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  • 1
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    (Table 2) Oxygen isotope composition of authigenic and detrital phosphates from ODL Leg 201 sites (2010)
    PANGAEA
    In:  Supplement to: Jaisi, Deb P; Blake, Ruth E (2010): Tracing sources and cycling of phosphorus in Peru Margin sediments using oxygen isotopes in authigenic and detrital phosphates. Geochimica et Cosmochimica Acta, 74(11), 3199-3212, https://doi.org/10.1016/j.gca.2010.02.030
    Details
    Publication Date: 2024-01-09
    Description: Many (bio)geochemical processes that bring about changes in sediment chemistry normally begin at the sediment-water interface, continue at depth within the sediment column and may persist throughout the lifetime of sediments. Because of the differential reactivity of sedimentary phosphate phases in response to diagenesis, dissolution/precipitation and biological cycling, the oxygen isotope ratios of phosphate (d18OP) can carry a distinct signature of these processes, as well as inform on the origin of specific P phases. Here, we present results of sequential sediment extraction (SEDEX) analyses combined with d18OP measurements, aimed at characterizing authigenic and detrital phosphate phases in continental margin sediments from three sites (Sites 1227, 1228 and 1229) along the Peru Margin collected during ODP Leg 201. Our results show that the amount of P in different reservoirs varies significantly in the upper 50 m of the sediment column, but with a consistent pattern, for example, detrital P is highest in siliciclastic-rich layers. The d18OP values of authigenic phosphate vary between 20.2 per mil and 24.8 per mil and can be classified into at least two major groups: authigenic phosphate precipitated at/near the sediment-water interface in equilibrium with paleo-water oxygen isotope ratios (d18Ow) and temperature, and phosphate derived from hydrolysis of organic matter (Porg) with subsequent incomplete to complete re-equlibration and precipitated deeper in the sediments column. The d18OP values of detrital phosphate, which vary from 7.7-15.4 per mil, suggest two possible terrigenous sources and their mixtures in different proportions: phosphate from igneous/metamorphic rocks and phosphate precipitated in source regions in equilibrium with d18Ow of meteoric water. More importantly, original isotopic compositions of at least one phase of authigenic phosphates and all detrital phosphates are not altered by diagenesis and other biogeochemical changes within the sediment column. These findings help to understand the origin and provenance of P phases and paleoenvironmental conditions at/near the sediment-water interface, and to infer post-depositional activities within the sediment column.
    Keywords: 201-1227; 201-1228; 201-1229; COMPCORE; Composite Core; DEPTH, sediment/rock; Event label; Joides Resolution; Leg201; Mass spectrometer Finnigan Delta Plus XL; Ocean Drilling Program; ODP; South Pacific Ocean; δ18O, phosphates, authigenic; δ18O, phosphates, detrital; δ18O, standard deviation
    Type: Dataset
    Format: text/tab-separated-values, 90 data points
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    DATA PANGAEA
  • 2
    Electronic Resource
    Electronic Resource
    Radical Vinyl Polymerization. Reactions of Benzoyl Peroxide during Bulk Polymerization of Styrene with Labeled Initiator (1977)
    s.l. : American Chemical Society
    Macromolecules 10 (1977), S. 1075-1080 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma60059a035
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  • 3
    Electronic Resource
    Electronic Resource
    Structure and 900 ^oC hot corrosion behavior of chromium-modified platinum aluminide coatings
    Amsterdam : Elsevier
    Surface & Coatings Technology 36 (1988), S. 13-26 
    Details
    ISSN: 0257-8972
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0257-8972(88)90132-6
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  • 4
    Electronic Resource
    Electronic Resource
    Temporal response of a SF"6 saturable absorber to short pulses of CO"2 laser at 10.6μm
    Amsterdam : Elsevier
    Infrared Physics 33 (1992), S. 531-537 
    Details
