A continuous solvent pulping process is practiced with oxygen free gas (e.g. nitrogen) purges of all major treatment vessels during the time when the process is arrested or terminated. The wood chips or other cellulosic fibrous material to be pulped is steamed in a first horizontal steaming zone at pressure of about 10-20 psi, and then in a second horizontal steaming zone at a pressure of about 20-75 psi. The first and second zones are isolated by a low pressure feeder. Steam is introduced into the material in the second steaming zone to flow cocurrently with it. Gases, including vaporized solvent (e.g. ethanol or other alcohol) are vented from the steaming zones, and solvent is added to the steamed material prior to feeding to a high pressure feeder. The high pressure feeder introduces the material into the top of a single digesting vessel, liquid and chips being separated at the top of the digester vessel without mechanical means that could cause a spark. Lignin containing liquid is withdrawn from a central portion of the digester and passed through flash tanks and ultimately for lignin and alcohol recovery. A recirculating screen and system is disposed between the central extraction portion and the top of the digester vessel. A portion of the liquid removed for recirculation is instead passed to lignin recovery, while fresh solvent containing liquid is added to the rest of the recirculated liquid.

One alternative to the production of paper pulp by conventional kraft and sulfite chemical pulping technologies in solvent pulping. Most proposed solvent pulping processes, such as disclosed in U.S. Pat. Nos. 4,764,596 and 4,100,016, use alcohol as a solvent, particularly an ethanol and methanol mixture. The alcohol is introduced with wood chips into a batch digester, and after cooking the material is subjected to three different washes in the batch digester, the first wash with a slightly weakened cooking liquor (containing alcohol), the second wash with a weak cooking liquor, and the third wash with water. One of the proposed advantages of the solvent pulping technique is that lignin may be recovered from the "black liquor" produced from the process (a solution of lignin in a water miscible organic solvent such as a lower aliphatic alcohol). It is necessary, in order to make the system economical to recover as much of the alcohol as possible. Significant markets may also develop for the lignin, which may make solvent pulping economical and advantageous.
At the present time, there are no known large scale commercial installations in which solvent pulping is practiced. One of the most significant reasons for this is the inability to recover a substantial enough portion of the alcohol. If one utilizes a batch digester, with washing in the digester, as/described above, the alcohol consumption may be such as to make the procedure economically unattractive.
There are certain problems associated with proposed solvent pulping systems. One is the potential safety hazard as a result of solvent vapor, oxygen (i.e. an oxidative gas), and a condition--such as a spark--capable of producing an explosion, combining. In order to guard against this, when the operation of the batch digester is being arrested or terminated, any portions thereof where vapor can collect are purged with nitrogen, or a like substantially oxygen free gas.
It has been recognized for many years that the solvent pulping process could theoretically be improved if it were made continuous, such as the majority of commercial kraft and sulfite pulping systems. However the safety problems described above, plus the need for equipment to maintain sufficient pressures to accommodate solvent pulping (which pressures are much higher than for kraft pulping) made the realization of that ideal difficult to achieve. It was also recognized that the lack of recovery of a substantial portion of the alcohol as a result of washing was a major drawback, but techniques for significantly reducing the alcohol loss were not envisioned.
According to the present invention, it is possible to make the solvent pulping process continuous. Also, according to the present invention, it is possible to wash pulp produced by solvent pulping (either by a continuous process or batch process) so that the alcohol loss per ton of pulp is at an economical level (e.g. about ten gallons or less; an economically acceptable level).
In the design of equipment to make the solvent pulping process continuous, to the extent possible conventional Kamyr.RTM. vessels and equipment from kraft and sulfite chemical pulping processes are utilized. However it is necessary to provide additional equipment, reconfigure the equipment, and substitute components capable of handling higher pressure, in order for the system to work effectively.
In the production of washing equipment which can effectively wash the lignin from the pulp, and also wash the alcohol therefrom so that a substantial portion of the alcohol is effectively recovered, again conventional Kamyr.RTM. and Ahlstrom equipment is utilized to the maximum extent possible. However the equipment must be configured in a novel system, and various changes made thereto.
According to one aspect of the present invention, apparatus is provided for steaming comminuted cellulosic fibrous material chips for feeding from a high pressure feeder to a continuous digester, and a method for steaming such chips during solvent pulping thereof. The apparatus comprises: A chips bin, having a chips outlet at the bottom thereof. A first horizontally extending steaming vessel having a chips inlet and outlet, a steam inlet, and a gas vent. A second horizontally extending steaming vessel having a chips inlet and outlet, and a gas vent. A first low pressure feeder between the chips bin outlet and the first steaming vessel chips inlet. A second low pressure feeder between the second steaming vessel chips inlet and the first steaming vessel chips outlet, including a first conduit extending from the second low pressure feeder to the second steaming vessel chips inlet. A second conduit extends from the second steaming vessel chips outlet and is connected to the high pressure feeder inlet. And, means for introducing steam into the second steaming vessel through the first conduit so as to flow with chips from the second low pressure feeder into the second steaming vessel chips inlet.
The gas vent from the second steaming vessel extends upwardly therefrom on the discharge end, and the second conduit extends downwardly from the second steaming vessel generally opposite the gas vent. For safety, means are provided for introducing a substantially oxygen free purging gas into the second conduit to flow upwardly into the second steaming vessel during shutdown of the apparatus. Solvent recovery means is operatively connected to the steaming vessel gas vents.
In the method of steaming cellulosic fibrous material during solvent pulping thereof according to the invention, first and second steam zones are utilized. The method comprises the steps of continuously: (a) Adding steam to material in the first steaming zone while maintaining the pressure at about 10-20 psi. (b) Isolating the first steaming zone from the second steaming zone. (c) Maintaining the pressure in the second steaming zone at about 20-75 psi. (d) Purging the second steaming zone with steam by introducing steam into the material to flow concurrently with the material into and through the second steaming zone. (e) Venting gases, including vaporized solvent, from the fist and second steaming zones. (f) Discharging steamed material from the second steaming zone to the high pressure feeder. And, (g), adding solvent to the discharged material from the second seaming zone prior to its introduction into the high pressure feeder. The material is moved generally horizontally within the first and second steaming zones, and step (g) is practiced by adding ethanol as the solvent, preferably with about 10% methanol added thereto. The second steaming zone is purged with nitrogen or other substantially oxygen free gas when the practice of steps (a)-(g) is arrested or terminated.
According to another aspect of the present invention, the digester vessel itself is configured so as to minimize the risk of explosion and to maximize extraction of lignin containing liquid. In the solvent pulping process the ratio of liquid to cellulosic fibrous material is much higher than in kraft pulping, typically on the order of about 6-9 to 1, as opposed to a 4-5 to 1 ratio for kraft pulping. These goals are accomplished according to the invention by utilizing a vessel free of mechanical liquid/material separating devices at the top thereof. Heretofore, all single vessel continuous digesting systems have utilized a mechanical separator at the top, typically a screw rotating in a perforate cylinder. According to the invention, however, separation is accomplished utilizing a plurality of screens, and controlling the operation of the screens so that liquid is periodically withdrawn from one, then withdrawal is terminated, and then started again, etc., at all times at least some of the screens operating, and at all times at least some of the screens being dormant. The excess extraction is handled by adding screens to the digester, and--in a recirculating loop between the central extraction portion for the lignin containing liquor, in the top of the digester--removing a portion of the withdrawn liquid from the recirculating loop, sending that removed portion (which contains a substantial amount of lignin) to lignin recovery, and making up for the removed portion with fresh solvent cooking liquor, which is heated with the recirculated liquid and reintroduced into the digester via the central pipe bundle, exiting in the center of the chip column at an elevation slightly above or below the respective extraction screen. The recirculating loop screen and system comprises a withdrawal conduit having an isolation valve and a flow control valve, and a replacement liquid conduit having an isolation valve and flow control valve.
The method of solvent pulping to accomplish the objectives set forth above is practiced by the steps of continuously: (a) Steaming the material to remove the air therefrom. (b) Mixing the material with solvent pulping liquid to produce a mixture. (c) Feeding the mixture of material and solvent pulping liquid under pressure to the top of the vessel. (d) Separating some liquid from the material at the top of the vessel in a manner positively precluding the generation of electrical or mechanical sparks. (e) Returning the separated liquid from step (d) to step (b). (f) Withdrawing a liquor having a high concentration of dissolved lignin from a central portion of the vessel. And, (g) withdrawing produced pulp from the bottom of the vessel. Step (d) is practiced by the steps consisting essentially of providing a plurality of screens at the top of the vessel, withdrawing liquid through at least one screen while liquid is not being withdrawn through at least one other screen, and periodically switching which screens liquid is and is not being withdrawn through. During arresting or terminating the practice of steps (a)-(c), oxygen free gas is passed through the material countercurrent to the normal direction of flow of the material to prevent explosive vapor from collecting. Countercurrent diffusion washing of lignin from the pulp begins in the lower portion of the digester vessel where filtrate from the external washing stages is introduced and flows upward through the vessel counter to the flow of chips. The rate of flow of washing medium counter to the chip flow in the digester will be in the range of 1-4 tons of alcohol/water mixture per ton of dried pulp leaving the digester.
Washing of the pulp produced by solvent pulping--either by a batch or continuous process--is accomplished in a number of stages, at high pressures. The first stage is preferably a pressure diffuser, which is capable of operating at up to about 600 psi, and typically will operate at a pressure of at least about 350 psi, typically about 425-450 psi. In the pressure diffuser, the lignin is washed out of the pulp utilizing as the wash liquid a mixture of solvent and water, typically at least about 50% ethanol-methanol, and the rest water. The pulp from the pressure diffuser passes to storage vessel, and then to a first multi stage drum displacer washer, and then to a second multi stage drum displacer washer. Fresh water washes alcohol from the pulp in the second multi stage drum displacer washer, with the spent wash liquid therefrom used as the wash liquid in the first multi stage drum displacer washer, and the spent liquid from the first multi stage drum displacer washer used--with make-up alcohol--in the pressure diffuser. In all of these vessels it is necessary to purge any portions thereof where vapor may collect during normal operation and when operation is arrested or terminated, the purging taking place using nitrogen or a like substantially oxygen free gas.
The lignin rich spent wash liquid from the pressure diffuser, which also contains a large amount of alcohol, passes through a fiber filter. A first stream--which has been filtered so that it is substantially free of fibers--then passes to lignin and alcohol recovery, while a second stream--which still has fibers therein--is returned to the pulping system, to be introduced into the steamed chips as part of the solvent mixture slurrying the chips for the high pressure feeder, or into the bottom of the digester vessel to be used as wash medium in the countercurrent diffusion washing zone. Utilizing such a washing system it is possible to recover substantially all of the alcohol, that is all except for about ten gallons or less per ton of pulp produced.
It is the primary object of the present invention to provide a continuous solvent pulping method and apparatus, and/or to provide for effective washing of pulp produced by solvent pulping, so as to maximize alcohol recovery. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.

