Veronica sublobata M. Fischer in Nederland?

NARCIS (Netherlands)

Jongh, de S.E.

1968-01-01

A form of Veronica hederifolia L. s. lat., clearly distinguishable from the well-known form of arable land and occurring in the Netherlands in woods, thickets or sometimes along roads is most possibly identical with V. sublobata M. Fischer. Knowledge of the chromosome number of the Dutch material is

Strain differences of cadmium-induced hepatotoxicity in Wistar-Imamichi and Fischer 344 rats: involvement of cadmium accumulation

International Nuclear Information System (INIS)

Shimada, Hideaki; Takamure, Yasutaka; Shimada, Akinori; Yasutake, Akira; Waalkes, Michael P.; Imamura, Yorishige

2004-01-01

We previously reported that Wistar-Imamichi (WI) rats have a strong resistance to cadmium (Cd)-induced lethality compared to other strains such as Fischer 344 (Fischer) rats. The present study was designed to establish biochemical and histological differences in Cd toxicity in WI and Fischer rats, and to clarify the mechanistic basis of these strain differences. A single Cd (4.5 mg/kg, s.c.) treatment caused a significant increase in serum alanine aminotransferase activity, indicative of hepatotoxicity, in Fischer rats, but did not in WI rats. This difference in hepatotoxic response to Cd was supported by pathological analysis. After treatment with Cd at doses of 3.0, 3.5 and 4.5 mg/kg, the hepatic and renal accumulation of Cd was significantly lower in the WI rats than in the Fischer rats, indicating a kinetic mechanism for the observed strain differences in Cd toxicity. Thus, the remarkable resistance to Cd-induced hepatotoxicity in WI rats is associated, at least in part, with a lower tissue accumulation of the metal. Hepatic and renal zinc (Zn) contents after administration were similarly lower in WI than in Fischer rats. When Zn was administered in combination with Cd to Fischer rats, it decreased Cd contents in the liver and kidney, and exhibited a significant protective effect against the toxicity of Cd. We propose the possibility that Zn transporter plays an important role in the strain difference of Cd toxicity in WI and Fischer rats

Fischer-Tropsch synthesis. Development and perspectives

Energy Technology Data Exchange (ETDEWEB)

Schaub, G.; Rohde, M.; Mena Subiranas, A. [Karlsruhe Univ. (Germany). Engler-Bunte-Institut

2006-07-01

Production of synthetic hydrocarbons via Fischer-Tropsch (FT) synthesis has the potential to produce high-value automotive fuels and petrochemicals from fossil and renewable sources. The availability of cheap natural gas and solid raw materials like coal and biomass has given momentum to synthesis technologies first developed in the mid-twentieth century. The present paper summarizes the fundamentals and describes some general aspects regarding driving forces, catalyst and reaction, synthesis reactor, and overall process. In this way, it indicates the context of present and future developments. Worldwide plant capacities will increase significantly in the next future, with natural gas favored as feedstock. Substitution of petroleum as well as production of improved products (like automotive fuels) are the most significant incentives. Energy loss and additional fossil CO{sub 2} emissions caused by the conversion process will be a problem in extended applications with fossil feedstocks. The current R and D activities worldwide, in all areas related to Fischer-Tropsch synthesis, will contribute to further process improvements and extended applications. (orig.)

First report of the genus Coeliniaspis Fischer (Hymenoptera, Braconidae, Alysiinae) from China and Russia

NARCIS (Netherlands)

Zheng, M.-L.; Chen, J.-H.; Achterberg, van C.

2017-01-01

Coeliniaspis Fischer, 2010 (Braconidae, Alysiinae, Dacnusini) is recorded from China and Russia for the first time. Coeliniaspis insularis (Tobias, 1998) is reported from China (Fujian), redescribed and illustrated. A key to the species of the genus Coeliniaspis Fischer is added. Coeliniaspis

Radiation effects on Fischer-Tropsch syntheses

International Nuclear Information System (INIS)

Hatada, M.; Matsuda, K.

1977-01-01

Radiation effects on Fischer-Tropsch synthesis has been examined using high dose rate electron beams and Fe-Cu-diatomaceous earth catalyst. Yields of saturated hydrocarbons were found to increase by irradiation, but the yields of these compounds were decreased by raising reaction temperature without irradiation, suggesting the presence of radiation chemical process in catalytic reactions. (author)

Comprehensive characterisation of products from cobalt catalysed Fischer-Tropsch reaction

Energy Technology Data Exchange (ETDEWEB)

Marion, M.C.; Bertoncini, F.; Hugues, F.; Forestiere, A. [IFP, Vernaison (France)

2006-07-01

Fischer-Tropsch reaction synthesis has been studied in presence of supported cobalt catalysts. The experimental work has been performed by using a slurry pilot plant. All the gaseous and liquid products, including by-products recovered in the water phase produced, have been analysed in order to determine the whole products distribution and the catalyst selectivity. Apart from paraffin which are the main products obtained via cobalt-catalyzed Fischer-Tropsch synthesis, olefins and oxygenates by-products present also their own distribution. These detailed data are available thanks to new dedicated analytical methods developed in IFP laboratories. (orig.)

Plesiophysa guadeloupensis ("Fischer" Mazé, 1883

Directory of Open Access Journals (Sweden)

W Lobato Paraense

2003-06-01

Full Text Available A description is presented of the shell and anatomic characters of the planorbid mollusk Plesiophysa guadeloupensis ("Fischer" Mazé, 1883, based on topotypic specimens from a pond in Borricaud (Grande Terre, Guadeloupe. Comparison with previous descriptions of nominal species of Plesiophysa points to its identity with P. ornata (Haas, 1938, of which it is a senior synonym.

Nonsmooth Newton method for Fischer function reformulation of contact force problems for interactive rigid body simulation

DEFF Research Database (Denmark)

Silcowitz, Morten; Niebe, Sarah Maria; Erleben, Kenny

2009-01-01

contact response. In this paper, we present a new approach to contact force determination. We reformulate the contact force problem as a nonlinear root search problem, using a Fischer function. We solve this problem using a generalized Newton method. Our new Fischer - Newton method shows improved...... qualities for specific configurations where the most widespread alternative, the Projected Gauss-Seidel method, fails. Experiments show superior convergence properties of the exact Fischer - Newton method....

Niobia-supported Cobalt Catalysts for Fischer-Tropsch Synthesis

NARCIS (Netherlands)

den Otter, J.H.

2016-01-01

In this thesis niobia has been shown to be an attractive support for application in Fischer-Tropsch catalysis at industrially relevant conditions without apparent deactivation up to at least 200 hours of operation. This proves that the level of potentially poisoning contaminants is sufficiently low

Petroleum formation by Fischer-Tropsch synthesis in plate tectonics

Energy Technology Data Exchange (ETDEWEB)

Szatmari, P. (Petrobras Research Center, Rio de Janeiro (Brazil))

1989-08-01

A somewhat speculative hypothesis of petroleum genesis in the upper lithosphere is proposed, based on Fischer-Tropsch synthesis. This hypothesis is distinct from both the organic (biogenic) model and the inorganic model of hydrocarbon degassing from the Earth's interior. The hypothesis presented in this paper proposes that petroleum liquids form by Fischer-Tropsch synthesis on magnetite and hematite catalysts when carbon dioxide (derived by massive metamorphic or igneous decarbonation of subducted sedimentary carbonates) reacts with hydrogen generated by the serpentinization (in the absence of air) of shallow-mantle lithosphere and ophiolite thrust sheets. Oblique plate movements may favor hydrocarbon formation by creating deep faults that aid fluid flow and serpentinization. The world's richest oil provinces, including those of the Middle East, may be tentatively interpreted to have formed by this mechanism. 8 figs., 1 tab.

Structure-performance relationships for supported cobalt Fischer-Tropsch catalysts

NARCIS (Netherlands)

Eschemann, T.O.|info:eu-repo/dai/nl/33082712X

2015-01-01

The Fischer-Tropsch synthesis (FTS) involves the heterogeneously catalyzed conversion of synthesis gas into water and hydrocarbons and offers a promising route for the synthesis of ultraclean fuels, chemicals and lubricants. The synthesis gas can be generated from different feedstocks, such as coal

The Application of Moessbauer Emission Spectroscopy to Industrial Cobalt Based Fischer-Tropsch Catalysts

International Nuclear Information System (INIS)

Loosdrecht, J. van de; Berge, P. J. van; Craje, M. W. J.; Kraan, A. M. van der

2002-01-01

The application of Moessbauer emission spectroscopy to study cobalt based Fischer-Tropsch catalysts for the gas-to-liquids process was investigated. It was shown that Moessbauer emission spectroscopy could be used to study the oxidation of cobalt as a deactivation mechanism of high loading cobalt based Fischer-Tropsch catalysts. Oxidation was observed under conditions that are in contradiction with the bulk cobalt phase thermodynamics. This can be explained by oxidation of small cobalt crystallites or by surface oxidation. The formation of re-reducible Co 3+ species was observed as well as the formation of irreducible Co 3+ and Co 2+ species that interact strongly with the alumina support. The formation of the different cobalt species depends on the oxidation conditions. Iron was used as a probe nuclide to investigate the cobalt catalyst preparation procedure. A high-pressure Moessbauer emission spectroscopy cell was designed and constructed, which creates the opportunity to study cobalt based Fischer-Tropsch catalysts under realistic synthesis conditions.

Coupling of glycerol processing with Fischer-Tropsch synthesis for production of liquid fuels

DEFF Research Database (Denmark)

Simonetti, D.A.; Rass-Hansen, Jeppe; Kunkes, E.L.

2007-01-01

Liquid alkanes can be produced directly from glycerol by an integrated process involving catalytic conversion to H-2/CO gas mixtures (synthesis gas) combined with Fischer-Tropsch synthesis. Synthesis gas can be produced at high rates and selectivities suitable for Fischer-Tropsch synthesis (H-2/CO...... between 1.0 and 1.6) from concentrated glycerol feed solutions at low temperatures (548 K) and high pressures (1-17 bar) over a 10 wt% Pt-Re/C catalyst with an atomic Pt : Re ratio of 1 : 1. The primary oxygenated hydrocarbon intermediates formed during conversion of glycerol to synthesis gas are ethanol...... in the liquid organic effluent stream and increasing the selectivity to C5+ alkanes by a factor of 2 ( from 0.30 to 0.60). Catalytic conversion of glycerol and Fischer-Tropsch synthesis were coupled in a two-bed reactor system consisting of a Pt-Re/C catalyst bed followed by a Ru/TiO2 catalyst bed...

BASELINE DESIGN/ECONOMICS FOR ADVANCED FISCHER-TROPSCH TECHNOLOGY; FINAL

International Nuclear Information System (INIS)

None

1998-01-01

Bechtel, along with Amoco as the main subcontractor, developed a Baseline design, two alternative designs, and computer process simulation models for indirect coal liquefaction based on advanced Fischer-Tropsch (F-T) technology for the U. S. Department of Energy's (DOE's) Federal Energy Technology Center (FETC)

On the Deactivation of Cobalt-based Fischer-Tropsch Catalysts

NARCIS (Netherlands)

Cats, K.H.

2016-01-01

The Fischer-Tropsch Synthesis (FTS) process is an attractive way to obtain synthetic liquid fuel from alternative energy sources such as natural gas, coal or biomass. However, the deactivation of the catalyst, consisting of cobalt nanoparticles supported on TiO2, currently hampers the industrial

God has moved. Long live the God! / Rene Fischer

Index Scriptorium Estoniae

Fischer, Rene

2004-01-01

Reklaamifirma Tank senine shveitslasest loovjuht Rene Fischer oma tööst ettevõttes, firma edukuse võimalikest põhjustest, olukorrast Baltimaade reklaamiturul, Läti reklaamifirma Bates/Red Cell loovjuhiks lahkumise põhjustest ning eesmärkidest uuel töökohal. Lisad: Other stuff; Technical data

The Fischer 344 rat as a model of presbycusis

Czech Academy of Sciences Publication Activity Database

Syka, Josef

2010-01-01

Roč. 264, 1-2 (2010), s. 70-78 ISSN 0378-5955 R&D Projects: GA ČR GA309/07/1336; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390703 Keywords : Rat * Fischer 344 * Presbycusis Subject RIV: FH - Neurology Impact factor: 2.428, year: 2010

Taani tahab meid ELi kutsuda / Mariann Fischer Boel ; interv. Marianne Mikko

Index Scriptorium Estoniae

Fischer Boel, Mariann

2002-01-01

Taani põllumajandusminister Mariann Fischer Boel vastab küsimustele Eesti soovitud piimakvoodi, EL-i tulevaste liikmesriikide otsetoetuste, Taanis maa ostmise, Eesti üliliberaalse majanduse ja sotsiaalse heaolu ühendamise võimaluse kohta

Physiatrie and German maternal feminism: Dr. Anna Fischer-Dückelmann critiques academic medicine.

Science.gov (United States)

Meyer, Paulette

2006-01-01

Alternative medicine and reform strategies made Anna Fischer-Dückelmann a most controversial, notorious, and widely read women doctor before World War I. She published a dozen titles in 13 languages asserting that national well-being depended on maternal prowess. To her critics, Fischer-Dückelmann's commitment to medical self-help and practices of Physiatrie amounted to medical quackery. Her career has been largely unexamined, yet her feminist critiques and social concerns are not far removed from modern social medicine. For this pioneering doctor, treating physical and emotional ills and promoting the health of families were first steps toward healing the divisions of a world at war.

Determination of the water content in tetra-ammonium uranyl tricarbonate by the Karl Fischer reagent method

International Nuclear Information System (INIS)

Sisti, C.; Grigoletto, T.

1990-08-01

Two methods are compared for the determination of water content in tetra-ammonium uranyl tricarbonate by the Karl Fischer reagent method. In the first method it is Known that the carbonate reacts stoichiometrically with the iodine content of the Karl Fischer reagent in the same way it reacts with the water (mole of apparent H 2 O per mole of carbonate is produced). In this case, the carbonate content in the sample is determined and a suitable correction is applied to take into account the apparent water results. In the second method it is performed an extraction of the moisture by adding methanol to the sample in an independent flask. After the decantation, an aliquot of the clear supernatant methanol is taken for the determination of water content by the Karl Fischer reagent method. (author) [pt

33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...

The role of Fischer-Tropsch catalysis in solar nebula chemistry

NARCIS (Netherlands)

Kress, ME; Tielens, AGGM

Fischer-Tropsch catalysis, the iron/nickel catalyzed conversion of CO and H(2) to hydrocarbons, would have been the only thermally-driven pathway available in the solar nebula to convert CO into other forms of carbon. A major issue in meteoritics is to determine the origin of meteoritic organics:

Male reproductive effects of octylphenol and estradiol in Fischer and Wistar rats

DEFF Research Database (Denmark)

Hossaini, Alireza; Dalgaard, Majken; Vinggaard, Anne

2003-01-01

to vehicle or 400 mg/kg bw of 4-tert-octylphenol administrated orally by gavage. Estradiol benzoate, at a dose of 40 mug/kg bw, was used as positive control agent. Treatment with estradiol benzoate decreased serum levels of testosterone, LH, FSH, inhibin and increased prolactin. Additionally, estradiol...... benzoate decreased the weight of all investigated reproductive organs, decreased sperm production and increased seminiferous tubular degeneration in both strains. More progressive effects on testis weight and histopathology were observed in the Fischer rats. Oral administration of octylphenol at 400 mg....../kg bw to both rat strains increased prolactin levels but had no effect on LH, FSH, testosterone or inhibin. In the octylphenol-treated Fischer rats the weights of the seminal vesicles and the levator ani/bulbocavernosus muscle were significantly decreased, whereas only the levator ani...

Design of generic coal conversion facilities: Indirect coal liquefaction, Fischer-Tropsch synthesis

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

A comprehensive review of Fischer-Tropsch (F-T) technology, including fixed, fluidized, and bubble column reactors, was undertaken in order to develop an information base before initiating the design of the Fischer-Tropsch indirect liquefaction PDU as a part of the Generic Coal Conversion Facilities to be built at the Pittsburgh Energy Technology Center (PETC). The pilot plant will include a fixed bed and slurry bubble column reactor for the F-T mode of operation. The review encompasses current status of both these technologies, their key variables, catalyst development, future directions, and potential improvement areas. However, more emphasis has been placed on the slurry bubble column reactor since this route is likely to be the preferred technology for commercialization, offering process advantages and, therefore, better economics than fixed and fluidized bed approaches.

Moessbauer spectroscopic investigations of Fe/Mn-Fischer-Tropsch-catalysts

International Nuclear Information System (INIS)

Deppe, P.; Papp, H.; Rosenberg, M.

1986-01-01

The phase composition of Fe/Mn oxide catalysts of different compositions after 200 h of Fischer-Tropsch synthesis have been investigated by Moessbauer spectroscopy at room temperature, 77 K and 5 K. The final composition of the bulk catalysts depends strongly on the Mn content and the temperature of reduction before the synthesis. Catalytic activity and selectivity are partly correlated to this phase composition. (Auth.)

Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis

KAUST Repository

Wezendonk, Tim A.; Sun, Xiaohui; Dugulan, A. Iulian; van Hoof, Arno J.F.; Hensen, Emiel J.M.; Kapteijn, Freek; Gascon, Jorge

2018-01-01

high-temperature Fischer-Tropsch (HTFT) resulted in the formation of χ-Fe5C2. Furthermore, the different activation methods did not alter other important catalyst properties, as pre- and post-reaction transmission electron microscopy (TEM

Collagen changes in the cochlea of aged Fischer 344 rats

Czech Academy of Sciences Publication Activity Database

Buckiová, Daniela; Popelář, Jiří; Syka, Josef

2006-01-01

Roč. 41, - (2006), s. 296-302 ISSN 0531-5565 R&D Projects: GA ČR GA309/04/1074; GA MZd NR8113; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390512 Keywords : Presbycusis * Rat * Fischer 344 strain Subject RIV: FH - Neurology Impact factor: 2.930, year: 2006

Dilemmas of 19th-century Liberalism among German Academic Chemists: Shaping a National Science Policy from Hofmann to Fischer, 1865-1919.

Science.gov (United States)

Johnson, Jeffrey Allan

2015-04-01

This paper's primary goal is to compare the personalities, values, and influence of August Wilhelm Hofmann and Emil Fischer as exemplars and acknowledged leaders of successive generations of the German chemical profession and as scientists sharing a 19th-century liberal, internationalist outlook from the German wars of unification in the 1860s to Fischer's death in 1919 in the aftermath of German defeat in World War I. The paper will consider the influence of Hofmann and Fischer on the shaping of national scientific institutions in Germany, from founding of the German Chemical Society in 1867 to the first institutes of the Kaiser Wilhelm Society founded in 1911, their academic leadership in other areas including the shaping of a successful academic-industrial symbiosis in organic chemistry, and finally their response to war as a force disruptive of scientific internationalism. All of these developments posed serious dilemmas, exacerbated by emerging strains of nationalism and anti-Semitism in German society. Whereas Hofmann's lifework came to a relatively successful end in 1892, Fischer was not so fortunate, as the war brought him heavy responsibilities and terrible personal losses, but with no German victory and no peace of reconciliation--a bleak end for Fischer and the 19th-century liberal ideals that had inspired him.

Metal-carbon nanosystem IR-PVA/Fe-Co for catalysis in the Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Vasilev, A A; Dzidziguri, E L; Ivantsov, M I; Efimov, M N

2016-01-01

Metal-carbon nanosystems consisting of nanodimensional bimetallic particles of Fe- Co dispersed in a carbon matrix for the Fischer-Tropsch synthesis were studied. Prepared metal-carbon nanopowders samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It was shown formation of FeCo nanoparticles with body-centered cubic structures started at 400 °C. FeCo nanoparticles have spherical form, the mean size is 7 - 12 nm and uniform distribution in a carbon matrix. The metal-carbon nanosystem demonstrates a catalytic activity in the Fischer- Tropsch synthesis. The maximum yield of liquid hydrocabons C 5+ was 92 g/m 3 while the selectivity for the target product - 35%. (paper)

The role of magnetite in Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Rao, K.R.P.M.; Huggins, F.E.; Mahajan, V.; Huffman, G.P.; Rao, V.U.S.

1994-01-01

Moessbauer spectroscopy studies of iron catalysts from a Fischer-Tropsch (FT) Pilot Plant run at different time-on-stream periods were carried out. Magnetite Fe 3 O 4 was found to be active for the water-gas-shift (WGS) reaction which accompanies the FT synthesis reaction over Fe-based catalysts. A correlation between the ratio of the occupancy of octahedral sites to the tetrahedral sites in magnetite to the WGS activity was found. Cation-deficient magnetite gave higher WGS activity as compared to the stoichiometric phase. (orig.)

Co-Zn-Al based hydrotalcites as catalysts for Fischer-Tropsch process

Energy Technology Data Exchange (ETDEWEB)

Bianchi, C.L.; Pirola, C.; Boffito, D.C.; Di Fronzo, A. [Univ. degli Studi di Milano (Italy). Dipt. di Chimica Fisica ed Elettrochimica; Di Michele, A. [Univ. degli Studi di Perugia (Italy). Dipt. di Fisica; Vivani, R.; Nocchetti, M.; Bastianini, M.; Gatto, S. [Univ. degli Studi di Perugia (Italy). Dipt. di Chimica

2011-07-01

Co-Zn-Al based hydrotalcites have been investigated as catalysts for the well-known Fischer- Tropsch synthesis. A series of ternary hydrotalcites in nitrate form was prepared with the urea method in order to obtain active catalysts for the above mentioned process. The thermal activation at 350 C gives raise to finely dispersed metallic Co on the mixed oxides, so resulting in retaining the metal distribution of the parent compounds. An optimization study concerning the amount of cobalt of the prepared catalysts (range 15-70% mol, metal based) and the reaction temperature (220-260 C) is reported. All the samples have been fully characterized (BET, ICP-OES, XRPD, TG-DTA, FT-IR, SEM and TEM) and tested in a laboratory pilot plant. Tests to evaluate the stability of these materials were carried out in stressed conditions concerning both the activation and the operating temperatures and pressures (up to 350 C and 2.0 MPa). The obtained results suggest the possibility of using synthetic hydrotalcites as suitable Co-based catalysts for the Fischer-Tropsch synthesis. (orig.)

Cobalt supported on carbon nanofibers as catalysts for the Fischer-Tropsch synthesis

NARCIS (Netherlands)

Bezemer, G.L.

2006-01-01

The Fischer-Tropsch (FT) process converts synthesis gas (H2/CO) over a heterogeneous catalyst into hydrocarbons. Generally, cobalt catalysts supported on oxidic carriers are used for the FT process, however it appears to be difficult to obtain and maintain fully reduced cobalt particles. To overcome

Dvě ontologie české demokracie: T. G. Masaryk a J. L. Fischer

Czech Academy of Sciences Publication Activity Database

Pauza, Miroslav

2015-01-01

Roč. 63, č. 2 (2015), s. 233-245 ISSN 0015-1831 Institutional support: RVO:67985955 Keywords : Masaryk * Fischer * democracy * providence * order * structure * function * individuality * sociality * crisis Subject RIV: AA - Philosophy ; Religion

Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis

KAUST Repository

Wezendonk, Tim A.

2018-04-19

Iron carbides are unmistakably associated with the active phase for Fischer-Tropsch synthesis (FTS). The formation of these carbides is highly dependent on the catalyst formulation, the activation method and the operational conditions. Because of this highly dynamic behavior, studies on active phase performance often lack the direct correlation between catalyst performance and iron carbide phase. For the above reasons, an extensive in situ Mössbauer spectroscopy study on highly dispersed Fe on carbon catalysts (Fe@C) produced through pyrolysis of a Metal Organic Framework was coupled to their FTS performance testing. The preparation of Fe@C catalysts via this MOF mediated synthesis allows control over the active phase formation and therefore provides an ideal model system to study the performance of different iron carbides. Reduction of fresh Fe@C followed by low-temperature Fischer-Tropsch (LTFT) conditions resulted in the formation of the ε′-Fe2.2C, whereas carburization of the fresh catalysts under high-temperature Fischer-Tropsch (HTFT) resulted in the formation of χ-Fe5C2. Furthermore, the different activation methods did not alter other important catalyst properties, as pre- and post-reaction transmission electron microscopy (TEM) characterization confirmed that the iron nanoparticle dispersion was preserved. The weight normalized activities (FTY) of χ-Fe5C2 and ε′-Fe2.2C are virtually identical, whilst it is found that ε′-Fe2.2C is a better hydrogenation catalyst than χ-Fe5C2. The absence of differences under subsequent HTFT experiments, where χ-Fe5C2 is the dominating phase, is a strong indication that the iron carbide phase is responsible for the differences in selectivity.

Particle Size and Crystal Phase Effects in Fischer-Tropsch Catalysts

OpenAIRE

Jin-Xun Liu; Peng Wang; Wayne Xu; Emiel J.M. Hensen

2017-01-01

Fischer-Tropsch synthesis (FTS) is an increasingly important approach for producing liquid fuels and chemicals via syngas—that is, synthesis gas, a mixture of carbon monoxide and hydrogen—generated from coal, natural gas, or biomass. In FTS, dispersed transition metal nanoparticles are used to catalyze the reactions underlying the formation of carbon-carbon bonds. Catalytic activity and selectivity are strongly correlated with the electronic and geometric structure of the nanoparticles, which...

Nitrogen isotope fractionations in the Fischer-Tropsch synthesis and in the Miller-Urey reaction

International Nuclear Information System (INIS)

Chun-Chan Kung; Hayatsu, R.; Studier, M.H.; Clayton, R.N.; Chicago Univ., IL; Chicago Univ., IL

1979-01-01

Nitrogen isotope fractionations have been measured in Fischer-Tropsch and Miller-Urey reactions in order to determine whether these processes can account for the large 15 N/ 14 N ratios found in organic matter in carbonaceous chondrites. Polymeric material formed in the Fischer-Tropsch reaction was enriched in 15 N by only 3 promille relative to the starting material (NH 3 ). The 15 N enrichment in polymers from the Miller-Urey reaction was 10-12 promille. Both of these fractionations are small compared to the 80-90 promille differences observed between enstatite chondrites and carbonaceous chondrites. These large differences are apparently due to temporal or spatial variations in the isotopic composition of nitrogen in the solar nebula, rather than to fractionation during the production of organic compounds. (orig.)

Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

Science.gov (United States)

Huffman, Gerald P.

2012-11-13

A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

Emil Fischer and the "art of chemical experimentation".

Science.gov (United States)

Jackson, Catherine M

2017-03-01

What did nineteenth-century chemists know? This essay uses Emil Fischer's classic study of the sugars in 1880s and 90s Germany to argue that chemists' knowledge was not primarily vested in the theories of valence, structure, and stereochemistry that have been the subject of so much historical and philosophical analysis of chemistry in this period. Nor can chemistry be reduced to a merely manipulative exercise requiring little or no intellectual input. Examining what chemists themselves termed the "art of chemical experimentation" reveals chemical practice as inseparable from its cognitive component, and it explains how chemists integrated theory with experiment through reason.

The role of zeolites in the deactivation of multifunctional fischer-tropsch synthesis catalysts: the interaction between HZSM-5 and Fe-based Ft-catalysts

Directory of Open Access Journals (Sweden)

P. C. Zonetti

2013-12-01

Full Text Available In order to produce gasoline directly from syngas, HZSM-5 can be added to the Fischer-Tropsch catalyst. However, this catalytic system shows an important deactivation rate. Aiming at describing this phenomenon, Fe-based catalysts and physical mixtures containing these catalysts and HZSM-5 were employed in this reaction. All these systems were characterized using the following techniques: XRD, XPS, TPR and TPD of CO. This work shows that HZSM-5 interacts with the Fe-based Fischer-Tropsch catalyst during the reduction step, decreasing the Fe concentration on the catalytic surface and thus lowering the activity of the catalytic system in the Fischer-Tropsch Synthesis.

The role of zeolites in the deactivation of multifunctional Fischer-Tropsch Synthesis catalysts: the interaction between HZSM-5 and Fe-based FT-catalysts

International Nuclear Information System (INIS)

Zonetti, P.C.; Gaspar, A.B.; Mendes, F.M.T.; Appel, L.G.; Avillez, R. R. de; Sousa-Aguiar, E.F.

2013-01-01

In order to produce gasoline directly from syngas, HZSM-5 can be added to the Fischer-Tropsch catalyst. However, this catalytic system shows an important deactivation rate. Aiming at describing this phenomenon, Fe-based catalysts and physical mixtures containing these catalysts and HZSM-5 were employed in this reaction. All these systems were characterized using the following techniques: XRD, XPS, TPR and TPD of CO. This work shows that HZSM-5 interacts with the Fe-based Fischer-Tropsch catalyst during the reduction step, decreasing the Fe concentration on the catalytic surface and thus lowering the activity of the catalytic system in the Fischer-Tropsch Synthesis. (author)

The role of zeolites in the deactivation of multifunctional Fischer-Tropsch Synthesis catalysts: the interaction between HZSM-5 and Fe-based FT-catalysts

Energy Technology Data Exchange (ETDEWEB)

Zonetti, P.C.; Gaspar, A.B.; Mendes, F.M.T.; Appel, L.G., E-mail: lucia.appel@int.gov.br [Instituto Nacional de Tecnologia (INT/MCT), Rio de Janeiro, RJ (Brazil); Avillez, R. R. de [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Sousa-Aguiar, E.F. [Centro de Pesquisa Leopoldo Americo Miguez de Mello (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil)

2013-10-15

In order to produce gasoline directly from syngas, HZSM-5 can be added to the Fischer-Tropsch catalyst. However, this catalytic system shows an important deactivation rate. Aiming at describing this phenomenon, Fe-based catalysts and physical mixtures containing these catalysts and HZSM-5 were employed in this reaction. All these systems were characterized using the following techniques: XRD, XPS, TPR and TPD of CO. This work shows that HZSM-5 interacts with the Fe-based Fischer-Tropsch catalyst during the reduction step, decreasing the Fe concentration on the catalytic surface and thus lowering the activity of the catalytic system in the Fischer-Tropsch Synthesis. (author)

Development of Hydrotalcite Based Cobalt Catalyst by Hydrothermal and Co-precipitation Method for Fischer-Tropsch Synthesis

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Muhammad Faizan Shareef

2017-10-01

Full Text Available This paper presents the effect of a synthesis method for cobalt catalyst supported on hydrotalcite material for Fischer-Tropsch synthesis. The hydrotalcite supported cobalt (HT-Co catalysts were synthesized by co-precipitation and hydrothermal method. The prepared catalysts were characterized by using various techniques like BET (Brunauer–Emmett–Teller, SEM (Scanning Electron Microscopy, TGA (Thermal Gravimetric Analysis, XRD (X-ray diffraction spectroscopy, and FTIR (Fourier Transform Infrared Spectroscopy. Fixed bed micro reactor was used to test the catalytic activity of prepared catalysts. The catalytic testing results demonstrated the performance of hydrotalcite based cobalt catalyst in Fischer-Tropsch synthesis with high selectivity for liquid products. The effect of synthesis method on the activity and selectivity of catalyst was also discussed. Copyright © 2017 BCREC Group. All rights reserved Received: 3rd November 2016; Revised: 26th February 2017; Accepted: 9th March 2017; Available online: 27th October 2017; Published regularly: December 2017 How to Cite: Sharif, M.S., Arslan, M., Iqbal, N., Ahmad, N., Noor, T. (2017. Development of Hydrotalcite Based Cobalt Catalyst by Hydrothermal and Co-precipitation Method for Fischer-Tropsch Synthesis. Bulletin of Chemical Reaction Engineering & Catalysis, 12(3: 357-363 (doi:10.9767/bcrec.12.3.762.357-363

Sprague-Dawley and Fischer Female Rats Differ in Acute Effects of Fluoxetine on Sexual Behavior

Science.gov (United States)

Miryala, C.S.J.; Hiegel, C.; Uphouse, L.

2012-01-01

Introduction The selective serotonin reuptake inhibitor (SSRI), fluoxetine, leads to sexual dysfunction in a substantial proportion of women. In studies with the Fischer inbred rat, the 5-HT1A receptor has been implicated in this sexual dysfunction. Whether this association with 5-HT1A receptors holds for other rat strains is not known. Aim The effects of acute fluoxetine on sexual behavior in two strains of rats that differ in their response to a 5-HT1A receptor agonist were examined. Whether the strain difference is comparable in naturally cycling and hormonally primed, ovariectomized rats was determined. Main Outcome Measures Lordosis to mount ratios, lordosis quality, and proceptive behaviors were quantified. Sprague-Dawley and Fischer females were compared on each of these measures. The IC50 for inhibition of lordosis behavior was determined. Methods Proestrous rats and ovariectomized rats, hormonally primed with estradiol benzoate and progesterone, were treated with varying doses of fluoxetine. Sexual behavior was examined before and after treatment with the SSRI. Results In both the intact and the hormonally-primed, ovariectomized model, Sprague-Dawley females were less sensitive to the effects of fluoxetine on sexual behavior. In both groups, fluoxetine showed dose-dependency in behavioral inhibition, but a higher dose was required for Sprague-Dawley than for Fischer females. Naturally cycling, proestrous rats required a higher dose of fluoxetine than hormonally-primed ovariectomized rats to produce significant inhibition of sexual behavior. Thus, the strain difference in the response to fluoxetine does not parallel strain differences in the response to a 5-HT1A receptor agonist. Conclusions Acute treatment with fluoxetine inhibits lordosis behavior in both Fischer and Sprague-Dawley females and the strain difference cannot be explained by reported strain differences in the response to a 5-HT1A receptor agonist. Fluoxetine’s inhibition of female rat

Age-related changes in cochlear and brainstem auditory functions in Fischer 344 rats

Czech Academy of Sciences Publication Activity Database

Popelář, Jiří; Groh, Daniel; Pelánová, Jana; Canlon, B.; Syka, Josef

2006-01-01

Roč. 27, č. 3 (2006), s. 490-500 ISSN 0197-4580 R&D Projects: GA ČR GA309/04/1074; GA MZd NR8113 Institutional research plan: CEZ:AV0Z50390512 Keywords : Fischer 344 rats * Hearing threshold * Otoacoustic emissions Subject RIV: FH - Neurology Impact factor: 5.599, year: 2006

Heterosexual Persons' Perceptions Regarding Language Use in Counseling: Extending Dorland and Fischer (2001)

Science.gov (United States)

Ross, Amanda D.; Waehler, Charles A.; Gray, Torie N.

2013-01-01

An important original study by Dorland and Fischer noted how the use of inclusive language can affect the therapeutic relationship positively for gay, lesbian, and bisexual clients. In this extension of that study with heterosexual participants ("N" = 179), there seemed to be low, but positive, salience of the language used by the…

Cerium Modified Pillared Montmorillonite Supported Cobalt Catalysts for Fischer Tropsch Synthesis

International Nuclear Information System (INIS)

Ahmad, N.; Ali, Z.; Abbas, S. M.; Hussain, F.

2015-01-01

Fischer-Tropsch (FT) synthesis was accomplished over Al-pillared Montmorillonite supported 20 wt% Co modified with different weight% of cerium catalysts. These catalysts were prepared by impregnation method while structural characterizations of the prepared samples were performed by XRD, TPR, NH/sub 3/TPD, TGA, BET, XRF and SEM techniques. The Fischer Tropsch reaction was studied in fixed bed micro catalytic reactor at temperature range of 220, 260 and 275 degree C and at different pressure (1, 5 and 10 bars). From the activity results, it was found that by pillaring NaMMT with Al higher catalytic activity and lower methane selectivity of NaMMT was achieved. Furthermore, the results of FT synthesis reaction revealed that cerium incorporation increased the dispersion of Co/sub 3/O/sub 4/ on the surface and consequently resulted in enhanced catalytic activity. Additionally, the C/sub 5/-C/sub 12/ hydrocarbons and methane selectivity increased while C/sub 22+/ hydrocarbons selectivity was decreased over cerium modified catalysts. Higher reaction temperature (>220 degree C) resulted in significant enhancement in CO conversion and methane selectivity. Though, increase in pressure from 1 to 10 bars eventually resulted in increase in C/sub 5+/ hydrocarbons and decrease in methane and C/sub 2/-C/sub 5/ hydrocarbons selectivity. (author)

Emissions characteristics of Military Helicopter Engines Fueled with JP-8 and a Fischer-Tropsch Fuel

International Nuclear Information System (INIS)

Corporan, E.; DeWitt, M.; Klingshirn, Christopher D.; Striebich, Richard; Cheng, Mengdawn

2010-01-01

The rapid growth in aviation activities and more stringent U.S. Environmental Protection Agency regulations have increased concerns regarding aircraft emissions, due to their harmful health and environmental impacts, especially in the vicinity of airports and military bases. In this study, the gaseous and particulate-matter emissions of two General Electric T701C engines and one T700 engine were evaluated. The T700 series engines power the U.S. Army's Black Hawk and Apache helicopters. The engines were fueled with standard military JP-8 fuel and were tested at three power settings. In addition, one of the T701C engines was operated on a natural-gas-derived Fischer-Tropsch synthetic paraffinic kerosene jet fuel. Test results show that the T701C engine emits significantly lower particulate-matter emissions than the T700 for all conditions tested. Particulate-matter mass emission indices ranged from 0.2-1.4 g/kg fuel for the T700 and 0.2-0.6 g/kg fuel for the T701C. Slightly higher NOx and lower CO emissions were observed for the T701C compared with the T700. Operation of the T701C with the Fischer-Tropsch fuel rendered dramatic reductions in soot emissions relative to operation on JP-8, due primarily to the lack of aromatic compounds in the alternative fuel. The Fischer-Tropsch fuel also produced smaller particles and slight reductions in CO emissions.

Una villa en Villa de Leyva, obra del arquitecto Guillermo Fischer Villa de Leyva, Colombia

Directory of Open Access Journals (Sweden)

Juan Pablo Aschner Rosselli

2010-12-01

Full Text Available Desde las impresiones que despierta una casa de recreo diseñada por Guillermo Fischer en Villa de Leyva se pretende una aproximación al significado y a la historia de la villa, entendida como tipología edilicia que responde a un determinado modo de habitar en el campo. En este escrito, se esbozan hipótesis con respecto a la relación estética y moral de la casa con preexistencias edilicias y con tradiciones sociales arraigadas y se describen los acercamientos y distanciamientos de la villa en relación con su contexto espacial y temporal. En la villa de Villa de Leyva atendemos a un despertar de la tipología, gracias a la atenta lectura de la historia y a la sensibilidad proyectual de su arquitecto Guillermo Fischer.

TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

Energy Technology Data Exchange (ETDEWEB)

Burtron H. Davis

1999-01-30

The effects of copper on Fischer-Tropsch activity, selectivity and water-gas shift activity were studied over a wide range of syngas conversion. Three catalyst compositions were prepared for this study: (a) 100Fe/4.6Si/1.4K, (b) 100Fe/4.6Si/0.10Cu/1.4K and (c) 100Fe/4.6Si/2.0Cu/1.4K. The results are reported in Task 2. The literature review for cobalt catalysts is approximately 90% complete. Due to the size of the document, it has been submitted as a separate report labeled Task 6.

Indústria, ordenamento do território e transportes – a contribuição de André Fischer

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Áurea Breitbach

2009-03-01

Full Text Available Indústria, ordenamento do território e transportes – a contribuição de André Fischer, Organização Olga Lúcia C. Firkowski e Eliseu S. Sposito, Editora Expressão Popular, 2008, 160 p.Este livro é uma iniciativa conjunta dos Programas de Pós-Graduação em Geografia da Universidade Federal do Paraná e da Universidade Estadual Paulista/Presidente Prudente. Conforme os organizadores, a intenção foi publicar um livro que homenageasse André Fischer e, para tanto, foram reunidos diversos textos escrit...

40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

Science.gov (United States)

2010-07-01

...-alkane, branched and linear. 721.10103 Section 721.10103 Protection of Environment ENVIRONMENTAL..., branched and linear. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS No...

Abstraction of methyl from neutral Fischer-type carbene complexes: A new site for nucleophilic attack

Energy Technology Data Exchange (ETDEWEB)

Toomey, L.M.; Atwood, J.D. [State Univ. of New York, Buffalo, NY (United States)

1997-02-04

Reactions of Fischer-type carbene complexes, M(CO){sub 5}(C(OMe)pH) (M = Cr, W), with metal carbonyl anions (M`{sup -} = CpFe(CO){sub 2}{sup -@}, Re(CO){sub 5}{sup -}, Mn(CO){sub 4}PPh{sub 3}{sup -}, Co(CO){sub 3}PPh{sub 3}{sup -}, Cp{sup *}Cr(CO){sub 3}{sup -}, CpMo(CO){sub 3}{sup -}) result in demethylation of the carbene complexes. The products are M(CO){sub 5}C(O)Ph{sup -} and M`-Me, characterized by infrared and NMR spectroscopy. A slower rate for reaction with W(CO){sub 5}(C(OEt)Ph) in comparison to the methyl analogue is consistent with nucleophilic attack of the metal carbonyl anion on the methyl of the methoxy group of the carbene. This is a new type of nucleophilic attack of a Fischer-type carbene. 22 refs., 1 fig., 1 tab.

The effect of age on digoxin pharmacokinetics in Fischer-344 rats

International Nuclear Information System (INIS)

Evans, R.L.; Owens, S.M.; Ruch, S.; Kennedy, R.H.; Seifen, E.

1990-01-01

Digoxin protein binding and pharmacokinetics were studied in 4-, 14-, and 25-month-old male Fischer-344 rats to determine if there were age-dependent changes in digoxin disposition. Serum protein binding did not differ among age groups. The average percentage unbound digoxin for all animals was 61.3 ± 5.3% (means ± SD, n = 15). For pharmacokinetic studies, [ 3 H]digoxin and 1 mg/kg unlabeled digoxin were administered as an intravenous bolus dose to animals from each age group. The [ 3 H]digoxin terminal elimination half-life was 2.0, 2.3, and 2.5 hr, respectively. The steady-state volume of distribution in the three age groups was 1.51, 1.49, and 1.27 liters/kg, respectively. Total body clearance for the three age groups was 14.2, 12.1, and 7.5 ml/min/kg, respectively. Analysis of variance of these data followed by Duncan's multiple range test indicated a significant decrease in clearance in the aged rats (25-month-old, p less than 0.05). This age-dependent decrease in clearance suggested that digoxin pharmacokinetics could be a significant factor in age-related alterations in digoxin cardiotoxicity in the rat, as it is in humans, and that the Fischer-344 rat could be a useful model for studies of digoxin pharmacokinetic changes with age

Size and Promoter Effects on Stability of Carbon-Nanofiber-Supported Iron-Based Fischer-Tropsch Catalysts

NARCIS (Netherlands)

Xie, Jingxiu; Torres Galvis, Hirsa; Koeken, Ard C J; Kirilin, Alexey; Dugulan, A Iulian; Ruitenbeek, Matthijs; de Jong, Krijn P

2016-01-01

The Fischer-Tropsch Synthesis converts synthesis gas from alternative carbon resources, including natural gas, coal, and biomass, to hydrocarbons used as fuels or chemicals. In particular, iron-based catalysts at elevated temperatures favor the selective production of C2-C4 olefins, which are

Moessbauer study of CO-precipitated Fischer-Tropsch iron catalysts

International Nuclear Information System (INIS)

Rao, K.R.P.M.; Huggins, F.E.; Mahajan, V.; Huffman, G.P.; Bukur, D.B.; Rao, V.U.S.

1994-01-01

Moessbauer spectroscopy studies of precipitated Fischer-Tropsch (FT) iron catalysts, viz. 100 Fe/5 Cu/4.2 K/x SiO 2 , where x = 0, 8, 16, 24, 25, 40, or 100, have shown that reduction of the oxide precursor in CO gives rise to χ-carbide Fe 5 C 2 whose amount decreases with an increase of SiO 2 content. The χ-carbide is converted into magnetite Fe 3 O 4 while catalyzing the FT synthesis reaction. A correlation between FT activity and the content of χ-carbide in the catalysts was found, which indicated that χ-carbide is active for FT synthesis reaction. (orig.)

Synthesis in situ of gold nanoparticles by a dialkynyl Fischer carbene complex anchored to glass surfaces

International Nuclear Information System (INIS)

Bertolino, María Candelaria; Granados, Alejandro Manuel

2016-01-01

Highlights: • Fischer carbene 1-W reacts via cycloaddition without Cu(I) with azide terminal surface. • This reaction on the surface is regioselective to internal triple bond of 1-W. • 1-W bound to glass surface produce AuNps in situ fixed to the surface. • This ability is independent of how 1-W is bonded to the surface. • This hybrid surface can be valuable as SERS substrate or in heterogeneous catalysis. - Abstract: In this work we present a detailed study of classic reactions such as “click reaction” and nucleophilic substitution reaction but on glass solid surface (slides). We used different reactive center of a dialkynylalcoxy Fischer carbene complex of tungsten(0) to be anchored to modified glass surface with amine, to obtain aminocarbene, and azide terminal groups. These cycloaddition reaction showed regioselectivity to internal triple bond of dialkynyl Fischer carbene complex without Cu(I) as catalyst. Anyway the carbene anchored was able to act as a reducing agent to produce in situ very stable gold nanoparticles fixed on surface. We showed the characterization of modified glasses by contact angle measurements and XPS. Synthesized nanoparticles were characterized by SEM, XPS, EDS and UV–vis. The modified glasses showed an important enhancement Raman-SERS. This simple, fast and robust method to create a polifunctional and hybrid surfaces can be valuable in a wide range of applications such as Raman-SERS substrates and other optical fields.

Synthesis in situ of gold nanoparticles by a dialkynyl Fischer carbene complex anchored to glass surfaces

Energy Technology Data Exchange (ETDEWEB)

Bertolino, María Candelaria, E-mail: cbertolino@fcq.unc.edu.ar; Granados, Alejandro Manuel, E-mail: ale@fcq.unc.edu.ar

2016-10-15

Highlights: • Fischer carbene 1-W reacts via cycloaddition without Cu(I) with azide terminal surface. • This reaction on the surface is regioselective to internal triple bond of 1-W. • 1-W bound to glass surface produce AuNps in situ fixed to the surface. • This ability is independent of how 1-W is bonded to the surface. • This hybrid surface can be valuable as SERS substrate or in heterogeneous catalysis. - Abstract: In this work we present a detailed study of classic reactions such as “click reaction” and nucleophilic substitution reaction but on glass solid surface (slides). We used different reactive center of a dialkynylalcoxy Fischer carbene complex of tungsten(0) to be anchored to modified glass surface with amine, to obtain aminocarbene, and azide terminal groups. These cycloaddition reaction showed regioselectivity to internal triple bond of dialkynyl Fischer carbene complex without Cu(I) as catalyst. Anyway the carbene anchored was able to act as a reducing agent to produce in situ very stable gold nanoparticles fixed on surface. We showed the characterization of modified glasses by contact angle measurements and XPS. Synthesized nanoparticles were characterized by SEM, XPS, EDS and UV–vis. The modified glasses showed an important enhancement Raman-SERS. This simple, fast and robust method to create a polifunctional and hybrid surfaces can be valuable in a wide range of applications such as Raman-SERS substrates and other optical fields.

Kinetics of phototoxicity of Fischer's medium for L5178Y leukemic cells

International Nuclear Information System (INIS)

Griffin, F.M.; Ashland, G.; Capizzi, R.L.

1981-01-01

The uncontrolled exposure of Fischer's medium to cool white fluorescent (CWF) light or other sources emitting near-ultraviolet or visible light absorbance by riboflavin is a crucial random variable in experiments which utilize L5178Y cells and this medium. The radiation effects of CWF light result in the rapid development of toxic photoproducts in the medium which are cytostatic at lower doses of radiation and cytotoxic at higher doses. After a 24-hr suspension in medium irradiated for 3 or 48 hr, the cloning efficiencies of cells subsequently plated in light-protected medium were 87 and 3%, respectively. The corresponding near-ultraviolet doses for these periods of exposure to CWF light were 0.22 x 10(4) for a 3-hr exposure and 3.47 x 10(4) J/sq m for a 48-hr exposure. Cells incubated in lightly irradiated medium resumed growth at nearly normal rates following a 24- to 48-hr period in which no increase in cell numbers occurred. Exposure of medium containing riboflavin, but not tryptophan or tyrosine, to CWF light also produces toxic medium. Tryptophan enhances riboflavin-induced phototoxicity, whereas tyrosine diminishes this effect. As photosusceptibility of this system is very high, Fischer's medium must be fully protected from all sources of light absorbable by riboflavin

Fischer-Tropsch synthesis in slurry-phase reactors using Co/SBA-15 catalysts

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, J.J.; Lima, L.A.; Lima, W.S.; Rodrigues, M.G.F. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia Quimica], e-mail: meiry@deq.ufcg.edu.br; Fernandes, F.A.N. [Universidade Federal do Ceara (UFCE), CE (Brazil). Dept. de Engenharia Quimica

2011-07-15

The objective of this work is to describe the production of bifunctional catalysts using the incipient humidity method, producing catalysts with 15 wt.% cobalt supported in SBA-15 molecular sieve, to be applied in the Fischer-Tropsch (FT) reaction. The originality of this work is its focus on the use of a 15 wt.% Co/SBA-15 catalyst in FT synthesis in slurry reactors. The deposition of cobalt over SBA-15 support was accomplished by impregnation with a 0.1-M aqueous solution of cobalt nitrate. The Fischer-Tropsch synthesis was carried out with the catalyst at 240 deg C and 20 atm, under a COH{sub 2} atmosphere (molar ratio= 1), in a slurry reactor for 8 hours. X-ray diffraction measurements showed that the calcined cobalt catalyst did not modify the structure of SBA-15, proving that Co was present under the form of Co{sub 3}O{sub 4} in the catalyst. The addition of cobalt in the SBA-15 decreased the specific superficial area of the molecular sieve. The 15 wt.% Co/SBA-15 catalyst had a 40% CO conversion rate and a high selectivity towards the production of C{sub 5}{sup +} (53.9% after 8 hours). (author)

Fischer aminocarbene complexes of chromium and iron: Anomalous electrochemical reduction of p-carbonyl substituted derivatives

Czech Academy of Sciences Publication Activity Database

Hoskovcová, I.; Zvěřinová, R.; Roháčová, J.; Dvořák, D.; Tobrman, T.; Záliš, Stanislav; Ludvík, Jiří

2011-01-01

Roč. 56, č. 19 (2011), s. 6853-6859 ISSN 0013-4686 R&D Projects: GA AV ČR IAA400400813 Institutional research plan: CEZ:AV0Z40400503 Keywords : DFT calculations * electrochemistry * Fischer aminocarbene complexes Subject RIV: CG - Electrochemistry Impact factor: 3.832, year: 2011

Fischer-Tropsch Synthesis on Multicomponent Catalysts: What Can We Learn from Computer Simulations?

Directory of Open Access Journals (Sweden)

José L. C. Fajín

2015-01-01

Full Text Available In this concise review paper, we will address recent studies based on the generalized-gradient approximation (GGA of the density functional theory (DFT and on the periodic slab approach devoted to the understanding of the Fischer-Tropsch synthesis process on transition metal catalysts. As it will be seen, this computational combination arises as a very adequate strategy for the study of the reaction mechanisms on transition metal surfaces under well-controlled conditions and allows separating the influence of different parameters, e.g., catalyst surface morphology and coverage, influence of co-adsorbates, among others, in the global catalytic processes. In fact, the computational studies can now compete with research employing modern experimental techniques since very efficient parallel computer codes and powerful computers enable the investigation of more realistic molecular systems in terms of size and composition and to explore the complexity of the potential energy surfaces connecting reactants, to intermediates, to products of reaction. In the case of the Fischer-Tropsch process, the calculations were used to complement experimental work and to clarify the reaction mechanisms on different catalyst models, as well as the influence of additional components and co-adsorbate species in catalyst activity and selectivity.

TECHNOLOGY DEVELOPMENT FOR IRON FISCHER-TROPSCH CATALYSTS

Energy Technology Data Exchange (ETDEWEB)

Davis, B.H.

1998-07-22

The goal of the proposed work described in this Final Report was the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The work described here has optimized the catalyst composition and pretreatment operation for a low-alpha catalyst. In parallel, work has been conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies have been conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors have been studied at the laboratory scale. Catalyst performance has been determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

Reduction and reoxidation of cobalt Fischer-Tropsch catalysts

Energy Technology Data Exchange (ETDEWEB)

Hilmen, Anne-Mette

1996-12-31

The Fischer-Tropsch synthesis involves the hydrogenation of carbon monoxide to produce mainly hydrocarbons, water and carbon dioxide, but also alcohols, aldehydes and acids are formed. The distribution of these products is determined by the choice of catalyst and synthesis conditions. This thesis studies the reduction and reoxidation of 17%Co/Al{sub 2}O{sub 3} and 17%Co-1%Re/Al{sub 2}O{sub 3} by means of several characterization techniques. The effect of small amounts of Re on the reduction properties of Al{sub 2}O{sub 3}-supported Co catalysts has been studied by temperature-programmed reduction (TPR). An intimate mixture of CoAl{sub 2}O{sub 3} and Re/Al{sub 2}O{sub 3} catalysts showed a promoting effect of Re similar to that for co impregnated CoRe/Al{sub 2}O{sub 3}. A loose mixture of Co/Al{sub 2}O{sub 3} + Re/Al{sub 2}O{sub 3} did not show any effect of Re on the reduction of Co. But a promoting effect was observed if the mixture had been pre-treated with Ar saturated with water before the TPR. It is suggested that Re promotes the reduction of Co oxide by hydrogen spillover. It is shown that a high temperature TPK peak at 1200K assigned to Co aluminate is mainly caused by the diffusion of Co ions during the TPR and not during calcination. The Co particle size measured by x-ray diffraction on oxidized catalysts decreased compared to the particle size on the calcined catalysts, while the dispersion measured by volumetric chemisorption decreased somewhat after the oxidation-reduction treatment. The role of water in the deactivation of Co/Al{sub 2}O{sub 3} and CoRe/Al{sub 2}O{sub 3} Fischer-Tropsch catalysts has been extensively studied. There were significant differences in the reducibility of the phases formed for the two catalysts during exposure to H{sub 2}O/He. 113 refs., 76 figs., 18 tabs.

Synthesis gas solubility in Fischer-Tropsch slurry: Final report

Energy Technology Data Exchange (ETDEWEB)

Chao, K.C.; Lin, H.M.

1988-01-01

The objective is to investigate the phase equilibrium behavior of synthesis gases and products in a Fischer-Tropsch slurry reactor. A semi-flow apparatus has been designed and constructed for this purpose. Measurements have been made for hydrogen, cabon monoxide, methane, ethane, ethylene, and carbon dioxide in a heavy n-paraffin at temperatures from 100 to 300)degree)C and pressures 10 to 50 atm. Three n-paraffin waxes: n-eicosane (n-C/sub 20/), n-octacosane )n-C/sub 28/), and n-hexatriacontane (n-C/sub 36/), were studied to model the industrial wax. Solubility of synthesis gas mixtures of H/sub 2/ and CO in n-C/sub 28/ was also determined at two temperatures (200 and 300)degree)C) for each of three gas compositions (40.01, 50.01, and 66.64 mol%) of hydrogen). Measurements were extended to investigate the gas solubility in two industrial Fischer-Tropsch waxes: Mobilwax and SASOL wax. Observed solubility increases in the order: H/sub 2/, CO, CH/sub 4/, CO/sub 2/, C/sub 2/H/sub 4/, C/sub 2/H/sub 6/, at a given temperature pressure, and in the same solvent. Solubility increases with increasing pressure for all the gases. Lighter gases H/sub 2/ and CO show increased solubility with increasing temperature, while the heavier gases CO/sub 2/, ethane, and ethylene show decreased solubility with increasing temperature. The solubility of methane, the intermediate gas, changes little with temperature, and shows a shallow minimum at about 200)degrees)C or somewhat above. Henry's constant and partial molal volume of the gas solute at infinite dilution are determinedfrom the gas solubility data. A correlation is developed from the experimental data in the form on an equation of state. A computer program has been prepared to implement the correlation. 19 refs., 66 figs., 39 tabs.

Alkali promotion effect in Fischer-Tropsch cobalt-alumina catalyst

Energy Technology Data Exchange (ETDEWEB)

Eliseev, O.L.; Tsapkina, M.V.; Davydov, P.E.; Kazantsev, R.V. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Inst. of Organic Chemistry; Belousova, O.S.; Lapidus, A.L. [Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation)

2011-07-01

Promoting Co-alumina Fischer-Tropsch synthesis catalysts with alkali and alkaline-earth metals was studied. XRD, oxygen titration and CO chemisorption were used for the characterization of the catalysts. The best results in terms of catalyst selectivity and long-chain alkanes content in synthesized products were obtained with K-promoted catalyst. Catalytic performance strongly depends on K:Co atomic ratio as well as preparation procedure. Effect of K loading on selectivities is non-linear with extreme point at K:Co=0.01. Significant increase in C{sub 5+} selectivity of K-promoted catalyst may be explained as a result of strong CO adsorption on the catalyst surface, as was confirmed in CO chemisorption experiments. (orig.)

Large-scale production of Fischer-Tropsch diesel from biomass. Optimal gasification and gas cleaning systems

International Nuclear Information System (INIS)

Boerrigter, H.; Van der Drift, A.

2004-12-01

The paper is presented in the form of copies of overhead sheets. The contents concern definitions, an overview of Integrated biomass gasification and Fischer Tropsch (FT) systems (state-of-the-art, gas cleaning and biosyngas production, experimental demonstration and conclusions), some aspects of large-scale systems (motivation, biomass import) and an outlook

Effect of structural promoters on Fe-based Fischer-Tropsch synthesis of biomass derived syngas

Science.gov (United States)

Pratibha Sharma; Thomas Elder; Leslie H. Groom; James J. Spivey

2014-01-01

Biomass gasification and subsequent conversion of this syngas to liquid hydrocarbons using Fischer–Tropsch (F–T) synthesis is a promising source of hydrocarbon fuels. However, biomass-derived syngas is different from syngas obtained from other sources such as steam reforming of methane. Specifically the H2/CO ratio is less than 1/1 and the CO

The formation and influence of carbon on cobalt-based Fischer-Tropsch synthesis catalysts : an integrated review

NARCIS (Netherlands)

Moodley, D.J.; Loosdrecht, van de J.; Saib, A.M.; Niemantsverdriet, J.W.; Davis, B.H.; Occelli, M.L.; Speight, J.G.

2010-01-01

Cobalt-based Fischer-Tropsch synthesis (FTS) catalysts are the systems of choice for use in gas-to-liquid (GTL) processes. As with most catalysts, cobalt systems gradually lose their activity with increasing time on stream. There are various mechanisms that have been proposed for the deactivation of

Techno-economic assessment of integrating methanol or Fischer-Tropsch synthesis in a South African sugar mill.

Science.gov (United States)

Petersen, Abdul M; Farzad, Somayeh; Görgens, Johann F

2015-05-01

This study considered an average-sized sugar mill in South Africa that crushes 300 wet tonnes per hour of cane, as a host for integrating methanol and Fischer-Tropsch synthesis, through gasification of a combined flow of sugarcane trash and bagasse. Initially, it was shown that the conversion of biomass to syngas is preferably done by catalytic allothermal gasification instead of catalytic autothermal gasification. Thereafter, conventional and advanced synthesis routes for both Methanol and Fischer-Tropsch products were simulated with Aspen Plus® software and compared by technical and economic feasibility. Advanced FT synthesis satisfied the overall energy demands, but was not economically viable for a private investment. Advanced methanol synthesis is also not viable for private investment since the internal rate of return was 21.1%, because it could not provide the steam that the sugar mill required. The conventional synthesis routes had less viability than the corresponding advanced synthesis routes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ruthenium Modification on Mn and Zr-Modified Co/SiO2 Catalysts for Slurry-Phase Fischer-Tropsch Synthesis

Directory of Open Access Journals (Sweden)

Tomohisa Miyazawa

2015-01-01

Full Text Available The addition of Ru to Mn and Zr-modified Co/SiO2 catalysts, while applying different preparation orders and loading amounts, was investigated as a means of enhancing the Fischer-Tropsch synthesis reaction. The coimpregnation of Zr/SiO2 with Co, Mn and Ru gave the most attractive catalytic properties. This can be attributed to the higher dispersion of Co metal resulting from the coimpregnation of Co and Mn as well as enhanced reducibility due to the presence of Ru. The addition of a moderate amount of Ru together with the appropriate order of addition affected both the Co reducibility and the catalytic activity, primarily because of increased reducibility. The addition of even 0.1 wt.% Ru resulted in an obvious enhancement of Fischer-Tropsch synthesis activity.

Moessbauer investigations of the Fe-Cu-Mn catalysts for Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Spanu, V.; Filoti, G.; Ilie, I.; Zamfirescu, E.

1990-01-01

In the selective process of the syngas conversion to synthetic gasoline a bifunctional catalytic system has to be used. It was obtained by combination a Fischer-Tropsch catalyst with the HZSM-5 zeolite. The phase compositions of the precursor and the fresh catalyst were established as well as the optimum thermal treatment. The catalyst was reduced in pure H 2 or in a H 2 +CO mixture. The influence of the reduction and reaction conditions on the catalyst structure was investigated. (orig.)

Preparation of Fischer-Tropsch catalysts from cobalt/iron hydrotalcites

Energy Technology Data Exchange (ETDEWEB)

Howard, B.H.; Boff, J.J.; Zarochak, M.F. [Pittsburgh Energy Technology Center, PA (United States)] [and others

1995-12-31

Compounds with the (hydrotalcites) have properties that make them attractive as precursors for Fischer-Tropsch catalysts. A series of single-phase hydrotalcites with cobalt/iron atom ratios ranging from 75/25 to 25/75 has been synthesized. Mixed cobalt/iron oxides have been prepared from these hydrotalcites by controlled thermal decomposition. Thermal decomposition at temperatures below 600 {degrees}C typically produced a single-phase mixed metal oxide with a spinel structure. The BET surface areas of the spinal samples have been found to be as high as about 150 m{sup 2}/g. Appropriate reducing pretreatments have been developed for several of these spinels and their activity, selectivity, and activity and selectivity maintenance have been examined at 13 MPa in a fixed-bed microreactor.

