zr(Hf)-phase must have been precipitated within the fossil bone sample at a late stage of burial history, thereby incorporating radiogenic 176Hf released from apatite surfaces over geological timescales. A second focus of our study is the effect of different sediment matrices and of crystal size on the preservation of pristine Lu-Hf isotope compositions in bioapatite. Because near-depositional Lu-Hf ages of phosphate fossils have previously been reported for the London Clay (England) and a calcareous marl from Tendaguru (Tanzania), we herein investigate specimens fossilised in carbonate matrices (calcareous marl from Oker, Germany; carbonate concretions from the Santana Formation, Brazil; carbonate from the Eifel, Germany) and argillaceous

Innovation in the energy sector – The role of fossil fuels and developing economies

International Nuclear Information System (INIS)

Brutschin, Elina; Fleig, Andreas

2016-01-01

This paper analyzes the effects of fossil fuel rents on R&D expenditures and patent grants in the field of energy-related technology. We argue that an increasing share of fossil fuel rents lessens the innovation of new energy technologies. We consider a sample of countries beyond the common selection of OECD members and investigate innovation efforts in the energy sector of 116 countries from 1980 to 2012. We observe the gradually growing influence of resource-abundant countries on global R&D expenditures and find that increasing fossil fuel rents have a negative effect on patent grants. This study contributes to the ongoing debate concerning the potential effects of resource abundance. More importantly, it increases our understanding of innovation activities within the energy sector and further underscores the need to extend future research to countries that have not been taken into account thus far. - Highlights: • We investigate a sample of 116 countries, a pool beyond the commonly considered OECD members. • We find that high oil prices induce increased R&D expenditures in developed countries. • Fossil rents are associated with decreasing patent grants when developing economies are included. • We use multiple imputation to handle the problem of missing data.

Energetic efficiency of agroecosystems as an indicator of sustainability; Eficiencia energetica de agroecossistemas como indicador de sustentabilidade

Energy Technology Data Exchange (ETDEWEB)

Bueno, Osmar de Carvalho [Universidade Estadual Paulista Julio de Mesquita Filho (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas; Colen, Fernando [Universidade Federal de Minas Gerais (ICA/UFMG), Montes Claros, MG (Brazil). Inst. de Ciencias Agrarias; Campos, Alessandro Torres [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia

2010-07-01

The dependence of modern agriculture in relation to non-renewable energy sources became more pronounced over time. The intensive use of non-renewable energy in agroecosystems, especially fossil fuels, increased the physical output of food and raw materials, reducing the painfulness of work and the improvement of income in the sector. However, complex problems brought individually or in jail, which transformed human life in terms of ecological, social and economic development. It should build indexes in order to relate the inputs and outputs of energy in ecosystems. A breakthrough in the relationship between sustainability and energy analysis of farms is the use of energy efficiency index, the relationship between outputs and inputs of non-renewable energy in agroecosystems. This paper aims to present the energy efficiency of different agroecosystems. The results demonstrate the dependence of agroecosystems in relation to fossil energy sources. It was concluded that it is necessary to make efficient use of exhaustible natural resources, particularly fossil fuels. (author)

Estimating thumb–index finger precision grip and manipulation potential in extant and fossil primates

Science.gov (United States)

Feix, Thomas; Kivell, Tracy L.; Pouydebat, Emmanuelle; Dollar, Aaron M.

2015-01-01

Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb–index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation of Australopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon. PMID:25878134

Vanadium in organic fossils as determined by nuclear-physical methods of analysis

International Nuclear Information System (INIS)

Nadirov, N.N.; Solodukhin, V.P.

1998-01-01

Results are presented of several year investigation to study possibilities of the NPMA for the determination of vanadium in organic fossils and applications of these methods to scientific and practical tasks. For these purposes, various versions of activation analysis (AA), X-ray fluorescence analysis (XRFA), electron spin resonance (ESR) spectroscopy and atomic emission with inductively coupled plasma spectroscopy (AES-ICP). Advantages and pitfalls of individual methods are discussed. The techniques developed can be used for estimation and calculation of stocks of vanadium in organic fossils at the territories of Kazakstan, Tatarstan and along the Volga-river. Analysis results helped in discovering new, industrially important deposits of this valuable metal. Quantitative determination of vanadium was carried out at different stages of technological processes of its extraction from high-viscous oils and oil-bitumen rocks. Results of analyses allowed to reveal the most effective versions of technologies of demetallization of these fossils. Content of vanadium was also studied in different locations of high-viscous oil deposits being explored by the method of inside-stratum burning. Results of analyses showed that the concentration of vanadium in oil decreases considerably with increasing temperature, that is, a considerable part of vanadium (up to 60 percent) may be lost irretrievably. Thus, for the exploration of these deposits a method of vapor-thermal influence onto the stratum was recommended, by using of which the loss of vanadium is insignificant

Preservation of three-dimensional anatomy in phosphatized fossil arthropods enriches evolutionary inference.

Science.gov (United States)

Schwermann, Achim H; Dos Santos Rolo, Tomy; Caterino, Michael S; Bechly, Günter; Schmied, Heiko; Baumbach, Tilo; van de Kamp, Thomas

2016-02-05

External and internal morphological characters of extant and fossil organisms are crucial to establishing their systematic position, ecological role and evolutionary trends. The lack of internal characters and soft-tissue preservation in many arthropod fossils, however, impedes comprehensive phylogenetic analyses and species descriptions according to taxonomic standards for Recent organisms. We found well-preserved three-dimensional anatomy in mineralized arthropods from Paleogene fissure fillings and demonstrate the value of these fossils by utilizing digitally reconstructed anatomical structure of a hister beetle. The new anatomical data facilitate a refinement of the species diagnosis and allowed us to reject a previous hypothesis of close phylogenetic relationship to an extant congeneric species. Our findings suggest that mineralized fossils, even those of macroscopically poor preservation, constitute a rich but yet largely unexploited source of anatomical data for fossil arthropods.

Measure Guideline. High Efficiency Natural Gas Furnaces

Energy Technology Data Exchange (ETDEWEB)

Brand, L. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Rose, W. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

2012-10-01

This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

Highly Efficient Estimators of Multivariate Location with High Breakdown Point

NARCIS (Netherlands)

Lopuhaa, H.P.

1991-01-01

We propose an affine equivariant estimator of multivariate location that combines a high breakdown point and a bounded influence function with high asymptotic efficiency. This proposal is basically a location $M$-estimator based on the observations obtained after scaling with an affine equivariant

Environmental benefits of electrification and end-use efficiency

International Nuclear Information System (INIS)

McMenamin, J.S.; Monforte, F.A.; Sioshansi, F.P.

1997-01-01

Significant reductions in greenhouse gases and criteria pollutants can be achieved through continued substitution of clean, efficient electrotechnologies for fossil fuel-based technologies. Continued improvements in the efficiency of electrical appliances already in use will further increase the environmental benefits of electricity. Over the last several decades, electricity use in the US has grown strongly. Over a 35 year period 1960-95, electric utility sales increased more than fourfold, from under 700 billion kWh (BkWh) to almost 3,000 BkWh. This increase was due, in part, to a growing economy, but it also reflects the increasingly broad application of electricity to provide comfort, convenience, entertainment, safety and productivity. Reflecting this expanding role, energy used for electricity generation by utilities has nearly doubled, increasing from 19 percent of US primary energy use in 1960 to about 36 percent in 1995. Environmental factors have also provided support to policies that promote improved end-use efficiency. More efficient end-use equipment allows consumers to obtain the same level of end-use services with less electricity. Reduced electricity consumption levels imply reduced generation requirements and therefore, lower levels of emissions associated with generation. Beginning in the mid-1970's, and stimulated by abrupt increases in fossil fuel prices, both government and utility policies began to emphasize end-use efficiency

Electron Microscopy and Analytical X-ray Characterization of Compositional and Nanoscale Structural Changes in Fossil Bone

Science.gov (United States)

Boatman, Elizabeth Marie

highly conserved in these four fossil specimens. Finally, the results of this study indicate that bioapatite can be preserved in even the most ancient vertebrate specimens, further supporting the idea that fossilization is a preservational process. This work also underlines the importance of using appropriately selected characterization and analytical techniques for the study of fossil bone, especially from the perspective of spatial resolution and the scale of the bone structural features in question.

Fossilization History of Fossil Resin from Jambi Province (Sumatra, Indonesia Based on Physico-Chemical Studies

Directory of Open Access Journals (Sweden)

Beata Naglik

2018-03-01

Full Text Available A unique specimen of fossil resin originating from the Dipterocarpaceae tree family found in Miocene brown coal deposits in Jambi Province (Sumatra, Indonesia was investigated via microscopic observations, microhardness testing and infrared and Raman spectroscopic methods. Its form is rare in nature, being an aggregate of three varieties of resin differing in colour, transparency and internal structure. This suggests the formation of the resins at different stages. Further alteration processes, including fossilization and maturation of the resin in a swamp environment resulted in stepwise aromatization of the cyclohexane ring in steroids and cross-linking through formation of ester bonds as well as carbon–carbon bonds between steroid molecules. The various environmental and geological conditions affecting the formation processes of the resins were recorded in their physico-chemical properties. Additionally, heating conditions accelerated by volcanism were proposed as a factor determining the maturation grade of the resin.

