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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 101-113 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Adherent films of copolymers on different metal surfaces were formed by an electrolytically initiated polymerization of acrylonitrile (AN) and acrylic acid (AA) in 0.05N H2SO4 aqueous solution. The electrolysis was carried out under a constant current. Hydrogen overvoltages for five different metals used as the cathode were measured in order to interpret the nature and quality of the coating. Solutions containing varying volume fractions of AN and containing different electrolytes gave rise to coatings of varying film thickness. Based on the analyses of copolymer compositions, it is believed that the polymer was formed at the cathode by a free-radical propagation mechanism. The film hardness and the adhesion between the polymer and the metal surface were measured with an Arco microknife. Furthermore, the scanning electron microscope (SEM) was used to examine the structure of the film surface and cross section. The corrosion rates of the coated and uncoated metals in substitute ocean water were also measured for purposes of evaluation of the coatings.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 2837-2852 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The formation and deposition of a polymer as a thin, uniform solid film on a metal particle substrate is investigated in detail in a fluidized electrode bed reactor. Experiments were carried out in different designs of fluidized bed electrode cell reactor, using various metal particles and monomers. It was observed that diacetone acrylamide (DAA) monomer in 0.1N H2SO4 with aluminum particles (3530 μm) as cathode, in a concentric dual compartment cell, appeared to yield the best films. Infrared and elemental analyses were used to characterize the polymer film on the metal particles. Scanning electron microscopy (SEM) was employed to examine the surface and cross-sectional profiles of the films. The potential profiles in both particulate and solution phases were measured and the importance of particulate electrical conductivity in the polymerization is thus explained. It was observed that the optimum particulate conductivity and hence the maximum yield occurs in the range of 10-20% bed expansion. The experimental product yields for various liquid superficial velocities (i.e., bed expansion) at different feeder current densities were compared to explain the possible controlling mechanism in packed and fluidized bed cells, noting that both chemical reaction and mass transfer control in the low bed expansion region while chemical reaction controls in the high bed expansion region. The current effciency decreases in the high current region due to side reactions at the fluidized bed electrode and due to pore diffusion in the polymer film.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 3587-3596 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Our previous studies on electroinitiated polymerization for formation of coatings on metal surfaces have all been in stationary cell systems. The feasibility of using either a packed bed or a fluidized bed cell in electroinitiated polymerization is now demonstrated, the objective being to form polymeric coatings on metallic and metal-coated nonmetallic particles. The metallic particles that have been used are aluminum and stainless steel and the monomer-electrolyte system used is DAA-sulfuric acid. A comparison of current densities under various cathode potentials for the packed and fluidized bed systems is presented. The coatings obtained are analyzed through IR to establish the polymer functional groups. Additionally, both elemental analyses and thermal neutron activation analyses have been carried out to establish the compositions of the polymer coatings.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 2020-02-12
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 5
    Publication Date: 2013-08-17
    Description: PRC2 (Polycomb repressive complex 2) mediates epigenetic gene silencing by catalyzing the triple methylation of histone H3 Lys-27 (H3K27me3) to establish a repressive epigenetic state. PRC2 is involved in the regulation of many fundamental biological processes and is especially essential for embryonic stem cells. However, how the formation and function of PRC2 are regulated is largely unknown. Here, we show that a microRNA encoded by the imprinted Dlk1-Dio3 region of mouse chromosome 12, miR-323-3p, targets Eed (embryonic ectoderm development) mRNA, which encodes one of the core components of PRC2, the EED protein. Binding of miR-323-3p to Eed mRNA resulted in reduced EED protein abundance and cellular H3K27me3 levels, indicating decreased PRC2 activity. Such regulation seems to be conserved among mammals, at least between mice and humans. We demonstrate that induced pluripotent stem cells with varied developmental abilities had different miR-323-3p as well as EED and H3K27me3 levels, indicating that miR-323-3p may be involved in the regulation of stem cell pluripotency through affecting PRC2 activity. Mouse embryonic fibroblast cells had much higher miR-323-3p expression and nearly undetectable H3K27me3 levels. These findings identify miR-323-3p as a new regulator for PRC2 and provide a new approach for regulating PRC2 activity via microRNAs.