Method for steaming comminuted cellulosic fibrous material during continuous solvent pulping


A crash load absorption structure of a vehicular body having a side member at a bottom of the vehicular body extending in a forward-rearward direction and a pillar extending in an upward-downward direction. The structure of the vehicular body includes a side body bar located upward from the side member at a side portion of the vehicular body, the side body bar extending in the forward-rearward direction and being adapted to transfer a portion of the crash load to the pillar, and a connecting bar that connects the side member and the side body bar.

1. Field of the Invention
The present invention relates to a structure of a vehicular body, and more particularly to a vehicular body structure designed to absorb an impact.
2. Description of Related Art
A related structure of a vehicular body includes a pair of right and left side members extending along the front-rear direction of a vehicle and disposed underneath the vehicular body. The rear ends of the side members are connected to each other using a rear end cross member. In such a structure, a crash load exerted on the rear end cross member is transmitted from the rear end cross member to the side members. To this end, the side members become deformed when absorbing the crash load. However, to absorb a high crash load by using such a structure, the side members must be long, thereby causing the vehicle to be longer in size.


A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature Tα between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.

There is a requirement to refine the microstructure of a titanium aluminide alloy, in particular cast titanium aluminide alloy, which does not involve hot working of the titanium aluminide alloy.
Our published European patent application EP1378582A1 discloses a method of heat-treating a titanium aluminide alloy having a single alpha phase field and being capable of producing a massively transformed gamma microstructure. In that method of heat-treating the titanium aluminide alloy is heated to a temperature above the alpha transus temperature, is maintained above the alpha transus temperature in the single alpha phase field for a predetermined time period, is cooled from the single alpha phase field to ambient temperature to produce a massively transformed gamma microstructure, is heated to a temperature below the alpha transus temperature in the alpha and gamma phase field, is maintained at the temperature below the alpha transus temperature for a predetermined time period to precipitate alpha plates in the massively transformed gamma microstructure such that a refined microstructure is produced and is then cooled to ambient temperature.
A problem with this heat-treatment is that the cooling, quenching, of the titanium aluminide from above the alpha transus to ambient temperature induces quenching stresses in the titanium aluminide. The quenching stresses may result in cracking of castings. A further problem is that the heat-treatment is only suitable for relatively thin castings.
Our published European patent application EP1507017A1 discloses a method of heat-treating a titanium aluminide alloy having a single alpha phase field and being capable of producing a massively transformed gamma microstructure. In that method of heat-treating the titanium aluminide alloy is heated to a temperature above the alpha transus temperature, is maintained above the alpha transus temperature in the single alpha phase field for a predetermined time period, is cooled from the single alpha phase field to a temperature in the range 900° C. to 1200° C. to produce a massively transformed gamma microstructure, is heated to a temperature below the alpha transus temperature in the alpha and gamma phase field, is maintained at the temperature below the alpha transus temperature for a predetermined time period to precipitate alpha plates in the massively transformed gamma microstructure such that a refined microstructure is produced and is then cooled to ambient temperature.
In this heat-treatment the cooling, quenching, of the titanium aluminide from above the alpha transus to a temperature in the range 900° C. to 1200° C. reduces quenching stresses in the titanium aluminide and hence reduces cracking of castings. The heat-treatment is suitable for thin castings and for thicker castings.
Cracking during cooling, quenching, from a temperature above the alpha transus temperature, is related to both cooling rate and the dimensions of the titanium aluminide castings. Generally, cracking is promoted by relatively high cooling rates and by relatively large dimension castings.

Method of heat treating titanium aluminide


A golf ball range finder that rests in either a custom leveled and aligned pin, or a standard pin of a golf green, and rotationally and vertically aligns a laser range finder onto all the golf balls in the vicinity. The golf ball range finder has mechanisms to align it vertically, horizontally and to adjust for differences in the depth of the pin so that its rotational axis resides collinear with a vertical axis passing through the midpoint of the pin.

Golf has become a game of gambling for the wealthy. Many of the games are based on attaining the close proximity to the golf ball hole. The problem is when a lot of money is at stake, the art of measuring may be brought into question.
Heretofore, there has been a plethora of measuring devices utilized, however most are only accurate to within a ¼ of an inch or so. This is because there is has not been a good way to establish the center of the golf ball hole, compensate for sag in the measuring device or account for non mid center-ball measurements. This inaccuracy in measurement is not acceptable in high stake situations
Thus, a more controllable and consistent measuring device that can accurately measure the distance between a golf ball and the center of a golf ball hole, regardless of the location or distance of the ball from the golf ball hole, would fulfill a long felt need in the sport of golf. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems and accomplish this.


This invention provides a system and method for printing continuous web and feeding ink to printing pens (or cartridges) that employs an array of interleaved ink-jet pens that are arranged to receive bulk ink through a manifold. The manifold and pens are mounted on a fixed array suspended over the web feed path. The manifold includes a plurality of self-sealing quick-disconnect couplings that each serve a discrete ink-jet pen. The pens lay down ink in a registered manner across the full width of the web. The pens are organized into two parallel, multi-pen arrays that are each diagonally oriented with respect to the feed direction. The feed path allows for duplex printing with a second web-side's array located on a lower level of the device, generally beneath the first-side's array. Duplex printing is facilitated due to its inherent length of the feed path. The printed part of the web is free of contact over predetermined lengths that ensure sufficient time for the drying of ink. Each pen is interconnected with a connection to a respective manifold that maintains a vacuum so as to prevent seepage of ink from the pen nozzles. The vacuum is maintained by a draw pump, while ink is continuously provided to the manifold via a float switch in a pressure regulator. The regulator is fed by a bulk ink supply using a feed pump. A check-valve standpipe on each manifold assists in removing any trapped air from the system, thus assisting in maintaining the vacuum.

1. Field of the Invention
This invention relates to devices for printing a continuous web and more particularly to devices that print using ink-jet pens.
2. Background Information
Electronic inline printing and processing of a continuous web of paper has become ubiquitous in recent years for a variety of purposes and industries. Such industries include publishing and "print-on-demand," direct mail marketing, billing and the like. Typically, a web is directed from a large stand-mounted roll to one or more high-speed (typically greater than 100 pages per minute) electronic printers that deposit and fuse toner to the web. The web is then directed to further processing units that variously print, emboss, cut, sort, stack and fold the web, among other possible processes.
It is often desirable to apply a color heading, logo, decoration or other device to the web either before or after the electronic printer has applied toner print. One technique for applying variable colored printing is to employ a color toner print engine. Such engines typically employ one or more individual toner sources that feed one or more image-transfer elements. The image transfer elements lay the toner onto the web and fuse it via heating. However, this approach uses expensive color toner and may be prone to speed and reliability limitations.
A more efficient and cost-effective technique to applying colored print is to employ a so-called "ink-jet" pen or "cartridge." The ink jet cartridge defines an ink source contained within a unitary housing. The ink source is an impelled fluid that is dispensed as droplets at a print head located at the bottom end of the cartridge (also referred to as a pen) through a microscopic gridwork of nozzles that define the print pixels of the cartridge. The nozzles are individually addressed through a print controller so that they dispense ink at an appropriate time with respect to the movement of the printing media (paper, etc.).
In a conventional ink-jet printer, the nozzle grid is relatively small (less than one-inch square), and the printing media is driven through the printer at a rate that allows the cartridge(s) to traverse the width of the media on a motorized carriage so as to provide a print line of a given thickness. In general, the cartridge's inherent speed of ink deposition and the carriage speed both serve to limit the throughput rate of the print media. This throughput rate is typically significantly slower that 100 pages per minute. Hence, a conventional ink-jet printer with traversing head(s) is seldom suitable for providing color print to a high-speed moving web.
In addition, the internal ink supply of even the largest, commercial ink-jet cartridge is relatively small, requiring cartridges to be frequently replaced and/or manually refilled. The replenishment of ink/cartridges would, thus, prove inconvenient and time-consuming for a large production run—particularly where only a small number of cartridges on a traversing carriage are used.
Accordingly, it is highly desirable to provide a system and method for applying color print to a high-speed moving web that is efficient and low maintenance. This system and method should allow for large production runs without requiring replenishment and should allow variable printing across the entire width of a web without halting the feed of the web. The system and method should support printing in a large array of possible colors that may be combined on a single web when desired.

