A method for preventing an emission head or arm assembly from entering an exclusion zone or for preventing a collision between an object and the emission head and/or arm assembly. The method may include modeling a treatment room using a computer-aided design (CAD) tool, and calculating an exclusion zone for a radiosurgery system in the treatment room using the modeled treatment room.

In radiosurgery, very intense and precisely focused doses of radiation in a beam from a source outside a patient's body are delivered to a target region in the body, in order to destroy tumorous cells. Typically, the target region consists of a volume of tumorous tissue. Radiosurgery requires an extremely accurate spatial localization of the targeted tumors. Radiosurgery offers obvious advantages over conventional surgery, during which a surgeon's scalpel removes the tumor, by avoiding the common risks and problems associated with open surgery. These problems include invasiveness, high costs, the need for in-hospital stays and general anesthesia, and complications associated with post-operative recovery. When a cancerous tumor is located close to critical organs, nerves, or arteries, the risks of open surgery are even greater.
As a first step in performing radiosurgery, it is necessary to deteIn1ine with great precision the location of tumors and any surrounding critical structures, relative to the reference frame of the treatment device. CT and MRI scans enable practitioners to precisely locate a tumor relative to skeletal landmarks or implanted fiducial markers. However, it is also necessary to control the position of the radiation source so that its beam can be precisely directed to the target tissue, with control of propagation in and through other body structures.
To effect such beam position control, stereotactic frames have been developed and used in the past for treatment of brain tumors. Stereotactic frames are rigid metal frames that are attached to the patient's skull and locked in place to provide a frame of reference for the surgeon during CT/MRI imaging, and for subsequent therapeutic treatment. A stereotactic frame is typically attached to the patient prior to scanning/imaging. The frame must remain in place while the surgeon is developing a computerized treatment plan, as well as during the actual treatment. During treatment, an x-ray or gamma ray source is precisely positioned with respect to the frame, so that the radiation can be administered according to the treatment plan.
While there are well-developed methods for attaching stereotactic frames to the skull for brain tumor treatment, attaching these frames to anatomical regions other than the skull in order to establish a stable frame of reference is too difficult to be practical. As one prior art example, a stereotactic frame that was deliberately constructed for the rest of the body (outside the head/neck region) required screws to be placed in the pelvis, incisions to be made along the spine to accommodate spinal clamps, and ten hours of general anesthesia to be administered to the patient while the frame was being attached to the patient, CT imaging performed, and radiosurgery undertaken. It is clearly not practical to perform such frame-based radiosurgery on areas other than the skull, and therefore the use of frame-based radiosurgery has so far been restricted to the treatment of intra-cranial tumors.
Despite the advantages of radiosurgery over open surgery, including significantly lower cost, less pain, fewer complications, no infection risk, no general anesthesia, and shorter hospital stays (most radiosurgical treatments are outpatient procedures), frame-based radiosurgery has a number of drawbacks. These drawbacks mostly relate to the use of the stereotactic frame. A stereotactic frame causes pain to the patient, since it has to be attached with screws. Also, a frame cannot be easily re-attached in precisely the same position for a subsequent radiation procedure, so that frame-based radio surgical treatment is limited to smaller tumors (generally less than about three centimeters in diameter) that can be treated in a single procedure. Moreover, the frame must remain in place from the time of diagnostic CT and/or MRI scanning, through the entire period of treatment, which may extend over a multi-day period. Finally, the biggest drawback is that frame-based radiosurgery cannot be used for tumors located outside of the head and neck region, because of the above-described difficulty of attaching these frames to anatomical regions other than the skull. Frame-based radiosurgery therefore cannot be used to treat ninety percent of all solid tumors, because they occur outside of the head/neck region.
These drawbacks have lead to the development of a frameless stereotactic radiosurgery system, exemplified by the CyberKnife system (henceforth "CyberKnife") made by Accuray, Inc., Sunnyvale, Calif. CyberKnife is an image guided robotic system which eliminates the need for the rigid stereotactic frames described above, and enables the treatment of extra-cranial tumor sites. CyberKnife provides numerous advantages compared to conventional stereotactic radiosurgery systems, including but not limited to: ability to treat tumors throughout the body, not just those located within the head/neck region; increased access to, and coverage of, any target volume; ability to treat tumors that are larger than about three centimeters in diameter; minimal constraints on patient set-up; ability to deliver a plurality of fractionated treatments; and enhanced ability to avoid damaging critical structures.
CyberKnife includes a robotic system onto which an x-ray linear accelerator ("linac") is mounted, and a controller. The linac is adapted to selectively provide a precisely shaped and timed radiation beam. The controller uses CT and possibly MRI data, or other types of image data, that define the target tissue and important other bodily structures, together with treatment planning and delivery software to identify a series of landmarks within the treatment region, prior to surgery. CyberKnife may further include a stereo x-ray imaging system, which during treatment repeatedly measures the location and orientation of these landmarks relative to the linac. Prior to the delivery of radiation at each delivery site, the controller directs the robotic system to adjust the position and orientation of the linac in accordance with the measurements made by the x-ray imaging system, so that a desired series of radiation beams can be applied to the body, optimally dosing the target tissue while minimizing radiation to other body structures. In this way, CyberKnife allows accurate delivery of high doses of radiation, without requiring a stereotactic frame.
It is important to ensure that during the successive positionings of the linac during a treatment, the robotic system does not collide with objects (for example, parts of the patient's body, its own structure, or other equipment in the treatment room). Since patient setup is minimally constrained by a frameless radiosurgery system, it is difficult to have complete knowledge of the patient's body position when preparing a treatment plan, particularly regarding their arms and legs. An obstacle detection/collision avoidance system would therefore be desirable in frameless radiosurgery systems such as the CyberKnife,
Because of its ability to deliver fractionated treatments, CyberK11ife is well adapted for radiotherapy, as well as for radiosurgery. The term radiotherapy refers to a procedure in which radiation is applied to a target region for therapeutic, rather than necrotic, purposes. The amount of radiation utilized in radiotherapy is typically about an order of magnitude smaller, as compared to the amount used in radiosurgery. Radiotherapy is frequently used to treat early stage, curable cancers. In addition to delivering radiation to cancerous tissue, radiotherapy systems generally also irradiate a certain amount of normal tissue surrounding the tumor. Typically, a series of relatively small doses are delivered over a number of days. Each radiation dose not only kills a little of the tumor, but also creates some collateral damage to healthy surrounding tissue, which however usually heals by itself, because it has a greater ability to repair, compared to cancerous tissue.
A collision avoidance system, referred to above, would also be desirable when CyberKnife is being used for radiotherapy, as well as for radiosurgery. For convenience, the term "radiosurgery" in this application shall henceforth mean "radiosurgery and/or radiotherapy."
The present invention provides a frameless radiosurgery system having a collision avoidance subsystem.
In an exemplary embodiment, a frameless radiosurgery system in accordance with the present invention includes an x-ray source, and a robot. The robot includes an arm assembly extending from a base unit. The x-ray source, which in a preferred form is a linac, has an emission head mounted at a distal end of the arm assembly. The x-ray emission head is adapted for selectively emitting an x-ray beam along a beam axis. The arm assembly may be articulated (i.e., have a series of rigid elements linked by rotatable couplings), may be flexible (i.e., have a series of rigid or flexible elements linked by flexible couplings), or may be a combination of both articulated and flexible portions.
The radiosurgery system further includes an associated controller for selectively orienting the x-ray emission head whereby the x-ray beam extends along a succession of treatment axes. The radiosurgery system further includes a collision avoidance subsystem, including means for preventing the x-ray emission head and the arm assembly from effecting a collision with an object in one or more pre-defined exclusion zones.
In one exemplary embodiment of the invention, the collision avoidance subsystem includes a light source (such as a laser or an LED (light-emitting-diode) effective to establish a substantially planar (or sheet-like) light beam between the exclusion zone and the emission head. The planar light beam may be fan-shaped. In this embodiment, the controller is responsive to observation of an object extending through the light beam, to interrupt any further motion of the head toward the exclusion zone. The light source may be fixedly positioned with respect to the x-ray emission head, defining an exclusive zone that "travels" with the head. Alternatively, the light source may be fixedly positioned with respect to the base unit of the robot, for example by being mounted on a wall of the treatment room, defining an exclusive zone that is fixed with respect to the treatment room.
In another embodiment of the invention, the collision avoidance subsystem includes a least one optical emitter-receiver pair that is effective to detect the breaking of a light beam when an object extends into the one or more exclusion zones. The optical emitter is a light source, as described in paragraph 15 above. The optical receiver is constructed and arranged to receive light that 1) has reached an object that has intruded into one or more of the exclusion zones, and 2) is back-scattered from the object.
In another embodiment of the invention, the collision avoidance subsystem includes a laser range finder that can detect movement of an object into a light beam. The laser rangefinder includes a transmitter that generate laser light and transmits the light toward one or more exclusion zones, and a receiver/photodetector for receiving and detecting laser light that is backscattered from any object that intrudes into the one or more exclusion zones. The laser range finder includes means for determining, from the received back-scattered laser light, the distance to the object.
In another embodiment of the invention, a plurality of exclusion zones may be defined. In other words, multiple "layers" of exclusion zones may be defined. In one of many possible exemplary embodiments, a first "shell-like" exclusion zone may be defined which slows down the motion of the head. In this exemplary embodiment, a second exclusion zone may be defined, which completely stops any further motion of the head, when the head reaches one or more boundaries between the first exclusion zone and the second exclusion zone. In another embodiment of the invention, at least one of the exclusion zones is not a static zone, but rather is a variable dimension exclusion zone. In another embodiment of the invention, the collision avoidance subsystem includes an array of acoustic transducers fixedly coupled to the x-ray emission head. Each of the transducers transmits a succession of acoustic pulses along a transmission axis extending from the head, and detects acoustic energy backscattered along the transmission axis from an object disposed along the transmission axis. The beam axes are mutually aligned whereby cross-sections of adjacent pairs of the pulses transverse to the transmission axis are contiguous at a predetermined distance from the head. In this embodiment, the collision avoidance subsystem includes means for determining, from the received backscattered acoustic energy, the distance between the head and the object.
The collision avoidance subsystem further includes means for inteJ11lpting, in response to the determined distance being at or less than a predetermined value, any further motion of the head toward the exclusion zone.
In another embodiment of the invention, the collision avoidance subsystem includes a sensor disposed on a surface of the articulated arm assembly. The sensor is operative to generate an alarm signal upon impact of the sensor with an object, during motion of the arm assembly and/or the x-ray emission head. The subsystem further includes means responsive to the alaIn1signal to interrupt any further motion of the arm and/or head. The sensor may be a tactile sensor, or other type of sensor adapted for proximity sensing. By way of example, the sensor may consist of a fluid-filled bladder, and a pressure transducer coupled to the bladder, in one embodiment of the invention. In other embodiments, the sensor may be an infrared (IR) sensor, or an electrostatic capacitance sensor.
In any of the above described collision avoidance systems, the detection of breach of the exclusion zone and the system's response to such detection may be automatic (e.g., under control of the controller) or may be manually implemented (e.g., when a human observer detects a breach, that observer initiates the system response (e.g., halting further advance of the head).

