We show experimentally that the sliding friction on sand is greatly reduced by addition of some—but not too much—water. The formation capillary water bridges increases shear modulus sand, which facilitates sliding. Too much water, other hand, makes coalesce, resulting in a decrease modulus; this case, we observe coefficient again. Our results, therefore, directly related to has important repercussions for transport granular materials. In addition, polydispersity shown also have large effect...

The extremely slow compaction dynamics of wet granular assemblies is studied experimentally. cohesion, due to capillary bridges between neighboring grains, tuned using different liquids having specific surface tension values. a cohesive packing obeys an inverse logarithmic law, like most dry random packings. However, the characteristic relaxation time τ grows strongly with cohesion. A model, based on free volume kinetic equations and presence energy barrier, able reproduce quantitatively...

Droplet formation of suspensions is present in many industrial and technological processes such as coating food engineering. Whilst the finite-time singularity minimum neck diameter capillary break-up simple liquids can be described by well-known self-similarity solutions, pinching non-Brownian suspension depends a complex way on particle dynamics thinning thread. Here we focus very dilute regime where filament contains only isolated beads to identify physical mechanisms leading pronounced...

The influence of relative humidity (RH) on the extremely slow compaction dynamics a granular assembly has been experimentally investigated. Millimeter-sized glass beads are considered. Compaction curves fitted by stretched exponentials with characteristic time $\ensuremath{\tau}$ and exponent $\ensuremath{\delta}$, which seen to be deeply affected moisture content. A kinetic model, taking into account both triboelectric capillary effects, is in excellent agreement our results. It confirms...

A comparative study of the solid‐state reaction synthesis cordierite with and without use a flux was performed, varying sintering temperatures between 900° 1400°C. Bi 2 O 3 proved to be useful additive for lowering temperature needed take place. The deviation from ordered β‐cordierite phase analyzed using distortion index Δ as factor merit. values obtained in all compositions showed that tended much‐ordered structure increased temperatures.

We investigated the stress-strain behavior of sand with and without small amounts liquid under steady oscillatory shear. Since dry has a lower shear modulus, one would expect it to deform more easily. Using new technique quasistatically push through tube an enforced parabolic (Poiseuille-like) profile, we minimize effect avalanches localization. observe that resistance against deformation wet (partially saturated) is much smaller than sand, latter dissipates energy flow. This also observed...

An original experiment is introduced that allows students to relate the of a set particles their macroscopic external and constant first applied so self-organize into chains. When removed, then freely diffuse from positions in chain, starting same coordinate on axis perpendicular initial chain. This configuration thus enables an observer study one dimensional process, while also observing underlying microscopic particles. Moreover, by studying evolution particle distribution, coefficient can...

Copper – tungsten functionally graded material has been produced by Cu infiltration of a preform which is self formed through segregation effect in weakly excited bimodal W granular media. Electrical and elastic properties the final materials are strongly influenced microstructural evolution obtained during vibration. The optimal microstructure for electrical consists highly 3-D interconnected phase (skeleton type microstructure), while structure highest E-modulus.

The influence of cohesive forces inside a granular material is analyzed with compaction experiments. To begin, model considered. This made millimetric grains cohesion induced by an external magnetic field. Therefore, the between adjusted through intensity applied Afterward, capillary bridges are In first study concerning forces, neighboring liquid in wet material. cohesiveness tuned using different liquids having specific surface tension values. second performed concerns initially dry...

Vertical movement of zirconia-yttria stabilized 2 mm balls is measured by a laser facility at the surface vibrated 3D granular matter under gravity. Realizations z(t) are from top container tuning fluidized gap with 1D measurement window in direction The statistics obeys Fermi-like configurational approach which tested relation between dispersions amplitude and velocity. We introduce generalized equipartition law to characterize ensemble particles cannot be described terms Brownian motion....

I-V characteristics of a polycrystalline Y-Ba-Cu-O sample rectangular cross section were measured while varying the specimen thickness by successive polishings. The critical current density (Jc) was found to increase with reduction (e). A model based on junctions decoupling due self-magnetic field generated transport is proposed explain our results. For this particular geometry and assuming uniform distribution along sample, magnetic inside calculated. From this, an expression for Jc as...

The Cu/W functionally graded material (FGM) was produced by vibration of W agglomerates in order to obtain the skeleton with a gradient porosity, which after pressureless sintering infiltrated molten Cu. Certain mechanisms are suggested for these complex structures. segregation two different sizes controlled time. Different duration resulted types microstructure: type microstructure shorter time and extended times. final Cu-infiltrated FGMs were characterized microstructurally their...

Abstract We report a study on granular matter with and without small additions of silicon oil, under low-frequency large amplitude oscillatory shear strain constant normal pressure, by running experiments rotational rheometer cup-and-plate geometry. analysed the expansion Chebyshev polynomials orthogonal decomposition stress–strain Lissajous–Bowditch loops. found onset for yielding regime indicated change from filament-like structures grains to grain rearrangements dry granulate oscillations...

A laser facility based on a linear image sensor with sampling period of 100microseconds allows to investigate the dissipative dynamics vibrated granular matter under gravity. The reveals vertical movement an individual Zirconia-Ytria stabilized 2mm ball at surface weakly excited 3D bed. stochastic realizations are measured from top container. Then, power spectra measurements reveal different cooperative fluidized gap. We also carried out for one steel and many balls in 1D systems. fit...