The present invention is a combination scrub brush, for use with or without a shaft, that presents a finished appearance regardless of whether or not the shaft is in use. The brush includes a grip, a base plate, and a bristle block holding several bristles formed into a substantially flat bristle surface and a curved bristle surface. The base plate is attached lengthwise to the grip, and the grip has a shaft line that is parallel to and offset from the base plate. An internal screw thread in the grip allows the user to attach a shaft to the grip so that otherwise inaccessible surfaces can be cleaned. When the shaft is not in use, a plug inserted into the grip provides a finished appearance to the brush. The plug includes a slot and loop combination used to secure the plug to the grip when the plug is removed and the shaft is installed. The slot and loop combination can also be used to store the entire brush when the shaft is removed and the plug is installed.

Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention relates generally to cleaning devices. More specifically, it relates to a scrub brush that always presents a finished appearance and that is adapted for removable attachment to a shaft.
2. Background of the Invention
Combination brushes for use as a hand-held brush and optionally with a shaft are well known in the art. It is also known to provide a cap or plug that allows the brush to present a finished appearance even when the shaft is removed. For example, U.S. Pat. Nos. 3,473,183 and 3,369,268 to Burns et. al. teach hand-held paint tools with gripping portions adapted for reception of an extension pole or cap. The cap closes the gripping portion when the extension pole is not in use, thereby allowing the paint tool to present a finished appearance. However, the Burns patents do not provide a way to secure the cap to the tool when the extension pole is in use. Thus, when the extension pole is attached to the tool the cap must be stored apart from the tool and may easily become lost.
Also, most combination brushes are configured such that extension poles attach crosswise directly to the head of the brush. Therefore, for most brushes, the shaft line or primary axis of extension poles inserted into the brush intersect the brush head and have no offset from the brush head. Even in U.S. Pat. No. 4,215,448, where the handle is offset and parallel to the brush head, an extension pole is attached crosswise to the brush at the brush head and the shaft line intersects the brush head. Although the handle is offset and parallel to the brush head in U.S. Pat. Nos. 3,473,183 and 3,369,268 the extension pole attaches crosswise to brush. In U.S. Pat. No. 5,551,115, an extension pole can attach parallel to and lengthwise to the brush, but the pole is not offset from the handle.
It is in view of the above problems that the present invention was developed. The invention is a combination brush, adapted for use with a shaft or hand-held without a shaft, including a plug that allows the brush to present a finished appearance when the shaft is not in use and means for securing the plug to the brush when the shaft is in use. The brush has a hollow grip, a base plate, and a bristle block holding several bristles with frayed ends that form a substantially flat bristle surface and a curved bristle surface. The base plate is attached lengthwise to the grip, and the shaft line is parallel to and offset from the base plate.
In the preferred embodiment of the invention, the grip and base plate are integrally formed, and the grip is contoured to fit comfortably into the user""s hand. A plug is provided at one end of the grip, removably attached thereto by an external screw thread on the plug and an internal screw thread on the grip. When inserted, the plug gives the brush a finished appearance. The plug also has a slot and loop combination that can be used to secure the plug to the grip when it is not inserted (that is, when the shaft is in use). The slot and loop combination can also be used to store the entire brush, for example by hanging it on a hook, when the plug is inserted. When the plug is removed, the internal screw threads on the grip can accept an externally threaded shaft.
It is an object of the present invention to provide a scrub brush that can be hand-held or optionally attached lengthwise to a shaft through an offset and parallel shaft line.
It is another object of the present invention to provide a combination brush that presents a finished appearance at all times, regardless of whether or not the shaft is in use.
It is yet another object of the present invention to provide a combination brush with a cap that includes means for securing the cap to the brush when the cap is not in use.
Further objects and advantages of the present invention will be apparent from the description below with reference to the accompanying drawings in which like numbers indicate like elements.


Systems and methods are described for dynamic switching techniques for space-time coding/decoding based on channel status information for a MIMO-OFDM system. The system and method for dynamic switching of space-time coding mode include a determining step for determining a space-time coding mode based on feedback information by a transmitter; a mapping step for mapping the determined coding mode to a corresponding coder so that a number of sets symbol streams corresponding to respective transmit antennas are generated after coding a modulated symbol sequence for desired coding; and a feedback step for periodically feeding used coding mode information back to a receiver via a forward control channel.

A Multiple-Input Multiple-Output (MIMO) system is capable of obtaining frequency efficiency proportional to the number of transmit antennas in an environment of rich scattering and of obtaining very high wireless transmission rate in a condition of not sacrificing frequency resource and transmit power, and thereby it is widely concerned.
An Orthogonal Frequency Division Multiplexing (OFDM) system modulates transmit symbols onto orthogonal narrow-band sub-carriers so that the symbols transmitted on each sub-carrier is only subject to flat fading and thus design for receivers is largely simplified, which is an efficient solution to high rate wireless data transmission under multipath fading channels.
It is assumed that the channel is flat in an existing MIMO structure, but the actual wireless communication channel is frequency-selective. Therefore, combination of MIMO and OFDM will meet requirement of MIMO on channel selection and is one of advanced wireless communication solutions in future.
MIMO has two basic space-time structures. One is space-time coding and the main object thereof is to obtain coding gain. The other is space multiplexing and the main object thereof is to obtain data rate gain. There are three basic structures in space-time coding schemes: it is referred to as space-time block coding if space diversity is obtained by jointly coding the transmitted information symbol stream in space and time domains; it is referred to as space-frequency block coding if space diversity is obtained by jointly coding the transmitted information symbol stream in space and frequency domains; it is referred to as space-time-frequency block coding if space diversity is obtained by jointly coding the transmitted information symbol stream in space, time and frequency domains. Although diversity in space, time and frequency domains can be obtained by space-time-frequency coding, the space-time block coding and the space-frequency block coding (it is recorded as space-time/space-frequency block coding) is more efficient in an actual application since the space-time-frequency coding relatively has high complexity and low flexibility.
The existing technical solution is described as follows taking example for a two-transmit-two-receive MIMO-OFDM system.
FIG. 1 and FIG. 2 respectively illustrated structures of transmitter and receiver for space-time block coding or space-frequency block coding in an existing MIMO-OFDM system. In the transmitter, the transmitted source bit sequence is mapped to a modulated constellation to generate a modulated symbol sequence after channel coding and interleaving. The modulated symbol sequence is space-time block coded (space-frequency block coded) to generate two sets of symbol streams respectively corresponding to transmit antenna 1 and transmit antenna 2. After pilot symbols are inserted according to pilot pattern, the respective symbol streams of the transmit antennas are inverse fast fourier transformed (IFFT) to generate OFDM symbols, each of which has circle prefix inserted at the head to generate a spread OFDM symbol. A number of spread OFDM symbols form a time slot, and a pseudo random synchronization sequence is inserted prior to each time slot for timing synchronization. A number of time slots form a transmission frame of minimum transmission unit.
In the receiver, the received symbols streams are first frame synchronized, time slot synchronized and symbol synchronized based on synchronization sequences. The synchronized spread OFDM symbols are fast fourier transformed (FFT) after the circle prefix is removed. A frequency domain pilot is extracted from the OFDM sub-carrier for channel estimation. The estimated channel frequency response is assistant for decoding of remain data symbols by a space-time block coding decoder/a space-frequency block coding decoder. The generated symbol streams are demodulated, deinterleaved and channel decoded to generate an estimated source bit sequence.
The main differences between the space-time block coding and the space-frequency block coding are described as follows in FIG. 3 and FIG. 4.
As shown in FIG. 3, the pre-transmitted modulated symbols S1 and S2 are coded by a space-frequency block coder to generate a symbol stream S1, S1*, S2 and −S2*. Then, S1 and S1* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 1; S2 and −S2* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 2. As such, the next set of pre-transmitted modulated symbols S3 and S4 are coded by the space-frequency block coder to generate a symbol stream S3, S3*, S4 and −S4*. Then, S3 and −S4* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 1; S4 and S3* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 2.
As shown in FIG. 4, the pre-transmitted modulated symbols S1 and S2 are coded by a space-time block coder to generate a symbol stream S1, S1*, S2 and −S2*. Then, S1 and −S2* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 1; S2 and S1* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 2. The pre-transmitted modulated symbols S3 and S4 are coded by the space-time block coder to generate a symbol stream S3, S3*, S4 and −S4*. Then, S3 and −S4* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 1; S4 and S3* are mapped to adjacent sub-carriers of the same OFDM symbol and transmitted by antenna 2.
It is assumed that the channel matrix is constant between adjacent coded OFDM symbols in the space-time block coding designed based on orthogonal signals. However, the symbol interval of the OFDM system largely increases compared with a single carrier system with the same bandwidth so that the condition that the channel matrix is constant between adjacent coded OFDM symbols is difficult to be achieved, and thus the performance of space-time block coding is degraded. Particularly, since the future mobile communication system supports users with higher frequency band and higher moving speed, signals subject to fast fading will badly degrade performance of the space-time block coding. Similarly, the channel matrix is constant between adjacent coded OFDM symbols in the space-frequency block coding designed based on orthogonal signals. However, the actual channel is usually frequency-selective, so that the condition that the channel matrix is constant between adjacent coded OFDM symbols is difficult to be achieved, and thus the performance of space-frequency block coding is degraded.
FIG. 5 and FIG. 6 respectively illustrate comparison of performances of the space-time block coding and the space-frequency block coding at different delay spreading and different moving speed. When delay spreading of channel is less, the same bit error rate (BER) performance is obtained in a range of moving speed of 5-120 kmph for the space-frequency block coding (SFBC). Even when the moving speed is up to 500 kmph, performance as good as at a low speed can be obtained for the space-frequency block coding if an ideal technique for removing interference between carriers is used. When delay spreading of channel is greater, performance will be badly degraded in a variety of ranges of moving speed for the space-frequency block coding, which attributes to channel frequency-selection caused by greater delay spreading resulting in non-constant between adjacent carriers of the space-time block coding. Similarly, good BER performance can be obtained for the space-time block coding at a low moving speed of 5 kmph no matter how much the channel delay spreading is. However, in a range of moving speed of 120-150 kmph, the performance of the space-time block coding is badly degraded, which attributes to fast channel fading caused by greater Doppler shift resulting in non-constant channel between coded symbols in the time domain.
In one word, the space-time coding can operate at frequency-selective channels, but it is subject to effect on orthogonality by Doppler shift, which badly degrades performance; the space-frequency coding can operate at Doppler shift channels, but it is subject to effect on orthogonality by frequency-selection, which badly degrades performance.
Therefore, there is a certain limit in the environment of any existing space-time coding scheme.

