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  • 1
    Electronic Resource
    Electronic Resource
    Relationship between directed visual attention and saccadic reaction times (1988)
    Springer
    Experimental brain research 73 (1988), S. 546-552 
    Details
    ISSN: 1432-1106
    Keywords: Attention ; Fixation ; Saccades ; Saccadic reaction times
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Saslow (1967) and Fischer and Ramsperger (1984) found that saccadic reaction time (SRT) depends on the interval between the fixation point offset and the target onset. Using a continuously visible fixation point, we asked whether a similar function would be obtained if subjects attended to a peripherally viewed point extinguished at variable intervals before or after the target onset. The interval was varied between -500ms (i.e., attention stimulus offset after saccade target onset = overlap trials) and 500ms (i.e., attention stimulus offset before saccade target onset = gap trials). The results show a constant mean SRT of about 240 ms for overlap trials, and a U-shaped function with a minimum of 140 ms, at a gap duration of 200 ms, for gap trials. These findings suggest that saccadic latencies do not depend on the cessation of fixation per se, but rather on the disengagement of attention from any location in the visual field. The time required for subjects to disengage their attention is approximately 100 ms. This disengaged state of attention — during which short latency (express) saccades can be made — can be sustained only for a gap duration of 300 ms. At longer gap durations mean SRTs increase again.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406613
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  • 2
    Electronic Resource
    Electronic Resource
    Effects of reappearance of fixated and attended stimuli upon saccadic reaction time (1990)
    Springer
    Experimental brain research 81 (1990), S. 318-324 
    Details
    ISSN: 1432-1106
    Keywords: Attention ; Fixation ; Saccadic reaction time Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of visual attention and fixation upon the distribution of saccadic latencies: express (E-), fast regular (FR-), and slow regular (SR-) saccades were investigated. Extinguishing a fixation or an attention point 200–300 ms before target onset increases the incidence of E-saccades while concurrently decreasing the proportion of SR-saccades. Since this extinction forces a disengaging of attention, these changes in relative proportions of saccades reflect the elimination of one of the steps involved in programming saccades. It is shown that a previously attended stimulus has a favored status relative to other stimuli in the visual field. If, after being turned off, the previously attended fixation point or a peripheral attention stimulus is turned on near the time of the target's appearance, the occurrence of the E-saccades is greatly reduced. However, the appearance of any other stimulus in the visual field at or near the time of the target onset does not inhibit E-saccades. Contrary to the conclusions reached by Posner and Cohen (1984), a stimulus presented at the formerly attended location can attract attention more efficiently than a stimulus presented at another, new location.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228122
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  • 3
    Electronic Resource
    Electronic Resource
    Berichte über Tagungen und Messen (1972)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 3 (1972), S. 98-103 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19720030212
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  • 4
    Electronic Resource
    Electronic Resource
    Beiträge zur Untersuchung der Korrosion An Modellwerkzeugstählen für kunststoffverarbeitende MaschinenMitteilung aus dem Deutschen Kunststoff-Institut, Darmstadt (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 31-38 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Contributions to the Study of the Corrosion on Models of the Alloy Steels for Plastic Processing MachinesThe corrosion on the alloy steels 9 S 20 K and 165 X CrMoV 12 during processing of glassfiber reinforced and non-reinforced plastic melts of styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-butadiene-copolymer and polycarbonate were tested. The volatile compounds evolved during injection molding were condensed and analysed by means of gas-chromatography (GC), gas-chromatography-mass-spectroscopy (GC-MS) and nuclear-magnetic-resonance (NMR). They mainly consisted of hydrocarbons and monomers form the degraded plastics. Because of the absence of water, electrochemical corrosion need not be considered. A mechanism on the basis of chemical reactions between the polymer melt and the steel surface was considered to cause corrosion. By means of scanning electron microscopy differences in the surfaces of the steels corroded with different polymer melts could be observed. Analysis of the surfaces by secundary-ion-mass-spectroscopy (SIMS) resulted in changes being specific for the polymers. On all the corroded steel surfaces high spectral carbon intensities were detected compared with non corroded ones, as well as higher intensities for the steel compounds like chromium, manganese and vanadium. Chemical reactions of these compounds with the polymer melt were considered to cause changes in the lattices of the steel resulting in a change of the properties.
