ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • 1
    Electronic Resource
    Electronic Resource
    An optical microscope for the study of biopolymer solutions under shear field (2001)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 4252-4260 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Recently, it has been found that some biopolymer solutions show aggregate formation or shear-induced mixing when they are exposed to shear field. An optical microscope was constructed for the study of these behaviors. A phase-contrast microscope is installed to obtain clear images from sample solutions where the refractive index difference of the domains is too small to be observed with common bright field microscopes. A modular type is adopted for the design of microscope for easy adjustment of optical components, alignment, and positioning it to the sample compartment. As a light source, a strobe type flash lamp is employed and its ignition is synchronized with a charge coupled device camera to avoid yielding smeared images. Shear fields are generated by a cone and plate geometry that is directly attached to a microstepper motor with a controllable simple shear rate range of 0.025–2500 s−1. In the case of oscillatory shear, accessible range is 0–120 rad/s. A dual temperature controller allows temperature control of the sample compartment from ambient temperature to 200 °C with ±0.1 °C accuracy. Several starch solutions were used to demonstrate the performance and capability of the instrument. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1412263
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effect of Starch Granule Size on Viscosity of Starch-Filled Poly(hydroxy ester ether) Composites (2000)
    Springer
    Journal of polymers and the environment 8 (2000), S. 145-150 
    Details
    ISSN: 1572-8900
    Keywords: Starch ; particle size ; composite ; viscosity ; polyester
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The effect of starch granule size on the viscosity of starch-filled poly(hydroxy ester ether) (PHEE) composites was characterized using size-fractionated potato starch, as well as unfractionated starches (rice, corn, wheat, and potato). Potato starch was separated using an air classifier into four particle size fractions: 〈18 μm, 18-24 μm, 24-30 μm, and 〉30 μm. The starch was dried to a moisture content of 0.5% to minimize moisture effects on composite rheology. PHEE and potato starch were extruded with starch volume fractions of 0.46 and 0.66. Stress relaxation, frequency and strain sweep, and temperature-dependence measurements were carried out. Although small variations in viscosity were seen with the different potato starch fractions, differences were not significant at a volume fraction of 0.46. Viscosity differences between the different particle size fractions were more pronounced at a volume fraction of 0.66. The temperature dependence could be described by an Arrhenius relation, with an apparent activation energy of 84 kJ/mole. At a volume fraction of 0.46, the starch/PHEE viscosities increased in the order potato starch 〈 wheat starch ≃ corn starch 〈 rice starch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1014829916940
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Processing and mechanical properties of biodegradable Poly(hydroxybutyrate-co-valerate)-starch compositions (1995)
    Springer
    Journal of polymers and the environment 3 (1995), S. 97-105 
    Details
    ISSN: 1572-8900
    Keywords: Poly(hydroxybutyrate-co-valerate) ; starch ; blends ; processing ; mechanical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Poly(hydroxybutyrate-co-valerate) (PHBV) is a completely biodegradable thermoplastic polyester produced by microbial fermentation. The current market price of PHBV is significantly higher than that of commodity plastics such as polyethylene and polystyrene. It is therefore desirable to develop low-cost PHBV based materials to improve market opportunities for PHBV. We have produced low-cost environmentally compatible materials by blending PHBV with granular starch and environmentally benign CaCO3. Such materials can be used for specific applications where product biodegradability is a key factor and where certain mechanical properties can be compromised at the expense of lower cost. The inclusion of granular starch (25 wt%) and CaCO3 (10 wt%) in a PHBV matrix (8% HV, 5% plasticizer) reduces the cost by approximately 40% and has a tensile strength of 16 MPa and flexural modulus of 2.0 Gpa, while the unfilled PHBV/plasticizer matrix has a tensile strength of 27 MPa and a flexural modulus of 1.6 GPa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02067485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Rheology of thermoplastic starch: Effects of temperature, moisture content, and additives on melt viscosity (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 202-210 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 melt viscosity of thermoplastic starch has been investigated as a function of temperature, moisture content, and processing conditions. The effects of various low molecular weight additives have also been studied. Starch melts exhibit power law behavior over the range of shear rates studied. Melt viscosity decreased with increasing temperature and moisture content (MC). The power law index m increased with increasing temperature. The consistency K decreased with increasing temperature and increasing moisture content. Moisture content during the pelletizing step influenced melt viscosities measured after equilibration to different MCs. All additives studied except glycerol monostearate (GMS) significantly lowered the melt viscosity of starch, some more effectively than water relative to starch with 15% MC. Starch with GMS had viscosities essentially the same as, or slightly higher than, starch/water. This behavior may be due to the presence of unmelted helical inclusion complexes of starch and GMS. Starch formulations at 160°C exhibited melt visocosities similar to an LDPE of melt index 1.8.