Disclosed is a pelletizer vessel and a prilling head assembly for use in the pelletizer vessel for prilling a hard resid material. The pellitizer vessel has an has an upright pelletizing vessel with an upper prilling zone, a sphere-forming zone below the prilling zone, a cooling zone below the sphere-forming zone, a bath below the cooling zone, and a prilling head in the prilling zone rotatable along a vertical axis and having a plurality of discharge orifices for throwing molten material radially outwardly. A vertical height of the sphere-forming zone is sufficient to allow material discharged from the prilling head to form substantially spherical liquid pellets. Nozzles are provided for spraying water inwardly into the cooling zone to cool and at least partially solidify the liquid pellets to be collected in the bath. The prilling head assembly has a a feed inlet to allow for the introduction of resid material, rotary union with a fluid tight seal, a rotatable pipe to convey a resid material to the prilling head, a drive wheel to provide rotation to the rotatable pipe, a support housing having a mount for attachment to the pellitizer vessel, and a prilling head with a flow passage in fluid communication with the rotatable pipe and radially offset orifices. Bearings are provided for stablizing and guiding the rotatable pipe. Inert gas is introduced into the annular spaces of the support housing to prohibit foreign matter.

The present invention is directed to an apparatus for pelletizing a petroleum resid wherein the resid is prilled in a molten state using a rotating prilling head, liquid particles of the resid made by the prilling head are formed into spheres before solidifying, and the spherical particles are then quenched and solidified in substantially spherical shape. More particularly, the invention is directed to a prilling head assembly and a prilling vessel equipped with the assembly.
The residue from petroleum distillation has a wide number of uses, including paving asphalt and fuel. Paving grade asphalt used in road construction must meet a number of specifications, including the latest SHRP specification, viscosity (usually 200-5000 poises at 60xc2x0 F.), penetration (usually greater than 30 to 200 dmm), penetration ratio 15xc2x0 F./25xc2x0 F. (usually above about 0.3), ductility, temperature susceptibility, and others.
Contacting the petroleum resid fraction with air at an elevated temperature, also referred to as xe2x80x9cair blowing,xe2x80x9d is a conventional way to improve the characteristics of certain grades of resid to make them suitable for use as a paving; asphalt. However, the prior art does not appear to disclose the practical application of air blowing a relatively soft resid to obtain a relatively hard resid that can be pelletized for storage and/or shipment. As used in the present specification and claims, a xe2x80x9csoft reside xe2x80x9d or a xe2x80x9clow softening point temperaturexe2x80x9d refers to a petroleum residue having a penetration above 0 and Ring and Ball (RandB) softening point temperature below 200xc2x0 F. A xe2x80x9chard residxe2x80x9d or a xe2x80x9chigh softening point temperaturexe2x80x9d refers to a petroleum residue with a penetration of essentially 0 and RandB softening point temperature above 200xc2x0 F.
Representative references disclosing resid or asphaltene air blowing equipment and methodology include U.S. Pat. No. 2,616,837 to Roediger; U.S. Pat. No. 2,627,498 to Firik et al; U.S. Pat. No. 2,861,939 to Biribauer et al; U.S. Pat. No. 2,889,296 to Morris et al; U.S. Pat. No. 3,462,359 to Fauber; U.S. Pat. No. 3,598,716 to Fauber; U.S. Pat. No. 3,751,278 to Alexander; U.S. Pat. No. 3,779,892 to Forster et al; U.S. Pat. No. 3,868,315 to Forster et al; U.S. Pat. No. 3,935,093 to Senolt et al; U.S. Pat. No. 3,989,616 to Pagen et al; U.S. Pat. No. 4,052,290 to cushman et al; U.S. Pat. No. 4,207,117 to Espenscheid et al; U.S. Pat. No. 4,283,230 to Clementoni et al; U.S. Pat. No. 4,332,671 to Boyer; U.S. Pat. No. 4,933,067 to Rankel; U.S. Pat. No. 4,975,176 to Begliardi et al; U.S. Pat. No. 5,228,977 to Moran et al; U.S. Pat. No. 5,320,739 to Moran et al; U.S. Pat. No. 5,932,186 to Romine et al; and U.S. Pat. No. 5,939,474 to Gooswilligen et al. Air blowing technology is commercially available under the trade designation BITUROX, for example.
In contrast to paving asphalt, the specifications for fuel grade petroleum resid that is burned as a fuel are much less stringent. The resid generally has a higher calorific value and better combustion characteristics compared to coal and petroleum coke, which is why resid has been added to coal and coke as an additive to improve calorific value and aid combustion. However, heavy resid with a low softening point temperature is difficult to store and/or transport without significant handling and packaging requirements. Over time, even when they initially may appear to be solid at ambient conditions, these low-softening-point-materials exhibit liquid flow characteristics. These materials have typically been transported as a semi-solid product, as a neat liquid product, or as a cutback liquid product. The semi-solid form must be shipped in a closed container to prevent leakage and spillage, is usually reheated prior to use, and the high cost, of packaging and handling the material in this manner usually limits application to relatively small volumes of product.
As a neat liquid product, heavy resid is maintained at elevated temperatures sufficient to keep the material in a liquid state. This method is also expensive and has limited practical application.
As a cutback liquid product, heavy resid is mixed with light aromatic hydrocarbon cutterstocks to maintain the mixture in a liquid state at lower temperatures. As a result, the lighter hydrocarbons with which the resid is blended are substantially downgraded in value.
A pelletized resid that remains solid would be free flowing and could be readily stored, packaged, transported and handled. Previous attempts at pelletizing resid with a low softening point temperature have relied on encapsulating the resid with a solid coating. Coating the resid complicates the encapsulating process, results in a compositionally heterogeneous product, adds cost due to the generally expensive nature of the coating material, is not always effective due to rupture or breakage of the coating and/or to dissolution of the coating by water if the coating is water soluble, and the coating can adversely affect the combustion characteristics of the resid. Representative references teaching various encapsulation apparatus and methodology include U.S. Pat. No. 3,015,128 to Somerville; U.S. Pat. No. 3,310,612 to Somerville; U.S. Pat. No. 4,123,206 to Dannelly; U.S. Pat. No. 4,128,409 to Dannelly; U.S. Pat. No. 4,386,895 to Sodickson; and U.S. Pat. No. 5,637,350 to Ross.
U.S. Pat. No. 4,931,231 to Teppo et al discloses a method for manufacturing discrete pellets of asphaltic material by flowing the asphaltic material in molten form as an elongated annular stream directly into cooling water to solidify and shatter the elongated stream into discrete solid particles. The particles formed as a result of shattering are not spherical and have undesirable flow and/or handling characteristics. For example, the particles may be dust-free when made, but because of any jagged edges, might result in formation of considerable dust upon handling.
U.S. Pat. No. 3,877,918 to Cerbo discloses apparatus for producing spherical glass particles by centrifugally projecting solid crushed glass particles into the draft tube of a bead furnace using a rotary receptacle. The rotary receptacle forms a cloud of evenly dispersed solid glass particles, which are directed upwardly into the expansion chamber of the furnace to heat and shape the glass-particles by surface tension into spheres.
The prior art does not appear to disclose a method or apparatus for making spherical petroleum resid pellets by feeding the resid in a molten state to a rotating prilling head, allowing the resid discharged from the prilling head to break into particles and form into spheres due to the surface tension of the molten resid as the particles pass by gravity through a high temperature zone, and then quenching the molten material in a cooling medium to solidify the particles in their substantially spherical form. Nor does there appear to be any prior disclosure of substantially spherical, compositionally homogeneous. (uncoated) petroleum resid pellets having a high softening point temperature, nor of a method or apparatus for making spherical resid pellets for ambient temperature storage and shipment for use in combustion processes as a fuel or fuel additive.
The present invention produces substantially spherical particles from a material such, as petroleum resid that is normally solid at ambient temperature, but can be liquefied at an elevated temperature. The present invention produces a compositionally homogeneous pelletized petroleum resid product suitable for ambient-temperature storage and shipment prior to an end use. The pellets are relatively hard and have a softening point temperature above 200xc2x0 F. so that they do not stick together at ambient storage and transportation temperatures. If the resid feedstock is not sufficiently hard, it can be hardened by oxidation with air at elevated temperature. The resid is prilled at molten temperatures using a rotating prilling head that discharges the molten resid into a high temperature vapor space. As the resid is thrown away from the prilling head and falls by gravity, it breaks into small pieces that form into spheres while liquid. After the spheres are formed in a liquid state, the pellets are cooled and solidified, for example, by passing the spheres through a water mist and collecting them in a water bath.
Broadly, the invention provides a process for pelletizing a petroleum resid. The process comprises (1) heating the resid to a temperature at which it is in a liquid state, (2) continuously feeding the molten resid to an inlet of a centrifugal prilling head comprising a plurality of radially arrayed discharge orifices in fluid communication with, the inlet, (3) rotating the prilling head to discharge the resid from the orifices into free space near an upper end of a pelletizing vessel having a diameter larger than a throw-away diameter of the discharged resid, (4) allowing the discharged resid to break apart and form into substantially spherical pellets in a high temperature zone of the pelletizing vessel at which the resid is liquid, and to fall downwardly into contact with a cooling medium in which the resid is insoluble and which is maintained at a temperature effective to cool/solidify the pellets, (5) withdrawing a mixture of the solidified pellets and the cooling medium from the pelletizing vessel, and (6) substantially separating the pellets from the cooling medium.