Material Flow Analysis of Fossil Fuels in China during 2000–2010

Science.gov (United States)

Wang, Sheng; Dai, Jing; Su, Meirong

2012-01-01

Since the relationship between the supply and demand of fossil fuels is on edge in the long run, the contradiction between the economic growth and limited resources will hinder the sustainable development of the Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000–2010 via the material flow analysis (MFA) that takes hidden flows into account. With coal, oil, and natural gas quantified by MFA, three indexes, consumption and supply ratio (C/S ratio), resource consumption intensity (RCI), and fossil fuels productivity (FFP), are proposed to reflect the interactions between population, GDP, and fossil fuels. The results indicated that in the past 11 years, China's requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to a single energy consumption structure as well as excessive dependence on the domestic exploitation. It is advisable to control the fossil fuels consumption by energy recycling and new energy facilities' popularization in order to lead a sustainable access to nonrenewable resources and decrease the soaring carbon emissions. PMID:23365525

Impacts of curatorial and research practices on the preservation of fossil hominid remains.

Science.gov (United States)

Le Cabec, Adeline; Toussaint, Michel

2017-12-30

Fossil remains are the only physical evidence of past forms of life which researchers can use to study the evolutionary biology of a species, especially regarding the human lineage. We review and consider the way in which the conditions surrounding a fossil's discovery and its use for scientific research impacts its long-term preservation. The deterioration of the body starts soon after death, continues in the sediments and only a subsample of the anatomical elements will persist and may finally be unearthed by archeologists. From their recovery onwards, fossil remains are exposed to many sources of further damage: from handling, restoration, measuring to invasive sampling. On the one hand, curators are faced with the inherent challenge of balancing their responsibility to protect fossil specimens with allowing researchers to perform specific analyses or invasive sampling detrimental to the preservation of the fossil. On the other hand, scientists may find their analyses complicated by multiple factors including taphonomy, or restoration techniques (e.g., consolidants, cleaning chemicals). We provide several historical examples illustrating the complex nature of the factors acting on fossil preservation. We discuss concerns about producing and sharing (digital) data from fossils. Finally, we also suggest and support some curatorial practices which maximize the traceability of treatments underwent by a fossil.

Hydrogen production econometric studies. [hydrogen and fossil fuels

Science.gov (United States)

Howell, J. R.; Bannerot, R. B.

1975-01-01

The current assessments of fossil fuel resources in the United States were examined, and predictions of the maximum and minimum lifetimes of recoverable resources according to these assessments are presented. In addition, current rates of production in quads/year for the fossil fuels were determined from the literature. Where possible, costs of energy, location of reserves, and remaining time before these reserves are exhausted are given. Limitations that appear to hinder complete development of each energy source are outlined.

Prediction and design of efficient exciplex emitters for high-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes.

Science.gov (United States)

Liu, Xiao-Ke; Chen, Zhan; Zheng, Cai-Jun; Liu, Chuan-Lin; Lee, Chun-Sing; Li, Fan; Ou, Xue-Mei; Zhang, Xiao-Hong

2015-04-08

High-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes based on exciplex emitters are demonstrated. The best device, based on a TAPC:DPTPCz emitter, shows a high external quantum efficiency of 15.4%. Strategies for predicting and designing efficient exciplex emitters are also provided. This approach allow prediction and design of efficient exciplex emitters for achieving high-efficiency organic light-emitting diodes, for future use in displays and lighting applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The taphonomy of unmineralised Palaeozoic fossils preserved as siliciclastic moulds and casts, and their utility in assessing the interaction between environmental change and the fossil record

Science.gov (United States)

MacGabhann, Breandán; Schiffbauer, James; Hagadorn, James; Van Roy, Peter; Lynch, Edward; Morrsion, Liam; Murray, John

2015-04-01

The enhanced preservation potential of biomineralised tissues in fossil organisms is a key factor in their utility in the investigation of palaeoenvironmental change on fossil ecosystems. By contrast, the considerably lower preservation potential of entirely unmineralised organisms severely reduces the utility of their temporal and spatial distribution in such analyses. However, understanding the taphonomic processes which lead to the preservation of such soft-bodied fossils may be an under-appreciated source of information, particularly in the case of specimens preserved as moulds and casts in coarser siliciclastic sediments. This information potential is well demonstrated by fossil eldonids, a Cambrian to Devonian clade of unmineralised asymmetrical discoidal basal or stem deuterostomes, with an apparently conservative biology and no clear palaeoenvironmental or biogeographical controls on their distribution. We investigated the taphonomic processes involved in the preservation of fossil eldonids as moulds and casts on bedding surfaces and within event beds from sandstones of the Ordovician Tafilalt lagerstätte in south-eastern Morocco, and from siltstones of the Devonian West Falls Group of New York, USA. Laser Raman microspectroscopy, SEM BSE imaging and EDS elemental mapping of fossil specimens reveals that moulded biological surfaces are coated by a fossil surface veneer primarily consisting of mixed iron oxides and oxyhydroxides (including pseudomorphs after pyrite), and aluminosilicate clay minerals. Moreover, comparison to fossil eldonids preserved as carbonaceous compressions in the Burgess Shale reveals that the biological structures preserved in the Tafilalt and New York specimens - the dorsal surface and a coiled sac containing the digestive tract - represent only specific portions of the anatomy of the complete animal. We suggest that the preserved remains were the only parts of these eldonid organisms composed primarily of complex organic

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-01

High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-28

High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

Influence of microbial biofilms on the preservation of primary soft tissue in fossil and extant archosaurs.

Directory of Open Access Journals (Sweden)

Joseph E Peterson

Full Text Available BACKGROUND: Mineralized and permineralized bone is the most common form of fossilization in the vertebrate record. Preservation of gross soft tissues is extremely rare, but recent studies have suggested that primary soft tissues and biomolecules are more commonly preserved within preserved bones than had been presumed. Some of these claims have been challenged, with presentation of evidence suggesting that some of the structures are microbial artifacts, not primary soft tissues. The identification of biomolecules in fossil vertebrate extracts from a specimen of Brachylophosaurus canadensis has shown the interpretation of preserved organic remains as microbial biofilm to be highly unlikely. These discussions also propose a variety of potential mechanisms that would permit the preservation of soft-tissues in vertebrate fossils over geologic time. METHODOLOGY/PRINCIPAL FINDINGS: This study experimentally examines the role of microbial biofilms in soft-tissue preservation in vertebrate fossils by quantitatively establishing the growth and morphology of biofilms on extant archosaur bone. These results are microscopically and morphologically compared with soft-tissue extracts from vertebrate fossils from the Hell Creek Formation of southeastern Montana (Latest Maastrichtian in order to investigate the potential role of microbial biofilms on the preservation of fossil bone and bound organic matter in a variety of taphonomic settings. Based on these analyses, we highlight a mechanism whereby this bound organic matter may be preserved. CONCLUSIONS/SIGNIFICANCE: Results of the study indicate that the crystallization of microbial biofilms on decomposing organic matter within vertebrate bone in early taphonomic stages may contribute to the preservation of primary soft tissues deeper in the bone structure.

Carbon dioxide from fossil fuels. Adapting to uncertainty

Energy Technology Data Exchange (ETDEWEB)

Chen, K; Winter, R C; Bergman, M K

1980-12-01

The world is likely to experience noticeable carbon dioxide induced global warming by the beginning of the next century if high annual growth rates of fossil fuel energy use continue. This article proposes some ideas about what can be done from a policy-making perspective if the CO$SUB$2 effects occur, and how, in addition, we can deal now with the uncertainties. It also considers questions concerning the potential for control of CO$SUB$2 emissions drawing up on current work in long range coal-based energy technology assessment. (70 refs.)

Oxygen and Hydrogen Stable Isotope Composition of Eocene ( ~45 million year old) Fossil Tree Cellulose

Science.gov (United States)

Jahren, H.