Method and apparatus for dynamic switching of space-time coding/decoding method


Process for producing a copolyester of desired quality at low cost with high productivity, preferably a process for producing P(3HB-co-3HH) of 4 mol % or more 3HH content with a productivity as high as 40 g/L or more. In particular, a process for producing a copolyester of 3HB and 3HH comprising culturing a microorganism with the use of, as a carbon source, a fat or oil containing lauric acid as a constituent fatty acid under such conditions that phosphorus as a source of nutrition is limited.

Up to now, a large number of microorganisms have been known to store polyester as an energy source substance within cells. A typical example of the polyester is poly-3-hydroxybutyric acid (hereinafter referred to briefly as "P(3HB)"). P(3HB) is a thermoplastic polymer and is biodegradable in the natural environment and, thus, has recently attracted attention as an ecofriendly green plastic. However, since P(3HB) is high in crystallinity, it is hard and fragile, so that the range of practical application thereof is limited. Therefore, studies have been undertaken to modify the P(3HB) for improving these properties.
In the course of the study, a copolymer P(3HB-co-3HV) derived from 3-hydroxybutyric acid (3HB) and 3-hydroxyvaleric acid (hereinafter referred to briefly as "3HV"), and a production method thereof have been developed (Japanese Kokai Publication Sho-57-150393, Japanese Kokai Publication Sho-59-220192 and Japanese Kohyo Publication Hei-11-500008). This P(3HB-co-3HV) is rich in flexibility as compared with P(3HB), hence it was considered to have a wide application range.
Methods for producing the copolymer P(3HB-co-3HV) described in these patent documents comprise growing cells in the first stage and culturing a microorganism with restricting nitrogen or phosphorus in the latter stage to produce the copolymer similarly to the conventional methods for producing P(3HB).
Moreover, as for P(3HB-co-3HV), since the flexibility changes as a content of 3HV increases, researches for controlling the 3HV content have also been made. For example, propionic acid is used in Japanese Kokai Publication Sho-57-150393 and Japanese Kokai Publication Sho-63-269989, and propan-1-ol is used in Japanese Kokoku Publication Hei-7-79705, and by changing an addition amount thereof to a medium, the 3HV content in P(3HB-co-3HV) is controlled to produce P(3HB-co-3HV) having the 3HV content of 10 to 90 mol %.
Actually, however, P(3HB-co-3HV) shows only slight changes in the characteristics even when the 3HV content is increased. In particular, the flexibility is not improved to such an extent required for its use in films and the like. Thus, it has been used only in the field of rigid shaped articles such as shampoo bottles and disposable razor grips.
Under such circumstances, for making up the above-mentioned drawbacks of the copolymer derived from 3HB and 3HV, copolymers containing, as a component, a hydroxyalkanoic acid other than 3HB and 3HV such as 3-hydroxypropionic acid (hereinafter referred to briefly as "3HP"), 3-hydroxyhexanoic acid (hereinafter referred to briefly as "3HH"), 3-hydroxyoctanoic acid (hereinafter referred to briefly as "3HO"), 3-hydroxynonanoic acid (hereinafter referred to briefly as "3HN"), 3-hydroxydecanoic acid (hereinafter referred to briefly as "3HD") or 3-hydroxydodecanoic acid (hereinafter referred to briefly as "3HDD") are intensively studied (Poirier, Y., Nawrath C., Somerville C, BIO/TECHNOLOGY, 13, 142–150, 1995).
Among them, noteworthy studies are those on a copolyester comprising 3HB and 3HH units, particularly a copolymer P(3HB-co-3HH) derived only from 3HB and 3HH, and on a production method thereof (Japanese Kokai Publication Hei-05-93049 and Japanese Kokai Publication Hei-07-265065). The production methods of copolyesters such as P(3HB-co-3HH) described in these patent documents comprise a fermentation production from fatty acids such as oleic acid or oils and fats such as olive oil by using Aeromonas caviae isolated from soil.
A study regarding characteristics of P (3HB-co-3HH) has also been conducted (Y. Doi, S. Kitamura, H. Abe, Macromolecules 28, 4822–4823, 1995). This document reports a fermentation production of P (3HB-co-3HH) with a 3HH content of 11 to 19 mol % by culturing A. caviae with a fatty acid of not less than 12 carbon atoms. The result shows that, as the 3HH content increases, P(3HB-co-3HH) exhibits a gradual increase of flexibility from the hard and brittle characteristics of P (3HB) and finally shows more flexibility than P(3HB-co-3HV).
Additionally, it was reported that a polyhydroxyalkanoic acid(PHA) synthase gene from A. caviae was cloned and introduced into R. eutropha having an accumulating ability of polyhydroxybutyric acid(PHB) of not less than 90% to generate a recombinant strain, which was then used to produce P (3HB-co-3HH) using fatty acids as a carbon source (T. Fukui, Y. Doi, J. Bacteriol., vol. 179, No. 15, 4821–4830, 1997 and Japanese Kokai Publication Hei-10-108682). In these documents, it is reported that P (3HB-co-3HH) having the 3HH content of 10 to 20 mol % may be produced by using sodium octanoate as a carbon source.
Furthermore, a method has been recently disclosed which comprises using multiple carbon sources in producing a polyester using the above recombinant strain, and it was revealed that a carbon number of an oil or fat or a fatty acid used as a carbon source had an influence on the 3HH-content of P(3HB-co-3HH) (Japanese Kokai Publication 2001-340078).
If the 3HH content of P(3HB-co-3HH) can be controlled optionally in a wide range in the future, both hard copolymers and soft copolymers may be produced by fermentation, and such copolymers will find a broad range of applications, from chassis for TV-set, which is required to be hard, to a thread or a film, which are required to be flexible.
However, when a practical application of P(3HB-co-3HH) is considered, what becomes a barrier is the production cost. For example, in any methods which have already been disclosed, the productivity of P(3HB-co-3HH) is low and it is as much as 30 g/L. Additionally, a fatty acid having the carbon number of not less than 12, which is expensive as a carbon source, is used as the only carbon source, or an addition of an expensive fatty acid (hexanoic acid) is required to improve the 3HH content. Thus, it is scarcely possible to apply such technologies to an industrial production method of said polymer.
As described above, characteristics of P(3HB-co-3HH) are remarkably affected by the 3HH content. As a result of the investigation conducted by the present inventors, it is preferable to secure not less than 4 mol % of the 3HH content in order to enable wide applications of P(3HB-co-3HH). However, in the conventional culture methods, not only an expensive carbon source is required but also the productivity tends to be more deteriorated when trying to improve the 3HH content (see Japanese Kokai Publication 2001-340078).
Whereupon, it has been long awaited to develop a technology for realizing a high productivity of cells and polymer content in low cost, and from an industrial point of view, a technology capable of producing P(3HB-co-3HH) having the higher productivity, and preferably, a technology capable of producing P(3HB-co-3HH) having not less than 4 mol % of the 3HH content while securing that productivity.


A method for characterizing formation fluid using flowline viscosity and density data in an oil-based mud environment includes: making an initial estimate of the density and viscosity of the individual components of the sampled fluid; measuring the volume fractions, density, and viscosity of the total mixture of formation fluid; computing the density and viscosity of the total mixture using the estimate and the measured volume fractions; comparing the computed values with the measured values; and updating the estimate based on the comparison until convergence. The process is repeated as additional data are acquired until the converged computed values differ only by an acceptable amount.