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760350214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Water sorption and diffusion in starch/polyolefin blends (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1184-1190 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 kinetics of water sorption by starch filled polyolefins has been investigated using blends of commercial starch masterbatch with low density polyethylene (LDPE), high density PE (HDPE), and copolymers of ethylene with methyl acrylate (EMA), ethyl (EEA), AND n-butyl acrylate (EBA). Transient state diffusion coefficients (D) of water in the blends were determined using Fickian analysis of the initial stages of the sorption isotherms. Measured D values were several orders of magnitude lower than values reported for either pure starch of LIDPE by various investigators. Resin effects on D were on the order DHDPE 〈 DLDPE ≪ DEBA 〈 DEEA 〈 DEMA. The resin effects diminished as the starch content increased. The lower magnitude of D in the blends relative to pure LDPE was attributed to the sorption of water by the dry starch particles, in a manner similar to dual-mode sorption in glassy polymers. Copolymer effects were consistent with reduction in crystallinity caused by the comonomers. The dependence of the diffusion coefficient on starch content was not described by mixing models of heterogeneous systems of percolation theory.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760351409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The role of chain scission in fracture of amorphous polymers (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 2583-2589 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We have investigated the role of chain scission in glassy polymers by monitoring the molecular weight changes induced by microtoming thin slices of monodisperse polystyrenes. The changes in number-average molecular weight allow determination of Nf, the number of bond scissions per unit area. It is found that Nf is independent of initial molecular weight and has the value 6.50 × 1013 scissions/cm2 at room temperature; Nf decreases with increasing temperature, suggesting that chain pullout increases with temperature. The work required to create unit surface area in polystyrene is several orders of magnitude greater than the energy required to break Nf bonds, indicating that plastic deformation plays a major role in deformation and fracture of glassy polymers.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1986.090241114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Mechanical properties of LDPE/granular starch compositesThe mention of firm names or trade products does not imply that they are endorsed or recommended by the U. S. Department of Agriculture over other firms or similar products not mentioned. (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 54 (1994), S. 1685-1695 
    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: The mechanical properties of composites of granular starch and low density polyethylene (PE) have been studied as functions of starch volume fraction φ, granule size, and presence of compatibilizer. Property-volume fraction relationships were interpreted using various theories of composite properties. The dependence of elongation (∊ ∼ φ1/3) and tensile strength (σ ∼ φ2/3) agree with theoretical predictions, although the proportionality constants are less negative than theoretical values. The addition of compatibilzer (ethylene-co-acrylic acid copolymer, EAA) did not significantly affect the elongation or tensile strength, but significantly increased the composite tensile modulus. The cornstarch/PE moduli could be described by the Kerner or Halpin-Tsai equations. Analysis of the composite moduli data using the Halpin-Tsai equation allowed the estimation of the modulus of granular starch. The value obtained, 15 GPa, is considerably greater than most unfilled synthetic polymers of commercial importance, but significantly lower than the modulus of cellulose. It is also greater than a previously reported value of 2.7 GPa. © 1994 John Wiley & Sons, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070541112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    facet.materialart.
    Unknown
    Structural basis of toxicity and immunity in contact-dependent growth inhibition (CDI) systems (2012)
    National Academy of Sciences
    Details
    Publication Date: 2012-12-10
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Static and Dynamic Solution Properties of Corn Amylose inN,N-Dimethylacetamide with 3 LiCl (2000)
    American Chemical Society
    Details
    Publication Date: 2000-05-01
    Print ISSN: 0024-9297
    Electronic ISSN: 1520-5835
    Topics: Chemistry and Pharmacology , Physics
    Published by American Chemical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Preparation of Acetonides from Soybean Oil, Methyl Soyate, and Fatty Esters (2011)
    American Chemical Society
    Details
    Publication Date: 2011-04-13
    Print ISSN: 0021-8561
    Electronic ISSN: 1520-5118
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Published by American Chemical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...