2001-05-01

I report on \\delta18O and \\deltaD values gained from unusually old tree fossils, collected on Axel Heiberg Island of the Canadian High Arctic. A variety of workers have measured the δ ^{18}O value of cellulose and the δ D value of cellulose nitrate isolated from modern trees and compared it to various environmental parameters (esp. Epstein et al., 1977: 14 tree species sampled at 16 sites ranging from 18 \\deg to 62 \\deg North latitude; \\delta18O of cellulose ranged from +20 to +33 \\permil; \\deltaD of cellulose nitrate ranged from -181 to +18). To date the paleoenvironmental interpretations resulting from these studies have been restricted to application in recent and Quaternary earth history due to the lack of sufficiently preserved cellulose and tree ring structure in older tree fossils. An exception to this generalization are the middle Eocene (\\sim45 my old) fossil forests of Axel Heiberg Island, which contain abundant stumps, branches, twigs, cones and leaves of Metasequoia trees in exquisite preservational condition. These deciduous trees grew at a paleolatitude of 80 ° North, and endured prolonged periods of continuous daylight in the summer and continuous darkness in the winter, making the ecosystem completely unlike any forest community existing today. Fossil wood samples from the site have been slightly compressed, but otherwise exhibit minimal alteration: %C and % cellulose (by mass) are similar to modern Metasequoia wood. δ ^{18}O analyses on cellulose isolated from 14 fossil individuals has yielded the following results: range = +17 to +20 ‰ ; mean = +19 ‰ ; variability within an individual = 0.5 to 1.0 ‰ . In presentation, I will complement these results with δ D determinations on cellulose nitrate isolated from the same individuals, as well as from small plants presently growing in the arctic. I will also discuss the surprising result that Axel Heiberg fossil trees appear to have stable isotope composition as low or lower than trees

High efficiency carbon nanotube thread antennas

Science.gov (United States)

Amram Bengio, E.; Senic, Damir; Taylor, Lauren W.; Tsentalovich, Dmitri E.; Chen, Peiyu; Holloway, Christopher L.; Babakhani, Aydin; Long, Christian J.; Novotny, David R.; Booth, James C.; Orloff, Nathan D.; Pasquali, Matteo

2017-10-01

Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These measurements are crucial for any practical application of CNT materials in wireless communication. In this letter, we report a measurement technique to accurately characterize the radiation efficiency of λ/4 monopole antennas made from the CNT thread. We measure the highest absolute values of radiation efficiency for CNT antennas of any type, matching that of copper wire. To capture the weight savings, we propose a specific radiation efficiency metric and show that these CNT antennas exceed copper's performance by over an order of magnitude at 1 GHz and 2.4 GHz. We also report direct experimental observation that, contrary to metals, the radiation efficiency of the CNT thread improves significantly at higher frequencies. These results pave the way for practical applications of CNT thread antennas, particularly in the aerospace and wearable electronics industries where weight saving is a priority.

Doping efficiency analysis of highly phosphorous doped epitaxial/amorphous silicon emitters grown by PECVD for high efficiency silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

El-Gohary, H.G.; Sivoththaman, S. [Waterloo Univ., ON (Canada). Dept. of Electrical and Computer Engineering

2008-08-15

The efficient doping of hydrogenated amorphous and crystalline silicon thin films is a key factor in the fabrication of silicon solar cells. The most popular method for developing those films is plasma enhanced chemical vapor deposition (PECVD) because it minimizes defect density and improves doping efficiency. This paper discussed the preparation of different structure phosphorous doped silicon emitters ranging from epitaxial to amorphous films at low temperature. Phosphine (PH{sub 3}) was employed as the doping gas source with the same gas concentration for both epitaxial and amorphous silicon emitters. The paper presented an analysis of dopant activation by applying a very short rapid thermal annealing process (RTP). A spreading resistance profile (SRP) and SIMS analysis were used to detect both the active dopant and the dopant concentrations, respectively. The paper also provided the results of a structural analysis for both bulk and cross-section at the interface using high-resolution transmission electron microscopy and Raman spectroscopy, for epitaxial and amorphous films. It was concluded that a unity doping efficiency could be achieved in epitaxial layers by applying an optimized temperature profile using short time processing rapid thermal processing technique. The high quality, one step epitaxial layers, led to both high conductive and high doping efficiency layers.

Measure Guideline: High Efficiency Natural Gas Furnaces

Energy Technology Data Exchange (ETDEWEB)

Brand, L.; Rose, W.

2012-10-01

This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

Innovative-Simplified Nuclear Power Plant Efficiency Evaluation with High-Efficiency Steam Injector System

International Nuclear Information System (INIS)

Shoji, Goto; Shuichi, Ohmori; Michitsugu, Mori

2006-01-01

It is possible to establish simplified system with reduced space and total equipment weight using high-efficiency Steam Injectors (SI) instead of low-pressure feedwater heaters in Nuclear Power Plant (NPP). The SI works as a heat exchanger through direct contact between feedwater from condensers and extracted steam from turbines. It can get higher pressure than supplied steam pressure. The maintenance and reliability are still higher than the feedwater ones because SI has no movable parts. This paper describes the analysis of the heat balance, plant efficiency and the operation of this Innovative-Simplified NPP with high-efficiency SI. The plant efficiency and operation are compared with the electric power of 1100 MWe-class BWR system and the Innovative-Simplified BWR system with SI. The SI model is adapted into the heat balance simulator with a simplified model. The results show that plant efficiencies of the Innovated-Simplified BWR system are almost equal to original BWR ones. The present research is one of the projects that are carried out by Tokyo Electric Power Company, Toshiba Corporation, and six Universities in Japan, funded from the Institute of Applied Energy (IAE) of Japan as the national public research-funded program. (authors)

Fossil Polypodiaceae and their spores

NARCIS (Netherlands)

Uffelen, van Gerda A.

1991-01-01

In this publication emphasis is laid on the modern definition of the family Polypodiaceae (Filicales), which is based on an extensive study of Recent material and which is much restricted with respect to older circumscriptions of the family as usually applied by palaeobotanists. Fossils of fems

Turbulence and fossil turbulence lead to life in the universe

International Nuclear Information System (INIS)

Gibson, Carl H

2013-01-01

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than all the other forces that tend to damp the eddies out. Fossil turbulence is a perturbation produced by turbulence that persists after the fluid ceases to be turbulent at the scale of the perturbation. Because vorticity is produced at small scales, turbulence must cascade from small scales to large, providing a consistent physical basis for Kolmogorovian universal similarity laws. Oceanic and astrophysical mixing and diffusion are dominated by fossil turbulence and fossil turbulent waves. Observations from space telescopes show turbulence and vorticity existed in the beginning of the universe and that their fossils persist. Fossils of big bang turbulence include spin and the dark matter of galaxies: clumps of ∼10 12 frozen hydrogen planets that make globular star clusters as seen by infrared and microwave space telescopes. When the planets were hot gas, they hosted the formation of life in a cosmic soup of hot-water oceans as they merged to form the first stars and chemicals. Because spontaneous life formation according to the standard cosmological model is virtually impossible, the existence of life falsifies the standard cosmological model. (paper)

Role of non-fossil energy in meeting China's energy and climate target for 2020

International Nuclear Information System (INIS)

Zhou, Sheng; Tong, Qing; Yu, Sha; Wang, Yu; Chai, Qimin; Zhang, Xiliang

2012-01-01

China is the largest energy consumer and CO 2 emitter in the world. The Chinese government faces growing challenges of ensuring energy security and reducing greenhouse gas emissions. To address these two issues, the Chinese government has announced two ambitious domestic indicative autonomous mitigation targets for 2020: increasing the ratio of non-fossil energy to 15% and reducing carbon dioxide emissions per unit of GDP by 40–45% from 2005 levels. To explore the role of non-fossil energy in achieving these two targets, this paper first provides an overview of current status of non-fossil energy development in China; then gives a brief review of GDP and primary energy consumption; next assesses in detail the role of the non-fossil energy in 2020, including the installed capacity and electricity generation of non-fossil energy sources, the share and role of non-fossil energy in the electricity structure, emissions reduction resulting from the shift to non-fossil energy, and challenges for accomplishing the mitigation targets in 2020; finally, conclusions and policy measures for non-fossil energy development are proposed.

The oldest Mahonia (Berberidaceae) fossil from East Asia and its biogeographic implications.

Science.gov (United States)

Huang, Jian; Su, Tao; Lebereton-Anberrée, Julie; Zhang, Shi-Tao; Zhou, Zhe-Kun

2016-03-01

Interpretation of the biogeography of the genus Mahonia (Berberidaceae) is limited by the lack of fossil records in East Asia. Compressed fossil foliage, described here as Mahonia mioasiatica sp. nov., were collected from the Upper Miocene Xiaolongtan Formation in Wenshan, Yunnan, southwest China. These specimens represent the oldest reliable fossil record of Mahonia in East Asia. This new fossil species shows a general similarity to Group Orientales and is most similar to the extant eastern Asian Mahonia conferta. Considering other fossil evidence of Mahonia, we propose a migration route of this genus to Asia over the North Atlantic Land Bridge rather than the Bering Land Bridge. Our results also suggest that North America, Europe and East Asia have been successive centers of diversity for the genus, as a consequence of diversification in Group Orientales potentially related to historical climate change.

Nuclear versus fossil power plants: evolution of economic evaluation techniques

International Nuclear Information System (INIS)

Thuesen, G.J.