The invention also provides a prilling head assembly for a vessel for pelletizing a petroleum resid. The prilling head assembly is preferably mountable on the upper end of a pelletizing vessel for throwing feed material radially outward into an upper prilling zone in the vessel. The assembly includes: (1) a rotary union including a housing, a feed inlet, a rotatable pipe depending from the housing, a flow path between the feed inlet and an upper end of the rotatable pipe disposed within the housing, and a fluid tight seal between an exterior surface of the pipe and an opening in the housing; (2) a lower end of the rotatable pipe connected to a prilling head having a flow passage in fluid communication between an outlet from the-lower end of the rotatable pipe and a plurality of orifices radially offset from an axis of the rotatable pipe; (3) a support housing having a mount for attachment to the pelletizing vessel and upper and lower bearings adjacent respective upper and lower ends of the support housing for rotatably receiving the rotatable pipe; and (4) a drive wheel secured to the rotatable pipe. Preferably, the prilling head assembly further comprises a detachable coupling on the rotatable pipe between the rotary union and the upper bearing. The upper bearing is preferably mounted to the top flange, and the lower bearing to a lower bearing mount flange.
The mount in the prilling head assembly preferably includes a mounting flange and the support housing includes a fixed pipe with a larger inside diameter than the outside diameter of the rotatable pipe. The fixed pipe depends from the mounting flange. The prilling head assembly preferably includes a lower dust seal at a lower end of the fixed pipe adjacent an opening in a lower end panel located between the lower bearing and the prilling head, and an upper dust seal adjacent an opening in the mounting flange receiving the rotatable pipe. The support housing preferably includes a port for introducing inert gas into the annulus between the fixed pipe and the rotatable pipe.
The support housing preferably includes a top flange secured by a bracket in spaced. relation above the mounting flange. The upper bearing is secured to the top flange. The drive wheel can be conveniently disposed between the top flange and the mounting flange. The discharge orifices in the prilling head are preferably arrayed at a circumference of the prilling head in a plurality of vertically spaced upper and lower rows. The lower row or rows can be disposed at a smaller diameter from the axis of rotation of the prilling head than the upper row or rows. The prilling head preferably has a circumference tapered from an uppermost row of orifices to a lowermost row, and can be rotated at from about 100 to about 5000 rpm. The prilling head preferably has a diameter from about 2 inches to about 5 feet, the orifices a diameter from about {fraction (1/32)}-inch to about 1 inch and a production capacity of from about 1 to about 1000 lbs/hr of resid per orifice, the throw-away diameter from about 1 foot to about 15 feet, and the pellets a size range from about 0.1 mm to about 10 mm.
The cooling medium is preferably water, and the water bath is maintained in the pelletizing vessel at a temperature from about 40xc2x0 to about 190xc2x0 F. The water is preferably introduced into the pelletizing vessel as an inwardly directed spray, e.g. a fine mist, in a cooling zone above the bath to-at least partially cool the spherical pellets before they enter the bath. The slurry withdrawn from the pelletizing vessel is preferably no more than about 50xc2x0 F. warmer than the water introduced into the cooling zone. The process can also include the steps of collecting water from the separation step, and filtering, cooling, and recirculating the cooled water to the cooling zone.
The process can also include the step of venting vapor near an upper end of the pelletizing vessel and/or the step of heating an upper end of the pelletizing vessel to maintain a substantially constant temperature zone in the vicinity of the prilling head. The process can further comprise the step of transporting the recovered pellets at ambient temperature to a location remote from the pelletization vessel where the pellets are used for combustion, as a combustion improver or additive to coke and/or coal, in admixture with a cutterstock for fuel oil, or the like.
The petroleum resid fed to the heating step preferably has a penetration of essentially 0 and a softening point temperature from 200xc2x0 to 400xc2x0 F., more preferably having a-softening point temperature from about 230xc2x0 to about 350xc2x0 F. The resid is preferably obtained as the asphaltene-rich fraction from a solvent deasphalting process. The resid feed is preferably heated to a temperature from about 350xc2x0 to about 700xc2x0 F., and the pellets recovered from the separation can have a residual water content of from 0.1 to 10 weight percent. The process can also include burning the transported resid pellets, for example, as a combustion fuel, as an additive in the combustion of coal and/or petroleum coke or as a blend component with cutterstock in a fuel oil.
The process can further comprise the step of contacting a soft petroleum resid with air at a temperature from about 350xc2x0 to about 700xc2x0 F. for a period of time effective to reduce the penetration of the resid to essentially 0 and increase the softening point temperature to above 200xc2x0 F. to form a hard resid suitable for use as the resid feed in the heating step. The soft resid can be obtained as atmospheric tower resid or the asphaltene-rich fraction from solvent deasphalting of a petroleum residue, especially propane deasphalting. The air-contacting step is preferably for a period of time from about 2 to about 5 hours.
In another aspect of the invention, there is provided a process for making petroleum resid pellets from a soft petroleum resid. The process includes contacting a soft resid having a penetration greater than 0 and a softening point temperature below about 200xc2x0 F. with air at a temperature from about 350xc2x0 to about 700xc2x0 F. for a period of time effective to form a hard resid having a penetration of essentially 0 and a softening point temperature above 200xc2x0 F., and forming the hard resid into pellets. The process can also include burning the pellets as a fuel or fuel additive, for example.
In a further aspect of the invention, there is provided a pelletizer for making spherical pellets from a material such as petroleum resid which is normally solid at ambient temperature, but which can be liquefied at elevated temperature. The pelletizer includes an upright pelletizing vessel having an upper prilling zone, a hot sphere-forming zone below the prilling zone, a cooling zone below the sphere-forming zone, and a lower liquid cooling bath below the cooling zone. A prilling head is centrally disposed in the prilling zone, and is rotatable along a vertical axis. The prilling head has a plurality of discharge orifices for throwing the molten materially radially outwardly. A throw-away diameter of the prilling head is less than an inside diameter of the pelletizing vessel. A process line is provided for supplying the material to the prilling head. A vertical height of the sphere-forming zone is sufficient to allow liquid material discharged from the prilling head to form into a substantially spherical shape while in the liquid state. Nozzles can be provided for spraying liquid cooling medium, preferably water in the form of a mist, inwardly into the cooling zone to cool and solidify at least an outer surface of the spheres to be collected in the bath. Another line is provided for supplying water to the nozzles and the bath to maintain the relatively low temperature of the bath in the pelletizing vessel. A further line is provided for withdrawing a slurry of the pellets in the bath water. A liquid-solid separator is provided for dewatering the pellets from the slurry.
The pelletizer can also include an oxidation vessel for contacting a soft resid, having a penetration greater than 0, and preferably less than 100 dmm, with air at a temperature from about 350xc2x0 to about 700xc2x0 F. for a period of time effective to reduce the penetration of the resid to essentially 0 and to increase the softening point temperature to above 200xc2x0 F. to form a hard resid suitable for feed to the prilling head. The pelletizer can preferably further include a solvent deasphalting unit for obtaining the soft resid as the asphaltene fraction from solvent de-asphalting of a petroleum residue.
The discharge orifices of the prilling head are preferably arrayed at a circumference of the prilling head in a plurality of vertically spaced upper and lower rows wherein the lower row or rows are disposed at a smaller diameter from the axis of rotation of the prilling head than the upper row or rows. The prilling head can have a circumference tapered, either continuously or stepped, from an uppermost row at a relatively large diameter to a lowermost row at a relatively small diameter. In one alternative embodiment, the prilling head preferably comprises a plurality of rings of different diameter with orifices formed in an outer circumference of each ring, wherein the rings are secured to the prilling head in a descending fashion, each successively lower ring having a smaller diameter than the preceding ring. The pelletizer preferably has a drive for rotating the prilling head at from about 100 to about 5000 rpm wherein the prilling head has a diameter from about 2 inches to about 5 feet, and wherein the orifices have a diameter from about {fraction (1/32)}-inch to about 1-inch and a production capacity of from about 1 to about 1000 lbs/hr of molten material per orifice.
The cooling medium is preferably water and the pelletizer also preferably includes a cooler for maintaining the bath in the pelletizing vessel at a temperature from about 600 to about 190xc2x0 F. The aqueous bath preferably contains a minor amount of a non-foaming surfactant. The vessel preferably has a conical bottom containing the bath and a discharge at a lower end of the conical bottom for feeding the slurry into the withdrawal line. A filter can be provided for filtering water recovered from the liquid-solid separator, a cooler provided for cooling the filtered water and a recirculation line provided for recirculating the cooled water to the supply line.
A vent line is preferably provided for withdrawing vapor from the pelletizing vessel near an upper end thereof. A heater can also be provided for heating an upper end of the vessel to maintain a substantially constant temperature zone adjacent the prilling head, particularly during startup operations. In one preferred embodiment, a line is provided for introducing steam into the sphere-forming zone.
The liquid-solid separator preferably comprises a vibrating screen. The pelletizer can further comprise a conveyor belt for transporting the pellets from the vibrating screen to ambient temperature storage, packaging and/or shipment.
In another aspect, the present invention provides substantially spherical, homogeneous petroleum resid pellets suitable for combustion having a size range between 0.1 and 10 mm, a penetration of essentially 0, a softening point temperature from about 200xc2x0 to about 400xc2x0 F., preferably from about 230xc2x0 to about 350xc2x0 F., a residual water content of from 0.1 to 10 weight percent, and a sulfur content less than 10 weight percent. The resid pellets can comprise a hard resid produced by a process comprising contacting a soft resid with air at an elevated temperature for a period of time effective to convert the soft resid to hard resid, preferably from 2 to 5 hours.

