Some Properties of a Scanned Circular Array

Abstract

The impedance, pattern and gain properties of a circular array of dipoles (or isotropic sources) is discussed. In particular the variation of these properties as the antenna beam is scanned is investigated. Computed results for typical arrays are shown and the meaning of the results are discussed, and further areas of investigation are indicated.

Effects of soil compaction and moisture on the growth of Juncus tenuis

“…Similarly, Bowen (1981) reported that the root growth of agronomic crops was generally restricted in silt loam soils with a bulk density of ≥1.65 g cm -3 . These results support the conclusions of LaPage (1967) and Liddle (1991) that J. tenuis can persist in compacted soils.…”

Detection, Tracking and Related Costs of Ablation Catheters in the Treatment of Cardiac Arrhythmias

“…More sophisticated mapping technologies that involve the fusion of imaging modalities (i.e. using preoperative MRI/CT, to fluoroscopy) are also discussed [45]. Two sample visualizations of the above technologies are seen in Figure 3.…”

“…Currently there are two robotic systems -the Stereotaxis Magnetic Navigation System (Stereotaxis, Inc.) and the Hansen Sensei Robotic Catheter System (Hansen Medical). Both systems allow the physician to perform the mapping and ablation procedure while sitting in a control room remote from the patient [48]. Ongoing robotic developments use a magnetic tracking device to track the distal part of the ablation catheter in real time, and a master-slave robot-assisted system for actuation of a steerable catheter [49].…”