Fischer-Tropsch Synthesis on Multicomponent Catalysts: What Can We Learn from Computer Simulations?

OpenAIRE

Fajin, Jose L. C.; Cordeiro, M. Natalia D. S.; Gomes, Jose R. B.

2015-01-01

In this concise review paper, we will address recent studies based on the generalized-gradient approximation (GGA) of the density functional theory (DFT) and on the periodic slab approach devoted to the understanding of the Fischer-Tropsch synthesis process on transition metal catalysts. As it will be seen, this computational combination arises as a very adequate strategy for the study of the reaction mechanisms on transition metal surfaces under well-controlled conditions and allows separati...

Deactivation and Regeneration of Commercial Type Fischer-Tropsch Co-Catalysts—A Mini-Review

OpenAIRE

Erling Rytter; Anders Holmen

2015-01-01

Deactivation of commercially relevant cobalt catalysts for Low Temperature Fischer-Tropsch (LTFT) synthesis is discussed with a focus on the two main long-term deactivation mechanisms proposed: Carbon deposits covering the catalytic surface and re-oxidation of the cobalt metal. There is a great variety in commercial, demonstration or pilot LTFT operations in terms of reactor systems employed, catalyst formulations and process conditions. Lack of sufficient data makes it difficult to correlat...

Effect of Lanthanum as a Promoter on Fe-Co/SiO2 Catalyst for Fischer-Tropsch Synthesis

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Ali Abbasi

2014-03-01

Full Text Available Iron-Cobalt catalyst is well known from both operational and economical aspects for Fischer-Tropsch synthesis. Effort to increase the efficiency of this kind of catalyst is an important research topic. In this work, the effect of lanthanum on characteristic behavior, conversion and selectivity of a Fe-Co/SiO2 Fischer-Tropsch catalyst was studied. The Fe-Co-La/SiO2 Catalysts were prepared using an incipient wetness impregnation method. These catalysts were then characterized by XRF-EDAX, BET and TPR techniques, and their performance were evaluated in a lab-scale reactor at 250ºC, H2/CO = 1.8 of molar ratio, 16 barg pressure and GHSV=600 h-1. TPR analysis showed that the addition of La lowered the reduction temperature of Fe-Co catalyst, and due to a lower temperature, the sintering of the catalyst can be mitigated. Furthermore, from the micro reactor tests (about 4 days, it was found that lanthanum promoted catalyst had higher selectivity toward hydrocarbons, and lower selectivity toward CO2.Received: 8th July 2013; Revised: 18th November 2013; Accepted: 1st December 2013[How to Cite: Abbasi, A., Ghasemi, M., Sadighi, S. (2014. Effect of Lanthanum as a Promoter on Fe-Co/SiO2 Catalyst for Fischer-Tropsch Synthesis. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 23-27. (doi:10.9767/bcrec.9.1.5142.23-27][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5142.23-27

Reactions of Fischer carbene complexes with Electron-deficient olefins: Scope and limitations of this route to donor-acceptor-substituted cyclopropanes

Energy Technology Data Exchange (ETDEWEB)

Wienand, A.; Reissig, H.U. (Inst. fuer Organische Chemie der Technischen Hochschule Darmstadt (West Germany))

1990-12-01

The Fischer carbene complex ((CO){sub 5}Cr{double bond}C(OMe)Ph) (1) is able to transfer its carbene ligand to a variety of electron-deficient olefins and provides donor-acceptor-substituted cyclopropanes in good yields. Apt activating groups with respect to the alkene are ester, amide, nitrile, sulfone, and dialkyl phosphonate functions. Methyl vinyl ketone (19) affords products in low yield that may arise from an intermediate cyclopropane derivative. Phenyl vinyl sulfoxide (24) mainly acts as an oxidizing agent, transforming 1 into methyl benzoate. for olefin 24 and {alpha}-(N-methylanilino)acrylonitrile the authors found products that should be formed on an olefin metathesis pathway. The methyl-substituted carbene complex 48 also affords the expected donor-acceptor-substituted cyclopropanes; however, acyclic isomers are formed in higher amounts. The molybdenum and tungsten complexes 55 and 56, respectively, also furnish cyclopropane derivatives, but the yields are lower than with the chromium compound 1. Disubstituted olefins and complex 1 still give the cyclopropanes in moderate yields, while all trisubstituted and most of the difunctionalized alkenes do not react with this Fischer carbene complex. The cyclopropanes synthesized can be deprotonated and alkylated or transformed into ring-opened products. These model reactions demonstrate the synthetic potentials of donor-acceptor-substituted cyclopropanes prepared via Fischer carbene complexes.

Effect of pre-heat treatment on a Fischer-Tropsch iron catalyst

International Nuclear Information System (INIS)

Rao, K.R.P.M.; Huggins, F.E.; Ganguly, B.; Mahajan, V.; Huffman, G.P.; Davis, B.; O'Brien, R.J.; Xu Liguang; Rao, V.U.S.

1994-01-01

Moessbauer spectroscopy was used to investigate the effect of heating the Fischer-Tropsch catalyst 100 Fe/5 Cu/4.2 K/24 SiO 2 in two different atmospheres while ramping the temperature of the catalyst from room temperature to 280 C in 5.5 h prior to pretreatment of the catalyst. Preheating in H 2 /CO = 0.7 gave rise to an iron (Fe 2+ ) silicate, while preheating in helium resulted in the formation of ε'-carbide Fe 2.2 C. Iron oxides and χ-carbide Fe 5 C 2 were also formed in both preheat treatments. (orig.)

[I don't want to be eternally imprisoned in the cage of my own self . . .". assumptions about the relationship between Sigmund Freud and his juvenile patient Arthur Fischer-Colbrie (1895-1968)].

Science.gov (United States)

Walder, Christine

2010-01-01

The Austrian writer A. Fischer-Colbrie underwent an analysis with Freud in 1915-16 and then again in 1919. Based on his literary estate, this article tries to shed some light on the biographical background and the precipitating factors of his mental problems. When the cure had to be interrupted because of the young man's military service, Freud sustained an unusual correspondence with him that reflected his efforts to maintain their therapeutic contact. At the same time his letters witness Fischer-Colbrie's burgeoning literary talents.--An appendix presents Freud's letters to Fischer-Colbrie, edited and annotated by Michael Schröter.

Reference test methods for total water in lint cotton by Karl Fischer Titration and low temperature distillation

Science.gov (United States)

In a study of comparability of total water contents (%) of conditioned cottons by Karl Fischer Titration (KFT) and Low Temperature Distillation (LTD) reference methods, we demonstrated a match of averaged results based on a large number of replications and weighing the test specimens at the same tim...

Influence of Reduction Promoters on Stability of Cobalt/g-Alumina Fischer-Tropsch Synthesis Catalysts

OpenAIRE

Gary Jacobs; Wenping Ma; Burtron H. Davis

2014-01-01

This focused review article underscores how metal reduction promoters can impact deactivation phenomena associated with cobalt Fischer-Tropsch synthesis catalysts. Promoters can exacerbate sintering if the additional cobalt metal clusters, formed as a result of the promoting effect, are in close proximity at the nanoscale to other cobalt particles on the surface. Recent efforts have shown that when promoters are used to facilitate the reduction of small crystallites with the aim of increasing...

Fischer matrices of Dempwolff group $2^{5}{^{cdot}}GL(5,2$

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Ayoub Basheer Mohammed Basheer

2012-12-01

Full Text Available In cite{Demp2} Dempwolff proved the existence of a group of theform $2^{5}{^{cdot}}GL(5,2$ (a non split extension of theelementary abelian group $2^{5}$ by the general linear group$GL(5,2$. This group is the second largest maximal subgroup of thesporadic Thompson simple group $mathrm{Th}.$ In this paper wecalculate the Fischer matrices of Dempwolff group $overline{G} =2^{5}{^{cdot}}GL(5,2.$ The theory of projective characters isinvolved and we have computed the Schur multiplier together with aprojective character table of an inertia factor group. The fullcharacter table of $overline{G}$ is then can be calculated easily.

Nanostructured Thin Films Obtained from Fischer Aminocarbene Complexes

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Rosa E. Lazo-Jiménez

2016-03-01

Full Text Available The synthesis of four amphiphilic organometallic complexes with the general formula RC = M(CO5NH(CH215CH3, where R is a ferrocenyl 2(a-b or a phenyl 4(a-b group as a donor moiety and a Fischer carbene of chromium (0 or tungsten (0 as an acceptor group, are reported. These four push-pull systems formed Langmuir (L monolayers at the air-water interface, which were characterized by isotherms of surface pressure versus molecular area and compression/expansion cycles (hysteresis curves; Brewster angle microscopic images were also obtained. By using the Langmuir–Blodgett (LB method, molecular monolayers were transferred onto glass substrates forming Z-type multilayers. LB films were characterized through ultraviolet-visible spectroscopy, atomic force microscopy and X-ray diffraction techniques. Results indicated that films obtained from 2b complex [(Ferrocenyl(hexadecylaminemethylidene] pentacarbonyl tungsten (0 are the most stable and homogeneous; due to their properties, these materials may be incorporated into organic electronic devices.

Nanostructured Thin Films Obtained from Fischer Aminocarbene Complexes

Science.gov (United States)

Lazo-Jiménez, Rosa E.; Ortega-Alfaro, M. Carmen; López-Cortés, José G.; Alvarez-Toledano, Cecilio; Chávez-Carvayar, José Á.; Ignés-Mullol, Jordi; González-Torres, Maykel; Carreón-Castro, Pilar

2016-01-01

The synthesis of four amphiphilic organometallic complexes with the general formula RC = M(CO)5NH(CH2)15CH3, where R is a ferrocenyl 2(a-b) or a phenyl 4(a-b) group as a donor moiety and a Fischer carbene of chromium (0) or tungsten (0) as an acceptor group, are reported. These four push-pull systems formed Langmuir (L) monolayers at the air-water interface, which were characterized by isotherms of surface pressure versus molecular area and compression/expansion cycles (hysteresis curves); Brewster angle microscopic images were also obtained. By using the Langmuir–Blodgett (LB) method, molecular monolayers were transferred onto glass substrates forming Z-type multilayers. LB films were characterized through ultraviolet-visible spectroscopy, atomic force microscopy and X-ray diffraction techniques. Results indicated that films obtained from 2b complex [(Ferrocenyl)(hexadecylamine)methylidene] pentacarbonyl tungsten (0) are the most stable and homogeneous; due to their properties, these materials may be incorporated into organic electronic devices. PMID:28773289

Aversive properties of negative incentive shifts in Fischer 344 and Lewis rats

Science.gov (United States)

Brewer, Adam; Johnson, Patrick; Stein, Jeff; Schlund, Michael; Williams, Dean C.

2018-01-01

Research on incentive contrast highlights that reward value is not absolute but rather is based upon comparisons we make to rewards we have received and expect to receive. Both human and nonhuman studies on incentive contrast show that shifting from a larger more-valued reward to a smaller less-valued reward is associated with long periods of nonresponding—a negative contrast effect. In this investigation, we used two different genetic rat strains, Fischer 344 and Lewis rats that putatively differ in their sensitivity to aversive stimulation, to assess the aversive properties of large-to-small reward shifts (negative incentive shifts). Additionally, we examined the extent to which increasing cost (fixed-ratio requirements) modulates negative contrast effects. In the presence of a cue that signaled the upcoming reward magnitude, lever pressing was reinforced with one of two different magnitudes of food (large or small). This design created two contrast shifts (small-to-large, large-to-small) and two shifts used as control conditions (small-to-small, large-to-large). Results showed a significant interaction between rat strain and cost requirements only during the negative incentive shift with the emotionally reactive Fischer 344 rats exhibiting significantly longer response latencies with increasing cost, highlighting greater negative contrast. These findings are more consistent with emotionality accounts of negative contrast and results of neurophysiological research that suggests shifting from a large to a small reward is aversive. Findings also highlight how subjective reward value and motivation is a product of gene-environment interactions. PMID:27864048

Case 3018. Cervus gouazoubira Fischer, 1814 (currently Mazama gouazoubira; Mammalia, Artiodactyla): proposed conservation as the correct original spelling

Science.gov (United States)

Gardner, A.L.

1999-01-01

The purpose of this application is to conserve the spelling of the specific name of Cervus gouazoubira Fischer, 1814 for the brown brocket deer of South America (family Cervidae). This spelling, rather than the original gouazoubira, has been in virtually universal usage for almost 50 years.

Synthetic production of fuels by the Fischer Tropsch reaction using iron catalysts

International Nuclear Information System (INIS)

Rodriguez Cepeda, Rodrigo; Pacheco Ochoa, Luis

2004-01-01

A series of iron catalysts were prepared on three different types of supports: alumina and two activated carbons from eucalyptus woods and tagua seeds. Potassium was used as promoter and palladium was deposited by the excess wetness impregnation method. The catalysts were characterized by N 2 adsorption at 77 K, XRD and TPR analysis and evaluated as Fischer-Tropsch catalysts. The carbon supported catalysts favour the production of liquid hydrocarbons and decrease the aqueous phase. Those supported with alumina form gases and aqueous phase as the main products. The α p parameters of the Schulz-Flory distribution show hydrocarbons between gasoline and diesel

Activity and selectivity control through periodic composition forcing over Fischer-Tropsch catalysts

Energy Technology Data Exchange (ETDEWEB)

Silveston, P L; Hudgins, R R; Adesina, A A; Ross, G S; Feimer, J L

1986-01-01

Data collected under steady-state and periodic composition forcing of the Fischer-Tropsch synthesis over three commonly used catalysts demonstrate that both activity and selectivity can be changed by the latter operating mode. Synthesis of hydrocarbons up to C/sub 7/are favored at the expense of the higher carbon numbers for the Co catalyst, while for the Ru catalyst, only the C/sub 3/ and lower species are favored. Only methane production is stimulated with the Fe catalyst. Fe and Ru catalysts shift production from alkenes to alkanes. Transient data is interpreted in the paper.

Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

OpenAIRE

Eva Tavčar; Erika Turk; Samo Kreft

2012-01-01

The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes p...

One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes

Directory of Open Access Journals (Sweden)

Priyabrata Roy

2010-05-01

Full Text Available One-pot three-component coupling of o-alkynylheteroaryl carbonyl derivatives with Fischer carbene complexes and dienophiles leading to the synthesis of quinoxaline and phenazine ring systems has been investigated. This involves the generation of furo[3,4-b]pyrazine and furo[3,4-b]quinoxaline as transient intermediates, which were trapped with Diels–Alder dienophiles. This is the first report on furo[3,4-b]pyrazine intermediates.

Effect of dietary galacto-oligosaccharides on azoxymethane-induced aberrant crypt foci and colorectal cancer in Fischer 344 rats

NARCIS (Netherlands)

Wijnands, M.V.W.; Schoterman, H.C.; Bruijntjes, J.P.; Hollanders, V.M.H.; Woutersen, R.A.

2001-01-01

The aim of the present study was to investigate the effects of galacto-oligosaccharides (GOS, Elix'or) on the development of aberrant crypt foci (ACF) and colorectal tumours in rats treated with azoxymethane (AOM). Two groups of 102 male Fischer 344 rats were injected twice with AOM to induce

Oral carcinogenicity study with nickel sulfate hexahydrate in Fischer 344 rats

International Nuclear Information System (INIS)

Heim, Katherine E.; Bates, Hudson K.; Rush, Rusty E.; Oller, Adriana R.

2007-01-01

Until now, existing data on the oral carcinogenicity of nickel substances have been inconclusive. Yet, the assessment of oral carcinogenicity of nickel has serious scientific and regulatory implications. In the present study, nickel sulfate hexahydrate was administered daily to Fischer 344 rats by oral gavage for 2 years (104 weeks) at exposure levels of 10, 30 and 50 mg NiSO 4 ·6H 2 O/kg. This treatment produced a statistically significant reduction in body weight of male and female rats, compared to controls, in an exposure-related fashion at 30 and 50 mg/kg/day. An exposure-dependent increase in mortality was observed in female rats. However, the overall study survival rate (males and females) was at least 25 animals per group (compliant with OECD guidelines) in the treated animals. Daily oral administration of nickel sulfate hexahydrate did not produce an exposure-related increase in any common tumor type or an increase in any rare tumors. One tumor type was statistically increased in a nickel sulfate-treated group compared to the study controls (keratoacanthoma in the 10 mg NiSO 4 ·6H 2 O/kg/day males), but there was no exposure-response relationship for this common tumor type. This study achieved sufficient toxicity to reach the Maximum Tolerated Dose (MTD) while maintaining a sufficiently high survival rate to allow evaluation for carcinogenicity. The present study indicated that nickel sulfate hexahydrate does not have the potential to cause carcinogenicity by the oral route of exposure in the Fischer 344 rat. Data from this and other studies demonstrate that inhalation is the only route of exposure that might cause concern for cancer in association with nickel exposures

Techno-economic performance analysis of bio-oil based Fischer-Tropsch and CHP synthesis platform

International Nuclear Information System (INIS)

Ng, Kok Siew; Sadhukhan, Jhuma

2011-01-01

The techno-economic potential of the UK poplar wood and imported oil palm empty fruit bunch derived bio-oil integrated gasification and Fischer-Tropsch (BOIG-FT) systems for the generation of transportation fuels and combined heat and power (CHP) was investigated. The bio-oil was represented in terms of main chemical constituents, i.e. acetic acid, acetol and guaiacol. The compositional model of bio-oil was validated based on its performance through a gasification process. Given the availability of large scale gasification and FT technologies and logistic constraints in transporting biomass in large quantities, distributed bio-oil generations using biomass pyrolysis and centralised bio-oil processing in BOIG-FT system are technically more feasible. Heat integration heuristics and composite curve analysis were employed for once-through and full conversion configurations, and for a range of economies of scale, 1 MW, 675 MW and 1350 MW LHV of bio-oil. The economic competitiveness increases with increasing scale. A cost of production of FT liquids of 78.7 Euro/MWh was obtained based on 80.12 Euro/MWh of electricity, 75 Euro/t of bio-oil and 116.3 million Euro/y of annualised capital cost. -- Highlights: → Biomass to liquid process and gas to liquid process synthesis. → Biorefinery economic analysis. → Pyrolysis oil to biofuel. → Gasification and Fischer-Tropsch. → Process integration, pinch analysis and energy efficiency.

Deposition and retention of 67Ga-labelled diesel particles in Fischer-344 rats

International Nuclear Information System (INIS)

Wolff, R.K.; Sun, J.D.; Lopez, J.A.; Wolf, I.; Cheng, Y.S.; McClellan, R.O.

1981-01-01

Fischer-344 rats were exposed nose-only to 67 Ga radiolabeled diesel exhaust particles produced from a 1 cylinder engine and diluted 10:1 with filtered air. Volume median diameters of the particles were 0.14 to 0.16 μm measured using an electrical aerosol analyzer, a diffusion battery and a cascade impactor. Initial lung deposition was 7 +- 2% and 12 +- 2% in two separate experiments. Gallium-67 left the lung rapidly with a clearance half-time of about 10 days, indicating that the 67 Ga label dissociated from diesel particles

Reversible alkyne insertion in the benzannulation reaction of Fischer carbene complexes with alkynes

Energy Technology Data Exchange (ETDEWEB)

Waters, M.L.; Bos, M.E.; Wulff, W.D. [Univ. of Chicago, IL (United States)

1995-12-31

The benzannulation reaction of Fischer carbene complexes with alkynes to give phenols is highly regioselective with terminal alkynes, and reasonably regioselective with internal alkynes. This has been attributed to steric factors in intermediates, where one form is favored due to close contact between the R substituent and a cis-CO ligand. Whether alkyne insertion is kinetically or thermodynamically controlled has not been determined. The authors now have evidence from regioselectivity studies that alkyne insertion into the metal-carbon bond is reversible. Implications of these results and further mechanistic considerations will be presented.

Determination of water in nuclear materials by means of the Karl Fischer method

International Nuclear Information System (INIS)

Pereira, W.; Rocha, S.M.R.; Atalla, L.T.; Abrao, A.

1987-06-01

Karl Fischer Method was adapted for water determination in uranium coumpounds and substances of nuclear interest, by using a comercial equipment. The experimental conditions for the analysis of U 3 O 8 , UO 3 , UO 2 , UF 4 KFnHF and (NH 4 ) 4 UO 2 (CO 3 ) 3 were established. The influence of the agitation and contact time between sample and solvent, of the sample weight, of the reaction end point determination and of the sample granulometry on the precision and accuracy of results was also studied. (Author) [pt

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

Energy Technology Data Exchange (ETDEWEB)

Dragomir B. Bukur; Gilbert F. Froment; Lech Nowicki; Jiang Wang; Wen-Ping Ma

2003-09-29

This report covers the first year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H{sup 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we have completed one STSR test with precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany). This catalyst was initially in commercial fixed bed reactors at Sasol in South Africa. The catalyst was tested at 13 different sets of process conditions, and had experienced a moderate deactivation during the first 500 h of testing (decrease in conversion from 56% to 50% at baseline process conditions). The second STSR test has been initiated and after 270 h on stream, the catalyst was tested at 6 different sets of process conditions.

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

International Nuclear Information System (INIS)

Dragomir B. Bukur; Gilbert F. Froment; Lech Nowicki; Jiang Wang; Wen-Ping Ma

2003-01-01

This report covers the first year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H 2 O, CO 2 , linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we have completed one STSR test with precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany). This catalyst was initially in commercial fixed bed reactors at Sasol in South Africa. The catalyst was tested at 13 different sets of process conditions, and had experienced a moderate deactivation during the first 500 h of testing (decrease in conversion from 56% to 50% at baseline process conditions). The second STSR test has been initiated and after 270 h on stream, the catalyst was tested at 6 different sets of process conditions

Technology development for iron Fischer-Tropsch catalysts

Energy Technology Data Exchange (ETDEWEB)

O`Brien, R.J.; Raje, A.; Keogh, R.A. [and others

1995-12-31

The objective of this research project is to develop the technology for the production of physically robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry phase synthesis reactor development. The catalysts that are developed shall be suitable for testing in the Advanced Fuels Development Facility at LaPorte, Texas, to produce either low-or high-alpha product distributions. Previous work by the offeror has produced a catalyst formulation that is 1.5 times as active as the {open_quotes}standard-catalyst{close_quotes} developed by German workers for slurry phase synthesis. In parallel, work will be conducted to design a high-alpha iron catalyst this is suitable for slurry phase synthesis. Studies will be conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors will be studied at the laboratory scale. Catalyst performance will be determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

Reference method for total water in lint cotton by automated oven drying combined with volumetric Karl Fischer titration

Science.gov (United States)

In a preliminary study to measure total water in lint cotton we demonstrated that volumetric Karl Fischer Titration of moisture transported by a carrier gas from an attached small oven is more accurate than standard oven drying in air. The objective of the present study was to assess the measuremen...

Bark consumption by the spiny rat Euryzygomatomys spinosus (G. Fischer (Echimyidae on a Pinus taeda Linnaeus (Pinaceae plantation in South Brazil Consumo de Pinus taeda (Pinaceae pelo rato-de-espinho Euryzygomatomys spinosus (G. Fischer (Echimyidae em plantações no Sul do Brasil

Directory of Open Access Journals (Sweden)

Gislene L. Gonçalves

2007-03-01

Full Text Available Feeding damage caused by Euryzygomatomys spinosus (G. Fischer, 1814 (Echimyidae is documented for a Pinus taeda Linnaeus (Pinaceae plantation located in Cambará do Sul, Rio Grande do Sul State, Brazil. Under laboratory conditions, feeding acceptance of P. taeda trunk sections was tested with positive results for E. spinosus, but not for other three co-occurring sigmodontine rodents: Akodon montensis Thomas, 1913, Oligoryzomys nigripes (Olfers, 1818 and Delomys dorsalis (Hensel, 1872.Esse estudo documenta os danos causados por Euryzygomatomys spinosus (G. Fischer, 1814 em plantações de Pinus taeda Linnaeus (Pinaceae localizadas em Cambará do Sul, Estado do Rio Grande do Sul, Brasil. Em laboratório foi testada positivamente a utilização de troncos de Pinus como recurso por E. spinosus, mas não para os outros roedores sigmodontíneos ocorrentes na área: Akodon montensis Thomas, 1913, Oligoryzomys nigripes (Olfers, 1818 e Delomys dorsalis (Hensel, 1872.

Particle Size and Crystal Phase Effects in Fischer-Tropsch Catalysts

Directory of Open Access Journals (Sweden)

Jin-Xun Liu

2017-08-01

Full Text Available Fischer-Tropsch synthesis (FTS is an increasingly important approach for producing liquid fuels and chemicals via syngas—that is, synthesis gas, a mixture of carbon monoxide and hydrogen—generated from coal, natural gas, or biomass. In FTS, dispersed transition metal nanoparticles are used to catalyze the reactions underlying the formation of carbon-carbon bonds. Catalytic activity and selectivity are strongly correlated with the electronic and geometric structure of the nanoparticles, which depend on the particle size, morphology, and crystallographic phase of the nanoparticles. In this article, we review recent works dealing with the aspects of bulk and surface sensitivity of the FTS reaction. Understanding the different catalytic behavior in more detail as a function of these parameters may guide the design of more active, selective, and stable FTS catalysts.

Reliability in the Location of Hindlimb Motor Representations in Fischer-344 Rats

Science.gov (United States)

Frost, Shawn B.; Iliakova, Maria; Dunham, Caleb; Barbay, Scott; Arnold, Paul; Nudo, Randolph J.

2014-01-01

Object The purpose of the present study was to determine the feasibility of using a common laboratory rat strain for locating cortical motor representations of the hindlimb reliably. Methods Intracortical Microstimulation (ICMS) techniques were used to derive detailed maps of the hindlimb motor representations in six adult Fischer-344 rats. Results The organization of the hindlimb movement representation, while variable across individuals in topographic detail, displayed several commonalities. The hindlimb representation was positioned posterior to the forelimb motor representation and postero-lateral to the motor trunk representation. The areal extent of the hindlimb representation across the cortical surface averaged 2.00 +/− 0.50 mm2. Superimposing individual maps revealed an overlapping area measuring 0.35 mm2, indicating that the location of the hindlimb representation can be predicted reliably based on stereotactic coordinates. Across the sample of rats, the hindlimb representation was found 1.25–3.75 mm posterior to Bregma, with an average center location ~ 2.6 mm posterior to Bregma. Likewise, the hindlimb representation was found 1–3.25 mm lateral to the midline, with an average center location ~ 2 mm lateral to midline. Conclusions The location of the cortical hindlimb motor representation in Fischer-344 rats can be reliably located based on its stereotactic position posterior to Bregma and lateral to the longitudinal skull suture at midline. The ability to accurately predict the cortical localization of functional hindlimb territories in a rodent model is important, as such animal models are being used increasingly in the development of brain-computer interfaces for restoration of function after spinal cord injury. PMID:23725395

Effects of manganese oxide and sulphate on the olefin selectivity of iron catalysts in the Fischer Tropsch reaction

NARCIS (Netherlands)

Dijk, van W.L.; Niemantsverdriet, J.W.; Kraan, van der A.M.; van der Baan, Hessel

1982-01-01

Although it has been claimed by various authors that the addition of manganese oxide, MnO, to an iron catalyst gives a marked increase in the olefin selectivity of iron catalysts, we have been unable to confirm these claims in Fischer Tropsch experiments at 513 K for an iron manganese oxide catalyst

Bárbara Mujica, ed., Shakespeare and the Spanish «Comedia». Translation, Interpretation, Performance. Essays in Honor of Susan L. Fischer

Directory of Open Access Journals (Sweden)

Alejandro García-Reidy

2016-01-01

Full Text Available Reseña de Bárbara Mujica, ed., Shakespeare and the Spanish «Comedia». Translation, Interpretation, Performance. Essays in Honor of Susan L. Fischer, Bucknell University Press, Lewisburg, 2013, 298 pp. ISBN 9781611485172.

Macromolecules and Enzymes: The Geneva Heritage from Kurt H. Meyer and Edmond H. Fischer.

Science.gov (United States)

Fischer, Edmond H; Piguet, Alfred

2009-12-01

On the 26th May 2009, Edmond Fischer, winner with Ed Krebs of the Nobel prize in physiology or medicine in 1992, and his colleague at the time of his research activities at the Ecole de chimie of the University of Geneva, Alfred Piguet, met with Andreas Hauser, Claude Piguet and Howard Riezman of the Section de chimie et biochimie of the University of Geneva to talk about how they became scientists under the impetus of Kurt H. Meyer and what became of them thereafter.

Immobilised carbon nanotubes as carrier for Co-Fischer-Tropsch synthesis catalysts

Energy Technology Data Exchange (ETDEWEB)

Thiessen, J.; Rose, A.; Kiendl, I.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering; Curulla-Ferre, D. [Total S.A., Gas and Power, Paris La Defense (France)

2011-07-01

A possibility to immobilise carbon nanotubes (CNT) to make them applicable in a technical scale fixed bed reactor is studied. The approach to fabricate millimetre scale composites containing CNT presented in this work is to confine the nano-carbon in macro porous ceramic particles. Thus CNT were grown on the inner surface of silica and alumina pellets and spheres, respectively. Cobalt nano particles were successfully deposited on the carbon surface inside the two types of ceramic carriers and the systems were tested in Fischer - Tropsch synthesis (FTS). The cobalt mass related activity of these novel catalysts is similar to a conventional system. The selectivities of the Co/CNT/ceramic composites were compared with non supported CNT and carbon nanofibres (CNF). (orig.)

469-475

Indian Academy of Sciences (India)

tribpo

Alpha effect, current and kinetic helicities for magnetically driven turbulence, and solar dynamo (G. Belvedere, V. V. Pipin & G. Rudiger), 387. PAH. A new scheme .... Remote sensing of the heliospheric solar wind using radio astronomy methods and numerical simulations (S. Ananthakrishnan), 439. Tomography of the solar ...

Comparison between amperometric and true potentiometric end-point detection in the determination of water by the Karl Fischer method.

Science.gov (United States)

Cedergren, A

1974-06-01

A rapid and sensitive method using true potentiometric end-point detection has been developed and compared with the conventional amperometric method for Karl Fischer determination of water. The effect of the sulphur dioxide concentration on the shape of the titration curve is shown. By using kinetic data it was possible to calculate the course of titrations and make comparisons with those found experimentally. The results prove that the main reaction is the slow step, both in the amperometric and the potentiometric method. Results obtained in the standardization of the Karl Fischer reagent showed that the potentiometric method, including titration to a preselected potential, gave a standard deviation of 0.001(1) mg of water per ml, the amperometric method using extrapolation 0.002(4) mg of water per ml and the amperometric titration to a pre-selected diffusion current 0.004(7) mg of water per ml. Theories and results dealing with dilution effects are presented. The time of analysis was 1-1.5 min for the potentiometric and 4-5 min for the amperometric method using extrapolation.

An investigation of the physical and chemical changes occuring in a Fischer-Tropsch fixed bed catalyst during hydrocarbon synthesis

International Nuclear Information System (INIS)

Duvenhage, D.J.

1990-01-01

Deactivation studies: making use of fixed bed reactors, wet chemical analysis, surface area, pore volume determinations and X-ray diffraction spectrometry, scanning electron microscope spectrometry and secondary ion mass spectrometry techniques; were performed on a low temperature iron Fischer-Tropsch catalyst. It was revealed that this catalyst is mainly deactivated by sulphur poisoning, oxidation of the catalytic reactive phases, sintering of the iron crystallites and to a lesser extent deactivation through fouling of the catalytic surface by carbonaceous deposits. It was found that the top entry section of the catalyst bed deactivated relatively fast, the bottom exit section also deactivated, but not as fast as the top section. The central portion of the catalyst bed was least affected. Sulphur contaminants in the feed gas, even though present in only minute quantities, results in a loss of catalyst performance of the top section of the catalyst bed, while water, produced as a product from the Fischer-Tropsch reaction, oxidized and sintered the catalyst over the bottom section of the catalyst bed. 88 figs., 7 tabs., 224 refs

Six-flow operations for catalyst development in Fischer-Tropsch synthesis : Bridging the gap between high-throughput experimentation and extensive product evaluation

NARCIS (Netherlands)

Sartipi, S.; Jansma, H.; Bosma, D.; Boshuizen, B.; Makkee, M.; Gascon, J.; Kapteijn, F.

2013-01-01

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature

Changes in Groundwater Flow and Volatile Organic Compound Concentrations at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1993-2009

Science.gov (United States)

Sloto, Ronald A.

2010-01-01

The 38-acre Fischer and Porter Company Superfund Site is in Warminster Township, Bucks County, Pa. Historically, as part of the manufacturing process, trichloroethylene (TCE) degreasers were used for parts cleaning. In 1979, the Bucks County Health Department detected TCE and other volatile organic compounds (VOCs) in water from the Fischer and Porter on-site supply wells and nearby public-supply wells. The Fischer and Porter Site was designated as a Superfund Site and placed on the National Priorities List in September 1983. A 1984 Record of Decision for the site required the Fischer and Porter Company to pump and treat groundwater contaminated by VOCs from three on-site wells at a combined rate of 75 gallons per minute to contain groundwater contamination on the property. Additionally, the Record of Decision recognized the need for treatment of the water from two nearby privately owned supply wells operated by the Warminster Heights Home Ownership Association. In 2004, the Warminster Heights Home Ownership Association sold its water distribution system, and both wells were taken out of service. The report describes changes in groundwater levels and contaminant concentrations and migration caused by the shutdown of the Warminster Heights supply wells and presents a delineation of the off-site groundwater-contamination plume. The U.S. Geological Survey (USGS) conducted this study (2006-09) in cooperation with the U.S. Environmental Protection Agency (USEPA). The Fischer and Porter Site and surrounding area are underlain by sedimentary rocks of the Stockton Formation of Late Triassic age. The rocks are chiefly interbedded arkosic sandstone and siltstone. The Stockton aquifer system is comprised of a series of gently dipping lithologic units with different hydraulic properties. A three-dimensional lithostratigraphic model was developed for the site on the basis of rock cores and borehole geophysical logs. The model was simplified by combining individual lithologic

Reliability in the location of hindlimb motor representations in Fischer-344 rats: laboratory investigation.

Science.gov (United States)

Frost, Shawn B; Iliakova, Maria; Dunham, Caleb; Barbay, Scott; Arnold, Paul; Nudo, Randolph J

2013-08-01

The purpose of the present study was to determine the feasibility of using a common laboratory rat strain for reliably locating cortical motor representations of the hindlimb. Intracortical microstimulation techniques were used to derive detailed maps of the hindlimb motor representations in 6 adult Fischer-344 rats. The organization of the hindlimb movement representation, while variable across individual rats in topographic detail, displayed several commonalities. The hindlimb representation was positioned posterior to the forelimb motor representation and posterolateral to the motor trunk representation. The areal extent of the hindlimb representation across the cortical surface averaged 2.00 ± 0.50 mm(2). Superimposing individual maps revealed an overlapping area measuring 0.35 mm(2), indicating that the location of the hindlimb representation can be predicted reliably based on stereotactic coordinates. Across the sample of rats, the hindlimb representation was found 1.25-3.75 mm posterior to the bregma, with an average center location approximately 2.6 mm posterior to the bregma. Likewise, the hindlimb representation was found 1-3.25 mm lateral to the midline, with an average center location approximately 2 mm lateral to the midline. The location of the cortical hindlimb motor representation in Fischer-344 rats can be reliably located based on its stereotactic position posterior to the bregma and lateral to the longitudinal skull suture at midline. The ability to accurately predict the cortical localization of functional hindlimb territories in a rodent model is important, as such animal models are being increasingly used in the development of brain-computer interfaces for restoration of function after spinal cord injury.

Emissions from Diesel and Gasoline Vehicles Fuelled by Fischer-Tropsch Fuels and Similar Fuels

DEFF Research Database (Denmark)

Larsen, Ulrik; Lundorff, Peter; Ivarsson, Anders

2007-01-01

and an alkylate fuel (Aspen), which was taken to be the ultimate formula of FT gasoline. FT based diesel generally showed good emission performance, whereas the FT based gasoline not necessary lead to lower emissions. On the other hand, the Aspen fuel did show many advantages for the emissions from the gasoline...... vehicles fuelled by Fischer Tropsch (FT) based diesel and gasoline fuel, compared to the emissions from ordinary diesel and gasoline. The comparison for diesel fuels was based on a literature review, whereas the gasoline comparison had to be based on our own experiments, since almost no references were...

Overview of reactors for liquid phase Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Davis, Burtron H.

2002-01-01

The following overview is divided roughly into three sections. The first section covers the period from the late 1920s when the first liquid phase synthesis was first conducted until about 1960 when the interest in Fischer-Tropsch synthesis (FTS) declined because of the renewed view of an abundance of petroleum at a low price. The second period includes the activity that resulted from the oil shortage due to the Arab embargo in 1972 and covers from about 1960 to 1985 when the period of gloomy projections for rapidly increasing prices for crude had faded away. The third section covers the period from when the interest in FTS was no longer driven by the projected supply and/or price of petroleum but by the desire to monetize stranded natural gas and/or terminate flaring the gas associated with petroleum production and other environmental concerns (1985 to date). These sections are followed by a brief overview of the current status of the scientific and engineering understanding of slurry bubble column reactors

Una reconsideración matemática del modelo de "overshooting" del tipo de cambio

OpenAIRE

Macaya, Alejo

2005-01-01

Este trabajo trata sobre la solución generalizada o distribucional del modelo de "overshooting" del tipo de cambio de Dornbusch. Se muestra que la solución del ejercicio de modificación de la oferta monetaria puede encontrarse utilizando funciones generalizadas.

Meteorites, Organics and Fischer-Tropsch Type Reaction: Production and Destruction

Science.gov (United States)

Johnson, Natasha M.; Burton, A. S.; Nurth, J. A., III

2011-01-01

There has been an ongoing debate about the relative importance about the various chemical reactions that fonned organics in the early solar system. One proposed method that has long been recognized as a potential source of organics is Fischer-Tropsch type (FTT) synthesis. This process is commonly used in industry to produce fuels (i.e., complex hydrocarbons) by catalytic hydrogenation of carbon monoxide. Hill and Nuth were the first to publish results of FTT experiments that also included Haber-Bosch (HB) processes (hydrogenation of nitrogen. Their findings included the production of nitrilebearing compounds as well as trace amounts of methyl amine. Previous experience with these reactions revealed that the organic coating deposited on the grains is also an efficient catalyst and that the coating is composed of insoluble organic matter (10M) and could be reminiscent of the organic matrix found in some meteorites. This current set of FTT-styled experiments tracks the evolution of a set of organics, amino acids, in detail.

Gas to liquids. Fischer Tropsch: what does the future hold?

International Nuclear Information System (INIS)

Maisonnier, G.

2005-01-01

The process concerning the chemical transformation of natural gas into oil-based products (a so-called 'clean' diesel) known under the term GTL FT (Gas To Liquids - Fischer Tropsch) will turn a new page in its history with the start-up of a major unit in Qatar in 2006 Up until now only two GTL units were deployed, in the early 1990's (Moss as and Shell) without however resulting in the widespread expansion of this process. The technological breakthroughs achieved around the year 2000 combined with a favourable background context (concerning geopolitical tension, ears of oil production peaks, significant increases in the price of crude) now account for much of the interest shown in this solution. Consequently, outside Qatar, projects are also being looked at in various natural gas producing countries such as Nigeria or Algeria. It would be justified however to think that a new wave of natural gas recycling will gradually emerge as part of the global energy market. (author)

New perspectives in the Fischer-Tropsch synthesis using cobalt supported on mesoporous molecular sieves; Novas perspectivas na sintese de Fischer-Tropsch usando cobalto suportado em peneiras moleculares mesoporosas

Energy Technology Data Exchange (ETDEWEB)

Souza, M.J.B.; Silva, A.O.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica; Fernandes Junior, V.J.; Araujo, A.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Quimica

2004-07-01

The conversion of synthesis gas to liquid products via Fischer-Tropsch synthesis (FTS) is an important process in the generation of clean fuels of sulfur and nitrogen compounds. Catalysts based on iron are very used in the conventional process due its cheap manufacture price. Recently the use of cobalt as promoter gave good results. MCM-41 mesoporous materials were discovered by Mobil scientists in the nineties and ever since they have great successes as support and catalyst in several processes of the oil industry as catalytic cracking, reformer and hydrotreating. In this work are presented new alternatives for FTS with the use of cobalt supported on molecular sieves of the type MCM-41. A comparative study with the usual catalysts based on silica was accomplished with different levels of cobalt. (author)

Fe/MCM-41 sylilated catalyst: structural changes determination during the Fischer-Tropsch reaction

International Nuclear Information System (INIS)

Bengoa, J. F.; Fellenz, N. A.; Cagnoli, M. V.; Cano, L. A.; Gallegos, N. G.; Alvarez, A. M.; Marchetti, S. G.

2010-01-01

Two Fe/MCM-41 systems, one of them sylilated, were obtained to be used as catalysts in Fischer-Tropsch reaction. They have more than 90% of the iron species located inside the support channels, leading to a narrow crystal size distribution accessible to reactive gases. The samples were characterized by X-ray diffraction, atomic absorption spectroscopy, N 2 adsorption, Moessbauer spectroscopy and Fourier transformer infrared spectroscopy. Moessbauer spectroscopy allowed us to demonstrate that the catalytic active species were the same in both catalysts. The only difference between them was the surface hydrophobicity, which decreases the 'water gas shift reaction' in the sylilated catalyst. Besides, this solid is more active for hydrocarbon production, with a lower methane yield.

Two months make a difference in spatial orientation learning in very old hybrid Fischer 344 X Brown Norway (FBNF1) rats

NARCIS (Netherlands)

Staay, van der F.J.

2006-01-01

Age-related changes in cognitive performance may be more pronounced in the period near or exceeding the median life span. Therefore, we compared the acquisition of a Morris water escape task by two groups of very old Fischer344 × Brown Norway hybrid rats. The mean age difference between the two

Structure and Development of the Gametophytes of Philippine Cheilanthoid Ferns, III. Cheilanthes concolor (Langsdorff et Fischer R. Tryon

Directory of Open Access Journals (Sweden)

Prescillano Zamora

1993-12-01

Full Text Available The gametophytes of Cheilanthes concolor (Langsdorff et Fischer R. Tryon from the Philippines (Quezon City are no different in pattern of development and in morphology from those from India with one possible notable difference, which is, that the gametophytes under report (which were grown from spores produced from 32-sporate sporangia are apogamous while those from India (sporangial type of source was not stated are sexual.

Morphological transformation during activation and reaction of an iron Fischer-Tropsch catalyst

Energy Technology Data Exchange (ETDEWEB)

Jackson, N.B.; Kohler, S.; Harrington, M. [Sandia National Lab., Albuquerque, NM (United States)] [and others

1995-12-31

The purpose of this project is to support the development of slurry-phase bubble column processes being studied at the La Porte Alternative Fuel Development Unit. This paper describes the aspects of Sandia`s recent work regarding the advancement and understanding of the iron catalyst used in the slurry phase process. A number of techniques were used to understand the chemical and physical effects of pretreatment and reaction on the attrition and carbon deposition characteristics of iron catalysts. Unless otherwise stated, the data discussed was derived form experiments carried out on the catalyst chosen for the summer 1994 Fischer-Tropsch run at LaPorte, UCI 1185-78-370, (an L 3950 type) that is 88% Fe{sub 2}O{sub 3}, 11% CuO, and 0.052%K{sub 2}O.

Disposition of citral in male Fischer rats

International Nuclear Information System (INIS)

Diliberto, J.J.; Usha, G.; Birnbaum, L.S.

1988-01-01

The disposition of citral, an essential oil occurring in many foods and fragrances, was studied in male Fischer rats after iv, po, and dermal treatments. The pattern of distribution and elimination was the same after iv or oral exposure. Urine was the major route of elimination of citral-derived radioactivity, followed by feces, 14 CO 2 , and expired volatiles. However, after dermal exposure, relatively less of the material was eliminated in the urine and more in the feces, suggesting a role for first-pass metabolism through the skin. Citral was almost completely absorbed orally; due to its extreme volatility, much of an applied dermal dose was lost. The citral remaining on the skin was fairly well absorbed. No effect of oral dose, from 5 to 500 mg/kg, was detected on disposition. Although the feces was a minor route of excretion, approximately 25% of the administered dose was eliminated via the bile within 4 hr of an iv dose. The metabolism of citral was both rapid and extensive. Within 5 min of an iv dose, no unmetabolized citral could be detected in the blood. Repeated exposure to citral resulted in an increase in biliary elimination, without any significant change in the pattern of urinary, fecal, or exhaled excretion. This suggests that citral may induce at least one pathway of its own metabolism. The rapid metabolism and excretion of this compound suggest that significant bioaccumulation of citral would not occur

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

International Nuclear Information System (INIS)

Dragomir B. Bukur

2004-01-01

This report covers the second year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H 2 O, CO 2 , linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the second year of the project we completed the STSR test SB-26203 (275-343 h on stream), which was initiated during the first year of the project, and another STSR test (SB-28603 lasting 341 h). Since the inception of the project we completed 3 STSR tests, and evaluated catalyst under 25 different sets of process conditions. A precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany) was used in all tests. This catalyst was used initially in commercial fixed bed reactors at Sasol in South Africa. Also, during the second year we performed a qualitative analysis of experimental data from all three STSR tests. Effects of process conditions (reaction temperature, pressure, feed composition and gas space velocity) on water-gas-shift (WGS) activity and hydrocarbon product distribution have been determined

Parental Characteristics, Ecological Factors, and the Academic Achievement of African American Males

Science.gov (United States)

Hines, Erik M.; Holcomb-McCoy, Cheryl

2013-01-01

Parental characteristics, ecological factors, and the academic achievement of African American male high school students were examined. One hundred fifty-three 11th and 12th grade African American males completed the Parenting Style Index (Steinberg, Lamborn, Darling, Mounts, & Dornbusch, 1994) and a demographic questionnaire. Results…

Assessing economic impacts to coastal recreation and tourism from oil and gas development in the Oregon and Washington Outer Continental Shelf. Inventory and evaluation of Washington and Oregon coastal recreation resources

Energy Technology Data Exchange (ETDEWEB)

Ellis, G.M.; Johnson, N.S.; Chapman, D.

1991-05-01

The purpose of the three-part study was to assist Materials Management Service (MMS) planners in evaluation of the anticipated social impact of proposed oil and gas development on the environment. The purpose of the report is primarily to analyze the econometric models of the Dornbusch study. The authors examine, in detail, key aspects of the gravity, consumer surplus, and economic effects (input-output) models. The purpose is two-fold. First, the authors evaluate the performance of the model in satisfying the objective for which it was developed: analyzing economic impacts of OCS oil and gas development in California. Second, the authors evaluate the applicability of the modeling approach employed in the Dornbusch study for analyzing potential OCS development impacts in Washington and Oregon. At the end of the report, the authors offer suggestions for any future study of economic impacts of OCS development in Washington and Oregon. The recommendations concern future data gathering procedures and alternative modeling approaches for measuring economic impacts.

Silylated Co/SBA-15 catalysts for Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Jia Lihong; Jia Litao; Li Debao; Hou Bo; Wang Jungang; Sun Yuhan

2011-01-01

A series of silylated Co/SBA-15 catalysts were prepared via the reaction of surface Si-OH of SBA-15 with hexamethyldisilazane (HMDS) under anhydrous, vapor-phase conditions, and then characterized by FT-IR, N 2 physisorption, TG, XRD, and TPR-MS. The results showed that organic modification led to a silylated SBA-15 surface composed of stable hydrophobic Si-(CH 3 ) 3 species even after calcinations and H 2 reduction at 673 K. Furthermore, the hydrophobic surface strongly influenced both metal dispersion and reducibility. Compared with non-silylated Co/SBA, Co/S-SBA (impregnation after silylation) showed a high activity, due to the better cobalt reducibility on the hydrophobic support. However, S-Co/SBA (silylation after impregnation) had the lowest FT activity among all the catalysts, due to the lower cobalt reducibility along with the steric hindrance of grafted -Si(CH 3 ) 3 for the re-adsorption of α-olefins. -- Graphical abstract: The silylation of an SBA-15 before cobalt impregnation enhanced the reducibility of cobalt oxides on an SBA-15-supported cobalt catalyst and consequently increased the catalytic activity for Fischer-Tropsch synthesis. Display Omitted

FeRu/TiO2 and Fe/TiO2 catalysts after reduction and Fischer-Tropsch synthesis studied by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Kraan, A.M. van der; Nonnekens, R.C.H.; Niemantsverdriet, J.W.

1986-01-01

A series of TiO 2 -supported bimetallic FeRu catalysts with different Fe:Ru ratios (infinity; 10:1; 3:1; 1:1; 1:3) has been studied by means of in situ Moessbauer spectroscopy. The influence of reduction and Fischer-Tropsch synthesis on the state of iron in the FeRu/TiO 2 catalysts is derived. (Auth.)

Examination of the Relationship Amongst Parenting Dimensions, Academic Achievement, Career Decision Making, and Commitment Anxiety among African American High School Students

Science.gov (United States)

Bennett-Garraway, Jocelyn M.

2011-01-01

Do parents play a significant role in the academic achievement and career decision making process of African American children? Studies have confirmed the importance of the role of parents and have even identified preferred parenting styles as having the best academic achievement (Dornbusch, Ritter, Leiderman, Roberts, & Fraleigh, 1987;…

Comparison of American and Chinese College Students' Perception of Instructor Authority

Science.gov (United States)

Li, Ting

2012-01-01

Teacher authority has long been recognized as one of the critical factors that contribute to the formation of effective learning circumstances (Haywood-Metz, 2006). A survey was developed based on Dornbusch and Scott's (1975) theoretical framework of distinction between formal authority and informal authority, named "The Attitude towards…

Optimization of hydrogen production via coupling of the Fischer-Tropsch synthesis reaction and dehydrogenation of cyclohexane in GTL technology

International Nuclear Information System (INIS)

Rahimpour, M.R.; Bahmanpour, A.M.

2011-01-01

In this study, a thermally-coupled reactor containing the Fischer-Tropsch synthesis reaction in the exothermic side and dehydrogenation of cyclohexane in the endothermic side has been modified using a hydrogen perm-selective membrane as the shell of the reactor to separate the produced hydrogen from the dehydrogenation process. Permeated hydrogen enters another section called permeation side to be collected by Argon, known as the sweep gas. This three-sided reactor has been optimized using differential evolution (DE) method to predict the conditions at which the reactants' conversion and also the hydrogen recovery yield would be maximized. Minimizing the CO 2 and CH 4 yield in the reactor's outlet as undesired products is also considered in the optimization process. To reach this goal, optimal initial molar flow rate and inlet temperature of three sides as well as pressure of the exothermic side have been calculated. The obtained results have been compared with the conventional reactor data of the Research Institute of Petroleum Industry (RIPI), the membrane dual - type reactor suggested for Fischer-Tropsch synthesis, and the membrane coupled reactor presented for methanol synthesis. The comparison shows acceptable enhancement in the reactor's performance and that the production of hydrogen as a valuable byproduct should also be considered.

Simple modification of karl-Fischer titration method for determination of water content in colored samples.

Science.gov (United States)

Tavčar, Eva; Turk, Erika; Kreft, Samo

2012-01-01

The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R(2) = 0.997).

Computational Fluid Dynamics Study of Channel Geometric Effect for Fischer-Tropsch Microchannel Reactor

International Nuclear Information System (INIS)

Na, Jonggeol; Jung, Ikhwan; Kshetrimayum, Krishnadash S.; Park, Seongho; Park, Chansaem; Han, Chonghun

2014-01-01

Driven by both environmental and economic reasons, the development of small to medium scale GTL(gas-to-liquid) process for offshore applications and for utilizing other stranded or associated gas has recently been studied increasingly. Microchannel GTL reactors have been preferred over the conventional GTL reactors for such applications, due to its compactness, and additional advantages of small heat and mass transfer distance desired for high heat transfer performance and reactor conversion. In this work, multi-microchannel reactor was simulated by using commercial CFD code, ANSYS FLUENT, to study the geometric effect of the microchannels on the heat transfer phenomena. A heat generation curve was first calculated by modeling a Fischer-Tropsch reaction in a single-microchannel reactor model using Matlab-ASPEN integration platform. The calculated heat generation curve was implemented to the CFD model. Four design variables based on the microchannel geometry namely coolant channel width, coolant channel height, coolant channel to process channel distance, and coolant channel to coolant channel distance, were selected for calculating three dependent variables namely, heat flux, maximum temperature of coolant channel, and maximum temperature of process channel. The simulation results were visualized to understand the effects of the design variables on the dependent variables. Heat flux and maximum temperature of cooling channel and process channel were found to be increasing when coolant channel width and height were decreased. Coolant channel to process channel distance was found to have no effect on the heat transfer phenomena. Finally, total heat flux was found to be increasing and maximum coolant channel temperature to be decreasing when coolant channel to coolant channel distance was decreased. Using the qualitative trend revealed from the present study, an appropriate process channel and coolant channel geometry along with the distance between the adjacent

Geologic and hydrostratigraphic map of the Anhalt, Fischer, and Spring Branch 7.5-minute quadrangles, Blanco, Comal, and Kendall Counties, Texas

Science.gov (United States)

Clark, Allan K.; Robert R. Morris,

2015-01-01

This report describes the geology and hydrostratigraphy of the Edwards and Trinity Groups in the Anhalt, Fischer, and Spring Branch 7.5-minute quadrangles, Blanco, Comal, and Kendall Counties, Texas. The hydrostratigraphy was defined based on variations in the amount and type of porosity of each lithostratigraphic unit, which varies depending on the unit’s original depositional environment, lithology, structural history, and diagenesis.

Fischer-Tropsch synthesis in supercritical phase carbon dioxide: Recycle rates

Science.gov (United States)

Soti, Madhav

With increasing oil prices and attention towards the reduction of anthropogenic CO2, the use of supercritical carbon dioxide for Fischer Tropsch Synthesis (FTS) is showing promise in fulfilling the demand of clean liquid fuels. The evidence of consumption of carbon dioxide means that it need not to be removed from the syngas feed to the Fischer Tropsch reactor after the gasification process. Over the last five years, research at SIUC have shown that FTS in supercritical CO2reduces the selectivities for methane, enhances conversion, reduces the net CO2produces in the coal to liquid fuels process and increase the life of the catalyst. The research has already evaluated the impact of various operating and feed conditions on the FTS for the once through process. We believe that the integration of unreacted feed recycle would enhance conversion, increase the yield and throughput of liquid fuels for the same reactor size. The proposed research aims at evaluating the impact of recycle of the unreacted feed gas along with associated product gases on the performance of supercritical CO2FTS. The previously identified conditions will be utilized and various recycle ratios will be evaluated in this research once the recycle pump and associated fittings have been integrated to the supercritical CO2FTS. In this research two different catalysts (Fe-Zn-K, Fe-Co-Zn-K) were analyzed under SC-FTS in different recycle rate at 350oC and 1200 psi. The use of recycle was found to improve conversion from 80% to close to 100% with both catalysts. The experiment recycle rate at 4.32 and 4.91 was clearly surpassing theoretical recycle curve. The steady state reaction rate constant was increased to 0.65 and 0.8 min-1 for recycle rate of 4.32 and 4.91 respectively. Carbon dioxide selectivity was decreased for both catalyst as it was converting to carbon monoxide. Carbon dioxide consumption was increased from 0.014 to 0.034 mole fraction. This concluded that CO2is being used in the system and

Rate and selectivity modification in Fischer-Tropsch synthesis over charcoal supported molybdenum by forced concentration cycling

International Nuclear Information System (INIS)

Dun, J.W.; Gulari, E.

1985-01-01

Forced concentration cycling of the feed between pure CO and pure H/sub 2/ was used to successfully change both the selectivities and reactivities of promoted and unpromoted charcoal supported molybdenum catalysts in Fischer-Tropsch synthesis. It was found that with the unpromoted catalyst the rate enhancement increases with temperature and selectivity shifts towards methane. At the lower temperatures concentration cycling increases selectivity to ethane and higher hydrocarbons to levels only achievable with promised catalysts. Periodic operation with the potassium promoted catalyst results in small rate enhancements but the olefin to paraffin ratio is dramatically changed without changing the carbon number distribution

{alpha},{beta}-Unsaturated Fischer carbene complexes as chemical multitalents

Energy Technology Data Exchange (ETDEWEB)

Meijere, A. de [Institut fuer Organische Chemie der George-August-Universitaet Goettingen (Germany)

1995-12-31

The well established reaction of {alpha},{beta}-unsaturated Fischer carbenechromium complexes 6(R{sup 1} = H) with alkynes normally proceeds with carbonyl insertion to yield 4-alkoxyphenols 9. Led by the incidental formation of a cyclopentadiene 3 from certain {beta}-aminosubstituted complexes 6(X = NR{sub 2}{sup 3}, R{sup 1} = cPr) the authors have studied the influences of the nature of substituents (R{sup 1}, X on 6; R{sub L}, R{sub S} in the alkyne; R{sup 3} in the amino group), solvents, and temperature on the outcome of the reaction. Imino substitution on complexes 6 leads to 2H-pyrroles 1, a free primary amino group (X = NH{sub 2}) to pyridines 5, and bulky substituents R{sup 1} to cyclopenta[b]pyrans 8 with double insertion of an alkyne. Eventually, appropriate conditions have been developed which permit to selectively prepare either 3-alkoxy-5-(dialkylamino)cyclopentadienes 3 (as synthetic equivalents of cyclopentenones 4), 5-(dialkylaminomethylene)cyclopent-2-enones 7, 3-alkoxy-2-(1{prime}-morpholino-1{prime}-alkenyl)cyclopent-2-enones 10, and 2-acyl-3-(dialkylamino)cyclopent-2-enones 11 from easily accessible carbene complexes 6 (X = NR{sub 2}{sup 3}) in high yields. Mechanistic aspects and implications of these novel transformations will be discussed.

TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

International Nuclear Information System (INIS)

Burtron H. Davis

1999-01-01

The impact of activation procedure on the phase composition of precipitated iron Fischer-Tropsch (FT) catalysts has been studied. Catalyst samples taken during activation and FT synthesis have been characterized by Moessbauer spectroscopy. Formation of iron carbide is necessary for high FT activity. Hydrogen activation of precipitated iron catalysts results in reduction to predominantly metallic iron and Fe(sub 3)O(sub 4). Metallic iron is not stable under FT 3 4 conditions and is rapidly converted to(epsilon)(prime)-Fe(sub 2.2)C. Activation with carbon monoxide or syngas 2.2 with low hydrogen partial pressure reduces catalysts to(chi)-Fe(sub 5)C(sub 2) and a small amount of 5 2 superparamagnetic carbide. Exposure to FT conditions partially oxidizes iron carbide to Fe(sub 3)O(sub 4); however, catalysts promoted with potassium or potassium and copper maintain a constant carbide content and activity after the initial oxidation. An unpromoted iron catalyst which was activated with carbon monoxide to produce 94%(chi)-Fe(sub 5)C(sub 2), deactivated rapidly as the carbide was oxidized to Fe(sub 3)O(sub 4). No difference in activity, stability or deactivation rate was found for(chi)-Fe(sub 5)C(sub 2) and(epsilon)(prime)-Fe(sub 2.2)C

TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

Energy Technology Data Exchange (ETDEWEB)

Burtron H. Davis

1999-04-30

The impact of activation procedure on the phase composition of precipitated iron Fischer-Tropsch (FT) catalysts has been studied. Catalyst samples taken during activation and FT synthesis have been characterized by Moessbauer spectroscopy. Formation of iron carbide is necessary for high FT activity. Hydrogen activation of precipitated iron catalysts results in reduction to predominantly metallic iron and Fe{sub 3}O{sub 4}. Metallic iron is not stable under FT 3 4 conditions and is rapidly converted to {epsilon}{prime}-Fe{sub 2.2}C. Activation with carbon monoxide or syngas 2.2 with low hydrogen partial pressure reduces catalysts to {chi}-Fe{sub 5}C{sub 2} and a small amount of 5 2 superparamagnetic carbide. Exposure to FT conditions partially oxidizes iron carbide to Fe{sub 3}O{sub 4}; however, catalysts promoted with potassium or potassium and copper maintain a constant carbide content and activity after the initial oxidation. An unpromoted iron catalyst which was activated with carbon monoxide to produce 94% {chi}-Fe{sub 5}C{sub 2}, deactivated rapidly as the carbide was oxidized to Fe{sub 3}O{sub 4}. No difference in activity, stability or deactivation rate was found for {chi}-Fe{sub 5}C{sub 2} and {epsilon}{prime}-Fe{sub 2.2}C.

Lump Kinetic Analysis of Syngas Composition Effect on Fischer-Tropsch Synthesis over Cobalt and Cobalt-Rhenium Alumina Supported Catalyst

Directory of Open Access Journals (Sweden)

Dewi Tristantini

2016-03-01

Received: 10th November 2015; Revised: 10th February 2016; Accepted: 16th February 2016 How to Cite: Tristantini, D., Suwignjo, R.K. (2016. Lump Kinetic Analysis of Syngas Composition Effect on Fischer-Tropsch Synthesis over Cobalt and Cobalt-Rhenium Alumina Supported Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 84-92. (doi:10.9767/bcrec.11.1.424.84-92 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.424.84-92

Fischer 344 and Lewis rat strains as a model of genetic vulnerability to drug addiction

Directory of Open Access Journals (Sweden)

Cristina eCadoni

2016-02-01

Full Text Available Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60 % of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis to differences in mesolimbic dopamine (DA transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neurons functionality.Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigations, results from the reviewed studies might open new vistas in

Fischer 344 and Lewis Rat Strains as a Model of Genetic Vulnerability to Drug Addiction.

Science.gov (United States)

Cadoni, Cristina

2016-01-01

Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60% of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore, the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis on differences in mesolimbic dopamine (DA) transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA) axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neuron functionality. Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigation, results from the reviewed studies might open new vistas in understanding aberrant

Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

Science.gov (United States)

Tavčar, Eva; Turk, Erika; Kreft, Samo

2012-01-01

The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R 2 = 0.997). PMID:22567558

Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

Directory of Open Access Journals (Sweden)

Eva Tavčar

2012-01-01

Full Text Available The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD=4.3%, accuracy, and linearity (2=0.997.

Studies of carbon deposition and consumption on Ru/TiO2 during Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Yokomizo, G.; Bell, A.T.; Duncan, T.M.

1986-01-01

Isotropic tracer techniques have been used to characterize the dynamics of carbon deposition on the surface of a Ru/TiO 2 catalyst during Fischer-Tropsch synthesis and 13 C-NMR spectroscopy has been used to characterize the structure of the deposited carbon. Elemental carbon, designated C/sub α/ is formed very rapidly, whereas alkyl carbon, designated C/sub β/ accumulates much more slowly. The influence of catalyst reduction on temperature, reaction conditions, and time under reaction conditions on the surface concentrations and reactivity of C/sub α/ and C/sub β/ will be discussed. It will be shown that C/sub β/ progressively becomes less reactive and may be the precursor to the formation of graphitic carbon

Transient Effects in Fischer-Tropsch Reactor with a Fixed Bed of Catalyst Particles

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I. V. Derevich

2015-01-01

Full Text Available Based on analysis of small temperature disturbances in the Fischer-Tropsch reactor with a fixed bed of catalyst particles various scenarios of thermal instability were investigated. There are two possible scenarios of thermal instability of the reactor. First, thermal explosion may occur due to growth of temperature disturbances inside a catalytic granule. Second scenario connected with loss of thermal stability as a result of an initial increase in temperature in the reactor volume. The boundaries of thermal stability of the reactor were estimated by solving the eigenvalue problems for spherical catalyst particles and cylindrical reactor. Processes of diffusional resistance inside the catalytic granule and heat transfer from wall of the reactor tube are taken into account. Estimation of thermal stability area is compared with the results of numerical simulation of behavior of temperature and concentration of synthesis gas.

Morphology Changes of Co Catalyst Nanoparticles at the Onset of Fischer-Tropsch Synthesis

DEFF Research Database (Denmark)

Høydalsvik, Kristin; Fløystad, Jostein B.; Voronov, Alexey

2014-01-01

Cobalt nanoparticles play an important role as catalysts for the Fischer-Tropsch synthesis, which is an attractive route for production of synthetic fuels. It is of particular interest to understand the varying conversion rate during the first hours after introducing synthesis gas (H-2 and CO......) to the system. To this end, several in situ characterization studies have previously been done on both idealized model systems and commercially relevant catalyst nanoparticles, using bulk techniques, such as X-ray powder diffraction and X-ray absorption spectroscopy. Since catalysis takes place at the surface...... of the cobalt particles, it is important to develop methods to gain surface-specific structural information under realistic processing conditions. We addressed this challenge using small-angle X-ray scattering (SAXS), a technique exploiting the penetrating nature of X-rays to provide information about particle...

Fischer Indole Synthesis in the Gas Phase, the Solution Phase, and at the Electrospray Droplet Interface.

Science.gov (United States)

Bain, Ryan M; Ayrton, Stephen T; Cooks, R Graham

2017-07-01

Previous reports have shown that reactions occurring in the microdroplets formed during electrospray ionization can, under the right conditions, exhibit significantly greater rates than the corresponding bulk solution-phase reactions. The observed acceleration under electrospray ionization could result from a solution-phase, a gas-phase, or an interfacial reaction. This study shows that a gas-phase ion/molecule (or ion/ion) reaction is not responsible for the observed rate enhancement in the particular case of the Fischer indole synthesis. The results show that the accelerated reaction proceeds in the microdroplets, and evidence is provided that an interfacial process is involved. Graphical Abstract GRAPHICAL ABSTRACT TEXT HERE] -->.

Fischer-Tropsch Cobalt Catalyst Activation and Handling Through Wax Enclosure Methods

Science.gov (United States)

Klettlinger, Jennifer L. S.; Yen, Chia H.; Nakley, Leah M.; Surgenor, Angela D.

2016-01-01

Fischer-Tropsch (F-T) synthesis is considered a gas to liquid process which converts syn-gas, a gaseous mixture of hydrogen and carbon monoxide, into liquids of various hydrocarbon chain length and product distributions. Cobalt based catalysts are used in F-T synthesis and are the focus of this paper. One key concern with handling cobalt based catalysts is that the active form of catalyst is in a reduced state, metallic cobalt, which oxidizes readily in air. In laboratory experiments, the precursor cobalt oxide catalyst is activated in a fixed bed at 350 ?C then transferred into a continuous stirred tank reactor (CSTR) with inert gas. NASA has developed a process which involves the enclosure of active cobalt catalyst in a wax mold to prevent oxidation during storage and handling. This improved method allows for precise catalyst loading and delivery into a CSTR. Preliminary results indicate similar activity levels in the F-T reaction in comparison to the direct injection method. The work in this paper was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

Effect of the Polymeric Stabilizer in the Aqueous Phase Fischer-Tropsch Synthesis Catalyzed by Colloidal Cobalt Nanocatalysts

Directory of Open Access Journals (Sweden)

Jorge A. Delgado

2017-03-01

Full Text Available A series of small and well defined cobalt nanoparticles were synthesized by the chemical reduction of cobalt salts in water using NaBH4 as a reducing agent and using various polymeric stabilizers. The obtained nanocatalysts of similar mean diameters (ca. 2.6 nm were fully characterized and tested in the aqueous phase Fischer-Tropsch Synthesis (AFTS. Interestingly, the nature and structure of the stabilizers used during the synthesis of the CoNPs affected the reduction degree of cobalt and the B-doping of these NPs and consequently, influenced the performance of these nanocatalysts in AFTS.

Stereoisomeric products of electrochemical reduction of heterocyclic Fischer aminocarbene Cr(0) complexes. Development of the electrochemistry-mass spectrometry tandem approach using biphasic (acetonitrile-hexane) preparative electrolysis

Czech Academy of Sciences Publication Activity Database

Metelková, R.; Hoskovcová, I.; Polášek, Miroslav; Urban, Jiří; David, T.; Ludvík, Jiří

2015-01-01

Roč. 162, APR 2015 (2015), s. 17-23 ISSN 0013-4686 R&D Projects: GA ČR GAP206/11/0727 Institutional support: RVO:61388955 Keywords : Fischer aminocarbene complexes biphasic electrolysis * EC-MS * HPLC-NMR Subject RIV: CG - Electrochemistry Impact factor: 4.803, year: 2015

Preparation, surface characterization and performance of a Fischer-Tropsch catalyst of cobalt supported on silica nanosprings

International Nuclear Information System (INIS)

Kengne, Blaise-Alexis Fouetio; Alayat, Abdulbaset M.; Luo, Guanqun; McDonald, Armando G.; Brown, Justin; Smotherman, Hayden; McIlroy, David N.

2015-01-01

Graphical abstract: - Highlights: • Determined that the reduction of Co nanoparticles on silica nanosprings 200 °C higher than the reduction temperature of Co in a solgel support. • The high reduction temperature of Co supported on silica nanosprings is attributed to the heat transfer properties of the nanosprings due to their high surface area. Co-silica nanospring Fischer-Tropsch catalyst can be used to produce drop in fuels such as JP-4. - Abstract: The reduction of cobalt (Co) catalyst supported on silica nanosprings for Fischer-Tropsch synthesis (FTS) has been monitored by X-ray photoelectron spectroscopy (XPS) and compared to FT catalytic activity. The cobalt is present in the starting catalyst as a Co 3 O 4 spinel phase. A two-step reduction of Co 3 O 4 to CoO and then to Co 0 is observed, which is consistent with the results of H 2 -temperature programmed reduction. During the reduction the two steps occur concurrently. The deconvolution of the Co 2p core level state for the catalyst reduced at 385 °C and 1.0 × 10 −6 Torr of H 2 revealed signatures of Co 0 , CoO, and Co 3 O 4 . The reduction saturates at a Co o concentration of approximately 41% after 20 h, which correlates with the activity and lifetime of the catalyst during FTS testing. Conversely, at 680 °C and 10 Torr of H 2 , the catalyst is completely reduced after 10 h. The evolution of the Co d-band at the Fermi level in the valence band XPS spectrum definitively verifies the metallic phase of Co. FTS evaluation of the Co/NS catalyst reduced at 609 °C showed higher production rate (3-fold) of C 6 -C 17 hydrocarbons than the catalyst reduced at 409 °C and is consistent with the XPS analysis.

A preliminary plant design study for the production of diesel from coal via fischer-tropsch synthesis

International Nuclear Information System (INIS)

Kamil, M.; Saleem, M.

2010-01-01

Pakistan's reliance on conventional means of producing energy has proven to be an inadequate strategy for overcoming it. The situation direly demands diversification of our energy resources not only to overcome current fiasco but also in planning for future. Among the other alternative sources, coal is the main source for producing cheaper electricity being available as huge reserves. This paper presents the preliminary plant design and cost estimation for the production of diesel from coal via coal gasification and fischer-Tropschs synthesis. Prelimnary design calculations and cost estimation are presented along with underlying assumptions. The results reveal that the diesel produced from this process might be cheaper than the crude oil based diesel. (author)

Fischer-344 Tp53-knockout rats exhibit a high rate of bone and brain neoplasia with frequent metastasis

Directory of Open Access Journals (Sweden)

Sarah A. Hansen

2016-10-01

Full Text Available Somatic mutations in the Tp53 tumor suppressor gene are the most commonly seen genetic alterations in cancer, and germline mutations in Tp53 predispose individuals to a variety of early-onset cancers. Development of appropriate translational animal models that carry mutations in Tp53 and recapitulate human disease are important for drug discovery, biomarker development and disease modeling. Current Tp53 mouse and rat models have significant phenotypic and genetic limitations, and often do not recapitulate certain aspects of human disease. We used a marker-assisted speed congenic approach to transfer a well-characterized Tp53-mutant allele from an outbred rat to the genetically inbred Fischer-344 (F344 rat to create the F344-Tp53tm1(EGFP-PacQly/Rrrc (F344-Tp53 strain. On the F344 genetic background, the tumor spectrum shifted, with the primary tumor types being osteosarcomas and meningeal sarcomas, compared to the hepatic hemangiosarcoma and lymphoma identified in the original outbred stock model. The Fischer model is more consistent with the early onset of bone and central nervous system sarcomas found in humans with germline Tp53 mutations. The frequency of osteosarcomas in F344-Tp53 homozygous and heterozygous animals was 57% and 36%, respectively. Tumors were highly representative of human disease radiographically and histologically, with tumors found primarily on long bones with frequent pulmonary metastases. Importantly, the rapid onset of osteosarcomas in this promising new model fills a current void in animal models that recapitulate human pediatric osteosarcomas and could facilitate studies to identify therapeutic targets.

Comparative study of regulated and unregulated gaseous emissions during NEDC in a light-duty diesel engine fuelled with Fischer Tropsch and biodiesel fuels

Energy Technology Data Exchange (ETDEWEB)

Bermudez, Vicente; Lujan, Jose M.; Pla, Benjamin; Linares, Waldemar G. [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

2011-02-15

In this study, regulated and unregulated gaseous emissions and fuel consumption with five different fuels were tested in a 4-cylinder, light-duty diesel EURO IV typically used for the automotive vehicles in Europe. Three different biodiesel fuels obtained from soybean oil, rapeseed oil and palm oil, a Fischer Tropsch fuel and an ultra low sulphur diesel were studied. The test used was the New European Driving Cycle (NEDC), this allowed tests to be carried out on an engine warmed up beforehand to avoid the effect of cold starts and several tests a day. Regulated emissions of NO{sub X}, CO, HC and CO{sub 2} were measured for each fuel. Unburned Hydrocarbon Speciation and formaldehyde were also measured in order to determine the maximum incremental reactivity (MIR) of the gaseous emissions. Pollutants were measured without the diesel oxidation catalyst (DOC) to gather data about raw emissions. When biodiesel was used, increases in regulated and unregulated emissions were observed and also significant increases in engine fuel consumption. The use of Fischer Tropsch fuel, however, caused lower regulated and unregulated emissions and fuel consumption than diesel. (author)

Lipid synthesis under hydrothermal conditions by Fischer-Tropsch-type reactions.

Science.gov (United States)

McCollom, T M; Ritter, G; Simoneit, B R

1999-03-01

Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated or Mars and elsewhere as well). Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.

Emissions from Diesel and Gasoline Vehicles Fuelled by Fischer-Tropsch Fuels and Similar Fuels

DEFF Research Database (Denmark)

Larsen, Ulrik; Lundorff, Peter; Ivarsson, Anders

2007-01-01

The described investigation was carried out under the umbrella of IEA Advanced Motor Fuels Agreement. The purpose was to evaluate the emissions of carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH) from...... vehicles fuelled by Fischer Tropsch (FT) based diesel and gasoline fuel, compared to the emissions from ordinary diesel and gasoline. The comparison for diesel fuels was based on a literature review, whereas the gasoline comparison had to be based on our own experiments, since almost no references were...... found in this field. In this context measurement according to the Federal Test Procedure (FTP) and the New European Driving Cycle (NEDC) were carried out on a chassis dynamometer with a directly injected gasoline vehicle. Experiments were carried out with a reference fuel, a fuel based 70% on FT...

Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

OpenAIRE

Sartipi, S.; Jansma, H.; Bosma, D.; Boshuizen, B.; Makkee, M.; Gascon, J.; Kapteijn, F.

2013-01-01

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4?mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under...

The effect of zirconium on cobalt catalyst in fischer-tropsch synthesis

International Nuclear Information System (INIS)

Moradi, GH.R.; Mahbob Basir, M.; Taeb, A.

2003-01-01

A series of 10 wt % Co/SiO 2 catalysts with different loading ratios of zirconia (0, 5, 10, 15, 20) has been prepared through an original pseudo sol-gel method. All catalysts were characterized by BET, XRD, SEM, and TPR experiments. The catalytic performance of the catalysts for the so-called fischer- tropsch synthesis was examined under H 2 /CO=2 at 230 d ig C and 8 bar in a fixed bed microreactor. By increasing zirconia, the Co-SiO 2 interaction decreases and is replaced by Co-Zr interaction which favours reduction of the catalyst at lower temperatures. While it leads to a higher degree of reduction and as increase in the metallic cobalt atoms on the surface. The activity of the promoted catalysts increases with the addition of zirconia (max. by a factor 2.5). The C 1 0 + selectivity increased with the addition of zirconia (from 42.3% in unpromoted catalyst to 68.8 % in the 20 % ZrO 2 promoted. This can be attributed to the higher amount of the surface Cobalt metal present and to the larger Cobalt particle size

SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

Energy Technology Data Exchange (ETDEWEB)

James K. Neathery; Gary Jacobs; Burtron H. Davis

2004-03-31

In this reporting period, a fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of production since the reaction is highly exothermic. Consequently, heavy wax products must be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase FTS. The separation problem is further compounded by catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. Existing pilot-scale equipment was modified to include a filtration test apparatus. After undergoing an extensive plant shakedown period, filtration tests with cross-flow filter modules using simulant FTS wax slurry were conducted. The focus of these early tests was to find adequate mixtures of polyethylene wax to simulate FTS wax. Catalyst particle size analysis techniques were also developed. Initial analyses of the slurry and filter permeate particles will be used by the research team to design improved filter media and cleaning strategies.

Monetization of Nigeria coal by conversion to hydrocarbon fuels through Fischer-Tropsch process

Energy Technology Data Exchange (ETDEWEB)

Oguejiofor, G.C. [Nnamdi Azikiwe University, Awka (Nigeria). Dept. of Chemical Engineering

2008-07-01

Given the instability of crude oil prices and the disruptions in crude oil supply chains, this article offers a complementing investment proposal through diversification of Nigeria's energy source and dependence. Therefore, the following issues were examined and reported: A comparative survey of coal and hydrocarbon reserve bases in Nigeria was undertaken and presented. An excursion into the economic, environmental, and technological justifications for the proposed diversification and roll-back to coal-based resource was also undertaken and presented. The technology available for coal beneficiation for environmental pollution control was reviewed and reported. The Fischer-Tropsch synthesis and its advances into Sasol's slurry phase distillate process were reviewed. Specifically, the adoption of Sasol's advanced synthol process and the slurry phase distillate process were recommended as ways of processing the products of coal gasification. The article concludes by discussing all the above-mentioned issues with regard to value addition as a means of wealth creation and investment.

Aplicación de los métodos de pirólisis Rock-Eval y Fischer al estudio de la materia orgánica contenida en rocas sedimentarias de Guipúzcoa

Directory of Open Access Journals (Sweden)

González G., A.

1987-08-01

Full Text Available The sedimentary rocks are geochemically studied throughout the geological history of the provinces of Guipúzcoa and Vizcaya. The pyrolisis is made following fischer's modified method. On a whole of one hundred and eigthy five samples. We haven't found oil shale, except in Garay (Durango-Vizcaya, where we have managed to distil appreciable quantities of oil from the samples, oscillating between 1.5 l/Tm. and 28 l/Tm. From these ones, whe have choosed twenty which showed a bigger content of organic material than the otheres. We have made the rock-eval pyrolisis with the purpose of checking fischer's modified method. We have managed to define that the petroliferous potential is variable. As for the type of organic material and its stage of evolution (maturity, we have concluded that it is a type II (marine origin with a stage of evolution that places us on the oil generation.Se estudian geoquímicamente rocas sedimentarias a lo largo de la historia geológica de las provincias de Guipúzcoa y Vizcaya. Se realiza la pirólisis según el método modificado de Fischer sobre un total de ciento ochenta y cinco muestras. No se han encontrado rocas bituminosas, salvo en Garay (Durango-Vizcaya donde se han llegado a destilar de las muestras, cantidades apreciables de aceite, que oscilan entre 1,5 l/Tm. y 28 l/Tm. De éstas, hemos escogido veinte que presentaban un contenido mayor de materia orgánica que el resto. Hemos realizado la pirólisis Rock-Eval de ellas con el fin de contrastar el método modificado de Fischer. Hemos llegado a definir que el potencial petrolífero es variable. En cuanto al tipo de materia orgánica y su grado de evolución (madurez, hemos concluido que se trata de un tipo II (origen marino, con un grado de evolución que nos coloca en la ventana de generación de aceite.

Consumo de Pinus taeda (Pinaceae) pelo rato-de-espinho Euryzygomatomys spinosus (G. Fischer) (Echimyidae) em plantações no Sul do Brasil

OpenAIRE

Gonçalves, Gislene L.; Faria-Correa, Mariana A.; Cunha, Adriano S.; Freitas, Thales R. O.

2007-01-01

Feeding damage caused by Euryzygomatomys spinosus (G. Fischer, 1814) (Echimyidae) is documented for a Pinus taeda Linnaeus (Pinaceae) plantation located in Cambará do Sul, Rio Grande do Sul State, Brazil. Under laboratory conditions, feeding acceptance of P. taeda trunk sections was tested with positive results for E. spinosus, but not for other three co-occurring sigmodontine rodents: Akodon montensis Thomas, 1913, Oligoryzomys nigripes (Olfers, 1818) and Delomys dorsalis (Hensel, 1872).Esse...

The Fischer 344 rat as a model of presbycusis.

Science.gov (United States)

Syka, Josef

2010-06-01

Due to the rising number of the aged human population all over the world, presbycusis is a phenomenon that deserves the increasing attention of the medical community as regards to prevention and treatment. This requires finding appropriate animal models for human presbycusis that will be useful in future experiments. Among the available rat strains, the Fischer 344 (F344) strain promises to serve as a model producing prompt and profound presbycusis. Hearing thresholds begin to increase in this strain during the first year of life; toward the end of the second year, the thresholds are very high. The threshold shifts progress independently in both ears. The rapid deterioration of distortion product otoacoustic emissions, with the majority of outer hair cells (OHC) being present and morphologically intact, is apparently produced by the disruption of prestin. The age-related changes within inner ear function are accompanied by deterioration of acoustical signal processing within central auditory system, mainly due to impaired GABA inhibition. The loss of GABA inhibition in old animals is expressed primarily in the inferior colliculus but is also present in the cochlear nuclei and the auditory cortex. Sound-evoked behavioral reactions are also impaired in old F344 rats. Taken together, the described characteristics of the aging F344 rat auditory system supports the idea that this strain may serve as a suitable model for studying the mechanisms of presbycusis, its prevention and treatment. Copyright 2009 Elsevier B.V. All rights reserved.

DEVELOPMENT OF ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

International Nuclear Information System (INIS)

Adeyinka A. Adeyiga

2001-01-01

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H 2 ) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. The use of iron-based catalysts is attractive not only due to their low cost and ready availability, but also due to their high water-gas shift activity which makes it possible to use these catalysts with low H 2 /CO ratios. However, a serious problem with use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, makes the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. Recently, fundamental understanding of physical attrition is being addressed by incorporating suitable binders into the catalyst recipe. This has resulted in the preparation of a spray dried Fe-based catalyst having aps of 70 mm with high attrition resistance. This Fe-based attrition resistant, active and selective catalyst gave 95% CO conversion through 125 hours of testing in a fixed-bed at 270 C, 1.48 MPa, H 2 /CO=0.67 and 2.0 NL/g-cat/h with C 5 + selectivity of >78% and methane selectivity of <5%. However, further development of the catalyst is needed to address the chemical attrition due to phase changes that any Fe-catalyst goes through potentially causing internal stresses within the particle and resulting in weakening, spalling or cracking. The objective of this research is to develop robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry bubble column reactor. Specifically we aim to develop to: (i) improve the performance and preparation procedure of the high activity, high attrition resistant, high alpha iron

Preparation, characterization and testing of SiC-based catalytic sponges as structured catalysts for Fischer-Tropsch synthesis

Energy Technology Data Exchange (ETDEWEB)

Baudry, A.; Schaub, G. [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Engler-Bunte-Inst.

2011-07-01

Solid sponges (open-cell foams) may be used as catalyst support, due to favorable thermal properties and low pressure drop. As an example, they may lead to improved temperature control in Fischer-Tropsch applications, if compared to fixed beds of catalyst particles. The aim of this study was to develop and test a wet method for impregnating ceramic foam materials with a CoRe/{gamma}-Al{sub 2}O{sub 3} catalyst. Defined catalyst layers were generated on 20 ppi SiC-sponges. Resulting catalytic activities are nearly identical to those of the corresponding powder catalyst material. The difference observed can be explained by either mass transfer limitation or backmixing in the fixed bed configuration used. (orig.)

The effects of subchronic acrylamide exposure on gene expression, neurochemistry, hormones, and histopathology in the hypothalamus-pituitary-thyroid axis of male Fischer 344 rats

International Nuclear Information System (INIS)

Bowyer, J.F.; Latendresse, J.R.; Delongchamp, R.R.; Muskhelishvili, L.; Warbritton, A.R.; Thomas, M.; Tareke, E.; McDaniel, L.P.; Doerge, D.R.

2008-01-01

Acrylamide (AA) is an important industrial chemical that is neurotoxic in rodents and humans and carcinogenic in rodents. The observation of cancer in endocrine-responsive tissues in Fischer 344 rats has prompted hypotheses of hormonal dysregulation, as opposed to DNA damage, as the mechanism for tumor induction by AA. The current investigation examines possible evidence for disruption of the hypothalamic-pituitary-thyroid axis from 14 days of repeated exposure of male Fischer 344 rats to doses of AA that range from one that is carcinogenic after lifetime exposure (2.5 mg/kg/d), an intermediate dose (10 mg/kg/d), and a high dose (50 mg/kg/d) that is neurotoxic for this exposure time. The endpoints selected include: serum levels of thyroid and pituitary hormones; target tissue expression of genes involved in hormone synthesis, release, and receptors; neurotransmitters in the CNS that affect hormone homeostasis; and histopathological evaluation of target tissues. These studies showed virtually no evidence for systematic alteration of the hypothalamic-pituitary-thyroid axis and do not support hormone dysregulation as a plausible mechanism for AA-induced thyroid cancer in the Fischer 344 rat. Specifically, there were no significant changes in: 1) mRNA levels in hypothalamus or pituitary for TRH, TSH, thyroid hormone receptor α and β, as well 10 other hormones or releasing factors; 2) mRNA levels in thyroid for thyroglobulin, thyroid peroxidase, sodium iodide symporter, or type I deiodinases; 3) serum TSH or T3 levels (T4 was decreased at high dose only); 4) dopaminergic tone in the hypothalamus and pituitary or importantly 5) increased cell proliferation (Mki67 mRNA and Ki-67 protein levels were not increased) in thyroid or pituitary. These negative findings are consistent with a genotoxic mechanism of AA carcinogenicity based on metabolism to glycidamide and DNA adduct formation. Clarification of this mechanistic dichotomy may be useful in human cancer risk

Bulk and surface structure of a NixFe/Al2O3 catalyst for Fischer-Tropsch synthesis studied by Moessbauer, infrared spectroscopy and magnetic methods

International Nuclear Information System (INIS)

Boellaard, E.; Kraan, A.M. van der; Geus, J.W.

1992-01-01

Deposition precipitation of a stoichiometric nickel-ironcyanide complex onto a alumina support and subsequent calcination and reduction has resulted in the formation of a homogeneous metallic alloy which exhibits activity for Fischer-Tropsch synthesis. During hydrocarbon synthesis conditions only a fraction of the metallic phase is converted in a phase which is most likely a thermally unstable (nickel-)iron carbide. (orig.)

Effect of K promoter on the structure and catalytic behavior of supported iron-based catalysts in fischer-tropsch synthesis

Directory of Open Access Journals (Sweden)

F. E. M Farias

2011-09-01

Full Text Available Effects of K addition on the performance of supported Fe catalysts for Fischer - Tropsch synthesis (FTS were studied in a slurry reactor at 240 to 270ºC, 2.0 to 4.0 MPa and syngas H2/CO = 1.0. The catalysts were characterized by N2 adsorption, H2 temperature programmed reduction, X - ray diffraction, X - ray fluorescence, thermogravimetric analysis, scanning electron microscopy and dispersive X - ray spectroscopy. A strong interaction was observed between Fe and K, which inhibited the reduction of Fe catalyst. Addition of potassium increased the production of heavy hydrocarbons (C20+.

Fischer-Tropsch Performance of an SiO2-Supported Co-Based Catalyst Prepared by Hydrogen Dielectric-Barrier Discharge Plasma

International Nuclear Information System (INIS)

Fu Tingjun; Huang Chengdu; Lv Jing; Li Zhenhua

2014-01-01

A silica-supported cobalt catalyst was prepared by hydrogen dielectric-barrier discharge (H 2 -DBD) plasma. Compared to thermal hydrogen reduction, H 2 -DBD plasma treatment can not only fully decompose the cobalt precursor but also partially reduce the cobalt oxides at lower temperature and with less time. The effect of the discharge atmosphere on the property of the plasma-prepared catalyst and the Fischer-Tropsch synthesis activity was studied. The results indicate that H 2 -DBD plasma treatment is a promising alternative for preparing Co/SiO 2 catalysts from the viewpoint of energy savings and efficiency

SEPARATION OF FISCHER-TROPSCH WAX FROM CATALYST BY SUPERCRITICAL EXTRACTION

Energy Technology Data Exchange (ETDEWEB)

Patrick C. Joyce; Mark C. Thies

1999-03-31

The objective of this research project was to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, is to be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Aspen Plus{trademark} was used to perform process simulation studies on the proposed extraction process, with Redlich-Kwong-Soave (RKS) being used for the thermodynamic property model. In summary, we have made comprehensive VLE measurements for short alkane + long alkane systems over a wide range of pressures and temperatures, dramatically increasing the amount of high-quality data available for these simple, yet highly relevant systems. In addition, our work has demonstrated that, surprisingly, no current thermodynamic model can adequately predict VLE behavior for these systems. Thus, process simulations (such as those for our proposed SCF extraction process) that incorporate these systems can currently only give results that are qualitative at best. Although significant progress has been made in the past decade, more experimental and theoretical work remain to be done before the phase equilibria of asymmetric alkane mixtures can be predicted with confidence.

DEVELOPMENT OF PRECIPITATED IRON FISCHER-TROPSCH CATALYSTS

International Nuclear Information System (INIS)

Bukur, Dragomir B.; Lang, X.; Chokkaram, S.; Nowicki, L.; Wei, G.; Ding, Y.; Reddy, B.; Xiao, S.

1999-01-01

Despite the current worldwide oil glut, the US will ultimately require large-scale production of liquid (transportation) fuels from coal. Slurry phase Fischer-Tropsch (F-T) technology, with its versatile product slate, may be expected to play a major role in production of transportation fuels via indirect coal liquefaction. Some of the F-T catalysts synthesized and tested at Texas A and M University under DOE Contract No. DE-AC22-89PC89868 were more active than any other known catalysts developed for maximizing production of high molecular weight hydrocarbons (waxes). The objectives of the present contract were to demonstrate repeatability of catalyst performance and reproducibility of preparation procedures of two of these catalysts on a laboratory scale. Improvements in the catalyst performance were attempted through the use of: (a) higher reaction pressure and gas space velocity to maximize the reactor productivity; (b) modifications in catalyst preparation steps; and (c) different pretreatment procedures. Repeatability of catalyst performance and reproducibility of catalyst synthesis procedure have been successfully demonstrated in stirred tank slurry reactor tests. Reactor space-time-yield was increased up to 48% by increasing reaction pressure from 1.48 MPa to 2.17 MPa, while maintaining the gas contact time and synthesis gas conversion at a constant value. Use of calcination temperatures above 300 C, additional CaO promoter, and/or potassium silicate as the source of potassium promoter, instead of potassium bicarbonate, did not result in improved catalyst performance. By using different catalyst activation procedures they were able to increase substantially the catalyst activity, while maintaining low methane and gaseous hydrocarbon selectivities. Catalyst productivity in runs SA-0946 and SA-2186 was 0.71 and 0.86 gHC/g-Fe/h, respectively, and this represents 45-75% improvement in productivity relative to that achieved in Rheinpreussen's demonstration plant

Membrane Bioreactor (MBR) as Alternative to a Conventional Activated Sludge System Followed by Ultrafiltration (CAS-UF) for the Treatment of Fischer-Tropsch Reaction Water from Gas-to-Liquids Industries

NARCIS (Netherlands)

Laurinonyte, Judita; Meulepas, Roel J.W.; Brink, van den Paula; Temmink, Hardy

2017-01-01

The potential of a membrane bioreactor (MBR) system to treat Fischer-Tropsch (FT) reaction water from gas-to-liquids (GTL) industries was investigated and compared with the current treatment system: a conventional activated sludge system followed by an ultrafiltration (CAS-UF) unit. The MBR and

Preparation, surface characterization and performance of a Fischer-Tropsch catalyst of cobalt supported on silica nanosprings

Energy Technology Data Exchange (ETDEWEB)

Kengne, Blaise-Alexis Fouetio [Department of Physics, University of Idaho, Moscow, ID 83844-0903 (United States); Alayat, Abdulbaset M. [Environmental Science Program, University of Idaho, Moscow, ID 83844-3006 (United States); Luo, Guanqun [Department of Forest, Rangeland & Fire Sciences, University of Idaho, Moscow, ID 83844-1132 (United States); McDonald, Armando G. [Environmental Science Program, University of Idaho, Moscow, ID 83844-3006 (United States); Department of Forest, Rangeland & Fire Sciences, University of Idaho, Moscow, ID 83844-1132 (United States); Brown, Justin; Smotherman, Hayden [Department of Physics, University of Idaho, Moscow, ID 83844-0903 (United States); McIlroy, David N., E-mail: dmcilroy@uidaho.edu [Department of Physics, University of Idaho, Moscow, ID 83844-0903 (United States)

2015-12-30

Graphical abstract: - Highlights: • Determined that the reduction of Co nanoparticles on silica nanosprings 200 °C higher than the reduction temperature of Co in a solgel support. • The high reduction temperature of Co supported on silica nanosprings is attributed to the heat transfer properties of the nanosprings due to their high surface area. Co-silica nanospring Fischer-Tropsch catalyst can be used to produce drop in fuels such as JP-4. - Abstract: The reduction of cobalt (Co) catalyst supported on silica nanosprings for Fischer-Tropsch synthesis (FTS) has been monitored by X-ray photoelectron spectroscopy (XPS) and compared to FT catalytic activity. The cobalt is present in the starting catalyst as a Co{sub 3}O{sub 4} spinel phase. A two-step reduction of Co{sub 3}O{sub 4} to CoO and then to Co{sup 0} is observed, which is consistent with the results of H{sub 2}-temperature programmed reduction. During the reduction the two steps occur concurrently. The deconvolution of the Co 2p core level state for the catalyst reduced at 385 °C and 1.0 × 10{sup −6} Torr of H{sub 2} revealed signatures of Co{sup 0}, CoO, and Co{sub 3}O{sub 4}. The reduction saturates at a Co{sup o} concentration of approximately 41% after 20 h, which correlates with the activity and lifetime of the catalyst during FTS testing. Conversely, at 680 °C and 10 Torr of H{sub 2}, the catalyst is completely reduced after 10 h. The evolution of the Co d-band at the Fermi level in the valence band XPS spectrum definitively verifies the metallic phase of Co. FTS evaluation of the Co/NS catalyst reduced at 609 °C showed higher production rate (3-fold) of C{sub 6}-C{sub 17} hydrocarbons than the catalyst reduced at 409 °C and is consistent with the XPS analysis.

Greenhouse impact assessment of peat-based Fischer-Tropsch diesel life-cycle

International Nuclear Information System (INIS)

Kirkinen, Johanna; Soimakallio, Sampo; Maekinen, Tuula; Savolainen, Ilkka

2010-01-01

New raw materials for transportation fuels need to be introduced, in order to fight against climate change and also to cope with increasing risks of availability and price of oil. Peat has been recognised suitable raw material option for diesel produced by gasification and Fischer-Tropsch (FT) synthesis. The energy content of Finnish peat reserves is remarkable. In this study, the greenhouse impact of peat-based FT diesel production and utilisation in Finland was assessed from the life-cycle point of view. In 100 year's time horizon the greenhouse impact of peat-based FT diesel is likely larger than the impact of fossil diesel. The impact can somewhat be lowered by producing peat from the agricultural peatland (strong greenhouse gas emissions from the decaying peatlayer are avoided) with new peat production technique, and utilising the produced biomass from the after-treatment area for diesel also. If diesel production is integrated with pulp and paper mill to achieve energy efficiency benefits and if the electricity demand can be covered by zero emission electricity, the greenhouse impact of peat-based FT diesel reduces to the level of fossil diesel when agricultural peatland is used, and is somewhat higher when forestry-drained peatland is used as raw material source.

Important roles of Fischer-Tropsch synfuels in the global energy future

International Nuclear Information System (INIS)

Takeshita, Takayuki; Yamaji, Kenji

2008-01-01

This paper examines the potential roles of Fischer-Tropsch (FT) synfuels in the 21st century with a global energy model treating the entire fuel supply chain in detail. The major conclusions are the following. First, FT synfuels become a major alternative fuel regardless of CO 2 policy due to their low transportation costs and compatibility with existing petroleum infrastructure and vehicles. Secondly, the FT process brings stranded gas to world markets until around 2050. In a 550 ppm CO 2 stabilization case thereafter, producing FT synfuels from biomass, whose competitiveness is robust against its capital costs, and their interregional trade enable a worldwide diffusion of carbon-neutral fuels. This provides a significant source of income for developing regions, such as Latin America and Sub-Saharan Africa. Thirdly, FT synfuels play a crucial role in meeting the growing transportation energy demand and assuring diversified supplies of transportation fuels. Increasing portions of FT liquids are refined to FT-kerosene to be provided for the rapidly growing aviation sector in the second half of the century. Furthermore, upgrading FT-naphtha into FT-gasoline proves to be critically important. FT synfuels' participation could help the development in Africa through technological contributions of the South African leading companies in the world synfuel industry

Effects of repeated light-dark phase shifts on voluntary ethanol and water intake in male and female Fischer and Lewis rats.

Science.gov (United States)

Rosenwasser, Alan M; Clark, James W; Fixaris, Michael C; Belanger, Gabriel V; Foster, James A

2010-05-01

Several lines of evidence implicate reciprocal interactions between excessive alcohol (ethanol) intake and dysregulation of circadian biological rhythms. Thus, chronic alcohol intake leads to widespread circadian disruption in both humans and experimental animals, while in turn, chronobiological disruption has been hypothesized to promote or sustain excessive alcohol intake. Nevertheless, the effects of circadian disruption on voluntary ethanol intake have not been investigated extensively, and prior studies have reported both increased and decreased ethanol intake in rats maintained under "shift-lag" lighting regimens mimicking those experienced by shift workers and transmeridian travelers. In the present study, male and female inbred Fischer and Lewis rats were housed in running wheel cages with continuous free-choice access to both water and 10% (vol/vol) ethanol solution and exposed to repeated 6-h phase advances of the daily light-dark (LD) cycle, whereas controls were kept under standard LD 12:12 conditions. Shift-lag lighting reduced overall ethanol and water intake, and reduced ethanol preference in Fischer rats. Although contrary to the hypothesis that circadian disruption would increase voluntary ethanol intake, these results are consistent with our previous report of reduced ethanol intake in selectively bred high-alcohol-drinking (HAD1) rats housed under a similar lighting regimen. We conclude that chronic circadian disruption is a form of chronobiological stressor that, like other stressors, can either increase or decrease ethanol intake, depending on a variety of poorly understood variables. 2010 Elsevier Inc. All rights reserved.

Cobalt Fischer-Tropsch catalysts: influence of cobalt dispersion and titanium oxides promotion

Energy Technology Data Exchange (ETDEWEB)

Azib, H

1996-04-10

The aim of this work is to study the effect of Sol-Gel preparation parameters which occur in silica supported cobalt catalysts synthesis. These catalysts are particularly used for the waxes production in natural gas processing. The solids have been characterized by several techniques: transmission electron microscopy (TEM), X-ray absorption near edge spectroscopy (XANES), programmed temperature reduction (TPR), infrared spectroscopy (IR), ultraviolet spectroscopy (UV), Magnetism, thermodesorption of H{sub 2} (TPD). The results indicate that the control of the cobalt dispersion and oxide phases nature is possible by modifying Sol-Gel parameters. The catalytic tests in Fischer-Tropsch synthesis were conducted on a pilot unit under pressure (20 atm) and suggested that turnover rates were independent of Co crystallite size, Co phases in the solids (Co deg., cobalt silicate) and titanium oxide promotion. On the other methane, the C{sub 3}{sup +} hydrocarbon selectivity is increased with increasing crystallite size. Inversely, the methane production is favoured by very small crystallites, cobalt silicate increase and titanium addition. However, the latter, used as a cobalt promoter, has a benefic effect on the active phase stability during the synthesis. (author). 149 refs., 102 figs., 71 tabs.

Emissions from Road Vehicles Fuelled by Fischer Tropsch Based Diesel and Gasoline

Energy Technology Data Exchange (ETDEWEB)

Larsen, U; Lundorf, P; Ivarsson, A; Schramm, J [Technical University of Denmark (Denmark); Rehnlund, B [Atrax Energi AB (Sweden); Blinge, M [The Swedish Transport Institute (Sweden)

2006-11-15

The described results were carried out under the umbrella of IEA Advanced Motor Fuels Agreement. The purpose was to evaluate the emissions of carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH) from vehicles fuelled by Fischer Tropsch (FT) based diesel and gasoline fuel, compared to the emissions from ordinary diesel and gasoline. The comparison for diesel fuels was based on a literature review, whereas the gasoline comparison had to be based on our own experiments, since almost no references were found in this field. In this context measurement according to the Federal Test Procedure (FTP) and the New European Driving Cycle (NEDC) were carried out on a chassis dynamometer with a directly injected gasoline vehicle. Experiments were carried out with a reference fuel, a fuel based 70% on FT and an alkylate fuel (Aspen), which was supposed to be very similar, in many ways, to FT fuel. FT based diesel generally showed good emission performance, whereas the FT based gasoline not necessary lead to lower emissions. On the other hand, the Aspen fuel did show many advantages for the emissions from the gasoline vehicle.

Development of improved iron Fischer-Tropsch catalysts. Final technical report: Project 6464

Energy Technology Data Exchange (ETDEWEB)

Bukur, D.B.; Ledakowicz, S.; Koranne, M. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemical Engineering] [and others

1994-02-28

Despite the current worldwide oil glut, the United States will ultimately require large-scale production of liquid (transportation) fuels from coal. Slurry phase Fischer Tropsch (FT) technology, with its versatile product slate, may be expected to play a major role in production of transportation fuels via indirect coal liquefaction. Texas A&M University (TAMU) with sponsorship from the US Department of Energy, Center for Energy and Mineral Resources at TAMU, Texas Higher Education Coordinating Board, and Air Products and Chemicals, Inc., has been working on development of improved iron FT catalysts and characterization of hydrodynamic parameters in two- and three-phase bubble columns with FT derived waxes. Our previous studies have provided an improved understanding of the role of promoters (Cu and K), binders (silica) and pretreatment procedures on catalyst activity, selectivity and longevity (deactivation). The objective of the present contract was to develop improved catalysts with enhanced slurry phase activity and higher selectivity to liquid fuels and wax. This was accomplished through systematic studies of the effects of pretreatment procedures and variations in catalyst composition (promoters and binders). The major accomplishments and results in each of these two main areas of research are summarized here.

The effect of dietary administration of Disperse Blue 1 on the urinary system of the Fischer 344 rat.

Science.gov (United States)

Burnett, C M; Squire, R A

1986-04-01

Disperse Blue 1 (containing 50% lignosulphonate dispersants) was fed to Fischer 344 rats at dietary levels of 0.01 and 0.1% for 19 months and at 1.0% for 6 months. Fischer 344 rats were also given the dye by gavage at 1 g/kg for 1-3 days or in the diet at 0.5 or 1% for 4 days, and corresponding dietary levels of the colouring without dispersant were also fed for 4 days. Bladders and kidneys were examined after the 1-4 day treatments, in animals dying or killed from month 6 to termination (19 months) in the chronic study and in those killed at wk 5, 9 and 17. At the latter three times, autoradiography following injection of tritiated thymidine showed increased DNA synthesis in the urothelium of high-dose rats, but no other increased labelling in any group. Bladder lesions were seen only at the 1.0% level, epithelial erosion with adhering dye particles being seen by day 4, calculi and hyperplasia by wk 5 and squamous metaplasia by wk 9. The calculi contained more dye in males than in females and more calcium in females. By month 6, dye particles were embedded in the bladder wall, with some evidence of histiocyte accumulation in their vicinity. Two papillomas and one carcinoma, but no leiomyosarcomas, were diagnosed. The earliest tumours, two papillomas, were detected at wk 17. Tumour incidence following surgical removal of calculus was about double that in rats not subjected to surgery and the incidence of normal bladders at month 19 was higher in the latter group. Compound-related effects in the kidneys--inflammation, pelvic epithelial hyperplasia and tubular degeneration and regeneration with interstitial fibrosis--were seen only in the high-dose group. Dye present in the tubules and renal pelvis persisted in many rats for a year after cessation of treatment.

Sperm mRNA transcripts are indicators of sub-chronic low dose testicular injury in the Fischer 344 rat.

Directory of Open Access Journals (Sweden)

Sara E Pacheco

Full Text Available Current human reproductive risk assessment methods rely on semen and serum hormone analyses, which are not easily comparable to the histopathological endpoints and mating studies used in animal testing. Because of these limitations, there is a need to develop universal evaluations that reliably reflect male reproductive function. We hypothesized that toxicant-induced testicular injury can be detected in sperm using mRNA transcripts as indicators of insult. To test this, we exposed adult male Fischer 344 rats to low doses of model testicular toxicants and classically characterized the testicular injury while simultaneously evaluating sperm mRNA transcripts from the same animals. Overall, this study aimed to: 1 identify sperm transcripts altered after exposure to the model testicular toxicant, 2,5-hexanedione (HD using microarrays; 2 expand on the HD-induced transcript changes in a comprehensive time course experiment using qRT-PCR arrays; and 3 test these injury indicators after exposure to another model testicular toxicant, carbendazim (CBZ. Microarray analysis of HD-treated adult Fischer 344 rats identified 128 altered sperm mRNA transcripts when compared to control using linear models of microarray analysis (q<0.05. All transcript alterations disappeared after 3 months of post-exposure recovery. In the time course experiment, time-dependent alterations were observed for 12 candidate transcripts selected from the microarray data based upon fold change and biological relevance, and 8 of these transcripts remained significantly altered after the 3-month recovery period (p<0.05. In the last experiment, 8 candidate transcripts changed after exposure to CBZ (p<0.05. The two testicular toxicants produced distinct molecular signatures with only 4 overlapping transcripts between them, each occurring in opposite directions. Overall, these results suggest that sperm mRNA transcripts are indicators of low dose toxicant-induced testicular injury in the rat.

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYSTHESIS

International Nuclear Information System (INIS)

Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

2005-01-01

This report covers the third year of this research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis (FTS) on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (H 2 O, CO 2 , linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we utilized experimental data from the STSR, that were obtained during the first two years of the project, to perform vapor-liquid equilibrium (VLE) calculations and estimate kinetic parameters. We used a modified Peng-Robinson (PR) equation of state (EOS) with estimated values of binary interaction coefficients for the VLE calculations. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Occasional discrepancies (for some of the experimental data) between calculated and experimental values of the liquid phase composition were ascribed to experimental errors. The VLE calculations show that the vapor and the liquid are in thermodynamic equilibrium under reaction conditions. Also, we have successfully applied the Levenberg-Marquardt method (Marquardt, 1963) to estimate parameters of a kinetic model proposed earlier by Lox and Froment (1993b) for FTS on an iron catalyst. This kinetic model is well suited for initial studies where the main goal is to learn techniques for parameter estimation and statistical analysis of estimated values of model parameters. It predicts that the chain growth parameter (α) and olefin to paraffin ratio are independent of carbon number, whereas our experimental data show that they vary with the carbon number. Predicted molar flow

Subtask 3.4 - Fischer - Tropsch Fuels Development

Energy Technology Data Exchange (ETDEWEB)

Strege, Joshua; Snyder, Anthony; Laumb, Jason; Stanislowski, Joshua; Swanson, Michael

2012-05-01

Under Subtask 3.4, the Energy & Environmental Research Center (EERC) examined the opportunities and challenges facing FischerTropsch (FT) technology in the United States today. Work was completed in two distinct budget periods (BPs). In BP1, the EERC examined the technical feasibility of using modern warm-gas cleanup techniques for FT synthesis. FT synthesis is typically done using more expensive and complex cold-gas sweetening. Warm-gas cleanup could greatly reduce capital and operating costs, making FT synthesis more attractive for domestic fuel production. Syngas was generated from a variety of coal and biomass types; cleaned of sulfur, moisture, and condensables; and then passed over a pilot-scale FT catalyst bed. Laboratory and modeling work done in support of the pilot-scale effort suggested that the catalyst was performing suboptimally with warm-gas cleanup. Long-term trends showed that the catalyst was also quickly deactivating. In BP3, the EERC compared FT catalyst results using warm-gas cleanup to results using cold-gas sweetening. A gas-sweetening absorption system (GSAS) was designed, modeled, and constructed to sweeten syngas between the gasifier and the pilot-scale FT reactor. Results verified that the catalyst performed much better with gas sweetening than it had with warm-gas cleanup. The catalyst also showed no signs of rapid deactivation when the GSAS was running. Laboratory tests in support of this effort verified that the catalyst had deactivated quickly in BP1 because of exposure to syngas, not because of any design flaw with the pilot-scale FT reactor itself. Based on these results, the EERC concludes that the two biggest issues with using syngas treated with warm-gas cleanup for FT synthesis are high concentrations of CO{sub 2} and volatile organic matter. Other catalysts tested by the EERC may be more tolerant of CO{sub 2}, but volatile matter removal is critical to ensuring long-term FT catalyst operation. This subtask was funded through

Determination of water traces in various organic solvents using Karl Fischer method under FIA conditions.

Science.gov (United States)

Dantan, N; Frenzel, W; Küppers, S

2000-05-31

Flow injection methods utilising the Karl Fischer (KF) reaction with spectrophotometric and potentiometric detection are described for the determination of the trace water content in various organic solvents. Optimisation of the methods resulted in an accessible (linear) working range of 0.01-0.2% water for many solvents studied with a typical precision of 1-2% R.S.D. Only 50 mul of organic solvent was injected and the sampling frequency was about 120 samples per h. Since the slopes of the calibration curves were different for different solvents appropriate calibration was required. Problems associated with spectrophotometric detection and caused by refractive index changes were pointed out and a nested-loop configuration was proposed to overcome this kind of interference. The potentiometric method with a novel flow-through detector cell was shown to surpass the performance of spectrophotometric detection in any respect. The characteristics of the procedures developed made them well applicable for on-line monitoring of technical solvent distillations in an industrial plant.

Effect of Surface Modification by Chelating Agents on Fischer- Tropsch Performance of Co/SiO{sub 2} Catalysts

Energy Technology Data Exchange (ETDEWEB)

Bambal, Ashish S.; Kugler, Edwin L.; Gardner, Todd H.; Dadyburjor, Dady B.

2013-11-14

The silica support of a Co-based catalyst for Fischer-Tropsch (FT) synthesis was modified by the chelating agents (CAs) nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA). After the modification, characterization of the fresh and spent catalysts show reduced crystallite sizes, a better-dispersed Co₃O₄ phase on the calcined samples, and increased metal dispersions for the reduced samples. The CA-modified catalysts display higher CO conversions, product yields, reaction rates and rate constants. The improved FT performance of CA-modified catalysts is attributed to the formation of stable complexes with Co. The superior performance of the EDTA-modified catalyst in comparison to the NTA-modified catalyst is due to the higher affinity of the former for complex formation with Co ions.

Effect of pretreatment temperature on catalytic performance of the catalysts derived from cobalt carbonyl cluster in Fischer-Tropsch Synthesis

Directory of Open Access Journals (Sweden)

Byambasuren O

2017-02-01

Full Text Available The monometallic cobalt-based catalysts were prepared by pretreating the catalysts derived from carbonyl cluster precursor (CO6Co2CC(COOH2 supported on γ-Al2O3 with hydrogen at 180, 220, and 260°C respectively. The temperature effect of the pretreatments on the structure evolution of cluster precursors and the catalytic performance of the Fischer-Tropsch (F-T synthesis was investigated. The pretreated catalyst at 220°C with unique phase structure exhibited best catalytic activity and selectivity among three pretreated catalysts. Moreover, the catalysts exhibited high dispersion due to the formation of hydrogen bonds between the cluster precursor and γ-Al2O3 support.

Synthesis of Fischer carbene complexes of iridium by C-H bond activation of methyl and cyclic ethers: Evidence for reversible {alpha}-hydrogen migration

Energy Technology Data Exchange (ETDEWEB)

Luecke, H.F.; Arndtsen, B.A.; Burger, P.; Bergman, R.G. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

1996-03-13

We report here a mild and versatile route to Fischer carbene complexes of iridium via the activation of C-H bonds of methyl and cyclic ethers, along with our preliminary studies of this rare family of carbene complexes. Theoretical studies suggest that {alpha}-hydrogen migrations can be kinetically favorable if a coordinatively unsaturated species can be accessed. Thus, the lability of the triflate ligand presumably facilitates this process. Further evidence for the rapidity, as well as reversibility, of this rearrangement was obtained by NMR analysis. 20 refs.

Influence of liquid medium on the activity of a low-alpha Fischer-Tropsch catalyst

Energy Technology Data Exchange (ETDEWEB)

Gormley, R.J.; Zarochak, M.F.; Deffenbaugh, P.W.; Rao, K.R.P.M.

1995-12-31

The purpose of this research was to measure activity, selectivity, and the maintenance of these properties in slurry autoclave experiments with a Fischer-Tropsch (FT) catalyst that was used in the {open_quotes}FT II{close_quotes} bubble-column test, conducted at the Alternative Fuels Development Unit (AFDU) at LaPorte, Texas during May 1994. The catalyst contained iron, copper, and potassium and was formulated to produce mainly hydrocarbons in the gasoline range with lesser production of diesel-range products and wax. The probability of chain growth was thus deliberately kept low. Principal goals of the autoclave work have been to find the true activity of this catalyst in a stirred tank reactor, unhindered by heat or mass transfer effects, and to obtain a steady conversion and selectivity over the approximately 15 days of each test. Slurry autoclave testing of the catalyst in heavier waxes also allows insight into operation of larger slurry bubble column reactors. The stability of reactor operation in these experiments, particularly at loadings exceeding 20 weight %, suggests the likely stability of operations on a larger scale.

Incorporation of catalytic dehydrogenation into Fischer-Tropsch synthesis to lower carbon dioxide emissions

Science.gov (United States)

Huffman, Gerald P

2012-09-18

A method for producing liquid fuels includes the steps of gasifying a starting material selected from a group consisting of coal, biomass, carbon nanotubes and mixtures thereof to produce a syngas, subjecting that syngas to Fischer-Tropsch synthesis (FTS) to produce a hyrdrocarbon product stream, separating that hydrocarbon product stream into C1-C4 hydrocarbons and C5+ hydrocarbons to be used as liquid fuels and subjecting the C1-C4 hydrocarbons to catalytic dehydrogenation (CDH) to produce hydrogen and carbon nanotubes. The hydrogen produced by CDH is recycled to be mixed with the syngas incident to the FTS reactor in order to raise the hydrogen to carbon monoxide ratio of the syngas to values of 2 or higher, which is required to produce liquid hydrocarbon fuels. This is accomplished with little or no production of carbon dioxide, a greenhouse gas. The carbon is captured in the form of a potentially valuable by-product, multi-walled carbon nanotubes (MWNT), while huge emissions of carbon dioxide are avoided and very large quantities of water employed for the water-gas shift in traditional FTS systems are saved.

Correlation between Fischer-Tropsch catalytic activity and composition of catalysts

Directory of Open Access Journals (Sweden)

Subbarao Duvvuri

2011-11-01

Full Text Available Abstract This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on alumina. The catalysts were prepared by a wet impregnation method. Samples were characterized using temperature-programmed reduction (TPR, temperature-programmed oxidation (TPO, CO-chemisorption, transmission electron microscopy (TEM, field emission scanning electron microscopy (FESEM-EDX and N2-adsorption analysis. Fischer-Tropsch synthesis (FTS was carried out in a fixed-bed microreactor at 543 K and 1 atm, with H2/CO = 2 v/v and space velocity, SV = 12L/g.h. The physicochemical properties and the FTS activity of the bimetallic catalysts were analyzed and compared with those of monometallic cobalt and iron catalysts at similar operating conditions. H2-TPR analysis of cobalt catalyst indicated three temperature regions at 506°C (low, 650°C (medium and 731°C (high. The incorporation of iron up to 30% into cobalt catalysts increased the reduction, CO chemisorption and number of cobalt active sites of the catalyst while an opposite trend was observed for the iron-riched bimetallic catalysts. The CO conversion was 6.3% and 4.6%, over the monometallic cobalt and iron catalysts, respectively. Bimetallic catalysts enhanced the CO conversion. Amongst the catalysts studied, bimetallic catalyst with the composition of 70Co30Fe showed the highest CO conversion (8.1% while exhibiting the same product selectivity as that of monometallic Co catalyst. Monometallic iron catalyst showed the lowest selectivity for C5+ hydrocarbons (1.6%.

Fischer-Tropsch synthesis in a two-phase reactor with presaturation

Energy Technology Data Exchange (ETDEWEB)

Wache, W. [Bayernoil Raffineriegesellschaft mbH, Ingolstadt (Germany); Datsevich, L.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

2006-07-01

In industry, the Fischer-Tropsch (FTS) synthesis is mostly carried out in multiphase slurry or multitubular reactors (MTR), where gaseous reactants and liquid products (hydrocarbons up to waxes) are contacted in the presence of a solid catalyst. Such reactors are characterized by a complex temperature control, necessity of gas recycling, complicated design and problematic scale-up. A new alternative to conventional FTS-processes is the presaturated-one-liquid-phase (POLF) technology. The basic principle of this concept is a recirculation of the liquid phase, in which a gaseous reactant(s) is (are) solved before entering the fixed-bed reactor. In a simple column reactor, this technology ensures the effective heat removal and intensive fluid-solid mass transfer. In comparison to conventional reactors, the plant design is very simple, the temperature control is uncomplicated and there is no danger of any runaways. That results in lower investment and operation costs as well as in higher reliability. The experiments show that the conversion of CO and the product distribution of hydrocarbons are practically independent on the mode of operation (two- or three-phase system). However, in the lab-scale apparatus, water is accumulated in the loop, which leads to a loss of the catalyst activity (due to Fe-carbonate). In a technical process, the water accumulation in a loop can be eluded by taking an oil free of water from the oil work-up unit. Our experiments with the removal of water from the stream by a zeolite demonstrate a much promising applicability of the POLF process to the industrial FTS. (orig.)

Evidence for H2/D2 isotope effects on Fischer-Tropsch synthesis over supported ruthenium catalysts

International Nuclear Information System (INIS)

Kellner, C.S.; Bell, A.T.

1981-01-01

The effects of using D 2 rather than H 2 during Fischer-Tropsch synthesis were investigated using alumina- and silica-supported Ru catalysts. For the alumina-supported catalysts, the rate of CD 4 formation was 1.4 to 1.6 times faster than the formation of CH 4 . A noticeable isotope effect was also observed for higher molecular weight products. The magnitude of the isotope effects observed using the silica-supported catalyst was much smaller than that found using the alumina-supported catalysts. The formation of olefins relative to paraffins was found to be higher when H 2 rather than D 2 was used, independent of the catalyst support. The observed isotope effects are explained in terms of a mechanism for CO hydrogenation and are shown to arise from a complex combination of the kinetic and equilibrium isotope effects associated with elementary processes occurring on the catalyst surface

Enhancing the properties of Fischer-Tropsch fuel produced from syngas over Co/SiO2 catalyst: Lubricity and Calorific Value

Science.gov (United States)

Doustdar, O.; Wyszynski, M. L.; Mahmoudi, H.; Tsolakis, A.

2016-09-01

Bio-fuel produced from renewable sources is considered the most viable alternatives for the replacement of mineral diesel fuel in compression ignition engines. There are several options for biomass derived fuels production involving chemical, biological and thermochemical processes. One of the best options is Fischer Tropsch Synthesis, which has an extensive history of gasoline and diesel production from coal and natural gas. FTS fuel could be one of the best solutions to the fuel emission due to its high quality. FTS experiments were carried out in 16 different operation conditions. Mini structured vertical downdraft fixed bed reactor was used for the FTS. Instead of Biomass gasification, a simulated N2 -rich syngas cylinder of, 33% H2 and 50% N2 was used. FT fuels products were analyzed in GCMS to find the hydrocarbon distributions of FT fuel. Calorific value and lubricity of liquid FT product were measured and compared with commercial diesel fuel. Lubricity has become an important quality, particularly for biodiesel, due to higher pressures in new diesel fuel injection (DFI) technology which demands better lubrication from the fuel and calorific value which is amount of energy released in combustion paly very important role in CI engines. Results show that prepared FT fuel has desirable properties and it complies with standard values. FT samples lubricities as measured by ASTM D6079 standard vary from 286μm (HFRR scar diameter) to 417μm which are less than limit of 520μm. Net Calorific value for FT fuels vary from 9.89 MJ/kg to 43.29 MJ/kg, with six of the samples less than EN 14213 limit of 35MJ/kg. Effect of reaction condition on FT fuel properties was investigated which illustrates that in higher pressure Fischer-Tropsch reaction condition liquid product has better properties.

Toxicity of inhaled 239PuO2 in Fischer 344 rats

International Nuclear Information System (INIS)

Redman, H.C.; Boecker, B.B.; Muggenburg, B.A.; Griffith, W.C.; Guilmette, R.A.; Mewhinney, J.A.; Scott, B.R.

1979-01-01

Studies on the biological effects of inhaled particles of 239 PuO 2 have been initiated in the Fischer 344 rat. To obtain information on the importance of homogeneity or nonhomogeneity of radiation dose to the lung, young adult (84 +- 7 days) animals have been exposed to monodisperse aerosols (sigma/sub g/ 239 PuO 2 of 1.0 and 2.8 μm aerodynamic diameter (AD). To determine the effects of age at exposure, aged rats (600 to 660 days) have been exposed to monodisperse aerosols of 239 PuO 2 of 1.0 μm aerodynamic diameter. To date, 480 young adult rats have been exposed to 239 PuO 2 : 240 rats to 1.0 μm AD particles and 240 rats to 2.85 μm AD particles. The projected exposure level ranged from 0.012 to 0.115 μCi/kg body weight. One hundred sixty rats were sham-exposed and maintained as controls. Also, 240 aged rats have been exposed to date to 1.0 μm AD particles of 239 PuO 2 . The projected activity level ranged from 0.012 to 0.115 μCi/kg body weight. Eighty rats were sham-exposed and maintained as controls. In addition, a serial sacrifice study to determine radiation-dose pattern in rats resulting from the inhalation of these monodisperse aerosols of 239 PuO 2 has been initiated in the young adult rat

The role of mitochondrial DNA large deletion for the development of presbycusis in Fischer 344 rats.

Science.gov (United States)

Yin, Shankai; Yu, Zhiping; Sockalingam, Ravi; Bance, Manohar; Sun, Genlou; Wang, Jian

2007-09-01

Age-related hearing loss, or presbycusis, has been associated with large-scale mitochondrial DNA (mtDNA) deletion in previous studies. However, the role of this mtDNA damage in presbycusis is still not clear because the deletion in inner ears has not been measured quantitatively and analyzed in parallel with the time course of presbycusis. In the present study, the deletion was quantified using quantitative real-time PCR (qRT-PCR) in male Fischer 344 rats of different ages. It was found that the deletion increased quickly during young adulthood and reached over 60% at 6 months of age. However, a significant hearing loss was not seen until after 12 months of age. The results suggest that the existence of the deletion per se does not necessarily imply cochlear damage, but rather a critical level of the accumulated deletion seems to precede the hearing loss. The long delay may indicate the involvement of mechanisms other than mtDNA deletion in the development of presbycusis.

The Natural History of Pneumonic Tularemia in Female Fischer 344 Rats after Inhalational Exposure to Aerosolized Francisella tularensis Subspecies tularensis Strain SCHU S4.

Science.gov (United States)

Hutt, Julie A; Lovchik, Julie A; Dekonenko, Alexander; Hahn, Andrew C; Wu, Terry H

2017-02-01

The inbred Fischer 344 rat is being evaluated for testing novel vaccines and therapeutics against pneumonic tularemia. Although primary pneumonic tularemia in humans typically occurs by inhalation of aerosolized bacteria, the rat model has relied on intratracheal inoculation of organisms because of safety and equipment issues. We now report the natural history of pneumonic tularemia in female Fischer 344 rats after nose-only inhalational exposure to lethal doses of aerosolized Francisella tularensis subspecies tularensis, strain SCHU S4. Our results are consistent with initial uptake of aerosolized SCHU S4 from the nasal cavity, lungs, and possibly the gastrointestinal tract. Bacteremia with hematogenous dissemination was first detected 2 days after exposure. Shortly thereafter, the infected rats exhibited fever, tachypnea, and hypertension that persisted for 24 to 36 hours and then rapidly decreased as animals succumbed to infection between days 5 and 8 after exposure. Tachycardia was observed briefly, but only after the core body temperature and blood pressure began to decrease as the animals were near death. Initial neutrophilic and histiocytic inflammation in affected tissues became progressively more fibrinous and necrotizing over time. At death, as many as 10 10 colony-forming units were found in the lungs, spleen, and liver. Death was attributed to sepsis and disseminated intravascular coagulation. Overall, the pathogenesis of pneumonic tularemia in the female F344 rat model appears to replicate the disease in humans. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

How to make Fischer-Tropsch catalyst scale-up fully reliable?

Energy Technology Data Exchange (ETDEWEB)

Fischer, L.; Heraud, J.P.; Forret, A.; Gazarian, J. [IFP Energies nouvelles, Solaize (France); Cornaro, U. [Eni S.p.A., San Donato Milanese (Italy). R and M Div.; Carugati, A. [Eni S.p.A., San Donato Milanese (Italy). E and P Div.

2011-07-01

Several players use Fischer-Tropsch catalysts and technologies industrially [1,2] or declare to be ready for industrial application [e.g. 3]. Present R and D aims to further increase capacities per train [4] or improve catalyst selectivity towards middle distillates [5]. For transforming promising laboratory results into industrial reality, representative catalyst testing is of particular importance for slurry bubble column FT. In the Italian eni's refinery of Sannazzaro, a 20 BPD slurry bubble column pilot plant has cumulated more than 20,000 hours time on stream in different campaigns. Non reactive slurry bubble columns corresponding to reactor capacities between 20 BPD and 1000 BPD permitted to determine the profiles for gas hold up and liquid velocities as a function of gas flow, catalyst loading, reactor diameter and internals. A hydrodynamic model based on those data led to design a Large Validation Tool, which can reproduce under reaction conditions a high mechanical stress on the catalyst equivalent to the one experienced in an industrial 15000 BPD reactor. While those tools have proven to be efficient for developing an industrial scale FT catalyst [3], they predict today in a representative manner fines formation, activity and selectivity of improved catalysts and / or for optimization of operation conditions to increase the capacity per train. We compare the here presented approach to others. We have found that it is mandatory to combine chemical stress from the reaction products with mechanical stress as experienced in an industrial slurry bubble column, in order to evaluate in a reliable way catalyst performance stability and fines formation. The potential of improvements are discussed. (orig.)

Effect of Manganese Promotion on Al-Pillared Montmorillonite Supported Cobalt Nanoparticles for Fischer-Tropsch Synthesis

International Nuclear Information System (INIS)

Ahmad, N.; Hussain, S. T.; Abbas, S. M.; Khan, Y.; Muhammad, B.; Ali, N.

2013-01-01

The effect of Mn-promotion on high surface area Al-pillared montmorillonite (AlMMT) supported Co nanoparticles prepared by hydrothermal method have been investigated. A series of different weight% Mn-promoted Co nanoparticles were prepared and characterized by XRD, TPR, TGA, BET and SEM techniques. An increase in the surface area of MMT is observed with Al-pillaring. Fischer-Tropsch catalytic activity of the as prepared catalysts was studied in a fixed bed micro reactor at 225 .deg. C, H 2 /CO = 2 and at 1 atm pressure. The data showed that by the addition of Mn the selectivity of C 1 dropped drastically while that of C 2 -C 12 hydrocarbons increased significantly over all the Mn-promoted Co/AlMMT catalysts. The C 13 -C 20 hydrocarbons remained almost same for all the catalysts while the selectivity of C 21+ long chain hydrocarbons decreased considerably with the addition of Mn. The catalyst with 3.5%Mn showed lowest C 21+ and highest C 2 -C 12 hydrocarbons selectivity due to cracking of long chain hydrocarbons over acidic sites of MMT

Biosyngas Fischer. Tropsch conversion by high Fe loaded supported catalysts prepared with ultrasound and microwave

Energy Technology Data Exchange (ETDEWEB)

Pirola, C.; Di Fronzo, A.; Boffito, D.C.; Bianchi, C. [Milano Univ. (Italy). Dipt. di Chimica; Di Michele, A. [Perugia Univ. (Italy). Dipt. di Fisica

2012-07-01

Catalysts with iron high loading of 30 wt%, promoted with K (2.0 wt%) and Cu (3.75 wt%), have been synthesized according to three different methods: (1) the traditional impregnation method (TR); (2) Ultrasound (US) assisted TR method; (3) Microwave (MW) assisted TR method. All the samples have been fully characterized by BET, ICP/OES, XRPD, TG-DTA, FT-IR, TPR, SEM and TEM and tested in a laboratory pilot plant for Fischer-Tropsch synthesis working at 220 C and 20 bar. The results of the catalysts characterization indicated that the morphology of the samples strongly depends on the method of preparation. The best FTS results in term of C{sub 2+} yield (41%) has been obtained using MW with a good value of the selectivity towards heavy hydrocarbons, while in term of CO conversion (58%), using US. The samples prepared with non-traditional methods show FTS better results, probably due to a more wide and uniform distribution of Fe in the medium during the synthesis phase. (orig.)

Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

Energy Technology Data Exchange (ETDEWEB)

Gangwal, Santosh K. [Southern Research Institute, Durham, NC (United States); McCabe, Kevin [Southern Research Institute, Durham, NC (United States)

2015-04-30

The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIG^TM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H₂/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

Deactivation and Regeneration of Commercial Type Fischer-Tropsch Co-Catalysts—A Mini-Review

Directory of Open Access Journals (Sweden)

Erling Rytter

2015-03-01

Full Text Available Deactivation of commercially relevant cobalt catalysts for Low Temperature Fischer-Tropsch (LTFT synthesis is discussed with a focus on the two main long-term deactivation mechanisms proposed: Carbon deposits covering the catalytic surface and re-oxidation of the cobalt metal. There is a great variety in commercial, demonstration or pilot LTFT operations in terms of reactor systems employed, catalyst formulations and process conditions. Lack of sufficient data makes it difficult to correlate the deactivation mechanism with the actual process and catalyst design. It is well known that long term catalyst deactivation is sensitive to the conditions the actual catalyst experiences in the reactor. Therefore, great care should be taken during start-up, shutdown and upsets to monitor and control process variables such as reactant concentrations, pressure and temperature which greatly affect deactivation mechanism and rate. Nevertheless, evidence so far shows that carbon deposition is the main long-term deactivation mechanism for most LTFT operations. It is intriguing that some reports indicate a low deactivation rate for multi-channel micro-reactors. In situ rejuvenation and regeneration of Co catalysts are economically necessary for extending their life to several years. The review covers information from open sources, but with a particular focus on patent literature.

Influence of Reduction Promoters on Stability of Cobalt/g-Alumina Fischer-Tropsch Synthesis Catalysts

Directory of Open Access Journals (Sweden)

Gary Jacobs

2014-03-01

Full Text Available This focused review article underscores how metal reduction promoters can impact deactivation phenomena associated with cobalt Fischer-Tropsch synthesis catalysts. Promoters can exacerbate sintering if the additional cobalt metal clusters, formed as a result of the promoting effect, are in close proximity at the nanoscale to other cobalt particles on the surface. Recent efforts have shown that when promoters are used to facilitate the reduction of small crystallites with the aim of increasing surface Co0 site densities (e.g., in research catalysts, ultra-small crystallites (e.g., <2–4.4 nm formed are more susceptible to oxidation at high conversion relative to larger ones. The choice of promoter is important, as certain metals (e.g., Au that promote cobalt oxide reduction can separate from cobalt during oxidation-reduction (regeneration cycles. Finally, some elements have been identified to promote reduction but either poison the surface of Co0 (e.g., Cu, or produce excessive light gas selectivity (e.g., Cu and Pd, or Au at high loading. Computational studies indicate that certain promoters may inhibit polymeric C formation by hindering C-C coupling.

Development of the Fischer-Tropsch Process: From the Reaction Concept to the Process Book

Directory of Open Access Journals (Sweden)

Boyer C.

2016-05-01

Full Text Available The process development by IFP Energies nouvelles (IFPEN/ENI/Axens of a Fischer-Tropsch process is described. This development is based on upstream process studies to choose the process scheme, reactor technology and operating conditions, and downstream to summarize all development work in a process guide. A large amount of work was devoted to the catalyst performances on one hand and the scale-up of the slurry bubble reactor with dedicated complementary tools on the other hand. Finally, an original approach was implemented to validate both the process and catalyst on an industrial scale by combining a 20 bpd unit in ENI’s Sannazzaro refinery, with cold mock-ups equivalent to 20 and 1 000 bpd at IFPEN and a special “Large Validation Tool” (LVT which reproduces the combined effect of chemical reaction condition stress and mechanical stress equivalent to a 15 000 bpd industrial unit. Dedicated analytical techniques and a dedicated model were developed to simulate the whole process (reactor and separation train, integrating a high level of complexity and phenomena coupling to scale-up the process in a robust reliable base on an industrial scale.

Study of (Fe/HZM-5) catalyst be used in the Fischer-Tropsch synthesis: preparation and characterization; Estudo do catalisador (Fe/HZSM-5) a ser utilizado na sintese de Fischer-Tropsch: preparacao e caracterizacao

Energy Technology Data Exchange (ETDEWEB)

Gonzaga, Arthur C. [Universidade Estadual do Maranhao (UEMA0), MA (Brazil); Sousa, Bianca V. de; Lima, Wellington S.; Rodrigues, Meiry G.F. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia Quimica

2008-07-01

In this work it was developed an iron catalyst supported on the ZSM-5 zeolite to be used in the Fischer-Tropsch Synthesis (FTS). The NH{sub 4}{sup +}ZSM-5 zeolitic support was submitted to the wet impregnation, using the 0.1 M of the Fe(NO{sub 3}){sub 3}.9H{sub 2}O solution to obtain the Fe/NH{sub 4}{sup +}ZSM-5 sample in the content of iron 5% wt. After, the material was submitted for the drying process and in the following, for the calcination one, obtaining the Fe/HZSM-5 form. The EDS characterization analyses showed that in the Fe/HZSM-5 sample the iron is in the Fe{sub 2}O{sub 3} form and that the impregnation and calcination processes did not cause significant exchanges in the zeolitic support framework. The results of the N{sub 2} physical adsorption of the 5% Fe/HZSM-5 showed the presence of the micropores and mesopores. From these results, the obtained material (5% Fe/HZSM-5) presents a great potential to be used like a catalyst in the FTS. (author)

On the Real Exchange Rate as a Measure of Australia’s External Competitiveness

OpenAIRE

Layton, A.P.; McLaren, J.

1991-01-01

The use of a country’s real effective exchange rate as a measure of external competitiveness implicitly assumes that, in the long run, purchasing power parity prevails between the country and its trading partners [Dornbusch (1985)]. A testable definition of long run equilibrium existing among non-stationary time series is provided in the recently developed theory of cointegration [Engle and Granger (1987)]. The paper extends earlier U.S. work in this area by Layton and Stark (1990) by investi...

Development of an Innovative XRD-DRIFTS Prototype Allowing Operando Characterizations during Fischer-Tropsch Synthesis over Cobalt-Based Catalysts under Representative Conditions

Directory of Open Access Journals (Sweden)

Scalbert Julien

2015-03-01

Full Text Available An original system combining both X-Ray Diffraction and diffuse reflectance infrared Fourier transform spectroscopy was developed with the aim to characterize Fischer-Tropsch catalysts in relevant reaction conditions. The catalytic properties of a model PtCo/silica catalyst tested with this prototype have shown to be in the same range of those obtained in similar conditions with classical fixed-bed reactors. No bulk cobalt oxidation nor sintering were observed on operando XRD patterns. The formation of linear carbonyls and adsorbed hydrocarbons species at the surface of the catalyst was observed on operando DRIFT spectra. The surface of the catalyst was also suspected to be covered with carbon species inducing unfavorable changes in selectivity.

Aging influences multiple indices of oxidative stress in the heart of the Fischer 344/NNia x Brown Norway/BiNia rat.

Science.gov (United States)

Asano, Shinichi; Rice, Kevin M; Kakarla, Sunil; Katta, Anjaiah; Desai, Devashish H; Walker, Ernest M; Wehner, Paulette; Blough, Eric R

2007-01-01

We report the influence of aging on multiple markers of oxidative-nitrosative stress in the heart of adult (6-month), aged (30-month) and very aged (36-month) Fischer 344/NNiaHSd x Brown Norway/BiNia (F344/NXBN) rats. Compared to adult (6-month) hearts, indices of oxidative (superoxide anion [O2*-], 4-hydroxy-2-nonenal [4-HNE]) and nitrosative (protein nitrotyrosylation) stress were 34.1 +/- 28.1%, 186 +/- 28.1% and 94 +/- 5.8% higher, respectively, in 36-month hearts and these findings were highly correlated with increases in left ventricular wall thickness (r > 0.669; r > 0.710 and P lead to age-associated alterations in cardiac oxidative stress.

Performance characterization of CNTs and γ-Al2O3 supported cobalt catalysts in Fischer-Tropsch reaction

International Nuclear Information System (INIS)

Ali, Sardar; Zabidi, Noor Asmawati Mohd; Subbarao, Duvvuri

2014-01-01

Catalysts were prepared via a wet impregnation method. Different physicochemical properties of the samples were revealed by transmission electron microscope (TEM), temperature programmed reduction (H 2 -TPR) and carbon dioxide desorption (CO 2 -desorption). Fischer-Tropsch reaction (FTS) was carried out in a fixed-bed microreactor at 220°C and 1 atm, with H 2 /CO = 2v/v and space velocity, SV of 12L/g.h for 5 h. Various characterization techniques revealed that there was a stronger interaction between Co and Al 2 O 3 support compared to that of CNTs support. CNTs support increased the reducibility and decreased Co particle size. A significant increase in % CO conversion and FTS reaction rate was observed over CNTs support compared to that of Co/Al 2 O 3 . Co/CNTs resulted in higher C 5+ hydrocarbons selectivity compared to that of Co/Al 2 O 3 catalyst. CNTs are a better support for Co compared to Al 2 O 3

A combined in situ XAS-XRPD-Raman study of Fischer-Tropsch synthesis over a carbon supported Co catalyst

DEFF Research Database (Denmark)

Tsakoumis, Nikolaos E.; Dehghan, Roya; Johnsen, Rune

2013-01-01

A cobalt based Fischer-Tropsch synthesis (FTS) catalyst, supported on a carbon nanofibers/carbon felt composite (Co/CNF/CF) was studied in situ at realistic conditions. The catalyst was monitored by Xray absorption spectroscopy (XAS), high-resolution X-ray powder diffraction (HR-XRPD) and Raman...... spectroscopy, while changes in the gas phase were observed by mass spectrometry (MS). Transmission electron microscopy (TEM) was also applied to characterise the catalyst. The catalyst has a bimodal particle size distribution and exhibits a high deactivation rate. During the in situ study the catalyst appears...... to reduce further at the induction period of FTS, while crystallite growth is been detected in the same period. At steady state FTS the amount of metallic Co is constant. A change in the volumetric flow towards higher conversions did not affect the degree of reduction or the crystallite size of the catalyst...

Potential for Coal-to-Liquids Conversion in the United States-Fischer-Tropsch Synthesis

International Nuclear Information System (INIS)

Patzek, Tad W.; Croft, Gregory D.

2009-01-01

The United States has the world's largest coal reserves and Montana the highest potential for mega-mine development. Consequently, a large-scale effort to convert coal to liquids (CTL) has been proposed to create a major source of domestic transportation fuels from coal, and some prominent Montanans want to be at the center of that effort. We calculate that the energy efficiency of the best existing Fischer-Tropsch (FT) process applied to average coal in Montana is less than 1/2 of the corresponding efficiency of an average crude oil refining process. The resulting CO 2 emissions are 20 times (2000%) higher for CTL than for conventional petroleum products. One barrel of the FT fuel requires roughly 800 kg of coal and 800 kg of water. The minimum energy cost of subsurface CO 2 sequestration would be at least 40% of the FT fuel energy, essentially halving energy efficiency of the process. We argue therefore that CTL conversion is not the most valuable use for the coal, nor will it ever be, as long as it is economical to use natural gas for electric power generation. This finding results from the low efficiency inherent in FT synthesis, and is independent of the monumental FT plant construction costs, mine construction costs, acute lack of water, and the associated environmental impacts for Montana

Fischer's Plants in folk beliefs and customs: a previously unknown contribution to the ethnobotany of the Polish-Lithuanian-Belarusian borderland.

Science.gov (United States)

Kujawska, Monika; Klepacki, Piotr; Łuczaj, Łukasz

2017-03-23

Historical ethnobotanical studies are useful starting points for further diachronic analysis. The aim of this contribution is to present archival data from the Polish-Lithuanian-Belarusian borderland, which were collected by Adam Fischer, a Polish ethnographer from Lviv, in the 1930s. These data were originally gathered for publication in the first part of the Lexicon of Slavic beliefs and customs, dedicated to plant uses in traditional Slavonic culture. It was intended to be a joint international enterprise, but was never actually fulfilled. In this article we used information from historical Lithuania (the Great Duchy of Lithuania), nowadays a border region between Poland, Lithuania and Belarus. We applied cultural importance indices such as Use Value, Relative Importance value and Sørensen similarity coefficient, in order to compare our data with a western Ukraine data set from the same research framework. In total, 153 plant taxa were registered as used in peasant culture in the Polish-Lithuanian-Belarusian borderland in the 1930s. The species which achieved the highest Use Values were: Calendula officinalis, Cyanus segetum, Helichrysum arenarium, Betula sp., Prunella vulgaris, and Nuphar lutea or Lilium sp. The most salient use categories were medicinal, followed by food and home garden plants. The overall similarity to plants recorded in western Ukraine within the same project of Fischer's is quite low (46%), which may be explained by the partly different flora found in the regions, and a cultural discontinuity, revealed by the difference in species with the highest UV. Moreover, the field collaborators were different in the two regions and may have paid attention to different cultural spheres of use. The presented ethnobotanical data are a valuable contribution to the ethnobotany of Eastern Europe as a whole. In particular, the presented list of plants may be a rich source for future studies on the ethnobotany of the Polish diaspora in Lithuania, and

Grape Powder Improves Age-Related Decline in Mitochondrial and Kidney Functions in Fischer 344 Rats

Directory of Open Access Journals (Sweden)

Indira Pokkunuri

2016-01-01

Full Text Available We examined the effects and mechanism of grape powder- (GP- mediated improvement, if any, on aging kidney function. Adult (3-month and aged (21-month Fischer 344 rats were treated without (controls and with GP (1.5% in drinking water and kidney parameters were measured. Control aged rats showed higher levels of proteinuria and urinary kidney injury molecule-1 (KIM-1, which decreased with GP treatment in these rats. Renal protein carbonyls (protein oxidation and gp91phox-NADPH oxidase levels were high in control aged rats, suggesting oxidative stress burden in these rats. GP treatment in aged rats restored these parameters to the levels of adult rats. Moreover, glomerular filtration rate and sodium excretion were low in control aged rats suggesting compromised kidney function, which improved with GP treatment in aged rats. Interestingly, low renal mitochondrial respiration and ATP levels in control aged rats were associated with reduced levels of mitochondrial biogenesis marker MtTFA. Also, Nrf2 proteins levels were reduced in control aged rats. GP treatment increased levels of MtTFA and Nrf2 in aged rats. These results suggest that GP by potentially regulating Nrf2 improves aging mitochondrial and kidney functions.

X-ray physico-chemical imaging during activation of cobalt-based Fischer-Tropsch synthesis catalysts

Science.gov (United States)

Beale, Andrew M.; Jacques, Simon D. M.; Di Michiel, Marco; Mosselmans, J. Frederick W.; Price, Stephen W. T.; Senecal, Pierre; Vamvakeros, Antonios; Paterson, James

2017-11-01

The imaging of catalysts and other functional materials under reaction conditions has advanced significantly in recent years. The combination of the computed tomography (CT) approach with methods such as X-ray diffraction (XRD), X-ray fluorescence (XRF) and X-ray absorption near-edge spectroscopy (XANES) now enables local chemical and physical state information to be extracted from within the interiors of intact materials which are, by accident or design, inhomogeneous. In this work, we follow the phase evolution during the initial reduction step(s) to form Co metal, for Co-containing particles employed as Fischer-Tropsch synthesis (FTS) catalysts; firstly, working at small length scales (approx. micrometre spatial resolution), a combination of sample size and density allows for transmission of comparatively low energy signals enabling the recording of `multimodal' tomography, i.e. simultaneous XRF-CT, XANES-CT and XRD-CT. Subsequently, we show high-energy XRD-CT can be employed to reveal extent of reduction and uniformity of crystallite size on millimetre-sized TiO2 trilobes. In both studies, the CoO phase is seen to persist or else evolve under particular operating conditions and we speculate as to why this is observed. This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

Anthocyanin-Rich Juice Lowers Serum Cholesterol, Leptin, and Resistin and Improves Plasma Fatty Acid Composition in Fischer Rats.

Directory of Open Access Journals (Sweden)

Daniela Graf

Full Text Available Obesity and obesity-associated diseases e.g. cardiovascular diseases and type 2 diabetes are spread worldwide. Anthocyanins are supposed to have health-promoting properties, although convincing evidence is lacking. The aim of the present study was to investigate the effect of anthocyanins on several risk factors for obesity-associated diseases. Therefore, Fischer rats were fed anthocyanin-rich grape-bilberry juice or an anthocyanin-depleted control juice for 10 weeks. Intervention with anthocyanin-rich grape-bilberry juice reduced serum cholesterol and tended to decrease serum triglycerides. No effects were seen for serum non-esterified fatty acids, glucose, and insulin. Anthocyanin-rich grape-bilberry juice intervention reduced serum leptin and resistin, but showed no influence on serum adiponectin and secretion of adipokines from mesenteric adipose tissue. Furthermore, anthocyanin-rich grape-bilberry juice increased the proportion of polyunsaturated fatty acids and decreased the amount of saturated fatty acids in plasma. These results indicate that anthocyanins possess a preventive potential for obesity-associated diseases.

Raising distillate selectivity and catalyst life time in Fischer-Tropsch synthesis by using a novel dual-bed reactor

International Nuclear Information System (INIS)

Tavasoli, A.; Sadaghiani, K.; Khodadadi, A. A.; Mortazavi, Y.

2007-01-01

In a novel dual bed reactor Fischer-Tropsch synthesis was studied by using two diff rent cobalt catalysts. An alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a Raiment promoted cobalt catalyst in the second bed. The activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed reactor system. The methane selectivity in the dual-bed reactor was about 18.9% less compared to that of the single-bed reactor. The C 5+ selectivity for the dual-bed reactor was 10.9% higher than that of the single-bed reactor. Accelerated deactivation of the catalysts in the dual-bed reactor was 42% lower than that of the single-bed reactor. It was revealed that the amount of catalysts activity recovery after regeneration at 400 d eg C in the dual-bed system is higher than that of the single-bed system

Appraisal of the Fischer-DiPasquale-Wheaton (FDW real estate model and development of an integrated property and asset market model

Directory of Open Access Journals (Sweden)

H Du Toit

2004-04-01

Full Text Available This paper provides a concise overview of the development of an integrated property and asset market model (IPAMM for South African property markets, utilising the Pretoria office market as case study. The IPAMM simulates the interrelationships between property and asset markets in a diagrammatic quadrant model configuration. The Fischer-DiPasquale-Wheaton (FDW real estate model, arguably the most advanced diagrammatic quadrant real estate model available at present, served as basis for the development of IPAMM. IPAMM is essentially a regression model based on a system of stochastic equations that captures the interrelationships between property and asset markets. The model advances beyond mere conceptualisation of these relationships to a quantified interpretation and application of the theoretical premises that represent the micro-foundations of economic behaviour in property and asset markets.

Baseline design/economics for advanced Fischer-Tropsch technology. Quarterly report, January--March 1992

Energy Technology Data Exchange (ETDEWEB)

1992-09-01

The objectives of the study are to: Develop a baseline design for indirect liquefaction using advanced Fischer-Tropsch (F-T) technology. Prepare the capital and operating costs for the baseline design. Develop a process flow sheet simulation (PFS) model. This report summarizes the activities completed during the period December 23, 1992 through March 15, 1992. In Task 1, Baseline Design and Alternates, the following activities related to the tradeoff studies were completed: approach and basis; oxygen purity; F-T reactor pressure; wax yield; autothermal reformer; hydrocarbons (C{sub 3}/C{sub 4}s) recovery; and hydrogenrecovery. In Task 3, Engineering Design Criteria, activities were initiated to support the process tradeoff studies in Task I and to develop the environmental strategy for the Illinois site. The work completed to date consists of the development of the F-T reactor yield correlation from the Mobil dam and a brief review of the environmental strategy prepared for the same site in the direct liquefaction baseline study.Some work has also been done in establishing site-related criteria, in establishing the maximum vessel diameter for train sizing and in coping with the low H{sub 2}/CO ratio from the Shell gasifier. In Task 7, Project Management and Administration, the following activities were completed: the subcontract agreement between Amoco and Bechtel was negotiated; a first technical progress meeting was held at the Bechtel office in February; and the final Project Management Plan was approved by PETC and issued in March 1992.

Pyrolysis-GCMS Analysis of Solid Organic Products from Catalytic Fischer-Tropsch Synthesis Experiments

Science.gov (United States)

Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

2015-01-01

Abiotic synthesis of complex organic compounds in the early solar nebula that formed our solar system is hypothesized to occur via a Fischer-Tropsch type (FTT) synthesis involving the reaction of hydrogen and carbon monoxide gases over metal and metal oxide catalysts. In general, at low temperatures (less than 200 C), FTT synthesis is expected to form abundant alkane compounds while at higher temperatures (greater than 200 C) it is expected to product lesser amounts of n-alkanes and greater amounts of alkene, alcohol, and polycyclic aromatic hydrocarbons (PAHs). Experiments utilizing a closed-gas circulation system to study the effects of FTT reaction temperature, catalysts, and number of experimental cycles on the resulting solid insoluble organic products are being performed in the laboratory at NASA Goddard Space Flight Center. These experiments aim to determine whether or not FTT reactions on grain surfaces in the protosolar nebula could be the source of the insoluble organic matter observed in meteorites. The resulting solid organic products are being analyzed at NASA Johnson Space Center by pyrolysis gas chromatography mass spectrometry (PY-GCMS). PY-GCMS yields the types and distribution of organic compounds released from the insoluble organic matter generated from the FTT reactions. Previously, exploratory work utilizing PY-GCMS to characterize the deposited organic materials from these reactions has been reported. Presented here are new organic analyses using magnetite catalyst to produce solid insoluble organic FTT products with varying reaction temperatures and number of experimental cycles.

Metabolism and disposition of ethylene carbonate in male Fischer 344 rats

International Nuclear Information System (INIS)

Hanley, T.R. Jr.; Schumann, A.M.; Langvardt, P.W.; Rusek, T.F.; Watanabe, P.G.

1989-01-01

Ethylene carbonate (EC) has a toxicity profile which resembles that of ethylene glycol (EG). To determine whether the toxicity of EC could be explained on the basis of its metabolism to EG, male Fischer 344 rats were given 200 mg/kg of uniformly labeled [ 14 C]EC in water by gavage and the disposition of the radiolabel was then followed for 72 hr. EC was rapidly metabolized, with approximately 57 and 27% of the administered dose eliminated in the expired air as 14CO2 and in the urine, respectively; the remainder was found in the carcass. Separation of the urinary metabolites using liquid chromatography revealed a single radioactive peak. This metabolite was unequivocally identified as ethylene glycol via gas chromatography-mass spectrometry with the aid of 13C enrichment of the EC dose. Measurement of whole blood levels of EC and EG in rats given 200 mg/kg of EC by gavage revealed blood levels of EG approximately 100-fold higher than the levels of EC in these same animals, with a half-life of EG in blood of 2 hr, indicating rapid conversion of EC to EG. In a separate group of animals administered an equimolar dose of [ 14 C]EG (141 mg/kg), approximately 37% of the dose was expired as 14 CO 2 and 42% was excreted in the urine as parent compound. When expressed on the basis of the ethanediol moiety, the disposition of EC was identical to that of EG. In view of the rapid and extensive biotransformation of EC to EG and the similarity of the existing (though limited) toxicity data base of EC compared to EG, utilization of the extensive EG systemic toxicity data base for assessing the safety of EC appears justified

Moessbauer study of iron-carbide growth and Fischer-Tropsch activity

Energy Technology Data Exchange (ETDEWEB)

Rao, K.R.P.M.; Huggins, F.E.; Huffman, G.P. [Univ. of Kentucky, Lexington, (United States)] [and others

1995-12-31

There is a need to establish a correlation between the Fischer-Tropsch (FT) activity of an iron-based catalyst and the catalyst phase during FT synthesis. The nature of iron phases formed during activation and FT synthesis is influenced by the nature of the gas and pressure apart from other parameters like temperature, flow rate etc., used for activation. Moessbauer investigations of iron-based catalysts subjected to pretreatment at two different pressures in gas atmospheres containing mixtures of CO, H{sub 2}, and He have been carried out. Studies on UCI 1185-57 (64%Fe{sub 2}O{sub 3}/5%CuO/1%K{sub 2}O/30% Kaolin) catalyst indicate that activation of the catalyst in CO at 12 atms. leads to the formation of 100% magnetite and the magnetite formed gets rapidly converted to at least 90% of {chi}-Fe{sub 5}C{sub 2} during activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation of the catalyst in synthesis gas at 12 atms. leads to formation of Fe{sub 3}O{sub 4} and it gets sluggishly converted to {chi}-Fe{sub 5}C{sub 2} and {epsilon}-Fe{sub 2.2}C during activation and both continue to grow slowly during FT synthesis. FT activity is found to be poor. Pretreatment of the catalyst, 100fe/3.6Si/0.71K at a low pressure of 1 atms. in syngas gave rise to the formation of {chi}-Fe{sub 5}C{sub 2} and good FT activity. On the other hand, pretreatment of the catalyst, 100Fe/3.6Si/0.71K at a relatively high pressure of 12 atms. in syngas did not give rise to the formation any carbide and FT activity was poor.

Fischer's Lexicon of Slavic beliefs and customs: a previously unknown contribution to the ethnobotany of Ukraine and Poland.

Science.gov (United States)

Kujawska, Monika; Łuczaj, Łukasz; Typek, Joanna

2015-12-24

Historical ethnobotanical studies are important, even if they are only descriptive, because they help to throw light on the missing chains needed for diachronic analysis. However, the documentation of traditional uses of plants in some countries, e.g. Ukraine, is still fragmentary. The aim of this contribution is to fill the gap and present a portion of the data set, from western Ukraine, which was collected by Adam Fischer, a Polish ethnographer from Lviv, in the 1930s. These data were originally gathered to be published in the first part of the Lexicon of Slavic beliefs and customs, dedicated to plant uses in traditional Slavonic culture. The idea of writing the Lexicon arose in 1929 during the I Congress of Slavic Philologists in Prague and was intended to be a joint international enterprise, but has never actually been fulfilled. In this article we used information from south-eastern Poland at that time - nowadays western Ukraine, collected in four provinces, 11 counties and 28 localities by Fischer's collaborators. The majority of the information was accompanied by voucher specimens, which were determined by botanists at the Jan Kazimierz University. These data are still unpublished and stored on filecards in the archives of the Polish Ethnological Society in Wrocław, Poland. In our analysis we applied two indices: one to measure general plant versatility - Use Value, and another regarding medicinal plants - Relative Importance Value. In total, 179 plant taxa used in peasant culture in the western Ukraine in the 1930s were registered. The species which achieved the highest Use Values were: Achillea millefolium, Allium sativum, Vinca minor, Hypericum sp. and Juniperus communis. Among the collected plant names, Polish names dominate (59%) over clearly Ukrainian and Ruthenian ones (31%). The remaining 10% of names were of unclear origin or could have been used by both groups. The most salient use categories were medicinal, followed by ritual - chiefly plants

Comparison of PM emissions from a commercial jet engine burning conventional, biomass, and Fischer-Tropsch fuels.

Science.gov (United States)

Lobo, Prem; Hagen, Donald E; Whitefield, Philip D

2011-12-15

Rising fuel costs, an increasing desire to enhance security of energy supply, and potential environmental benefits have driven research into alternative renewable fuels for commercial aviation applications. This paper reports the results of the first measurements of particulate matter (PM) emissions from a CFM56-7B commercial jet engine burning conventional and alternative biomass- and, Fischer-Tropsch (F-T)-based fuels. PM emissions reductions are observed with all fuels and blends when compared to the emissions from a reference conventional fuel, Jet A1, and are attributed to fuel properties associated with the fuels and blends studied. Although the alternative fuel candidates studied in this campaign offer the potential for large PM emissions reductions, with the exception of the 50% blend of F-T fuel, they do not meet current standards for aviation fuel and thus cannot be considered as certified replacement fuels. Over the ICAO Landing Takeoff Cycle, which is intended to simulate aircraft engine operations that affect local air quality, the overall PM number-based emissions for the 50% blend of F-T fuel were reduced by 34 ± 7%, and the mass-based emissions were reduced by 39 ± 7%.

Effect of Drying Temperature on Iron Fischer-Tropsch Catalysts Prepared by Solvent Deficient Precipitation

Directory of Open Access Journals (Sweden)

Michael K. Albretsen

2017-01-01

Full Text Available A novel solvent deficient precipitation (SDP method to produce nanoparticles was studied for its potential in Fischer-Tropsch synthesis (FTS catalysis. Using Fe(NO33·9H2O as the iron-containing precursor, this method produces ferrihydrite particles which are then dried, calcined, reduced, and carbidized to form the active catalytic phase for FTS. Six different drying profiles, including final drying temperatures ranging between 80 and 150°C, were used to investigate the effect of ammonium nitrate (AN, a major by-product of reaction between Fe(NO33·9H2O and NH4HCO3 in the SDP method. Since AN has two phase-transitions within this range of drying temperatures, three different AN phases can exist during the drying of the catalyst precursors. These AN phases, along with physical changes occurring during the phase transitions, may affect the pore structure and the agglomeration of ferrihydrite crystallites, suggesting possible reasons for the observed differences in catalytic performance. Catalysts dried at 130°C showed the highest FTS rate and the lowest methane selectivity. In general, better catalytic performance is related to the AN phase present during drying as follows: phase III > phase II > phase I. However, within each AN phase, lower drying temperatures led to better catalytic properties.

To the biology of the Damalacantha vacca (Fischer von Waldheim, 1846 (Orthoptera: Tettigonnidae: Bradyporinae with the description of eggs

Directory of Open Access Journals (Sweden)

I. I. Temreshev

2017-12-01

Full Text Available The article gives a new data on the biology and fecundity of the grasshopper Damalacantha vacca (Fischer von Waldheim, 1846, a rare species of the Orthopterans, listed in the Red Book of the Republic of Kazakhstan. Earlier in the literature it was noted that this species eats saltwort (Salsola. When the Damalacantha vacca was kept in the cage, in addition to plant foods (except for Amaranthaceae and Chenopodiaceae plants, cereals, mostly spikelets and young leaves, and thinly sliced pieces of various vegetables - cabbage, potatoes, carrots were eaten, and animals (dead grasshoppers, flies and butterflies - Owlet moths. Egg laying by females carried out in batches of 5-6 pieces per soil, with preference given to areas with compacted soil, permeated with interlaced plant roots. Fecundity of two females, who made a full clutch, was 49 and 54 eggs, respectively. For the first time the description of the egg is given and the structure of the chorion.

A DFT Study on Selected Physical Organic Aspects of the Fischer Carbene Intermediates [(M(CO4(C(OMeMe

Directory of Open Access Journals (Sweden)

Tareq Irshaidat

2010-01-01

Full Text Available Fischer carbenes are important starting materials for C-C bond formation via coupling reactions between carbene and wide variety of substituted alkenes or alkynes. This DFT study shed light on unique fundamental organic/organometallic aspects for the C(OMeMe carbene in the free form and in case of bonding with M(CO4 (M= Cr, Mo, W. The data illustrate that the structures of the title intermediates include a unique structure stabilizing intramolecular M…C-H interaction (agostic interaction. This conclusion was made based on calculated NMR data (for carbon and hydrogen, structural parameters, energy calculations of conformers (C-C conformation, selected IR stretching frequencies (C-O, C-C, and C-H, and atomic charges. The agostic interaction is most efficient in case of chromium and in general is described as an overlap between the σ-bond electron pair of C-H with an empty d-orbital of the metal. These characterized examples are new addition to the orbital interaction theory.

Performance of Cobalt-Based Fischer-Tropsch Synthesis Catalysts Using Dielectric-Barrier Discharge Plasma as an Alternative to Thermal Calcination

International Nuclear Information System (INIS)

Bai Suli; Huang Chengdu; Lv Jing; Li Zhenhua

2012-01-01

Co-based catalysts were prepared by using dielectric-barrier discharge (DBD) plasma as an alternative method to conventional thermal calcination. The characterization results of N 2 -physisorption, temperature programmed reduction (TPR), transmission electron microscope (TEM), and X-ray diffraction (XRD) indicated that the catalysts prepared by DBD plasma had a higher specific surface area, lower reduction temperature, smaller particle size and higher cobalt dispersion as compared to calcined catalysts. The DBD plasma method can prevent the sintering and aggregation of active particles on the support due to the decreased treatment time (0.5 h) at lower temperature compared to the longer thermal calcination at higher temperature (at 500° C for 5 h). As a result, the catalytic performance of the Fischer-Tropsch synthesis on DBD plasma treated Co/SiO 2 catalyst showed an enhanced activity, C 5+ selectivity and catalytic stability as compared to the conventional thermal calcined Co/SiO 2 catalyst.

Characterization of catalysts by Moessbauer spectroscopy: An application to the study of Fischer-Tropsch, hydrotreating and super Claus catalysts

International Nuclear Information System (INIS)

Kraan, A.M. van der; Boellaard, E.; Craje, M.W.J.

1993-01-01

Moessbauer spectroscopy is an excellent in-situ technique for the identification of phases present in catalysts. Applied to metallic iron catalysts used in the Fischer-Tropsch reaction it reveals a detailed picture of the carburization process and provides insight into the relation between the properties of the catalytic material and its activity. The influence of a support and the effect of alloying iron with an (in)active metal on the catalytic performance is discussed for Fe, Cu-Fe and Ni-Fe systems. In addition, Moessbauer spectroscopy is used for the identification of 'Co-sulfide' species present in sulfided Co and CoMo catalysts applied in one of the largest chemical processes in the world, the hydrotreatment of crude oil. A structural model is proposed. Finally, the contribution of Moessbauer spectroscopic studies to the development of a new catalyst for cleaning of Claus tail gas via selective oxidation of hydrogen sulfide to elemental sulfur is discussed. (orig.)

Risks and chances of an ecologically oriented energy industry. Revised version of the speech of the Hessian Minister for Environment, Energy and Federal Issues, Joschka Fischer (Die Gruenen), on the occasion of the IZE communication meeting 1992

International Nuclear Information System (INIS)

Kukuck, H.A.

1994-01-01

During the 1992 'Discussion Day' of the IZE, held under the motto 'Energy and Environment: Public Relations in the field of tension between economy and ecology', Joschka Fischer, the environment minister of Hessen, delivered an address that met with great attention. It resulted in a lively discussion of his theses with the attendants of the meeting. (orig./UA) [de

Focus: Digital

DEFF Research Database (Denmark)

Technology has been an all-important and defining element within the arts throughout the 20th century, and it has fundamentally changed the ways in which we produce and consume music. With this Focus we investigate the latest developments in the digital domain – and their pervasiveness and rapid...... production and reception of contemporary music and sound art. With ‘Digital’ we present four composers' very different answers to how technology impact their work. To Juliana Hodkinson it has become an integral part of her sonic writing. Rudiger Meyer analyses the relationships between art and design and how...

DMG的中国布局——记DMG新闻发布会

Institute of Scientific and Technical Information of China (English)

2011-01-01

@@ 2011年4月12日,第十二届中国国际机床展览会举办期间,DMG"您的愿景,我的关注"新闻发布会在北京中国国际国际展览中心隆重举行,吉特迈董事会主席Dr.Rudiger Kapitza、DMG亚洲区CEO兼中国区总裁汉诺先生、执行董事Mr.Christian Thones、执行董事Mr.Harry Junger出席了此次发布会.

Thermodynamic optimization of biomass gasification for decentralized power generation and Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Buragohain, Buljit; Mahanta, Pinakeswar; Moholkar, Vijayanand S.

2010-01-01

In recent years, biomass gasification has emerged as a viable option for decentralized power generation, especially in developing countries. Another potential use of producer gas from biomass gasification is in terms of feedstock for Fischer-Tropsch (FT) synthesis - a process for manufacture of synthetic gasoline and diesel. This paper reports optimization of biomass gasification process for these two applications. Using the non-stoichometric equilibrium model (SOLGASMIX), we have assessed the outcome of gasification process for different combinations of operating conditions. Four key parameters have been used for optimization, viz. biomass type (saw dust, rice husk, bamboo dust), air or equivalence ratio (AR = 0, 0.2, 0.4, 0.6, 0.8 and 1), temperature of gasification (T = 400, 500, 600, 700, 800, 900 and 1000 o C), and gasification medium (air, air-steam 10% mole/mole mixture, air-steam 30%mole/mole mixture). Performance of the gasification process has been assessed with four measures, viz. molar content of H 2 and CO in the producer gas, H 2 /CO molar ratio, LHV of producer gas and overall efficiency of gasifier. The optimum sets of operating conditions for gasifier for FT synthesis are: AR = 0.2-0.4, Temp = 800-1000 o C, and gasification medium as air. The optimum sets of operating conditions for decentralized power generation are: AR = 0.3-0.4, Temp = 700-800 o C with gasification medium being air. The thermodynamic model and methodology presented in this work also presents a general framework, which could be extended for optimization of biomass gasification for any other application.

Photon activation therapy of RG2 glioma carrying Fischer rats using stable thallium and monochromatic synchrotron radiation.

Science.gov (United States)

Ceberg, Crister; Jönsson, Bo-Anders; Prezado, Yolanda; Pommer, Tobias; Nittby, Henrietta; Englund, Elisabet; Grafström, Gustav; Edvardsson, Anneli; Stenvall, Anna; Strömblad, Susanne; Wingårdh, Karin; Persson, Bertil; Elleaume, Hélène; Baldetorp, Bo; Salford, Leif G; Strand, Sven-Erik

2012-12-21

75 RG2 glioma-carrying Fischer rats were treated by photon activation therapy (PAT) with monochromatic synchrotron radiation and stable thallium. Three groups were treated with thallium in combination with radiation at different energy; immediately below and above the thallium K-edge, and at 50 keV. Three control groups were given irradiation only, thallium only, or no treatment at all. For animals receiving thallium in combination with radiation to 15 Gy at 50 keV, the median survival time was 30 days, which was 67% longer than for the untreated controls (p = 0.0020) and 36% longer than for the group treated with radiation alone (not significant). Treatment with thallium and radiation at the higher energy levels were not effective at the given absorbed dose and thallium concentration. In the groups treated at 50 keV and above the K-edge, several animals exhibited extensive and sometimes contra-lateral edema, neuronal death and frank tissue necrosis. No such marked changes were seen in the other groups. The results were discussed with reference to Monte Carlo calculated electron energy spectra and dose enhancement factors.

Synthetic gasoline and diesel oil produced by Fischer-Tropsch Technology. A possibility for the future? IEA/AMF annex XXXI

Energy Technology Data Exchange (ETDEWEB)

Rehnlund, B., (Atrax Energy AB, Goeteborg (SE)); Blinge, M., (The Swedish Transport Research Institute, TFK (SE)); Schramm, J.; Larsen, Ulrik, (Technical Univ. of Denmark, DTU, Kgs. Lyngby (DK))

2007-03-15

This report is the result of an annex (annex XXXI, Fischer-Tropsch Fuels) initiated by the International Energy Agency's Implementing Agreement on Advanced Motor Fuels. The annex has been managed by Atrax Energi AB, Bjorn Rehnlund, acting as the operating agent of the annex. The work in the annex has been carried out in co-operation with the Swedish Transportation Research Institute - TFK, Magnus Blinge and the Technical University of Denmark - DTU, Jesper Schramm and Ulrik Larsen. In this report the possibilities to produce synthetic gasoline and synthetic diesel oil from biomass, and also from natural gas, by Fischer-Tropsch (FT) Technology are analysed and discussed. After an introduction of the technology as such, environmental aspects and the life cycle perspective of synthetic gasoline and diesel oil are discussed, and some possible national/regional scenarios are analysed and presented. Vehicle emission tests with synthetic gasoline carried out at DTU are described and discussed in this report as well. Based on the result of the analysis and the vehicle emission tests presented in the report, a first SWOT analysis of Fischer-Tropsch technology is then presented, and finally some main conclusions are drawn. During the execution of the annex Sasol in South Africa, Nykomb Synergetics in Sweden, Chemrec in Sweden, the Technical University of Denmark, VTT in Finland, the Varnamo gasification research project in Sweden, and the Black liquor gasification project in Pitea, Sweden have been visited. Some of the most important conclusions are that: 1) FT-Fuels such as FT-Diesel (FTD) and FT-Gasoline (FTG) produced through CoalTo-Liquid, (CTL), Gas-To-Liquid (GTL) and Biomass-To-Liquid (BTL) technologies can contribute to reducing the dependency on crude oil. 2) FTD and FTG are attractive for use in neat form and also as components in blends with low quality diesel and gasoline, to upgrade fuels to meet the ever more stringent regulations. 3) Production and use of

ANÁLISE MORFOLÓGICA DO APARELHO UNGUEAL DO VEADO-CATINGUEIRO (Mazama gouazoubira, Fischer, 1814 (Artiodactyla, Cervidae

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Lorenna Cardoso Rezende

2013-06-01

Full Text Available The species studied in this research is known as gray brocketdeer. Two Mazama gouazoubira (Fischer, 1814 adult exemplars, donated to the Laboratory of Anatomy of Domestic and Wild Animals, Faculty of Veterinary Medicine, São Paulo University, were preserved in formaldehyde (10%. There are four ungulas or hulls on each member and they protect the distal end of the limb, covering the distal phalanx. The angle of the hoof was measured and samples of the digits were processed for light microscopy and scanning electron microscopy. In macroscopy, the length of the dorsal wall of the hoof measured approximately 2.5 cm, the angle formed at the step was 35° for the forelimb and 33° for the hindlimb. In microscopy, we could visualize the outer stratum as a very thin layer (141.5 μm, the middle stratum, composed of keratin tubular pigment, which is the main support structure of the wall of the hull, and the inner layer containing parallel slides in a longitudinal distribution, which is important to connect the hoof wall to the dorsal and lateral surface of the distal phalanx. The data from the ungular apparatus of the deers studied may help to elucidate the growth and identification of the footprints of these animals.

Effects of Caloric Restriction and Exercise Training on Skeletal Muscle Histochemistry in Aging Fischer 344 Rats

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David T. Lowenthal

2006-01-01

Full Text Available The purpose of this study was to determine the effects of calorie restriction and exercise on hindlimb histochemistry and fiber type in Fischer 344 rats as they advanced from adulthood through senescence. At 10 months of age, animals were divided into sedentary fed ad libitum, exercise (18 m/min, 8% grade, 20 min/day, 5 days/week fed ad libitum, and calorie restricted by alternate days of feeding. Succinic dehydrogenase, myosin adenosine triphosphatase (mATPase at pH 9.4, nicotine adenonine dinucleotide reductase, and Periodic Acid Shiff histochemical stains were performed on plantaris and soleus muscles. The results indicated that aging resulted in a progressive decline in plantaris Type I muscle fiber in sedentary animals, while exercise resulted in maintenance of these fibers. The percent of plantaris Type II fibers increased between 10 and 24 months of age. Exercise also resulted in a small, but significant, increase in the percentage of plantaris Type IIa fibers at 24 months of age. The soleus fiber distribution for Type I fibers was unaffected by increasing age in all groups of animals. The implications of these results suggest the implementation of exercise as a lifestyle modification as early as possible.

Dose patterns for 106RuO4 inhaled by Fischer-344 rats and Beagle dogs

International Nuclear Information System (INIS)

Runkle, G.E.; Snipes, M.B.

1978-01-01

Ruthenium-106 is an abundant fission product radionuclide in the nuclear fuel cycle which has potential for release as ruthenium tetroxide. Ruthenium tetroxide is a vapor, diffuses rapidly through air and porous materials, is chemically reactive and is rapidly reduced by any organic material to the dioxide form. Current ICRP recommendations consider the lung and gastrointestinal tract as critical organs for inhaled particles of radioactive ruthenium. This study was designed to provide additional data needed to adequately assess the risk for humans potentially exposed to 106 Ru encountered in this vapor form. Fischer-344 rats and Beagle dogs were given a nose-only exposure to 106 RuO 4 vapor to determine its distribution and retention patterns. The largest percentage of the initial body burden was found in the nasopharyngeal region of the respiratory tract. Less than 1% of the initial body burden was deposited in the pulmonary region. Most of the 106 Ru was cleared via the feces. A biomathematical simulation model was developed to fit the tissue and excreta data from the rat. This model was used to assess the short-term and long-term risks after inhalation of 106 RuO 4 . The observed deposition, retention and dose patterns for ruthenium tetroxide indicate the nasopharyngeal region should be considered as a critical region when considering the consequences of human exposure to this vapor

A STUDY OF FISCHER 344 RATS EXPOSED TO SILICA DUST FOR SIX MONTHS AT CONCENTRATIONS OF 0, 2, 10 OR 20 MG / M3.

Energy Technology Data Exchange (ETDEWEB)

KUTZMAN,R.S.

1984-02-01

The major objective of this study was to relate the results of a series of functional tests to the compositional and structural alterations in the rat lung induced by subchronic exposure to silica dust. Fischer-344 rats were exposed for 6 hours/day, 5 days/week for 6 months to either 0, 2, 10, or 20 mg SiO{sub 2}/m{sup 3}. The general appearance of the exposed rats was not different from that of the controls. Interestingly, female rats exposed to silica dust, at all tested concentrations, gained more weight than the controls. The lung weight and the lung-to-body weight ratio was greater in the male rats exposed to the highest concentration of silica dust.

Performance characterization of CNTs and γ-Al{sub 2}O{sub 3} supported cobalt catalysts in Fischer-Tropsch reaction

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Ali, Sardar, E-mail: alikhan-635@yahoo.com [Centralized Analytical Laboratory, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Zabidi, Noor Asmawati Mohd, E-mail: noorasmawati-mzabidi@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Subbarao, Duvvuri, E-mail: duvvuri-subbarao@petronas.com.my [Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

2014-10-24

Catalysts were prepared via a wet impregnation method. Different physicochemical properties of the samples were revealed by transmission electron microscope (TEM), temperature programmed reduction (H{sub 2}-TPR) and carbon dioxide desorption (CO{sub 2}-desorption). Fischer-Tropsch reaction (FTS) was carried out in a fixed-bed microreactor at 220°C and 1 atm, with H{sub 2}/CO = 2v/v and space velocity, SV of 12L/g.h for 5 h. Various characterization techniques revealed that there was a stronger interaction between Co and Al{sub 2}O{sub 3} support compared to that of CNTs support. CNTs support increased the reducibility and decreased Co particle size. A significant increase in % CO conversion and FTS reaction rate was observed over CNTs support compared to that of Co/Al{sub 2}O{sub 3}. Co/CNTs resulted in higher C{sub 5+} hydrocarbons selectivity compared to that of Co/Al{sub 2}O{sub 3} catalyst. CNTs are a better support for Co compared to Al{sub 2}O{sub 3}.

From Nanoparticles to Process An Aberration Corrected TEM Study of Fischer Tropsch Catalysts at Various Steps of the Process

International Nuclear Information System (INIS)

Braidy, N.; Blanchard, J.; Abatzoglou, N.; Andrei, C.

2011-01-01

χThe nanostructure of Fischer-Tropsch (FT) Fe carbides are investigated using aberration-corrected high-resolution transmission electron microscopy (TEM). The plasma-generated Fe carbides are analyzed just after synthesis, following reduction via a H2 treatment step and once used as FT catalyst and deactivated. The as-produced nanoparticles (NPs) are seen to be abundantly covered with graphitic and amorphous carbon. Using the extended information limit from the spherical aberration-corrected TEM, the NPs could be indexed as a mixture of NPs in the θ-Fe 3 C and χ-Fe 5 C 2 phases. The reduction treatment exposed the NPs by removing most of the carbonaceous speSubscript textcies while retaining the χ-Fe 5 C 2 . Fe-carbides NPs submitted to conditions typical to FT synthesis develop a Fe3O4 shell which eventually consumes the NPs up to a point where 3-4 nm residual carbide is left at the center of the particle. Subscript textVarious mechanisms explaining the formation of such a microstructure are discussed. (author)

Dietary fat composition influences tissue lipid profile and gene expression in Fischer-344 rats.

Science.gov (United States)

Zhou, Albert L; Hintze, Korry J; Jimenez-Flores, Rafael; Ward, Robert E

2012-12-01

The AIN-76A diet causes fatty liver in rodents when fed for long periods of time. The aim of this study was to utilize fatty acid analysis and transcriptomics to investigate the effects of different fat sources in the AIN-76A diet on tissue lipid profiles and gene expression in male, weanling Fischer-344 rats. Animals were fed isocaloric diets that differed only in the fat source: (1) corn oil (CO) (2) anhydrous milk fat (AMF), and (3) AMF supplemented with 10% phospholipids from the milk fat globule membrane (AMF-MFGM). There were no differences in food intake, body weight, growth rate, or body fat composition among the groups, and the fatty acid compositions of red blood cells (RBC), plasma, muscle, and visceral adipose tissues reflected the dietary fat sources. Modifying the fat source resulted in 293 genes differentially regulated in skeletal muscle, 1,124 in adipose, and 831 in liver as determined by analysis of variance (ANOVA). Although tissue fatty acid profiles mostly reflected the diet, there were several quantitative differences in lipid classes in the liver and plasma. The AMF diet resulted in the highest level of hepatic triacylglycerols, but the lowest level in plasma. The CO diet resulted in significant accumulation of hepatic unesterified fatty acids and decreased DGAT expression and activity, a potential trigger for steatohepatitis. These results indicate that the fatty acid composition and presence of polar lipids in the AIN-76A diets have significant effects on lipid partitioning, gene expression, and potentially the development of liver pathology.

Fischer-Tropsch diesel production over calcium-promoted Co/alumina catalyst: Effect of reaction conditions

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A.R. de la Osa; A. De Lucas; A. Romero; J.L. Valverde; P. Sanchez [University of Castilla-La Mancha, Ciudad Real (Spain). Chemical Engineering Department

2011-05-15

The effects of reaction conditions on the Fischer-Tropsch activity and product distribution of an alkali-earth metal promoted cobalt based catalyst were studied. The influence of the promoter on the reducibility and cobalt particle size was studied by different techniques, including N{sub 2} adsorption, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption and acid-base titrations. Experiments were carried out on a bench-scale fixed bed reactor and catalysts were prepared by incipient wetness impregnation. It was observed that addition of a small amount of calcium oxide as a promoter (0.6 wt.%) improved the cobalt oxide reducibility and reduced the formation of cobalt-aluminate species. A positive correlation between basicity and particle size was observed. In terms of FTS results, CO conversion and C{sub 5}{sup +} selectivity were found to be enhanced by the addition of this promoter. It was important to note that the addition of calcium shifted the distribution to mainly C{sub 16}-C{sub 18} hydrocarbons fraction, which could be greatly considered for a diesel formulation. Furthermore, the variation of the reaction conditions seemed to influence product distribution in a lesser extent than unpromoted catalyst. Also, a displacement of hydrocarbon distribution to higher molecular weight with decreasing space velocity and temperature was observed. Moreover, the addition of calcium to the cobalt based catalyst was found to greatly maintain selectivity to C{sub 5}{sup +} for a wide range of H{sub 2}/CO molar ratios. 60 refs., 10 figs., 5 tabs.

Efficiency of methods for Karl Fischer determination of water in oils based on oven evaporation and azeotropic distillation.

Science.gov (United States)

Larsson, William; Jalbert, Jocelyn; Gilbert, Roland; Cedergren, Anders

2003-03-15

The efficiency of azeotropic distillation and oven evaporation techniques for trace determination of water in oils has recently been questioned by the National Institute of Standards and Technology (NIST), on the basis of measurements of the residual water found after the extraction step. The results were obtained by volumetric Karl Fischer (KF) titration in a medium containing a large excess of chloroform (> or = 65%), a proposed prerequisite to ensure complete release of water from the oil matrix. In this work, the extent of this residual water was studied by means of a direct zero-current potentiometric technique using a KF medium containing more than 80% chloroform, which is well above the concentration recommended by NIST. A procedure is described that makes it possible to correct the results for dilution errors as well as for chemical interference effects caused by the oil matrix. The corrected values were found to be in the range of 0.6-1.5 ppm, which should be compared with the 12-34 ppm (uncorrected values) reported by NIST for the same oils. From this, it is concluded that the volumetric KF method used by NIST gives results that are much too high.

Insight on Biomass Supply and Feedstock Definition for Fischer-Tropsch Based BTL Processes

International Nuclear Information System (INIS)

Coignac, Julien

2013-01-01

Process chains of thermo chemical conversion of lignocellulosic biomass through gasification and Fischer-Tropsch synthesis (known as BTL) represent promising alternatives for biofuels production. Since biomass is heterogeneous and not homogeneously spread over territories, one of the major technological stakes of the project is to develop a flexible industrial chain capable of co-treating the widest possible range of biomass and fossil fuel feedstock. The present study aims at characterizing biomass diversity (availability and potentials by area, cost and mineral composition) by carrying out a state of the art, as a preliminary step in order to define a series of biomass to be tested in the demonstration plant and therefore define specifications for the process. Fifty different biomass were considered for their bio-energy application potential and were finally classified into four categories: agricultural by-products, dedicated energy crops, (Very) Short Rotation Coppice ((V)SRC) and forestry biomass. Biomass availability and potentials were investigated by the mean of a literature review of past and current projects (e.g. RENEW project, Biomass Energy Europe Project, etc.) and scientific articles. Most collected data are technical potentials, meaning that they take into account biophysical limits of crops and forests, technological possibilities, competition with other land uses and ecological constraints (e.g. natural reserves). Results show various emerging markets: North and South America have considerable amounts of agricultural by-products, forest residues, and large land areas which could be dedicated to energy crops; Africa shows relevant possibilities to grow Short Rotation Forestry (SRF) and energy crops; Russia has large available quantities of agricultural by-products and forest residues, as well as little valuable land where energy crops and SRC could be grown, and Asia shows relevant amounts of forest residues and possibilities of growing SRC, as well

Hydroprocessing of Fischer-Tropsch biowaxes to second-generation biofuels

Energy Technology Data Exchange (ETDEWEB)

Schablitzky, Harald Walter; Hafner, C. [OMV Refining and Marketing, Centre of Excellence-Fuels, Innovation and Quality, Schwechat (Austria); Lichtscheidl, J.; Hutter, K. [OMV Refining and Marketing, New Technology, Schwechat (Austria); Rauch, R. [Bioenergy, Graz (Austria); Hofbauer, H. [Bioenergy, Graz (Austria); Vienna University of Technology, Institute of Chemical Engineering, Vienna (Austria)

2011-03-15

Upgrading of Fischer-Tropsch (FT) biowaxes to second-generation biofuels via hydroprocessing is the final step for increasing the fuel amount of the overall biomass conversion route: gasification of lignocellulosic biomass, FT synthesis, and hydroprocessing. The typical FT product portfolio consists of high molecular weight paraffinic waxes as the main product and FT fuels in the diesel and naphtha boiling range. OMV's objective and contribution to the project focus on achieving coprocessing of FT biowaxes with fossil feedstock using existing hydrotreating plants of crude oil refineries. Various test runs have been examined with a conventional refining catalyst under mild conditions (380-390 C, 5.8 MPa; WHSV, 0.7-1.3 h{sup -1}) in a pilot plant. Pure FT biowax is converted to gases, fuels, and an oil/waxy residue in a fixed-bed reactor with a porous catalyst layer technology. The presence of hydrogen in the reaction chamber reduces the fast deactivation of the catalyst caused by the formation of a coke layer around the catalyst particle surface and saturates cracked hydrocarbon fragments. Another approach is the creation of synthetic biodiesel components with excellent fuel properties for premium fuel application. Basically, premium diesel fuel differs from standard diesel quality by cetane number and cold flow properties. Hydroprocessed synthetic biodiesel (HPFT diesel) has compared to conventional diesel advantages in many aspects. Depending on the catalyst selected, premium diesel quality can be obtained by shifting cold flow operability properties of HPFT fuels to a range capable even under extreme cold conditions. In addition, a high-quality kerosene fraction is obtained to create bio jet fuels with an extremely deep freezing point, as low as -80 C. The isomerization degree, as well as the carbon number distribution of high paraffinic profile, and the branching degree have a major impact on the cold flow properties and cetane number. FT diesel has

Extension of the Single-Event Methodology to Metal Catalysis: Application to Fischer-Tropsch Synthesis Extension de la méthodologie des événements constitutifs à la catalyse métallique : Application à la synthèse Fischer-Tropsch

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Lozano-Blanco G.

