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  • 1
    Publication Date: 2009-11-01
    Description: INTRODUCTIONThe Ehrenberg collection of microfossils in the Natural History Museum, Berlin contains the original reference material for a single genus of agglutinated foraminifera – Bolivinopsis Yakovlev, 1891. Among the foraminiferal specimens preserved in the collection, a single specimen was selected and illustrated by Ehrenberg (1854) as Spiroplecta rosula. This species was subsequently designated by Kisselman (1964) as the senior synonym of Bolivinopsis capitata Yakovlev, 1891, making it the type species of Bolivinopsis by virtue of synonymy. According to Kisselman (1964), the type specimens of B. capitata were deposited in the Central Geological Museum in St Petersburg, and were lost during the war. Indeed, the name B. capitata is not used in the Soviet literature, and such forms are consistently attributed to B. rosula. As part of the work undertaken for a Catalogue of Agglutinated Foraminiferal Genera, we undertook a search of the Ehrenberg Collection in order to establish the status of the type specimen(s) of Spiroplecta rosula.MATERIAL AND METHODSThe Ehrenberg collection of microfossils at the Museum für Naturkunde in Berlin consists of innumerable specimens embedded in Canada Balsam mounted on small mica disks that served as microscope slides. Small paper rings pressed onto the surface of the disks were used by Ehrenberg to mark specimens of importance, such as illustrated in Ehrenberg’s (1854) book Mikrogeologie. A catalogue of the collection was compiled originally by Ehrenberg’s daughter Clara and has been supplemented by new collection databases. We used these sources to locate and examine all the micas from the . . .
    Print ISSN: 0262-821X
    Electronic ISSN: 2041-4978
    Topics: Geosciences
    Published by Copernicus on behalf of Micropalaeontological Society.
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  • 2
    Publication Date: 1992-06-01
    Description: INTRODUCTIONTrochamminoides elegans (Grzybowski) [= Trochammina elegans Grzybowski, 1898] is a familiar species that is commonly recorded from the Paleogene of the Carpathian flysch. However, during the course of work on a taxonomic revision of the Grzybowski Collection, it has become apparent that the name of this taxon is in actuality, invalid.The designation Trochammina elegans was first used by Rzehak (1887), but since the name only appeared in a table (without a description or illustration) the name is unavailable under Article 12 of the ICZN. Grzybowski (1898), who had received specimens from Rzehak, referred to this species as “Trochammina elegans Rzehak”, but the authorship of the species belongs to Grzybowski under Article 50 of the ICZN. Grzybowski (1898) described Trochammina elegans as follows: Test agglutinated, surface rough; circular in outline, spirally coiled in two and one-half to three whorls. Chambers spherical, increasing in size, numerous, with depressed sutures; there are thirteen to fifteen of them in the last whorl. Aperture at the lower edge of the last chamber, just above the rounded periphery. Diameter 1.3 mm.However, transferring the authorship of this species makes Trochammina elegans Grzybowski, 1898 a primary junior homonym of Trochammina elegans Egger, 1893 (Article 53c of the ICZN). As such, the name must be permanently rejected (Article 52a). Because no junior synonym exists, we propose the replacement name Trochamminoides grzybowskii Kaminski & Geroch, nom. nov.SYSTEMATIC DESCRIPTIONSuborder:Textulariina Delage & Herouard, 1896Genus: Trochamminaides Cushman, 1910Trochamminoides grzybowskii Kaminski & Geroch, nom.nov. for Trochammina elegans. . .
