Fossil struthionid eggshells from Laetoli, Tanzania: Taxonomic and biostratigraphic significance

Science.gov (United States)

Harrison, Terry; Msuya, Charles P.

2005-04-01

Recent paleontological investigations at Laetoli and neighboring localities in northern Tanzania have produced a large collection of fossil ostrich eggshells from the Pliocene-aged Laetolil Beds (˜3.5-4.5 Ma) and Ndolanya Beds (˜2.6-2.7 Ma). A detailed analysis of the morphology of the eggshells and their taxonomic affinities indicates that two different species of Struthio are represented. In the Lower Laetolil Beds and in the Upper Laetolil Beds below Tuff 3 a new species is recognized— Struthio kakesiensis. This is replaced in the Upper Laetolil Beds by Struthio camelus, the modern species of ostrich. Since radiometric age determinations are available for the stratigraphic sequence at Laetoli, it is possible to precisely date the first appearance of S. camelus at ˜3.6-3.8 Ma. Comparisons of the Laetoli material with specimens from the well-dated sequences at Lothagam and Kanapoi in northern Kenya, allow the taxonomic and biochronological analysis to be extended back in time to the late Miocene. At about 6.5 Ma, Diamantornis and elephant birds were replaced in East Africa by ostriches belonging to the genus Struthio. Three time-successive species of ostriches are identified in the fossil record of East Africa, beginning with Struthio. cf. karingarabensis (˜6.5-4.2 Ma), followed by S. kakesiensis (˜4.5-3.6 Ma) and then S. camelus (˜3.8 Ma onwards). A similar sequence of taxa has previously been recorded from localities in Namibia, but at these sites there is no possibility to precisely calibrate the ages of the different species using radiometric dating. Nevertheless, the broadly similar evolutionary sequence and the close correspondence in inferred ages for the succession of species in East Africa and Namibia suggest that ostrich eggshells are a very useful tool for biochronological correlation of paleontological sites in sub-Saharan Africa.

Nitrogen compounds in pressurised fluidised bed gasification of biomass and fossil fuels

NARCIS (Netherlands)

De Jong, W.

2005-01-01

Fossil fuels still dominate the energy supply in modern societies. The resources, however, are depleting. Therefore, other energy sources are to be exploited further within this century. Biomass is one of the practically CO2 neutral, renewable contributors to the future energy production. Nowadays

Water availability and flood hazards in the John Day Fossil Beds National Monument, Oregon

Science.gov (United States)

Frank, Frank J.; Oster, E.A.

1979-01-01

The rock formations of the John Day Fossil Beds National Monument area are aquifers that can be expected to yield less than 10 gallons of water per minute to wells. The most permeable of the geologic units is the alluvium that occurs at low elevations along the John Day River and most of the smaller streams. Wells in the alluvial deposits can be expected to yield adequate water supplies for recreational areas; also, wells completed in the underlying bedrock at depths ranging from 50 to 200 feet could yield as much as 10 gallons per minute. Pumping tests on two unused wells indicated yields of 8 gallons per minute and 2 gallons per minute. Nine of the ten springs measured in and near the monument area in late August of 1978 were flowing 0.2 to 30 gallons per minute. Only the Cant Ranch spring and the Johnny Kirk Spring near the Sheep Rock unit had flows exceeding 6 gallons per minute. Chemical analyses of selected constituents of the ground water indicated generally low concentrations of dissolved minerals. Although cloudbursts in the Painted Hills unit could generate a flood wave on the valley floors, flood danger can be reduced by locating recreational sites on high ground. The campground in Indian Canyon of the Clarno unit is vulnerable to cloudburst flooding. About 80 percent of the proposed campground on the John Day River in the Sheep Rock unit is above the estimated level of 1-percent chance flood (100-year flood) of the river. The 1-percent chance flood would extend about 120 feet from the riverbank into the upstream end of the campground. (USGS).

Fossil Fuel (CO₂) Emission Verification Capability07-ERD-064Final Report

Energy Technology Data Exchange (ETDEWEB)

Guilderson, T. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cameron-Smith, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lucas, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-04-26

This work focused exclusively on designing a system for California as a test-bed. Fossil fuel CO₂ emissions account for ~96% of the total California anthropogenic CO₂ emissions (CEC GHG Inventory, 2006).

History of Snake River Canyon Indicated by Revised Stratigraphy of Snake River Group Near Hagerman and King Hill, Idaho: With a Section on Paleomagnetism

Science.gov (United States)

Malde, Harold E.; Cox, Allan

1971-01-01

. From that place the former Snake River canyon, also now concealed by lava, continued west to Bancroft Springs and thence along a route close to the present canyon to King Hill. To become entrenched in a canyon 500 feet deep, the Snake River downstream from Hagerman became progressively more incised while its upstream route was pushed south in several earlier canyons by intermittent lava flows. Distinctive gravel deposits help to establish the episodes of progressive canyon cutting and to determine the routes of ancestral drainage, including the former position of the Wood River. As canyon cutting continued, springs began to emerge where lavas had filled the earlier canyons. When the Snake River canyon eventually attained its approximate present depth, the Wendell Grade Basalt erupted near Shoshone and, as several tongues, spread west to the canyon rim opposite Hagerman. One tongue crossed the future route of the Wood River, and another covered an upland area of Sand Springs Basalt that had previously reached the canyon floor at Hagerman. The McKinney Basalt then erupted from McKinney Butte northeast of Bliss and spread southward as a subaerial flow, covering part of the Wendell Grade Basalt. It filled the ancestral Wood River canyon and the Snake River canyon of that time west of Bliss as far downstream as King Hill. The resulting dam of lava impounded a deep lake, which extended upstream in the canyon beyond Hagerman. Copious amounts of the McKinney spilled into this temporary lake and produced pillow lava. About 2 miles west of Bliss, pillow lava 500 feet thick completely fills the former canyon and is protected by rimrock of the subaerial McKinney Basalt. From Bliss, the pillow facies extends upstream as far as the McKinney rimrock - about 5 miles. Eruption of the McKinney Basalt diverted the Wood River to a course along the southeast edge of this lava flow. The temporary lake that was dammed by McKinney Basalt west of Bliss spilled along the sou

The Westphalian D fossil lepidodendrid forest at Table Head, Sydney Basin, Nova Scotia: Sedimentology, paleoecology and floral response to changing edaphic conditions

Science.gov (United States)

Calder, J.H.; Gibling, M.R.; Eble, C.F.; Scott, A.C.; MacNeil, D.J.

1996-01-01

Strata of Westphalian D age on the western coast of the Sydney Basin expose a fossil forest of approximately 30 lepidodendrid trees within one of several clastic splits of the Harbour Seam. A mutidisciplinary approach was employed to interpret the origins of the coal bed, the depositional history of the site and the response of the fossil forest to changing edaphic conditions. The megaspore and miospore records indicate that the mire vegetation was dominated by arboreous lycopsids, especially Paralycopodites, with subdominant tree ferns. Petrographic, palynological and geochemical evidence suggest that the Harbour coal bed at Table Head originated as a rheotrophic (cf. planar) mire (eutric histosol). The mire forest is interpreted to have been engulfed by prograding distributary-channel sediments; sparse protist assemblages are suggestive of a freshwater delta-plain lake environment occasionally in contact with brackish waters. Lepidodendrids persisted as site colonizers of clastic substrates even after burial of the rheotrophic peatland and influenced the morphology of deposited sediment, but apparently were unable to colonize distributary channels. Equivocal taxonomic data (compression fossils) show the fossil forest to have been composed of both monocarpic (Lepidodendron) and polycarpic (Diaphorodendron, Paralycopodites, ?Sigillaria) lycopsids, genera recorded in the palynology of the uppermost ply of the underlying coal bed. Comparatively rare within the clastic beds of the fossil forest, however, is the stem compression of Paralycopodites, whose dispersed megapores and miospores dominate the underlying coal bed. Tree diameter data recorded equivalent to breast height indicate a forest of mixed age. These data would appear to suggest that some lepidodendrids employing a polycarpic reproductive strategy were better able to cross the ecological barrier imposed between peat and clastic substrates. Foliar compressions indicate that an understory or stand of

In situ ∼2.0 Ma trees discovered as fossil rooted stumps, lowermost Bed I, Olduvai Gorge, Tanzania.

Science.gov (United States)

Habermann, Jörg M; Stanistreet, Ian G; Stollhofen, Harald; Albert, Rosa M; Bamford, Marion K; Pante, Michael C; Njau, Jackson K; Masao, Fidelis T

2016-01-01

The discovery of fossil rooted tree stumps in lowermost Lower Bed I from the western Olduvai Basin, Tanzania, age-bracketed by the Naabi Ignimbrite (2.038 ± 0.005 Ma) and Tuff IA (1.88 ± 0.05 Ma), provides the first direct, in situ, and to date oldest evidence of living trees at Olduvai Gorge. The tree relicts occur in an interval dominated by low-viscosity mass flow and braided fluvial sediments, deposited at the toe of a largely Ngorongoro Volcano-sourced volcaniclastic fan apron that comprised a widely spaced network of ephemeral braided streams draining northward into the Olduvai Basin. Preservation of the trees occurred through their engulfment by mass flows, post-mortem mold formation resulting from differential decay of woody tissues, and subsequent fluvially-related sediment infill, calcite precipitation, and cast formation. Rhizolith preservation was triggered by the interaction of root-induced organic and inorganic processes to form rhizocretionary calcareous root casts. Phytolith analyses were carried out to complete the paleoenvironmental reconstruction. They imply a pronounced seasonality and indicate a wooded landscape with grasses, shrubs, and sedges growing nearby, comparable to the low, open riverine woodland (unit 4c) along the Garusi River and tributaries in the Laetoli area. Among the tree stump cluster were found outsized lithic clasts and those consisting of quartzite were identified as Oldowan stone tool artifacts. In the context of hominin activity, the identification of wooded grassland in association with nearby freshwater drainages and Oldowan artifacts significantly extends our paleoenvironmental purview on the basal parts of Lower Bed I, and highlights the hitherto underrated role of the yet poorly explored western Olduvai Gorge area as a potential ecologically attractive setting and habitat for early hominins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Factors affecting the amounts of emissions arising from fluidized bed combustion of solid fuels

International Nuclear Information System (INIS)

Horbaj, P.

1996-01-01

The factors affecting the amounts of nitrogen oxides (NO x ) and sulfur oxides (SO x , i.e. SO 2 + SO 3 ) formed during fluidized bed combustion of fossil fuels are analyzed using both theoretical concepts and experimental data. The factors treated include temperature, excess air, fuel parameters, pressure, degree of combustion gas recycling, combustion distribution along the combustion chamber height, and sulfur trapping processes for NO x , and the Ca/S ratio, fluidized layer height and fluidization rate, granulometry and absorbent type, fluidized layer temperature, and pressure during combustion for SO x . It is concluded that fluidized bed boilers are promising power generating facilities, mitigating the environmental burden arising from fossil fuel combustion. (P.A.). 12 figs., 9 refs

Dust control products at Hagerman National Wildlife Refuge, Texas: environmental safety and performance

Science.gov (United States)

Kunz, Bethany K.; Little, Edward E.

2015-01-01

Controlling fugitive dust while protecting natural resources is a challenge faced by all managers of unpaved roads. Unfortunately, road managers choosing between dust control products often have little objective environmental information to aid their decisions. To address this information gap, the U.S. Geological Survey and the U.S. Fish and Wildlife Service collaborated on a field test of three dust control products with the objectives of (a) evaluating product performance under real-world conditions, (b) verifying the environmental safety of products identified as practically nontoxic in laboratory tests, and (c) testing the feasibility of several environmental monitoring techniques for use in dust control tests. In cooperation with refuge staff and product vendors, three products (one magnesium chloride plus binder, one cellulose, and one synthetic fluid plus binder) were applied in July 2012 to replicated road sections at the Hagerman National Wildlife Refuge in Texas. These sections were monitored periodically for 12 months after application. Product performance was assessed by mobile-mounted particulate-matter meters measuring production of fugitive dust and by observations of road conditions. Environmental safety was evaluated through on-site biological observations and leaching tests with samples of treated aggregate. All products reduced dust and improved surface condition during those 12 months. Planned environmental measurements were not always compatible with day-to-day refuge management actions; this incompatibility highlighted the need for flexible biological monitoring plans. As one of the first field tests of dust suppressants that explicitly incorporated biological endpoints, this effort provides valuable information for improving field tests and for developing laboratory or semifield alternatives.

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

Fossils mollusc asemblage found at Zagarzazu, marine Pleistocene, Uruguay

International Nuclear Information System (INIS)

Rojas, A. . E mail: alejandra@fcien.edu.uy

2004-01-01

There are presented the results of the paleoecological analysis of the mollusc assemblage found at Zagarzazu, Colonia department. The fossils are well preserved, arranged in thin shell-beds with some specimens in life position. The assemblage is indicative of higher temperatures than present, and a strong marine influence. It is important to stress that new thermophilic molluscs for the marine Quaternary were found and that this locality represents a new Pleistocene marine record in Uruguay [es

Stratigraphy, age and environments of the late Miocene Mpesida Beds, Tugen Hills, Kenya.

Science.gov (United States)

Kingston, John D; Fine Jacobs, Bonnie; Hill, Andrew; Deino, Alan

2002-01-01

Interpretations of faunal assemblages from the late Miocene Mpesida Beds in the Tugen Hills of the Central Kenyan Rift Valley have figured prominently in discussions of faunal turnover and establishment of the modern East African communities. These faunal changes have important implications for the divergence of the human lineage from the African apes ca. 8-5 Ma. While fossil material recovered from the Mpesida Beds has traditionally been analyzed collectively, accumulating evidence indicates that Mpesida facies span the 7-6 Ma interval and are scattered more than 25 km along the eastern flanks of the Tugen Hills. Stratigraphic distinctions between Mpesida facies and younger sediments in the sequence, such as the Lukeino Formation, are not yet fully resolved, further complicating temporal assessments and stratigraphic context of Mpesida facies. These issues are discussed with specific reference to exposures of Mpesida facies at Rurmoch, where large fossil tree fragments were swept up in an ancient ash flow. Preserved anatomical features of the fossil wood as well as estimated tree heights suggest a wet, lowland rainforest in this portion of the rift valley. Stable isotopic analyses of fossil enamel and paleosol components indicate the presence of more open habitats locally. Overlying air-fall tuffs and epiclastic debris, possibly associated with the ash flow, have yielded an assemblage of vertebrate fossils including two teeth belonging to one of the earliest colombines of typical body size known from Africa, after the rather small Microcolobus. Single-crystal, laser-fusion,(40)Ar/(39)Ar dates from a capping trachyte flow as well as tuffs just below the lava contact indicate an age of greater than 6.37 Ma for the fossil material. Copyright 2002 Academic Press.

Shell Bed Identification of Kaliwangu Formation and its Sedimentary Cycle Significance, Sumedang, West Java

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Aswan Aswan

2014-07-01

Full Text Available DOI: 10.17014/ijog.v8i1.151Kaliwangu Formation cropping out around Sumedang area contains mollusk fossils dominated by gastropods and bivalves. In terms of sequence stratigraphy, each sedimentary cycle generally consists of four shell bed types: Early Transgressive Systems Tract (Early TST deposited above an erosional surface or sequence boundary, that is characterized by shell disarticulation, trace fossils, gravelly content, no fossil orientation direction, and concretion at the bottom; Late Transgressive Systems Tract (Late TST identified by articulated (conjoined specimen in its life position, that shows a low level abration and fragmentation, adult specimen with complete shells, and variation of taxa; Early Highstand Systems Tract (Early HST characterized by adult taxa that was found locally in their life position with individual articulation, juvenile specimens frequently occured; Late Highstand Systems Tract (Late HST determined as multiple-event concentrations, disarticulated shell domination, and some carbon or amber intercalation indicating terrestrial influence. Shell bed identification done on this rock unit identified nineteen sedimentary cycles.

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

Dinosaur Footprints and Other Ichnofauna from the Cretaceous Kem Kem Beds of Morocco

Science.gov (United States)

Ibrahim, Nizar; Varricchio, David J.; Sereno, Paul C.; Wilson, Jeff A.; Dutheil, Didier B.; Martill, David M.; Baidder, Lahssen; Zouhri, Samir

2014-01-01

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age ‘lower’ and ‘upper’ units of the ‘Kem Kem beds’ in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous. PMID:24603467

Stable carbon isotope ratios and intrinsic water-use efficiency of Miocene fossil leaves compared to modern congeners

Energy Technology Data Exchange (ETDEWEB)

Marshall, J.D.; Zhang, J.; Rember, W.C.; Jennings, D.; Larson, P. (Univ. of Idaho, Moscow, ID (United States))

1994-06-01

Miocene fossil leaves of forest trees were extracted from the Clarkia, Idaho fossil beds and their stable carbon isotope ratios were analyzed. Fossils had higher lignin concentrations and lower cellulose concentrations that modern leaves due to diagenesis and the HF used to extract the fossils. Therefore, [delta][sup 13]C of extracted fossil lignin was compared to that of modern lignin. Fossil lignin [delta][sup 13]C was significantly different from that of congeneric modern leaves (paired t-test, P<0.0001), but was 1.9% less negative. Gymnosperms (Metasequoia, Taxodium) were less negative than angiosperms (e.g., Magnolia, Quercus, Acer, Persea), but no difference between evergreen and deciduous species was detected. Using published estimates of the concentration and [delta][sup 13]C of atmospheric CO[sub 2] during the Miocene was estimated the CO[sub 2] partial pressure gradient across the stomata (intrinsic water-use efficiency). Intrinsic water-use efficiency was at least 70% higher during this past [open quotes]greenhouse[close quotes] period than at present.

Detrital zircon dating and tracing the provenance of dinosaur bone beds from the Late Cretaceous Wangshi Group in Zhucheng, Shandong, East China

Directory of Open Access Journals (Sweden)

Wei An

2016-01-01

Full Text Available The mass burial of dinosaur bone fossils in the Late Cretaceous Wangshi Group in Zhucheng, Shandong Province has been a research focus in recent years. However, the provenance of the dinosaur bone fossils and the accurate depositional age of the bone beds remain ambiguous. Through U–Pb dating of detrital zircons collected from six conglomerate samples from the dinosaur bone beds, we found that the youngest single grain age (YSG of sample 090414-24-D was 77.3 Ma, representing the maximum depositional age of the dinosaur fossil beds and sediments. This also indicates that the Hongtuya Formation was deposited during the Campanian. Dating results revealed an age peak of 120–110 Ma, which corresponds with the peak age of volcanic rocks of the Lower Cretaceous Qingshan Group. The volcanic rocks of the Qingshan Group are mainly exposed in Laiyang, to the north of Zhucheng, although a few also appear to the south and northwest. Through analysis of conglomerate composition and palaeocurrents in the sediments containing the bone beds, we found that the three different data sets of gravel compositions of the conglomerates were mainly composed of volcanic or pyroclastic rocks. Three different data sets of palaeocurrents suggested that the main sediment source of the Wangshi Group dinosaur bone beds was from the north−northwest of the Basin. Only one data set had a provenance south of the basin. This study revealed that the areas of Laiyang and the Yishu Fault Zone were the main provenance areas of both the dinosaur bone fossils and the sediments of the Wangshi Group in Zhucheng. The southern margin of the Zhucheng Basin may be a secondary source area. This research provides an important basis for judging the deposition time and the sediment source of fossil layers in the Wangshi Group, as well as reconstructing the palaeogeography of the Wangshi Group in the Jiaolai Basin.

14C age of the Satsunai pumice bed, Noboribetsu City, SW Hokkaido, Japan

International Nuclear Information System (INIS)

Kawachi, Shinpei; Matsui, Masaru; Miyasaka, Shogo; Akamatsu, Morio; Kasugai, Akira.

1980-01-01

A sample of carbonized fallen tree piece (Picea or Pinus; diameter 5 cm and length 15 cm) was discovered in a crop in the Noboribetsu pumice flow deposit, where fossil-rootless fumaroles had been found recently. It existed in the loam layer immediately above the Satsunai pumice bed covering the Noboribetsu formation and the fumaroles below it. Its 14 C age was determined to be 11,330 +- 320 Y.B.P. Though the distribution and eruption source of Satsunai pumice bed are still unknown, the 14 C age has significance as follows in the Quaternary chronology. (1) The Satsunai pumice bed is important as a pumice bed indicating the boundary between the pleistocene and the Recent epoch. (2) By means of the Satsunai pumice bed, the age of upper Noboribetsu formation is given. (3) As there is no high bench deposit on the Noboribetsu pumice flow deposit, the time gap may be small between the Satsunai pumice bed and the Noboribetsu formation below it. (J.P.N.)

Fossil mega- and microflora from the Březno Beds s.s. (Bohemian Cretaceous Basin, Coniacian)

Czech Academy of Sciences Publication Activity Database

Halamski, A. T.; Kvaček, J.; Svobodová, Marcela

2018-01-01

Roč. 253, June 2018 (2018), s. 123-138 ISSN 0034-6667 Institutional support: RVO:67985831 Keywords : fossil plant * Cretaceous * taxonomy * paleobotany * Coniacian * Czech Republic Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Paleontology Impact factor: 1.817, year: 2016

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,…

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 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.

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.

Bioenergy originating from biomass combustion in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Crujeira, T.; Gulyurtlu, I.; Lopes, H.; Abelha, P.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

2008-07-01

Bioenergy could significantly contribute to reducing and controlling greenhouse emissions (GHG) and to replace fossil fuels in large power plants. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply chain of biomass in most European countries. In addition, there are also technical barriers as requirements of biomass combustion may differ from those of coal, which could mean significant retrofitting of existing installations. The combustion behaviour of different biomass materials were studied on a pilot fluidised bed combustor, equipped with two cyclones for particulate matter removal. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, heavy metals and dioxins and furans (PCDD/F). The results obtained indicated that the combustion of these materials did not present any operational problem, although for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass materials studied. Most of the combustion of biomass, contrary to what is observed for coal, takes place in the riser where the temperature was as much as 150{sup o}C above that of the bed. Stable combustion conditions were achieved as well as high combustion efficiency. When compared with the emissions of bituminous coal, the most used fossil fuel, the emissions of CO and SO2 were found to be lower and NOx emissions were similar to those of coal. HCl and PCDD/F could be considerable with biomasses containing high chlorine levels, as in the case of straw. It was observed that the nature of ash could give rise serious operating problems.

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 1997

Energy Technology Data Exchange (ETDEWEB)

R. C. Bartholomay (USGS); L. M. Williams (USGS); L. J. Campbell (Idaho Department of Water Resources)

1998-12-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled 18 sites as part of the fourth round of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radiochemical and chemical constituents. The samples were collected from seven domestic wells, six irrigation wells, two springs, one dairy well, one observation well, and one stock well. Two quality-assurance samples also were collected and analyzed. None of the radiochemical or chemical constituents exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide- and inorganic-constituent concentrations were greater than their respective reporting levels.

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...

Proceedings of the second US Department of Energy environmental control symposium. Volume 1. Fossil energy

Energy Technology Data Exchange (ETDEWEB)

None

1980-06-01

These proceedings document the presentations given at the Second Environmental Control Symposium. Symposium presentations highlighted environmental control activities which span the entire DOE. Volume I contains papers relating to coal preparation, oil shales, coal combustion, advanced coal utilization (fluidized bed combustion, MHD generators, OCGT, fuel cells), coal gasification, coal liquefaction, and fossil resource extraction (enhanced recovery). Separate abstracts for individual papers are prepared for inclusion in the Energy Data Base. (DMC)

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

Taphonomy of the fossil insects of the middle Eocene Kishenehn Formation

Directory of Open Access Journals (Sweden)

Dale E. Greenwalt

2015-12-01

Full Text Available The lacustrine oil shales of the Coal Creek Member of the Kishenehn Formation in northwestern Montana comprise a relatively unstudied middle Eocene fossil insect locality. Herein, we detail the stratigraphic position of the fossiliferous unit, describe the insect fauna of the Coal Creek locality and document its bias towards very small but remarkably pre-served insects. In addition, the depositional environment is examined and the mineral constituents of the laminations that comprise the varves of the Kishenehn oil shale are defined. Fifteen orders of insects have been recorded with the majority of all insects identified as aquatic with the families Chironomidae (Diptera and Corixidae (Hemiptera dominant. The presence of small aquatic insects, many of which are immature, the intact nature of >90% of the fossil insects and the presence of Daphnia ephippia, all indicate that the depositional environment was the shallow margin of a large freshwater lake. The fossil insects occur within fossilized microbial mat layers that comprise the bedding planes of the oil shale. Unlike the fossiliferous shales of the Florissant and Okanagan Highlands, the mats are not a product of diatomaceous algae nor are diatom frustules a component of the sediments or the varve structure. Instead, the varves are composed of very fine eolian siliciclastic silt grains overlaid with non-diatomaceous, possibly cyanobacteria-derived microbial mats which contain distinct traces of polyaromatic hydrocarbons. A distinct third layer composed of essentially pure calcite is present in the shale of some exposures and is presumably derived from the seasonal warming-induced precipitation of carbonate from the lake’s waters. The Coal Creek locality presents a unique opportunity to study both very small middle Eocene insects not often preserved as compression fossils in most Konservat-Lagerstätte and the processes that led to their preservation.

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.

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)

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 1998

Energy Technology Data Exchange (ETDEWEB)

R. C. Bartholomay; B. V. Twining (USGS); L. J. Campbell (Idaho Department of Water Resources)

1999-06-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled 18 sites as part of the fourth round of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. The samples were analyzed for selected radiochemical and chemical constituents. The samples were collected from 2 domestic wells, 12 irrigation wells, 2 stock wells, 1 spring, and 1 public supply well. Two quality-assurance samples also were collected and analyzed. None of the reported radiochemical or chemical constituent concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide- and inorganic-constituent concentrations were greater than the respective reporting levels. Most of the organic-constituent concentrations were less than the reporting levels.

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.

Fruits and wood of Parinari from the early Miocene of Panama and the fossil record of Chrysobalanaceae.

Science.gov (United States)

Jud, Nathan A; Nelson, Chris W; Herrera, Fabiany

2016-02-01

Chrysobalanaceae are woody plants with over 500 species in 20 genera. They are among the most common trees in tropical forests, but a sparse fossil record has limited our ability to test evolutionary and biogeographic hypotheses, and several previous reports of Chrysobalanaceae megafossils are doubtful. We prepared fossil endocarps and wood collected from the lower Miocene beds along the Panama Canal using the cellulose acetate peel technique and examined them using light microscopy. We compared the fossil endocarps with previously published fossils and with fruits from herbarium specimens. We compared the fossil wood with photographs and descriptions of extant species. Parinari endocarps can be distinguished from other genera within Chrysobalanaceae by a suite of features, i.e., thick wall, a secondary septum, seminal cavities lined with dense, woolly trichomes, and two ovate to lingulate basal germination plugs. Fossil endocarps from the Cucaracha, Culebra, and La Boca Formations confirm that Parinari was present in the neotropics by the early Miocene. The earliest unequivocal evidence of crown-group Chrysobalanaceae is late Oligocene-early Miocene, and the genus Parinari was distinct by at least 19 million years ago. Parinari and other Chrysobalanaceae likely reached the neotropics via long-distance dispersal rather than vicariance. The presence of Parinari in the Cucaracha flora supports the interpretation of a riparian, moist tropical forest environment. Parinari was probably a canopy-dominant tree in the Cucaracha forest and took advantage of the local megafauna for seed dispersal. © 2016 Botanical Society of America.

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…

Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1995

International Nuclear Information System (INIS)

Bartholomay, R.C.; Williams, L.M.; Campbell, L.J.

1996-09-01

The US Geological Survey and the Idaho Department of Water Resources, in cooperation with the US Department of Energy, sampled 17 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from 11 irrigation wells, 2 domestic wells, 2 stock wells, 1 spring, and 1 public-supply well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituents, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide and inorganic constituent concentrations were greater than their respective reporting levels. All samples analyzed for dissolved organic carbon had concentrations that were greater than the minimum reporting level

New dinosaur fossils from ANA locality, Arcillas de Morella Formation (Aptian, Lower Cretaceous, Cinctorres, Spain)

Science.gov (United States)

Santos-Cubedo, A.; de Santisteban, C.; Suñer, M.; Galobart, A.

2009-04-01

Ana is one of the several dinosaur bone sites located in the Arcillas de Morella Formation (Aptian, Lower Cretaceous; eastern Iberian Chain, Spain). This site was discovered in 1998, but it remained unexcavated until 2002, when a palaeontologist team formed by members of the Institut Paleontología Miquel Crusafont from Sabadell and the Grup Guix from Vila-real unearthed the first fossil from the locality. Nowadays there are five hundred fossils collected, including vertebrate and invertebrate species. Dinosaur bones (Theropoda and Ornithopoda) are abundant in this assemblage and in the last field season bones determined as Sauropoda were found. Taxonomically, Ana is dominated by disarticulated remains of Ornithopoda, which are usually fragmentary and abraded. Many of the elements may have been reworked (spatial averaging and/or time averaging), and the fossil concentration constitutes an autochthonous to parautochthonous association, in a spatial sense. The remains found in the Ana fossils site are placed in sandstones and limes containing marine autochthonous fauna. These deposits were formed during the transgressive infilling of an incised valley. Sedimentological features indicate that fossils were finally deposited in starved shallow estuarine environment. Mineralogically, the sediment including the fossils contains grains of quartz, illite/mica, kaolinite/clorite, K-feldspar and plagioclase, distributed in two mainly grain populations, a silty-clay and a coarse sand size grain, indicating that the sediments were bedded in a low-medium energy depositional environment. Nowadays we identified in Ana, teeth of Theropoda indet. and Baryonychinae indet., and bones of Iguanodon sp. Herein, we report new fossil findings from Ana site. These materials have been determined as Iguanodontia, Titanosauriformes and Theropoda. These new findings will help to understand the dinosaur fauna present in the Lower Cretaceous of Els Ports (Castellón, Spain). Acknowledgments This

Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

Science.gov (United States)

Hansen, Larissa; Callow, Richard; Kane, Ian; Kneller, Ben

2017-08-01

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel-belts (external levees). Terraces are flat-lying features that are elevated above the active channel within a broad channel-belt. Despite the ubiquity of terraces and levees in modern submarine channel systems, the recognition of these environments in outcrop and in the subsurface is challenging. In this outcrop study of the Upper Cretaceous Rosario Formation (Baja California, Mexico), lateral transects based on multiple logged sections of thin-bedded turbidites reveal systematic differences in sandstone layer thicknesses, sandstone proportion, palaeocurrents, sedimentary structures and ichnology between channel-belt and external levee thin-bedded turbidites. Depositional terrace deposits have a larger standard deviation in sandstone layer thicknesses than external levees because they are topographically lower, and experience a wider range of turbidity current sizes overspilling from different parts of the channel-belt. The thickness of sandstone layers within external levees decreases away from the channel-belt while those in depositional terraces are less laterally variable. Depositional terrace environments of the channel-belt are characterized by high bioturbation intensities, and contain distinctive trace fossil assemblages, often dominated by ichnofabrics of the echinoid trace fossil Scolicia. These assemblages contrast with the lower

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.)

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.

Tritium concentrations in flow from selected springs that discharge to the Snake River, Twin Falls-Hagerman area, Idaho

International Nuclear Information System (INIS)

Mann, L.J.

1989-01-01

Concern has been expressed that some of the approximately 30,900 curies of tritium disposed to the Snake River Plain aquifer from 1952 to 1988 at the INEL (idaho National Engineering Laboratory) have migrated to springs discharging to the Snake River in the Twin Falls-Hagerman area. To document tritium concentrations in springflow, 17 springs were sampled in November 1988 and 19 springs were sampled in March 1989. Tritium concentrations were less than the minimum detectable concentration of 0.5 pCi/mL (picocuries/mL) in November 1988 and less than the minimum detectable concentration of 0.2 pCi/mL in March 1989 the minimum detectable concentration was smaller in March 1989. The maximum contaminant level of tritium in drinking water as established by the US Environmental Protection Agency is 20 pCi/mL. US Environmental Protection Agency sample analyses indicate that the tritium concentration has decreased in the Snake River near Buhl since the 1970's. In 1974-79, tritium concentrations were less than 0.3 ± 0.2 pCi/mL in 3 of 20 samples; in 1983-88, 17 of 23 samples contaminated less than 0.3 ± 0.2 pCi/mL of tritium; the minimum detectable concentration is 0.2 pCi/mL. On the basis of decreasing tritium concentrations in the Snake River, their correlation to cessation of atmospheric weapons tests tritium concentrations in springflow less than the minimum detectable concentration, and the distribution of tritium in groundwater at the INEL, aqueous disposal of tritium at the INEL has had no measurable effect on tritium concentrations in springflow from the Snake River Plain aquifer and in the Snake River near Buhl. 15 refs., 2 figs., 3 tabs

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…

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.

Radionuclides, inorganic constitutents, organic compounds, and bacteria in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1992

International Nuclear Information System (INIS)

Bartholomay, R.C.; Edwards, D.D.; Campbell, L.J.

1994-01-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in response to a request from the U.S. Department of Energy, sampled 18 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, inorganic constituents, organic compounds, and bacteria. The samples were collected from 13 irrigation wells, 1 domestic well, 1 spring, 2 stock wells, and 1 public supply well. Quality assurance samples also were collected and analyzed. None of the samples analyzed for radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. Most of the samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting levels. None of the samples contained reportable concentrations of purgeable organic compounds or pesticides. Total coliform bacteria was present in nine samples

Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

Science.gov (United States)

Marquis, G. A.; Roy, A. G.

2012-02-01

This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

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.

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.

Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area, Idaho, 1993

Science.gov (United States)

Bartholomay, Roy C.; Edwards, Daniel D.; Campbell, Linford J.

1994-01-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in response to a request from the U.S. Department of Energy, sampled 19 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from seven irrigation wells, four domestic wells, two springs, one stock well, three dairy wells, one observation well, and one commercial well. Two quality assurance samples also were collected and analyzed. None of the radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concen- trations exceeded their respective laboratory reporting levels. All samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting level. Ethylbenzene concentrations exceeded the reporting level in one water sample.

A new archosauriform (Reptilia: Diapsida) from the Manda beds (Middle Triassic) of southwestern Tanzania.

Science.gov (United States)

Nesbitt, Sterling J; Butler, Richard J; Gower, David J

2013-01-01

Archosauria and their closest relatives, the non-archosaurian archosauriforms, diversified in the Early and Middle Triassic, soon after the end-Permian extinction. This diversification is poorly documented in most Lower and Middle Triassic rock sequences because fossils of early groups of archosauriforms are relatively rare compared to those of other amniotes. The early Middle Triassic (? late Anisian) Manda beds of southwestern Tanzania form an exception, with early archosaur skeletons being relatively common and preserved as articulated or associated specimens. The Manda archosaur assemblage is exceptionally diverse for the Middle Triassic. However, to date, no non-archosaurian archosauriforms have been reported from these rocks. Here, we name a new taxon, Asperoris mnyama gen. et sp. nov., from the Manda beds and thoroughly describe the only known specimen. The specimen consists of a well-preserved partial skull including tooth-bearing elements (premaxilla, maxilla), the nasal, partial skull roof, and several incomplete elements. All skull elements are covered in an autapomorphic highly rugose sculpturing. A unique combination of character states indicates that A. mnyama lies just outside Archosauria as a stem archosaur within Archosauriformes, but more precise relationships of A. mnyama relative to other early archosauriform clades (e.g., Erythrosuchidae) cannot be determined currently. Asperoris mnyama is the first confirmed non-archosaurian archosauriform from the Manda beds and increases the morphological and taxonomic diversity of early archosauriforms known from the Middle Triassic. The direct association of A. mnyama with species referable to Archosauria demonstrates that non-archosaurian archosauriforms were present during the rise and early diversification of Archosauria. Non-archosaurian archosauriforms and archosaurs co-occur in fossil reptile assemblages across Pangaea from the late Early Triassic to the end of the Late Triassic.

Trace fossil analysis of lacustrine facies and basins

Science.gov (United States)

Buatois, L.A.; Mangano, M.G.

1998-01-01

Two ichnofacies are typical of lacustrine depositional systems. The Scoyenia ichnofacies characterizes transitional terrestrial/nonmarine aquatic substrates, periodically inundated or desiccated, and therefore is commonly present in lake margin facies. The Mermia ichnofacies is associated with well oxygenated, permanent subaqueous, fine-grained substrates of hydrologically open, perennial lakes. Bathymetric zonations within the Mermia ichnofacies are complicated by the wide variability of lacustrine systems. Detected proximal-distal trends are useful within particular lake basins, but commonly difficult to extrapolate to other lakes. Other potential ichnofacies include the typically marine Skolithos ichnofacies for high-energy zones of lakes and substrate-controlled, still unnamed ichnofacies, associated to lake margin deposits. Trace fossils are useful for sedimentologic analysis of event beds. Lacustrine turbidites are characterized by low-diversity suites, reflecting colonization by opportunistic organisms after the turbidite event. Underflow current beds record animal activity contemporaneous with nearly continuous sedimentation. Ichnologic studies may also help to distinguish between marine and lacustrine turbidites. Deep-marine turbidites host the Nereites ichnofacies that consists of high diversity of ornate grazing traces and graphoglyptids, recording highly specialized feeding strategies developed to solve the problem of the scarcity of food in the deep sea. Deep lacustrine environments contain the Mermia ichnofacies, which is dominated by unspecialized grazing and feeding traces probably related to the abundance and accessibility of food in lacustrine systems. The lower diversity of lacustrine ichnofaunas in comparison with deep-sea assemblages more likely reflects lower species diversity as a consequence of less stable conditions. Increase of depth and extent of bioturbation through geologic time produced a clear signature in the ichnofabric record of

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)

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 2002

Science.gov (United States)

Rattray, Gordon W.; Campbell, Linford J.

2004-01-01

The U.S. Geological Survey, Idaho Department of Water Resources, and the State of Idaho INEEL Oversight Program, in cooperation with the U.S. Department of Energy, sampled water from 17 sites as part of the sixth round of a long-term project to monitor water quality of the eastern Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. The samples were collected from eight irrigation wells, three domestic wells, one stock well, one dairy well, one commercial well, one observation well, and two springs and analyzed for selected radiochemical and chemical constituents. One quality-assurance sample, a sequential replicate, also was collected and analyzed. Many of the radionuclide and inorganic-constituent concentrations were greater than the reporting levels and most of the organic-constituent concentrations were less than the reporting levels. However, none of the reported radiochemical- or chemical-constituent concentrations exceeded the maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. Statistical evaluation of the replicate sample pair indicated that, with 95 percent confidence, 132 of the 135 constituent concentrations of the replicate pair were equivalent.

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

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

Radionuclides, inorganic constituents, organic compounds, and bacteria in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1990

International Nuclear Information System (INIS)

Bartholomay, R.C.; Edwards, D.D.; Campbell, L.J.

1992-03-01

The US Geological Survey and the Idaho Department of Water Resources, in response to a request from the US Department of Energy, sampled 19 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for manmade pollutants and naturally occurring constituents. The samples were collected from seven irrigation wells, five domestic wells, two springs, one stock well, two dairy wells, one observation well, and one commercial well. Two quality assurance samples also were collected and analyzed. The water samples were analyzed for selected radionuclides, inorganic constituents, organic compounds, and bacteria. None of the radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. All samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting level. Toluene concentrations exceeded the reporting level in one water sample. Two samples contained fecal coliform bacteria counts that exceeded established maximum contaminant levels for drinking water

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)

Proceedings of the US Department of Energy environmental control symposium. Volume 1. Plenary session and fossil fuels

Energy Technology Data Exchange (ETDEWEB)

None

1979-09-01

Volume one of the proceedings (Plenary Session and Fossil Fuels) contains papers on environmental pollution control which resulted mainly from US DOE's research programs in coal (preparation, desulfurization, gasification, liquefaction, combustion, fluidized-bed combustion, and pollution control methods with respect to SO/sub 2/, NO/sub x/, and CO/sub 2/ (global effects and feasibility studies); a few papers deal with oil shale operations and the enhanced recovery of petroleum. Papers have been entered individually into EDB and ERA, with 3 also into EAPA; six papers had been entered previously from other sources. (LTN)

Radiochemical and chemical constituents in water from selected wells and springs from the southern boundary of the Idaho National Laboratory to the Hagerman Area, Idaho, 2003

Science.gov (United States)

Rattray, Gordon W.; Wehnke, Amy J.; Hall, L. Flint; Campbell, Linford J.

2005-01-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled water from 14 sites as part of an ongoing study to monitor the water quality of the eastern Snake River Plain aquifer between the southern boundary of the Idaho National Laboratory (INL) and the Burley-Twin Falls-Hagerman area. The State of Idaho, Department of Environmental Quality, Division of INL Oversight and Radiation Control cosampled with the U.S. Geological Survey and the Idaho Department of Water Resources and their analytical results are included in this report. The samples were collected from four domestic wells, two dairy wells, two springs, four irrigation wells, one observation well, and one stock well and analyzed for selected radiochemical and chemical constituents. Two quality-assurance samples, sequential replicates, also were collected and analyzed. None of the concentrations of radiochemical or organic-chemical constituents exceeded the maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. However, the concentration of one inorganic-chemical constituent, nitrate (as nitrogen), in water from site MV-43 was 20 milligrams per liter which exceeded the maximum contaminant level for that constituent. Of the radiochemical and chemical concentrations analyzed for in the replicate-sample pairs, 267 of the 270 pairs (with 95 percent confidence) were statistically equivalent.

Infant's bed climate and bedding in the Japanese home.

Science.gov (United States)

Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

2012-06-01

to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 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

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 energy use and the environment

International Nuclear Information System (INIS)

Sage, P.W.

1994-01-01

Energy demand projections indicate that fossil energy will provide some ninety per cent of global primary energy demand for the foreseeable future. This paper considers the principal environmental impacts associated with fossil energy use and describes approaches to minimise them. Technologies are now available to reduce significantly pollutant emissions from fossil fuel use. Emerging technologies offer higher conversion efficiencies to reduce still further specific emissions per unit of energy output. It is essential, particularly in those areas of rapid growth in energy use, that best practice and technology are deployed. Technology transfer and training will help to achieve this and enable fossil energy use to be fully compatible with increasingly stringent environmental requirements. (author) 4 figs., 12 refs

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.)

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

Stratigraphy, correlation, and age estimates for fossils from Area 123, Koobi Fora.

Science.gov (United States)

Feibel, Craig S; Lepre, Christopher J; Quinn, Rhonda L

2009-08-01

Geological data from the Bura Hasuma region at Koobi Fora provide important constraints for estimating the ages of hominin fossils recovered there, including the cranium KNM-ER 1813. Strata of the upper Burgi, KBS, and Okote members in this part of Koobi Fora reflect three depositional regimes driven by changing paleogeography through time. The upper Burgi and lowermost KBS sequence in the southern Bura Hasuma region accumulated in a lacustrine to delta front setting, with highly localized depositional patterns, limiting the lateral extent of lithostratigraphic markers. Farther north, uppermost upper Burgi through KBS member strata document a fluctuating lake margin, with complex facies patterns. This interval is marked by laterally extensive lithostratigraphic markers, including molluscan packstones, beach sandstones, and stromatolite beds. The uppermost KBS and Okote members show a transition to dominantly fluvial character, with localized and discontinuous accumulation. An age model for the richly fossiliferous Area 123 sequence demonstrates the complexity of terrestrial accumulation patterns. Early lacustrine and delta front accumulation is marked by fairly continuous sedimentation, and high accumulation rates (up to ca. 91 cm/k.yr.). The fluctuating lake margin interval reflects lower sedimentation rates coupled with intervals of exposure, decreasing accumulation significantly (to ca. 13 cm/k.yr.). The capping fluvial interval is marked by significant erosion surfaces, breaks which may drop the overall accumulation rate even lower (ca. 0.3 cm/k.yr.). The data provided here establish a geological framework at odds with a recent proposal of ages considerably younger (by ca. 250 k.yr.) for many of the fossils from Area 123 and elsewhere. Tests of age models demonstrate that the younger ages are not possible. While minor refinements to age estimates for fossils are indicated by improved chronostratigraphic control, in the case of KNM-ER 1813, an age of younger

Fossil bird eggs from the Pliocene of Laetoli, Tanzania: Their taxonomic and paleoecological relationships

Science.gov (United States)

Harrison, Terry

2005-04-01

Recent paleontological investigations at the Pliocene site of Laetoli and at neighboring localities on the Eyasi Plateau of northern Tanzania have led to the recovery of a sizable collection of fossil bird eggs. The material comes from the Upper Laetolil Beds, dated at ˜3.6-3.8 Ma, and the Lower Laetolil Beds, dated at 3.8 Ma to older than 4.3 Ma. The preservation of relatively complete eggs (other than those of ratites) is an extremely rare occurrence in the fossil record, and Laetoli is the only locality in Africa that has produced such well-preserved eggs. Deposition of carbonatite air-fall tuffs led to the rapid burial of the eggs sub-aerially, and they were then preserved in paleosols that were geochemically conducive to their preservation. The collection of fossil eggs from Laetoli can be assigned to at least five different species of ground-nesting birds, including two or three species of francolins, a species of guineafowl, and a larger bird of uncertain taxonomic status about the size of a bustard. Most of the eggs can be assigned to a large species of Francolinus, similar in size to the extant F. afer and F. leucoscepus. A smaller species of francolin, about the size of Francolinus coqui or F. sephaena, is also represented, but is less common. A single egg may represent an even smaller species of francolin, about the size of Francolinus lathami or F. nahani, but its attribution to Francolinus is less certain. The evidence of at least two species of Francolinus at Laetoli indicates that francolins were already taxonomically diverse in East Africa by the mid-Pliocene. Three eggs are similar in their overall dimensions and morphology to the living Numida meleagris, the helmeted guineafowl. An avian community including at least one small species of francolin, a larger francolin, and a guineafowl (as well as ostriches and a vulture) implies that the paleoecology at Laetoli was likely to have been open woodland, bushland, savanna or grassland. However

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.)

Bed Bugs

Science.gov (United States)

Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

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.

Bed agglomeration characteristics of palm shell and corncob combustion in fluidized bed

International Nuclear Information System (INIS)

Chaivatamaset, Pawin; Sricharoon, Panchan; Tia, Suvit

2011-01-01

Bed particle agglomeration was studied experimentally in an atmospheric laboratory scale fluidized bed combustor using quartz sand as bed material. Palm shell and corncob were tested. The objectives of the study were (i) to describe the contributions of the biomass ash properties and the operating conditions on the bed agglomeration tendency in term of the bed defluidization time (t def ) and the extent of potassium accumulation in the bed (K/Bed) and (ii) to further elucidate the ash inorganic behaviors and the governing bed agglomeration mechanisms. Defluidization caused by the bed agglomeration was experienced in all experiments during combustion of these biomasses, as a consequence of the presence of potassium in biomass. The experimental results indicated that biomass ash characteristics were the significant influence on the bed agglomeration. The increasing bed temperature, bed particle size and static bed height and the decreasing fluidizing air velocity enhanced the bed agglomeration tendency. The SEM/EDS analyses on the agglomerates confirmed that the agglomeration was attributed to the formation of potassium silicate liquid enriched on the surface of quartz sand particles in conjunction with the high surface temperature of the burning biomass char particles. Thermodynamic examination based on the phase diagram analysis confirmed that the molten phase formation was responsible for the agglomeration. In this study, the high molten ash fraction resulting from the high potassium content in biomass promoted the agglomeration and thus defluidization. - Highlights: → Palm shell and corncob of Thailand are tested their bed agglomeration behaviors during fluidized bed combustion. → The increase of bed temperature, bed particle size and static bed height and the decrease of air velocity enhance bed agglomeration. → The formation of ash derived potassium silicate melts enriched on sand surface is the key process. → The collision between char and sand

The characteristics of bed agglomeration during fluidized bed combustion of eucalyptus bark

International Nuclear Information System (INIS)

Chaivatamaset, Pawin; Tia, Suvit

2015-01-01

The bed agglomeration behaviors were investigated experimentally when eucalyptus bark was burning tested in a laboratory scale fluidized bed reactor. The focuses of this work were the influences of operating conditions and bed materials on the bed agglomeration tendency and the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease in measured bed pressure. The growth of bed particle and accumulation of agglomerates during combustion provided the partial to complete defluidization. The defluidization was promoted by the increase of bed temperature and bed particle size, and the decrease of fluidizing air velocity. The SEM-EDS analyses revealed that the bed agglomeration was mainly attributed to the formation of potassium silicate compounds as liquid phase during the combustion. This was initiated by the chemical reaction between the bed particle and the released ash constituents. In this study, the inorganic migration from fuel particle to bed particle was likely dominated by the condensation/reaction. The thermodynamic examination by ternary phase diagram analysis corroborated that the liquid phase formation of the ash derived materials controlled the agglomeration. The alumina sand prevented the bed agglomeration since it was inactive in the formation of viscous molten substances during combustion at the observed temperatures. - Highlights: • The behaviors of bed agglomeration were studied during the fluidized bed combustion of eucalyptus bark. • The increase in bed temperature and sand size, and the decrease of air velocity promoted bed defluidization. • The formation of molten potassium silicate compounds conduced to the bed agglomeration. • Condensation/reaction was the dominant inorganic migration mechanism from fuel particle to bed particle. • The alumina sand prevented effectively the bed

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.

Paleovegetation changes recorded by n-alkyl lipids bound in macromolecules of plant fossils and kerogens from the Cretaceous sediments in Japan

Science.gov (United States)

Miyata, Y.; Sawada, K.; Nakamura, H.; Takashima, R.; Takahashi, M.

2014-12-01

significantly higher than that of conifer fossil leaf from Ashizawa coal bed. From these results, we propose that the proportions of long chain n-alkanols released from terrigenous kerogens are applicable for paleovegetation reconstruction.

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.)

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.

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.

Experimental, kinetic and numerical modeling of hydrogen production by catalytic reforming of crude ethanol over a commercial catalyst in packed bed tubular reactor and packed bed membrane reactor

International Nuclear Information System (INIS)

Aboudheir, Ahmed; Akande, Abayomi; Idem, Raphael

2006-01-01

The demand for hydrogen energy has increased tremendously in recent years essentially because of the increase in the word energy consumption as well as recent developments in fuel cell technologies. The energy information administration has projected that world energy consumption will increase by 59% over the next two decades, from 1999 to 2020, in which the largest share is still dominated by fossil fuels (oil, natural gas and coal). Carbon dioxide (CO 2 ) emissions resulting from the combustion of these fossil fuels currently are estimated to account for three-fourth of human-caused CO 2 emissions worldwide. Greenhouse gas emission, including CO 2 , should be limited, as recommended at the Kyoto Conference, Japan, in December 1997. In this regard, hydrogen (H 2 ) has a significant future potential as an alternative fuel that can solve the problems of CO 2 emissions as well as the emissions of other air contaminants. One of the techniques to produce hydrogen is by reforming of hydrocarbons or biomass. Crude ethanol (a form of biomass, which essentially is fermentation broth) is easy to produce, is free of sulphur, has low toxicity, and is also safe to handle, transport and store. In addition, crude ethanol consists of oxygenated hydrocarbons, such as ethanol, lactic acid, glycerol, and maltose. These oxygenated hydrocarbons can be reformed completely to H 2 and CO 2 , the latter of which could be separated from H 2 by membrane technology. This provides for CO 2 capture for eventual storage or destruction. In the case of using crude ethanol, this will result in negative CO 2 , emissions. In this paper, we conducted experimental work on production of hydrogen by the catalytic reforming of crude ethanol over a commercial promoted Ni-based catalyst in a packed bed tubular reactor as well as a packed bed membrane reactor. As well, a rigorous numerical model was developed to simulate this process in both the catalytic packed bed tubular reactor and packed bed membrane

The Safety of Hospital Beds: Ingress, Egress, and In-Bed Mobility.

Science.gov (United States)

Morse, Janice M; Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K; Bloswick, Donald

2015-01-01

To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients' ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients' use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated.

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

Tephrochronology of Bed II, Olduvai Gorge, Tanzania, and placement of the Oldowan-Acheulean transition.

