A method and apparatus for reducing unwanted harmonics in direct digital synthesizer (DDS) output. The method comprises the steps of providing a set of k phase-shifted clock signals, examining, in succession, each DDS accumulator state, and determining whether the DDS accumulator state has a defined transition-state. For each DDS accumulator state having a defined transition-state, an interpolation is performed based upon the value of the preceding DDS accumulator state, an element of the set of phase-shifted clock signals is selected based upon the interpolation, and the most significant bit (MSB) is repositioned using the selected element of the phase-shifted clock signals. The apparatus comprises means for providing a set of k phase-shifted clock signals, means for examining, in succession, each DDS accumulator state, and means for determining whether the DDS accumulator state has a defined transition-state. The apparatus further includes means for performing an interpolation, for each DDS accumulator state having a defined transition-state, based upon the value of the preceding DDS accumulator state, means for selecting an element of the set of phase-shifted clock signals based upon the interpolation, and means for repositioning the MSB using the selected element of the phase-shifted clock signals.

A Direct Digital Synthesiser (DDS) typically consists of an n-Bit adder and a clocked register. This arrangement, forming a numerically controlled oscillator or NCO, produces, at time intervals determined by an input clock, a digital number sequence with a periodicity determined by a digital input data signal. The MSB of the digital output represents a digitally controlled synthesized output clock signal.
Advantages of Direct digital synthesizers such as the DDS 100 depicted in FIG. 1 is that they do not use a variable oscillator. Consequently, a DDS has a very fast lock time and very small frequency steps can be selected.
The DDS is essentially a register or accumulator 103 to which a predetermined frequency control value 101 is added on every cycle of an input clock 102. The digital value from the accumulator 103 is often applied to a read-only memory (ROM) 104 that contains sinusoidal output values. The values from the ROM 104 are applied to a digital-to-analog converter 105 and filtered through a low-pass filter 106 to provide an output signal 107 with reduced spurious components. This method requires considerable additional power and its effectiveness is limited to output clock frequencies as determined by the filter characteristics.
A DDS can be reduced to its simplest terms as shown in FIG. 2. The DDS 200 is merely an accumulator 203 to which a frequency control value 201 is added under control of a clock signal 202. The most significant bit (MSB) of the accumulator 203 provides a digital wave output signal 204. Even if one excludes harmonics, however, the DDS 200 will have a high level of spurious signals for many of the possible values of the frequency control word 201, because the output signal instantaneous frequency will change periodically.
As outlined, there are inherent deviations from the ideal that may limit the application of a DDS. The MSB of the DDS output signal is not a spectrally pure signal, because its frequency and "mark-space" ratio are modulated due to discrete sampling by the input clock. This produces timing jitter with maximally 1 clock period duration and a distribution determined by the digital input signal. For a given required output clock frequency, the timing jitter is proportional to the input clock duration, and hence can be optimized by operating the DDS at a high input clock frequency.
This approach requires the NCO to function at a very high speed, and therefore demands complicated adder architectures, adding significantly to power consumption.
Other known methods employ the generation of analog waveforms at predetermined values of the NCO number sequence, and via a comparator generating a digital output signal which is not synchronous with the input reference clock signal. Such an improvement to the simple DDS 200 hereinbefore described is achieved through the analog compensation technique illustrated in FIG. 3. Here, the DDS 300 includes a D-to-A converter 304 at the accumulator output, and the analog voltage at the D/A output is applied to a differential amplifier. A delayed version of the D/A output signal is applied to the other input of the differential amp 305. The differential amplifier 305 provides a square wave pulse train to the integrator 307, which converts the square wave into a sawtooth wave.
The sawtooth waveform is applied to a comparator 308 with a reference voltage 311 at one input. The reference voltage 311 is chosen to be half of the voltage represented by a maximum output from the accumulator 303. The square wave output of the comparator 308 is still asymmetric, but the leading edges occur at intervals with less jitter. If this square wave signal is then applied to a toggle flip-flop 309, the jitter of the output signal 310 will be reduced, and will contain a reduced number of unwanted signals with the exception of the odd harmonics. The notable disadvantage of the DDS 300 of FIG. 3 is that it uses analog techniques to reduce spurious output signals, and similarly to the previous case, this approach requires additional power and its effectiveness depends significantly on maintaining the precision of the analog waveforms for variable input and output.
The advantages of the analog means to reduce the jitter as opposed to techniques that involve the increase of the clocking frequency has resulted in many prior art devices employing predominantly analog means to reduce output signal timing jitter. Unfortunately the usage of an analog solution to the jitter problem suffers from traditional analog problems in that it is more difficult to implement, is non-predictable in its output and is a heavy power consumer. Accordingly, a need arises for a DDS that accomplishes jitter reduction entirely by digital means, and thus avoids parametric variations that plague analog solutions. Such a need has been acknowledged by Goldberg in Chapter four of DDS General Architecture in his book entitled "Digital Frequency Synthesis demystified", published by LLH Technology Publishing wherein he suggests one solution based on using the carry output bit as an output, and delaying the carry signal so as to effect a more regular interval between transitions. Although this does provide an all digital solution it suffers because it is implemented on the carry signal. The solution described by Goldberg is restricted to the narrow pulse of the carry signal thereby leading to significant unwanted signal components. A reduction of these requires a division of the carry signal frequency by at least a factor of 2, thus reducing the output frequency range. There remains therefore a need for an all digital DDS adapted to achieve reduction of timing jitter over a wide range of input and output clock frequencies using digital data processing without incurring significant increases in complexity and power consumption.

Direct digital synthesizer with output signal jitter reduction


A surgical tool which comprises an elongated body having a proximal end and a distal end, first and second sets of tissue approximating structures having deployed and retracted positions relative to the elongated body, an actuating mechanism extending from the proximal end of the elongated body for independently deploying and retracting each of the first and second sets of tissue approximating structures, a drainage lumen extending from a drainage aperture at the distal end of the elongated body to the proximal end, a main balloon adjacent to the distal end of the elongated body, and a strap connector extending from the elongated body that is connectable with a stabilization strap.

Anastomosis procedures are required for connecting or re-connecting certain body tissues, such as in performing part of a surgical procedure. In particular, anastomosis procedures are used for joining one hollow vessel or structure to another hollow vessel or structure so that the interior portions of the vessel can fluidly communicate with each other. In one type of procedure, which may be referred to as an end-to-end anastomosis, severed tissues of a first vessel are coupled, usually by suturing or stapling, to severed tissues of a second vessel. The tissues may be part of a body lumen such as a blood vessel, intestinal or other digestive system tissue, or tissues relating to the urinary system. As one example, in a radical prostatectomy, a surgeon removes all or most of a patient's prostate. Because the urethra travels through the prostate immediately before reaching the bladder, the upper part of the urethra is also removed with the surgery. The procedure leaves a severed urethral stump and a severed bladder neck. To restore proper urinary functions, the bladder and the urethra must be reconnected, which can be a relatively difficult and complex procedure. These difficulties can occur as a result of the tendency of the urethral stump to retract into adjacent tissue after being severed and also due to the fact that the urethral stump is obscured by the pubic bone. These and other factors can make the area difficult to access by the surgeon, particularly for extending periods of time when performing the surgical procedure.
Conventionally, a surgeon may execute delicate suturing operations with tiny, fine needles to reconnect these or other anatomical bodies. However, installation of sutures with a needle to connect severed tissues can be a difficult and technique-sensitive task. Many factors can make the task difficult, including a very small amount of tissue to work with (e.g., at the urethral stump and at the bladder neck), and proximal sensitive tissues such as ureters at a bladder and a proximal nerve bundle and sphincter at a urethral stump. These factors result in complicated and delicate suturing procedures that, if not performed properly, could result in complications such as leakage, difficulty in healing or failure to heal, or specific conditions such as incontinence or impotence.
To reduce the risks involved in conventional suturing procedures, anastomosis devices have been developed that include a drainage feature and tissue approximating structures that allow for reconnection of tissues without using traditional sutures. These anastomosis devices advantageously use tissue approximating structures to reconnect severed tissues during anastomosis procedures, which can both reduce the risks during the surgical procedure and also provide a significant reduction in the amount of time required to perform certain anastomosis procedures. The tissue approximating structures can be activated by a number of different actuation mechanisms that the surgeon can use to extend and retract the tissue approximating structures relative to adjacent tissue structures, as desired. There is a need, however, to provide a variety of actuation mechanisms for anastomosis devices in different surgical situations, and also a desire to provide additional safety features and removal features for anastomosis devices.

Anastomosis device configurations and methods


An elastic wave device making use of an SH plate wave propagating in LiNbO3 substrates includes a LiNbO3 substrate, IDT electrodes located on at least one surface of the LiNbO3 substrate, and a support which is bonded to the LiNbO3 substrate such that the support is located outside a region provided with the IDT electrodes and supports the LiNbO3 substrate, wherein θ of the Euler angles (0°, θ, 0°) of the LiNbO3 substrate ranges from about 92° to about 138° and the thickness of the LiNbO3 substrate ranges from about 0.05λ to about 0.25λ, where λ is the wavelength determined by the pitch between electrode fingers of the IDT electrodes.