1975-01-01

The purpose of this presentation is to document the evolution of methods used by an electric utility for comparing the economic attractiveness of nuclear versus fossil electric power generation. This process of change is examined as it took place within the Georgia Power Company (GPC), a company spending in the neighborhood of half a billion dollars annually for capital improvements. This study provides a look at the variety of richness of information that can be made available through the application of different methods of economic analysis. In addition, the varied presentations used to disclose relationships between alternatives furnish evidence as to the effectiveness of providing pertinent information in a simple, meaningful manner. It had been generally accepted throughout GPC that nuclear power was economically desirable as an alternative for the production of base-load power. With inflation increasing, its advantage over fossil power appeared to be significantly increasing as the large operating costs of fossil generation seemed to be more vulnerable to inflation than the costs of operating a nuclear facility. An early indication that the company should reevaluate this position was the experience gained with the installation of their first nuclear plant. Here, actual total costs were exceeding their original construction estimates by a factor of two. Thus the question arose ''Does the high capital cost of nuclear generation offset its operating advantages when compared to similar-sized coal-burning plants.'' To answer this question, additional analyses were undertaken

Energy efficiency in the world and Turkey and investigation of energy efficiency in Turkish Industry

International Nuclear Information System (INIS)

Kavak, K.

2005-09-01

The reserves of fossil fuels which currently respond to the major part of world energy requirements are being running out very fast. Because it is forecasted that reserves of some fossil fuels like oil and natural gas will come to an end in the second half of this century, exploiting all energy resources in an efficient manner has great importance. Throughout the world where the energy demand grows continuously but the resources decrease gradually, many types of programs are implemented to provide efficient energy use. In Turkey, although there have been some efforts in last two decades, the importance of the issue could not be undersood yet. Turkey'sgeneral energy policy still focuses on supply security and finding ways to meet the growing demand, rather than decreasing the demand by energy efficiency. In this study, the possible opportunities and benefits that Turkey would gain by energy efficiency is pointed out. The studies about energy efficiency which have been conducted in the world and Turkey are examined. The measurement that can be taken in the sectors such as industry, power plants, buildings, transportation and the utilities of these measures for energy economy are indicated. The successful practices of energy efficiency studies in various countries, the state of some countries which pioneer efficiency implementations. Turkey's situation in energy in the light of basic indicators such as energy consumption per capita and enrgy intensity, the energy efficiency studies that have been done and should be done in various sectors of Turkey are also discussed in this thesis. Turkish industry's energy comsumption is analyzed as a seperate chapter by taking into consideration energy efficiency, energy intensity and energy resources. The general energy consumption and energy intensity tendencies of main manufacturing industries between 1995 and 2002 are explored and resource utilization ratios are investigated. This chapter provides to find out what kind of

Energy efficiency indicators for high electric-load buildings

Energy Technology Data Exchange (ETDEWEB)

Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar; Le Strat, Pascale; Shibata, Yoshiaki; Varone, Frederic

2003-06-01

Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

High Efficiency Centrifugal Compressor for Rotorcraft Applications

Science.gov (United States)

Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

2017-01-01

A centrifugal compressor research effort conducted by United Technologies Research Center under NASA Research Announcement NNC08CB03C is documented. The objectives were to identify key technical barriers to advancing the aerodynamic performance of high-efficiency, high work factor, compact centrifugal compressor aft-stages for turboshaft engines; to acquire measurements needed to overcome the technical barriers and inform future designs; to design, fabricate, and test a new research compressor in which to acquire the requisite flow field data. A new High-Efficiency Centrifugal Compressor stage -- splittered impeller, splittered diffuser, 90 degree bend, and exit guide vanes -- with aerodynamically aggressive performance and configuration (compactness) goals were designed, fabricated, and subquently tested at the NASA Glenn Research Center.

Quasi-kinoform type multilayer zone plate with high diffraction efficiency for high-energy X-rays

International Nuclear Information System (INIS)

Tamura, S; Yasumoto, M; Kamijo, N; Uesugi, K; Takeuchi, A; Terada, Y; Suzuki, Y

2009-01-01

Fresnel zone plate (FZP) with high diffraction efficiency leads to high performance X-ray microscopy with the reduction of the radiation damage to biological specimens. In order to attain high diffraction efficiency in high energy X-ray region, we have developed multilevel-type (6-step) multilayer FZPs with the diameter of 70 micron. The efficiencies of two FZPs were evaluated at the BL20XU beamline of SPring-8. For one FZP, the peak efficiency for the 1st-order diffraction of 51% has been obtained at 70 keV. The efficiencies higher than 40% have been achieved in the wide energy range of 70-90 keV. That for the 2nd-order diffraction of 46% has been obtained at 37.5 keV.

Displacement efficiency of alternative energy and trans-provincial imported electricity in China.

Science.gov (United States)

Hu, Yuanan; Cheng, Hefa

2017-02-17

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ∼0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ∼10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

International Nuclear Information System (INIS)

O'Brien, James E.

2010-01-01

Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a 'hydrogen economy.' The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

High-efficiency organic glass scintillators

Science.gov (United States)

Feng, Patrick L.; Carlson, Joseph S.

2017-12-19

A new family of neutron/gamma discriminating scintillators is disclosed that comprises stable organic glasses that may be melt-cast into transparent monoliths. These materials have been shown to provide light yields greater than solution-grown trans-stilbene crystals and efficient PSD capabilities when combined with 0.01 to 0.05% by weight of the total composition of a wavelength-shifting fluorophore. Photoluminescence measurements reveal fluorescence quantum yields that are 2 to 5 times greater than conventional plastic or liquid scintillator matrices, which accounts for the superior light yield of these glasses. The unique combination of high scintillation light-yields, efficient neutron/gamma PSD, and straightforward scale-up via melt-casting distinguishes the developed organic glasses from existing scintillators.

SUZAKU OBSERVATIONS OF THE X-RAY BRIGHTEST FOSSIL GROUP ESO 3060170

International Nuclear Information System (INIS)

Su, Yuanyuan; White, Raymond E. III; Miller, Eric D.

2013-01-01

'Fossil' galaxy groups, each dominated by a relatively isolated giant elliptical galaxy, have many properties intermediate between groups and clusters of galaxies. We used the Suzaku X-ray observatory to observe the X-ray brightest fossil group, ESO 3060170, out to R 200 , in order to better elucidate the relation between fossil groups, normal groups, and clusters. We determined the intragroup gas temperature, density, and metal abundance distributions and derived the entropy, pressure, and mass profiles for this group. The entropy and pressure profiles in the outer regions are flatter than in simulated clusters, similar to what is seen in observations of massive clusters. This may indicate that the gas is clumpy and/or the gas has been redistributed. Assuming hydrostatic equilibrium, the total mass is estimated to be ∼1.7 × 10 14 M ☉ within a radius R 200 of ∼1.15 Mpc, with an enclosed baryon mass fraction of 0.13. The integrated iron mass-to-light ratio of this fossil group is larger than in most groups and comparable to those of clusters, indicating that this fossil group has retained the bulk of its metals. A galaxy luminosity density map on a scale of 25 Mpc shows that this fossil group resides in a relatively isolated environment, unlike the filamentary structures in which typical groups and clusters are embedded

Fossil organic carbon in wastewater and its fate in treatment plants.

Science.gov (United States)

Law, Yingyu; Jacobsen, Geraldine E; Smith, Andrew M; Yuan, Zhiguo; Lant, Paul

2013-09-15

This study reports the presence of fossil organic carbon in wastewater and its fate in wastewater treatment plants. The findings pinpoint the inaccuracy of current greenhouse gas accounting guidelines which defines all organic carbon in wastewater to be of biogenic origin. Stable and radiocarbon isotopes ((13)C and (14)C) were measured throughout the process train in four municipal wastewater treatment plants equipped with secondary activated sludge treatment. Isotopic mass balance analyses indicate that 4-14% of influent total organic carbon (TOC) is of fossil origin with concentrations between 6 and 35 mg/L; 88-98% of this is removed from the wastewater. The TOC mass balance analysis suggests that 39-65% of the fossil organic carbon from the influent is incorporated into the activated sludge through adsorption or from cell assimilation while 29-50% is likely transformed to carbon dioxide (CO2) during secondary treatment. The fossil organic carbon fraction in the sludge undergoes further biodegradation during anaerobic digestion with a 12% decrease in mass. 1.4-6.3% of the influent TOC consists of both biogenic and fossil carbon is estimated to be emitted as fossil CO2 from activated sludge treatment alone. The results suggest that current greenhouse gas accounting guidelines, which assume that all CO2 emission from wastewater is biogenic may lead to underestimation of emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

First report of fossil "keratose" demosponges in Phanerozoic carbonates: preservation and 3-D reconstruction.