Science.gov (United States)

McHenry, Lindsay J; Stanistreet, Ian G

2018-04-12

Tuffaceous marker beds, derived from volcanic products from the Ngorongoro Volcanic Highlands, help define a stratigraphic framework for the world-renowned fossil and stone tool record exposed at Olduvai Gorge, Tanzania. However, previous efforts to constrain this tuff record, especially for Olduvai Bed II, have been limited because of erosion, contamination, reworking, and the alteration of volcanic glass under saline-alkaline conditions. This paper applies previously defined geochemical and mineralogical "fingerprints" for several major Bed II marker tuffs, based on glass (where available) and phenocrysts more resistant to alteration (feldspar, hornblende, augite, and titanomagnetite), to tuffs from stratigraphic sections in the Olduvai Junction Area, including previously and recently excavated Acheulean and Oldowan sites (HWK EE (Locality (Loc) 42), EF-HR (Loc 12a), FLK (Loc 45), and MNK (Loc 88)). The Middle Bed II Bird Print Tuff (BPT) is found to be more compositionally variable than previously reported but is still valuable as a stratigraphic marker over short distances. The confirmation of blocks of Tuff IID in conglomerate helps constrain Upper Bed II stratigraphy at sites where in-situ tuffs are absent. This paper also compiles the results of published geochronological research, providing stratigraphic context and updating previously reported dates using a consistent 40 Ar/ 39 Ar reference standard age. The results of this work support the following paleoanthropologically relevant conclusions: 1) the early Acheulean site EF-HR (Loc 12a) is situated above the level of Hay's Tuff IIC, and thus sits in Upper rather than Middle Bed II, (2) the HWK EE (Loc 42) Oldowan site is constrained between Tuff IIA and Tuff IIB, just above the boundary between Lower and Middle Bed II, and 3) the Acheulean site at FLK W most likely lies within the Middle Augitic Sandstone, above Tuff IIB, similar to the placements by Leakey and Hay for the earliest Acheulean at Olduvai

Dating the Naisiusiu Beds, Olduvai Gorge, by electron spin resonance

Science.gov (United States)

Skinner, A. R.; Hay, R. L.; Masao, F.; Blackwell, B. A. B.

2003-05-01

The lower beds at Olduvai Gorge are well known for containing early hominid fossils and Oldowan stone tools, and their ages have been established by 40Ar/ 39Ar dating and paleomagnetic stratigraphy. Ages are generally less certain for the upper deposits at Olduvai Gorge because of the scarcity of datable tuffs. The youngest archaeologically significant site at Olduvai is microlithic LSA, which lies in the type section of the Naisiusiu Beds. The age for the site is controversial, with 14C dates of 17,000-17,550 (Hay, R.L., 1976 Geology of Olduvai Gorge, University of California Press, Berkeley) and >42,000 BP (Manega, P.C., 1993. Geochronology, geochemistry, and isotopic study of the Plio-Pleistocene Hominid sites and the Ngorongoro Volcanic Highland in Northern Tanzania. Unpublished Ph.D. Thesis, University of Colorado, Boulder, CO). The tuff bed in the zone with artifacts does not contain materials datable by 40Ar/ 39Ar, and some other dating method was needed. In the summer of 2001, five equid teeth were collected from the type Naisiusiu site. Another tooth had previously been collected. ESR ages have been determined for three teeth from the archaeological level and their ages cluster around 62±5 ka, assuming linear uranium uptake. Another tooth from a level without artifacts and believed to be significantly younger dated to 39±5 ka, again assuming LU. These dates are considerably older than previous estimates and suggest that the East African MSA/LSA transition occurred very early.

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.

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)

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

7 CFR 2902.15 - Bedding, bed linens, and towels.

Science.gov (United States)

2010-01-01

... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

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 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.

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

Evaluation of a clay-based acidic bedding conditioner for dairy cattle bedding.

Science.gov (United States)

Proietto, R L; Hinckley, L S; Fox, L K; Andrew, S M

2013-02-01

This study investigated the effects of a clay-based acidic bedding conditioner on sawdust bedding pH, dry matter (DM), environmental pathogen counts, and environmental bacterial counts on teat ends of lactating dairy cows. Sixteen lactating Holstein cows were paired based on parity, days in milk, milk yield, and milk somatic cell count, and were negative for the presence of an intramammary pathogen. Within each pair, cows were randomly assigned to 1 of 2 treatments with 3-wk periods in a crossover design. Treatment groups consisted of 9 freestalls per group bedded with either untreated sawdust or sawdust with a clay-based acidic bedding conditioner, added at 3- to 4-d intervals over each 21-d period. Bedding and teat ends were aseptically sampled on d 0, 1, 2, 7, 14, and 21 for determination of environmental bacterial counts. At the same time points, bedding was sampled for DM and pH determination. The bacteria identified in the bedding material were total gram-negative bacteria, Streptococcus spp., and coliform bacteria. The bacteria identified on the teat ends were Streptococcus spp., coliform bacteria, and Klebsiella spp. Teat end score, milk somatic cell count, and intramammary pathogen presence were measured weekly. Bedding and teat cleanliness, environmental high and low temperatures, and dew point data were collected daily. The bedding conditioner reduced the pH, but not the DM, of the sawdust bedding compared with untreated sawdust. Overall environmental bacterial counts in bedding were lower for treated sawdust. Total bacterial counts in bedding and on teat ends increased with time over both periods. Compared with untreated sawdust, the treated bedding had lower counts of total gram-negative bacteria and streptococci, but not coliform counts. Teat end bacterial counts were lower for cows bedded on treated sawdust for streptococci, coliforms, and Klebsiella spp. compared with cows bedded on untreated sawdust. The clay-based acidic bedding conditioner

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.

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.

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

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.

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.

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.

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.

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.

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)

Modules for estimating solid waste from fossil-fuel technologies

International Nuclear Information System (INIS)

Crowther, M.A.; Thode, H.C. Jr.; Morris, S.C.

1980-10-01

Solid waste has become a subject of increasing concern to energy industries for several reasons. Increasingly stringent air and water pollution regulations result in a larger fraction of residuals in the form of solid wastes. Control technologies, particularly flue gas desulfurization, can multiply the amount of waste. With the renewed emphasis on coal utilization and the likelihood of oil shale development, increased amounts of solid waste will be produced. In the past, solid waste residuals used for environmental assessment have tended only to include total quantities generated. To look at environmental impacts, however, data on the composition of the solid wastes are required. Computer modules for calculating the quantities and composition of solid waste from major fossil fuel technologies were therefore developed and are described in this report. Six modules have been produced covering physical coal cleaning, conventional coal combustion with flue gas desulfurization, atmospheric fluidized-bed combustion, coal gasification using the Lurgi process, coal liquefaction using the SRC-II process, and oil shale retorting. Total quantities of each solid waste stream are computed together with the major components and a number of trace elements and radionuclides

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.

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

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.)

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

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)

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....

A simulation of a pebble bed reactor core by the MCNP-4C computer code

Directory of Open Access Journals (Sweden)

Bakhshayesh Moshkbar Khalil

2009-01-01

Full Text Available Lack of energy is a major crisis of our century; the irregular increase of fossil fuel costs has forced us to search for novel, cheaper, and safer sources of energy. Pebble bed reactors - an advanced new generation of reactors with specific advantages in safety and cost - might turn out to be the desired candidate for the role. The calculation of the critical height of a pebble bed reactor at room temperature, while using the MCNP-4C computer code, is the main goal of this paper. In order to reduce the MCNP computing time compared to the previously proposed schemes, we have devised a new simulation scheme. Different arrangements of kernels in fuel pebble simulations were investigated and the best arrangement to decrease the MCNP execution time (while keeping the accuracy of the results, chosen. The neutron flux distribution and control rods worth, as well as their shadowing effects, have also been considered in this paper. All calculations done for the HTR-10 reactor core are in good agreement with experimental results.

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...

Palaeoenvironmental signatures revealed from rare earth element (REE compositions of vertebrate microremains of the Vesiku Bone Bed (Homerian, Wenlock, Saaremaa Island, Estonia

Directory of Open Access Journals (Sweden)

Alexandre Fadel

2015-02-01

Full Text Available Rare earth elements (REEs have been analysed from fossil vertebrate microremains (thelodont scales from the Vesiku Bone Bed, Saaremaa, Estonia, using in situ microsampling by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS. Well-preserved scales of three species of the genus Thelodus (T. carinatus, T. laevis and Thelodus sp. show very uniform REE patterns with slightly lower overall REE concentrations in enameloid than in dentine, with enrichment in middle REEs, depletion in heavy REEs and pronounced negative europium anomaly, but no cerium anomaly. The results of this study suggest a similar diagenetic history and possibly contemporaneous habitats for all three Thelodus species, as well as possible suboxic to anoxic conditions of the bottom and pore waters during the formation of the Vesiku Bone Bed.

Management bedding : vrijloopstal met composterende bedding van houtsnippers

NARCIS (Netherlands)

Boer, de H.C.; Wiersma, M.; Galama, P.J.; Szanto, G.L.

2015-01-01

In de vrijloopstal liggen de koeien meestal op een organische bedding en scheiden daar mest (feces en urine) uit. Om de bedding voldoende droog en schoon te houden wordt er regelmatig nieuw strooisel aangevoerd en wordt de toplaag bewerkt. Op basis van onderzoek- en praktijkervaringen tot nu toe

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.

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

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

Effect of bed particles to combustion of gases in fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Raiko, R.; Wallen, V.; Etelaeaho, R.; Correia, S. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

1997-10-01

The objective of this project was to obtain experimental data on effects of sand particles to the combustion of gases. The effect of the surface area of the particles was tested using different sized particles. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 42 mm surrounded by an electric heater. The test rig was built in the Laboratory of Energy and Process Engineering at Tampere University of Technology. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies were conducted with both fresh bed particles and used bed particles. These measurements indicate that carbon monoxide significantly reacts with oxygen in the particulate or emulsion phase of a fluidized bed, if the residence time is long enough. The reaction rate depends mainly on temperature, air coefficient, residence time and particle size of the solids. It seems that the combustion enhances if the average particle size increases. Whether this is caused by increased free path length or reduced specific surface area of the bed is yet unknown. The first might be more probable cause because the majority of reactions often took place in the freeboard right above the bed. It was clear that the bed hindered proper combustion in several cases. (orig.)

Bed retained products in swept fixed bed (SFB) coal hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Mastral, A.M.; Perez-Surio, M.J. [CSIC, Zaragosa (Spain). Inst. de Carboquimica

1997-12-31

The hydropyrolysis of a low rank coal in a swept fixed bed (SFB) reactor is carried out by fixing the hydrogen pressure (40 kg/cm{sup 2}), the hydrogen flow (2 l/min) and the residence time (10 min) at increasing temperatures (400 C, 500 C and 600 C) and coal bed heights (h, 1.5h, 2h, 2.5h and 3h). It is shown that the percentages of tars and char directly depend on the coal bed height and that there is not only a quantitative dependence, but also the height of the coal bed is very important and plays a relevant role on the nature of the conversion products. (orig.)

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.

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.

Flue gas cleanup using the Moving-Bed Copper Oxide Process

Energy Technology Data Exchange (ETDEWEB)

Pennline, Henry W; Hoffman, James S

2013-10-01

The use of copper oxide on a support had been envisioned as a gas cleanup technique to remove sulfur dioxide (SO{sub 2}) and nitric oxides (NO{sub x}) from flue gas produced by the combustion of coal for electric power generation. In general, dry, regenerable flue gas cleanup techniques that use a sorbent can have various advantages, such as simultaneous removal of pollutants, production of a salable by-product, and low costs when compared to commercially available wet scrubbing technology. Due to the temperature of reaction, the placement of the process into an advanced power system could actually increase the thermal efficiency of the plant. The Moving-Bed Copper Oxide Process is capable of simultaneously removing sulfur oxides and nitric oxides within the reactor system. In this regenerable sorbent technique, the use of the copper oxide sorbent was originally in a fluidized bed, but the more recent effort developed the use of the sorbent in a moving-bed reactor design. A pilot facility or life-cycle test system was constructed so that an integrated testing of the sorbent over absorption/regeneration cycles could be conducted. A parametric study of the total process was then performed where all process steps, including absorption and regeneration, were continuously operated and experimentally evaluated. The parametric effects, including absorption temperature, sorbent and gas residence times, inlet SO{sub 2} and NO{sub x} concentration, and flyash loadings, on removal efficiencies and overall operational performance were determined. Although some of the research results have not been previously published because of previous collaborative restrictions, a summary of these past findings is presented in this communication. Additionally, the potential use of the process for criteria pollutant removal in oxy-firing of fossil fuel for carbon sequestration purposes is discussed.

In-bed accountability of tritium in production scale metal hydride storage beds

International Nuclear Information System (INIS)

Klein, J.E.

1995-01-01

An ''in-bed accountability'' (IBA) flowing gas calorimetric measurement method has been developed and implemented to eliminate the need to remove tritium from production scale metal hydride storage beds for inventory measurement purposes. Six-point tritium IBA calibration curves have been completed for two, 390 gram tritium metal hydride storage beds. The calibration curves for the two tritium beds are similar to those obtained from the ''cold'' test program. Tritium inventory errors at the 95 percent confidence level ranged from ± 7.3 to 8.6 grams for the cold test results compared to ± 4.2 to 7.5 grams obtained for the two tritium calibrated beds

Revised stratigraphy of Area 123, Koobi Fora, Kenya, and new age estimates of its fossil mammals, including hominins.

Science.gov (United States)

Gathogo, Patrick N; Brown, Francis H

2006-11-01

Recent geologic study shows that all hominins and nearly all other published mammalian fossils from Paleontological Collection Area 123, Koobi Fora, Kenya, derive from levels between the KBS Tuff (1.87+/-0.02 Ma) and the Lower Ileret Tuff (1.53+/-0.01 Ma). More specifically, the fossils derive from 53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, especially those units containing molluscs and algal stromatolites. The upper Burgi Member (approximately 2.00-1.87 Ma) crops out only in the southwestern part of Area 123. Adjacent Area 110 contains larger exposures of the member, and there the KBS Tuff is preserved as an airfall ash in lacustrine deposits and also as a fluvially redeposited ash. We observed no mammalian fossils in situ in this member in Area 123, but surface specimens have been documented in some monographic treatments. Fossil hominins from Area 123 were attributed to strata above the KBS Tuff in the 1970s, but later they were assigned to strata below the KBS Tuff (now called the upper Burgi Member). This study definitively places the Area 123 hominins in the KBS Member. Most of these hominins are between 1.60 and 1.65 myr in age, but the youngest may date to only 1.53 Ma, and the oldest, to 1.75 Ma. All are 0.15-0.30 myr younger than previously estimated. The new age estimates, in conjunction with published taxonomic attributions of fossils, suggest that at least two species of Homo coexisted in the region along with A. boisei until at least 1.65 Ma. Comparison of crania KNM-ER 1813 and KNM-ER 1470, which were believed to be of comparable age, is at the focus of the debate over whether Homo habilis sensu lato is in fact composed of two species: Homo habilis and Homo rudolfensis. These two crania are separated in time by approximately 0.25 myr, and therefore, arguments for their conspecificity no longer need to confront the issue of unusually high contemporaneous variation within a single species.

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)

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)

Thermal Analysis of Fluidized Bed and Fixed Bed Latent Heat Thermal Storage System

Science.gov (United States)

Beemkumar, N.; Karthikeyan, A.; Shiva Keshava Reddy, Kota; Rajesh, Kona; Anderson, A.

2017-05-01

Thermal energy storage technology is essential because its stores available energy at low cost. Objective of the work is to store the thermal energy in a most efficient method. This work is deal with thermal analysis of fluidized bed and fixed bed latent heat thermal storage (LHTS) system with different encapsulation materials (aluminium, brass and copper). D-Mannitol has been used as phase change material (PCM). Encapsulation material which is in orbicular shape with 4 inch diameter and 2 mm thickness orbicular shaped product is used. Therminol-66 is used as a heat transfer fluid (HTF). Arrangement of encapsulation material is done in two ways namely fluidized bed and fixed bed thermal storage system. Comparison was made between the performance of fixed bed and fluidized bed with different encapsulation material. It is observed that from the economical point of view aluminium in fluidized bed LHTS System has highest efficiency than copper and brass. The thermal energy storage system can be analyzed with fixed bed by varying mass flow rate of oil paves a way to find effective heat energy transfer.

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

Bed care for patients in palliative settings: considering risks to caregivers and bed surfaces.

Science.gov (United States)

Fragala, Guy

2015-02-01

Ensuring patients are comfortable in bed is key to effective palliative care, but when moving and positioning patients in bed, health professionals face an occupational risk of injury. The turning and positioning (TAP) system is a new method of moving patients in bed, that evidence has shown to reduce the risk of injury to caregivers. Providing the correct bed surface is another aspect of bed care essential to the comfort of the palliative patient, and to aid wound prevention and treatment. It is important to take a patient-centred approach when considering the most appropriate bed surface patients. This article provides an overview and discussion of these two aspects of bed care for palliative patients.

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....

Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

International Nuclear Information System (INIS)

Campos-Diaz, K. E.; Limas-Ballesteros, R.

2009-01-01

Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

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.

Cleaning of porous filters in fossilized bed reactors; Estudio de limpieza de filtros porosos en reactores de lecho fluidizado

Energy Technology Data Exchange (ETDEWEB)

Rodrigo Otero, A; Sancho Rod, J

1965-07-01

In this report are established the optimum working conditions of a filter cleaning system by blow back. For this purpose it was determined in the first place the blow back air rate necessary to have a good cleaning. The reasons for which it was not possible until now to control the pressure in a fluidized bed calcination reactor are analyzed and a criteria is established to calculate the optimum floe necessary to clean efficiently a porous by this procedures. (Author)

The stratigraphic distribution of large marine vertebrates and shell beds in the Pliocene of Tuscany

Science.gov (United States)

Dominici, Stefano; Benvenuti, Marco; Danise, Silvia

2015-04-01

The record of 337 shark fossils, 142 cetaceans and 10 sea cows from the Pliocene of Tuscany, mostly from historical museum collections, is revised. The majority of these fossils are concentrated at a few geographic sites from separated hinterland basins, on the South-Western side of the Northern Apennines. To better understand the meaning of these concentrations, the sequence stratigraphic distribution of more recent findings of large marine vertebrates is reconstructed against a high-resolution framework based on sedimentary facies analysis. These remains are usually covered by, or included in mudstones deposited far from the coast (N=12), skeletons being usually articulated, slightly displaced, and often bioeroded. A minor part of better preserved articulated skeletons is associated with sandstones from deltaic paleonenvironments (N=2). Marine mammal and shark remains may be associated with laterally-continuous shell accumulations, a type of concentration occurring at maximum flooding surfaces, separating relatively coarse-grained facies from open marine mudstones. Shell beds were bulk-sampled at 66 locations from six basins, covering a wide range of sedimentary facies, and spanning a chronologic interval of about 2.5 million years. A dataset of 62,655 mollusc specimens belonging to 496 species formed the basis of a statistical study to reconstruct the structure of the benthic communities, and to estimate paleodepths from intertidal to upper bathyal settings. Mollusc associations closely mirror the distribution of sedimentary facies, allowing for a fine tuning of the sequence stratigraphic architecture. Merging paleogeographic, stratigraphic and paleoecologic data, we conclude that the more abundant and diverse accumulations of large vertebrates took place in settings under the influence of coastal upwelling. A modern analogue occurs today in the Ligurian Sea, on the Tuscan offshore, where abundant nutrients carried by deep-marine currents of Western origin

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.

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.

Design and optimization of a fixed - bed reactor for hydrogen production via bio-ethanol steam reforming

International Nuclear Information System (INIS)

Maria A Goula; Olga A Bereketidou; Costas G Economopoulos; Olga A Bereketidou; Costas G Economopoulos

2006-01-01

Global climate changes caused by CO 2 emissions are currently debated around the world. Renewable sources of energy are being sought as alternatives to replace fossil fuels. Hydrogen is theoretically the best fuel, environmentally friendly and its combustion reaction leads only to the production of water. Bio-ethanol has been proven to be effective in the production of hydrogen via steam reforming reaction. In this research the steam reforming reaction of bio-ethanol is studied at low temperatures over 15,3 % Ni/La 2 O 3 catalyst. The reaction and kinetic analysis takes place in a fixed - bed reactor in 130 - 250 C in atmospheric pressure. This study lays emphasis on the design and the optimization of the fixed - bed reactor, including the total volume of the reactor, the number and length of the tubes and the degree of ethanol conversion. Finally, it is represented an approach of the total cost of the reactor, according to the design characteristics and the materials that can be used for its construction. (authors)

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)

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)

Pebble-bed reactor

International Nuclear Information System (INIS)

Lohnert, G.; Mueller-Frank, U.; Heil, J.

1976-01-01

A pebble-bed nuclear reactor of large power rating comprises a container having a funnel-shaped bottom forming a pebble run-out having a centrally positioned outlet. A bed of downwardly-flowing substantially spherical nuclear fuel pebbles is positioned in the container and forms a reactive nuclear core maintained by feeding unused pebbles to the bed's top surface while used or burned-out pebbles run out and discharge through the outlet. A substantially conical body with its apex pointing upwardly and its periphery spaced from the periphery of the container spreads the bottom of the bed outwardly to provide an annular flow down the funnel-shaped bottom forming the runout, to the discharge outlet. This provides a largely constant downward velocity of the spheres throughout the diameter of the bed throughout a substantial portion of the down travel, so that all spheres reach about the same burned-out condition when they leave the core, after a single pass through the core area

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.

The Safety of Hospital Beds

Science.gov (United States)

Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

2015-01-01

To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

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

Fluid-bed combustion

Energy Technology Data Exchange (ETDEWEB)

Hunt, G.; Schoebotham, N.

1981-02-01

In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

Apparatus for controlling fluidized beds

Science.gov (United States)

Rehmat, A.G.; Patel, J.G.

1987-05-12

An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

Experimental study of flow field characteristics on bed configurations in the pebble bed reactor

International Nuclear Information System (INIS)

Jia, Xinlong; Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jia, Haijun; Jiang, Shengyao

2017-01-01

Highlights: • PTV study of flow fields of pebble bed reactor with different configurations are carried out. • Some criteria are proposed to quantify vertical velocity field and flow uniformity. • The effect of different pebble bed configurations is also compared by the proposed criteria. • The displacement thickness is used analogically to analyze flow field characteristics. • The effect of mass flow variation in the stagnated region of the funnel flow is measured. - Abstract: The flow field characteristics are of fundamental importance in the design work of the pebble bed high temperature gas cooled reactor (HTGR). The different effects of bed configurations on the flow characteristics of pebble bed are studied through the PTV (Particle Tracking Velocimetry) experiment. Some criteria, e.g. flow uniformity (σ) and mass flow level (α), are proposed to estimate vertical velocity field and compare the bed configurations. The distribution of the Δθ (angle difference between the individual particle velocity and the velocity vector sum of all particles) is also used to estimate the resultant motion consistency level. Moreover, for each bed configuration, the thickness of displacement is analyzed to measure the effect of the funnel flow zone based on the boundary layer theory. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity and other characteristics; and the sequence of levels of each estimation criterion is obtained for all bed configurations. In addition, a good design of the pebble bed configuration is suggested and these estimation criteria can be also applied and adopted in testing other geometry designs of pebble bed.

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)

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.

Bed diameter effects and incipient slugging in gas fluidized beds

International Nuclear Information System (INIS)

Agarwal, P.K.

1986-01-01

The coalescence and growth of bubble swarms formed at the distributor of a fluidized bed gives rise to lateral as well as vertical distributions of bubble properties. However, existing models employ average bubble properties obtained largely from semi-empirical considerations. In a recent Paper, the author developed a bubble growth model based on a population balance approach. Analytical expressions were derived for the bubble characteristic distributions and averages. However, the model, developed for unconstrained growth, did not take into account the effect of the bed diameter and the possibility of slugging. In this Paper, the model is extended to take these aspects into account. A slugging criterion is also developed which is expected to be valid for the regime where incipient slugging depends on the bed height as well as the region where bed height does not significantly affect minimum slugging conditions

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

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

Effect of bed configuration on pebble flow uniformity and stagnation in the pebble bed reactor

International Nuclear Information System (INIS)

Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jiang, Shengyao

2014-01-01

Highlights: • Pebble flow uniformity and stagnation characteristics are very important for HTR-PM. • Arc- and brachistochrone-shaped configuration effects are studied by DEM simulation. • Best bed configurations with uniform flow and no stagnated pebbles are suggested. • Detailed quantified characteristics of bed configuration effects are shown for explanation. - Abstract: Pebble flow uniformity and stagnation characteristics are very important for the design of pebble bed high temperature gas-cooled reactor. Pebble flows inside some specifically designed contraction configurations of pebble bed are studied by discrete element method. The results show the characteristics of stagnation rates, recycling rates, radial distribution of pebble velocity and residence time. It is demonstrated clearly that the bed with a brachistochrone-shaped configuration achieves optimum levels of flow uniformity and recycling rate concentration, and almost no pebbles are stagnated in the bed. Moreover, the optimum choice among the arc-shaped bed configurations is demonstrated too. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity. In addition, a good design of the pebble bed configuration is suggested

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.

Experimental Simulation of Methane Hydrate Extraction at High Pressure Conditions: Influence of the Sediment Bed

Science.gov (United States)

Agudo, J. R.; Park, J.; Luzi, G.; Williams, M.; Rauh, C.; Wierschem, A.; Delgado, A.

2017-10-01

Being a clean alternative to other fossil fuels, Methane Hydrate (MH) is currently considered as one of the most important potential sources for hydrocarbon fuels [1]. In addition, the high energy density of MH and its stability at higher temperatures as compared to LNG (Liquefied Natural Gas) makes MH a potential greener method for energy transportation. At the same time, the low thermodynamic stability of MH strongly questions the future exploitation of gas hydrate deposits, turning its extraction into a possible geohazard [2]. Fluctuations in pressure, temperature, salinity, degree of saturation or sediment bed properties may cause methane gas release from the water lattice. We experimentally study the influence of the sediment bed geometry during formation-dissociation of MH. For this purpose, MH is synthesized within regular substrates in a 93 cm3 high pressure vessel. The regular substrates are triangular and quadratic arrangements of identical glass spheres with a diameter of 2 and 5 mm, respectively. MH formation within regular substrate reduces the possibility of spontaneous nucleation to a unique geometrical configuration. This fact permits us to characterize the kinetics of MH formation-dissociation as a function of the sediment bed geometry. Preliminary experimental results reveal a strong dependence of MH formation on the geometry of the regular substrate. For instance, under the same pressure and temperature, the kinetics of MH production is found to change by a factor 3 solely depending on the substrate symmetry, i.e. triangular or quadratic.

