11,684 research outputs found
Linear -positive sets and their polar subspaces
In this paper, we define a Banach SNL space to be a Banach space with a
certain kind of linear map from it into its dual, and we develop the theory of
linear -positive subsets of Banach SNL spaces with Banach SNL dual spaces.
We use this theory to give simplified proofs of some recent results of
Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder
theorem.Comment: 11 pages. Notational changes since version
Heart Rate Patterns Observed in Medical Monitoring
Medical monitoring of heart rate patterns during conditions of sleep, quiet rest, breath-holding, hypoxia, and increased g forces of aircraft fligh
Optically controlled GaAs dual-gate MESFET and permeable base transistors
Optically induced voltage and dc characteristics of the GaAs Dual-gate MESFET and the Permeable Base Transistor (PBT) with optical illumination at wavelength below 0.87 microns were obtained and compared with GaAs MESFET. It was observed that PBT can handle higher current density when illuminated
A 1-W, 30-ghz, CPW Amplifier for ACTS Small Terminal Uplink
The progress is described of the development of a 1 W, 30 GHz, coplanar waveguide (CPW) amplifier for the Advanced Communication Technology Satellite (ACTS)Small Terminal Uplink. The amplifier is based on Texas Instruments' monolithic microwave integrated circuit (MMIC) amplifiers; a three stage, low power amplifier, and a single stage, high power amplifier. The amplifiers have a power output of 190 mW and 0.710 W, gain of 23 and 4.2 dB, and efficiencies of 30.2 and 24 percent for the three stage and one stage amplifiers, respectively. The chips are to be combined via a CPW power divider/combiner circuit to yield the desired 1 W of output power
Microwave characterization and modeling of GaAs/AlGaAs heterojunction bipolar transistors
The characterization and modeling of a microwave GaAs/AlGaAs heterojunction Bipolar Transistor (HBT) are discussed. The de-embedded scattering parameters are used to derive a small signal lumped element equivalent circuit model using EEsof's Touchstone software package. Each element in the equivalent circuit model is shown to have its origin within the device. The model shows good agreement between the measured and modeled scattering parameters over a wide range of bias currents. Further, the MAG (maximum available power gain) and the h sub 21 (current gain) calculated from the measured data and those predicted by the model are also in good agreement. Consequently, the model should also be capable of predicting the f sub max and the f sub T of other HBTs
Conditions for extreme sensitivity of protein diffusion in membranes to cell environments
We study protein diffusion in multicomponent lipid membranes close to a rigid
substrate separated by a layer of viscous fluid. The large-distance, long-time
asymptotics for Brownian motion are calculated using a nonlinear stochastic
Navier-Stokes equation including the effect of friction with the substrate. The
advective nonlinearity, neglected in previous treatments, gives only a small
correction to the renormalized viscosity and diffusion coefficient at room
temperature. We find, however, that in realistic multicomponent lipid mixtures,
close to a critical point for phase separation, protein diffusion acquires a
strong power-law dependence on temperature and the distance to the substrate
, making it much more sensitive to cell environment, unlike the logarithmic
dependence on and very small thermal correction away from the critical
point.Comment: 19 pages, 4 figure
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