A system and method for high resolution digital x-ray imaging which utilizes multiple imaging sensors is disclosed. In the preferred embodiment, the system includes multiple imaging sensors with overlapping fields of view. The imaging sensors are preferably interfaced with a general purpose computer capable of seamlessly combining the multiple images captured by the multiple imaging sensors.

The present invention relates to high resolution digital imaging and in particular to a digital x-ray imaging system and method utilizing multiple digital cameras.
In conventional x-ray imaging a photographic film is exposed to visible light produced by a fluorescent imaging screen in response to x-ray energy which has passed through an object, in order to capture the image of the object being x-rayed. The x-rays are passed through the object and impinge on the fluorescent imaging screen, such as a phosphor imaging screen. The phosphor imaging screen converts some of the radiation into a selected spectral component (typically visible light). The exposure of the photographic film to the spectral component from the phosphor imaging screen produces the image of the object on the photographic film.
Recent advances in x-ray imaging however have resulted in filmless x-ray methods and apparatus. Such a system is disclosed in U.S. Pat. No. 5,309,496, entitled xe2x80x9cFILMLESS X-RAY APPARATUS AND METHOD OF USING THE SAMExe2x80x9d, issued to Winsor, which is hereby incorporated herein by reference. In the preferred embodiment of Winsor, a video camera and a frame grabber are used to provide still x-ray images.
However, in x-ray imaging it is desirable to get very high resolution images so that a health care provider could accurately diagnose a patient. The use of photographic films as used in conventional x-ray imaging systems does not provide the high degree of resolution desirable in x-rays. Moreover, the video camera and frame grabber of Winsor do not provide the desired high degree of resolution because in the preferred embodiment video camera and frame grabber implementation of Winsor, an image in analog format is filmed by the video camera and a frame grabber used to capture one or more frames. The captured frames may then be digitized. Because of the conversion of the image from analog format to digital format, the desired degree of resolution may not be obtained. Also, as the video tube of the video camera has a fixed life span, it deteriorates over time and accordingly the quality of the image deteriorates over time, which may be evidenced for example by a decrease in the contrast of the image.
Furthermore, in any imaging system, because of the curvature of the lens (or lens assembly), more light passes through the center of the lens than through the edges. Therefore, the intensity of the pixels in the center is greater than the intensity of the pixels at the edges. Because of limitations of the video camera and frame grabber of the preferred embodiment of Winsor, the pixel contrast and/or intensities cannot be modified on an individual basis and therefore, in the final x-ray image the pixels at the center are brighter than those at the edges.
An alternative structure for capturing images is a CCD (charge coupled device) camera. However, high resolution digital CCD cameras are very expensive and still do not provide the high level of resolution necessary for diagnostic x-ray imaging. Because of the difficulty of obtaining large CCD chips of consistent quality and the cost of manufacturing such large CCD chips, multiple digital CCD cameras may be used in place of a single digital camera. The use of multiple digital cameras is known in other fields. In such applications, different cameras are used to capture different portions of the entire image thereby providing multiple images, which are later merged together in order to create a single image. However, in such applications, a known reference point is added to the original image itself. The different images are merged together using the known reference point. By utilizing the known reference point in the merging process, the combining of the images may be accomplished more efficiently. But this procedure adds unwanted artifacts (the reference point itself) to the image. The presence of artifacts in the combined image would be specially undesirable in an x-ray imaging system because of the degree of accuracy preferred in rendering a correct diagnosis of the patient based on the x-rays.
Therefore, there is a need in the art for a system and method for rendering high resolution digital x-ray images of an object.
There is also a need in the art for a system and method for quickly, accurately and seamlessly combining multiple overlapping x-ray images into a single image without adding unwanted artifacts to the final image.
These and other objects, features and technical advantages are achieved by an x-ray imaging system and method which utilizes multiple imaging sensors to acquire an image from an imaging screen.
In a preferred embodiment, the x-ray imaging system comprises at least two imaging sensors, such as digital CCD cameras, with overlapping fields of view. The digital cameras preferably acquire the image from an imaging screen, such as for example, a fluorescent phosphor screen used in x-ray imaging. The digital cameras are positioned so that the field of view of the digital cameras substantially covers the imaging screen. The use of multiple imaging sensors facilitates increasing the resolution of the image as each imaging sensor can capture a smaller portion of the imaging screen.
In the preferred embodiment, the imaging apparatus also includes a host processor based system comprising camera interfaces for receiving and processing the images from the multiple cameras. Such a host processor based system may be for example, a general purpose computer. A preferred method for combining the overlapping images is preferably implemented by software associated with such a general purpose computer. The method comprises calibrating the x-ray imaging system by combining an initial set of two or more overlapping calibration images of different sizes and orientations. During the calibration process, the amount by which an image is to be offset in order to properly align with another image is calculated. The optimal offsets for joining the images in the overlap region are preferably calculated by determining the best correlation of the images in the region common to each of the images. These optimal offsets may be stored in the computer system and used to quickly combine a subsequent series of images of substantially the same size and orientation as the calibration images.
The offsets for a particular camera setting may be calculated periodically, for example once a month, to adjust for any change in the positions of the cameras since the last calibration. Accordingly, in the preferred embodiment, the offsets need not be calculated each time the multiple images of an x-rayed object are to be joined or combined together, i.e., once the offsets for a particular camera setting using the calibration images have been calculated, the offsets may be used to quickly combine or join subsequent individual images into a single image.
Moreover, in a preferred embodiment, in order to provide seamless joining or stitching of the multiple images, the intensities of the pixels of the individual images in the overlapped region may be adjusted. Any noticeable seam between the images may be removed by gradually merging the images in the common overlapping region. This is preferably accomplished by adjusting the intensity values of the individual images in the overlap region so that there is a gradual transition from one individual image to the other.
Accordingly, it is a technical advantage of a preferred embodiment of the present invention to provide a high resolution digital x-ray imaging system.
It is another technical advantage of a preferred embodiment of the present invention to provide a seamless x-ray image.
It is still another technical advantage of a preferred embodiment of the present invention to quickly, accurately and seamlessly combine multiple overlapping images into a single image.
It is yet another technical advantage of a preferred embodiment of the present invention to combine multiple images without the use of known reference points.
It is yet another technical advantage of a preferred embodiment of the present invention to provide high resolution x-ray images without any undesirable image artifacts.
It is yet another technical advantage of a preferred embodiment of the present invention that each pixel in the overlap region can be modified individually.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.


