摘要:
A plurality of heavy mass irregularities attached to an inner wall of the drill collar attenuate waves traveling through the collar. The plurality of heavy mass irregularities are spaced and sized for the maximum attenuation of acoustic pulses in a predetermined frequency range. The mass irregularities may be rings secured to the inner surface of the collar by neck pieces, extending outwardly from the outer circumference of the ring. The mass irregularities may be made of steel or tungsten and are between six and ten in number. The spacing of the irregularities may lie between twelve and fourteen centimeters. A center pipe may be included to isolate the irregularities from the fluid flow associated with the drilling operation. The pipe may be of a soft material such as rubber to reduce transfer of acoustic noise along the drill string. The irregularities may be in an oil based fluid with the pipe fitting closely in the center of the rings. In another embodiment of the invention, each of the mass irregularities is attached to the drill collar over substantially the entire length of the mass irregularity, enabling the attenuation of high frequencies. In yet another embodiment of the invention, the attenuator comprises a substantially cylindrical body with a plurality of recesses on the inside and/or outside of the cylindrica body, with the length of the recesses selected to provide attenuation within a specified band. In another embodiment of the invention, the attenuator comprises a plurality of sections each having an inner diameter and an outer diameter, each section acting like a waveguide with an associated passband and reject-band.
摘要:
A plurality of heavy mass irregularities attached to an inner wall of the drill collar attenuate waves traveling through the collar. The plurality of heavy mass irregularities are spaced and sized for the maximum attenuation of acoustic pulses in a predetermined frequency range. The mass irregularities may be rings secured to the inner surface of the collar by neck pieces, extending outwardly from the outer circumference of the ring. The mass irregularities may be made of steel or tungsten and are between six and ten in number. The spacing of the irregularities may lie between twelve and fourteen centimeters. A center pipe may be included to isolate the irregularities from the fluid flow associated with the drilling operation. The pipe may be of a soft material such as rubber to reduce transfer of acoustic noise along the drill string. The irregularities may be in an oil based fluid with the pipe fitting closely in the center of the rings. In another embodiment of the invention, each of the mass irregularities is attached to the drill collar over substantially the entire length of the mass irregularity, enabling the attenuation of high frequencies. In yet another embodiment of the invention, the attenuator comprises a substantially cylindrical body with a plurality of recesses on the inside and/or outside of the cylindrica body, with the length of the recesses selected to provide attenuation within a specified band. In another embodiment of the invention, the attenuator comprises a plurality of sections each having an inner diameter and an outer diameter, each section acting like a waveguide with an associated passband and reject-band.
摘要:
A plurality of heavy mass irregularities attached to an inner wall of the drill collar attenuate waves traveling through the collar. The plurality of heavy mass irregularities are spaced and sized for the maximum attenuation of acoustic pulses in a predetermined frequency range. The mass irregularities may be rings secured to the inner surface of the collar by neck pieces, extending outwardly from the outer circumference of the ring. The mass irregularities may be made of steel or tungsten and are between six and ten in number. The spacing of the irregularities may lie between twelve and fourteen centimeters. A center pipe may be included to isolate the irregularities from the fluid flow associated with the drilling operation. The pipe may be of a soft material such as rubber to reduce transfer of acoustic noise along the drill string. The irregularities may be in an oil based fluid with the pipe fitting closely in the center of the rings. In another embodiment of the invention, each of the mass irregularities is attached to the drill collar over substantially the entire length of the mass irregularity, enabling the attenuation of high frequencies. In yet another embodiment of the invention, the attenuator comprises a substantially cylindrical body with a plurality of recesses on the inside and/or outside of the cylindrica body, with the length of the recesses selected to provide attenuation within a specified band. In another embodiment of the invention, the attenuator comprises a plurality of sections each having an inner diameter and an outer diameter, each section acting like a waveguide with an associated passband and reject-band.
摘要:
A wireless communication device capable of determining its location in an indoor environment is disclosed. In an indoor environment, a wireless communication device may have insufficient access to GNSS satellites or cellular towers to make an accurate determination as to its location. Therefore, the wireless communication device generates a fingerprint map of the environment by estimating its position and scanning multiple positions within the environment for accessible access points and characteristics. The device stores this information in memory, which it can later refer to for determining its current position.
摘要:
This invention relates to rolls for use in or in contact with molten metal comprising a roll drum having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said roll drum, said thermally sprayed coating comprising from about 66 to about 88 weight percent of tungsten, from about 2.5 to about 6 weight percent of carbon, from about 6 to about 20 weight percent of cobalt, and from about 2 to about 9 weight percent of chromium; a process for preparing the rolls; a method for forming a metal layer on a metal sheet utilizing the rolls, e.g., galvanization; and a thermal spray powder for coating the outer peripheral surface of the rolls.
摘要:
Provided is a process for isolating zirconium peroxosulfate and its use, either as is or to prepare high purity zirconium compounds including powders of zirconium dioxide and stabilized zirconia. The process is based on precipitating a peroxide compound from an acidic peroxide solution of zirconium and provides a simple, economical method for producing the zirconium peroxosulfate powder and its derivatives with degree of zirconium recovery more than 99%. This process further provides an effective method for the separation and purification of zirconium from a variety of elements and/or naturally occurring ores.
摘要:
A radiation hardened latch is presented. The radiation hardened latch uses two redundant inverter paths to duplicate an input signal. The duplicated inverter paths are coupled with a radiation hardened inverter that will only produce an inverted signal if both input signals have equivalent voltage levels. The radiation hardened inverter and its output signal produce a radiation hardened node that drives either one of the duplicated inverter paths back to an appropriate voltage level in the event of an SET. Because, the radiation hardened node and duplicated inverter paths are isolated, the latch may be optimized for factors such as signal speed and driving strength. These factors may be optimized without affecting radiation hardness. The radiation hardened latch may also be used to build more complex circuits such as a flip-flop.
摘要:
A wireless communication device capable of determining its location in an indoor environment is disclosed. In an indoor environment, a wireless communication device may have insufficient access to GNSS satellites or cellular towers to make an accurate determination as to its location. Therefore, the wireless communication device generates a fingerprint map of the environment by estimating its position and scanning multiple positions within the environment for accessible access points and characteristics. The device stores this information in memory, which it can later refer to for determining its current position.
摘要:
A wireless communication device capable of more accurately estimating its location in an indoor environment is disclosed. In an indoor environment, the wireless communication device may seek to generate a fingerprint map so as to later identify its location within the environment. However, the map requires the device to at least estimate its current position. Therefore, the device includes one or more sensors to identify each of a bearing and a speed of the device. For example, the speed may be determined based on sensed steps and a stored step length. This information may then be used to estimate the device's location as it moves through the indoor environment.
摘要:
Provided is a process for isolating zirconium peroxosulfate and its use, either as is or to prepare high purity zirconium compounds including powders of zirconium dioxide and stabilized zirconia. The process is based on precipitating a peroxide compound from an acidic peroxide solution of zirconium and provides a simple, economical method for producing the zirconium peroxosulfate powder and its derivatives with degree of zirconium recovery more than 99%. This process further provides an effective method for the separation and purification of zirconium from a variety of elements and/or naturally occurring ores.