System and method for printing a continuous web employing a plurality of interleaved ink-jet pens fed by a bulk ink source


A touchscreen fuel panel. In embodiments, the fuel panel includes a touchscreen display and a controller coupled to the touchscreen display. The controller is configured to generate a graphical user interface at the touchscreen display and receive user inputs via the touchscreen display. In embodiments, the graphical user interface includes a pump menu, valve control icons, pump status indications, fuel quantity indications, and fuel calculations. The controller may be configured to present requested information and/or generate a control signal for at least one fuel system component in response to receiving a user input representing a user interaction with the graphical user interface.

Currently employed fuel panels rely on hard switches and digital readouts to manage and monitor fuel in aircrafts. This requires flight crew to manually perform several control operations and critical calculations. Improved fuel panels are needed in order to reduce human error, relieve flight crew of tasks that can be handled automatically, and provide flight crew with better access to information.

Touchscreen fuel panel with real time architecture generation and status


An electro-acoustic micro-converter can be applied in an audio device, and in particular in a hearing aid. The micro-converter is at least substantially block-shaped and includes an at least substantially rectangular acoustic membrane tensioned therein transversely of a longitudinal direction. A coil element is carried by the membrane and extends in a magnetic field maintained by magnet elements, including a permanently magnetic magnet body, in a coil gap around the magnet body.

1. Field of the Invention
The present invention relates to an electro-acoustic micro-converter for generating sound from an electronic input signal, in particular for a device worn in an ear of a user, comprising a device housing with a sound output in which a membrane assembly is suspended with freedom of movement, the membrane assembly comprising an acoustic membrane and a coil element connected thereto, wherein the coil element is provided with connecting means for receiving the electronic input signal and extends in a coil gap, and wherein the device housing comprises magnet means which maintain a magnetic field in the coil gap, the magnet means comprising a permanently magnetic magnet body.
Such a converter is also referred to as a transceiver or receiver and is normally applied for the purpose of acoustic reproduction of sound on the basis of an electronic audio signal. As such, electro-acoustic converters find their way into electronic devices of diverse nature, such as for instance (mobile) phones, computers and, by no means least, hearing aids and other audio devices worn in the ear and having a device housing which is worn wholly or largely concealed in the ear, such as earphones and active audio filters.
A great challenge in the case of this latter group is the far-reaching miniaturization of the components received therein because of the limited placing space in an auditory canal of a user. This miniaturization also applies for the electro-acoustic converter applied therein, which in this case is therefore normally referred to as miniature or micro-converter. An extreme degree of miniaturization of an electro-acoustic converter does however quickly result in a limitation of the surface area available for the active membrane, and thereby in a reduction in the maximum acoustic output power that can be produced. Miniaturization moreover involves the danger of an audible deterioration in the sound quality.
Micro-converters of the so-called balanced armature type are usually applied for hearing aids. Such a micro-converter is based on magnetic forces exerted between a pair of magnetic poles of permanent magnet bodies located opposite each other on a magnetically susceptible armature element. The armature element is suspended here for movement between a pair of coil elements to which an electronic audio signal is supplied. A rapidly changing electronic audio input signal is sent through the coils, whereby the armature element suspended therebetween is set into vibration and transmits its movement to an acoustic membrane connected to the armature element. The membrane thus set into vibration in turn produces sound which is representative of the supplied audio signal and which can exit from the sound output.
A relatively high efficiency can be achieved with such a device by selecting an eigenfrequency of the armature assembly in an efficient acoustic frequency range. This relatively high efficiency does not however apply at all outside this range, whereby such converter is intended mainly for a high acoustic output power in a relatively narrow frequency range. For more wideband applications, such as for pure audio reproduction, i.e. over a relatively wide frequency spectrum, such a balanced armature converter is therefore a less likely solution. A balanced armature converter is moreover relatively expensive due to the relatively large number of components applied therein and the manufacturing steps required therefore. Particularly the exact placing and alignment of the armature element precisely in the centre of the air gap between the two magnetic poles, in addition to the magnetic balance required between these two latter, require high precision and result in an increase in the cost price.
A more natural and therefore clearer audio reproduction can be achieved with a converter of the type stated in the preamble, which is also referred to as the so-called moving coil type. Converters of this type are therefore not infrequently applied in loudspeakers of hi-fi systems, in headphones and earphones and in mobile electronic products such as telephones and computers. A characteristic of this type of converter is that the acoustic membrane is coupled to an electronic coil element which is suspended with freedom of movement in a permanent magnetic field maintained by a permanent magnet body. This type of converter is generally less well suited for miniature applications, such as in a device worn in the ear, because of the generally inadequate conversion efficiency. The converter therefore requires relatively large dimensions which are not consistent with a miniature application, such as in the ear, and moreover consumes a relatively large amount of power, which is likewise disadvantageous for a miniature application such as in the ear, which normally is wholly dependent for its electrical power supply on the relatively modest capacity of a battery or accumulator.
2. Description of the Related Art
An example of a miniature electroacoustic moving coil converter is described in the American patent application USP 2008/0044044. This known micro-converter comprises a device housing having therein a permanent magnetic body provided with pole bodies which together maintain a permanent magnetic field through a coil element extending from an acoustic membrane suspended in freely movable manner. For the purpose of increasing the acoustic output power, this known converter here comprises not one but two acoustic membranes, each with such a coil element in the magnetic field of the magnet means. A drawback hereof is however an increased complexity of the device as a whole and the necessity of a sound channel in which the sound waves of both membranes are brought together acoustically and carried to a shared sound output. The device hereby becomes more voluminous. For application deep in an auditory canal of a user, such as in the case of a device worn in the ear and in particular a completely-in-canal (CIC) hearing aid, the known construction is therefore far from optimal.

Micro converter, audio device and hearing aid


A lifting track of curtain is composed of a track, a plurality of winding mechanisms each having a carrying seat, a cord-winding shaft, and a cord fastened at one end thereof with the cord-winding shaft and at another end thereof with the curtain. As the cord-winding shaft is turned, the cord is wound on the cord-winding shaft such that the cord slides from a large diametrical end of a cylindrical body of the cord-winding shaft toward a small diametrical end of the cylindrical body of the cord-winding shaft. The carrying seat is provided with a concave surface for preventing the intertwining of the cord at the time when the cord is wound on the cord-winding shaft.

As shown in FIGS. 1 and 2 of the attached patent document, a lifting track of curtain of the prior art consists of a cord B for holding the curtain. The curtain can not be lowered or lifted in a uniform manner in view of the fact that the cord B can not be wound regularly on a cord-winding shaft A. The Taiwanese Patent Publication No. 168230 discloses a lifting track to overcome the drawback of the prior art lifting track of curtain described above. The second prior art lifting track of curtain consists of a cord-winding shaft 30 which is provided in the periphery thereof with threads and a guiding member 40 fastened with the shaft 30 such that the guiding member 40 is capable of a translational motion at the time when the cord-winding shaft 30 turns. The shaft 30 is further provided with a plurality of locating members 50 to serve as locating points at the time when the curtain is lowered or lifted. When the cord-winding shaft 30 turns, the cord 33 is guided by the guiding member 40 to wind on the shaft 30 in a regular manner. The second prior art described above is complicated in construction and is not cost-effective.


A semiconductor device includes a semiconductor substrate including first trenches defining outer sidewalls of a pair of active pillars and a second trench defining opposing inner sidewalls of the pair of active pillars. The second trench may have a bottom surface located at a higher level than bottom surface of the first trench. Auxiliary conductive lines may be disposed in the first trenches to cover and cross the outer sidewalls of the pair of active pillars. A pair of main conductive lines may be disposed in a pair of recessed regions that are laterally recessed from lower portions of the inner sidewalls of the active pillars into the pair of active pillars. A common impurity region may be disposed in the semiconductor substrate under the second trench. Upper impurity regions may be disposed in upper portions of the active pillars.

1. Technical Field
The present disclosure relates to semiconductor devices and methods for manufacturing the same.
2. Description of Related Art
Process technologies for reducing line widths of patterns have been continuously developed to increase the integration density of semiconductor devices. However, the process technologies for forming fine and small patterns for future semiconductor devices may require new and expensive photolithography processes.
Three-dimensional electronic structures, such as vertical MOS transistors, that increase the integration density of semiconductor devices have been developed. A vertical MOS transistor may include vertical source/drain regions, with a channel region positioned between them. The vertical orientation of such a device may allow for higher integration density while, at the same time, overcoming some of the obstacles to higher-level integration of planar MOS transistors, such as short-channel effects, for example. Innovative structures and methods of manufacturing three-dimensional electronic devices would be highly desirable.

Semiconductor devices and methods for manufacturing the same


An optical fingerprint sensor and a fingerprint identification method are provided. The optical fingerprint sensor includes a photosensitive element and a signal processing circuit. The signal processing circuit includes a logic unit, a variable/programmable gain amplifier and a processing unit. The logic unit is electrically coupled to the photosensitive element. The variable/programmable gain amplifier is electrically coupled to the logic unit. The processing unit is electrically coupled to the variable/programmable gain amplifier and the logic unit. The variable/programmable gain amplifier adaptively switches a gain between a first gain value and a second gain value, wherein the second gain value is larger than the first gain value. After the signals inputted into the variable/programmable gain amplifier are properly processed according to the first gain value or the second gain value, the optical fingerprint sensor acquires a sharp sensing image.