A mounting system facilitates attachment of a luminaire assembly to a mounting surface at various positions to vary the direction of the maximum output of the luminaire assembly. A preferred embodiment of the luminaire assembly includes a mounting system that comprises a substantially U-shaped body having a wall formed with multiple discrete angularly inclined mounting sections. The mounting sections have associated mounting tabs for securing the luminaire assembly to a surface. The mounting system also includes a tab-receiving embossment on each mounting section to receive an associated tab of an adjacent mounting system for mounting multiple luminaire assemblies in a flush end-to-end relation.

There are currently available various mounting systems for cove-mounted fluorescent luminaire assemblies. Such mounting systems are, however, limited to directing in only one direction the peak light output emanating from a luminaire assembly. For example, many fluorescent mounting systems hang down from a room ceiling in a drop-mounted fashion to downwardly direct most of the light emanating from a luminaire assembly. Such an arrangement creates harsh lighting conditions for some applications. Other mounting systems, such as wall-mounted fixtures, have only one mounting position. These systems are also limited in that they provide maximum light output in only one direction for either direct or indirect lighting. Depending on the application, such lighting from currently available wall-mounted systems may be either inadequate or excessive. To obtain various lighting conditions for different applications would require a different mounting system for each desired lighting condition. Such a requirement would be impractical from a design standpoint, in addition to being costly.
The lack of flexibility in prior luminaire assembly mounting systems extends to luminaire assemblies mounted in an end-to-end fashion. Current lighting systems do provide some type of joining mechanism for connecting adjacent luminaire assemblies; however, their mounting systems offer limited flexibility in adjustment of the direction of maximum light output.


A method of decontaminating articles, comprising the steps of:                (a) moving a plurality of articles having a known temperature along a first path;        (b) conveying a carrier gas along a second path that includes an elongated plenum, the second path intersecting the first path downstream from the plenum;        (c) heating the carrier gas to a temperature of at least about 105° C. at a location upstream of the plenum;        (d) introducing into the carrier gas in the plenum an atomized mist of a liquid hydrogen peroxide of known concentration; and        (e) controlling the following:                    (1) the volumetric flow of carrier gas along the second path;            (2) the volume of hydrogen peroxide introduced into the carrier gas; and            (3) the temperature of the carrier gas introduced into the plenum, such that the concentration of the vaporized hydrogen peroxide in the carrier gas where the first path intersects the second path has a dew point temperature below the known temperature of the articles.

It is known to use hydrogen peroxide (H2O2) in sterilization and other processes. In a sterilization process, liquid hydrogen peroxide is vaporized to form vaporized hydrogen peroxide (VHP). The vaporized hydrogen peroxide is typically produced from a liquid mixture of hydrogen peroxide and water. Care must be taken when vaporizing this mixture due to the difference in the boiling points between water and hydrogen peroxide. In this respect, water boils at 100° C., whereas pure hydrogen peroxide boils at 150° C. Accordingly, when a mixture of water and hydrogen peroxide is vaporized, the water tends to boil before the hydrogen peroxide unless the mixture is flash vaporized. In conventional systems, flash vaporization is accomplished by dripping a small amount of the water and the hydrogen peroxide mixture on a hot surface. Air is directed over the hot surface to conduct away the vaporized hydrogen peroxide.
U.S. Pat. No. 2,491,732 discloses a conventional vaporized hydrogen peroxide (VHP) vaporizer. A problem with the aforementioned drip method of vaporization is that a hot surface must be maintained to vaporize the liquid hydrogen peroxide and water mixture. Testing has shown that an injection rate of up to 5 grams per minute per injection port can be achieved with current drip-method vaporizers. At higher injection rates, individual droplets can no longer be maintained. In other words, the drip-type vaporizer is limited in the amount of vaporized hydrogen peroxide it can produce within given size limits. This limitation prevents drip-type vaporizers from being used in certain high volume sterilizing processes where it is necessary to sterilize large numbers of articles and devices in a short period of time.
Another problem with vaporized hydrogen peroxide decontamination systems is preventing condensation of the vaporized hydrogen peroxide on the articles or surfaces to be decontaminated.
It is therefore desirable to have a high-capacity vaporized hydrogen peroxide generator capable of generating high volumes of vaporized hydrogen peroxide at concentration levels that will not condensate on the articles or surfaces to be decontaminated.
The present invention provides a hydrogen peroxide vaporizer capable of generating large volumes of vaporized hydrogen peroxide at concentration levels that will not condensate on the articles or surfaces to be decontaminated.


Window treatment structures formed from a felted fibrous material such as needle punched felt as the material of construction. The felted fibrous material is adapted to accept grooved score lines to define living hinges for bending of the material to form top and/or side portions of the finished structure using a singe panel of such material.

Window treatment structures such as cornices and lambrequins are well known. Typically in the past such structures have been formed from board stock materials such as wood or the like with segments of such material being cut to predefined shapes and thereafter being nailed, stapled or glued together to yield a desired construction. While such materials have been useful, they have faced limitations due to their relatively high weight as well as their inability to be easily bent to different geometries.

Window treatment formation assemblies of fibrous felt construction


A wireless communication system with one or more remote transceivers for transmitting a wireless data signal at an actual frequency that is different than the expected frequency and a base transceiver that can automatically adjust to receive the actual frequency. Each remote transceiver is adapted to initiate a wireless data signal at a selected time that is unique to that remote transceiver. The expected frequency is sequentially pre-determined in a pseudo-random sequence with each remote transceiver having a unique sequence. The base transceiver can respond to the remote transceiver at the actual frequency. Both the remote transceiver and the base transceiver can convert the wireless signals in a single step to baseband.