1. Field of the Invention
This invention relates broadly to oil exploration and production. More particularly, this invention relates to methods for determining the viscosity and density of formation fluids.
2. State of the Art
Various methods and tools are used to describe reservoir fluid and formation properties in an oil well. Some of these methods and tools aim to determine the relative volume of oil, water, and gas, for example. Other methods and tools aim to qualitatively describe the reservoir oil. This can be done by sampling the oil and by determining the density and viscosity of the sampled oil. However, when the sampled fluid is contaminated with mud-filtrate, making a direct measurement of reservoir oil density and/or viscosity is difficult.
Using the Schlumberger Modular Formation Dynamics Tester (MDT), fluid samples can be taken from the formation wall. Modules in the MDT test the samples in a variety of ways and with appropriate sensors could provide density and viscosity measurements for the mixture sampled. If the mixture were pure formation fluid, characterization of the oil in the reservoir could be accurately determined. However, the fluid is nearly always contaminated with at least some drilling mud. This prevents an absolutely accurate characterization of the oil in the reservoir.
During the drilling process, mud is pumped into the wellbore surrounding the drilling tool. The mud serves several purposes. It acts as a buoyant medium, cuttings transporter, lubricant, coolant, as well as a medium through which downhole telemetry may be achieved. The mud is usually kept overbalanced, i.e. at a higher pressure than the pressure of the formation fluids. This leads to "invasion" of the mud into the formation and the buildup of mudcake on the borehole wall. This is the environment in which samples are taken with a tool such as the MDT. Although the MDT filters out the solids from the samples, mud filtrate is always present in the samples.
When the mud filtrate is immiscible with the formation fluids, it is possible to separate it from the formation fluids by centrifuge or by settling due to gravity. However, when a well is drilled with oil-based-mud (OBM) the filtrate may miscibly mix with the formation fluid. When samples are taken, the first samples are nearly all OBM and if one waits long enough the last samples are nearly all formation fluid. However, it is unlikely that even the last sample will be pure enough to provide highly accurate measurements of viscosity and density of the formation fluids.

Formation fluid characterization using flowline viscosity and density data an oil-based mud environment


Provided is an electromechanical transducer device including a substrate that is conductive, and a plurality of electromechanical transducer elements disposed on a first surface of the substrate. A groove that electrically isolates the plurality of electromechanical transducer elements from each other is formed in the substrate, the groove extending from a second surface side of the substrate toward the first surface side of the substrate, the second surface being opposite the first surface. The width of the groove on the first surface side of the substrate is smaller than the width of the groove on the second surface side of the substrate.

1. Field of the Invention
The present invention relates to an electromechanical transducer device, such as an ultrasonic transducer, and to a method of making the electromechanical transducer device.
2. Description of the Related Art
Ultrasonic transducers, which convert an electric signal into ultrasound and vice versa, are used as probes for medical imaging and non-destructive testing. There is a type of ultrasonic transducer called a capacitive micromachined ultrasound transducer (CMUT). A CMUT includes, for example, a substrate including a lower electrode, a membrane that is supported by a supporting unit formed on the substrate, and an upper electrode. The lower electrode, the membrane, the upper electrode, and the supporting unit surround a cavity. The CMUT emits a sound wave (oscillatory wave) when a voltage is applied between the lower electrode and the upper electrode and thereby the membrane is vibrated. On the other hand, a CMUT detects a sound wave (oscillatory wave) when the sound wave is received and vibrates the membrane and thereby the capacitance between the lower electrode and the upper electrode is changed.
Traditionally, CMUTs have been made by so-called surface micromachining, bulk micromachining, and the like. Examples of wiring methods include a method of forming an element including a plurality of membranes and cavities on a silicon substrate and connecting the element to a circuit board through the silicon substrate that serves as a lower electrode and a through-hole interconnection (US 2006/0075818 A1). Referring to FIG. 6, this method will be described. A CMUT 1007 includes a plurality of elements 1008, and each of the elements 1008 individually sends and receives ultrasound. Each of the elements 1008 includes an upper electrode 1000, a membrane 1001, a cavity 1002, and a lower electrode 1003. Grooves 1004 are formed so as to electrically isolate and insulate the elements 1008 that are adjacent to each other. The CMUT 1007 is connected to an ASIC substrate 1006 through bumps 1005.
In the existing CMUT, it is necessary to form the separation grooves each having a width of several hundred micrometers in order to electrically isolate the elements from each other, each of the elements including one or a plurality of cavities. Because the mechanical strength of a portion surrounding a cavity is low, it is necessary to support the portion with a supporting member. However, cavities cannot be formed in a region that corresponds to the separation groove (directly above the separation groove) and for which it is difficult to support a cavity. Therefore, the number of cavities that can be formed per unit area of a substrate is limited. As a result, the fill factor (which refers to the proportion of the area occupied by electromechanical transducer elements in the present specification) is reduced. Therefore, the sensitivity of the device is reduced.

Electromechanical transducer device and method of making the same


A production system includes at least one production component having a production cycle which is interruptible by a detected production failure, at least one detector configured to monitor an output of the at least one production component, the detector configured to detect a production failure and to generate a signal indicative of the production failure, and a control unit. The control unit is configured to, in response to the signal from the detector, cause the respective production component to reject production material for a first predetermined duration of time, and in response to the expiration of the first predetermined duration of time, to slow down production for at least a second predetermined duration of time. The control unit can further return the production system to a normal production state in response to receiving a restart signal before the expiration of the first or second predetermined duration of time.

Production systems, such as injection molding systems, which are employed to create production materials such as optical disks, usually include more than one production component, such as injection molding machines. The injection molding machines form clear substrates employed in the manufacture of optical disks, such as DVDs, CDs or other plastic media. In a system where two or more injection molders are employed, it is sometimes difficult to shut parts of the system down when other parts are producing rejectable product.
In DVD replication lines, two or more injection molding machines, one metalizer-bonding machine and one scanner may be integrated. The injection molding machines have a drop limit condition (the condition is fixed by software), such that when the quality of a disk as measured by the scanner is inadequate, the injection molding machines are shut down. One major disadvantage is that with the drop limit, it is not possible to run lower than 20 shots (discs) per injection molding machine. This is the minimal number of shots before the line can be shut down. Therefore, with every downstream interruption of production, at least twenty clear substrates are wasted by each injection molding machine.
In addition, in prior art production systems, completely shutting down the production components causes startup delays when trying to restart the production system. Also, if one injection molding machine stops the other machines are unaware of the shut down and continue running and making clear discs which will be wasted.

Method, apparatus and system for reducing waste in production systems


Each image in a first set of images includes respective exposures of an image capture device to a beam of radiation, each of a plurality of components of a radiation delivery system being at respective specified orientations with respect to a three-dimensional coordinate system during each of the exposures. Respective beam images are reconstructed from each of the exposures by drawing a line at a predetermined angle to the first image and through a center of a radiation beam shown on each first image. The reconstructed beam images are combined on a second image.

"Star Shots" (also called "spoke shots") are used for quality assurance in radiation therapy systems. Such images are so named because they feature images of radiation beams that generally form a star or spoke pattern. Star shots are typically obtained on film placed parallel to a radiation beam (for a gantry star shot) or perpendicular to the beam (for couch, primary collimator, or MLC star shots). A star shot may be used to determine the radiation isocenter location (i.e., center of rotation) for components of a radiation delivery system, e.g., a gantry, couch, primary collimator, and MLC (multi-leaf collimator) relating to a radiation device such as a linear accelerator, a Cobalt-60 unit, a Radiation Therapy simulator, etc. Accordingly, a goal of the star shot is to ensure that the center of rotation of the element of the radiation delivery system (gantry, couch, primary collimator, or MIX) is within a certain specification during normal rotational operation, thereby ensuring that the beam of radiation hits its intended target when delivered from different angles.
Obtaining desired precision can be particularly challenging, especially in the case of a linear accelerator gantry weighing several tons, and where the typical requirement for a standard linear accelerator gantry is that the beams must intersect within a circle of two millimeters (mm) in diameter, and less than one mm for linear accelerators capable of performing stereotactic treatments. Compounding the difficulty is that, in addition to the size of the radiation beam intersection circle being within tolerance, it is also a requirement that the location of the beam intersection center be within 1 mm of the mechanical isocenter of the radiation delivery system for all mechanical motion in the system, including motion of the gantry, couch, primary collimator, and/or MLC collimator rotations.
Present systems for obtaining a star shot to determine radiation isocenters typically depend on use of film, which is difficult to use, expensive, and increasingly difficult to obtain. Further, present systems for obtaining a star shot do not provide information relating to the mechanical isocenter of a system unless the mechanical isocenter is manually labeled, which is inefficient and prone to error.

Radiation delivery isocenter analysis tool


A control system for an electric motor. Field Oriented Control, FOC, uses a digital control system, and attempts to maintain the rotating stator magnetic field ninety degrees ahead of the rotor field, in order to maximize torque. However, if a three-phase motor is used, which is very common, large amounts of computation are required, to convert from a three-phase coordinate system to an orthogonal coordinate system. The invention replaces the three-phase motor with a two-phase motor, which has been found to impose certain additional costs, but also provides benefits.