    Notes: Der Verschleiß an den Modellwerkzeugstählen 9 S 20 K und 165 X CrMoV 12 bei der Thermoplastverarbeitung wurde mit den Schmelzen von glasfaserverstärkten und unverstärkten Styrol-Acryl-nitril-Copolymeren (SAN), Polypropylen, Acrylnitril-Butadien-Styrol-Pfropfpolymeren (ABS) und Polycarbonat untersucht. Die beim Spritzgißen freigesetzten flüchtigen Substanzen wurden isoliert und mit Gaschromatographie (GC), Gaschromatographie-Massenspektrometrie (GC-MS) und Kernresonanzspektroskopie (NMR) charkterisiert; es handelt sich vorwiegend um Kohlenwasserstoffe und Monomere der Kunststoffrohstoffe. Aufgrund der nachweislichen Abwesenheit von Wasser kommt eine elektrochemische Korrosion nicht in Betracht, weshalb chemische Reaktionen vorwiegend zwischen Kunststoffschmelze und Stahloberfläche als Korrosionsursache angesehen werden müssen. Mit Hilfe von rasterelektronenmikroskopischen (REM) Untersuchungen wurden Unterschiede zwischen den mit verschiedenen Schmelzen korrodierten Stählen festgestellt. Untersuchungen der Metalloberflächen mit Sekundärionenmassenspektrometrie (SIMS) ergaben kunststoffspezifische Veränderungen. Auf allen korrodierten Stahloberflächen traten im Vergleich zu den unkorrodierten sowohl hohe spektrale Kohlenstoffintensitäten als auch verstärkte Signale von Verbindungen der Stahlbestandteile Chrom, Mangan und Vanadium auf. Die Reaktion dieser Bestandteile mit der Kunststoffschmelze kann als Ursache für Gitteränderungen im Stahl und die damit verbundenen Eigenschaftsänderungen betrachtet werden.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19850160108
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  • 5
    Electronic Resource
    Electronic Resource
    ESCA-Untersuchungen an einer durch PA 6 und PA 6.6 korrodierten CrMoV-Sonderstahloberfläche (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 344-347 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: ESCA-Studies on PA 6 and PA 6.6 Corroded Surface of CrMoV-SteelA CrMoC screw tip of an injection molding machine has been corroded during the processing of glassfibre reinforced polyamide and has been spectroscopically studied in order to determine the chemical modifications of the steel surface. Survey and depth profile ESCA spectra (Electron Spectroscopy for Chemical Analysis) from one segment of the screw tip were measured.In this way chemical changes due to the chemical reactions of polyamide melt with the steel surface up to 2-4 μm depth were determined. The depth and the typ on the surface modifications were found to depend on the corrosion environment (polyamide melt) and on the steel surface composition.The corrosion due to polyamide melt leads to impoverishment both of the chromium and of the manganese in the investigated depth (2-4 μm) of the steel surface.A demage of the extremely hard upperlayer (mainly consisting of Fe2B und FeB) occurs during the processing of the polyamide melt. An enrichment of carbon on the steel surface due to deposits of organic materials from the polyamide melt was found.