1. Field of the Invention
The invention relates generally to a wireless communication system and more particularly to a wireless communication system having a base transceiver that can adjust to a carrier frequency transmitted by a remote transceiver and respond on that same frequency. The remote transceiver receiver and the base transceiver can convert wireless signals directly to baseband.
2. Description of the Prior Art
Wireless communication systems are useful for transmitting information between remote sites and a user location. Typically, such systems include a transceiver at each remote site, a base transceiver at the user location, and a wireless communication link coupling the remote transceivers to the base transceiver.
Two important figures of merit for such systems are system cost and remote transceiver battery lifetime. When multiple remote transceivers are used, the cost of the remote transceiver becomes a determining factor in the cost of the system. Because line power is frequently unavailable at remote sites, most remote transceivers are powered by an internal battery. In order to maximize battery lifetime the remote transceiver is switched on for a minimum period of time when information is communicated and switched off or to standby otherwise.
A difficulty with such systems is that the remote transceiver must be capable of receiving a signal of the frequency transmitted by the base transceiver. One existing solution is to include a frequency sweep capability in the remote transceiver to search frequencies until the correct frequency is found. However, this solution adds cost and reduces battery life due to the additional power on time required for the frequency sweep. Another existing solution is to provide a stable, accurate frequency source in the remote transceiver. This solution also adds to the system cost due to the need for stable, accurate components to provide the frequency in the remote transceiver. Another solution is to use a wide bandwidth in the remote transceiver to receive the frequency transmitted from the base transceiver without requiring a search or a stable, accurate frequency source. However, with the wide bandwidth the remote transceiver will receive more noise and will have less selectivity between frequency channels.
Wireless receivers and transmitters are categorized as simplex, full-duplex, or half-duplex. Simplex receivers only receive and simplex transmitters only transmit. Full-duplex transceivers transmit and receive simultaneously. Half-duplex transceivers transmit and receive sequentially. A problem with simplex receivers and transmitters is that control information cannot be received by the transceiver sending the application information and vice versa. Full-duplex transceivers have the advantage that more information can be communicated in a given time period. However, full-duplex transceivers are more expensive than half-duplex transceivers due to the additional circuitry required to transmit and receive in parallel. Known, half duplex transceivers transmit and receive at different frequencies. A problem with using different frequencies is that each frequency requires circuitry that adds to the cost of the transceiver. Another problem is that the time to switch between frequencies and for the frequencies to stabilize adds to the on time in the transceiver, thereby increasing power consumption and decreasing battery life.
Most full-duplex and half-duplex transceivers down convert the frequency of the wireless signal to an intermediate frequency in a first step and down convert the intermediate frequency to baseband in a second step. An advantage of a two step down conversion is that the close-in phase noise of the local oscillator signal used to down convert the wireless signal does not decrease the sensitivity of the system. However, the circuitry for two conversion steps is more complex than the circuitry for one conversion step, thereby adding cost and power consumption of the system.
In most systems, a base transceiver initiates the communication with a remote transceiver. A problem with initiating communication from the base transceiver is that the remote transceiver is required to be at least partially operational for at least some time before the communication arrives. The time and the partial operation require battery power to be consumed.
There is a need for a wireless communication system wherein the cost of the system is minimized by reducing the cost of the remote transceivers. There is a further need to minimize the power consumption in the remote transceiver in order to increase the lifetime of its internal battery.

Wireless communication system for adapting to frequency drift


A method and circuit for stabilizing a frequency of a clock generator comprising a ring oscillator with respect to manufacturing process variations and a circuit temperature. A bias circuit comprising a current mirror and cascade circuits provides a compensated bias current based on a gate source voltage and drain source voltage of an output transistor, where the two voltages are independent of transistor parameters and circuit temperature. As a result, the ring oscillator frequency is stabilized with respect to those parameters.

A clock generator is a circuit that produces a timing signal (known as a clock signal) for use in synchronizing a circuit's operation. Clock generators are used in most electronic devices and their implementation can range from a simple crystal oscillator to complicated circuits.
A ring oscillator, an example of a clock generator, is a device composed of a chain of stages closed in a loop whose output oscillates between two voltage levels. The output levels may represent true and false in binary logic circuits. The stages of a ring oscillator may include inverters, differential buffers, and the like, and are typically attached in a chain. The output of the last stage is fed back into the first stage. The final output signal is asserted a finite amount of time after the first input is asserted. The feedback of this last output to the input causes the oscillation.
A ring oscillator typically requires only power to operate. Above a certain threshold voltage, oscillations begin spontaneously. To increase the frequency of oscillation, the applied voltage may be increased. This increases both the frequency of the oscillation and the power consumed, which is dissipated as heat. The dissipated heat may limit a speed of a particular ring oscillator. A size of the ring oscillator may also be used to affect its frequency. A smaller ring oscillator may result in a higher frequency of oscillation for a given power consumption.
Thus, it is with respect to these considerations and others that the present invention has been made.

Integrated clock generator tolerant to device parameter variation


The current differential relay operates without adjustable settings, and includes a phase current differential element with a predetermined threshold, responsive to local phase current values and remote phase current values, to detect three-phase faults and producing a first output signal if the threshold value is exceeded. Either a negative sequence current differential element or two phase current differential elements, also having predetermined threshold values and responsive to the local and remote phase currents, detect phase-to-phase faults and phase-to-phase-to-ground faults and produces a second output signal if the predetermined threshold is exceeded. A negative sequence or zero sequence current differential current element, with a predetermined threshold value is responsive to the local and remote phase currents to detect phase-to-ground faults and to produce a third output signal if the threshold is exceeded. If any one of the first, second and third output signals occurs, a trip signal is generated and directed to the associated circuit breaker. The thresholds are selected to permit use of the relay in a wide range of possible applications.