Visualization of bed material movement in a simulated fluidized bed heat exchanger by neutron radiography

International Nuclear Information System (INIS)

Umekawa, Hisashi; Ozawa, Mamoru; Takenaka, Nobuyuki; Matsubayashi, Masahito

1999-01-01

The bulk movement of fluidized bed material was visualized by neutron radiography by introducing tracers into the bed materials. The simulated fluidized bed consisted of aluminum plates, and the bed material was sand of 99.7% SiO 2 (mean diameter: 0.218 mm, density: 2555 kg/m 3 ). Both materials were almost transparent to neutrons. Then the sand was colored by the contamination of the sand coated by CdSO 4 . Tracer particles of about 2 mm diameter were made by the B 4 C, bonded by the vinyl resin. The tracer was about ten times as large as the particle of fluidized bed material, but the traceability was enough to observe the bed-material bulk movement owing to the large effective viscosity of the fluidized bed. The visualized images indicated that the bubbles and/or wakes were important mechanism of the behavior of the fluidized bed movement

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

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

Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

Energy Technology Data Exchange (ETDEWEB)

Badger, Phillip C.; Dunn, Jr., Kenneth J.

2015-09-01

A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

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

Fluidised bed combustion system

International Nuclear Information System (INIS)

McKenzie, E.C.

1976-01-01

Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

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.

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.

WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

Energy Technology Data Exchange (ETDEWEB)

Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-05-06

This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

International Nuclear Information System (INIS)

Hansen, E. K.

2015-01-01

This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

Bacillus cereus in free-stall bedding.

Science.gov (United States)

Magnusson, M; Svensson, B; Kolstrup, C; Christiansson, A

2007-12-01

To increase the understanding of how different factors affect the bacterial growth in deep sawdust beds for dairy cattle, the microbiological status of Bacillus cereus and coliforms in deep sawdust-bedded free stalls was investigated over two 14-d periods on one farm. High counts of B. cereus and coliforms were found in the entire beds. On average, 4.1 log(10) B. cereus spores, 5.5 log(10) B. cereus, and 6.7 log(10) coliforms per gram of bedding could be found in the upper layers of the sawdust likely to be in contact with the cows' udders. The highest counts of B. cereus spores, B. cereus, and coliforms were found in the bedding before fresh bedding was added, and the lowest immediately afterwards. Different factors of importance for the growth of B. cereus in the bedding material were explored in laboratory tests. These were found to be the type of bedding, pH, and the type and availability of nutrients. Alternative bedding material such as peat and mixtures of peat and sawdust inhibited the bacterial growth of B. cereus. The extent of growth of B. cereus in the sawdust was increased in a dose-dependent manner by the availability of feces. Urine added to different bedding material raised the pH and also led to bacterial growth of B. cereus in the peat. In sawdust, a dry matter content greater than 70% was needed to lower the water activity to 0.95, which is needed to inhibit the growth of B. cereus. In an attempt to reduce the bacterial growth of B. cereus and coliforms in deep sawdust beds on the farm, the effect of giving bedding daily or a full replacement of the beds was studied. The spore count of B. cereus in the back part of the free stalls before fresh bedding was added was 0.9 log units lower in stalls given daily bedding than in stalls given bedding twice weekly. No effect on coliform counts was found. Replacement of the entire sawdust bedding had an effect for a short period, but by 1 to 2 mo after replacement, the counts of B. cereus spores in the

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

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)

Astronomical cycle origin of bedded chert: A middle Triassic bedded chert sequence, Inuyama, Japan

Science.gov (United States)

Ikeda, Masayuki; Tada, Ryuji; Sakuma, Hironobu

2010-09-01

Astronomical forcing is one of the main drivers of climate change, and astronomical cyclicity recorded in sediments provides a clue to understand the dynamics of the global climate system. Bedded cherts consist of rhythmic alternations of chert and shale beds. Although previous studies have hypothesized that the origin of bedded chert is related to astronomical cycles (e.g. Fischer, 1976; Hori et al., 1993), conclusive proof remains elusive. To explore this possibility, we established a continuous, high-resolution lithostratigraphy of middle Triassic bedded chert in Central Japan. The average duration of each chert-shale couplet is 20 kyr, similar to that of the precession cycle. Spectral analysis of a bed number series of thickness variations in chert beds was performed assuming that each chert-shale couplet represents a 20-kyr precession cycle. The results reveal cycles involving approximately 200, 20, 5, and 2-3 beds, corresponding to periodicities of approximately 4000, 400, 100, and 40-60 kyr, respectively. By further assuming that the 20-bed cycle represents a 405-kyr eccentricity cycle of constant and stable periodicity, we converted the bed number series to a time series. Spectral analysis of the time series revealed distinct periodicities of 3600, 117, 97, and 38 kyr, in addition to 405 kyr. Besides 3600 kyr, these periodicities agree well with the 120, 95, and 37 kyr periodicities for eccentricity cycles and the obliquity cycle during the Triassic. Moreover, we detected amplitude modulation of the approximately 100-kyr cycle of thickness variations in chert beds with a 405-kyr periodicity, which may correspond to amplitude modulation of 100-kyr climatic precession cycle with the 405-kyr periodicity. The approximately 3600-kyr periodicity described above and 1800-kyr periodicity manifested as the amplitude modulation of the 405-kyr cycle are correlated to present-day long-term eccentricity cycles of 2400 and 4800 kyr evolved by chaotic behavior of solar

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.

Application of CaO-Based Bed Material for Dual Fluidized Bed Steam Biomass Gasification

Science.gov (United States)

Koppatz, S.; Pfeifer, C.; Kreuzeder, A.; Soukup, G.; Hofbauer, H.

Gasification of biomass is a suitable option for decentralized energy supply based on renewable sources in the range of up to 50 MW fuel input. The paper presents the dual fluidized bed (DFB) steam gasification process, which is applied to generate high quality and nitrogen-free product gas. Essential part of the DFB process is the bed material used in the fluidized reactors, which has significant impact on the product gas quality. By the use of catalytically active bed materials the performance of the overall process is increased, since the bed material favors reactions of the steam gasification. In particular, tar reforming reactions are favored. Within the paper, the pilot plant based on the DFB process with 100kW fuel input at Vienna University of Technology, Austria is presented. Actual investigations with focus on CaO-based bed materials (limestone) as well as with natural olivine as bed material were carried out at the pilot plant. The application of CaO-based bed material shows mainly decreased tar content in the product gas in contrast to experiments with olivine as bed material. The paper presents the results of steam gasification experiments with limestone and olivine, whereby the product gas composition as well as the tar content and the tar composition are outlined.

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.

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.

Biodegradation of phenolic waste liquors in stirred-tank, packed-bed, and fluidized-bed bioreactors

Energy Technology Data Exchange (ETDEWEB)

Holladay, D W; Hancher, G W; Chilcote, D D; Scott, C D

1978-11-01

The biological degradation of phenolic scrub liquors similar to those that arise in coal conversion processes was studied for symbiotic bacterial populations contained in a continuously stirred tank bioreactor, a three-phase packed-bed bioreactor, and a three-phase, fluidized-bed bioreactor. The conversions of phenol compounds were comparable in the three-phase, packed-bed bioreactor and the continuously stirred tank bioreactor; however, the packed-bed bioreactor degradation rates were as much as twice those in the continuously stirred tank bioreactor, and packed-bed bioreactor retention times were as low as one- tenth those of the continuously stirred tank bioreactors (minimum time was 12 hours).

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)

Bed and bed-site reuse by western lowland gorillas (Gorilla g. gorilla) in Moukalaba-Doudou National Park, Gabon.

Science.gov (United States)

Iwata, Yuji; Ando, Chieko

2007-01-01

In this paper we describe bed (nest) and bed-site reuse by western lowland gorillas (Gorilla g. gorilla) in Moukalaba-Doudou National Park, south-eastern Gabon. During an eight-month study 44 bed sites and 506 beds were found. Among these, 38.6% of bed sites and 4.1% of beds were reused. We analyzed the monthly frequency of bed-site reuse in relation to rainfall, fruit abundance, and fruit consumption by the gorillas. The different frequency of bed-site reuse in the rainy and dry seasons was not significant. More bed-site reuse was observed during the fruiting season than during the non-fruiting season. Results from fecal analysis suggested that gorillas ate more fruit in the fruiting season than in the non-fruiting season. The frugivorous diet of western gorillas may possibly cause gorillas to stay in some areas and, consequently, reuse their bed sites. Reuse of bed sites by gorillas suggests their frequent return to an area where preferred fruit is readily available. A higher percentage of arboreal beds may also affect bed-site reuse, because of the shortage of bed material.

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.)

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

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.

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

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 effect of vibration on bed voidage behaviors in fluidized beds with large particles

Directory of Open Access Journals (Sweden)

H. Jin

2007-09-01

Full Text Available The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s-1, amplitude (0 mm-1 mm, bed height (0.1 m-0.4 m as well as four kinds of particles (belonging to Geldart's B and D groups. The axial and radial voidage distribution with vibration is compared with that without vibration, which shows vibration can aid in the fluidization behaviors of particles. For a larger vibration amplitude, the vibration seriously affects bed voidage. The vibration energy can damp out for particle layers with increasing the bed height. According to analysis of experimental data, an empirical correlation for predicting bed voidage, giving good agreement with the experimental data and a deviation within ±15%, was proposed.

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.

Loading and Unloading Weaned Pigs: Effects of Bedding Types, Ramp Angle, and Bedding Moisture

Directory of Open Access Journals (Sweden)

Arlene Garcia

2014-12-01

Full Text Available The use of non-slip surfaces during loading and unloading of weaned pigs plays an important role in animal welfare and economics of the pork industry. Currently, the guidelines available only suggest the use of ramps below 20° to load and unload pigs. Three ramp angles (0°, 10° or 20°, five bedding materials (nothing, sand, feed, wood shavings or wheat straw hay, two moistures (dry or wet bedding; >50% moisture over two seasons (>23.9 °C summer, <23.9 °C winter were assessed for slips/falls/vocalizations (n = 6,000 pig observations. “Score” was calculated by the sum of slips, falls, and vocalizations. With the exception of using feed as a bedding, all beddings provided some protection against elevated slips, falls, and vocalizations (P < 0.01. Providing bedding reduced (P < 0.05 scores regardless of whether the bedding was dry or wet. Scores increased as the slope increased (P < 0.01. Provision of bedding, other than feed, at slopes greater than zero, decreased slips, falls and vocalizations. The total time it took to load and unload pigs was

Experimental studies on the coolability of packed beds. Flooding of hot dry packed beds

International Nuclear Information System (INIS)

Leininger, S.; Kulenovic, R.; Laurien, E.

2013-01-01

In case of a severe accident in a nuclear power plant meltdown of the reactor core can occur and form a packed bed in the lower plenum of the reactor pressure vessel (RPV) after solidification due to contact with water. The removal of after-heat and the long-term coolability is of essential interest. The efficient injection of cooling water into the packed bed has to be assured without endangering the structural integrity of the reactor pressure vessel. The experiments performed aimed to study the dry-out and the quenching (flooding) of hot dry packed beds. Two different inflow variants, bottom- and top-flooding including the variation of the starting temperature of the packed bed and the injection rate were studied. In case of bottom flooding the quenching time increases with increasing packed bed temperature and decreasing injection rate. In case of top flooding the flow pattern is more complex, in a first phase the water flows preferentially toward the RPV wall, the flow paths conduct the water downwards. The flow resistance of the packed bed increases with increasing bed temperatures. The quenching temperatures increase significantly above average.

Environmental protection stability of river bed and banks using convex, concave, and linear bed sills.

Science.gov (United States)

Keshavarzi, Alireza; Noori, Lila Khaje

2010-12-01

River bed scourings are a major environmental problem for fish and aquatic habitat resources. In this study, to prevent river bed and banks from scouring, different types of bed sills including convex, concave and linear patterns were installed in a movable channel bed in a laboratory flume. The bed sills were tested with nine different arrangements and under different flow conditions. To find the most effective bed sill pattern, the scouring depth was measured downstream of the bed sill for a long experimental duration. The scour depth was measured at the middle and at the end of each experimental test for different ratios of the arch radius to the channel width [r/w]. The experimental results indicated that the convex pattern with r/w=0.35 produced minimum bed scouring depth at the center line whereas the concave pattern with r/w=0.23 produced the minimum scour depth at the wall banks. Therefore, the convex pattern was the most effective configuration for prevention of scouring at the center line of the river while the concave pattern was very effective to prevent scouring at the river banks. These findings can be suggested to be used in practical applications.

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.)

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.

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

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.

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

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

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.

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.

The effect of bed non-uniformities and porosity of particles on dryout in boiling particle beds

International Nuclear Information System (INIS)

Macbeth, R.V.; Mogford, D.J.; Willshire, S.J.

1988-03-01

This report relates to an on-going experimental programme concerned with the coolability of beds of reactor core debris or rubble immersed in a liquid coolant, as might occur in an accident situation. The objectives are to develop experimental techniques, improve the understanding of bed cooling mechanisms, determine dry-out limitations of various bed configurations and particle shapes and sizes and devise ways of improving bed coolability. The report concentrates on a recently discovered effect on bed coolability of particle porosity, such as exists in fragmented UO 2 fuel pellets. It is shown that porosity can lower bed dry-out powers by a factor of 4 or 5. A mechanism which explains the effect is presented. The report also gives results of bed non-uniformities obtained by mixing glass particles with the dielectrically heated 'ferrite' particles used in the experiments. (author)

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.

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.

Education Program on Fossil Resources Including Coal

Science.gov (United States)

Usami, Masahiro

Fossil fuels including coal play a key role as crucial energies in contributing to economic development in Asia. On the other hand, its limited quantity and the environmental problems causing from its usage have become a serious global issue and a countermeasure to solve such problems is very much demanded. Along with the pursuit of sustainable development, environmentally-friendly use of highly efficient fossil resources should be therefore, accompanied. Kyushu-university‧s sophisticated research through long years of accumulated experience on the fossil resources and environmental sectors together with the advanced large-scale commercial and empirical equipments will enable us to foster cooperative research and provide internship program for the future researchers. Then, this program is executed as a consignment business from the Ministry of Economy, Trade and Industry from 2007 fiscal year to 2009 fiscal year. The lecture that uses the textbooks developed by this program is scheduled to be started a course in fiscal year 2010.

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,

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

Air gasification of agricultural waste in a fluidized bed gasifier: hydrogen production performance

Energy Technology Data Exchange (ETDEWEB)

Wan Ab Karim Ghani, W. A.; Moghadam, R. A.; Mohd Salleh, M. A. [Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Alias, A. B. [Chemical Engineering, Universiti Teknologi MARA Malaysia, 54500 Shah Alam, Selangor (Malaysia)

2009-07-01

Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell) by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900 {sup o}C), fluidization ratio (2 to 3.33 m/s), static bed height (10 to 30 mm) and equivalence ratio (0.16 to 0.46) were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol%) could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900 {sup o}C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidising velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced. (author)

Air Gasification of Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

Directory of Open Access Journals (Sweden)

A. B. Alias

2009-05-01

Full Text Available Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900°C, fluidization ratio (2 to 3.33 m/s, static bed height (10 to 30 mm and equivalence ratio (0.16 to 0.46 were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol% could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900°C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidizing velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced.

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

Bed Bug Infestations and Control Practices in China: Implications for Fighting the Global Bed Bug Resurgence

Directory of Open Access Journals (Sweden)

Changlu Wang

2011-04-01

Full Text Available The bed bug resurgence in North America, Europe, and Australia has elicited interest in investigating the causes of the widespread and increasing infestations and in developing more effective control strategies. In order to extend global perspectives on bed bug management, we reviewed bed bug literature in China by searching five Chinese language electronic databases. We also conducted telephone interviews of 68 pest control firms in two cities during March 2011. In addition, we conducted telephone interviews to 68 pest control companies within two cities in March 2011. Two species of bed bugs (Cimex lectularius L. and Cimex hemipterus (F. are known to occur in China. These were common urban pests before the early1980s. Nationwide “Four-Pest Elimination” campaigns (bed bugs being one of the targeted pests were implemented in China from 1960 to the early 1980s. These campaigns succeeded in the elimination of bed bug infestations in most communities. Commonly used bed bug control methods included applications of hot water, sealing of bed bug harborages, physical removal, and applications of residual insecticides (mainly organophosphate sprays or dusts. Although international and domestic travel has increased rapidly in China over the past decade (2000–2010, there have only been sporadic new infestations reported in recent years. During 1999–2009, all documented bed bug infestations were found in group living facilities (military dormitories, worker dormitories, and prisons, hotels, or trains. One city (Shenzhen city near Hong Kong experienced significantly higher number of bed bug infestations. This city is characterized by a high concentration of migratory factory workers. Current bed bug control practices include educating residents, washing, reducing clutter, putting items under the hot sun in summer, and applying insecticides (pyrethroids or organophosphates. There have not been any studies or reports on bed bug insecticide

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…

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.

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 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)

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.

Agglomeration of bed material: Influence on efficiency of biofuel fluidized bed boiler

Directory of Open Access Journals (Sweden)

Ryabov Georgy A.

2003-01-01

Full Text Available The successful design and operation of a fluidized bed combustor requires the ability to control and mitigate ash-related problems. The main ash-related problem of biomass filing boiler is agglomeration. The fluidized bed boiler with steam capacity of 66 t/h (4 MPa, 440 °C was started up at the Arkhangelsk Paper-Pi dp-Plant in 2001. This boiler was manufactured by the Russian companies "Energosofin" and "Belenergomash" and installed instead of the existing boiler with mechanical grate. Some constructional elements and steam drum of existing boiler remained unchanged. The primary air fan was installed past the common air fan, which supply part of the air into 24 secondary airports. First operating period shows that the bed material is expanded and then operator should increase the primary air rate, and the boiler efficiency dramatically decreases. Tills paper presents some results of our investigations of fuel, bed and fly ash chemical compositions and other characteristics. Special experiments were carried out to optimize the bed drain flow rate. The influence of secondly air supply improvement on mixing with the main flow and boiler efficiency are given.

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.

Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape

Science.gov (United States)

Eggertsen, L.; Ferreira, C. E. L.; Fontoura, L.; Kautsky, N.; Gullström, M.; Berkström, C.

2017-09-01

Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

Investigation of heat transfer in bed and freeboard of fluidized bed combustors

International Nuclear Information System (INIS)

Mitor, V.V.; Matsnev, V.V.; Sorokin, A.P.

1986-01-01

Experimental results for heat transfer between immersed bundles of bare tubes and fluidized beds are reported. The experimental results are obtained on industrial boilers with a bed area from 2,5 to 4 m/sup 2/ under conditions of long term operation. The bed temperature range has been 1073 0 K-1233 0 K, gas velocity between 1,8-4,5 m/s, mean particle size from 1,5 mm to 6,0 mm, freeboard furnace height of 2,3 and 5 m. The obtained data are compared with experimental results from literature

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...

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

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.

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.

Improved lignin pyrolysis for phenolics production in a bubbling bed reactor--Effect of bed materials.

Science.gov (United States)

Li, Dongbing; Briens, Cedric; Berruti, Franco

2015-01-01

Lignin pyrolysis was studied in a bubbling fluidized bed reactor equipped with a fractional condensation train, using nitrogen as the fluidization gas. The effect of different bed materials (silica sand, lignin char, activated lignin char, birch bark char, and foamed glass beads) on bio-oil yield and quality was investigated for a pyrolysis temperature of 550 °C. Results how that a bed of activated lignin char is preferable to the commonly used silica sand: pyrolysis of Kraft lignin with a bed of activated lignin char not only provides a pure char product, but also a higher dry bio-oil yield (with a relative increase of 43%), lower pyrolytic water production, and better bio-oil quality. The bio-oil obtained from Kraft lignin pyrolysis with a bed of activated lignin char has a lower average molecular weight, less tar, more phenolics, and less acidity than when sand is used as bed material. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Uranium bed oxidation vacuum process system

International Nuclear Information System (INIS)

McLeland, H.L.

1977-01-01

Deuterium and tritium gases are occluded in uranium powder for release into neutron generator tubes. The uranium powder is contained in stainless steel bottles, termed ''beds.'' If these beds become damaged, the gases must be removed and the uranium oxidized in order not to be flammable before shipment to ERDA disposal grounds. This paper describes the system and methods designed for the controlled degassing and oxidation process. The system utilizes sputter-ion, cryo-sorption and bellows pumps for removing the gases from the heated source bed. Removing the tritium gas is complicated by the shielding effect of helium-3, a byproduct of tritium decay. This effect is minimized by incremental pressure changes, or ''batch'' processing. To prevent runaway exothermic reaction, oxidation of the uranium bed is also done incrementally, or by ''batch'' processing, rather than by continuous flow. The paper discusses in detail the helium-3 shielding effect, leak checks that must be made during processing, bed oxidation, degree of gas depletion, purity of gases sorbed from beds, radioactivity of beds, bed disposal and system renovation

Practice Hospital Bed Safety

Science.gov (United States)

... Home For Consumers Consumer Updates Practice Hospital Bed Safety Share Tweet Linkedin Pin it More sharing options ... It depends on the complexity of the bed." Safety Tips CDRH offers the following safety tips for ...

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.

Particle fuel bed tests

International Nuclear Information System (INIS)

Horn, F.L.; Powell, J.R.; Savino, J.M.

1985-01-01

Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

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.

Modelling turbulent fluid flows in nuclear and fossil-fired power plants

International Nuclear Information System (INIS)

Viollet, P.L.

1995-06-01

The turbulent flows encountered in nuclear reactor thermal hydraulic studies or fossil-fired plant thermo-aerodynamic analyses feature widely varying characteristics, frequently entailing heat transfers and two-phase flows so that modelling these phenomena tends more and more to involve coupling between several branches of engineering. Multi-scale geometries are often encountered, with complex wall shapes, such as a PWR vessel, a reactor coolant pump impeller or a circulating fluidized bed combustion chamber. When it comes to validating physical models of these flows, the analytical process highlights the main descriptive parameters of local flow conditions: tensor characterizing the turbulence anisotropy, characteristic time scales for turbulent flow particle dynamics. Cooperative procedures implemented between national or international working parties can accelerate validation by sharing and exchanging results obtained by the various organizations involved. With this principle accepted, we still have to validate the products themselves, i.e. the software used for the studies. In this context, the ESTET, ASTRID and N3S codes have been subjected to a battery of test cases covering their respective fields of application. These test cases are re-run for each new version, so that the sets of test cases systematically benefit from the gradually upgraded functionalities of the codes. (author). refs., 3 figs., 6 tabs

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.

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...

Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

Science.gov (United States)

Chen, D.; Zhang, Y.

2008-12-01

The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

Computational fluid dynamics simulation for chemical looping combustion of coal in a dual circulation fluidized bed

International Nuclear Information System (INIS)

Su, Mingze; Zhao, Haibo; Ma, Jinchen

2015-01-01

Highlights: • CFD simulation of a 5 kW_t_h CLC reactor of coal was conducted. • Gas leakage, flow pattern and combustion efficiency of the reactor was analyzed. • Optimal condition was achieved based on operation characteristics understanding. - Abstract: A dual circulation fluidized bed system is widely accepted for chemical looping combustion (CLC) for enriching CO_2 from the utilization of fossil fuels. Due to the limitations of the measurement, the details of multiphase reactive flows in the interconnected fluidized bed reactors are difficult to obtain. Computational Fluid Dynamics (CFD) simulation provides a promising method to understand the hydrodynamics, chemical reaction, and heat and mass transfers in CLC reactors, which are very important for the rational design, optimal operation, and scaling-up of the CLC system. In this work, a 5 kW_t_h coal-fired CLC dual circulation fluidized bed system, which was developed by our research group, was first simulated for understanding gas leakage, flow pattern and combustion efficiency. The simulation results achieved good agreement with the experimental measurements, which validates the simulation model. Subsequently, to improve the combustion efficiency, a new operation condition was simulated by increasing the reactor temperature and decreasing the coal feeding. An improvement in the combustion efficiency was attained, and the simulation results for the new operation condition were also validated by the experimental measurements in the same CLC combustor. All of the above processes demonstrated the validity and usefulness of the simulation results to improve the CLC reactor operation.

Chaotic hydrodynamics of fluidized beds

Energy Technology Data Exchange (ETDEWEB)

Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

1996-12-31

The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

Comparison of packed bed and fluidized bed membrane reactors for methane reforming

NARCIS (Netherlands)

Gallucci, F.; van Sint Annaland, M.; Kuipers, J.A.M.

2009-01-01

In this work the performance of different membrane reactor concepts, both fluidized bed and packed bed membrane reactors, have been compared for the reforming of methane for the production of ultra-pure hydrogen. Using detailed theoretical models, the required membrane area to reach a given

Effects of bed-load movement on flow resistance over bed forms

Indian Academy of Sciences (India)

Abstract. The effect of bed-load transport on flow resistance of alluvial channels with undulated bed was experimentally investigated. The experiments were carried out in a tilting flume 250mm wide and 12·5m long with glass-sides of rectan- gular cross-section and artificial dune shaped floor that was made from Plexi-glass.

Staged fluidized-bed combustion and filter system

International Nuclear Information System (INIS)

Mei, J.S.; Halow, J.S.

1994-01-01

A staged fluidized-bed combustion and filter system are described for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste. 10 figures

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

Bed Bugs and Schools

Science.gov (United States)

Bed bugs have long been a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. They are successful hitchhikers, and can move from an infested site to furniture, bedding, baggage, boxes, and clothing.

Calculation of local bed to wall heat transfer in a fluidized-bed

International Nuclear Information System (INIS)

Kilkis, B.I.

1987-01-01

Surface to bed heat transfer in a fluidized-bed largely depends upon its local and global hydrodynamical behavior including particle velocity, particle trajectory, gas velocity, and void fraction. In this study, a computer program was developed in order to calculate the local bed to wall heat transfer, by accounting for the local and global instantaneous hydrodynamics of the bed. This is accomplished by utilizing the CHEMFLUB computer program. This information at a given location is interpreted so that the most appropriate heat transfer model is utilized for each time increment. These instantaneous heat transfer coefficient for the given location. Repeating the procedure for different locations, a space average heat transfer coefficient is also calculated. This report briefly summarizes the various heat transfer models employed and gives sample computer results reporting the case study for Mickley - Trilling's experimental set-up. Comparisons with available experimental data and correlations are also provided in order to compare and evaluate the computer results

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.

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.

Protecting Your Home from Bed Bugs

Science.gov (United States)

... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... with Bed Bug Problems Discover. Accessibility EPA Administrator Budget & Performance Contracting Grants January 19, 2017 Web Snapshot ...

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.

An Apparatus for Bed Material Sediment Extraction From Coarse River Beds in Large Alluvial Rivers

Science.gov (United States)

Singer, M. B.; Adam, H.; Cooper, J.; Cepello, S.