Science.gov (United States)

Luo, Cui; Reitner, Joachim

2014-06-01

Fossil record of Phanerozoic non-spicular sponges, beside of being important with respect to the lineage evolution per se, could provide valuable references for the investigation of Precambrian ancestral animal fossils. However, although modern phylogenomic studies resolve non-spicular demosponges as the sister group of the remaining spiculate demosponges, the fossil record of the former is extremely sparse or unexplored compared to that of the latter; the Middle Cambrian Vauxiidae Walcott 1920, is the only confirmed fossil taxon of non-spicular demosponges. Here, we describe carbonate materials from Devonian (Upper Givetian to Lower Frasnian) bioherms of northern France and Triassic (Anisian) microbialites of Poland that most likely represent fossil remnants of keratose demosponges. These putative fossils of keratose demosponges are preserved as automicritic clumps. They are morphologically distinguishable from microbial fabrics but similar to other spiculate sponge fossils, except that the skeletal elements consist of fibrous networks instead of assembled spicules. Consistent with the immunological behavior of sponges, these fibrous skeletons often form a rim at the edge of the automicritic aggregate, separating the inner part of the aggregate from foreign objects. To confirm the architecture of these fibrous networks, two fossil specimens and a modern thorectid sponge for comparison were processed for three-dimensional (3-D) reconstruction using serial grinding tomography. The resulting fossil reconstructions are three-dimensionally anastomosing, like modern keratose demosponges, but their irregular and nonhierarchical meshes indicate a likely verongid affinity, although a precise taxonomic conclusion cannot be made based on the skeletal architecture alone. This study is a preliminary effort, but an important start to identify fossil non-spicular demosponges in carbonates and to re-evaluate their fossilization potential.

Fossilization Processes in Thermal Springs

Science.gov (United States)

Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)

1995-01-01

To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular

Influence of fossil-fuel power plant emissions on the surface fine particulate matter in the Seoul Capital Area, South Korea.

Science.gov (United States)

Kim, Byeong-Uk; Kim, Okgil; Kim, Hyun Cheol; Kim, Soontae

2016-09-01

pollution is challenging when fossil-fuel-based electricity production is increasing. We show that an air quality forecasting system based on a photochemical model can be utilized to efficiently estimate PM2.5 contributions from and health impacts of domestic power plants. We derived PM2.5 concentrations per unit amount of electricity production from existing fossil-fuel power plants in South Korea. We assessed the health impacts of existing fossil-fuel power plants and the PM2.5 concentrations per unit electricity production to quantify the significance of existing and future fossil-fuel power plants with respect to the planned PM2.5 reduction target.

Pollution and exhaustibility of fossil fuels

NARCIS (Netherlands)

Withagen, C.A.A.M.

1994-01-01

The use of fossil fuels causes environmental damage. This is modeled and the ‘optimal’ rate of depletion is derived. Also this trajectory is compared with the case where there occurs no environmental damage.

Prudence in a fossil generation

International Nuclear Information System (INIS)

Ruschak, R.R.; Yost, R.E.

1991-01-01

During the last decade, regulatory agencies have increasingly required that to be reimbursed for an investment in facilities, utilities must first prove their generating facility construction projects were prudently managed. The proof was almost always solicited when the plants were nearing completion. Utilities failing this retrospective prudence test have often suffered severe financial penalties. Thus far fossil plants have been spared the brunt of the prudence challenge. However, this situation may change. Regulatory agencies are honing the prudence concept into a broad tool. Application of this regulatory method is not likely to wane but rather just change its focus - from that of nuclear to other large utility expenditures. The primary ones being fossil construction, fuel purchases, and transmission facilities. For new plant construction to begin again and successfully pass the prudence challenge, the industry must learn from the troubles of the nuclear era, and change the way that decisions are made, documented and archived. Major decisions resulting in the commitment of millions of dollars over extended time periods (and governmental administrations) must be appropriately structured, packaged, collated to key issues and stored for ease of retrieval when the Prudence questions are asked. This paper describes how utilities can anticipate fossil-related prudence and shield themselves from extensive retrospective reconstruction of decisions made years ago. Through the establishment of a formal program of prudence safeguards, utility management can reduce its exposure to potentially adverse prudence reviews. In many cases, the resulting focus on, and improvements in, the decision making process can have beneficial side effects - such as better decisions that lead to lower project costs

Fossil Energy Advanced Research and Technology Development Materials Program

Energy Technology Data Exchange (ETDEWEB)

Cole, N.C.; Judkins, R.R. (comps.)

1992-12-01

Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

The thermodynamic characteristics of high efficiency, internal-combustion engines

International Nuclear Information System (INIS)

Caton, Jerald A.

2012-01-01

Highlights: ► The thermodynamics of an automotive engine are determined using a cycle simulation. ► The net indicated thermal efficiency increased from 37.0% to 53.9%. ► High compression ratio, lean mixtures and high EGR were the important features. ► Efficiency increased due to lower heat losses, and increased work conversion. ► The nitric oxides were essentially zero due to the low combustion temperatures. - Abstract: Recent advancements have demonstrated new combustion modes for internal combustion engines that exhibit low nitric oxide emissions and high thermal efficiencies. These new combustion modes involve various combinations of stratification, lean mixtures, high levels of EGR, multiple injections, variable valve timings, two fuels, and other such features. Although the exact combination of these features that provides the best design is not yet clear, the results (low emissions with high efficiencies) are of major interest. The current work is directed at determining some of the fundamental thermodynamic reasons for the relatively high efficiencies and to quantify these factors. Both the first and second laws are used in this assessment. An automotive engine (5.7 l) which included some of the features mentioned above (e.g., high compression ratios, lean mixtures, and high EGR) was evaluated using a thermodynamic cycle simulation. These features were examined for a moderate load (bmep = 900 kPa), moderate speed (2000 rpm) condition. By the use of lean operation, high EGR levels, high compression ratio and other features, the net indicated thermal efficiency increased from 37.0% to 53.9%. These increases are explained in a step-by-step fashion. The major reasons for these improvements include the higher compression ratio and the dilute charge (lean mixture, high EGR). The dilute charge resulted in lower temperatures which in turn resulted in lower heat loss. In addition, the lower temperatures resulted in higher ratios of the specific heats which

Structural coloration in a fossil feather.

Science.gov (United States)

Vinther, Jakob; Briggs, Derek E G; Clarke, Julia; Mayr, Gerald; Prum, Richard O

2010-02-23

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs.

Experiments on high efficiency aerosol filtration

International Nuclear Information System (INIS)

Mazzini, M.; Cuccuru, A.; Kunz, P.

1977-01-01

Research on high efficiency aerosol filtration by the Nuclear Engineering Institute of Pisa University and by CAMEN in collaboration with CNEN is outlined. HEPA filter efficiency was studied as a function of the type and size of the test aerosol, and as a function of flowrate (+-50% of the nominal value), air temperature (up to 70 0 C), relative humidity (up to 100%), and durability in a corrosive atmosphere (up to 140 hours in NaCl mist). In the selected experimental conditions these influences were appreciable but are not sufficient to be significant in industrial HEPA filter applications. Planned future research is outlined: measurement of the efficiency of two HEPA filters in series using a fixed particle size; dependence of the efficiency on air, temperatures up to 300-500 0 C; performance when subject to smoke from burning organic materials (natural rubber, neoprene, miscellaneous plastics). Such studies are relevant to possible accidental fires in a plutonium laboratory

Performance of a high efficiency high power UHF klystron

International Nuclear Information System (INIS)

Konrad, G.T.

1977-03-01

A 500 kW c-w klystron was designed for the PEP storage ring at SLAC. The tube operates at 353.2 MHz, 62 kV, a microperveance of 0.75, and a gain of approximately 50 dB. Stable operation is required for a VSWR as high as 2 : 1 at any phase angle. The design efficiency is 70%. To obtain this value of efficiency, a second harmonic cavity is used in order to produce a very tightly bunched beam in the output gap. At the present time it is planned to install 12 such klystrons in PEP. A tube with a reduced size collector was operated at 4% duty at 500 kW. An efficiency of 63% was observed. The same tube was operated up to 200 kW c-w for PEP accelerator cavity tests. A full-scale c-w tube reached 500 kW at 65 kV with an efficiency of 55%. In addition to power and phase measurements into a matched load, some data at various load mismatches are presented

Using extant taxa to inform studies of fossil footprints

Science.gov (United States)

Falkingham, Peter; Gatesy, Stephen

2016-04-01

Attempting to use the fossilized footprints of extinct animals to study their palaeobiology and palaeoecology is notoriously difficult. The inconvenient extinction of the trackmaker makes direct correlation between footprints and foot far from straightforward. However, footprints are the only direct evidence of vertebrate motion recorded in the fossil record, and are potentially a source of data on palaeobiology that cannot be obtained from osteological remains alone. Our interests lie in recovering information about the movements of dinosaurs from their tracks. In particular, the Hitchcock collection of early Jurassic tracks held at the Beneski Museum of Natural History, Amherst, provide a rare look into the 3D form of tracks at and below the surface the animal walked on. Breaking naturally along laminations into 'track books', the specimens present sediment deformation at multiple levels, and in doing so record more of the foot's motion than a single surface might. In order to utilize this rich information source to study the now extinct trackmakers, the process of track formation must be understood at a fundamental level; the interaction of the moving foot and compliant substrate. We used bi-planar X-ray techniques (X-ray Reconstruction of Moving Morphology) to record the limb and foot motions of a Guineafowl traversing both granular and cohesive substrates. This data was supplemented with photogrammetric records of the resultant track surfaces, as well as the motion of metal beads within the sediment, to provide a full experimental dataset of foot and footprint formation. The physical experimental data was used to generate computer simulations of the process using high performance computing and the Discrete Element Method. The resultant simulations showed excellent congruence with reality, and enabled visualization within the sediment volume, and throughout the track-forming process. This physical and virtual experimental set-up has provided major insight into

Process development for high-efficiency silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

1991-12-31

Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

Nuclear power as a substitute for fossil fuels

International Nuclear Information System (INIS)

Bahramabadi, G. A.; Shirzadi, C.

