Shields

About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.

Anti-nuclear electromagnetic pulse cable

Abstract: The utility model discloses an anti-nuclear electromagnetic pulse cable The anti-nuclear electromagnetic pulse cable comprises conductors, insulations, shields, a combination shield and a sheath, wherein the peripheries of the conductors which adopt tinned circular copper twisted wires or silver-plated circular copper twisted wires are provided with the high-temperature resistant fluoroplastic insulations extruded by a high-temperature extrusion apparatus, the peripheries of the high-temperature resistant fluoroplastic insulations are provided with the shields which are braided by high-braiding tinned circular copper wires, the peripheries of the shields are provided with the combination shield formed by twisting a control line and a data line through a cabling machine, and the periphery of the combination shield is provided with the low-temperature resistant elastomer sheath which is extruded by a normal-temperature extruder The preparation process is as follows: a method of combing the wrapped shields and the braided shields are adopted and a 300 T conductive cloth instead of a metal is adopted for the first time for wrapping materials The anti-nuclear electromagnetic pulse cable has the advantages of anti-nuclear electromagnetic pulse property, flexible property and high wear resistance, mildew resistance, humidity resistance and acid and alkali erosion resistance properties; the provided cable maintains excellent data transmission performance in a complex electromagnetic environment; and the cable plays the role of information transmission at special positions when used in a hydraulic information control system

Transmission of Medium Energy Neutrons Through Concrete Shields

Abstract: Transmission measurements of medium energy neutrons through concrete shields are described. Neutrons which were produced by the bombardment of 75 MeV protons on a thick Cu target, were collimated to a 7.5 cm diameter beam, and injected onto concrete shields of 20, 50 and 100 cm thickness. Neutrons transmitted through the shields were measured by an NE-213 scintillator. The Monte Carlo simulation of the neutron transport was made using the MORSE code based on the DLC-87 Hilo multigroup cross sections. It was seen from the comparison between the calculated and measured fluence that the attenuation profile of the integrated fluence above 20 MeV, as well as the penetrated neutron spectra, were well reproduced by the DLC-87

Experimental study of the reduction of high temperatures and radiation using heat shields associated with flare towers of offshore oil and gas platforms

Abstract: On oil and gas platforms, a flare system is used to burn excess and unusable gas and oil. This system is normally installed on the bow or stern of the topside structure to limit hazardous working conditions such as exposure to high temperatures or heat radiation. In general, when burning gas and oil, continuous flaring systems reach a maximum temperature of approximately 1200 °C and a heat flux of over 400 kW/m2. As extreme temperature and heat flux can harm workers and damage structures near the flare system, heat shields are used to decrease temperature and radiation. The aims of this study were to investigate the effects of heat shields and to determine how different numbers and types of heat shields block heat flux and temperature. Two types of shields, i.e., flat and perforated plates, were examined. In examining perforated heat shields, tests were performed with single and double shields. In addition, the heat flux and temperature reduction rates achieved by heat shields at varying distances from a ...

Superconducting and high-permeability shields modeled for biomagnetism and nondestructive testing

Abstract: Numerical modeling studies have been carried out for the design of superconducting and high-permeability shields for SQUID-based nondestructive evaluation and biomagnetic measurements. We used finite-element-method software to model magnetic shields with both axial and planar symmetry in axial and transverse uniform noise fields. Improvements in signal-to-noise ratio at the location of the SQUID were calculated for different shield geometries with line current and magnetic dipole sources at various locations near the shield

Lifetime Prediction for Structural Elements of a Tamman Vacuum High-Temperature Furnace by Means of Mathematical Models

Abstract: A mathematical structural model of a Tamman vacuum high-temperature electric furnace with a heater in the form of a coal or graphite pipe and thermal insulation in the form of graphite cylinder shields is developed and implemented in the Simulink software package. The thermal resistance of the thermal conductivity of graphite shields, which is traditionally neglected in the calculation of widespread thin metal shields, was taken into account in the simulation of thermal processes. Also, the model takes into account the mass flow of the material of the elements of the furnace structure (the speed of the mass flow depends on the temperature and pressure in the working space), causing a change of the size and, correspondingly, the coefficients of the heat transfer caused by the radiation of the elements of the structure. The temperature regime of separate structural elements (heaters, shields, etc.) is analyzed both for a constant supply voltage of heaters and for the case in which a closed temperature control system is used. The influence of the temperature regime of structural elements on the wear of heating elements and shields is shown.