This discussion will first explain how a simple synchronous motor operates, and then explain one type of prior-art speed control used with such a motor.
Synchronous Motor
FIG. 1 illustrates schematically three stator coils 3, 6, and 9, which are contained in a three-phase synchronous motor (not shown). FIG. 2 shows the coils, but with connecting wires W of FIG. 1 omitted, to avoid clutter. In FIG. 2, currents 13, 16, and 19 are generated in the respective coils. Each current produces a magnetic field B3, B6, and B9, as indicated.
The coils 3, 6, and 9 are physically positioned to be 120 degrees apart, as shown, so that the fields B3, B6, and B9 are also positioned 120 spatial degrees apart. This arrangement allows creation of a magnetic field which rotates in space at a constant speed, if proper currents are generated in the coils, as will now be explained.
FIG. 3 illustrates three-phase currents. The vertical axis on the coordinates runs from negative unity to positive unity for simplicity. In practice, one would multiply the values of unity by the actual peak-to-peak values of the currents being used.
Currents in the form of sine waves SIN3, SIN6, and SIN9 are created respectively in coils 3, 6, and 9, as indicated. Coil 3 resides at zero physical degrees. SIN3 begins at zero electrical degrees, as indicated on the plot.
Similarly, coil 6 stands at 120 degrees from coil 3. SIN6 begins at 120 degrees, as indicated on the plot. Similarly, coil 9 stands at 240 degrees from coil 3. Correspondingly, SIN9 begins at 240 degrees, as indicated on the plot.
Each coil 3, 6, and 9 produces a magnetic field, as indicated. Those three magnetic fields add vectorially to produce a single magnetic field. Two examples will illustrate this vectorial addition.
In the first example, time T1 is chosen in FIG. 3, which corresponds to 255 electrical degrees. T1 is also indicated in FIG. 4. At this time T1, the values of the currents I3, I6, and I9 are indicated. Those currents exist in coils 3, 6, and 9 in FIGS. 2 and 3. Those currents produce magnetic fields which are roughly proportional to the currents.
Since the coils 3, 6, and 9 are physically positioned at angles of zero, 120, and 240 degrees, the magnetic fields are also positioned at those angles. The magnetic fields are indicated as B3, B6, and B9 in FIG. 4.
It is noted that field B3 is positioned at 180 degrees, rather than zero degrees. This occurs because current 13 is negative, thus producing a magnetic field B3 which is 180 degrees from the magnetic field which would be produced by a positive current.
Field-vectors B3, B6, and B9 are re-positioned within circle C1, to show vector addition. They sum to the resultant vector R1. Resultant R1 represents the vector sum of the three magnetic fields, and is an actual magnetic field vector located in space. Resultant R1 is the magnetic field produced by the three coils, and is termed the stator field.
In the second example, time T2 in FIG. 3 is chosen, which corresponds to 330 electrical degrees. T2 is also indicated in FIG. 5. At this time T2, the particular values of currents I3, I6, and I9 are indicated.
It is noted that I3 and I6 are superimposed over each other: the same arrow represents both. It should be observed that these two identical currents produce two magnetic fields of the same size at this time. However, because the two currents I3 and I6 are applied to coils which are physically 120 degrees apart, the magnetic fields are oriented differently in space.
The magnetic field vectors produced are indicated as B3, B6, and B9 in FIG. 5.
It is noted that fields B3 and B6 are positioned at 180 and 300 degrees, respectively, rather than at zero and 120 degrees. As before, this occurs because currents I3 and I6 are negative, producing magnetic fields B3 and B6 which are 180 degrees rotated from the magnetic field which would be produced by positive voltages.
Field-vectors B3, B6, and B9 are re-positioned within circle C2, to show vector addition. They sum to the resultant vector R2. Resultant R2 represents the vector sum of the three magnetic fields, and is an actual magnetic field vector located in space. It is the stator field.
If these two examples are repeated for every angle from zero to 360 in FIG. 3, it will be found that a resultant R in FIG. 6 is produced at each angle, and that all resultants R are identical in length. It will also be found that, as one computes resultant R for sequential angles, that resultant R rotates at a uniform speed around circle C.
The arrangement just described produces a constant magnetic field which rotates at a constant speed. This rotating field can be used as shown in FIG. 7.
FIG. 7 illustrates the coils of FIG. 2. A rotor ROT is added, which contains a rotor magnetic field RF, produced by a magnetic field source FS, which may be a permanent magnet or electrical coil. Because of the laws of physics, the rotor field RF will attempt to follow the rotating resultant R. Consequently, the rotating resultant R induces rotation in the rotor ROT, producing motor-action.
Control System
A prior-art approach to controlling speed of the motor just described will be given. In one approach, the basic idea is to maintain the resultant stator field R in FIG. 7 at 90 degrees ahead of the rotor field RF. (FIG. 7 shows the resultant R at zero degrees with respect to RF.)
The particular approach to be explained is sometimes termed "Field Oriented Control," FOC. In FOC, the stator field is transformed, or superimposed, onto a rotating coordinate system, and is then compared with the rotor field, within the rotating coordinate system. Under this approach, two fields (stator and rotor) are, ideally, not changing with respect to each other and, when they do change, they change slowly, with respect to each other. FOC reduces bandwidth requirements, especially in Proportional Integral controllers, used to control the error between the two fields.
Perhaps an analogy can explain the bandwidth reduction. Assume two race horses traveling on a circular track. Each, in essence, can be represented by a hand on a clock. In one approach, a stationary observer can, say, every second, compute position of each horse, compare the positions, and deduce a difference between positions. In essence, the observer computes an angle for each hand of the clock, and continually compares those changing angles. However, even if the horses are running nose-to-nose, the observer still must compute an angle for each horse every second, and each angle changes, second-to-second.
In the FOC approach, the observer, in essence, rides along with the horses. If the horses are nose-to-nose, the observer computes a steady zero difference. When one horse passes the other, the observer computes a slowly changing difference.
The FOC approach reduces the number of a certain type of computation which must be done, thereby reducing bandwidth requirements.
In explaining FOC, a current in a coil will sometimes be treated interchangeably with the magnetic field which the coil produces. One reason is that the two parameters are approximately proportional to each other, unless the coil is saturated. Thus, a current and the field it produces differ only by a constant of proportionality.
FIG. 8 is a schematic of the connection of the three coils C3, C6, and C9 in one type of synchronous motor (not shown). They are connected in a WYE configuration, with point PN representing neutral.
A significant feature of the WYE configuration is that the currents in the coils are not mutually independent. Instead, by virtue of Kirchoffs Current Law, the three currents must sum to zero at point PN. Thus, only two independent currents are present, because once they are specified, the third is thereby determined. One significance of this feature will be explained later, in connection with the present invention.
A CONTROLLER 50 measures and controls the currents I3, I6, and I9, in a manner to be described. It is again emphasized that each current I3, I6, and I9 produces a respective magnetic field B3, B6, and B9 which are separated in space by 120 degrees, as indicated. (B3, B6, and B9 in FIG. 8 only show the different directions in space, but not different magnitudes.)
The CONTROLLER 50 undertakes the processes which will be explained with reference to FIGS. 9–14. Block 55 in FIG. 9 indicates that the CONTROLLER 50 in FIG. 8, or an associated device, measures each current I3, I6, and I9. In block 57 in FIG. 9, a data point, or vector, for each current is computed, giving the magnitude and direction of the magnetic field produced by each current. For example, if the measurement occurred at time T1 in FIG. 4, then vectors B3, B6, and B9 would be computed. Those vectors are shown adjacent block 57 in FIG. 9.
In block 60, two orthogonal vectors are computed which produce the equivalent magnetic field to the resultant of the vectors computed in block 57. The two graphs adjacent block 60 illustrate the concept. STATOR FIELD is the vector sum of the three vectors B3, B6, and B9 which were previously computed in block 57. Two orthogonal vectors a and b are now computed, which are equivalent to that vector sum, namely, the STATOR FIELD. Parameter a is the length of a vector parallel with the x-axis. Parameter b is the length of a vector parallel with the y-axis.
FIG. 10 illustrates how this computation is performed, and is presented to illustrate one complexity in the prior art which the present invention eliminates, or reduces. FIG. 10 illustrates three generalized vectors I1, I2, and I3, which are illustrated across the top of FIG. 10. The overall procedure is to (1) compute the x- and y-coordinates for each vector, (2) add the x-coordinates together, and (3) add the y-coordinates together. The result is two orthogonal vectors.
As to the x-coordinates, as indicated at the top center of FIG. 10, the x-coordinate of I2 is I2(COS 120). As indicated at the top right, the x-coordinate of I3 is I3(COS 240). As indicated at the top left, the x-coordinate of I1 is I1(COS 180). These three x-coordinates are added at the lower left, producing a vector Ia.
As to the y-coordinates, as indicated at the top center of FIG. 10, the y-coordinate of I2 is I2(SIN 120). As indicated at the top right, the y-coordinate of I3 is I3(SIN 240). There is no y-coordinate for I1, because it always stands at either zero or 180 degrees. These y-coordinates are added at the lower right, producing a vector Ib.
FIG. 11 shows the two vectors Ia and Ib. Their vector sum is the STATOR FIELD, as indicated. These two vectors Ia and Ib correspond to the two vectors computed in block 60 in FIG. 9.
In block 70 in FIG. 12, rotor angle, theta, is measured. A shaft encoder (not shown) is commonly used for this task. Rotor angle is an angle which indicates the rotor field vector, either directly or through computation.
In block 80, the two vectors computed in block 60 in FIG. 9 are transformed into a coordinate system which rotates with the rotor. (The angle theta is continually changing.) The graphs adjacent block 80 illustrate the concept. The STATOR FIELD, as computed in block 60 in FIG. 9, is on the left, and has x-y coordinates of (a,b). Block 80 transforms the coordinates to a1 and b1, shown on the right, which are the coordinates for the same STATOR FIELD, but now in a rotating u-v coordinate system.
FIG. 13 illustrates how this transformation may be accomplished. Plot 100 illustrates a generalized point P, representing a generalized stator field vector, having coordinates (a, b) in an x-y coordinate system. Plot 105 illustrates how the u-coordinate, of value a1, can be computed for a rotated u-v coordinate system. Plot 110 illustrates how the v-coordinate, of value b1, can be computed for the rotated u-v coordinate system. Equations 115 summarize the results.
Parameters a1 and b1 are the variables computed by block 80 in FIG. 12. It is noted that coordinate b1 corresponds to a vector which is parallel to the LEADING ORTHOGONAL in the graph adjacent block 90. The significance of this will become clear shortly.
Block 90 in FIG. 12 computes the error, if any, between the STATOR FIELD (shown adjacent block 80) and the LEADING ORTHOGONAL in the plot adjacent block 90. The LEADING ORTHOGONAL is a vector which is perpendicular to the ROTOR FIELD, and leads the ROTOR field. In order to maximize torque, the stator field is controlled so that it continually remains aligned parallel with the LEADING ORTHOGONAL, also called the quadrature vector to the ROTOR FIELD. (In generator action, as opposed to motor action, the quadrature vector lags the ROTOR FIELD.) This evaluation is done in the rotating coordinate system u-v, as block 90 indicates.
Block 130 in FIG. 14 indicates that the vector coordinates of the required stator field are computed, but in the rotating coordinate system. The graph adjacent block 130 illustrates the concept. The NEEDED FIELD is that which is orthogonal with the ROTOR FIELD. In the graph, the STATOR FIELD illustrated is not orthogonal, and corrective action must be taken.
The coordinates computed in block 130 for the required stator field lie in the rotating u-v coordinate system. Block 135 transforms those coordinates into the stationary x-y coordinate system, using inverses of the operations shown in FIG. 13. The inverse operations arex=u COS (theta)−v SIN (theta)y=u SIN (theta)+v COS (theta)
Block 140 in FIG. 14 then computes the required voltages needed for the coils to attain the required stator field. In concept, block 135 specifies a vector analogous to resultant R1 in FIG. 4. Block 140 in FIG. 14 computes the voltages analogous to V3, V6, and V9 required to produce that vector R1.
The computation of block 140 is of the same type as that shown in FIG. 10. In the latter, two orthogonal vectors are derived which are equivalent to three vectors. In block 140, three vectors are derived from two orthogonal vectors.
Then the processes of FIGS. 9–14 are continually repeated during operation of the motor.
The preceding was a simplification. In practice, various prior art control strategies are used in the process of converging the stator field to the required stator field, that is, in reducing the error of block 90 to zero, by adjusting the currents in the coils. These control strategies were not discussed.
The Inventors have developed a less expensive approach to controlling a synchronous motor.