1. Field of the Invention
The present invention relates to elastic wave devices used as resonators or band-pass filters and particularly relates to an elastic wave device making use of an SH plate wave propagating in LiNbO3 substrates.
2. Description of the Related Art
Hitherto, various elastic wave devices making use of a plate wave propagating in LiNbO3 have been proposed. For example, Japanese Unexamined Patent Application Publication No. 2002-152007 below discloses an elastic wave resonator shown in FIG. 16. The elastic wave resonator 1001 includes a LiNbO3 single-crystalline substrate 1002 as shown in FIG. 16. The center of the LiNbO3 single-crystalline substrate 1002 is a thin plate portion 1002a. That is, a central portion of the LiNbO3 single-crystalline substrate 1002 is thin and has a thickness h. In an example described in Japanese Unexamined Patent Application Publication No. 2002-152007, the thickness h is 0.03λ0.
The upper surface of the thin plate portion 1002a is overlaid with IDT electrodes 1003. Supposing the pitch between electrode fingers of the IDT electrodes 1003 is λ0, the width L of the electrode fingers is 0.125λ0.
Japanese Unexamined Patent Application Publication No. 2002-152007 describes that when the orientation of LiNbO3 is rotated about the X-axis at an angle of −10° to 70° in a direction from the Y-axis to the Z-axis, a major component of elastic vibration is an SH wave and a piezoelectric effect is large.
In the example described in Japanese Unexamined Patent Application Publication No. 2002-152007, the IDT electrodes 1003 are made of an Al-0.7% Cu alloy. On the other hand, the LiNbO3 single-crystalline substrate 1002 is a 40° Y substrate. This means that θ of Euler angles (φ, θ, ψ) is equal to 130°.
On the other hand, paragraph [0051] of Japanese Unexamined Patent Application Publication No. 2002-368576 below discloses an elastic wave element containing LiNbO3 with a rotation angle of 36°±20°, that is, LiNbO3 with Euler angles (0°, 106° to 146°, 0°). Herein, an elastic wave-propagating surface of a piezoelectric substrate made of LiNbO3 is mechanically free and the thickness of the piezoelectric substrate made of LiNbO3 is less than the wavelength λ of an elastic wave.
However, Japanese Unexamined Patent Application Publication No. 2002-152007 merely describes that when the orientation of LiNbO3 is within the above specific range, that is, a range specified in terms of Euler angles (0°, 80° to 160°, 0°), the piezoelectric effect due to the SH plate wave is large. A configuration using the SH plate wave described in Japanese Unexamined Patent Application Publication No. 2002-152007 cannot necessarily achieve a sufficiently large electromechanical coupling coefficient k2 and therefore is limited in increasing the fractional bandwidth, or bandwidth ratio. Incidentally, Japanese Unexamined Patent Application Publication No. 2002-152007 does not particularly refer to the thickness of the IDT electrodes.
Japanese Unexamined Patent Application Publication No. 2002-368576 discloses the elastic wave device containing LiNbO3 with the above Euler angles and a structure having an elastic wave-propagating region which is mechanically free and, however, does not describe any configuration using an SH plate wave.


A run-time data type extension mechanism describes the kinds of performance information collected within a registry located in a main memory of a computer. The data type extension mechanism comprises a base node of a multi-linked tree data structure having associated therewith a buffer portion for storing the collected performance information and a description portion for describing that information. Writer entities specify the contents of these latter portions, i.e., the collected information and its description, at run time to provide an arrangement for dynamically extending the kinds of information collected at the registry.

Software instrumentation generally includes software entities used for collecting, storing and retrieving performance metrics of a computer system. These software entities typically include writer entities for collecting the performance information and storing that information in a designated area of main memory, called a repository. The repository preferably holds the performance information for retrieval by reader entities, which may include application programs executing on the computer.
Namespace services impose a uniform structure on the information stored in repositories. A namespace is a collection of information managed by an operating system of the computer and a namespace service, or registry, is the entity that stores and organizes that information. The registry generally provides an application programming interface (API), which is a mechanism for an application program to obtain services from the operating system. APIs typically include a collection of system calls to the operating system requesting, for example, establishment of network connections on behalf of an application. Specifically, the application may, via system calls to the registry API, create, modify, request, add and delete information in the registry.
The performance information collected at the registry typically includes metrics relating to components of the computer system, such as a central processor unit (CPU), main memory, the operating system and input/output (I/O) system. Examples of the collected information include loading metrics of the CPU and bandwidth parameters of the memory, along with timing latencies for execution of a particular request involving the I/O system, e.g., how long it takes to complete the (entire or portions of the) request.
By collecting and retrieving performance information, the software instrumentation provides access to the internal state and behavior, i.e., "views", of the operating system and application software executing on the computer. Operating systems are complex pieces of software configured to, e.g., handle asynchronous events within a computer (such as interrupts from I/O devices), provide interprocess communication capabilities and implement complex network protocols. Operating systems also control execution of application programs; instances of those programs in execution are called processes.
Knowledge of the internal characteristics of an operating system and application processes is useful for debugging, optimization and design verification of a computer. The internal views provided by software instrumentation fall into two general categories: (i) tracing, which provides a view into the behavior of a software program by recording the time and details of its state at interesting points in a running system, and (ii) statistics, which record when and how resources, such as device drivers of the operating system, are used.
Tracing is a form of interprocess communication that enables a process to observe the execution of another process; a trace, therefore, consists of a display that chronicles the actions and results of that program execution. Specifically, the trace provides a detailed record of the program's execution path by, e.g., taking an application program and placing it under observation by a special routine that monitors the progress of the program.
Typically, primitive abstract data types are used by the writer entities to collect performance information, such as statistics and traces. These primitive data types generally include simple counters, histograms, maximum values, minimum values, averages and rates. In many cases, it may be desirable to expand upon the kinds of performance information collected by the writer entities to further enhance knowledge of the internal characteristics of software executing on the computer. In order to extend the types of information collected at the registry, however, it is necessary to describe that information so that the reader entities can manipulate the information.
A conventional way of describing type information involves designating name, type, length and offset parameters for each primitive data type. For example, a "flat" C data structure struct, set forth below, comprises primitive data type elements such as an integer of maximum value, an integer of minimum value, an unsigned count and a 64-bit int64 value.
______________________________________ struct { int max int min unsigned count int64 valuesum }; name type length (bytes) offset (bytes) ______________________________________ "max" MAX 4 0 "min" MIN 4 4 "count" COUNTER 4 8 "valuesum" SUM 8 16 ______________________________________
Referring to the first primitive data type element shown above, max is the name of the integer data element having a type designator MAX, a length of 4 bytes and an offset, relative to the beginning of the structure, of 0 bytes.
This description convention is generally used for describing parameters of trace messages as well as statistics information stored in the registry. The data type elements, e.g., int, int, unsigned and int64, are primitive in that they are implemented by the hardware of the computer, whereas type designators max, min, count, and valuesum are abstract data types using those primitive data types.
Several known operating systems have capabilities to acquire and register performance information, such as trace messages and statistics. The UNIX.RTM. operating system uses various software entities, known as KMEM readers, to access performance information stored in data structures within privileged memory for purposes of, e.g., displaying that information. Here, the performance information is collected solely within the operating system and registration is effected with a symbol table of a compiler.
In UNIX, the description of data must be previously known to the readers because there is no description of the information in the running system. That is, data description information must be compiled into the KMEM readers. Since the readers must be aware of all possible data types prior to accessing the information, the extensibility of data collection is limited.
Another known registration mechanism allows applications to access performance information without knowledge of the various types of collected information. In other words, applications can query the operating system as to the existence and types of collected information. However, there is no mechanism in the operating system for describing newly-created data types for collecting performance information. Accordingly, although the collected information can be easily added to the registry, the reader entities must have knowledge of their types in order to access them.
Therefore, it is among the objects of the invention to provide a mechanism for extending the types of information collected and stored in a registry.
Another object of the present invention is to provide a mechanism for describing the kinds of information collected and stored in a registry.

Run-time data type description mechanism for performance information in an extensible computer system


A method of manufacturing a layered core. The method includes the steps of: arranging a first plurality of yoke parts to define a first configuration magnetic pole sheet layer having first and second oppositely facing sides; arranging a second plurality of yoke parts to define a second configuration pole sheet layer having third and fourth oppositely facing sides; stacking the first plurality of yoke parts upon the second plurality of yoke parts so that the second side of the first configuration magnetic pole sheet layer is placed against the third side of the second configuration magnetic pole sheet layer; providing a circumferentially opening first female connector on a first yoke part; providing a first male connector on a second yoke part; and directing the first male connector into the first female connector.

1. Field of the Invention
The invention concerns a method of manufacturing a layered, stationary core, such as a core of a stator on an electrical motor.
2. Background Art
A stationary core, operational and productive as a coil for a magnetic pole, is commonly manufactured using a plurality of joined sections formed, as by a punching operation, from sheet material. The sections are stacked to form portions of a magnetic pole core around which wire is wound. After winding, the partial magnetic pole core portions are assembled into a circular shape and connected to complete the stationery core. Using this method, winding of the wire is facilitated but, in assembling the magnetic pole core portions to each other, a long time may be required.
For this reason, a method has been proposed recently whereby, core portions, made as described above, are connected to each other for relative movement. In this way, assembly of the core portions after winding is easily and effectively carried out. According to this method, as shown in FIGS. 7–9, magnetic pole sheet layers 10,12, shown in FIGS. 7 and 8, respectively, having first and second different configurations, are used. The first configuration magnetic pole sheet layer 10 has a plurality of arcuate yoke parts 14,14′,14″, each furnished with radially spaced depressions 16 and terminating at a radially inward location at a pole part 18. On one circumferential pointed end 20,20″ of each yoke part 14,14″, a connector 22,22″ is formed, each having a concave part 24,24″ on an upper side 26 and a convex part 28,28″ on a lower side 29.
The second configuration magnetic pole sheet layer 12, that is stacked with the first configuration magnetic pole sheet layer 10, has a plurality of arcuate yoke parts 30,30′,30″, corresponding to the yoke parts 14,14′,14″. The yoke parts 14,14′, 14″ are each furnished with radially spaced depressions 32 and terminate at a radial inward location at a pole part 34. Each yoke part 30,30′ has a pointed circumferential end 36,36′ pointing oppositely to the circumferential end 20,20″ on each yoke part 14,14″ on the first configuration magnetic pole sheet layer 10. At the ends 36,36′, a connector 38,38′ is formed having a concave part 40,40′ on an upper side 42 and a convex part 44,44′ on a lower side 46.
With this construction, the second configuration magnetic pole sheet layers 12 are formed and alternatingly stacked with the first configuration magnetic pole sheet layers 10 so that the convex parts 44,44′ of the connectors 38,38′ fit within the concave parts 24,24″ of the connectors 22,22″ of the first configuration magnetic pole sheet layer 10. As the magnetic pole sheet layers 10,12 are stacked, the depressions 16,32 nest. With this arrangement, the magnetic pole sheet layers 10,12 can be connected so that the stacked yoke parts 14,14′,14″, 30,30′,30″ can pivot freely back and forth relative to each other at the locations of the connectors 22,22″, 38,38′.
However, because the first and second configuration magnetic pole sheet layers 10,12 have yoke parts 14,14′,14″, 30,30′,30″ with oppositely pointing circumferential ends 20,20″, 36,36′, the layering process becomes complicated for each layering step.
Also, the formation of the concave 24,24″, 40,40′ and convex 28,28″, 44,44′ parts of the connectors 22,22″, 38,38′, as shown in FIG. 9, requires a punch 48 (FIG. 9) with a diameter D to advance towards a die element 49 furnished with openings 50 having a diameter D1 that is less than the diameter D. The punch 48 passes guidingly through a press plate 52, which sandwiches the sheet material 54, from which the yoke parts 14,14′,14″, 30,30′,30″ are formed, against the die element 49. In this case, if a thin metal laminate is being used for the sheet material, in constructing the first and second configuration magnetic pole sheet layers 10,12, it is difficult to stabilize the concave 24,24″, 40,40′ and convex 28,28″, 44,44′ parts. This instability at the connectors 22,22″, 38,38′ is a problem.


A system and method for controlling a rotational speed associated with a shaft or rotor of an electric motor comprises establishing a target rotational speed associated with a shaft or rotor of an electric motor. A sensor detects an actual rotational speed associated with the shaft or rotor of an electric motor. Speed error data is determined. The speed error defined as a difference between the target rotational speed and the actual rotational speed. A first duty cycle factor is determined based on the speed error data and a first gain constant. A second duty cycle factor is determined based on the speed error data and a second gain constant. Duty cycle input data is calculated for the electric motor based on a sum of the first duty cycle factor, the second duty cycle factor, and the target speed.

An electric motor may be used to drive an output shaft or member, such as one or more cutting blades of a mower or another implement. The speed of the cutting blades (e.g., reel mower cutting blade) may vary with the load presented by variations in ground elevation, vegetation density, vegetation moisture content, or otherwise. In addition, the speed of the cutting blades may fluctuate based on variation in the system voltage of equipment, because of other electrical loads associated with the equipment, electrical energy storage system health (e.g., battery health or state of charge), or otherwise. The fluctuation in the speed of the cutting blades may detract from finish and uniformity of the cut or mowed vegetation, for instance. Thus, there is a need to maintain a constant speed of the cutting blade to improve cutting or mower performance.


A detector response correction arrangement and method is proposed for online determination of correction factors for arbitrary positions from arbitrary incident fluence distributions. As modern radiotherapy utilizes more of the available degrees of freedom of radiation machines, dosimetry has to be able to present reliable measurements for all these degrees of freedom. To determine correction factors online during measurement, Monte Carlo technique is used to precalculate fluence pencil kernels from a monodirectional beam to fully describe the particle fluence in an irradiated medium. Assuming that the particle fluence is not significantly altered by the introduction of a small detector volume, the fluence pencil kernels (212) can be integrated (214), and correction factors (216) determined, e.g. by Cavity Theory, in different positions for the detector material.

Exposure for ionizing radiation is used in many technical fields, both therapeutical and non-therapeutical, e.g. for sterilizing purposes, radiotherapy, material modification etc. Common for most applications is that there is a need for dosimetry. Dosimetry deals with the process of determining the absorbed dose to an irradiated medium. Such a determining is generally applicable for all kinds of applications and therefore not a part of any treatment or diagnosing of a human being.
In radiotherapy, patients are treated for cancer with beams of ionizing radiation. The aim is to sterilize the tumor cells while spearing the healthy tissue surrounding them as far as possible. It is imperative that the planning, delivery and quality assurance through measurements of the absorbed dose, is done with high accuracy as to ensure precisely tailored treatments. There are different modalities of radiations used, such as conventional photon beams, intensity modulated photons (IMRT), electrons, protons or light ions.
In the document "Refinements of the finite-size pencil beam model of three-dimensional photon dose calculation" by O. Z. Ostapiak et al in Med. Phys. 24(5), May 1997, pp. 743-750, photon dose calculation algorithms are presented. The dose calculation is based on a convolution of the photon fluence and a radiation dose kernel ("dose spread kernel"). Such dose calculations are frequently used for clinical dose planning, but are not possible to utilize in connection with quality assurance problems. The present invention instead relates solely to the quality assurance problem, and does not concern any treatment planning of radiation.
A variety of detectors can be used, e.g. ionization chambers, calorimeters, solid state detectors, diodes, film, or thermoluminescence detectors (TLD), for different applications such as in vitro dosimetry or in vivo dosimetry. In vitro dosimetry relates to quality assurance of the irradiation using phantoms of water or tissue equivalent plastics. In in vitro dosimetry, detectors are placed in contact with a patient.
As mentioned above, dosimetry deals with the process of determining the absorbed dose to an irradiated medium. However, the introduction of a measurement device itself, i.e. a dosimeter, will introduce changes in the radiation conditions. It is not trivial to obtain the actual absorbed dose in an irradiated object from the reading from a measurement device. Placing a detector in, or on the surface of, an object to be irradiated the reading will give a different value than what is the actual dose deposition in equivalent volumes in the irradiated object. Knowing the proportion between deposited dose in different materials at different positions enables the determination of the dose to the object. In dosimetry, correction factors are used to express such relations.
In prior art radiation devices, correction factors are typically determined experimentally in water phantoms along the central axis of the radiation field, and tabulated as correction factors for different depths for standard field sizes. An alternative approach is to calculate correction factors, e.g. through extensive and lengthy Monte Carlo simulations of the radiation transport and interactions as to determine the full spectral distribution of particles incident on the detector.
In modern radiotherapy, one modulates and shape the beam as to adjust the delivered dose to the tumor in order to spare the healthy tissue surrounding it to the outermost extent. Similar needs for customizing the irradiation field are present also in other applications. Modulating the irradiation field is done with different techniques, e.g. by dividing the treatment irradiation into partitions delivered with different amounts and field shapes, from different incident angles. Shaping the field, and their partitions, can be done either with adjustable collimator leaves, specific molded collimators or by scanning a narrow beam.


Disclosed herein is a method and apparatus for maintaining communication between a dependent and a communications network when the dependent is outside a coverage area associated with its master using a controller and a communications network. In one embodiment, when the dependent is in a piconet, the dependent is within communication range of its master using a communication channel on frequency band fband(1). When the dependent moves outside the piconet, the dependent should be within communication range of the controller and, thus, switches to another communication channel within frequency band fband(1) such that it may communicate with the controller. When the dependent moves outside the communication range of the controller, the dependent should be within communication range of a communications network or a base station and, thus, switches to a communication channel within another frequency band fband(2).

FIG. 1 depicts a wireless network 10 referred to herein as a piconet in accordance with the prior art. Piconet 10 comprises a master 12 and one or more dependents 14. Master 12 is a communication device that may be directly or indirectly connected to communications network 16, such as a Public Switching Telephone Network (PSTN) or another wireless network. Master 12 being operable to communicate with dependents 14 over a wireless interface and having hardware and software for controlling and managing data or voice transmissions among dependents 14 and communications network 16. Dependents 14 are devices for communicating with master 12 over a wireless interface. For example, suppose master 12 is a telephone switchboard that is connected to a PSTN and dependent 14 is a wireless telephone. In this example, the communication path goes from the wireless telephone to the telephone switchboard to the PSTN, and vice-versa.
Master 12 and dependents 14 are operable to communicate with each other so long as dependents 14 are within the coverage area of the piconet, which is defined by the communication range of master 12. Typically, master 12 has a communication range of a few meters. If dependents 14 are mobile devices, such as wireless terminals, and move beyond the communication range of master 12, dependents 14 would be unable to communicate with master 12 and, thus, be unable to maintain a communication link with communications network 16. Accordingly, there exists a need for dependents 14 to maintain communication with communications network 16 when dependents 14 move outside the coverage area of the piconet.

Method for maintaining a communication link in wireless network groups


Spreadsheet apparatus enables reformatting and renaming of items forming the spreadsheet. A series of items forms a dimension along an axis of the spreadsheet. A label icon or labelling entity is user nameable to describe the series of items of an axis. Repositioning of the label icons repositions respective series of items and thus redefines/rearranges the axes of the spreadsheet. Sub-axes to an axis are similarly formed by series of items associated with a respective label icon. Order of label icons in predefined areas of a working screen view determine hierarchy of main axis and sub-axes for the label icons. There is a different predefined area for the possible vertical axes, possible horizontal axes, and the possible orthogonal axes of the spreadsheet. A cell module holds spreadsheet data in a matrix of memory cells. A symbol table translates between current specified names of items in the spreadsheet and indexes to cells of the cell module. Thus, a user is able to rearrange and/or relabel icons in the spreadsheet screen view to reformat the spreadsheet, and the supporting computer members provide display of the spreadsheet rearranged according to position of the icons without losing data of the items as held in respective intersections of the spreadsheet.