    ISSN: 0020-0891
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0020-0891(92)90069-6
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  • 5
    Electronic Resource
    Electronic Resource
    Polymer-Mischlösungsmittel-Systeme. 1. Mitt. Polystyrol in Aceton/Cyclohexan-Mischungen (1979)
    Springer
    Colloid & polymer science 257 (1979), S. 672-672 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01548845
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  • 6
    Electronic Resource
    Electronic Resource
    Studies of toxic effects of Hg(II) on Pistia stratiotes (1985)
    Springer
    Water, air & soil pollution 24 (1985), S. 351-360 
    Details
    ISSN: 1573-2932
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The uptake of Hg(II) and toxicity effect of the metal on some biochemical parameters in Pistia stratiotes L. were studied. The uptake of Hg(II) by the plants gradually increased with increase in concentration of Hg(II) in the culture medium. Maximum accumulation of Hg(II) was noted within 1 day. Maximum removal (about 90%) of Hg(II) was recorded below 20 ppm Hg(II). Accumulation of Hg(II) in roots was about four times higher than that in shoots. At 20 ppm, Hg(II) promoted senescence of Pistia plants by decreasing chlorophyll, protein, RNA, dry weight and activities of catalase and protease as well as increasing free amino acid content, peroxidase activity and the ratio of acid to alkaline pyrophosphatase activity over control values. At Hg concentrations below 20 ppm, these constituents were least affected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00282487
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  • 7
    Electronic Resource
    Electronic Resource
    Studies on tri-n-butyltin methacrylate (TBTM). IV. Antifouling compositions based on copolymers of tri-n-butyltin methacrylate and methyl methacrylate (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 775-783 
    Details
    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: Based on reactivity ratios reported earlier, a number of copolymers of methyl methacrylate and tri-n-butyltin methacrylate has been prepared. Release of tri-n-butyltin oxide into seawater from the copolymer films has been determined at 30°C as a function of time. The copolymers behave in a typical manner - an initial increase in leaching rate followed by a steady state which is reached after about 60 days. Pigmented copolymer films behave in a similar manner, even though the overall leaching rate is slightly lower. Release rate data are also presented for a typical antifouling paint formulation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070340228
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  • 8
    Electronic Resource
    Electronic Resource
    Studies on tributyl tin methacrylate II. Temperature dependence of the polymerization of tributyl tin methacrylate (1982)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 103 (1982), S. 77-85 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In Fortsetzung der früheren Mitteilung berichten wir hier über eine detaillierte kinetische Analyse der Polymerisation von Tributylzinnmethacrylat, initiiert mit Azoisobutyronitril bei Temperaturen von 50-80°C. Es zeigte sich, daß sich der Initiator-exponent mit der Temperatur und Viskosität des Mediums ändert und bei 50°C einen niedrigen Wert von 0,40 erreicht. Dies wurde als Folge des Primärradikalabbruchs erklärt, der in diesem System von Bedeutung ist, besonders bei niedrigen Temperaturen. Die Fließaktivierungsenergie für dieses Monomere ergab sich zu ungefähr 4,2 kcal/mol, was beträchtlich höher als für Methylmethacrylat ist. Die Aktivierungsenergie für die Folgereaktion wurde nach dem Verfahren von Fischer und Schulz bestimmt, sie liegt bei 4,6 kcal/mol, was dem Wert von Methylmethacrylat vergleichbar ist. Die im Vergleich zu anderen Methacrylaten höhere Polymerisationsgeschwindigkeit dieser Monomeren wurde auf die niedrigere Abbruchgeschwindigkeit infolge der sterischen Hinderung und des Viskositätseffektes zurückgeführt. Die Aktivierungsenergie zur Initiierung dieses Monomeren erscheint ziemlich hoch und ist vergleichbar mit den Werten, die für andere Vinylmonomere erhalten wurden.
