Fiber reinforced polymeric composites can be employed for the construction of structures that are highly durable and easy to fabricate. At EMPA, a prototype footbridge with girders and deck made of pultruded composite sections has been designed and constructed. For thin-wall pultruded sections such as I-beam or T-beam, delaminations can form easily at the web/flange junction. If the delaminatio...

The Tinius Olson Universal Testing machine (see Figure 1.1) is capable of loading a test specimen to a maximum load of 60,000 lb. The load applying section of this machine consists of three thick metal plates. The top and the bottom plates are rigidly connected together with thick tie rods. This assembly is connected on the bottom to a hydraulic cylinder which is contained within the base of th...

The x-ray radiation shielding requirements beyond the first optics enclosure have been considered for the beam transport of the 2-ID-B and 2-ID-C branch lines of Sector 2 (SRI-CAT) of the APS. The first three optical components (mirrors) of the 2-ID-B branch are contained within the shielded first optics enclosure. Calculations indicate that scattering of the primary synchrotron beam by beamlin...

A concept is described for the high-accuracy absolute calibration of the instrumental polarization introduced by the primary mirror of a large-aperture telescope. This procedure requires a small aperture with polarization-calibration optics (e.g., mounted on the dome) followed by a lens that opens the beam to illuminate the entire surface of the mirror. The Jones matrix corresponding to this ca...

We report the design of a spectral modification system (SMS) for use with the proposed NEAL linac-pulse stretcher ring, cw electron beam facility. The SMS allows tailoring of the energy distribution of electrons in beams produced by a pulsed linac operating in the transient beam loading (TBL) regime. Modification of the energy distribution of electrons injected into the pulse stretcher ring wil...

When the out-of-plane stiffness of a beam is remarkably lower than the in-plane stiffness, the lateral-torsional buckling occurs. In this study, the behavior of mono-symmetric I-beams with discrete torsional and lateral bracings under the concentrated moment is investigated using the finite element analyses. Then, based on the numerical analyses, equation for the stiffness requirement is propos...

The High Current Experiment (HCX) is being built to explore heavy-ion beam transport at a scale appropriate to the low-energy end of a driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge dominated heavy-ion beams at high space-charge intensity (line-charge density ~ 0.2 μC/m) over long p...

Using a self-consistent three-dimensional simulation running on parallel supercomputers, we have modeled the beam-beam interaction at the PEP-II asymmetric e+e− collider. To provide guidance for luminosity improvement, we scanned the tunes and currents in both rings and computed their impact on the luminosity and transverse beam sizes. We also studied the effects of colliding the beams with a s...

The role of parallel fibers (PFs) in cerebellar physiology remains controversial. Early studies inspired the "beam" hypothesis whereby granule cell (GC) activation results in PF-driven, postsynaptic excitation of beams of Purkinje cells (PCs). However, the "radial" hypothesis postulates that the ascending limb of the GC axon provides the dominant input to PCs and generates patch-like responses....