2010-10-01

Full Text Available The single-event methodology has been extended to metal catalysis using Fischer-Tropsch synthesis on an iron-based catalyst as case study. The reaction mechanism has been assessed in terms of elementary steps that could be categorized in reaction families such as reductive elimination, β-hydride elimination and methylene insertion. A computer code has been developed for the generation of the reaction network containing these elementary steps. The representation of reacting and intermediate species explicitly takes into account metal-carbon bonds as well as the presence of oxygen. The model has been validated using iron-based catalytic data at 623 K, 0.6 to 2.1 MPa, inlet molar H2/CO ratio between 2 and 6. 14 parameters, among which 10 activation energies and 4 atomic chemisorption enthalpies have been adjusted to the experimental data. Experimentally observed trends in alkane and 1-alkene product yields with the carbon number were adequately reproduced as well as the individual molar yields of the non-hydrocarbon products. La méthodologie par événements constitutifs a été étendue à la catalyse métallique en utilisant la synthèse Fischer-Tropsch sur un catalyseur au fer comme cas d'étude. Le mécanisme réactionnel a été décomposé en étapes élémentaires qui peuvent être classées par type de réactions, telles que l'élimination réductrice, l'élimination d'hydrure en β, et l'insertion de groupe méthylène. Un code de calcul a été développé pour générer le réseau réactionnel impliquant ces étapes élémentaires. La représentation des réactifs et des espèces intermédiaires prend en compte explicitement les liaisons carbone-métal et inclut la présence d'atomes d'oxygène. Le modèle a été validé sur une base de données obtenues sur un catalyseur à base de fer à 623 K, sur une plage de 0,6 à 2,1 MPa, un ratio H2/CO en entrée variant de 2 à 6. Quatorze paramètres, dont 10 énergies d'activation et 4

The role of palladium in iron based Fischer-Tropsch catalysts prepared by flame spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Minnermann, M.; Zielasek, V.; Baeumer, M. [Bremen Univ. (DE). Inst. of Applied and Physical Chemistry (IAPC); Pokhrei, S.; Maedler, L. [Bremen Univ. (DE). Foundation Inst. of Materials Science (IWT); Thiel, K. [Fraunhofer Institute for Manufactoring Technology and Applied Materials Research, Bremen (Germany)

2011-07-01

Flame spray pyrolysis (FSP) is a novel technique for the fabrication of nanostructured catalysts with far-reaching options to control structure and composition even in cases where complex composites need to be prepared. In this study, we took advantage of this technique to synthesize highly dispersed pure and Pd-doped iron oxide nanoparticles and investigated them as Fischer-Tropsch (FT) catalysts. By systematically varying the Pd content over a large range from 0.1 wt % to 10 wt %, we were able to directly analyze the influence of the Pd content on activity and selectivity. In addition to catalytic measurements, the structure and composition of the particles were characterized before and after these measurements, using transmission electron microscopy, adsorption measurements, X-ray diffraction and EXAFS. The comparison revealed, on the one hand, that small Pd clusters (diameter: 1-2 nm) evolve from initially homogeneously distributed Pd and, on the other hand, that the iron oxide transforms into iron carbides depending on the Pd content. The presence of Pd influences the particle size in the pristine samples (8 - 11 nm), resulting in specific surface areas that increase as the Pd content increases. However, after activation and reaction the specific surface areas become similar due to partial agglomeration and sintering. In a fixed bed FT reaction test, enhanced FT activity was observed with increasing Pd content while the selectivity shifts to longer chain hydrocarbons, mainly paraffins. (orig.)

Structural equation modeling identifies markers of damage and function in the aging male Fischer 344 rat.

Science.gov (United States)

Grunz-Borgmann, Elizabeth A; Nichols, LaNita A; Wiedmeyer, Charles E; Spagnoli, Sean; Trzeciakowski, Jerome P; Parrish, Alan R

2016-06-01

The male Fischer 344 rat is an established model to study progressive renal dysfunction that is similar, but not identical, to chronic kidney disease (CKD) in humans. These studies were designed to assess age-dependent alterations in renal structure and function at late-life timepoints, 16-24 months. Elevations in BUN and plasma creatinine were not significant until 24 months, however, elevations in the more sensitive markers of function, plasma cystatin C and proteinuria, were detectable at 16 and 18 months, respectively. Interestingly, cystatin C levels were not corrected by caloric restriction. Urinary Kim-1, a marker of CKD, was elevated as early as 16 months. Klotho gene expression was significantly decreased at 24 months, but not at earlier timepoints. Alterations in renal structure, glomerulosclerosis and tubulointerstitial fibrosis, were noted at 16 months, with little change from 18 to 24 months. Tubulointerstitial inflammation was increased at 16 months, and remained similar from 18 to 24 months. A SEM (structural equation modeling) model of age-related renal dysfunction suggests that proteinuria is a marker of renal damage, while urinary Kim-1 is a marker of both damage and function. Taken together, these results demonstrate that age-dependent nephropathy begins as early as 16 months and progresses rapidly over the next 8 months. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characterization of working iron Fischer-Tropsch catalysts using quantitative diffraction methods

Science.gov (United States)

Mansker, Linda Denise

This study presents the results of the ex-situ characterization of working iron Fischer-Tropsch synthesis (F-TS) catalysts, reacted hundreds of hours at elevated pressures, using a new quantitative x-ray diffraction analytical methodology. Compositions, iron phase structures, and phase particle morphologies were determined and correlated with the observed reaction kinetics. Conclusions were drawn about the character of each catalyst in its most and least active state. The identity of the active phase(s) in the Fe F-TS catalyst has been vigorously debated for more than 45 years. The highly-reduced catalyst, used to convert coal-derived syngas to hydrocarbon products, is thought to form a mixture of oxides, metal, and carbides upon pretreatment and reaction. Commonly, Soxhlet extraction is used to effect catalyst-product slurry separation; however, the extraction process could be producing irreversible changes in the catalyst, contributing to the conflicting results in the literature. X-ray diffraction doesn't require analyte-matrix separation before analysis, and can detect trace phases down to 300 ppm/2 nm; thus, working catalyst slurries could be characterized as-sampled. Data were quantitatively interpreted employing first principles methods, including the Rietveld polycrystalline structure method. Pretreated catalysts and pure phases were examined experimentally and modeled to explore specific behavior under x-rays. Then, the working catalyst slurries were quantitatively characterized. Empirical quantitation factors were calculated from experimental data or single crystal parameters, then validated using the Rietveld method results. In the most active form, after pretreatment in H 2 or in CO at Pambient, well-preserved working catalysts contained significant amounts of Fe7C3 with trace alpha-Fe, once reaction had commenced at elevated pressure. Amounts of Fe3O 4 were constant and small, with carbide dpavg 65 wt%, regardless of pretreatment gas and pressure, with

Sexual dimorphism in development of kidney damage in aging Fischer-344 rats.

Science.gov (United States)

Sasser, Jennifer M; Akinsiku, Oladele; Moningka, Natasha C; Jerzewski, Katie; Baylis, Chris; LeBlanc, Amanda J; Kang, Lori S; Sindler, Amy L; Muller-Delp, Judy M

2012-08-01

Aging kidneys exhibit slowly developing injury and women are usually protected compared with men, in association with maintained renal nitric oxide. Our purpose was to test 2 hypotheses: (1) that aging intact Fischer-344 (F344) female rats exhibit less glomerular damage than similarly aged males, and (2) that loss of female ovarian hormones would lead to greater structural injury and dysregulation of the nitric oxide synthase (NOS) system in aging F344 rat kidneys. We compared renal injury in F344 rats in intact, ovariectomized, and ovariectomized with estrogen replaced young (6 month) and old (24 month) female rats with young and old intact male rats and measured renal protein abundance of NOS isoforms and oxidative stress. There was no difference in age-dependent glomerular damage between young or old intact male and female F344 rats, and neither ovariectomy nor estrogen replacement affected renal injury; however, tubulointerstitial injury was greater in old males than in old females. These data suggest that ovarian hormones do not influence these aspects of kidney aging in F344 rats and that the greater tubulointerstitial injury is caused by male sex. Old males had greater kidney cortex NOS3 abundance than females, and NOS1 abundance (alpha and beta isoforms) was increased in old males compared with both young males and old females. NOS abundance was preserved with age in intact females, ovariectomy did not reduce NOS1 or NOS3 protein abundance, and estrogen replacement did not uniformly elevate NOS proteins, suggesting that estrogens are not primary regulators of renal NOS abundance in this strain. Nicotinamide adenine dinucleotide phosphate oxidase-dependent superoxide production and nitrotyrosine immunoreactivity were increased in aging male rat kidneys compared with females, which could compromise renal nitric oxide production and/or bioavailability. The kidney damage expressed in aging F344 rats is fairly mild and is not related to loss of renal cortex NOS3

Comparing a Fischer-Tropsch Alternate Fuel to JP-8 and Their 50-50 Blend: Flow and Flame Visualization Results

Science.gov (United States)

Hicks, Yolanda R.; Tacina, M.

2013-01-01

Combustion performance of a Fischer-Tropsch (FT) jet fuel manufactured by Sasol was compared to JP-8 and a 50-50 blend of the two fuels, using the NASA/Woodward 9 point Lean Direct Injector (LDI) in its baseline configuration. The baseline LDI configuration uses 60deg axial air-swirlers, whose vanes generate clockwise swirl, in the streamwise sense. For all cases, the fuel-air equivalence ratio was 0.455, and the combustor inlet pressure and pressure drop were 10-bar and 4 percent. The three inlet temperatures used were 828, 728, and 617 K. The objectives of this experiment were to visually compare JP-8 flames with FT flames for gross features. Specifically, we sought to ascertain in a simple way visible luminosity, sooting, and primary flame length of the FT compared to a standard JP grade fuel. We used color video imaging and high-speed imaging to achieve these goals. The flame color provided a way to qualitatively compare soot formation. The length of the luminous signal measured using the high speed camera allowed an assessment of primary flame length. It was determined that the shortest flames resulted from the FT fuel.

Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

Energy Technology Data Exchange (ETDEWEB)

Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States)

2013-02-15

Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H₂S, NH₃, HCN, AsH₃, PH₃, HCl, NaCl, KCl, AS₃, NH₄NO₃, NH₄OH, KNO₃, HBr, HF, and HNO₃) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

Assessment of fuel-cycle energy use and greenhouse gas emissions for Fischer-Tropsch diesel from coal and cellulosic biomass

International Nuclear Information System (INIS)

Xie, X.; Wang, M.; Han, J.

2011-01-01

This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.

Incentivizing wood-based Fischer-Tropsch diesel through financial policy instruments: An economic assessment for Norway

International Nuclear Information System (INIS)

Bright, Ryan M.; Stromman, Anders H.

2010-01-01

The objective of this study is to evaluate a select set of financial incentive instruments that can be employed by the Norwegian government for encouraging early investment and production experience in wood-based Fischer-Tropsch diesel (FTD) technologies as a means to accelerate reductions in greenhouse gas emissions (GHG) stemming from road-based transport. We start by performing an economic analysis of FTD produced from Norwegian forest biomass at a pioneer commercial plant in Norway, followed with a cost growth analysis to estimate production costs after uncertainty in early plant performance and capital cost estimates are considered. Results after the cost growth analysis imply that the initial production cost estimates for a pioneer producer may be underestimated by up to 30%. Using the revised estimate we then assess, through scenarios, how various financial support mechanisms designed to encourage near-term investment would affect production costs over a range of uncertain future oil prices. For all policy scenarios considered, we evaluate trade-offs between the levels of public expenditure, or subsidy, and private investor profitability. When considering the net present value of the subsidy required to incentivize commercial investment during a future of low oil prices, we find that GHG mitigation via wood-FTD is likely to be considered cost-ineffective. However, should the government expect that mean oil prices in the coming two decades will hover between $97 and 127/bbl, all the incentive policies considered would likely spur investment at net present values ≤$-100/tonne-fossil-CO 2 -equivalent avoided.

Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

International Nuclear Information System (INIS)

Sartipi, Sina; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge; Kapteijn, Freek

2013-01-01

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors

Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

Energy Technology Data Exchange (ETDEWEB)

Sartipi, Sina, E-mail: S.Sartipi@tudelft.nl, E-mail: J.Gascon@tudelft.nl; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge, E-mail: S.Sartipi@tudelft.nl, E-mail: J.Gascon@tudelft.nl; Kapteijn, Freek [Department of Chemical Engineering, Catalysis Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft (Netherlands)

2013-12-15

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.

Viviendas unifamiliares de “de Wit” y “de Billiaert”. Flandes Bélgica

Directory of Open Access Journals (Sweden)

Vael, Rudiger

1978-02-01

Full Text Available In Rudiger Vael's architecture, a concept stands out which is difficult to find in modern buildings, and even more difficult to conjugate with being functional: that is, fantasy. In effect, the fantasy of the interior spaces and the façades of Vael defines in his works a singular and attractive atmosphere, due to a great degree to the use of different levels in the differentiation of spaces —different levels which at the same time serve to integrate the different ambients, avoiding static forming of compartments by walls—, of dynamic roofing in slate supported on a wooden framework seen from the inside, and a very personal woodwork on the façade, in the form of a triangle, which lends the architecture a gothic reminiscence integrated in the planning and design of a modern construction.

En la arquitectura de Rudiger Vael sobresale un concepto difícil de encontrar en las construcciones modernas, y más difícil aún de conjugar con el buen funcionamiento: la fantasía. Efectivamente, la fantasía de los espacios interiores y de las fachadas de Vael define en sus obras una atmósfera singular y atractiva, debida en buena parte al recurso del desnivel en la diferenciación de espacios —desnivel que al mismo tiempo sirve para integrar los distintos ambientes, evitando la compartimentación estática de los muros—, a las dinámicas cubiertas de pizarra apoyadas en un entramado de madera visto desde el interior, y a una carpintería de fachada muy personal, triangulada, que confiere a la arquitectura una reminiscencia gótica integrada al planteamiento y diseño de una edificación moderna.

Biodistribution and pharamacokinetics of /sup 195m/Pt-labeled cis-dichlorotrans-dihydroxo-bis(isopropylamine)platinum(IV), CHIP, in normal female Fischer 344 rat

International Nuclear Information System (INIS)

Hoeschele, J.D.; Ferren, L.A.; Roberts, J.A.; Whitfield, L.R.

1983-01-01

The discovery and successful clinical application of the potent anti-tumor compound, cis-Dichlorodiammineplatinum(II), cis-DDP* has stimulated considerable interest in developing effective but less toxic second-generation platinum antitumor drugs. One such candidate drug is cis-Dichloro-trans-dihydroxo-bis-(isopropylamine)platinum(IV), cis-trans-[PtCl 2 (OH) 2 (i-PrNH 2 ) 2 ], (CHIP). An important feature of this Pt(IV) agent is that in addition to exhibiting a generally milder clinical toxicity than cisplatin, the dose-limiting toxicity of CHIP is the more common myelosuppression rather than the less desirable nephrotoxicity. Also, CHIP has been reported recently to be more effective than cisplatin against both alkylating agent sensitive and resistant strains of the Yoshida sarcoms. A microscale synthesis for /sup 195m/Pt-labelled CHIP and the tissue distribution and pharmacokinetic properties of this agent in normal female Fischer 344 rats are reported. A comparison with similar data for /sup 195m/Pt-cis-DDP is included

Strain difference of cadmium-induced testicular toxicity in inbred Wistar-Imamichi and Fischer 344 rats

Energy Technology Data Exchange (ETDEWEB)

Shimada, Hideaki; Narumi, Rika [Kumamoto University, Faculty of Education, Kumamoto (Japan); Nagano, Masaaki; Yasutake, Akira [National Institute for Minamata Disease, Biochemistry Section, Kumamoto (Japan); Waalkes, Michael P. [National Cancer Institute at the National Institute of Environmental Health Sciences, Inorganic Carcinogenesis Section, Laboratory of Comparative Carcinogenesis, Research Triangle Park, NC (United States); Imamura, Yorishige [Kumamoto University, Graduate School of Pharmaceutical Sciences, Kumamoto (Japan)

2009-07-15

Previously, we reported that Wistar-Imamichi (WI) rats are highly resistant to cadmium (Cd)-induced lethality and hepatotoxicity compared to Fischer 344 (F344) rats. Since the testes are one of the most sensitive organs to acute Cd toxicity, we examined possible strain-related differences in Cd-induced testicular toxicity between inbred WI and F344 rats. Rats were treated with a single dose of 0.5, 1.0 or 2.0 mg Cd/kg, as CdCl{sub 2}, sc and killed 24 h later. Cd at doses of 1.0 and 2.0 mg/kg induced severe testicular hemorrhage, as assessed by pathological and testis hemoglobin content, in F344 rats, but not WI rats. After Cd treatment (2.0 mg/kg), the testicular Cd content was significantly lower in WI rats than in the F344 rats, indicating a toxiokinetic mechanism for the observed strain difference. Thus, the remarkable resistance to Cd-induced testicular toxicity in WI rats is associated, at least in part, with lower testicular accumulation of Cd. When zinc (Zn; 10 mg/kg, sc) was administered in combination with Cd (2.0 mg/kg) to F344 rats, the Cd-induced increase in testicular hemoglobin content, indicative of hemorrhage, was significantly reduced. Similarly, the testicular Cd content was significantly decreased with Zn co-treatment compared to Cd treatment alone. Thus, it can be concluded that the testicular Cd accumulation partly competes with Zn transport systems and that these systems may play an important role in the strain-related differences in Cd-induced testicular toxicity between WI and F344 rats. (orig.)

Disposition of 1,2,3-trichloropropane in the Fischer 344 rat: conventional and physiological pharmacokinetics

International Nuclear Information System (INIS)

Volp, R.F.; Sipes, I.G.; Falcoz, C.; Carter, D.E.; Gross, J.F.

1984-01-01

To investigate the disposition of 1,2,3-trichloropropane (TCP), [14C]-TCP was administered iv to male Fischer 344 rats. Unchanged TCP and total radiolabel were determined in tissues and excreta at varying intervals after administration. The compound was distributed and eliminated rapidly. Initial and terminal half-lives of unchanged TCP in the blood were 0.29 and 23 hr. Adipose tissue accumulated 37% of the dose within 15 min and retained more of the dose than any other tissue until 4 hr; most (69%) of the radiolabel in adipose tissue through 4 hr was unchanged TCP. After 4 hr, the liver contained the largest fraction of the dose, primarily as metabolites. Thus TCP disappeared from adipose tissue while metabolites appeared in liver and other tissues. Excretion was nearly complete (90% of the dose) in 24 hr and was predominantly via the urine (47% of the dose). Expiration was the only route by which unchanged TCP (5% of the dose) was excreted. In addition, 25% of the dose was expired as carbon dioxide. There were numerous other metabolites, none accounting for more than 10% of the dose. Nonvolatile metabolites were longer lived than the parent compound. On the basis of high water solubility, reaction with 2,4-dinitrofluorobenzene, and diminished radiolabel in bile of glycidol-treated rats, glutathione conjugation is suggested as an important metabolic route for TCP. A physiological pharmacokinetic model was developed to describe the time course of trichloropropane concentration in tissues. The model demonstrates the possibility of using physiological and pharmacokinetic data to predict concentration-time relations for toxic compounds

Epistatic effects contribute to variation in BMD in Fischer 344 x Lewis F2 rats.

Science.gov (United States)

Koller, Daniel L; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J; Foroud, Tatiana; Turner, Charles H

2008-01-01

To further delineate the factors underlying the complex genetic architecture of BMD in the rat model, a genome screen for epistatic interactions was conducted. Several significant interactions were identified, involving both previously identified and novel QTLs. The variation in several of the risk factors for osteoporotic fracture, including BMD, has been shown to be caused largely by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We have previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 595 female F(2) progeny of Fischer 344 and Lewis rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted BMD (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine a genome-wide significance threshold for the epistasis or interaction LOD score corresponding to an alpha level of 0.01. Novel loci on chromosomes 12 and 15 showed a strong epistatic effect on total BMD at the femoral midshaft by pQCT (LOD = 5.4). A previously reported QTL on chromosome 7 was found to interact with a novel locus on chromosome 20 to affect whole lumbar BMD by pQCT (LOD = 6.2). These results provide new information regarding the mode of action of previously identified rat QTLs, as well as identifying novel loci that act in combination with known QTLs or with other novel loci to contribute to the risk factors for osteoporotic fracture.

Maternal environment alters social interactive traits but not open-field behavior in Fischer 344 rats.

Science.gov (United States)

Yamamuro, Yutaka

2008-10-01

Although it is recognized that the genetic background governs behavioral phenotypes, environmental factors also play a critical role in the development of various behavioral processes. The maternal environment has a major impact on pups, and the cross-fostering procedure is used to determine the influence of early life experiences. The present study examined the influence of maternal environment on behavioral traits in inbred Fischer 344 (F344) rats. F344/DuCrlCrlj and Wistar (Crlj:WI) pups were fostered from postnatal day 1 as follows: Wistar pups raised by Wistar dams, F344 raised by Wistar, Wistar raised by F344, and F344 raised by F344. At 10 weeks of age, rats were randomly assigned to an open-field test and social interaction test. In the open-field test, irrespective of the rearing conditions, the activity during the first 1 min was significantly lower in F344 rats than in Wistar rats. Latency to the onset of movement showed no difference between groups. In the social interaction test, the recognition performance during the first 1 min in F344 raised by F344 was significantly shorter than that in the other groups. The onset of recognition to a novel social partner in F344 raised by F344 was significantly delayed, and the delay disappeared upon cross-fostering by Wistar dams. These results raise the possibility that the behavioral phenotype of F344 rats results from the interplay of genetic factors and maternal environment during early life, and that F344 rats are a strain with high susceptibility to rearing conditions for the formation of their emotionality.

PROGRESS TOWARDS MODELING OF FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

Energy Technology Data Exchange (ETDEWEB)

Donna Post Guillen; Tami Grimmett; Anastasia M. Gandrik; Steven P. Antal

2010-11-01

The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

Enhanced treatment of Fischer-Tropsch wastewater using up-flow anaerobic sludge blanket system coupled with micro-electrolysis cell: A pilot scale study.

Science.gov (United States)

Wang, Dexin; Han, Yuxing; Han, Hongjun; Li, Kun; Xu, Chunyan

2017-08-01

The coupling of micro-electrolysis cell (MEC) with an up-flow anaerobic sludge blanket (UASB) system in pilot scale was established for enhanced treatment of Fischer-Tropsch (F-T) wastewater. The lowest influent pH (4.99±0.10) and reduced alkali addition were accomplished under the assistance of anaerobic effluent recycling of 200% (stage 5). Simultaneously, the optimum COD removal efficiency (93.5±1.6%) and methane production (2.01±0.13m 3 /m 3 ·d) at the lower hydraulic retention time (HRT) were achieved in this stage. In addition, the dissolved iron from MEC could significantly increase the protein content of tightly bound extracellular polymeric substances (TB-EPS), which was beneficial to formation of stable granules. Furthermore, the high-throughput 16S rRNA gene pyrosequencing in this study further confirmed that Geobacter species could utilize iron oxides particles as electron conduit to perform the direct interspecies electron transfer (DIET) with Methanothrix, finally facilitating the syntrophic degradation of propionic acid and butyric acid and contributing completely methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation for Pt-Loaded Zeolite Catalysts Using w/o Microemulsion and Their Hydrocracking Behaviors on Fischer-Tropsch Product

Directory of Open Access Journals (Sweden)

Toshiaki Hanaoka

2015-02-01

Full Text Available Pt-loaded β-type zeolite catalysts with constant Pt content (0.11 wt.% and similar pore structure were prepared using a water-in-oil (w/o microemulsion. The effect of Pt particle synthesis conditions using microemulsion (a type of Pt complex-forming agents and the molar ratio of complex-forming agent to Pt4+ on loaded Pt particle size was investigated. The Pt particle size of the Pt catalyst using tetraethylammonium chloride (TEAC as a complex-forming agent with the molar TEAC/Pt ratio 10 was the minimum value (3.8 nm, and was much smaller than that (6.7 nm prepared by the impregnation method. The utilization of the complex-forming agent of which hydrophobic groups occupied a small volume and the appropriate complex-forming agent/Pt ratio were favorable for synthesis of small Pt particles. The effect of loaded Pt particle size on the hydrocracking of the Fischer-Tropsch (FT product was investigated using the Pt-loaded zeolite catalysts at 250 °C with an initial H2 pressure of 0.5 MPa, and reaction time of 1 h. The Pt catalyst with a Pt particle size of 4.2 nm prepared using the microemulsion exhibited the maximum corresponding jet fuel yield (30.0%, which was higher than that of the impregnated catalyst.

Stress Alters the Discriminative Stimulus and Response Rate Effects of Cocaine Differentially in Lewis and Fischer Inbred Rats

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Therese A. Kosten

2012-03-01

Full Text Available Stress enhances the behavioral effects of cocaine, perhaps via hypothalamic-pituitary-adrenal (HPA axis activity. Yet, compared to Fischer 344 (F344 rats, Lewis rats have hyporesponsive HPA axis function and more readily acquire cocaine self-administration. We hypothesized that stress would differentially affect cocaine behaviors in these strains. The effects of three stressors on the discriminative stimulus and response rate effects of cocaine were investigated. Rats of both strains were trained to discriminate cocaine (10 mg/kg from saline using a two-lever, food-reinforced (FR10 procedure. Immediately prior to cumulative dose (1, 3, 10 mg/kg cocaine test sessions, rats were restrained for 15-min, had 15-min of footshock in a distinct context, or were placed in the shock-paired context. Another set of F344 and Lewis rats were tested similarly except they received vehicle injections to test if stress substituted for cocaine. Most vehicle-tested rats failed to respond after stressor exposures. Among cocaine-tested rats, restraint stress enhanced cocaine’s discriminative stimulus effects in F344 rats. Shock and shock-context increased response rates in Lewis rats. Stress-induced increases in corticosterone levels showed strain differences but did not correlate with behavior. These data suggest that the behavioral effects of cocaine can be differentially affected by stress in a strain-selective manner.

Effect of long-term caloric restriction on brain monoamines in aging male and female Fischer 344 rats.

Science.gov (United States)

Kolta, M G; Holson, R; Duffy, P; Hart, R W

1989-05-01

The present study examines the changes in central monoamines and their metabolites in aged male and female rats after long-term caloric restriction. Fischer 344 rats of both sexes (n = 5-10/group) were maintained on one of two dietary regimens: ad libitum NIH 31 diet or 60% by weight of the ad lib. intake (restricted), supplemented with vitamins and minerals. Animals received these diets from the age of 14 weeks until killed at 22.25 months of age. Caudate nucleus (CN), hypothalamus (HYPO), olfactory bulb (OB) and nucleus accumbens (NA) were assayed for content of norepinephrine (NE), dopamine (DA) and its metabolites (dihydroxyphenylacetic acid, DOPAC, and homovanillic acid, HVA) and serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) using HPLC/EC. Relative to the ad lib. group, restricted rats of both sex showed significant decreases in NE content in CN, HYPO and OB. DA and 5-HT content were decreased significantly in the CN and HYPO. No significant changes were found in the levels of DA metabolites in all brain regions studied. While the 5-HIAA level was significantly reduced in the HYPO and NA of the female restricted rats, it was increased several-fold in the OB of the male restricted animals. These preliminary results suggest that long-term caloric restriction alters brain monoamine concentrations, an effect which may in turn modify the normal rate of aging.

Fischer-Tropsch diesel production in a well-to-wheel perspective: A carbon, energy flow and cost analysis

International Nuclear Information System (INIS)

van Vliet, Oscar P.R.; Faaij, Andre P.C.; Turkenburg, Wim C.

2009-01-01

We calculated carbon and energy balances and costs of 14 different Fischer-Tropsch (FT) fuel production plants in 17 complete well-to-wheel (WTW) chains. The FT plants can use natural gas, coal, biomass or mixtures as feedstock. Technical data, and technological and economic assumptions for developments for 2020 were derived from the literature, recalculating to 2005 euros for (capital) costs. Our best-guess WTW estimates indicate BTL production costs break even when oil prices rise above $75/bbl, CTL above $60/bbl and GTL at $36/bbl. CTL, and GTL without carbon capture and storage (CCS), will emit more CO 2 than diesel from conventional oil. Driving on fuel from GTL with CCS may reduce GHG emissions to around 123 g CO 2 /km. Driving on BTL may cause emissions of 32-63 g CO 2 /km and these can be made negative by application of CCS. It is possible to have net climate neutral driving by combining fuels produced from fossil resources with around 50% BTL with CCS, if biomass gasification and CCS can be made to work on an industrial scale and the feedstock is obtained in a climate-neutral manner. However, the uncertainties in these numbers are in the order of tens of percents, due to uncertainty in the data for component costs, variability in prices of feedstocks and by-products, and the GHG impact of producing biomass. (author)

Decline of prefrontal cortical-mediated executive functions but attenuated delay discounting in aged Fischer 344 × brown Norway hybrid rats.

Science.gov (United States)

Hernandez, Caesar M; Vetere, Lauren M; Orsini, Caitlin A; McQuail, Joseph A; Maurer, Andrew P; Burke, Sara N; Setlow, Barry; Bizon, Jennifer L

2017-12-01

Despite the fact that prefrontal cortex (PFC) function declines with age, aged individuals generally show an enhanced ability to delay gratification, as evident by less discounting of delayed rewards in intertemporal choice tasks. The present study was designed to evaluate relationships between 2 aspects of PFC-dependent cognition (working memory and cognitive flexibility) and intertemporal choice in young (6 months) and aged (24 months) Fischer 344 × brown Norway F1 hybrid rats. Rats were also evaluated for motivation to earn rewards using a progressive ratio task. As previously reported, aged rats showed attenuated discounting of delayed rewards, impaired working memory, and impaired cognitive flexibility compared with young. Among aged rats, greater choice of delayed reward was associated with preserved working memory, impaired cognitive flexibility, and less motivation to work for food. These relationships suggest that age-related changes in PFC and incentive motivation contribute to variance in intertemporal choice within the aged population. Cognitive impairments mediated by PFC are unlikely, however, to fully account for the enhanced ability to delay gratification that accompanies aging. Copyright © 2017 Elsevier Inc. All rights reserved.

Epistatic Effects Contribute to Variation in BMD in Fischer 344 × Lewis F2 Rats

Science.gov (United States)

Koller, Daniel L; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J; Foroud, Tatiana; Turner, Charles H

2008-01-01

To further delineate the factors underlying the complex genetic architecture of BMD in the rat model, a genome screen for epistatic interactions was conducted. Several significant interactions were identified, involving both previously identified and novel QTLs. Introduction The variation in several of the risk factors for osteoporotic fracture, including BMD, has been shown to be caused largely by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We have previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 595 female F2 progeny of Fischer 344 and Lewis rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Materials and Methods Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted BMD (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine a genome-wide significance threshold for the epistasis or interaction LOD score corresponding to an α level of 0.01. Results and Conclusions Novel loci on chromosomes 12 and 15 showed a strong epistatic effect on total BMD at the femoral midshaft by pQCT (LOD = 5.4). A previously reported QTL on chromosome 7 was found to interact with a novel locus on chromosome 20 to affect whole lumbar BMD by pQCT (LOD = 6.2). These results provide new information regarding the mode of action of previously identified rat QTLs, as well as identifying novel loci that act in combination with known QTLs or with other novel loci to contribute to the risk factors for osteoporotic fracture. PMID:17907919

Disposition of 2,4-dichlorophenoxyacetic acid dimethylamine by Fischer 344 rats dosed orally and dermally

International Nuclear Information System (INIS)

Pelletier, O.; Ritter, L.; Caron, J.; Somers, D.

1989-01-01

The dimethylamine salt of 14C-ring-labeled 2,4-D was administered to Fischer 344 rats orally (1 and 0.4 mg/kg body weight) and dermally (10 mg/kg body weight). Absorption, distribution, and elimination were determined from 14C-labeled 2,4-D in blood, tissues, and excreta. Quantitatively, most of the orally administered dose (94-96%) became systemically available within 6 h. Following dermal administration 10% of the dose became systemically available over 72 h. However, peak concentrations in blood and kidneys were achieved within 30 min of dosing by either route. By 1.5 h after dosing, 2,4-D concentrations in blood, muscle, liver, and kidneys had decreased in both the orally dosed and dermally dosed animals. Between 2 and 8 h, the blood, muscle, liver and kidney concentrations in dermally dosed animals maintained a plateau while urinary excretion increased, presumably due to continued absorption of 2,4-D from the skin. The concentrations in orally dosed animals continued to decrease. Following 7 h of dermal exposure, skin cleansing removed about 63% of the applied dose; about 17% of the applied dose remained at the site of dermal dosing. At 8 h, 2,4-D concentrations in blood, muscle, liver, and kidneys of dermally dosed animals began to decrease, most likely a result of the removal of the reservoir on the skin. However, 2,4-D continued to be absorbed from skin site, resulting in a slower decline of the 2,4-D concentrations in these tissues over remainder of the 72-h study period. By comparison, in animals that had been orally dosed, the absorbed dose was almost completely excreted within 24 h

Life cycle assessment of climate impact of Fischer-Tropsch diesel based on peat and biomass

Energy Technology Data Exchange (ETDEWEB)

Holmgren, Kristina; Hagberg, Linus

2009-02-15

By combining biomass gasification and Fischer-Tropsch synthesis it is possible to produce biodiesel. Vapo is investigating the possibilities for a plant where a mixture of different biomass fractions and peat would be used as raw material. In this study the climate impact of such synthetic diesel is calculated in terms of radiative forcing. The calculations show that the following parameters have large impact on the results: the emission factors associated with external power demand (purchased electricity) the use of carbon capture and storage the time perspective used in the analysis the raw material mix (amount of peat vs. amount of forest residues) the reference scenario for the peat production (type of peatland) All the FT-diesel scenarios with a peat input of 90% will have higher climate impact than fossil diesel after 100 years, except when CCS is applied and Swedish electricity mix is assumed for the external power demand. In order to have lower climate impact than conventional diesel after 100 years, the peat input must be significantly lower than the biomass input. Substantial reductions of the climate impact can be achieved by applying CCS. With CCS, all peat based FT-diesel scenarios (except the ones based on 90% peat) result in lower climate impact than fossil diesel after both 100 and 300 years. For scenarios with marginal electricity, the reductions are 50-84% after 100 years compared to conventional diesel. For scenarios with Swedish electricity mix the reductions are 100-135% (i.e. zero or negative radiative forcing). The scenarios in this study are based on the assumption that the biodiesel refinery is located close to a harbour so that transportation of captured CO{sub 2} to a storage site can be made by ship. An inland location would require truck transport or pipelines and the cost, infrastructure and logistics for this might not be feasible

Fischer-Tropsch Cobalt Catalyst Improvements with the Presence of TiO2, La2O3, and ZrO2 on an Alumina Support

Science.gov (United States)

Klettlinger, Jennifer Lindsey Suder

2012-01-01

The objective of this study was to evaluate the effect of titanium oxide, lanthanum oxide, and zirconium oxide on alumina supported cobalt catalysts. The hypothesis was that the presence of lanthanum oxide, titanium oxide, and zirconium oxide would reduce the interaction between cobalt and the alumina support. This was of interest because an optimized weakened interaction could lead to the most advantageous cobalt dispersion, particle size, and reducibility. The presence of these oxides on the support were investigated using a wide range of characterization techniques such as SEM, nitrogen adsorption, x-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed reduction after reduction (TPR-AR), and hydrogen chemisorptions/pulse reoxidation. Results indicated that both La2O3 and TiO2 doped supports facilitated the reduction of cobalt oxide species in reference to pure alumina supported cobalt catalysts, however further investigation is needed to determine the effect of ZrO2 on the reduction profile. Results showed an increased corrected cluster size for all three doped supported catalysts in comparison to their reference catalysts. The increase in reduction and an increase in the cluster size led to the conclusion that the support-metal interaction weakened by the addition of TiO2 and La2O3. It is also likely that the interaction decreased upon presence of ZrO2 on the alumina, but further research is necessary. Preliminary results have indicated that the alumina-supported catalysts with titanium oxide and lanthanum oxide present are of interest because of the weakened cobalt support interaction. These catalysts showed an increased extent of reduction, therefore more metallic cobalt is present on the support. However, whether or not there is more cobalt available to participate in the Fischer-Tropsch synthesis reaction (cobalt surface atoms) depends also on the cluster size. On one hand, increasing cluster size alone tends to decrease the

Ultra-clean Fischer-Tropsch (F-T) Fuels Production and Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Stephen P. Bergin

2006-06-30

The objective of the DOE-NETL Fischer-Tropsch (F-T) Production and Demonstration Program was to produce and evaluate F-T fuel derived from domestic natural gas. The project had two primary phases: (1) fuel production of ultra-clean diesel transportation fuels from domestic fossil resources; and (2) demonstration and performance testing of these fuels in engines. The project also included a well-to-wheels economic analysis and a feasibility study of small-footprint F-T plants (SFPs) for remote locations such as rural Alaska. During the fuel production phase, ICRC partnered and cost-shared with Syntroleum Corporation to complete the mechanical design, construction, and operation of a modular SFP that converts natural gas, via F-T and hydro-processing reactions, into hydrogensaturated diesel fuel. Construction of the Tulsa, Oklahoma plant started in August 2002 and culminated in the production of over 100,000 gallons of F-T diesel fuel (S-2) through 2004, specifically for this project. That fuel formed the basis of extensive demonstrations and evaluations that followed. The ultra-clean F-T fuels produced had virtually no sulfur (less than 1 ppm) and were of the highest quality in terms of ignition quality, saturation content, backend volatility, etc. Lubricity concerns were investigated to verify that commercially available lubricity additive treatment would be adequate to protect fuel injection system components. In the fuel demonstration and testing phase, two separate bus fleets were utilized. The Washington DC Metropolitan Area Transit Authority (WMATA) and Denali National Park bus fleets were used because they represented nearly opposite ends of several spectra, including: climate, topography, engine load factor, mean distance between stops, and composition of normally used conventional diesel fuel. Fuel evaluations in addition to bus fleet demonstrations included: bus fleet emission measurements; F-T fuel cold weather performance; controlled engine dynamometer

Anion-modified zirconia. Effect of metal promotion and hydrogen reduction on hydroisomerization of n-hexadecane and Fischer-Tropsch waxes

Energy Technology Data Exchange (ETDEWEB)

Zhang, S.; Zhang, Y.; Tierney, J.W.; Wender, I. [Department of Chemical and Petroleum Engineering, 1249 Benedum Hall, University of Pittsburgh, 15261 Pittsburgh, PA (United States)

2001-01-01

The effect of metal promoters on the activity and selectivity of tungstated zirconia (8 wt.% W) for n-hexadecane isomerization in a trickle bed continuous reactor is studied by using different metals (Pt, Ni, and Pd) and, in one case, by varying metal loading. Platinum is found to be the best promoter. The effect of hydrogen reduction is investigated using platinum-promoted tungstated zirconia catalysts (Pt/WO{sub 3}/ZrO{sub 2}, 0.5 wt.% Pt and 6.5 wt.% W). Pretreatment at temperatures between 300 and 400C for 3 h in hydrogen is found to be slightly beneficial for achieving high yields of isohexadecane. A platinum promoted sulfated zirconia (Pt/SO{sub 4}/ZrO{sub 2}) is compared with a Pt/WO{sub 3}/ZrO{sub 2} catalyst for the hydroisomerization of n-hexadecane in the same reactor at the same n-hexadecane conversion. The former is a good cracking catalyst and the latter is suitable for use as a hydroisomerization catalyst. In a 27-ml microautoclave reactor, studies of the hydroisomerization and hydrocracking of two Fischer-Tropsch (F-T) wax samples are carried out. Severe cracking can be effectively suppressed using a Pt/WO{sub 3}/ZrO{sub 2} catalyst so as to obtain branched isomers in the diesel fuel or lube-base oil range.

A comparison of Lewis and Fischer rat strains on autoshaping (sign-tracking), discrimination reversal learning and negative auto-maintenance.

Science.gov (United States)

Kearns, David N; Gomez-Serrano, Maria A; Weiss, Stanley J; Riley, Anthony L

2006-05-15

Lewis (LEW) and Fischer (F344) rat strains differ on a number of physiological characteristics, such as hypothalamic-pituitary-adrenal (HPA) axis activity, as well as on behavioral tasks, including those that measure impulsivity and drug reward. Since autoshaping, the phenomenon where animals approach and contact reward-paired conditioned stimuli, has been linked to HPA axis functioning, impulsivity and drug taking, the present study compared LEW and F344 rats on the rate of acquisition and performance of the autoshaping response. Rats were trained on an autoshaping procedure where insertions of one retractable lever (CS(+)) were paired response-independently with food, while insertions of another lever (CS(-)) were not paired with food. LEW rats acquired the autoshaping response more rapidly and also performed the autoshaping response at a higher rate than F344 rats. No differences between the strains were observed when rats were trained on a discrimination reversal where the CS(+) and CS(-) levers were reversed or during a negative auto-maintenance phase where CS(+) lever contacts cancelled food delivery. Potential physiological mechanisms that might mediate the present results, including strain differences in HPA axis and monoamine neurotransmitter activity, are discussed. The finding that LEW (as compared to F344 rats) more readily acquire autoshaping and perform more responses is consistent with research indicating that LEW rats behave more impulsively and more readily self-administer drugs of abuse.

Effect of culture media on virulence of Hirsutella thompsonii (Fischer) (Deuteromycetes) to control Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae)

International Nuclear Information System (INIS)

Rossi-Zalaf, Luciana S.; Alves, Sergio B.; Vieira, Solange A.

2008-01-01

The virulence of Hirsutella thompsonii (Fischer) to Brevipalpus phoenicis (Geijskes) was evaluated in laboratory, grown on complete and solid culture media (MC-S); complete and liquid culture media (MC-L); rice (APC) and powdered rice (APC-SM). Adults were confined to arenas prepared with citrus leaves in acrylic dishes containing water-agar. Conidial suspensions were prepared at different concentration (3.2 x 10 5 to 1 x 10 7 spores/ml) and applied on mites to establish the table curve-response on fourth day. For field evaluation, adults were maintained in arenas prepared with fruits which were placed in plants. In this test, four treatments were tried: H. thompsonii cultured on rice (APC) at two concentrations (20 kg/ha and 10 kg/ha), H. thompsonii produced by liquid fermentation (MC-L) (5 L/ha) and control (sterile water). Adult survival, number of eggs and nymphs per fruit were observed 10 and 20 days after the fungus application. The lowest LC 25 value calculated was from pathogen produced in MC-S (1.9 x 10 5 conidia/ml).The LC 25 values calculated to APC and APC-SM did not differ statistically. The LC 25 values to MC-L and MC-S were 1.9 x 10 6 infective cells/ml and 2.2 x 10 5 conidia/ml. In the fi eld, concentration and time to death differed between treatments and control. The applications resulted in reduction of adult survival and number of eggs. (author)

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS. FOURTH ANNUAL TECHNICAL PROGRESS REPORT

International Nuclear Information System (INIS)

Bukur, Dragomir B.; Froment, Gilbert F.; Olewski, Tomasz

2006-01-01

This report covers the fourth year of a research project conducted under the University Coal Research Program. The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (water, carbon dioxide, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the fourth year of the project, an analysis of experimental data collected during the second year of this project was performed. Kinetic parameters were estimated utilizing product distributions from 27 mass balances. During the reporting period two kinetic models were employed: a comprehensive kinetic model of Dr. Li and co-workers (Yang et al., 2003) and a hydrocarbon selectivity model of Van der Laan and Beenackers (1998, 1999) The kinetic model of Yang et al. (2003) has 24 parameters (20 parameters for hydrocarbon formation, and 4 parameters for the water-gas-shift (WGS) reaction). Kinetic parameters for the WGS reaction and FTS synthesis were estimated first separately, and then simultaneously. The estimation of these kinetic parameters employed the Levenberg-Marquardt (LM) method and the trust-region reflective Newton large-scale (LS) method. A genetic algorithm (GA) was incorporated into estimation of parameters for FTS reaction to provide initial estimates of model parameters. All reaction rate constants and activation energies were found to be positive, but at the 95% confidence level the intervals were large. Agreement between predicted and experimental reaction rates has been fair to good. Light hydrocarbons are predicted fairly accurately, whereas the model underpredicts values of higher molecular weight

Kinetics of Slurry Phase Fischer-Tropsch Synthesis

Energy Technology Data Exchange (ETDEWEB)

Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski; Lech Nowicki; Madhav Nayapati

2006-12-31

The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. Three STSR tests of the Ruhrchemie LP 33/81 catalyst were conducted to collect data on catalyst activity and selectivity under 25 different sets of process conditions. The observed decrease in 1-olefin content and increase in 2-olefin and n-paraffin contents with the increase in conversion are consistent with a concept that 1-olefins participate in secondary reactions (e.g. 1-olefin hydrogenation, isomerization and readsorption), whereas 2-olefins and n-paraffins are formed in these reactions. Carbon number product distribution showed an increase in chain growth probability with increase in chain length. Vapor-liquid equilibrium calculations were made to check validity of the assumption that the gas and liquid phases are in equilibrium during FTS in the STSR. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Discrepancies between the calculated and experimental values for the liquid-phase composition (for some of the experimental data) are ascribed to experimental errors in the amount of wax collected from the reactor, and the relative amounts of hydrocarbon wax and Durasyn 164 oil (start-up fluid) in the liquid samples. Kinetic parameters of four kinetic models (Lox and Froment, 1993b; Yang et al., 2003; Van der Laan and Beenackers, 1998, 1999; and an extended kinetic model of Van der Laan and Beenackers) were estimated from experimental data in the STSR tests. Two of these kinetic models (Lox and Froment, 1993b; Yang et al., 2003) can predict a complete product distribution (inorganic species and hydrocarbons), whereas the kinetic model of Van der Laan and Beenackers (1998, 1999) can

Kinetics of Slurry Phase Fischer-Tropsch Synthesis

International Nuclear Information System (INIS)

Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski; Lech Nowicki; Madhav Nayapati

2006-01-01

The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. Three STSR tests of the Ruhrchemie LP 33/81 catalyst were conducted to collect data on catalyst activity and selectivity under 25 different sets of process conditions. The observed decrease in 1-olefin content and increase in 2-olefin and n-paraffin contents with the increase in conversion are consistent with a concept that 1-olefins participate in secondary reactions (e.g. 1-olefin hydrogenation, isomerization and readsorption), whereas 2-olefins and n-paraffins are formed in these reactions. Carbon number product distribution showed an increase in chain growth probability with increase in chain length. Vapor-liquid equilibrium calculations were made to check validity of the assumption that the gas and liquid phases are in equilibrium during FTS in the STSR. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Discrepancies between the calculated and experimental values for the liquid-phase composition (for some of the experimental data) are ascribed to experimental errors in the amount of wax collected from the reactor, and the relative amounts of hydrocarbon wax and Durasyn 164 oil (start-up fluid) in the liquid samples. Kinetic parameters of four kinetic models (Lox and Froment, 1993b; Yang et al., 2003; Van der Laan and Beenackers, 1998, 1999; and an extended kinetic model of Van der Laan and Beenackers) were estimated from experimental data in the STSR tests. Two of these kinetic models (Lox and Froment, 1993b; Yang et al., 2003) can predict a complete product distribution (inorganic species and hydrocarbons), whereas the kinetic model of Van der Laan and Beenackers (1998, 1999) can

Dietary Chemoprevention of PhIP Induced Carcinogenesis in Male Fischer 344 Rats with Tomato and Broccoli

Science.gov (United States)

Canene-Adams, Kirstie; Sfanos, Karen S.; Liang, Chung-Tiang; Yegnasubramanian, Srinivasan; Nelson, William G.; Brayton, Cory; De Marzo, Angelo M.

2013-01-01

The heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-B]pyridine (PhIP), found in meats cooked at high temperatures, has been implicated in epidemiological and rodent studies for causing breast, prostate, and colorectal cancers. A previous animal study using a xenograft model has shown that whole tomato and broccoli, when eaten in combination, exhibit a marked effect on tumor reduction compared to when eaten alone. Our aim was to determine if PhIP-induced carcinogenesis can be prevented by dietary consumption of whole tomato + broccoli powders. Male Fischer 344 rats (n = 45) were randomized into the following treatment groups: control (AIN93G diet), PhIP (200 ppm in AIN93G diet for the first 20 weeks of the study), or tomato + broccoli + PhIP (mixed in AIN93G diet at 10% each and fed with PhIP for 20 weeks, and then without PhIP for 32 weeks). Study animals were monitored for 52 weeks and were euthanized as necessary based on a set of criteria for health status and tumor burden. Although there appeared to be some hepatic and intestinal toxicity due to the combination of PhIP and tomato + broccoli, these rodents had improved survival and reduced incidence and/or severity of PhIP-induced neoplastic lesions compared to the PhIP-alone treated group. Rats eating tomato + broccoli exhibited a marked decrease in the number and size of cribiform prostatic intraepitheilial neoplasia/carcinoma in situ (cribiform PIN/CIS) lesions and in the incidence of invasive intestinal adenocarcinomas and skin carcinomas. Although the apparent toxic effects of combined PhIP and tomato + broccoli need additional study, the results of this study support the hypothesis that a diet rich in tomato and broccoli can reduce or prevent dietary carcinogen-induced cancers. PMID:24312188

The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO

International Nuclear Information System (INIS)

Warringham, Robbie; McFarlane, Andrew R.; Lennon, David; MacLaren, Donald A.; Webb, Paul B.; Tooze, Robert P.; Taylor, Jon; Ewings, Russell A.; Parker, Stewart F.

2015-01-01

An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe 2 O 3 ) is distinguished by a relatively intense band at 810 cm −1 , which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered

Inhibition of beta-catenin and KRAS expressions by Piper betle in azoxymethane-induced colon cancer of male Fischer 344 rats.

Science.gov (United States)

Esa, Faezah; Ngah, Wan Zurinah Wan; Jamal, A Rahman A; Mohd Yusof, Yasmin Anum

2013-12-01

To investigate the chemopreventive effect of Piper betle (PB) on preneoplastic lesions (aberrant crypt foci [ACF]) induced by azoxymethane (AOM) in rats and its effect on colorectal cancer biomarkers (beta-catenin, KRAS, p53 and p21). A total of 32 male Fischer 344 rats were divided into phase 1 and phase 2 groups (8 and 24 weeks of AOM administration, respectively). Each phase was divided into 4 groups: control or normal saline (NS) (1 mL/kg), AOM (15 mg/kg body weight, once weekly for 2 weeks), PB (75 mg/kg body weight) and AOM + PB. PB was force-fed to rats a week after the second dose of AOM and NS. The colon was cut open longitudinally for methylene blue and immunohistochemistry staining. AOM administration showed formation of ACF at 8 and 24 weeks. PB, however, did not reduce ACF formation at either week, but it managed to reduce beta-catenin expression and KRAS found highly expressed in the AOM group of phase 1 rats. No immunoreactivities of p53 and p21 were detected in phase 2 rats, but instead inflammatory cells were visible in between the lesions. PB may act as a potential chemopreventive agent in the early stage of colon carcinogenesis by suppressing the expressions of beta-catenin and KRAS.

Pathological Outcomes in Kidney and Brain in Male Fischer Rats Given Dietary Ochratoxin A, Commencing at One Year of Age

Science.gov (United States)

Mantle, Peter G.; Nolan, Christopher C.

2010-01-01

Malignant renal carcinoma, manifest in morbid ageing rats, is the striking component of an otherwise silent response after about nine months of exposure to ochratoxin A in the first year of life (daily intake ~100-250 µg/kg body weight). Reasons for the long latency are unclear, as is whether there would be a similar carcinogenic response if toxin exposure started at one year of age. Therefore, 24 male Fischer rats were given 100 µg ochratoxin A as a daily dietary contaminant for 35 weeks from age 50 weeks. Plasma ochratoxin A concentration reached a maximum value of ~8 µg/mL within one month of starting the toxin regimen. No renal carcinomas occurred. Four renal adenomas, two of which were only microscopic, were found among the six rats surviving for 110 weeks. The findings raise new questions about a difference between young adults and mature adults in sensitivity of male rats to the ochratoxin A-induced DNA damage necessary for renal carcinogenesis. A pilot histological study of perfuse-fixed brains of the toxin-treated rats showed no gross abnormalities, correlating with the consistent absence of behavioral or neurological disorders from chronic ochratoxin A exposure regimens in the range 100-250 µg/kg/day during the second half of life. Reasoned questioning concerning ochratoxin A as a neurotoxic mycotoxin is made. PMID:22069628

Pathological Outcomes in Kidney and Brain in Male Fischer Rats Given Dietary Ochratoxin A, Commencing at One Year of Age

Directory of Open Access Journals (Sweden)

Peter G. Mantle

2010-05-01

Full Text Available Malignant renal carcinoma, manifest in morbid ageing rats, is the striking component of an otherwise silent response after about nine months of exposure to ochratoxin A in the first year of life (daily intake ~100–250 µg/kg body weight. Reasons for the long latency are unclear, as is whether there would be a similar carcinogenic response if toxin exposure started at one year of age. Therefore, 24 male Fischer rats were given 100 µg ochratoxin A as a daily dietary contaminant for 35 weeks from age 50 weeks. Plasma ochratoxin A concentration reached a maximum value of ~8 µg/mL within one month of starting the toxin regimen. No renal carcinomas occurred. Four renal adenomas, two of which were only microscopic, were found among the six rats surviving for 110 weeks. The findings raise new questions about a difference between young adults and mature adults in sensitivity of male rats to the ochratoxin A-induced DNA damage necessary for renal carcinogenesis. A pilot histological study of perfuse-fixed brains of the toxin-treated rats showed no gross abnormalities, correlating with the consistent absence of behavioral or neurological disorders from chronic ochratoxin A exposure regimens in the range 100–250 µg/kg/day during the second half of life. Reasoned questioning concerning ochratoxin A as a neurotoxic mycotoxin is made.

A general chelate-assisted co-assembly to metallic nanoparticles-incorporated ordered mesoporous carbon catalysts for Fischer-Tropsch synthesis.

Science.gov (United States)

Sun, Zhenkun; Sun, Bo; Qiao, Minghua; Wei, Jing; Yue, Qin; Wang, Chun; Deng, Yonghui; Kaliaguine, Serge; Zhao, Dongyuan

2012-10-24

The organization of different nano objects with tunable sizes, morphologies, and functions into integrated nanostructures is critical to the development of novel nanosystems that display high performances in sensing, catalysis, and so on. Herein, using acetylacetone as a chelating agent, phenolic resol as a carbon source, metal nitrates as metal sources, and amphiphilic copolymers as a template, we demonstrate a chelate-assisted multicomponent coassembly method to synthesize ordered mesoporous carbon with uniform metal-containing nanoparticles. The obtained nanocomposites have a 2-D hexagonally arranged pore structure, uniform pore size (~4.0 nm), high surface area (~500 m(2)/g), moderate pore volume (~0.30 cm(3)/g), uniform and highly dispersed Fe(2)O(3) nanoparticles, and constant Fe(2)O(3) contents around 10 wt %. By adjusting acetylacetone amount, the size of Fe(2)O(3) nanoparticles is readily tunable from 8.3 to 22.1 nm. More importantly, it is found that the metal-containing nanoparticles are partially embedded in the carbon framework with the remaining part exposed in the mesopore channels. This unique semiexposure structure not only provides an excellent confinement effect and exposed surface for catalysis but also helps to tightly trap the nanoparticles and prevent aggregating during catalysis. Fischer-Tropsch synthesis results show that as the size of iron nanoparticles decreases, the mesoporous Fe-carbon nanocomposites exhibit significantly improved catalytic performances with C(5+) selectivity up to 68%, much better than any reported promoter-free Fe-based catalysts due to the unique semiexposure morphology of metal-containing nanoparticles confined in the mesoporous carbon matrix.

Histograms showing variations in oil yield, water yield, and specific gravity of oil from Fischer assay analyses of oil-shale drill cores and cuttings from the Piceance Basin, northwestern Colorado

Science.gov (United States)

Dietrich, John D.; Brownfield, Michael E.; Johnson, Ronald C.; Mercier, Tracey J.

2014-01-01

Recent studies indicate that the Piceance Basin in northwestern Colorado contains over 1.5 trillion barrels of oil in place, making the basin the largest known oil-shale deposit in the world. Previously published histograms display oil-yield variations with depth and widely correlate rich and lean oil-shale beds and zones throughout the basin. Histograms in this report display oil-yield data plotted alongside either water-yield or oil specific-gravity data. Fischer assay analyses of core and cutting samples collected from exploration drill holes penetrating the Eocene Green River Formation in the Piceance Basin can aid in determining the origins of those deposits, as well as estimating the amount of organic matter, halite, nahcolite, and water-bearing minerals. This report focuses only on the oil yield plotted against water yield and oil specific gravity.

The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO

Energy Technology Data Exchange (ETDEWEB)

Warringham, Robbie; McFarlane, Andrew R.; Lennon, David, E-mail: David.Lennon@Glasgow.ac.uk [School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, Scotland G12 8QQ (United Kingdom); MacLaren, Donald A. [School of Physics and Astronomy, University of Glasgow, The Kelvin Building, Glasgow, Scotland G12 8QQ (United Kingdom); Webb, Paul B.; Tooze, Robert P. [Sasol Technology UK Ltd., Purdie Building, North Haugh, St Andrews, Fife KY16 9ST (United Kingdom); Taylor, Jon; Ewings, Russell A.; Parker, Stewart F. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

2015-11-07

An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe{sub 2}O{sub 3}) is distinguished by a relatively intense band at 810 cm{sup −1}, which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

Effects of grafts of single anterior pituitary glands on the incidence and type of mammary neoplasm in neutron- or γ-irradiated Fischer female rats

International Nuclear Information System (INIS)

Clifton, K.H.; Douple, E.B.; Sridharan, B.N.

1976-01-01

Three batches comprised of 48 young adult Fischer female rats each were subjected to total-body irradiation with 50 rads modified fission neutrons, or were given 600 rads 137 Cs γ-rays, or served as unirradiated controls. On the day following exposure, one-half of each batch was grafted with a single anterior pituitary gland beneath the left kidney capsule. The animals were observed for mammary neoplasia and all those that died during the experiment were autopsied. The experiment was terminated 538 +- 13 days after irradiation when all neutron-irradiated, pituitary-grafted animals had one or more mammary tumors. Only 2 of the 23 untreated rats that survived until termination of the experiment developed mammary fibroadenomas, and none had mammary carcinomas. The incidence of fibroadenomas was increased, and a single carcinoma was found in unirradiated rats with pituitary grafts. Irradiation alone caused an increase in the incidence of mammary fibroadenomas and the appearance of carcinomas. Fibroadenomas were markedly increased by the addition of pituitary grafts to irradiation. Carcinoma incidence was less markedly affected. The neutron dose of 50 rads was slightly more effective in inducing mammary neoplasms than the 600-rad dose of γ-rays

DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

Energy Technology Data Exchange (ETDEWEB)

Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

2011-12-01

The Hybrid Energy Systems Testing (HYTEST) Laboratory at the Idaho National Laboratory was established to develop and test hybrid energy systems with the principal objective of reducing dependence on imported fossil fuels. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions are performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. These SBCRs operate in the churn-turbulent flow regime, which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer. Our team is developing a research tool to aid in understanding the physicochemical processes occurring in the SBCR. A robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) consisting of thirteen species, which are CO reactant, H2 reactant, hydrocarbon product, and H2O product in small bubbles, large bubbles, and the bulk fluid plus catalyst is outlined. Mechanistic submodels for interfacial momentum transfer in the churn-turbulent flow regime are incorporated, along with bubble breakup/coalescence and two-phase turbulence submodels. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield. The model includes heat generation produced by the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. A property method approach is employed to incorporate vapor-liquid equilibrium (VLE) in a robust manner. Physical and thermodynamic properties as functions of changes in both pressure and temperature are obtained from VLE calculations performed external to the CMFD solver. The novelty of this approach is in its simplicity, as well as its

Enhanced anaerobic degradation of Fischer-Tropsch wastewater by integrated UASB system with Fe-C micro-electrolysis assisted.