With the advancement and development of science and technology, an image sensing technology is widely used in the field of biometric identification. As known, an optical fingerprint sensor is used to identify the changes of ridges, valleys and protrusion lines. Consequently, the optical fingerprint sensor plays an important role in the security of the mobile device.
FIG. 1 is a schematic circuit diagram illustrating the conventional optical fingerprint sensor. The optical fingerprint sensor 1 includes a photosensitive element 11 and a signal processing circuit 12. The signal processing circuit 12 is electrically coupled to the photosensitive element 11. The photosensitive element 11 includes a plurality of photosensitive pixels 111 in an array arrangement. During the operation of the optical fingerprint sensor 1, the photosensitive element 11 is exposed to the light beams. According to the light amount received by each photosensitive pixel 111, each photosensitive pixel 111 outputs a pixel signal S11 to the signal processing circuit 12. Since the pixel signal S11 outputted from the photosensitive pixel 111 is an analog signal, the signal processing circuit 12 includes an analog front end (AFE) circuit 121 for converting the pixel signal S11 from analog-form into digital-form. After the pixel signal S11 is processed in a subsequent step, a fingerprint image is acquired.
Please refer to FIG. 2. FIG. 2 is a schematic circuit diagram illustrating the analog front end circuit of the optical fingerprint sensor as shown in FIG. 1. The analog front end circuit 121 includes an amplifier 1211 and an analog-to-digital converter (ADC) 1212. The amplifier 1211 is electrically connected between the photosensitive element 11 and the analog-to-digital converter 1212, and the amplifier 1211 is configured to amplify the pixel signal S11 so as to adjust the pixel signal S11 lies in the input range of the analog-to-digital converter 1212. However, the conventional optical fingerprint sensor 1 still has some drawbacks. For example, if the magnitude difference between two pixel signals S11 from the photosensitive pixels 111 is much lower than the magnitude of respective pixel signals S11, the analog-to-digital converter 1212 with the smaller input range and the insufficient resolution performs the analog-to-digital conversion difficultly. Under this circumstance, the fingerprint image acquired in the subsequent step is possibly blurred.
For illustration purpose, we assume the magnitude of each pixel signal S11 from the photosensitive pixel 111 is within the range from 0V to 5V, and the magnitude of the input signal of the analog-to-digital converter 1212 should be within the range from 0V to 1V and the resolution of the analog-to-digital converter 1212 is 1 millivolt (mV). For adjusting the magnitude of the input signal to lie in the allowable range of the analog-to-digital converter 1212, the gain value of the amplifier 1211 is set as 0.1. More particularly, if the magnitudes of two pixel signals S11 transmitted from the photosensitive pixels 111 are 4.001V and 4.002V, respectively. The amplifier 1121 adjusts the two pixel signals S11 and outputs two processed signals S12 with the magnitude of 400.1 mV and 400.2 mV respectively and transmits the processed signals S12 to the analog-to-digital converter 1212. Although the magnitudes of the two processed signals S12 lie in the allowable input range of the analog-to-digital converter 1212, some drawbacks occur. For example, since the resolution of the analog-to-digital converter 1212 is only 1 mV, the two processed signals S12 with the magnitudes of 400.1 mV and 400.2 mV are converted into two digital signals S12′ with the magnitude of 400 mV. Thus, since the magnitudes of two digital signals S12′ are identical, the signal processing circuit 12 is unable to discriminate the difference between the sensing results of the two photosensitive pixels 111.
For overcoming the drawbacks of the conventional optical fingerprint sensor, an analog-to-digital converter with the wide dynamic input range and the high resolution has been introduced into the market. However, the use of this analog-to-digital converter increases the fabricating cost of the optical fingerprint sensor. Therefore, it is an important issue to provide an optical fingerprint sensor for acquiring a sharp fingerprint image without largely increasing the fabricating cost.

Optical fingerprint sensor and fingerprint identification method thereof


A proton computed tomography (pCT) detector system, including two tracking detectors in sequence on a first side of an object to be imaged, two tracking detectors in sequence on an opposite side of the object to be imaged, a calorimeter, and a computer cluster, wherein the tracking detectors include plastic scintillation fibers. All fibers in the detector system are read out by Silicon Photomultipliers (SiPM). A method of imaging an object by emitting protons from a source through two tracking detectors, through and around the object, and through two opposite tracking detectors, detecting energy of the protons with a calorimeter, and imaging the object.

1. Technical Field
The present invention relates to three-dimensional computing. In particular, the present invention relates to proton-computed tomography.
2. Background Art
Generating an internal 3D image of an object with proton computed tomography (pCT) starts by firing many protons through the object. Each proton's path (i.e., trace history) is recorded and the collection of all the trace histories are used as input to a computer program that generates the image. Some posit that images generated through pCT will be more effective in proton-based treatments of cancer than images produced through X-rays.
The algorithms that produce images from proton trace histories are complex and involve many stages. The computer memory and speed needed to produce a quality 3D image of an object for which proton-based cancer treatment can be applied (e.g., a human head or pelvis) within clinically meaningful time frames exceeds the capacity of even the most powerful desktop computers available today. Therefore, there is a need for an algorithm to make images from proton trace histories more effectively.
Detectors for pCT in the prior art employ larger bulky plastic cube shaped tubes (such as in Pemler, et al.) with large and bulky photon sensors that require much larger volumes that present problems when mounted on a proton gantry with limited space around the patient. Penner, et al. describes the possibility to perform radiography with protons and used a single X-Y plane in front of the object being analyzed and a single X-Y plane after. Pemler, et al. also uses vacuum photomultipliers, square fibers, and combinatorial readout. Amaldi, et al. describes a Proton Range Radiography system with an imaging area of 10 cm×10 cm with a stack of thirty thin plastic scintillators. The current pCT detector at Lorna Linda uses silicon wafers that are limited in available area (9 cm×9 cm), thus requiring a mosaic of overlapping tiles to achieve large area (27×36 cm). The maximum size now produced of silicon wafers is 10 cm×10 cm. The tiles are shingle overlapped or placed with edges butting, which create dead space in the detector or double layers that require "mathematical removal" during image calculations.
Therefore, there also remains a need for a detector for pCT that eliminates dead space and double layers created by the arrangement of tiles.

This patent is subject to a terminal disclaimer.

High performance computing for three dimensional proton computed tomography (HPC-pCT)

Board of Trustees of Northern Illinois University


A defibrillator for providing a constant low pulsed current to a patient's heart has a high voltage capacitor for storing electrical energy. An inductor connected to the capacitor smooths out the discharge curve and produces a low current low frequency defibrillator pulse supplied to a patient's heart. The pulse is usually biphasic.

