Highly turbulent natural circulation in an enclosed tall rod bundle is investigated using Large Eddy Simulation (LES). The consists of 36 heated rods and insulated central tubeenclosed by a cooled containment wall. This geometry directly relevant to nuclear fuel bundles generic heat exchangers. For bundles, importance accident scenarios. A 60° azimuthally periodic sector the modelled. Rayleigh ...

Identifying what causes fuel assembly vibrations downstream of Mixing Vane Grids (MVG) in Pressurized Water reactor (PWR) is paramount importance for nuclear community to understand grid-to-rod fretting wear. Experiments, called CALIFS, were carried out by the Atomic Energy Commission (CEA) on a 5 × MVG at hydraulic Reynolds number 66,000, order measure flow velocity and pressure along central ...

A hitherto unknown rod-shaped cytoplasmic component which consists of a bundle of fine tubules, enveloped by a tightly fitted membrane, was regularly found in endothelial cells of small arteries in various organs in rat and man. It is about 0.1 micro thick, measures up to 3 micro in length, and contains several small tubules, approximately 150 A thick, embedded in a dense matrix, and disposed p...

In meiotic DNA recombination, the Hop2-Mnd1 complex promotes Dmc1-mediated single-stranded DNA (ssDNA) invasion into homologous chromosomes to form a synaptic complex by a yet-unclear mechanism. Here, the crystal structure of Hop2-Mnd1 reveals that it forms a curved rod-like structure consisting of three leucine zippers and two kinked junctions. One end of the rod is linked to two juxtaposed wi...

Integrins are alphabeta heterodimeric receptors that mediate attachment of cells to the extracellular matrix and therefore play important roles in cell adhesion, migration, proliferation and survival. Among the cytoskeletal proteins that interact directly with the beta-chain cytoplasmic domain, talin has emerged as playing a critical role in integrin activation and linkage to the actin cytoskel...

The bacterial flagellar hook connects the helical flagellar filament to the rotary motor at its base. Bending flexibility of the hook allows the helical filaments to form a bundle behind the cell body to produce thrust for bacterial motility. The hook protein FlgE shows considerable sequence and structural similarities to the distal rod protein FlgG; however, the hook is supercoiled and flexibl...

A theory of discrete Cosserat rods is formulated in the language of discrete Lagrangian mechanics. By exploiting Kirchhoff’s kinetic analogy, the potential energy density of a rod is a function on the tangent bundle of the configuration manifold and thus formally corresponds to the Lagrangian function of a dynamical system. The equilibrium equations are derived from a variational principle usin...