Science.gov (United States)

Wang, Dexin; Ma, Wencheng; Han, Hongjun; Li, Kun; Xu, Hao; Fang, Fang; Hou, Baolin; Jia, Shengyong

2016-12-01

Coupling of the Fe-C micro-electrolysis (IC-ME) into the up-flow anaerobic sludge blanket (UASB) was developed for enhanced Fischer-Tropsch wastewater treatment. The COD removal efficiency and methane production in R 3 with IC-ME assisted both reached up to 80.6 ± 1.7% and 1.38 ± 0.11 L/L·d that higher than those values in R 1 with GAC addition (63.0 ± 3.4% and 0.95 ± 0.09 L/L·d) and R 2 with ZVI addition (74.5 ± 2.8% and 1.21 ± 0.09 L/L·d) under the optimum HRT (5 d). The Fe corrosion as electron donor reduced the ORP values and stimulated the activities of hydrogenotrophic methanogens to lower H 2 partial pressure in R 2 and R 3 . Additionally, Fe 2+ as by-product of iron corrosion, its presence could effectively increase the percentage of protein content in tightly bound extracellular polymeric substances (TB-EPS) to promote better bioflocculation, increasing to 90.5 mg protein/g·VSS (R 2 ) and 106.3 mg protein/g·VSS (R 3 ) while this value in R1 was simply 56.6 mg protein/g·VSS. More importantly, compared with R 1 , the excess accumulation of propionic acid and butyric acid in system was avoided. The macroscopic galvanic cells around Fe-C micro-electrolysis carriers in R 3 , that larger than microscopic galvanic cells in R 2 , further accelerate to transfer the electrons from anodic Fe to cathodic carbon that enhance interspecies hydrogen transfer, making the decomposition of propionic acid and butyric acid more thermodynamically feasible, finally facilitate more methane production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical composition and bio-pesticidal values of essential oil isolated from the seed of Heracleum persicum Desf. ex Fischer (Apiaceae

Directory of Open Access Journals (Sweden)

Asgar Ebadollahi

2014-11-01

Full Text Available The present investigation was aimed to analyse the chemical composition of essential oil isolated from Heracleum persicum Desf. ex Fischer and assess its lethal and sub-lethal effects against Tribolium castaneum (Herbst. Essential oil from hydro-distilled seeds of H. persicum was analyzed by gas chromatography-mass spectrometry (GC-MS, and hexyl butyrate (50.58%, octyl acetate (9.80% and hexyl hexanoate (8.75% were found as principal constituents. Repellent activity, contact and fumigant toxicity and antifeedant effects of this oil were assessed against the adults of T. castaneum. The essential oil strongly repelled T. castaneum adults even at the lowest concentration (0.035 μL cm-2. Complete repellency (100% occurred when the highest concentration (0.212 μL cm-2 was applied for 8 h. T. castaneum was very susceptible to H. persicum oil at both contact and fumigant bioassays. In the fumigant toxicity, essential oil killed the larvae, pupae and adults and significantly decreased larvae emerged from treated eggs. LC10 to LC40 values of fumigation adult’s bioassay as sub-lethal concentrations were used to evaluate the antifeedant effects. H. persicum essential oil has significant antifeedant effects on T. castaneum adults and decrease of feeding happened when oil concentrations increased. The results of the present study indicate that essential oil of H. persicum, with wide bio-effects on T. castaneum, is a source of biologically active agents which may potentially prove to be efficient insecticides.

Effect of CO Concentration on the α-Value of Plasma-Synthesized Co/C Catalyst in Fischer-Tropsch Synthesis

Directory of Open Access Journals (Sweden)

James Aluha

2017-02-01

Full Text Available A plasma-synthesized cobalt catalyst supported on carbon (Co/C was tested for Fischer-Tropsch synthesis (FTS in a 3-phase continuously-stirred tank slurry reactor (3-φ-CSTSR operated isothermally at 220 °C (493 K, and 2 MPa pressure. Initial syngas feed stream of H2:CO ratio = 2 with molar composition of 0.6 L/L (60 vol % H2 and 0.3 L/L (30 vol % CO, balanced in 0.1 L/L (10 vol % Ar was used, flowing at hourly space velocity (GHSV of 3600 cm3·h−1·g−1 of catalyst. Similarly, other syngas feed compositions of H2:CO ratio = 1.5 and 1.0 were used. Results showed ~40% CO conversion with early catalyst selectivity inclined towards formation of gasoline (C4–C12 and diesel (C13–C20 fractions. With prolonged time-on-stream (TOS, catalyst selectivity escalated towards the heavier molecular-weight fractions such as waxes (C21+. The catalyst’s α-value, which signifies the probability of the hydrocarbon chain growth was empirically determined to be in the range of 0.85–0.87 (at H2:CO ratio = 2, demonstrating prevalence of the hydrocarbon-chain propagation, with particular predisposition for wax production. The inhibiting CO effect towards FTS was noted at molar H2:CO ratio of 1.0 and 1.5, giving only ~10% and ~20% CO conversion respectively, although with a high α-value of 0.93 in both cases, which showed predominant production of the heavier molecular weight fractions.

Lewis and Fischer 344 rats as a model for genetic differences in spatial learning and memory: Cocaine effects.

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Fole, Alberto; Miguéns, Miguel; Morales, Lidia; González-Martín, Carmen; Ambrosio, Emilio; Del Olmo, Nuria

2017-06-02

Lewis (LEW) and Fischer 344 (F344) rats are considered a model of genetic vulnerability to drug addiction. We previously showed important differences in spatial learning and memory between them, but in contrast with previous experiments demonstrating cocaine-induced enhanced learning in Morris water maze (MWM) highly demanding tasks, the eight-arm radial maze (RAM) performance was not modified either in LEW or F344 rats after chronic cocaine treatment. In the present work, chronically cocaine-treated LEW and F344 adult rats have been evaluated in learning and memory performance using the Y-maze, two RAM protocols that differ in difficulty, and a reversal protocol that tests cognitive flexibility. After one of the RAM protocols, we quantified dendritic spine density in hippocampal CA1 neurons and compared it to animals treated with cocaine but not submitted to RAM. LEW cocaine treated rats showed a better performance in the Y maze than their saline counterparts, an effect that was not evident in the F344 strain. F344 rats significantly took more time to learn the RAM task and made a greater number of errors than LEW animals in both protocols tested, whereas cocaine treatment induced deleterious effects in learning and memory in the highly difficult protocol. Moreover, hippocampal spine density was cocaine-modulated in LEW animals whereas no effects were found in F344 rats. We propose that differences in addictive-like behavior between LEW and F344 rats could be related to differences in hippocampal learning and memory processes that could be on the basis of individual vulnerability to cocaine addiction. Copyright © 2017 Elsevier Inc. All rights reserved.

75 FR 50999 - Certain Orange Juice From Brazil: Final Results of Antidumping Duty Administrative Review and...

Science.gov (United States)

2010-08-18

...., Fischer S.A. Comercio, Industria, and Agricultura (Fischer) and Cutrale). The Department has conducted... Manufacturer/exporter margin Fischer S.A. Comercio, Industria, and Agricultura 5.26 Sucocitrico Cutrale, S.A 8...

Revision of the subfamily Opiinae (Hymenoptera, Braconidae) from Hunan (China), including thirty-six new species and two new genera

Science.gov (United States)

Li, Xi-Ying; van Achterberg, Cornelis; Tan, Ji-Cai

2013-01-01

van Achterberg & Li, gen. n. (type species: Areotetes carinuliferus sp. n.) and Coleopioides van Achterberg & Li, gen. n. (type species: Coleopioides postpectalis sp. n. are described. All species are illustrated and keyed. In total 30 species of Opiinae are sequenced and the cladograms are presented. Neopius Gahan, 1917, Opiognathus Fischer, 1972, Opiostomus Fischer, 1972, and Rhogadopsis Brèthes, 1913, are treated as a valid genera based on molecular and morphological differences. Opius vittata Chen & Weng, 2005 (not Opius vittatus Ruschka, 1915), Opius ambiguus Weng & Chen, 2005 (not Wesmael, 1835) and Opius mitis Chen & Weng, 2005 (not Fischer, 1963) are primary homonymsandarerenamed into Phaedrotoma depressa Li & van Achterberg, nom. n., Opius cheni Li & van Achterberg, nom. n. andOpius wengi Li & van Achterberg, nom. n., respectively. Phaedrotoma terga (Chen & Weng, 2005) comb. n.,Diachasmimorpha longicaudata (Ashmead, 1905) and Biosteres pavitita Chen & Weng, 2005, are reported new for Hunan, Opiostomus aureliae (Fischer, 1957) comb. n. is new for China and Hunan; Xynobius maculipennis(Enderlein, 1912) comb. n. is new for Hunan and continental China and Rhogadopsis longuria (Chen & Weng, 2005) comb. n. is new for Hunan. The following new combinations are given: Apodesmia puncta (Weng & Chen, 2005) comb. n., Apodesmia tracta (Weng & Chen, 2005) comb. n., Areotetes laevigatus (Weng & Chen, 2005) comb. n., Phaedrotoma dimidia (Chen & Weng, 2005) comb. n., Phaedrotoma improcera (Weng & Chen, 2005) comb. n., Phaedrotoma amputata (Weng & Chen, 2005) comb. n., Phaedrotoma larga (Weng & Chen, 2005) comb. n., Phaedrotoma osculas (Weng & Chen, 2005) comb. n., Phaedrotoma postuma (Chen & Weng, 2005) comb. n., Phaedrotoma rugulosa (Chen & Weng, 2005) comb. n., Phaedrotoma tabularis (Weng & Chen, 2005) comb. n., Rhogadopsis apii (Chen & Weng, 2005) comb. n., Rhogadopsis dimidia (Chen & Weng, 2005) comb. n., Rhogadopsis diutia (Chen & Weng, 2005) comb. n., Rhogadopsis

Dietary milk fat globule membrane reduces the incidence of aberrant crypt foci in Fischer-344 rats.

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Snow, Dallin R; Jimenez-Flores, Rafael; Ward, Robert E; Cambell, Jesse; Young, Michael J; Nemere, Ilka; Hintze, Korry J

2010-02-24

Milk fat globule membrane (MFGM) is a biopolymer composed primarily of membrane proteins and lipids that surround the fat globules in milk. Although it is considered to have potential as a bioactive ingredient, few feeding studies have been conducted to measure its potential benefits. The aim of this investigation was to determine if dietary MFGM confers protection against colon carcinogenesis compared to diets containing corn oil (CO) or anhydrous milk fat (AMF). Male, weanling Fischer-344 rats were randomly assigned to one of three dietary treatments that differed only in the fat source: (1) AIN-76A diet, corn oil; (2) AIN-76A diet, AMF; and (3) AIN-76A diet, 50% MFGM, 50% AMF. Each diet contained 50 g/kg diet of fat. With the exception of the fat source, diets were formulated to be identical in macro and micro nutrient content. Animals were injected with 1,2-dimethylhydrazine once per week at weeks 3 and 4, and fed experimental diets for a total of 13 weeks. Over the course of the study dietary treatment did not affect food consumption, weight gain or body composition. After 13 weeks animals were sacrificed, colons were removed and aberrant crypt foci (ACF) were counted by microscopy. Rats fed the MFGM diet (n = 16) had significantly fewer ACF (20.9 +/- 5.7) compared to rats fed corn oil (n = 17) or AMF (n = 16) diets (31.3 +/- 9.5 and 29.8 +/- 11.4 respectively; P < 0.05). Gene expression analysis of colonic mucosa did not reveal differential expression of candidate colon cancer genes, and the sphingolipid profile of the colonic mucosa was not affected by diet. While there were notable and significant differences in plasma and red blood cell lipids, there was no relationship to the cancer protection. These results support previous findings that dietary sphingolipids are protective against colon carcinogenesis yet extend this finding to MFGM, a milk fat fraction available as a food ingredient.

Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula

Science.gov (United States)

Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

2014-01-01

Abiotic generation of complex organic compounds, in the early solar nebula that formed our solar system, is hypothesized by some to occur via Fischer-Tropsch (FT) synthesis. In its simplest form, FT synthesis involves the low temperature (300degC) produces FT products that include lesser amounts of n-alkanes and greater alkene, alcohol, and polycyclic aromatic hydrocarbon (PAH) compounds. We have begun to experimentally investigate FT synthesis in the context of abiotic generation of organic compounds in the early solar nebula. It is generally thought that the early solar nebula included abundant hydrogen and carbon monoxide gases and nano-particulate matter such as iron and metal silicates that could have catalyzed the FT reaction. The effect of FT reaction temperature, catalyst type, and experiment duration on the resulting products is being investigated. These solid organic products are analyzed by thermal-stepwise pyrolysis-GCMS and yield the types and distribution of hydrocarbon compounds released as a function of temperature. We show how the FT products vary by reaction temperature, catalyst type, and experimental duration and compare these products to organic compounds found to be indigenous to ordinary chondrite meteorites. We hypothesize that the origin of organics in some chondritic meteorites, that represent an aggregation of materials from the early solar system, may at least in part be from FT synthesis that occurred in the early solar nebula.

Ototoxic potential of JP-8 and a Fischer-Tropsch synthetic jet fuel following subacute inhalation exposure in rats.

Science.gov (United States)

Fechter, Laurence D; Gearhart, Caroline A; Fulton, Sherry

2010-07-01

This study was undertaken to identify the ototoxic potential of two jet fuels presented alone and in combination with noise. Rats were exposed via a subacute inhalation paradigm to JP-8 jet fuel, a kerosene-based fuel refined from petroleum, and a synthetic fuel produced by the Fischer-Tropsch (FT) process. Although JP-8 contains small ( approximately 5%) concentrations of aromatic hydrocarbons some of which known to be ototoxic, the synthetic fuel does not. The objectives of this study were to identify a lowest observed adverse effect level and a no observed adverse effect level for each jet fuel and to provide some preliminary, but admittedly, indirect evidence concerning the possible role of the aromatic hydrocarbon component of petroleum-based jet fuel on hearing. Rats (n = 5-19) received inhalation exposure to JP-8 or to FT fuel for 4 h/day on five consecutive days at doses of 500, 1000, and 2000 mg/m(3). Additional groups were exposed to various fuel concentrations followed by 1 h of an octave band of noise, noise alone, or no exposure to fuel or noise. Significant dose-related impairment in the distortion product otoacoustic emissions (DPOAE) was seen in subjects exposed to combined JP-8 plus noise exposure when JP-8 levels of at least 1000 mg/m(3) were presented. No noticeable impairment was observed at JP-8 levels of 500 mg/m(3) + noise. In contrast to the effects of JP-8 on noise-induced hearing loss, FT exposure had no effect by itself or in combination with noise exposure even at the highest exposure level tested. Despite an observed loss in DPOAE amplitude seen only when JP-8 and noise were combined, there was no loss in auditory threshold or increase in hair cell loss in any exposure group.

CERN Library - Journal cancellations in 2008

CERN Multimedia

2007-01-01

In 2007, the CERN Library has been allocated a smaller budget than in 2006. Since subscriptions must be paid in advance, the current budget is being used to pay the journal collection for the year 2008 and is unfortunately not sufficient to maintain the information resources at the 2007 level. Consequently, the Working Group for Acquisitions (WGA) was obliged to identify candidates for cancellation for 2008. The list of candidates is shown here. As in the past, readers will be able to order articles from journals not available in the CERN Library through the Interlibrary Loan (ILL) service; generally articles are sent within 24h. Library users are invited to send comments on this proposal not later than 4 August 2007 to the WGA Chairman, Rudiger Voss, with a copy to the Head Librarian, Jens Vigen.

Carbon-14 studies on the role of oxygen-containing compounds in the reaction mechanism of the Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Aksoy, H.A.

1975-01-01

In this work the behaviour of organic oxygen compounds has been studied in the reaction mechanism of Fischer-Tropsch synthesis using the tracer method. As an oxygen carrying tracer materials i-propanole (2- 14 C), acetone (2- 14 C) and ethanole (1- 14 C) have been added to the synthesis gas. The synthesis experiments are performed under standard conditions: The synthesis products are separated in suitable fractions and then studied by gas- and radio-gaschromatography. As a result the C-number distributions of the synthesis products are obtained as a function of concentration (weight %, mol %) and radioactivity (activity %). On this basis the relative molar activities have been calculated for certain compounds and fractions. Adding i-propanole- 14 C a great part of the tracer compound is transformed to acetone- 14 C, however adding acetone- 14 C to the synthesis gas a large amount of i-propanole- 14 C is produced. The main hydrocarbon reaction product from i-propanol and acetone is propane. Besides propane also propene is produced with equal molar radioactivity. This indicates that the formation of adsorbed oxygen compounds, as they may also be produced by chemisorption from alcohols or carbonyle compounds, is the first step in the formation of hydrocarbons by hydrogenolytic separation of oxygen. Comparing the results obtained with ethanole- 14 C and i-propanole- 14 C as a tacer material, for ethane an essentially lower molar activity is obtained when adding ethanole- 14 C compared with propane when adding i-propanole- 14 C. This corresponds with a particularly low desorption probability at the C 2 -hydrocarbon level. (orig./HK) [de

Synthesis of Hydrocarbons from H2-Deficient Syngas in Fischer-Tropsch Synthesis over Co-Based Catalyst Coupled with Fe-Based Catalyst as Water-Gas Shift Reaction

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Ting Ma

2015-01-01

Full Text Available The effects of metal species in an Fe-based catalyst on structural properties were investigated through the synthesis of Fe-based catalysts containing various metal species such, as Mn, Zr, and Ce. The addition of the metal species to the Fe-based catalyst resulted in high dispersions of the Fe species and high surface areas due to the formation of mesoporous voids about 2–4 nm surrounded by the catalyst particles. The metal-added Fe-based catalysts were employed together with Co-loaded beta zeolite for the synthesis of hydrocarbons from syngas with a lower H2/CO ratio of 1 than the stoichiometric H2/CO ratio of 2 for the Fischer-Tropsch synthesis (FTS. Among the catalysts, the Mn-added Fe-based catalyst exhibited a high activity for the water-gas shift (WGS reaction with a comparative durability, leading to the enhancement of the CO hydrogenation in the FTS in comparison with Co-loaded beta zeolite alone. Furthermore, the loading of Pd on the Mn-added Fe-based catalyst enhanced the catalytic durability due to the hydrogenation of carbonaceous species by the hydrogen activated over Pd.

DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

Energy Technology Data Exchange (ETDEWEB)

Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

2010-09-01

The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

Age-dependent exposure to radioactive iodine (131I) in the thyroid and total body of newborn, pubertal and adult fischer 344 rats

International Nuclear Information System (INIS)

Nitta, Yumiko; Fujimoto, Nariaki; Kamiya, Kenji; Hoshi, Masaharu; Endo, Satoru

2001-01-01

Female rats of the Fischer 344 strain at ages of 1, 4 and 9 weeks were exposed to 131 I intraperitoneally with activities of 0.38, 1.03 and 3.42 kBq per gram of body weight under the condition of iodine deficiency. The absorbed doses in the thyroid increased linearly depending on the injected activities. Irradiation at 1 week old caused heavier exposure than those at 4 and 9 weeks old by 7.5 and 7.7 times, respectively; however, damage of the thyroid tissue was more obvious in the 4-week-old groups than in the 1-week-old groups. The absorbed doses in the total body were proportional to the square root of the injected activities. The one-week-old groups were exposed more heavily than the 4- and 9-week-old groups by 3.6 and 4.7 times, respectively, shown by the slow excretion of 131 I with the values of effective half-life of 131 I activity (T eff ). An IDD-treatment was not so effective to enhance the 131 I absorption in the total body, as in the thyroid. No matter how the iodine concentration in the blood changed, the 1-week-old groups could not react to normalize the level. We drew standard curves, which enabled us to estimate the absorbed doses in the thyroid and the total body in the case of the injected activities of 131 I for the newborn, pubertal and adult rats. (author)

The effects of the selective 5-HT(2C) receptor antagonist SB 242084 on learned helplessness in male Fischer 344 rats.

Science.gov (United States)

Strong, Paul V; Greenwood, Benjamin N; Fleshner, Monika

2009-05-01

Rats exposed to an uncontrollable stressor demonstrate a constellation of behaviors such as exaggerated freezing and deficits in shuttle box escape learning. These behaviors in rats have been called learned helplessness and have been argued to model human stress-related mood disorders. Learned helplessness is thought to be caused by hyperactivation of serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) and a subsequent exaggerated release of 5-HT in DRN projection sites. Blocking 5-HT(2C) receptors in the face of an increase in serotonin can alleviate anxiety behaviors in some animal models. However, specific 5-HT receptor subtypes involved in learned helplessness remain unknown. The current experiments tested the hypothesis that 5-HT(2C) receptor activation is necessary and sufficient for the expression of learned helplessness. The selective 5-HT(2C) receptor antagonist SB 242084 (1.0 mg/kg) administered i.p. to adult male Fischer 344 rats prior to shuttle box behavioral testing, but not before stress, blocked stress-induced deficits in escape learning but had no effect on the exaggerated shock-elicited freezing. The selective 5-HT(2C) receptor agonist CP-809101 was sufficient to produce learned helplessness-like behaviors in the absence of prior stress and these effects were blocked by pretreatment with SB 242084. Results implicate the 5-HT(2C) receptor subtype in mediating the shuttle box escape deficits produced by exposure to uncontrollable stress and suggest that different postsynaptic 5-HT receptor subtypes underlie the different learned helplessness behaviors.

A novel water perm-selective membrane dual-type reactor concept for Fischer-Tropsch synthesis of GTL (gas to liquid) technology

International Nuclear Information System (INIS)

Rahimpour, M.R.; Mirvakili, A.; Paymooni, K.

2011-01-01

The present study proposes a novel configuration of Fischer-Tropsch synthesis (FTS) reactors in which a fixed-bed water perm-selective membrane reactor is followed by a fluidized-bed hydrogen perm-selective membrane reactor. This novel concept which has been named fixed-bed membrane reactor followed by fluidized-bed membrane reactor (FMFMDR) produces gasoline from synthesis gas. The walls of the tubes of a fixed-bed reactor (water-cooled reactor) of FMFMDR configuration are coated by a high water perm-selective membrane layer. In this new configuration, two membrane reactors instead of one membrane reactor are developed for FTS reactions. In other words, two different membrane layers are used. In order to investigate the performance of FMFMDR, a one-dimensional heterogeneous model is taken into consideration. The simulation results of three schemes named fluidized-bed membrane dual-type reactor (FMDR), FMFMDR and conventional fixed-bed reactor (CR) are presented. They have been compared in terms of temperature, gasoline and CO 2 yields, H 2 and CO conversions and the water permeation rate through the membrane layer. Results show that the gasoline yield in FMFMDR is higher than the one in FMDR. The FMFMDR configuration not only decreases the undesired product such as CO 2 but also produces more gasoline. -- Research highlights: → The application of H-SOD membrane layer in FTS reactors. → Approximate 7.5% and 37% increase in the gasoline yield in terms of [g/g feed x 100] in comparison with FMDR and CR, respectively. → A remarkable decrease in CO 2 emission to the environment. → A good configuration mainly due to reduction in catalysts sintering as a result of in situ water removal.

A SUBCHRONIC INHALATION STUDY OF FISCHER 344 RATS EXPOSED TO 0, 0.4, 1.4 OR 4.0 PPM ACROLEIN

International Nuclear Information System (INIS)

KUTZMAN, R.S.

1981-01-01

Fischer 344 rats were exposed to 0.0, 0.4, 1.4, or 4.0 ppm acrolein for 62 days. The major objective of the study was to relate the results of a series of pulmonary function tests to biochemical and pathological alterations observed in the lung. Cytological and reproductive potential endpoints were also assessed after acrolein exposure. Rats were exposed to acrolein for 6 hours/day, 5 days/week for 62 days. Mortality was observed only in the 4.0 ppm chamber where 32 of 57 exposed males died; however, none of the 8 exposed females died. Most of the mortality occurred within the first 10 exposure days. Histologic examination indicated that the animals died of acute bronchopneumonia. The surviving males and females exposed to 4.0 ppm acrolein gained weight at a significantly slower rate than control animals. The growth of both sexes in the 0.4 and 1.4 ppm groups was similar to that of their respective controls. Histopathologic examination of animals after 62 days of exposure revealed bronchiolar epithelial necrosis and sloughing, bronchiolar edema with macrophages, and focal pulmonary edema in the 4.0 ppm group. These lesions were, in some cases, associated with edema of the trachea and peribronchial lymph nodes, and acute rhinitis which indicated an upper respiratory tract effect of acrolein. Of particular interest was the variability of response between rats in the 4.0 ppm group, some not affected at all while others were moderately affected. Intragroup variability in toxicity was also apparent in the 1.4 ppm exposure group where only 3 of 31 animals examined had lesions directly related to acrolein exposure. Extra respiratory organs appeared unaffected

Modeling and optimization of Fischer-Tropsch synthesis over Co-Mn-Ce/SiO_2 catalyst using hybrid RSM/LHHW approaches

International Nuclear Information System (INIS)

Zohdi-Fasaei, Hossein; Atashi, Hossein; Farshchi Tabrizi, Farshad; Mirzaei, Ali Akbar

2017-01-01

Operating conditions considerably affect the energy required for Fischer-Tropsch synthesis, depending on the catalyst composition and reactor type (catalyst system). This paper reports the use of cobalt-manganese-cerium supported on silica as a novel CO hydrogenation catalyst, to produce hydrocarbons in a fixed bed micro-reactor. Response surface methodology (RSM) was applied to study the effects of temperature, pressure, feed ratio and their interactions on CO consumption rate, and the selectivity of light olefins (light olefinity), methane and C_5_+ hydrocarbons. Quadratic mathematical models adequately described the responses in this catalyst system. According to Langmuir Hinshelwood Hougen Watson (LHHW) approach, kinetic mechanism of the reaction was found to be an associative adsorption of H_2 and CO. Statistical analysis demonstrated that pressure and feed ratio were the most important factors for the production of C_5_+ and light alkenes, respectively. Model graphs indicated that minimum methane selectivity was achieved at 523.15 k and 2 bar. The maximum amounts of light olefins and heavier hydrocarbons were obtained at H_2/CO = 1 and H_2/CO = 2, respectively. Characterization of precursor and calcined catalyst (before and after the reaction) was carried out using SEM and BET techniques. - Highlights: • The performance of a new catalytic system was studied using RSM as a research plan. • Interactions between significant factors were investigated using mathematical models. • Based on LHHW approach, kinetic mechanism was molecular adsorptions of H_2 and CO. • RSM rate expression was in consistent with the LHHW kinetic model. • Hybrid RSM/LHHW is promising for optimization, mechanism and selectivity studies.

On the Use of Fourier Transform Infrared (FT-IR) Spectroscopy and Synthetic Calibration Spectra to Quantify Gas Concentrations in a Fischer-Tropsch Catalyst System

Science.gov (United States)

Ferguson, Frank T.; Johnson, Natasha M.; Nuth, Joseph A., III

2015-01-01

One possible origin of prebiotic organic material is that these compounds were formed via Fischer-Tropsch-type (FTT) reactions of carbon monoxide and hydrogen on silicate and oxide grains in the warm, inner-solar nebula. To investigate this possibility, an experimental system has been built in which the catalytic efficiency of different grain-analog materials can be tested. During such runs, the gas phase above these grain analogs is sampled using Fourier transform infrared (FT-IR) spectroscopy. To provide quantitative estimates of the concentration of these gases, a technique in which high-resolution spectra of the gases are calculated using the high-resolution transmission molecular absorption (HITRAN) database is used. Next, these spectra are processed via a method that mimics the processes giving rise to the instrumental line shape of the FT-IR spectrometer, including apodization, self-apodization, and broadening due to the finite resolution. The result is a very close match between the measured and computed spectra. This technique was tested using four major gases found in the FTT reactions: carbon monoxide, methane, carbon dioxide, and water. For the ranges typical of the FTT reactions, the carbon monoxide results were found to be accurate to within 5% and the remaining gases accurate to within 10%. These spectra can then be used to generate synthetic calibration data, allowing the rapid computation of the gas concentrations in the FTT experiments.

Food patterns characterization for Mexico and Sonora’s households, 2005-2006

Directory of Open Access Journals (Sweden)

Carlos Borbón-Morales

2010-01-01

Full Text Available This paper shows a descriptive analysis about the characterization of the consumption’s pattern in Mexico and Sonora, by determining how much money is spent in households and the proportion that those intended to consume on goods and services. Income level is considered to account for such classification. A comparison between the patterns of consumption is made for Mexico and Sonora in 2005, by emphasizing on food expenditures and some specific food products such as vegetables; including tomatoes, cucumbers, and peppers. The study also performs a look into the spending behavior in Mexico from 2000 to 2006, by contrasting the hypothesis of Modigliani and Friedman (Dornbusch, 2004; Camacho, 2000 and the mathematical formulation of Campbell and Mankiw (1989 on the assumption of the society’s consumption. It finally outlines a series of proposals for future studies.

Il ruolo della “Scuola di Copenaghen” nel “Rimodellamento” Coseriano degli assiomi Saussuriani

DEFF Research Database (Denmark)

Jensen, Viggo Bank

2015-01-01

Based on a correspondence between Eugenio Coseriu (1921-2002) and Eli Fischer-Jørgensen (1911-2010), the article discusses the importance of Louis Hjelmslev (1899-1965) for the development of the theory of Coseriu. In a letter dated 1955, Fischer-Jørgensen agrees with Coseriu in his criticism of ...... to be a slight change in Coseriu’s view on content substance. This way, the article aims to show that Fischer-Jørgensen played an important role as a critical mediator between Hjelmslev and Coseriu.......Based on a correspondence between Eugenio Coseriu (1921-2002) and Eli Fischer-Jørgensen (1911-2010), the article discusses the importance of Louis Hjelmslev (1899-1965) for the development of the theory of Coseriu. In a letter dated 1955, Fischer-Jørgensen agrees with Coseriu in his criticism...

Effect of interleukin-2 on cell proliferation, sister-chromatid exchange induction, and nuclear stress protein phosphorylation in PHA-stimulated Fischer 344 rat spleen lymphocytes: Modulation by 2-mercaptoethanol

Energy Technology Data Exchange (ETDEWEB)

Morris, S.M.; Aidoo, A.; Domon, O.E.; McGarrity, L.J.; Kodell, R.L.; Schol, H.M.; Hinson, W.G.; Pipkin, J.L.; Casciano, D.A. (National Center for Toxicological Research, Jefferson, AR (USA))

1990-01-01

The effect of interleukin-2 (IL-2) on cell proliferation, sister-chromatid exchange (SCE) frequency, and the phosphorylation of nuclear stress proteins was evaluated in phytohemagglutinin (PHA)-stimulated spleen lymphocytes isolated from Fischer 344 rats. In addition, the ability of 2-mercaptoethanol (2-ME) to modulate the induction of these biological responses was characterized. Cell proliferation, as measured by the mitotic index, increased significantly. The average generation time (AGT) did not respond to IL-2 in a concentration-dependent manner and decreased significantly. The number of SCE increased significantly from control frequencies, to frequencies of 18.5 to 21.5 SCE per cell as the concentration of IL-2 in the culture medium increased to 50 half-maximal units per ml. A reduction in SCE frequency was observed when cells were cultured with 20 {mu}M 2-ME and IL-2 compared to IL-2 alone. Three nuclear proteins, with relative molecular masses of approximately 13,000-18,000, 20,000, and 80,000, were phosphorylated in IL-2-exposed G{sub 1}-phase nuclei. Elicitation of these nuclear proteins in IL-2-exposed cells was not affected by exposure to 2-ME.

Absorption, distribution, metabolism and excretion of intravenously and orally administered tetrabromobisphenol A [2,3-dibromopropyl ether] in male Fischer-344 rats

International Nuclear Information System (INIS)

Knudsen, G.A.; Jacobs, L.M.; Kuester, R.K.; Sipes, I.G.

2007-01-01

Tetrabromobisphenol A bis[2,3-dibromopropyl ether],2,2-bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]propane is a brominated flame retardant with substantial U.S. production. Due to the likelihood of human exposure to TBBPA-DBPE and its probable metabolites, studies regarding the absorption, distribution, metabolism, and excretion were conducted. Male Fischer-344 rats were dosed with TBBPA-DBPE (20 mg/kg) by oral gavage or IV administration. Following a single oral administration of TBBPA-DBPE, elimination of [ 14 C] equivalents in the feces was extensive and rapid (95% of dose by 36 h). Following repeated daily oral doses for 5 or 10 days, route and rate of elimination was similar to single administrations of TBBPA-DBPE. After IV administration, fecal excretion of [ 14 C] equivalents was much slower (27% of dose eliminated by 36 h, 71% by 96 h). Urinary elimination was minimal ( 1/2β : 24.8 h; CL b : 0.1 mL min -1 . Kinetic constants following oral dosing were: t 1/2α : 2.5 h; t 1/2β : 13.9 h; CL b : 4.6 mL min -1 . Systemic bioavailability was 2.2%. Liver was the major site of disposition following oral or IV administration. After oral administration, 1% of the dose was eliminated in bile in 24 h (as metabolites). In in vitro experiments utilizing hepatocytes or liver microsomal protein, no detectable metabolism of TBBPA-DBPE occurred. These data indicate that TBBPA-DBPE is poorly absorbed from the gastrointestinal tract. Compound which is absorbed is sequestered in the liver, slowly metabolized, and eliminated in the feces

Wabash Valley Integrated Gasification Combined Cycle, Coal to Fischer Tropsch Jet Fuel Conversion Study

Energy Technology Data Exchange (ETDEWEB)

Shah, Jayesh [Lummus Technology Inc., Bloomfield, NJ (United States); Hess, Fernando [Lummus Technology Inc., Bloomfield, NJ (United States); Horzen, Wessel van [Lummus Technology Inc., Bloomfield, NJ (United States); Williams, Daniel [Lummus Technology Inc., Bloomfield, NJ (United States); Peevor, Andy [JM Davy, London (United Kingdom); Dyer, Andy [JM Davy, London (United Kingdom); Frankel, Louis [Canonsburgh, PA (United States)

2016-06-01

This reports examines the feasibility of converting the existing Wabash Integrated Gasification Combined Cycle (IGCC) plant into a liquid fuel facility, with the goal of maximizing jet fuel production. The fuels produced are required to be in compliance with Section 526 of the Energy Independence and Security Act of 2007 (EISA 2007 §526) lifecycle greenhouse gas (GHG) emissions requirements, so lifecycle GHG emissions from the fuel must be equal to or better than conventional fuels. Retrofitting an existing gasification facility reduces the technical risk and capital costs associated with a coal to liquids project, leading to a higher probability of implementation and more competitive liquid fuel prices. The existing combustion turbine will continue to operate on low cost natural gas and low carbon fuel gas from the gasification facility. The gasification technology utilized at Wabash is the E-Gas™ Technology and has been in commercial operation since 1995. In order to minimize capital costs, the study maximizes reuse of existing equipment with minimal modifications. Plant data and process models were used to develop process data for downstream units. Process modeling was utilized for the syngas conditioning, acid gas removal, CO₂ compression and utility units. Syngas conversion to Fischer Tropsch (FT) liquids and upgrading of the liquids was modeled and designed by Johnson Matthey Davy Technologies (JM Davy). In order to maintain the GHG emission profile below that of conventional fuels, the CO₂ from the process must be captured and exported for sequestration or enhanced oil recovery. In addition the power utilized for the plant’s auxiliary loads had to be supplied by a low carbon fuel source. Since the process produces a fuel gas with sufficient energy content to power the plant’s loads, this fuel gas was converted to hydrogen and exported to the existing gas turbine for low carbon power production. Utilizing low carbon fuel gas and

Amphetamine self-administration and dopamine function: assessment of gene × environment interactions in Lewis and Fischer 344 rats.

Science.gov (United States)

Meyer, Andrew C; Bardo, Michael T

2015-07-01

Previous research suggests both genetic and environmental influences on substance abuse vulnerability. The current work sought to investigate the interaction of genes and environment on the acquisition of amphetamine self-administration as well as amphetamine-stimulated dopamine (DA) release in nucleus accumbens shell using in vivo microdialysis. Inbred Lewis (LEW) and Fischer (F344) rat strains were raised in either an enriched condition (EC), social condition (SC), or isolated condition (IC). Acquisition of amphetamine self-administration (0.1 mg/kg/infusion) was determined across an incrementing daily fixed ratio (FR) schedule. In a separate cohort of rats, extracellular DA and the metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) were measured in the nucleus accumbens shell following an acute amphetamine injection (1 mg/kg). "Addiction-prone" LEW rats had greater acquisition of amphetamine self-administration on a FR1 schedule compared to "addiction-resistant" F344 rats when raised in the SC environment. These genetic differences were negated in both the EC and IC environments, with enrichment buffering against self-administration and isolation enhancing self-administration in both strains. On a FR5 schedule, the isolation-induced increase in amphetamine self-administration was greater in F344 than LEW rats. While no group differences were obtained in extracellular DA, gene × environment differences were obtained in extracellular levels of the metabolite DOPAC. In IC rats only, LEW rats showed attenuation in the amphetamine-induced decrease in DOPAC compared to F344 rats. IC LEW rats also had an attenuated DOPAC response to amphetamine compared to EC LEW rats. The current results demonstrate gene × environment interactions in amphetamine self-administration and amphetamine-induced changes in extracellular DOPAC in nucleus accumbens (NAc) shell. However, the behavioral and neurochemical differences were not related directly, indicating that

Comparative electrophysiological evaluation of hippocampal function following repeated inhalation exposures to JP-8, Jet A, JP-5, and the synthetic Fischer Tropsch fuel.

Science.gov (United States)

Rohan, Joyce G; McInturf, Shawn M; Miklasevich, Molly K; Gut, Chester P; Grimm, Michael D; Reboulet, James E; Howard, William R; Mumy, Karen L

2018-01-01

Exposure to fuels continues to be a concern in both military and general populations. The aim of this study was to examine effects of in vivo rat repeated exposures to different types of jet fuel utilizing microelectrode arrays for comparative electrophysiological (EP) measurements in hippocampal slices. Animals were exposed to increasing concentrations of four jet fuels, Jet Propellant (JP)-8, Jet A, JP-5, or synthetic Fischer Tropsch (FT) fuel via whole-body inhalation for 20 d (6 hr/d, 5 d/week for 28 d) and synaptic transmission as well as behavioral performance were assessed. Our behavioral studies indicated no significant changes in behavioral performance in animals exposed to JP-8, Jet A, or JP-5. A significant deviation in learning pattern during the Morris water maze task was observed in rats exposed to the highest concentration of FT (2000 mg/m 3 ). There were also significant differences in the EP profile of hippocampal neurons from animals exposed to JP-8, Jet A, JP-5, or FT compared to control air. However, these differences were not consistent across fuels or dose dependent. As expected, patterns of EP alterations in brain slices from JP-8 and Jet A exposures were more similar compared to those from JP-5 and FT. Further longitudinal investigations are needed to determine if these EP effects are transient or persistent. Such studies may dictate if and how one may use EP measurements to indicate potential susceptibility to neurological impairments, particularly those that result from inhalation exposure to chemicals or mixtures.

Jean-Marie Dufour 1937-2007

CERN Multimedia

2007-01-01

Picture taken by Rudiger Voss in the Legal Service LibraryJean-Marie Dufour, CERN Legal Advisor from 1974 until his retirement in 2001, passed away on 8 July. For us, his colleagues in the Legal Service, Jean-Marie was a tutor and a reference, who passed on to us his passion for the practice of law in an intergovernmental organisation. As a boss, his abiding managerial quality was his unstinting loyalty to his collaborators. Jean-Marie joined CERN in 1966 and for the next 35 years was to be the guardian of the Laboratory’s rules. This was his view of the Organization: "...I have discovered [at CERN] a fascinating universe driven by two forces: science and Europe; a world of physicists and engineers who, encouraged by the States of Europe, run a remarkable Laboratory, where Europeans have achieved reconciliation and restored the grand tradition of European physics, attracting physicists from around the world; a Laboratory that transcends not only the fro...

Method for customizing an organic Rankine cycle to a complex heat source for efficient energy conversion, demonstrated on a Fischer Tropsch plant

International Nuclear Information System (INIS)

DiGenova, Kevin J.; Botros, Barbara B.; Brisson, J.G.

2013-01-01

Highlights: ► Methods for customizing organic Rankine cycles are proposed. ► A set of cycle modifications help to target available heat sources. ► Heat sources with complex temperature–enthalpy profiles can be matched. ► Significant efficiency improvements can be achieved over basic ORC’s. -- Abstract: Organic Rankine cycles (ORCs) provide an alternative to traditional steam Rankine cycles for the conversion of low grade heat sources into power, where conventional steam power cycles are known to be inefficient. A large processing plant often has multiple low temperature waste heat streams available for conversion to electricity by a low temperature cycle, resulting in a composite heat source with a complex temperature–enthalpy profile. This work presents a set of ORC design concepts: reheat stages, multiple pressure levels, and balanced recuperators; and demonstrates the use of these design concepts as building blocks to create a customized cycle that matches an available heat source. Organic fluids are modeled using a pure substance database. The pinch analysis technique of forming composite curves is applied to analyze the effect of each building block on the temperature–enthalpy profile of the ORC heat requirement. The customized cycle is demonstrated on a heat source derived from a Fischer Tropsch reactor and its associated processes. Analysis shows a steam Rankine cycle can achieve a 20.6% conversion efficiency for this heat source, whereas a simple organic Rankine cycle using hexane as the working fluid can achieve a 20.9% conversion efficiency. If the ORC building blocks are combined into a cycle targeted to match the temperature–enthalpy profile of the heat source, this customized ORC can achieve 28.5% conversion efficiency.

Evidence and possible mechanism for the permanent decline in tuberoinfundibular dopaminergic neuronal activity after chronic estradiol administration in Fischer 233 rats

International Nuclear Information System (INIS)

Gottschall, P.E.

1986-01-01

The objective of these studies was to determine if the decline in tuberoinfundibular dopaminergic (TIDA) neuronal function observed during chronic estradiol-17-β (E 2 ) administration persisted after E 2 was removed. Ovariectomized (OVX) Fischer 344 rats were implanted with an E 2 -containing Silastic capsule for 4 weeks. Anterior pituitary (AP) weight and serum prolactin was greatly increased at the end of the E 2 treatment, that persisted 4 and 26 weeks after E 2 was withdrawn. Ag the end of E 2 treatment and 4 weeks after E 2 was withdrawn, TIDA function, as evaluated by electrical stimulation of median eminence tissue in vitro after allowing for uptake of 3 H-DA, was decreased compared to OVX controls. In an attempt to elucidate the mechanism by which E 2 results in a permanent decline in TIDA function, F344 rats were given daily bromocryptine injections in addition to a 30-day E 2 treatment. TIDA neuronal release was reduced in both E 2 and E 2 and bromocryptine treated groups. However, by 30 days after discontinuing treatment only rats given E 2 alone showed a persistent decline in TIDA function. Since permanent damage to hypothalamic neurons by an enlarged AP was speculated to be the result of E 2 treatment, neurons which regulate other AP hormones may also be damaged. To evaluate this possibility, pulsatile release of prolactin, growth hormone (GH) and luteinizing hormone (LH) was evaluated in OVX control rats, chronically E 2 -treated rats, and rats 120 days after chronic E 2 treatment. Only the frequency of prolactin pulses, but not the frequency of GH and LH pulses, was reduced in rats 120 days after E 2 treatment. This suggests selectivity in the hypothalamic damage produced by the enlarged AP

Domestic Implementation of a Chemical Weapons Treaty

Science.gov (United States)

1989-10-01

objective3 may sometimes conflict with each other (Scheinman, 1985; Scheinman, 1987; Fischer and Szasz , 1985). Safeguard activities consume about 35...civilian nuclear facilities. A number of studies (Scheinman, 1987, Fischer and Szasz , 1985) have reviewed the recent history of the Safe- guards...mentation procedures that could offer useful precedents for the CWC. Fischer and Szasz , Scheinman’s two reviews, and the U.S. Code of Federal Regulations

77 FR 77017 - Certain Orange Juice From Brazil: Notice of Court Decision Not in Harmony With Final Results of...

Science.gov (United States)

2012-12-31

... redetermination pursuant to the CIT's remand order in Fischer S.A. Comercio, Industria and Agricultura v. United.... Comercio, Industria, and Agricultura's (Fischer's) financial statements in its financial expense ratio...

The chemotherapeutic potential of glycol alkyl ethers: structure-activity studies of nine compounds in a Fischer-rat leukemia transplant model.

Science.gov (United States)

Dieter, M P; Jameson, C W; Maronpot, R R; Langenbach, R; Braun, A G

1990-01-01

Structure-activity studies with nine glycol alkyl ethers were conducted with a cellular leukemia transplant model in male Fischer rats. This in vivo assay measures the effects of chemical treatment on neoplastic progression in transplant recipients. Chemicals were given ad libitum in the drinking water simultaneously with the transplants and continued throughout the study. In all, 20 million leukemic cells were injected s.c. into syngeneic rats, which after 60 days resulted in a 10-fold increase in relative spleen weights, a 100-fold increase in white blood cell counts, and a 50% reduction in red blood cell (RBC) indices and platelet counts. At this interval, ethylene glycol monomethyl ether (2-ME) given at a dose of 2.5 mg/ml in the drinking water completely eliminated all clinical, morphological, and histopathological evidence of leukemia, whereas the same dose of ethylene glycol monoethyl ether (2-EE) reduced these responses by about 50%. Seven of the glycol ethers were ineffective as anti-leukemic agents, including ethylene glycol, the monopropyl, monobutyl, and monophenyl ethylene glycol ethers, diethylene glycol, and the monomethyl and monoethyl diethylene glycol ethers. 2-ME more than doubled the latency period of leukemia expression and extended survival for at least 210 days. A minimal effective dose for a 50% reduction in the leukemic responses was 0.25 mg/ml 2-ME in the drinking water (15 mg/kg body weight), whereas a 10-fold higher dose of 2-EE was required for equivalent antileukemic activity. In addition, the in vitro exposure of a leukemic spleen mononuclear cell culture to 2-ME caused a dose- and time-dependent reduction in the number of leukemia cells after a single exposure to 1-100 microM concentrations, whereas the 2-ME metabolite, 2-methoxyacetic acid, was only half as effective. The two glycol alkyl ethers with demonstrable anti-leukemic activity, 2-ME and 2-EE, also exhibited a favorable efficacy-to-toxicity ratio and should be considered for

Reductions in greenhouse gas emissions and oil use by DME (di-methyl ether) and FT (Fischer-Tropsch) diesel production in chemical pulp mills

International Nuclear Information System (INIS)

Joelsson, Jonas M.; Gustavsson, Leif

2012-01-01

Using energy systems analysis, we examine the potential to reduce CO 2 emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-FT (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill’s heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO 2 emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO 2 emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. -- Highlights: ► CO 2 emission and oil use reductions quantified for pulp mill-based biorefineries. ► Black liquor gasification gives larger reductions than solid biomass gasification. ► Lower mill steam demand increases the black liquor gasification advantage. ► Biomass directly replacing coal or oil in stationary plants gives larger reductions.

Influence of oxalate ligand functionalization on Co/ZSM-5 activity in Fischer Tropsch synthesis and hydrodeoxygenation of oleic acid into hydrocarbon fuels.

Science.gov (United States)

Ayodele, Olumide Bolarinwa

2017-08-30

Achieving high degree of active metal dispersions at the highest possible metal loading and high reducibility of the metal remains a challenge in Fischer Tropsch synthesis (FTS) as well as in hydrogeoxygenation (HDO).This study therefore reports the influence of oxalic acid (OxA) functionalization on the metal dispersion, reducibility and activity of Co supported ZSM-5 catalyst in FTS and HDO of oleic acid into paraffin biofuel. The Brunauer-Emmett-Teller (BET) results showed that cobalt oxalate supported ZSM-5 catalyst (CoOx/ZSM-5) synthesized from the incorporation of freshly prepared cobalt oxalate complex into ZSM-5 displayed increase in surface area, pore volume and average pore size while the nonfunctionalized cobalt supported on ZSM-5 (Co/ZSM-5) catalyst showed reduction in those properties. Furthermore, both XRD and XPS confirmed the presence of Co° formed from the decomposition of CoOx during calcination of CoOx/ZSM-5 under inert atmosphere. The HRTEM showed that Co species average particle sizes were smaller in CoOx/ZSM-5 than in Co/ZSM-5, and in addition, CoOx/ZSM-5 shows a clear higher degree of active metal dispersion. The FTS result showed that at CO conversion over Co/ZSM-5 and CoOx/ZSM-5 catalysts were 74.28% and 94.23% and their selectivity to C 5+ HC production were 63.15% and 75.4%, respectively at 4 h TOS. The HDO result also showed that the CoOx/ZSM-5 has higher OA conversion of 92% compared to 59% over Co/ZSM-5. In addition CoOx/ZSM-5 showed higher HDO and isomerization activities compared to Co/ZSM-5.

Disease: H01404 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H01404 Punctate palmoplantar keratoderma (PPKP), including: Brauer-Buschke-Fischer disease; Porokeratosis...ypes; PPKP1 (Brauer-Buschke-Fischer disease), PPKP2 (porokeratosis punctata palmaris et plantaris), and PPKP

77 FR 63291 - Certain Orange Juice From Brazil: Final Results of Antidumping Duty Administrative Review and...

Science.gov (United States)

2012-10-16

... administrative review (i.e., Fischer S.A. Comercio, Industria, and Agricultura (Fischer), Louis Dreyfus..., Industria, and Agricultura 4.72 Louis Dreyfus Commodities Agroindustrial S.A 20.34 Montecitrus Trading S.A...

Effect of CO{sub 2} and H{sub 2}O content in syngas on activity and selectivity of a cobalt based Fischer-Tropsch synthesis catalyst

Energy Technology Data Exchange (ETDEWEB)

Poehlmann, F.; Kaiser, P.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

2013-11-01

When liquid hydrocarbons are to be used as CO{sub 2} neutral storage media for electrical energy, it is necessary to convert CO{sub 2} from e.g. flue gas and hydrogen from water electrolysis to synthesis gas (CO/H{sub 2}). This can be achieved by a high temperature reverse water gas shift (RWGS) reaction. Due to thermodynamic limitations, the product gas of RWGS reactors operated at technically feasible temperatures of around 900 C will always contain significant amounts of water and carbon dioxide, which can influence the activity of Fischer-Tropsch synthesis (FTS) catalysts for the actual hydrocarbon production. In this study, a commercial cobalt catalyst was investigated under low temperature FTS conditions (2.5 MPa, 215 C) regard to activity and selectivity in the presence of H{sub 2}O and CO{sub 2}. A continuous flow apparatus including a fixed-bed reactor for the synthesis step was used to conduct all experiments. The experimental data reveals that the CO/CO{sub 2}-ratio does not affect the activity and product selectivity until the CO{sub 2}-concentration reaches 75 vol.-% (CO{sub 2}/(CO+CO{sub 2})). On increasing the carbon dioxide concentration to 100 vol.-% (H{sub 2}/CO{sub 2} = 2), the methane selectivity rose up to 70 % and even above. Addition of water caused an initial loss of activity. After the initial loss of activity the FT catalyst activity was found to remain constant, irrespectively of if the water was removed from the feed or not. Thus, the deactivation was permanent. (orig.)

DNA adduct formation in B6C3F1 mice and Fischer-344 rats exposed to 1,2,3-trichloropropane.

Science.gov (United States)

La, D K; Lilly, P D; Anderegg, R J; Swenberg, J A

1995-06-01

1,2,3-Trichloropropane (TCP) is a multispecies, multisite carcinogen which has been found to be an environmental contaminant. In this study, we have characterized and measured DNA adducts formed in vivo following exposure to TCP. [14C]TCP was administered to male B6C3F1 mice and Fischer-344 rats by gavage at doses used in the NTP carcinogenesis bioassay. Both target and nontarget organs were examined for the formation of DNA adducts. Adducts were hydrolyzed from DNA by neutral thermal or mild acid hydrolysis, isolated by HPLC, and detected and quantitated by measurement of radioactivity. The HPLC elution profile of radioactivity suggested that one major DNA adduct was formed. To characterize this adduct, larger yields were induced in rats by intraperitoneal administration of TCP (300 mg/kg). The DNA adduct was isolated by HPLC based on coelution with the radiolabeled adduct, and compared to previously identified adducts. The isolated adduct coeluted with S-[1-(hydroxymethyl)-2-(N7-guanyl)-ethyl]glutathione, an adduct derived from the structurally related carcinogen 1,2-dibromo-3-chloropropane (DBCP). Analysis by electrospray mass spectrometry suggested that the TCP-induced adduct and the DBCP-derived adduct were identical. The 14C-labeled DNA adduct was distributed widely among the organs examined. Adduct levels varied depending on species, organ, and dose. In rat organs, adduct concentrations for the low dose ranged from 0.8 to 6.6 mumol per mol guanine and from 7.1 to 47.6 mumol per mol guanine for the high dose. In the mouse, adduct yields ranged from 0.32 to 28.1 mumol per mol guanine for the low dose and from 12.2 to 208.1 mumol per mol guanine for the high dose. The relationship between DNA adduct formation and organ-specific tumorigenesis was unclear. Although relatively high concentrations of DNA adducts were detected in target organs, several nontarget sites also contained high adduct levels. Our data suggest that factors in addition to adduct formation

Disposition and metabolism of aniline in Fischer 344 rats and C57BL/6 X C3H F1 mice

International Nuclear Information System (INIS)

McCarthy, D.J.; Waud, W.R.; Struck, R.F.; Hill, D.L.

1985-01-01

We examined the metabolism and disposition of aniline, which induces spleen hemangiosarcomas in rats but no tumors in mice, in normal and predosed Fischer 344 rats, and C57BL/6 X C3H F1 mice administered low (50 and 100 mg/kg, respectively) or high (250 and 500 mg/kg, respectively) doses. Of 11 tissues examined, the highest levels of binding of [ 14 C]aniline to DNA were in the kidney, large intestine, and spleen of high-dose rats that had received prior dosing; these tissues had covalent binding indices of 14.2, 4.3, and 3.7 mumol/mol nucleotides/dose, respectively. Protein and RNA were the major macromolecular targets for binding of radioactivity from [ 14 C]aniline. Relative to controls, most tissues from predosed mice (low dose and high dose) showed less binding to protein and RNA; but for most tissues from predosed rats administered 50-mg/kg doses of [ 14 C]aniline, there was more extensive binding. Also relative to controls, binding of radioactivity in the spleen of predosed rats given [ 14 C]aniline (50 mg/kg) was 148% greater for protein and 302% greater for RNA. For rats administered 250 mg of [ 14 C]aniline per kg, however, there were no outstanding differences in binding to RNA and protein between normal and predosed animals. The profiles of urinary metabolites produced by rats and mice were not appreciably different in animals predosed with aniline. For rats, however, the profiles were different for the low and high doses, suggesting that the main metabolic pathway was saturated at the higher dose. p-Acetamidophenyl sulfate represented over 70% of the total radioactivity recovered from the urine of rats dosed with 50 mg of aniline per kg but only 30% in the urine of those dosed with 250 mg/kg. The urine of the high-dose rats contained greater percentages of p-aminophenyl sulfate, p-acetamidophenyl glucuronide, and unconjugated metabolites

Reductions in greenhouse gas emissions and oil use by DME (di-methyl ether) and FT (Fischer-Tropsch) diesel production in chemical pulp mills

Energy Technology Data Exchange (ETDEWEB)

Joelsson, Jonas M., E-mail: joelsson.jonas@hotmail.com [Ecotechnology and Environmental Science, Mid Sweden University, SE-831 25 Oestersund (Sweden); Gustavsson, Leif [Linnaeus University, SE- 351 95 Vaexjoe (Sweden)

2012-03-15

Using energy systems analysis, we examine the potential to reduce CO{sub 2} emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-FT (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill's heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO{sub 2} emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO{sub 2} emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. -- Highlights: Black-Right-Pointing-Pointer CO{sub 2} emission and oil use reductions quantified for pulp mill-based biorefineries. Black-Right-Pointing-Pointer Black liquor gasification gives larger reductions than solid biomass gasification. Black-Right-Pointing-Pointer Lower mill steam demand increases the black liquor gasification advantage. Black-Right-Pointing-Pointer Biomass directly replacing coal or oil in stationary plants gives larger reductions.

Mucosal immunization with live attenuated Francisella novicida U112ΔiglB protects against pulmonary F. tularensis SCHU S4 in the Fischer 344 rat model.

Directory of Open Access Journals (Sweden)

Aimee L Signarovitz

Full Text Available The need for an efficacious vaccine against Francisella tularensis is a consequence of its low infectious dose and high mortality rate if left untreated. This study sought to characterize a live attenuated subspecies novicida-based vaccine strain (U112ΔiglB in an established second rodent model of pulmonary tularemia, namely the Fischer 344 rat using two distinct routes of vaccination (intratracheal [i.t.] and oral. Attenuation was verified by comparing replication of U112ΔiglB with wild type parental strain U112 in F344 primary alveolar macrophages. U112ΔiglB exhibited an LD(50>10(7 CFU compared to the wild type (LD(50 = 5 × 10(6 CFU i.t.. Immunization with 10(7 CFU U112ΔiglB by i.t. and oral routes induced antigen-specific IFN-γ and potent humoral responses both systemically (IgG2a>IgG1 in serum and at the site of mucosal vaccination (respiratory/intestinal compartment. Importantly, vaccination with U112ΔiglB by either i.t. or oral routes provided equivalent levels of protection (50% survival in F344 rats against a subsequent pulmonary challenge with ~25 LD(50 (1.25 × 10(4 CFU of the highly human virulent strain SCHU S4. Collectively, these results provide further evidence on the utility of a mucosal vaccination platform with a defined subsp. novicida U112ΔiglB vaccine strain in conferring protective immunity against pulmonary tularemia.

Participación de agentes en mercados financieros: aplicación de los modelos Chakraborty-Ray y Dornbusch

OpenAIRE

Giovanni Reyes

2011-01-01

La finalidad fundamental de este estudio es establecer modelos sobre el comportamiento, factores que influyen, y condicionantes generales macroeconómicas, que afectan la conducta de agentes financieros en dos ambientes diferenciados: (i) financiamiento directo; y (ii) financiamiento indirecto. Se considera el comportamiento de trabajadores con excedentes, inversionistas profesionales e intermediarios financieros, en particular instituciones bancarias. Se hace una aplicación de los modelos de ...

CERN Library - Reduction of subscriptions to scientific journals

CERN Multimedia

2005-01-01

The Library Working Group for Acquisitions has identified some scientific journal subscriptions as candidates for cancellation. Although the 2005 budget is unchanged with respect to 2004 thanks to the efforts of the Management, it does not take account of inflation, which for many years has been much higher for scientific literature than the normal cost-of-living index. For 2006, the inflation rate is estimated to be 7-8%. Moreover, the Library does not only intend to compensate for the loss of purchasing power but also to make available some funds to promote new Open Access publishing models. (See Bulletin No.15/2005) The list of candidates can be found on the Library homepage (http://library.cern.ch/). In addition, some subscriptions will be converted to online-only, i.e. CERN will no longer order the print version of certain journals. We invite users to carefully check the list (http://library.cern.ch/). Comments on this proposal should be sent to the WGA Chairman, Rudiger Voss, with a copy to the Hea...

Short-term global warming mitigation costs of fischer-tropsch diesel production and policy scenarios in Norway

Energy Technology Data Exchange (ETDEWEB)

Bright, Ryan M.; Stroemman, Anders Hammer

2010-07-01

Full text: Increasing the supply of advanced biofuels like synthetic diesel produced from woody biomass require attractive investment environments so that novel technologies are deployed and technological learning can lead to reduced production costs and accelerated market diffusion. Technology-specific biofuel policy designed to minimize perceived risk may encourage shortterm investment into those biofuels offering superior environmental benefits - particularly climate mitigation benefits - thereby leading to steeper learning curves and deeper greenhouse gas (GHG) emission cuts over the medium- and long-term horizon. We perform both a Life Cycle Assessment (LCA) and an economic analysis of Fischer-Tropsch diesel (FTD) produced from Norwegian forest biomass at an 'nth' commercial plant (a plant with the same technologies that have been employed in previous commercial plants). This is followed with a cost growth analysis in order to derive production costs likely to be borne by pioneer commercial plants in Norway in the short-term (2016). LCA results are used to calculate shortterm GHG mitigation costs. We then assess, through scenarios, how various policy measures and financial support mechanisms would reduce production costs for incentivizing short-term investment and expediting commercial deployment in Norway. Because 'top-down' or 'market pull' biofuel support policy like excise tax exemptions or carbon taxes do not directly encourage investment into specific biofuel technologies like wood-FTD in the short term, we choose to analyze three 'bottom-up' or 'market push' policy scenarios to assess their effects on reducing levelized unit production costs. These include a Capital Grant, a low-interest Loan Guarantee, a Corporate Tax Credit, and a Feedstock Credit scenario. Under the Capital Grant scenario, we assess the change in levelized production and thus GHG abatement costs when a 50% capital grant (TCI) is

76 FR 30655 - Certain Orange Juice From Brazil: Final Results of the Expedited Sunset Review of the Antidumping...

Science.gov (United States)

2011-05-26

... Agricultura, Montecitrus Trading S.A., and Sucocitrico Cutrale, S.A. Excluded from the scope of the order are...- Manufacturers/Exporters/Producers average margin (percent) Fischer S.A. Comercio, Industria, and Agricultura....A. Comercio, Industria, and Agricultura is the successor-in- interest to Fischer S/A--Agroindustria...

Resonance journal of science education

Indian Academy of Sciences (India)

July 2011 Volume 16 Number 7. GENERAL ARTICLES. 606 Hermann Emil Fischer: Life and Achievements. G Nagendrappa. 620 Carbohydrate Chemistry from Fischer to Now. N R Krishnaswamy. 640 One Hundred Years of Peptide Chemistry. V V Suresh Babu. 648 Fermat: A Versatile Genius. Utpal Mukhopadhyay. O. HO.

