Low-phase-noise microwave oscillators are important to a wide range of subjects, including communications, radar and metrology. Photonic-based microwave-wave sources now provide record, close-to-carrier phase-noise performance, and compact sources using microcavities are available commercially. Photonics-based solutions address a challenging scaling problem in electronics, increasing attenuatio...

We report on the microwave properties of a resonant cylindrical cavity made of bulk MgB2 superconductor, produced by the reactive liquid Mg infiltration process. The frequency response of the cavity has been measured in the range 5÷ 13 GHz. Among the various modes, the TE011, resonating at 9.79 GHz, exhibits the highest quality factor. For this mode, we have determined the temperature dependenc...

The S-DALINAC is a 130 MeV superconducting recirculating electron accelerator serving several nuclear and radiation physics experiments as well as driving an infrared free-electron laser. A system of normal conducting rf resonators for noninvasive beam position and current measurement was established. For the measurement of gammaradiation inside the accelerator cave a system of Comptondiodes ha...

A PbTiO3 crystal and Sr1 xBaxTiO3 lms have been studied by neareld scanning microwave microscopy (SMM). In the PbTiO3 crystal, dielectric properties and topography are obtained simultaneously. In Sr1 xBaxTiO3 lms, local variations and sample-to-sample di erences are observed. To quantitatively determine local dielectric permittivity and loss, we also carry out theoretical calculations on depend...

We describe the design, fabrication and bench-study of a mm-wave cavity employed as a relativistic klystron output structure. The OFE copper cavity was prepared by electrodischarge machining and diffusion bonding, cleaned, and tuned to 91.4 GHz. Measured cavity characteristics are presented and compared with theory, including quality factor, Q, coupling parameter ß, scattering matrix S11, and a...

The universal use of dose as a normalizing parameter in radiobiology is based entirely on the availability of measuring instruments. It is a poor basis for predicting or understanding the relationship between an irradiation and the resulting end point. Energy deposited is not the cause of an interaction. It is a secondary effect. The interaction is best described by fluence and cross section. E...

We use a near-field scanning microwave microscope to simultaneously image the dielectric constant, loss tangent, and topography in a PbTiO3 crystal. By this method, we study the effects of the local dielectric constant and loss tangent in the geometry of periodic domains on the measured resonant frequency, and quality factor. We also carry out theoretical calculations and the results agree well...

PURPOSE The aim of this paper is to highlight the contributions that complementary efficacy, effectiveness, and cost-effectiveness studies can make to assessing the outcomes of assistive technology interventions for enhancing mobility. METHOD The terms, 'assistive technology outcomes research' and 'assistive technology interventions', are defined. Several bases are examined for the shortage o...

These modes of analysis [cost-effectiveness and cost-benefit] are neither good for nothing nor good for everything, and one cannot speak of them as wholly good or bad. It is much more useful to try to specify some conditions under which they would or would not be helpful for various purposes.

We have evaluated radiosensitivity parameters for cellular transformation from published experimental data on neoplastic transformations induced in C3H10T1/2 cells by BEVALAC ions. The measured RBE values are well reproduced by a track theory calculation using sets of m-target parameters with either m = 2 or m = 3, suggesting a quadratic or cubic extrapolation to low doses of gamma rays. Using ...