    Notes: In continuation of the earlier communication, we report here a detailed kinetic analysis of the polymerization of tributyl tin methacrylate initiated by azobisisobutyronitrile at the temperature range of 50-80°C. The initiator exponents are found to vary with temperature and viscosity of the medium reaching a low value of 0.40 at 50°C. This has been explained as due to primary radical termination which is very important in this system particularly at low temperatures. Energy of activation of viscous flow for this monomer is found to be approximately 4.2 kcal/mol which is substantially higher than for methyl methacrylate. The energy of activation for propagation has been determined applying the procedure of Fischer and Schulz and is 4.6 kcal/mol which is quite comparable to that of methyl methacrylate. The faster rate of polymerization of this monomer compared to other methacrylates has been attributed to lower rate of termination because of steric hindrance and viscosity effects. The energy of activation for initiation in this monomer seems to be quite high and comparable to values obtained for other vinyl monomers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1982.051030107
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  • 9
    Electronic Resource
    Electronic Resource
    Studies on the polymerization of tributyl tin methacrylate (TBTM) I (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 80 (1979), S. 137-142 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zinnorganische Polymere bilden eine sehr wichtige Materialklasse, die sich besonders für die Herstellung von Unterwasserschutzanstrichfarben eignet. Über das Polymerisationsverhalten derartiger Monomeren ist jedoch nur wenig bekannt. Es wird ein vorläufiger Bericht über die Polymerisationskinetik von Tributylzinnmethacrylat mit AIBN bei 60°C gegeben. K2w/ka wird zu 3,8 bis 5,7 · 10-1 gefunden, je nach der Effektivität des Starters. Diese Werte liegen erheblich höher als beim entsprechenden Alkylmethacrylat. Die hohe Viskosität des Monomeren (≈ 2,026 cP) erklärt die hohen Werte nur teilweise. Die Polymerisation des Monomeren zeigt Abweichungen vom Idealverhalten: der Initiatorexponent ist für höhere Konzentrationen niedriger als 0,5. Die beobachtete Reaktionsgeschwindigkeit läßt sich aber durch Berücksichtigung eines Primärradikalabbruches sehr gut erklären. Der zugehörige charakteristische Quotient kprt/(kikw) hat die Größenordnung 104.
    Notes: Organo-tin polymers are a very important class of material, useful, particularly for making paints of high anti-fouling life for underwater structures. However, very little is known on the polymerisation behaviour of the respective monomers. In this communication, we present a preliminary report on the kinetics of polymerisation of tributyl tin methacrylate initiated by azo-bis-isobutyronitrile at 60°C. k2p/kt for this monomer is found to be in the range of 3.8 × 10-1 to 5.70 × 10-1 depending on the efficiency of initiation. This value is substantially higher than that of the corresponding alkyl methacrylate. The high viscosity of the monomer (≈2.026 cP) does not fully explain such a high value of k2p/kt. Polymerization of the monomer shows deviations from ideal behaviour in that the initiator exponent falls below 0.5 at high concentrations of initiator. It was found that the rate data could be very well explained on the basis of primary radical termination. The value of kprt/kikp, the characteristic constant of primary radical termination is found to be in the order of 104.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1979.050800110
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  • 10
    Electronic Resource
    Electronic Resource
    Grafting. IV. Graft tercopolymers as antifouling resin (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 1007-1010 
    Details
    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: A graft tercopolymer CLR-g-(MMA-TBTMA) based on chlorinated rubber as the backbone and binary copolymer of methyl methacrylate and tributyltin methacrylate as grafted chains has been synthesized. This graft copolymer has been used for the formulation of controlled-release antifouling paints, and leaching rate behavior of toxin from such paints has been studied. The data have been compared with those obtained using controlled-release antifouling paint based on linear chain copolymer of methyl methacrylate and tributyltin methacrylate. The paint based on grafted copolymer is characterized by having a lower leaching rate and reduced time for attainment of steady-state leaching. Raft exposure studies indicate longer antifouling life compared to that of linear chain copolymer-based paint both having the same dry paint film thickness.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070430519
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