Radiosurgery x-ray system with collision avoidance subsystem


A pressure sensitive acoustic wave sensor and actuator include an acoustic wave cavity foπned in a substrate, a transducer generating an acoustic wave substantially trapped in the acoustic wave cavity and an acoustic wave absorbing member that absorbs more acoustic wave energy in the acoustic wave cavity in response to increased pressure on the member. The speed and/or braking of an electric vehicle is controlled through operator input of a foot pedal, using the pressure sensitive acoustic wave sensor.

Vehicles such as forklifts, utility carts, golf carts and other electric vehicles are known to use a variety of controls for operating, accelerating and/or braking functions of the electric drive system. For example, it is known to use various types of position sensors, both mechanical and optical, to determine the position of an accelerator pedal and to control acceleration accordingly. Electromechanical potentiometers use a resistive element that is swept by a contacting member. The contacting member moves with the foot pedal or other similar actuation system. As the contacting member moves across the resistive element, the voltage changes across the device, causing the output voltage of the device to vary with pedal position. Another known system uses a magnetic field to change the state of a solid state element. As the magnet moves past the device, the state of electronics within the device changes, indicating that the pedal or other actuator has moved. Known as "Hall Effect" devices, some read the change in the magnetic field and interpret the change like a potentiometer, varying the output voltage with the change in magnetic field polarity and amplitude.
Electromechanical systems have limited life due to mechanical wear. Since such devices depend on two surfaces contacting and wiping against one another, friction and debris can cause the materials to wear and the potentiometer to fail prematurely. Wear is accelerated if the components are not aligned properly. Misalignment of components can occur quickly and unexpectedly because of the sometimes rugged use to which the vehicles are exposed. Significant wear can occur before the misalignment is detected during routine inspections or maintenance.
Hall Effect devices and some optical systems have high manufacturing costs in addition to mechanical limitations. Hall Effect devices require microchips that are specially provided to work with the Hall Effect, and can add considerable cost to the device. Optical devices often require an encoder disk with precisely located and etched markings that can be read by optical elements. Often the disks are laser etched and expensive. The optical devices can be very sensitive to contaminants that change the optical properties of the disk. Sealing the device may be effective in avoiding contamination, but adds further cost to the assembly.
Acoustic wave sensors and switches are known in which a transducer is mounted on or adjacent to an acoustic wave cavity formed in a substrate to generate an acoustic wave that is a standing wave trapped in the acoustic wave cavity. These acoustic wave sensors or switches have been used to detect a touch on a surface of the substrate opposite from the surface on which the transducer is mounted by sensing changes in the standing wave.
There is a need for durable, yet accurate controls for electric vehicles that can be provided at reasonable expense.

Accelerator/brake control using acoustic sensing


The invention concerns a method for the physico-chemical treatment of water characterized in that it comprises at least a step consisting in causing the water to be treated in at least one settler providing non-thickened sludge and in at least one settler-thickener treating the sludge from the two settlers and part of the water to be treated. The invention also concerns a plant for implementing said method comprising means for supplying the water to be treated (6), at least a settler providing non-thickened sludge (2), at least a settler-thickener (5, 5a), means for conveying (7) at least part of the non-thickened sludge coming from the settler providing non-thickened sludge (2) to the settler-thickener (5, 5a), means for evacuating (9, 9a) treated water coming from said settler providing non-thickened sludge (2) and from said settler-thickener (5, 5a) and means for evacuating (8) the thickened sludge coming from said settler-thickener.