Prilling head assembly for pelletizer vessel


An image forming apparatus used with a replaceable process cartridge mounted therein, including: a new article detecting unit which detects whether or not the mounted process cartridge is a new process cartridge; a detection storage unit which stores a number of times of detection that the new article detecting unit has detected that the mounted process cartridge is a new process cartridge; and a type determining unit which determines a type of the mounted process cartridge, based on the number of times of detection stored in the detection storage unit, when the new article detecting unit has detected that the mounted process cartridge is a new process cartridge.

1. Field of the Invention
The present invention relates to an image forming apparatus used with a replaceable process cartridge mounted therein.
2. Description of the Related Art
Conventionally, in an image forming apparatus used with a process cartridge mounted therein, when the residual amount of toner filled in the process cartridge decreases, a notification is sent to a user to replace the process cartridge with a new process cartridge.
At this time, in order to correctly detect that the residual amount of toner decreases, for instance, the amount of consumed toner is accumulated whenever images are formed, then the toner consumption amount is compared with the capacity of the toner (reference value for determining 'toner empty') which has been stored in an image forming apparatus in advance, and then the residual amount is considered as decreased (toner empty state) when the consumption amount approaches the amount of the toner stored in the image forming apparatus (refer to JP-A-2001-80163 (for instance, after section [0020]).

Image forming apparatus to detect a new process cartridge


A power-shiftable transmission, in particular an automatic transmission for a vehicle, which comprises a plurality of frictional shifting elements and at least one interlocking shifting element (A, B, C, D, E) and a plurality of gearwheels which can be engaged in a power flow by the shifting elements (A, B, C, D, E). In order to engage a gear step, at least two associated shifting elements (A, B, C, D, E) are engaged and at least one interlocking shifting element (B), as a shifting element (B) to be engaged, is associated with a gear step to be engaged with a supporting gear.

For example from the document EP 0 434 525 A1 an automatic multi-gear transmission for vehicles is known, which comprises a number of planetary gearsets which are shifted by means of frictional elements such as clutches and brakes and are usually connected to a starting element such as a hydraulic torque converter or a fluid coupling with a protective action and which is optionally provided with a bridging clutch. However, such automatic transmissions have the disadvantage that all their shifting elements are in the form of frictional disk clutches or disk brakes, which take up a lot of space and are cost-intensive.
Furthermore, from the document DE 102 44 023 A1 a transmission is known, which comprises a plurality of shifting elements and a number of shiftable gearwheels which, by means of the shifting elements, can be engaged in a power flow, wherein to obtain a gear in each case at least one of the shifting elements is closed. The shifting elements to be engaged for upshifts are in the form of frictional shifting elements and the shifting elements which, in each case, are those only one of which has to be disengaged for upshifts, are in the form of shape-interlocking shifting elements. Owing to the numerous frictional shifting elements used, drag losses in the known transmission and also its costs and space occupation are high.


A liquid level controller including a pilot valve switchable between snap and throttle modes. A displacer translates changing liquid level in a tank into movement that is transferred to the pilot valve which will provide output gas to a control valve to allow or to prevent the discharge of fluid from the tank. The pilot valve has a throttle supply inlet and a snap supply inlet and a single output passage. When the pilot valve is in the throttle mode, the snap supply inlet is a vent passage and when the pilot valve is in the snap mode, the throttle supply gas inlet is a vent passage.

The present invention relates generally to a pilot valve and more specifically to a pilot valve that is selectively switchable between modes of operation.
For example, as is known in the art, pilot valves are used in a number of different industries, typically to control process conditions or parameters, by controlling the operation of a process control unit, such as a process control valve. Numerous industries utilize process control valves to control the rate of flow of liquid and to control the level of liquid in tanks and vessels. The process control valves in many cases are operated with a control signal, which may be, for example, a pneumatic signal transmitted from a pilot valve. In such a case, the liquid level in a tank or other vessel may be sensed with a float or other element which moves when the liquid reaches a certain level. Movement of the float will actuate a control device, such as a pilot valve, which will send a signal to the process control valve to open or close the process control valve to either allow flow of liquid from the vessel or to prevent flow therefrom.
In the oil and gas industry, liquid level controllers may be used to control the level of oil, water or other liquids in a tank or other vessel. Liquid level controllers may include a float, or displacer placed inside the tank. When the liquid level in the tank is such that it engages the displacer, the displacer will move as the level of the liquid changes. The changes in the liquid level are transmitted to a pilot valve which will signal the process control valve to either open or close in response to the changing liquid level in the tank which will either allow flow or stop flow from the tank.
The pilot valve may be a pneumatic pilot valve to which a supply gas is provided. The pilot valve will direct the supply gas to the process control valve depending upon the level of liquid in the tank and the process control valve will open or close depending on the signal received from the pilot valve. When the process control valve is a pressure to open valve, the pilot valve will modulate output gas to the control valve which will open the control valve. Liquid level controllers may be referred to as direct and throttle in operation if an increase in the level in the tank results in a proportional increase in outlet pressure from the pilot valve to the process control valve. In such a case the process control valve may move from closed to partially open and ultimately to fully open or anywhere in between the fully open and fully closed positions since the gas pressure supplied to the process control valve from the pilot valve will vary.
When the pilot valve is in snap mode, the pilot valve provides a sudden increase in output pressure, or a sudden decrease to the process control valve so that the control valve will open fully, or close fully, almost immediately. For example, in a direct snap mode, when the level of liquid in the tank increases and moves the float to a predetermined level, there will be a sudden increase in output pressure from the pilot valve which will cause the pressure to open process control valve to move almost immediately from the fully closed to a fully open position to discharge liquid from the tank. When the liquid level falls to a preselected lowermost level, a sudden decrease in output pressure from the pilot valve will occur, which will cause the process control valve to move from the fully open to the fully closed position.
Liquid level controllers are available both in throttle and snap and there is some art that discusses pilot valves that are convertible from the snap to the throttle modes with connection changes, and other modifications. However, those devices may require excessive manipulation in order to change from snap to direct and vice versa, which can be time-consuming and undesirable. Thus, there is a need for a liquid level controller that includes a pilot switch or pilot valve that is selectively switchable quickly and efficiently from a snap to a throttle mode and that can be adjusted to desired sensitivities.

Liquid level controller and pilot switch


An x-ray system acquires medical images stored as an array of pixel values. Bright regions in the image produced by collimation or protective devices on the patient are automatically detected and filled with dark pixel values to reduce glare and improve the readability of the image. Automatic detection is achieved on a down sampled copy of the image in which edges of bright background regions are detected. The bright background regions in the down sampled image are filled with dark pixel values and an up sampled copy of this filled image is merged with the original image to produce the final image.

The field of the invention is medical imaging, and particularly, the processing of digitized medical images.
There are a number of medical imaging systems in use today which produce images in the form of digitized data arrays. Such systems may use x-rays, ultrasound, magnetic resonance, positron emission, or gamma ray emission as the modality for acquiring the image data. Regardless of the modality used to acquire it, once the image is digitized as an array of pixel intensity values, it can be processed using filters and image enhancers to improve the diagnostic quality of the image.
While the field of view of the imaging system can be controlled during image acquisition to focus on the anatomy of interest to the diagnostician, sometimes considerable background is included in the image. If the background is very bright, it can be very distracting and a hindrance to an accurate reading of the image. For example, x-ray images are often acquired with collimators placed on the machine or the patient to limit the amount of radiation reaching unintended anatomical regions. Collimators basically reduce the amount of radiation reaching the area shadowed by them. As a result, the region covered by the collimators is highly attenuated and appears bright on the final image. When such an image is viewed on a view box by a radiologist, the bright areas in the image can be quite significant and hence create a glare. This glare is very discomforting to the radiologist and can affect adversely the film reading ability of the radiologist. If the bright areas caused by the collimation can be eliminated from the image, the accuracy of reading the film can be improved.
Methods previously used to detect and remove bright background regions from medical images are either very computationally expensive, not very robust, or require considerable manual input. Such methods are described by Jiebo Luo, et al. "Collimation Detection For Digital Radiology", SPIE Vol. 3034 (1997) and the publications referred therein.