    Notes: Eine Spritzgießschneckenspritze aus CrMo V-Sonderstahl, die durch die Verarbeitung mit glasfaserverstärktem Polyamid korrodiert war, wurde spektroskopisch untersucht, um die chemischen Veränderungen auf der Stahloberfläche zu bestimmen. Von einem Segment dieser Spitze wurden mit ESCA (Electron Spectroscopy for Chemical Analysis) Übersichtsspektren und Tiefenprofile angefertigt.So werden chemische Veränderungen, hervorgerufen durch chemische Reaktionen zwischen der Polyamidschmelze under der Stahloberfläche, bis zu Schichttiefen von 2-4 μm nachgewiesen. Tiefe und Art der Korrosionserscheinungen sind vom Korrosionsmedium (Polyamidschmelze) und der Stahlbeschaffenheit abhänging.Die Polyamidschmelzekorrosion führt zur Verarmung sowohl von Chrom als auch von Mangan in den obersten Schichten.Die vorwiegend aus Fe2B (FeB) bestehende, besonders harte Oberflächenschicht wird durch die Verarbeitung der PA-Schmelze abgetragen. Es kommt zur Kohlenstoffanreicherung auf der Oberfläche durch Ablagerungen organischen Ursprungs aus der Polyamidschmelze.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19850161005
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  • 6
    Electronic Resource
    Electronic Resource
    Toughened blends of polystyrene and polybutadiene filled with chalk (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 60 (1996), S. 981-990 
    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: Brittle thermoplastics are hardened and embrittled by mineral fillers and softened and (sometimes) toughnened by elastomers. We investigated the possibility of combining these effects favorably in filled blends of a thermoplastic, polystyrene (PS); an elastomer, poly-butadiene (BR); and a filler, chalk. The success had to be measured in comparison to commercial high-impact polystyrene (HIPS) which is produced by in situ polymerization. At low concentrations of BR, simple blends of PS/BR are tougher than PS itself, but not considerably. This could be improved by adding chalk. The blends PS/BR/chalk feature a core-shell domain morphology, with BR enveloping chalk aggregates on the micrometer scale. At BR contents of less than 10 Vol %, the stress-strain behavior of the filled blends PS/BR/chalk compares well to that of HIPS. The blends exhibit multicrazing with char-acteristic patterns and can be easily without breaking. At higher BR contents, however, the blends go back to brittle failure. © 1996 John Wiley & Sons, Inc.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Photoinduzierte Polymerisation von Methylmethacrylat in Gegenwart von niederund hochmolekularen Chinoxalinderivaten (1975)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 43 (1975), S. 125-143 
    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: The photoinduced polymerization of methyl methacrylate in presence of 2,3-diphenylquinoxaline and 6-acrylamido-2,3-diphenylquinoxaline polymers is investigated. As photoexcited quinoxaline molecules are capable of hydrogen abstraction, which can be followed by hydrogen transfer, the formation of starting radicals in the considered system is referred to a hydrogen transfer from a H-donor to monomer molecules with monohydroquinoxaline radicals as transferring reagent. The polymerization mechanism based on this reaction is confirmed by endgroup analysis of the polymers and by the polymerization kinetics.
    Notes: Die photoinduzierte Polymerisation von Methylmethacrylat in Gegenwart von 2,3-Diphenylchinoxalin und 6-Acrylamido-2,3-diphenylchinoxalin-Polymeren wird untersucht. Aufgrund der Fähigkeit der Chinoxaline, als Wasserstoffüberträger zu wirken, wird angenommen, daß der Start der Polymerisation durch. Radikale erfolgt, die bei der Übertragung von Wasserstoff aus H-Donatoren auf Monomermoleküle entstehen. Dieser radikalische Polymerisationsmechanismus wird durch Endgruppenanalysen der erhaltenen Polymeren und durch die ermittelte Polymerisationskinetik gestützt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1975.050430109
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  • 8
    Electronic Resource
    Electronic Resource
    Isolierung und Charakterisierung von niedermolekularem Polyvinylchlorid (1980)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 89 (1980), S. 111-125 
    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: Using suitable conditions of polymerisation low molecular weight PVC was prepared in CCl4 in the presence of isobutylen. The rate of thermal degradation increased as the molecular weight of the fraction decreased. The heat stability was less when dicyclohexylperoxodicarbonate was used instead of azoisobutyronitrile as an initiator. The substances with the lowest molecular weight were obtained as a colorless liquid by destillation of the polymerisation solvent at 90°C-110°C (10-4 Torr). The analysis of the products revealed the presence of structures which were not identical with those of PVC-homologues with low degree of polymerisation, but combination products of CCl4 and isobutylen.