The invention relates in general to a defibrillator and in particular, to a defibrillator for supplying a high energy pulse at a relatively low steady current to avoid causing discomfort to a patient to whom the defibrillator pulse is supplied while providing effective atrial defibrillation.
Cardiac defibrillators are used to provide a high energy electric pulse from a high voltage capacitor to a patient's heart for the purpose of restoring normal sinus rhythm. In some cases, persons who have previously had myocardial infarctions may be prone to ventricular or atrial tachycardia, unwanted racing of one or more chambers of the heart. Such tachycardia may lead to fibrillation of the myocardium usually of the ventricle. Fibrillation is the random firing of the muscle fibers of the myocardium. The random firing prevents the uniform pulsatile contraction normally associated with pumping of the heart. When fibrillation occurs all effective pumping stops, The normal sinus rhythm must be restored within a few minutes in order to prevent damage to tissues needing large amounts of oxygen such as the brain. Failure to restore normal sinus rhythm leads to death.
Paddle-type defibrillators typically provide up to 400 joules of electrical energy through the surface of the chest and into the heart to restore the normal sinus rhythm. Typically the discharge of current leads to a "resetting" of the electrical condition of the heart cells. The cells can then depolarize in a depolarization wave traveling along the heart. The depolarization wave causes the uniform pumping contraction of the heart characteristic of normal sinus rhythm.
However, it is also known that discharging that amount of electrical energy into the body of a patient is extremely painful and can cause the patient great discomfort. Normally, however, the patient in ventricular fibrillation has already lost consciousness and does not experience pain.
It is also known that although some patients do not have problems with ventricular fibrillation, particularly the elderly, they may suffer from atrial fibrillation. Unlike ventricular fibrillation which leads to total loss of the cardiac pumping function, atrial fibrillation, while not immediately life-threatening may nevertheless be dangerous. Atrial fibrillation causes a loss in the pumping capacity of the atriums which deliver blood to the ventricles. In particular, in atrial fibrillation a portion of the blood volume, which is normally ejected from the atriums into the ventricles, will remain behind. This can lead to stagnation of the blood within the atriums and increase the risk of the formation of a thrombus or a release of an embolus. Such emboli may be pumped out of the atrium through the ventricle and out into the generalized circulation of the body. The embolus may lodge in the brain causing a cerebrovascular accident or stroke. It may cause phlebitis if it lodges in one of the limbs such as the legs. If the embolus is generated in the right atrium, it may be carried into the circulatory system of the lungs leading to a pulmonary embolism. While none of the these conditions other than stroke, are immediately life threatening, once the embolus travels and lodges the eventual damage can be extremely debilitating or even ultimately fatal.
It is presently known that in order to provide cardioversion or the restoration of normal rhythm to an atrium, this may be accomplished by the introduction of a catheter, such as a Swan-Ganz catheter, into the brachial artery of the arm. The catheter is then passed through the pulmonary artery into one of the right atrium of the heart. While the patient is normally unconscious or heavily sedated in situations where ventricular cardioversion is to take place, and time is of the essence, patients are often not so heavily sedated or are unconscious for atrial cardioversion. As a result, the normal discharge of electrical energy through the heart for atrial cardioversion can be disconcerting and in some cases painful. One reason why the atrial cardioversion current can be painful is because a typical capacitive discharge starts at a very high current and then decays exponentially with time to a low current. The large magnitude of the current at the onset tends to cause pain in and of itself. In addition, at the beginning of the exponentially-decaying current discharge the time rate of change of the current is very large. This tends to be at a rate which directly stimulates pain nerves associated with the heart and adds additional pain.
It is also known from physiological studies that the rapidly changing high onset current, which often results in the pain, is not particularly effective for atrial cardioversion. Rather, it is the total current over the exponential curve that is required to be at a minimum level in order to achieve cardioversion. Typically, for instance, five to ten joules can be used for atrial cardioversion. Thirty joules would have to be delivered to the heart for ventricular cardioversion.
Some workers in the art may have partially solved these problems by providing defibrillators having high voltage discharge capacitors that supply defibrillating current to inductors for later delivery to the patient. As discussed in U.S. Pat. No. 4,566,457 to Stemple, U.S. Pat. No. 5,249,573 to Fincke et al., U.S. Pat. No. 5,443,490 to Flugstad, U.S. Pat. No. 5,591,209 to Kroll and U.S. Pat. No. 5,607,454 to Cameron et al., the inductors are used for pulse shaping. Cameron et al. cite Anderson et al., "The Efficacy of Trapezoidal Wave Forms for Ventricular Defibrillation," Chest, 70(2):298-300 (1976) which discloses that trapezoidal waveform current pulses may be used for defibrillation. The use of triangular and trapezoidal waveforms for defibrillation is also disclosed in Schuder, J. C., Rahmoeller, G. A., and Stoeckle, H., "Transthoracic Ventricular Defibrillation with Triangular and Trapezoidal Waveforms," Circulation Research, vol. XIX, pp. 689-694, October 1966. Schuder et al. cite Schuder, J. C., Stoeckle, H., West, J. K. and Dolan, A. M., "A Very High Power Amplifier for Experimental External Defibrillation," 16th Annual Conference on Engineering in Medicine and Biology, p. 40, (1963).
A switching defibrillation system is disclosed in U.S. Pat. No. 5,222,492 to Morgan et al. The Morgan et al. system includes a capacitor coupled by a series-connected field effect transistor switch connected to an inductor. The transistor is switched multiple times during a defibrillation pulse for the purpose of providing the pulse with a sinusoidal shape. A control circuit receives feedback representative of the defibrillation pulse and controls the pulse shape by controlling the pulse widths into a gate of the field effect transistor.
What is needed then is a way of supplying a uniform current without the high onset current and high time rate of change of current produced by present atrial defibrillators.

High energy defibrillator employing current control circuitry


An improved hand tool includes an improved handle apparatus. The handle apparatus includes an elongated handle having a non-circular external cross-section and further includes an elongated support that comprises an elongated end extending from the handle and having a substantially circular cross-sectional shape. A tool apparatus includes a tool and a socket, with the socket having an opening formed therein. The end of the handle apparatus is received with an interference fit in the opening formed in the socket to retain the handle apparatus and the tool apparatus together. A collar can additionally be provided about the socket to improve the aesthetic properties of the connection between the socket and handle and to increase the toughness of the connection therebetween.

Field
The disclosed and claimed concept relates generally to hand tools and, more particularly, to an improved method of mounting a handle having a non-circular exterior surface to a tool, and an associated method.
Related Art
Numerous hand tools such as shovels, rakes, trowels, and the like are well known in the relevant art. The handles of such hand tools have historically been of a substantially round, i.e., substantially circular, cross-section, but more recently a number of non-circular handles have been introduced that are ergonomically superior for use in the hand.
It has also been known to connect such handles, both those having a round cross-section and those having a non-round cross-section, to a tool with the use of a mechanical fastener. For example, an elongated rivet or bolt extends across the diameter of the handle and also extends through the sides of a socket within with the end of the handle is disposed, whereby the mechanical fastener helps to retain the handle in the socket. It can be understood, however, that such mechanical fasteners undesirably add to the cost and weight of a tool. While methodologies have been developed for mounting a handle having a round cross-section to a tool without the use of such an additional mechanical fastener, it has not yet been possible to apply such methodologies to a handle having a non-round cross-sectional external shape.

Hand tool with handle apparatus and associated method


A method of reducing the fringe capacitance between a gate and a substrate in a semiconductor device. A silicon nitride is formed over a substrate with a buffer oxide layer thereon and patterned to form an opening. The buffer oxide layer within the opening is removed and another oxide layer is formed at the same place as a gate oxide layer. A poly-gate is formed at the opening with a wider width than the opening. Thus, a part of the poly-gate at both ends covers a part of the silicon nitride layer. The silicon nitride layer is then removed and leaves the poly-gate as a T-shape with two ends suspended over the substrate. With a large angle, a light dopant is implanted into the substrate under the suspended part of the poly-gate to form a lightly doped region. With another smaller angle, a heavy dopant is implanted into the substrate beside the poly-gate. Therefore, a source/drain is formed. A undoped silicate glass layer and a borophosphosilicate layer are formed in sequence, and an air gap is formed between the suspended part of the poly-gate and the substrate.

1. Field of the Invention
The invention relates to methods of fabricating an integrated circuit, and more particularly to a method of reducing the fringe capacitance between a gate and a substrate.
2. Description of the Related Art
The dimension of semiconductor integrated circuits is being made smaller and smaller. During fabrication, every parameter is required to be accurate and precise since even a very tiny deviation may cause a fatal failure.
In FIG. 1, one conventional method of making a semiconductor device is presented. A semiconductor device including a substrate 100, a source 102 /drain 104, a poly-gate 106, a gate oxide 108 between the gate 106 and the substrate 100, and a pair of spacers 110 on the side wall of the gate 106 are shown in the figure. In addition, due to the hot electrons caused by a short channel, a pair of lightly doped regions are form between the source 102 and drain 104 under the gate 106.
If the thickness of the gate 106 is noted as H.sub.int, the thickness of the gate oxide 108 is t.sub.ox, there exists a gate fringe capacitance near the edge of the gate. The fringe capacitance C can be written as: ##EQU1## Thus, provided that all geometric parameters, such as H.sub.int and t.sub.ox, are kept in the same condition, the fringe capacitance C is proportional to the dielectric constant .epsilon. of the medium. In this case, the medium are the spacers 110. In conventional semiconductor devices, the material of the spacers is normally silicon oxide or silicon nitride. The dielectric constants of these two materials are about 3.9 and 7.5, respectively. It is known that the delay time .tau. is equal to the product of resistance R and the capacitance C. That is, .tau.=RC. Therefore, the very high dielectric constant of silicon oxide or silicon nitride causes a measurable fringe capacitance. Thus, a very long delay time which deteriorates the operation of device, or even the whole integrated circuit, occurs.


According to some embodiments, a pre-poled, single-domain body of a ferroelectric crystalline material such as lithium tantalate or lithium niobate is electrically reduced by applying a voltage across the body in a non-oxidizing environment while the body is heated to a process temperature below its Curie temperature. The voltage generates an electric field along the polar axis of the body. Electrodes may be formed on the body surface by applying an acetate-based silver paint. Exemplary methods allow achieving electrical conductivity values of 10−11 to 10−9 Siemens/cm.

The present invention relates generally to systems and methods for increasing the electrical conductivity of ferroelectric materials such as lithium niobate and lithium tantalate.
Lithium tantalate (LiTaO3) and lithium niobate (LiNbO3) are well known ferroelectric materials. Their single polar properties coupled with their transparency from 350 nm to 4000 nm make them useful for many non-linear optical applications. The piezoelectric properties of these crystals have found wide application as substrates for Surface Acoustic Wave (SAW) devices. A thin film inter digital transducer (IDT) deposited on the free surface of a piezoelectric crystal may be used for RF filters and IF filters in cellular phones and base stations, among others. Various rotated-axis cuts of LiTaO3 have also been used to realize new and unique SAW devices for a number of applications. The trend for SAW devices using this material is to smaller area footprints and thinner wafer material.
Substantial progress has been made in producing exceptionally flat LiTaO3 material with improved techniques in polishing and grinding. At the same time, many of the lithium tantalate treatment processes expose the material to potentially damaging high electrical fields due to pyroelectric effects produced within the crystal during various process heat treatments. High electric fields can be developed across semi-insulating pyroelectric crystals with relatively small changes in temperature. For a crystal such as LiTaO3, whose pyroelectric coefficient is 10−8 Coul/cm2 deg K and dielectric constant is 46, a 25° C. change can produce an electric field on the order of 50 kV, easily enough to create a discharge within the crystal or breakdown the air surrounding it. Pyroelectric effects can cause device fabrication problems including eventual device performance degradation, and in some cases catastrophic crystal fractures. To work around the inconvenience of these effects makes the fabrication process more costly and time consuming.
Charge build up during processing can be reduced by creating a more conductive crystal substrate. Increasing crystal conductivity may be achieved by using a reducing agent in a heat treatment close to the Curie temperature of the crystal. In U.S. Pat. No. 6,932,957, Miles et al. describe a method of increasing the bulk conductivity of lithium tantalate by placing the lithium tantalate in an environment including zinc vapor, and heating the lithium tantalate to below its Curie temperature.

