The aim of this study is to investigate the formation and ejection behavior of droplets created by a squeeze mode piezoelectric inkjet printing device using a single pulse voltage pattern. The test liquids are de-ionized (DI) water and ethylene glycol. The experimental results and acoustic wave theory are used to discuss the effects of operating frequency, positive voltage keeping time and puls...

Tighter immigration laws are leaving health organisations struggling for staff, particularly to care for older people, the RCN claims.

The solidification process during squeeze casting is analyzed based on the classical solidification and plastic deformation theory. The linear relationship between punch velocity and the solidification rate is established if the density change of molten meals is neglected. To obtain defect-free castings, the punch velocity should be larger than the solidification rate. The densification mechani...

Putting a competitive squeeze on a cooperative group has long been considered to encourage cheats. Now we learn that competition, by driving diversification among cooperators, can create groups that are both more productive and more resistant to defection.

Related Articles A new instrument for dynamic helical squeeze flow which superposes oscillatory shear and oscillatory squeeze flow Rev. Sci. Instrum. 83, 085105 (2012) The effects of hydrodynamic interaction and inertia in determining the high-frequency dynamic modulus of a viscoelastic fluid with two-point passive microrheology Phys. Fluids 24, 073103 (2012) MHD free convection flow of a visco...

An analysis has been performed to study magneto-hydrodynamic MHD squeeze flow between two parallel infinite disks where one disk is impermeable and the other is porous with either suction or injection of the fluid. We investigate the combined effect of inertia, electromagnetic forces, and suction or injection. With the introduction of a similarity transformation, the continuity and momentum equ...

We consider squeeze film gas damping during microbeam motion away and toward a substrate as occurs during opening and closing of RF switches and other MEMS devices. The numerical solution of the gas damping problem in two-dimensional geometries is obtained based on the Boltzmann-ESBGK equation. The difference in damping force between downward and upward moving beams is shown to vary from as lit...

Squeeze film dampers are widely used in aircraft engines, land-based gas turbines, and other rotating machines to improve system damping. They often have entrained air within the oil film, which is usually not taken into account in rotordynamics analysis due to lack of good formulations of the effects involved. The effects on the damping force calculation can be significant. This work presents ...

The dynamics of the expulsion of the last liquid monolayer of molecules confined between two surfaces (measured recently for the first time) has been analyzed by solving the two-dimensional Navier-Stokes equation combined with kinetic Monte Carlo simulations. Instabilities in the boundary line of the expelled film were observed. We show that the instabilities produce a rough boundary for all le...

in this paper, unsteady two phase simulation of nanofluid flow and heat transfer between moving parallel plates, in presence of the magnetic field is studied. the significant effects of thermophoresis and brownian motion have been contained in the model of nanofluid flow. the three governing equations are solved simultaneously via galerkin method. comparison with other works indicates that this...