There is provided a polymer electroluminescent device, which comprises a transparent substrate, an anode, a polymer emitting layer, a polymer insulating nanolayer and a cathode. The polymer insulating nanolayer having the dielectric constant (∈) of less than 3.0 is located between the cathode and the polymer emitting layer. According to the present invention, it is possible to obtain the polymer electroluminescent device showing more improved luminance efficiency.

An electroluminescent device utilizes the electroluminescence (EL) phenomenon, wherein an electron injected from a cathode and a hole injected from an anode form an exciton in the polymer emitting layer. A light of a particular wavelength is emitted from the formed exciton. The electroluminescent device does not need back light and has many advantageous features (e.g., light weight, thin thickness, self-illumination, low driving voltage, fast switching speed, etc.) so that it can be widely utilized as a new display device.
As reported by R. H. Friend in 1990, the polymer electroluminescent device in which the thin film is formed by spin coating is fabricated by a more simple process when compared to the low molecular organic electroluminescent device in which the thin film is formed by thermal vapor deposition. Furthermore, the device has a high thermal stability and an excellent mechanical strength. Therefore, many institutes have studied and investigated the polymer electroluminescent device, especially in order to improve the luminance efficiency thereof.
The studies for improving the luminance efficiency are primarily focused on a hole injecting layer or an electron injecting layer. For example, one investigation discloses that the hole injecting layer or the electron injecting layer is filled with an ionomer to improve the luminance efficiency (Lee H. M. et al., Appl. Phys. Lett., 72, 2382, 1998). However, the ionomer limits the free movement of the ion, whereby the injection of the electron or the hole becomes restricted and the durability thereof may become significantly deteriorated if the ion of the ionomer is diffused into the polymer emitting layer.
Moreover, it was described that lithium fluoride (LiF), which could effectively inject the electron, was used in the electron injecting layer to increase the luminance efficiency (T. M. Brown et al., Applied Physics Letters, 77(19), pp. 3096–3098, 2000). The material, however, requires a vacuum deposition so that it is not possible to apply the material for fabricating a large area of device.
In addition, U.S. Pat. Nos. 5,537,000, 5,817,431 and 5,994,835 suggested the methods of using an inorganic nanoparticle, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), chelate metal complex and the like for injecting the electron more effectively. However, it is difficult to fabricate a large area of the device by such method due to the vacuum deposition process.
Therefore, there is a need in the art for a polymer electroluminescent device, which has the improved luminance efficiency and which can be prepared in an easy and convenient manner.

High-efficiency polymer electroluminescent device with a polymer insulating nanolayer

Korea Institute of Science and Technology


A wireless positioning server using clock offset compensation and a wireless positioning method using the same. The wireless positioning server using clock offset compensation estimates a precise position of a tag requiring position information by effectively predicting information regarding a distance between a beacon for performing positioning and the tag requiring position information. An error in the positioning estimation result due to a clock offset is minimized by measuring a relative clock frequency ratio between beacons and by compensating for clock frequencies of the beacons when a distance between a beacon and a tag is estimated.

1. Field of the Invention
The present invention relates to a wireless positioning server using clock offset compensation and a wireless positioning method using the same, and more particularly, to a wireless positioning server using clock offset compensation that may estimate a precise position of a tag requiring position information by effectively predicting information regarding a distance between a beacon for performing positioning and the tag requiring position information, and a wireless positioning method using the wireless positioning server.
2. Description of the Related Art
An indoor/outdoor wireless positioning technique is essential to implementation of a location based service (LBS) technique that has recently emerged. Since signals can be received from a global positioning system (GPS) that are clock-synchronized between satellites outdoors, positioning can be performed using a GPS technique. However, indoors where signals cannot be received from the GPS, a wireless positioning system that is suitable for an indoor environment, is required. Thus, research into a wireless positioning technique that is suitable for indoor wireless positioning, has proceeded briskly.
In general, information regarding a distance between a beacon of a positioning system and a tag that requires position information is required to perform wireless positioning. A wireless positioning technique that is based on time information, such as time of arrival (ToA) or time difference of arrival (TDoA), is mainly used to estimate the information regarding the distance between two devices, i.e., between the beacon and the tag.
Time information between the beacon and the tag for wireless positioning is estimated based on clock information between beacons. However, since an independent clock offset exists in clocks of the beacons, an error occurs in the estimated time information. Due to the effect of the clock offset, an error occurs in the result of estimating the distance between the beacon and the tag.
Although a relative clock offset in the beacons is a minor difference in units of part per million (ppm), the error in the clock information causes an error in the time information. Thus, the wireless positioning system that is based on time information, is very sensitive to the clock offset. Thus, clock offset compensation between the beacons is essential to a low error in position information that requires indoor wireless positioning.
In order to solve these problems, in the related art, Korean Patent Application Publication No. 2011-0051319 discloses a method of reducing a position estimating/updating period of a movement node and improving precision of positioning through line compensation of an error element in a wireless positioning network. However, in the related art, a two way ranging (TWR) method is used to estimate a position of a tag. Thus, the tag should transmit pulse twice, power consumption of the tag is large. In addition, since the ToA technique is used, a process in which the tag participates in time synchronization, is additionally required.

Wireless positioning server using clock offset calibration positioning method using the same

SOONGSIL UNIVERSITY RESEARCH CONSORTIUM TECHNO-PARK

KOREA ELECTROTECHNOLOGY RESEARCH INSTITUTE


A strain gauge for measuring strain in a structural member, including: a light modulator adapted to be attached to the structural member, further including: a plurality of deformable elements, each of said deformable elements having a reflective surface and a resonant frequency that varies as a function of strain on the element; means for exerting a force to the deformable elements to cause them to deform at their resonant frequency between first and second operating states, an optical system for directing incident light onto the light modulator, and directing modulated light from the light modulator to a sensor that provides an output signal that varies as a function of the resonate frequency of said deformable elements; and means for generating a representation of the strain in the structural member from said output signal.

This invention relates to measuring instruments. More particularly, the invention relates to an instrument for measuring strain in structural members, incorporating a resonant light modulator, that is particularly suitable for a wide range of environmental conditions, including both cryogenic and high temperatures.
Advances in micromachining technology have given rise to a variety of micro-electromechanical systems (MEMS) including micromachined light modulators for low cost display applications. Such light modulators provide high-resolution, high operating speeds (KHz frame rates), multiple gray scale levels, color adaptability, high contrast ratio, and compatibility with VLSI technology. Representative examples of these light modulators are disclosed in U.S. Pat. Nos. 4,492,435 issued Jan. 8, 1985 to Banton et al. entitled Multiple Array Full Width Electromechanical Modulator, U.S. Pat. No. 4,596,992 issued Jun. 24, 1986 to Hornbeck entitled Linear Spatial Mechanical Light Modulator and Printer, U.S. Pat. No. 5,311,360 issued May 10, 1994 to Bloom et al entitled Method And Apparatus For Modulating a Light Beam; U.S. Pat. No. 5,661,593 issued Aug. 26, 1997 to Engle entitled Linear Electrostatic Modulator, U.S. Pat. No. 5,757,536 issued May 26, 1998 to Ricco et al. entitled Electrically-Programmable Diffraction Grating; U.S. Pat. No. 6,038,057 issued Mar. 14, 2000 to Brazas, Jr. et al. entitled Method and System for Actuating Electro-mechanical Ribbon Elements in Accordance to a Data Stream; and U.S. Pat. No. 6,061,166 issued May 9, 2000 to Furlani et al. entitled Diffractive Light Modulator. Micromachined diffractive light modulators are of particular interest and versatility for strain gauge applications.
Other MEMS devices have been used to sense various physical properties such as acceleration, pressure, mass flow, temperature, humidity, air density or weight. Representative devices are disclosed in U.S. Pat. No. 5,090,254 issued Feb. 25, 1992 to Guckel et al. entitled Polysilicon Resonating Beam Transducers; U.S. Pat. No. 5,275,055 issued Jan. 4, 1994 to Zook et al. entitled Resonant Gauge With Microbeam Driven In Constant Electric Field; U.S. Pat. No. 5,417,115 issued May 23, 1995 to Burns entitled Dielectrically Isolated Resonant Microsensors; and U.S. Pat. No. 5,550,516 issued Aug. 27, 1996 to Burns et al. entitled Integrated Resonant Microbeam Sensor and Transistor Oscillator. The sensors disclosed in these patents are said to operate on the principal that the natural frequency of vibration (i.e. resonate frequency of an oscillating beam or other member) is a function of the strain induced in the member. More particularly, tensile forces tending to elongate the member increase its resonate frequency, while forces tending to compress the member reduce its resonate frequency. The dual vibrating beam transducers disclosed in U.S. Pat. No. 4,901,586 issued Feb. 20, 1990 to Blake et al. entitled Electrostatically Driven Dual Vibrating Beam Force Transducer, are said to operate in an apparently similar manner. All of the above mentioned transducers and sensors use integrated electrical means to sense the motion of the moving member. This limits the design and placement of both the sensors and the associated electronics. There is a need therefore for an improved strain gauge.
The present invention provides a strain gauge for measuring strain in a structural member, including: a light modulator adapted to be attached to the structural member, further including: a plurality of deformable elements, each of said deformable elements having a reflective surface and a resonant frequency that varies as a function of strain on the element; means for exerting a force to the deformable elements to cause them to deform at their resonant frequency between first and second operating states; an optical system for directing incident light onto the light modulator, and directing modulated light from the light modulator to a sensor that provides an output signal that varies as a function of the resonate frequency of said deformable elements; and means for generating a representation of the strain in the structural member from said output signal.
One advantage of the strain gauge of the invention is that the strain of a structural member can be sensed at locations remote from the structural member. Another advantage is the sensitivity of the strain gauge due to the size of its features. Specifically, the strain gauge features are on the order of microns, and it can measure changes in length on the order of nanometers. Other features and advantages of this invention will be apparent from the following detailed description.