Systems and methods for electrically reducing ferroelectric materials to increase bulk conductivity


Methods, apparatus, and kits are described, one method embodiment comprising loading a solids-laden screen into a carriage of a washing enclosure, the solids-laden screen comprising a screen mesh partially obstructed with solids from a well drilling or work-over operation, and spraying a cleaning composition onto first and second sides of the screen while vibrating the screen. Apparatus and kits for practicing the methods are also described. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims.

1. Field of Invention
The present invention relates generally to the field of cleaning equipment used in oilfield operations, and more specifically to methods and apparatus for cleaning screens used in solid/liquid separations in oilfield operations.
2. Related Art
The need for solids control, such as in conjunction with the use of drilling mud during hydrocarbons well drilling, has long been known. Drilling mud, typically a mixture of clay and water and various additives, is pumped through a hollow drill string (pipe, drill collars, bit etc.) down into the well and ejected through holes in the drill bit. Among other functions the mud picks up cuttings, rock and other solids from the bottom of the well and carries these solids away from the bit upward and out of the well in a space between the well walls and the drill string. At the top of the well, the solids-laden mud is directed to the shale shaker, a device consisting essentially of a series of screens which catch and remove solids from the mud as the mud passes through the screens. Each screen is caused to vibrate by vibrating equipment (shale shakers), in such a manner as to create a longitudinal flow of trapped solids in either direction on the top surface of the screen for removal and disposal of the solids. This filtering, along with other cleaning processes allows the mud to be reused.
The fineness or coarseness (mesh size of the mesh of a screen may vary depending on such factors as flow rate and size of solids to be separated by the screen. During this process the openings in the screen mesh tend to plug or solids get trapped and the fluid components of the mud are restricted from passing through the screen, reducing the flow capacity of the screen.
Once solids are separated by the screens in the shale shaker, in accordance with the prior art, upon completion of drilling the well the screens are taken off of the shale shaker, washed and cleaned in an open environment, and prepared to be used on the next well, or the screens are discarded if there was damage to the screen mesh during prior drilling operations. A typical practice is to simply lean the screens against a railing or other support on a drilling rig or work-over rig and hydroblast the screens, perhaps with some cleaning agent, with the excess water and cleaning agent simply draining into the local environment. As will be noted, this practice may allow contaminants and potentially hazardous materials to enter the environment. In addition, since the water and cleaning agent are not recycled, the volume of water and any cleaning agent used is quite voluminous and undesirable.
It would be advantageous and an advance in the art of cleaning drill cuttings screens to eliminate or substantially reduce the amount of contaminants and potentially hazardous materials entering the environment during cleaning of such screens, and to reduce the amount of water and other cleaning agents used.

Methods and apparatus for cleaning screens used in solid/liquid separations in oilfield operations


There is provided a projection optical system capable of projecting an image formed on an image forming unit on a projection plane, which has an extremely short projection distance and a small size.

1. Technical Field
The present invention relates to a projection optical system, and an image display apparatus provided with the projection optical system.
2. Description of the Related Art
The image display apparatuses, such as projectors, are usually provided with a projection optical system that magnifies and projects an image on a projection plane such as a screen. Recently, a demand for a projector of which projection distance is extremely short and which can greatly magnify a display size of an image on a screen (can implement a large screen display), that is, a front projection type projector with an ultra-short projection distance has been increased. In addition, a request for miniaturization of the projector has also been increased.

Projection optical system and image display apparatus


Disclosed herein are modified plant zinc finger proteins; compositions comprising modified plant zinc finger proteins and methods of making and using modified plant zinc finger proteins. The modified plant zinc finger proteins, in contrast to naturally-occurring plant zinc finger proteins, have a binding specificity that is determined by tandem arrays of modular zinc finger binding units.

Zinc finger proteins (ZFPs) are proteins that bind to DNA, RNA and/or protein, in a sequence-specific manner, by virtue of a metal stabilized domain known as a zinc finger. See, for example, Miller et al. (1985) EMBO J. 4:1609-1614; Rhodes et al (1993) Sci. Amer. February :56-65; and Klug (1999) J. Mol. Biol. 293:215-218. There are at least 2 classes of ZFPs which co-ordinate zinc to form a compact DNA-binding domain. Each class can be distinguished by the identities of the conserved metal-binding amino acids and by the associated architecture of the DNA-binding domain.
The most widely represented class of ZFPs, known as the C2H2 ZFPs, comprises proteins that are composed of zinc fingers that contain two conserved cysteine residues and two conserved histidine residues. Over 10,000 C2H2 zinc fingers have been identified in several thousand known or putative transcription factors. Each C2H2 zinc finger domain comprises a conserved sequence of approximately 30 amino acids that contains the invariant cysteines and histidines in the following arrangement: -Cys-(X)2-4-Cys-(X);2-His-(X)3-5-His (SEQ ID NO: 1). In animal genomes, polynucleotide sequences encoding this conserved amino acid sequence motif are usually found as a series of tandem duplications, leading to the formation of multi-finger domains within a particular transcription factor.
Several structural studies have demonstrated that the conserved C2H2 amino acid motif folds into a beta turn (containing the two invariant cysteine residues) and an alpha helix (containing the two invariant histidine residues). The alpha helix and beta turn associate along a hydrophobic interface and are held together through the tetrahedral coordination of a zinc atom by the conserved cysteines and histidines.
The three-dimensional structure of a complex between a DNA target site and a polypeptide comprising three C2H2 zinc fingers derived from the mouse immediate early protein zif268 (also known as Krox-24) has been determined by x-ray crystallography. Pavletich et al. (1991) Science 252:809-817. The structure reveals that the amino acid side chains on each zinc finger alpha helix interact specifically with functional groups of the nucleotide bases exposed in the DNA major groove. Each finger interacts with DNA as a module; changes in the sequence of amino acids of the recognition helix can result in corresponding changes in target site specificity. See, for example, Wolfe et al. (1999) Annu. Rev. Biophys. Biomol. Struct. 3:183-212.
Another class of ZFPs includes the so-called C3H ZFPs. See, e.g. Jiang et al. (1996) J. Biol. Chem. 271:10723-10730 for a discussion of Cys-Cys-His-Cys (C3H) ZFPs.
The modular nature of sequence-specific interactions between zinc fingers and DNA sequences (i.e., a particular zinc finger of defined sequence binds to a DNA triplet or quadruplet of defined sequence) allows certain DNA-binding domains of predetermined specificity to be designed and/or selected. See, for example, Blackburn (2000) Curr. Opin. Struct. Biol. 10:399-400; Segal et al. (2000) Curr. Opin. Chem. Biol. 4:34-39. To this end, numerous modifications of animal C2H2 zinc finger proteins, most often either mouse zif268 or human SP-1, have been reported. See, e.g., U.S. Pat. Nos. 6,007,988; 6,013,453; 6,140,081; 6,140,466; GB Patent No. 2,348,424; PCT WO98/53057; PCT WO98/53058; PCT WO98/53059; PCT WO98/53060; PCT WO98/54311; PCT WO00/23464; PCT WO 00/42219; Choo et al. (2000) Curr. Opin. Struct. Biol. 10:411-416; Segal et al. (2000) supra; and references cited in these publications. The results of these and other studies are generally consistent with the idea that it is possible to obtain C2H2 ZFPs, based on, for example, the mouse zif268 ZFP or the human SP-1 ZFP, of desired target site specificity. Such target-specific ZFPs are generally obtained by selection or design of individual fingers, each of which has a 3-4 nucleotide target specificity, and assembly of such fingers into a ZFP having a target site specificity of 9-20 nucleotides.
C2H2 ZFPs have been identified in plants, where they are involved in, for example, developmental regulation of various floral and vegetative organs. See, e.g., Takatsuji (1999) Plant Mol. Biol. 39:1073-1078. In plant ZFPs, however, zinc fingers do not generally occur in closely-spaced tandem arrays. For example, in a family of DNA binding proteins identified in Petunia (the EPF family), two canonical Cys2-His2 zinc finger motifs are separated by an intervening stretch of between 19 and 232 amino acids. The binding capability of this class of proteins appears to be determined by both the zinc fingers and the intervening amino acids, suggesting that plant zinc finger proteins have a different mechanism of DNA binding that do the zif268 and SP-1 zinc finger proteins, for example. In addition, the sequence specificity of DNA binding by EPF-type plant ZFPs is dependent upon different positions in the recognition helix of the zinc finger than is the specificity of DNA binding by most zif268-type ZFPs. See, for example, Takatsuji (1996) Biochem. Biophys. Res. Comm. 224:219-223.
Targeted gene regulation in plants would facilitate numerous applications such as, for example, the optimization of crop traits affecting nutritional value, yield, stress tolerance, pathogen resistance, and resistance to agrochemicals. In addition, targeted gene regulation could be used to study gene function in plants, and to adapt plants for use as biological factories for the production of pharmaceutical compounds or industrial chemicals. Such regulation could theoretically be achieved by design of plant transcriptional regulatory proteins of predetermined DNA sequence specificity. However, to date, naturally occurring plant ZFPs that recognize DNA by using a tandem arrangement of modular zinc finger binding domains (as do zif268 and related ZFPs) have not been described. Therefore, it remains difficult, if not impossible, to design a plant ZFP capable of recognizing and binding to a particular predetermined nucleotide sequence. Furthermore, since the mechanism of DNA binding by plant ZFPs remains largely unknown, no immediate solution to this problem is apparent. Accordingly, the ability to design and/or select plant zinc finger proteins of predetermined target specificity would be desirable.