In computer data processing, the term "spreadsheet" generally refers to a grid-like table or matrix for holding desired data. Typically, the grid-like table or matrix is formed of a series of columns intersecting a series of rows. The columns extend from a peripheral horizontal axis of the matrix while the rows extend from a peripheral vertical axis of the matrix. Each row is labelled with a numeral (1, 2, 3 . . . ) along the peripheral vertical axis and each column is labelled with a letter (A, B, C . . . ) along the peripheral horizontal axis. An intersection of a row and column forms a cell which receives a label formed by the composite of the respective labels of the row and column (e.g. C5). Each cell holds data according to a respective formula.
According to the foregoing grid structure, spreadsheets were referred to as two-dimensional, i.e. having two axes along which information could be located. More recently, a series of such spreadsheets have been used as a collection to provide a third dimension. Each spreadsheet in the series or collection is thought to extend from a position along a third axis. That is, the third axis provides a link from one spreadsheet to another in the series. Each spreadsheet in the series has the two axis format with numbered rows and lettered columns. And each cell has a composite label as described previously but with an additional indication of particular spreadsheet in the series of spreadsheets on which the cell is located. Additional dimensions provide links between different series of spreadsheets.
There are various disadvantages to such spreadsheets, both two-dimensional and multi-dimensional based on a series of spreadsheets. For the most part, labels of the spreadsheet are non-descriptive of the data being held by the spreadsheet. Further, the two axis format of the unit spreadsheet does not always present the stored data in a manner which is easy to read or of a desirable arrangement with respect to the reader. Both labelling scheme and display format of spreadsheets are static and unchangeable for different users' needs. Hence, current spreadsheets are too rigid and fixed in structure/format.
Another disadvantage is that only per cell formulas are employable in current spreadsheets. That is, cells are referenced by the fixed row/column labelling scheme. Hence, a degree of effort and care is required to maintain coordination between cells and respective cell formulas.
Accordingly, the need exists for a more flexibly structured spreadsheet such that one spreadsheet can satisfy needs of different users.

Data processing apparatus and method for a reformattable multidimensional spreadsheet


The invention provides an organic-inorganic porous membrane which includes metal organic silica nano-particles impregnated in a polymer. The polymer includes a property of generating porous membrane using a phase inversion technique. The invention also provides a method for preparing the organic-inorganic porous membrane.

Different types of membranes are used for gas separation and water purification. Porous and non-porous membranes are widely used for gas separation and water purification. A membrane is largely determined by membrane transport properties. The membrane transport properties include permeability of the membrane and selectivity for a specific molecule in a mixture.
The porous membranes are rigid, high voided with randomly distributed pores. The porous membranes which are used for separation are specifically designed to preferentially separate molecules in a mixture. For example, porous membranes with pore diameter smaller than the mean free path of a gas molecule are designed. The separation of gas using the porous membranes is based on pore size and pore distribution. The gas molecules can be separated using porous membrane only if sizes of gas molecules differ considerably in a gas mixture. Further, the porous membranes exhibit high level of flux but inherit low selectivity values. Thus, the porous membranes have high permeability but low selectivity properties.
The non-porous membranes are designed to adsorb specific molecules from a mixture on to the solid surface of the non-porous membranes. For example, a non-porous membrane prepared using mineral zeolite specifically adsorbs carbon dioxide (CO2) from a gas stream. Thus, the porous membranes have high selectivity but low permeability properties.
When permeability of a membrane increases, selectivity decreases and when the selectivity increases, the permeability decreases. Therefore, there is a need to develop an improved membrane for gas separation and water purification.

Organic-inorganic porous membrane and a method for preparing the same

King Abdulaziz City for Science and Technology (KACST)


A method of depositing a metal film on a silyl hydride surface of a solid such as silica gel, the solid normally having hydroxyl groups, the metal with a valence of zero being deposited on the surface by reaction of a metal ion in a solution with the hydrogens of the silyl hydrides. The above method is used to easily remove metal ions from a solution and also the method is a basis for determining the number of silyl hydride groups on the surface of the solid.

Solids such as silica gel and alumina normally have hydroxyl groups. U.S. Pat. No. 5,017,540 (Sandoval & Pesek) discloses the preparation of a silica surface with surface silicon hydride groups by replacing the normal hydroxyl groups. One way of modifying a surface of an inorganic oxide is to convert the normal hydroxyl groups to surface hydride groups by reaction with a silane such as trichlorosilane. Reaction of trichlorosilane and silica gel surfaces at elevated temperatures was reported in Kol'tsov S. I., Aleskovskii, V. B., Russ J. Phys. Chem., 1967, 4, 336.
It would be desirable to provide an efficient, well-controlled method of depositing metal with a valence of zero on a solid normally having hydroxyl groups, the metal film produced providing a clean surface for chemical reactions and the metal film being a catalytic film.

Method of depositing a metal film on a silyl hydride containing surface of a solid and products produced thereby


A braking band for a disc-brake disc includes opposed annular braking surfaces which extend from an inner edge facing towards the axis of rotation to an outer edge facing towards the outside of the disc. The braking band has a uniform distribution of grooves having a pattern or module that is repeated circumferentially in a manner such that the distribution is circumferentially uniform. According to an example embodiment, each of the grooves is closed and extends along a predominant line of extent defining an axis. The module extends from an inner radius to an outer radius which define an annular portion. The module further includes a first groove extending from the inner radius to the outer radius, a second groove, and a third groove that are shorter than the first groove. The axes of the second groove and of the third groove have an opposite inclination to the axis of the first groove.

Conventional grooved rotors for discs and clutches are known in the art. Conventional grooved bands have a distribution of grooves that are generally not optimal for achieving an optimal mean coefficient of friction or for balancing the stresses on the pads and thus eliminating the vibrations induced in the disc and in the pad by their interaction during the braking operation.
In such conventional braking bands, the expression "principal direction of rotation of the disc" defines the direction of rotation corresponding to forward movement of the vehicle. An axis lying in a plane perpendicular to the axis of rotation of the braking band and intersecting the axis of rotation is referred to as a "radial direction". An axis tangential to a circle lying in a plane perpendicular to the axis of rotation of the braking band and having a point on the axis of rotation at its centre is referred to as a "tangential direction". The circle defines a circumferential direction of the disc.

Disc brake braking band and disc for a disc brake


The present invention relates an electrode notching apparatus. The electrode notching apparatus comprises: a notching unit shaping an electrode into a predetermined pattern; a heating unit drying the electrode processed by the notching unit; and a collecting unit collecting the electrode dried by the heating unit, wherein the heating unit comprises: a heating body having a drying space through which the electrode supplied by the notching unit passes; and heating members directly heating a surface of the electrode passing through the drying space to dry moisture remaining on the electrode.

In general, secondary batteries refer to chargeable and dischargeable batteries, unlike primary batteries that are not chargeable. The secondary batteries are being widely used in the high-tech electronic fields such as mobile phones, notebook computers, and camcorders.
Such a secondary battery comprises an electrode assembly in which electrodes and separators are alternately stacked and a case accommodating the electrode assembly, and the electrode assembly has a structure in which the plurality of electrodes and the plurality of separators are alternately stacked.
Also, a method for manufacturing the secondary battery comprises a process of manufacturing an electrode, a process of stacking the manufactured electrode and a separator to manufacture an electrode assembly, and a process of accommodating the manufactured electrode assembly in a case to manufacture the secondary battery.
Here, the electrode manufacturing process further comprises a notching process of notching the electrode. In the notching process, a processing process of shaping the electrode into an electrode pattern and a drying process of drying moisture remaining on a surface of the shaped electrode are performed. In the drying process, an electrode active material applied to a collector of the electrode is dried by using hot air to evaporate the moisture.
However, since the drying process uses the hot air, it takes a long time to dray the electrode active material applied to the collector. Thus, the electrode may be significantly deteriorated in productivity. Particularly, the notching process has a problem in that the processing process and the drying process are separately performed to significantly deteriorate work efficiency.

Notching apparatus and method for secondary battery


A downhole tool for sealing a wellbore. The downhole tool includes a packer with a ball seat defined therein. A sealing ball is carried with the packer into the well. The movement of the sealing ball away from the ball seat is limited by a ball cage which is attached to the upper end of the packer. The ball cage has a plurality of ports therethrough for allowing flow into the ball cage and through the packer at certain flow rates. A spring is disposed in a longitudinal opening of the packer and engages the sealing ball to prevent the sealing ball from engaging the ball seat until a predetermined flow rate is reached. When the packer is set in the hole, flow through the frac plug below a predetermined flow rate is permitted. Once a predetermined flow rate in the well is reached, a spring force of the spring will be overcome and the sealing ball will engage the ball seat so that no flow through the frac plug is permitted.

