The mechanical response of a metal–matrix composite to dynamic shearing deformations has been measured, using a new design of the thin-walled tubular specimen for the torsional Kolsky bar experiment that allows working with these difficult-to-machine materials. The advantages of using the new specimen design are as follows: (i) the thickness of the thin wall along the axial direction is very un...

Shear zones geometry in the Paraíba do Sul belt, southeastern Brazil, delineates a NE-trending fan-like structure. Shear zones dip towards SE in the northern limb, and towards NW in the southern one. This geometry has been interpreted either due to transpression or to late folding of flat-lying thrust surfaces. Stretching lineation plunges to ENE-ESE in the northern limb and towards NNE-NE in t...

Mechanical properties of hydrate-bearing sediments (HBS) are crucial for evaluating drilling- and production-induced geo-hazards. However, investigations on mechanical behaviors clayey-silt samples containing hydrate insufficient due to low efficiency in preparing reconstituted samples. Herein, we carried out a series triaxial shear tests analyze the deformation tetrahydrofuran (THF) hydrate. T...

Guide RNAs (gRNAs) are encoded both in the maxicircle and minicircle components of the mitochondrial DNA of trypanosomatid protozoa. These RNAs mediate the precise insertion and deletion of U residues in transcripts of the maxicircle DNA. We showed previously that the old UC laboratory strain of Leishmania tarentolae apparently lost more than 40 minicircle-encoded gRNAs that are present in the ...

Wepresent results from laboratory experiments and anumericalmodel for frictional weakening and shear localization. Experiments document strain localization in sheared layers at normal stresses of 0.5 to 5MPa, layer thicknesses of 3 to 10mm, and imposed slip velocities of 10 to 100 μm/s. Passive strain markers and the response to load perturbations indicate that the degree of shear localization ...

Experiments and simulations reveal that rigid fibers suspended at high concentration in a viscous fluid can be aligned the vorticity direction using shearing flow. Creating alignment requires an oscillatory shear over limited range of strain amplitudes. The suspension must also confined, as only those particles near bounding walls align.

Families of inextensible fibers forming a surface are considered. Each fiber supports a twisting couple proportional to the torsion of the fiber. The strain energy density is written in an additive form, such that the contributions due to shearing, twisting and bending effects are taken into account separately. The equilibrium equations, here obtained, are a particular case of the ones obtained...

A method that gives high recovery of deoxyribonucleic acid (DNA) from crude bacterial lysates using ethidium bromide-cesium chloride density gradient centrifugation is presented. After Pronase digestion and shearing of the lysate, essentially 100% recovery of chromosomal DNA and a reproducible recovery of covalently closed circular (CCC) plasmid DNA is obtained for a specific plasmid in a given...

We present a constitutive model capturing some of the experimentally observed features of soft biological tissues: nonlinear viscoelasticity, nonlinear elastic anisotropy, and nonlinear viscous anisotropy. For this model we derive the equation governing rectilinear shear motion in the plane of the fiber reinforcement; it is a nonlinear partial differential equation for the shear strain. Special...