This invention relates to the field of water treatment for purification or for making it drinkable, and particularly but not exclusively urban or industrial waste water and rain water.
Standard practice includes various physicochemical water treatment techniques making use of different types of settling tanks that can achieve different hydraulic treatment velocities that depend particularly on their architecture and their size.
With simple settling tanks it is hardly possible to achieve velocities higher than 2.5 m/h, but these velocities can be as high as 10 to 15 m/h when the internal structure of the settling tanks used includes lamellar elements. In particular, lamellar settling tanks of this type are marketed by the Applicant under the trade name MULTIFLO (registered trademark). Furthermore, when the settling step itself is preceded by a coagulation-flocculation step, velocities of the order of 30 m/h, or even 80 m/h, can be achieved if a sludge recirculation step is included. An even more advanced technique developed by the Applicant and marketed under the brand ACTIFLO (registered trademark) consists of using settling tanks with flocs ballasted by appropriate ballasting material, and particularly micro-sand. A technique of this type is described in detail in patents FR 2 627 704 and FR 2 719 734 issued to the Applicant. With this type of ballasting of flocs formed in settling tanks, treatment velocities of 50 m/h and up to 200 m/h can be achieved.
Settling tanks of the type described above produce unthickened sludge. The sludge concentration at the outlet from ballasted floc settling tanks using a granular material usually varies between 0.5 g/l and 20 g/l of dry matter (DM). Therefore, this sludge has to be thickened using thickeners to achieve a concentration of between 20 and 250 g/l of DM (corresponding to a dryness ratio of 2 to 25%), and preferably between 20 and 90 g/l of DM (corresponding to a dryness ratio of 3 to 9%).
Within the framework of the ACTIFLO technique described above, a thickener is designed to recover sludge from the settling tank, and overflow water from thickeners is returned to the top of the settling tank. This return of water from the thickener overflow to the beginning of the line increases the water influent entering the installation to be treated.
In other settling tanks according to the standard practice, the sludge thickening function is built into the settling tanks themselves. These settling tanks are then conventionally called xe2x80x9cthickener settling tanksxe2x80x9d. In this respect, note the technique also developed by the applicant and marketed under the name MULTIFLO E or EF, or many other techniques described in patent document FR 2 156 277. Similar techniques also use sludge recirculation (U.S. Pat. No. 4, 388, 195, FR 2 553 082). With these thickener settling tanks, hydraulic treatment velocities of the order of 30 to 50 m/h, or even 80 m/h in some cases, can be obtained to produce a sludge with a dryness that can vary from 2 to 25%, with an average of 3 to 8% (corresponding to 30 to 80 g/l of dry matter). However, they cannot obtain velocities as high as the velocities possible with ballasted floc settling tanks.
Concerning the technique used for thickeners, static thickeners based on a load on the base mat corresponding to the maximum allowable mass flow of dry matter per unit area. Conventionally, this base mat load is between 20 and 100 kg/DM/m2/d. A lamellar thickener preceded by an unthickened sludge flocculation step can increase base mat loads to between 500 and 3000 kg DM/m2/d, and sometimes more.
The main purpose of this invention is to describe a process capable of benefiting from the advantages of ballasted floc settling tanks with a granular material that can operate at very high hydraulic velocities (up to 200 m/h as mentioned above) and the advantages of lamellar thickener settling tanks that give very good thickening of the sludge, but the maximum hydraulic velocities are not as high as the velocities possible with ballasted floc settling tanks.
Another purpose of this invention is to describe such a process making use of settling tanks with base mat areas smaller than the areas that would conventionally be used according to standard practice for optimized hydraulic treatment velocities and sludge drynesses, and therefore reduce the size of the corresponding installations for embodiment of this process.
Another objective of this invention is to divulge such a process that can overcome the need to return water overflowing from thickeners to the beginning of the installation.
Another objective of this invention is to propose a process that can enable efficient treatment of water when the flow or mass content of the water to be treated increases, even suddenly, for example during rainstorms.
These various objectives are achieved according to the invention which relates to a process for the physicochemical treatment of water, characterized in that it comprises at least one step that consists of passing the water to be treated in at least one settling tank of the type that produces unthickened sludge, and in at least one thickener settling tank, the said thickener settling tank treating the sludge from the two settling tanks and part of the water to be treated.
Therefore the main innovation of this process according to this invention is the characteristic according to which the thickener settling tank is not used only to treat sludge from a settling tank producing thickened sludge, but it is also used to treat some of the water itself (influent). As described in detail later, it is thus possible to reduce the size of the installations since the settling tank function of the thickener settling tank can increase the available settling area to treat the influent.
According to one particularly interesting variant of the invention, the said settling tank of the type producing unthickened sludge is a ballasted floc settling tank ballasted by at least one granular material, preferably micro-sand, and the said thickener settling tank is a lamellar thickener settling tank. The granular material will preferably consist of micro-sand, although almost any granular material known to those skilled in the art could be envisaged.
The invention thus combines the advantages of settling tanks with flocs ballasted by a granular material capable of functioning at very high hydraulic velocities (up to 200 m/h as mentioned above), and the advantages of lamellar thickener settling tanks that provide a very good sludge thickening function. Thus, in a preferred variant of the invention, ACTIFLO ballasted floc settling tanks can be used with MULTIFLO E or EF thickener settling tanks marketed by the Applicant and described above. Within the framework of this type of preferred embodiment, it will be noted that the sludge originating from such a settling tank with flocs ballasted by a granular material thickens very well and does not cause any disturbance in the thickener settling tank. All that is necessary to achieve this is to reduce the water flow treated on this structure, and increase the water flow treated on the settling tank with flocs ballasted by the granular material.
The size of a thickener settling tank depends on two parameters, namely the hydraulic velocity for settling and the mass load on the base mat for thickening. The hydraulic velocity is usually the controlling factor. With the process according to the invention, returning unthickened sludge from the lamellar settling tank with flocs ballasted by the granular material, the concentration of sludge in the thickener settling tank increases such that the maximum allowable hydraulic velocity can be increased, and thus the maximum hydraulic velocity corresponding to the velocity of the mass load on the base mat can be used. Therefore, with the process according to the invention, the thickener settling tank is sized as a function of the maximum allowable load on the base mat and the ballasted floc settling tank is sized to handle the additional amount that cannot be accepted hydraulically by the thickener settling tank.
According to another embodiment of the invention, the lamellar thickener settling tank used may also include sludge recirculation. In this case, the process according to the invention advantageously comprises a step in which the said unthickened sludge from the settling tank of the type producing unthickened sludge is mixed with sludge recirculated from the lamellar thickener settling tank with sludge recirculation.
According to one variant of the invention, the process consists of passing water to be treated through the said settling tank producing unthickened sludge and then in the said thickener settling tank, the said settling tanks then being supplied in series.
According to another variant, the said settling tank producing unthickened sludge and the said thickener settling tank can be configured in parallel.
This type of variants to the process will be used to adapt it to the conditions in which it is used and particularly to variations in the material and water flows to be treated.
According to another interesting aspect of the invention, the process comprises an additional step consisting of adding at least one reagent in order to improve settling and thickening of the sludge in the said thickener settling tank. This reagent may be added continuously to the water, in other words the said reagent is added directly into the influent to be treated or in a coagulation-flocculation step included on the inlet side of the said thickener settling tank, or included in it. Advantageously, it may be envisaged as part of an installation using the ECOFLOC prolonged coagulation process developed by the applicant and described in French patent FR 2 631 021.
The main advantages of this invention that consists of the combined use of a settling tank of the type producing unthickened sludge (preferably a settling tank with flocs ballasted by at least one granular material) and a thickener settling tank (preferably lamellar with or without sludge recirculation) are as follows.
The process according to the invention is more competitive than processes according to standard practice mentioned in the preamble (settling tank + thickener or settling tank with integrated thickener) particularly due to the fact that it reduces the dimensions of installations necessary for its embodiment.
This invention eliminates the need to return overflows from thickeners to the beginning of the installation, which are necessary when settling tanks coupled with a sludge thickener are used alone.
Furthermore, if unthickened but pre-flocculated sludge obtained from the ballasted floc settling tank is injected into the thickener settling tank, it is possible to:
obtain a higher concentration of SS (suspended solids) at the inlet to the thickener settling tank, that enables optimized hydraulic treatment velocities within this thickener settling tank;
obtain sludge with a higher dryness ratio;
if applicable, reduce the recirculated sludge flow rate when it is decided to use a thickener settling tank with sludge recirculation;
possibly reduce the content of reagents used in the thickener settling tank;
increase the load on the thickener settling tank base mat (since the sludge is mixed, it thickens more quickly so that the load on the base mat of the thickener part of the thickener settling tank can be increased and therefore improved) while keeping the water quality conform with the required quality;
easily accommodate variations in pollutant flows to be treated;
adapt the process to treat dry weather or wet weather water and material flows.
The invention also relates to any installation for use of the process as described above, characterized in that it comprises means of conveying the water to be treated to the inlet, at least one settling tank of the type producing unthickened sludge, at least one thickener settling tank, means of transporting at least part of the unthickened sludge from the settling tank of the type producing unthickened sludge to the thickener settling tank, means of conveying treated water away from the said settling tank of the type producing unthickened sludge and from the said thickener settling tank and means of conveying thickened sludge away from the said thickener settling tank.
If required, this type of installation could be preceded by conventional means for preliminary treatment of the water to be treated (for example screening, sand removal and degreasing, or simply screening). Sludge from thickened sludge removal means can be conveyed in a known manner to means of treatment of this sludge. Finally, a post-treatment can then be applied to treated water outlet from the installation.
Preferably, said means of conveyance of water to be treated of the installation according to the invention are such that the said settling tank of the type producing unthickened sludge and the said thickener settling tank can be configured either in series or in parallel. This type of installation could thus be easily configured to adapt to variations in content and/or flow of the influent. Advantage could also be taken of this characteristic when the installation is started up.
Preferably, the said settling tank of the type producing unthickened sludge is a lamellar settling tank with flocs ballasted by at least one granular material (for example such as an ACTIFLO settling tank marketed by the Applicant).
Also preferably, the said thickener settling tank is a lamellar thickener settling tank or a lamellar thickener settling tank with sludge recirculation.
Advantageously, the installation also comprises means of adding at least one coagulating or flocculating reagent in the said thickener settling tank.
The invention also relates to processes for use of this installation.
In particular, the invention also relates to a process that consists of supplying the said settling tank of the type producing unthickened sludge and the said thickener settling tank in series when starting up of the installation, and supplying the said settling tanks in parallel once the installation has been started up.
The invention also relates to a process that consists of supplying the said settling tank of the type producing unthickened sludge and the said thickener settling tank in series when a normal flow and/or inlet of water to be treated is input into the said installation, and supplying the said settling tanks in parallel during peak water or material flows.

Process for physico-chemical treatment of water and installation for embodiment of this process


A memory may include a plurality of word lines coupled to one or more memory cells; a target address generation unit suitable for generating one or more target addresses using a stored address; and a control unit suitable for sequentially refreshing the plurality of word lines in response to a refresh command which is periodically inputted, and refreshing a word line corresponding to the target address in response to the refresh command at a random time.

1. Field
Exemplary embodiments of the present invention relate to a memory and a memory system including the same.
2. Description of the Related Art
A memory cell of a memory includes a transistor serving as a switch and a capacitor that store a charge (data). Depending on whether charge is stored in the capacitor of the memory cell, that is, whether a terminal voltage level of the capacitor is high or low, the data may be identified as high (logic 1) or low (logic 0) data.
Data is stored in a capacitor and no power is consumed in theory. However, since leakage current leakage in the PN junction of the MOS transistor as well as other places, the initial charge accumulated in the capacitor may decrease and data may be lost. In order to prevent data loss, data of the memory cell must be read and the charge in the capacitor must be refreshed. This is called a refresh operation
FIG. 1 is a diagram illustrating part of a cell array included in a memory that will be used to explain a phenomenon called word lime disturbance. In FIG. 1, BL represents a bit line.
Referring to FIG. 1, three word lines WLK−1, WLK, and WLK+1 in the cell array are arranged in parallel. Furthermore, the K-th word line WLK with notation "HIGH_ACT" has been has been activated numerous times (i.e. the activation frequency of the K-th word line WLK is high). The (K−1)th and (K+1)th word lines are adjacent to the active K-th word line WLK. Furthermore, (K−1)th, K-th and (K+1)th memory cells CELL_K−1, CELL_K, and CELL_K+1 are coupled to the (K−1)th, K-th and (K+1)th word lines WLK−1, WLK, and WLK+1, respectively. The (K−1)th, K-th and (K+1)th memory cells CELL_K−1, CELL_K and CELL_K+1 include (K−1)th, K-th and (K+1)th cell transistors TR_K−1, TR_R, and TR_K+1 and K−1)th K-th and (K+1)th cell capacitors CAP_K−1, CAP_K and CAP_K+1 respectively.
When the K-th word line WLK is activated and precharged (deactivated), the voltages of the adjacent (K−1)th and (K+1)th word lines WLK−1 and WLK+1 fluctuate from coupling between the K-th word line WLK and the adjacent (K−1)th and (K+1)th word lines WLK−1 and WLK+1, thereby influencing charges stored in the (K−1)th and (K+1)th cell capacitors CAP_K−1 and CAP_K+1. Thus, when the K-th word line WLK is frequently activated-precharged to toggle between the active state and precharge state, data stored in the (K−1)th and (K+1)th memory cells CELL_K−1 and CELL_K+1 may be affected by the impact on charges stored in the (K−1)th and (K+1)th capacitors CAP_K−1 and CAP_K+.
Furthermore, electronic waves, which are generated while a word line toggles between the active state and the precharge state, may introduce/discharge electrons into/from a cell capacitor included in a memory cell coupled to an adjacent word line, thereby affecting the data of the memory cell.