Automated removal of background regions from radiographic images


A method and apparatus is provided for on-the-fly calibration of and correction for time interleave error, including generation of correction data associated with an interleave corrector employed by a system for converting a time-domain input stream, corresponding to samples acquired from an interleaved system of digitizers having impairment due to interleave mismatch, to a time-domain output stream. The method includes determining at least one time-domain acquisition segment; determining at least one frequency-domain acquisition segment; determining at least one frequency-domain block acquisition segment, whereby the frequency-domain block acquisition segment comprises a block of tone values; determining the suitability of the frequency-domain block acquisition segment for use in the generation of adjusted correction data; determining a block dominant tone segment from the frequency-domain block acquisition segment; and determining a block impairment transfer column vector in accordance with the block dominant tone segment and the frequency-domain block acquisition segment.

The present invention relates generally to the operation of measurement instruments. More specifically, the invention relates to measurement instruments consisting of analog-to-digital converters (ADCs) which are used to sample and digitize an analog signal, converting the analog signal to a sequence of values whose magnitude represents the voltage of the signal and the time location in the sequence represents when the signal was sampled. Furthermore, the present invention relates to digitizing systems, which consist of multiple, interleaved ADCs.
Systems used to digitize analog signals utilize ADCs that sample an analog signal at a time specified by a sample clock that is fed to the ADC. On prescribed rising and/or falling edges of this sample clock, the ADC samples the analog signal providing a digital value at its output. This digital value is typically stored in a memory of some sort for later use.
Waveform digitizing systems such as digital oscilloscopes are used by scientists and engineers to build ever faster electronic equipment. Because the speed of electronic equipment continues to increase, there is an ever increasing demand for faster waveform digitizing systems. For very fast waveform digitizing requirements, the speed demands placed on waveform digitizing systems exceed the physical capabilities of ADCs. In other words, ADCs cannot sample signals fast enough to meet the demands of the electronics industry and the scientific community.
In order to overcome this physical limitation and make waveform digitizing systems that sample signals at a higher rate, a technique called time interleaving is often used. Interleaving involves the usage of multiple ADCs in a waveform digitizing system. These ADCs are used in a manner in which generally all ADCs sample at the same rate, but they sample the signal at different times. For example, a waveform digitizing system utilizing two ADCs could sample a signal at an effective sample rate equal to the sum of each ADC sample rate if each ADC took every other sample of the signal. At the end of such a waveform acquisition, the resulting array of data points would contain data where half of the data were generated from one ADC and the other half from the other. More specifically, every other point in the resulting acquired signal would have been acquired by one of the ADCs while the remaining points were acquired by the other. This method of interleaving ADCs has been used with great success.
While bandwidth and sample rates of waveform digitizer systems are perhaps the most important qualities, signal fidelity is equally important. In other words, the waveform digitizing system is expected to produce a digital representation of the sampled analog waveform with a high degree of accuracy. Said differently, the digitizing system is expected to faithfully reproduce an image of the analog signal being digitized. In systems utilizing a single ADC to digitize a waveform, the problem of faithful reproduction of the analog signal reduces to the solution of engineering problems in the design of the digitizer system involving front-end non-linearity and noise, ADC integral and differential non-linearity, sample clock accuracy and stability etc. In interleaved systems, these problems are exacerbated by the use of multiple digitizers.
In interleaved systems, to avoid degradation, the signal path to each digitizer must have identical characteristics. Any time delay, attenuation or gain applied differently in the path to each digitizer will result in noticeable degradation of the quality of the acquired signal. The same must be said for the sample clock delivery to the digitizers. Any variation in the timing from digitizer to digitizer will reduce the signal quality. Furthermore, each digitizer or ADC in an interleaved system will have characteristics that may vary from the other digitizers, the most important characteristic being frequency response. Differing frequency response manifests itself as a mismatching gain and time, or phase delay of the signal at various frequencies. Differences in frequency response are more likely at higher frequencies where digitizer matching becomes more difficult. As mentioned previously, high bandwidth is another feature desired of digitizing systems, and high bandwidth means that high frequency signals or signals with components at high frequencies are being digitized. This means that matching digitizer frequency response characteristics is a particular problem in high bandwidth systems that are used to digitize high frequency signals.
The current state of technology deals with these problems in several ways. In the design of a digital oscilloscope or other waveform digitizing system, good engineering practice is applied to ensure that the sample clock does not jitter and is delivered accurately to each digitizer. Furthermore, the paths to each digitizer are carefully designed and routed to provide as good signal path matching as practically possible. Finally, demands are placed on the design of ADC chips to meet stringent frequency response specifications.
Additionally, ADCs are sometimes built with controls provided to precisely adjust the offset, gain, and sample clock delay to the ADC. Some systems dynamically measure and adjust the offset, gain and delay characteristics of the individual digitizers in the interleaved system using internal calibration signals and hardware controls. Even with the provision of these controls, it is still impossible to adjust for gain and delay characteristics of the digitizers that vary with frequency.
An effect of mismatched digitizers is the creation of spurs that degrade signal fidelity and effective number of bits (ENOB).
To deal with frequency dependent interleaved digitizer mismatch, several methods have been proposed.
In U.S. Pat. No. 7,978,104, filed Jun. 21, 2007 titled "Compensation of Mismatch Errors in a Time-interleaved Analog-to-digital Converter" to Johansson, a time-domain polyphase filter is disclosed for performing interleave correction.
In U.S. Pat. No. 6,567,030, filed Feb. 27, 2002, titled "Sample Synthesis for Matching Digitizers in Interleaved Systems" to Pupalaikis, a feedback structure is employed for performing interleave correction.
In U.S. Pat. No. 6,819,279, filed Mar. 5, 2003, titled "Method and Apparatus for the Recovery of Signals Acquired by an Interleaved System of Digitizers with Mismatching Frequency Response Characteristics" to Pupalaikis, a frequency-domain correction method preferably employing the discrete Fourier transform (DFT) is disclosed.
In U.S. Pat. No. 7,386,409, filed Nov. 16, 2005, titled "Method and Apparatus for Artifact Signal Reduction in Systems of Mismatched Interleaved Digitizers" to Mueller, et al, a time-domain, filter based system for directly targeting spur tones is disclosed.
These methods attempt to compensate for error due to interleave mismatch, but require a priori knowledge of the digitizer mismatch characteristics. This a priori knowledge can be gained by factory calibration with reference signals or during internal instrument calibration utilizing built in standards. Factory calibration is possible in some instruments such as oscilloscopes, but this calibration degrades over time due to temperature and drift. Internal calibration signals are generally expensive, especially for very high frequencies and internal calibration must generally be performed with the digitizers offline.
What is needed are methods of determining correction information for use with, for example, the aforementioned methods utilizing user signals applied to the system during normal operation.
In U.S. Pat. No. 7,741,982, filed Feb. 4, 2005, titled "Estimation of Timing Errors in a Time-interleaved Analog-to-digital Converter System" to Johansson, et al., a method is provided for specifically estimating timing errors for incorporation into a correction, but there are limitations on signals usable for estimation of timing errors that are onerous and not generally applicable to time-interleaved systems and anyway only addresses timing error or delay match.
Some methods include U.S. Pat. No. 8,441,379, filed Feb. 11, 2009 titled "Device and Method for Digitizing a Signal" to Eklund et al. This method provides for on-the-fly correction for interleave error but pertains to sub-banded acquisition systems containing overlapping sub-bands and does not pertain to the general time-interleaving problem.
In U.S. Pat. No. 8,307,248, filed Jun. 30, 2006 titled "Method and a System for Estimating Errors Introduced in a Time-interleaved Analog-to-digital Converter System" to Johansson et al, the inventors provide means for on-the-fly calibration of an interleave correction system using unknown input signals, but the method is an iterative, loss minimization method pertaining to gain, offset and delay mismatch. Thus, a loss function representing a difference between a reference signal and remaining signals is employed. While gain, offset and delay mismatch are certainly important criteria in interleaved digitizer matching, the frequency dependent aspects are also of importance and the invention does not address this. Furthermore, the loss function is such that it is used in an estimation that minimizes the differences between a reference and remaining signals and does not directly address spur tones arising from interleave mismatch.
The inventors of the present invention have recognized that these methods each suffer from combinations of problems including lack of handling of frequency dependent digitizer mismatch as occurs from general frequency response mismatch, lack of directly targeting spurious tones arising from interleave mismatch, requirements for different topologies such as sub-banded architectures, and iterative non-linear equation solving methods.
What is needed is a system for on-the-fly correction for interleave mismatch that provides for correction of frequency dependent effects and directly targets spurious tones arising from said mismatch. What is further needed is a system that is capable of correction based on user supplied signals.