2008-01-01

The challenge in energy policy is to reduce CO 2 emissions and the worlds dependence on oil while satisfying a substantially increased demand for energy. Putting aside the still-speculative possibility of sequestering carbon dioxide, this challenge reduces to that of using energy more efficiently and finding substitutes for fossil fuels. Alternatives to fossil fuels fall into two broad categories: Renewable sources. Most of these sources-including hydroelectric power, wind power, direct solar heating, photovoltaic power, and biomass-derive their energy ultimately from the Sun and will not be exhausted during the next billion years. Geothermal energy and tidal energy are also renewable, in this sense, although they do not rely on the sun. However, there is almost an inverse correlation between the extent to which the source b now being used and the size of the potentially trap able resource. Thus, expansion of hydroelectric power (which is substantially used) is constricted by limited sites and environmental objections, whereas wind (for which the resource is large) is as yet less used and thus is not fully proven as a large-scale contributor. Nuclear sources. The two nuclear possibilities are fission and fusion. The latter would be inexhaustible for all practical purposes, but developing an effective fusion system remains an uncertain hope. Fission energy would also have an extremely long time span if breeder reactors arc employed, but with present-day reactors limits on uranium (or thorium) resources could be an eventual problem. At present, fission power faces problems of public acceptance and economic competitiveness. The broad alternatives of renewable energy and nuclear energy can be considered as being in competition, with one or the other to be the dominant choice, or complementary, with both being extensively employed

Fossil Coral Records of ENSO during the Last Glacial Period

Science.gov (United States)

Partin, J. W.; Taylor, F. W.; Shen, C. C.; Edwards, R. L.; Quinn, T. M.; DiNezro, P.

2017-12-01

Only a handful of paleoclimate records exist that can resolve interannual changes, and hence El Nino/Southern Oscillation (ENSO) variability, during the last glacial period, a time of altered mean climate. The few existing data suggest reduced ENSO variability compared to the Holocene, possibly due to a weaker zonal sea surface temperature gradient across the tropical Pacific and/or a deeper thermocline in the eastern tropical Pacific. Our goal is to add crucial data to this extremely limited subset using sub-annually resolved fossil corals that grew during this time period to reconstruct ENSO. We seek to recover fossil corals from Vanuatu, SW Pacific (16°S, 167°E) with the objective of using coral δ18O to reconstruct changes in the ENSO during and near the Last Glacial Maximum (LGM). Modern δ18O coral records from Vanuatu show a high degree of skill in capturing ENSO variability, making it a suitable site for reconstructing ENSO variability. We have custom designed and are building a drill system that can rapidly core many 0-25 m holes resulting in much more meters of penetration than achieved by previous land-based reef drilling. As the new drill system is extremely portable and can be quickly relocated by workers without landing craft or vehicles, it is time and cost efficient. Because the proposed drilling sites have uplifted extremely fast, 7 mm/year, the LGM shoreline has been raised from 120-140 m depth to within a depth range of 10 below to 20 m above present sea level. This enables all the drilling to be within the time range of interest ( 15-25 ka). A last advantage is that the LGM corals either are still submersed in seawater or emerged only within the last 2000 years at the uplift rate of 7 mm/yr. This greatly reduces the chances of disruption of the original climate signal because sea water is less diagenetically damaging than meteoric water in the mixed, phreatic, or vadose zones. LGM coral records will enable us to compare the proxy variability

Time-dependent climate benefits of using forest residues to substitute fossil fuels

International Nuclear Information System (INIS)

Sathre, Roger; Gustavsson, Leif

2011-01-01

In this study we analyze and compare the climate impacts from the recovery, transport and combustion of forest residues (harvest slash and stumps), versus the climate impacts that would have occurred if the residues were left in the forest and fossil fuels used instead. We use cumulative radiative forcing (CRF) as an indicator of climate impacts, and we explicitly consider the temporal dynamics of atmospheric carbon dioxide and biomass decomposition. Over a 240-year period, we find that CRF is significantly reduced when forest residues are used instead of fossil fuels. The type of fossil fuel replaced is important, with coal replacement giving the greatest CRF reduction. Replacing oil and fossil gas also gives long-term CRF reduction, although CRF is positive during the first 10-25 years when these fuels are replaced. Biomass productivity is also important, with more productive forests giving greater CRF reduction per hectare. The decay rate for biomass left in the forest is found to be less significant. Fossil energy inputs for biomass recovery and transport have very little impact on CRF. -- Highlights: → Cumulative radiative forcing (CRF) can measure climate impacts of dynamic systems. → Climate impact is reduced when forest slash and stumps are used to replace fossil fuels. → Forest biofuels may cause short-term climate impact, followed by long-term climate benefit. → Forest residues should replace coal to avoid short-term climate impact. → Fossil energy used for biofuel recovery and transport has very little climate impact.

The shape of pterosaur evolution: evidence from the fossil record.

Science.gov (United States)

Dyke, G J; McGowan, A J; Nudds, R L; Smith, D

2009-04-01

Although pterosaurs are a well-known lineage of Mesozoic flying reptiles, their fossil record and evolutionary dynamics have never been adequately quantified. On the basis of a comprehensive data set of fossil occurrences correlated with taxon-specific limb measurements, we show that the geological ages of pterosaur specimens closely approximate hypothesized patterns of phylogenetic divergence. Although the fossil record has expanded greatly in recent years, collectorship still approximates a sigmoid curve over time as many more specimens (and thus taxa) still remain undiscovered, yet our data suggest that the pterosaur fossil record is unbiased by sites of exceptional preservation (lagerstätte). This is because as new species are discovered the number of known formations and sites yielding pterosaur fossils has also increased - this would not be expected if the bulk of the record came from just a few exceptional faunas. Pterosaur morphological diversification is, however, strongly age biased: rarefaction analysis shows that peaks of diversity occur in the Late Jurassic and Early Cretaceous correlated with periods of increased limb disparity. In this respect, pterosaurs appear unique amongst flying vertebrates in that their disparity seems to have peaked relatively late in clade history. Comparative analyses also show that there is little evidence that the evolutionary diversification of pterosaurs was in any way constrained by the appearance and radiation of birds.

Cogeneration: One way to use biomass efficiently

International Nuclear Information System (INIS)

Gustavsson, L.; Johansson, B.

1993-01-01

Cogeneration in district heating systems is the most energy-efficient way to convert biomass into heat and electricity with current or nearly commercial technologies. Methanol produced from biomass and used in vehicles instead of petrol or diesel could reduce carbon dioxide emissions nearly as much per unit of biomass as if the biomass were used to replace natural gas for cogeneration, but at some higher cost per unit of carbon dioxide reduction. The most energy-efficient way to use biomass for cogeneration appears to be combined cycle technology, and the world's first demonstration plant is now being built. Potentially, this technology can be used for electricity production in Swedish district heating systems to provide nearly 20% of current Swedish electricity production, while simultaneously reducing carbon dioxide emissions from the district heating systems by some 55%. The heat costs from cogeneration with biomass are higher than the heat costs from fossil fuel plants at current fuel prices. Biomass can only compete with fossil fuel if other advantages, for example a lower environmental impact are considered. (au) (35 refs.)

Combustion efficiency: Greenhouse gas emission reductions from the power generation sector

Energy Technology Data Exchange (ETDEWEB)

Kane, R.; South, D.W.; Fish, A.L. [Argonne National Laboratory, Upton, IL (United States)

1993-12-31

Concern for the possibility of an enhanced greenhouse effect and global climate change (GCC) has often been associated with energy use in general, and fossil fuel combustion in particular, because of associated emissions of CO{sub 2} and other greenhouse gases (GHG). Therefore, energy policies play a significant role in determining greenhouse gas emissions. The generation of electricity and power from more efficient fossil energy technologies provides an opportunity to significantly lower GHG emissions, together with other pollutants. The U.S. government oversees a broad-based program to facilitate the development, demonstration, and deployment of these technologies. Advanced fossil technologies offer other benefits as well, in that they permit continued use of widely available fuels such as coal. An international perspective is critical for assessing the role of these fuels, since countries differ in terms of their ability to maximize these benefits. Often, new technologies are considered the domain of industrialized countries. Yet more efficient technologies may have their greatest potential - to concurrently permit the utilization of indigenous fuels and to lower global GHG emissions in developing countries, especially those in the Asia-Pacific region.