Historically, digital protective relays have had an adjustable "settings" capability, which enables a protection engineer to customize the operation of a protective relay to a particular protection task in a power system. This is often a challenging exercise. For example, with a conventional overcurrent relay, the protection engineer must first determine the expected fault current and the maximum load current of the power system at the point in the system where the relay is connected. The protection engineer then establishes the operating settings of the overcurrent relay to provide a trip signal when the currents it measures from the power line reach a predetermined level above the maximum load current but below the anticipated fault current.
The determination of the anticipated fault current involves a rather complex calculation, which takes into account the source strength and voltage, the impedance of downstream transformers and the impedance of the line from the relay out to the end of the protection zone covered by the relay. In addition, the protection engineer must also often coordinate the relay which is being set with other protective relays, located both closer to the source and closer to the load than the relay being set. Further, if the line protected by the relay being set can provide power and serve load in both directions from the protective relay, the setting task becomes even more complicated.
The setting task also becomes more complicated when the protection engineer must coordinate the protection provided by the relay being set with other protective relays set by another entity, an example being when utilities connect their respective power tie lines together or when utilities connect to heavy industrial loads having privately owned generators. Such connections are typically referred to as "interties". The relays at both ends of the intertie line portion must work together as a unit to properly protect the intertie; hence, their respective settings must be coordinated for proper operation and to prevent a malfunction, which can occur in the event of a miscalculation or misapplication of a relay at either end of the intertie.
Accordingly, it is desirable for a protective relay to be able to protect a variety of electric power arrangements and configurations without the need to calculate and apply protective relay settings. Further, it would be desirable to simplify the protection of an intertie line portion to prevent misoperation of the protection.

Protective relay capable of protection applications without protection settings

Schweitzer Engineering Laboratories, Inc.


The present invention relates to a pressure vessel (1) having a pressure vessel wall (1a) which completely surrounds a reaction chamber (2) as a pressure space for the initiation and/or promotion of chemical and/or physical pressure reactions of a sample (P) to be heated which is accommodated in the reaction chamber (2), wherein the pressure vessel wall (1a) has an infrared-permeable high-pressure window (30) which extends away outward in a direction from the reaction chamber (2) and which is supported in the pressure vessel wall (1a) with respect to a pressure in the reaction chamber (2), wherein the pressure vessel (1) furthermore has an infrared to temperature sensor (40) which is situated directly opposite the high-pressure window (30), in order to measure the temperature of a sample (P), accommodated in the reaction chamber (2), during a pressure reaction through the high-pressure window (30).

Pressure vessels of the types mentioned in the introduction are basically known from the prior art. For the purpose of temperature measurement, use is generally made of an infrared temperature sensor, which, because of the high pressure in the reaction chamber, is arranged outside the pressure vessel. In order that the infrared radiation emitted by the heated samples in the reaction chamber are, during a pressure reaction, effectively conducted to the infrared sensor for temperature measurement, it is known from the prior art to use a light-conducting tube which extends from the infrared sensor, provided outside the pressure vessel, as far as the vicinity of the reaction chamber. Thus, since the infrared temperature sensor is relatively far away from the reaction chamber, to be precise outside the pressure vessel, a relatively large, in particular tall, pressure vessel is the result.

Pressure vessel with high-pressure window


A set of security templates is maintained including first and second templates. The first template specifies time and location stamp authentication for a file, and contextual security conditions that must be met before the file can be accessed. The second template specifies the time and location stamp authentication, but not the contextual security conditions. One of the first or second security templates is applied to the particular file. When the second security template is applied, a GPS-crypto device adds a time and location stamp to the particular file. The particular file is signed using a private key associated with the GPS-crypto device to generate an authentication signature based on the time and location stamp. The authentication signature is added to the particular file to allow a recipient to verify the time and location stamp of the particular file using a public key corresponding to the private key.

Digital forgery refers to the modification of file contents, file attributes, properties, or file metadata. Digital forgery is a major problem in the modern world. For example, by changing the time and date of a file, the file can serve as false evidence that an event occurred at a time that is different from the actual time that the event occurred. A photo could falsely implicate a suspect or falsely provide an alibi. A business could claim a document was created earlier than it had been. There is a need for digital attestation of a document's authenticity to prevent such scenarios. It is currently difficult to validate a file source—such as where and when a file was created. This challenge spans the industry from corporate security, law enforcement and government intelligence agencies. It is also challenging to control when and where a file is accessed, so if an unauthorized user were to copy the file and know the password, they may access the file at will.
There is a need for improved systems and techniques for authenticating and securing files.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.


Disclosed as one embodiment is a method of producing useful articles from ground whole tire waste, which includes the steps of continuously extruding a heated mixture of ground whole tire waste and thermoplastic binder material into a continuously cooled, open-ended casting chamber.