This invention relates generally to downhole tools for use in oil and gas wellbores and methods of drilling such apparatus out of wellbores, and more particularly, to such tools having drillable components made from metallic or non-metallic materials, such as soft steel, cast iron, engineering grade plastics and composite materials. This invention relates particularly to downhole packers and frac plugs.
In the drilling or reworking of oil wells, a great variety of downhole tools are used. For example, but not by way of limitation, it is often desirable to seal tubing or other pipe in the casing of the well, such as when it is desired to pump cement or other slurry down the tubing and force the slurry out into a formation. It thus becomes necessary to seal the tubing with respect to the well casing and to prevent the fluid pressure of the slurry from lifting the tubing out of the well. Downhole tools referred to as packers and bridge plugs are designed for these general purposes and are well known in the art of producing oil and gas.
The EZ Drill SV(copyright) squeeze packer, for example includes a set ring housing, upper slip wedge, lower slip wedge, and lower slip support made of soft cast iron. These components are mounted on a mandrel made of medium hardness cast iron. The EZ Drill(copyright) squeeze packer is similarly constructed. The Halliburton EZ Drill(copyright) bridge plug is also similar, except that it does not provide for fluid flow therethrough.
All of the above-mentioned packers are disclosed in Halliburton Servicesxe2x80x94Sales and Service Catalog No. 43, pages 2561-2562, and the bridge plug is disclosed in the same catalog on pages 2556-2557.
The EZ Drill(copyright) packer and bridge plug and the EZ Drill SV(copyright) packer are designed for fast removal from the wellbore by either rotary or cable tool drilling methods. Many of the components in these drillable packing devices are locked together to prevent their spinning while being drilled, and the harder slips are grooved so that they will be broken up in small pieces. Typically, standard xe2x80x9ctri-conexe2x80x9d rotary drill bits are used which are rotated at speeds of about 75 to about 120 rpm. A load of about 5,000 to about 7,000 pounds of weight is applied to the bit for initial drilling and increased as necessary to drill out the remainder of the packer or bridge plug, depending upon its size. Drill collars may be used as required for weight and bit stabilization.
Such drillable devices have worked well and provide improved operating performance at relatively high temperatures and pressures. The packers and bridge plugs mentioned above are designed to withstand pressures of about 10,000 psi (700 kg/cm2) and temperatures of about 425xc2x0 F. (220xc2x0 C.) after being set in the wellbore. Such pressures and temperatures require using the cast iron components previously discussed.
However, drilling out iron components requires certain techniques. Ideally, the operator employs variations in rotary speed and bit weight to help break up the metal parts and reestablish bit penetration should bit penetration cease while drilling. A phenomenon known as xe2x80x9cbit trackingxe2x80x9d can occur, wherein the drill bit stays on one path and no longer cuts into the downhole tool. When this happens, it is necessary to pick up the bit above the drilling surface and rapidly recontact the bit with the packer or plug and apply weight while continuing rotation. This aids in breaking up the established bit pattern and helps to reestablish bit penetration. If this procedure is used, there are rarely problems. However, operators may not apply these techniques or even recognize when bit tracking has occurred. The result is that drilling times are greatly increased because the bit merely wears against the surface of the downhole tool rather than cutting into it to break it up.
In order to overcome the above long standing problems, the assignee of the present invention introduced to the industry a line of drillable packers and bridge plugs currently marketed by the assignee under the trademark FAS DRILL(copyright). The FAS DRILL(copyright) line of tools consists of a majority of the components being made of non-metallic engineering grade plastics to greatly improve the drillability of such downhole tools. The FAS DRILL(copyright) line of tools has been very successful and a number of U.S. patents have been issued to the assignee of the present invention, including U.S. Pat. No. 5,271,468 to Streich et al., U.S. Pat. No. 5,224,540 to Streich et al., U.S. Pat. No. 5,390,737 to Jacobi et al., U.S. Pat. No. 5,540,279 to Branch et al., U.S. Pat. No. 5,701,959 to Hushbeck et al., U.S. Pat. No. 5,839,515 to Yuan et al., and U.S. Pat. No. 5,984,007 to Yuan et al. The preceding patents are specifically incorporated herein by reference.
The tools described in all of the above references typically make use of metallic or non-metallic slip-elements, or slips, that are initially retained in close proximity to the mandrel but are forced outwardly away from the mandrel of the tool to engage a casing previously installed within the wellbore in which operations are to be conducted upon the tool being set. Thus, upon the tool being positioned at the desired depth, the slips are forced outwardly against the wellbore to secure the packer, or bridge plug as the case may be, so that the tool will not move relative to the casing when for example operations are being conducted for tests, to stimulate production of the well, or to plug all or a portion of the well.
The FAS DRILL(copyright) line of tools includes a frac plug which is well known in the industry. A frac plug is essentially a downhole packer with a ball seat for receiving a sealing ball. When the packer is set and the sealing ball engages the ball seat, the casing or other pipe in which the frac plug is set is sealed. Fluid, such as a slurry, can be pumped into the well after the sealing ball engages the seat and forced into a formation above the frac plug. Prior to the seating of the ball, however, flow through the frac plug is allowed.
One way to seal the frac plug is to drop the sealing ball from the surface after the packer is set. Although ultimately the ball will reach the ball seat and the frac plug will perform its desired function, it takes time for the sealing ball to reach the ball seat, and as the ball is pumped downwardly a substantial amount of fluid can be lost through the frac plug.
The ball may also be run into the well with the packer. Fluid loss and lost time to get the ball seated can still be a problem, however, especially in deviated wells. Some wells are deviated to such an extent that even though the ball is run into the well with the packer, the sealing ball can drift away from the packer as it is lowered into the well through the deviated portions thereof As is well known, some wells deviate such that they become horizontal or at some portions may even angle slightly upwardly. In those cases, the sealing ball can be separated from the packer a great distance in the well. Thus, a large amount of fluid and time is taken to get the sealing ball moved to the ball seat, so that the frac plug seals the well to prevent flow therethrough. Thus, while standard frac plugs work well, there is a need for a frac plug which will allow for flow therethrough until it is set in the well and the sealing ball engages the ball seat, but that can be set with a minimal amount of fluid loss and loss of time. The present invention meets that need.
Another object of the present invention is to provide a downhole tool that will not spin as it is drilled out. When the drillable tools described herein are drilled out, the lower portion of the tool being drilled out will be displaced downwardly in the well once the upper portion of the tool is drilled through. If there is another tool in the well therebelow, the portion of the partially drilled tool will be displaced downwardly in the well and will engage the tool therebelow. As the drill is lowered into the well and engages the portion of the tool that has dropped in the well, that portion of the tool sometimes has a tendency to spin and thus can take longer than is desired to drill out. Thus, there is a need for a downhole tool which will not spin when an undrilled portion of that tool engages another tool in the well as it is being drilled out of the well.
The present invention provides a downhole tool for sealing a wellbore. The downhole tool comprises a frac plug which comprises a packer having a ball seat defined therein and a sealing ball for engaging the ball seat. The packer has an upper end, a lower end and a longitudinal flow passage therethrough. The frac plug of the present invention also has a ball cage disposed at the upper end of the packer. The sealing ball is disposed in the ball cage and thus is prevented from moving past a predetermined distance away from the ball seat. The packer includes a packer mandrel having an upper and lower end, and has an inner surface that defines the longitudinal flow passage. The ball seat is defined by the mandrel, and more particularly by the inner surface thereof.
A spring may be disposed in the mandrel and has an upper end that engages the sealing ball. The spring has a spring force such that it will keep the sealing ball from engaging the ball seat until a predetermined flow in the well is achieved. Once the predetermined flow rate is reached, the sealing ball will compress the spring and will engage the ball seat to close the longitudinal flow passage. Flow downwardly through the longitudinal flow passage is prevented when the sealing ball engages the ball seat. The present invention may be used with or without the spring.
The packer includes slips and a sealing element disposed about the mandrel such that when it is set in the wellbore and when the sealing ball is engaged with the ball seat, no flow past the frac plug is allowed. A slurry or other fluid may thus be directed into the formation above the frac plug. The ball cage has a plurality of flow ports therein so that fluid may pass therethrough into the longitudinal central opening thus allowing for fluid flow through the frac plug when the packer is set but the sealing ball has not engaged the ball seat. Fluid can flow through the frac plug so long as the flow rate is below the rate which will overcome the spring force and cause the sealing ball to engage the ball seat. Thus, one object of the present invention is to provide a frac plug which allows for flow therethrough but which alleviates the amount of fluid loss and loss of time normally required for seating a ball on the ball seat of a frac plug. Additional objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such preferred embodiment.


A printed circuit board is disclosed. Pins of a plurality of resistors on the PCB are connected to the same input line. At least two out of the resistors are connected to the same input line with access pins overlapped. One shared bonding pad is located in every overlapped area, electrical components are bonded on the shared bonding pads. As at least two out of the resistors are connected to the same input line with the access pins overlapped, the utilization of space is maximized. In this way, not only the dimension of the PCB is reduced, but also the manufacturing cost is reduced at the same time.

1. Field of the Invention
The present disclosure relates to circuit board manufacturing technology, and more particularly to a printed circuit board (PCB).
2. Discussion of the Related Art
Generally, PCBs include a plurality of components welded thereon. The more the components have been welded, the larger the PCB is needed, and the higher the manufacturing cost.
As shown in FIG. 1, the first resistor R1 and the second resistor R2 respectively include a first bonding pad S01 and a second bonding pad S02. One pin of the first resistor R1 connects to the first bonding pad S01, and one pin of the second resistor R2 connects to the second bonding pad S02. Afterward, the first bonding pad S01 and the second bonding pad S02 are electrically connected. Also referring to FIG. 2, the PCB includes a plurality of output line O1, O2, . . . and On, wherein the n is an integer larger than or equal to 2. Usually, the input line I0 is connected to another pin of the first resistor R1 when one component has to be connected to one output line O1. Afterward, the electrical component is mounted on the first bonding pad S01. However, only one bonding pad of the PCB is connected with the input line I0, and it can be understood that other bonding pads are idle, which not only waste the space of the PCB, but also increase the manufacturing cost.

Shenzhen China Star Optoelectronics Technology Co., Ltd


A swash plate compressor comprises a swash plate located for rotation in a housing and a compression unit that forms a part of the housing. The compression unit has cylinder bores that guide pistons in reciprocation as the swash plate rotates. Each cylinder bore has a cross section formed of any other closed curve than a circle. The closed curve is defined by curve elements and straight elements.

1. Field of the Invention
The present invention relates to a swash plate compressor adapted for use in a refrigerating system.
2. Description of the Related Art
A swash plate compressor of this type is described in Jpn. Pat. Appln. KOKAI Publication No. 6-159238, for example. This conventional compressor is provided with a rotatable main shaft, on which a swash plate is mounted. The swash plate rotates together with the main shaft in one direction. The rotation of the swash plate causes pistons in cylinder bores to reciprocate.
The cross section of each cylinder bore is not in the shape of a perfect circle, and has the shape of a closed curve that is formed of a plurality of curve elements smoothly connected to each other. The curve elements have their respective curvature radii.
According to the compressor described above, the cross section of each cylinder bore is not in the shape of a perfect circle, so that each piston cannot rotate around its own axis, that is, its rotation is favorably prevented by the cylinder bore.
Since the cross-sectional shape of each cylinder bore is complicated, however, it is very hard to work the bore.