Method and apparatus for correction of time interleaved ADCs


An electronically calibrated sensor (100) includes a sensing element (102) with an output coupled to a signal conditioning circuit (104). The signal conditioning circuit (104) is adapted to be highly computationally efficient and operable for compensating for temperature and part-to-part variation on the sensing element output for providing a useable sensor output signal. The signal conditioning circuit (104) includes an analog-to-digital/digital-to-analog (ADC/DAC) conversion device (112). The ADC/DAC (112) is operable to perform both analog input signal analog-to-digital conversion and digital output signal digital-to-analog conversion. The ADC/DAC (112) is further adapted to provide analog control signals to input signal conditioning circuits (104, 106).

The world is full of sensor devices for detecting physical phenomena and for providing a signal in response to the phenomena. For example, a thermometer converts the physical condition temperature into a visual signal, a height of mercury in a glass column. Another example of a temperature-sensing device is a thermocouple which converts the physical condition temperature into an electrical signal. To be useful the sensor signal has to be understood to correspond with a particular physical phenomenon. For example, the thermometer has lines on the glass column to indicate the degrees of temperature. The lines, of course, have to be in the right locations on the glass column to have meaning, and the process by which the lines are properly located is known as calibration. During calibration the sensor is subjected to a known physical condition or conditions and its response is observed. Observing the response of the sensor to the known conditions allows one to predict the sensor response for a wide range of conditions.
Pressure sensors are devices that provide a signal indicative of pressure, for example, the amount of air pressure within a tire. As with other types of sensors, pressure sensors require calibration to be useful. A specific kind of pressure sensor known as a piezoresistive pressure sensor provides a voltage signal indicative of pressure. The piezoresistive pressure sensor poses a number of problems in application. For example, the piezoresistive sensing element provides a relatively low level voltage signal. In addition, the piezoresistive sensing element may provide a signal that is sensitive to changing temperature and that does not change linearly with changing pressure. Moreover, the signal voltage characteristic from one sensing element to another sensing element may not be consistent. Therefore, special signal conditioning circuitry is required for a sensor product that provides a high level sensor output that is sufficiently accurate across a wide range of operating temperatures and pressures. Importantly, the device has to be capable of mass production, at low cost and with a high degree of part-to-part repeatability.
Most low cost signal conditioning approaches use analog circuits that are adjusted during a calibration process. For example, it is known to use amplifier circuits coupled to resistor networks. In one such application, the resistor network includes a number of resistive elements coupled by fusible links. Though limited in the degree of adjustment available, various resistive values may be established for providing an acceptable output from the amplifier network. In another application, the resistor network includes laser trimmable resistive elements. During a calibration process, the resistive elements are trimmed using a laser to achieve the correct resistive values to provide an acceptable output from the amplifier network. In either application access to the circuit may be required during processing in order to fuse links and/or laser trim components. Hence manufacturing processing options are limited. Also, in certain applications offset, sensitivity and linearity may be difficult to compensate for independently. Furthermore, processing activities following calibration may introduce error that can not be corrected in the final product. And, the laser trim process requires expensive processing hardware and suffers increased cycle time.
An alternative design provides for electronic calibration of the sensing element. Sensors adapted for electronic calibration have included a microprocessor coupled to the sensor element via suitable signal conditioning circuitry and to a memory in which a calibration method is retained. During processing, the sensing element is tested under various known-operating conditions. Calibration values are established and stored in the memory. In operation, the microprocessor in conjunction with the method and calibration values operates to provide a sensor output. Other implementations use digital signal processors (DSPs) to perform the required calculations on digitized values of the sensor element output.
Systems implemented using digital technology generally consist of 1) front-end analog signal conditioning, 2) analog-to-digital conversion, 3) digital processing, 4) digital-to-analog conversion and 5) back-end analog signal output drive. The front-end conditioning often consists of digitally programmable gain and offset functions, in which the offset signal is usually generated by some form of digital-to-analog converter (DAC). If the signal conditioning circuit also includes some form of disturbance variable compensation, the disturbance variable signal is also front-end conditioned and digitized.
It is possible, then, that the sensor signal conditioning circuit may require at least two analog-to-digital converters (ADCs). One to digitize the sensing element output and one to digitize the disturbance variable signal. Front-end signal conditioning of the sensing element output and disturbance variable may require DAC devices to provide the appropriate control signal to the conditioning circuits. Also, the digitized corrected sensor output requires conversion back to analog. Thus, the signal conditioning circuit may require two ADCs and as many as three DACs. These devices are die area intensive in integrated circuit implementations, particularly in that the accuracy of ADCs and DACs is directly related to the physical size of the matching components (capacitors, resistors, transistors, etc.) used to make up the devices. The substantial amount of die area required to implement the several analog-to-digital and digital-to-analog operations has hampered the use of digital technology in sensor signal conditioning applications.
The typical successive approximation implementation of an ADC includes at least one DAC. It has been recognized in the art that where both analog-to-digital and digital-to-analog conversion (A/D and D/A, respectively) are required it may be possible to reuse the DAC in the ADC device. Examples of this architecture fail to address circuit implementations requiring numerous A/D and D/A conversion operations such as required in the sensors signal conditioning circuit, which includes several D/A outputs and several A/D inputs.
Therefore, there remains a need for an electronically calibrated sensing device using digital signal processing that makes efficient use of ADC and DAC devices so as to minimize the number of such devices in the signal conditioning circuit. The sensing device preferably includes a signal processing circuit that provides for digital calibration of the sensor and its analog input conditioning circuits. Essentially, a more silicon efficient and accurate approach is needed.

Signal conditioning circuit including a combined ADC/DAC, sensor system, and method therefor


A method and apparatus for automatically controlling partial pressure of oxygen in the breathing loop of a rebreather diving system. A diver may adjustably select a control parameter to maintain partial pressure of oxygen at a setpoint that varies with ambient pressure and is within a range between a maximum safe partial pressure of oxygen at depth and a minimum safe partial pressure of oxygen for the purpose of biasing the performance of the rebreather either towards minimizing gas venting from the rebreather breathing loop or minimizing decompression time. A method and apparatus for managing and monitoring the use of dive resources in comparison with a target dive time specified by the diver, calculating and indicating remaining dive time based on dive resource values and calculating and indicating dive resource values required to meet preselected dive resource end values and dive requirements.