Electric power steering system for a vehicle


A device for increasing the optical power of a solid state light source in the green and/or yellow bands, is disclosed. The device has an integral body having an ingress surface configured to receive light from an emitting portion of the solid state light source, an egress surface substantially opposite the ingress surface, and a recess formed within the body. The recess has an input opening in the ingress surface, an output opening in the egress surface, and a recess surface within the body extending between the input opening and the output opening. The recess surface is configured to reflect visible light with Lambertian scatter characteristics.

Solid state technology has progressed very far in recent decades. However there is still significant room for improvement in the green/yellow/amber range of the electromagnetic spectrum, approximately 520-600 nm. Direct light emitting diodes (LEDs) or laser diodes in this range are traditionally very low powered and/or inefficient from an electro-optical perspective. This issue with solid state lighting producing light at wavelengths in the green/yellow/amber range is fundamentally limited by the physics of the semiconductor materials used in the construction of these devices, as the band-gap of the materials does not favor emission of light in this spectral range. This problem is commonly referred to in the industry as the 'green gap'.
Solid state lighting solutions are sought after in all areas of general lighting to improve energy efficiency and increase luminaire lifetime. However, existing solid state apparatuses and methods for generating green light that meets optical power requirements for fluorescence imaging applications are generally costly. The conventional approach has been either devices having low output in the green-yellow band or low coupling efficiency for large area LEDs. LED array or laser pumped crystal or phosphor solutions are relatively expensive compared to arc lamps for some applications with low cost requirements.
A conventional approach to producing broadband light, such as white, is to use ultra violet light, royal blue, or near-ultra violet light from LEDs which have a phosphor powder deposited onto the LED surface. The most popular of these methods is creation of a 'white' LED which includes a phosphor of Ce:YAG (cerium doped yttrium aluminum garnet, Y3Al5O12:Ce3+) suspended in an encapsulating material such as silicone, embedded in a transmissive ceramic, or deposited directly onto a blue LED die or die array with a peak wavelength between about 445 nm and 475 nm. The light absorbed by the phosphor is converted to a broadband green/yellow/amber light, which combines with un-absorbed scattered blue light to produce a spectrum that appears white. The brightness of white light is limited by the blue light intensity from the LED, phosphor quantum efficiency, and thermal quenching, especially in the yellow (approximately 560 nm) and amber (approximately 590 nm) spectral bands. Higher power LEDs are available, but the increase in power scales with an increase in the LED emitting area. The coupling efficiency from the illumination source (LED surface) to the objective plane of a microscope objective is inversely proportional to the source size at the same light intensity. Thus, the power delivered to the microscope objective plane cannot typically be increased by simply increasing the LED surface area (it is an Etendue limited optical system).
Another way to achieve bright yellow and amber light is using single crystal Ce:YAG LED pumped by an LED array. The efficiency of such a device is limited by the total internal reflection of such a luminescent material due to its high index of refraction, and more importantly, coupling from LED to crystal. This results in a need of a large number of LEDs to achieve the brightness needed, which increases cost, size, and thermal/electrical requirements on systems employing this method. For example, see U.S. patent Ser. No. 12/187,356.
A third way of generating high powers of light in the green gap consists of using Ce:YAG in crystal form and pumping this structure with a blue (approximately 440-490 nm) laser from the front or back of the crystal. For example, U.S. patent application Ser. No. 13/900,089 describes an optical system using this concept and the predicted improvement in electro-optical coupling efficiency to the focal plane of a microscope has been validated. This approach is very effective in producing a scalable amount of power in the green/yellow band but can be costly. The particular shape and size of the crystal, multiple laser diodes, and cooling methods lead to increased assembly and manufacturing costs.
Other combinations of lasers and phosphors have also been suggested for many high brightness applications including fluorescence illumination, such as U.S. patent application Ser. No. 13/897,237, and other applications such as automotive headlights, for example, U.S. patent application Ser. No. 13/697,782, and digital projection systems, such as U.S. patent application Ser. No. 13/942,603, but these methods are still unable to meet the same cost targets as mercury or xenon arc lamps, which are currently the industry standard. Therefore, there is a need in the industry to address one or more of the above mentioned shortcomings.

Integrating cone for an illumination device


Methods of trend analysis for information related to released criminal offenders, the methods include accessing geospatial location information including date and time information for released criminal offenders and identifying repeated visits by one of the released criminal offenders within a defined proximity of a particular geospatial location, identifying a movement pattern of one of the released criminal offenders, correlating the movements of one the released criminal offenders to the movements of a subscriber, correlating the proximity of one of the released criminal offenders to a location where criminal activity has occurred, or comparing the geospatial location with previous activity of the released offender to predict potential future criminal activity.

Today, released criminal offenders on community supervision, either probation or parole, are monitored by a criminal justice supervising agency, such as a department of corrections or local law enforcement. The monitoring is based on a sentence, and often includes exclusion areas and inclusion areas with a schedule for the day of the week and a range of times associated with those areas when the released criminal offender is required to be or required not to be in those areas. A released criminal offender's geospatial location at a given date and time is monitored and recorded by tracking devices worn by the released criminal offender. This geospatial information, including date and time information, can be used to determine a released criminal offender's compliance with their sentence. Activities of released criminal offenders can be reported to the criminal justice supervising agency or to a probation or parole officer by fax, page, text message or email generated by a monitoring center unique to the criminal justice supervising agency.
Currently, an offender's geospatial location and associated date and time information can be determined by a number of different methods. These methods range from: (1) voice verification whereby an offender calls in by land line to verify his current geospatial location at a given date and time by using caller ID for a wired line phone, (2) radio frequency monitoring whereby the supervised released criminal offender wears a tamper resistant tag that communicates with receivers at a known geospatial location or geospatial locations using short range (i.e. in the range of 100 meters) radio frequency communications, to (3) tamper resistant tracking devices that record or report geospatial location points along with date and time information either in a batch mode or real time mode using a geospatial location, date and time means such as GPS, cellular triangulation, IP (Internet Protocol) address and/or a wired telephone land line caller ID for batch mode, or wireless communications for both real time and batch modes.
Just as multiple systems are used to determine a released criminal offender's geospatial location at a given date and time, multiple databases exist containing released criminal offender geospatial location information along with date and time information. These databases are owned or operated by contracted companies providing released criminal offender monitoring products and services. Or the criminal justice supervising agency may deploy and operate released offender monitoring and reporting devices produced by vendors. These databases are disparate in terms of their physical location, operation and reporting mechanisms. These databases are heterogeneous in terms of data format since there is no formatting standard for the data collected or stored for supervised released criminal offenders, and there are multiple vendors providing products and services to monitor or locate supervised released criminal offenders. Within a single jurisdiction as small as a city or county, there may be one or more of each type of system described above, each with their own separate unique databases and unique reporting implementations. Disparate systems also do not share geospatial location information along with date and time information with each other. A system which reports supervised released criminal offender's geospatial location, date, and time information and movement history to only one of multiple agencies that may benefit from or need such information is known in the art as a stovepipe system. Further, existing databases track historical geospatial information, including date and time information, related to released offenders. While these databases provide information regarding where an offender has been or what a released offender may have done, they do not provide information predicting future movement and/or action of a released offender, and therefore are not useful in predicting or identifying high risk of crime so that it cart be prevented. There exists a need for an improved method of monitoring released criminal offenders.