High efficiency confinement mode by electron cyclotron heating

International Nuclear Information System (INIS)

Funahashi, Akimasa

1987-01-01

In the medium size nuclear fusion experiment facility JFT-2M in the Japan Atomic Energy Research Institute, the research on the high efficiency plasma confinement mode has been advanced, and in the experiment in June, 1987, the formation of a high efficiency confinement mode was successfully controlled by electron cyclotron heating, for the first time in the world. This result further advanced the control of the formation of a high efficiency plasma confinement mode and the elucidation of the physical mechanism of that mode, and promoted the research and development of the plasma heating by electron cyclotron heating. In this paper, the recent results of the research on a high efficiency confinement mode at the JFT-2M are reported, and the role of the JFT-2M and the experiment on the improvement of core plasma performance are outlined. Now the plasma temperature exceeding 100 million deg C has been attained in large tokamaks, and in medium size facilities, the various measures for improving confinement performance are to be brought forth and their scientific basis is elucidated to assist large facilities. The JFT-2M started the operation in April, 1983, and has accumulated the results smoothly since then. (Kako, I.)

Combining fossil and molecular data to date the diversification of New World Primates.

Science.gov (United States)

Schrago, C G; Mello, B; Soares, A E R

2013-11-01

Recent methodological advances in molecular dating associated with the growing availability of sequence data have prompted the study of the evolution of New World Anthropoidea in recent years. Motivated by questions regarding historical biogeography or the mode of evolution, these works aimed to obtain a clearer scenario of Platyrrhini origins and diversification. Although some consensus was found, disputed issues, especially those relating to the evolutionary affinities of fossil taxa, remain. The use of fossil taxa for divergence time analysis is traditionally restricted to the provision of calibration priors. However, new analytical approaches have been developed that incorporate fossils as terminals and, thus, directly assign ages to the fossil tips. In this study, we conducted a combined analysis of molecular and morphological data, including fossils, to derive the timescale of New World anthropoids. Differently from previous studies that conducted total-evidence analysis of molecules and morphology, our approach investigated the morphological clock alone. Our results corroborate the hypothesis that living platyrrhines diversified in the last 20 Ma and that Miocene Patagonian fossils compose an independent evolutionary radiation that diversified in the late Oligocene. When compared to the node ages inferred from the molecular timescale, the inclusion of fossils augmented the precision of the estimates for nodes constrained by the fossil tips. We show that morphological data can be analysed using the same methodological framework applied in relaxed molecular clock studies. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Children Are Likely to Suffer Most from Our Fossil Fuel Addiction

Science.gov (United States)

Perera, Frederica P.

2008-01-01

Background The periods of fetal and child development arguably represent the stages of greatest vulnerability to the dual impacts of fossil fuel combustion: the multiple toxic effects of emitted pollutants (polycyclic aromatic hydrocarbons, particles, sulfur oxides, nitrogen oxides, metals) and the broad health impacts of global climate change attributable in large part to carbon dioxide released by fossil fuel burning. Objectives In this commentary I highlight current scientific evidence indicating that the fetus and young child are at heightened risk of developmental impairment, asthma, and cancer from fossil fuel pollutants and from the predicted effects of climate disruption such as heat waves, flooding, infectious disease, malnutrition, and trauma. Increased risk during early development derives from the inherently greater biologic vulnerability of the developing fetus and child and from their long future lifetime, during which early insults can potentially manifest as adult as well as childhood disease. I cite recent reports concluding that reducing dependence on fossil fuel and promoting clean and sustainable energy is economically feasible. Discussion Although much has been written separately about the toxicity of fossil fuel burning emissions and the effects of climate change on health, these two faces of the problem have not been viewed together with a focus on the developing fetus and child. Adolescence and old age are also periods of vulnerability, but the potential for both immediate and long-term adverse effects is greatest when exposure occurs prenatally or in the early years. Conclusions Consideration of the full spectrum of health risks to children from fossil fuel combustion underscores the urgent need for environmental and energy policies to reduce fossil fuel dependence and maximize the health benefits to this susceptible population. We do not have to leave our children a double legacy of ill health and ecologic disaster. PMID:18709169

Children are likely to suffer most from our fossil fuel addiction.

Science.gov (United States)

Perera, Frederica P

2008-08-01

The periods of fetal and child development arguably represent the stages of greatest vulnerability to the dual impacts of fossil fuel combustion: the multiple toxic effects of emitted pollutants (polycyclic aromatic hydrocarbons, particles, sulfur oxides, nitrogen oxides, metals) and the broad health impacts of global climate change attributable in large part to carbon dioxide released by fossil fuel burning. In this commentary I highlight current scientific evidence indicating that the fetus and young child are at heightened risk of developmental impairment, asthma, and cancer from fossil fuel pollutants and from the predicted effects of climate disruption such as heat waves, flooding, infectious disease, malnutrition, and trauma. Increased risk during early development derives from the inherently greater biologic vulnerability of the developing fetus and child and from their long future lifetime, during which early insults can potentially manifest as adult as well as childhood disease. I cite recent reports concluding that reducing dependence on fossil fuel and promoting clean and sustainable energy is economically feasible. Although much has been written separately about the toxicity of fossil fuel burning emissions and the effects of climate change on health, these two faces of the problem have not been viewed together with a focus on the developing fetus and child. Adolescence and old age are also periods of vulnerability, but the potential for both immediate and long-term adverse effects is greatest when exposure occurs prenatally or in the early years. Consideration of the full spectrum of health risks to children from fossil fuel combustion underscores the urgent need for environmental and energy policies to reduce fossil fuel dependence and maximize the health benefits to this susceptible population. We do not have to leave our children a double legacy of ill health and ecologic disaster.

Decay of velvet worms (Onychophora), and bias in the fossil record of lobopodians.

Science.gov (United States)

Murdock, Duncan Je; Gabbott, Sarah E; Mayer, Georg; Purnell, Mark A

2014-11-29

Fossil lobopodians, including animals proposed to have close affinity to modern onychophorans, are crucial to understanding the evolution of the panarthropod body plan and the phylum-level relationships between the ecdysozoan groups. Unfortunately, the key features of their anatomy are un-mineralized and subject to biases introduced during death, decay and preservation, yet the extent to which these fossils have been affected by the processes of post-mortem decay is entirely untested. Recent experimental work on chordates has highlighted a profound bias caused by decay, resulting in the erroneous interpretation of badly decayed specimens as primitive members of a clade (stemward slippage). The degree to which this bias affects organisms other than chordates is unknown. Here we use experimental decay of velvet worms (Onychophora) to examine the importance of decay bias in fossil lobopodians. Although we find stemward slippage is not significant in the interpretation of non-mineralized lobopodian fossils, the affect of decay is far from unbiased. Quantitative analysis reveals significant changes in body proportions during decay, a spectrum of decay resistance across anatomical features, and correlated decay of topologically associated characters. These results have significant implications for the interpretation of fossil lobopodian remains, demonstrating that features such as body outline and relative proportions are unreliable for taxonomy or phylogenetic reconstruction, unless decay is taken into account. Similarly, the non-independent loss of characters, due to juxtaposition in the body, during decay has the potential to bias phylogenetic analyses of non-biomineralized fossils. Our results are difficult to reconcile with interpretations of highly decay-prone tissues and structures, such as neural tissue, and complex musculature, in recently described Cambrian lobopodians. More broadly, we hypothesize that stemward slippage is unlikely to be a significant factor

Risoe energy report 9. Non-fossil energy technologies in 2050 and beyond

International Nuclear Information System (INIS)

Larsen, Hans; Soenderberg Petersen, L.

2010-11-01

This Risoe Energy Report, the ninth in a series that began in 2002, analyses the long-term outlook for energy technologies in 2050 in a perspective where the dominating role of fossil fuels has been taken over by non-fossil fuels, and CO 2 emissions have been reduced to a minimum. Against this background, the report addresses issues like: 1) How much will today's non-fossil energy technologies have evolved up to 2050? 2) Which non-fossil energy technologies can we bring into play in 2050, including emerging technologies? 3) What are the implications for the energy system? Further, Volume 9 analyses other central issues for the future energy supply: 4) The role of non-fossil energy technologies in relation to security of supply and sustainability 5) System aspects in 2050 6) Examples of global and Danish energy scenarios in 2050 The report is based on the latest research results from Risoe DTU, together with available international literature and reports. (Author)

Risoe energy report 9. Non-fossil energy technologies in 2050 and beyond

Energy Technology Data Exchange (ETDEWEB)

Larsen, Hans; Soenderberg Petersen, L. (eds.)

