This paper presents CMOS circuits for integrated analog filters at very high frequencies, based on transconductance-C integrators. First a differential transconductance element based on CMOS inverters is described. With this circuit a linear, tunable integrator for very-high-frequency integrated filters can be made. This integrator has good linearity properties (1% relative gm error for 2-V,, i...

The best established lateralized cerebral function is speech production, with the majority of the population having left hemisphere dominance. An important question is how to best assess the laterality of this function. Neuroimaging techniques such as functional Magnetic Resonance Imaging (fMRI) are increasingly used in clinical settings to replace the invasive Wada-test. We evaluated the usefu...

OBJECTIVE To assess the level of knowledge regarding viral hemorrhagic fever (VHF) among healthcare personnel at two largest tertiary care hospitals in Karachi, Pakistan. METHODS A cross sectional convenience survey was conducted in February 2001 among doctors, nurses, laboratory technicians and janitors/orderlies of Jinnah Postgraduate Medical Centre and Civil Hospital, Karachi. The question...

This paper describes a small scale VHF Spaced Antenna Boundary Layer Radar which has been developed using only three antennas. This radar was deployed at Buckland Park, Adelaide Australia for five days in October 2003. Comparisons with a 27 antenna VHF Boundary Layer Radar installed at the same site show excellent agreement with comparable coverage.

A 5-pole lumped element bandpass filter (BPF) of center frequency 264.05 MHz and fractional bandwidth (FBW) 0.76% is designed and fabricated using YBa 2 Cu 3 O 7-d (YBCO) thin films deposited on both sides of a MgO substrate(40 mm × 40 mm × 0.5 mm). The return loss, minimum insertion loss and ripple were measured to be 20.0 dB, less than 0.1 dB and less than 0.1 dB at 70 K, respectively. These ...

Hydrogenated microcrystalline silicon ðmc Si : HÞ growth by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) is studied in an industrial-type parallel plate KAI reactor. Combined plasma and material characterization techniques allow to assess critical deposition parameters for the fabrication of high quality material. A relation between low intrinsic stress of the depos...

Satellite-based VHF lightning detection is characterized at GPS orbit by using a VHF receiver system recently launched on the GPS SVN 54 satellite. Collected lightning triggers consist of Narrow Bipolar Events (80%) and strong negative return strokes (20%). The results are used to evaluate the performance of a future GPS-satellite-based VHF global lightning monitor. INTRODUCTION Over the last f...

Because the pulse frequency of VHF micro-EDM power supply (30–300 MHz) is higher than that traditional EDM and has two characteristics positive negative bipolar, it impossible to use discharge state detection technology meet requirements detection. And during experiment, was found resonant would migrate with change circuit impedance, leading voltage amplitude. In order break through limitations...

Photoswitch triads comprising two dihydroazulene (DHA) units in conjugation with a central trans-azobenzene (AZB) unit were prepared stepwise protocols starting from meta- and para-disubstituted azobenzenes. The para-connected triad had significantly altered optical properties lacked the photoactivity of separate photochromes. In contrast, for meta-connected triad, all three photochromes could ...