Redundant screwjack

Device uses differential gears to drive either one of two nut-screw assemblies. In event that one assembly jams, second assembly is driven at twice its normal rate with no loss in overall performance

Wideband printed bowtie antenna element development for post reception synthetic focusing surface penetrating radar

A printed bowtie antenna for a Post Reception Synthetic Focussing Surface Penetrating Radar (PRSF-SPR) has been developed with the aid of FDTD analysis. Antenna free space characteristics were compared against practical measurements and its performance was analysed when soil is present

A FDTD model for the post-reception synthetic focusing surface penetrating radar with mine detecting applications

Surface penetrating radar (SPR) is extensively used in military, civil, geophysical and archaeological applications. There has been an increasing emphasis on the use of SPR in the identification of buried unexploded ordnance, such as anti-tank mines, antipersonnel mines etc., which can be metallic or plastic in nature. Mine detection methods can be classified as destructive or non-destructive. Non-destructive mine detection methods employ metal detectors, magnetometers, infrared sensors and SPR. However, neither the metal detector nor the magnetometer can differentiate a mine from metallic debris and the infrared sensor merely notes a difference in thermal conductivity. In most battle fields the soil is contaminated by large quantity of shrapnel, metal scraps and cartridge cases which will give a high false alarm rate in the identification process. In this scenario the SPR is a promising technique for identification of both metallic and plastic mines. The use of finite difference time domain (FDTD) model to analyse the SPR, which makes use of post-reception synthetic focusing (PRSF) techniques, is presented

Microwave detection of buried mines using non-contact, synthetic near-field focusing

Existing ground penetrating radars (GPR) are limited in their 3-D resolution. For the detection of buried land-mines, their performance is also seriously restricted by `clutter'. Previous work by the authors has concentrated on removing these limitations by employing multi-static synthetic focusing from a 2-D real aperture. This contribution presents this novel concept, describes the proposed implementation, examines the influence of clutter and of various ground features on the system's performance, and discusses such practicalities as digitisation and time-sharing of a single transmitter and receiver. Experimental results from a variety of scenarios are presented

Bridging the Gap: Exploring the Basic Health Insurance Option for New York

Explores New York state's options, costs, and benefits of creating a basic health plan under health reform, including available federal funding, take-up rates by various population groups, types of plans, and impact on state exchange and uninsured rates

Control of corn diseases in Illinois

"In cooperation with Office of Cereal Crops and Diseases, Bureau of Plant Industry, U.S. Department of Agriculture.