    Notes: Unter geeigneten Polymerisationsbedingungen wurde niedermolekulares PVC in CCl4 in Gegenwart von Isobutylen hergestellt. Beim thermischen Abbau der fraktionierten, festen Anteile aus dem Polymerisationsansatz nimmt die Abbaugeschwindigkeit mit abnehmendem Molekulargewicht zu. Bei Verwendung von Dicyclohexylper-oxodicarbonat als Initiator gegenüber. Azoisobutyronitril verschlechtert sich die thermische Stabilität merklich. Die Substanzen mit dem niedrigsten Molekulargewicht wurden aus dem bei der Polymerisation verwendeten Lösungsmittel als farblose Flüsigkeit bei 90°C-110°C (10-4 Torr) destilliert. Es handelt sich hierbei jedoch nicht um PVC-Homologe mit niedrigem Polymerisationsgrad; vielmehr konnte mit spektroskopischen Methoden nachgewiesen werden, daß der Hauptanteil des erhaltenen Germisches eine Verbindung ist, die aus der Kombination von Tetrachlorkohlenstoff und Isobutylen entsteht.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1980.050890111
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  • 9
    Electronic Resource
    Electronic Resource
    Influence of plasticizing on the rate of thermal dehydrochlorination of poly (vinyl chloride), (1969)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 9 (1969), S. 186-189 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1969.050090117
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  • 10
    Electronic Resource
    Electronic Resource
    Chemische Untersuchungen zum Abbau vernetzter Phenol-Formaldehyd-HarzeHerrn Prof. Dr. B. Vollmert mit besten Wünschen zum 60. Geburtstag gewidmet (1980)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 92 (1980), S. 169-189 
    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 addition to pyrolysis and degradation with superheated steam the hydrogenolytic degradation of cured phenolic resins induced by hydrogen-donors has been investigated. Especially with 1,2,3,4-tetrahydronaphthalene (tetralin) a considerable amount of transferred hydrogen to the dispersed resin particles, involved with formation of naphthalene, has been observed at 400°C. With total maximal yields of 98 wt.-% (ref. to the initial amount of phenolic resin) of phenol, methyl phenols, and oligomerous phenolic degradation products a recovering of industrial phenolic resin wastes should be possible. Kinetic and scanning electron microscopic investigations are employed to give some mechanistic explanations involving the hydrogenolytic liquefaction of cured phenolic resins.
    Notes: Neben der Pyrolyse und dem Abbau mit überhitztem Wasserdampf wird insbesondere die hydrogenolytische Spaltung ausgehärteter Phenol-Formaldehyd-Harze in Gegenwart von Wasserstoff-Donatoren untersucht. Als H-Donor wird hierbei 1,2,3,4-Tetrahydronaphthalin (Tetralin) eingesetzt, das bei Temperaturen um 400°C unter Wasserstoff-Transfer an die dispergierten Harzpartikel zu Naphthalin rearomatisiert. Bei maximalen Ausbeuten von insgesamt 98 Gew.-% (bez. auf die eingesetzte Harzmenge) Phenol, Methylphenolen und oligomeren phenolischen bruchstücken wird eine Nutzung technischer Phenolharzabfälle unter Gewinnung verwertbarer Spaltprodukte diskutiert. Anhand von Abbau-Kurven und rasterelektronenmikroskopischen Untersuchungen wird auf den Mechanismus der extraktiven hydrogenolytischen Phenolharzverflüssigung eingegangen.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1980.050920114
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