1. Field of the Invention
The present invention relates to a process and apparatus for extruding mixtures of thermoplastic and thermoset polymers and to articles made therefrom. More particularly, the present invention relates to a process and apparatus for extruding mixtures of thermoplastic and thermoset polymers and to articles made therefrom, wherein at least one of the polymers is recycled. Still more particularly, the present invention relates to a process and apparatus for extruding mixtures of polyolefins and recycled rubber and to articles made therefrom. Still yet more particularly, the present invention relates to a process and apparatus for extruding mixtures of polyethylene and tire particles and to articles made therefrom.
2. Description of the Related Art
Plastic materials are finding utility in more and more applications everyday. For example, plastics are used in all sorts of disposable applications such as diapers, product packaging, utensils, plates, cups, syringes, drink containers and shrink wrap. As another example, plastics are used as a major material of construction for electronic products such as telephones, computers, radios, stereos, kitchen appliances. As further example, plastics are utilized in automobiles in such applications as body molding, bumper guards, hoses, light covers, interior paneling, mud guards, floor mats and tires. In the construction industry, plastics are utilized in electrical wire, telephone wire, as paneling, horizontal surface tops, switches and moldings. Other examples, include the use of plastics in articles of clothing.
Unfortunately, as plastic materials proliferate into every facet of life, such materials become a larger portion of the waste stream. Disposable plastic items are used then disposed. Goods comprising plastic are trashed once the end of the useful life of the good is reached. Plastic waste is even generated during the process of making plastic articles in the form of off-spec material or "flash". Off-spec material may be rejected because of appearance or physical property deficiency. "Flash" refers to excess polymer on a formed article that must be removed from the formed article. The environmental pressures of today stress recycling these waste plastic materials whenever possible.
Plastics fall into one of two categories, thermoplastics and thermosets.
Thermoplastics are polymers that will have a softening temperature and a melting temperature. Examples of thermoplastics include polyvinyl chloride, nylon, polyurethane and polyolefins. Heating a thermoplastic above its softening temperature will soften it, and heating it above its melting temperature will melt it. It is easy to see that thermoplastics can be formed into a shape, melted and reformed. Thus thermoplastics lend themselves to recycling.
Thermosets, on the other hand, do not readily lend themselves to recycling. A thermoset is a polymer that solidifies or "sets" irreversibly. Examples of thermosets include, phenolics, polyesters, rubber and synthetic rubber. Since these polymers irreversibly set, heating them does not melt them into a reformable liquid. Thermosets are thus difficult to recycle.
As old vehicle tires are generally considered to constitute an environmental eyesore, many efforts have been made to recycle tires.
U.S. Pat. No. 3,210,301, issued Oct. 5, 1965, to White discloses a rubber compounding product that is made by recycling vulcanized reclaimed rubber from tires by first removing fibers and then mechanically working the rubber in the presence of 0.1-35 parts atactic polypropylene per hundred parts rubber.
Several patents disclose the use of rubber in making a molding composition. For example, U.S. Pat. No. 3,267,187, issued Aug. 6, 1966 to Slosberg et al., discloses that rubber granules may be mixed with a thermoplastic resin and molded into sheets. Also, U.S. Pat. No. 4,320,082, issued Mar. 16, 1982 to Houle, discloses a molding composition made from rubber, nylon and a vulcanizing agent, such as sulfur or magnesium oxide. U.S. Pat. No. 4,481,335, issued Nov. 6, 1984, discloses a rubber molding composition comprising tire rubber scrap, a sulfur curable polymeric binder and a curing agent for the binder. Finally, U.S. Pat. No. 4,795,603, issued Jan. 3, 1989 to Nagayasu, discloses an injection molding composition comprising 10-30 percent rubber particles and 70-90 percent polyethylene or polypropylene waste. However, these compositions are generally for batch type molding processes rather than a continuous extrusion type process.
U.S. Pat. No. 4,028,288, issued Jun. 7, 1977, and U.S Pat. No. 4,003,408, issued Jan. 18, 1977, both to Turner, both disclose processes for reclaiming tire rubber utilizing particalized tires, but excluding the metallic content thereof. Turner '288 limites the amount of cord content to less than 10 percent. Thus neither Turner patent discloses a method for processing the whole tire.
Finally, U.S. Pat. No. 4,970,043, issued Nov. 13, 1990, discloses a method of recycling "high grade" rubber having reduced debris as compared to reground rubber obtained from many automobile tires. The high grade rubber is extruded with a thermoplastic to form a semi-stable moldable product which is then cooled to form a stable moldable product. Since this process requires "high grade" rubber, tires containing debris cannot be processed.
While many attempts have been made to reuse old tires, these attempts have not been successful in producing products in processes which reuse whole tire waste, including metal and fabric belts and tire beads, or in producing products for which a sufficient need exists to utilize all of the available tire waste.

Process for extruding mixtures of thermoplastic and thermoset materials


A method for receiving a database query language statement and performance information about the statement at an optimizer and generating one or more tuning actions for the statement with the performance information is disclosed.