Induction of glutathione S-transferase placental form positive foci in liver and epithelial hyperplasia in urinary bladder, but no tumor development in male Fischer 344 rats treated with monomethylarsonic acid for 104 weeks

International Nuclear Information System (INIS)

Shen Jun; Wanibuchi, Hideki; Salim, Elsayed I.; Wei Min; Doi, Kenichiro; Yoshida, Kaoru; Endo, Ginji; Morimura,; Fukushima, Shoji

2003-01-01

The carcinogenicity of monomethylarsonic acid (MMA(V)), a major metabolite of inorganic arsenics in human and experimental animals, was investigated in male Fischer 344 rats. A total of 129 rats at 10 weeks of age were randomly divided into three groups and received drinking water containing MMA(V) at doses of 0 (Control), 50, and 200 ppm ad libitum for 104 weeks. No significant differences were found between the control and the MMA(V)-treated groups regarding clinical signs, mortality, hematological, and serum biochemistry findings. Quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci in liver revealed a significant increase of numbers and areas in the 200 ppm MMA(V)-treated group. In the urinary bladder MMA(V) induced simple hyperplasia and significantly elevated the proliferating cell nuclear antigen (PCNA)-positive index in the urothelium. A variety of tumors developed in rats of all groups, including the controls, but all were histologically similar to those known to occur spontaneously in F344 rats and there were no significant differences among the groups. Thus, it could be concluded that, under the present experimental conditions, MMA(V) induced lesions in the liver and urinary bladder, but did not cause tumor development in male F344 rats even after 2 years exposure

De variabiliteit van Veronica hederifolia L. in Nederland

NARCIS (Netherlands)

Jongh, de S.E.; Kern, J.H.

1971-01-01

The variation and distribution of Veronica hederifolia in the Netherlands is more thoroughly discussed than in the preliminary paper bij DE JONGH (1968). It is shown that only two of the five taxa distinguished by M. Fischer occur, V. hederifolia L. and V. sublobata M. Fischer. The earlier records

Genetics Home Reference: Griscelli syndrome

Science.gov (United States)

... Tezcan I, Ersoy F, Houdusse A, Fischer A, de Saint Basile G. Griscelli syndrome restricted to hypopigmentation results from a melanophilin defect ( ... N, Bianchi D, Fischer A, Le Deist F, de Saint Basile G. Mutations in RAB27A ... syndrome associated with haemophagocytic syndrome. Nat Genet. 2000 Jun; ...

Lack of Effect of 94 GHz Radio Frequency Radiation Exposure in an Animal Model of Skin Carcinogenesis

Science.gov (United States)

2001-10-01

Phillips,J.L. and Haggren,W. (1999) Spontaneous and nitrosourea -induced primary tumors of the central nervous system in Fischer 344 rats chronically...MacMurray,A., Stagg,R.B. and Zimmerman,G. (2000) Spontaneous and nitrosourea -induced primary tumors of the central nervous system in Fischer 344 rats

Motorcycle Diaries

Science.gov (United States)

Gibbs, Hope J.

2005-01-01

This article relates the experiences of Jeff Fischer, an instructor in the Computer Integrated Machining department at South Central College (SCC) in North Mankato, Minnesota. Facing dwindling student enrollment and possible departmental budget costs, Fischer was able to turn his passion for custom-built cycles and the intricate machining that…

Novel inorganic precursors [Co.sub.4.32./sub.Zn.sub.1.68./sub.(HCO.sub.2./sub.).sub.18./sub.(C.sub.2./sub.H.sub.8./sub.N).sub.6./sub.]/SiO.sub.2./sub. and Co.sub.4.32./sub.Zn.sub.1.68./sub.(HCO2).sub.18./sub.(C.sub.2./sub.H.sub.8./sub.N).sub.6./sub.]/Al.sub.2./sub.O.sub.3./sub. for Fischer-Tropsch synthesis

Czech Academy of Sciences Publication Activity Database

Saheli, S.; Rezvani, A.R.; Malekzadeh, A.; Dušek, Michal; Eigner, Václav

2018-01-01

Roč. 43, č. 2 (2018), s. 685-694 ISSN 0360-3199 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk(CZ) LO1603 EU Projects: European Commission(CZ) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : Fischer-Tropsch synthesis * coordination polymers * inorganic precursor * impregnation * catalytic performance Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.582, year: 2016

Model studies of secondary hydrogenation in Fischer-Tropsch synthesis studied by cobalt catalysts

Energy Technology Data Exchange (ETDEWEB)

Aaserud, Christian

2003-07-01

Mass transfer effects are very important in Fischer-Tropsch (FT) synthesis. In order to study the FT synthesis without the influence of any transport limitations, cobalt foils have been used as model catalysts. The effect of pretreatment (number of calcinations and different reduction times) for cobalt foil catalysts at 220 {sup o}C, 1 bar and H{sub 2}/CO = 3 has been studied in a microreactor. The foils were examined by Scanning electron microscopy (SEM). It was found that the catalytic activity of the cobalt foil increases with the number of pretreatments possibly due to an increase in the surface area of the cobalt foil. The SEM results support the assumption that the surface area of the cobalt foil increases with the number of pretreatments. The reduction time was also found to influence the catalytic activity of the cobalt foil. Highest activity was obtained using a reduction time of only five min (compared to one and thirty min). The decrease in activity after reduction for thirty min compared to five min was suggested to be due to restructuring of the surface of the cobalt foil and a reduction time of only 1 min was not enough to reduce the cobalt foil sufficiently. Time of reduction did also influence the product distribution. Increased reduction time resulted in a lower selectivity to light products and increased selectivity to heavier components. The paraffin/olefin ratio increased with increasing CO-conversion also for cobalt foils. The paraffin/olefin ratio also increased when the reduction period of the cobalt foil was increased at a given CO-conversion. Hydrogenation of propene to propane has been studied as a model reaction for secondary hydrogenation of olefins in the FT synthesis. The study has involved promoted and unpromoted cobalt FT catalysts supported on different types of supports and also unsupported cobalt. Hydrogenation of propene was carried out at 120 {sup o}C, 1.8 bar and H{sub 2}/C{sub 3}H{sub 6} 6 in a fixed bed microreactor. The rate

Skeletal muscle function and hypertrophy are diminished in old age.

NARCIS (Netherlands)

Degens, H.; Alway, S.E.

2003-01-01

Muscle loss occurs during aging. To investigate whether the hypertrophic response is attenuated at old age, we used male Fischer 344 (26 months old; n = 5) and Fischer 344 x Brown Norway rats (6, 9, and 33 months old; n = 8, 10, and 6, respectively). Hypertrophy of the left plantaris muscle was

Riia on Liivimaa akadeemia jaoks kohaseim ja sobivaim paik / Enn Küng

Index Scriptorium Estoniae

Küng, Enn, 1963-

2010-01-01

Esitatud on kaks dokumenti, kus Liivimaa kindralkuberner Jakob Johann Hastfer ja Liivimaa ülemkonsistooriumi juht Johann Fischer esitavad oma seisukohad ja nägemuse, kus peaks Tartu ülikool (Academia Gustaviana) pärast Vene-Rootsi sõda (1659-1661) taas tegutsemist alustama. Hastfer eelistas Riiat ja Fischer Pärnut. Lisatud autori kommentaar

The Eni - IFP/Axens GTL technology. From R and D to a successful scale-up

Energy Technology Data Exchange (ETDEWEB)

Zennaro, R. [Eni S.p.A., Milan (Italy); Hugues, F. [Institut Francais du Petrole, Lyon (France); Caprani, E. [Axens, Paris (France)

2006-07-01

Proven natural gas reserves had reached about 184 Tscm in 2006 to which 36% is stranded gas far from the final market. Fischer Tropsch based GtL options today represent a viable route to develop such remote gas resources into high quality fuels and specialties. Thus opening different markets for the gas historically linked to the oil. Thanks to R and D successful improvements in the field of catalysis and reactor technology coupled with optimized integration and economies of scale have reduced the investment cost for building a Fischer Tropsch GtL complex. Basically all major Oil and Gas companies are involved in proprietary GtL development, and today several industrial projects have been announced. The most advanced is the Oryx project (QP-Sasol) which has been inaugurated the 6{sup th} of June '06 and currently in the starting up phase. Eni and IFP-Axens have developed a proprietary GtL Fischer-Tropsch and Upgrading technology in a close collaboration between the two groups. The Eni/IFP-Axens technology is based on proprietary catalysts and reactor, designed according to scale-up criteria defined in ten years of R and D activity. Unique large scale hydrodynamic facilities (bubble columns, loops) bench-scale dedicated pilot units, as well as large scale Fischer-Tropsch pilot plant, have been developed and operated to minimize reactor and ancillaries scale-up risks. The large scale Fischer-Tropsch pilot plant has been built and operated since 2001. The plant, located within the Eni refinery of Sannazzaro de' Burgondi (Pavia, Italy) is fully integrated to the refinery utilities and network. It reproduces at 20 bpd scale the overall Fischer Tropsch synthesis section: from slurry handling (loading, make-up, withdrawal), to reactor configuration and products separation units. Today the scale-up basis has been completed and the technology is ready for industrial deployment. (orig.)

Study on the genus Daptus ground-beetles (Coleoptera: Carabidae from Korea

Directory of Open Access Journals (Sweden)

Ik Je Choi

2016-03-01

Full Text Available A genus Daptus Fischer von Waldheim, 1823 of the tribe Harpalini Bonelli, 1810 (Coleoptera: Carabidae is reported for the first time from Korea, based on the Daptus vittatus Fischer von Waldheim from Incheon, Korea. Redescription of the species and illustrations of diagnostic characteristics, including genitalia characteristics of both sexes, are provided.

Assessing the plasmonics of gold nano-triangles with higher order laser modes

Directory of Open Access Journals (Sweden)

Laura E. Hennemann

2012-10-01

Full Text Available Regular arrays of metallic nano-triangles – so called Fischer patterns – are fabricated by nano-sphere lithography. We studied such gold nano-triangle arrays on silicon or glass substrates. A series of different samples was investigated with a parabolic mirror based confocal microscope where the sample is scanned through the laser focus. By employing higher order laser modes (azimuthally and radially polarised laser beams, we can excite the Fischer patterns using either a pure in-plane (x,y electric field or a strongly z-directional (optical axis of the optical microscope electric field. We collected and evaluated the emitted luminescence and thereby investigated the respectively excited plasmonic modes. These varied considerably: firstly with the light polarisation in the focus, secondly with the aspect ratio of the triangles and thirdly with the employed substrate. Moreover, we obtained strongly enhanced Raman spectra of an adenine (sub-monolayer on gold Fischer patterns on glass. We thus showed that gold Fischer patterns are promising surface-enhanced Raman scattering (SERS substrates.

The Role of Biotransformation and Oxidative Stress in 3,5-Dichloroaniline (3,5-DCA) Induced Nephrotoxicity in Isolated Renal Cortical Cells from Male Fischer 344 Rats

Science.gov (United States)

Racine, Christopher R.; Ferguson, Travis; Preston, Debbie; Ward, Dakota; Ball, John; Anestis, Dianne; Valentovic, Monica; Rankin, Gary O.

2016-01-01

Among the mono- and dichloroanilines, 3,5-Dichloroaniline (3,5-DCA) is the most potent nephrotoxicant in vivo and in vitro. However, the role of renal biotransformation in 3,5-DCA induced nephrotoxicity is unknown. The current study was designed to determine the in vitro nephrotoxic potential of 3,5-DCA in isolated renal cortical cells (IRCC) obtained from male Fischer 344 rats, and the role of renal bioactivation and oxidative stress in 3,5-DCA nephrotoxicity. IRCC (~4 million cells/ml) from male rats were exposed to 3,5-DCA (0-1.0 mM) for up to 120 min. In IRCC, 3,5-DCA was cytotoxic at 1.0 mM by 60 min as evidenced by the increased release of lactate dehydrogenase (LDH), but 120 min was required for 3,5-DCA 0.5 mM to increase LDH release. In subsequent studies, IRCC were exposed to a pretreatment (antioxidant or enzyme inhibitor) prior to exposure to 3,5-DCA (1.0 mM) for 90 min. Cytotoxicity induced by 3,5-DCA was attenuated by pretreatment with inhibitors of flavin-containing monooxygenase (FMO; methimazole, N-octylamine), cytochrome P450 (CYP; piperonyl butoxide, metyrapone), or peroxidase (indomethacin, mercaptosuccinate) enzymes. Use of more selective CYP inhibitors suggested that the CYP 2C family contributed to 3,5-DCA bioactivation. Antioxidants (glutathione, N-acetyl-L-cysteine, α-tocopherol, ascorbate, pyruvate) also attenuated 3,5-DCA nephrotoxicity, but oxidized glutathione levels and the oxidized/reduced glutathione ratios were not increased. These results indicate that 3,5-DCA may be activated via several renal enzyme systems to toxic metabolites, and that free radicals, but not oxidative stress, contribute to 3,5-DCA induced nephrotoxicity in vitro. PMID:26808022

Sufficient condition for the linearization stability of N = 1 supergravity: A preliminary report

International Nuclear Information System (INIS)

Bao, D.

1984-01-01

This paper outlines how the methods developed by Fischer, Marsden, and Moncrief (A. Fischer and J. Marsden, ''Isolated Gravitating Systems in General Relativity,'' (J. Ehlers, Ed.), Proceedings of the International School of Physics Enrico Fermi Course XVII, North-Holland, Amsterdam, 1979; A. Fischer, J. Marsden, and V. Moncrief, Ann. Inst. Henri Poincare 33 (1980), 147-194) for general relativity are being used to show that classical N = 1 supergravity, as a non-linear system of partial differential equtions, is linearization stable at any solution which lacks Killing symmetry. It is assumed (for convenience) throughout that the underlying spacetime is topologically Σ 0 x R, where Σ 0 is a compact, spacelike, and boundaryless 3-dimensional hypersurface

The New Special Relationship: Redefining America’s Strategic Partnership With Germany

Science.gov (United States)

2015-05-01

confidence in his government, which narrowly succeeded.21 Additionally, both Chancellor Schröder and then-Foreign Minister Joschka Fischer were instrumental...support within international institutions. Foreign Minister Fischer in particular labored to coordinate a common European position as well as...Damon M. Wilson, and Jeff Lightfoot, Anchoring the Alliance (Washington, DC: Atlantic Council of the United States, 2012 33 Sebastian Schulte

Detection Of Malware Collusion With Static Dependence Analysis On Inter-App Communication

Science.gov (United States)

2016-12-08

app permission leakage.” IEEE Transactions on Software Engineering, 2015 [4]. Bugiel, Sven, Lucas Davi, Alexandra Dmitrienko, Thomas Fischer , Ahmad...Dmitrienko, Thomas Fischer , and Ahmad-Reza Sadeghi. “Xmandroid: A new android evolution to mitigate privilege escalation attacks.”, Technical Report...Technical report, Department of Computer Science, University of Maryland, College Park, 2009. [12]. Gordon, Michael I., Deokhwan Kim, Jeff H. Perkins

ALICE comes to life

CERN Multimedia

2002-01-01

On 26 March, a first major part of the ALICE detector arrived at CERN: one of the four cylinders in composite material for the Time Projection Chamber (TPC). The construction of the TPC 'field cage' (the structure that defines the configuration of the electrical field of the TPC) is the fruit of exceptional collaboration between CERN and the Austrian manufacturer Fischer Advanced Composite Components (Fischer ACC).

Iron on mixed zirconia-titania substrate F-T catalyst

International Nuclear Information System (INIS)

Dyer, P.N.; Nordquist, A.F.; Pierantozzi, R.

1988-01-01

This patent deals with a Fischer-Tropsch catalyst comprising iron co-deposited with or deposited on particles comprising a mixture of zirconia and titania, preferably formed by co-precipitation of compounds convertible to zirconia and titania, such as zirconium and titanium alkoxide. The invention also comprises the method of making this catalyst and an improved Fischer-Tropsch reaction process in which the catalyst is utilized

Mucorales (Zygomycotina da Mata Atlântica da Reserva Biológica do Alto da Serra de Paranapiacaba, Santo André, SP Mucorales (Zygomycotina of the Atlantic Rainforest in the "Reserva Biológica do Alto da Serra de Paranapiacaba", Santo André, SP, Brazil

Directory of Open Access Journals (Sweden)

Iracema Helena Schoenlein-Crusius

1997-07-01

Full Text Available Treze táxons de Mucorales (Zygomycotina, distribuídos num total de 266 registros, foram isolados de folhas de Alchornea triplinervia (Spreng. Müll. Arg. colocadas em ambientes terrestre e aquático, e de amostras de solo e de água de riacho, coletadas mensalmente, de julho de 1988 a maio de 1990 na Reserva Biológica do Alto da Serra de Paranapiacaba, no município de Santo André, SP. As espécies que apresentaram os maiores números de registro de ocorrência foram Mucor hiemalis Wehmer (78 registros, Mucor circinelloides van Tieghem f. janssenii (Ledner Schipper (42 registros e Rhizopus arrhizus Fischer (30 registros. Cinqüenta por cento dos Mucorales encontrados na região são constituídos por espécies que estão sendo citadas pela primeira vez para a Mata Atlântica: Mucor hiemalis Wehmer f. silvaticus (Hagem Schipper, Rhizopus arrhizus Fischer, Rhizopus oligosporus Fischer, Rhizopus oryzae (Went. & Prinsen Geerlings, Zygorhynchus japonicus Vuill. e Zygorhynchns macrocarpus Ling-Young.Thirteen taxa of Mucorales (Zygomycotina, distributed in 266 occurrences were isolated from leaves of Alchornea triplinervia (Spreng. Müll. Arg. disposed in the terrestrial and aquatic environment, and of soil and stream water samples, monthly taken from July of 1988 to May of 1990, in the "Reserva Biológica do Alto da Serra de Paranapiacaba", in the municipality of Santo André, São Paulo State, Brazil. Mucor hiemalis Wehmer (78 records, Mucor circinelloides van Tieghem f. janssenii (Ledner Schipper (42 records and Rhizopus arrhizus Fischer (30 records were the most frequent species. Fifty percent of the Mucorales found are formed by species that are mentioned for the first time in the Atlantic Rainforest: Mucor hiemalis Wehmer f. silvaticus (Hagem Schipper, Rhizopus arrhizus Fischer, Rhizopus oligosporus Fischer, Rhizopus oryzae (Went. & Prinsen Geerlings, Zygorhynchus japonicus Vuill. and Zygorhynchus macrocarpus Ling-Young.

Prospects for Finland and Sweden to Pursue Closer Defense Cooperation With NATO

Science.gov (United States)

2016-09-01

in my naval career. I would also like to recognize Professor Jeff Kline for taking special interest in my thesis topic and for providing the...Challenges for Disarmament and Peace Operations on the Political Agenda, eds. Peter Fischer - Bollin and Thomas Knirsch. VII Conference on Forte de Copacabana...Agenda, edited by Peter Fischer -Bollin and Thomas Knirsch. VII Conference on Forte de Copacabana International Security. Rio de Janeiro: Konrad-Adenauer

Ebb and Flow: Maintaining the Close Air Support Relationship through History

Science.gov (United States)

2016-05-10

3-09.3, Close Air Support (Washington, DC: Government Printing Office, 2014), xi. 20 Scott Fischer , LtCol, USAF, “Army and Air Force Subcultures...also happens that airmen and ground forces can 30 Jeff Schogol, "Welsh: The Air Force cares about...Advanced Military Studies, 2004), 59. 60 Fischer , “Army Air Force Subcultures,” 15. 61 Bolton, “Army Fixed-Wing Attack,” 5-6. 21 external

Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization

Science.gov (United States)

2015-08-24

nanoenergetic composites finding extensive use in ordnance and industrial applications, because of its high heat of combustion (~32 kJ/g) (S. H. Fischer ...2011. Farley, Cory. "Reactions of Aluminum with Halogen Containing Oxides." Dissertation. Lubbock, TX, May 2013. Gesner, Jeff , Michelle Pantoya, and...characteristics of novel hybrid nanoenergetic formulations." Combustion and Flame 158 (2011): 964- 978. S. H. Fischer , M. C. Grubelich. "Theoretical

The Comparison of Hydrotreated Vegetable Oils With Respect to Petroleum Derived Fuels and the Effects of Transient Plasma Ignition in a Compression-Ignition Engine

Science.gov (United States)

2012-09-01

Content per Combustion J FAME Fatty Acid Methyl Ester FMEP Friction Mean Effective Pressure PSI or Bar FT Fischer-Tropsch h Heat...recently, algae-derived oils. Biodiesel has gained popularity in North America over the past decade, but the ester content of Fatty Acid Methyl ... Ester ( FAME ) fuel creates both cold weather and water- based operational issues. The Fischer-Tropsch (FT) process produces liquid fuels from “syngas,” a

Characterization of a Cytokinin Response Factor in Arabidopsis thaliana

OpenAIRE

Ketelsen, Bernd

2012-01-01

The papers of this thesis are not available in Munin: 1. Bernd Ketelsen, Rainer Schwacke, Kirsten Krause and Karsten Fischer: 'Transcriptional activation by Cytokinin Response Factor 5 is governed by an acidic Cterminus containing two conserved domains' (manuscript) 2. Bernd Ketelsen, Stian Olsen, Kirsten Krause and Karsten Fischer: 'Cytokinin responsive factor 5 (CRF5) is involved in root development, hormonal crosstalk and sugar metabolism in Arabidopsis thaliana' (manuscript) 3. Bernd K...

Atomic-Scale Design of Iron Fischer-Tropsch Catalysts; A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

Energy Technology Data Exchange (ETDEWEB)

Manos Mavrikakis; James Dumesic; Rahul Nabar; Calvin Bartholonew; Hu Zou; Uchenna Paul

2008-09-29

This work focuses on (1) searching/summarizing published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) preparation and characterization of unsupported iron catalysts with/without potassium/platinum promoters; (3) measurement of H{sub 2} and CO adsorption/dissociation kinetics on iron catalysts using transient methods; (3) analysis of the transient rate data to calculate kinetic parameters of early elementary steps in FTS; (4) construction of a microkinetic model of FTS on iron, and (5) validation of the model from collection of steady-state rate data for FTS on iron catalysts. Three unsupported iron catalysts and three alumina-supported iron catalysts were prepared by non-aqueous-evaporative deposition (NED) or aqueous impregnation (AI) and characterized by chemisorption, BET, temperature-programmed reduction (TPR), extent-of-reduction, XRD, and TEM methods. These catalysts, covering a wide range of dispersions and metal loadings, are well-reduced and relatively thermally stable up to 500-600 C in H{sub 2} and thus ideal for kinetic and mechanistic studies. Kinetic parameters for CO adsorption, CO dissociation, and surface carbon hydrogenation on these catalysts were determined from temperature-programmed desorption (TPD) of CO and temperature programmed surface hydrogenation (TPSR), temperature-programmed hydrogenation (TPH), and isothermal, transient hydrogenation (ITH). A microkinetic model was constructed for the early steps in FTS on polycrystalline iron from the kinetic parameters of elementary steps determined experimentally in this work and from literature values. Steady-state rate data were collected in a Berty reactor and used for validation of the microkinetic model. These rate data were fitted to 'smart' Langmuir-Hinshelwood rate expressions derived from a sequence of elementary steps and using a combination of fitted steady-state parameters and parameters specified from the transient

Electron pairing analysis of the Fischer-type chromium-carbene complexes (CO){sub 5}Cr=C(X)R (X=H, OH, OCH{sub 3}, NH{sub 2}, NHCH{sub 3} and R=H, CH{sub 3}, CH=CH{sub 2}, Ph, C-CH )

Energy Technology Data Exchange (ETDEWEB)

Poater, Jordi; Cases, Montserrat; Fradera, Xavier; Duran, Miquel; Sola, Miquel

2003-10-15

The electron-pair density distributions of a series of 25 Fischer carbene complexes of the type (CO){sub 5}Cr=C(X)R (X=H, OH, OCH{sub 3}, NH{sub 2}, NHCH{sub 3} and R=H, CH{sub 3}, CH=CH{sub 2}, Ph, C-CH) are analyzed using the Atoms in Molecules theory. Localization and delocalization indices are used to characterize the electron pairing taking place in the Cr=C---X moiety in these complexes. Electron delocalization between the Cr and C atoms and between the C atom and the X group are related to the {pi}-donor strength of the X group and the degree of back-donation between the chromium pentacarbonyl and the carbene fragments. The results obtained with the Atoms in Molecules theory complement those obtained in a previous study by means of energy and charge decomposition analyses. Electron delocalization between the Cr atom and the X group is consistent with the hypothesis of a weak 3-center 4-electron bonding interaction in the Cr=C-X group of atoms. Except for X=H, {delta}(Cr,X) increases with the decrease of the {pi}-donor character of the X group.

Role of UDP-Glucuronosyltransferase (UGT) 2B2 in Metabolism of Triiodothyronine: Effect of Microsomal Enzyme Inducers in Sprague Dawley and UGT2B2-Deficient Fischer 344 Rats

Science.gov (United States)

Richardson, Terrilyn A.; Klaassen, Curtis D.

2010-01-01

Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) can impact thyroid hormone homeostasis in rodents. Increased glucuronidation can result in reduction of serum thyroid hormone and a concomitant increase in thyroid-stimulating hormone (TSH). UGT2B2 is thought to glucuronidate triiodothyronine (T3). The purposes of this study were to determine the role of UGT2B2 in T3 glucuronidation and whether increased T3 glucuronidation mediates the increased TSH observed after MEI treatment. Sprague Dawley (SD) and UGT2B2-deficient Fischer 344 (F344) rats were fed a control diet or diet containing pregnenolone-16α-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum thyroxine (T4), T3, and TSH concentrations, hepatic androsterone/T4/T3 glucuronidation, and thyroid follicular cell proliferation were determined. In both SD and F344 rats, MEI treatments decreased serum T4, whereas serum T3 was maintained (except with PCB treatment). Hepatic T4 glucuronidation increased significantly after MEI in both rat strains. Compared with the other MEI, only PCN treatment significantly increased T3 glucuronidation (281 and 497%) in both SD and UGT2B2-deficient F344 rats, respectively, and increased both serum TSH and thyroid follicular cell proliferation. These data demonstrate an association among increases in T3 glucuronidation, TSH, and follicular cell proliferation after PCN treatment, suggesting that T3 is glucuronidated by other PCN-inducible UGTs in addition to UGT2B2. These data also suggest that PCN (rather than 3-MC or PCB) promotes thyroid tumors through excessive TSH stimulation of the thyroid gland. PMID:20421340

Multi-Phase Combustion and Transport Processes Under the Influence of Acoustic Excitation

Science.gov (United States)

2014-01-01

waveguide. Alcohol fuels (ethanol and methonal) as well as aviation fuel replacements ( Fischer -Tropsch (FT) synfuel and an FT blend with JP-8) were studied...replacements ( Fischer -Tropsch (FT) synfuel and an FT blend with JP-8) were studied here. During acoustic excitation, the flame surrounding the droplet was...Wegener is approved. Chris R. Anderson Jeff D. Eldredge Ivett A. Leyva Owen I. Smith Ann R. Karagozian, Committee Chair University of California, Los

U.S. Nuclear Policy, Strategy, and Force Structure: Insights and Issues from the 1994, 2001, and 2010 Nuclear Posture Reviews

Science.gov (United States)

2014-09-01

community.”251 Senator Jeff Sessions, in the April 17, 2013 Hearing to Receive Testimony on Nuclear Forces and Policies, expressed concern that allies...Sagan’s NFU argument, Timothy Fischer , in a U.S. Army War College study from 2012, countered that the United States should retain a policy of possible...nuclear response to WMD because of the important role of ambiguity in national security policy flexibility and deterrence. Fischer recommended that the

A 90-day continuous vapor inhalation toxicity study of JP-8 jet fuel followed by 20 or 21 months of recovery in Fischer 344 rats and C57BL/6 mice.

Science.gov (United States)

Mattie, D R; Alden, C L; Newell, T K; Gaworski, C L; Flemming, C D

1991-01-01

The kerosene-type jet fuel, JP-8, consists of a complex mixture of aliphatic and aromatic hydrocarbons. Because of the utility of JP-8, studies have been conducted to identify the potential long-term consequence of occupational inhalation exposure. Fischer 344 rats and C57BL/6 mice of both sexes were exposed to JP-8 vapors at 0, 500, and 1,000 mg/m3 on a continuous basis for 90 days, then followed by recovery until approximately 24 months of age. Occurrence of necrotizing dermatitis associated with fighting resulted in an increase in mortality in mice (male greater than female) during the 2 week to 9 month post-exposure recovery period. The male rat kidney developed a reversible ultrastructural increase in size and propensity for crystalloid changes of phagolysosomal proteinic reabsorption droplets in the proximal convoluted tubular epithelium. A specific triad of persisting light microscopic renal lesions occurred but functional change was limited to a decrease in urine concentration compared to controls that persisted throughout the recovery period. The response is comparable to the chronic effect of lifetime exposure of the male rat to unleaded gasoline, d-limonene, and p-dichlorobenzene, except for the absence of tubular tumorigenesis. The active toxicologic response presumably must occur over a greater proportion of the male rat's life span for the tumor component of this male rat hydrocarbon nephropathy syndrome. The predictiveness for humans must be questioned, since the pathologic response to JP-8 involved only one tissue in one sex of one species, and since the male rat response appears to be linked to an inherent renal protein peculiarity.

Fickle Allies: Regular and Irregular Confederate Forces in Missouri during the American Civil War

Science.gov (United States)

2014-05-22

238-239, 242. 58Kel N. Pickens, “The Battle of Wilson’s Creek, Missouri, August 10, 1861,” in Civil War Battles in the West, ed. LeRoy H. Fischer ...force with nearby Confederate Army Brigadier General William Hardee and MSG Brigadier General M. Jeff . Thompson, and open a new front to ultimately...West, ed. LeRoy H. Fischer (Manhattan, KS: Sunflower University Press, 1981), 40. 101Shea, War in the West, 18-19, 26, 34-35. 30

Department of Defense and Security Cooperation: Improving Prioritization, Authorities, and Evaluations

Science.gov (United States)

2016-03-09

March 9, 2016 Chairman Fischer , Ranking Member Nelson, and distinguished members of the subcommittee, thank you for the opportunity to testify...on the important subject of U.S. security cooperation. It’s a pleasure to appear before you today along with my colleagues, Jeff Eggers and Melissa...based evaluations. Chairman Fischer , Ranking Member Nelson, and members of the subcommittee, I appreciate the opportunity to offer this testimony, and I look forward to assisting the committee in its vital work.

Diatom-Based Material Production Demonstration

Science.gov (United States)

2016-03-14

Haeger 0.02 Sean Hoban 0.05 Leila Kamakele 0.06 Jeff Kataoka 0.08 Randi Keipper 0.16 Brendan Lagather 0.17 Stephen Woods 0.10 Rodney Corpuz 0.13 Aga...to Cathleen Fischer at Dresden University of Technology for testing as a substrate for catalysis. Material is available for any other testing...also thank Dr. Pat Kociolek from University of Colorado for help with identifying girdle bands of GAI-216. Bibliography Jantschke A., C. Fischer

Interaction of Jet Fuel Hydrocarbon Components with Red Blood Cells and Hemoglobin

Science.gov (United States)

2014-06-24

Directorate (RHDJ), Wright-Patterson AFB, OH. The authors would like to thank Maj. Paul Eden, Nicole Schaeublin, Christin Grabinski, Dr. Jeff Gearhart...We would also like to thank LtCol. Norman Fox (Laboratory Flight Commander), Mrs. Nersa Loh (Supervisor, Transfusion Services), and Mr. Dan Fischer ...Approximately 7.8 mg of hemoglobin sample was concentrated into a total volume of 5 mL of Fischer PBS pH 7.5 buffer using an Amicon Centrifugal Filter Unit

Improved Fischer-Tropsch Slurry Reactors

International Nuclear Information System (INIS)

Lucero, Andrew

2009-01-01

The conversion of synthesis gas to hydrocarbons or alcohols involves highly exothermic reactions. Temperature control is a critical issue in these reactors for a number of reasons. Runaway reactions can be a serious safety issue, even raising the possibility of an explosion. Catalyst deactivation rates tend to increase with temperature, particularly of there are hot spots in the reactor. For alcohol synthesis, temperature control is essential because it has a large effect on the selectivity of the catalysts toward desired products. For example, for molybdenum disulfide catalysts unwanted side products such as methane, ethane, and propane are produced in much greater quantities if the temperature increases outside an ideal range. Slurry reactors are widely regarded as an efficient design for these reactions. In a slurry reactor a solid catalyst is suspended in an inert hydrocarbon liquid, synthesis gas is sparged into the bottom of the reactor, un-reacted synthesis gas and light boiling range products are removed as a gas stream, and heavy boiling range products are removed as a liquid stream. This configuration has several positive effects for synthesis gas reactions including: essentially isothermal operation, small catalyst particles to reduce heat and mass transfer effects, capability to remove heat rapidly through liquid vaporization, and improved flexibility on catalyst design through physical mixtures in addition to use of compositions that cannot be pelletized. Disadvantages include additional mass transfer resistance, potential for significant back-mixing on both the liquid and gas phases, and bubble coalescence. In 2001 a multiyear project was proposed to develop improved FT slurry reactors. The planned focus of the work was to improve the reactors by improving mass transfer while considering heat transfer issues. During the first year of the project the work was started and several concepts were developed to prepare for bench-scale testing. PowerEnerCat was unable to raise their cash contribution for the project, and the work was stopped. This report summarizes some of the progress of the project and the concepts that were intended for experimental tests.

Euroopa kaks tulevikku / Joschka Fischer

Index Scriptorium Estoniae

Fischer, Joschka, 1948-

2007-01-01

Autor analüüsib Euroopa Liidu tulevikku, põhiseaduse lepingu väljavaateid ja rõhutab EL-i vajadust toime tulla üleilmsete väljakutsetega, sest 21. sajandil jätkub suurte riikide nagu Hiina, India, USA ja Jaapani tõus. EL-il on kaks võimalust: kas maailmaga kaasa minna või hääbuda, kirjutab autor

Cerium promoted Fischer-Tropsch catalysts

International Nuclear Information System (INIS)

Fiato, R.A.; Bar-Gadda, R.; Miseo, S.

1987-01-01

This patent describes a hydrocarbon synthesis catalyst composition comprising sintered combination metal oxides having the following components in the stated weight percentage of the catalyst composition: (a) about 5 to about 80 weight percent Fe oxide; (b) about 4 to about 20 weight percent Zn oxide; (c) about 10 to about 40 weight percent Ti and/or Mn oxide; (d) about 1 to about 5 weight percent K, Rb, and/or Cs oxide; and (e) about 1 to about 10 weight percent Ce oxide, such that where the catalyst contains Fe, the sintered combination comprises a series of Fe, Zn, and/or Ti and/or Mn spinels and oxides of K, Rb and/or Cs, dispersed in a Ce oxide matrix

Fischer-Tropsch Slurry Reactor modeling

Energy Technology Data Exchange (ETDEWEB)

Soong, Y.; Gamwo, I.K.; Harke, F.W. [Pittsburgh Energy Technology Center, PA (United States)] [and others

1995-12-31

This paper reports experimental and theoretical results on hydrodynamic studies. The experiments were conducted in a hot-pressurized Slurry-Bubble Column Reactor (SBCR). It includes experimental results of Drakeol-10 oil/nitrogen/glass beads hydrodynamic study and the development of an ultrasonic technique for measuring solids concentration. A model to describe the flow behavior in reactors was developed. The hydrodynamic properties in a 10.16 cm diameter bubble column with a perforated-plate gas distributor were studied at pressures ranging from 0.1 to 1.36 MPa, and at temperatures from 20 to 200{degrees}C, using a dual hot-wire probe with nitrogen, glass beads, and Drakeol-10 oil as the gas, solid, and liquid phase, respectively. It was found that the addition of 20 oil wt% glass beads in the system has a slight effect on the average gas holdup and bubble size. A well-posed three-dimensional model for bed dynamics was developed from an ill-posed model. The new model has computed solid holdup distributions consistent with experimental observations with no artificial {open_quotes}fountain{close_quotes} as predicted by the earlier model. The model can be applied to a variety of multiphase flows of practical interest. An ultrasonic technique is being developed to measure solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 180 {degrees}C and 0.1 MPa. The data show that both the sound speed and attenuation are well-defined functions of both the solid and gas concentrations in the slurries. The results suggest possibilities to directly measure solids concentration during the operation of an autoclave reactor containing molten wax.

ICT and Romania's Development Towards the Knowledge Economy

Directory of Open Access Journals (Sweden)

2007-01-01

Full Text Available The new stage of the market-based economy is more strongly and more directly rooted in the production, distribution and use of knowledge. Knowledge creation and knowledge diffusion are key driving forces in the economy and knowledge has become an economic resource in its own right (Fischer and Atalik, 2002. Accordingly, firms are more and more interested in absorbing the advances in technological and organizational knowledge and in applying it in the production process and organization of work. In this context, any discussion about knowledge invariably leads to the question of the relationship between information and knowledge. Thus, according to Fischer, the common understanding is that "information does not become knowledge unless its value is enhanced through interpretation, organization, filtration, selection or engineering" (Fischer, 2002, p. 18. Moreover, nowadays the ICT revolution and the knowledge-based economy are closely interrelated. The convergence of computing, information and telecommunication technologies has changed the conditions for the production and dissemination of knowledge and its connection with the production system as well. New flexible information and communication technologies such as internet, web, intranet, extranet, data warehousing and data mining, as well as collaborative groupware technologies are responsible for the major changes in current abilities to handle data and information, to codify knowledge and to transmit codified knowledge (Fischer, 2006.

Understanding Drug Resistance to Targeted Therapeutics in Malignant B-Cell Lymphoproliferative Disorders (B-LPDs)

Science.gov (United States)

2014-10-01

1063-70. PMC2783430. 2. Zhang J, Jima DD, Jacobs C, Fischer R, Gottwein E, Huang G, Lugar PL, Lagoo AS, Rizzieri DA, Friedman DR, Weinberg JB...Khoury, Thomas R Klumpp, Hillard M Lazarus, Victor A Lewis, Philip L McCarthy, David A Rizzieri, Mitchell Sabloff, Jeff Szer, Martin S Tallman, and...malignant human B cells identifies hundreds of novel microRNAs. Blood. 2010;116(23):e118-27 5. Zhang J, Jima DD, Jacobs C, Fischer R, Gottwein E, Huang G

The direct conversion of synthesis gas to chemicals / Ernest du Toit

OpenAIRE

Du Toit, Ernest

2002-01-01

The catalytic conversion of synthesis gas, obtainable from the processing of coal, biomass or natural gas, to a complex hydrocarbon product stream can be achieved via the Fischer-Tropsch process. The Fischer-Tropsch synthesis process has evolved from being mainly a fuel producing process in the early 1950's to that of a solvent and speciality wax production process towards the end of the 1970's. From the early 1980's there has been a clear shift towards the production of commod...

Carbon monoxide hydrogenation over ruthenium zeolites

Energy Technology Data Exchange (ETDEWEB)

Jacobs, P.A.; Nijs, H.H.; Verdonck, J.J.; Uytterhoeven, J.B.

1978-03-01

Ru zeolites are active and stable methanation catalysts. Under Fischer--Tropsch conditions they show a narrow product distribution. Further work is needed to assign this to a possible effect exerted by the zeolite cages. When the size of the Ru particles enclosed in the zeolite cages is increased, a lower methanation activity is found and a higher amount of C/sub 2/ and C/sub 3/ products are formed under Fischer--Tropsch conditions. This effect has not been reported until now on other supports. The less acidic zeolites act as promoters of the CO hydrogenation: under methanation conditions the activity is increased; under Fischer--Tropsch conditions, the selectivity is shifted toward higher hydrocarbons. This is explained by the particular zeolite property that electron deficient metal agglomerates seem to be formed on the acidic zeolites. With respect to kinetic behavior, relative activity of different metals, influence of reaction temperature on product distribution, the zeolite behaves in the same way a conventional alumina support. 4 figs., 4 tables.

Fischer-Tropsch synthesis: Support and cobalt cluster size effects on kinetics over Co/Al{sub 2}O{sub 3} and Co/SiO{sub 2} catalysts

Energy Technology Data Exchange (ETDEWEB)

Wenping Ma; Gary Jacobs; Dennis E. Sparks; Muthu K. Gnanamani; Venkat Ramana Rao Pendyala; Chia H. Yen; Jennifer L.S. Klettlinger; Thomas M. Tomsik; Burtron H. Davis [University of Kentucky, Lexington, KY (USA). Center for Applied Energy Research

2011-02-15

The influence of support type and cobalt cluster size (i.e., with average diameters falling within the range of 8-40 nm) on the kinetics of Fischer-Tropsch synthesis (FT) were investigated by kinetic tests employing a CSTR and two Co/{gamma}-Al{sub 2}O{sub 3} catalysts having different average pore sizes, and two Co/SiO{sub 2} catalysts prepared on the same support but having different loadings. A kinetic model -r{sub CO}=kP{sup a}{sub co}P{sup b}{sub H2}/(1 + mP{sub H2O}/P{sub H2}) that contains a water effect constant 'm' was used to fit the experimental data obtained with all four catalysts. Kinetic parameters suggest that both support type and average Co particle size impact FT behavior. Cobalt cluster size influenced kinetic parameters such as reaction order, rate constant, and the water effect parameter.Decreasing the average Co cluster diameter by about 30% led to an increase in the intrinsic reaction rate constant k, defined on a per g of catalyst basis, by 62-102% for the {gamma}-Al{sub 2}O{sub 3} and SiO{sub 2}-supported cobalt catalysts. Moreover, less inhibition by adsorbed CO and greater H{sub 2} dissociation on catalysts having smaller Co particles was suggested by the higher a and lower b values obtained for the measured reaction orders. Irrespective of support type, the catalysts having smaller average Co particles were more sensitive to water. Comparing the catalysts having strong interactions between cobalt and support (Co/Al{sub 2}O{sub 3}) to the ones with weak interactions (Co/SiO{sub 2}), the water effect parameters were found to be positive (indicating a negative influence on CO conversion) and negative (denoting a positive effect on CO conversion), respectively. Greater a and a/b values were observed for both Al{sub 2}O{sub 3}-supported Co catalysts, implying greater inhibition of the FT rate by strongly adsorbed CO on Co/Al{sub 2}O{sub 3} relative to Co/SiO{sub 2}. 78 refs., 4 figs., 3 tabs.

Shape-selective catalysts for Fischer-Tropsch chemistry. Final report: January 1, 2001 - December 31, 2008

International Nuclear Information System (INIS)

Cronauer, D.C.

2011-01-01

Argonne National Laboratory carried out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry-specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it was desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It was desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The original goal was to produce shape-selective catalysts that had the potential to limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' This cage would also restrict their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. Such catalysts were prepared with silica-containing fractal cages. The activity and strength was essentially the same as that of catalysts without the cages. Since there was no improvement, the program plan was modified as discussed below. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those expected for

APF-The Lick Observatory Automated Planet Finder

Science.gov (United States)

2014-04-01

WILLIAM DEICH,1 BRIAN DUPRAW,1 WAYNE EARTHMAN,1 HARLAND EPPS,1 SANDRA FABER,1 DEBRA FISCHER ,3 ELINOR GATES,1 DAVID HILYARD,1 BRAD HOLDEN,1 KEN JOHNSTON,4...SANDY KEISER,2 DICK KANTO,1 MYRA KATSUKI,1 LEE LAITERMAN,1 KYLE LANCLOS,1 GREG LAUGHLIN,1 JEFF LEWIS,1 CHRIS LOCKWOOD,1,5 PAUL LYNAM,1 GEOFFREY MARCY,6...with S. Vogt as principal investigator, G. Marcy and D. Fischer as coinvestgators, and M. Radovan as project manager and principal engineer. A large

Assessment of immunotoxicity in female Fischer 344/N and Sprague Dawley rats and female B6C3F1 mice exposed to hexavalent chromium via the drinking water.

Science.gov (United States)

Shipkowski, Kelly A; Sheth, Christopher M; Smith, Matthew J; Hooth, Michelle J; White, Kimber L; Germolec, Dori R

2017-12-01

Sodium dichromate dihydrate (SDD), an inorganic compound containing hexavalent chromium (Cr(VI)), is a common environmental contaminant of groundwater sources due to widespread industrial use. There are indications in the literature that Cr(VI) may induce immunotoxic effects following dermal exposure, including acting as both an irritant and a sensitizer; however, the potential immunomodulatory effects of Cr(VI) following oral exposure are relatively unknown. Following the detection of Cr(VI) in drinking water sources, the National Toxicology Program (NTP) conducted extensive evaluations of the toxicity and carcinogenicity of SDD following drinking water exposure, including studies to assess the potential for Cr(VI) to modulate immune function. For the immunotoxicity assessments, female Fischer 344/N (F344/N) and Sprague Dawley (SD) rats and female B 6 C 3 F 1 mice were exposed to SDD in drinking water for 28 consecutive days and evaluated for alterations in cellular and humoral immune function as well as innate immunity. Rats were exposed to concentrations of 0, 14.3, 57.3, 172, or 516 ppm SDD while mice were exposed to concentrations of 0, 15.6, 31.3, 62.5, 125, or 250 ppm SDD. Final mean body weight and body weight gain were decreased relative to controls in 250 ppm B 6 C 3 F 1 mice and 516 ppm SD rats. Water consumption was significantly decreased in F344/N and SD rats exposed to 172 and 516 ppm SDD; this was attributed to poor palatability of the SDD drinking water solutions. Several red blood cell-specific parameters were significantly (5-7%) decreased in 250 ppm mice; however, these parameters were unaffected in rats. Sporadic increases in the spleen IgM antibody response to sheep red blood cells (SRBC) were observed, however, these increases were not dose-dependent and were not reproducible. No significant effects were observed in the other immunological parameters evaluated. Overall, exposure to Cr(VI) in drinking water had limited effects on

Black Liquor Gasification with Motor Fuel Production - BLGMF II - A techno-economic feasibility study on catalytic Fischer-Tropsch synthesis for synthetic diesel production in comparison with methanol and DME as transport fuels

Energy Technology Data Exchange (ETDEWEB)

Ekbom, Tomas; Berglin, Niklas; Loegdberg, Sara [Nykomb Synergetics AB, Stockholm (Sweden)

2005-06-15

The present project presents additional results to the former BLGMF project, which investigate Black Liquor Gasification with Motor Fuels (BLGMF) production. The objectives were to investigate, based on the KAM 2 program Ecocyclic Pulp Mill (2,000 ADt/day of pulp) the feasibility of synthetic fuels production. Specifically the route to Fischer-Tropsch diesel fuels is investigated as comparison to earlier work on methanol/DME. As modern kraft pulp mills have a surplus of energy, they could become key suppliers of renewable fuels. It is thus of great interest to convert the spent cooking product 'black liquor' to an energy carrier of high value. The resulting biomass-to-fuel energy efficiency when only biomass is used as an external energy source was 43% for FTD or 65% for FT products compared with 66% for methanol and 67% for DME. The FTD calculation is considerably more complicated and based on assumptions, therefore the uncertainty is higher. Would the diesel be taken out with a T95% of 320 deg C the FTD efficiency would be 45%. FT synthesis also opens up a possibility to produce e.g. lube oils from waxes produced. The total net FT-products output equals 4115 barrels/day. The FTD production cost is calculated as the energy share of the total production cost and assumes an offset of naphtha covering its own costs, where it is essential that it finds a market. Assuming same petrol (methanol) and diesel (DME, FTD) costs for the consumer the payback time were 2.6, 2.9 and 3.4 years with an IRR of 40%, 45% and 30%, respectively. In conclusion, there are necessary resources and potential for large-scale methanol (or DME, FTD) production and substantial economic incentive for making plant investments and achieving competitive product revenues.

Et tõlkida piiblit eesti ja läti keelde ... / Kai Tafenau

Index Scriptorium Estoniae

Tafenau, Kai, 1975-

2010-01-01

Vastuoludest Eestimaa Konsistooriumi ja Liivimaa superintendendi vahel eestikeelse Uue Testamendi väljaandmise küsimuses. Keda volitas kuningas Karl XI tegelema Uue Testamendi eestikeelse tõlkega? Ilmselt võib superintentent Fischerile antud korraldust nimetada mitmetitõlgendatavaks, tõenäoliselt ei saanud Fischer 1682. aastal selgesõnalist korraldust tallinnakeelse piibli väljaandmiseks. Tallinnakeelse piibli väljaandmise vastu hakkas Fischer tõsisemat huvi tundma 1684. aastal, kuid ka kuninga 1685. aasta 11. juuli korralduses ei tehtud Fischerile ülesandeks selge sõnaga tallinnakeelse Uue Testamendi tõlkimist-trükkimist

Biosynthesis of plasmalogens by the microsomal fraction of Fischer R-3259 sarcoma. Influence of specific 2-acyl chains on the desaturation of 1-alkyl-2-acyl-sn-gycero-3-phosphoethanolamine

Energy Technology Data Exchange (ETDEWEB)

Wykle, R.L.; Schremmer, J.M.

1979-08-07

In the Fischer R-3259 sarcoma, ethanolamine plasmalogens are synthesized from 1-akyl-2-acyl-sn-glycero-3-phosphoethanolamine by a microsomal desaturase that inserts a ..delta../sup 1/ double bond in the alkyl chain. In the present study, a series of 1-(1-/sup 14/C)hexadecyl-2-acyl-GPE substrates containing specific acyl groups ranging from C/sub 2/ /sub 0/ to C/sub 20/ /sub 4/ at the 2 position were prepared and tested as substrates for the microsomal ..delta../sup 1/-alkyl desaturase. The microsomal preparations contained an acyl hydrolase that removed the C/sub 2/ /sub 0/, C/sub 4/ /sub 0/, and C/sub 7/ /sub 0/ acyl groups from the 2 position. By inhibiting the hydrolase with diisopropyl fluorophosphate, it was possible to test conversion of the unaltered substrates to plasmalogens. The alkyl desaturase exhibited little discrimination among the specific acyl derivatives tested. The highest rate of desaturation was obtained with 1-(1-/sup 14/C)-hexadecyl-2-acyl-GPE synthesized in situ in the microsomes via acylation of 1-(1-/sup 14/C)hexadecyl-GPE; this rate was threefold that observed with exogenously acylated substrates. The 1-(1-/sup 14/C)hexadecyl-2-acyl-GPE synthesized in situ contained highly unsaturated acyl groups; no selectivity of the desaturase for specific acyl chains was detected when the different molecular species of 1-(1-/sup 14/C)alkyl-2-acyl-GPE and 1-(1-/sup 14/C)alk-1'-eyl-2-acyl-GPE were compared. The short-chain substrates, being moe hydrophilic, mimicked the chromatographic behavior of 1-alkyl-GPE, yet they did not resemble the lyso compound in its higher conversion to plasmalogens. Thus, despite their similar R/sub f/ values, the packing of the short-chain acyl homologues in the membrane may be quite different from that of the lyso compound. Binding of 1-hexadecyl-2-acyl-GPE and 1-hexadecyl-GPE to microsomal membranes was similar.

Economics of gas to liquids manufacture

International Nuclear Information System (INIS)

Gradassi, M.J.

1998-01-01

The last year has seen a great deal in the literature about the rebirth of gas to liquids processes, most notably, Fischer Tropsch processes. This renewed interest has been brought about by a technology that is said to have been so improved that it is now a commercially attractive option for natural gas monetization. No one single reason can be cited for this positive economic change. Rather, it is the result of several technological improvements that together have cut the capital cost of Fischer-Tropsch gas to liquids projects in half. Among these technological improvements are lower cost syngas preparation and lower cost gas to liquids reactors. This paper examines the economics of Fischer-Tropsch gas to liquids manufacture, using recent literature articles to develop process capital costs, operating expenses, liquid product value parameters, and other economic factors, to paint a general picture of the technology's current economic status. While manufacturing economics are reviewed, the answer to the question of gas to liquids project profitability is left to the individual investor whose economic thresholds must, in the final analysis, be met. 15 refs

Shape-selective catalysts for Fischer-Tropsch chemistry. Final report : January 1, 2001 - December 31, 2008.

Energy Technology Data Exchange (ETDEWEB)

Cronauer, D. C. (Chemical Sciences and Engineering Division)

2011-04-11

Argonne National Laboratory carried out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry-specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it was desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It was desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The original goal was to produce shape-selective catalysts that had the potential to limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' This cage would also restrict their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. Such catalysts were prepared with silica-containing fractal cages. The activity and strength was essentially the same as that of catalysts without the cages. Since there was no improvement, the program plan was modified as discussed below. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those

Fischer-Tropsch synthesis: study of the promotion of Pt on the reduction property of Co/Al2O3 catalysts by in situ EXAFS of Co K and Pt LIII edges and XPS

International Nuclear Information System (INIS)

Jacobs, G.; Chaney, J.A.; Patterson, P.M.; Das, T.K.; Maillot, J.C.; Davis, B.H.

2004-01-01

The addition of platinum metal to cobalt/alumina-based Fischer-Tropsch synthesis (FTS) catalysts increases both the reduction rate and, consequently, the density of active cobalt sites. Platinum also lowers the temperature of the two-step conversion of cobalt oxide to cobalt metal observed in temperature programmed reduction (TPR) as Co 3 O 4 to CoO and CoO to Co 0 . The interaction of the alumina support with cobalt oxide ultimately determines the active site density of the catalyst surface. This interaction can be controlled by varying the cobalt loading and dispersion, selecting supports with differing surface areas or pore sizes, or changing the noble metal promoter. However, the active site density is observed to depend primarily on the cluster size and extent of reduction, and there is a direct relationship between site density and FTS rate. In this work, in situ extended X-ray absorption fine structure (EXAFS) at the L III edge of Pt was used to show that isolated Pt atoms interact with supported cobalt clusters without forming observable Pt-Pt bonds. K-edge EXAFS was also used to verify that the cobalt cluster size increases slightly for those systems with Pt promotion. X-ray absorption near-edge spectroscopy (XANES) was used to examine the remaining cobalt clusters after the first stage of TPR, and it revealed that the species were almost entirely cobalt (II) oxide. After the second stage of TPR to form cobalt metal, a residual oxide persists in the sample, and this oxide has been identified as cobalt (II) aluminate using X-ray photoelectron spectroscopy (XPS). Sequential in situ reduction of promoted and unpromoted systems was also monitored through XPS, and Pt was seen to increase the extent of cobalt reduction by a factor of two. (orig.)

Comparative acute nephrotoxicity of salicylic acid, 2,3-dihydroxybenzoic acid, and 2,5-dihydroxybenzoic acid in young and middle aged Fischer 344 rats.

Science.gov (United States)

McMahon, T F; Stefanski, S A; Wilson, R E; Blair, P C; Clark, A M; Birnbaum, L S

1991-03-11

Experimental evidence suggests that the oxidative metabolites 2,3- and 2,5-dihydroxybenzoic acid (DIOH) may be responsible for the nephrotoxicity of salicylic acid (SAL). In the present study, enzymuria in conjunction with glucose (GLU) and protein (PRO) excretion were used as endpoints to compare the relative nephrotoxicity of SAL with 2,3- and 2,5-DIOH. In addition, the effect of age on enzymuria and GLU and PRO excretion following treatment with SAL or 2,3- and 2,5-DIOH was investigated because the elderly are at greater risk for SAL-induced nephrotoxicity. Three and 12-month male Fischer 344 rats were administered either no treatment, vehicle, SAL, 2,3-DIOH, or 2,5-DIOH at 500 mg/kg p.o. in 5 ml/kg corn oil/DMSO (5:1). Effects of these treatments on functional integrity of renal tissue was assessed from 0--72 h after dosing by measurement of urinary creatinine, GLU, and PRO, as well as excretion of proximal and distal tubular renal enzymes. Enzymes measured as indicators of proximal tubular damage were N-acetyl-beta-glucosaminidase (NAG), gamma glutamyltransferase (GGT), alanine aminotransferase (ALT), and alkaline phosphatase (AP), while urinary lactate dehydrogenase (LD) and aspartate aminotransferase (AST) were measured as indicators of distal tubular damage. In comparison to 3-month vehicle-treated rats, 2,3- and 2,5-DIOH caused a significant increase between 0-8 h in excretion of urinary GLU and activities of AST, NAG, and LD, with peak effects occurring between 4-8 h. Toxic effects of either metabolite were not evident beyond 24 h, and toxicity of 2,5-DIOH was significantly greater in comparison to 2,3-DIOH. SAL treatment resulted in similar effects on enzymuria as well as GLU and PRO excretion, but peak effects did not occur until 16-24 h, and often persisted until 72 h after dosing. Maximal enzymuria in response to SAL treatment was significantly greater in 12- vs. 3-month rats for AST, NAG, and LD. In response to 2,3-DIOH treatment, the maximal

An Investigation into the Effects of Mn Promotion on the Activity and Selectivity of Co/SiO₂ for Fischer - Tropsch Synthesis: Evidence for Enhanced CO Adsorption and Dissociation

Energy Technology Data Exchange (ETDEWEB)

Johnson, Gregory R.; Werner, Sebastian; Bell, Alexis T. (LBNL); (UCB)

2016-03-04

Mn is an effective promoter for improving the activity and selectivity of Co-based Fischer-Tropsch synthesis (FTS) catalysts, but the mechanism by which this promoter functions is poorly understood. The work reported here was aimed at defining the manner in which Mn interacts with Co and determining how these interactions affect the activity and selectivity of Co. Detailed measurements are reported for the kinetics of FTS as a function of Mn/Co ratio, temperature, and reactant partial pressure. These data are described by a single, two-parameter rate expression. Mn promotion was found to increase both the apparent rate constant for CO consumption and the CO adsorption constant. Further evidence for enhanced CO adsorption and dissociation was obtained from measurements of temperature-programmed desorption of CO and CO disproportionation rates, respectively. Our quantitative analysis of elemental maps obtained by STEM-EDS revealed that the promoter accumulates preferentially on the surface of Co nanoparticles at low Mn loadings, resulting in a rapid onset of improvements in the product selectivity as the Mn loading increases. For catalysts prepared with loadings higher than Mn/Co = 0.1, the additional Mn accumulates in the form of nanometer-scale particles of MnO on the support. In situ IR spectra of adsorbed CO show that Mn promotion increases the abundance of adsorbed CO with weakened C-O bonds. Furthermore, it is proposed that the cleavage of the C-O bond is promoted through Lewis acid-base interactions between the Mn²⁺ cations located at the edges of MnO islands covering the Co nanoparticles and the O atom of CO adsorbates adjacent to the MnO islands. The observed decrease in selectivity to CH₄ and the increased selectivity to C₅₊ products with increasing Mn/Co ratio are attributed to a decrease in the ratio of adsorbed H to CO on the surface of the supported Co nanoparticles.

Fischer-Tropsch synthesis : catalysts and chemistry

NARCIS (Netherlands)

Loosdrecht, van de J.; Botes, F.G.; Ciobica, I.M.; Ferreira, A.C.; Gibson, P.; Moodley, D.J.; Saib, A.M.; Visagie, J.L.; Weststrate, C.J.; Niemantsverdriet, J.W.; Reedijk, J.; Poeppelmeier, K.

2013-01-01

The Fischer–Tropsch synthesis represents a time-tested and fully proven technology for the conversion of synthesis gas (CO + H2) into paraffins, olefins, and oxygenated hydrocarbons. Depending on the origin of the syngas, one speaks of gas-to-liquids, coal-to-liquids, biomass-to-liquids, or

Hvatit govorit - pora dumat / Joschka Fischer

Index Scriptorium Estoniae

Fischer, Joschka, 1948-

2006-01-01

Saksamaa endine välisminister kirjutab sellest, missuguseid konkreetseid samme peab ette võtma maailma päästmiseks tuumaohust: USA peab alustama kahepoolseid läbirääkimisi Põhja-Koreaga tuumarelva väljatöötamise tõkestamiseks

Kaks rongi kokkupõrkekursil / Joschka Fischer

Index Scriptorium Estoniae

Fischer, Joschka, 1948-

2006-01-01

Saksa endine välisminister on seisukohal, et Euroopa huve kaitsvate positsioonide kindlustamiseks tuleb rajada sild Türgi kui regiooni turvalisuse nurgakiviga, kuid Euroopa püüab Türgit vältida. Euroopa suhtumine tõukab Türgit oma seniste regionaalsete rivaalide, Venemaa ja Iraani poole

Hermann Emil Fischer: Life and Achievements

Indian Academy of Sciences (India)

in his studies and passed with distinction from high school in. 1869. Emil had great ... was impressed by Kekule's teaching, he moved in1872, along with his cousin Otto ..... killed himself as he could not bear the military training. The eldest son ...

Carbohydrate Chemistry from Fischer to Now

Indian Academy of Sciences (India)

In this brief article, this intriguing field of natural products chemistry is ... six carbon atoms, five hydroxyl groups (one primary and the other ..... to elucidate the mechanism of ..... As a postscript, a quotation from the review by P H Seeberger and.

Elections to the Senior Staff Advisory Committee 
("The Nine") 2007

CERN Multimedia

2007-01-01

The electronic voting process for the Senior Staff Advisory Committee ("The Nine") was closed on Friday 1st June. Of the 449 Senior Staff members called to vote, 281 cast a vote, of which 279 were valid. The results are as follows: Electoral Group 1 Name\tDepartment\tVotes Patrick Janot\tPH\t50 Rolf Landua\tDSU\t86 Marcello Mannelli\tPH\t22 Thomas Ruf\tPH\t30 Electoral Group 2Name\tDepartment\tVotes Olivier Brunner\tAB\t47 Doris Burckhart\tPH\t44 Helmut Burkhardt\tAB\t31 Marco Cattaneo\tPH\t48 Paul Collier\tAB\t66 Hubert Gerwig\tPH\t19 Eugenia Hatziangeli\tAB\t34 Miguel Angel Marquina\tIT\t36 Malika Meddahi\tAB\t51 Alberto Pace\tIT\t123 Stephan Russenschuck\tAT\t35 Alan Silverman\tIT\t47 Detlef Swoboda\tTS\t25 Elena Wildner\tAT\t52 Rolf Landua is therefore elected in Group 1, and Alberto Pace, Paul Collier and Elena Wildner are elected in Group 2. Their mandate is from July 2007 to June 2010. The Committee now consists of these newly-elected members together with Monica Pepe-Altarelli, Rudiger Schmidt, R. Martens, A. Unnervik and E. Tsesmelis...

