Shields

About: Shields is a(n) research topic. Over the lifetime, 1456 publication(s) have been published within this topic receiving 10896 citation(s).

Design and Performance Equations for Advanced Meteoroid and Debris Shields

Abstract: This paper provides equations defining the performance capability of various types of meteoroid and debris shielding systems. These equations have been developed at the NASA Johnson Space Center (JSC) Hypervelocity Impact Test Facility (HIT-F). Equations are included that are applicable for aluminum Whipple shields, Nextel® Multi-Shock (MS) shields, hybrid Nextel®/Aluminum MS shields, and Mesh Double-Bumper (MDB) shields. The MS and MDB shields are advanced shields with demonstrated weight and performance advantages over conventional Whipple shields.

Mechanised Shield Tunnelling

Abstract: This book is translated from German. The development potential of the mechanised shield tunnelling method is far greater than that of the shotcrete method and other traditional tunnelling machines because it is a safer, more effective method of tunnel construction. This book considers the planning of the construction method and design of the machine in harmony with the geological and hydrological conditions, settlement requirements and safety considerations. The technological developments in Germany and world-wide are presented. The book includes chapters on tunnel lining, tailskin seals, grouting and injection procedures, open-faced shields, compressed air shields, slurry shields, earth pressure balance shields, combined shields and special configuration shields and special construction methods.

Shielding Effectiveness of Braided-Wire Shields

Abstract: An analysis of the shielding effectiveness of braidedwire shields is made using the parameters of the woven wire and the theory of electromagnetic coupling through small irises. The coupling through the rhombic-shaped holes in the braid is approximated by using the electric and magnetic polarizabilities of elliptical holes of the same width and length as the rhombus. The analysis develops the transfer impedance and the mutual capacitance of the shield. The transfer impedance is calculated and plotted for shields of different optical coverages. The variation of mutual capacitance and mutual inductance with the weave angle of the braid are examined.

Shielded magnetic tunnel junction magnetoresistive read head

Abstract: A magnetic tunnel junction (MTJ) magnetoresistive read head for a magnetic recording system has the MTJ device located between two spaced-apart magnetic shields. The magnetic shields, which allow the head to detect individual magnetic transitions from the magnetic recording medium without interference from neighboring transitions, also function as electrical leads for connection of the head to sense circuitry. Electrically conductive spacer layers are located at the top and bottom of the MTJ device and connect the MTJ device to the shields. The thickness of the spacer layers is selected to optimize the spacing between the shields, which is a parameter that controls the linear resolution of the data that can be read from the magnetic recording medium. To reduce the likelihood of electrical shorting between the shields if the shield-to-shield spacing is too small, each of the shields can have a pedestal region with the MTJ device located between the two pedestals, so that the shield-to-shield spacing outside the pedestal regions is greater than in the pedestal regions.

Plasma treatment apparatus

Abstract: A plasma gaseous reaction apparatus including a reaction chamber, a system for supplying reaction gas to the reaction chamber and an exhaust system for exhausting unnecessary reaction products. Specifically, the apparatus includes a pair of facing electrodes disposed in the reaction chamber which are covered by shields except the area in which the electrodes face each other. The shields may include a first and second shield wherein the inner first shield is electrically insulated from the electrodes and the outer second shield is kept at earth potential. The apparatus further includes a substrate container for supporting substrates which surrounds the substrates by a frame. The outside of the substrate container is kept in the earth potential and is covered by a conductor plate electrically insulated from the container. The shields and substrate container are configured such that plasma generated by electric power supplied by the electrodes is confined in a space surrounded by the shields and the container.