Janssen model

Some of the results of the Janssen model are quite interesting. It was found that a high viscosity of the dispersed phase promotes a finer dispersion due to the delay of thread breakup and coalescence. In general, lower viscosities of either phase result in coarser morphology. Highly viscous systems cannot be dispersed finer than 0.1 micron since coalescence starts to dominate as the drop size reduces much below 1 micron. 

Flows of cohesive granular materials will not be discussed, setting aside the notion of powder flowability whose introduction requires to be complemented by drawing on examples from continuum mechanics. For non-cohesive granular materials, we shall propound a macroscopic approach, which describes phenomena within the framework of continuum mechanics. This approach, with the highly classical Janssen model (1895), enables the silo effect in pressure distribution to be... 

There have been several attempts at models incorporating breakup and coalescence. Two concepts underlie many of these models binary breakup and a flow subdivision into weak and strong flows. These ideas were first used by Manas-Zloczower, Nir, and Tadmor (1982,1984) in modeling the dispersion of carbon black in an elastomer in a Banbury internal mixer. A similar approach was taken by Janssen and Meijer (1995) to model blending of two polymers in an extruder. In this case the extruder was divided into two types of zones, strong and weak. The strong zones correspond to regions... 

Raes (1987) presents the results of additional cluster formation modeling studies based on the methods he presented earlier (Raes, 1985 Raes and Janssens, 1985). These results would suggest that the ultrafine mode is the result of ion-based cluster formation. 

Janssen EM, van Oosterhout AJM, Nijkamp FP, van Eden W, Wauben MHM The efficacy of immunotherapy in an experimental murine model of allergic asthma is related to the strength and site of T cell activation during immunotherapy. J Immunol 2000 165 7207-7214. 

Janssen EM. van Oosterhout AJ, van Rensen AJ. van Eden W. Nijkamp FP. Wauben MH Modulation of Th2 responses by peptide analogues in a murine model of allergic asthma amelioration or deterioration of the disease process depends on the Thl or Th2 skewing characteristics of the therapeutic peptide. J Immunol 2000 164 580-588. 

Recently. Weber and Newman " " introduced a framework for bridging the gap between the Bernard and Verbrugge and the Springer et al. membrane approaches. The membrane model was used in a simple fuel-cell model, and it showed good agreement with experimentally measured water-balance data under a variety of conditions. The fuel-cell model was similar to the model of Janssen. who used chemical potential as a driving force in the... 

Janssens, M.L. 2002. Evaluating Computer Tire Models. Fire Protection Engineering, (13). 

Janssen-Jurkovicova et al. (1994) presented a conceptual model for CCB weathering, which breaks the process into four phases. Figure 2 illustrates their model for weathering of alkaline fly ash (i.e., fly ash producing alkaline water extracts defined as fly ash having Ca/S > 2.5 by Ainsworth Rai 1987), modified using observations of Warren Dudas (1984). In phase 1, oxides and soluble salts present on ash particle surfaces dissolve in contact with water. Hydrolysis of metal oxides (especially CaO) results in a rapid rise of pH to values of approxi-... 

Two different approaches have been taken by researchers to determine the secondary mineralogy of CCBs (1) direct observation, which is accomplished via analysis of weathered ash materials, and (2) prediction, based on chemical equilibrium solubility calculations for ash pore-waters and/or experimental ash leachate or extractant solutions. Because the secondary phases are typically present in very low abundance, their characterization by direct analysis is difficult. On the other hand, predictions based on chemical equilibrium modelling or laboratory leaching experiments may not be reliable indicators of element leachability or accurately indicate the secondary phases that will form under field conditions (Eighmy et al. 1994 Janssen-Jurkovicova et al. 1994). 

Fig. 2. Model for alkaline fly ash weathering (am, amorphous) (modified from Janssen-Jurkovicova et al. 1994).

Some adenosine nucleoside transport inhibitors have been reported to be useful against pain, especially neuropathic pain (animal models) (Meert and van Belle (Janssen Pharm), 1998 Deleo and Schubert, 2000). 

Janssen et al., 1986] Janssen, A. J. E. M., Veldhuis, R., and Vries, L. B. (1986). Adaptive interpolation of discrete-time signals that can be modeled as AR processes. IEEE Trans. Acoustics, Speech and Signal Processing, ASSP-34(2) 317-330. 

The authors thank Rik Moereels (Janssen Research Foundation, Beerse, Belgium) for his direction during the de novo model building stage of the project and Harold Almond, Jr., for helpful discussions. We also thank Marco Ceruso for his advice and analysis of the final receptor model in particular, he examined phi-psi space for angle violations and relaxed the relevant regions through molecular dynamics simulations. 

Snijders, H., Huyghe, J.M., and Janssen, J.D. (1995) Triphasic finite element model for swelling porous media. International Journal for Numerical Methods 20, 1039-1046... 

Figure 8.6. Janssen s model for stress distribution in cylindrical bins (a) Schematic of the forces applied to a differential slice (b) Wall pressure distribution Eq. (8.16).

A simple model for the estimation of stress distribution in cohesionless bulk solids stored in a tall cylindrical bin was presented by Janssen in 1895. The system of consideration is shown in Fig. 8.6(a). In Janssen s model, it is assumed that... 

It should be noted that the stresses in Janssen s model are cross-sectionally averaged. Therefore, Janssen s results in principle are not applicable for local stress analysis. This argument can be clearly shown by the inconsistency of Eqs. (8.15) and (8.16) with the equations of equilibrium. 

Janssen K. P. and Schleicher M. (2001b) Dictyostelium discoideum a genetic model system for the study of professional phagocytes. Profilin, phosphoinositides and the Imp gene family in Dictyostelium. Biochim. Biophys. Acta. 1525, 228-233. 

An excellent historical review and applications of this type of extruder were produced by White (53), and the flow was modeled by Janssen et al. (62) and Wyman (63), whose derivation we follow. The easiest way to visualize the conveying mechanism of a counterrotating intermeshing TSE is to place a robot viewer into the screw channel at point 0 in Fig. 6.37(d) and let it report its observations. We first stop the rotation of the screws and tell our viewer to explore the space around it. It will report that the space is entirely confined by steel walls the barrel surface from above, the flights of screw A at either side, and the intermeshing flight of screw B both up-channel and down-channel. The space is a helically distorted C-shaped channel that can be shown schematically, as in Fig. 6.46, or by molding silicone rubber into the space in Fig. 6.47. Clearly, by fully... 

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