Introduction It is becoming increasingly important to develop accurate mathematical models of human tissue for use in finite element analysis and in the development of replacement materials. For modelling the impingement of bone fragments on the spinal cord during fracture, the properties of the dura mater are required but only limited data is available. Failure stresses under tensile loading h...

A summary of the evidence linking exercise and osteoarthritis is given in the table. In summary, normal joints appear to tolerate prolonged vigorous low impact exercise without accelerated development of osteoarthritis. The risk of developing osteoarthritis appears to be increased in sporting activities that continually expose normal joints to high levels of impact or torsional loading and in i...

A model is presented that describes the interaction of electrons with both longitudinal and transverse waves in a cold plasma. Starting from the Lagrangian for the system of fields, background plasma, and particles, a finite dimensional self-consistent model is derived using the envelope approximation for the waves. The ~squared! wave amplitudes and phases form action-angle variables in the clo...

A bunch compressor design for the Next Linear Collider (NLC) is described. The compressor reduces the bunch length by a factor of 40 in two stages. The first stage at 2 GeV consists of an rf section and a wiggler. The second stage at 10 GeV is formed by an arc, an rf section, and a chicane. The final bunch phase is insensitive to initial phase errors and to beam loading in the intermediate Sban...

We have demonstrated a storage ring for ultracold neutral atoms. Atoms with mean velocities of 1 m/s corresponding to kinetic energies of approximately 100 neV are confined to a 2 cm diameter ring by magnetic forces produced by two current-carrying wires. Up to 10(6) atoms are loaded at a time in the ring, and seven revolutions are clearly observed. Additionally, we have demonstrated multiple l...

The helix geometry model of 3D braided composites has been presented, which truly reflects the braided manner and coincides with the actual configuration of the braided composites. The longitudinal tensile stress-strain relationships and the strength of 3D braided composites under the tension loading have been predicted by a finite multiphase element method (FMEM) based on the helix geometry mo...

Vibration damping in polycrystalline TbDy alloys was studied at cryogenic temperatures. Mechanical hysteretic losses were measured at various strains, frequencies, and loading configurations at 77 K. Some textured TbDy materials demonstrated 22.6% energy dissipation in mechanical measurements at low frequency ~0.01 Hz! and a mean logarithmic decrement of 0.23 at a higher frequency ~25 kHz!. Ult...

To study mechanical behaviors of shear walls built with precast two-way hollow slabs, two shear walls with different details of hollow slabs were quasi-statically tested under low cyclic loading. The failure mode was analyzed, which vertical macro-cracks appeared on walls due to the details of hollow slabs. Brittle shear failure can be avoided in terms of the failure behaviors evolved from inte...

background menarche is considered as a milestone in the women’s reproductive life. most existing studies on factors influencing menarcheal age had cross-sectional designs and their finding were controversial. objectives we aimed to determine some factors affecting the age at menarche in a cohort study with an average of ten-year follow-up; the study was conducted within the framework of tehran ...

BACKGROUND Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix ...