| 1. |
|
|
| 2. |
- Schreurs, G., et al.
(författare)
-
Analogue benchmarks of shortening and extension experiments
- 2006. - 253
-
Ingår i: <em> </em>Analogue and Numerical Modeling of Crustal-Scale Processes. - : Geological Society of London. - 1862391912 ; , s. 1-27
-
Bokkapitel (refereegranskat)abstract
- We report a direct comparison of scaled analogue experiments to test thereproducibility of model results among ten different experimental modelling laboratories.We present results for two experiments: a brittle thrust wedge experiment and a brittleviscousextension experiment. The experimental set-up, the model construction technique,the viscous material and the base and wall properties were prescribed. However, each laboratoryused its own frictional analogue material and experimental apparatus. Comparisonof results for the shortening experiment highlights large differences in model evolutionthat may have resulted from (1) differences in boundary conditions (indenter or basal-pullmodels), (2) differences in model widths, (3) location of observation (for example, sidewallversus centre of model), (4) material properties, (5) base and sidewall frictional properties,and (6) differences in set-up technique of individual experimenters. Six laboratories carriedout the shortening experiment with a mobile wall. The overall evolution of their models isbroadly similar, with the development of a thrust wedge characterized by forward thrustpropagation and by back thrusting. However, significant variations are observed inspacing between thrusts, their dip angles, number of forward thrusts and back thrusts, andsurface slopes. The structural evolution of the brittle-viscous extension experiments issimilar to a high degree. Faulting initiates in the brittle layers above the viscous layer in close vicinity to the basal velocity discontinuity. Measurements of fault dip angles and faultspacing vary among laboratories. Comparison of experimental results indicates an encouragingoverall agreement in model evolution, but also highlights important variations in thegeometry and evolution of the resulting structures that may be induced by differences inmodelling materials, model dimensions, experimental set-ups and observation location
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Sowman, J., et al.
(författare)
-
Nonlinear model predictive control applied to multivariable thermal and chemical control of selective catalytic reduction aftertreatment
- 2019
-
Ingår i: International Journal of Engine Research. - : SAGE Publications Ltd. - 1468-0874 .- 2041-3149. ; 20:10, s. 1017-1024
-
Tidskriftsartikel (refereegranskat)abstract
- Manufacturers of diesel engines are under increasing pressure to meet progressively stricter NO x emission limits. A key NO x abatement technology is selective catalytic reduction in which ammonia, aided by a catalyst, reacts with NO x in the exhaust stream to produce nitrogen and water. The conversion efficiency is temperature dependent: at low temperature, reaction rates are temperature limited, resulting in suboptimal NO x removal, whereas at high temperatures, they are mass transfer limited. Maintaining sufficiently high temperature to allow maximal conversion is a challenge, particularly after cold start, as well as during conditions in which exhaust heat is insufficient, such as periods of low load or idling. In this work, a nonlinear model predictive controller simultaneously manages urea injection and power to an electric catalyst heater, in the presence of constraints.
|
|
| 8. |
|
|
| 9. |
- Cruden, A.R., et al.
(författare)
-
Diapiric basal entrainment of mafic into felsic magma.
- 1995
-
Ingår i: Earth and Planetary Science Letters. - 0012-821X. ; 131:3-4, s. 321-340
-
Tidskriftsartikel (refereegranskat)abstract
- One consequence of partial melting of the lower crust by heat transfer from a mantle-derived underplate is that the resultant buoyant, felsic magma layer (density ϱ2, viscosity μ2, thickness h2) will overllie a denser mafic layer (density ϱ3, viscosity μ3, thickness h3, which can be fully liquid to completely solid, depending on its thermal history. Laboratory experiments and finite-difference numerical models have been used to determine the conditions that favour the entrainment of the mafic layer into the overlying felsic magma as it ascends diapirically. Large amounts of entrainment occur when (where ϱ1 is the density of the crust), , and . When these conditions occur, the buoyancy and viscous effects acting to maintain the stability of the felsic-mafic layer interface are minimized. The role of m is much more important in the diapiric entrainment phenomenon than in the comparable problem of axial withdrawal from a density- and viscosity-stratified magma chamber with rigid walls.Favourable conditions for entrainment are likely to occur during the evolution of many lower crustal felsic magma source regions with a mafic underplate. Low amounts of entrainment result in minimal interaction (i.e., mixing) between the felsic host and entrained mafic material. If a large amount of entrainment occurs, our models combined with other studies show that mafic magma can remain in the centre of the conduit (low to high Reynolds number (Re), m ≈ 1), become fully mixed with the felsic host (high Re, low m), or become encapsulated by the felsic magma (low Re, m < 0.6). Such mechanical processes may account for the textural and compositional complexity shown by some plutons.
|
|
| 10. |
|
|