This patent is subject to a terminal disclaimer.

Memory performing target refresh operation and memory system including the same


Hole punch apparatus which automatically places a reinforcement ring precisely around each punched hole concurrently with the creation of each hole and using the same motion that punches the holes. In a preferred embodiment, the punch shaft has a ring compression disk affixed around it at a location above the punch face. The compression disk has a ring cushion and a stack of reinforcement rings extending along the punch shaft toward the punch face, but spaced therefrom to permit the punch face to puncture a sheet before the lowermost reinforcement ring is then compressed against the sheet in precise axial alignment with the punched hole. The rings each have sufficient adhesive to adhere to the sheet, one and only one ring at each hole, while disengaging from the remaining rings in the stack. A sheet interface unit is installed on the lower surface of a punch bracket enclosure and provides a sheet retainer so that the sheet cannot rise significantly above the bracket base and thus will pull the lowermost reinforcement ring away from the stack as the punch lever is released. When re-supply is needed, a new ring stack is readily installed using a ring stack cassette, which in the preferred embodiment also replaces the sheet interface unit including the sheet retainer.

1. Field of the Invention
The present invention relates generally to the field of office supplies. The invention relates more specifically to hole punches with the additional feature of automatically installing a reinforcement ring around each punched hole concurrently with the creation of the hole.
2. Background Art
Mechanical hole punches have been a standard office supply accessory for many years. Handle-operated, plunger type, two and three hole punches are especially useful office implements for creating hard copy paper files using ACCO fasteners and loose-leaf notebooks. Historically, the holes made in paper or card-stock sheets have been strengthened with a thin, glue-coated reinforcement ring positioned coaxially around the punched hole perimeter. However, reinforcement rings are typically purchased separately in matchbox style packages and require intense manual effort to install. Each such reinforcement ring must first be wetted to activate the glue and then applied one by one to each previously punched hole including carefully aligning the ring hole with the punched hole before pressing the ring into contact with the sheet with sufficient care to avoid folding or otherwise distorting the ring. Those rings that are improperly placed or inadvertently distorted or misshaped, often must be removed and replaced with another ring. Thus, the application of such reinforcement rings is a highly inefficient and often messy and time-consuming process.
Therefore, there is an ongoing need for a way to obviate the conventional reinforcement ring installation process which suffers from the aforementioned deficiencies.

Hole punch with automatic reinforcement ring placement


A bulk material conveying system for use with a bulk material holding tank having at least one outlet. The conveying system includes a main supply line for carrying pressurized gas and a material conveying line having an inlet and an outlet. The material conveying line is in communication with the holding tank outlet for transporting the bulk material from the holding tank to the conveying line outlet. The inlet of the material conveying line is in communication with the main supply line for receiving the pressurized gas whereby the gas moves the bulk material in the conveying line towards the conveying line outlet. The system further includes an aerator line having an inlet and an outlet and at least one connector for feeding the pressurized gas into the bulk material holding tank to agitate the bulk material and push it towards the holding tank outlet and a pressure sensor for sensing when the pressure in the material conveying line exceeds a predetermined level. A shut-off valve is connected to the main supply line for establishing communication between the main supply line and the aerator line and operable in response to the pressure sensor sensing the exceeding of pressure for shutting off flow of the pressurized gas from the main supply line to the aerator line thereby increasing gas flow to the material conveying line for eliminating buildup of bulk material in the material conveying line.

This invention relates generally to trailer systems for carrying bulk material and more specifically to a system for unblocking an unloading line of the trailer. Bulk material is typically transported in a large hopper which is carried on a trailer of a truck. Upon the truck reaching its destination, the bulk material is unloaded from the hopper into a storage facility such as bin, hopper or elevator. Pressurized air or other gases are used to mix the bulk material within the hopper and force the bulk material out of the hopper and into the unloading line of the trailer. The bulk material commonly forms clumps while being fed through the unloading line thus requiring the line to be disassembled and cleaned. The unloading process is therefore time consuming due to clogging of the bulk material within the unloading line of the trailer. Material conveying systems have been developed wherein pressurized air external to the trailer system is piped into the unloading line at various locations to attempt to eliminate blockage within the line. These systems are generally expensive and require extensive modification to the trailer system due to the large number of electronic valves required to sense the pressure at various locations along the length of the line and the pneumatic valves and external air supply required to supply pressurized air at these locations.
There is a need, therefore, for a material unloading system, that is adaptable to existing trailer systems, compact, cost efficient, easy to use and effective in reducing the time required to unload bulk material from a hopper.

Apparatus and method for unblocking conveying pipe


A method of drilling in a subterranean formation. A method may include providing a direct emulsion drilling fluid comprising an aqueous fluid, an oil, and a polysorbate emulsifier; circulating the direct emulsion drilling fluid from a surface, through a wellbore, and back to the surface; and extending the wellbore in the subterranean formation while circulating the direct emulsion drilling fluid.

Drilling fluids are the complex fluids used for the drilling of subterranean oil and gas wells. The successful completion of an oil and gas well and production of hydrocarbons from the oil and gas reservoir depends upon, to a considerable extent, the properties of drilling fluids selected. The selection of an appropriate fluid and the maintenance of the properties primarily influence the production rate while drilling. The complex fluids perform several functions simultaneously. For example, drilling fluids clean the well; hold the cuttings in suspension; reduce friction between the drill string and sides of the well; maintain the stability of a wellbore by imposing hydrostatic pressure on the walls thereof; prevent fluid loss to the formation to avoid formation damage and differential pipe sticking by making thin, impermeable filter cakes; cool and lubricate drilling tools; and contribute to the evaluation of the formation by raising the cuttings from the wellbore bottom up to the surface of the well.
Drilling fluid density may be an important factor to monitor during drilling operations, as the hydrostatic pressure exerted by the drilling fluid is directly proportional to the density of the drilling fluid. Hydrostatic pressure may increase with increasing density of the drilling fluid and height of fluid column. Excess hydrostatic pressure above the fracture gradient of the formation may lead to premature fracturing of the formation and resultant formation damage and fluid loss.
To remedy these and other issues, lower density drilling fluids may be required. Oil may be added to a drilling fluid to reduce the density, but these systems may not be stable at static conditions. Furthermore, these systems may become increasingly unstable at high salinity, particularly in certain aqueous-based drilling fluids.

Emulsifiers for direct emulsion drilling fluids


An ice thickness probe includes a longitudinally-extending probe rod, an insulator casing and a sleeve. The probe rod is fabricated from an electrically-conductive material. The insulator casing is fabricated from an electrically-insulative material and is wrapped around, is in contact with and extends along the probe rod. The sleeve is fabricated from a stiff yet resilient material and is wrapped around, is in contact with and extends along the insulator casing. The insulator casing and the sleeve are concentrically disposed about the probe rod as viewed in cross-section. An ice thickness probe assembly includes a frame structure, a reference bar and at least one ice thickness probe. An ice thickness monitoring apparatus is used in a thermal storage coil having a tank containing water and a tube disposed in the water so that, when the thermal ice storage coil is energized, ice is produced and accumulates on the tube.