Strain gauge with resonant light modulator


III-nitride materials are used to form isolation structures in high voltage ICs to isolate low voltage and high voltage functions on a monolithic power IC. Critical performance parameters are improved using III-nitride materials, due to the improved breakdown performance and thermal performance available in III-nitride semiconductor materials. An isolation structure may include a dielectric layer that is epitaxially grown using a III-nitride material to provide a simplified manufacturing process. The process permits the use of planar manufacturing technology to avoid additional manufacturing costs. High voltage power ICs have improved performance in a smaller package in comparison to corresponding silicon structures.

1. Field of the Invention
The present invention relates generally to an isolation technique for devices constructed with high band gap materials, and relates more particularly to a III-nitride device and method for isolation in monolithic power IC.
2. Description of Related Art
III-nitride semiconductors are presently known that exhibit a large dielectric breakdown field of greater than 2.2 MV/cm. III-nitride heterojunction structures are also capable of carrying extremely high currents, which makes devices fabricated in the III-nitride material system excellent for power applications.
Development of devices based on III-nitride materials has generally been aimed at high power-high frequency applications such as emitters for cell phone base stations. The devices fabricated for these types of applications are based on general device structures that exhibit high electron mobility and are referred to variously as heterojunction field effect transistors (HFETs), high electron mobility transistors (HEMTs) or modulation doped field effect transistors (MODFETs). These types of devices are typically able to withstand high voltages such as in the range of 100 Volts, while operating at high frequencies, typically in the range of 2-100 GHz. These types of devices may be modified for a number of types of applications, but typically operate through the use of piezoelectric polarization fields to generate a two dimensional electron gas (2DEG) that allows transport of very high current densities with very low resistive losses. The 2DEG is formed at an interface of AlGaN and GaN materials in these conventional III-nitride HEMT devices. Due to the nature of the AlGaN/GaN interface, and the formation of the 2DEG at the interface, devices that are formed in the III-nitride materials system tend to be nominally on, or depletion mode devices. The high electron mobility of the 2DEG at the interface of the AlGaN/GaN layers permits the III-nitride device, such as a HEMT device, to conduct without the application of a gate potential.
One of the advantages attained with power semiconductor devices for manufacturing purposes is the ability to produce compact structures on a single wafer or on a single die. A number of III-nitride devices can be formed on a given wafer or die to speed production and increase efficiency. When the devices are formed on a wafer or die, they are isolated from each other to provide proper independent operation. Accordingly, it would be desirable to produce a number of III-nitride power devices on a single wafer or die with some type of insulation or isolation between the devices.
A drawback of III-nitride devices that permit high current densities with low resistive losses is the limited thickness that can be achieved in the strained AlGaN/GaN system. The difference in the lattice structures of these types of materials produces a strain that can result in dislocation of films grown to produce the different layers. This results in high levels of leakage through a barrier layer such as an insulator, for example, and makes device isolation problematic.
One solution to provide isolation is to add insulation barriers around the device to produce the desired isolation. Typical layers used for this purpose are silicon oxide, silicon nitride, sapphire, or other insulators, disposed between devices. However, these processes and structures are difficult to implement and are not always commercially feasible.
Materials in the III-nitride material system may include Gallium, Aluminum and Indium, as well as their nitrides, GaN, AiN and InN. Gallium nitride (GaN) and its alloys such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN) and indium aluminum gallium nitride (InAlGaN) are also included in this material system. These materials are semiconductor compounds that have a relatively wide direct bandgap that permits highly energetic electronic transitions to occur. Gallium nitride materials have been formed on a number of different substrates including silicon carbide (SiC), sapphire and silicon. Silicon substrates are readily available and relatively inexpensive, and silicon processing technology has been well developed.
Another solution to attain isolation in a III-nitride semiconductor device is through the use of a dielectric. For example, in silicon semiconductors, native oxides are available, such as silicon dioxide, that can serve as a suitable dielectric. However, no equivalent material to the native oxides in silicon is available for suitable dielectrics in the III-nitride material system. Dielectric materials that would otherwise be suitable in silicon semiconductors, for example, do not transfer well to III-nitride devices. Typically, the large dielectric breakdown field produced in the III-nitride material system causes large electric fields in the III-nitride semiconductor devices that are greater than can be withstood with conventional dielectric materials. For example, if silicon dioxide or silicon nitride were to be used for a dielectric in a III-nitride device, these conventional dielectrics may rupture or otherwise fail.
High voltage isolation of devices or components on a substrate or die is known in which different portions of the semiconductor structure are built to have a voltage well, where the device is constructed in the well and, voltage isolated to a particular voltage level. These isolation wells may be formed with a number of barrier structures to prevent leakage from one potential well to another, but such structures are often complicated and expensive to manufacture. For example, isolation of low voltage logic functions from high voltage switching functions often accomplished through junction isolation or dielectric isolation. Junction isolation is less than ideal because the IC is usually operating in a high temperature environment, which causes unacceptably high leakage currents due to thermal generation of carriers. With dielectric isolation, silicon does not provide an acceptably high breakdown field to isolate logic functions from various power functions, as discussed above. Accordingly, complex processes using silicon dioxide are often used. However, silicon dioxide has a low thermal conductivity, which tends to exaggerate the carrier generation that occurs every high temperature environment.
Another way to obtain isolation in conventional semiconductors is to apply an etch process to the semiconductor material over an insulating substrate or semiconductor layer. However, etch processes, including plasma etch processes, induce surface damage and roughness in the etched semiconductor material, which may nevertheless be acceptable for a number of low power, conventional semiconductor devices typically realized in silicon. However, surface damage and roughness in the semiconductor material is particularly problematic for high power electronic devices where problems develop with surface breakdown and leakage currents between device structures.
Accordingly, it would be desirable to devise an isolation technique for semiconductor structures on a substrate or a semiconductor die that is simple and inexpensive to implement.
It is also desirable to obtain isolation without a number of additional steps or the use of additional materials or complexity.
Furthermore, it would be desirable to provide a technique for isolation that produces little or no damage to the semiconductor devices or underlying material.
It would also be desirable to obtain isolation for control and high voltage switching functions in a power IC composed of high band gap materials, including, for example, III-nitride materials.


A plurality of chip regions are defined over a surface of a semiconductor substrate and separated from one another by a scribe region. A plurality of main pads are disposed in the chip regions and a test element group is disposed at the scribe region. The test element group is electrically connected to the main pads through interconnections.

1. Field of the Invention
The present invention relates to semiconductor devices and, more specifically, to semiconductor devices having test element groups for testing characteristics of a device at a chip region.
2. Description of the Related Art
In general, a plurality of chip regions are defined on a wafer and an integrated circuit is formed at each of the chip regions in order to fabricate a semiconductor device. When a fabrication process is completed, characteristics of a device are tested so as to detect whether the device operates normally. Thus, a test element group is formed at a predetermined region of a wafer to test electrical characteristics of the semiconductor device. Chip regions into which the semiconductor chip is divided are conventionally separated from each other by a predetermined distance. A space between the chip regions is called a "scribe region". The test element group includes various kinds of test elements to test several electrical characteristics.
FIG. 1 illustrates a typical semiconductor device. Referring to FIG. 1, a plurality of main chips are formed on a wafer. A space between chip regions 2 is a scribe region 4 which separates the chip regions from each other after a fabricating process is completed. A plurality of test regions 6 are ordinarily disposed at the scribe region 4 to test electrical characteristics of the semiconductor device in the wafer.
FIG. 2 is a view showing a conventional arrangement of a test element group in a semiconductor device. Referring to FIG. 2, a test element group 10 having a plurality of test patterns is disposed at a scribe region 4 between chip regions 2. A plurality of test pads 12 are disposed at both sides of the test element group 10. The test pads 12 are connected to any test element constituting the test element group 10 through interconnections 14. Main pads 8 for inputting/outputting electrical signals to a chip region are disposed at edges of the chip regions 2.
Although wide scribe regions are needed to divide semiconductor devices in the background art, there is a desire to decrease a width of the scribe region consistent with advances in developing precise apparatuses. However, in the conventional semiconductor devices, test pads are disposed at both sides of a test element group, so that it is difficult to decrease a width of the scribe region.

Semiconductor device having test element groups


A surgical instrument comprising a handle assembly, and actuation member, an elongated body portion, and a locking mechanism is disclosed. The locking mechanism is disposed in mechanical cooperation with the actuation member, and is configured to substantially prevent at least a partial movement of the actuation member when the elongated body portion is not engaged with a loading unit. The locking mechanism comprises a link, a bushing, and a connecting member. The link is configured for mechanical engagement with a portion of a loading unit. At least a portion of the busing is disposed proximally of at least a portion of the link. At least a portion of the connecting member is disposed proximally of at least a portion of the bushing. Engagement between a loading unit and the elongated body portion causes proximal movement of the link, the bushing, and the connecting member.

1. Technical Field
This application relates to a surgical instrument, and more particularly, to an endoscopic surgical fastening instrument having a loading unit for applying a plurality of surgical fasteners to body tissue, and to a bushing for use with the surgical instrument.
2. Background of Related Art
Various types of surgical instruments used to surgically join tissue are known in the art, and are commonly used, for example, for closure of tissue or organs in transection, resection, anastomoses, for occlusion of organs in thoracic and abdominal procedures, and for electrosurgically fusing or sealing tissue.
One example of such a surgical instrument is a surgical stapling instrument, which may include an anvil assembly, a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the cartridge and anvil assemblies, and a firing mechanism for ejecting the surgical staples from the cartridge assembly.
Using a surgical stapling instrument, it is common for a surgeon to approximate the anvil and cartridge members. Next, the surgeon can fire the instrument to emplace staples in tissue. Additionally, the surgeon may use the same instrument or a separate instrument to cut the tissue adjacent or between the row(s) of staples.