2005-12-01

Grain size distributions of bed material sediment in large alluvial rivers are required in applications ranging from habitat mapping, calibration of sediment transport models, high resolution sediment routing, and testing of existing theories of longitudinal and cross steam sediment sorting. However, characterizing bed material sediment from coarse river beds is hampered by difficulties in sediment extraction, a challenge that is generally circumvented via pebble counts on point bars, even though it is unclear whether the bulk grain size distribution of bed sediments is well represented by pebble counts on bars. We have developed and tested a boat-based sampling apparatus and methodology for extracting bulk sediment from a wide range of riverbed materials. It involves the use of a 0.4 x 0.4 x 0.2 meter stainless steel toothed sampler, called the Cooper Scooper, which is deployed from and dragged downstream by the weight of a jet boat. The design is based on that of a river anchor such that a rotating center bar connected to a rope line in the boat aligns the sampler in the downstream direction, the teeth penetrate the bed surface, and the sampler digs into the bed. The sampler is fitted with lead weights to keep it from tipping over. The force of the sampler `biting' into the bed can be felt on the rope line held by a person in the boat at which point they let out slack. The boat then motors to the spot above the embedded sampler, which is hoisted to the water surface via a system of pulleys. The Cooper Scooper is then clipped into a winch and boom assembly by which it is brought aboard. This apparatus improves upon commonly used clamshell dredge samplers, which are unable to penetrate coarse or mixed bed surfaces. The Cooper Scooper, by contrast, extracts statistically representative bed material sediment samples of up to 30 kilograms. Not surprisingly, the sampler does not perform well in very coarse or armored beds (e.g. where surface material size is on the

Biomass gasification in fixed bed type down draft: theoretical and experimental aspects; Gasificacao de biomassa em leito fixo tipo concorrente: aspectos teoricos e experimentais

Energy Technology Data Exchange (ETDEWEB)

Martinez, Juan Daniel; Andrade, Rubenildo Vieira; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Excelencia em Geracao Termeletrica e Distribuida

2008-07-01

Actually are recognizing the advantages of biomass in reducing dependence on fossil fuels and significant reduction in emissions of greenhouse effect gases such as Co2. Also are known the different conversion of biomass routes for their use or exploitation, such as thermochemical process (gasification, pyrolysis and combustion), the biological process (fermentation and transesterification) and the physical process (densification, reducing grain and mechanical pressing). In this sense, the gasification is regarded as the most promising mechanism to obtain a homogeneous gaseous fuel with sufficient quality in the small scale distributed generation. This work presents some aspects of biomass gasification in fixed bed, as well as some preliminary results in the evaluation and operation of fixed bed down draft gasifier with double stage air supply of the NEST, identifying the adequate air supply quantity (equivalence ratio in the range of 0,35 to 0,45) for obtaining a fuel gas with lower heating value around 4 MJ/N m3. (author)

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

Implicit CO_2 prices of fossil fuel use in Switzerland

International Nuclear Information System (INIS)

Schleiniger, Reto

2016-01-01

This study aims to assess the efficiency of the fossil fuel taxation scheme currently in effect in Switzerland. To this end, the concept of implicit CO_2 prices is introduced, based on which prices for different fossil fuel uses are derived. Implicit CO_2 prices are defined as the difference between actual prices paid by consumers and efficient domestic fuel prices. Efficient domestic fuel prices, in turn, consist of private production costs, a uniform value added tax and only local external costs, not including external costs due to CO_2 emissions and global climate change. The resulting prices differ substantially, which suggests that there is considerable cost-saving potential in reducing CO_2 emissions in Switzerland. For passenger cars and air traffic, the implicit prices are negative. For these uses, higher fuel charges would therefore be beneficial from a purely domestic perspective, i.e., without considering the negative repercussions of global warming. - Highlights: •Efficient fossil fuel policy must take into account local and global externalities. •Implicit CO_2 prices are applied as efficiency indicator of fossil energy policy. •Implicit CO_2 prices vary strongly for different fossil fuel uses in Switzerland. •There is a large cost-saving potential in terms of reducing CO_2 emissions.

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)

Apparatus and process for controlling fluidized beds

Science.gov (United States)

Rehmat, Amirali G.; Patel, Jitendra G.

1985-10-01

An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

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.

Rare earth and trace elements of fossil vertebrate bioapatite as palaeoenvironmental and sedimentological proxies

Science.gov (United States)

Žigaitė, Živilė; Fadel, Alexandre; Pérez-Huerta, Alberto; Jeffries, Teresa

2015-04-01

Rare earth (REE) and trace element compositions of fossil vertebrate dental microremains have been studied in Silurian and Devonian vertebrate dental scales and spines in-situ, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Samples were selected from the well-known Silurian bone beds of Vesiku and Ohesaare in Saaremaa island of Estonia, and a number of Lower Devonian localities from Spitsbergen (Svalbard), Andrée Land group. Biomineral preservation was assessed using spot semi-quantitative elemental chemistry (SEM-EDS) and electron back-scatter difractometry (EBSD) for cristallinity imaging. The obtained PAAS shale-normalised REE concentrations were evaluated using basic geochemical calculations and quantifications. The REE patterns from the Lower Devonian vertebrate apatite from Andrée Land, Spitsbergen (Wood Bay and Grey Hœk formations) did not show any recognisable taxon-specific behavior, but had rather well expressed differences of REE compositions related to biomineral structure and sedimentary settings, suggesting REE instead to reflect burial environments and sedimentological history. The Eu anomaly recorded in two of the studied localities but not in the other indicate different taphonomic conditions and palaeoenvironment, while La/Sm, La/Yb ratios sugeest considerable influence of terrestrial freshwater during the early diagenesis. The La/Yb and La/Sm plots also agree with the average REE concentrations, reflecting domination of the adsoption over substitution as principal REE uptake mechanism in the fossils which had significantly lower overall REE concentrations, and vice versa. Vesiku (Homerian, Wenlock) microremains yielded very uniform REE patterns with slightly lower overall REE concentrations in enameloid than in dentine, with strong enrichment in middle REE and depletion in heavy REE. Negative Europium (Eu) anomaly was pronounced in all the profiles, but Cerium (Ce) anomalies were not detected suggesting possible

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.

Fluidized bed boiler feed system

Science.gov (United States)

Jones, Brian C.

1981-01-01

A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

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 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

Fluidized bed incinerator development

International Nuclear Information System (INIS)

Ziegler, D.L.; Johnson, A.J.

1976-01-01

A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

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.

Separation of harmful impurities from refuse derived fuels (RDF) by a fluidized bed.

Science.gov (United States)

Krüger, B; Mrotzek, A; Wirtz, S

2014-02-01

In firing systems of cement production plants and coal-fired power plants, regular fossil fuels are increasingly substituted by alternative fuels. Rising energy prices and ambitious CO2-reduction goals promote the use of alternative fuels as a significant contribution to efficient energy recovery. One possibility to protect energy resources are refuse-derived fuels (RDF), which are produced during the treatment of municipal solid, commercial and industrial waste. The waste fractions suitable for RDF have a high calorific value and are often not suitable for material recycling. With current treatment processes, RDF still contains components which impede the utilization in firing systems or limit the degree of substitution. The content of these undesired components may amount to 4 wt%. These, in most cases incombustible particles which consist of mineral, ceramic and metallic materials can cause damages in the conveying systems (e. g. rotary feeder) or result in contaminations of the products (e. g. cement, chalk). Up-to-date separation processes (sieve machine, magnet separator or air classifier) have individual weaknesses that could hamper a secure separation of these particles. This article describes a new technology for the separation of impurities from refuse derived fuels based on a rotating fluidized bed. In this concept a rotating motion of the particle bed is obtained by the tangential injection of the fluidization gas in a static geometry. The RDF-particles experience a centrifugal force which fluidized the bed radially. The technical principle allows tearing up of particle clusters to single particles. Radially inwards the vertical velocity is much lower thus particles of every description can fall down there. For the subsequent separation of the particles by form and density an additionally cone shaped plate was installed in the centre. Impurities have a higher density and a compact form compared to combustible particles and can be separated with a high

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.

Petrology and geochemistry of samples from bed-contact zones in Tunnel Bed 5, U12g-Tunnel, Nevada Test Site

International Nuclear Information System (INIS)

Connolly, J.R.; Keil, K.; Mansker, W.L.; Allen, C.C.; Husler, J.; Lowy, R.; Fortney, D.R.; Lappin, A.R.

1984-10-01

This report summarizes the detailed geologic characterization of samples of bed-contact zones and surrounding nonwelded bedded tuffs, both within Tunnel Bed 5, that are exposed in the G-Tunnel complex beneath Rainier Mesa on the Nevada Test Site (NTS). Original planning studies treated the bed-contact zones in Tunnel Bed 5 as simple planar surfaces of relatively high permeability. Detailed characterization, however, indicates that these zones have a finite thickness, are depositional in origin, vary considerably over short vertical and horizontal distances, and are internally complex. Fluid flow in a sequence of nonwelded zeolitized ash-flow or bedded tuffs and thin intervening reworked zones appears to be a porous-medium phenomenon, regardless of the presence of layering. There are no consistent differences in either bulk composition or detailed mineralogy between bedded tuffs and bed-contact zones in Tunnel Bed 5. Although the original bulk composition of Tunnel Bed 5 was probably peralkaline, extensive zeolitization has resulted in a present peraluminous bulk composition of both bedded tuffs and bed-contact zones. The major zeolite present, clinoptilolite, is intermediate (Ca:K:Na = 26:35:39) and effectively uniform in composition. This composition is similar to that of clinoptilolite from the tuffaceous beds of Calico Hills above the static water level in hole USW G-1, but somewhat different from that reported for zeolites from below the static water level in USW G-2. Tunnel Bed 5 also contains abundant hydrous manganese oxides. The similarity in composition of the clinoptilolites from Tunnel Bed 5 and those above the static water level at Yucca Mountain indicates that many of the results of nuclide-migration experiments in Tunnel Bed 5 would be transferrable to zeolitized nonwelded tuffs above the static water level at Yucca Mountain

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.

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.

Theoretical comparison of packed bed and fluidized bed membrane reactors for methane reforming

NARCIS (Netherlands)

Gallucci, F.; van Sint Annaland, M.; Kuipers, J.A.M.

2010-01-01

In this theoretical work the performance of different membrane reactor concepts, both fluidized bed and packed bed membrane reactors, has been compared for ultra-pure hydrogen production via methane reforming. Using detailed theoretical models, the required membrane area to reach a given conversion

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

Development of a new generation of ion exchange resin for nuclear and fossil power plant

International Nuclear Information System (INIS)

Tsuzuki, Shintaro; Tagawa, Hidemi; Yamashita, Futoshi; Okamoto, Ryutaro

2008-01-01

It is required to maintain water quality supplied to steam generator to the water designed based on its water chemistry in order to keep the sound operation of nuclear power plants or fossil power plants. Condensate Polishing Plant (CPP) is installed for removing ions in the water which uses a mixed bed of cation exchange resin and anion exchange resin. We have developed new generation of CPP resin. The product is a unique combination of super high exchange capacity cation exchange resin and high fouling resistant anion exchange resin. The CPP resin has been used in many power plants. Amberjet 1006 was developed as a cation exchange resin with high oxidative stability, high operational capacity and New IRA900CP was developed as an anion exchange resin with high fouling resistant to leachables released out of cation exchange resin by oxidative degradation over the service period. The novel CPP resin was first used in 2000 and has now been used in many power plants in Japan. The CPP resin has been giving excellent quality of water. (author)

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.

Fossil fuel toxicology

International Nuclear Information System (INIS)

Anon.

1976-01-01

A program is described for the investigation of the toxicology of coal-derived effluents that will utilize a battery of cellular and mammalian test systems and end points to evaluate the toxicological effects of acute, sub-acute, and long-term, low-level exposure to gaseous and particulate effluents from combustion of coal, with special emphasis on fluidized bed combustion

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.

Fluid-bed process for SYNROC production

International Nuclear Information System (INIS)

Ackerman, F.J.; Grens, J.Z.; Ryerson, F.J.; Hoenig, C.L.; Bazan, F.; Peters, P.E.; Smith, R.; Campbell, J.H.

1983-01-01

SYNROC is a titanate-based ceramic waste developed for the immobilization of high-level nuclear reactor waste. Lawrence Livermore National Laboratory (LLNL) has investigated a fluid-bed technique for the large-scale production of SYNROC precursor powders. Making SYNROC in a fluid bed permits slurry drying, calcination and reduction-oxidation reactions to be carried out in a single unit. We present the results of SYNROC fluid-bed studies from two fluid-bed units 10 cm in diameter: an internally heated fluid-bed unit developed by Exxon Idaho and an externally heated unit constructed at LLNL. Bed operation over a range of temperatures, feed rates, fluidizing rates, and redox conditions indicate that SYNROC powders of a high density and a uniform particle size can be produced. These powders facilitate the densification step and yield dense ceramics (greater than 95% theoretical density) with well-developed phases and low leaching rates

Clinical evaluation of an automated turning bed.

Science.gov (United States)

Melland, H I; Langemo, D; Hanson, D; Olson, B; Hunter, S

1999-01-01

The purposes of this study were to assess client comfort and sleep quality, client physiologic response (skin and respiratory status), the effect on the need for caregiver assistance, and cost when using an automated turning bed. Nonexperimental, evaluative study. Twenty-four adult home or long-term care resident subjects who had a degenerative disease, spinal cord injury, stroke, cerebral palsy, or back surgery. Each subject agreed to use the automated turning bed for four weeks. Researchers completed a demographic survey and skin assessment, and assessed each subject for pressure ulcer risk and for the need of assistance of a care giver for turning before and after the four weeks of using the turning bed. Subjects rated the turning bed in terms of comfort and sleep quality. Subjects rated the turning bed as more comfortable than their own bed and expressed satisfaction at the pain relief attained when on the turning bed. While using the turning bed, there was a significant improvement in sleep quality. No skin breakdown or deterioration in respiratory status occurred. Fewer subjects required the assistance of a caregiver for turning when on the turning bed. This automated turning bed shows great promise in meeting a need for patients with limited mobility whether they are homebound or in a residential community. Future studies that further investigate use of the turning bed for postoperative back patients while still in the acute care setting are indicated. Replicative studies with a larger sample size are also indicated.

Predicting fractional bed load transport rates: Application of the Wilcock‐Crowe equations to a regulated gravel bed river

Science.gov (United States)

Gaeuman, David; Andrews, E.D.; Krause, Andreas; Smith, Wes

2009-01-01

Bed load samples from four locations in the Trinity River of northern California are analyzed to evaluate the performance of the Wilcock‐Crowe bed load transport equations for predicting fractional bed load transport rates. Bed surface particles become smaller and the fraction of sand on the bed increases with distance downstream from Lewiston Dam. The dimensionless reference shear stress for the mean bed particle size (τ*rm) is largest near the dam, but varies relatively little between the more downstream locations. The relation between τ*rm and the reference shear stresses for other size fractions is constant across all locations. Total bed load transport rates predicted with the Wilcock‐Crowe equations are within a factor of 2 of sampled transport rates for 68% of all samples. The Wilcock‐Crowe equations nonetheless consistently under‐predict the transport of particles larger than 128 mm, frequently by more than an order of magnitude. Accurate prediction of the transport rates of the largest particles is important for models in which the evolution of the surface grain size distribution determines subsequent bed load transport rates. Values of τ*rm estimated from bed load samples are up to 50% larger than those predicted with the Wilcock‐Crowe equations, and sampled bed load transport approximates equal mobility across a wider range of grain sizes than is implied by the equations. Modifications to the Wilcock‐Crowe equation for determining τ*rm and the hiding function used to scale τ*rm to other grain size fractions are proposed to achieve the best fit to observed bed load transport in the Trinity River.

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.

DNA profiling of trace DNA recovered from bedding.

Science.gov (United States)

Petricevic, Susan F; Bright, Jo-Anne; Cockerton, Sarah L

2006-05-25

Trace DNA is often detected on handled items and worn clothing examined in forensic laboratories. In this study, the potential transfer of trace DNA to bedding by normal contact, when an individual sleeps in a bed, is examined. Volunteers slept one night on a new, lower bed sheet in their own bed and one night in a bed foreign to them. Samples from the sheets were collected and analysed by DNA profiling. The results indicate that the DNA profile of an individual can be obtained from bedding after one night of sleeping in a bed. The DNA profile of the owner of the bed could also be detected in the foreign bed experiments. Since mixed DNA profiles can be obtained from trace DNA on bedding, caution should be exercised when drawing conclusions from DNA profiling results obtained from such samples. This transfer may have important repercussions in sexual assault investigations.

Utility of Recycled Bedding for Laboratory Rodents

OpenAIRE

Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

2009-01-01

Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared wi...

Bed-To-Wall Heat Transfer in a Supercritical Circulating Fluidised Bed Boiler

Directory of Open Access Journals (Sweden)

Błaszczuk Artur

2014-06-01

Full Text Available The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.

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.

Taphonomy of the vertebrate bone beds from the Klūnas fossil site, Upper Devonian Tērvete Formation of Latvia

Directory of Open Access Journals (Sweden)

Jeļena Vasiļkova

2012-05-01

Full Text Available Combined sedimentological and taphonomical study of the siliciclastic sequence of the Tērvete Formation in the stratotypical area was aimed at revealing the formation of the three oryctocoenoses discovered and related structural and textural features of the deposits, as well as at detailed observation of the taphonomical peculiarities of the obtained palaeontological material. The fossil vertebrate assemblage is represented by 14 taxa comprising placoderms, acanthodians, sarcopterygians and actinopterygians. The three oryctocoenoses, first recognized in 2010, differ in the proportions of repeatedly buried material, in the number and degree of preservation of small and fragile skeletal elements, as well as in the evaluated current velocity and the transportation distance. Sedimentary concentrations of marine vertebrate remains, dominated by the antiarchs Bothriolepis ornata and B. jani, have been formed under the influence of fluvial and tidal processes in the shallow-water environment, deltaic or estuarine settings. Elongated placoderm and sarcopterygian bones are probably better indicators of the palaeoflow direction than acanthodian spines or sarcopterygian teeth.

Bed Load Variability and Morphology of Gravel Bed Rivers Subject to Unsteady Flow: A Laboratory Investigation

Science.gov (United States)

Redolfi, M.; Bertoldi, W.; Tubino, M.; Welber, M.

2018-02-01

Measurement and estimation of bed load transport in gravel bed rivers are highly affected by its temporal fluctuations. Such variability is primarily driven by the flow regime but is also associated with a variety of inherent channel processes, such as flow turbulence, grain entrainment, and bed forms migration. These internal and external controls often act at comparable time scales, and are therefore difficult to disentangle, thus hindering the study of bed load variability under unsteady flow regime. In this paper, we report on laboratory experiments performed in a large, mobile bed flume where typical hydromorphological conditions of gravel bed rivers were reproduced. Data from a large number of replicated runs, including triangular and square-wave hydrographs, were used to build a statistically sound description of sediment transport processes. We found that the inherent variability of bed load flux strongly depends on the sampling interval, and it is significantly higher in complex, wandering or braided channels. This variability can be filtered out by computing the mean response over the experimental replicates, which allows us to highlight two distinctive phenomena: (i) an overshooting (undershooting) response of the mean bed load flux to a sudden increase (decrease) of discharge, and (ii) a clockwise hysteresis in the sediment rating curve. We then provide an interpretation of these findings through a conceptual mathematical model, showing how both phenomena are associated with a lagging morphological adaptation to unsteady flow. Overall, this work provides basic information for evaluating, monitoring, and managing gravel transport in morphologically active rivers.

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.

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)

Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China.

Science.gov (United States)

Xu, Jian-wei; Liao, Yuan-mei; Liu, Hui; Nie, Ren-hua; Havumaki, Joshua

2014-01-01

Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas. This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, Pcash income per person (ACIP) was an independent factor that influenced bed net use (PHigh bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.

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.

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.

Numerical calculation of wall-to-bed heat transfer coefficients in gas-fluidized beds

NARCIS (Netherlands)

Kuipers, J.A.M.; Prins, W.; van Swaaij, W.P.M.

1992-01-01

A computer model for a hot gas-fluidized bed has been developed. The theoretical description is based on a two-fluid model (TFM) approach in which both phases are considered to be continuous and fully interpenetrating. Local wall-to-bed heat-transfer coefficients have been calculated by the

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.

New Palaeogene horntail wasps (Hymenoptera, Siricidae) and a discussion of their fossil record.

Science.gov (United States)

Wedmann, Sonja; Pouillon, Jean-Marc; Nel, André

2014-09-29

The phylogenetic placement of siricid hymenopterans and especially the relationships among Siricidae are not resolved, and are in need of further investigation. The fossil record helps to illuminate the evolutionary history of this group. In this paper, Xoanon? eocenicus sp. nov. is newly described from the Eocene Fossillagerstätte Grube Messel (Germany). Although several characters of the wing venation of this fossil are similar to the extant genus Xoanon, there remain some doubts concerning the generic placement. A newly found fossil is attributed to Urocerus ligniticus (Piton, 1940) from the Paloecene Fossillagerstätte Menat (France) and provides more morphological information on this species. An overview of the fossil record of Siricidae in the strict sense is given and the state of knowledge on the different fossils is reviewed.

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

Fossil Energy Planning for Navajo Nation

Energy Technology Data Exchange (ETDEWEB)

Acedo, Margarita [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-11

This project includes fossil energy transition planning to find optimal solutions that benefit the Navajo Nation and stakeholders. The majority of the tribe’s budget currently comes from fossil energy-revenue. The purpose of this work is to assess potential alternative energy resources including solar photovoltaics and biomass (microalgae for either biofuel or food consumption). This includes evaluating carbon-based reserves related to the tribe’s resources including CO₂ emissions for the Four Corners generating station. The methodology for this analysis will consist of data collection from publicly available data, utilizing expertise from national laboratories and academics, and evaluating economic, health, and environmental impacts. Finally, this report will highlight areas of opportunities to implement renewable energy in the Navajo Nation by presenting the technology requirements, cost, and considerations to energy, water, and environment in an educational structure.

REE compositions in fossil vertebrate dental tissues indicate biomineral preservation

Science.gov (United States)

Žigaite, Ž.; Kear, B.; Pérez-Huerta, A.; Jeffries, T.; Blom, H.

2012-04-01

Rare earth element (REE) abundances have been measured in a number of Palaeozoic and Mesozoic dental tissues using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS). Fossil vertebrates analysed comprise scales and tesserae of Silurian and Devonian acanthodians, chondrichthyans, galeaspids, mongolepids, thelodonts, as well as teeth of Cretaceous lungfish and marine reptiles. The evaluation of fossil preservation level has been made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections, using Energy Dispersive X-ray Spectroscopy (EDS). Fossil teeth and scales with significant structure and colour alteration have shown elevated heavy element concentrations, and the silicification of bioapatite has been common in their tissues. Stable oxygen isotope measurements (δ18O) of bulk biomineral have been conducted in parallel, and showed comparatively lower heavy oxygen values in the same fossil tissues with stronger visible alteration. Significant difference in REE concentrations has been observed between the dentine and enamel of Cretaceous plesiosaurs, suggesting the enamel to be more geochemically resistant to diagenetic overprint.

VA National Bed Control System

Data.gov (United States)

Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

Tritium measurement technique using ''in-bed'' calorimetry

International Nuclear Information System (INIS)

Klein, J.E.; Mallory, M.K.; Nobile, A. Jr.

1991-01-01

One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium ''heels'' from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and ''in-bed'' tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to 3 He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of ±1.6% of a tritium filled hydride storage bed

Transitional fossils and the origin of turtles.

Science.gov (United States)

Lyson, Tyler R; Bever, Gabe S; Bhullar, Bhart-Anjan S; Joyce, Walter G; Gauthier, Jacques A

2010-12-23

The origin of turtles is one of the most contentious issues in systematics with three currently viable hypotheses: turtles as the extant sister to (i) the crocodile-bird clade, (ii) the lizard-tuatara clade, or (iii) Diapsida (a clade composed of (i) and (ii)). We reanalysed a recent dataset that allied turtles with the lizard-tuatara clade and found that the inclusion of the stem turtle Proganochelys quenstedti and the 'parareptile' Eunotosaurus africanus results in a single overriding morphological signal, with turtles outside Diapsida. This result reflects the importance of transitional fossils when long branches separate crown clades, and highlights unexplored issues such as the role of topological congruence when using fossils to calibrate molecular clocks.

Global climate change: a synopsis of current activities in the Office of Fossil Energy

International Nuclear Information System (INIS)

South, D.W.; Kane, R.

1990-01-01

This paper reports on the US DOE Office of Fossil Energy investigation and monitoring of several aspects of global climate change as it relates to fossil fuels. The paper consists of the overheads from the presentation. The topics of this paper include greenhouse gases from fossil fuels, scientific uncertainties, legislation and protocols, mitigation strategies and policies, energy and economic impacts, and the role of clean coal technologies and fossil fuels in global climate change

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.

76 FR 3517 - Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial...

Science.gov (United States)

2011-01-20

... Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial-Institutional, and... following: Category NAICS \\1\\ Examples of regulated entities Industry 221112 Fossil fuel-fired electric utility steam generating units. Federal Government 22112 Fossil fuel-fired electric utility steam...

Equilibrium modeling of gasification: Gibbs free energy minimization approach and its application to spouted bed and spout-fluid bed gasifiers

International Nuclear Information System (INIS)

Jarungthammachote, S.; Dutta, A.

2008-01-01

Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO 2 , CH 4 , H 2 O, H 2 and N 2 , were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed

Adult Bed-Wetting: A Concern?

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Adult bed-wetting: A concern? My 24-year-old husband has started to wet the bed at ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

Getting Rid of Bed Bugs

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... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... to be careful in how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ...

EPA-Registered Bed Bug Products

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... rest or hide in hampers, bed frames, even furniture); Failing to treat adjacent areas where bed bugs ... to work (some pesticides, such as desiccators or growth regulators, may be very effective but take some ...

Fossil rhinoceroses from Hopefield, South Africa

NARCIS (Netherlands)

Hooijer, D.A.; Singer, R.

1960-01-01

INTRODUCTION The fossil specimens of rhinoceroses recovered at the "Elandsfontein" site, Hopefield, Cape Province, belong to the two living species of Africa, viz., Ceratotherium simum (Burchell) and Diceros bicornis (L.) (Singer, 1954). Both are widely distributed in the African Pleistocene (see

Control of the Bed Temperature of a Circulating Fluidized Bed Boiler by using Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

AYGUN, H.