Swash plate compressors with non-circular pistons and cylinders


A testing system for examining the coating and open cooling-air holes of turbine blades includes a positioning device for an infrared camera with two degrees of freedom, a rotating-pivoting device for positioning the turbine blade, and a rotatable air duct arranged on the rotating-pivoting device. The rotatable air duct is configured for introducing into the turbine blade air at a temperature higher or lower in comparison with the turbine blade.

The examination of the coating and of open cooling-air holes on turbine blades is realized by means of an infrared camera. This involves excitation by means of hot air and flash lamps and recording of the resultant heat flux by an infrared camera. In order to examine suitable regions and/or image portions, the component, such as for example a turbine blade, and the camera must be correspondingly positioned.
A known testing system is described on the basis of FIGS. 1 and 2. In the case of the known testing system, the infrared camera is positioned by means of an industrial robot. The turbine blade is fixed on a rotary table. The rotary table usually has two receptacles for turbine blades, which are arranged such that one receptacle is located in an enclosure of the robot for testing while the other receptacle is externally accessible for the loading or removal of the turbine blade.
The tester's working place, located outside the enclosure, is shielded from flash and flow noises. In a testing procedure, firstly the type of test, the testing position and the focus of the infrared camera are established. Then, the parameters are transferred into a system database. The robot travels over a testing path, in order in this way to position the infrared camera.
WO 98/05949 A1 discloses a testing system for testing gas turbine blades for delamination, with a rotating device for the blade and a three-axis positioning device for an IR camera. To check the internal structure, hot air may be introduced into the blade.
EP 1 739 409 A1 discloses a testing system for determining the location and the angular position of holes in a turbine blade, with a fixed-in-place receptacle for the blade, a positioning device for an IR camera and a radiant heater for heating the turbine blade.
US 2008/237466 A1 discloses a testing system for determining the gas flow through holes in a turbine blade, with a fixed-in-place receptacle for the turbine blade and an IR camera arranged on a robot arm. Warm air is passed through the receptacle and through the turbine blade.
WO 03/038403 A2 discloses an inspection system for a turbine blade, with a fixed-in-place receptacle for holding and introducing air or gas into the turbine blade. A number of mirrors are arranged around the receptacle, in order to make more than one side or edge of the turbine blade accessible to an IR camera.
U.S. Pat. No. 5,111,046 A discloses a device for the inspection of channels of a turbine blade, with a fixed-in-place receptacle for holding and introducing air or gas into the turbine blade and an IR camera for recording heating-up and cooling-down processes.

Testing system for examining turbine blades


What is described is a recombinant poxvirus, such as avipox virus, containing foreign DNA from porcine circovirus 2. What are also described are immunological compositions containing the recombinant poxvirus for inducing an immunological response in a host animal to which the immunological composition is administered. Also described are methods of treating or preventing disease caused by porcine circovirus 2 by administering the immunological compositions of the invention to an animal in need of treatment or susceptible to infection by porcine circovirus 2.

The present invention relates to vectors, such as recombinant vectors; for instance, recombinant viruses, such as poxviruses, e.g., modified poxviruses and to methods of making and using the same. In some embodiments, the invention relates to recombinant avipox viruses, such as canarypox viruses, e.g., ALVAC. The invention further relates to such vectors, e.g., poxviruses, that express gene products, e.g., antigen(s), ORF(s), and/or epitope(s) of interest therefrom, of porcine circovirus 2 (PCV2); to immunological compositions or vaccines. The invention yet further relates to such vectors, e.g., poxviruses, that induce an immune response directed to or against PCV2 gene products and/or PCV2; and, to advantageously, such compositions that are immunological, immunogenic or vaccine compositions and/or confer protective immunity against infection by PCV2. The invention yet further relates to the uses of and methods for making and using such vectors and compositions, as well as intermediates thereof, and said intermediates. And, the invention relates to the products therefrom, e.g., from the uses and methods involving the inventive recombinant or poxvirus, such as antibodies from expression.
Postweaning multisystemic wasting syndrome (PMWS) is a recently recognized disease of young pigs. PMWS is characterized clinically by progressive weight loss and other symptoms such as tachypnea, dyspnea and jaundice. Pathologically, lymphocytic and granulomatous infiltrates, lymphadenopathy, and, more rarely, lymphocytic and granulomatous hepatitis and nephritis have been observed (Clark, 1997; Harding, 1997).
This disease has been described in different European countries as well as in North America. Treatment and prevention of this disease are not currently available.
Several lines of evidence point to porcine circovirus as the etiologic agent of PMWS (Ellis et al., 1998). Circoviruses have been recovered from pigs with PMWS, and antibodies to porcine circovirus have been demonstrated in pigs with the disease.
Circoviruses are single stranded circular DNA viruses found in a range of animal and plant species. Porcine circovirus was originally isolated as a contaminant from a continuous pig kidney cell line. The cell culture isolate has been designated PK-15 (Meehan et al., 1997). More recently, porcine circovirus obtained from pigs with PMWS has been compared to PK-15. Such viruses differ substantially from PK-15 at the nucleotide and protein sequence level, and have been designated PCV2 (Meehan et al., 1998; Hamel et al., 1998).
As many as thirteen open reading frames (ORFs) have been identified in the PCV2 genome (COL1 to COL13 in the French patent application 98 03707). Four of these ORFs share substantial homology with analogous ORFs within the genome of PK-15. ORF1 (Meehan et al., 1998; corresponding to COL4 in the French patent application 98 03707), comprising nt 398-1342 (GenBank accession number AF055392), has the potential to encode a protein with a predicted molecular weight of 37.7 kD. ORF2 (Meehan et al., 1998; corresponding to COL13 in the French patent application 98 03707), comprising nt 1381-1768 joined to 1-314 (GenBank accession number AF055392), may encode a protein with a predicted molecular weight of 27.8 kD. ORF3 (Meehan et al., 1998; corresponding to COL7 in the French patent application 98 03707), comprising nt 1018-704 (GenBank accession number AF055392), may encode a protein with a predicted molecular weight of 11.9 kD. ORF4 (Meehan et al., 1998; corresponding to COL10 in the French patent application 98 03707), comprising nt 912-733 (GenBank accession number AF055392), may encode a protein with a predicted molecular weight of 6.5 kD.
ORF1 of PCV2 is highly homologous (86% identity) to the ORF1 of the PK-15 isolate (Meehan et al., 1998). The ORF1 protein of PK-15 has been partially characterized (Meehan et al., 1997; Mankertz et al., 1998a). It is known to be essential for virus replication, and is probably involved in the viral DNA replication.
Protein sequence identity between the respective ORF2s was lower (66% identity) than that of the ORF1s but each of the ORF2s shared a highly conserved basic N-terminal region, similar to that observed in the N-terminal region of the major structural protein of the avian circovirus chicken anemia virus (CAV) (Meehan et al., 1998). Recently, Mankertz et al. (1998b) has suggested that the ORF2 of the PK-15 isolate (designated ORF 1 in Mankertz et al., 1998b) codes for a capsid protein.
Greater differences were observed between the respective ORF3s and ORF4s of the PK-15 isolate and PCV2. In each case, there was a deletion of the C-terminal region of PCV2 ORF4 and ORF3 compared to the corresponding ORFs present in the genome of the PK-15 isolate. The highest protein sequence homology was observed at the N-terminal regions of both ORF3 and ORF4 (Meehan et al., 1998).
The transcription analysis of the genome of PCV2 has not been published yet. Recent data obtained with the PK-15 isolate indicated that the ORF2 transcript is spliced (Mankertz et al., 1998b).
Vaccinia virus has been used successfully to immunize against smallpox, culminating in the worldwide eradication of smallpox in 1980. With the eradication of smallpox, a new role for poxviruses became important, that of a genetically engineered vector for the expression of foreign genes (Panicali and Paoletti, 1982; Paoletti et al., 1984). Genes encoding heterologous antigens have been expressed in vaccinia, often resulting in protective immunity against challenge by the corresponding pathogen (reviewed in Tartaglia et al., 1990). A highly attenuated strain of vaccines, designated MVA, has also been used as a vector for poxvirus-based vaccines. Use of MVA is described in U.S. Pat. No. 5,185,146.
Two additional vaccine vector systems involve the use of naturally host-restricted poxviruses, avipox viruses. Both fowlpoxvirus (FPV; Taylor et al. 1988a, b) and canarypoxvirus (CPV; Taylor et al., 1991 and 1992) have been engineered to express foreign gene products. Fowlpox virus (FPV) is the prototypic virus of the Avipox genus of the Poxvirus family. The virus causes an economically important disease of poultry which has been well controlled since the 1920""s by the use of live attenuated vaccines. Replication of the avipox viruses is limited to avian species (Matthews, 1982) and there are no reports in the literature of avipoxvirus causing a productive infection in any non-avian species including man. This host restriction provides an inherent safety barrier to transmission of the virus to other species and makes use of avipoxvirus based vaccine vectors in veterinary and human applications an attractive proposition.
FPV has been used advantageously as a vector expressing antigens from poultry pathogens. The hemagglutinin protein of a virulent avian influenza virus was expressed in an FPV recombinant (Taylor et al., 1988c). After inoculation of the recombinant into chickens and turkeys, an immune response was induced which was protective against either a homologous or a heterologous virulent influenza virus challenge (Taylor et al., 1988c). FPV recombinants expressing the surface glycoproteins of Newcastle Disease Virus have also been developed (Taylor et al., 1990; Edbauer et al., 1990).
Other attenuated poxvirus vectors have been prepared by genetic modifications of wild type strains of virus. The NYVAC vector, derived by deletion of specific virulence and host-range genes from the Copenhagen strain of vaccinia (Tartaglia et al., 1992) has proven useful as a recombinant vector in eliciting a protective immune response against an expressed foreign antigen.
Another engineered poxvirus vector is ALVAC, derived from canarypox virus (ALVAC was deposited with American Type Culture Collection, P.O. Box 1549, Manassas, Va. 20108, USA, under the terms of the Budapest Treaty on Nov. 14, 1996, and is designated as Accession Number VR-2547). ALVAC does not productively replicate in non-avian hosts, a characteristic thought to improve its safety profile (Taylor et al., 1991 and 1992). Both ALVAC and NYVAC are BSL-1 vectors.
One approach to the development of a subunit PCV2 vaccine is the use of live viral vectors to express relevant PCV2 ORFs. Recombinant poxviruses can be constructed in two steps known in the art and analogous to the methods for creating synthetic recombinants of poxviruses such as the vaccinia virus and avipox virus described in U.S. Pat. Nos. 4,769,330; 4,722,848; 4,603,112; 5,110,587; 5,174,993; 5,494,807; and 5,505,941, the disclosures of which are incorporated herein by reference. It can thus be appreciated that provision of a PCV2 recombinant poxvirus, and of compositions and products therefrom particularly ALVAC based PCV2 recombinants and compositions and products therefrom, especially such recombinants containing ORFs 1 and/or 2 of PCV2, and compositions and products therefrom would be a highly desirable advance over the current state of technology.
It is therefore an object of this invention to provide compositions and methods for treatment and prophylaxis of infection with PCV2. It is also an object to provide a means to treat or prevent PMWS.
In one aspect, the present invention relates to an antigenic, immunological, immunogenic, or vaccine composition or a therapeutic composition for inducing an antigenic, immunogenic or immunological response in a host animal inoculated with the composition. The composition advantageously includes a carrier or diluent and a recombinant virus, such as a recombinant poxvirus. The recombinant virus or poxvirus contains and expresses an exogenous nucleic acid molecule encoding an ORF, antigen, immunogen, or epitope of interest from PCV2, or a protein that elicits an immunological response against PCV2 or conditions caused by PCV2, such as PMWS. For instance, the recombinant virus can be a modified recombinant virus or poxvirus; for example, such a virus or poxvirus that has inactivated therein virus-encoded genetic functions, e.g., nonessential virus-encoded genetic functions, so that the recombinant virus has attenuated virulence and enhanced safety. And, the invention further provides the viruses used in the composition, as well as methods for making and uses of the composition and virus.
The virus used in the composition according to the present invention is advantageously a poxvirus, particularly a vaccinia virus or an avipox virus, such as fowlpox virus or canarypox virus and more advantageously, ALVAC. The modified recombinant virus can include, e.g., within a non-essential region of the virus genome, a heterologous DNA sequence which encodes an antigenic protein, e.g., derived from PCV2 ORFs, e.g., PCV2 ORF 1 and/or 2.
In yet another aspect, the present invention relates to an immunogenic composition containing a modified recombinant virus having inactivated nonessential virus-encoded genetic functions so that the recombinant virus has attenuated virulence and enhanced safety. The modified recombinant virus includes, e.g., within a non-essential region of the virus genome, a heterologous DNA sequence which encodes an antigenic protein (e.g., derived from PCV2 ORFs, especially ORFS 1 and/or 2) wherein the composition, when administered to a host, is capable of inducing an immunological response specific to the antigen.
In a still further aspect, the present invention relates to a modified recombinant virus having nonessential virus-encoded genetic functions inactivated therein so that the virus has attenuated virulence, and wherein the modified recombinant virus further contains DNA from a heterologous source, e.g., in a nonessential region of the virus genome. The DNA can code for PCV2 genes such as any or all of PCV2 ORF1, ORF2, ORF3, or ORF4 (Meehan et al., 1998), or epitope(s) of interest therefrom. The genetic functions can be inactivated by deleting an open reading frame encoding a virulence factor or by utilizing naturally host-restricted viruses. The virus used according to the present invention is advantageously a poxvirus, e.g., a vaccinia virus or an avipox virus, such as fowlpox virus or canarypox virus.
Advantageously, the open reading frame that is deleted from the poxvirus or virus geneome is selected from the group consisting of J2R, B13R+B14R, A26L, A56R, C7Lxe2x88x92K1L, and I4L (by the terminology reported in Goebel et al., 1990); and, the combination thereof. In this respect, the open reading frame comprises a thymidine kinase gene, a hemorrhagic region, an A type inclusion body region, a hemagglutinin gene, a host range gene region or a large subunit, ribonucleotide reductase; or, the combination thereof.
A suitable modified Copenhagen strain of vaccinia virus is identified as NYVAC (Tartaglia et al., 1992), or a vaccinia virus from which has been deleted J2R, B13R+B14R, A26L, A56R, C7Lxe2x88x92K11 and 14L or a thymidine kinase gene, a hemorrhagic region, an A type inclusion body region, a hemagglutinin gene, a host range region, and a large subunit, ribonucleotide reductase (See also U.S. Pat. Nos. 5,364,773, 5,494,807, and 5,762,938, with respect to NYVAC and vectors having additional deletions or inactivations from those of NYVAC that are also useful in the practice of this invention).
Preferably, the poxvirus vector is an ALVAC or, a canarypox virus which was attenuated, for instance, through more than 200 serial passages on chick embryo fibroblasts (Rentschler vaccine strain), a master seed therefrom was subjected to four successive plague purifications under agar from which a plague clone was amplified through five additional passages. (See also U.S. Pat. Nos. 5,756,103 and 5,766,599 with respect to ALVAC and TROVAC (an attenuated fowlpox virus useful in the practice of this invention); and U.S. Pat. Nos. 6,004,777, 5,990,091, 5,770,212, 6,033,904, 5,869,312, 5,382,425, and WO 95/30018, with respect to vectors that also can be used in the practice of this invention, such as vectors having enhanced expression, vectors having functions deleted therefrom and vectors useful with respect to porcine hosts (for instance, vectors useful with porcine hosts can include a poxvirus, including a vaccinia virus, an avipox virus, a canarypox virus, and a swinepox virus), as well as with respect to terms used and teachings herein such as xe2x80x9cimmunogenic compositionxe2x80x9d, xe2x80x9cimmunological compositionxe2x80x9d, xe2x80x9cvaccinexe2x80x9d, and xe2x80x9cepitope of interestxe2x80x9d, and dosages, routes of administration, formulations, adjuvants, and uses for recombinant viruses and expression products therefrom).
The invention in yet a further aspect relates to the product of expression of the inventive recombinant poxvirus and uses therefor, such as to form antigenic, immunological or vaccine compositions for treatment, prevention, diagnosis or testing; and, to DNA from the recombinant poxvirus which is useful in constructing DNA probes and PCR primers.
These and other embodiments are disclosed or are obvious from and encompassed by the following detailed description.