A cleaning apparatus for optical or magneto-optical storage disks includes a first rectangular part having four lateral edges and a raised interior, the interior having at least three troughs for holding utensils for cleaning the optical or magneto-optical storage disks; a second rectangular part having four lateral edges, an interior which is shaped complementary to the interior of the first rectangular part, and a border which runs completely along its four lateral edges for enclosing a disk cassette of a magneto-optical or optical storage disk inserted for cleaning; and a back strap for connecting the two parts to each other such that the two parts can be folded together, similarly to a book, and locked along their lateral edges. The second part further includes a disk bearing which, when the storage disk is inserted, raises the storage disk inside the disk cassette to such an extent that the storage disk is rotatable without friction. A locking device is provided on the interior of the second part for keeping a shutter of the disk cassette open. The interiors of the first and second parts, together with the troughs, the edge beads, the locking device, the disk bearing, and the border are deep-drawn from plastics film.

The invention relates to a cleaning apparatus for optical or magneto-optical disks which includes two rectangular or square parts which are connected to one another by a back strap and which can be folded together, similarly to a book, and locked along their lateral edges.
After prolonged use, for example 1000 operating hours, optical and magneto-optical storage disks must be cleaned to remove dust, fingerprints and electrostatic surface charges on the recording layer. The shutter of the disk cassette which encloses the storage disk must be opened and locked during the cleaning process. The utensils required for cleaning the recording layer, such as brushes, liquids, pads, cloths and turning handle for the storage disk, are, as far as possible, kept ready for use in a common container.
EP-A-0417726 discloses, for example, a book-like container in which a disk cassette with an optical storage disk is kept, with the shutter open. The container contains a shutter locking means for opening the disk cassette shutter and a spindle which supports the optical storage disk so that it can rotate. An attachment for rotating the storage disk simplifies the manual rotation of the storage disk during the cleaning process, which is carried out with the aid of a cleaning cloth and a cleaning liquid. The rotary attachment and the cleaning materials are housed in the book-like housing.
Another cleaning means on the market has an electrically driven spindle bearing on which the storage disk to be cleaned is mounted in order to be rotated by the electrical drive during the cleaning process. Cleaning is carried out by pressing a cleaning cloth impregnated with the cleaning liquid against that section of the storage disk which is exposed by the shutter. This cleaning means operates completely automatically in that the cleaning cloth or the cleaning pad is moved by a motor rarotary knobly toward the circumference of the storage disk while the latter rotates. More detailed investigations show that, in the case of this completely automatic cleaning means, the cleaning pads very frequently rest unevenly on the surface of the storage disk to be cleaned, so that cleaning takes place in a very nonuniform manner. Individual gauging of the contact pressure of the cleaning pad against the storage disk is not possible.
A further cleaning means on the market, in which the storage disk is manually rotated, contains a spindle bearing having a spindle and a locking means for the disk cassette shutter, which are incorporated in the cleaning means. The storage disk is mounted on the spindle bearing and caused to rotate by means of a handle, while that region of the storage disk which is exposed by the open shutter is cleaned with the cleaning cloth impregnated with a cleaning liquid.
A further known, fully automatic cleaning means contains a motor-driven brush which is provided with a spiral groove as a cleaning element. The storage disk to be cleaned is driven by an electrically operated bearing on which the storage disk rests. The cleaning brush rotates in its position synchronously with this drive. Wet cleaning is not possible with this cleaning means.

Cleaning apparatus for optical and magneto-optical disks


An electrical structure and method comprising a first substrate electrically and mechanically connected to a second substrate. The first substrate comprises a first electrically conductive pad and a second electrically conductive pad. The second substrate comprises a third electrically conductive pad, a fourth electrically conductive pad, and a first electrically conductive member. The fourth electrically conductive pad comprises a height that is different than a height of the first electrically conductive member. The electrically conductive member is electrically and mechanically connected to the fourth electrically conductive pad. A first solder ball connects the first electrically conductive pad to the third electrically conductive pad. The first solder ball comprises a first diameter. A second solder ball connects the second electrically conductive pad to the first electrically conductive member. The second solder ball comprises a second diameter. The first diameter is greater than said second diameter.

1. Technical Field
The present invention relates to an electrical structure for producing multiple size interconnections between substrates.
2. Related Art
Joining substrates together in electrical applications typically requires a large number of connections between the substrates. The substrates may not be large enough to accommodate the large number of connections. Therefore there exists a need to accommodate the large number of connections necessary to join substrates together in electrical applications.

Structure and method for producing multiple size interconnections

International Business Machines Corporation


A surgical instrument that includes a rigid outer member within which is disposed a hollow inner member having rigid proximal and distal ends and a region disposed between the rigid proximal and distal ends that is relieved to render such region relatively flexible. The flexible region is integral with a portion of the proximal end disposed adjacent to the flexible region. The inner member transmits force (such as torsion) applied to its proximal end to move a cutting implement disposed at its distal end and cause it to cut tissue admitted through an opening in the distal region of the outer member. In another aspect, a region of the inner member is weakened (e.g., by relieving an integral region of the member) with respect to the remainder of the inner member to cause this region to break if the force (e.g., torque) applied to the inner member exceeds a predetermined threshold. In yet another aspect, the flexible region is relieved by forming openings therein, and pliable material (such as silicone rubber) is disposed in the openings.

This invention relates to surgical instruments, and in particular to powered arthroscopic surgical instruments.
Arthroscopic surgical instruments typically include an rigid outer tube within which a rigid inner tube is rotated by a motor. A cutting implement, such as a blade or abrading burr, is disposed on the distal end of the inner tube. Tissue or bone is exposed to the cutting implement through an opening in the distal end of the outer tube, and tissue or bone fragments cut by the rotating blade or burr are drawn through the interior of the inner tube along with irrigating fluid by the use of suction applied at the proximal end of the instrument. Examples of such surgical instruments are described in U.S. Pat. Nos. 4,203,444, 4,274,414, 4,834,729, and 4,842,578, all of which are assigned to the present assignee.
In some instruments, the cutting implement is a hinged jaw mounted on the outer tube near its distal end, and is actuated by the rotating inner tube to pivot on the hinges and cut tissue. Examples of these surgical instruments are described in U.S. Pat. Nos. 4,522,206, 4,662,371, both of which are assigned to the present assignee.
Typical arthroscopic surgical instruments are linear, that is, straight between their proximal and distal ends. It is sometimes useful for such instruments to be curved to facilitate positioning the cutting implement against tissue to be cut without requiring that the instrument be removed from the body and reinserted through an additional puncture. A region of the inner tube is flexible to enable the inner tube to accept the curvature imposed by the outer tube while transmitting the torsion applied by the motor to the blade.
In Trott, U.S. Pat. No. 4,646,738, the inner tube is made flexible with a separate flexible section made from a series of coaxial, spiral layers wound in opposition. The cutting blade is welded to the distal end of the counter-wound helical coils, and the rigid proximal end of the inner tube is secured to the other end of the flexible structure. During operation, torque generated by rotation of the motor in one direction is transmitted to the blade by the tightening of the coil or coils that are wound in that direction, which also serves to counteract the tendency of the oppositely wound coils to be unwound by the rotation.


A process for the production of a molding containing at least one zeolite, wherein the at least one zeolite contains a titanium-, zirconium-, chromium-, niobium-, iron- or vanadium-containing zeolite:

1. Field of the Invention
The present invention relates to a molding containing at least one porous oxidic material, a process for its production, and its use for the reaction of organic compounds, in particular for the epoxidation of organic compounds having at least one Cxe2x80x94C double bond. The molding described herein has high abrasion resistance and excellent mechanical properties.
2. Description of the Background
Abrasion-resistant moldings comprising catalytically active materials are employed in many chemical processes, in particular in processes using a fixed bed. Accordingly, there is a huge wealth of literature on this subject. There is significantly less literature on the use of catalysts based on porous oxidic materials, for example zeolites, and especially relating to the molding of such materials.
For the production of solids, a binder, an organic viscosity-enhancing compound and a liquid for converting the material into a paste are generally added to the catalytically active material, ie. the porous oxidic material, and the mixture is compacted in a mixing or kneading apparatus or an extruder. The resulting plastic material is then molded, in particular using an extrusion press or an extruder, and the resulting moldings are dried and calcined.
A number of inorganic compounds are used as binders.
For example, according to US-A 5,430,000, titanium dioxide or hydrated titanium dioxide is used as the binder. Examples of further prior art binders are:
hydrated alumina or other aluminum-containing binders (WO 94/29408);
mixtures of silicon and aluminum compounds (WO 94/13584);
silicon compounds (EP-A 0 592 050);
clay minerals (JP-A 03 037 156);
alkoxysilanes (EP-B 0 102 544).
The organic viscosity-enhancing substances used are generally hydrophilic polymers, eg. cellulose or polyacrylates.
The Applicant itself, in DE-A 196 23 611.8, furthermore describes an oxidation catalyst having a zeolite structure and molded by compacting shaping processes, and its use in the preparation of epoxides from olefins and hydrogen epoxide, and, in DE-A 196 23 609.6, an oxidation catalyst which is based on titanium or vanadium silicalites having the zeolite structure and which has likewise been molded by compacting shaping processes and contains from 0.01 to 30% by weight of one or more noble metals as defined therein.
In all publications according to the prior art cited above, water is used in the preparation of the moldings described there, as a liquid for converting the material into a paste (pasting agent).
However, the moldings described above and based on a porous oxidic material, for example zeolites and in particular titanium silicalites, have several disadvantages. Thus many of the moldings described in the above literature have insufficient mechanical strength for use as a catalyst in a fixed bed.
This is particularly important when secondary reactions of certain binders are undesirable and for this reason whole classes of binders which can impart sufficient strength to such a molding cannot be used, for example because of other adverse properties. For example, aluminum-containing binders cannot be used in the preparation of titanium silicalite which is used as a catalyst for the epoxidation of, for example, propylene with hydrogen peroxide, since the acidity induced by the aluminum-containing binder results in a greater degree of ring cleavage and formation of by-products. Moreover, titanium-containing binders can lead to high decomposition rates of the hydrogen peroxide used if these titanium-containing binders result in detectable titanium dioxide contents in the molding.
It is also undesirable to use binders which contain  greater than 100 ppm of alkali metals or alkaline earth metals. By using such binders, the catalytic activity of, for example, titanium silicalite can be severely adversely affected since the catalytically active Ti centers are inactivated by the alkali metal or alkaline earth metal ions.
It is thus an object of the present invention to provide a molding which contains at least one porous oxidic material and has sufficient mechanical stability to be used as a catalyst in a fixed bed. When it is used for catalytic reactions, the activity or selectivity losses due to secondary reactions of the added binder should be avoided in comparison with the prior art catalysts. A process for its production is also provided.
We have found surprisingly, that this object is achieved and, a molding which contains at least one porous oxidic material and exhibits virtually no activity and selectivity losses, or none at all, when used as a catalyst can be obtained if a mixture containing at least one alcohol and water is used as a pasting agent in its production.
Further improved moldings of the type under discussion here are obtained if a metal acid ester or a mixture of two or more thereof is used as the binder in addition to the pasting agent defined above.
Accordingly, the present invention relates to a molding containing at least one porous oxidic material and obtainable by a process which comprises the following stages:
(I) addition of a mixture containing at least one alcohol and water to a mixture containing a porous oxidic material or a mixture of two or more thereof and
(II) kneading, molding, drying and calcination of the mixture according to stage (I) after addition, and
a process for the production of a molding containing at least one porous oxidic material, which comprises the following stages:
(I) addition of a mixture containing at least one alcohol and water to a mixture containing a porous oxidic material or a mixture of two or more thereof, and
(II) kneading, molding, drying and calcination of the mixture according to stage (I) after addition.
The novel preparation of the moldings described above starting from a porous oxidic material in powder form comprises the formation of a plastic material which contains at least one porous oxidic material, a binder, a mixture containing at least one alcohol and water, if required one or more organic viscosity-enhancing substances and further prior art additives.
The plastic material obtained by thorough mixing, in particular kneading, of the above components is preferably molded by means of extrusion pressing or extruding and the resulting molding is then dried and finally calcined.
There are no particular restrictions with regard to the porous oxidic materials which may be used for the production of the novel molding, as long as it is possible to prepare a molding as described herein starting from these materials.
The porous oxidic material is preferably a zeolite, particularly preferably a titanium-, zirconium-, chromium-, niobium-, iron- or vanadium-containing zeolite, in particular a titanium silicalite.
Zeolites are known to be crystalline aluminosilicates having ordered channel and cage structures which have micropores. The term micropores as used in the present invention corresponds to the definition in Pure Appl. Chem. 45 (1976), p. 71 et seq., in particular p. 79, and denotes pores having a diameter of less than 2 nm. The network of such zeolites is composed of SiO4 and AlO4 tetrahedra which are linked via common oxygen bridges. An overview of the known structures is given, for example, by W. M. Meier and D. H. Olson in the Atlas of Zeolite Structure Types, Elsevier, 4th Edition, London 1996.
There are also zeolites which contain no aluminum and in which some of the Si(IV) has been replaced by titanium as Ti(IV) in the silicate lattice. The titanium zeolites, in particular those having a crystal structure of the MFI type, and possibilities for their preparation are described, for example in EP-A 0 311 983 or EP-A 0 405 978. Apart from silicone and titanium, such materials can also contain additional elements, such as aluminum, zirconium, tin, iron, cobalt, nickel, gallium, boron or small amounts of fluorine.
In the zeolites described, some or all of the titanium itself therein may be replaced by vanadium, zirconium, chromium, niobium or iron. The molar ratio of titanium and/or vanadium, zirconium, chromium, niobium or iron to the sum of silicon and titanium and/or vanadium, zirconium, chromium, niobium or iron is generally from 0.01:1 to 0.1:1.
Titanium zeolites having the MFI structure are known to be identifiable by a certain pattern in their X-ray diffraction photographs and additionally by a structural vibration band in the infrared region (IR) at about 960 cmxe2x88x921 and thus differ from alkali metal titanates or crystalline and amorphous TiO2 phases.
Usually, the stated titanium, zirconium, chromium, niobium, iron and vanadium zeolites are prepared by reacting an aqueous mixture comprising an SiO2 source, a titanium, zirconium, chromium, niobium, iron or vanadium source, for example titanium dioxide or a corresponding vanadium oxide, zirconium alcoholate, chromium oxide, niobium oxide or iron oxide, and a nitrogen-containing organic base as a template, eg. tetrapropylammonium hydroxide, if necessary also with the addition of basic compounds, in a pressure-resistant container at elevated temperature for several hours or a few days, a crystalline product being formed. This is filtered off, washed, dried and subjected to combustion at elevated temperatures to remove the organic nitrogen base. In the powder thus obtained, some or all of the titanium or of the zirconium, chromium, niobium, iron and/or vanadium is present within the zeolite structure in varying amounts with 4-, 5- or 6-fold coordination. To improve the catalytic behavior, repeated washing with hydrogen peroxide solution containing sulfuric acid may also be carried out subsequently, after which the titanium or zirconium, chromium, niobium, iron or vanadium zeolite powder must once again be dried and subjected to combustion; this may be followed by a treatment with alkali metal compounds in order to convert the zeolite from the H form into the cationic form. The titanium or zirconium, chromium, niobium, iron or vanadium zeolite powder prepared in this manner is then processed to give a molding as described below.
Preferred zeolites are titanium, zirconium, chromium, niobium or vanadium zeolites, particularly preferably those having a pentasil zeolite structure, in particular the types assigned by X-ray analysis to the BEA, MOR, TON, MTW, FER, MFI, MEL, CHA, ERI, RHO, GIS, BOG, NON, EMT, HEU, KFI, FAU, DDR, MTT, RUT, LTL, MAZ, GME, NES, OFF, SGT, EUO, MFS, MCM-22 or MFI/MEL mixed structure. Zeolites of this type are described, for example, in the abovementioned publication by Meier and Olson. Titanium-containing zeolites having the UDT-1, CIT-1, CIT-S, ZSM48, MCM-48, ZSM-12, ferrierite, xcex2-zeolite or mordenite structure are also possible for the present invention. Such zeolites are described, inter alia, in US-A 5 430 000 and WO 94/29408, the content of which in this context is fully incorporated by reference in the present Application.
There are also no particular restrictions with regard to the pore structure of the novel moldings, ie. the novel molding may have micropores, mesopores, macropores, micro- and mesopores, micro- and macropores or micro-, meso- and macropores, the definition of the terms mesopores and macropores likewise corresponding to those in the abovementioned literature according to Pure Appl. Chem. and denoting pores having a diameter of from  greater than 2 nm to about 50 nm and  greater than  about 50 nm, respectively.
Furthermore, the novel molding may be a material based on a mesoporous silicon-containing oxide and a silicon-containing xerogel.
Silicon-containing mesoporous oxides which also contain Ti, V, Zr, Sn, Cr, Nb or Fe, in particular Ti, V, Zr, Cr, Nb or a mixture of two or more thereof, are particularly preferred.
Suitable binders are in principle all compounds used to date for such purposes. Compounds, in particular oxides, of silicon, of aluminum, of boron, of phosphorus, of zirconium and/or of titanium are preferably used. Of particular interest as a binder is silica, where the SiO2 may be introduced into the shaping step as a silica sol or in the form of tetraalkoxysilanes. Oxides of magnesium and of beryllium and clays, for example montmorillonites, kaolins, bentonites, halloysites, dickites, nacrites and anauxites, may furthermore be used as binders.
However, a metal acid ester or a mixture of two or more thereof is preferably added as a binder in stage (I) of the novel process. Particular examples of these are orthosilicic esters, trialkoxysilanes, tetraalkoxytitanates, trialkoxyaluminates, tetraalkoxyzirconates and a mixture of two or more thereof.
However, tetraalkoxysilanes are particularly preferably used as binders in the present invention. Specific examples are tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and tetrabutoxysilane, the analogous tetraalkoxytitanium and tetraalkoxyzirconium compounds and trimethoxy-, triethoxy-, tripropoxy- and tributoxyaluminum, tetramethoxysilane and tetraethoxysilane being particularly preferred.
The novel molding preferably contains up to about 80, particularly preferably from about 1 to about 50, % by weight in particular from about 3 to about 30, % by weight, of the binder, in each case based on the total mass of the molding, the binder content being calculated from the amount of metal oxide formed.
The metal acid ester preferably used is employed in an amount such that the resulting metal oxide content in the molding is from about 1 to about 80, % by weight, preferably from about 2 to about 50, % by weight, in particular from about 3 to about 30, % by weight, based on the total mass of the molding.
As is already evident from the above, mixtures of two or more of the abovementioned binders may of course also be employed.
It is essential for the present invention that a mixture containing at least one alcohol and water is used as a pasting agent in the production of the novel molding. The alcohol content of this mixture is in general from about 1 to about 80, % by weight, preferably from about 5 to about 70, % by weight, in particular from about 10 to about 60, % by weight, in each case based on the total weight of the mixture.
The alcohol used preferably corresponds to the alcohol component of the metal acid ester preferably used as the binder, but it is also not critical to use another alcohol.
There are no restrictions at all with regard to the alcohols which may be used, provided that they are water-miscible. Accordingly, both monoalcohols of 1 to 4 carbon atoms and water-miscible polyhydric alcohols may be used. In particular, methanol, ethanol, propanol, n-butanol, isobutanol, tert-butanol and mixtures of two or more thereof are used.
The organic viscosity-enhancing substance used may likewise be any prior art substances suitable for this purpose. Those preferred are organic, in particular hydrophilic polymers, eg. cellulose, starch, polyacrylates, polymethacrylates, polyvinyl alcohol, polyvinylpyrrolidone, polyisobutene and polytetrahydrofuran. These substances primarily promote the formation of a plastic material during the kneading, molding and drying step by bridging the primary particles and moreover ensuring the mechanical stability of the molding during the molding and drying process. These substances are removed from the molding during calcination.
Amines or amine-like compounds, for example tetraalkylammonium compounds or aminoalcohols, and carbonate-containing substances, such as calcium carbonate, may be used as further additives. Such further additives are described in EP-A 0 389 041, EP-A 0 200 260 and WO 95/19222, which are incorporated fully by reference in the context of the present Application.
Instead of basic additives, it is also possible to use acidic additives. These can effect, inter alia, a more rapid reaction of the metal acid ester with the porous oxidic material. Organic acidic compounds which can be burnt out by calcination after the molding step are preferred. Carboxylic acids are particularly preferred. It is of course also possible to incorporate mixtures of two or more of the abovementioned additives.
The order of addition of the components of the material containing the porous oxidic material is not critical. It is possible either to add first the binder, then the organic viscosity-enhancing substance and, if required, the additive and finally the mixture containing at least one alcohol and water or to interchange the order with respect to the binder, the organic viscosity-enhancing substance and the additives.
After the addition of the binder to the porous oxide powder, to which the organic viscosity-enhancing substance may already have been added, the generally still pulverulent material is homogenized for from 10 to 180 minutes in a kneader or extruder. As a rule, temperatures of from about 10xc2x0 C. to the boiling point of the pasting agent and atmospheric or slightly superatmospheric pressure are employed. The remaining components are then added, and the mixture thus obtained is kneaded until a plastic material capable of being molded in an extrusion press or extruder is formed.
In principle, the kneading and the molding can be effected using all conventional kneading and molding apparatuses or methods, many of which are disclosed in the
As already indicated, however, preferred processes are those in which molding is effected by extrusion in conventional extruders, for example to give extrudates having a diameter of, usually, from about 1 to about 10 mm, in particular from about 2 to about 5 mm. Such extrusion apparatuses are described, for example, in Ullmann""s Enzylopxc3xa4die der Technischen Chemie, 4th Edition, Vol. 2, p. 295 et seq., 1972. In addition to the use of an extruder, an extrusion press is preferably also used for molding.
After the end of the extrusion pressing or extruding, the resulting moldings are dried at, in general, from about 30 to 140xc2x0 C. (for from 1 to 20 hours at atmospheric pressure) and calcined at from about 400 to about 800xc2x0 C. (for from 3 to 10 hours at atmospheric pressure).
The resulting moldings or extrudates can of course be comminuted. They are preferably comminuted to give granules or chips having a particle diameter of from 0.l to 5 mm, in particular from 0.5 to 2 mm.
These granules or these chips and also moldings produced by another method contain virtually no fractions and particles finer than those with a minimum particle diameter of about 0.1 mm.
The moldings according to the invention containing a porous oxidic material or produced by the novel process have improved mechanical stability while at the same time retaining the activity and selectivity in comparison with corresponding prior art moldings.
The moldings according to the invention or produced according to the invention can be employed for the catalytic conversion of organic molecules. Reactions of this type are, for example, oxidations, the epoxidation of olefins, for example the preparation of propylene oxide from propylene and H2O2, the hydroxylation of aromatics, for example hydroquinone from phenol and H2O2, the conversion of alkanes into alcohols, aldehydes and acids, isomerization reactions, for example the conversion of epoxides into aldehydes, and further reactions described in the literature with such moldings, in particular zeolite catalysts, as described, for example, in W. Hxc3x6lderich, Zeolites: Catalysts for the Synthesis of Organic Compounds, Elsevier, Stud. Surf. Sci. Catal., 49, Amsterdam (1989), pp. 69 to 93, and, in particular for possible oxidation reactions, by B. Notari in Stud. Surf. Sci. Catal., 37 (1987), 413 to 425.
The zeolites discussed in detail above are particularly suitable for the epoxidation of olefins, preferably those of 2 to 8 carbon atoms, particularly preferably ethylene, propylene or butene, in particular propene, to give the corresponding olefin oxides. Accordingly, the present invention relates in particular to the use of the molding described herein for the preparation of propylene oxide starting from propylene and hydrogen peroxide.
The present invention in its most general embodiment moreover relates to the use of a mixture containing at least one alcohol and water as a pasting agent, preferably in combination with a metal acid ester as a binder, for the preparation of moldable mixtures which contain at least one porous oxidic material.