Zinc finger proteins for DNA binding and gene regulation in plants


The present invention provides a polymorphic marker found in a region of the interferon receptor gene that can be used to assess the efficacy of interferon therapy. Thus, the present invention also relates to methods of assessing the efficacy of interferon therapy in an individual and means for accomplishing such a method.

There are about 2,000,000 individuals infected with the hepatitis C virus (hereinafter abbreviated HCV) in Japan. Chronic hepatitis occurs in about 70% of infected individuals, a part of which is considered to lead to the onset ofhepatic cancer 10 to 20 years later. Such chronic hepatitis can be treated effectively with interferon (hereinafter abbreviated IFN) α or β. However, the efficacy of IFN α/β has been reported to vary greatly depending on host and viral factors.
Taking into account the substantial side effects associated with IFN treatment, the prolonged treatment period and the high price of the treatment, treating a patient with IFN for whom successful results are not expected creates not only distress for the patient but also a substantial waste of healthcare money paid by the patient or the nation. Accordingly, there is a significant need to develop a method for estimating whether or not successful results can be expected in an individual patient with a particular IFN therapy.
Thus, an object of the invention is to provide a method for estimating whether or not successful results can be expected in an individual patient with a particular IFN therapy.

Polymorphic marker that can be used to assess the efficacy of interferon therapy


A method involves plating pillars of electrically conductive material up from a seed layer located on a substrate, surrounding the pillars with a fill material so that the pillars and fill material collectively define a first package, and removing the substrate from the first package.

U.S. patent application Ser. Nos. 11/329,481, 11/329,506, 11/329,539, 11/329,540, 11/329,556, 11/329,557, 11/329,558, 11/329,574, 11/329,575, 11/329,576, 11/329,873, 11/329,874, 11/329,875, 11/329,883, 11/329,885, 11/329,886, 11/329,887, 11/329,952, 11/329,953, 11/329,955, 11/330,011 and 11/422,551, incorporated herein by reference, describe various techniques for forming small, deep vias in, and electrical contacts for, semiconductor wafers. Our techniques allow for via densities and placement that was previously unachievable and can be performed on a chip, die or wafer scale. However, if these techniques are used to form high density interconnects, there is presently no "off the shelf" or low cost commercially available packaging that can be used with them.
There is therefore a present need for low cost packaging that can be used with such high density interconnects.


The invention relates to methods of enriching for hematopoietic cell populations enriched in myeloid and/or lymphoid progenitor cells based on cell specific markers. The methods also provide an enriched population of prethymic lymphoid-committed progenitor population lacking long-term hematopoietic reconstitution potential. Compositions enriched for the cells and populations of cells obtained therefrom are also provided by the invention. Methods of use of the cells are also included. Methods of genetically modifying the cells are provided as are cells obtained thereby.

Mammalian hematopoietic (blood) cells provide a diverse range of physiologic activities. Hematopoietic cells are divided into lymphoid, myeloid and erythroid lineages. The lymphoid lineage, comprising B, T and natural killer (NK) cells, provides for the production of antibodies, regulation of the cellular immune system, detection of foreign agents in the blood, detection of cells foreign to the host, and the like. The myeloid lineage, which includes monocytes, granulocytes, megakaryocytes, as well as other cells, monitors for the presence of foreign bodies, provides protection against neoplastic cells, scavenges foreign materials, produces platelets, and the like. The erythroid lineage provides the red blood cells, which act as oxygen carriers.
All publications cited herein are hereby incorporated herein by reference in their entirety.
Despite the diversity of the nature, morphology, characteristics and function of hematopoietic cells, it is presently believed that these cells are derived from a single cell population, termed hematopoietic "stem cells." Unlike more "mature" blood cells, stem cells are capable of self-regeneration but may also divide into progenitor cells that are no longer pluripotent and have a limited self-regeneration. These progenitor cells divide repeatedly to form more mature cells which eventually become terminally differentiated to form the various mature hematopoietic cells. Thus the large number of mature hematopoietic cells is derived from a small reservoir of stem cells by a process of proliferation and differentiation.
Progenitor cells mature into bipotential cells and then become lineage committed, that is, are incapable of maturing into more than one lineage. The use of the words progenitor or progenitor cells indicates cell populations which are no longer stem cells but which have not yet become terminally differentiated. The use of the word lymphoid, myeloid or erythroid in conjunction with progenitor indicates the potential cell populations into which the progenitor is capable of maturing.
Highly purified populations of stem cells currently find use in repopulation of the entire hematopoietic system. Purified progenitor cells of individual lineages would find use in repopulating or augmenting the various lineages. As progenitors are not believed to be extensively self-regenerating, the repopulation or augmentation would be limited.
Stem cells and progenitor cells constitute only a small percentage of the total number of hematopoietic cells. Hematopoietic cells are identifiable by the presence of a variety of cell surface protein "markers." Such markers may be either specific to a particular lineage or be present on more than one cell type. The markers also change with stages of differentiation. Currently, it is not known how many of the markers associated with differentiated cells are also present on stem and progenitor cells. One marker, CD34, is found on stem cells and a significant number of progenitors. U.S. Pat. No. 5,061,620 describes a composition comprising human stem cells.
Table 1 summarizes probable phenotypes of stem cells in fetal, adult, and mobilized peripheral blood. As used herein both infra, supra and in Table 1, the negative sign or, uppercase negative sign, (-) means that the level of the specified marker is undetectable above Ig isotype controls by immunoflow cytometry analysis, and may include cells with very low expression of the specified marker that would be below the sensitivity threshold of the technique.
TABLE 1 __________________________________________________________________________ Probable Stem Cell Phenotypes Other Natural Killer and B cell Myelomonocytic Markers T cell markers markers Markers HLA- P-gp CD2 CD3 CD8 CD10 CD19 CD20 CD14 CD15 CD16 CD33 CD34 CD38 DR C-Kit Thy Rho Activity __________________________________________________________________________ Fetal - - - - - - - - - ? + - + + + lo + Bone Marrow Adult - - - - - - - - - - + ? lo/-- + + lo + Bone Marrow Adult - - - - - - - - - lo/-- + ? lo/-- ? + lo + Mobilized Peripheral Blood __________________________________________________________________________
The exact series of differentiation steps which occurs from stem cells to lineage commitment and to terminal differentiation is unknown; likewise, the various subpopulations of cells involved have not been well characterized.
Lymphocytes are highly specialized hematopoietic cells. During the development of the B and T lymphoid lineages, phenotypic and molecular differentiation of primitive cells leads to mature stages where rearrangement of the lymphocyte antigen receptors occur, namely the immunoglobulin (Ig) or T-cell receptor (TCR) chains. Van Noesel and Lier (1993) Blood 82:363-373; and Godfrey and Zlotnik (1993) Immunol. Today 14:547-553. Commitment to the B-cell lineage, expression of the B-cell receptor complex and Ig gene rearrangements take place in the bone marrow or fetal liver. Uckun (1990) Blood 76:1908-1923; and Li et al. (1993) J. Exp. Med. 178:951-960.
In man, the extensive analyses of leukemias, fetal liver and bone marrow have shown that the earliest recognizable population of cells committed to the B lineage express the markers CD34, HLA-DR and CD10 and have intranuclear terminal deoxynucleotidyl transferase activity with Ig genes in germline configuration. Uckun (1990). The marker CD19 is subsequently expressed and remains expressed throughout most later stages of B-cell differentiation, which stages are further identified by the expression of an array of markers including surface Ig. The marker CD2 is transiently found on early B-cell precursors at the time of CD19 expression, so the earliest B-cell precursor can be identified by expression of CD34 and CD10 but in the absence of CD19 and CD2. Uckun (1990). CD10, or CALLA, is a neutral endopeptidase expressed by several hematopoietic and non-hematopoietic cells. LeBien and McCormack (1989) Blood 73:625.
Unlike B-cell differentiation, T-cell development requires passage of T-progenitor cells through the thymus gland to achieve efficient T-cell receptor (TCR) rearrangement and major histocompatibility complex (MHC)-restriction. At the thymic stage, immature T cells are called thymocytes. The intrathymic stages of T-cell development have been extensively studied in mice and to a lesser extent in man. Godfrey and Zlotnik (1993); Galy et al. (1993) J. Exp. Med. 178:391-401; Terstappen et al. (1992) Blood 79:666-677; and Sanchez et al. (1993) J. Exp. Med. 178:1857-1866. With use of T-cell differentiation assays and multiparameter flow cytometry, it has been shown that CD34 is expressed on the most immature thymocytes which lack cell surface expression of CD1, CD4, CD8 and CD3 antigens. Galy et al. (1993); and Terstappen et al. (1992). CD34 levels decrease while T-cell maturation proceeds, as is the case with maturation along the myeloid, erythroid and B-cell lineages. Terstappen et al. (1991) Blood 77:1218-1227. Studies in animals using mice or quail/chick chimeras and studies in man with constructs of fetal liver and thymus implanted into surrogate severe combined immunodeficiency (SCID) mice, have shown that a constant input of hematopoietic cells is needed to sustain thymopoiesis. Le Douarin and Jotereau (1973) Nature New Biol. 246:25-27; Scollay et al. (1986) Immunol. Rev. 91:129-157; and McCune et al. (1988) Science 241:1632-1639.
The nature of the pro-thymocyte progenitor is however ill-defined. In man, pre-thymic cells with T-cell differentiative capability have been retrieved from various hematopoietic tissues. Intrathymic T-cell reconstitution is achieved following injection of CD34.sup.+ cells devoid of lineage-specific antigens (Lin.sup.-) isolated from fetal liver (FL). Galy et al. (1993); and Peault et al. (1991) J. Exp. Med. 174:1283-1286. Further fractionation of the CD34.sup.+ Lin.sup.- FL cells has shown that T-lymphoid potential is present in both the CD7.sup.- and CD7dull subsets. Barcena et al. (1993) Blood 82:3401-3414. T-cell differentiation can be initiated with CD34.sup.+ Lin.sup.- fetal bone marrow (FBM) cells and is found in both the CD34.sup.+ Thy-1.sup.+ and CD34.sup.+ Thy-1.sup.- compartments. Baum et al. (1992) Proc. Natl. Acad. Sci. USA 89:2802-2804.
Differentiation into thymocytes can also be achieved with adult tissues. CD34.sup.+ Lin.sup.- cells isolated from normal adult bone marrow (ABM) or from the apheresed cytokine-mobilized peripheral blood (MPB) of cancer patients have recently been shown to undergo de novo thymopoiesis and subsequently proceed toward complete maturation into TCR.alpha..beta..sup.+ and TCR.gamma..delta..sup.+ T-cells. Galy et al. (1994) Blood 84:104-110.
It has been recently reported that after in utero injection into sheep fetuses, CD34.sup.+ HLA.sup.- DR.sup.- cells isolated from human ABM provide long-term (7 months) multilineage hematopoiesis, including production of mature T-cells and B-cells. Srour et al. (1993) Blood 82:3333-3342. These reports provide a preliminary mapping of pre-thymic T-progenitor cell activity, but the phenotypic composition of the T progenitor cell pool as well as the hierarchical ordering of its components remain largely unexplored.
In contrast, extensive phenotypic fractionation of ABM CD34.sup.+ cells has been performed to study myelopoiesis and erythropoiesis. Terstappen et al. (1991); Baum et al. (1992); Lansdorp and Dragowska (1992) J. Exp. Med. 175:1501-1509; Srour et al. (1991) Blood Cells 17:287-295; Craig et al. (1993) J. Exp. Med. 177:1331-1342; and Udomsakdi et al. (1991) Exp. Hematol. 19:338-342. In particular, CD45 isoforms have been useful markers to distinguish primitive from committed myeloid cells. Lansdorp et al. (1990) J. Exp. Med. 1,72:363-366. CD45 antigens are protein tyrosine phosphatases which exist in various isoforms created by alternative splicing. Thomas (1989) Ann. Rev. Immunol. 7:339-369. The high molecular isoforms (p205-p220) have been designated CD45RA and are not expressed on the cell surface of ABM primitive progenitors having long-term culture initiating-cell (LTCIC) activity. Lansdorp and Dragowska (1992). In contrast, CD45RA is found on less primitive bone marrow progenitors as well as on subsets of mature T-cells where it is thought to correlate with specific functional properties (naive T-cells). Sanders et al. (1988) Immunol. Today 9:195-199.
CD45RA is also expressed on a fraction of thymocytes, particularly on cells at a very early stage of intrathymic development. Deans et al. (1991) J. Immunol. :147:4060-4068. It has actually been speculated with the use of multiparameter flow cytometry that the immediate pre-thymic bone marrow-derived progenitor cells might express CD45RA, but functional evidence has not been provided. Terstappen et al. (1992).
The definitive T cell marker is the T cell antigen receptor (TCR). There are presently two defined types of TCR; TCR-2 is a heterodimer of 2 disulfide-linked transmembrane polypeptides (.alpha. and .beta.), TCR-1 is structurally similar but consists of .gamma. and .delta. polypeptides. The .alpha. and .beta. or .gamma. and .delta. polypeptides form a heterodimer which contains an antigen recognition site. These heterodimers recognize antigen in association with MHC molecules on the surface of antigen-presenting cells. All of these proteins contain a variable region which contributes to the antigen recognition site and a constant region which forms the bulk of the molecule and includes the transmembrane region and cytoplasmic tail. Both receptors are associated with a complex of polypeptides making up the CD3 complex. The CD3 complex comprises the .gamma., .zeta. and .epsilon. transmembrane polypeptides. The CD3 complex mediates signal transduction when T cells are activated by antigen binding to the TCR.
Approximately 95% of blood T cells express TCR-2 and up to 5% have TCR-1. The TCR-2 bearing cells can be subdivided further into two distinct non-overlapping populations. CD4.sup.+ T cells which generally recognize antigens in association with MHC class II molecules, and CD8.sup.+ T cells which recognize antigens in association with MHC class I molecules.
A number of markers are carried by B cells but not by resting T cells. The majority of B cells carry MHC class II antigens which are important in cooperation with T cells. Fc receptors for IgG (FcRII, CDw32) are also present.