Porcine circovirus recombinant poxvirus vaccine


A composite sandwich structure is produced by providing a core structure, applying cover layers on opposite sides of the core structure, and forming an edge seal. The core structure has a folded cell structure with fold valleys forming continuous open channels with open ends and/or open channel sides at edges of the core structure. The channels extend along and are bounded between the fold valleys and the cover layers. The edge seal is formed to have a limited spatial volume in an edge region at an edge of the core structure, to close and seal open ends and/or open channel sides of the channels of the core, without an uncontrolled penetration of the seal material from the edge region to a greater depth into the open channels.

Due to their extraordinarily good ratio of stiffness or strength to density, core composites have a broad range of application especially in the field of aircraft construction.
Well-known conventional core composites are generally formed of an upper and a lower cover layer or cover ply, between which is located, for example, a honeycomb-type core structure formed of vertically extending cells with a hexagonal cross section, for increasing the stiffness of the resulting composite sandwich structure.
For example metallic corrosion-protected aluminum foils, or non-metallic materials, such as Nomex®- or Kevlar®/N636-paper for example, are used for forming the core structure. Both the Nomex®-paper as well as the Kevlar®/N636-paper are coated with phenolic resin in a submersion process for increasing the mechanical strength thereof.
The provision of edge seals in such core structures, as represented by the above described true honeycomb structures, is not problematic. Due to the small-volume repeat units represented by the individual hexagonal cells extending perpendicularly between the cover layers, seal material for the formation of the edge seal can be troweled, painted, filled, pressed, foamed or poured locally into edge regions of the core structure. Thereby the seal material is confined in the cells directly in this edge region, and cannot flow or spread uncontrollably into the remaining interior of the core structure away from the edge region. The material forming the edge seal can, for example, be a curable synthetic plastic material, for example in the form of a synthetic resin and/or synthetic plastic foam.
In contrast to the above described core composites having true honeycomb cell configurations, in which a spatial limitation or bounding of the cells is always present, new types of core composites, especially formed of three-dimensional folded or pleated comb structures, comprise an open or drainable structure. Namely, such pleated or folded core structures include fold or pleat valleys that form open channels extending continuously in the plane of the composite structure, i.e. along or parallel to the cover layers from edge-to-edge of the composite structure. Thus, the core channels of such a core composite remain drainable or ventilatable through the edges even after the opposite major surfaces of the core structure have been covered with the cover layers. Thereby, for example, it is possible to guide various types of lines (e.g. electrical lines, hydraulic lines, water lines, air lines, etc.) through the core composite without previously having to cut or machine a passage therethrough while impairing the mechanical properties of the core composite.
If, for the formation of an edge seal of the above described drainable core structures, a pasty or viscous curable seal material is introduced into edge regions of the core structure, then this material can spread out, depending on the viscosity, more or less uncontrolledly throughout the open channels of the open core structure. In other words, the seal material would not remain confined to the edge region, but rather could flow or run from the edge region freely deeper toward the center of the core structure along the open fold valley channels. Thus, viscous or pasty substances can spread out uncontrollably over larger distances when using open drainable core structures. In contrast, in true honeycomb structures, basically only a limited number of structural units (e.g. hexagonal cells) are opened by a separating cut at the edge of the structure, so that any seal substances introduced into the open cells in the edge region are always spatially limited to those cells. Thus the standard edge-sealing methods according to the state of the art are not usable for providing spatially limited edge seals in open drainable core structures.

