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  • 1
    Electronic Resource
    Electronic Resource
    How does the toad's visual system discriminate different worm-like stimuli? (1991)
    Springer
    Biological cybernetics 64 (1991), S. 251-261 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Behavioral experiments show that toads exhibit stimulus- and locus-specific habituation. Different worm-like stimuli that toads can discriminate at a certain visual location form a dishabituation hierarchy. What is the neural mechanism which underlies these behaviors? This paper proposes that the toad discriminates visual objects based on temporal responses, and that discrimination is reflected in different average neuronal firing rates at some higher visual center, hypothetically anterior thalamus. This theory is developed through a large-scale neural simulation which includes retina, tectum and anterior thalamus. The neural model based on this theory predicts that retinal R2 cells play a primary role in the discrimination via tectal small pear cells (SP) and R3 cells refine the feature analysis by inhibition. The simulation demonstrates that the retinal response to the trailing edge of a stimulus is as crucial for pattern discrimination as the response to the leading edge. The new dishabituation hierarchies predicted by this model by reversing contrast and shrinking stimulus size need to be tested experimentally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00201986
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  • 2
    Electronic Resource
    Electronic Resource
    Creep effect on dynamic visco-elastic properties of polymer matrix composite (1994)
    Springer
    Applied composite materials 1 (1994), S. 125-133 
    Details
    ISSN: 1573-4897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper deals with the creep effect on dynamic visco-elastic properties of short fibre reinforced polymer SMC composite. The vibration-creep-vibration test procedure was applied to examine the influence of creep on dynamic modulus E and loss tangent tgδ of the material. The results show that creep causes appreciable influence on E and tgδ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00567574
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  • 3
    Electronic Resource
    Electronic Resource
    On convergence rate of finite element eigenvalue analysis with mass lumping by nodal quadrature (1991)
    Springer
    Computational mechanics 8 (1991), S. 249-256 
    Details
    ISSN: 1432-0924
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Error bounds are obtained for the finite element eigenvalue analysis using the diagonal mass matrix lumped by nodal quadrature. Finite element results of various two-dimensional 2nd order eigenvalue problems and a one-dimensional 4th order eigenvalue problem are compared favorably with the theoretical predictions. Estimates of error bounds, particularly those for eigenvalues, are significantly improved over the existing results, and their range of applicability is broadened. Special attention has been focused on the cases where shape functions have incomplete polynomials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00577378
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis of flexible polyarylate by interfacial polycondensation (1994)
    Springer
    Journal of polymer research 1 (1994), S. 1-6 
    Details
    ISSN: 1572-8935
    Keywords: Polyarylate ; Bisphenol-A ; Terephthalic acid ; Ethylene glycol ; Interfacial polycondensation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Products with hydroxyl ends were synthesized from the esterification of bisphenol-A, terephthalic acid and ethylene glycol. These ester products were then used for synthesis of polyarylate by interfacial polycondensation. Not only the relative concentrations of reactants for esterification but also the conditions for interfacial polycondensation, such as the monomer ratio between two phases and the reaction time, play significant roles in affecting the properties of final products. Under proper synthesis conditions, the polyarylate formed could possess equivalent thermal characteristics and much higher impact strength in comparison with unmodified polyarylate due to the incorporation of flexible aliphatic segments from ethylene glycol. X-ray diffraction showed the existence of aliphatic segments would induce small degree of orderly alignment locally in structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01378588
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  • 5
    Electronic Resource
    Electronic Resource
    Surface analytical study of the interaction between γ-amino propyl triethoxysilane and E-glass surface (1992)
    Springer
    Journal of materials science 27 (1992), S. 36-48 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Time-of-flight secondary ion mass spectrometry has been used to study the interaction of γ-amino propyl triethoxysilane with an E-glass surface. The fragmentation pattern has been interpreted by assigning a series of mass peaks to the structural unit of the poly(aminosiloxane). The composition of the coating is complicated by the presence of polydimethylsiloxane and its copolymers. The highest mass fragment was obtained from the coating exposed by extraction with warm water (697 AMU). The largest molecular fragments would appear to have degrees of polymerization of 6 with differing numbers of silanol groups. On re-extraction with hot water the fragment size decreased. It is postulated that the network chain length of the three-dimensional polymer decreased as the interface was approached. At the glass surface a chemically bound molecular layer could be identified. The full chemical nature of the deposit is complicated by the incorporation of aluminium from the substrate into the coating. It was also possible to confirm that a layer of warm-water soluble oligomers existed at the air interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00553834
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  • 6
    Electronic Resource
    Electronic Resource
    TOF SIMS and XPS study of the interaction of silanized E-glass with epoxy resin (1993)
    Springer
    Journal of materials science 28 (1993), S. 1396-1408 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The interaction of a silanized E-glass plate surface with the diglycidyl ether of bisphenol S (DGEBS) has been studied using time-of-flight secondary ion mass spectrometry (TOF SIMS) and X-ray photoelectron spectroscopy (XPS). In the TOF SIMS spectra, in addition to a series of ion fragments readily assigned to the parent DGEBS epoxy resin, some new ion fragments attributable to the reaction product of DGEBS with the polymeric hydrolysed γ-aminopropyl triethoxysilane (HAPS) precoating have been observed. In the XPS spectra a mixed coating of HAPS and DGEBS was demonstrated by the presence of intense N1s and S2p peaks. With the previous demonstration that the HAPS deposit is strongly bound to the E-glass plate surface, direct confirmation of the formation of chemical bonds at the E-glasssilane-resin interfaces has been obtained. These conclusions were complicated by the presence of polydimethylsiloxane (PDMS) and the incorporation of aluminium and calcium ions from the HAPS silanized glass plate into the mixed coating of HAPS and DGEBS epoxy resin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01191984