1. Field of the Invention
The present invention relates generally to diving systems and more particularly to systems and apparatuses for controlling and monitoring rebreather systems and managing the use of dive resources.
2. Background Discussion
Self-contained breathing apparatuses used for underwater diving traditionally are categorized either as open circuit systems or rebreather systems. Open circuit systems are relatively simple and well understood in the art but are inefficient and typically require a large breathing gas supply to provide a reasonable dive time. Each breath inhaled by a diver from art open circuit system is exhaled to the surrounding environment, wasting any oxygen in the breathing gas that is not metabolized by the diver during the respiration cycle.
Rebreather systems recycle each breath exhaled by a diver by removing the carbon dioxide generated by the diver and replacing the oxygen consumed by the diver during the respiration cycle. Essential components of rebreather systems are a breathing loop comprising a diver's lungs, a mouthpiece, breathing gas supply, a solenoid or flow valve adapted to add breathing gas to the breathing loop, a pressure regulator for the breathing gas supply, a scrubber canister adapted to remove exhaled carbon dioxide, a counterlung, a valve adapted to vent or purge gas from the breathing loop if the total gas pressure in the breathing loop exceeds a preselected pressure value, flexible, gas-impermeable hoses connecting the various components and uni-directional check valves to control the flow of breathing gas through the loop. Rebreather systems may father be categorized as semi-closed circuit systems or closed circuit systems, with each type of rebreather system comprising additional suitable components. Examples of semi-closed circuit and closed circuit rebreather breathing loops are shown in, for example, U.S. Pat. Nos. 5,503,145 and 6,302,106.
In a semi-closed circuit system known in the art, the breathing gas supply commonly comprises one high pressure cylinder containing an oxygen-enriched gas mixture, which typically is introduced to the breathing loop at a preselected, constant flowrate to replace oxygen consumed during a dive.
In a closed circuit system known in the art, the breathing gas supply commonly comprises one high pressure cylinder containing pure oxygen. A closed circuit system known in the art would additionally typically comprise one or more oxygen sensors adapted to measure the partial pressure of oxygen in the breathing loop during a dive and a computer processor adapted to control the solenoid for the purpose of adding oxygen to the breathing loop as needed to maintain the oxygen partial pressure above a minimum, viable value. A closed circuit system also commonly comprises a high pressure cylinder containing an inert gas or mixture of inert gases, also referred to as diluent gases, that may be added to the breathing loop via a solenoid and pressure regulator to prevent the counterlung from collapsing due to increasing ambient pressure.
A primary consideration in the design and use of semi-closed and closed circuit rebreather systems is the minimization of the risks of hypoxia, in which the diver is deprived of a life-sustaining oxygen supply, and hyperoxia, which occurs when the diver breathes unsafe elevated oxygen levels. Hypoxia can render a diver unconscious and cause drowning. Hyperoxia may lead to oxygen toxicity, which can have severe physiological effects that can lead to the death of the diver. Oxygen toxicity can manifest as either central nervous system (CNS) oxygen toxicity or pulmonary oxygen toxicity.
Hypoxia and hyperoxia are understood as depending on the partial pressure of oxygen in the breathing gas loop. The partial pressure of oxygen is equal to the product of the total pressure of the gas mixture and the concentration, or fraction, of oxygen in the gas mixture, also expressed as PPO2=Ptotal×FO2. Total gas pressure in the breathing loop increases with ambient pressure, which increases by one atmosphere, or bar, per each ten meters of depth. Accordingly, at a constant oxygen concentration, the partial pressure of gas in the breathing loop increases as depth increases and decreases as depth decreases.
Hypoxia occurs when the partial pressure of oxygen in the breathing loop is less than 0.21 bar, which is the ambient partial pressure of oxygen in the atmosphere at sea level. The minimum life-sustaining value of partial pressure of oxygen is 0.16 bar. Maintaining the partial pressure of oxygen in the breathing loop above 0.21 bar will minimize decompression time for the diver. However, pulmonary oxygen toxicity can result from prolonged exposure to oxygen partial pressures above approximately 0.5 bar, and CNS oxygen toxicity becomes a significant risk when the partial pressure of oxygen in the breathing loop is greater than 1.6 bar.
In semi-closed circuit systems, the oxygen-enriched gas mixture is usually added to the breathing loop at a constant rate selected to maintain the partial pressure of oxygen in the breathing loop between 0.21 bar and 1.6 bar based on the estimated oxygen consumption profile of the diver during a dive. However, the rate of addition typically is not automatically adjusted during a dive in response to the actual partial pressure of oxygen in the breathing loop, even though a diver's rate of oxygen consumption, and therefore the oxygen concentration in the breathing loop, may deviate considerably from the rate of consumption estimated prior to the dive. Inequality between the rate of addition and rate of consumption of oxygen can result in depletion or accumulation of oxygen in the breathing loop. Therefore, transient states may occur and persist in semi-closed systems during which the breathing loop contains either hypoxic (i.e. less than 0.21 bar) or hyperoxic (i.e. greater than 1.6 bar) oxygen levels.
Closed circuit rebreather systems provide monitoring and adjustable control of the partial pressure of oxygen in the rebreather breathing loop during a dive. In recognition of the safety and performance concerns outlined above, closed circuit rebreather systems will usually be configured to maintain the partial pressure of oxygen in the breathing loop at a preselected value between 0.21 bar and 1.6 bar for the purpose of reducing the risk of hypoxia and hyperoxia. However, the sensors and automated control systems in closed circuit systems are susceptible to malfunctions, which can lead to hypoxic or hyperoxic oxygen levels in the breathing loop. Additionally, the use of pure oxygen in closed circuit systems creates handling and cleanliness issues with regard to the breathing gas supply.
A further disadvantage of semi-closed circuit and closed circuit systems is that excessive venting of gas from the breathing loop may occur. Semi-closed circuit systems are inherently inefficient because the fixed rate of addition of the oxygen-enriched gas mixture to the breathing loop may exceed the diver's rate of oxygen consumption and cause continual venting or purging of gas from the breathing loop to maintain total gas pressure in the breathing loop below a threshold value.
In closed circuit systems, excessive venting may occur during the ascent phase, during which ambient pressure, and correspondingly total gas pressure and partial pressure of oxygen in the breathing loop, decrease. For example, if the preselected control value for oxygen partial pressure in the breathing loop is set close to 1.6 bar for the purpose of minimizing the diver's decompression time, the closed circuit rebreather control system will increase the addition of oxygen to the breathing loop to compensate for the decrease in partial pressure of oxygen that results from the decrease in ambient pressure. However, the increased volume of gas added to the breathing loop will be vented to maintain total gas pressure in the breathing loop below a threshold value.
The rate of venting of unutilized breathing gas from semi-closed circuit and closed circuit systems may be less than typically experienced with an open circuit system but may nonetheless be sufficient to reduce total dive time or necessitate the use of a larger gas supply to accommodate decompression time during ascent. Additionally, the venting of gas from the breathing loop creates bubbles that may, for example, startle marine life that the diver is attempting to observe, visibly indicate the presence of the diver to observers on the surface or have other undesirable effects.
In view of the limitations of rebreather systems brown in the art, a need exists for a rebreather system that provides adjustable control over the partial pressure of oxygen in the breathing loop as well as control over the volume of gas in the breathing loop, and therefore the rate of gas venting from the breathing loop. Such a system would also desirably be free of the disadvantages of using pure oxygen as a breathing gas supply.
Dive monitoring systems known in the art continuously measure, calculate and display parameters such as remaining gas supply, decompression time, partial pressure of oxygen in the breathing loop and depth during a dive to keep a diver informed of the dive profile. These devices are typically configured to display the current status or value of one or more parameters corresponding to dive resources and may also be adapted to assist the diver in pre-planning the dive based on end-of-dive requirements. There is a need for a dive monitoring system configured to continuously inform the diver of remaining dive time based on current dive resources and their usage, inform the diver of the dive resources required based on the dive plan specified by the diver and automatically adjust partial pressure of oxygen in the breathing loop as needed to make it possible for a diver to achieve a target dive time.

Rebreather control parameter system and dive resource management system


A two-photon stimulated emission depletion composite microscope, comprising a two-photon imaging unit (100) and an STED imaging unit (200), wherein the two-photon imaging unit (100) can be used for a relatively thick sample, and the STED super-resolution imaging unit can be used for a region of interest on a surface of a sample, and the microscope makes light spots generated by an excitation light and a depletion light after being focused by an objective lens (OL) accurately coincide in a three-dimensional distribution. The two-photon stimulated emission depletion composite microscope (10) integrates two functions of STED imaging and two-photon imaging and makes the two types of light spots generated by an excitation light and a depletion light after being focused by an objective lens accurately coincide in a three-dimensional distribution, thereby providing a powerful tool for cutting-edge biomedical research.

The imaging resolution of optical super-resolution microscopy has exceeded the limit derived from optical diffraction, and the imaging resolution thereof is much higher than that of traditional optical microscopes, which has been a research hotspot in recent years and various types of optical super-resolution microscopes have emerged. The stimulated emission depletion (STED) microscopy is the first far-field optical microscopy that breaks through the optical diffraction limit directly, which is based on the laser confocal microscopy imaging. As compared to other types of super-resolution microscopy, the stimulated emission depletion microscopy has relatively fast imaging speed, and can be used in live cell imaging, and can detect finer structures in biomedical research.
The STED imaging has very high degree of resolution, but has shallow imaging depth. The two-photon microscopic imaging has poor degree of resolution but has deep imaging depth due to the use of a near-infrared light. However, there has been no technical report of a composite microscope integrating both functions of STED imaging and two-photon imaging, wherein, for thicker samples, the two-photon imaging can be used, and for regions of interest on the surface of samples, the STED super-resolution imaging can be used.

This patent is subject to a terminal disclaimer.

Composite microscope employing two-photon excitation and stimulated emission depletion techniques

Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences

Suzhou Guoke Medical Technology Development (Group) Co., Ltd.


A system includes a pump configured to pressurize a first fluid, and a pressure exchanger (PX). The PX is configured to receive a second fluid, to receive the pressurized first fluid, and to utilize the pressurized first fluid to pressurize the drilling mud for transport to a well.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
The subject matter disclosed herein relates to fluid handling, and, more particularly, to systems and methods for pressurizing and pumping drilling fluids ("drilling mud") to a drilling rig to be sent down a drill string.
Drilling mud is used in oil and gas drilling applications to provide hydraulic power, cooling, well control (e.g., using the weight and pressure of the mud to control the well, which may encounter pressurized fluids in the formation), to cool the drilling head and to carry cuttings away from the cutting head. In drilling applications, drilling mud is typically pressurized (e.g., 5,000 to 7,500 PSI or more) and pumped using a mud pump to a drilling rig and down the drilling pipe to a cutting head via a drill string. The used drilling mud and the cuttings then flow back up through an annulus between the drilling pipe and a casing. However, in some embodiments, the drilling mud flow down through the annulus between the drilling pipe and the casing and then up the drilling pipe to the rig.
Drilling mud may include cuttings, clay, various minerals, aggressive chemicals, salts, and miscellaneous other components that may place stress on the mud pump, and in some cases shorten the lifespan of the mud pump. Accordingly, when selecting a mud pump, durability may be a driving factor.

System for using pressure exchanger in mud pumping application


A lithium secondary battery of the present invention comprises a positive electrode; a negative electrode; a separator interposed between the positive and negative electrodes; and an electrolyte on the separator, wherein the electrolyte includes a non-aqueous organic solvent, a lithium salt, and a linear polymer having P═O bonds. The electrolyte improves the swelling characteristics of lithium secondary batteries. A lithium secondary battery with the electrolyte and a method for preparing the electrolyte and battery is described.

