Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989  (4)
  • 1980-1984  (6)
  • 1
    Electronic Resource
    Electronic Resource
    Analysis of the complex-dissociation model for free-radical copolymerization (1983)
    s.l. : American Chemical Society
    Macromolecules 16 (1983), S. 1295-1300 
    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/ma00242a008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Analysis of the mechanism of copolymerization of styrene and acrylonitrile (1982)
    s.l. : American Chemical Society
    Macromolecules 15 (1982), S. 960-966 
    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/ma00232a004
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    O'Brien, "A Character of Hugh Legaré" (Book Review) (1987)
    State College, Miss. : Periodicals Archive Online (PAO)
    Mississippi Quarterly. 41:1 (1987/1988:Winter) 102 
    Details
    ISSN: 0026-637X
    Topics: English, American Studies
    Notes: BOOK REVIEWS
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:5220-1987-041-01-000010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Thermophysical properties of asbestos-reinforced rubbers (1985)
    Springer
    Journal of materials science 20 (1985), S. 1093-1104 
    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 Factors influencing the sealing characteristics of gaskets made from asbestos-reinforced rubbers include mechanical properties, thermal properties and moisture absorption characteristics. Existing knowledge of the temperature dependence of the mechanical behaviour has been augmented by investigations of the specific heat capacity, thermal expansion and thermal conductivity at temperatures up to 250° C, as well as moisture absorption characteristics at ambient temperature of as-prepared and thermally cycled material. The measurements have provided an insight into thermally induced structural changes within the matrix, which are relevant to component operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585754
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The high resolution 13C NMR spectrum of poly(N,N′-bis(phenoxyphenyl) pyromellitimide), (Kapton) (1984)
    Springer
    Polymer bulletin 12 (1984), S. 319-325 
    Details
    ISSN: 1436-2449
    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: Summary The high resolution 13C NMR spectrum of Kapton in sulfuric acid solution is reported. Assignments to the spectrum were made by comparison with non-proton-decoupled spectra, and with improved solid-state spectra. The solid-state spectrum of the reprecipitate from a H2SO4 solution showed that no change in the chemical structure of Kapton occurred during dissolution, but that the regular morphology present in the original film had been disrupted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263146
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Determination of H-crosslinks in γ-irradiated polybutadiene by 13C-NMR (1985)
    Springer
    Polymer bulletin 14 (1985), S. 339-346 
    Details
    ISSN: 1436-2449
    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: Summary The solid-state 13C NMR spectra of a 99% cis-1,4-polybutadiene after γ-irradiation at 25°C showed a reduction in the intensity of the -CH=resonance at 130.1 ppm and the development of a broad resonance at 45.8 ppm due to H-crosslinks. The -CH2-signal comprises the original narrow resonance at 28.2 ppm due to -CH2-groups remote from crosslinks, and a broad resonance centred at 30.5 ppm attributable to -CH2-groups adjacent to crosslinks. There was an increase in the intensity of the -CH2-resonance at 33.6 ppm due to trans -CH2-groups resulting from radiation-induced isomerization. Quantitative determinations of (i) the decrease in -CH= and (ii) the increase in crosslinked carbon atoms both gave G values of about 14 after 3 MGy. The crosslinks are evidently located in clusters, since literature G(X) values derived from gel contents and swelling ratios range from 3 to 6. The high G(X) value from NMR is consistent with a chain reaction for the crosslinking process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00254958
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Anionic copolymerization of butadiene and isoprene: Applicability of the terminal model to high conversion (1983)
    Springer
    Polymer bulletin 9 (1983), S. 292-298 
    Details
    ISSN: 1436-2449
    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: Summary The compositions of copolymers of butadiene (B) and isoprene (I), produced by anionic copolymerization with sec-butyl lithium initiator in hexane at 20–40°C gave a good fit at low conversions to the terminal model for copolymerization. Non-linear, “best estimates” of the reactivity ratios rB and rI were 2.82 and 0.42, 1.72 and 0.36, 2.18 and 0.35 at 20, 30 and 40°C. The rates of copolymerization at conversions up to 98% of total monomer gave a smooth relationship with the instantaneous feed composition, calculated using the terminal model, at each temperature and independent of the initial feed composition. These results are in accord with the terminal model being applicable to this anionic copolymerization from low to hiqh conversions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00262721