2012-05-01

Full Text Available Circulating fluidized bed boilers are increasingly used in the power generation due to their higher combustion efficiency and lower pollutant emissions. Such boilers require an effective control of the bed temperature, because it influences the boiler combustion efficiency and the rate of harmful emissions. A Particle-Swarm-Optimization-Proportional-Integrative-Derivative (PSO-PID controller for the bed temperature of a circulating fluidized bed boiler is presented. In order to prove the capability of the proposed controller, its performances are compared at different boiler loads with those of a Fuzzy Logic (FL controller. The simulation results demonstrate some advantages of the proposed controller.

Identification of remanie fossils using amino acid racemisation

International Nuclear Information System (INIS)

Murray-Wallace, C.V.

1997-01-01

The reworking of fossils into younger sediments presents a significant problem for dating Quaternary marginal marine strata. Studies that involve isotopic dating of carbonate sediment fractions may be subject to error, owing to the difficulties of quantifying the residence times of skeletal carbonate fragments and fossils in some coastal environments. The random and often episodic nature of reworking also means that the value of residence times (i.e. interval from death of an organism to its final incorporation within a sediment), as expressed in years, may vary spatially and temporally. This problem is particularly marked in the dating of skeletal carbonate sands. Thus, the validity of numeric dates for 'whole-rock' carbonate samples, based on methods such as radiocarbon or uranium-series disequilibrium, has on occasions been difficult to establish. This problem is compounded when a specific component of a carbonate sediment is selected for dating. This paper documents the potential of the application of amino acid racemisation reactions as a method for identifying reworked Quaternary fossils, based on case studies from coastal and continental shelf depositional environments

Proceedings of the 18th Annual Conference on Fossil Energy Materials.

Energy Technology Data Exchange (ETDEWEB)

Judkins, RR

2004-11-02

The 18th Annual conference on Fossil Energy Materials was held in Knoxville, Tennessee, on June 2 through June 4, 2004. The meeting was sponsored by the U.S. Department of Energy's (DOE) Office of Fossil Energy through the Advanced Research Materials Program (ARM). The objective of the ARM 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 Oak Ridge Operations Office and Oak Ridge National Laboratory (ORNL). The research is performed by staff members at ORNL and by researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) structural, ceramics, (2) new alloys and coatings, (3) functional materials, and (4) technology development and transfer.

Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents.

Science.gov (United States)

Kimura, Yuri; Hawkins, Melissa T R; McDonough, Molly M; Jacobs, Louis L; Flynn, Lawrence J

2015-09-28

Time calibration derived from the fossil record is essential for molecular phylogenetic and evolutionary studies. Fossil mice and rats, discovered in the Siwalik Group of Pakistan, have served as one of the best-known fossil calibration points in molecular phylogenic studies. Although these fossils have been widely used as the 12 Ma date for the Mus/Rattus split or a more basal split, conclusive paleontological evidence for the nodal assignments has been absent. This study analyzes newly recognized characters that demonstrate lineage separation in the fossil record of Siwalik murines and examines the most reasonable nodal placement of the diverging lineages in a molecular phylogenetic tree by ancestral state reconstruction. Our specimen-based approach strongly indicates that Siwalik murines of the Karnimata clade are fossil members of the Arvicanthini-Otomyini-Millardini clade, which excludes Rattus and its relatives. Combining the new interpretation with the widely accepted hypothesis that the Progonomys clade includes Mus, the lineage separation event in the Siwalik fossil record represents the Mus/Arvicanthis split. Our test analysis on Bayesian age estimates shows that this new calibration point provides more accurate estimates of murine divergence than previous applications. Thus, we define this fossil calibration point and refine two other fossil-based points for molecular dating.

A Pilot Study to Evaluate California's Fossil Fuel CO2 Emissions Using Atmospheric Observations

Science.gov (United States)

Graven, H. D.; Fischer, M. L.; Lueker, T.; Guilderson, T.; Brophy, K. J.; Keeling, R. F.; Arnold, T.; Bambha, R.; Callahan, W.; Campbell, J. E.; Cui, X.; Frankenberg, C.; Hsu, Y.; Iraci, L. T.; Jeong, S.; Kim, J.; LaFranchi, B. W.; Lehman, S.; Manning, A.; Michelsen, H. A.; Miller, J. B.; Newman, S.; Paplawsky, B.; Parazoo, N.; Sloop, C.; Walker, S.; Whelan, M.; Wunch, D.

2016-12-01

Atmospheric CO2 concentration is influenced by human activities and by natural exchanges. Studies of CO2 fluxes using atmospheric CO2 measurements typically focus on natural exchanges and assume that CO2 emissions by fossil fuel combustion and cement production are well-known from inventory estimates. However, atmospheric observation-based or "top-down" studies could potentially provide independent methods for evaluating fossil fuel CO2 emissions, in support of policies to reduce greenhouse gas emissions and mitigate climate change. Observation-based estimates of fossil fuel-derived CO2 may also improve estimates of biospheric CO2 exchange, which could help to characterize carbon storage and climate change mitigation by terrestrial ecosystems. We have been developing a top-down framework for estimating fossil fuel CO2 emissions in California that uses atmospheric observations and modeling. California is implementing the "Global Warming Solutions Act of 2006" to reduce total greenhouse gas emissions to 1990 levels by 2020, and it has a diverse array of ecosystems that may serve as CO2 sources or sinks. We performed three month-long field campaigns in different seasons in 2014-15 to collect flask samples from a state-wide network of 10 towers. Using measurements of radiocarbon in CO2, we estimate the fossil fuel-derived CO2 present in the flask samples, relative to marine background air observed at coastal sites. Radiocarbon (14C) is not present in fossil fuel-derived CO2 because of radioactive decay over millions of years, so fossil fuel emissions cause a measurable decrease in the 14C/C ratio in atmospheric CO2. We compare the observations of fossil fuel-derived CO2 to simulations based on atmospheric modeling and published fossil fuel flux estimates, and adjust the fossil fuel flux estimates in a statistical inversion that takes account of several uncertainties. We will present the results of the top-down technique to estimate fossil fuel emissions for our field

Hydrogen movement and the next action: fossil fuels industry and sustainability economics

International Nuclear Information System (INIS)

Nejat Veziroglu, T.

1997-01-01

Since the hydrogen movement started in 1974, there has been progress in research, development, demonstration and commercialization activities, covering all aspects of the hydrogen energy system. In order to solve the interrelated problems of depletion of fossil fuels and the environmental impact of the combustion products of fossil fuels, it is desirable to speed up the conversion to the hydrogen energy system. Most established industries have joined the hydrogen movement. There is one exception: the fossil fuel industry. A call is made to the fossil fuel industry to join the hydrogen movement. It is also proposed to change the present economic system with a sustainability economics in order to account for environmental damage, recyclability and decommissioning, and thus, ensure a sustainable future. (Author)

Expanded-bed chromatography in primary protein purification.

Science.gov (United States)

Anspach, F B; Curbelo, D; Hartmann, R; Garke, G; Deckwer, W D

1999-12-31

Chromatography in stable expanded beds enables proteins to be recovered directly from cultivations of microorganisms or cells and preparations of disrupted cells, without the need for prior removal of suspended solids. The general performance of an expanded bed is comparable to a packed bed owing to reduced mixing of the adsorbent particles in the column. However, optimal operating conditions are more restricted than in a packed bed due to the dependence of bed expansion on the size and density of the adsorbent particles as well as the viscosity and density of the feedstock. The feedstock composition may become the most limiting restriction owing to interactions of adsorbent particles with cell surfaces, DNA and other substances, leading to their aggregation and consequently to bed instabilities and channeling. Despite these difficulties, expanded-bed chromatography has found widespread applications in the large scale purification of proteins from mammalian cell and microbial feedstocks in industrial bioprocessing. The basics and implementation of expanded-bed chromatography, its advantages as well as problems encountered in the use of this technique for the direct extraction of proteins from unclarified feedstocks are addressed.

Fluidization quality analyzer for fluidized beds

Science.gov (United States)

Daw, C.S.; Hawk, J.A.

1995-07-25

A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

Fluidised bed heat exchangers

International Nuclear Information System (INIS)

Elliott, D.E.; Healey, E.M.; Roberts, A.G.

1974-01-01

Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

Solid fuel feed system for a fluidized bed

Science.gov (United States)

Jones, Brian C.

1982-01-01

A fluidized bed for the combustion of coal, with limestone, is replenished with crushed coal from a system discharging the coal laterally from a station below the surface level of the bed. A compartment, or feed box, is mounted at one side of the bed and its interior separated from the bed by a weir plate beneath which the coal flows laterally into the bed while bed material is received into the compartment above the plate to maintain a predetermined minimum level of material in the compartment.

Global aquifers dominated by fossil groundwaters but wells vulnerable to modern contamination

Science.gov (United States)

Jasechko, Scott; Perrone, Debra; Befus, Kevin M.; Bayani Cardenas, M.; Ferguson, Grant; Gleeson, Tom; Luijendijk, Elco; McDonnell, Jeffrey J.; Taylor, Richard G.; Wada, Yoshihide; Kirchner, James W.

2017-06-01

The vulnerability of groundwater to contamination is closely related to its age. Groundwaters that infiltrated prior to the Holocene have been documented in many aquifers and are widely assumed to be unaffected by modern contamination. However, the global prevalence of these `fossil' groundwaters and their vulnerability to modern-era pollutants remain unclear. Here we analyse groundwater carbon isotope data (12C, 13C, 14C) from 6,455 wells around the globe. We show that fossil groundwaters comprise a large share (42-85%) of total aquifer storage in the upper 1 km of the crust, and the majority of waters pumped from wells deeper than 250 m. However, half of the wells in our study that are dominated by fossil groundwater also contain detectable levels of tritium, indicating the presence of much younger, decadal-age waters and suggesting that contemporary contaminants may be able to reach deep wells that tap fossil aquifers. We conclude that water quality risk should be considered along with sustainable use when managing fossil groundwater resources.

Combustion of peanut shells in a cone-shaped bubbling fluidized-bed combustor using alumina as the bed material

International Nuclear Information System (INIS)

Arromdee, Porametr; Kuprianov, Vladimir I.

2012-01-01

Highlights: ► We propose burning of peanut shells in a conical fluidized bed using alumina sand. ► We examine hydrodynamic, combustion and emission characteristics of the reactor. ► High, over 99%, combustion efficiency is achievable. ► Emissions of CO and NO from the combustor meet the national emission limits. ► Composition of the bed material undergoes significant changes during the combustion. -- Abstract: This paper reports experimental studies on burning peanut shells in the conical fluidized-bed combustor using alumina sand as the fluidizing agent. Prior to combustion tests, hydrodynamic regimes and characteristics of a conical alumina–biomass bed were investigated under cold-state conditions for variable percentage of peanut shells in the mixture and static bed height. With selected particle sizes (300–500 μm) and static bed height (30 cm), alumina ensured bubbling fluidization regime of the bed at operating conditions specified for firing biomass. Combustion tests were performed at 60 kg/h and 45 kg/h fuel feed rates, while ranging excess air from 20% to 80% at a fixed combustor load. Temperature and gas concentrations (O 2 , CO, C x H y as CH 4 , and NO) were measured along radial and axial directions inside the reactor as well as at stack in order to characterize combustion and emission performance of the combustor for the ranges of operating conditions. For firing 60 kg/h peanut shells, excess air of 40% can be selected as an appropriate value ensuring high, about 99%, combustion efficiency and rather low emissions of CO and NO: 520 ppm and 125 ppm, respectively (both on a dry basis and at 6% O 2 ). With reducing combustor load, the combustion efficiency and emission characteristics were improved to a little extent. No evidence of bed agglomeration was found during 30-h combustion tests on this conical fluidized-bed combustor using alumina sand as the bed material. However, the timescale effect on the composition of the bed material was

Fossil Energy Program Annual Progress Report for the Period April 1, 2000 through March 31, 2001

Energy Technology Data Exchange (ETDEWEB)

Judkins, RR

2001-06-14

This report covers progress made at Oak Ridge National Laboratory (ORNL) on research and development projects that contribute to the advancement of fossil energy technologies. Projects on the ORNL Fossil Energy Program are supported by the U.S. Department of Energy (DOE) Office of Fossil Energy, the DOE National Energy Technology Laboratory (NETL), the DOE Fossil Energy Clean Coal Technology (CCT) Program, the DOE National Petroleum Technology Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve (SPR). The ORNL Fossil Energy Program research and development activities cover the areas of coal, clean coal technology, gas, petroleum, and support to the SPR. An important part of the Fossil Energy Program is technical management of all activities on the DOE Fossil Energy Advanced Research (AR) Materials Program. The AR Materials Program involves research at other DOE and government laboratories, at universities, and at industrial organizations.

Wood-energy: success depends on the price of fossil energies and on the carbon tax level

International Nuclear Information System (INIS)

Defaye, Serge; Maindrault, Marc

2016-01-01

Illustrated by several graphs indicating the structure of fossil energy prices, the comparison between domestic fuel and wood-energy for public network exploitation, the levels of fossil prices and carbon tax for non-subsidised projects, this article analyses the development of biomass (and more particularly wood-energy), the success of which depends on the price of fossil energies and on the carbon tax level. It outlines the differences of price-building elements between fossil and renewable heat, that subsidies are necessary if reference prices are low. It discusses the influence of carbon tax level and of fossil prices. It finally identifies conditions to be met (reduction of fossil energy supply and therefore higher fossil prices, introduction of a carbon tax) to reach COP objectives

Paleoenvironmental conditions and strontium isotope stratigraphy in the Paleogene Gafsa Basin (Tunisia) deduced from geochemical analyses of phosphatic fossils

Science.gov (United States)

Kocsis, László; Ounis, Anouar; Chaabani, Fredj; Salah, Neili Mohamed

2013-06-01

Fossil shark teeth and coprolites from three major phosphorite occurrences in the Gafsa Basin (southwestern Tunisia) were investigated for their geochemical compositions to improve local stratigraphy and to better assess paleoenvironmental conditions. 87Sr/86Sr isotope ratios of shark teeth from the Early Maastrichtian El Haria Formation and from the Early Eocene Métlaoui s.s. Formation yielded Sr isotope ages of 68 ± 1 and 47.9 ± 1.3 Ma, respectively, which accord with the expected stratigraphic positions of these sediments. Conversely, shark teeth from the Paleocene-Eocene Chouabine Formation have large variation in Sr isotope ratios even within individual layers. After statistical treatment and then elimination of certain outlier samples, three age-models are proposed and discussed. The most reasonable solution includes three subsequent Sr ages of 61.8 ± 2.2 Ma, 57.2 ± 1.8 and 54.6 ± 1.6 for layer IX, layers VIII-V and layers IV-0, respectively. Three scenarios are discussed for explanation of the presence of the outliers: (1) diagenesis, (2) re-working and (3) locally controlled seawater Sr isotope ratio. The most plausible account for the higher 87Sr/86Sr ratios relative to the global ocean in some fossils is enhanced intrabasinal re-working due to low sea level. Conversely, the sample with lower 87Sr/86Sr than the global seawater may link to diagenesis or to seawater influenced by weathering of Late Cretaceous marine carbonates, which latter is supported by model calculation as well. The ɛNd values of these fossils are very similar to those reported for Paleogene and Late Cretaceous Tethyan seawater and are compatible with the above interpretations. The relatively low oxygen isotope values in shark teeth from the topmost phosphate bed of the Chouabine Formation, together with the Sr isotope results, point toward recovering better connections with the open sea. These δ18O data reflect elevated ambient temperature, which may link to the Early Eocene

A comprehensive economic evaluation of integrated desalination systems using fossil fuelled and nuclear energies and including their environmental costs

International Nuclear Information System (INIS)

Nisan, S.; Benzarti, N.

2008-01-01

Seawater desalination is now widely accepted as an attractive alternative source of freshwater for domestic and industrial uses. Despite the considerable progress made in the relevant technologies desalination, however, remains an energy intensive process in which the energy cost is the paramount factor. This Study is a first of a kind in that we have integrated the environmental costs into the power and desalination costs. The study has focused on the seawater desalination cost evaluation of the following systems. It is supposed that they will be operating in the co-generation mode (Simultaneous production of electrical power and desalted water) in 2015: Fossil fuelled based systems such as the coal and oil fired plants and the gas turbine combined cycle plant, coupled to MED, and RO; Pressurised water reactors such as the PWR-900 and the AP-600, coupled to MED, and RO; High temperature reactors such as the GT-MHR, the PBMR, coupled to MED, with the utilisation of virtually free waste-heat provided by these reactors. The study is made in real site-specific conditions of a site In Southern Europe. Sensitivity studies for different parameters such as the fossil fuel prices, interest and discount rates, power costs etc., have also been undertaken. The results obtained are then used to evaluate the financial interest of selected integrated desalination systems in terms of a detailed cash flow analysis, providing the net present values, pay back periods and the internal rate of returns. Analysis of the results shows that among the fossil fuelled systems the power and desalination costs by circulating fluidized bed coal fired plant would be the lowest with current coal prices. Those by oil fired plants would be highest. In all cases, integrated nuclear energy systems would lead to considerably lower power and water costs than the corresponding coal based systems. When external costs for different energies are internalized in power and water costs, the relative cost

The unstudied barriers to widespread renewable energy deployment: Fossil fuel price responses

International Nuclear Information System (INIS)

Foster, Edward; Contestabile, Marcello; Blazquez, Jorge; Manzano, Baltasar; Workman, Mark; Shah, Nilay

2017-01-01

Renewable energy policy focuses on supporting the deployment of renewable power generators so as to reduce their costs through scale economies and technological learning. It is expected that, once cost parity with fossil fuel generation is achieved, a transition towards renewable power should continue without the need for further renewable energy subsidies. However, this reasoning implicitly assumes that the cost of fossil fuel power generation does not respond to the large scale penetration of renewable power. In this paper we build a standard economic framework to test the validity of this assumption, particularly in the case of coal and gas fired power generation. We find that it is likely that the cost of fossil fuel power generation will respond to the large scale penetration of renewables, thus making the renewable energy transition slower or more costly than anticipated. More analysis is needed in order to be able to quantify this effect, the occurrence of which should be considered in the renewable energy discourse. - Highlights: • Renewables are increasingly competing with fossil fuel power generation. • This may have various effects on the fossil fuel generation value chain. • One such possible effect is a response of fossil fuel prices to renewables deployment. • We have tested this hypothesis using a supply-demand analytical framework. • We found that the effect is likely to occur and should be further investigated.

The fossilized birth–death process for coherent calibration of divergence-time estimates

Science.gov (United States)

Heath, Tracy A.; Huelsenbeck, John P.; Stadler, Tanja

2014-01-01

Time-calibrated species phylogenies are critical for addressing a wide range of questions in evolutionary biology, such as those that elucidate historical biogeography or uncover patterns of coevolution and diversification. Because molecular sequence data are not informative on absolute time, external data—most commonly, fossil age estimates—are required to calibrate estimates of species divergence dates. For Bayesian divergence time methods, the common practice for calibration using fossil information involves placing arbitrarily chosen parametric distributions on internal nodes, often disregarding most of the information in the fossil record. We introduce the “fossilized birth–death” (FBD) process—a model for calibrating divergence time estimates in a Bayesian framework, explicitly acknowledging that extant species and fossils are part of the same macroevolutionary process. Under this model, absolute node age estimates are calibrated by a single diversification model and arbitrary calibration densities are not necessary. Moreover, the FBD model allows for inclusion of all available fossils. We performed analyses of simulated data and show that node age estimation under the FBD model results in robust and accurate estimates of species divergence times with realistic measures of statistical uncertainty, overcoming major limitations of standard divergence time estimation methods. We used this model to estimate the speciation times for a dataset composed of all living bears, indicating that the genus Ursus diversified in the Late Miocene to Middle Pliocene. PMID:25009181

Coolability of volumetrically heated particle beds

Energy Technology Data Exchange (ETDEWEB)

Rashid, Muhammad

2017-03-22

In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al{sub 2}O{sub 3} particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m{sup 2}, polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements

Coolability of volumetrically heated particle beds

International Nuclear Information System (INIS)

Rashid, Muhammad

2017-01-01

In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al 2 O 3 particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m 2 , polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements in

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.

Flow characteristics of counter-current flow in debris bed

International Nuclear Information System (INIS)

Abe, Yutaka; Adachi, Hiromichi

2004-01-01

In the course of a severe accident, a damaged core would form a debris bed consisting of once-molten and fragmented fuel elements. It is necessary to evaluate the dryout heat flux for the judgment of the coolability of the debris bed during the severe accident. The dryout phenomena in the debris bed is dominated by the counter-current flow limitation (CCFL) in the debris bed. In this study, air-water counter-current flow behavior in the debris bed is experimentally investigated with glass particles simulating the debris beds. In this experiment, falling water flow rate and axial pressure distributions were experimentally measured. As the results, it is clarified that falling water flow rate becomes larger with the debris bed height and the pressure gradient in the upper region of the debris bed is different from that in the lower region of the debris bed. These results indicate that the dominant region for CCFL in the debris bed is identified near the top of the debris bed. Analytical results with annular flow model indicates that interfacial shear stress in the upper region of the debris bed is larger than that in the lower region of the debris bed. (author)

Fluidized-bed nuclear reactor

International Nuclear Information System (INIS)

Grimmett, E.S.; Kunze, J.F.

1975-01-01

A reactor vessel containing a fluidized-bed region of particulate material including both a neutron-moderating and a fertile substance is described. A gas flow including fissile material passes through the vessel at a sufficient rate to fluidize the particulate material and at a sufficient density to support a thermal fission reaction within the fluidized-bed region. The high-temperature portion of a heat transfer system is located within the fluidized-bed region of the reactor vessel in direct contact with the fluidized particles. Heat released by fission is thereby transferred at an enhanced rate to a coolant circulating within the heat transfer system. Fission products are continuously removed from the gas flow and supplemental fissile material added during the reactor operation. (U.S.)

New fossil seeds of Eurya (Theaceae from East Asia and their paleobiogeographic implications

Directory of Open Access Journals (Sweden)

Hai Zhu

2016-06-01

Full Text Available Eurya has an excellent fossil record in Europe, but it has only a few fossil occurrences in East Asia though this vast area houses the highest modern diversity of the genus. In this study, three-dimensionally preserved fossil seeds of Eurya stigmosa (Ludwig Mai from the late Pliocene of northwestern Yunnan, southwestern China are described. The seeds are compressed and flattened, slightly campylotropous, and nearly circular to slightly angular in shape. The surface of the seeds is sculptured by a distinctive foveolate pattern, consisting of funnel-shaped and finely pitted cells. Each seed valve contains a reniform or horseshoe-shaped embryo cavity, a characteristic condyle structure and an internal raphe. These fossil seeds represent one of the few fossil records of Eurya in East Asia. This new finding therefore largely extends the distributional ranges of Eurya during Neogene. Fossil records summarized here show that Eurya persisted in Europe until the early Pleistocene, but disappeared thereafter. The genus might have first appeared in East Asia no later than the late Oligocene, and dispersed widely in regions such as Japan, Nepal, and southwestern China.

Mapping Metal Elements of Shuangbai Dinosaur Fossil by Synchrotron X-ray Fluorescence Microprobe

International Nuclear Information System (INIS)

Wang, Y.; Qun, Y.; Ablett, J.

2008-01-01

The metal elements mapping of Shuangbai dinosaur fossil, was obtained by synchrotron x-ray fluorescence (SXRF). Eight elements, Ca, Mn, Fe, Cu, Zn, As, Y and Sr were determined. Elements As and Y were detected for the first time in the dinosaur fossil. The data indicated that metal elements are asymmetrical on fossil section. This is different from common minerals. Mapping metals showed that metal element As is few. The dinosaur most likely belongs to natural death. This is different from Zigong dinosaurs which were found dead from poisoning. This method has been used to find that metals Fe and Mn are accrete, and the same is true for Sr and Y. This study indicated that colloid granule Fe and Mn, as well as Sr and Y had opposite electric charges in lithification process of fossils. By this analysis, compound forms can be ascertained. Synchrotron light source x-ray fluorescence is a complementary method that shows mapping of metal elements at the dinosaur fossil, and is rapid, exact and intuitionist. This study shows that dinosaur fossil mineral imaging has a potential in reconstructing the paleoenvironment and ancient geology.

Diatoms: a fossil fuel of the future.

Science.gov (United States)

Levitan, Orly; Dinamarca, Jorge; Hochman, Gal; Falkowski, Paul G

2014-03-01

Long-term global climate change, caused by burning petroleum and other fossil fuels, has motivated an urgent need to develop renewable, carbon-neutral, economically viable alternatives to displace petroleum using existing infrastructure. Algal feedstocks are promising candidate replacements as a 'drop-in' fuel. Here, we focus on a specific algal taxon, diatoms, to become the fossil fuel of the future. We summarize past attempts to obtain suitable diatom strains, propose future directions for their genetic manipulation, and offer biotechnological pathways to improve yield. We calculate that the yields obtained by using diatoms as a production platform are theoretically sufficient to satisfy the total oil consumption of the US, using between 3 and 5% of its land area. Copyright © 2014 Elsevier Ltd. All rights reserved.

How do the stock prices of new energy and fossil fuel companies correlate? Evidence from China

International Nuclear Information System (INIS)

Wen, Xiaoqian; Guo, Yanfeng; Wei, Yu; Huang, Dengshi

2014-01-01

This study documents the return and volatility spillover effect between the stock prices of Chinese new energy and fossil fuel companies using the asymmetric BEKK model. Based on daily samples taken from August 30, 2006 to September 11, 2012, the dynamics of new energy/fossil fuel stock spillover are found to be significant and asymmetric. Compared with positive news, negative news about new energy and fossil fuel stock returns leads to larger return changes in their counter assets. News about both new energy and fossil fuel stock returns spills over into variances of their counter assets, and the volatility spillovers depend complexly on the respective signs of the return shocks of each asset. The empirical results demonstrate that new energy and fossil fuel stocks are generally viewed as competing assets, that positive news about new energy stocks could affect the attractiveness of fossil fuel stocks and that new energy stock investment is more speculative and riskier than fossil fuel stock investment. These results have potential implications for asset allocation, financial risk management and energy policymaking. - Highlights: • The dynamics of Chinese new energy/fossil fuel stock spillover are significant and asymmetric. • New energy and fossil fuel stocks are generally viewed as competing assets. • Positive news about new energy stocks affects the attractiveness of fossil fuel stocks. • New energy stock investment is more speculative and riskier than fossil fuel stock investment

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)

Proceedings of the ninth annual conference on fossil energy materials

Energy Technology Data Exchange (ETDEWEB)

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

1995-08-01

The Ninth Annual Conference on Fossil Energy materials was held in Oak Ridge, Tennessee, on May 16--18, 1995. The meeting was sponsored by the US Department of Energy`s (DOE) Office of Fossil Energy through the Advanced Research and Technology Development (AR&TD) Materials Program. 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 Oak Ridge Operations Office with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) structural ceramics, (2) new alloys and coatings, (3) functional materials, and (4) technology assessment and transfer. This conference is held each year to review the work on all of the projects of the Program. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.