Thermal storage systems have been in existence for many years. The purpose of a thermal storage system is to create thermal energy and store it for use at another time. In a typical thermal storage system, the refrigeration system, i.e., a chiller, generates ice at night when electrical utility rates are typically lowest (off-peak). During the day, when utility rates are higher (on-peak), the ice is then melted to provide, for example, cooling to a building.
One type of technology system that provides for thermal storage is referred to as "ice on coils". In this type of system, cylinders of ice are built onto tubes (coil tubes; also referred to as thermal storage coils). In many systems that use this technology, multiple banks of coils are submerged under water in concrete, metal or resin tanks.
Many thermal storage systems use glycol chillers to provide cooling necessary to generate ice on the coil tubes. Such thermal storage systems have two modes of operation, "ice build" and "ice melt". For ice build, the glycol chiller is energized during the off-peak period. The glycol chilling system generates low-temperature glycol that circulates through the coil tubes of the thermal storage coils. The circulating glycol removes heat from the water in the tank which causes water to freeze onto the exterior surface of the thermal storage coils. During ice melt, the glycol chilling system is shut off, i.e. de-energized. For one type of "ice melt" phase, the tank water is circulated over the ice built-up on the thermal storage coils to extract energy from the ice. The ice water is then circulated through a primary side of a heat exchanger.
A conventional component of one type of thermal storage system is a thermal storage coil assembly 2 as shown in FIG. 1. The thermal storage coil assembly 2 includes a tank 4 containing tank water (arrows in FIG. 2) and a plurality of thermal storage serpentine circuits 6 with each thermal storage serpentine circuit 6 including a plurality of horizontally-extending, integrally interconnected coil tubes 8.
As shown in FIG. 2, the geometry of the coil tubes 8 is such that ice I may overbuild (overbuilt ice OI) in the vertical direction but a vertically-extending clearance gap G is necessary between rows of horizontally-disposed coil tubes 8. Thus, the vertical clearance gap G between the rows of coil tubes 8 permits circulation of the tank water (illustrated as arrows in FIG. 2). Maintaining the clearance gap G as an open, serpentine, vertical passageway between the ice I building on respective one of the coil tubes 8 allows for efficient heat transfer between the tank water and the ice I on the coil tubes 8 of thermal storage serpentine circuits 6.
It is therefore beneficial to either measure or monitor the amount of ice that accumulates on the coil tubes 8 of the thermal storage serpentine circuits 6 to provide at least some assurance that the vertical clearance gap G is maintained throughout the ice build-up operation phase of the thermal storage system. There are several ways for measuring or monitoring the amount of ice I in the tank 4 of the thermal storage system. One method of measuring ice is by the level of tank water in the tank 4. Another method is to measure or monitor the amount of ice I accumulating on a coil tube 8 of a thermal storage serpentine circuit 6. One type of an ice thickness measuring device senses the thickness of the ice I by conductivity. Another conventional ice thickness measuring device 10, such as the one shown diagrammatically in FIG. 1, is placed on the coil tube 8 of the thermal storage serpentine circuit 6 to measure or monitor levels of the ice thickness to detect stages, i.e., percentages of full ice build, in the ice build cycle. When full ice build is reached, a controller 12 in electrical communication with the conventional ice thickness device 10, for example, by a wire 14, shuts off the glycol flow to the thermal storage coils 6 thereby discontinuing the ice build cycle.
The present invention provides an ice thickness probe, an ice thickness probe assembly and an ice thickness monitoring apparatus that are used to measure and/or monitor ice thickness and/or to shut off the thermal storage system when full ice build is reached.

Ice thickness probe, ice thickness probe assembly and ice thickness monitoring apparatus


An electrical connector includes an elongate insulative housing defining a central slot for receiving a module therein. latch device is positioned at each end of the housing. Each latch device includes a plastic member integrally extending from the housing, and a metal member cooperating with the plastic ember. A first plate of the metal member abuts against an outer surface of the plastic member and a first tang extending from the first plate, incorporates the first plate to confine the plastic member therebetween. The module can be released from the connector by applying an outward force to free ends of the latch devices. A second tang extending from the first plate abuts against the plastic member when the latch device reaches its outermost position thereby preventing over-extension and breakage thereof. A third tang downwardly extending from the first plate is received in a recess defined in an outer surface of the plastic member for limiting inward movement of the latch device thereby further preventing breakage thereof.

1. Field of The Invention
The present invention relates to an electrical connector having a latch device including a plastic member and a metal member in cooperation with each other for releasably securing a printed circuit board thereto.
2. The Related Art
U.S. Pat. Nos. 5,759,057 and 5,755,585 disclose SO DIMMs (Small Outline Dual In-line memory modules). The former discloses a latch device essentially consisting of a plastic member and a metal member, and the latter discloses a high profile design.
The integrally formed plastic member is used to retain a clipping portion of a daughter board and the metal member is used to release the daughter board from the plastic member. The metal member is separated from the housing. However, even though such latches provide improved resilience and strength, the plastic member tends to break when an excess force is exerted thereon.
In order to prevent the plastic member from breaking, the housing is provided with a stopper to limit movement of the plastic member. This inevitably increases the length of the connector and hinders the compactness thereof. In addition, plastic stoppers are not durable thereby hindering resilience of the plastic member. Furthermore, in locking or releasing the daughter board, the hybrid latches are pushed away from their original positions. The plastic member often breaks during this stage because a junction between the plastic member and the housing experiences a concentration of stress. The junction is a curved plane without any reinforced member mounted thereon.
Since a minimized dimension along a lengthwise direction of the connector is desired, the structures disclosed in the aforementioned applications require modification. The main body of the housing of the connector can not be changed due to the necessity for compliance with the circuit layout of the inserted module. Therefore, reducing the dimension of the latch device at either end of the housing is the only way to implement miniaturization and overcome the disadvantages of the prior art.


A glove includes: a palm; a suction cup coupled to the palm; and a suction releaser coupled to the suction cup. A method includes: positioning a suction cup over a drain, with the suction cup being coupled to a palm of a glove; and plunging the drain via the suction cup.

A plunger can include a shaft and a suction cup. This structure can make plunging difficult in some circumstances, such as in a sink drain, a toilet drain, a pan drain, a tub drain, or others, whether in a residential, industrial, or commercial setting, whether indoors or outdoors, such as a bathroom, a kitchen, a shower room, or others. Accordingly, there is a desire to improve.


The invention relates to a drilling rig with a drilling tower, a base structure, on which the drilling tower is arranged, and at least three support units being part of the base structure, each support unit having at least one wheel rotatable around a horizontal wheel axis, wherein at least one of the support units comprises a vertical steering axis, around which the at least one wheel can be turned by a steering drive. The invention further relates to a method for moving such a mobile drilling rig.

Drilling rigs are well known and used, for example, for oil and gas well drilling. Smaller drilling devices can be arranged on a vehicle/truck or trailer to be mobile. Larger drilling rigs have a stationary design and have to be disassembled for transportation.
For dislocation of larger drilling rigs within a range of up to some hundred kilometers, it is known to arrange at the basis structure of the drilling rig support units with large, over-sized wheels, by which the drilling rig can be lifted for being moveable. After lifting, the drilling rig is connected via one or more cables or rods with one or more tractor vehicles, by which the drilling rig is driven and pulled to a new location. By such a known arrangement a time-consuming and expensive disassembling and reassembling of the drilling rig can be avoided. Further, the used large wheels are expensive and difficult to replace. In case of a collapse of at least one of the large wheels during movement, the drilling rig might be destabilized. It might even happen that the remaining wheels are overloaded and collapse, too.
The fixing of the support units, the lifting motion by such support units as well as the connection and pulling of the drilling rig by tractor vehicles are delicate and complex tasks, in particular if the drilling rig has to be moved along a curved, non-linear way.


The instant invention provides a polymer composition suitable for clear graphic cling film applications, method of producing the same, articles made therefrom, and methods for making such articles. The polymer composition suitable for clear graphic cling film applications, according to the present invention, comprises: (a) a polyolefin composition selected from the group consisting of a propylene-based composition as described herein, and an ethylene-based composition as described herein, and (b) one or more alkyl phosphate-based release agent; wherein when said polyolefin composition is formed into a clear graphic cling film having a 7 (±2) mils, said clear graphic cling film has a haze of less than 4 percent, for example from 0.3 to 4 percent, measured according to ASTM-D 1003.

The use of polyvinyl chloride-based compositions in clear graphic cling film applications is generally known. Such films may be prepared via any known processes, for example, via calendaring process. However, there is a need to reduce the use of phthalate-plasticized, or polyvinyl chloride in graphic cling film applications, and instead use films that are substantially free of chlorine or plasticizers. Such plasticizers typically degrade over time, and as a result, the polyvinyl chloride-based film may deform; thus, having less tendency to adhere to glass windows when subjected to long term exposure to sunlight and/or extreme temperatures.
Therefore, there is a need for a polymer composition suitable for clear graphic cling film applications, which is free from phthalate-plasticized polyvinyl chloride, and clear graphic cling films made therefrom while providing improved film properties.


Systems and methods for controlling a converter for powering a load are provided. According to one embodiment of the invention, a method for powering a load is provided. A power converter may be provided. At least one gating control signal having a switching pattern may be supplied to the power converter, wherein the switching pattern has a waveform with an effective switching frequency greater than 1 times the fundamental frequency of the switching pattern and less than 2 times the fundamental frequency of the switching pattern. At least one output power signal may be output to the load responsive at least in part to the at least one gating control signal supplied.

