As the largest gravitationally bound structures known, clusters provide clear constraints on the formation of structure and on the composition of the universe. Despite their extreme importance for cos-mology the number of clusters at high redshift (z>0.75) is rather small. There are only a few X-ray emitting examples reported and a handful of optically-selected ones. These clusters can provide ...

The non–linear dynamics of self–gravitating irrotational dust is analyzed in a general relativistic framework, using synchronous and comoving coordinates. Writing the equations in terms of the metric tensor of the spatial sections orthogonal to the fluid flow allows an unambiguous expansion in inverse powers of the speed of light. The Newtonian and post–Newtonian approximations are derived in L...

Within the functional renormalization group approach we study the effective quantum field theory of Einstein gravity and one self-interacting scalar coupled to N(f) Dirac fermions. We include in our analysis the matter anomalous dimensions induced by all the interactions and analyze the highly nonlinear beta functions determining the renormalization flow. We find the existence of a nontrivial f...

We analyze the development of a collisional granular flow without gravitational accelerations in a shear cell shaped as a racetrack. Variations of the cross-sectional averaged solid volume fraction, mean velocity and fluctuation energy along the straight region of the cell are captured by an integral technique similar to the treatment of boundary layers. The results compare well with data from ...

Observations made on vessels seen directly beneath the pleura may not accurately reflect what occurs in vessels located deeper in the interior of the lung. We quantified flow to subpleural and deeper, interior regions under zone 1 or 2 conditions in excised (n = 5) and in vivo (n = 6) rabbit lungs, in the head-up or inverted position. After infusion of radiolabeled microspheres, lungs were drie...

OBJECTIVE The automated gravitational Vario Flow system with weighing-based electronic fluid deficit indicator was used in order to reduce the risk of fluid intravasation during continuous flow hysteroscopic procedures. Early experiences are reported. METHODS Between August 1996 and July 1997, the Vario Flow with fluid deficit indicator and alarm system was used in 203 hysteroscopic operation...

An explicit fluid flow simulation of electromagnetic wave propagation in the gravitational field of a Schwarzschild black hole is given. The fluid has a constant refractive index and a spherically symmetric inward directed flow. The resulting form of the metric leads to a new coordinate system in which the Schwarzschild vacuum is written in Gordon’s form. It is shown that a closely related coor...

The surface energy present in a small drop of liquid is used to pump the liquid through a microchannel. The flow rate is determined by the volume of the drop present on the pumping port of the microchannel. A flow rate of 1.25 microL s(-1) is demonstrated using 0.5 microL drops of water. Two other fluid manipulations are demonstrated using the passive pumping method: pumping liquid to a higher ...

As every circuit designer knows, the flow of energy is governed by impedance matching. Classical or quantum impedances, mechanical or electromagnetic, fermionic or bosonic, topological,... To understand the flow of energy it is essential to understand the relations between the associated impedances. The connection between electromagnetism and gravitation can be made explicit by examining the im...