Method of purifying a population of cells enriched for dendritic and/or lymphoid progenitors and populations of cells obtained thereby


Identification and use of compounds which inhibit the expression or activity of micro-RNAs for preventing and/or attenuating ageing. An in vitro method for screening for candidate compounds for preventing and/or attenuating ageing of the skin including (a) bringing at least one test compound in contact with a sample of fibroblasts, (b) measuring the expression or the activity of at least one microRNA chosen from miR-134 and miR-152 in said fibroblasts, and (c) selecting the compounds for which an inhibition of at least 20%, preferably at least 30%, preferably at least 40% of the expression or an inhibition of at least 20%, preferably at least 30%, preferably at least 40% of the activity of at least one microRNA is measured in the fibroblasts treated in (a) compared with the untreated fibroblasts.

Cellular senescence is a form of irreversible growth arrest, originally described for end-stage proliferative cells in culture, but known to be induced by several stimuli such as DNA damage, oxidative stress, chemotherapy and excess of mitotic stimuli such as oncogenic activation (Serrano et al 1997; Campisi 2001; Schmitt et al 2002). Cells enter in a stage of irreversible arrest, showing distinctive features, including enhanced beta-galactosidase activity and increased expression of key mediators including p53, promyelocitic leukemia protein (PML), p16INK4a and p19Arf (Serrano et al 1997; Narita et al 2003; Sharpless et al 2004). Although mostly studied in vitro, cellular senescence has been correlatively linked to the aging process at the level of the whole animal, thus implicating many of the factors that regulate senescence as contributing to organism aging (Sharpless and DePinho 2004, Campisi 2005).
All senescing cells undergo profound changes in gene expression. Comprehensive gene expression profiling has identified genes in cell cycle, insulin growth factor, interferon, MAP kinase and oxidative stress pathways as consistently dysregulated during cell senescence. Altered gene expression gives rise to the senescent phenotype, and is well established as part of the mechanisms and pathways that activate the senescence program in cells. However, the factors responsible for the alterations of gene expression during senescence remain elusive.
MicroRNAs (miRNAs) are key modulators of gene expression in various biological and pathological processes. Changes in miRNA expression levels occur in cellular senescence and organism aging (Grillari et al 2010; Hackl et al 2010), and have been linked to changes in levels of mRNAs that are putative targets of specific miRNAs (Lafferty et al 2009; He et al 2007; Maes et al 2009). Several studies have identified specific sets of miRNAs up-regulated in fibroblasts replicative senescence (Faraonio et al, 2012; Dhahbi et al, 2011; Yong Wang et al, 2010).
It is thus desirable and important to provide products or active agents which prevent, reduce or even inhibit the cellular senescence, particularly the fibroblast senescence.
The present invention thus provides a method for identifying such useful agents.

Inhibitors of micro-RNAs for use for preventing and/or attenuating skin ageing


A burner for a metal-melting furnace can releasably receive a tapered plug in sealing engagement with an access passage aligned with an air passage. The burner may be configured to extend through a wall of the metal-melting furnace so that the air passage is through a front face within the furnace and so that the access passage is through a rear face outside of the furnace. The access passage may be aligned with the air passage to permit a rigid structure to be passed through the burner from outside the furnace to dislodge build-up of solidified metal from the air passage. The tapered plug may be moveable between a sealing configuration of being received in a seat to seal the access passage during burner operation and a cleaning configuration of being removed from the seat to expose the access passage for insertion of the rigid structure.

Top charge furnaces can be utilized in a variety of metal-processing contexts. Typically scrap metal and/or other source material items are dropped through the top charge furnace's open top and into a zone where burners can provide heat to melt the inputted material. The resulting molten metal can be subsequently routed out of the charge furnace for use in other metal processing equipment.
In many scenarios, material dropped in to the top charge furnace may drop with sufficient force to cause liquid metal within the top charge furnace to splash in unknown or uncontrolled directions within the furnace. Such splashed liquid metal may land on different surfaces and ultimately solidify into obstructions or other buildup that negatively impact the burners or otherwise become problematic over time. Additionally, during melting of scrap, localized high gas velocity can sweep droplets of molten metal into the gas stream. In the case of regenerative burners, much of the exhaust gas stream is drawn through the burner(s) that are in the exhaust mode of the burner cycle. These droplets can impact, oxidize, and adhere to the faces of the burner, resulting in obstructions. Efforts to remove such buildup or obstructions may be expensive and/or time-consuming, such as in situations where production through a top charge furnace is halted to permit the top charge furnace to cool sufficiently to allow personnel to enter the top charge furnace and break away the buildup.