High-speed, high-power electric motors that operate at variable speed are increasingly utilized in a range of industrial, mining and drilling activities. Further, the activities often depend upon a high-degree of reliability. In operations such as crude oil pumping from remote global locations where access to pumping stations is difficult and time-consuming, reliability of motor operation may prevent dangerous, costly and extended outages. Simple, sturdy and reliable power converters are preferred for such high-speed, high-power motor operations. It is well known that providing multiple individual components, such as series or parallel semiconductor switches, may increase the likelihood that any one individual component switch may randomly fail. Added elements such as snubber circuits for semiconductor switches, further increases the number of components that can fail. It is desirable to arrange the power converter in a simple configuration, with as low a part component count as is possible. However, individual components, such as the semiconductor switches for the power converter, can be operated with satisfactory margin to thermal and other functional limits to avoid failures in the simplified configuration.
A power converter used in one example embodiment may be a simplified three-phase, wye-connected H-bridge converter configuration, such as is illustrated in FIG. 1. Each phase of the converter includes a power source/sink 20 with a de power shaping circuit, represented by capacitor 30. The power source/sink/20 and dc power shaping circuit, represented by capacitor 30, establish a dc-link voltage input to the semiconductor switches of the bridge. Insulated-gate bipolar transistors (IGBTs) 40 with built-in diodes 45 may form each leg of the H-bridges 50, for example, but other power semiconductor switches such as integrated-gate commutated thyristors (IGCTs) or metal-oxide semiconductor field-effect transistors (MOSFETs) could be used instead. The type of power semiconductor switch is not important to the analysis. Each H-bridge includes two legs, an output leg 60 and a neutral leg 65. Each phase output, phase A 70, phase B 75 and phase C 80 is connected to the midpoint 85 of the respective output bridge leg 60. Each neutral connection to wye-point 90 is tied to the midpoint 95 of the respective neutral output leg 65.
Gating controls 35 provide control signals 36, 37, 38 for switching semiconductor switches 40 of Phases A, B, and C of the H-bridge converter, according to predetermined switching patterns. Gating controls may provide for synchronous switching or asynchronous (pulse-width modulation, for example) switching of the semiconductors switches 40 of the H-bridge.
However, to improve availability of operation of the motor loads, it is desirable to further balance temperatures, reduce switching and power losses and harmonic distortion. Reduction in switching loss will keep semiconductor H-bridge switches operating at lower temperatures with a greater margin to failure.
Accordingly, there exists a need for systems and methods for controlling a converter for powering a load in order to balance temperatures, and to reduce switching loss and total harmonic distortion.


An image processing apparatus includes an alignment unit configured to align a first fundus oculi image that is an aberration-corrected image of an eye being examined and a second fundus oculi image having a larger view angle and a lower resolution than the first fundus oculi image, by using a third fundus oculi image having a smaller view angle and a higher resolution than the second fundus oculi image; a distance acquisition unit configured to acquire a distance from a macula lutea of the eye being examined to a certain position in the first fundus oculi image aligned by the alignment unit; and an evaluation unit configured to evaluate the state of the eye being examined from the distance and information concerning photoreceptor cells included in the first fundus oculi image.

1. Field of the Invention
The embodiments disclosed herein relate to an image processing apparatus and an image processing method.
2. Description of the Related Art
For the purpose of early diagnosis of lifestyle diseases or diseases that rank high as a cause of blindness, the inspection of the fundus oculi of the human eye has been widely used. A scanning laser ophthalmoscope (SLO), which is an ophthalmological instrument that utilizes the principle of confocal laser scanning microscopy, is a device that uses laser light, which serves as measurement light, to raster-scan the fundus oculi to quickly obtain a high-resolution two-dimensional image from the intensity of the return light of the laser light. In recent years, adaptive optics SLOs (AO-SLOs) including an AO system configured to measure the aberrations of the eye being examined in real time by using a wavefront sensor and to correct the aberration of the measurement light that occurs in the eye being examined or the aberration of the return light of the measurement light by using a wavefront correction device have been developed. The AO-SLOs facilitate the acquisition of high-lateral-resolution two-dimensional images (hereinafter sometimes referred to as "AO-SLO images"). In addition, the photoreceptor cells in the retina are extracted from obtained two-dimensional retinal images, and the density or distribution of the photoreceptor cells is analyzed to attempt the diagnosis of a disease or the evaluation of drug response.
Image processing for detecting the photoreceptor cells may be performed with high accuracy by utilizing medical knowledge of photoreceptor cells. For example, it is known that the density of photoreceptor cells decreases as the distance from the macula lutea increases. In order to take advantage of this knowledge, users need to know the distance from the macula lutea to the region being analyzed.
Due to the smaller view angle of AO-SLO images than SLO images, an AO-SLO image, which is obtained by imaging the region in which the density is to be evaluated, does not generally include the macula lutea. Thus, it is difficult to know the exact distance from the macula lutea to the region. Accurate evaluation of the photoreceptor cells is therefore difficult to achieve.

Image processing apparatus and image processing method


A novel and improved canine elbow prosthesis and method of implanting same including a unique bi-compartmental prosthesis having bone receiving members and transverse pegs which may be implanted with a minimally invasive surgical technique.

The article of manufacture and method relate broadly to a joint prosthesis and method of implanting same, and more particularly to a canine elbow prosthesis and novel and improved method of implanting same.
The elbow joint is a hinge-type synovial joint formed where the distal end of the humerus articulates with the proximal end of the radius and ulna. Elbow dysplasia is a common debilitating condition that affects many dogs. The current surgical techniques result in an unacceptable failure rate of the implant due to the technical difficulties associated with the implantation procedure as well as excessive post-surgical physical therapy needs as a result of the invasiveness of the procedure and the abundance of soft tissue damage.
There is therefore a need for a novel and improved joint arthroplasty that involves a minimally invasive surgical technique with a novel implant. The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above described problems have been reduced or eliminated, while further embodiments are directed to other improvements.

Joint prosthesis and method of implanting same


A method, apparatus, article of manufacture, and a memory structure for signaling the storage of motion information describing the depicted motion associated with digital pictures. In one embodiment, the method comprises signaling the replacement of a motion vector stored in connection with a previously coded picture with the motion vector of the currently coded frame. Another signal may be used to indicate motion vector replacement for all pictures in a sequence.

1. Field of the Invention
The present invention relates to systems and methods for encoding data, and in particular to a system and method for storing motion and retrieving data associated with high efficiency video coded data.
2. Description of the Related Art
There is rapid growth in the technologies associated with the generation, transmission, and reproduction of media programs. These technologies include coding schemes that permit digital versions of the media programs to be encoded to compress them to much smaller size and facilitate their transmission, storage, reception and playback. These technologies have application in personal video recorders (PVRs), video on demand (VOD), multiple channel media program offerings, interactivity, mobile telephony, and media program transmission.
Without compression, digital media programs are typically too large to transmit and/or store for a commercially acceptable cost. However, compression of such programs has made the transmission and storage of such digital media programs not only commercially feasible, but commonplace.
Initially, the transmission of media programs involved low to medium resolution images transmitted over high bandwidth transmission media such as cable television and satellite. However, such transmission has evolved to include lower bandwidth transmission media such as Internet transmission to fixed and mobile devices via computer networks, WiFi, Mobile TV and third and fourth generation (3G and 4G) networks. Further, such transmissions have also evolved to include high definition media programs such as high definition television (HDTV), which have significant transmission bandwidth and storage requirements.
The encoding and decoding of compressed video signals typically involves the storage and retrieval of large volumes of data by both the encoder of the signals and the decoder of the signals. As a consequence, such encoders and decoders require increased storage and processing capacity. What is needed is a system and method that reduces the storage and processing required in the encoder and decoder. The present invention satisfies this need.

Efficient storage of motion information for high efficiency video coding


A novel method for the preparation of an aqueous polyacrylate modified polyurethane dispersion is disclosed. The preparation method includes three main steps:                a) preparation of polyacrylate polymer or copolymer emulsion;        b) preparation of polyurethane prepolymer with carboxylic groups and neutralization treatment to the carboxylic groups; and        c) dispersion and chain-extension of polyurethane prepolymer by adding the polyacrylate emulsion into the polyurethane prepolymer under vigorous agitation, or other mechanical operation.

