Fast and slow magnetosonic shock formation is presented for stationary and axisymmetric magnetohydrodynamical (MHD) accretion flows onto a black hole. The shocked black hole accretion solution must pass through magnetosonic points at some locations outside and inside the shock location. We analyze critical conditions at the magnetosonic points and the shock conditions. Then, we show the restric...

The fuel entropy and required drive energy for an inertial confinement fusion implosion are set by a sequence of shocks that must be precisely timed to achieve ignition. This Letter reports measurements of multiple spherical shock waves in liquid deuterium that facilitate timing inertial confinement fusion shocks to the required precision. These experiments produced the highest shock velocity o...

We present and analyze a gedanken experiment and show that the assumption that an antenna operating at a single frequency can transmit more than two independent information channels to the far field violates the Second Law of Thermodynamics. Transmission of a large number of channels, each associated with an angular momenta 'twisted wave' mode, to the far field in free space is therefore not po...

An outstanding issue in the computational analysis of time-dependent problems is the imposition of appropriate radiation boundary conditions at artificial boundaries. In this work we develop accurate conditions based on the asymptotic analysis of wave propagation over long ranges. Employing the method of steepest descent, we identify dominant wave groups and consider simple approximations to th...

We present a numerical study of interactions between dispersive waves (DWs) and solitons during supercontinuum generation in photonic crystal fibers pumped with picosecond laser pulses. We show how the soliton-induced trapping potential evolves along the fiber and affects the dynamics of a DW-soliton pair. Individual frequency components of the DW periodically interact with the soliton resultin...

The dynamics of accretion onto a schwarzschild black hole is studied using Paczynski-Wiita pseudo newtonian potential. Steady state solution of the flow equations is obtained using thin disc approximation, including the effect of bremsstrahlung cooling in the energy equation. The topology of transonic solutions are got and the conditions for shock formation (Rankine-Hugoniot conditions) are che...

The doubly labeled water tecbnique represents an unobtrusive and noninvasive means lo measure total daily energy expenditure in free-living human subjects who are unaware that energy expenditure is being measured. When combined with measurement of resting energy expenditure, the doubly labeled water technique can also be used to estimate energy expenditure related to physical activity. The rela...

We discuss astrophysical scenarios relevant to the generation of gravitational waves (GW) and effects expected to arise from the interaction of GW and electromagnetic (EM) radiation. A strong programme of coordinated GW and EM astrophysical studies must be established in order to ensure the exploitation of the full scientific potential of the LISA mission. We describe on-going astrophysical wor...

A 66-year-old patient with a DR pacemaker for intermittent atrioventricular block presented with an electrocardiogram (ECG) showing some P waves non followed by QRS complexes, raising suspicion of device dysfunction. The device was equipped with a special algorithm (Managed Ventricular Pacing; Medtronic), and the observed ECG tracing was a normal consequence of the function of such algorithms. ...

Gravitational waves (GW) are tensor perturbations of the metric of curved spacetime that propagate. The metric g is a matrix (or differential 2-form, to be specific) that fully describes the 4-dimensional manifold of a spacetime in general relativity. The components of the full metric gμν are the sum of an unperturbed metric and the perturbation hμν , which varies on a smaller scale (separated ...