recently, mixtures of clay-tire chips are used as construction material in civil engineering projects. with respect to the tending for using these materials, it is necessary to know their mechanical behavior. thereby, a number of undrained monotonic triaxial tests are carried out on the specimens of pure clay and clay-tire chip mixtures. mixed specimens prepared by mixing pure clay with 10%, 20...

The use of composite structures is increasingly present in civil construction works. Steel-concrete composite beams, particularly, are structures consisting of two materials, a steel section located mainly in the tension region and a concrete section, located in the compression cross sectional area , both connected by metal devices known as shear connectors. The main functions of these connecto...

A shear-free ray congruence on Minkowski space is a 3-parameter family of null geodesics along which Lie transport of a complementary 2dimensional spacelike subspace (called the screen space) is conformal. Such congruences are defined by complex analytic surfaces in the associated twistor space CP 3 and are the basis of the construction of massless fields. On a more general space-time, it is un...

Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed ...

We propose and study a local map capable of describing the full variety of dynamical states, ranging from regular to chaotic, obtained when a nematic liquid crystal is subjected to a steady shear flow. The map is formulated in terms of a quaternion parametrization of rotations of the local frame described by the axes of the nematic director, subdirector, and the joint normal to these, with two ...

By the method of ρ-integration we obtain all Lanczos potentials LABCA′ of the Weyl spinor that, in a certain sense, are aligned to a geodesic shear-free expanding null congruence. We also obtain all spinors HABA′B′ = QABoA′oB′ , QAB = Q(AB) satisfying ∇(A ′HBC)A′B′ = LABCA′ . We go on to prove that HABA′B′ can be chosen so that ΓABCA′ = ∇(A ′HB)CA′B′ defines a metric asymmetric curvature-free c...

Douglas Gough & Michael McIntyre proposed, in 1998, the first global and self-consistent model of the solar tachocline. Their model is however far more complex than analytical methods can deal with. In order to validate their work and show how well it can indeed represent the tachocline dynamics, I report on progress in the construction of a fully nonlinear numerical model of the tachocline bas...

The purpose of this work is to return, with a new observation and rather unconventional point of view, to the study of asymptotically flat solutions of Einstein equations. The essential observation is that from a given asymptotically flat spacetime with a given Bondi shear, one can find (by integrating a partial differential equation) a class of asymptotically shear-free (but, in general, twist...