Bend radius

About: Bend radius is a research topic. Over the lifetime, 3303 publications have been published within this topic receiving 35415 citations. The topic is also known as: minimum bend radius.

submitter : Electro-mechanical characterization of MgB2 wires for the Superconducting Link Project at CERN

Abstract: In previous years, the R & D program between CERN and Columbus Superconductors SpA led to the development of several configurations of MgB2 wires. The aim was to achieve excellent superconducting properties in high-current MgB2 cables for the HL-LHC upgrade. In addition to good electrical performance, the superconductor shall have good mechanical strength in view of the stresses during operation (Lorenz forces and thermal contraction) and handling (tension and bending) during cabling and installation at room temperature. Thus, the study of the mechanical properties of MgB2 wires is crucial for the cable design and its functional use. In the present work we report on the electro-mechanical characterization of ex situ processed composite MgB2 wires. Tensile tests (critical current versus strain) were carried out at 4.2 K and in a 3 T external field by means of a purpose-built bespoke device to determine the irreversible strain limit of the wire. The minimum bending radius of the wire was calculated taking into account the dependence of the critical current with the strain and it was then used to obtain the minimum twist pitch of MgB2 wires in the cable. Strands extracted from cables having different configurations were tested to quantify the critical current degradation. The Young's modulus of the composite wire was measured at room temperature. Finally, all measured mechanical parameters will be used to optimize an 18-strand MgB2 cable configuration.

Apparatus, system, and method for installing and retrieving pipe in a well

Abstract: Pipe used in drilling and/or completing wells is stored in long rectangular segments or strings (13) in the space adjacent to a drilling rig (10) being used to construct a well. The pipe is introduced into the well, or extracted from the well, in long segments made up of multiple individual pipe sections. In one embodiment, long rectilinear segments of pipe are bent into a curve that extends from the rig (10) to the space surrounding the rig (10), where the pipe reassumes its rectilinear shape. The curve radius is greater than the pipe's yielding bending radius. On a water-based rig (10), the pipe is received in the water surrounding the rig (10) where it may be stored, tested, inspected, reassembled, treated, and/or otherwise processed. The pipe may be received within a long pipe storage sleeve (20) that is buoyed (18) laterally at or below the water surface or it may be secured to a guy line (27, 28) anchored between the rig (10) and the water bottom. In deepwater applications, long sections of the pipe are stored vertically in the water area between the surface drilling rig (10) and the water bottom. The pipe may also be stored within vertically oriented storage sleeves.

Anatomical Variations of the Proximal Radius and Their Effects on Osteosynthesis

Abstract: Purpose In fractures of the radial head and neck requiring open reduction and internal fixation, osteosynthesis may be safely applied in a limited zone. We conducted a morphometric study of the proximal radius at the level of the safe zone to identify different morphologic types of this anatomical region. Methods We analyzed 44 dried cadaveric radii. We measured the whole length of the radius, the length of the neck and head, and the minimum and maximum diameter of the radial head. The morphologic aspect of the neck–head curvature of the safe zone was evaluated qualitatively and quantitatively. Results The proximal radius at the level of the safe zone exhibited different radii of bending. In particular, we identified a morphologic type A, which showed a flat profile (25% of cases), morphologic types B and C, which showed a low concave curvature (64%), and a marked concave curvature (11%), respectively, of the safe zone. Conclusions The profile of the proximal radius in the safe zone shows substantial morphologic variations that should be taken into account when operating on fractures of the proximal radius, to avoid malunions, pain, and stiffness of the elbow joint. A preoperative radiograph of the contralateral uninjured radius may be helpful in selecting the most appropriate internal fixation device to reconstruct the proximal radius after comminuted fractures. Clinical relevance Knowledge of the proper bending radius of the safe zone allows the surgeon to select the most appropriate plate, and to achieve good fracture reduction and anatomical restoration of the proximal radius.

Flexible small-bore hollow fibers with an inner polymer coating.

Abstract: Flexible hollow-glass fibers with small-bore diameters of 250 and 320 µm have been developed for Er:YAG laser delivery. The fibers consist of a glass capillary tube and an inner coating of silver and polymer thin films that are deposited by use of a simple liquid-phase technique. The 250‐µm-bore fiber exhibits a straight loss of 0.8 dB/m and a bending loss of 1.2 dB when it is bent 180° at the output end, with a bending radius of 2 cm. The maximum energy delivered by the fibers is ∼100 mJ.

Fiber optic connector for coupling devices on intersecting planes

Abstract: A connector assembly for optically coupling a first optical waveguide array mounted to a first substrate to an optical device on an intersecting second substrate. The first waveguide array includes a plurality of parallel optical waveguides having a minimum desired bend radius. The first and the second substrate define a first and a second plane respectively and the longitudinal direction of the first waveguide array defines a first axis. The intersection of the two planes defines an intersection axis that is generally perpendicular to the first axis. The first waveguide array has a substrate portion mounted to the first substrate, a midspan portion, and an end portion. The connector assembly includes a first connector adapted to be detachably connected to the second substrate and aligned along a second axis generally perpendicular to the intersection axis. The first connector has a first retaining mechanism that receives and retains the end portion of the first optical waveguide array, where the end portion is suspended over the first plane at a distance along the second axis that is at least equal to the minimum desired bend radius. The midspan portion of the second optical waveguide array describes a suspended bend curve between the first and the second plane, the suspended bend curve having a bend radius that is equal to or greater than the desired minimum bend radius.