2010-11-15

This Risoe Energy Report, the ninth in a series that began in 2002, analyses the long-term outlook for energy technologies in 2050 in a perspective where the dominating role of fossil fuels has been taken over by non-fossil fuels, and CO{sub 2} emissions have been reduced to a minimum. Against this background, the report addresses issues like: 1) How much will today's non-fossil energy technologies have evolved up to 2050? 2) Which non-fossil energy technologies can we bring into play in 2050, including emerging technologies? 3) What are the implications for the energy system? Further, Volume 9 analyses other central issues for the future energy supply: 4) The role of non-fossil energy technologies in relation to security of supply and sustainability 5) System aspects in 2050 6) Examples of global and Danish energy scenarios in 2050 The report is based on the latest research results from Risoe DTU, together with available international literature and reports. (Author)

Morphometric variation of extant platyrrhine molars: taxonomic implications for fossil platyrrhines

Directory of Open Access Journals (Sweden)

Mónica Nova Delgado

2016-05-01

Full Text Available The phylogenetic position of many fossil platyrrhines with respect to extant ones is not yet clear. Two main hypotheses have been proposed: the layered or successive radiations hypothesis suggests that Patagonian fossils are Middle Miocene stem platyrrhines lacking modern descendants, whereas the long lineage hypothesis argues for an evolutionary continuity of all fossil platyrrhines with the extant ones. Our geometric morphometric analysis of a 15 landmark-based configuration of platyrrhines’ first and second lower molars suggest that morphological stasis may explain the reduced molar shape variation observed. Platyrrhine lower molar shape might be a primitive retention of the ancestral state affected by strong ecological constraints throughout the radiation of the main platyrrhine families. The Patagonian fossil specimens showed two distinct morphological patterns of lower molars, Callicebus—like and Saguinus—like, which might be the precursors of the extant forms, whereas the Middle Miocene specimens, though showing morphological resemblances with the Patagonian fossils, also displayed new, derived molar patterns, Alouatta—like and Pitheciinae—like, thereby suggesting that despite the overall morphological stasis of molars, phenotypic diversification of molar shape was already settled during the Middle Miocene.

Low energy buildings – the basis for realizing the strategy for independency of fossil fuels in 2050

DEFF Research Database (Denmark)

Svendsen, Svend

2011-01-01

The paper introduces how low energy buildings can be developed, designed, optimized, constructed and operated in the future and thereby make a significant contribution to the realization of aim of the energy policy of EU: to become independent of fossil fuels in 2050. The paper describes how low...... energy buildings can become independent of fossil fuels in 2020 based on the following activities. Innovation of building components and systems with improved energy performance. Heating of low energy building with low temperature district heating based on renewable heat. Integrated design...... without use of fossil fuels can be accomplished by the building sector by 2020. The building sector may in the process be transformed from an experience based sector to knowledge and research based sector with high quality sustainable products and very good business....

Upward revision of global fossil fuel methane emissions based on isotope database.

Science.gov (United States)

Schwietzke, Stefan; Sherwood, Owen A; Bruhwiler, Lori M P; Miller, John B; Etiope, Giuseppe; Dlugokencky, Edward J; Michel, Sylvia Englund; Arling, Victoria A; Vaughn, Bruce H; White, James W C; Tans, Pieter P

2016-10-06

Methane has the second-largest global radiative forcing impact of anthropogenic greenhouse gases after carbon dioxide, but our understanding of the global atmospheric methane budget is incomplete. The global fossil fuel industry (production and usage of natural gas, oil and coal) is thought to contribute 15 to 22 per cent of methane emissions to the total atmospheric methane budget. However, questions remain regarding methane emission trends as a result of fossil fuel industrial activity and the contribution to total methane emissions of sources from the fossil fuel industry and from natural geological seepage, which are often co-located. Here we re-evaluate the global methane budget and the contribution of the fossil fuel industry to methane emissions based on long-term global methane and methane carbon isotope records. We compile the largest isotopic methane source signature database so far, including fossil fuel, microbial and biomass-burning methane emission sources. We find that total fossil fuel methane emissions (fossil fuel industry plus natural geological seepage) are not increasing over time, but are 60 to 110 per cent greater than current estimates owing to large revisions in isotope source signatures. We show that this is consistent with the observed global latitudinal methane gradient. After accounting for natural geological methane seepage, we find that methane emissions from natural gas, oil and coal production and their usage are 20 to 60 per cent greater than inventories. Our findings imply a greater potential for the fossil fuel industry to mitigate anthropogenic climate forcing, but we also find that methane emissions from natural gas as a fraction of production have declined from approximately 8 per cent to approximately 2 per cent over the past three decades.

Direct fuel cell - A high proficiency power generator for biofuels

International Nuclear Information System (INIS)

Patel, P.S.; Steinfeld, G.; Baker, B.S.

1994-01-01

Conversion of renewable bio-based resources into energy offers significant benefits for our environment and domestic economic activity. It also improves national security by displacing fossil fuels. However, in the current economic environment, it is difficult for biofuel systems to compete with other fossil fuels. The biomass-fired power plants are typically smaller than 50 MW, lower in electrical efficiencies (<25%) and experience greater costs for handling and transporting the biomass. When combined with fuel cells such as the Direct Fuel Cell (DFC), biofuels can produce power more efficiently with negligible environmental impact. Agricultural and other waste biomass can be converted to ethanol or methane-rich biofuels for power generation use in the DFC. These DFC power plants are modular and factory assembled. Due to their electrochemical (non-combustion) conversion process, these plants are environmentally friendly, highly efficient and potentially cost effective, even in sizes as small as a few meagawatts. They can be sited closer to the source of the biomass to minimize handling and transportation costs. The high-grade waste heat available from DFC power plants makes them attractive in cogeneration applications for farming and rural communities. The DFC potentially opens up new markets for biofuels derived from wood, grains and other biomass waste products

Saving, efficiency and management of electric sector demand

International Nuclear Information System (INIS)

Sanchez de Tembleque, L. J.

2007-01-01

Spanish economic model of development is based on energy consumption, and its main source is imported fossil fuels, which have some environmental and scarcity consequences in the mid term, among others. These problems could be reduced in two ways: economic activity reduction or energy efficiency improvement. In the presence of these possibilities, It may be desirable to bet for saving and energy efficiency, to maintain the economic development. This assignment analyzes the main available regulatory and social mechanisms to promote saving and energy efficiency in the power sector, like systems to internalize social costs in the electricity price, efficiency standards, and encourage the new saving culture. (Author) 15 refs

Estimating thumb-index finger precision grip and manipulation potential in extant and fossil primates.

Science.gov (United States)

Feix, Thomas; Kivell, Tracy L; Pouydebat, Emmanuelle; Dollar, Aaron M

2015-05-06

Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb-index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation of Australopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

High-Order Dielectric Metasurfaces for High-Efficiency Polarization Beam Splitters and Optical Vortex Generators

Science.gov (United States)

Guo, Zhongyi; Zhu, Lie; Guo, Kai; Shen, Fei; Yin, Zhiping

2017-08-01

In this paper, a high-order dielectric metasurface based on silicon nanobrick array is proposed and investigated. By controlling the length and width of the nanobricks, the metasurfaces could supply two different incremental transmission phases for the X-linear-polarized (XLP) and Y-linear-polarized (YLP) light with extremely high efficiency over 88%. Based on the designed metasurface, two polarization beam splitters working in high-order diffraction modes have been designed successfully, which demonstrated a high transmitted efficiency. In addition, we have also designed two vortex-beam generators working in high-order diffraction modes to create vortex beams with the topological charges of 2 and 3. The employment of dielectric metasurfaces operating in high-order diffraction modes could pave the way for a variety of new ultra-efficient optical devices.

All passive architecture for high efficiency cascaded Raman conversion

Science.gov (United States)

Balaswamy, V.; Arun, S.; Chayran, G.; Supradeepa, V. R.

2018-02-01

Cascaded Raman fiber lasers have offered a convenient method to obtain scalable, high-power sources at various wavelength regions inaccessible with rare-earth doped fiber lasers. A limitation previously was the reduced efficiency of these lasers. Recently, new architectures have been proposed to enhance efficiency, but this came at the cost of enhanced complexity, requiring an additional low-power, cascaded Raman laser. In this work, we overcome this with a new, all-passive architecture for high-efficiency cascaded Raman conversion. We demonstrate our architecture with a fifth-order cascaded Raman converter from 1117nm to 1480nm with output power of ~64W and efficiency of 60%.

High-efficiency photovoltaic cells

Science.gov (United States)

Yang, H.T.; Zehr, S.W.

1982-06-21

High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.