Released offender geospatial location information trend analysis


Radial, soft magnetic rotor disk elements which engage in each other and soft magnetic stator disk elements form a magnetic bearing device. The elements are provided with teeth-like extensions which are arranged opposite to each other over an air gap on sides which are oriented towards each other. Magnetic fields, which may be produced by permanent magnets or electromagnets, are assigned to the stator disk elements to produce a magnetic maintaining flow which is oriented in an axial direction between the disk elements for radial adjustment. An electromagnetic winding is also provided in the region of the central plane of the bearing device for axial adjustment, which enables a magnetic control flow, which superimposes the magnetic maintaining flow, to be produced.

Described below is a device for magnetic bearing of a rotor shaft with respect to a stator having the following features:                a) a first bearing part is connected to the rotor shaft and is surrounded by a second bearing part, which is associated with the stator, with a distance between them,        b) the first bearing part contains rotor disk elements which are aligned at right angles to the axis of the rotor shaft, are arranged one behind the other in the direction of the axis and are each separated, forming an intermediate space,        c) the second bearing part contains stator disk elements, which are aligned at right angles to the rotor shaft axis, are arranged one behind the other in the direction of the rotor axis, are at a distance from one another and each project into one of the intermediate spaces of adjacent rotor disk elements,        d) a magnetic flux directed essentially in the axial direction is formed between the elements.A corresponding bearing device is disclosed, for example, in DE 38 44 563 C2.
Magnetic bearing devices allow non-contacting and wear-free bearing of moving parts. They require no lubricants and can be designed to have low friction. Known radial and axial magnetic bearing devices use magnetic forces between stationary electromagnets of a stator and ferromagnetic elements which rotate jointly of a rotor body. The magnetic forces are always attractive in the case of this bearing type. In principle, this means that it is impossible to achieve an inherently stable bearing in all three spatial directions. Magnetic bearing devices such as these therefore require active bearing regulation, controlling the currents of electromagnets by position sensors and control loops and counteracting discrepancies of the rotor body from its nominal position. The multichannel regulation to be carried-out requires complex power electronics. Corresponding magnetic bearing devices are used, for example, for turbo molecular pumps, ultra-centrifuges, high-speed spindles for machine tools and X-ray tubes with rotating anodes; they are also known to be used for motors, generators, turbines and compressors.
The basic design of a corresponding bearing device 30 is sketched in FIG. 1. The figure shows two active radial bearings 31 and 32 with excitation magnets 33 and 34 and radial bearing rotor disks 35 and 36 on a rotor shaft 37, an active axial bearing 38 with axial bearing rotor disks 39 and 40 on the rotor shaft 37 and concentric field windings 42i on the rotor disks, as well as five distance sensors 41a to 41e corresponding to the in each case two lateral degrees of freedom per radial bearing and the single degree of freedom of the axial bearing. Furthermore, five associated control loops r1 to r4 and z5 are required. Because the attraction forces increase as the bearing gap becomes smaller in a bearing device such as this, corresponding devices are non-stationary from the start. The position of the rotor shaft 37 must therefore be stabilized by the control loops, comprising distance measurement by the sensors 41a to 41e with a downstream regulator and downstream amplifier, which feeds the excitation magnets 33 and 34. Corresponding bearing devices are accordingly complex. In addition, a mechanical holding bearing must be provided as a precaution against sudden failure of a control loop.
Magnetic bearing devices with permanent magnets and high-Tc superconductor material are also known, for example from DE 44 36 831 C2. Bearing devices such as these are intrinsically stable, that is to say they do not require regulation. However, because of the required cryogenic operating temperature for the superconductor material, in particular of below 80 K, thermal insulation and a refrigerant supply are required by an appropriate cryogenic coolant or by a refrigeration machine.
The related art also includes bearing devices which are intrinsically stable in one direction with a magnetic flux, soft-magnetic parts such as those composed of iron, and with permanent magnets. In corresponding embodiments of bearing devices such as these, such as those disclosed in DE 34 09 047 A1 and the initially cited DE 38 44 563 C2, the permanent magnet rings on a shaft are axially primarily aligned with the poles of an iron yoke, and thus provide radial centering. In this case, the magnetic flux is enhanced by field coils, in which case the axially unstable degree of freedom may be stabilized by an electronic control loop. In this case, a plurality of stationary and rotating ring magnets, which alternate axially one behind the other, are arranged in a row or rows with the same axial magnetization and provide a radial bearing function. In this case as well, the axial degree of freedom must be actively stabilized.
All the bearing devices mentioned above and having permanent-magnet parts have relatively low supporting force and inadequate bearing stiffness, however.

Apparatus for magnetic bearing of rotor shaft with radial guidance and axial control


A chemical mechanical polishing machine is provided with a platen that has an integral sub-pad. A fixed abrasive polishing layer is mounted, without adhesive between the polishing layer and the sub-pad, to the top surface of the platen and the sub-pad. The polishing layer is vacuum mounted, for example, to the integral sub-pad of the platen. A cooling arrangement is provided in the platen that cools the polishing layer and improves product quality.

The present invention relates to polishing and planarizing of surfaces, such as semiconductor wafer surfaces, and more particularly, to fixed abrasive pad and platen arrangements for chemical-mechanical polishing/planarizing of semiconductor wafers.
In the process of fabricating modem semiconductor integrated circuits (ICs), it is necessary to form various material layers and structures over previously formed layers and structures. However, the prior formations often leave the top surface topography of an in-process wafer highly irregular, with bumps, areas of unequal elevation, troughs, trenches, and/or other surface irregularities. These irregularities cause problems when forming the next layer. For example, when printing a photographic pattern having small geometries over previously formed layers, a very shallow depth of focus is required. Accordingly, it becomes essential to have a flat and planar surface, otherwise, some parts of the pattern will be in focus and other parts will not. In fact, surface variations on the order of less than 1000 angstroms over a 25xc3x9725 mm die would be preferable. In addition, if the irregularities are not leveled at each major processing step, the surface topography of the wafer can become even more irregular, causing further problems as the layers stack up during further processing. Depending on the die type and the size of the geometries involved, it is desirable to effect some type of planarization, or leveling, of the IC structures. In fact, most high-density IC fabrication techniques make use of some method to form a planarized wafer surface at critical points in the manufacturing process.
One method for achieving semiconductor wafer planarization or topography removal is the chemical-mechanical planarization/polishing (CMP) process. In general, the CMP process involves holding the wafer against and moving the wafer relative to a polishing platen under a controlled pressure or friction force. A typical CMP apparatus includes a polishing head for holding the semiconductor wafer against the polishing platen. The polishing platen is covered with a pad. The pad is usually either an open cell foamed polyurethane (e.g. Rodel IC1000) or a sheet of polyurethane with a grooved surface (e.g. Rodel EX2000). The pad surface is wetted with a polishing slurry containing chemicals and, optionally, abrasive particles. This pad typically has a backing layer called a sub-pad that interfaces with the surface of the platen.
Another type of polishing pad is the xe2x80x9cfixed-abrasive padxe2x80x9d made from abrasive particles fixedly dispersed in a suspension medium. Unlike conventional CMP slurries, the planarizing liquid employed with a fixed abrasive pad may be free of abrasive particles, i.e., a polishing chemical solution. Chemical-mechanical polishing/planarization with a chemical solution on a fixed abrasive pad offers several desirable aspects: low chemical cost, low dishing, and a good top surface finishing.
One concern with metal CMP is the heat generated during the polishing process, caused by chemical reaction of the metal with the polishing chemical and the friction of the wafer against the fixed abrasive pad surface. Heat build-up may degrade the quality of the wafer being polished. Fixed abrasive pads with thick stacks exhibit poor thermal conductivity and, therefore, wafers are not readily cooled during CMP on such pads.
Another concern is the dishing observed generally in metal CMP. Dishing can be high if the pad modulus is low. A conventional fixed abrasive pad may include polishing elements of 40 xcexcm in height that are mounted in a thin Mylar(trademark) sheet. The other layers below the Mylar(trademark) sheet form a sub-pad stack, and may have five layers, for example. A top adhesive layer joins the Mylar(trademark) sheet to the sub-stack. A polycarbonate layer, which is supposed to provide the necessary pad modulus, is underneath the top adhesive layer, and a foam layer, which is supposed to provide long range flexibility, is joined to the polycarbonate layer by a middle adhesive layer. A bottom adhesive layer on the foam layer attaches the polishing pad formed by the Mylar(trademark) sheet and sub-pad stack to the top of the platen. However, due to the existence of the layer of very soft adhesive material between the very thin Mylar(trademark) sheet and the polycarbonate layer, the modulus of the integrated pad of six layers cannot be high enough for strict dishing requirements. Elimination of this adhesive layer would greatly increase the pad modulus and help the pad dishing performance.
A further concern is the consumable cost of fixed abrasive polishing pads. Although only the top Mylar(trademark) layer is subjected to wear during polishing, the entire pad is normally replaced when the Mylar(trademark) pad is excessively worn. This increases the cost of ownership.
Another concern is the system vibration that may occur when polishing with conventional fixed abrasive pads. Such vibrations can occur due to the typical construction of fixed abrasive pads, and their attachment on top of a platen. The foam pad that forms part of the polishing pad is not readily changeable to damp the system vibrations of an individual polisher.
The present invention overcomes problems with existing fixed abrasive polishing pads by providing a platen for a fixed abrasive pad arrangement, comprising a platen housing, a sub-structure integrally mounted on the platen housing, and a mounting arrangement configured to removably mount a fixed abrasive layer to the integral sub-structure.
One of the aspects of certain embodiments of the fixed abrasive pad arrangement of the present invention is that the fixed abrasive layer may be readily replaced since it is removably mounted to the sub-structure, or sub-pad. As the platen has an integral sub-pad, the sub-pad does not have to be replaced whenever the top polishing layer requires replacing. This reduces consumable expenses, as only the top polishing layer is replaced, rather than an entire polishing pad with sub-layers together.
As the sub-structure is integrally mounted on the platen housing, a cooling arrangement may be provided that improves the cooling of the overall sub-structure and fixed abrasive layer, in comparison to conventional fixed abrasive polishing pads that include a sub-structure stack and a fixed abrasive layer. Since the sub-structure is integral to the platen housing in certain embodiments of the invention, a cooling arrangement in accordance with embodiments of the invention may be provided that better cools the sub-structure and the fixed abrasive layer.
An aspect of the present invention provides a chemical-mechanical polishing machine comprising a platen housing, a sub-pad integral with the platen housing, and a mounting arrangement configured to removably mount a fixed abrasive layer to the sub-structure. In certain embodiments of the invention, the mounting arrangement includes a vacuum mounting arrangement that removably and quickly mounts the fixed abrasive layer to the sub-structure, without the use of adhesive. Eliminating the adhesive between the fixed abrasive layer and the sub-structure reduces the undesirable phenomenon of dishing.
The foregoing and other features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Platen arrangement for a chemical-mechanical planarization apparatus