Process for production of a zeolite-containing molding

Abstract: (I) adding a mixture consisting of at least one alcohol selected from the group consisting of methanol, ethanol, propanol or butanol, and water to a mixture containing said zeolite or a mixture of two or more thereof, and

Abstract: (II) kneading, molding, drying and calcining the mixture from (I);

Abstract: wherein the molding is useful as a catalyst, particularly in epoxidation reactions.


A low-dispersion single-mode fiber includes a core and claddings covering the core. The core layer has a radius in a range of 3-5 μm and a relative refractive index difference in a range of 0.15% to 0.45%. The claddings comprise a first depressed cladding, a raised cladding, a second depressed cladding, and an outer cladding arranged sequentially from inside to outside. The first depressed cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of −0.4% to 0.03%. The raised cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of 0.05% to 0.20%. The second depressed cladding has a unilateral width in a range of 0-8 μm and a relative refractive index difference in a range of 0% to −0.2%. The outer cladding is formed of pure silicon dioxide glass.

The 5G fronthaul colored solution works in a range from 1271 nm to 1371 nm, but the traditional G.652 single-mode fiber has large dispersion at a waveband ranging from 1351 nm to 1371 nm, which leads to a larger transmission power penalty. It is thus necessary to use an APD high sensitivity detector to realize power compensation. An APD, however costs much more than a PIN detector. Moreover, other fibers, such as dispersion-flattened fibers, non-zero dispersion-shifted single-mode fibers, and low dispersion slope non-zero dispersion-shifted single-mode fibers can be optimized in terms of dispersion thereof mostly in a range from 1450 nm to 1600 nm, which cannot meet requirements of the 5G fronthaul colored solution. Therefore, by preparing a new type of single-mode fiber that is compatible with the existing G.652 fiber and has lower dispersion in a range from 1270 nm to 1380 nm, the cost of 5G fronthaul can be greatly reduced.

Low-dispersion single-mode optical fiber

YANGTZE OPTICAL FIBRE AND CABLE JOINT STOCK LIMITED COMPANY


A throttle potentiometer adapter provides a direct connection between a pivot nut on a hand throttle linkage and the internal sleeve of a potentiometer. The potentiometer provides a voltage output to an electronic controller, the voltage output corresponding to the position of the hand throttle. The adapter is of one-piece construction and includes a socket engaging the pivot nut and a shaft extending into the internal sleeve.

Internal combustion engines for tractors and similar vehicles may include an throttle position sensor to provide electronic information about the position of the throttle to an electronic controller. The throttle position sensor may include a potentiometer that provides an output signal of a varying voltage. For example, a potentiometer may provide a voltage with a value of about 0.6 volts to about 1.2 volts for the lowest engine speed (typically about 950 rpm), and a value of about 3.6 volts to about 4.4 volts for the highest engine speed (typically about 2750 rpm). The electronic controller may have a calibration routine to determine the actual low and high engine speed throttle position voltage for each tractor and/or engine.
The calibrated voltages may then be used to map the throttle position sensor output voltage into a predicted engine speed. For example, the low engine speed calibrated voltage may map into a predicted engine speed of about 950 rpm, the high engine speed calibrated voltage may map into a predicted engine speed of about 2750 rpm, and voltages between the low and high engine speed calibrated voltages may map into engine speeds according to the mathematical rules of a mapping algorithm in the controller software.
The mapped engine speed that the throttle position sensor voltage signal provides to the controller may be used as a predicted engine speed. The controller may compare the predicted engine speed to the actual engine speed. If the actual engine speed is less than the predicted engine speed, for example, the controller may provide input to a hydrostatic transmission to reduce the output to the hydrostatic transmission swash plate position control pressure reducing proportional valve coil to command the hydrostatic pump to do less work and thereby attempt to bring the actual engine speed back up to the predicted engine speed. This action is typically referred to as an anti-stall feature.
The throttle position sensor output also may be a pulse width modulated output that varies based on rotary position. Alternatively, the rotary sensor may shape its output in such a manner relative to rotary position to duplicate or provide a similar effect of the controller mapping algorithm.
The throttle position sensor typically may be mechanically biased to a high voltage position. However, during assembly, the throttle position sensor must be preloaded to a low voltage position to represent a low idle. A voltage meter or similar calibration device may be used to determine if the throttle position sensor is at a voltage within a specified range. If the engine is at a low idle position, linkages from the throttle are connected such that the throttle position sensor will be in the low voltage position. If the engine is at a higher speed position (for example, high idle), linkages from the throttle are connected so that the throttle position sensor will be set at a higher voltage position. The throttle position sensor also may be calibrated for other engine speeds.
During assembly, adjustments to the throttle position sensor and/or linkages may be required to make sure that the throttle position sensor provides a voltage within a specified range for the predicted engine speed. It is difficult and takes time intensive to do this. A throttle position sensor and linkage is needed that will reduce the difficulty and time for calibration at one or more specified engine speeds.
Additionally, there may be a tolerance stack-up of parts and/or linkages that are assembled between the engine throttle and the throttle position sensor. Because of the tolerance stack-up, the throttle position sensor may need to be set slightly differently on each tractor or other vehicle. A throttle position sensor and linkage is needed to help reduce or minimize the tolerance stack-up problem and inconsistency of voltage settings from tractor to tractor.
Linkages and parts that connect the throttle to the throttle position sensor also may be subject to wear over time. This can lead to the throttle position sensor providing a voltage value that falls outside the specified range for a specified engine speed, reducing engine performance and requiring adjustment and recalibration. A throttle position sensor and linkage is needed that will provide a more consistent voltage setting regardless of wear and tear to the linkage, and that will maintain optimum engine performance and reduce or eliminate the need for adjustment and/or recalibration.