(a) Field of the Invention
The present invention relates to a lithium secondary battery, and a method of preparing the lithium secondary battery. More particularly, the present invention is directed to reducing swelling in a lithium secondary battery by using an electrolyte in accordance with the present invention.
(b) Description of the Related Art
The use of portable electronic instruments is increasing as electronic equipment gets smaller and lighter due to developments in high-tech electronic industries. Studies on lithium secondary batteries are actively being pursued in accordance with the increased need for a battery having high energy density for use as a power source in portable electronic instruments. Such a lithium secondary battery, having an average discharge potential of 3.7 V (i.e., a battery having substantially a 4 V average discharge potential) is considered to be an essential element in the digital generation since it is an indispensable energy source for portable digital devices such as cellular telephones, notebook computers, camcorders, etc. (i.e., the "3C" devices).
There has been extensive research on effective safety characteristics of batteries, such as the ability to prevent overcharge. When a battery is overcharged, an excess of lithium ions is deposited on the positive electrode, and an excess of lithium ions is inserted into the negative electrode which makes the positive and negative electrodes thermally unstable. An eruptive explosion may occur from the decomposition of the electrolytic organic solvent, and the thermal runaway that occurs causes serious safety concerns for batteries.
To overcome the above problems, it has been suggested that an aromatic compound such as an oxidation-reduction additive agent ("redox shuttle") be added to the electrolyte. For example, U.S. Pat. No. 5,709,968 discloses a non-aqueous lithium ion secondary battery to prevent thermal runaway resulting from an overcharge current by using a benzene compound such as 2,4-difluoroanisole. U.S. Pat. No. 5,879,834 discloses a method for improving battery safety by using a small amount of an aromatic compound such as biphenyl, 3-chlorothiophene, furan, etc. which is polymerized electrochemically to increase the internal resistance of a battery during unusual overvoltage conditions. Such redox shuttle additives increase the temperature inside the battery early due to heat produced by the oxidation-reduction reaction, and close pores of a separator through quick and uniform fusion of the separator to inhibit an overcharge reaction. The polymerization reaction of these redox shuttle additives consumes the overcharge current to improve battery safety.
However, the polymerization of these redox shuttle additives cannot sufficiently eliminate the overcharge current. In addition, decomposition of the additives may cause gas generation inside the battery, and thus, the battery swells. Therefore, improvements in the safety of the battery are limited when using the redox shuttle additives. Additionally, some redox shuttle additives have a deleterious effect on electrochemical properties such as high temperature or cycle life characteristics.
For solving the swelling phenomenon from gas generation inside the battery, a method has been disclosed in which the safety of a secondary battery including a non-aqueous electrolyte is improved by mounting a current breaker or a vent for ejecting the internal electrolyte solution when the internal pressure is increased above a predetermined level. However, a problem with the disclosed method is that the battery may operate incorrectly because of an increase in internal pressure itself.
Alternatively, Korean Patent Application No. 1999-10904 discloses an electrode that is subject to heat-treatment at 100 to 200° C. followed by cooling at room temperature in order to improve swelling inhibition characteristics.

Lithium secondary battery and a method for preparing the same


A method, device, and system are disclosed. In one embodiment the method includes supplying a processor with a first voltage. The method also includes allowing the processor to function within an enhanced processor halt state at the first voltage. The first voltage is a voltage below the lowest compatible voltage for the enhanced processor halt state. The method allows the processor to execute instructions upon waking from the enhanced processor halt state at the first voltage by throttling a maximum throughput rate of instructions being executed in the processor.

A modern processor, such as an Intel® architecture processor or another brand processor, generally has multiple power states available to allow for power conservation when the processor is not busy. Processors generally have a fully operational power state referred to as C0. C0 generally has a high frequency mode (HFM) and a low frequency mode (LFM). Another common processor power state is C1E. In the C1E state the processor is available for snoop servicing but does not execute or retire any instructions. Snoop servicing requires a certain voltage sufficient to keep the processor cache operational.

Processor power consumption control and voltage drop via micro-architectural bandwidth throttling


Tetrahydrofuranyl compounds are provided that are functionalized to include pendant conjugate groups, and which are useful in diagnostic assays and as research reagents. Novel intermediates for the synthesis of the compounds are also provided.

Oligonucleotides and their analogs have been developed and used in molecular biology in certain procedures as probes, primers, linkers, adapters, and gene fragments. Modifications to oligonucleotides used in these procedures include labeling with non-isotopic labels, e.g. fluorescein, biotin, digoxigenin, alkaline phosphatase, or other reporter molecules. Other modifications have been made to the ribose phosphate backbone to increase the nuclease stability of the resulting analog. These modifications include use of methyl and other alkyl phosphonates, phosphorothioates, phosphorodithioate, phosphoamidate and phosphotriester linkages, and 2'-O-methyl ribose sugar units. Further modifications include modification made to modulate uptake and cellular distribution. Phosphorothioate oligonucleotides are presently being used in human clinical trials for various disease states, including use as antiviral agents. In view of the success of these oligonucleotides for both diagnostic and therapeutic uses, there exists an ongoing demand for improved oligonucleotide analogs.
Oligonucleotides and like molecules can interact with native DNA and RNA in several ways. One of these is duplex formation between an oligonucleotide and a single stranded nucleic acid. A further method is via triplex formation between an oligonucleotide and double stranded DNA to form a triplex structure.
Naturally occurring or synthetic oligonucleotides, together with hybrid species having both synthetic and natural components, can collectively be referenced as "oligomeric compounds." Because of their properties, these oligomeric compounds are known to be useful in a number of different areas. They can be used as probes in cloning, blotting procedures, and in applications such as fluorescence in situ hybridization (FISH). Also, since local triplex formation inhibits gene transcription, such oligomeric compounds can be used to inhibit gene transcription. Labeled oligomers can also be used to directly map DNA molecules, such as by tagging an oligomer with a fluorescent label and effecting hybridization to complementary sequences in duplex DNA. Oligomers can also be used as identification tags in combinatorial chemical libraries as is disclosed in patent publication WO 94/08051 and Ohlmeyer et al., Proc. Natl. Acad. Sci. USA, 1993, 90, 10922-10926.
Considerable research is being directed to the application of oligonucleotides and oligonucleotide analogs that bind complementary DNA and RNA strands for use as diagnostics, research reagents and potential therapeutics.
For most uses, it is desirable to append to oligomeric compounds groups that modulate or otherwise influence their activity or their membrane or cellular transport. One method of increasing such transport is by the attachment of a pendant lipophilic group. U.S. application Ser. No. 117,363, filed Sep. 3, 1993, entitled "Amine-Derivatized Nucleosides and Oligonucleosides", describes several alkylamino functionalities and their use in the attachment of such pendant groups to oligonucleosides. Additionally, U.S. application Ser. No. 07/943,516, filed Sep. 11, 1992, entitled "Novel Amines and Methods of Making and Using the Same" and corresponding to published PCT application WO 94/06815 describe other novel amine-containing compounds, and their incorporation into oligonucleotides for, inter alia, the purposes of enhancing cellular uptake, increasing lipophilicity, causing greater cellular retention and increasing the distribution of the compound within the cell. U.S. application Ser. No. 08/116,801, filed Sep. 3, 1993, entitled "Thiol-Derivatized Nucleosides and Oligonucleosides", describes nucleosides and oligonucleosides derivatized to include a thioalkyl functionality, through which pendant groups are attached.
Although each of the above-noted patent applications describe useful compounds, there remains a need in the art for additional stable compounds that bind complementary DNA and RNA. There further remains a need in the art for additional methods of attaching pendant groups to oligomeric compounds to further enhance or modulate their binding, cellular uptake, or other activity.

4'-desmethyl nucleoside analogs, and oligomers thereof


Embodiments of the present invention provide for a method of identifying customer service and duplicate questions submitted by a user to a consultation system by creating a model from features extracted from questions previously identified as customer service questions, extracting features from a newly submitted question by performing phrasal analysis of the question, comparing the extracted features of the newly submitted question to the extracted features of the model, and determining whether the newly submitted question is a customer service question.

As Internet use becomes more common, a greater number of users with less technological sophistication are accessing the web. Websites owners are trying to accommodate the less tech savvy users by providing a more user friendly interface, a key component of which is a less cluttered, simple to view, use and interact with web page (also referred to as a landing page). Google®, the popular search engine is one example of this web page design philosophy. Google's landing page has as its center piece the question box where users must enter their query and the majority of the users' interactions with the website is through this question box. Other companies have tried to emulate this simplified design philosophy by creating landing pages with a few strategically laid out functional icons, and a simplified portal for user interaction with the website, with the goal of improving the user experience reducing confusion of the less sophisticated users. Presently, many online websites allow for exchange of information. Some of these websites provide a question and answer type capability whereby a user may post a question and one or more other users may reply. One example of an online consultation system is a question and answer website that allows users to ask questions for a fee of vetted experts, on a variety of topics. Among the many benefits and attractions of such a system is the ability of the users to receive answers tailored to their specific problem, from actual experts on specific subject matters. Another benefit of such an online consultation system is the access to experts and answers at any time of the day and night.
A large portion of the users of our exemplary online consultation system may be comprised of Internet users that are less sophisticated when it comes to navigating their way around the Internet, or finding their way around a web site. To better serve the less technology savvy users, a simple web page interface is desired. However, such an interface presents unique issues. Less technically savvy users may use the landing page question box to submit non-expert related questions. For example, the users may submit customer service questions such as request for a refund, or questions regarding their account. Alternatively, the users may use the question box to submit system help questions, asking for help on using the online consultation system's various features. Another type of non-expert related question may be duplicate or near duplicate questions. Users may resubmit a question if they have not received an answer to their question within the time they were waiting. Alternatively, users may resubmit the same question with additional information to supplement a previously submitted question. The question box interface is primarily designed to receive expert related questions with the goal of receiving tailored answers from subject matter experts on a given topic. So, customer service questions, help questions and duplicate questions require special handling.