    Print ISSN: 0262-821X
    Electronic ISSN: 2041-4978
    Topics: Geosciences
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  • 3
    Publication Date: 2014-05-16
    Description: Oxidation by hydroxyl radical (OH) and ozonolysis are the two major pathways of daytime biogenic volatile organic compounds (VOCs) oxidation and secondary organic aerosol (SOA) formation. In this study, we investigated the particle formation of several common monoterpenes (α-pinene, β-pinene, and limonene) by OH dominated oxidation, which has seldom been investigated. OH oxidation experiments were carried out in the SAPHIR chamber in Jülich, Germany, at low NOx (0.01–1 ppbV) and low ozone (O3) concentration. OH concentration and OH reactivity were measured directly so that the overall reaction rates of organic compounds with OH were quantified. Multi-generation reaction process, particle growth, new particle formation, particle yield, and chemical composition were analyzed and compared with that of monoterpene ozonolysis. Multi-generation products were found to be important in OH dominated SOA formation. The relative role of functionalization and fragmentation in the reaction process of OH oxidation was analyzed by examining the particle mass and the particle size as a function of OH dose. We developed a novel method which quantitatively links particle growth to the reaction of OH with organics in a reaction system. This method was also used to analyze the evolution of functionalization and fragmentation of organics in the particle formation by OH oxidation. It shows that functionalization of organics was dominant in the beginning of the reaction (within two lifetimes of the monoterpene) and fragmentation started to be dominant after that. We compared particle formation from OH oxidation with that from pure ozonolysis. In individual experiments, growth rates of the particle size did not necessarily correlate with the reaction rate of monoterpene with OH and O3. Comparing the size growth rates at the similar reaction rates of monoterpene with OH or O3 indicates that generally, OH oxidation and ozonolysis had similar efficiency in particle growth. The SOA yield of α-pinene and limonene by ozonolysis was higher than that of OH oxidation. Aerosol mass spectrometry (AMS) shows SOA elemental composition from OH oxidation follows a slope shallower than −1 in the O / C vs. H / C diagram, indicating that oxidation proceeds without significant loss of hydrogen. SOA from OH oxidation had higher H / C ratios than SOA from ozonolysis. In ozonolysis, a process with significant hydrogen loss seemed to play an important role in SOA formation.
    Electronic ISSN: 1680-7375
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 4
    Publication Date: 2014-02-25
    Description: Hydroxyl radicals (OH) are the most important reagent for the oxidation of trace gases in the atmosphere. OH concentrations measured during recent field campaigns in isoprene rich environments were unexpectedly large. A number of studies showed that unimolecular reactions of organic peroxy radicals (RO2) formed in the initial reaction step of isoprene with OH play an important role for the OH budget in the atmosphere at low mixing ratios of nitrogen monoxide (NO) of less than 100 pptv. It has also been suggested that similar reactions potentially play an important role for RO2 from other compounds. Here, we investigate the oxidation of methacrolein (MACR), one major oxidation product of isoprene, by OH in experiments in the simulation chamber SAPHIR under controlled atmospheric conditions. The experiments show that measured OH concentrations are approximately 50% larger than calculated by current chemical models for conditions of the experiments (NO mixing ratio of 90 pptv). The analysis of the OH budget reveals a so far unaccounted OH source, which is correlated with the production rate of RO2 radicals from MACR. In order to balance the measured OH destruction rate, (0.77±0.3) OH radicals need to be additionally reformed from each OH that has reacted with MACR. The strong correlation of the missing OH source with the production of RO2 radicals is consistent with the concept of OH formation from unimolecular isomerization and decomposition reactions of RO2. The comparison of observations with model calculations gives a lower limit of 0.03 s−1 for the reaction rate constant, if the OH source is attributed to an isomerization reaction of one RO2 species formed in the MACR+OH reaction as suggested in literature. This fast isomerization reaction would be competitive to the reaction of this RO2 species with minimum 150 pptv NO.
    Electronic ISSN: 1680-7375
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 5
    Publication Date: 2016-03-23
    Description: A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m−2 s−1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.
    Print ISSN: 1867-1381
    Electronic ISSN: 1867-8548
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 6
    Publication Date: 2014-08-08
    Description: Hydroxyl radicals (OH) are the most important reagent for the oxidation of trace gases in the atmosphere. OH concentrations measured during recent field campaigns in isoprene-rich environments were unexpectedly large. A number of studies showed that unimolecular reactions of organic peroxy radicals (RO2) formed in the initial reaction step of isoprene with OH play an important role for the OH budget in the atmosphere at low mixing ratios of nitrogen monoxide (NO) of less than 100 pptv. It has also been suggested that similar reactions potentially play an important role for RO2 from other compounds. Here, we investigate the oxidation of methacrolein (MACR), one major oxidation product of isoprene, by OH in experiments in the simulation chamber SAPHIR under controlled atmospheric conditions. The experiments show that measured OH concentrations are approximately 50% larger than calculated by the Master Chemical Mechanism (MCM) for conditions of the experiments (NO mixing ratio of 90 pptv). The analysis of the OH budget reveals an OH source that is not accounted for in MCM, which is correlated with the production rate of RO2 radicals from MACR. In order to balance the measured OH destruction rate, 0.77 OH radicals (1σ error: ± 0.31) need to be additionally reformed from each reaction of OH with MACR. The strong correlation of the missing OH source with the production of RO2 radicals is consistent with the concept of OH formation from unimolecular isomerization and decomposition reactions of RO2. The comparison of observations with model calculations gives a lower limit of 0.03 s−1 for the reaction rate constant if the OH source is attributed to an isomerization reaction of MACR-1-OH-2-OO and MACR-2-OH-2-OO formed in the MACR + OH reaction as suggested in the literature (Crounse et al., 2012). This fast isomerization reaction would be a competitor to the reaction of this RO2 species with a minimum of 150 pptv NO. The isomerization reaction would be the dominant reaction pathway for this specific RO2 radical in forested regions, where NO mixing ratios are typically much smaller.