A reappraisal of the stratigraphy and chronology of Early Pliocene palaeontological sites from Lanzarote Island containing fossil terrestrial animals

Science.gov (United States)

Lomoschitz, Alejandro; Sánchez Marco, Antonio; Huertas, María José; Betancort, Juan F.; Isern, Arnau; Sanz, Elena; Meco, Joaquín

2016-11-01

The Famara massif, in the north of Lanzarote Island, constitutes the remains of a former island inhabited by the oldest known vertebrate fauna of the Canary archipelago off the coast of Africa. In this study, new ages are offered for the underlying and overlying basaltic lava flows of two paleontological sites. The island's three major palaeontological sites, which contain remains of this ancient fauna (Valle Grande, Valle Chico and Fuente de Gusa), are intercorrelated according to their lithologies, sedimentology, palaeontological content and geochronology. The new K/Ar age interval for the fossiliferous sedimentary deposits ranges between 4.3 ± 0.7 and 3.78 ± 0.71 Ma, within the Early Pliocene, and shows that the first known terrestrial animals in Lanzarote were present on the island for about 500 ka. The principal component of the deposits is a bioclastic calcarenite of aeolian origin (sand sheet deposits), which is present in all three sites and constitutes 65% of the beds. The remaining 35% is of fluvial-aeolian origin (mainly stream deposits). All the beds contain the same fossils (insect egg pods, land snails, avian eggshells and tortoise eggshells). The local palaeogeography and the formation of the deposits were conditioned by a flat plain, larger than 16 km2, over which aeolian sands moved freely with a prevailing NNE-WSW wind direction. In agreement with previous investigations, the palaeoclimate in this interval (ca. 4.3 to 3.8 Ma) must have been mainly dry with some rainy episodes.

2D numerical model of particle-bed collision in fluid-particle flows over bed

Czech Academy of Sciences Publication Activity Database

Lukerchenko, Nikolay; Chára, Zdeněk; Vlasák, Pavel

2006-01-01

Roč. 44, č. 1 (2006), s. 70-78 ISSN 0022-1686 R&D Projects: GA AV ČR IAA2060201 Institutional research plan: CEZ:AV0Z20600510 Keywords : saltation * particle-bed collision * collision angle * bed roughness Subject RIV: BK - Fluid Dynamics Impact factor: 0.527, year: 2006

Fluidized-bed reactors processes and operating conditions

CERN Document Server

Yates, John G

2016-01-01

The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.

Effect of various drying bed on thermodynamic characteristics

Directory of Open Access Journals (Sweden)

Ali Motevali

2017-09-01

Full Text Available In this study thermodynamic parameter and energy consumption in drying of two plant dill and mint in three bed drying including fix, semi fix and fluid with using a hot air drying was investigated. Experimental was conducted in three bed drying including fix, semi fix and fluid and four levels temperature (30, 40, 50 and 60 °C. Maximum energy consumption in dill drying at 40 °C and fluid bed to be 16.41 MJ and minimum energy consumption at 30 °C and fix bed to be 2.77 MJ. Also minimum energy consumption in mint drying at 60 °C and fix bed to be 3.64 MJ and maximum energy consumption at 40 °C and fluid bed to be 28.65 MJ. The highest energy, drying and thermal efficiency for both mint and dill was achieved at 60 °C on the fixed bed, whereas the lowest efficiency was at 40 °C and on the fluidized bed. Also the highest power and specific heat consumption for both mint and dill was achieved at 40 °C on the fluid bed, whereas the lowest efficiency was at 30 °C and on the fluidized bed.

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

Deactivation and Storage Issues Shared by Fossil and Nuclear Facilities

International Nuclear Information System (INIS)

Thomas S. LaGuardia

1998-01-01

The deactivation of a power plant, be it nuclear or fossil fueled, requires that the facility be placed in a safe and stable condition to prevent unacceptable exposure of the public or the environment to hazardous materials until the facility can be decommissioned. The conditions at two Texas plants are examined. These plants are fossil fueled, but their conditions might be duplicated at a nuclear plant

Fluidized bed dry dense medium coal beneficiation

CSIR Research Space (South Africa)

North, Brian C

2017-10-01

Full Text Available medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal...

Dating of two human fossil bones from Romania by accelerator mass spectrometry

International Nuclear Information System (INIS)

Olariu, Agata; Skog, Goeran; Hellborg, Ragnar; Stenstroem, Kristina; Faarinen, Mikko; Persson, Per; Alexandrescu, Emilian

2005-01-01

In this study we have dated two fossil remains found in Romania, by the method of radiocarbon using the technique of the accelerator mass spectrometry. The human fossil remains from Woman's cave, Baia de Fier, have been dated to the age 30150 ± 800 years BP, and the skull, from the Cioclovina cave has been dated to the age 29000 ± 700 years BP. These are among the most ancient dated human fossil remains from Romania, possibly belonging to the upper Paleolithic, the Aurignacian period. (authors)

Effectiveness of Bed Bug Pesticides

Science.gov (United States)

Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

Carbon dioxide emissions from fossil-fuel use, 1751-1950

Energy Technology Data Exchange (ETDEWEB)

Andres, R.J.; Fielding, D.J. [Alaska Fairbanks Univ., Fairbanks AK (United States). Inst. of Northern Engineering; Marland, G.; Boden, T.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Kumar, N.; Kearney, A.T. [153 East 53rd Street, New York, NY (United States)

1999-09-01

Newly compiled energy statistics allow for an estimation of the complete time series of carbon dioxide (CO{sub 2}) emissions from fossil-fuel use for the years 1751 to the present. The time series begins with 3 x 10{sup 6} metric tonnes carbon (C). This initial flux represents the early stages of the fossil-fuel era. The CO{sub 2} flux increased exponentially until World War I. The time series derived here seamlessly joins the modern 1950 to present time series. Total cumulative CO{sub 2} emissions through 1949 were 61.0 x 10{sup 9} tonnes C from fossil-fuel use, virtually all since the beginning of the Industrial Revolution around 1860. The rate of growth continues to grow during present times, generating debate on the probability of enhanced greenhouse warming. In addition to global totals, national totals and 1 deg global distributions of the data have been calculated 18 refs, 4 figs, 2 tabs

Microalgal and Terrestrial Transport Biofuels to Displace Fossil Fuels

Directory of Open Access Journals (Sweden)

Lucas Reijnders

2009-02-01

Full Text Available 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, sugar beet or wheat and biodiesel from rapeseed. When terrestrial biofuels are to replace mineral oil-derived transport fuels, large areas of good agricultural land are needed: about 5x108 ha in the case of biofuels from sugarcane or oil palm, and at least 1.8-3.6x109 ha in the case of ethanol from wheat, corn or sugar beet, as produced in industrialized countries. Biofuels from microalgae which are commercially produced with current technologies do not appear to outperform terrestrial plants such as sugarcane in their ability to displace fossil fuels. Whether they will able to do so on a commercial scale in the future, is uncertain.

Thermal treatment of high-caloric waste in fluidized bed incineration plants in Austria

International Nuclear Information System (INIS)

Ragossnig, A.M.

2001-05-01

The importance of thermal treatment of waste and residues in Austria is expected to rise due to the current changes of the legal situation in waste management. Assessing the rank order of different thermal treatment processes for waste management it has been shown that - especially caused by the rising importance of the mechanical treatment step in the mechanical-biological residual waste treatment and the subsequent necessity of the thermal treatment of a high-caloric preprocessed waste stream - the importance of the fluidized bed technology will increase. The main advantages are the high existing capacities as well as the flexibility of this technology in regard of fuel properties and further on the fact of the lacking influence of the ash towards the quality of a product. This is true although the thermal treatment in fluidized bed incinerators requires some processing of the waste. This doctoral thesis also contains a thorough physical and chemical characterization of various waste fuels - especially those which have been used during full scale incineration experiments. This characterization includes a comparison with fossil fuel. The practical part contains the documentation and balancing of full scale incineration experiments. A comparison of a reference experiment with experiments when waste fuel has been thermally utilized showed that a significant increase of emissions to the atmosphere has not been observed. Based on the incineration experiments conclusions in regard of waste fuels as well as different categories of thermal treatment plants are being stated. Finally, a recommendation of the assignation of various waste streams to different categories of thermal treatment plants is being made. (author)

Response of bed mobility to sediment supply in natural gravel bed channels: A detailed examination and evaluation of mobility parameters

Science.gov (United States)

T. E. Lisle; J. M. Nelson; B. L. Barkett; J. Pitlick; M. A. Madej

1998-01-01

Recent laboratory experiments have shown that bed mobility in gravel bed channels responds to changes in sediment supply, but detailed examinations of this adjustment in natural channels have been lacking, and practical methodologies to measure bed mobility have not been tested. We examined six gravel-bed, alternate-bar channels which have a wide range in annual...

Torsion testing of bed joints

DEFF Research Database (Denmark)

Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

2008-01-01

This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

A low tritium hydride bed inventory estimation technique

Energy Technology Data Exchange (ETDEWEB)

Klein, J.E.; Shanahan, K.L.; Baker, R.A. [Savannah River National Laboratory, Aiken, SC (United States); Foster, P.J. [Savannah River Nuclear Solutions, Aiken, SC (United States)

2015-03-15

Low tritium hydride beds were developed and deployed into tritium service in Savannah River Site. Process beds to be used for low concentration tritium gas were not fitted with instrumentation to perform the steady-state, flowing gas calorimetric inventory measurement method. Low tritium beds contain less than the detection limit of the IBA (In-Bed Accountability) technique used for tritium inventory. This paper describes two techniques for estimating tritium content and uncertainty for low tritium content beds to be used in the facility's physical inventory (PI). PI are performed periodically to assess the quantity of nuclear material used in a facility. The first approach (Mid-point approximation method - MPA) assumes the bed is half-full and uses a gas composition measurement to estimate the tritium inventory and uncertainty. The second approach utilizes the bed's hydride material pressure-composition-temperature (PCT) properties and a gas composition measurement to reduce the uncertainty in the calculated bed inventory.

Fossil Hunting: Intracluster Stars in Virgo

NARCIS (Netherlands)

Murphy, Eric; Bridge, Carrie; Desai, Vandana; Kenney, Jeffrey; Krick, Jessica; Surace, Jason; van Gorkom, Jacqueline

2009-01-01

In dense clusters, galaxy interactions and mergers play a significant role in galaxy evolution. During these interactions, tidal forces can lead to the ejection of stars from their parent galaxies; these stars are a fossil record of environmentally-driven galaxy evolution. We propose to map the

Economic competitiveness of seawater desalinated by nuclear and fossil energy

International Nuclear Information System (INIS)

Tian Li; Wang Yongqing; Guo Jilin; Liu Wei

2001-01-01

The levelized discounted production water cost method and the new desalination economic evaluation program (DEEP1.1) were used to compare the economics of desalination using nuclear or fossil energy. The results indicate that nuclear desalination is more economic than fossil desalination with reverse osmosis (RO), multi-effect distillation (MED) and multi-stage flash (MSF). The desalination water cost varies depending on the desalination technology and the water plant size from 0.52-1.98 USD·m -3 with the lowest water price by RO and the highest by MSF. The sensitivity factors for the economic competitiveness increases in order of the discounted rate, desalination plant scale, fossil fuel price, specific power plant investment, seawater temperature and total dissolve solid (TDS). The highest water cost is about 22.6% more than the base case

Semi-dry flue gas desulfurization using Ca(OH)2 in a fluidized bed reactor with bed materials

International Nuclear Information System (INIS)

Park, Young Oak; Roh, Hak Jae; Oh, Chang Sup; Kim, Yong Ha

2010-01-01

The main objective of present work is to reduce sulfur dioxide emission from power plant for the environment protection. The fluidized bed (FB) was used as the reactor with bed materials in a new semi-dry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency (>98%). Fine powder of Ca(OH) 2 as sorbent and water were continuously fed separately to the bed reactor where bed materials (2 mm glass beads) were fluidized vigorously with flue gas (flow 720 Nm 3 / hr) using bench scale plant of stainless steel column. We have investigated different effects of water injection flow rate, Ca/ S molar ratio and weight of bed materials on SO 2 removal. The increments in the Ca/ S molar ratio and water injection flow rate have been resulted higher desulfurization efficiency with certain disadvantages such as higher sorbent cost and lower temperature of the treated flue gas, respectively. (author)

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.

A comparative study of the ocular skeleton of fossil and modern chondrichthyans

Science.gov (United States)

Pilgrim, Brettney L; Franz-Odendaal, Tamara A

2009-01-01

Many vertebrates have an ocular skeleton composed of cartilage and/or bone situated within the sclera of the eye. In this study we investigated whether modern and fossil sharks have an ocular skeleton, and whether it is conserved in morphology. We describe the scleral skeletal elements of three species of modern sharks and compare them to those found in fossil sharks from the Cleveland Shale (360 Mya). We also compare the elements to contemporaneous arthrodires from the same deposit. Surprisingly, the morphology of the skeletal support of the eye was found to differ significantly between modern and fossil sharks. All three modern shark species examined (spiny dogfish shark Squalus acanthias, porbeagle shark Lamna nasus and blue shark Prionace glauca) have a continuous skeletal element that encapsulates much of the eyeball; however, the tissue composition is different in each species. Histological and morphological examination revealed scleral cartilage with distinct tesserae in parts of the sclera of the porbeagle and blue shark, and more diffuse calcification in the dogfish. Strengthening of the scleral cartilage by means of tesserae has not been reported previously in the shark eye. In striking contrast, the ocular skeleton of fossil sharks comprises a series of individual elements that are arranged in a ring, similar to the arrangement in modern and fossil reptiles. Fossil arthrodires also have a multi-unit sclerotic ring but these are composed of fewer elements than in fossil sharks. The morphology of these elements has implications for the behaviour and visual capabilities of sharks that lived during the Devonian Period. This is the first time that such a dramatic variation in the morphology of scleral skeletal elements has been observed in a single lineage (Chondrichthyes), making this lineage important for broadening our understanding of the evolution of these elements within jawed vertebrates. PMID:19538630

Adaptation, plant evolution, and the fossil record

Science.gov (United States)

Knoll, A. H.; Niklas, K. J.

1987-01-01

The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases

Does Bedding Affect the Airway and Allergy?

Directory of Open Access Journals (Sweden)

RW Siebers

2011-03-01

Full Text Available Various cross-sectional and longitudinal studies have suggested that synthetic bedding is associated with asthma, allergic rhinitis and eczema while feather bedding seems to be protective. Synthetic bedding items have higher house dust mite allergen levels than feather bedding items. This is possibly the mechanism involved although fungal and bacterial proinflammatory compounds and volatile organic compounds may play a role. In this review we present and discuss the epidemiological evidence and suggest possible mechanisms. Primary intervention studies are required to show whether feather bedding is protective for the development of childhood asthma and allergic diseases while secondary intervention studies are required to potentially reduce symptoms and medication use in subjects with established disease.

Does bedding affect the airway and allergy?

Science.gov (United States)

Siebers, R W; Crane, J

2011-04-01

Various cross-sectional and longitudinal studies have suggested that synthetic bedding is associated with asthma, allergic rhinitis and eczema while feather bedding seems to be protective. Synthetic bedding items have higher house dust mite allergen levels than feather bedding items. This is possibly the mechanism involved although fungal and bacterial proinflammatory compounds and volatile organic compounds may play a role. In this review we present and discuss the epidemiological evidence and suggest possible mechanisms. Primary intervention studies are required to show whether feather bedding is protective for the development of childhood asthma and allergic diseases while secondary intervention studies are required to potentially reduce symptoms and medication use in subjects with established disease.

Comparative study between fluidized bed and fixed bed reactors in methane reforming with CO2 and O2 to produce syngas

International Nuclear Information System (INIS)

Jing Qiangshan; Lou Hui; Mo Liuye; Zheng Xiaoming

2006-01-01

Reforming of methane with carbon dioxide and oxygen was investigated over Ni/MgO-SiO 2 catalysts using fixed bed and fluidized bed reactors. The conversions of CH 4 and CO 2 in a fluidized bed reactor were close to thermodynamic equilibrium. The activity and stability of the catalyst in the fixed bed reactor were lower than that in the fluidized bed reactor due to carbon deposition and nickel sintering. TGA and TEM techniques were used to characterize the spent catalysts. The results showed that a lot of whisker carbon was found on the catalyst in the rear of the fixed bed reactor, and no deposited carbon was observed on the catalysts in the fluidized bed reactor after reaction. It is suggested that this phenomenon is related to a permanent circulation of catalyst particles between the oxygen rich and oxygen free zones. That is, fluidization of the catalysts in the fluidized bed reactor favors inhibiting deposited carbon and thermal uniformity in the reactor

Transient quenching of superheated debris beds during bottom reflood

International Nuclear Information System (INIS)

Tutu, N.K.; Ginsberg, T.; Klein, J.; Schwarz, C.E.; Klages, J.

1984-01-01

The experimental data suggest that for small liquid supply rate and low initial particle temperature, the bed quench process is a one-dimensional frontal phenomenon. The bed heat flux is constant during most of the duration of the quench period. The range of conditions which display one-dimensional frontal cooling characteristics is identified as the deep bed regime of bed quenching, and a limiting mathematical model was developed to describe the observed behavior. For large liquid supply rate and high initial bed temperature, the bed quench process is a complex phenomenon. Under these conditions, the bed heat flux displays a nonuniform time dependence. In order to characterize this shallow bed regime, it was necessary to develop a detailed transient model of the coolant-debris interaction. This model, while developed for the shallow bed regime, also applies to the deep bed regime. Numerical computations clearly demonstrate the importance of developing a general reliable model for the solid-fluid heat transfer coefficients

The Importance of Splat Events to the Spatiotemporal Structure of Near-Bed Fluid Velocity and Bed Load Motion Over Bed Forms: Laboratory Experiments Downstream of a Backward Facing Step

Science.gov (United States)

Leary, K. C. P.; Schmeeckle, M. W.

2017-12-01

Flow separation/reattachment on the lee side of alluvial bed forms is known to produce a complex turbulence field, but the spatiotemporal details of the associated patterns of bed load sediment transported remain largely unknown. Here we report turbulence-resolving, simultaneous measurements of bed load motion and near-bed fluid velocity downstream of a backward facing step in a laboratory flume. Two synchronized high-speed video cameras simultaneously observed bed load motion and the motion of neutrally buoyant particles in a laser light sheet 6 mm above the bed at 250 frames/s downstream of a 3.8 cm backward facing step. Particle Imaging Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV) were used to characterize fluid turbulent patterns, while manual particle tracking techniques were used to characterize bed load transport. Octant analysis, conducted using ADV data, coupled with Markovian sequence probability analysis highlights differences in the flow near reattachment versus farther downstream. Near reattachment, three distinct flow patterns are apparent. Farther downstream we see the development of a dominant flow sequence. Localized, intermittent, high-magnitude transport events are more apparent near flow reattachment. These events are composed of streamwise and cross-stream fluxes of comparable magnitudes. Transport pattern and fluid velocity data are consistent with the existence of permeable "splat events," wherein a volume of fluid moves toward and impinges on the bed (sweep) causing a radial movement of fluid in all directions around the point of impingement (outward interaction). This is congruent with flow patterns, identified with octant analysis, proximal to flow reattachment.

Fluid-bed methane proposed

Energy Technology Data Exchange (ETDEWEB)

1981-05-01

The first full scale plant for the production of methane from organic waste could be built in the next few years believes M.J. Nyns of the University of Louvain, Belgium, utilizing either expanded bed or fluidised bed systems, with more than one stage, in a continuous flow arrangement. Up to 8.0 m cubed gas/m cubed digester/day could be produced with residence times reduced to 34 hours.

Thermomechanical interactions of particle bed-structural wall in a layered configuration. Pt. 1. Effect of particle bed thermal expansions

International Nuclear Information System (INIS)

Tehranian, F.

1995-01-01

Materials in the form of particle beds have been considered for shielding and tritium breeding as well as neutron multiplication in many of the conceptual reactor design studies. As the level of effort of the fusion blanket community in the area of out-of-pile and in-pile (ITER) testing of integrated test modules increases, so does the need for modelling capability for predicting the thermomechanical responses of the test modules under reactor environment.In this study, the thermomechanical responses of a particle bed-structural wall system in a layered configuration, subjected to bed temperature rise and/or external coolant pressure, were considered. Equations were derived which represent the dependence of the particle-to-particle and particle-to-wall contact forces and areas on the structural wall deformations and in turn on the thermomechanical loads. Using the derived equations, parametric analyses were performed to study the variations in the thermomechanical response quantities of a beryllium particle bed-stainless steel structural wall when subjected to thermomechanical loads. The results are presented in two parts. In Part I, presented in this paper, the derivation of the analytical equations and the effects of bed temperature rise are discussed. In Part II of this study, also presented in this symposium, the effects of external coolant pressure as well as the combined effects of bed temperature rise and coolant pressure on the thermomechanical responses are given.It is shown that, depending on the stiffness of the structural walls, uniform bed temperature rises in the range 100-400 C result in non-uniform effective thermal properties through the prticle bed and could increase the bed effective thermal conductivity by a factor of 2-5 and the bed-wall interface thermal conductance by even a larger factor. (orig.)

Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

Science.gov (United States)

Delfino, Massimo

2017-07-13

Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

Better backs by better beds?

DEFF Research Database (Denmark)

Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

2008-01-01

mattresses have a positive effect on LBP, and especially a hard mattress is commonly believed to have a positive effect. METHODS: One hundred sixty CLBP patients were randomized to 1 of 3 groups, having a mattress/bed mounted in their sleeping room for 1 month. The beds were: (1) waterbed (Akva), (2) body......-conforming foam mattress (Tempur), and (3) a hard mattress (Innovation Futon). At baseline and after 4 weeks, a blinded observer interviewed the patients on LBP levels (0-10), daily function (activities of daily living, 0-30), and on the amount of sleeping hours/night. RESULTS: Because of dropout of 19 patients...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

An embryological perspective on the early arthropod fossil record.

Science.gov (United States)

Chipman, Ariel D

2015-12-18

Our understanding of the early evolution of the arthropod body plan has recently improved significantly through advances in phylogeny and developmental biology and through new interpretations of the fossil record. However, there has been limited effort to synthesize data from these different sources. Bringing an embryological perspective into the fossil record is a useful way to integrate knowledge from different disciplines into a single coherent view of arthropod evolution. I have used current knowledge on the development of extant arthropods, together with published descriptions of fossils, to reconstruct the germband stages of a series of key taxa leading from the arthropod lower stem group to crown group taxa. These reconstruction highlight the main evolutionary transitions that have occurred during early arthropod evolution, provide new insights into the types of mechanisms that could have been active and suggest new questions and research directions. The reconstructions suggest several novel homology hypotheses - e.g. the lower stem group head shield and head capsules in the crown group are all hypothesized to derive from the embryonic head lobes. The homology of anterior segments in different groups is resolved consistently. The transition between "lower-stem" and "upper-stem" arthropods is highlighted as a major transition with a concentration of novelties and innovations, suggesting a gap in the fossil record. A close relationship between chelicerates and megacheirans is supported by the embryonic reconstructions, and I suggest that the depth of the mandibulate-chelicerate split should be reexamined.

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.

On partial fluidization in rotating fluidized beds

International Nuclear Information System (INIS)

Kao, J.; Pfeffer, R.; Tardos, G.I.

1987-01-01

In a rotating fluidized bed, unlike in a conventional fluidized bed, the granules are fluidized layer by layer from the (inner) free surface outward at increasing radius as the gas velocity is increased. This is a very significant and interesting phenomenon and is extremely important in the design of these fluidized beds. The phenomenon was first suggested in a theoretical analysis and recently verified experimentally in the authors' laboratory. However, in the first paper, the equations presented are too cumbersome and the influence of bed thickness is not clearly stated. In this note the authors present simplified equations, based on that paper, for the pressure drop and the minimum fluidizing velocities in a rotating fluidized bed. Experimental data are also shown and compared with the theoretical model, and the effect of bed thickness is shown. Furthermore, an explanation for the observation of a maximum in the pressure drop vs. velocity curve instead of the plateau derived by Chen is proposed

GREENHOUSE GAS EMISSIONS CONTROL BY OXYGEN FIRING IN CIRCULATING FLUIDIZED BED BOILERS

Energy Technology Data Exchange (ETDEWEB)

Nsakala ya Nsakala; Gregory N. Liljedahl

2003-05-15

Given that fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this study, ALSTOM Power Inc. (ALSTOM) has investigated several coal fired power plant configurations designed to capture CO{sub 2} from effluent gas streams for use or sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). Additionally, oxygen firing in Circulating Fluid Bed Boilers (CFB's) can be more economical than in PC or Stoker firing, because recirculated gas flow can be reduced significantly. Oxygen-fired PC and Stoker units require large quantities of recirculated flue gas to maintain acceptable furnace temperatures. Oxygen-fired CFB units, on the other hand, can accomplish this by additional cooling of recirculated solids. The reduced recirculated gas flow with CFB units results in significant Boiler Island cost savings. Additionally, ALSTOM has identified several advanced/novel plant configurations, which improve the efficiency and cost of the CO{sub 2} product cleanup and compression process. These advanced/novel concepts require long development efforts. An economic analysis indicates that the proposed oxygen-firing technology in circulating fluidized boilers could be developed and deployed economically in the near future in enhanced oil recovery (EOR) applications or enhanced gas recovery (EGR), such as coal bed methane recovery. ALSTOM received a Cooperative Agreement from the US

Theory and measurements of electrophoretic effects in monolith, fixed-bed, and fluidized-bed plasma reactors

International Nuclear Information System (INIS)

Morin, T.J.

