摘要:
A process for producing a lubricating oil basestock having at least 90 wt. % saturates and a VI of at least 105 by solvent extracting a feedstock to produce a raffinate, solvent dewaxing the raffinate, selectively hydroconverting the solvent dewaxed raffinate in a two step hydroconversion zone followed by a hydrofinishing zone and a dewaxing zone.
摘要:
It has been discovered that waxy feeds can be upgraded using a catalyst made by combining powdered dewaxing catalyst with powdered isomerization catalyst said mixture of powdered catalysts being formed into a discrete particle.
摘要:
A system consisting of a base GPS receiver with a clear view of the sky, one or more remote GPS receivers with restricted views of the sky and a processing center that batch processes range information provided by the GPS receivers determines the positions of the remote GPS receivers to within tight tolerances. The base GPS receiver and the remote GPS receivers produce range information based on the satellite signals that the respective receivers can track at a given time, and provide the range information to the processing center. The range information includes both code and carrier measurements for each of the signals that are being tracked by the respective GPS receivers. The center collects the range information over an extended period of time, for example, hours, days or weeks, and then batch processes the collected information in multiple passes through the data, to calculate the precise latitude, longitude and height of the receiver. The center batch processes the data using a floating ambiguity filter that, after a first pass through the data, is initialized with the position calculated in an earlier pass. The center also calculates the quality of the collected range information by fixing the position and position covariance of the floating ambiguity filter and using double differences with the base GPS receiver measurements, to ensure that the information used in subsequent position calculations is sufficiently reliable.
摘要:
A cylindrical roller apparatus for a glass tempering oven comprises a ceramic roller having a first end portion and a second end portion, a flat formed on each end portion of the roller, an end cap having a cylindrical wall mounted on each end portion of the roller, a metal retaining plate positioned on each flat, and a screw threaded through each end cap wall that screws into contact with the retaining plate for securing each end cap to the roller and for pushing the roller flush against the inner surface of the end cap wall. An acess hole can be provided in the end cap for welding together the screw, retaining plate, and end cap. Grooves can also be formed on the inner surface of the end cap, accessible through an opening formed through the end cap, to allow injection of adhesive between the roller and end cap to further secure the two together.
摘要:
A track model is created for use with a GPS receiver. In one embodiment, the track model is a set of planar surfaces which approximate the contiguous surface on which navigation takes place. The GPS receiver searches for an appropriate planar surface associated with its approximate position. Having found the appropriate planar surface, the GPS receiver constrains its position using the planar surface associated with its approximate position. Using the track model improves the accuracy of the computed position at the time and improves the ambiguity estimation process so that positions with greatly improved accuracy are available sooner.
摘要:
A GPS receiver embodying the invention includes a first channel that preferentially processes line-of-sight signals and a second channel that preferentially processes multipath signals. It then compares the results to determine if the multipath has degraded the results of the processing of the line-of-sight signals.
摘要:
An aromatic oil having an aniline point less than 120.degree. F., a mutagenicity index based on The Modified Ames Test of less than 2.0, a benzene, naphthalene and methyl substituted benzenes and naphthalenes individual component concentrations less than 100 wppm, and a clay gel aromatics fraction content of at least 50 weight % based on aromatic oil, said aromatics fraction characterized in that it has a naphthene-benzenes and dinaphthenebenzenes content of at least 50 volume % based on aromatics fraction. The invention also relates to a process for preparing the aromatic oil which comprises the steps of selective solvent extraction, selective distillation and two-stage hydrotreating with removal of hydrogen sulfide and/or ammonia. The aromatic oils are useful in agricultural formulations due to their low environmental impacts.
摘要:
A navigational apparatus includes a receiver, two antennas, and a computational unit to receive satellite positional signals and provides corrected position, azimuth, and pitch readings. The computational unit: determines differences in the signal carrier measurements output by the receiver; rejects or accepts carrier ambiguity candidates based on predefined criteria; and estimates multipath on successive pairs of carrier observations to obtain the corrected readings.
摘要:
A receiver for pseudorandom noise (PRN) encoded signals consisting of a sampling circuit and multiple channel circuits, with each channel circuit including a carrier and code synchronizing circuit and multiple digital correlators with dynamically adjustable code delay spacing. The sampling circuit provides high-rate digital samples of the incoming composite signal to each receiver channel. Within each channel, the synchronizing circuit detects cycle slips in a locally generated carrier reference signal as well as phase drift in a locally generated PRN code signal. The correlators compare the digital samples with a locally generated PRN code to produce early, late, and/or punctual correlation signals which are used to adjust the local PRN code. A non-linear sampling technique may be used to provide increased sensitivity in the presence of continuous wave interfering signals.
摘要:
Process and apparatus are provided for the preparation of crimped staple fibers. By automatically adjusting the pressure on the stuffer crimper box discharge means as a function of staple cutter speed, a crimped staple product with uniform fiber-to-fiber cohesion level is obtained.