    Print ISSN: 1680-7316
    Electronic ISSN: 1680-7324
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 7
    Publication Date: 2015-01-28
    Description: Oxidation by hydroxyl radical (OH) and ozonolysis are the two major pathways of daytime biogenic volatile organic compound (BVOC) oxidation and secondary organic aerosol (SOA) formation. In this study, we investigated the particle formation of several common monoterpenes (α-pinene, β-pinene and limonene) by OH-dominated oxidation, which has seldom been investigated. OH oxidation experiments were carried out in the SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction) chamber in Jülich, Germany, at low NOx (0.01 ~ 1 ppbV) and low ozone (O3) concentration (〈 20 ppbV). OH concentration and total OH reactivity (kOH) were measured directly, and through this the overall reaction rate of total organics with OH in each reaction system was quantified. Multi-generation reaction process, particle growth, new particle formation (NPF), particle yield and chemical composition were analyzed and compared with that of monoterpene ozonolysis. Multi-generation products were found to be important in OH-dominated SOA formation. The relative role of functionalization and fragmentation in the reaction process of OH oxidation was analyzed by examining the particle mass and the particle size as a function of OH dose. We developed a novel method which quantitatively links particle growth to the reaction rate of OH with total organics in a reaction system. This method was also used to analyze the evolution of functionalization and fragmentation of organics in the particle formation by OH oxidation. It shows that functionalization of organics was dominant in the beginning of the reaction (within two lifetimes of the monoterpene) and fragmentation started to play an important role after that. We compared particle formation from OH oxidation with that from pure ozonolysis. In individual experiments, growth rates of the particle size did not necessarily correlate with the reaction rate of monoterpene with OH and O3. Comparing the size growth rates at the similar reaction rates of monoterpene with OH or O3 indicates that, generally, OH oxidation and ozonolysis had similar efficiency in particle growth. The SOA yield of α-pinene and limonene by ozonolysis was higher than that of OH oxidation. Aerosol mass spectrometry (AMS) shows SOA elemental composition from OH oxidation follows a slope shallower than −1 in the O / C vs. H / C diagram, also known as Van Krevelen diagram, indicating that oxidation proceeds without significant loss of hydrogen. SOA from OH oxidation had higher H / C ratios than SOA from ozonolysis. In ozonolysis, a process with significant hydrogen loss seemed to play an important role in SOA formation.
    Print ISSN: 1680-7316
    Electronic ISSN: 1680-7324
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 8
    Publication Date: 2015-11-16
    Description: A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m−2 s−1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.
    Electronic ISSN: 1867-8610
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
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  • 9
    Publication Date: 2000-05-01
    Description: For a detailed biostratigraphic framework of the Foula Sub-basin, located west of the Shetland Islands (UK continental shelf), well 205/10-2B is chosen as a reference section. Based on the succession of last occurrence events of nominate taxa, ten stratigraphically distinct Campanian to Palaeocene assemblages are described. The regional applicability of these events is tested by correlation between three wells in the Foula Sub-basin (wells 205/10-2B, 206/3-1 and 206/5-1). Despite some local differences, the biostratigraphy of the Foula Sub-basin compares well with the biostratigraphy of the Western Tethys and the northern North Sea, and is therefore an important link between the southern and northern areas of the Northeast Atlantic margin. A morphogroup analysis of agglutinating foraminifera in well 205/10-2B indicates deposition of Campanian and Maastrichtian mudstones in a well oxygenated, lower bathyal environment, whereas Palaeocene sediments are deposited in a middle to upper bathyal environment.
    Print ISSN: 0262-821X
    Electronic ISSN: 2041-4978
    Topics: Geosciences
    Published by Copernicus on behalf of Micropalaeontological Society.
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