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  • 7
    Electronic Resource
    Electronic Resource
    The role of ε-martensite in the impact toughness of an Fe-17Mn alloy (1994)
    Springer
    Journal of materials science 29 (1994), S. 4399-4403 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of ε-martensite on the cryogenic toughness of an Fe-17 wt% Mn alloy was studied in this work. Alloys were tempered at various temperatures in order to systematically increase the volume fraction of ε-martensite. This was followed by Charpy impact testing conducted at room temperature and at−196°C. The experimental results indicated that although room-temperature toughness was not influenced by the ε-martensite content, the cryogenic toughness was strongly dependent on the volume fraction of ε-martensite. In particular, with the exception of the alloys tempered at 400 and 450°C, the impact toughness consistently increased with ε-martensite content. Microstructural and fractographic evaluations using SEM and TEM suggested that the toughness improvements were attributed to the ε→ α stress-induced martensite transformation. No microstructural evidence was found which could be ascribed to an effect of ε-martensite on the low-temperature embrittlement exhibited by Fe-Mn alloys tempered at 400–450°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414228
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  • 8
    Electronic Resource
    Electronic Resource
    Surface analytical study of the interaction between γ-amino propyl triethoxysilane and E-glass surface (1993)
    Springer
    Journal of materials science 28 (1993), S. 2481-2488 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Angle-resolved X-ray photoelectron spectroscopy (XPS) has been used to study the interaction of hydrolysed γ-aminopropyltriethoxysilane (HAPS) with a flat E-glass slide surface. Formation of a HAPS coating with a thickness of about 6 nm, which consists of three components of differing molecular structure on the glass surface, was confirmed. The results provided further evidence for the incorporation of aluminium ions from the glass substrate into the HAPS coating. At the outer surface, a warm-water-soluble oligomer exists in which the amino group of the HAPS molecule is in the form of a free -NH2. Beneath, there is a three-dimensional graded network whose ends, after extraction with warm water, are involved in an internally hydrogen-bonded structure between the amino and silanol groups, probably in a cyclised conformation. Adjacent to the glass surface, a molecular layer of HAPS remained after extraction with hot water, which was chemically bound to the glass surface through siloxane and/or aluminoxane bonds. The results tend to favour the former with Al(OH)3 copolymerized into the siloxanol deposit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01151683
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  • 9
    Electronic Resource
    Electronic Resource
    Surface analytical study of the interaction between γ-amino propyl triethoxysilane and E-glass surface (1992)
    Springer
    Journal of materials science 27 (1992), S. 36-48 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Time-of-flight secondary ion mass spectrometry has been used to study the interaction of γ-amino propyl triethoxysilane with an E-glass surface. The fragmentation pattern has been interpreted by assigning a series of mass peaks to the structural unit of the poly(aminosiloxane). The composition of the coating is complicated by the presence of polydimethylsiloxane and its copolymers. The highest mass fragment was obtained from the coating exposed by extraction with warm water (697 AMU). The largest molecular fragments would appear to have degrees of polymerization of 6 with differing numbers of silanol groups. On re-extraction with hot water the fragment size decreased. It is postulated that the network chain length of the three-dimensional polymer decreased as the interface was approached. At the glass surface a chemically bound molecular layer could be identified. The full chemical nature of the deposit is complicated by the incorporation of aluminium from the substrate into the coating. It was also possible to confirm that a layer of warm-water soluble oligomers existed at the air interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02403641
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  • 10
    Electronic Resource
    Electronic Resource
    Synthesis of non-nucleotide ATP analogues and characterization of their chemomechanical interaction with muscle fibres (1993)
    Springer
    Journal of muscle research and cell motility 14 (1993), S. 484-497 
    Details
    ISSN: 1573-2657
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To probe the substrate requirements for the actomyosin chemomechanical interaction, the effects of a series of eight new non-nucleotide ATP analogues on actomyosin-catalysed hydrolysis rates and on fibre mechanics have been investigated. These analogues have substitutions of new functional groups at the 2- and 4- positions of the ATP analogues, 2-[(4-azido-2-nitrophenyl)amino]ethyl triphosphate (NANTP), and 3-[(4-nitrophenyl)amino]propyl triphosphate (PrNANTP). Previous work has shown NANTP but not PrNANTP will support active tension and shortening in skinned muscle fibres in a manner almost identical to ATP. Here all 2- and 4- phenyl substituted analogues had myosin subfragment 1 (S1) NTPase hydrolysis rates higher than ATP and the rates were stimulated by addition of actin. In general, the replacement of the 4-azido group of NANTP with-H,-NO2 or-NH2 had small effects on fibre mechanics while replacement of 2-NO2 group with-H or-NH2 dramatically lowered the ability of the new analogues to support active tension and shortening. All PrNANTP-based analogues were ineffective in supporting active tension or shortening. We found no correlation between S1 or actoS1 NTPase rates and any mechanical parameters. However, for all analogues there was a strong correlation between the maximal velocity of shortening (V max) and isometric tension (P o). A three-state, chemomechanical model is proposed in which the analogues effect the transition rate into a strongly-bound, force-producing crossbridge state to account for this correlation. These studies identify 2-[(2-nitrophenyl)amino]ethyl triposphate as the chemically simplest ATP analogue which closely mimics the effect of ATP in skinned muscle fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297211
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