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Prolonged radionuclide transit in “nutcracker esophagus” (1983)
    Springer
    Digestive diseases and sciences 28 (1983), S. 775-779 
    Details
    ISSN: 1573-2568
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Symptomatic patients with abnormal esophageal manometry characterized by esophageal peristaltic waves of increased amplitude (“the nutcracker esophagus,” NE) have been recognized with increasing frequency. Whether or not this represents a true functional abnormality is unresolved at this time. We have utilized radionuclide transit (RT), a true esophageal function test, to evaluate patients with NE. Eighteen consecutive symptomatic patients with the NE and ten clinically and manometrically normal subjects constituted this study group. RT in normals were 6.8±0.2 sec ( $$\bar X$$ ±Se) and 27.6±3.8 in patients with NE. RT was abnormal in 17/18 patients with NE. Chaotic bolus transit was seen in 11/18 patients with NE but not in normals. The defect was localized to the distal esophagus since transit through the proximal esophagus was not significantly different between the two groups. This defect in RT may be related to spontaneous simultaneous contractions seen in 50% of these patients. Further work will be necessary to determine if NE is a true functional abnormality or a marker for other motility abnormalities such as diffuse esophageal spasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01296898
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Daphnia size structure, vertical migration, and phosphorus redistribution (1987)
    Springer
    Hydrobiologia 150 (1987), S. 185-191 
    Details
    ISSN: 1573-5117
    Keywords: Daphnia ; diel cycle ; excretion ; migration ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The timing and magnitude of diel migration in two daphnid assemblages were determined from a series of vertical profiles of daphnid size distribution. Animals were collected concurrently for gut fullness determination. Only large daphnids (〉 1.4 mm) migrated, but these animals could account for substantial vertical and diel differences in phosphorus excretion rate. Gut fullness measurements and time courses of diel vertical migration suggested that large Daphnia can cause a net downward flux of phosphorus during summer in thermally stratified lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00006666
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A simplified data treatment for dead-end and high conversion polymerization kinetics (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 241-244 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A simplified approximation method for the treatment of dead-end and high conversion polymerization kinetics is presented. The method is based on the treatment of dead-end polymerization first described by Tobolsky. In appropriate circumstances, by contrast with Tobolsky's method, this method provides measurements of kd and kp/kt1/2 without recourse to the measurement of the monomer conversion at infinite time.Kinetic studies of free radical polymerizations are normally confined to measurements of initial rates. At low conversions the predictions of the general mechanism for chain-growth polymerization involving initiation, propagation, and termination steps are generally obeyed. Thus the polymerization rate should be first order in the vinyl monomer and half-order in the initiator concentrations.At high conversions, however, large deviations which can be ascribed to various effects can occur; for example, (1) the effect of the increasing viscosity of the polymerization medium on the termination rate constant kt, and possibly also on the propagation rate constant kp, which have been considered by North1 and Cardenas and O'Driscoll,2 or (2) depletion of the initiator as the polymerization progresses. This depletion will occur in all polymerizations but its significance will depend on the magnitude of the rate constant for initiator decomposition (kd) and the period of polymerization. Appropriate conditions will lead to limiting monomer conversion even after infinite polymerization time; this phenomenon has been called dead-end polymerization by Tobolsky.3Free radical polymerizations to high conversion are particularly important in the industrial context when initial kinetics are obviously inadequate. Suitable treatment of the conversion/time relationship is highly desirable.Senogles and Woolf4 have examined the polymerization of n-lauryl methacrylate at 60°C with 2-azobisisobutyronitrile as initiator under dead-end conditions.Here we propose a modification of Tobolsky's treatment of such polymerizations by using an approximation for the exponential decay in the initiator concentration. This method permits easy manipulation of the experimental data and the estimation of values for the kinetic parameters in favorable circumstances without recourse to the measurement of the conversion at infinite time or the evaluation of complicated functions of the monomer conversion. The method thus allows the duration of the laboratory experimentation to be significantly shortened and the complexity of the subsequent data analysis to be considerably reduced.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.170200126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...