Review of the East Palaearctic and North Oriental Psyttalia Walker, with the description of three new species (Hymenoptera, Braconidae, Opiinae).

Science.gov (United States)

Wu, Qiong; van Achterberg, Cornelis; Tan, Jiang-Li; Chen, Xue-Xin

2016-01-01

The East Palaearctic and North Oriental species of the genus Psyttalia Walker (Hymenoptera, Braconidae, Opiinae) are reviewed. Three new species are described and illustrated: Psyttalia latinervis Wu & van Achterberg, sp. n . and Psyttalia majocellata Wu & van Achterberg, sp. n . from China, and Psyttalia spectabilis van Achterberg, sp. n. from Japan. Coeloreuteus formosanus Watanabe, 1934, Opius (Lissosema) proclivis Papp, 1981, Opius (Psyttalia) subcyclogaster Tobias, 1998, Opius (Psyttalia) darasunicus Tobias, 1998, Opius (Psyttalia) cyclogastroides Tobias, 1998, Psyttalia extensa Weng & Chen, 2001, and Rhogadopsis longicaudifera Li & van Achterberg, 2013, are new synonyms of Psyttalia cyclogaster (Thomson, 1895); Opius (Psyttalia) ophthalmicus Tobias, 1977, and Opius (Psyttalia) brevitemporalis Tobias, 1998, of Psyttalia carinata (Thomson, 1895) and both Opius (Psyttalia) vacuus Tobias, 1998, and Opius (Lissosema) longurius Chen & Weng, 1995, of Rhogadopsis mediocarinata (Fischer, 1963). Phaedrotoma daghestanicum (Telenga, 1950), Rhogadopsis mediocarinata (Fischer, 1963) and Rhogadopsis mystica (Fischer, 1963) are new combinations. New records are Psyttalia carinata (Thomson, 1895) from The Netherlands and Norway, and Psyttalia cyclogaster (Thomson, 1895) from Japan. A lectotype is designated for Psyttalia carinata (Thomson, 1895) and Psyttalia cyclogaster (Thomson, 1895). A key to the East Palaearctic and North Oriental species of the genus Psyttalia Walker is included.

Review of the East Palaearctic and North Oriental Psyttalia Walker, with the description of three new species (Hymenoptera, Braconidae, Opiinae

Directory of Open Access Journals (Sweden)

Qiong Wu

2016-11-01

Full Text Available The East Palaearctic and North Oriental species of the genus Psyttalia Walker (Hymenoptera, Braconidae, Opiinae are reviewed. Three new species are described and illustrated: P. latinervis Wu & van Achterberg, sp. n. and P. majocellata Wu & van Achterberg, sp. n. from China, and P. spectabilis van Achterberg, sp. n. from Japan. Coeloreuteus formosanus Watanabe, 1934, Opius (Lissosema proclivis Papp, 1981, O. (Psyttalia subcyclogaster Tobias, 1998, O. (P. darasunicus Tobias, 1998, O. (P. cyclogastroides Tobias, 1998, Psyttalia extensa Weng & Chen, 2001, and Rhogadopsis longicaudifera Li & van Achterberg, 2013, are new synonyms of Psyttalia cyclogaster (Thomson, 1895; Opius (Psyttalia ophthalmicus Tobias, 1977, and O. (P. brevitemporalis Tobias, 1998, of Psyttalia carinata (Thomson, 1895 and both O. (P. vacuus Tobias, 1998, and O. (Lissosema longurius Chen & Weng, 1995, of Rhogadopsis mediocarinata (Fischer, 1963. Phaedrotoma daghestanicum (Telenga, 1950, Rhogadopsis mediocarinata (Fischer, 1963 and R. mystica (Fischer, 1963 are new combinations. New records are Psyttalia carinata (Thomson, 1895 from The Netherlands and Norway, and P. cyclogaster (Thomson, 1895 from Japan. A lectotype is designated for Psyttalia carinata (Thomson, 1895 and P. cyclogaster (Thomson, 1895. A key to the East Palaearctic and North Oriental species of the genus Psyttalia Walker is included.

Hydrogen retorting of oil shales from Eastern Canada

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E. (CANMET, Ottawa, Ontario (Canada)); Synnott, J.; Boorman, R.S.; Salter, R.S.

1984-04-01

The liquid production potential of thirty oil shale samples from Eastern Canada was determined by Fischer assay retort and pyrochem retort. For all shales, the presence of hydrogen during pyrochem retorting resulted in a significant increase in oil yields compared to Fischer assay yields. Ten oil shale samples were selected for detailed evaluation in the pyrochem retort in the presence of nitrogen and hydrogen. Besides increasing yields, the presence of hydrogen lowered the specific gravity of liquid products and the content of sulphur but increased the content of nitrogen. This was attributed to the stabilization of precursors to nitrogen compounds which prevented their polymerization. (J.H.K.)

A detailed gravimetric geoid from North America to Eurasia

Science.gov (United States)

Vincent, S. F.; Strange, W. E.; Marsh, J. G.

1972-01-01

A detailed gravimetric geoid of the United States, North Atlantic, and Eurasia, which was computed from a combination of satellite derived and surface gravity data, is presented. The precision of this detailed geoid is + or - 2 to + or - 3 m in the continents but may be in the range of 5 to 7 m in those areas where data is sparse. Comparisons of the detailed gravimetric geoid with results of Rapp, Fischer, and Rice for the United States, Bomford in Europe, and Heiskanen and Fischer in India are presented. Comparisons are also presented with geoid heights from satellite solutions for geocentric station coordinates in North America, the Caribbean, and Europe.

Synthetic-fuel production using Texas lignite and a very-high-temperature gas-cooled reactor for process heat and electrical power generation

International Nuclear Information System (INIS)

Ross, M.A.; Klein, D.E.

1981-05-01

This report presents two alternatives to increased reliance on foreign energy sources; each method utilizes the abundant domestic resources of coal, uranium, and thorium. Two approaches are studied in this report. First, the gasification and liquefaction of coal are accomplished with Lurgi gasifiers and Fischer-Tropsch synthesis. A 50,000 barrel per day facility, consuming 15 million tons of lignite coal per year, is used. Second, a nuclear-assisted coal conversion approach is studied using a very high temperature gas-cooled reactor with a modified Lurgi gasifier and Fischer-Tropsch synthesis. This is a preliminary report presenting background data and a means of comparison for the two approaches considered

Fe3O4 nanocubes assembled on RGO nanosheets: Ultrasound induced in-situ and eco-friendly synthesis, characterization and their excellent catalytic performance for the production of liquid fuel in Fischer-tropsch synthesis.

Science.gov (United States)

Abbas, Mohamed; Zhang, Juan; Lin, Ke; Chen, Jiangang

2018-04-01

In this study, Fe 3 O 4 nanocubes (NCs) decorated on RGO nanosheets (NSs) structures were successfully synthesized through an innovative and environmentally-friendly rapid sonochemical method. More importantly, iron(II) sulfate heptahydrate and GO were employed as precursors and water as reaction medium, meanwhile, NaOH within the generated free radicals from the high intensity ultrasound were sufficient as reducing and base agent in our clean synthesis. Moreover, the hydrothermal method as a conventional approach was employed to synthesize the same catalysts for the comparison with the ultrasonocation technique. The as-synthesized Fe 3 O 4 and RGO/Fe 3 O 4 NSs catalysts were exposed to industrially relevant Fischer-tropsch synthesis (FTS) conditions at various reaction temperatures (250-290 °C), and they subjected to fully characterization before and after FTS reaction using XRD, TEM, HRTEM, EDS mapping, XPS, FTIR, BET, H 2 -TPR, H 2 -TPD and CO-TPD to understand the structure-performance relationships. Notably, the catalysts produced using the sonochemical method had a better CO conversion rate [Fe 3 O 4 (80%), RGO/Fe 3 O 4 (82%)] than the hydrothermally synthesized catalysts. However, compared to the naked-Fe 3 O 4 catalysts, the sonochemically and hydrothermally synthesized RGO-supported Fe 3 O 4 catalysts had higher long chain hydrocarbon (C5+) selectivity values (72% and 67%) and C 2 -C 4 olefin/paraffin selectivity ratio (3.2 and 2) and low CH4 selectivity values (6% and 8.5%), respectively. This can be attributed to their high surface area, the degree of reducibility, and content of Hägg iron carbide (χ-Fe 5 C 2 ) as the most active phase of the FTS reaction. Proposed reaction mechanisms for the sonochemical and hydrothermal reaction synthesis of Fe 3 O 4 and RGO/Fe 3 O 4 nanoparticles are discussed. In conclusion, our developed surfactantless-sonochemical method holds promise for the eco-friendly synthesis of highly efficient catalysts materials for

Catalysis. Innovative applications in petrochemistry and refining. Preprints

Energy Technology Data Exchange (ETDEWEB)

Ernst, S.; Balfanz, U.; Jess, A.; Lercher, J.A.; Lichtscheidl, J.; Marchionna, M.; Nees, F.; Santacesaria, E. (eds.)

2011-07-01

Within the DGMK conference at 4th to 6th October, 2011 in Dresden (Federal Republic of Germany) the following lectures were held: (1) Developing linear-alpha-olefins technology - From laboratory to a commercial plant (A. Meiswinkel); (2) New developments in oxidation catalysis (F. Rosowski); (3) Study of the performance of vanadium based catalysts prepared by grafting in the oxidative dehydrogenation of propane (E. Santacesaria); (4) Hydrocracking for oriented conversion of heavy oils: recent trends for catalyst development (F. Bertoncini); (5) Acidic ionic liquids for n-alkane isomerization in a liquid-liquid or slurry-phase reaction mode (C. Meyer); (6) Dual catalyst system for the hydrocracking of heavy oils and residues (G. Bellussi); (7) Understanding hydrodenitrogenation on novel unsupported sulphide Mo-W-Ni catalysts (J. Hein); (8) Hydrocracking of ethyllaurate on bifunctional micro-/mesoporous composite materials (M. Adam); (9) Catalytic dehydration of ethanol to ethylene (Ying Zhu); (10) The Evonik-Uhde HPPO process for propylene oxide production (B. Jaeger); (11) A green two-step process for adipic acid production from cyclohexene: A study on parameters affecting selectivity (F. Cavani); (12) DISY: The direct synthesis of hydrogen peroxide, a bridge for innovative applications (R, Buzzoni); (13) Solid catalyst with ionic liquid layer (SCILL) - A concept to improve the selectivity of selective hydrogenations (A. Jess); (14) Co-Zn-Al based hydrotalcites as catalysts for Fischer-Tropsch process (C.L. Bianchi); (15) Honeycomb supports with high thermal conductivity for the Fischer-Tropsch synthesis (C.G. Visconti); (16) How to make Fischer-Tropsch catalyst scale-up fully reliable (L. Fischer); (17) New developments in FCC catalysis (C.P. Kelkar); (18) The potential of medium-pore zeolites for improved propene yields from catalytic cracking (F. Bager).

Breast MRI in the Evaluation of Locally Recurrent or New Breast Cancer in the Postoperative Patient: Correlation of Morphology and Enhancement Features with the BI-RADS Category

International Nuclear Information System (INIS)

Seely, J.M.; Nguyen, E.T.; Jaffey, J.

2007-01-01

Background: While breast magnetic resonance imaging (MRI) is a highly sensitive test for detecting breast carcinoma, its specificity is lower, and several methods have been described on how to optimize specificity. Purpose: To compare the specificity and sensitivity of the BI-RADS category with the Fischer score in breast MRI for diagnosing cancer in women previously treated for breast cancer. Material and Methods: Women referred for evaluation of possible local recurrence or new breast cancer underwent breast MRI examination. Morphologic and kinetic enhancement characteristics were evaluated. BI-RADS category and Fischer score were assigned for each enhancing lesion and compared using a chi-square test. Sensitivity, specificity, and positive predictive values for 27 morphologic and enhancement characteristics were calculated. Pathologic diagnosis was obtained in all patients with enhancing lesions who had ultrasound or mammographic correlation. In those without correlate, 6-, 12-, and 24-month follow-up breast MRIs were obtained. Interobserver kappa correlation was determined for each variable studied. Results: 34 benign and 32 malignant lesions were identified in 26 of 30 patients. BI-RADS category yielded a specificity of 77.1% and a sensitivity of 81.8%. Fischer score had a lower specificity and sensitivity (62.9% and 72.7%, respectively) (P 100% enhancement was more sensitive than BI-RADS for malignant lesions. Specificity was highest for rim enhancement (97.1%), but sensitivity was low (24.2%). Interobserver kappa correlation was good for all 27 characteristics ( = 0.84), and highest for BI-RADS assessment ( 0.91). Conclusion: BI-RADS category in breast MRI had the highest combination of specificity and sensitivity, and the highest interobserver correlation. Fischer score and other morphologic and enhancement features lack sensitivity or specificity and do not have high positive predictive values when analyzed as single independent variables

Synthetic Or Reformulated Fuels: a Challenge for Catalysis Carburants de synthèse ou reformulés : un défi pour la catalyse

Directory of Open Access Journals (Sweden)

Courty P.

2006-12-01

Full Text Available Despite comparative figures for wordwide crude oil and natural gas proven reserves, present time contribution of syngas chemistry to motorfuels remains marginal when the refining industry is faced to main constraints: market demand evolution, stringent specifications and environmental issues. Actually natural gas upgrading via syngas chemistry yields key products (e. g. methanol among which clean motorfuels (ethers, FT products should develop despite the huge investments required, mostly for syngas production. Main challenges and corresponding issues for catalysts and related technologies are identified for Fischer-Tropsch synthesis and motorfuels long-term reformulation. Among other, mastering the chain-growth (FT synthesis improving the FCC products: gasoline, and LCO for Diesel pool. All these issues need significant progresses in catalyst and technology to be solved. Lastly, our economical study, focused on Diesel-fuel production, shows up that clean diesel (from SR-LCO mixtures and FT Diesel reach similar production costs when cheap NG is available. In the future, FT middle distillates should amount to a few percent (5-150 Mt of the 1700-2000 Mt of transport middle distillates expected from oil refining. However they should more and more be a compulsory part of diesel pool if the level of investment for an FT process continues to decrease significantly. Malgré des réserves prouvées en pétrole et en gaz du même ordre de grandeur, la contribution de la chimie du gaz de synthèse à la production de carburants reste marginale, alors que l'industrie du raffinage est confrontée à des contraintes majeures : évolution de la demande, durcissement des spécifications des produits et contraintes environnementales. Cependant, la conversion chimique du gaz, via la chimie du gaz de synthèse, fournit des produits stratégiques (e. g. méthanol parmi lesquels les carburants propres (éthers, produits Fischer-Tropsch devraient se développer, bien

Exploring children's cognitive and affective skills related to conservation of mass using Fischer's dynamic skills model: What goes on in their minds and hearts?

Science.gov (United States)

Asghar, Anila

I conducted a mixed method study to examine: How, if at all, does middle school students' understanding of the conservation of mass develop as they engage in two different chemistry curricula (an interactive chemistry curriculum, DESIGNS, aimed at helping them to understand the conservation of mass and another presenting the same concepts from a traditional approach)? How do they feel about participating in the science activities, and how, if at all, do their feelings relate to their learning? I used the framework of the Dynamic Skills theory (Fischer, 1980) as a lens through which to understand their thinking and feelings and any changes in them. The study was conducted in two Massachusetts public schools. In each school, one class followed the DESIGNS curriculum (DESIGNS II, in press), while the other followed a traditional chemistry curriculum. Each teacher in the study taught two science classes and used the DESIGNS curriculum in one class and the traditional curriculum in the other. Seventy three middle school students from the two schools participated in this study. The data was gathered through (a) a concept assessment questionnaire and (b) affective response survey (both were administered before, during, and at the end of the curriculum). Additionally, qualitative interviews were conducted with 16 selected students (four from each class) twice (before and after the curriculum). The quantitative analysis revealed that students in the DESIGNS group demonstrated greater conceptual change, on average, as compared to the traditional group. In addition, pretest score and mother's education were also found to be associated with students' learning. The pretest score was negatively associated with the conceptual gain (the lower the pretest score the higher the gain), whereas mother's education had a positive relationship with conceptual understanding. A comparison of students' affective response to their respective curriculum showed that students felt more positive

Hepatocyte growth factor treatment ameliorates diarrhea and bowel inflammation in a rat model of inflammatory bowel disease.

Science.gov (United States)

Arthur, L Grier; Schwartz, Marshall Z; Kuenzler, Keith A; Birbe, Ruth

2004-02-01

Transfection of the HLA-B27 gene into normal Fischer rats induces phenotypic changes similar to inflammatory bowel disease (IBD). This study investigated the benefits of 2 doses of hepatocyte growth factor (HGF) on the manifestations of IBD in this rat model. Fischer rats and HLA-B27 rats were divided into 4 groups: Fischer rats treated with saline, HLA-B27 rats treated with saline, HGF at 150 microg/kg/d, and HGF at 300 microg/kg/d. HGF or saline was infused for 14 days via an osmotic pump attached to a catheter in the internal jugular vein. After treatment, rats were evaluated for diarrhea and reduction in gross and microscopic bowel inflammation. Statistics were determined using analysis of variance (ANOVA). A P value diarrhea by 40%, gross inflammation by 41%, and microscopic inflammation by 72% (P diarrhea by 46%, gross inflammation by 45%, and microscopic inflammation by 54% (P < or =.05). HGF administration reduces the clinical manifestations of IBD in this rat model. Similar effects were seen at both doses of HGF administration, implying that there is a plateau above which further increases in HGF levels provides no added benefit. HGF administration may be clinically useful in the management of IBD.

Mg-Fe-mixed oxides derived from layered double hydroxides: A study of the surface properties

Directory of Open Access Journals (Sweden)

Marinković-Nedučin Radmila P.

2011-01-01

Full Text Available The influence of surface properties on the selectivity of the synthesized catalysts was studied, considering that their selectivity towards particular hydrocarbons is crucial for their overall activity in the chosen Fischer- -Tropsch reaction. Magnesium- and iron-containing layered double hydroxides (LDH, with the general formula: [Mg1-xFex(OH2](CO3x/2?mH2O, x = = n(Fe/(n(Mg+n(Fe, synthesized with different Mg/Fe ratio and their thermally derived mixed oxides were investigated. Magnesium was chosen because of its basic properties, whereas iron was selected due to its well-known high Fischer-Tropsch activity, redox properties and the ability to form specific active sites in the layered LDH structure required for catalytic application. The thermally less stable multiphase system (synthesized outside the optimal single LDH phase range with additional Fe-phase, having a lower content of surface acid and base active sites, a lower surface area and smaller fraction of smaller mesopores, showed higher selectivity in the Fischer-Tropsch reaction. The results of this study imply that the metastability of derived multiphase oxides structure has a greater influence on the formation of specific catalyst surface sites than other investigated surface properties.

Proceedings of the DGMK-conference 'Synthesis gas chemistry'. Authors' manuscripts

Energy Technology Data Exchange (ETDEWEB)

Hoenicke, D; Kohlpaintner, C; Luecke, B; Reschetilowski, W [eds.

2000-07-01

The main topics of the DGMK-Conference ''Synthesis Gas Chemistry'' were: production of synthesis gas from several educts, new catalysts, Fischer-Tropsch synthesis, hydroformylation, steam reforming and carbonylation.

Attrition resistant Fischer-Tropsch catalyst and support

Science.gov (United States)

Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

2004-05-25

A catalyst support having improved attrition resistance and a catalyst produced therefrom. The catalyst support is produced by a method comprising the step of treating calcined .gamma.-alumina having no catalytic material added thereto with an acidic aqueous solution having an acidity level effective for increasing the attrition resistance of the calcined .gamma.-alumina.

Centaurea tchihatcheffii Fischer & C.A. Meyer (Asteraceae)

DEFF Research Database (Denmark)

Tan, Kit; Vural, Mecit

2007-01-01

Abstract   Centaurea tchihatcheffii is a steppic annual possessing some unique features absent in other Centaureas. The chromosome number is 2n = 20, differing from all other annual species of Centaurea sect. Cyanus. The type locality as published is erroneous and the correct provenance is provided....

Opalescence: Tooth Whitening Systems | Fischer | Tanzania Dental ...

African Journals Online (AJOL)

Tanzania Dental Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 2 (2009) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

Enzyme and Microbial Development | Bioenergy | NREL

Science.gov (United States)

metabolic pathway improvement. Photo of two Erlenmeyer flasks showing a comparison between a clean Fischer Crowley Bryon Donohoe David K. Johnson Eric Knoshaug Jeff Linger Vladimir Lunin Ashutosh Mittal Deanne

Determination of the analytical performance of a headspace capillary gas chromatographic technique and karl Fischer coulometric titration by system calibration using oil samples containing known amounts of moisture.

Science.gov (United States)

Jalbert, J; Gilbert, R; Tétreault, P

1999-08-01

Over the past few years, concerns have been raised in the literature about the accuracy of the Karl Fischer (KF) method for assessing moisture in transformer mineral oils. To better understand this issue, the performance of a static headspace capillary gas chromatographic (HS-CGC) technique was compared to that of KF coulometric titration by analyzing moisture in samples containing known amounts of water and various samples obtained from the National Institute of Standards and Technology (NIST). Two modes of adding samples into the KF vessel were used:  direct injection and indirect injection via an azeotropic distillation of the moisture with toluene. Under the conditions used for direct injection, the oil matrix was totally dissolved in the anolyte, which allowed the moisture to be titrated in a single-phase solution rather than in a suspension. The results have shown that when HS-CGC and combined azeotropic distillation/KF titration are calibrated with moisture-in-oil standards, a linear relation is observed over 0-60 ppm H(2)O with a correlation coefficient better than 0.9994 (95% confidence), with the regression line crossing through zero. A similar relation can also be observed when calibration is achieved by direct KF addition of standards prepared with octanol-1, but in this case an intercept of 4-5 ppm is noted. The amount of moisture determined by curve interpolation in NIST reference materials by the three calibrated systems ranges from 13.0 to 14.8 ppm for RM 8506 and 42.5 to 46.4 ppm for RM 8507, and in any case, the results were as high as those reported in the literature with volumetric KF titration. However, titration of various dehydrated oil and solvent samples showed that direct KF titration is affected by a small bias when samples contain very little moisture. The source of error after correction for the large sample volume used for the determination (8 mL) is about 6 ppm for Voltesso naphthenic oil and 4 ppm for toluene, revealing a matrix

Honeycomb supports with high thermal conductivity for the Tischer-Tropsch synthesis

Energy Technology Data Exchange (ETDEWEB)

Visconti, C.G.; Rronconi, E.; Groppi, G.; Lietti, L. [Politecnico di Milano (Italy). Dipt. di Energia; Iovane, M.; Rossini, S.; Zennaro, R. [Eni S.p.A., San Donato Milanese (Italy). Div. Exploration and Production

2011-07-01

The potential of multitubular reactors loaded with washcoated structured catalysts having highly conductive honeycomb supports is investigated herein in the low temperature Fischer- Tropsch synthesis by means of a theoretical investigation. Simulation results indicate that extruded aluminum honeycomb monoliths, washcoated with a Co-based catalyst, are promising for the application at the industrial scale, in particular when adopting supports with high cell densities and catalysts with high activity. Limited temperature gradients within the reactor are in fact possible even at extreme process conditions, thus leading to interesting volumetric reactor yields with negligible pressure drop. This result is achieved without the need of cofeeding to the reactor large amounts of liquid hydrocarbons to remove the reaction heat, as opposite to existing industrial Fischer-Tropsch packed-bed reactors. (orig.)

78 FR 10187 - Changes in Flood Hazard Determinations

Science.gov (United States)

2013-02-13

....com/ County (12-08- Fischer, 4430 South Adams index.php/colorado/ 0595P). Chairman, Adams County... Public Works http:// March 15, 2013 370498 Cornelius (12- Jeff Tarte, Department, 21445 www.bakeraecom...

Challenges for extension service to render efficient post-transformer ...

African Journals Online (AJOL)

Ben Stevens

; Jacobson,. 2013:30; Fischer, Van den ... 13 Unit for Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South. Africa. ..... dissemination media by extension personnel may adversely affect the potential for.

76 FR 50176 - Certain Orange Juice from Brazil: Final Results of Antidumping Duty Administrative Review...

Science.gov (United States)

2011-08-12

... Agricultura (Fischer). We received rebuttal briefs from the petitioners and Cutrale. The Department has... Agricultura Montecitrus Trading S.A * Sucocitrico Cutrale, S.A 0.42 (de minimis) * No shipments or sales...

Fischer Eco-Almanach. Data, facts, trends of the environmental discussion. Der Fischer Oeko-Almanach. Daten, Fakten, Trends der Umweltdiskussion

Energy Technology Data Exchange (ETDEWEB)

Michelsen, G; Kalberlah, F

1980-01-01

The pocket book is addressed to persons interested in ecology. Its aim is to give a guide to discussion points presently of interest. In the editors' opinion, it is neither an ecological book of terms nor a special scientific compensorium, it's intention is to indicate the dangers and hazards for man and environment. It is said that the argument of having to change nothing as long as the hazards of a technique or of a product are not proven can, in limited cases, lead to irrepairable catastrophes. In this sense, not only existing environment destructions are indicated (part A), but also dangers possible in the future (part B). An efficient solution is said to be only possible if alternatives to the present way of life are developed (part C).

Praemium Imperiale 2002 / Priit Kuusk

Index Scriptorium Estoniae

Kuusk, Priit, 1938-

2002-01-01

Preemia said: saksa kunstnik Sigmar Polke, itaalia skulptor Giuliano Vangi, inglise arhitekt Norman Foster, šveitsi filmirežissöör Jean-Luc Godard, saksa laulja ja dirigent Dietrich Fischer-Dieskau

IJAJ 3(4), S/No 12, September, 2014

African Journals Online (AJOL)

matthew

2014-09-12

Sep 12, 2014 ... employed by human beings (whether spoken, written or signs) to effect communication. Fischer .... reaction of audience member to mass communication message. Even when ..... language. Tenth Edition: New York: Pearson.

Proceedings of the DGMK-conference 'Synthesis gas chemistry'. Authors' manuscripts

Energy Technology Data Exchange (ETDEWEB)

Hoenicke, D.; Kohlpaintner, C.; Luecke, B.; Reschetilowski, W. [eds.

2000-07-01

The main topics of the DGMK-Conference ''Synthesis Gas Chemistry'' were: production of synthesis gas from several educts, new catalysts, Fischer-Tropsch synthesis, hydroformylation, steam reforming and carbonylation.

Alkyl Chain Growth on a Transition Metal Center: How Does Iron Compare to Ruthenium and Osmium?

Science.gov (United States)

Sainna, Mala A.; de Visser, Sam P.

2015-01-01

Industrial Fischer-Tropsch processes involve the synthesis of hydrocarbons usually on metal surface catalysts. On the other hand, very few homogeneous catalysts are known to perform a Fischer-Tropsch style of reaction. In recent work, we established the catalytic properties of a diruthenium-platinum carbene complex, [(CpRu)2(μ2-H)(μ2-NHCH3)(μ3-C)PtCH3(P(CH3)3)2](CO)n+ with n = 0, 2 and Cp = η5-C5(CH3)5, and showed it to react efficiently by initial hydrogen atom transfer followed by methyl transfer to form an alkyl chain on the Ru-center. In particular, the catalytic efficiency was shown to increase after the addition of two CO molecules. As such, this system could be viewed as a potential homogeneous Fischer-Tropsch catalyst. Herein, we have engineered the catalytic center of the catalyst and investigated the reactivity of trimetal carbene complexes of the same type using iron, ruthenium and osmium at the central metal scaffold. The work shows that the reactivity should increase from diosmium to diruthenium to diiron; however, a non-linear trend is observed due to multiple factors contributing to the individual barrier heights. We identified all individual components of these reaction steps in detail and established the difference in reactivity of the various complexes. PMID:26426009

Characterization of Catalyst Materials for Production of Aerospace Fuels

Science.gov (United States)

Best, Lauren M.; De La Ree, Ana B.; Hepp, Aloysius F.

2012-01-01

Due to environmental, economic, and security issues, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to non-petroleum sources as a feedstock for aviation (and other transportation) fuels. Additionally, efforts are concentrated on reducing costs coupled with fuel production from non-conventional sources. One solution to this issue is Fischer-Tropsch gas-to-liquid technology. Fischer-Tropsch processing of synthesis gas (CO/H2) produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fisher-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur or aromatic compounds. This process is most commonly catalyzed by heterogeneous (in this case, silver and platinum) catalysts composed of cobalt supported on alumina or unsupported alloyed iron powders. Physisorption, chemisorptions, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) are described to better understand the potential performance of Fischer-Tropsch cobalt on alumina catalysts promoted with silver and platinum. The overall goal is to preferentially produce C8 to C18 paraffin compounds for use as aerospace fuels. Progress towards this goal will eventually be updated and achieved by a more thorough understanding of the characterization of catalyst materials. This work was supported by NASA s Subsonic Fixed Wing and In-situ Resource Utilization projects.

Alkyl Chain Growth on a Transition Metal Center: How Does Iron Compare to Ruthenium and Osmium?

Directory of Open Access Journals (Sweden)

Mala A. Sainna

2015-09-01

Full Text Available Industrial Fischer-Tropsch processes involve the synthesis of hydrocarbons usually on metal surface catalysts. On the other hand, very few homogeneous catalysts are known to perform a Fischer-Tropsch style of reaction. In recent work, we established the catalytic properties of a diruthenium-platinum carbene complex, [(CpRu2(μ2-H (μ2-NHCH3(μ3-CPtCH3(P(CH332](COn+ with n = 0, 2 and Cp = η5-C5(CH35, and showed it to react efficiently by initial hydrogen atom transfer followed by methyl transfer to form an alkyl chain on the Ru-center. In particular, the catalytic efficiency was shown to increase after the addition of two CO molecules. As such, this system could be viewed as a potential homogeneous Fischer-Tropsch catalyst. Herein, we have engineered the catalytic center of the catalyst and investigated the reactivity of trimetal carbene complexes of the same type using iron, ruthenium and osmium at the central metal scaffold. The work shows that the reactivity should increase from diosmium to diruthenium to diiron; however, a non-linear trend is observed due to multiple factors contributing to the individual barrier heights. We identified all individual components of these reaction steps in detail and established the difference in reactivity of the various complexes.

Structural modifications under reactive atmosphere of cobalt catalysts; Modifications structurales sous atmospheres reactionnelles de catalyseurs a base de cobalt

Energy Technology Data Exchange (ETDEWEB)

Ducreux, O.

1999-11-23

The purpose of this work was to develop in situ methods under reactive dynamic conditions (XRD and Fourier transform infrared spectroscopy) to describe the active phase structure in order to understand Fischer-Tropsch catalyst behaviour and improve the natural gas conversion process performance. Experiments were designed to correlate structural modifications with catalytic results. The effect of ruthenium used as a promoter has also been studied. The impregnation process increases cobalt-support interaction. The presence of ruthenium promoter reduces this effect. Interactions between Co{sub 3}O{sub 4} oxide and support play an important role in the reducibility of cobalt and in the resulting metal structure. This in turn strongly influences the catalytic behaviour. Our results show a close correlation between structure modification and reactivity in the systems studied. Cobalt metal and CO can react to form a carbide Co{sub 2}C under conditions close to those of the Fischer-Tropsch synthesis. This carbide formation seems to be related to a deactivation process. The presence of interstitial carbon formed by dissociation of CO is proposed as a key to understanding the mechanism of the Fischer-Tropsch reaction. A specific catalyst activation treatment was developed to increase the catalytic activity. This work permits correlation of materials structure with their chemical properties and demonstrates the contribution of in situ physico-chemical characterisation methods to describe solids under reactive atmosphere. (author)

Effect of chronic alcohol ingestion on the progression of periodontitis induced in Fisher-344 rats

Directory of Open Access Journals (Sweden)

Éder Ricardo Biasoli

2009-01-01

Full Text Available Objective: Understand the effect of chronic alcohol on the progression of periodontitis induced in Fischer-344 rats.Methods: For the study, 22 Fischer-344 rats, two months old were used, divided into groups: alcohol (n=8, ligature (n=7 and control (n=7. On the first day, the animals in the alcohol group were exposed to ingestion of a water solution containing 20% alcohol (size/size, up to day 90. After thirty days from the beginning of the experiment, the animals in the alcohol group and the ligature group were submitted to the placement of a silk thread around the right maxillary second molar. Nothing was performed on the left side, serving as control. All the groups were submitted to euthanasia 60 days after ligature placement. To assess the destruction of periodontitis, a radiographic exam was used to measure the destruction of bone height. Results: The results of the study showed that on the side in which periodontitis was induced, the group that ingested alcohol suffered an increase in destruction, with statistical differences when compared with the ligature and control groups and increased bone destruction in the ligature group when compared to control. Conclusion: Within the limitations of the study, it was concluded that chronic alcohol consumption by Fischer-344 rats led to greater progression of induced periodontitis.

Raamaturappija / [Sinijärv, Karl Martin

Index Scriptorium Estoniae

Sinijärv, Karl Martin, 1971-

1997-01-01

Vandenberg, Philipp. Viies evangeelium; Fischer, Hans. Saatuslik armastus majas nr. 34; Bulgakov, Mihhail. Meister ja Margarita; Paju, Juhan. Katkenud romaan; Duby, Georges. Guillaume le Maréchal ehk Maailma parim rüütel

Research Reports: Heroin

Science.gov (United States)

... breathing by changing neurochemical activity in the brain stem,where automatic body functions such as breathing and ... 2010. 25. Lund,I.O.;Fischer,G.;Welle-Strand,G.K.;O’Grady,K.E.;Debelak,K.; ...

A photometric method for the estimation of the oil yield of oil shale

Science.gov (United States)

Cuttitta, Frank

1951-01-01

A method is presented for the distillation and photometric estimation of the oil yield of oil-bearing shales. The oil shale is distilled in a closed test tube and the oil extracted with toluene. The optical density of the toluene extract is used in the estimation of oil content and is converted to percentage of oil by reference to a standard curve. This curve is obtained by relating the oil yields determined by the Fischer assay method to the optical density of the toluene extract of the oil evolved by the new procedure. The new method gives results similar to those obtained by the Fischer assay method in a much shorter time. The applicability of the new method to oil-bearing shale and phosphatic shale has been tested.

Long Term Planning at IQ Metal

DEFF Research Database (Denmark)

2017-01-01

This is a Danish version. This case about long term planning at the owner-managed manufacturing firm IQ Metal shows how the future management and ownership may be organized to utilize owner assets and minimize roadblocks. Initially, the owner-manager Bo Fischer Larsen explains how he acquired...... a stake in 2007 in the company which at that time was named Braendstrup Maskinfabrik. He furthermore expalins how he has developed the company based on a strategic plan focusing on professionalization and outsourcing. Next, the video shows how to type Bo Fischer Larsen's replies to the questions...... in The Owner Strategy Map into the questionnaire available on www.ejerstrategi-kortet.dk. Lastly, the Owner Strategy Map's recommendation of how to organize the future management and ownership of IQ Metal is explained....

Culturally Diverse Communities and End-of-Life Care

Science.gov (United States)

... Azen, S.P. (1995). Ethnicity and attitudes toward patient autonomy. JAMA, 274, 820-5 . Phipps, E., True, G., & ... briefly about end-of-life options and neglect culture or values (Tulsky, Fischer, Rose, & Arnold, 1998). Speaking ...

Yosemite Waters Vehicle Evaluation Report: Final Results

Energy Technology Data Exchange (ETDEWEB)

Eudy, L.; Barnitt, R.; Alleman, T. L.

2005-08-01

Document details the evaluation of Fischer-Tropsch diesel, a gas-to-liquid fuel, in medium-duty delivery vehicles at Yosemite Waters. The study was conducted by NREL at the company's Fullerton, California, bottling headquarters.

Philosophical Papers - Vol 34, No 3 (2005)

African Journals Online (AJOL)

Free Will, Death, and Immortality: The Role of Narrative · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. John Martin Fischer, 379-403. http://dx.doi.org/10.1080/05568640509485164 ...

Maternal Neonatal Outcome in Relation to Placental Location ...

African Journals Online (AJOL)

Mubeen

Journal of Basic and Clinical Reproductive Sciences ・ July - December 2013 ... Background: Placenta, which is the vital link between mother and fetus, ... Georgia, USA) using Chi-square test and Fischer exact test for determining the statistical.

Echinococcus

Science.gov (United States)

... Echinococcosis is an infection caused by either the Echinococcus granulosus or Echinococcus multilocularis tapeworm. The infection is also ... References Fischer PR, Cabada MM, White AC. Echinococcosis ( Echinococcus granulosus and Echinococcus multilocularis ). In: Kliegman RM, Stanton BF, ...

Download this PDF file

African Journals Online (AJOL)

English exists, therefore, as a part of academic work not apart of it because it is .... of English required for the performance of academic writing skills. ... Fischer, Robert A. 1984 "Testing Written Communication Competence,". Modern Language ...

A Stable Glutamate Biosensor Based on MnO2 Bulk-modified ...

African Journals Online (AJOL)

2003-08-12

Aug 12, 2003 ... a simple, accurate and reliable method of glutamate determina- tion is vital in the ... determination through enzymatic oxidation because the other methods have .... drop of ammonia solution (Fischer Scientific). A vial of GlOD.

Vapor-Phase Infrared Absorptivity Coefficient of Cyclohexyl Isothiocyanate

National Research Council Canada - National Science Library

Samuels, Alan C; Miles, Jr., Ronald W; Williams, Barry R; Hulet, Melissa S

2008-01-01

...)) at a spectral resolution of 0.125 cm(-1). The chemical used in the feedstock was subjected to a rigorous analysis by gas chromatography-mass spectrometry, nuclear magnetic resonance, and Karl-Fischer titration to verify its purity...

Tanzania Dental Journal - Vol 15, No 2 (2009)

African Journals Online (AJOL)

Opalescence: Tooth Whitening Systems · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. D Fischer, C Thomson, T Schreuder. http://dx.doi.org/10.4314/tdj.v15i2.48401 ...

[The water content reference material of water saturated octanol].

Science.gov (United States)

Wang, Haifeng; Ma, Kang; Zhang, Wei; Li, Zhanyuan

2011-03-01

The national standards of biofuels specify the technique specification and analytical methods. A water content certified reference material based on the water saturated octanol was developed in order to satisfy the needs of the instrument calibration and the methods validation, assure the accuracy and consistency of results in water content measurements of biofuels. Three analytical methods based on different theories were employed to certify the water content of the reference material, including Karl Fischer coulometric titration, Karl Fischer volumetric titration and quantitative nuclear magnetic resonance. The consistency of coulometric and volumetric titration was achieved through the improvement of methods. The accuracy of the certified result was improved by the introduction of the new method of quantitative nuclear magnetic resonance. Finally, the certified value of reference material is 4.76% with an expanded uncertainty of 0.09%.

[Jean-Daniel Strub. Der gerechte Friede. Spannungsfelder eines friedensethnischen Leibegriffs.] / Andreas Pawlas

Index Scriptorium Estoniae

Pawlas, Andreas

2012-01-01

Arvustus: Strub, Jean-Daniel. Der gerechte Friede. Spannungsfelder eines friedensethnischen Leibegriffs. (Forum Systematik. beiträge zur Dogmatik, Ethik und ökumenischen Theologie, hg von Johannes Brosseder, Johannes Fischer und Joachim Track, Band 36), Verlag W. Kohlhammer, Stuttgart 2010

The Clam-Gallas Palace in Prague: Emblematic Architecture?

Czech Academy of Sciences Publication Activity Database

Konečný, Lubomír

2010-01-01

Roč. 18, - (2010), s. 1-10 ISSN 0885-968X Institutional research plan: CEZ:AV0Z80330511 Keywords : Clam-Gallas Palace * Johann Bernhard Fischer von Erlach * architecture * emblem s * imprints Subject RIV: AL - Art, Architecture, Cultural Heritage

Hydrodynamics and mass transfer in slurry bubble columns : scale and pressure effects

NARCIS (Netherlands)

Chilekar, V.P.

2007-01-01

Slurry bubble columns (SBC) are widely used in the chemical industry as a multiphase reactor. Applications include oxidation and hydrogenation reactions, fermentation, Fischer-Tropsch synthesis, and waste water treatment. The advantages of a SBC over other multiphase reactors are the simple

Pyrrolophenanthridines. I. Synthesis of 2!H and 13C NMR spectra of 1H-pyrrolo[2,3-c]- and 1H-pyrrolo[3,2-i]-phenanthridines

International Nuclear Information System (INIS)

Frolova, E.P.; Akhvlediani, R.N.; Krasnokut-skii, S.N.; Kurkovskaya, L.N.; Suvorov, N.N.

1987-01-01

A preparative method is proposed for the synthesis of 3- and 8-aminophenanthridines, from which the new heterocyclic systems 1H-pyrrolo[2,3-c]- and 1H-pyrrolo[3,2-i]phenanthridines were synthesized by means of the Fischer reaction

Genetics Home Reference: autosomal dominant partial epilepsy with auditory features

Science.gov (United States)

... for This Condition ADLTE ADPEAF Autosomal dominant lateral temporal lobe epilepsy Epilepsy, partial, with auditory features ETL1 Related Information ... W, Nakken KO, Fischer C, Steinlein OK. Familial temporal lobe epilepsy with aphasic seizures and linkage to chromosome 10q22- ...

Bifunctional catalysts for the direct production of liquid fuels from syngas

NARCIS (Netherlands)

Sartipi, S.

2014-01-01

Design and development of catalyst formulations that maximize the direct production of liquid fuels by combining Fischer-Tropsch synthesis (FTS), hydrocarbon cracking, and isomerization into one single catalyst particle (bifunctional FTS catalyst) have been investigated in this thesis. To achieve

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 4. Interconversion of Fischer and Zig-Zag Projections - Learning Stereochemistry with the Help of Hands. Syed R Hussaini. Classroom Volume 15 Issue 4 April 2010 pp 351-354 ...

Woody Alleni komöödia Rakveres / Peeter Raudsepp

Index Scriptorium Estoniae

Raudsepp, Peeter, 1974-

1999-01-01

Rakvere Teatris esietendub 15. okt "Suveöö seksikomöödia", Woody Alleni filmistsenaariumi on näidendiks kirjutanud Jürgen Fischer, lavastab külalisena Rednar Annus, kunstnikud on Ene -Liis Semper ja Raoul Kurvitz, muusikaline kujundaja Tamur Tohver.

Building Measures of Instructional Differentiation from Teacher Checklists

Science.gov (United States)

Williams, Ryan; Swanlund, Andrew; Miller, Shazia; Konstantopoulos, Spyros; van der Ploeg, Arie

2012-01-01

Differentiated instruction is commonly believed to be critical to improving the quality and efficiency of teachers' instructional repertoires (Fischer & Rose, 2001; Tomlinson, 2004). Tomlinson (2000) describes differentiation in four domains: content, process, product, and learning environment. Content differentiation involves varying…

Project Independence: Construction of an Integrated Biorefinery for Production of Renewable Biofuels at an Existing Pulp and Paper Mill

Energy Technology Data Exchange (ETDEWEB)

Freeman, Douglas

2012-06-01

Project Independence proposed to construct a demonstration biomass-to-liquids (BTL) biorefinery in Wisconsin Rapids, isconsin. The biorefinery was to be co-located at the existing pulp and paper mill, NewPage Wisconsin System Incorporated’s Wisconsin Rapids Mill, and when in full operation would both generate renewable energy for Wisconsin Rapids Mill and produce liquid fuels from abundant and renewable lignocellulosic biomass. The biorefinery would serve to validate the thermochemical pathway and economic models for BTL production using forest residuals and wood waste, providing a basis for proliferating BTL conversion technologies throughout the United States. It was a project goal to create a compelling new business model for the pulp and paper industry, and support the nation’s goal for increasing renewable fuels production and reducing its dependence on foreign oil. NewPage Corporation planned to replicate this facility at other NewPage Corporation mills after this first demonstration scale plant was operational and had proven technical and economic feasibility. An overview of the process begins with biomass being harvested, sized, conditioned and fed into a ThermoChem Recovery International (TRI) steam reformer where it is converted to high quality synthetic gas (syngas). The syngas is then cleaned, compressed, scrubbed, polished and fed into the Fischer-Tropsch (F-T) catalytic reactors where the gas is converted into two, sulfur-free, clean crude products which will be marketed as revenue generating streams. Additionally, the Fischer-Tropsch products could be upgraded for use in automotive, aviation and chemical industries as valuable products, if desired. As the Project Independence project set out to prove forest products could be used to commercially produce biofuels, they planned to address and mitigate issues as they arose. In the early days of the Project Independence project, the plant was sized to process 500 dry tons of biomass per day but would

Theoretical characterization of the surface composition of ruthenium nanoparticles in equilibrium with syngas

Science.gov (United States)

Cusinato, Lucy; Martínez-Prieto, Luis M.; Chaudret, Bruno; Del Rosal, Iker; Poteau, Romuald

2016-05-01

A deeper understanding of the relationship between experimental reaction conditions and the surface composition of nanoparticles is crucial in order to elucidate mechanisms involved in nanocatalysis. In the framework of the Fischer-Tropsch synthesis, a resolution of this complex puzzle requires a detailed understanding of the interaction of CO and H with the surface of the catalyst. In this context, the single- and co-adsorption of CO and H to the surface of a 1 nm ruthenium nanoparticle has been investigated with density functional theory. Using several indexes (d-band center, crystal overlap Hamilton population, density of states), a systematic analysis of the bond properties and of the electronic states has also been done, in order to bring an understanding of structure/property relationships at the nanoscale. The H : CO surface composition of this ruthenium nanoparticle exposed to syngas has been evaluated according to a thermodynamic model fed with DFT energies. Such ab initio thermodynamic calculations give access to the optimal H : CO coverage values under a wide range of experimental conditions, through the construction of free energy phase diagrams. Surprisingly, under the Fischer-Tropsch synthesis experimental conditions, and in agreement with new experiments, only CO species are adsorbed at the surface of the nanoparticle. These findings shed new light on the possible reaction pathways underlying the Fischer-Tropsch synthesis, and specifically the initiation of the reaction. It is finally shown that the joint knowledge of the surface composition and energy descriptors can help to identify possible reaction intermediates.A deeper understanding of the relationship between experimental reaction conditions and the surface composition of nanoparticles is crucial in order to elucidate mechanisms involved in nanocatalysis. In the framework of the Fischer-Tropsch synthesis, a resolution of this complex puzzle requires a detailed understanding of the interaction

The Metabolism of Tetralin in Fischer 344 Rats

Science.gov (United States)

1986-04-01

would die from the disease . The relevance of nephropathy observed in male rats exposed to various hydrocarbons to the occurrence of renal neoplasia in man...34 often obscure pathologic evaluations. "Old-rat nephropathy" is a common degenerative kidney disease predominantly seen in the male rat. By careful...studies have been performed with n-hexane and n-heptane to characterize their metabolism and role in neurotoxicity (Perbellini et al., 1982; Bahima et

Raketõ, neft i razdeljonnaja Jevropa / Joschka Fischer

Index Scriptorium Estoniae

Fischer, Joschka, 1948-

2007-01-01

Ilmunud ka: Delovõje Vedomosti, 18. apr. 2007, lk. 12. Autor kirjutab, et USA plaanid paigutada Poolasse ja Tšehhi raketitõrjesüsteemid ähvardavad Euroopat jagada samal kombel nagu Iraagi sõda. Venemaa suhtumisest, külma sõja ohust

Pärt, Arvo: "Miserere", "Festina lente" / Volkmar Fischer

Index Scriptorium Estoniae

Fischer, Volkmar

1991-01-01

Uuest heliplaadist Pärt, Arvo: "Miserere", "Festina lente", "Sarah Was Ninety Years Old". The Hilliard Ensemble. Orchester der Beethovenhalle Bonn. Dirigent Dennis Russel Davies (ECM Records, distr Amigo)

Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals. Technical Progress Report

International Nuclear Information System (INIS)

Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

2006-01-01

This project extends previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have shown unprecedented Fischer-Tropsch synthesis rate, selectivity for feedstocks consisting of synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic results previously reported. During the second reporting period, we prepared several Fe-based compositions for Fischer-Tropsch synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. During the third and fourth reporting periods, we improved the catalysts preparation method, which led to Fe-based FT catalysts with the highest FTS reaction rates and selectivities so far reported, a finding that allowed their operation at lower temperatures and pressures with high selectivity to desired products (C 5+ , olefins). During this fifth reporting period, we have studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influences the performance of these materials in the Fischer-Tropsch synthesis. The resulting procedures have been optimized to improve further upon the already unprecedented rates and C 5+ selectivities of the Fe-based catalysts that we have developed as part of this project. During this fifth reporting period, we have also continued our studies of optimal activation procedures, involving reduction and carburization of oxide precursors during the early stages of contact with synthesis gas. We have completed the analysis of the evolution of oxide, carbide, and metal phases of the active iron components during initial contact with synthesis gas using advanced synchrotron techniques based on X-ray absorption spectroscopy. We have confirmed that the Cu or Ru compensates for inhibitory effects of Zn, a surface

Synthesis, characterization and electrochemical investigation of hetaryl chromium(0) aminocarbene complexes

Czech Academy of Sciences Publication Activity Database

Metelková, R.; Tobrman, T.; Kvapilová, Hana; Hoskovcová, I.; Ludvík, Jiří

2012-01-01

Roč. 82, SI (2012), s. 470-477 ISSN 0013-4686 R&D Projects: GA AV ČR IAA400400813 Institutional support: RVO:61388955 Keywords : Fischer aminocarbene complexes * synthesis * Electrochemical oxidation and reduction Subject RIV: CG - Electrochemistry Impact factor: 3.777, year: 2012

Aspects of middle cretaceous pelagic sedimentation in Southern Europe : production and storage of organic matter, stable isotopes, and astronomical influences

NARCIS (Netherlands)

Boer, P.L. de

1983-01-01

Large amounts of organic carbon were stored as black shales in pelagic sediments during the Lower and Middle Cretaceous, especially within the Tethyan and North Atlantic oceans and their marginal basins (Schlanger & Jenkyns, 1976; Fischer &Arthur, 1977; Ryan & Cita, 1977; Thiede & van

Saksamaa poliitiline patiseis : Was nun? / Jeroen Bult

Index Scriptorium Estoniae

Bult, Jeroen

2005-01-01

Pärast parlamendivalimisi Saksamaal kujunenud poliitilisest patiseisust: võimulolev Sotsiaaldemokraatlik Partei ja Roheliste Partei kaotas parlamendis enamuse, samal ajal kui Kristlik Demokraatliku Partei ja Vabade Demokraatide ühisrinne ei saa vajalikul arvul kohti parempoolse koalitsiooni loomiseks. Vt. samas: Joshka Fischer tõmbub tagasi

Effects of Electromagnetic Fields on the Blood Brain Barrier

National Research Council Canada - National Science Library

Persson, Rolf

2000-01-01

...) in the 91 5-2450 MHz range on the permeability of the blood brain barrier (BBB) in rats. Male and female Fischer rats were exposed to continuous wave or pulse-modulated EMF, with different pulse powers and times up to 960 minutes...

dataTEL - Datasets for Technology Enhanced Learning

NARCIS (Netherlands)

Drachsler, Hendrik; Verbert, Katrien; Sicilia, Miguel-Angel; Wolpers, Martin; Manouselis, Nikos; Vuorikari, Riina; Lindstaedt, Stefanie; Fischer, Frank

2011-01-01

Drachsler, H., Verbert, K., Sicilia, M. A., Wolpers, M., Manouselis, N., Vuorikari, R., Lindstaedt, S., & Fischer, F. (2011). dataTEL - Datasets for Technology Enhanced Learning. STELLAR Alpine Rendez-Vous White Paper. Alpine Rendez-Vous 2011 White paper collection, Nr. 13., France (2011)

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

2014-01-11

correlated dynamics of two electrons in argon. V Sharma N Camus B Fischer M Kremer A Rudenko B Bergues M Kuebel N G Johnson M F Kling T Pfeifer J Ullrich R Moshammer. Invited Talks Volume 82 Issue 1 January 2014 ...

Municipal solid waste conversion to transportation fuels: a life-cycle estimation of global warming potential and energy consumption

DEFF Research Database (Denmark)

Pressley, Phillip N.; Aziz, Tarek N.; DeCarolis, Joseph F.

2014-01-01

This paper utilizes life cycle assessment (LCA) methodology to evaluate the conversion of U.S. municipal solid waste (MSW) to liquid transportation fuels via gasification and Fischer-Tropsch (FT). The model estimates the cumulative energy demand and global warming potential (GWP) associated...

Acting in solidarity : Testing an extended dual pathway model of collective action by bystander group members

NARCIS (Netherlands)

Saab, Rim; Tausch, Nicole; Spears, Russell; Cheung, Wing-Yee

We examined predictors of collective action among bystander group members in solidarity with a disadvantaged group by extending the dual pathway model of collective action, which proposes one efficacy-based and one emotion-based path to collective action (Van Zomeren, Spears, Fischer, & Leach,

Eurovolinikud GMO pärast vastamisi / Nastja Pertsjonok

Index Scriptorium Estoniae

Pertsjonok, Nastja

2006-01-01

ELi keskkonnavolinik Stavros Dimas väitis 6. aprillil Viinis peetud üleeuroopalisel konverentsil "Vaba valik", et Euroopa põllumehed ei hakka GMOsid kasvatama. Põllumajandusvolinik Mariann Fischer Boeli hinnangul GMOd on ja jäävad ning eurooplastel oleks parem nendega harjuda

Freeze-drying for controlled nanoparticle distribution in Co/SiO 2 Fischer–Tropsch catalysts

NARCIS (Netherlands)

Eggenhuisen, T.M.; Munnik, P.; Talsma, H.; de Jongh, P.E.; de Jong, K.P.

2013-01-01

Controlling the nanoparticle distribution over a support is considered essential to arrive at more stable catalysts. By developing a novel freeze drying method, the nanoparticle distribution was successfully manipulated for the preparation of Co/SiO2 Fischer-Tropsch catalysts using a commercial

2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole

Directory of Open Access Journals (Sweden)

Janina Wobbe

2011-09-01

Full Text Available 2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole was synthesized by reaction of cycloheptanone and (4-tert-butylphenylhydrazine hydrochloride in the presence of sodium acetate and sulfuric acid in glacial acetic acid via Fischer indole synthesis.

A Dialectic for Network Centric Warfare

Science.gov (United States)

2005-06-01

scientific realism through Salmon (1966), Popper (1934) and Kuhn (1962) to the epistemological anarchism of Feyerabend (1975). In this paper, we use an...Factors Society. Feyerabend , P. (1975), Against Method, Verso, London. Fischer, K., Muller, J.P. and Pischel, M. (1996). Cooperative

Effects of brand placement disclosures: An eye tracking study into the effects of disclosures and the moderating role of brand familiarity

NARCIS (Netherlands)

Smink, A.R.; van Reijmersdal, E.A.; Boerman, S.C.; Zabkar, V.; Eisend, M.

2017-01-01

Developments as advertising clutter and increased aversion towards commercials have led to an increased popularity of brand placements to unobtrusively reach the customer (Cain, 2011; Glass, 2007; Van Reijmersdal, Neijens, and Smit, 2007; Wei, Fischer, and Main, 2008). However, due to its

Government deficits, private investment and the current account: an intertemporal disequilibrium analysis

NARCIS (Netherlands)

van Wijnbergen, S.J.G.

1987-01-01

An analysis of the fiscal policy in the account of a model with intertemporal optimisation underlying private behaviour. Besides is incorporated explicitly the possibility of (short-run) labour and goods market disequilibrium caused by Fischer (1977)--Gray (1978) type contract-based real-wage

Haapsalu õudusfilmide festival / Margus Paju

Index Scriptorium Estoniae

Paju, Margus

2007-01-01

PÖFFi korraldatud õudusfilmide festivalil HÕFF Haapsalu Kultuurikeskuses (22.-25. märtsini) näidatavad õudusfilmid "Frankensteini needus" (Terence Fischer; Suurbritannia, 1957) ja "Murtud" (Adam Mason, Simon Boyes; Suurbritannia, 2006). Neid filme näeb 20.03. ka Tallinna Kinomajas

Toward better understanding of the support effect: test cases for CO dissociation on Fe n /TiO 2 (110), n=4,5

KAUST Repository

Jedidi, Abdesslem; Aziz, Saadullah G.; Cavallo, Luigi; Minot, Christian

2017-01-01

The Fischer-Tropsch reaction is initiated by direct CO dissociation for Iron catalyst even though a H-assisted mechanism may be easier on other metals. In the gas phase, the CO dissociation is only favorable for Fe-clusters composed by more than 11

Between Nationalism and Internationalism: The German Chemical Society In Comparative Perspective, 1867-1945.

Science.gov (United States)

Johnson, Jeffrey Allan

2017-09-04

One-hundred fifty years ago, on the eve of German unification, about one-hundred people gathered in Berlin to found the German Chemical Society (DChG) under the charismatic leadership of August Wilhelm von Hofmann, who attracted a large international membership by promoting modern organic chemistry. By 1892, when Emil Fischer succeeded Hofmann, the DChG was the world's largest chemical society. Under Fischer the Society promoted international collaboration with foreign societies, and in 1900 it opened an impressive headquarters, the Hofmann House, where it centralized its greatly expanded literary activity including abstracts and reference publications. Yet a half-century later, after war and racial-national extremism, the house lay in ruins and the Society had ceased to exist. In remembering the Society, one may well ask why its auspicious beginning should have led to this ignominious end. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A chromatographic determination of water in non-aqueous phases of solvent extraction systems

International Nuclear Information System (INIS)

Lyle, S.J.; Smith, D.B.

1975-01-01

The disadvantages of the Karl Fischer method for the determination of water in the non-aqueous phases of solvent extraction systems are pointed out, and a gas chromatographic method is described which is claimed to be potentially capable of overcoming these disadvantages. The method, as described, was developed to satisfy conditions relevant to measurement of the transfer rate of water from an aqueous phase into tri-n-butylphosphate in toluene, but it can be used for water determination in other solvent extraction systems. The apparatus used is described in detail. The concentration of water in water-saturated TBP was found to be 3.56 mol/litre, compared with a value of 3.55 obtained by Karl Fischer titration and previous literature values of 3.59 and 3.57. Measurements of water content in benzene solutions of long chain alkylamines were also sucessfully carried out. (U.K.)

CYTOCHROME P450-DEPENDENT METABOLISM OF TRICHLOROETHYLENE IN THE RAT KIDNEY

Science.gov (United States)

The metabolism of trichloroethylene (Tri) by cytochrome P450 (P450) was studied in microsomes from liver and kidney homogenates and from isolated renal proximal tubular (PT) and distal tubular (DT) cells from male Fischer 344 rats. Chloral hydrate (CH) was the only metabolite con...

Mitogenomic phylogenetics of fin whales (Balaenoptera physalus spp.) : Genetic evidence for revision of subspecies

NARCIS (Netherlands)

Archer, Frederick I.; Morin, Phillip A.; Hancock-Hanser, Brittany L.; Robertson, Kelly M.; Leslie, Matthew S.; Bérubé, Martine; Panigada, Simone; Taylor, Barbara L.

2013-01-01

There are three described subspecies of fin whales (Balaenoptera physalus): B. p. physalus Linnaeus, 1758 in the Northern Hemisphere, B. p. quoyi Fischer, 1829 in the Southern Hemisphere, and a recently described pygmy form, B. p. patachonica Burmeister, 1865. The discrete distribution in the North

Environmental Inventory Report. East St. Louis and Vicinity, Cahokia Canal Drainage Area, Madison and St. Clair Counties, Illinois. Volume 5.

Science.gov (United States)

1981-05-01

administers the Watershed Protection and Flood Protection Act, which provides for a partnership among the Federal Government, State governments, local...Burlene Goetz Roberta Price Michael Fischer Glenna Mel1 Al Relsing William Blumberg Thomas Loehr Robert Sudbring Rudolph Spanholtz ( ( XX-AIO C "" - WWF

Oceanographic validity of buffer zones for the east coast of India: A hydrometeorological perspective

Digital Repository Service at National Institute of Oceanography (India)

Mascarenhas, A.

, The Gazette of India, Not i- fication, S.O. No. 114(E), 20 February 1991. 37. Fischer, D. W. and Arredondo, M. C., Municipal coastal hazard planning: Los Angeles and Orange County city responses, Cal i- fornia. J. Coast. Res ., 1999, 15 , 974 ? 984...

Preliminary evidence of oxidation in standard oven drying of cotton: attenuated total reflectance/ Fourier transform spectroscopy, colorimetry, and particulate matter formation

Science.gov (United States)

Moisture is paramount to cotton fiber properties dictating harvesting, ginning, storage and spinning as well as others. Currently, oven drying in air is often utilized to generate the percentage of moisture in cotton fibers. Karl Fischer Titration another method for cotton moisture, has been compa...

Journal of East African Natural History - Vol 98, No 2 (2009)

African Journals Online (AJOL)

A preliminary checklist of the ants (Hymenoptera: Formicidae) of Kakamega Forest (Kenya). EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. FH Garcia, G Fischer, MK Peters, RR Snelling, JW Wägele. http://dx.doi.org/10.2982/028.098.0201 ...