Method for sealing edges of a core of a composite sandwich structure


A thrust apparatus for a rod string. The apparatus has a stationary frame, a thrust frame with a rod gripper, two hydraulic cylinders and two rams in fluid communication with the hydraulic cylinders. During low-load operations, the hydraulic cylinders act alone, providing the load to the grippers to pull or push the rod string. When higher loads are required, a check valve is activated, allowing fluid from the hydraulic cylinders to activate the rams. The rams provide additional force to the grippers, and may be activated without mechanical or significant hydraulic changes to the apparatus.

Threaded pipe or rod strings are used in horizontal installations for trenchless technology applications, particularly pipe bursting. High tensile loads are applied to pipe strings which pull bursting tooling through existing pipelines to facilitate replacement with a new product pipe. During push-out, the process of assembling the rod string from individual rods and pushing the assembled string through an existing host pipe takes a modest amount of thrust. During pullback, the portion of the process wherein the pipe is cracked and the surrounding soil is expanded, the load will be higher than during push-out. Variation in job size, host pipe material and adjacent soils all affect the maximum tensile load applied to the rod string.
To produce the tensile and thrust loads on the rod string, multiple hydraulic cylinders are often used as they provide an efficient means for producing large loads. These cylinders are part of a downhole device used to thrust, pull, assemble and disassemble said rod string. Further, these cylinders are actuated by hydraulics delivered by a hydraulic pump, most often turned by a gasoline or diesel engine.


An improved dispensing system for gasoline cans, comprising a hose adapter which replaces at least the typical spout and sealing disk associated with the gasoline can cap. The hose adapter is designed to accept common garden hose couplings, such that an ordinary piece of garden hose can be securely attached to the adapter and then cut to length for convenient pouring from any distance. In a first embodiment the hose adapter operates with the original cap. In a second embodiment the hose adapter has a built-in cap portion, and replaces the original cap.

Many gasoline cans sold today include a short spout which can be threaded onto the can in place of the cap, or in conjunction with a cap, to help pour gasoline from the can in a controlled manner. Many such cans include a short spout which can be turned upside down and stored inside the can, held in place by the cap. The standard spout-retaining cap typically includes a sealing disk which is removed so that the spout can be reversed and extended through the cap for pouring. There are a number of problems with these prior art cap/spout arrangements.
A short spout, coupled with a large, heavy can, is difficult to maneuver and hold for pouring. It is often necessary to hold a can containing several gallons of gasoline in some awkward, difficult-to-maintain position in order to keep the spout in the filler pipe of a fuel tank on a vehicle such as a boat, airplane or snowmobile.
Spouts which are stored inside the can and held in place by the cap are often covered with gasoline when removed and reversed for pouring, which is unpleasant for the user's hands and clothing.
The prior art spout arrangements have a tendency to leak as the tilt of the can approaches vertical. Yet another difficulty lies in controlling the flow of gasoline through the short spout, which dispenses gasoline immediately when the can is tilted.
One prior art attempt to improve on the standard cap and spout arrangement is disclosed in U.S. Pat. No. 5,419,467. This device is a combined cap and spout with a twist to open/twist to close mechanism for fine control over the flow of gasoline. This device is trademarked commercially as the Spill Saver.RTM. by Flotool International. The Spill Saver.RTM. spout consists of several sizes of spout adapter which replace the cap on the gasoline call. The adapters are internally threaded on their lower end to be screwed onto the threads on the mouth of the can, and are externally threaded on an upper cylindrical coupling to accept the spout mechanism. The spout mechanism is a two-piece, twist-to-open/close unit with an internal twist valve selectively opening and closing flow to an upper open end comprising a smooth, cylindrical plug or stem which receives a short, flexible piece of spout in a sliding friction fit. The spout is closed at its free end with a simple press-in cap retained on the spout with a flexible keeper strap.
The Spill Saver.RTM. spout is primarily designed to provide twist-controlled pouring. It leaves several of the above-mentioned problems unsolved. For example, it uses a short spout similar to the prior art. It apparently is not sufficiently leak- and vapor-tight to replace the original gas can cap for long term storage; in fact, the directions on commercial packaging say "remove spout when storing and replace with original cap". And because it cannot be left on the gas can for storage, the Spill Saver.RTM. spout requires multiple spout adapters to match different cans.


An RF interconnection between RF Printed Wiring Boards (PWBs) includes a waveguide transmission line coupled between the RF PWBs. The waveguide feeds are provided as integral parts of each PWB. In one embodiment, the waveguide interconnecting the PWBs is provided as an integral part of a support structure which supports the PWBs. By providing the interconnecting waveguide and the feeds at each end of the waveguide as integral pieces of other already existing structures, a reliable, low cost RF interconnection between RF PWBs having relatively few separate pieces is provided.

As is known in the art, in some applications it is necessary to couple radio frequency (RF) signals between multiple printed wiring boards (PWBs). Such connections are often made by using either a coaxial cable or a printed shielded RF conductor circuit (also referred to as a flex circuit). Both of these techniques are troubled by implementation complexity, reliability concerns, as well as cost issues.
A coaxial cable connection typically requires the mounting of a connecting pin on the PWB. The coaxial cable shield is stripped to expose a section of a center conductor which is then soldered to the connecting pin. This is done through a cover assembly, which is typically provided as a two-piece assembly, to provide a required level of isolation between different circuit portions. Although this type of connection results in a relatively high level of performance, it is a relatively complicated assembly requiring precision parts.
A multi-layer flex circuit PWB interconnection can be implemented by soldering a center conductor from a flex-print circuit to a signal path on a PWB. Although this approach has fewer parts, the flex-print circuit is relatively expensive because of the need to include ground planes and via holes to achieve desired isolation levels. Furthermore, it is relatively difficult to obtain a good electrical seal around a flex circuit and this makes it difficult to achieve a desired level of isolation between the PWBs being connected through the flex circuit. More, in high frequency applications, the losses through this type of structure can be relatively high.

Waveguide—printed wiring board (PWB) interconnection


This invention relates to a process for beneficiating a silicious phosphate ore by flotation, the process comprising the steps of conditioning an aqueous slurry of phosphate ore at a pH of from 7.5 to 10.5 with a fatty acid and a fuel oil and aerating the conditioned phosphate slurry to float the phosphate, the improvement comprising conditioning the aqueous phosphate slurry prior to aeration with a water dispersible sulfo-polyester having a glass transition temperature of 28.degree. C. to 60.degree. C. and consisting essentially of repeat units from a dicarboxylic acid, a diol and a difunctional sulfomonomer.

Florida accounts for more than 80% of the phosphate rock used in the United States and 30% of the world phosphate rock production. Each year more than 100 million tons of material is floated to generate 40-45 million tons of phosphate concentrate. Florida phosphate ore is known as matrix and consists of equal proportions of fluorapatite (a calcium phosphate containing fluorine), silica gangue and clays. Clays are separated from the matrix by washing and sizing leaving a phosphate and silica mixture. A three step process is used for separating phosphate from silica. In the first step, phosphate is separated from silica using a fatty acid and fuel oil mixture as a collector. The collector selectively coats the phosphate making it hydrophobic. When air is bubbled through the phosphate and silica suspension, the hydrophobic phosphate particles attach to the air bubbles and rise to the top where they are skimmed off. This method is known as rougher flotation. Silica is removed as a sink fraction and constitute rougher tailings. In the second step, the fatty acid and fuel oil layer are scrubbed off the phosphate particles by intense agitation and adjusting the pH to about 3. The treated material is washed until the pH is restored to a value of about 7. In the third step, fatty amine collectors are added to further reduce the amount of silica by rendering the surface of the silica hydrophobic leaving the phosphate hydrophilic. The floated silica particles constitute the froth whereas the phosphate particles sink and are referred to as the concentrate.
U.S. Pat. No. 3,164,549 discloses a process for beneficiating phosphate ores by froth flotation utilizing dodecyl benzene sulfonic acid. U.S. Pat. No. 4,034,863 discloses a process for beneficiating phosphate ores by froth flotation utilizing certain partial esters of a polycarboxylic acid. U.S. Pat. No. 4,172,029 discloses a process for beneficiating phosphate ores by froth flotation utilizing sulfonated aromatic compounds such as alkylated diphenyl ether sulfonate. However, the aforementioned patented flotation processes have not been of commercial value. The limited increased phosphate recovery effected by these processes is more than offset by the higher cost of the reagents relative to those used in the conventional process.
U.S. Pat. No. 4,719,009 discloses a process for concentrating zinc sulfide from complex sulfide ores containing siliceous gangue materials utilizing a depressant containing ether groups and metal sulfonate groups. The depressant is effective in an amount as low as 0.03 kg/ton of ore feed for the recovery of zinc sulfide concentrate. U.S. Pat. No. 4,719,009 is concerned with purifying zinc not increasing the yield of zinc. The sulfo-polyester acts to suppress silica. In phosphate flotation, on the other hand, the sulfo-polyester increases the phosphate yield without suppressing the silica. It is important to note that depressants are often found to be effective only in the treatment of certain specific ores due to the presence of salts in the water, the characteristics of ionic impurities associated with the siliceous gangue materials and other empirical factors, poorly understood.
The present inventors have unexpectedly determined that the addition of at least 0.6 kg/ton of a water dispersible, water dissipatable sulfo-polyester having a glass transition temperature (Tg) of 28.degree. C. to 60.degree. C. to a process for beneficiating a silicious phosphate ore by froth flotation increases the yield of phosphate.

Phosphate flotation using sulfo-polyesters