SQL tuning is a very critical aspect of database performance tuning. It is an inherently complex activity requiring a high level of expertise in several domains: query optimization, to improve the execution plan selected by the query optimizer; access design, to identify missing access structures; and SQL design, to restructure and simplify the text of a badly written SQL statement. Furthermore, SQL tuning is a time consuming task due to the large volume and evolving nature of the SQL workload and its underlying data.
Typically the database administrator (DBA) or an application developer performs the tuning process. However, it is often a very challenging task. First, it requires a high level of expertise in several complex areas: query optimization, access design, and SQL design. Second, it is a time consuming process because each statement is unique and needs to be tuned individually. Third, it requires an intimate knowledge of the database (i.e., view definitions, indexes, table sizes, etc.) as well as the application (e.g. process flow, system load). Finally, the SQL tuning activity is a continuous task because the SQL workload and the database are always changing.
For example, a compiler relies on data and system statistics to function properly. It uses the number of blocks and number of rows in order to cost the full scan of a table, when selecting the best access path to retrieve a table's data. These statistics may be missing or stale. In addition to base statistics, the compiler also can use statistics on intermediate results. For example, the compiler can estimate the number of rows from applying table filters when deciding which join algorithm to pick. These statistics are derived from base statistics using various methods, e.g., probabilistic models. These statistics may also be missing or stale.
Examples of factors that lead the optimizer to generate a sub-optimal plan include missing or stale base statistics, wrong estimates of intermediate result sizes, and incorrect settings for environmental parameters. Missing statistics cause the optimizer to apply guesses. For example, the optimizer assumes uniform data distribution even when the column used in a predicate is skewed, if there is no histogram. Wrong estimate of intermediate result sizes. For example, the predicate (filter or join) is too complex to use standard statistical methods to derive the number of rows (e.g., the columns are compared thru a complex expression like (a*b)/c=10). Inadequate settings for the environment parameters used during the optimization process. For example, the user may set a parameter to tell the query optimizer that it intends to fetch the complete result set produced by the query while it actually fetches only a few rows. In this case, the query optimizer will favour plans that return the complete result fast, while a better plan would be the one that returns the first few rows (e.g., 10) fast.
However, when a user performs a manual tuning process, tuning information can be collected from several different sources. The user often does not know how to integrate these different types of information. Also, the user typically does not know which factors to use to correct the plan. To help the DBA and the application developer overcome these challenges, several software companies have developed diagnostics tools that help identify SQL performance issues and suggest actions to fix them. However, these tools are not integrated with the query optimizer, the system component that is most responsible for SQL performance. Indeed, these tools interpret the optimization information outside of the database to perform the tuning, so their tuning results are less robust and limited in scope. Moreover, they cannot directly tackle the internal challenges faced by the query optimizer in producing an optimal execution plan. Finally, the recommended actions often require modification of the SQL text in the application source code, making the recommendations hard to implement by the DBA.
For example, the LEO (LEarning Optimizer) research project at IBM attempts to correct errors in the cardinality estimates made by the query optimizer. The corrections are done based on actual cardinality values gathered during query execution. The corrections are computed as adjustments to the optimizer's estimates and stored in dictionary tables. When a SQL statement is submitted to the query optimizer, the query optimizer will first check whether any adjustments are available as a result of a previous execution of a related query and if they do then it will apply them. However, LEO does not compensate for stale or missing statistics on base objects (e.g., number of distinct value of a column). LEO also does not automatically choose the appropriate optimization mode.
Also, a number of commercial products assist a DBA in some aspects of tuning-inefficient SQL statements. None, however, provide a complete tuning solution, partly because they are not integrated with the database server. For example, Quest Software's SQLab Vision provides a mechanism for identifying high load SQL based on several measures of resource utilization. It also can rewrite SQL statements into semantically equivalent, but potentially more efficient, alternative forms and suggests creation of indexes to offer more efficient access path to the data. Since the product resides outside of the RDBMS, the actual benefit of these recommendations to a SQL statement is unknown until they are actually implemented and executed.
LeccoTech's SQLExpert is a toolkit that scans new applications for problematic SQL statements as well as high load SQL statements in the system. It generates alternative execution plans for a SQL statement by rewriting it into all possible semantically equivalent forms. There are three problems with this approach. First, it cannot identify all the ways of rewriting a SQL statement (which is normally the domain of a query optimizer). Second, equivalent forms of a SQL statement do not guarantee that the query optimizer will find an efficient execution plan if the bad plan is a result of errors in the optimizer's internal estimates like cardinality of intermediate results. Third, all the alternative plans will have to be executed to actually determine which, if any, is superior to the default execution plan.
Microsoft SQL Server offers an Index Wizard to provide recommendations to the DBA on the indexes that can potentially improve the query execution plans.


A continuous passive motion device is provided having specific application to rehabilitative treatment of the elbow or shoulder. The device includes a motorized winch displacable in a first or second direction, a cord suspended from the winch by a variable extension length, which increases when the winch is displaced in the first direction and decreases when the winch is displaced in the second direction, and an arm harness associated with the cord. An arm of a patient is suspended from a suspension point on the cord and the motorized winch is activated to alternately displace the winch in the first and second directions, thereby providing a plurality of repetitive treatment cycles. Each treatment cycle moves the suspension point and correspondingly the elbow or shoulder from a lower treatment limit to an upper treatment limit and back to the lower treatment limit.

The proliferation of relatively non-invasive arthroscopic surgical procedures to repair joint and soft tissue injuries and ailments has significantly reduced the duration of post-operative hospital stays for patients of orthopedic surgeries. In many cases the arthroscopic surgical procedures have eliminated altogether the need for post-operative hospital stays. As a result, the bulk of post-operative recovery time from arthroscopic surgical procedures is typically spent in the home. The patient benefits from the familiar surroundings of the home, but usually lacks continuous access to a health care practitioner, which a hospital is able to provide. Nevertheless, it is generally incumbent that the patient receive immediate rehabilitative treatment following a surgical procedure on a joint or soft tissue, particularly when the joint or soft tissue is associated with the elbow or shoulder. The object of the rehabilitative treatment is to restore full range of motion to the involved joint, such as the elbow or shoulder, as soon as possible after a surgical procedure. Such rehabilitative treatments commonly include range of motion exercises which involve controlled movement of the arm without bearing substantial weight or placing an excessive force load on the elbow or shoulder. Unfortunately, the patient often cannot effectively perform such range of motion exercises without external assistance.
Automated motor-driven devices have been developed to assist post-operative patients when performing range of motion exercises with the goal of rehabilitating a joint and restoring range of motion to the joint in the absence of direct assistance from a health care practitioner. Such devices are termed continuous passive motion devices. For example, a continuous passive motion device for rehabilitation of the shoulder is disclosed in U.S. Pat. No. 5,179,939 to Donovan et al. The device moves the arm through a range of motion to simulate operation of the soft tissue and joint associated with the shoulder. It is a stated objective of the continuous passive motion device disclosed in U.S. Pat. No. 5,179,939 to Donovan et al. to allow the involved shoulder to follow a natural anatomical range of motion when the associated arm is moved through the range of motion. Nevertheless, the continuous passive motion device of U.S. Pat. No. 5,179,939 is relatively ineffective for this intended purpose because the linkage between the arm holder and drive motor is rigid, which limits the adaptability of the device to the varied anatomies and treatment requirements of each different patient. Furthermore, the continuous passive motion device of U.S. Pat. No. 5,179,939 requires careful anatomical alignment of the arm holder with the arm of the patient and strict monitoring of the motorized external force loads applied to the shoulder via the arm to prevent injury to the shoulder during rehabilitation thereof. Accordingly, the device is relatively complex for an inexperienced user to properly set up and operate, thereby requiring professional oversight which negates the goal of unassisted treatment.
As such, it is an object of the present invention to provide a continuous passive motion device for rehabilitation of a shoulder or elbow which is relatively simple to set up and operate, yet which is adaptable to a variety of patient anatomies and treatment requirements. More particularly, it is an object of the present invention to provide a continuous passive motion device for rehabilitation of a shoulder or elbow which is readily adaptable to different patient anatomies without requiring careful anatomical alignment of the device with the elbow or shoulder. It is a further object of the present invention to provide such a continuous passive motion device which can apply a motorized force to the elbow or shoulder for range of motion exercise thereof with a relatively low risk of injury. It is still another object of the present invention to provide such a continuous passive motion device which can be effectively operated by a patient lacking any specific medical knowledge, skill or experience with little or no oversight by a health care practitioner. It is yet another object of the present invention to provide such a continuous passive motion device which is fully self-contained and portable so that the device can be used by the patient in the home or other normal locales.
These objects and others are accomplished in accordance with the invention described hereafter.

