We have obtained intermediate resolution optical spectra of the black-hole candidate Nova Sco 1994 in June 1996, when the source was in an X-ray/optical active state (R ∼15.05). We measure the radial velocity curve of the secondary star and obtain a semi-amplitude of 279±10km s−1; a value which is 30 per cent larger than the value obtained when the source is in quiescence. Our large value for K...

We investigate the role of gravity on convection in a dense granular shear flow. Using a microgravity-modified Taylor-Couette shear cell under the conditions of parabolic flight microgravity, we demonstrate experimentally that secondary, convective-like flows in a sheared granular material are close to zero in microgravity and enhanced under high-gravity conditions, though the primary flow fiel...

The effect of fine particles on turbulence damping and reduction of flow friction coefficient in ribleted pipes, have been investigated experimentally. Tests have been conducted in a ribleted pipe with hydraulic diameter of 18.6 mm, and 20 stream wise riblets of 1.8 mm depth, along the pipe. Flows of water tap with Reynolds number from 5000 to 30000 were compared with flows containing silt-clay...

INTRODUCTION For access-challenged patients with bilateral upper extremity central venous stenosis, solutions include the Hemodialysis Reliable Outflow (HeRO) device or an autogenous AV fistula in the lower limb. We evaluated HeRO grafts and transpositions of the femoral vein in maintaining primary and secondary patency. METHODS We retrospectively analyzed 40 patients with a HeRO device and 1...

We determine a constitutive equation for developed three-dimensional granular flows based on series of discrete element method simulations. In order to capture non-local phenomena, normal stress differences, and secondary flows, we extend previously proposed temperature-sensitive rheological model by considering Rivlin-Ericksen tensors up second order. Three parameters are calibrated with the i...

There are dierent ways to code the geodesic flows on surfaces with negative curvature. Such code spaces give a useful tool to verify the dynamical properties of geodesic flows. Here we consider special subspaces of geodesic flows on Hecke surface whose arithmetic codings varies on a set with innite alphabet. Then we will compare the topological complexity of them by computing their topological ...

in the maximum flow network interdiction problem, an attacker attempts to minimize the maximum flow by interdicting flow on the arcs of network. in this paper, our focus is on the nodal interdiction for network instead of the arc interdiction. two path inequalities for the node-only interdiction problem are represented. it has been proved that the integrality gap of relaxation of the maximum fl...

channel flows have three components of velocity, 1component in flow direction and 2components in spanwise of channel. because of heterogeneity of velocity undulations, in the channel section the vortices are formed that are nominated “secondary current cells”. these cells cause the lateral shear stress in the channel walls and introduce the erosion and scour of the channel walls. heterogeneity ...

Most aquatic and terrestrial ecosystems are experiencing increased nutrient availability, which is affecting their structure and function. By altering community composition and productivity of consumers, enrichment can indirectly cause changes in the pathways and magnitude of material flows in food webs. These changes, in turn, have major consequences for material storage and cycling in the eco...