Let`1 ; ` 2 ; : : : ; ` d be disjoint parallel lines in the plane. A d-interval is a subset of their union that intersects eachì in a closed interval. Kaiser Discr. Comput. Geom. 18(1997) 195{203] showed that any system of d-intervals containing no subsystem of k + 1 pairwise disjoint d-intervals can be pierced by at most (d 2 ? d)k points. We show that this bound is close to being optimal, by ...

In this short review article we sketch some developments which should ultimately lead to the analogy of the Chern-Weil homomorphism for principle bundles in the realm of non commutative differential geometry. Principal bundles there should have Hopf algebras as structure ‘cogroups’. Since the usual machinery of Lie algebras, connection forms, etc., just is not available in this setting, we base...

One of the typically damaged steel beam-column connection during the Northridge earthquake of 1994 was bolted-web, welded-flange (BWWF), now known as “pre-Northridge” connection. Proposed post-Northridge connections are more ductile and capable of dissipating more energy, thus improving the behavior of steel moment resisting frames (SMRF). The post-Northridge connections with added ductility wi...

Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the U.K., Network Rail (the organization responsible for r...

In this paper, experimental testing and numerical analysis were used to investigate the effect of tube thickness on the face bending for concrete filled hollow sections connected to other structural members using Extended Hollobolts. Six samples were tested experimentally by applying pull-out load on the bolts. These samples were designed to fail by column face bending. The main variable in all...

The web of plate girders in bridges are usually reinforced by welded transverse stiffeners in order to improve their shear capacity.Due to problems associated with field welding and fatigue, welded stiffeners are not suitable for retrofitting existing bridges. Bolted stiffeners are a practical alternative for strengthening girders that are expected to experience shear stress in excess of their ...

Bolted stiffened end-plate moment connections are one of the most usable used as a prequalified connection in special steel frames. According to AISC design code, this can be considered important parts resisting frames with enough bolt pretension levels. In paper, using three full-scale bolted designed according AISC, effects levels have been examined experimentally under SAC cyclic-loading pro...

The bolt connection structure is widely used in the of aeroengine parts, and its quality very important, as it can directly affect geometric dynamic performance aeroengine. Taking preload entry point, research status bolted connections recent years summarized based on formation mechanism control technology this review. For mechanism, single multiple bolts arrays are analyzed. According to chara...

The spin-statistics connection is obtained for a simple formulation of a classical field theory containing even and odd Grassmann variables. To that end, the construction of irreducible canonical realizations of the rotation group corresponding to general causal fields is reviewed. The connection is obtained by imposing local commutativity on the fields and exploiting the parity operation to ex...