A method and apparatus for producing an amplitude value for use in controlling illumination of a pixel on a display, in response to a sampled sonar signal produced by an element of a sonar array. A pixel time associated with the pixel is found, the pixel time representing a time required for sound to travel a distance represented by the pixel, according to a range of distance to be viewed on the display. A sample point of the sampled sonar signal is then found, the sample point having a sample time nearest the pixel time. A delay value associated with the pixel is then found, the delay value including an array element delay value. A representation of a synthesized waveform is then produced, in response to the sonar signal, the representation comprising a plurality of sample points coinciding in time with the sample points of the sonar signal. An amplitude value representing an amplitude of the synthesized waveform at a time corresponding to the pixel time is then produced by finding an amplitude value of the waveform at a time value corresponding to the sum of the sample time and the delay value. The amplitude value is then made available for use in illuminating the pixel.

1. Field of Invention
This invention relates to sonar systems and more particularly to apparatus, methods, media and signals for producing an amplitude value for use in controlling illumination of a pixel on a display and apparatus and methods for controlling a sonar transducer unit.
2. Description of Related Art
Underwater imaging systems are often used to map or display underwater features such as an ocean floor and to detect the presence of underwater bodies, such as fish. Some conventional underwater imaging systems generate a sonar signal and underwater objects reflect the sonar signal, producing reflected sonar signals, which may be received at a plurality of array elements spaced apart in a receiver array, for example. The receiver array produces signals that are interpreted to produce a display image depicting the underwater object.
Conventional underwater imaging systems typically include a beamformer that delays the signals produced by each element of the receiver array by an appropriate amount to correct for differences in arrival times of sound wave reflections at the array. The array elements closer to a reflecting object receive a reflected sound wave from that object sooner than array elements farther away. Thus, the signals produced by the array elements must be delayed by amounts dependent upon the respective differences in travel time for the reflected sound wave to reach the respective array elements in order to combine the signals produced by the array elements to produce a composite signal indicative of the reflection received at the array. The appropriate amount of delay required for each received signal varies with the angle of view of the array.
To achieve the above mentioned delays, some conventional underwater imaging systems pass the signals produced by the array elements through a delay line having a fixed delay, such as a coaxial cable. The use of fixed delays, however, can only provide the appropriate delay for one viewing angle. Selecting among a variety of fixed delay lines associated with corresponding viewing angles increases the size and expense of the underwater imaging system.
Some conventional underwater imaging systems digitally sample the signals produced by the elements of the array to produce digital representations of the received signals. These digital representations may then be digitally delayed. The digital representations may be digitally delayed directly in the time domain or may be transformed to the frequency domain such as by a Fourier Transform, multiplied by a phase factor, and then transformed back to the time domain such as by an inverse Fourier Transform. The delay amounts may be calculated using, for example, correlation or filter functions implemented in the time domain or frequency domain, or may be pre-calculated delay amounts stored, for example, in look-up tables. However, sampling rates sufficiently high to digitally represent the received signals without introducing quantization error may not be feasible. Furthermore, delay amounts equal to a multiple of the interval of time between samples may not be sufficiently accurate. Attempts to digitally delay the digital representations by delay amounts which are not multiples of the sampling interval require specialized hardware components such as shift registers arranged in a parallel configuration which increases the cost, size and complexity of such imaging systems.
Some conventional underwater imaging systems use mixers to translate the frequency of the received signals to a lower frequency, thereby permitting the use of a lower sampling rate when digitally sampling the received signals. However, the problem of inaccurate delay when the delay amounts are multiples of the sampling interval is exacerbated by the use of a lower sampling rate. Furthermore, frequency translation alters the relationship between the period of the signal and the differences in the arrival times of the respective received signals.

Producing amplitude values for controlling pixel illumination on a sonar display


A processing apparatus includes a gas supply passage for supplying a corrosive gas having a halogen, a part of the passage being made of a metal; a stabilization reaction unit which has an energy generator for supplying light energy or heat energy to the corrosive gas that has passed through the metallic part of the gas supply passage and/or has an obstacle configured to apply a collision energy to the corrosive gas that has passed through the metallic part of the gas supply passage, the collision energy being generated from a collision between the obstacle and said corrosive gas. A reaction for stabilizing a compound containing the metal and the halogen contained in the corrosive gas takes place by means of at least one of the light energy, heat energy, and collision energy; and a trapping unit which traps the compound stabilized in the stabilization reaction unit.

A semiconductor device manufacturing process includes a process for forming a film by, e.g., CVD (Chemical Vapor Deposition), by supplying a gas to a semiconductor wafer (hereinafter, referred to as a "wafer") or a process for etching the film on a surface of the wafer by a gas supplied to the wafer. A film forming apparatus or an etching apparatus for performing the above-described process includes a processing chamber for accommodating a wafer, a storage unit for storing a processing gas used for film formation or etching, and a storage unit for storing a cleaning gas for dry cleaning an interior of the processing chamber. The storage units for storing such gases and the processing chamber are connected through a gas supply device including gas supply lines, valves disposed in the gas supply lines, or the like.
In order to ensure a high corrosion resistance, the gas supply device is made of, e.g., stainless steel. Further, a filter for removing solid or liquid particles contained in gases may be disposed in the gas supply lines.
For the film forming apparatus or the etching apparatus, highly reactive halogen-containing gases referred to as an F (fluorine)-based gas, a Cl (chlorine)-based gas and a Br (bromine)-based gas respectively containing F, Cl and Br may be used. For example, the F-based gas may be used as a cleaning gas in the film forming apparatus. The Cl-based gas and the Br-based gas may be used as etching gases in the etching apparatus.
The halogen-containing gases react with stainless steel forming the gas supply device for supplying such gases, thereby generating a ternary compound containing halogen, metal and oxygen and a binary compound containing halogen and metal. These compounds cause metal contamination of the gas. A ternary compound and a binary compound, each having a high vapor pressure, flow in a gaseous state through the gas supply lines, and thus are supplied into the processing chamber without being trapped by the filter. The ternary compound and the binary compound are decomposed by exposure to an atmosphere in the processing chamber, so that metals contained in these compounds may be solidified and adhered to the wafer and the processing chamber. If so, the wafer is not normally processed, and the production yield may be decreased.
The gas supplied to the processing chamber is introduced into the gas exhaust line for exhausting the processing chamber. When the interior of the gas exhaust line becomes a low vacuum region where a gas pressure is high and the collisions between gas molecules are more dominant than the collisions between gas molecules and the pipe wall of the gas exhaust line, the flow velocity of the gas in the gas exhaust line is highest at the central axis of the gas exhaust line, and is decreased as it goes close to the pipe wall of the gas exhaust line from the central axis thereof, and becomes zero at the pipe wall. The gas may be diffused toward the upstream side, i.e., toward the processing chamber, along the pipe wall at which the flow velocity is zero. When the gas is diffused toward the processing chamber as described above, the ternary compound and the binary compound in the gaseous state are converted into compounds containing solid metals and then are adhered to the wafer or the processing chamber, which may lead to a decrease in the production yield. Further, a sub-device such as a vacuum gauge or the like may be attached to the processing chamber via an auxiliary passage. In a line forming the auxiliary passage as well as in the gas exhaust line, the gas may be diffused toward the processing chamber from the pipe wall at which the flow velocity is zero. Moreover, the gas may be diffused toward the processing chamber from the sub-device side due to changes in the pressure in the processing chamber. Even when the gas is diffused from the auxiliary passage, the ternary compound and the binary compound in the gaseous state may be converted into compounds containing solid metals and then adhered to the wafer or the processing chamber.
In order to prevent the decrease in the production yield caused by the above-described phenomenon, the following processes are carried out: the halogen-containing gas is supplied into the processing chamber; a dummy wafer (wafer that is not a product wafer) is transferred into the processing chamber and subjected to etching or film formation; the dummy wafer to which the metal is adhered is unloaded from the processing chamber; and a normal wafer is transferred into the processing chamber and subjected to etching or film formation. Or, the following processes may be carried out: a predetermined gas is supplied into the processing chamber; a film that covers the metal adhered to the wall surface of the processing chamber to prevent scattering of the metal is formed; and the wafer is transferred into the processing chamber and subjected to treatment. However, even when the dummy wafer is used or when the scattering prevention film is formed in the processing chamber, the processes which do not contribute to the fabrication of semiconductors are performed. Therefore, the throughput is decreased, and the processing cost is increased.
Japanese Patent Application Publication No. 2002-222807 discloses a technique for preventing metal contamination of a wafer by coating a metal member that contacts a gas with chromium oxide. However, the halogen-containing gas reacts with chromium oxide, so that the above-described problems cannot be solved.