Continuous passive motion device for rehabilitation of the elbow or shoulder


A squeezable tongue-wagging toy figure with a squeeze mechanism which includes a squeaker provided within a space defined by four hinged panels in elliptical cylinder shape, and a toothed rack meshed with a gear chain that is coupled with a bar with a toy tongue. When the panels are squeezed, the rack drives the gear chain in one direction and in turn pivot the bar towards one side and the squeaker produces a sound, and when the panels are released, the rack drives the gear chain in an opposite direction and in turn pivot the bar towards an opposite side and the squeaker produces another sound.

In modern society, parents pay special attention to their children. It is indispensable for parents to choose toys for their children when they grow. With time changing and new technology being developed, new elements have been added in toys. Toys are no longer limited to motionless toys. Sounds and actions have been added, and interaction with players is possible. Existing toys with sound and interaction functions usually are very complicated and expensive. Electric motors are used to drive gears in gear boxes in order to drive the toys into action. Furthermore, speakers are required to produce sounds. As such, these toys require batteries which may be swallowed accidentally by children. Thus, these existing toys are large in size, heavy and high in manufacturing cost.
There is a need to produce a squeezable toy with squeeze and sound mechanisms which are simple in structure, light in weight, low in manufacturing cost, and does not require any motor, speaker or batteries.

Squeezable tongue-wagging toy and its squeeze mechanism


Methods for the diagnosis and evaluation of stroke and stroke sub-type employ a variety of bio-markers including cellular fibronectin (c-Fn) assembled as a panel for stoke diagnosis and evaluation. Methods are disclosed for selecting markers and correlating their combined levels with a clinical outcome of interest. In various aspects the methods permit early detection and differentiation of stroke subtypes, determination of the prognosis of a patient presenting stroke symptoms, and identification of a patient at risk for early hematoma growth and/or malignant massive cerebral artery infarction. The disclosed methods provide rapid, sensitive and specific assays to greatly increase the number of patients that can receive beneficial stroke treatment and therapy, and to reduce the human and economic costs associated with incorrect stroke diagnosis.

