Library

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
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 67 (2002), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Moistened (25% to 30% total basis) starches were processed on a pre-shearing rheometer under controlled conditions of temperature, residence time, and shear rate. The specific mechanical energy (30 to 1000 J.g-1) was measured and starch transformations assessed. The conversion of compacted native starch into a suspension of granule fragments in a melt was modeled by a simplified energy balance of the shearing zone. A theoretical fragmentation mechanism was proposed with a critical fracture energy of 125 J.m-2. The computed mechanical energy and time necessary for achieving this transition varied in agreement with experimental results, for different operating conditions and starch botanical origins. Interparticle friction influenced granule fragmentation, whereas crystal melting was associated with viscous dissipation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 54 (1989), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A model based on solving thermal balance and Stokes equation in a corotating twin-screw extruder with deep screw channels was developed. The present stage of the model described the evolution of temperature in the conveying section and the isothermal evolution of pressure in the melt pumping and reverse screw elements, with a Newtonian viscosity adapted to each part of the screw; residence time distribution in the whole extruder was also computed. Experimental validation was carried out on a pilot scale twin-screw extruder CLEXTRAL BC 45 fed with maize starch. Good agreement was found between the theoretical and actual temperature and pressure profiles, as well as with residence time distribution. In standard operating conditions (30 kg/hr, 200 rpm), the pressure generation in one C-shaped chamber was computed to be about 2.2 MPa, while pressure drops were about 0.3 MPa (intermeshing zone) and 0.5 MPa (reverse screw element) while the major part of the residence time per unit of screw length was spent in the reverse screw element.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 53 (1988), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model of the flow of molten starch through the reverse screw element of a twin screw extrusion-cooker was proposed. The assumptions included isothermicity, Newtonian flow in each part of the reverse screw element and quasi-steady geometry. The theoretical approach is based on solving Stokes equations in the direct screw element and then on writing flow rate conservation in each part of the reverse screw element. The various flow rates, the pressure drop and the residence time distribution through the reverse screw element were computed for a CLEXTAL BC 45 twin screw extruder under different operating and geometrical conditions; good agreement was found when comparing these results with previous experimental work. The pressure drop through the reverse screw element was low (0.5–1.0 MPa); the flow rates in the different channels of the reverse screw element were important compared to the total feed rate of the extruder (two to three times larger) which might explain the broadening of the residence time distribution in the reverse screw element.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Flow cytometry with the specific monoclonal antibody (MoAb) L31 was used to analyse the expression of HLA class I heavy chains not bound with β2-microglobulin (β2m) by neuroblastoma (NB) cell lines IMR-32 and LA-N-1. The cells, which express barely detectable amounts of β2m-free (L31-positive molecules) and β2m-complexed HLA class I antigens (W6.32- and BBM. I-reactive molecules), expressed MHC class I molecules not bound to light chains upon differentiation with either retinoic acid or serum starvation. The expression was not accompanied by an increase of surface heterodimers. Conversely, recombinant interferon-γ (rIFN-γ) treatment led IMR-32 and LA-N-1 cells to almost exclusively express β2m-complexed HLA class I heavy chains. Surface β2m-free MHC class I molecules displayed a molecular mass of ~45 kDa and did not bind exogenously added β2m. No changes in the synthesis of either HLA class I and β2m mRNAs or of L31 proteins were observed in differentiated NB cells, thus suggesting that the surface exposure of unusual HLA class I antigens is regulated post-translationally. These findings indicate that, in addition to activated lymphocytes, the surface expression of β2m-free class I heavy chains is a feature of other cell types, such as NB cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Human genetics 〈Berlin〉 49 (1979), S. 327-332 
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The frequencies of chromosome lesions were determined on 3537 mitoses in samples of varying sizes from cultures of 25 amniotic fluid specimens taken from patients at cytogenetic risk. The average percentage values of aberrant cells, including and excluding gaps, were 12.5 and 4.9, respectively. The corresponding values for fibroblasts and peripheral blood lymphocytes from normal adult donors, calculated under the same laboratory conditions, were 5.0 (including gaps) and 2.4 (excluding gaps) and 2.4 (including gaps) and 1.0 (excluding gaps), respectively. The hypothesis of a correlation between the increased incidence of chromosome lesions and the occurrence of abnormal karyotypes in amniotic fluid cell cultures is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...