A process and apparatus for incorporating additives into a circulating inventory of equilibrium catalyst in a fluid catalyst cracking (FCC) unit are disclosed. Hot regenerated catalyst is removed from the FCC regenerator, cooled, optionally subjected to magnetic catalyst separation, and at least a portion of the cooled catalyst is contacted with a solution of an additive material without forming a separated liquid phase. Additive treated catalyst is recycled to the FCC unit, preferably directly into the regenerator.

Fluidized catalytic cracking (FCC) is well known and widely used for conversion of heavier feeds boiling in the gas oil and heavier range to lighter products including gasoline.
One of the problems encountered in FCC processing is that the heavy feeds processed contain metals, such as nickel and vanadium, which deposit on the circulating FCC catalyst. The deposited Ni+V act as catalyst poisons, promoting undesirable coke formation as well as excessive hydrogen and light gas formation.
Refiners have resorted to several tactics to avoid nickel and vanadium poisoning during FCC processing. The approaches could be arbitrarily classified three ways:
1. Keep Ni+V out of the FCC feed; PA1 2. Leave Ni+V in the feed, but passivate or trap the metals once they reach the FCC catalyst; and PA1 3. Allow Ni+V to deposit on the catalyst and use a magnetic separation process to remove the oldest, most metals-contaminated catalyst.
Approach no. 1, keeping the Ni+V out of the feed, has been used for over fifty years. The simplest and highly effective way to keep metals out is to distill the FCC feed. Distilled feeds are usually metals-free, or have such low metals levels that no special steps need to be taken to deal with Ni/V contamination. Distillation is simple, inexpensive, and widely used. One drawback is that distillation keeps significant amounts of potentially high value, readily convertible hydrocarbon out of the FCC unit. Phrased another way, if a refiner limits the feed to the FCC unit to distillable feeds, a lot of profit is left in the non-distillable, or residue fraction of the crude oil charged to the refinery. Solvent deasphalting of heavy feeds is effective at removing most metal contaminants from even non-distillable hydrocarbon feed. Deasphalted oil (DAO) can be charged to the FCC, with the asphalt fraction used for road construction, or sent to a coker. The drawback to this approach is the significant capital and the operating expense of operating a de-asphalting unit.
Most refiners are driven by economics to process some residual fractions in their FCC units and use approach no. 2, metals passivation. Thus, many FCC units now process feeds with a few weight percent resid up to 10 or 20 weight percent resid. With such feeds comes Ni and/or V catalyst contamination. One way to tolerate higher metals levels on FCC equilibrium catalyst is to passivate the deposited contaminating metals. Although many metal passivators are known, an especially effective and widely used passivator is antimony.
Metals passivation, usually by antimony addition, is probably the most popular method in the world for solving the problem of heavy metals in feeds. There are some drawbacks to use of Sb for metals passivation. Antimony is expensive, potentially toxic, and fugacious. It is difficult to run an accurate antimony balance around a typical FCC unit. Some of the antimony is believed to deposit on the walls of fired heaters, or perhaps on other solid surfaces within the FCC unit. There is enough problem with such deposits that U.S. Pat. No. 4,167,471 was granted on the discovery that adding the antimony compound after the FCC feed heater, rather than before, increased the amount of antimony that ended up on the catalyst.
Even with antimony injection after the FCC feed preheater, much of the antimony addition has been difficult to trace. Because of difficulties with Sb addition, refiners are now considering approach no. 3, magnetic beneficiation. The third method of dealing with excessive amounts of Ni and/or V in the FCC feed is to use the MagnaCat.RTM. magnetic catalyst separation process developed by Ashland Petroleum Company, Refining Process Services and the M.W. Kellogg Company. More details of this process are disclosed in one or more of the following patents:
U.S. Pat. No. 4,406,773 discloses magnetic separation of high activity catalyst from low activity catalyst.
U.S. Pat. No. 5,106,486 (Re. 35,046) teaches adding iron compound continuously or periodically to the circulating catalyst.
U.S. Pat. No. 5,147,527 covers the concept of using a magnetic rare earth roller device (RERMS) for magnetic separation.
U.S. Pat. No. 5,171,424 teaches the use of highly paramagnetic heavy rare earths as Magnetic Hook.TM. additives that increase catalyst performance.
U.S. Pat. No. 5,190,635 teaches accumulation of iron on the catalyst and formation of superparamagnetic or ferromagnetic species.
U.S. Pat. No. 5,230,869 covers the discovery of a highly superparamagnetic species, which when present in aged equilibrium catalyst, further improves separation due to its high magnetic susceptibility compared to normal paramagnetic iron.
U.S. Pat. No. 5,328,594 teaches use of heavy rare earths as Magnetic Hook.TM. additives.
U.S. Pat. No. 5,364,827 teaches adding amounts of magnetically active moieties, over time, so the moiety deposits on catalyst or sorbent in an FCC unit or similar circulating hydrocarbon conversion unit which can be separated from catalyst which has been in the system a shorter time.
U.S. Pat. No. 5,393,412 teaches a catalyst recovery unit ancillary to an FCC or similar unit, which permits magnetic separation, sieving and attriting of equilibrium catalyst.
U.S. Pat. No. 5,538,624 teaches retaining specialty additives by doping them with lots of magnetic metals.

FCC metals passivation additives applied to catalyst


An electronic device that has a body portion having an internal track, a display portion having a follower member that runs along the internal track and a support arm pivotally coupled to the body portion and to the display portion and enabling the display portion to move between multiple distinct positions relative to the body portion is described. A tablet personal computer can be converted from the tablet mode to the laptop mode in a direct and efficient manner.

User interaction with computers continues to increase each day. More jobs require individuals to interact with computers and more people are choosing to interact with computers for both work and entertainment. Initially, personal computing devices were cumbersome devices that included a computer processing unit and monitor. As technology evolved in the area of computing devices, laptop style computers developed allowing users to transport work with them in a smaller and more convenient manner. Yet still, some environments were not conducive to a laptop style computer. During a meeting or conference call, users often find it easier to take notations or highlights of the meeting on a steno pad or paper. Any information had to be inputted into a computing device at a later time.
The development of the computing device then led to the tablet style computing device. Early personal digital assistants (PDAs) allowed users to write onto a surface and an application program on the device would interpret the handwritten strokes as inputs to the device. Users could now write notes during a meeting and have the information directly inputted in a computing device. Users accustomed to a monitor or display and keyboard could not use the tablet style computing devices as easily as a traditional computing device. Further, users had to have two separate computing devices if they wanted to have the ability to make handwritten notes and to type information with an elevated monitor or display. The technology continued to evolve and users were eventually given the option of a hybrid or convertible type computing device.
A convertible type computing device allows a user to convert between a traditional computing device that includes an elevated monitor and keyboard and a tablet style computing device that allows a user to input annotations as if writing on a sheet or paper or pad of paper. FIG. 1 is an example of such a convertible computing device. Convertible computing device 100 includes a monitor 110 and a computer processing hardware 120. Monitor 110 is configured to display images based upon an application program operating on the computer processing hardware 120. As shown in FIG. 1, monitor 110 swivels along a collar connection 130. Collar connection 130 is physically connected to the monitor 110 along an exterior edge of the monitor 110 and is also physically connected to the computer processing base 120 along a corresponding exterior edge of the computer processing hardware 120. The collar connection 130 is configured to rotate in a manner that allows the monitor to be in an upright position, similar to a conventional laptop computing device, or in a level position resting overtop the keyboard of the computing portion 120, similar to a conventional tablet style computing device. All electrical connections between the monitor 110 and the computer processing hardware 120 are housed within the collar connection 130.
Conventional convertible/hybrid computing device 100 requires a complex torque mechanism for operation of the collar connection 130. The internal wires must be specially designed to handle the twisting of the connection point to allow for the swivel between the tablet style and the laptop style formations. In addition, connection point 130 must be able to hold the entire weight of the monitor 110 while in the upright or laptop style formation. Further, collar connection 130 can be damaged if too much force is applied while swiveling the monitor 110 around.


A reciprocating air distribution system includes a valve housing, having a cylinder therein. A valve element is slidably mounted within the cylinder. Also provided is an inlet to the cylinder, an exhaust from the cylinder and air distribution passages which are controlled by the valve element to be connected either with the intake or the exhaust. A nonmetallic gasket of thermally insulative material and thickness is between the inlet and air distribution passages on one side and the valve element and exhaust on the other. The buna elastomer has carbon black filer to make the gasket statically dissipative. The nonmetallic gasket provides channels which are part of valve control passages which are associated with a pilot valve. The valve control passages are from the inlet to both ends of the cylinder with at least one passage controlled by the pilot valve. These channels are closed by one of the components between which the gasket is located. The reciprocating air distribution system includes a restricted inlet such that the air inlet ports are of a combined area of approximately 0.057 square inches and of a ratio of exhaust port area to inlet port area of approximately 8.0 for models achieving up to 180 gallons per minutes, and the air inlet ports are of a combined area of approximately 0.083 square inches and of a ratio of exhaust port area to inlet port area of approximately 5.4 for models achieving between 180 and 275 gallons per minutes. A muffler is in communication with the exhaust. The muffler includes a cavity open to the housing of the valve and separated by an exhaust gasket. The exhaust gasket includes a locking flange extending into the cavity of the muffler to resist the pressure within the cavity.