Over the decades, there has been a concerted effort to reduce atmospheric pollution caused by volatile solvents which are emitted during painting processes. Due to environmental concerns, volatile organic compounds (VOCs) have come under strict regulation by the government. Therefore, one of the major goals of the coating industry is to minimize the use of organic solvents by formulating waterborne coating compositions which provide a smooth, high gloss appearance, as well as good physical properties including resistance to acid rain. While the solvent-type coatings provide many benefits, such as that they are fast-drying, have a high hardness, a high abrasion-resistance, a high water-resistance, a high chemical-resistance and a low price, the waterborne coatings have environment-friendly benefits in that they are not flammable or explosive. The waterborne coatings use water as the system solvent and contain no poisonous chemicals. They require no or low amounts of volatile organic compounds.
In this context, aqueous polyurethane (PU) dispersions or emulsions have been replacing the solvent-type products in the fields of coatings, adhesives and ink. However, pure aqueous PU dispersions have some inherent drawbacks. In order to form a stable aqueous dispersion, the hydrophilic groups, for example, carboxylic, sulfonic, ammonium and other ionic groups should be introduced into the PU molecular chains. This modification however may lead to lower water-resistance of the aqueous PU dispersion compared to the solvent-type products. Therefore, it is necessary to modify the aqueous PU dispersions with other hard polymeric materials such as polyacrylates.
Polyacrylates (PAs) are the most important polymers used in modifying the PUs. The PA and the PU are complements in many aspects. The PU is advantageous in that it is cold-resistant, solvent-resistant, elastic and flexible, glossy and exhibits little change in hardness with changes in temperature, while the PU is disadvantageous in that it has low water-resistance and low mechanical strength. The PA is advantageous in that it has high mechanical properties and is anti-yellowing, aging-resistant and water-resistant, while the PA is disadvantageous in that it has low solvent-resistance and that the PA film is tacky under high temperature but brittle under low temperature. Accordingly, obviously the properties of the PU and the PA complement each other. The composite materials of PU and PA are more outstanding in terms of adhesion, film-formability, non-stickiness, weather-resistance, elongation and strength of the film than that of either the PA or the PU taken alone. Accordingly, since the development of PU, the modification of the PU by the PA has remained an active research topic in the art.
There are two kinds of modification to the PU by the PA: a physical method and a chemical method. The physical method is achieved by mechanical mixing. In the physical method, aqueous PA and PU dispersions (emulsions) are independently prepared first, and then both dispersions are mixed together under mechanical power. A high speed mechanical stirrer may be used for this purpose. It is a very convenient method that makes it easy to control the particle size and the stability of the dispersions. However, the properties of the mixed dispersion are often not very satisfactory, because the particles of PU and PA are separated in the dispersion and the phase separation occurs during film-formation. (D. Kukanja et al, J. Appl. Polym. Sci. 78, 67, 2000)
For these reasons, the chemical modification technology currently plays a more important role. The chemical method is achieved by post-polymerization of acrylates. In the chemical method, the PU dispersion can be prepared first, and then acrylates and other vinyl monomers can be polymerized in the PU dispersion. In most cases, core-shell emulsion polymerization is adopted. PU particles are used as core particles and the acrylates are polymerized in the PU particles due to high hydrophobicity of the acrylates. Therefore, the inverse core/shell structure is always obtained.
In addition, the free radicals are typically easily captured by N—H groups in the PU chains. As such, the PU can also serve as a chain transferring agent in the acrylates polymerization, and a graft of PA chains to PU chains is formed. Furthermore, if multi-double-bond (>2) unsaturated monomers are used in the emulsion polymerization, or multifunctional polyols or polyisocyanates are used in the preparation of PU, crosslinking and interpenetrating networks are formed in the core-shell particles. This leads to enhanced compatibility between the PU and the PA and the phase separation is minimized or even eliminated. This is likely the reason why the properties of the PU-PA composites produced by the chemical method are much better than those of the mixtures of both materials obtained by the physical method.
In the preparation of aqueous PU dispersions by the chemical method, a high viscosity for the prepolymer melt should be avoided so that good operability can be achieved in obtaining PU dispersions with a high molecular weight. For this purpose, such volatile organic solvents as acetone, methyl ethyl ketone, etc. are typically used in the reported literature or disclosed methods in the art. With the use of these solvents, the viscosity can be maintained at a low level. At the end of the preparation of aqueous PU dispersions, the solvents are typically removed from the dispersions under vacuum pressure.
For example, U.S. Pat. No. 5,556,912 discloses a preparation of aqueous binder dispersions including polyurethanes and water-based physically drying coating compositions containing these aqueous dispersions which are particularly suitable for plain and metallic colored base coats employed for automotive repair lacquer coatings. In the patent, the reaction proceeds in the presence of a solvent or in the presence of so-called reactive diluents, such as methyl ethyl ketone, methyl isobutyl ketone, acetone, tetrahydrofuran, toluene and xylene, which are subsequently eliminated by distillation.
In the chemical method, certainly acrylates and other ethylene unsaturated monomers without active-hydrogen in the molecules can be used as a solvent at first, and then they can be radical polymerized after the prepolymer of PU has been dispersed in water. For example, U.S. Pat. No. 7,001,952 discloses a preparation of aqueous PU dispersions including PU-acrylate particles dispersed in an aqueous medium.
In the stage of preparing the PU prepolymer by the chemical method, for example, a mixture of methyl methacrylate and butyl acrylate can be added into a reactor, so the viscosity of the reaction system is very low. After water is fed into the reactor and the PU prepolymer is extended and dispersed, radical initiators are added into the dispersions to create the emulsion copolymerization of methyl methacrylate and butyl acrylate. In said U.S. Pat. No. 7,001,952, in order to enhance the dispersibility and to reduce the particle size of the dispersion, a microfluidizer is used after the dispersion. The initiators adopted in the patent are of the redox-type, i.e. t-butylhydroperoxide/ferrous ammonium sulfate/sodium metabissulfate and isoascorbic acid/hydrogen peroxide.
In another U.S. Pat. No. 6,635,706, polyols, dimethylol propanic acid, bis(4-isocyanatocyclohexyl)methane and N-methylpyrrolidinone (cosolvent) are used in the preparation of PU prepolymer. A mixture of methyl methacrylate and butyl acrylate is added into the solution and then dispersed in water. At the final stage, emulsion polymerization is carried out under 75° C., by using Vazo-52 [2,2′-azobis(2,4-dimethylpentanenitrile)] as an initiator, and then using ammonium persulfate, tertiary butyl hydroperoxide, cumene hydroperoxide and hydrosulfite successively to accelerate the polymerization.
In addition, Japanese Patent No. 9 165 407 and U.S. Pat. No. 6,635,706 disclose that active acrylates, i.e., acrylates with hydroxyl groups, can react with a —NCO terminated polyurethane prepolymer so that vinyl groups can be introduced into the prepolymer chains. The advantages of this technology are: (i) the prepolymer with double bonds can copolymerize with acrylates in the later stage so that the PU and the PA can be crosslinked; (ii) NCO groups in the prepolymer are consumed by the hydroxyl groups in the active acrylates; and (iii) extending reaction of the prepolymer in the water can be ignored so that the dispersed phase in the aqueous PU emulsion is of low molecular weight materials, even oligomers of PUs. Thus, a stable and uniform emulsion can be obtained easily.
The PU can be modified by the PA and other polymer resins together. In U.S. Pat. No. 5,688,859, PAs and alkyd resins with hydroxyl and carboxylic groups are synthesized first, and then diisocyanates react with a mixture of the two resins in solution. Finally, neutralization and dispersion are conducted subsequently. The PU/PA hybrid emulsions obtained are in good appearance and the polymer film is of excellent properties. The solvent used in the manufacturing, however, is more than 5% in the product.
U.S. Pat. No. 6,166,150 also discloses that alkyd resins and PAs are used to modify the PU. The alkyd resins and the PU were prepared in organic medium, respectively, and then were blended. The solution was neutralized and dispersed in water afterwards. Acrylate monomers were then copolymerized in the alkyd resin-PU dispersion. The radical polymerization of acrylates would last for 10 hours.
Many more patents and research papers disclose the preparation of aqueous PA modified PU dispersions. However, the balance of polymer properties and operation complexity is still a challenge. Although the emulsion polymerization of acrylate monomers always leads to excellent properties, either the use of organic solvents or the tedious operations have to be considered as elements requiring improvement. The productivity is therefore markedly limited. In the PU industry, in fact, antioxidants are necessary to be added into most polyols, which will inhibit the radical polymerization of vinyl monomers drastically. Furthermore, as mentioned above, although the N—H groups in the PU chains are in favor of the grafting reaction of PA to PU, this "side reaction" will slow down the radical polymerization because the radicals are very easily transferred to PU chains, leading to the low conversion of the acrylate monomers into polymerization. As a result, the monomer conversion of the acrylates emulsion polymerization in the presence of PU is very low, ca. 60˜70%. In order to enhance the monomer conversion, some intensified strategies should be adopted in the radical polymerization stage, for example, either to extend the reaction time, or to use composite initiators as in U.S. Pat. No. 6,635,706. Besides, some PA/PU hybrid emulsions are yellowish or light brown. The appearance of these products looks unattractive. Therefore, it is an urgent need to conveniently produce PA/PU hybrid dispersions to obtain a high yield of the desired product.
In Chinese Patent No. 1 597 739A, a method is disclosed to prepare the PA emulsion in advance and then add the PA emulsion into a PU prepolymer solution directly during the dispersion stage. The method is easy to control and the obtained PA/PU hybrid bears enhanced properties. However, according to this method, volatile organic solvents must be used in the PU prepolymerization stage and the volatile organic solvents must be removed under vacuum at the end of process.
Meanwhile, as a way to achieve the desired properties of the PA/PU composite materials, chemical crosslinking between the PA and the PU chains has been employed. In this regard, one effective and feasible strategy is to adopt a two-packaged PA/PU system. There are quite a few patents found for two-packaged aqueous PA/PU coatings production, such as U.S. Pat. Nos. 6,515,068, 5,670,600 and 5,876,802.
U.S. Pat. No. 5,675,600 discloses a two-packaged PA/PU system. In this system, water-dilutable acrylates copolymers are prepared via solution polymerization using ethoxyethyl propionate; the polyacrylates are dispersed in water; and then the organic solvent is finally removed from the dispersion by azeotropic distillation. The aqueous polyacrylate dispersion can be blended with a water-dilutable polyisocyanate commercially available so that a transparent topcoat can be obtained. It is obvious that in this two-part PA/PU coating system, the PU component is used as a crosslinker and the PA is the main resin for the coating. Therefore, the properties of the film will mainly depend on the polyacrylate component.
U.S. Pat. No. 5,876,802 is an updated version of U.S. Pat. No. 5,675,600, with the essential strategy not changed.
U.S. Pat. No. 6,515,068 also uses the water-dilutable polyisocyanate as a crosslinker for the polyacrylate with hydroxyl groups.
Although two-packaged coatings provide a high performance, such coatings are not convenient for painting operations. Two components must be stored in separate containers and they must be mixed in accordance with a specific ratio before being applied. In this regard, the pot life of the "finished" coating products is always shorter than 3 hours. Therefore, a one-packaged product will tend to be superior to a two-packaged product in terms of operability.
Further, it will be much better if the crosslinking of PA and PU chains can be achieved under ambient temperature. For self-crosslinking systems under ambient temperature, some pairs of groups can be considered, for instance, epoxide/primary amine and acetoacetoxy systems.
U.S. Pat. No. 6,063,861 discloses a preparation of a pure polyurethane aqueous dispersion using a hydroxyl carboxylic acid method. In this patent, the PU is extended with amines and then the acrylates monomers and Acetoacetoxyethyl methacrylate (AAEM) are polymerized in the presence of the PU dispersion. The results of the patent show that AAEM in this system can lead to the self-crosslinking of the PA/PU hybrid dispersion.
In the present application, a method of preparing an aqueous PA modified PU dispersion with high stability is provided, without the use of volatile organic solvents but with high productivity and convenience in operation. Further, as a way to improve the properties of the modified PU dispersion, a method of preparing an aqueous PA modified PU dispersion with self-crosslinkability is provided.

