Wyniki wyszukiwania - BazTech

1

Rheological properties and stability behaviour of dispersions

Schwarz S., Mende M.

Farby i Lakiery

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2013

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nr 1

12--18

EN

Along with titanium oxides and alumina hydroxides calcium carbonates and china clays are the most important coating pigments in paper and coating industry. They are the main ingredients in coating colours and due to commercial reasons the solid content of such dispersions has to be as high as possible. In high solid dispersions particle particle interaction and interaction between particles and other ingredients differ considerable from the behaviour in dilute state and hence the storage stability of the dispersion could be strongly influenced. Storage stability and sedimentation velocity, respectively, of china clay dispersions were investigated by centrifugal separation analysis related to the rheological behaviour in dependence on solid concentration.

2

Zjawisko zamiany faz w wodno-organicznych dyspersjach plastizolu poli(chlorku winylu)

Makarewicz E., Dobiała I.

Przemysł Chemiczny

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2011

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T. 90, nr 8

1573-1578

3

Advection-dispersion pollutant and dissolved oxygen transport as a part of sewage biodegradation model

Łagód G., Sobczuk H., Suchorab Z.

Environment Protection Engineering

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2009

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Vol. 35, nr 3

305-317

EN

The need to simulate the conditions of transport of the pollutants and the dissolved oxygen in the flux of sewage arises in the modelling of sewage biode´gradation process in gravitational sewer system. In the properly kept sewers, sewage flow velocity is generally uniform, which allows the model describing the pollutant transport to be simplified. The application of further simplifying assumptions, justified by the conditions inside the modelled object, allows us to get the credible results with the acceptable efforts. These simplifications can be considered, depending on the costs of data for model calibration measurement and the numerical calculation costs. The present work is focused on finding the most convenient description of transport and transformation of dissolved and suspended substances by the advection-dispersion formulas, being one-dimensional description of sewage flow. The literature review concerning various treatment of longitudinal dispersion coefficient was presented. The influence of flow conditions in the modelled system on the dispersion coefficient was also shown. Finally, the matrix description of pollutant fraction transport and biodegradation in gravitational sanitation conduit based on advection-dispersion equation, along with the example of numerical procedure, was described.

4

Nanokompozy fenolowe

Ryszkowska J.

Czasopismo Techniczne. Mechanika

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2006

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R. 103, z. 6-M

429-432

PL

Polimery fenolowe otrzymywane w wyniku polikondensacji są porowate. Zmniejszenie ich porowatości i podwyższenie właściwości wytrzymałościowych można uzyskać w wyniku reakcji "in situ" z nanonapełniaczami. W pracy przedstawiono wpływ różnych technik dyspergowania nanonapełniacza na strukturę i właściwości nanokompozytów fenolowych

EN

Fenolic resins are inexpensive materials used as a composite matrix. These polymers obtained in the process of polycondensation are porous. Decreasing their porosity and increasing their durability can be achieved using in situ polymerization method with nanofillers. As a part of this research the influence of various techniques of nanofillers dispersion on the structure and properties of these nanocomposites was investigated.

5

Contact problem, novel polymer structure used in drilling mud to minimise formation damage

Kherfellah N., Bekkour K., Benhadid S.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, Spec. is

139-144

EN

A laboratory study has been undertaken to elucidate the influence of structural parameters of polymer/electrolyte systems commonly used for the formulation of water-based drilling fluids on their performances as filtrate reducers or viscosifiers.High temperatures and salt conditions encountered in the well may modify the rheological properties and this makes the use of polymers necessary. High molecular weight polymers (XC, gums, polyacrylamides, have been used in the formulation of water-based drilling fluids for reducing filtration, facilitating clay stabilisation, improving débris suspension capacity and drillstring lubrication in the drilling operation. The rheological behaviour has been modelised. The modele describe structural changes under shear or at rest as well as the associated stress growth makes it an attractive tool to use in order to improuve hydraulic predictions in drilling.

6

Rheological characterization of water-based drilling muds

Kherfellah N., Bekkour K., Benhadid S.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

339-344

EN

The thixotropic properties of the bentonite dispersions were analysed by the use of an approach derived from a Moore-Cheng model in which a single structure parameter 'lambda' varies within the range 0=<'lambda'<1. 'lambda'=0 corresponds to the complete break-down of structure at high shear rates, and 'lambda'=1 to the equilibrium gel structure at rest. In our method the Casson model (which was found to fit adequately the flow curves) was modified to incorporate the effect of changes in the structure parameter 'lambda'. This model was able to describe adequately the time-dependent behaviour of clay dispersions. Creep flow tests give indications about the elastic properties of the material. It was found that the viscoelastic behaviour of the bentonite dispersions could be represented by the generalised Kelvin-Voigt mechanical.