A curable epoxy resin composition comprising at least: (A) a crystalline epoxy resin, (B) a phenol resin, and (C) a silicone resin composed of epoxy-containing organic groups and phenyl groups that define an average unit formula of this component. Component (C) is used in an amount of 0.1 to 500 parts by weight for 100 parts by weight of the sum of weights of components (A) and (B). The composition of the invention is suitable for transfer and injection molding and may find use as a curable epoxy resin composition for sealing parts of electrical and electronic devices.

Although a curable epoxy resin composition that contains a halogenated epoxy resin or an antimony-type oxide such as an antimony trioxide produces a curable body with good resistance to combustion, when it burns it either generates toxic gases or a toxic antimony trioxide substance, which result in undesired impact on human health and environment. On the other hand, curable epoxy resin compositions that contain aluminum hydroxides, magnesium hydroxides, or similar metal oxides and phosphorus-type flame-retardants, or the like, have low moldability and low resistance to moisture in a cured body.
On the other hand, known in the art are the following compositions: a curable epoxy resin composition prepared from an epoxy resin, a curing agent, and a silicone resin with an epoxy-containing organic group and a phenyl group (see Japanese Unexamined Patent Application Publication (hereinafter referred to as "Kokai") 6-298897 and corresponding U.S. Pat. No. 5,952,439); a curable epoxy resin composition prepared from an epoxy resin, a curing agent, and a silicone resin with an epoxy-containing organic group (see Kokai 9-208806 and corresponding U.S. Pat. No. 5,891,969); and a curable epoxy resin composition prepared from an epoxy resin, curing agent, inorganic filler, and a silicone resin with a phenyl group and an alkoxy group (see Kokai 11-323086).
However, when the inventors of the present invention studied the curable epoxy resin composition disclosed in Kokai 6-298897, they found out that resistance of this composition to combustion can be drastically improved if the epoxy resin is represented by a crystalline epoxy resin and the curing agent is represented by a phenol resin. Furthermore, while studying the curable epoxy resin disclosed in Kokai 9-208806, the inventors of the present invention revealed that, if the amount of phenyl groups is less than 10 mole % relative to the total content of organic groups in the silicone resin, the aforementioned silicone resin cannot be efficiently dispersed in the epoxy resin, and the obtained cured body does not acquire sufficient resistance to combustion. The results of the inventors' study aimed at properties of the curable epoxy resin composition disclosed in Kokai 11-323086 showed that the silicone resin contained in this composition is subject to bleeding and therefore contaminates the mold. In addition, it has poor moldability, and the obtained cured body does not possess sufficient resistance to combustion.
As a result of the aforementioned studies, the inventors arrived at the present invention.
It is an object of the present invention to provide a curable epoxy resin composition which is characterized by good moldability, demonstrates excellent resistance to combustion in a cured body, is free of a halogenated epoxy resin and antimony oxides, and therefore does not produce an unfavorable impact on human health and environment.


During booting of a computing device, multiple security boundaries are generated. A security boundary refers to a manner of operation of a computing device or a portion of the computing device, with a program executing in one security boundary being prohibited from accessing data and programs in another security boundary. As part of booting the computing device measurements of (e.g., hash values or other identifications of) various modules loaded and executed as part of booting the computing device are maintained by a boot measurement system of the computing device. Additionally, as part of booting the computing device, a public/private key pair of one of the security boundaries is generated or otherwise obtained. The private key of the public/private key pair is provided to the one security boundary, and the public key of the public/private key pair is provided to the boot measurement system.

Computing devices have become commonplace in many areas of our lives. Given the number of computing devices available to us, it is oftentimes desirable to have two computing devices communicate with one another. However, situations can arise in which some parts of a computing device are trusted to receive data via communication with another device, yet other parts of the computing device are not trusted to receive such data. Allowing such communication but keeping data from parts of the computing device that are not trusted to receive the data can be difficult, leading to user dissatisfaction with their devices.

Identifying security boundaries on computing devices


A two-tier cover assembly for a field service box. The two-tier cover assembly can be retrofitted to an existing field service electrical box to protect the electrical device that is housed therein. The cover assembly provides two configurations for protecting the electrical box, including an expanded and a collapsed configuration. In the expanded configuration, the cover assembly provides two cord openings that are accessible with the cover plate closed. In the collapsed configuration, the cord openings are completely closed to seal all openings and thereby protect the electrical device from rain, dirt, insects and other hazards.

Electrical boxes for outdoor use, commonly termed "FS" or field service boxes, are typically mounted on the exterior of buildings for providing convenient access to electrical outlets and other electrical devices such as switches and timers. To keep dirt, insects, and other debris out of the FS box, a simple hinged cover plate is typically provided for closing the front opening of the box. As a result of being mounted outdoors, FS boxes are exposed to the elements, including heat, cold, rain, insect infiltration, and similar hazards, which eventually may negatively affect the appearance and functioning of the box. Field service boxes constructed of metal for example, typically include hinged covers that become rusted and cease to function after repeated years of exposure to the elements. Additionally, conventional hinged covers are large, extending a substantial distance from the exterior wall and therefore unsightly and unattractive to the homeowner. Conventional hinged electrical box covers typically include cord openings that are open to the elements regardless of whether an electrical cord is plugged into the electrical box or not. Therefore, the interior of the conventional cover is always exposed to the elements, regardless of whether or not an electrical cord is plugged into the electrical device within the cover.
What is needed therefore is a cover assembly that can be installed over an existing or a new FS box to provide better protection to an electrical receptacle installed therein and which also provides an overall lower profile when the receptacle is not in use. What is needed is an electrical cover assembly that is adjustable to provide a first level of protection when electrical cords are connected to the installed electrical device and a second, more secure level of protection when the electrical device is not in use.

Adjustable two-tier cover assembly for an electrical box


A convertible sled for use by a rider. The convertible sled includes a body, a mounting unit coupled to the body for coupling plural wheels or plural sledding members, and a steering unit moveably coupled to the body at the front portion of the body such that, when the convertible sled is arranged in a first configuration, the steering unit is operatively coupled to at least two of the plural pairs of wheels, as steering wheels, for steering the convertible sled. Further, the steering wheels on a first side of the body pivot about a first common point and the steering wheels on a second side of the body pivot about a second common point different from the first common point. Moreover, when the convertible sled is arranged in the second configuration, the steering unit is operatively coupled to a portion of the plural sledding members for steering the convertible sled.

It is well known that conventional sleds include sledding runners attached to sled to facilitate travel in snow or ice-covered environments. These sleds cannot be readily used, however, on high-friction terrains such as, for example, grass or concrete surfaces. Conventional sleds having both wheels and sledding members have been proposed for use on snow and land. These conventional sleds have a number of drawbacks, however, some of which are highlighted below.
These convertible sleds typically include either no steering system or, otherwise, include a rudimentary steering system that generally includes only a single pivot point for all of the steering wheels and all of the steering sledding members. Such a conventional steering system has the problem that, as the rider increases a turning angle (i.e., reduces the turning radius of the conventional sled), the conventional sled becomes more unstable due to the reduced distance of the wheel to the center line of the conventional sled. Moreover, lateral force on each of the steering wheels and steering sledding members is increased compared to having a pivot point for each set of steering wheels or each steering sledding member on a respective side of a sled. The conventional steering system also requires a bulkier frame and requires more force from a rider to steer the conventional sled.
In the conventional convertible sled, typically, only one set of steering wheels or steering sledding members is provided. Consequently, the rider can easily lose steering control when the wheels or members skid or skip. The risk of skids and skips increases, in particular, for uneven terrains such as grass and other off-road surfaces.
The conventional convertible sled generally does not include a braking system, or, otherwise, is implemented with a braking system which is difficult to control. Typically, the braking system may be a foot-applied brake having only a limited amount of braking feedback or, otherwise, may not be provided in a natural position of a hand of the rider.
Further, the conventional convertible sled does not provide for removal and replacement of the plural wheels. Therefore, the conventional convertible sled cannot be used with wheels of varying types and sizes optimized for specific terrain.
Still further, the conventional convertible sled does not include a large number of wheels (e.g., ten wheels). Nor does the conventional convertible sled have a high portion of them (e.g., four wheels) acting as steering wheels. Thus, the conventional convertible sled is not adaptable for most off-road terrains and steering control over such terrains is not adequate.
To overcome the shortcomings of conventional convertible sleds identified above, what is needed is an improved convertible sled suitable for all terrains.