1989-01-01

Pressure gradients and secondary flow fields generated by the passage of electrical current in a d.c. gas discharge or gas laser are topics of longstanding interest in the gaseous electronics literature. These hydrodynamic effects of space charge fields and charged particle density gradients have been principally exploited in the development of gas separation and purification processes. In recent characterization studies of fixed-bed and fluidized-bed plasma reactors several anomalous flow features have been observed. These reactors involve the contacting of a high-frequency, resonantly-sustained, disperse gas discharge with granular solids in a fixed or fluidized bed. Anomalies in the measured pressure drops and fluidization velocities have motivated the development of an appropriate theoretical approach to, and some additional experimental investigations of electrophoretic effects in disperse gas discharges. In this paper, a theory which includes the effects of space charge and diffusion is used to estimate the electric field and charged particle density profiles. These profiles are then used to calculate velocity fields and gas flow rates for monolith, fixed-bed, and fluidized-bed reactors. These results are used to rationalize measurements of gas flow rates and axial pressure gradients in high-frequency disperse gas discharges with and without an additional d.c. axial electric field

Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents

OpenAIRE

Kimura, Yuri; Hawkins, Melissa T. R.; McDonough, Molly M.; Jacobs, Louis L.; Flynn, Lawrence J.

2015-01-01

Time calibration derived from the fossil record is essential for molecular phylogenetic and evolutionary studies. Fossil mice and rats, discovered in the Siwalik Group of Pakistan, have served as one of the best-known fossil calibration points in molecular phylogenic studies. Although these fossils have been widely used as the 12 Ma date for the Mus/Rattus split or a more basal split, conclusive paleontological evidence for the nodal assignments has been absent. This study analyzes newly reco...

Proceedings of the tenth annual conference on fossil energy materials

Energy Technology Data Exchange (ETDEWEB)

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

1996-08-01

The Tenth Annual Conference on Fossil Energy Materials was held in Knoxville, Tennessee, on May 14-16, 1996. The meeting was sponsored by the U.S. Department of Energy`s (DOE) Office of Fossil Energy through the Advanced Research and Technology Development (AR&TD) Materials Program. 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 Oak Ridge Operations Office and Oak Ridge National Laboratory (ORNL). The research is performed by staff members at ORNL and by researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) structural ceramics, (2) new alloys and coatings, (3) functional materials, and (4) technology development and transfer. This conference is held each year to review the work on all of the projects of the program. The final program for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B. Selected items have been processed separately for inclusion in the Energy Science and Technology database.

Proceedings of the sixth annual conference on fossil energy materials

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.

21 CFR 880.6060 - Medical disposable bedding.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical disposable bedding. 880.6060 Section 880.6060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.6060 Medical disposable bedding. (a) Identification. Medical disposable bedding is a device...

Uranium-series dating of fossil bones from alpine caves

International Nuclear Information System (INIS)

Leitner-Wild, E.; Steffan, I.

1993-01-01

During the course of an investigation of fossil cave bear populations the uranium-series method for absolute age determination has been applied to bone material. The applicability of the method to bone samples from alpine caves is demonstrated by the concordance of U/Th and U/Pa ages and cross-checks with the radiocarbon method. Stratigraphic agreement between bone ages and carbonate speleothem ages also indicates the potential of the uranium-series method as a suitable tool for the age determination of fossil bones from alpine cave environments. (Author)

Wave Driven Fluid-Sediment Interactions over Rippled Beds

Science.gov (United States)

Foster, Diane; Nichols, Claire

2008-11-01

Empirical investigations relating vortex shedding over rippled beds to oscillatory flows date back to Darwin in 1883. Observations of the shedding induced by oscillating forcing over fixed beds have shown vortical structures to reach maximum strength at 90 degrees when the horizontal velocity is largest. The objective of this effort is to examine the vortex generation and ejection over movable rippled beds in a full-scale, free surface wave environment. Observations of the two-dimensional time-varying velocity field over a movable sediment bed were obtained with a submersible Particle Image Velocimetry (PIV) system in two wave flumes. One wave flume was full scale and had a natural sand bed and the other flume had an artificial sediment bed with a specific gravity of 1.6. Full scale observations over an irregularly rippled bed show that the vortices generated during offshore directed flow over the steeper bed form slope were regularly ejected into the water column and were consistent with conceptual models of the oscillatory flow over a backward facing step. The results also show that vortices remain coherent during ejection when the background flow stalls (i.e. both the velocity and acceleration temporarily approach zero). These results offer new insight into fluid sediment interaction over rippled beds.

A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

International Nuclear Information System (INIS)

McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T.; Pinto, F.; Franco, C.; Gulyurtlu, I.; Armesto, L.; Cabanillas, A.; Caballero, M.A.; Aznar, M.P.

2006-01-01

Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

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).

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

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)

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.

Forecasting production of fossil fuel sources in Turkey using a comparative regression and ARIMA model

International Nuclear Information System (INIS)

Ediger, Volkan S.; Akar, Sertac; Ugurlu, Berkin

2006-01-01

This study aims at forecasting the most possible curve for domestic fossil fuel production of Turkey to help policy makers to develop policy implications for rapidly growing dependency problem on imported fossil fuels. The fossil fuel dependency problem is international in scope and context and Turkey is a typical example for emerging energy markets of the developing world. We developed a decision support system for forecasting fossil fuel production by applying a regression, ARIMA and SARIMA method to the historical data from 1950 to 2003 in a comparative manner. The method integrates each model by using some decision parameters related to goodness-of-fit and confidence interval, behavior of the curve, and reserves. Different forecasting models are proposed for different fossil fuel types. The best result is obtained for oil since the reserve classifications used it is much better defined them for the others. Our findings show that the fossil fuel production peak has already been reached; indicating the total fossil fuel production of the country will diminish and theoretically will end in 2038. However, production is expected to end in 2019 for hard coal, in 2024 for natural gas, in 2029 for oil and 2031 for asphaltite. The gap between the fossil fuel consumption and production is growing enormously and it reaches in 2030 to approximately twice of what it is in 2000

Life cycle inventory analysis of fossil energies in Japan

International Nuclear Information System (INIS)

Yoon Sungyee; Yamada, Tatsuya

1999-01-01

Given growing concerns over global warming problems in recent years, a matter of great importance has been to grasp GHG emissions from fossil energy use as accurately as possible by figuring out how much GHGs result from a life cycle (production, transportation and consumption) of various fossil energies. The objective of this study is to make a life cycle inventory (LCI) analysis of major fossil energies (coal, oil, LNG, LPG) consumed in Japan pursuant to ISO 14040. On these fossil energies imported to Japan in 1997, LCI analysis results of GHG emissions (specifically carbon dioxide and methane) put CO 2 intensity during their combustion stage (gross heat value basis) at 100:121:138:179 among LNG:LPG:oil:coal. But, in life cycle terms, the ratios turned to be 100:110:120:154. The world average (gross heat value basis) gained from IPCC data, among others, puts the ratios among LNG:LPG:oil:coal at 100:105:110:151. In comparison, our study that focused on Japan found their corresponding figures at 100:110:120:154. COP 3 set forth country-by-country targets. Yet, global warming, that is a worldwide problem, also requires a more comprehensive assessment based on a life cycle analysis (LCA). The estimation results of our study can be of some help in shaping some criteria when considering energy and environmental policies from a global viewpoint. In addition, our study results suggest the importance of the best energy mix that is endorsed by LCI analysis results, if global warming abatement efforts should successfully be in advance. As specific institutional designs of Kyoto Mechanism are currently under examination, the introduction of LCI method deserves to be considered in discussing the baseline issue of joint implementation and clean development mechanism. In the days ahead, by gathering and analysing detailed-ever data, and through fossil-energy LCA by use, we had better consider supply and demand of the right energies in the right uses. (author)

Fossil fuel subsidy reform: lessons from the Indonesian case

International Nuclear Information System (INIS)

Savatic, Filip

2016-10-01

Global assessments of consumption and the Indonesian case show the relevance of non-household consumers of subsidized energy products. As shown in this study, understanding in more nuance how reforms affect them has the potential to improve the reforms that will be developed by policy-makers worldwide. Further study can reinforce the many benefits of successful reform for the countries and societies slowly turning away from these policies of the past. Estimates regarding the amount of public funds utilized to subsidize the production or consumption of fossil fuels are staggering. For 2011, they range from $83 billion in OECD member states, to nearly $4.1 trillion worldwide if environmental externalities are considered. Numerous studies have demonstrated that subsidies repress economic growth, undermine energy sector investment, increase public debt, benefit wealthy citizens over the poor, instigate a rise in illicit activities, and engender greater global and local pollution. The negative effects of fossil fuel subsidies have led numerous governments to reform their energy policies. There has also been a growing international consensus in favor of reform. While the components of successful reform programs have been identified through past case studies, the nature of reforms adopted by several governments that target non-households have not been systematically examined. Since the late 1990s, the Indonesian government has implemented numerous reforms of its fossil fuel subsidies, including measures targeting household as well as non-household energy consumption. In doing so, it has incurred significant fiscal savings. However, an innovative budgetary analysis reveals that households receive a minority, and a declining share, of fossil fuel subsidy funds. This is the case despite the fact that subsidies were implemented to ensure poor households have access to cheap energy. These findings demonstrate the need to consider non-household sectors in the design of fossil

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

Tracking channel bed resiliency in forested mountain catchments using high temporal resolution channel bed movement

Science.gov (United States)

Martin, Sarah E.; Conklin, Martha H.

2018-01-01

This study uses continuous-recording load cell pressure sensors in four, high-elevation (1500-1800 m), Sierra Nevada headwater streams to collect high-temporal-resolution, bedload-movement data for investigating the channel bed movement patterns within these streams for water years 2012-2014. Data show an annual pattern where channel bed material in the thalweg starts to build up in early fall, peaks around peak snow melt, and scours back to baseline levels during hydrograph drawdown and base flow. This pattern is punctuated by disturbance and recovery of channel bed material associated with short-term storm events. A conceptual model, linking sediment sources at the channel margins to patterns of channel bed fill and scour in the thalweg, is proposed building on the results of Martin et al. (2014). The material in the thalweg represents a balance between sediment supply from the channel margins and sporadic, conveyor-belt-like downstream transport in the thalweg. The conceptual model highlights not only the importance of production and transport rates but also that seasonal connectedness between the margins and thalweg is a key sediment control, determining the accumulation rate of sediment stores at the margins and the redistribution of sediment from margins to thalweg that feeds the conveyor belt. Disturbance and recovery cycles are observed at multiple temporal scales; but long term, the channel beds are stable, suggesting that the beds act as short-term storage for sediment but are in equilibrium interannually. The feasibility of use for these sensors in forested mountain stream environments is tested. Despite a high failure rate (50%), load cell pressure sensors show potential for high-temporal-resolution bedload measurements, allowing for the collection of channel bed movement data to move beyond time-integrated change measurements - where many of the subtleties of bedload movement patterns may be missed - to continuous and/or real-time measurements. This

Fluidized Bed Reactor as Solid State Fermenter

Directory of Open Access Journals (Sweden)

Krishnaiah, K.

2005-01-01

Full Text Available Various reactors such as tray, packed bed, rotating drum can be used for solid-state fermentation. In this paper the possibility of fluidized bed reactor as solid-state fermenter is considered. The design parameters, which affect the performances are identified and discussed. This information, in general can be used in the design and the development of an efficient fluidized bed solid-state fermenter. However, the objective here is to develop fluidized bed solid-state fermenter for palm kernel cake conversion into enriched animal and poultry feed.

Fungi solubilisation of low rank coal: performances of stirred tank, fluidised bed and packed bed reactors

CSIR Research Space (South Africa)

Oboirien, BO

2013-02-01

Full Text Available Coal biosolubilisation was investigated in stirred tank reactor, fluidised bed and fixed bed bioreactors with a view to highlight the advantages and shortcomings of each of these reactor configurations. The stirred aerated bioreactor and fluidised...

A fossil brain from the Cretaceous of European Russia and avian sensory evolution.

Science.gov (United States)

Kurochkin, Evgeny N; Dyke, Gareth J; Saveliev, Sergei V; Pervushov, Evgeny M; Popov, Evgeny V

2007-06-22

Fossils preserving traces of soft anatomy are rare in the fossil record; even rarer is evidence bearing on the size and shape of sense organs that provide us with insights into mode of life. Here, we describe unique fossil preservation of an avian brain from the Volgograd region of European Russia. The brain of this Melovatka bird is similar in shape and morphology to those of known fossil ornithurines (the lineage that includes living birds), such as the marine diving birds Hesperornis and Enaliornis, but documents a new stage in avian sensory evolution: acute nocturnal vision coupled with well-developed hearing and smell, developed by the Late Cretaceous (ca 90Myr ago). This fossil also provides insights into previous 'bird-like' brain reconstructions for the most basal avian Archaeopteryx--reduction of olfactory lobes (sense of smell) and enlargement of the hindbrain (cerebellum) occurred subsequent to Archaeopteryx in avian evolution, closer to the ornithurine lineage that comprises living birds. The Melovatka bird also suggests that brain enlargement in early avians was not correlated with the evolution of powered flight.

Renewable and nuclear sources of energy reduce the share of fossil fuels

International Nuclear Information System (INIS)

Koprda, V.

2009-01-01

In this paper author presents a statistical data use of nuclear energy, renewable sources and fossil fuels in the share of energy production in the Slovak Republic. It is stated that use of nuclear energy and renewable sources reduce the share of fossil fuels.

Renewable and nuclear sources of energy decreases of share of fossil fuels

International Nuclear Information System (INIS)

Koprda, V.

2009-01-01

In this paper author presents a statistical data use of nuclear energy, renewable sources and fossil fuels in the share of energy production in the Slovak Republic. It is stated that use of nuclear energy and renewable sources decreases of share of fossil fuels.

Fossil birds in the National Museum of Natural History, Sofia: composition, development and scientific value

NARCIS (Netherlands)

Boev, Z.N.

2005-01-01

A review of the fossil and subfossil avian record kept in Bulgaria is presented. The only collection of fossil birds in Bulgaria was established in the 1980s. 99.6% originates from 98 localities throughout Bulgaria. Foreign fossils originate from Azerbaijan, Greece, Hungary, Namibia and New Zealand.

Find a Bed Bug Pesticide Product

Science.gov (United States)

Introduces the Bed Bug Product Search Tool, to help consumers find EPA-registered pesticides for bed bug infestation control. Inclusion in this database is not an endorsement. Always follow label directions carefully.

A Total-Evidence Approach to Dating with Fossils, Applied to the Early Radiation of the Hymenoptera

Science.gov (United States)

Ronquist, Fredrik; Klopfstein, Seraina; Vilhelmsen, Lars; Schulmeister, Susanne; Murray, Debra L.; Rasnitsyn, Alexandr P.

2012-01-01

Abstract Phylogenies are usually dated by calibrating interior nodes against the fossil record. This relies on indirect methods that, in the worst case, misrepresent the fossil information. Here, we contrast such node dating with an approach that includes fossils along with the extant taxa in a Bayesian total-evidence analysis. As a test case, we focus on the early radiation of the Hymenoptera, mostly documented by poorly preserved impression fossils that are difficult to place phylogenetically. Specifically, we compare node dating using nine calibration points derived from the fossil record with total-evidence dating based on 343 morphological characters scored for 45 fossil (4--20 complete) and 68 extant taxa. In both cases we use molecular data from seven markers (∼5 kb) for the extant taxa. Because it is difficult to model speciation, extinction, sampling, and fossil preservation realistically, we develop a simple uniform prior for clock trees with fossils, and we use relaxed clock models to accommodate rate variation across the tree. Despite considerable uncertainty in the placement of most fossils, we find that they contribute significantly to the estimation of divergence times in the total-evidence analysis. In particular, the posterior distributions on divergence times are less sensitive to prior assumptions and tend to be more precise than in node dating. The total-evidence analysis also shows that four of the seven Hymenoptera calibration points used in node dating are likely to be based on erroneous or doubtful assumptions about the fossil placement. With respect to the early radiation of Hymenoptera, our results suggest that the crown group dates back to the Carboniferous, ∼309 Ma (95% interval: 291--347 Ma), and diversified into major extant lineages much earlier than previously thought, well before the Triassic. [Bayesian inference; fossil dating; morphological evolution; relaxed clock; statistical phylogenetics.] PMID:22723471

Biogeographic distribution and metric dental variation of fossil and living orangutans (Pongo spp.).

Science.gov (United States)

Tshen, Lim Tze

2016-01-01

The genus Pongo has a relatively richer Quaternary fossil record than those of the African great apes. Fossil materials are patchy in terms of anatomical parts represented, limited almost exclusively to isolated teeth, jaw and bone fragments. Fossil evidence indicates that the genus Pongo had a broadly continuous distribution across the southern part of the Indomalayan biogeographic region, ranging in time from Early Pleistocene to Holocene: southern China (77 fossil sites), Vietnam (15), Laos (6), Cambodia (2), Thailand (4), Peninsular Malaysia (6), Sumatra (4), Borneo (6) and Java (4). Within this distribution range, there are major geographical gaps with no known orangutan fossils, notably central and southern Indochina, central and southern Thailand, eastern Peninsular Malaysia, northern and southern Sumatra, and Kalimantan. The geological time and place of origin of the genus remain unresolved. Fossil orangutan assemblages usually show greater extent of dental metrical variation than those of modern-day populations. Such variability shown in prehistoric populations has partially contributed to confusion regarding past taxonomic diversity and systematic relationships among extinct and living forms. To date, no fewer than 14 distinct taxa have been identified and named for Pleistocene orangutans. Clear cases suggestive of predation by prehistoric human are few in number, and limited to terminal Pleistocene-Early Holocene sites in Borneo and a Late Pleistocene site in Vietnam.

The Fascinating Story of Fossil Fuels

Science.gov (United States)

Asimov, Isaac

1973-01-01

How this energy source was created, its meaning to mankind, our drastically reduced supply, and why we cannot wait for nature to make more are considered. Today fossil fuels supply 96 percent of the energy used but we must find alternate energy options if we are to combat the energy crisis. (BL)

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...

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

Synthetic bedding and wheeze in childhood.

Science.gov (United States)

Ponsonby, Anne-Louise; Dwyer, Terence; Kemp, Andrew; Cochrane, Jennifer; Couper, David; Carmichael, Allan

2003-01-01

The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available. Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze. Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy. In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.

Wall-to-bed heat transfer in gas-solid fluidized beds: a computational and experimental study

NARCIS (Netherlands)

Patil, D.J.; Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

2006-01-01

The wall-to-bed heat transfer in gas-solid fluidized beds is mainly determined by phenomena prevailing in a thermal boundary layer with a thickness in the order of magnitude of the size of a single particle. In this thermal boundary layer the temperature gradients are very steep and the local

The Physiology of Bed Rest. Chapter 39

Science.gov (United States)

Fortney, Suzanne M.; Schneider, Victor S.; Greenleaf, John E.

1996-01-01

Prolonged rest in bed has been utilized by physicians and other health-care workers to immobilize and confine patients for rehabilitation and restoration of health since time immemorial. The sitting or horizontal position is sought by the body to relieve the strain of the upright or vertical postures, for example during syncopal situations, bone fractures, muscle injuries, fatigue, and probably also to reduce energy expenditure. Most health-care personnel are aware that adaptive responses occurring during bed rest proceed concomitantly with the healing process; signs and symptoms associated with the former should be differentiated from those of the latter. Not all illnesses and infirmities benefit from prolonged bed rest. Considerations in prescribing bed rest for patients-including duration, body position, mode and duration of exercise, light-dark cycles, temperature, and humidity-have not been investigated adequately. More recently, adaptive physiological responses have been measured in normal, healthy subjects in the horizontal or slightly head-down postures during prolonged bed rest as analogs for the adaptive responses of astronauts exposed to the microgravity environment of outer and bed-rest research.

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.

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

Reliability estimation for multiunit nuclear and fossil-fired industrial energy systems

International Nuclear Information System (INIS)

Sullivan, W.G.; Wilson, J.V.; Klepper, O.H.

1977-01-01

As petroleum-based fuels grow increasingly scarce and costly, nuclear energy may become an important alternative source of industrial energy. Initial applications would most likely include a mix of fossil-fired and nuclear sources of process energy. A means for determining the overall reliability of these mixed systems is a fundamental aspect of demonstrating their feasibility to potential industrial users. Reliability data from nuclear and fossil-fired plants are presented, and several methods of applying these data for calculating the reliability of reasonably complex industrial energy supply systems are given. Reliability estimates made under a number of simplifying assumptions indicate that multiple nuclear units or a combination of nuclear and fossil-fired plants could provide adequate reliability to meet industrial requirements for continuity of service

in Spouted Bed

Directory of Open Access Journals (Sweden)

Bronislaw Buczek

2013-01-01

Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

Adiabatic Fixed-Bed Gasification of Colombian Coffee Husk Using Air-Steam Blends for Partial Oxidation

Directory of Open Access Journals (Sweden)

Javier Bonilla

2017-01-01

Full Text Available The increasing energy consumption, mostly supplied by fossil fuels, has motivated the research and development of alternative fuel technologies to decrease the humanity’s dependence on fossil fuels, which leads to pollution of natural sources. Small-scale biomass gasification, using air-steam blends for partial oxidation, is a good alternative since biomass is a neutral carbon feedstock for sustainable energy generation. This research presents results obtained from an experimental study on coffee husk (CH gasification, using air-steam blends for partial oxidation in a 10 kW fixed-bed gasifier. Parametric studies on equivalence ratio (ER (1.53 < ER < 6.11 and steam-fuel (SF ratio (0.23 < SF < 0.89 were carried out. The results show that increasing both SF and ER results in a syngas rich in CH4 and H2 but poor in CO. Also, decreased SF and ER decrease the peak temperature (Tpeak at the gasifier combustion zone. The syngas high heating value (HHV ranged from 3112 kJ/SATPm3 to 5085 kJ/SATPm3 and its maximum value was obtained at SF = 0.87 and ER = 4.09. The dry basis molar concentrations of the species, produced under those operating conditions (1.53 < ER < 6.11 and 0.23 < SF < 0.89, were between 1.12 and 4.1% for CH4, between 7.77 and 13.49% for CO, and between 7.54 and 19.07% for H2. Other species were in trace amount.

REVISITING THE FOSSIL GROUP CANDIDATES UGC 842 AND NGC 6034

International Nuclear Information System (INIS)

De Oliveira, R. Lopes; De Oliveira, C. Mendes; Bortoletto, D. R.; Cypriano, E.; Sodre, L.; Neto, G B. Lima; Carrasco, E. R.

2010-01-01

We present a new insight on NGC 6034 and UGC 842, two groups of galaxies previously reported in the literature as being fossil groups. The study is based on optical photometry and spectroscopy obtained with the CTIO Blanco telescope and Sloan Digital Sky Survey archival data. We find that NGC 6034 is embedded in a large structure, dominated by three rich clusters and other small groups. Its first and next four ranked galaxies have magnitude differences in the r band and projected distances which violate the optical criteria to classify it as a fossil group. We confirm that the UGC 842 group is a fossil group, but with about half the velocity dispersion that is reported in previous works. The velocity distribution of its galaxies reveals the existence of two structures in its line of sight, one with σ v ∼ 223 km s -1 and another with σ v ∼ 235 km s -1 , with a difference in velocity of ∼820 km s -1 . The main structure is dominated by passive galaxies, while these represent ∼60% of the second structure. The X-ray temperature for the intragroup medium of a group with such a velocity dispersion is expected to be kT ∼0.5-1 keV, against the observed value of kT ∼1.9 keV reported in the literature. This result makes UGC 842 a special case among fossil groups because (1) it represents more likely the interaction between two small groups, which warms the intragroup medium and/or (2) it could constitute evidence that member galaxies lost energy in the process of spiraling toward the group center, and decreased the velocity dispersion of the system. As far as we know, UGC 842 is the first low-mass fossil group studied in detail.

Two-phase flow in beds of spherical particles

International Nuclear Information System (INIS)

Schulenberg, T.; Mueller, U.

1984-02-01

A refined model for two-phase flow in beds of uniform spherical particles is presented. It includes the influence of interfacial drag forces between liquid and gas, which are important in beds of coarse particles, and an incrase of porosity due to vapour channels or similiar irreversible bed disturbances, which occur in beds of fine particles. The model is based on the momentum equations for separated flow, which are closed with empirical relations for wall shear stress and interfacial drag. To improve this model it is applied to volumetrically heated beds on a adiabatic bottom, which are saturated and superimposed with a boiling liquid. In case of fine particles only an impermeable bottom is considered, whereas in case of coarse particles also beds on a permeable support are discussed. (orig.) [de

Fossile Säugethierreste von Java und Japan

NARCIS (Netherlands)

Martin, K.

1884-01-01

Die Beschreibung eines Stegodontenzahnes von Java in der vorhergehenden Abhandlung dieses Bandes ist die Veranlassung geworden, dass De Koninklijke Natuurkundige Vereeniging in Nederlandsch Indië eine grosse Sammlung fossiler Säugethierreste dem Geologischen Museum in Leiden übersandte. Es befinden

Variability of bed mobility in natural, gravel-bed channels and adjustments to sediment load at local and reach scales

Science.gov (United States)

Thomas E. Lisle; Jonathan M. Nelson; John Pitlick; Mary Ann Madej; Brent L. Barkett

2000-01-01

Abstract - Local variations in boundary shear stress acting on bed-surface particles control patterns of bed load transport and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and sediment supply through mutual interactions among channel form, local grain size, and local flow dynamics that govern bed mobility...

Thermal-hydraulic and characteristic models for packed debris beds

International Nuclear Information System (INIS)

Mueller, G.E.; Sozer, A.

1986-12-01

APRIL is a mechanistic core-wide meltdown and debris relocation computer code for Boiling Water Reactor (BWR) severe accident analyses. The capabilities of the code continue to be increased by the improvement of existing models. This report contains information on theory and models for degraded core packed debris beds. The models, when incorporated into APRIL, will provide new and improved capabilities in predicting BWR debris bed coolability characteristics. These models will allow for a more mechanistic treatment in calculating temperatures in the fluid and solid phases in the debris bed, in determining debris bed dryout, debris bed quenching from either top-flooding or bottom-flooding, single and two-phase pressure drops across the debris bed, debris bed porosity, and in finding the minimum fluidization mass velocity. The inclusion of these models in a debris bed computer module will permit a more accurate prediction of the coolability characteristics of the debris bed and therefore reduce some of the uncertainties in assessing the severe accident characteristics for BWR application. Some of the debris bed theoretical models have been used to develop a FORTRAN 77 subroutine module called DEBRIS. DEBRIS is a driver program that calls other subroutines to analyze the thermal characteristics of a packed debris bed. Fortran 77 listings of each subroutine are provided in the appendix