    Print ISSN: 0021-9258
    Electronic ISSN: 1083-351X
    Topics: Biology , Chemistry and Pharmacology
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  • 6
    Publication Date: 2015-03-13
    Description: The current-voltage ( I-V ) characteristics with spin injection were investigated for the epitaxial La 0.7 Sr 0.3 MnO 3 /La 1.85 Sr 0.15 CuO 4 heterostructure rotated from H // c to H // ab in magnetic fields up to 14 T. It is found that all the I-V curves in various magnetic fields can be scaled with a three dimensional (3D) vortex glass model, and the spin injection can induce a better 3D scaling behavior, which is closely related to the decrease of the anisotropy parameter. A vortex phase diagram for the evolution of vortex glass transition field ( H g ) and upper critical field ( H c 2 ) indicates that both H g and H c 2 are suppressed by spin injection, and this effect becomes more obvious in the case of H // ab , which probably originates from the different suppression on the superconducting pairing strength by different injected spins' orientations.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
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  • 7
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    Unknown
    Mineralogical Society of America
    Publication Date: 2015-05-13
    Print ISSN: 0003-004X
    Electronic ISSN: 1945-3027
    Topics: Geosciences
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  • 8
    Publication Date: 2016-02-03
    Description: To constrain the behavior of Mg isotopes during deep crustal processes and the Mg isotopic composition of the middle and lower continental crust, 30 composite samples from high-grade metamorphic terranes and 18 granulite xenoliths were investigated. The composites derive from eight different high-grade metamorphic terranes in the two largest Archean cratons of China, including 13 TTG gneisses, 5 amphibolites, 4 felsic, 4 intermediate, and 4 mafic granulites. They have variable bulk compositions with SiO 2 ranging from 45.7 to 72.5%, representative of the middle crust beneath eastern China. The 26 Mg values of these samples vary from –0.40 to +0.12, reflecting heterogeneity of their protoliths, which could involve upper crustal sediments. The granulite xenoliths from the Cenozoic Hannuoba basalts also have a diversity of compositions with MgO ranging from 2.95 to 20.2%. These xenoliths equilibrated under high temperatures of 800–950 °C, corresponding to depths of the lower continental crust (〉30 km). They yield a large 26 Mg variation of –0.76 to –0.24. The light Mg isotopic compositions likely result from interactions with isotopically light metamorphic fluids, probably carbonate fluids. Together with previously reported data, the average 26 Mg values of the middle and lower continental crusts are estimated to be –0.21 ±0.07 and –0.26 ±0.06, respectively. The bulk continental crust is estimated to have an average 26 Mg of –0.24 ±0.07, which is similar to the average of the mantle. The large Mg isotopic variation in the continental crust reflects the combination of several processes, such as continental weathering, involvement of supracrustal materials in the deep crust, and fluid metasomatism.
    Print ISSN: 0003-004X
    Electronic ISSN: 1945-3027
    Topics: Geosciences
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  • 9
    Publication Date: 2015-11-19
    Description: The Mg isotopic compositions of garnet and clinopyroxene mineral separates and whole rocks from 21 xenolithic eclogites (11 low-MgO eclogites and 10 high-MgO eclogites) from the Koidu kimberlite complex, erupted within the Archean Man Shield, Sierra Leone, West Africa, provide new evidence bearing on the origin of cratonic eclogites. Garnet and clinopyroxene in both low-MgO and high-MgO eclogites generally record equilibrium inter-mineral Mg isotope partitioning, with 26 Mg varying from –2.15 to –0.46 in garnets and from –0.49 to +0.35 in clinopyroxenes. Bulk 26 Mg values (–1.38 to +0.05), constructed from garnet and clinopyroxene data, are similar to results from rock powders (–1.60 to +0.17), suggesting that kimberlite infiltration has had negligible influence on the Mg isotopic compositions of the xenoliths. The 26 Mg values of low-MgO eclogites (–0.80 to +0.05) exceed the range of mantle peridotite xenoliths (–0.25 ± 0.04), consistent with the eclogite’s derivation from recycled altered oceanic crust. Similarly variable 26 Mg values in high-MgO eclogites (–0.95 to –0.13), together with their high MgO and low FeO contents, suggest that high-MgO eclogites were produced by Mg-Fe exchange between partially molten low-MgO eclogites and surrounding peridotites. Our study shows that cratonic xenolithic eclogites preserve a record of Mg isotopic compositions produced by low-pressure, surficial isotope fractionations. The recycling of oceanic crust therefore increases the Mg isotope heterogeneity of the mantle.
    Print ISSN: 0091-7613
    Electronic ISSN: 1943-2682
    Topics: Geosciences
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  • 10
    Publication Date: 2018-02-03
    Keywords: Red Cells, Iron, and Erythropoiesis
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
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