Systems and methods for natural gas liquefaction capacity augmentation using supplemental cooling systems and methods to improve the efficiency of a liquefaction cycle for producing liquefied natural gas (LNG).

Process feed gas in an LNG plant generally goes through a series of pre-treatment stages to remove acid gas, mercury and moisture and avoid freezing or corrosion problems in the cryogenic section. A generic single mixed refrigerant (SMR) liquefaction cycle may be used to cool and liquefy process feed gas such as, for example, natural gas. The process feed gas typically passes through a heat exchanger with the SMR for cooling the process feed gas that is used for producing LNG. The SMR is cooled using a primary cooling system comprising water at a temperature that is—around 25° C. The primary cooling system may include one or more heat exchangers for cooling the SMR with the cooling water before it passes through the heat exchanger with the process feed gas. The SMR liquefaction cycle may include one or more compressors for circulating the SMR through the one or more heat exchangers and a separator. The compressors are typically driven by a gas turbine engine that produces waste heat in the form of a hot combusted gas,
A generic SMR liquefaction cycle requires about 40 MW to produce 1 million tons per annum (MTPA) of LNG. If the process feed gas was cooler, then the amount of LNG produced may be increased or the same amount of LNG may be produced with less energy consumption. In addition, the cooling water used in the primary cooling system and the waste heat from the gas turbine are not recycled or used in any supplemental manner to improve the efficiency of a liquefaction cycle for producing LNG.

Bechtel Hydrocarbon Technology Solutions, Inc.


A method of adding a device to an existing or new electrical or electronic automation or multimedia network. The invention facilitates adding a device to the network that can communicate using various protocols such as LonWorks, CEBus, X-10, etc. over media such as AC power line, IR, RF, twisted pair, optical fiber, etc. The method is a mechanism for adding a device to a system that can be used by an ordinary user of network capable electrical devices. The method comprises the steps an installer would perform including the handshaking that needs to occur between devices to accomplish the binding process. A Functional Profile for LonWorks networks is given as an example. This includes a Home Device profile that employs an automated explicit type messaging for all devices intended for use in a home environment. The invention includes adding to the device an install button and a visual indicator for status such as an LED. Alternatively, existing buttons and LEDs on the device may be used for installed and binding purposes. Other methods of binding can be employed by the use of wired or wireless handheld tools, remote controls, etc. Other interfaces and user feedback can be used such as touch screen, personal computers, cellular phones, PDAs, etc which can offer simple ‘virtual’ binding by the press of an icon versus the physical button on the device. The binding can be performed locally or remotely such as via LAN, WAN, Internet, etc.

Today, automation systems are being installed in more and more buildings, including both new construction and in structures that are being rebuilt. The incentives for putting automation systems into a building are numerous. High on the list are reduced operating costs, more efficient use of energy, simplified control of building systems, ease of maintenance and of effecting changes to the systems. Facility managers would prefer to install systems that can interoperate amongst each other and also be able to make additions and changes to the system in an efficient manner. Interoperability is defined by different products, devices and systems for different tasks and developed by different manufacturers, which can be linked together to form flexible, functional control networks.
An example of a typical automation system includes lighting controls, HVAC systems, security systems, fire alarm systems and motor drives all possibly provided by different manufacturers. It is desirable if these separate disparate systems can communicate and operate with each other.
One of the major technological issues, however, that have hindered the proliferation of automation systems (such as LonWorks and others) in the home, is that users feel (1) it takes too long, (2) that it always requires a computer and (3) that it is too complicated a process to install and setup a device. In particular, the part of the installation or configuration process that is most problematic is the binding portion, where electrical devices are configured to be recognized by other entities on the network once they have been physically and electrically installed.
The term 'home automation' has been around for more than 25 years, but the average homeowner does know what this term means. Within the home, it is becoming more and more popular to utilize devices which communication over a network or bus structure to autonomously control various aspects of the home environment without the need for direct interaction by the inhabitants. As an example, an application might be to use a motion sensor to detect the presence of a car in the driveway. The system would then send a signal to the home controller that something was present. In response, the controller may query the security portion of the system to check if the visitor is not an intruder, and upon the absence of an alarm condition, would open the garage door and change the status of the home from 'away' to 'home'. Subsequently, the system may disarm one or more security zones on the premises and has the lighting subsystem illuminate the driveway and walkway lighting systems. The HVAC subsystem may turn the hot water boiler on for an anticipated bath and turn on the air conditioner or heater in one or more rooms in the home. In addition, the entertainment system may recognize the homeowner and play chosen music selections, or turn on the television and tune to a favorite channel.
This type of automation control requires explicit communication between the various control, sensor and data devices in the home. The various subsystems that are required to communicate with each other include lighting, security, HVAC, entertainment and information/Internet, for example. The complexity in setting up the system grows, as the complexity of the features installed in the home becomes more sophisticated. Unfortunately, setting up a system using currently available devices is not as simple as choosing the desired devices and wiring them into the network. Wiring the devices is relatively simple and straightforward; the task of ensuring that devices know whom they are, what they are supposed to do and how to talk to other devices on the network is difficult.
Prior to installing a home automation system, the installer must (1) select suitable equipment and devices; (2) appraise the infrastructure requirements, e.g., phase couplers, repeaters, filters, routers, gateways, etc.; (3) appraise the tools required to physically and electrically install the devices; (4) appraise the tools to bind devices together; and (5) appraise the tools to set the functionality in each device.
The expertise needed to perform all these tasks dictates who the installer can be and ultimately who the customer can be. As the technical expertise of the installer increases, the cost to employ that installer increases, adding cost to the automation system. Currently, for proprietary networks, a specialized team or dealer network is trained to install the home automation products. For open protocols, often times a custom installer or system integrator is to integrate the various applications together. Here too, the individuals used to install and/or integrate the devices typically consist of a specialized team to integrate the various subsystems together.
The average homeowner typically does not have technical knowledge and thus most of the products directed to homeowners plug into wallbox receptacles or are battery operated. Communications, if present, is usually accomplished over AC wiring or via RF. If addressing is required, the devices come preconfigured, i.e., prebound, or the user interface includes setting a position on a switch. Popular examples of this type of product include X-10 plug-in products.
The do-it-yourselfer (DIY) is considered to have a bit more technical knowledge that the average homeowner. This person will install devices in place of currently present AC receptacles, switches, etc. in the home. They may modify the wiring within the home to accommodate the devices to be installed. An electrician may be called in to accomplish this. The user interface typically is very simple comprising of a few switches or perhaps a single computer program to setup and control the devices.
An electrician or security installer or audio/video installer represents a medium expense professional installer who is familiar with both high voltage and low voltage wiring and maybe with telecom wiring. They are not necessarily computer literate and may be trained to use a handheld LCD display with a keyboard attached to install and configure the system.
The systems integrator/custom installer/home automation installer is proficient with computers and low voltage wiring. They have the required technical knowledge to install, configure and troubleshoot connection problems on both high voltage and low voltage wiring. They can work with devices that do not have a physical user interface, but are configured using a software program on a PC that communications with the entire network in the home. Examples include CEBus, LonWorks, Lutron HomeWorks, LiteTouch, Vantage, etc.
Prior art automation systems each have specific mechanisms of adding new devices to the network. CEBus Home Plug and Play (Hpnp), for example, includes a recommended practice for the user interface which is to be used during configuration of newly installed or reconfigured devices. The recommended method, however, is very slow, tedious and confusing to a user. It also consumes considerable firmware overhead for each device. Groups are not supported and user feedback is not uniform permitting the same indication to mean several different modes of operation.
LonWorks has the disadvantage of requiring an installation tool. Such tools are relatively difficult to operate and are relatively expensive, placing them out of reach of the typical consumer.
The X-10 system does achieve quick configuration although it utilizes a primitive, slow protocol. It does not have any provisions for cross-linked groups and is generally a one-way system, providing for a limited number of devices with limited functionality.
Thus it is desirable to be able to add a device, i.e., a networked product, to an automation network system in a relatively simple manner. The configuration of a network product device should be quick and simple as possible. It is desirable that a majority of users find the configuration process to be:                1. Fast—configuration should take less than one a minute per device.        2. Simple—configuration should be easier than programming a VCR.        3. Uniform—manufacturers should use common user interfaces.        4. Reassuring—the user should be kept apprised of the current point in the configuration process.        5. Clear—error codes should clearly indicate problems in a uniform manner.        6. Inexpensive—the interface should not add much cost to the device, and may share existing hardware such as LEDs and switches.