摘要:
The present invention relates to an apparatus for measuring the capacitance and the dissipation factor in a transformer bushing and extracting gas dissolved in the insulating fluid of said bushing. The apparatus comprises a porous cylindrical member associated with a tap connector and covered by a thin layer of a gas permeable but liquid impermeable membrane. The porous member allows passive diffusion of the permeated gas extracted from the insulating fluid of a transformer bushing to a gas storage chamber for further analysis, thereby helping to prevent high costs related to damage or destruction of the bushing.
摘要:
The present invention relates to an apparatus for measuring the capacitance and the dissipation factor in a transformer bushing and extracting gas dissolved in the insulating fluid of said bushing. The apparatus comprises a porous cylindrical member associated with a tap connector and covered by a thin layer of a gas permeable but liquid impermeable membrane. The porous member allows passive diffusion of the permeated gas extracted from the insulating fluid of a transformer bushing to a gas storage chamber for further analysis, thereby helping to prevent high costs related to damage or destruction of the bushing.
摘要:
An oil, such as a mineral oil, for example, transformer oil, is contacted with calcium carbide and the mixture is stirred until a liquid phase containing less than 1 ppm water and a solid phase containing Ca(OH)2 and unreacted CaC2 are obtained. The oil obtained can be used to give samples of known quantities of water by adding corresponding amounts thereto.
摘要:
The present invention provides a programmable image antenna formed on the face plate of a cathode ray tube (CRT) or on another substrate. The inner CRT face is coated with a silicon semiconductor material replacing conventional phosphors utilized in CRTs for generating visual images. An electron beam impinging upon the silicon-coated CRT face plate creates conductive areas during liberation of minority carriers, in the form of electron-hole pairs. Antenna elements having a virtually unlimited variety of shapes and/or sizes can be formed on the CRT face.
摘要:
A miniature broadband monopole antenna design configured with integrated band-selecting filtering is disclosed. The antenna is electrically folded, and includes top and bottom monopole sections, with a meanderline to provide an inductive load between the two sections. The overall antenna structure can be embedded in a relatively small, RF transparent, composite structure (e.g., such as the fin of a guided munition), and has minimal impact on aerodynamics (low drag). The top, bottom, and meanderline elements of the antenna operate together to collectively provide multi-band operation (e.g., 30 MHz to 3 GHz).
摘要:
The present invention provides a low-cost, frequency-tunable, steerable, reflector array capable of simulating the electromagnetic effects of a parabolic or similarly-shaped reflector on a planar or conformal surface. Simple scatterers such as short circuited dipoles, disposed on a geometrically planar or conformal substrate, are configured from a series of scatterer sub-elements, electrically connected serially to one another by MEMS switches. These connected scatterer sub-elements form a reflective array disposed above a ground plane on the substrate. By properly controlling the length and spacing of the activated dipole elements, it is possible to simulate the equiphase reflection profile of a horn feed or sub-reflector feed of a parabolic or similar reflector. In addition, the array may be steered by selectively controlling the scatterer configurations.
摘要:
A wood article is submitted to a vacuum in an autoclave to remove air that it contains. Then, a solution which contains a wood preservative, a water-soluble cross-linkable prepolymer and a polymerization initiator is introduced into the autoclave. Polymerization to form a polymeric network in the wood article is carried out in an atmosphere substantially free of oxygen, while the preservative is chemically fixed to the wood. The result is a wood article with a permanently reduced hardness and an increased moisture content at equilibrium.
摘要:
Preservatives and oil are extracted from treated wood. For this purpose, treated wood that is intended to be discarded is comminuted, the chips are impregnated with an alkaline solution until softening of the chips and modification of the chemical state of the products to be extracted. Possibly, the chips may be treated with saturated steam at a temperature between 170.degree. C. and 210.degree. C. followed by an explosive decompression giving wood fragments. This is followed by a refining operation in a crusher permitting the grinding of the wood. The result is a substantial release of the preservatives and oil from the wood chips which are at least partly disintegrated. The chemical preservatives and the oil are collected separately from the wood chips in the aqueous phases which are produced in the impregnation, steam cooking-explosive decompression and refining steps.
摘要:
A gapless Vivaldi notch/meander line antenna is provided having a top plate with a Vivaldi notch, a cavity and a rearwardly-extending notch, with the top plate having integral side plates and a meander line bridging the rearwardly-extending notch at its distal end.
摘要:
The present invention features an RF-actuated microelectromechanical systems (MEMS) switch for use with switchable RF structures such as antennas. An antenna within each MEMS switch module is coupled to a tuned circuit and a detector. The DC voltage output of the detector is used as the control input to the MEMS switch. This allows arrays of MEMS switch modules to be actuated by remotely generated radio frequency signals thus alleviating the need for running metallic conductors or optical fibers to each MEMS switch. The MEMS switch is particularly suited for use in conjunction with both passive and active antenna elements to allow reconfiguration of antenna or other RF structures. Frequency response characteristics, phasing, and directionality characteristics may be altered easily.