The field of the present invention is air distribution systems for reciprocating pneumatic devices.
The present invention provides new features for the air distribution system of the air driven diaphragm pump disclosed in U.S. Pat. No. 5,957,670, the disclosure of which is incorporated herein by reference as if set forth here in full. Reference is also made to other disclosures of pumps and actuators found in U.S. Pat. Nos. 5,213,485; 5,169,296; 4,549,467; and 4,247,264. The foregoing patents are also incorporated herein by referenced. Another mechanism to drive an actuator valve is by solenoid such as disclosed in U.S. Pat. No. RE 38,239.
Reciprocating air distribution systems are employed to substantial advantage for driving pneumatically actuated equipment, such as air-driven double diaphragm pumps. These systems are advantageous when shop air or other convenient sources of pressurized air are available. Other pressurized gases are also used to drive these products. The term "air" is generically used to refer to any and all such gases. Driving products with pressurized air is often desirable because such systems avoid components which can create sparks. The actuators can also provide a constant source of pressure by simply being allowed to come to a stall point with the pressure equalized by the resistance of the driven device. As resistance by the driven device is reduced, the system will again begin to operate, creating a system of operations on demand.
A design consideration in the construction of reciprocating actuators is the prospect of developing ice within the device. Ice can disable operation and is most problematic in the exhaust. U.S. Pat. No. 5,957,670 addresses certain issues regarding actuator valve icing.
Other design considerations include performance. With reciprocating devices typically employing alternately charged pistons or diaphragms, increasing the size of the air flow passageways and decreasing flow restrictions improves device performance. This includes promoting flow from a source of pressurized air and rapidly reducing exhaust pressure to avoid resistance.
Air distribution systems providing reciprocating pressure have been made for air driven diaphragm pumps, among other devices. The pumps and associated distribution systems are typically of metal or of polymer material. The material has determined whether or not the device is statically dissipative, metal is and polymer is not. Certain applications require that the device be statically dissipative. A standard has been established for testing elements for their ability to dissipate static. Material considered not to be statically dissipative has a surface resistivity of 1×106 ohms or less under testing method ASTM D257.


A dual pivot mechanism for a disc drive having a base plate and an actuator arm driven by a pinion for moving a transducer head across a disc to read and write to the disc. One end of the pivot arm is pivotally connected to the actuator arm opposite the pinion, another end of the pivot arm has a fixed pivot connection to the base plate, the pivotal connection to the actuator arm being fixed axially. A constant preload mechanism is provided for biasing the pivot arm so that the actuator arm is in constant contact with the pinion.

Disc drive machines record and reproduce information stored on concentric circles or spiral tracks on magnetic or optical discs. Data is stored on tracks and is written and read by magnetic heads which must be accurately positioned over one of the tracks on the surface of the disc. The head or transducer, is supported by a flexure to fly over the surface of the disc, the flexure being incorporated in an actuator which responds to signals from a host computer to position the transducer over a selected track. Both linear and rotary actuators have been used for this purpose, but rotary actuators are especially useful in disc drives with small physical dimensions.
A common form of rotary actuator is a V-shaped dual arm assembly. One arm includes a head arm, flexure, and read/write transducer extending out from a pivot toward the tracks on the disc. Extending toward the pivot to form the V-shaped arm assembly is an actuator arm which is coupled to an actuator motor. Rotation of the motor moves the actuator arm and thereby the entire V-shaped assembly, moving the head from track to track. Such rotary actuator mechanisms require a very stable pivot mechanism to support the actuator arm and head support arm; any instability would produce serious positioning inaccuracies.
The pivot mechanism in prior art rotary actuators generally consists of a shaft supporting the juncture of two arms, i.e., an actuator drive arm coupled to the actuator motor and head arm. The pivot point of the actuator arm and head support arm are typically mounted for rotation about this fixed common pivot point. However, assembly of this pivot mechanism is expensive and time consuming to accomplish with proper alignment.
Another problem is that the actuator arm is fit tightly between the fixed pivot point and the pinion which is fit on the end of the actuator motor shaft to drive the actuator arm. This pinion, although designed to be perfectly round, always contains some tolerances which make it oval or otherwise not perfectly circular. This non-circularity causes the actuator arm to be pinched between the fixed pivot point and the pinion. The non-circularity also produces extraneous slack between the gear section of the actuator arm and the pinion, leading to premature wear of the gear section. Both of these conditions, i.e., pinching and slack, have deleterious effects on the actuator arm assembly by inducing undesired stress and wear. The effects of a non-circular pinion are generally referred to as runout.
Attempts to compensate for the effects of runout include those of U.S. Pat. No. 4,845,579 for a Disc Drive Incorporating Automatic Wear Compensation for a Pivoted Arm, by Richard A. Wilkinson, Jr., issued Jul. 4, 1989. In this configuration, the actuator arm and drive motor pinion are biased into engagement by a spring force exerted directly along the axis of the elongated actuator arm. Although this configuration relieves some of the problems induced by a rigidly fixed pivot point, the arrangement is still plagued by the effects of runout and is hampered by friction and wear of its plurality of parts. Furthermore, the configuration is more susceptible to the effects of differential thermal expansion.
A second prior art attempt has been to provide a leaf spring on one side of the pivot point, generally perpendicular to the longitudinal axis of the actuator arm.
There are also several undesirable aspects induced by the leaf spring mechanism. The tolerance of the spring steel used to create the leaf spring is very hard to maintain within critical limitations, as a result, the preload of the spring on the arm varies. Furthermore, since the leaf spring contains a certain amount of twist, a cantilever spring is required to keep the actuator arm from rising vertically. Moreover, mounting the leaf spring to the pivot mechanism requires high precision spot welding which is both time consuming and expensive.

Dual pivot disc drive apparatus and method


A pre-treatment device for wood chips for pulping comprises a tube through which the wood chips fall into a digester. Steam is injected into the tube through rings of nozzles, which are angled circumferentially to impart a rotary and turbulent motion to the falling chips. Some nozzles are angled downwardly to encourage the chips to flow freely through the tube, some are horizontal to encourage a longer dwell time near the nozzles. Digesting liquor is also sprayed onto the chips from spray nozzles after the first ring of steam nozzles. The heat and steam expel air and other non-condensable gases and volatiles from the chips, allowing them to absorb the liquor. At the bottom of the tube, the chips are propelled down and outwards by jets of higher-pressure steam, spreading and packing them into the digester.

The invention relates to the treatment of loose material with liquid and/or vapor. The invention relates in particular to the digestion of wood chips to produce pulp from which paper can be made, and in particular to a device and method for pre-treating the wood chips that are being loaded into the digester.
One method of producing wood pulp for paper-making comprises reducing wood to chips, and digesting the wood chips to pulp (by exposing them to steam and cooking liquor) at elevated temperature and pressure. Cooking liquor is heated to approximately 350xc2x0 F. (180xc2x0 C.), and a pressure of around 150 psi (1 MPa) is maintained to insure the liquor maintains temperature. The cooking liquor is circulated throughout the digester, which dissolves the organic and non-organic material in the cellulose material. This action results in a slurry consisting of cellulose fiber. The slurry is then cleaned and dewatered, which results in a product used for making paper. It has been found that the effectiveness and efficiency of the digestion process can be improved by pre-treatment of the wood chips before they are loaded into the digester.
According to one aspect of the invention, there is provided a pre-treatment unit designed to be installed in the wood chip conveying system, between a wood chip conveyor and an inlet that is located on top of the wood chip digester, or of any vessel that is used for processing wood chips. According to another aspect of the invention, there is provided a method of pre-treating wood chips using such a unit. According to further aspects of the invention, the pre-treatment unit and method may be used with particulate materials other than wood-chips and/or for other purposes.
A pre-treatment unit according to one aspect of the invention comprises a tube having an inlet for chips at an upper end and an open lower end forming an outlet for pre-treated chips. At least one ring of injection nozzles in the wall of the tube admits into the tube flows of gas or vapor angled circumferentially to impart a rotating motion to said chips. The chips are permitted to fall freely from the inlet to and through the outlet while being exposed to the gas or vapor.
Where the pre-treatment unit is intended to pre-treat wood chips for pulping, the gas or vapor is usually steam. A suitable supply of steam at the temperatures and pressures required is then preferably provided.
Preferably, there are several rows of steam injection nozzles, grouped into steam injectors spaced apart along the length of the unit. The nozzles in the bottom row of each unit are then preferably angled slightly downwards so as to urge the chips to flow down to the next injector, while the nozzles in the top row of each subsequent injector are horizontal, to encourage the chips to dwell within the steam injector, where they are most subject to the action of the injected steam.
Preferably, there is also a row of liquor injection nozzles, spraying digestive liquor onto the chips between two of the steam injectors.
The combined action of the heat and moisture in the steam has been found not only to preheat the wood chips but also to de-aerate them, replacing the air and non-condensable vapor in the pores of the wood chips with water or digestive liquor.
Preferably, at the bottom of the pre-treatment unit, the chips are propelled down and outwards by high pressure steam. This can serve both to compact the wood chips and to spread them evenly over the plan area of the digester.
By pre-heating, de-aerating, and compacting the wood chips, it is possible to realize an increase of wood chip throughput of between 15-18 percent per batch, a reduced cooking cost, and an improvement in pulp quality.

Apparatus for pre-treatment of wood chips