Method for preparing aqueous polyacrylate modified polyurethane dispersions

Abstract: The aqueous polyacrylate modified polyurethane dispersion has self-crosslinkability when an unsaturated acetoacetoxy compound is used for the preparation of the polyacrylate emulsion.

The Hong Kong University of Science and Technologhy


A front body structure of a vehicle body having a chassis and a body which is formed separately from the chassis and is mounted thereon includes a shroud panel which forms a side portion of the front portion of the body. A wheel apron is connected to the shroud panel at its front portion and a body strength member is connected to a rear portion of the wheel apron. An apron reinforcement extends in the longitudinal direction of the vehicle body and is connected to the shroud panel at a front portion and to the body strength member at a rear portion. A first mount portion for mounting the body on the chassis is provided in the lower portion of the shroud panel and a second mount portion for mounting the body on the chassis is provided near the connection of the body strength member to the wheel apron. A frame extends along the outer side edge portion of the shroud panel to the body strength member and is connected to the connection of the shroud panel and the apron reinforcement at an intermediate portion thereof.

1. Field of the Invention
This invention relates to a front body structure of a vehicle, and more particularly to a front body structure of a vehicle of a type in which the body is mounted on a chassis.
2. Description of the Prior Art
There has been known a vehicle body of a chassis frame structure comprising a chassis and a body mounted on the chassis. In such a vehicle body, a major strength of the vehicle is basically carried by the chassis, and a pair of mount portions supported by the chassis are often provided in front of and behind each front wheel apron. As the body side elements associated with the mount portions, there are a shroud panel which is connected to the forward portion of the wheel apron and forms a side portion of the front portion of the vehicle body, a hinge pillar connected to the rear sides of the wheel apron, a side sill and the like in addition to the wheel apron.
There has been known a shroud panel comprising a base panel, an upper member provided on the upper portion of the base panel, a side member provided on the inner side edge portion of the base panel, and the like. The wheel apron is generally provided with a apron reinforcement which extends in the longitudinal direction of the vehicle body.
When the vehicle running a rough road, vertical vibration acts between the mount portions in the body on the chassis, and accordingly, it is required that the body itself has a sufficient rigidity. In order to increase the rigidity of the body itself, the rigidity of the part around the front wheel apron must be increased. However when the shroud panel and/or the wheel apron are simply provided with additional reinforcement, satisfactory effect cannot be effected for increase in weight of the vehicle body. Particularly in the case of the vehicle body of chassis frame structure, it is not preferred that additional reinforcements are provided in a large weight since the chassis itself is heavy.


A method for making a lower intake manifold of an internal combustion engine includes the steps of (1) forming a main part from a plastic material by injection molding, (2) forming a runner insert for each engine cylinder from a plastic material by injection molding, and (3) individually attaching each runner insert to the main part to ensure the distance between two adjacent runner inserts is within a predetermined limit.

The air intake manifold of an internal combustion engine generally consists of upper and lower intake manifolds, which are attached to each other to form the air intake manifold. The lower intake manifold has "runners" (or conduits), each of which provides fluid communication between the intake manifold and a cylinder of the engine to allow airflow from the intake manifold to the cylinder.
At present, the lower intake manifold is made from aluminum and consists of two parts: a main casting and an insert. The insert is attached to the main casting with screws and sealed against the main casting with a gasket. The runners are part of the insert.
While it is efficient and cost-effective to make the lower intake manifold by injection-molding of a plastic material, a lower intake manifold, which is originally designed to be made from aluminum main casting and insert, can be difficult to make by injection-molding of a plastic material. First, because of the relatively complicated geometry of the lower intake manifold that is originally designed to be made from aluminum main casting and insert, mold cores cannot be removed intact after molding. Thus, only lost-core injection molding can be used to make the lower intake manifold in one piece. However, lost-core injection molding may be prohibitively expensive.
Second, although making the lower intake manifold from two injection-molded parts, such as a main part and an insert that includes the runners, allows removal of mold cores and thus is less expensive, injection-molded parts are often not sufficiently precise to satisfy the required tolerances. Specifically, it is often difficult to keep the distances between runners sufficiently consistent and precise to satisfy the required tolerances, due to, for example, the warping of the injection-molded insert.

Engine lower intake manifold and method for making the same


A method useful for evaluating the presence and/or the quality of the cement bond of a downhole tubular. The method involves measuring radial resonance modes of the tubular, and comparing those measured values to the unbound tubular resonant values of a calibration ring. For a well bonded tubular, the measured radial resonance should be greater than that of the unbound tubular calibration ring. In regions where a fluid, such as water surrounds the outside of the tubular, or the cement is otherwise not bonded to the outer surface of the tubular, the measured response should be less than the calibrated response. The calibration ring should have the same diameter, wall thickness, and be made of the same material as the tubular.

1. Field of the Invention
The invention relates generally to the field of the evaluation of wellbore casing. More specifically, the present invention relates to a method and apparatus to provide for the analysis of the bond that secures casing within a wellbore.
2. Description of Related Art
Hydrocarbon producing wellbores typically comprise tubulars, such as casing 8, set within the wellbore 5. Typically the casing 8 is bonded to the wellbore by adding cement 9 within an annulus formed between the outer diameter of the casing 8 and the inner diameter of the wellbore 5. The cement bond not only adheres the casing 8 within the wellbore 5, but also serves to isolate adjacent zones (Z1 and Z2) within the formation 18 from one another. Isolating adjacent zones can be important when one of the zones contains oil or gas and the other zone includes a non-hydrocarbon fluid such as water. Should the cement 9 surrounding the casing 8 be defective and fail to provide isolation of the adjacent zones, water or other undesirable fluid can migrate into the hydrocarbon-producing zone thus diluting or contaminating the hydrocarbons within the producing zone.
To detect possible defective cement bonds, downhole tools 14 have been developed for analyzing the integrity of the cement 9 bonding the casing 8 to the wellbore 5. These downhole tools 14 are lowered into the wellbore 5 by wireline 10 in combination with a pulley 12 and typically include transducers 16 disposed on their outer surface formed for acoustic coupling to the fluid in the borehole. These transducers 16 are generally capable of emitting acoustic waves into the casing 8 and recording the amplitude of the acoustic waves as they travel, or propagate, across the surface of the casing 8. Characteristics of the cement bond, such as its efficacy and integrity, can be determined by analyzing the attenuation of the acoustic wave.
One example of such an acoustic transducer is a piezoelectric device having a piezoelectric crystal that converts electrical energy into mechanical vibrations or oscillations. The vibrations produced by the piezoelectric device can be transmitted to the casing 8 that in turn form acoustic waves in the casing 8. The acoustic waves impart energy to the tubular member to create a frequency response from the tubular and monitored by receiver transducers. The measured response collected can be analyzed real-time or stored as data for subsequent analysis. The data can be in analog or digital format.

Casing resonant radial flexural modes in cement bond evaluation


A pressure control valve has a substantially closed housing, an armature provided with an integrated valve body, a valve seat with which the valve body cooperates, a spring acting on the valve body so that the valve body cooperates with the valve seat, an electromagnet arranged to adjust a control pressure. The magnet armature is somewhat bucket-shaped. A projection extends in an interior of the housing and operates for guiding a magnetic flux. The magnet armature surrounds the projection and is mounted on the valve body in a friction-transmitting manner. A second spring acts on the valve body so as to counteract an action of the first mentioned spring.

The present invention relates to pressure control valves. More particularly it relates to pressure control valves having a substantially closed housing, an armature arranged in the housing and having an integrated valve body which cooperates with the valve seat under the action of a spring.
Pressure control valves of the above mentioned general type are known in the art. In such valves the control pressure can be adjusted by a proportional magnet which acts as an actuating an adjusting device. The control curve of such a pressure control valve is dependent on the manufacturing and mounting tolerances to a high degree and especially on axial distance of magnet armature from the valve housing with the given distance of the valve body from the valve seat. Occurring deviations change the characteristic curve of each individual valve considerably so that often expensive adjusting steps must be taken. Moreover, such pressure control valves are long and have a tendency to be unstable in the control region, especially in the sense of deviation over the control point.