Unified phase diagram of reversible-irreversible, jamming and yielding transitions in cyclically sheared soft sphere packings

Self-organization, and transitions from reversible to irreversible behaviour, of interacting particle assemblies driven by externally imposed stresses or deformation is of interest in comprehending diverse phenomena in soft matter. They have been investigated in a wide range of systems, such as colloidal suspensions, glasses, and granular matter. In different density and driving regimes, such behaviour is related to yielding of amorphous solids, jamming, and memory formation, \emph{etc.} How these phenomena are related to each other has not, however, been much studied. In order to obtain a unified view of the different regimes of behaviour, and transitions between them, we investigate computationally the response of soft sphere assemblies to athermal cyclic shear deformation over a wide range of densities and amplitudes of shear deformation. Cyclic shear deformation induces transitions from reversible to irreversible behaviour in both unjammed and jammed soft sphere packings. Well above isotropic jamming density ($\bf{\phi_J}$), this transition corresponds to yielding. In the vicinity of the jamming point, up to a higher density limit we designate ${\bf \phi_J^{cyc}}$, an unjammed phase emerges between a localised, \emph{absorbing} phase, and a diffusive, {\emph irreversible} phase. The emergence of the unjammed phase signals the shifting of the jamming point to higher densities as a result of annealing, and opens a window where shear jamming becomes possible for frictionless packings. Below $\bf{\phi_J}$, two distinct localised states, termed point and loop reversibile, are observed. We characterise in detail the different regimes and transitions between them, and obtain a unified density-shear amplitude phase diagram

THE EFFECT OF IMPELLER BLADE DESIGN ON CENTRIFUGAL BLOWER – CFD APPROACH

A centrifugal blower is a mechanical device for moving air or other gases with a slight increase in pressure. While working with hot air, the heat absorbed by the impeller material should be dissipated effectively to avoid the accumulation of heat at one place, that may deform the part. The rate of dissipation depends on the heat transfer rate and the thickness of the blade material. The present work deals with the determination and analysis of heat transfer rate of blade made of Aluminum alloy, composite materials Graphite and Carbon Fiber with blade thickness 1mm, 2mm, 3mm. This is done using ANSYS software in thermal analysis. CREO parametric software is used for modeling the centrifugal blower. The performance of Blower depends on the change in static pressure for different input velocities of air. In CFD analysis change in pressure, outlet velocity, heat transfer coefficient of air is determined at different input velocities 14m/sec, 16m/sec, 18m/sec, 20m/sec and 22m/s

Stress-stress Correlations Reveal Force Chains in Gels

We investigate the spatial correlations of microscopic stresses in soft particulate gels, using 2D and 3D numerical simulations. We use a recently developed theoretical framework predicting the analytical form of stress-stress correlations in amorphous assemblies of athermal grains that acquire rigidity under an external load. These correlations exhibit a pinch-point singularity in Fourier space leading to long-range correlations and strong anisotropy in real space, which are at the origin of force-chains in granular solids. Our analysis for the model particulate gels at low particle volume fractions demonstrates that stress-stress correlations in these soft materials have characteristics very similar to those in granular solids and can be used to identify force chains. We show that the stress-stress correlations can distinguish floppy from rigid gel networks and the intensity patterns reflect changes in shear moduli and network topology, due to the emergence of rigid structures during solidification.Comment: 11 pages, 9 figure

Developing type 1 diabetes resources: a qualitative study to identify resources needed to upskill and support community sport coaches

IntroductionCommunity sport coaches in Western Australia lack an understanding, the confidence, and knowledge in supporting young people with Type 1 diabetes (T1D). This study aims to identify what T1D educational resources are required to upskill coaches in Western Australia.MethodsSemi-structured online interviews were conducted with i) young people living with T1D, ii) parents of young people living with T1D and iii) community sport coaches. The questions explored i) past experiences of T1D management in community sport ii) the T1D information coaches should be expected to know about and iii) the format of resources to be developed. Thematic analysis of interview transcripts was performed, and the themes identified were used to guide resource development.ResultsThirty-two participants (16 young people living with T1D, 8 parents, 8 coaches) were interviewed. From the interviews, young people wanted coaches to have a better understanding of what T1D is and the effect it has on their sporting performance, parents wanted a resource that explains T1D to coaches, and sports coaches wanted to know the actions to best support a player living with T1D. All groups identified that signs and symptoms of hypoglycaemia and hyperglycaemia needed to be a key component of the resource. Sports coaches wanted a resource that is simple, quick to read and available in a variety of different formats.ConclusionThe interviews resulted in valuable information gained from all groups and have reinforced the need for the development of specific resources to increase community knowledge and provide support for players with T1D, parents and sport coaches