Method and apparatus for identifying customer service and duplicate questions in an online consultation system


The present invention provides a method and apparatus for providing position detection using a unique binary sequence encoded in indexing bits stored in servo wedges. The present invention generates a unique binary sequence (UBS) code and stores the bits of such a code in the indexing bits of the servo wedges. The bits are read from the servo wedges and used to provide unique identification of head position. Each servo wedge and each data field can be uniquely identified, even servo wedges and data fields under different heads. The present invention may be used to provide initial position detection, position verification during normal operation, and position verification upon head switching. When used for position verification, the present invention uses a confidence block to determine the confidence level with which the head is believed to be correctly positioned. One or more programmable thresholds may be used to qualify operations such as reading information from a disk, writing information to a disk, or seeking a location on a disk. If these thresholds are not met for the corresponding operations, the initial position detection capability of the present invention may be used to provide position recovery.

1. Field of the Invention
The present invention relates to the field of data storage systems, particularly to electronic controllers for controlling the operation of rotating rewritable (read/write) data storage devices.
2. Background Art
Computer systems employ data storage devices, for example, disk drives, to store various data for use by the computer system. A typical data storage device includes storage media, in which the actual data is stored, a read head, and a mechanism, such as a motor, for imparting relative motion between the storage media and the read head. The relative motion allows access to various portions of the storage media, and, in the case of certain types of media, such as magnetic media, allows for the production of signals representative of the data stored in the storage media.
In general, disk memories are characterized by the use of one or more magnetic media disks mounted on a spindle assembly and rotated at a high rate of speed. Each disk typically is round and has two surfaces of magnetic media. In a typical rotating medium as a storage system, data is stored on magnetic or magneto-optical disks in a series of concentric "tracks," with each track being an addressable area of the memory array. A read/write head is provided for each surface of each disk in the disk storage system. These tracks are accessed by a read/write head that detects variations in the magnetic orientation of the disk surface. The read/write head moves back and forth radially on the disk under control of a head-positioning servo mechanism so that it can be selectively positioned over a selected one of the tracks. Once in position over a track, the servo mechanism causes the head to trace a path that follows the center line of the selected track.
A data storage device may have several modes of operation. For example, a device may have a read mode during which data from the media is recognized and gathered, a write mode during which the stored data is written onto the media, a signal gap mode between the read mode and the write mode during which no reading or writing activity occurs, and a servo mode during which positional information is derived from the storage media for use to maintain the correct relationship between the read head and the storage media. Disk drives are used to store data by recording it on rotating media.
Data is typically stored in concentric rings known as tracks. To ensure that data may be accurately retrieved from a disk drive, the data must be stored in known locations. A number of methods have been used to provide for the correct positioning of data on a disk and for correct positioning of the read/write head relative to the data. One such method is used in an "embedded servo" disk drive. An embedded servo disk drive has positioning (servo) information recorded on the disk along with the data. The positioning information is used to control a servomechanism that then continually adjusts the position of the read/write head so that data will be read from and/or written to the disk at the proper location. This positioning information is typically located in servo gaps that occur periodically along a track. The angular distance between adjacent servo gaps is referred to as the servo interval. While reading and writing of data may occur over the servo interval, the reading and writing of user data is temporarily suspended at the beginning of a servo gap and resumed at the end of the servo gap.
In conventional systems, the position information is usually described by an ID (identification) field, followed by a data field. However, for drives with a magnetoresistive (MR) type of head, the rotary actuator used to position the MR head is known to introduce a skew angle between the MR read element and the inductive write element relative to the data tracks. A method is known to compensate the skew angle by using two ID fields, one offset with the conventional ID field. However, the disadvantage of this method is that the redundant ID field causes a commensurate loss of storage capacity (typically about 9%).
Instead of using an ID field for position information, a large servo wedge, which contains multiple bits of head and wedge information in addition to other servo fields required for correct recovery, may be used for position detection. This headerless format, which does not have ID field in front of data field, avoids the skew angle problem with an MR head. However, this approach often requires major changes to the mode in existing subsystems servo rework.
Yet another approach uses binary counters. By counting both index and sector pulses, physical wedge positions can be determined. However, this technique is usually prone to errors because the timing cannot be resolved accurately enough and hence is not a reliable method.
A current servo field usually has a single bit associated with each servo wedge to perform indexing. Among all the wedges, a bit of 1 can, for example, be assigned to a particular wedge and bits of 0 can be assigned to all other wedges. Thus, when a 1 bit is detected twice, it is then known that one complete revolution of the medium has occurred. However, this technique uniquely identifies only the single wedge having the 1 bit. The technique fails to provide unique identification about all the wedges having 0 bits.
Furthermore, more information could be added to the servo wedge. This information could be the entire header ID. This creates a problem because each bit added to the servo wedge occupies space resulting from the fact that the servo wedge is always recorded at a lower frequency than the data. This results in lost capacity saving just to implement a headerless scheme. It is desirable to save as much space in the servo wedge as possible.
Thus, a technique is needed to provide servo information and to uniquely identify data fields while maximizing storage capacity and reliability and avoiding complicated redesign of the servo system.

Position detection scheme for headerless disk controller


Ion-storage layers for electrochromic devices (ECDs) that are tuned to be minimally color changing (MCC) during operation of the ECDs. In some embodiments, an ion-storage layer is composed of an n-type metal oxide that complements a p-type electrochromic (EC) layer, such as an EC layer made of a p-type EC polymer. In some embodiments, an ion-storage layer may be tuned to be MCC by configuring an ion-storage layer to have a total charge density that is higher than the total charge density of a corresponding EC layer or to have a coloration efficiency lower than the coloration efficiency of the corresponding EC layer, or both. Methods for preparing ion-storage layers are disclosed, including methods for creating highly structured metal oxide having reduced coloration efficiencies. ECD devices incorporating MCC ion-storage layers are also disclosed.

Electrochromic devices (ECDs) are being translated into practical products for a variety of applications, such as smart windows for buildings, self-dimming rearview mirrors, and electrochromic irises, among others. Generally, an ECD is a five-layer structure comprising an electrochromic (EC) layer, an ion-storage (or counter-electrode (CE)) layer, an electrolyte layer located between the EC and CE layers, and a pair of transparent conductive layers each electrically connected to a corresponding one of the EC and CE layers.
The color wheel of solution-processable p-type-dopable cathodically coloring electrochromic polymers (ECPs), which are colored in the neutral state and transmissive (bleached) in the p-type doped state, for use in ECDs has been expanding. It is believed that a large library of p-type ECPs are only about one step away from everyday products because of their desirable attributes, such as high optical contrast, fast response times, long-term optical stability, and, most importantly, solution processability that will allow for high-throughput and economical manufacturing. However, the lack of a CE layer that can be fabricated in a cost-efficient and high-throughput manner currently impedes further progress of developing products that utilize the growing library of p-type ECPs.
Counter electrode materials can be divided according to their electrochromic behavior into three categories, namely, complementary, non-color-changing, and minimally color changing (MCC) CE materials. Complementary CE materials usually have coloration efficiencies comparable to the coloration efficiencies of the corresponding electrochromic materials used in the electrochromic layer(s) of ECDs, and they have an obvious color change during the operation of the ECDs. Electrochromic devices that use complementary CE materials usually have a lower optical contrast compared to the contrast due to the sum of residue color in the bleached state of both the CE and electrochromic materials. A non-color-changing CE material is optically passive.
Currently, and in general, the most widely studied materials for CEs are p-type radical polymers that need oxidizing pretreatments when coupled with p-type dopable ECPs. As non-color-changing materials, these p-type radical polymers experience non-color-changing. Therefore, they would seem to be good candidates to couple with the high coloration efficiency p-type ECPs.
Researchers have developed N-alkyl-substituted poly(3,4-propylenedioxypyrrole) (PProDOP) as an MCC CE material. The PProDOP with N-C18 substitution has a low coloration efficiency of 35 cm2 C−1 at a 555 nm wavelength and was proposed as a solution-processable MCC CE material to pair with an ECP-magenta (p-type) EC material having a coloration efficiency of approximately 633 cm2 C−1 at 555 nm. However, PProDOP is also a p-type material. To pair with p-type cathodically coloring ECPs as a CE, the PProDOP must be either electrochemical or chemical pre-oxidized. This additional step of pre-oxidation for preparing a CE layer suitable for use with a p-type EC layer is undesirable from manufacturability and production-cost perspectives.

Minimally color changing n-type ion storage layers, electrochromic devices made therewith, and related methods