1. Field of the Invention
The present invention generally relates to the identification and use of diagnostic markers for cerebral injury. In a various aspects, the present invention particularly relates to methods for (1) the early detection and differentiation of secondary brain edema; (2) early growth of intracerebral hemorrhage (ICH); and (3) to identify patients who could benefit from aggressive therapies such as decompressive hemicraniectomy or hypothermia.
2. Background of the Invention
The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.
A stroke is a sudden interruption in the blood supply of the brain. Most strokes are caused by an abrupt blockage of arteries leading to the brain (ischemic stroke). Other strokes are caused by bleeding into brain tissue when a blood vessel bursts (hemorrhagic stroke). Because stroke occurs rapidly and requires immediate treatment, stroke is also called a brain attack. When the symptoms of a stroke last only a short time (less than an hour), this is called a transient ischemic attack (TIA) or mini-stroke. Stroke has many consequences.
The effects of a stroke depend on which part of the brain is injured, and how severely it is injured. A stroke may cause sudden weakness, loss of sensation, or difficulty with speaking, seeing, or walking. Since different parts of the brain control different areas and functions, it is usually the area immediately surrounding the stroke that is affected. Sometimes people with stroke have a headache, but stroke can also be completely painless. It is very important to recognize the warning signs of stroke and to get immediate medical attention if they occur.
Stroke or brain attack is a sudden problem affecting the blood vessels of the brain. There are several types of stroke, and each type has different causes. The three main types of stroke are listed below.
Ischemic stroke is the most common-type of stroke—accounting for almost 80% of strokes—and is caused by a clot or other blockage within an artery leading to the brain.
Intracerebral hemorrhage (ICH) is a type stroke caused by the sudden rupture of an artery within the brain. Blood is then released into the brain, compressing brain structures.
Subarachnoid hemorrhage is also a type of stroke caused by the sudden rupture of an artery. A subarachnoid hemorrhage differs from an intracerebral hemorrhage in that the location of the rupture leads to blood filling the space surrounding the brain rather than inside of it.
ICH causes a 35% to 50% 30-day mortality. Half of this mortality occurs within the first 2 days as a result of brain herniation, mainly caused by the continued bleeding that provokes an enlargement of the hematoma during the first 24 hours (Kazui S, Naritomi H, Yamamoto H, Sawada T, Yamaguchi T. Enlargement of spontaneous intracerebral hemorrhage. Incidence and time course. Stroke. 1996; 27:1783-1787.). Early hematoma growth (EHG) has been associated with early neurological worsening and poor outcome, but no clinical or radiological predictive factors have been identified and the pathogenesis remains unclear (see for instance Brott T, Broderick J, Kothari R, Barsan W, Tomsick T, Sauerbeck L, Spilker J, Duldner J, Khouri J. Early hemorrhage growth in patients with intracerebral hemorrhage. Stroke. 1997; 28:1-5; Fujii Y, Tanaka R, Takeuchi S, Koike T, Minakawa T, Sasaki O. Hematoma enlargement in spontaneous intracerebral hemorrhage. J Neurosyrg. 1994; 80:51-57.).
The pathophysiology of brain edema and secondary neuronal injury in ICH is as follows. After the initial arterial rupture, the activation of the coagulation cascade produces a large quantity of thrombin that is implicated in several functions, including chemotaxis of leukocytes, expression of adhesion molecules, release of inflammatory cytokines, blood-brain barrier disruption, and local metalloproteinase generation (see for instance Xi G et al 1998; Lee K R, Colon G P, Betz A L, Keep R F, Kim S, Hoff J T. Edema from intracerebral hemorrhage: the role of thrombin. J. Neurosurg. 1996; 84:91-96.). Furthermore, the release of iron after erythrocyte lysis may contribute to blood-brain barrier dysfunction, possibly through a free radical-mediated damage of endothelial wall (see for instance Xi G, Hua Y, Bhasin R R, Ennis S R, Keep R F, Hoff J T. Mechanisms of edema formation after intracerebral hemorrhage. Effects of extravasated red blood cells on blood flow and blood-brain barrier integrity. Stroke. 2001; 32:2932-2938.). Although all these mechanisms seem to be involved in edema formation after ICH (see for instance Castillo et al 2002; Abilleira S, Montaner J, Molina C, Monasterio J, Castillo J, Alvarez-Sabý'n J. Matrix metalloproteinase-9 concentration alter spontaneous intracerebral hemorrhage. J Neurosurg. 2003; 99:65-70.), their role in the EHG remains unclear.
EHG has been related to multifocal bleeding in the periphery of the clot caused by the rupture of arterioles and venules in the perilesional low-flow zone. Secondary brain injury has been attributed to ischemic damage and particularly to the toxic effects of thrombin generation by the clot (see for example Mendelow A D. Mechanisms of ischemic brain damage with intracerebral hemorrgae. Stroke. 1993; 24(suppl 1):115-117.). In experimental ICH, thrombin activates the inflammatory cascade and the expression of matrix metalloproteinases (MMPs), causing the breakdown of the blood-brain barrier and edema formation (see for example Xi G, Wagner K R, Keep R F, Hua Y, de Courten-Mayers G, Broderick J P, Brott T G, Hoff J T. Role of blood clot formation on early edema development after experimental intracerebral hemorrhage. Stroke. 1998; 29:2580-2586; Rosenberg G A, Navratil M. Metalloproteinase inhibition blocks edema in intracerebral hemorrhage in the rat. Neurology. 1997; 48: 921-926.). In this context, high serum concentrations of cytokines and MMP-9 have been associated with a large volume of peripheral hypodensity in human ICH (see for example Castillo J, Davalos A, Alvarez-Sabin J, Pumar J M, Leira R, Silva Y, Montaner J, Kase C S. Molecular signatures of brain injury after intracerebral hemorrhage. Neurology. 2002; 58:624-629.). MMPs are able to degrade the basal membrane components, such as cellular fibronectin (c-Fn), a glycoprotein especially important for the adhesion of platelets to fibrin, a function necessary for the blockade of bleeding.
The knowledge of the underlying mechanisms and factors associated with EHG is crucial because they represent potential targets for therapeutic interventions. In the only previous prospective study, Brott et al. failed to reveal any clinical, radiological, or analytic predictor of ICH growth (Brott T, Broderick J, Kothari R, Barsan W, Tomsick T, Sauerbeck L, Spilker J, Duldner J, Khouri J. Early hemorrhage growth in patients with intracerebral hemorrhage. Stroke. 1997; 28: 1-5.).
Massive middle cerebral artery (MCA) infarction accounts for 10% to 15% of all MCA infarctions, and of these patients, malignant MCA (m-MCA) reaches 40% to 50%. The syndrome of m-MCA infarction, which is attributable to brain edema, is more frequent in younger patients and has a poor prognosis both short and long term. In 80% of patients, it leads to death, and those patients who survive experience severe neurological deficits.
Conservative treatments fail to improve mortality and disability. Early hemicraniectomy and hypothermia are feasible and have been proposed as effective treatments for this condition because they change the natural history of the disease.5 However, those patients who will develop m-MCA syndrome are currently not revealed by clinical, neuroimaging, or biochemical markers sufficiently early and with sufficient accuracy as to indicate an aggressive management.
The loss of integrity of the endothelial basal lamina is believed to be the primary cause of edema after focal cerebral ischemia. Matrix metalloproteinase-9 (MMP-9), a proteolytic zinc-dependent enzyme for which expression is increased during stroke (for example see Clark A W, Krekoski C A, Bou S S, Chapman K R, Edwards D R. Increased gelatinase A (MMP-2) and gelatinase B (MMP-9) activities in human brain after focal ischemia. Neurosci Lett. 1997; 238:53-56.), and in experimental models of focal ischemia, 9 it degrades the endothelial basal lamina10 and plays an essential role in producing edema and hemorrhagic transformation (for example see Hoe Heo J, Lucero J, Abumiya T, Koziol J A, Copeland B R, del Zoppo G J. Matrix metalloproteinases increase very early during experimental focal cerebral ischemia. J Cereb Blood Flow Metab. 1999; 19:624-633; Rosenberg G A, Mun-Bryce S, Wesley M, Kornfeld M. Collagenase induced intracerebral hemorrhage in rats. Stroke. 1990; 21:801-807.).
In a recent study, serum cellular-fibronectin (c-Fn), a component of the basal lamina, was shown to be a more accurate predictor of hemorrhagic transformation than MMP-9 in acute ischemic stroke patients treated with tissue plasminogen activator (tPA). (For example see Castellanos M, Leira R, Serena J, Blanco M, Pedraza S, Castillo J, Davalos A. Plasma cellular-fibronectin concentration predicts hemorrhagic transformation after thrombolytic therapy in acute ischemic stroke. Stroke. 2004; 35:1671-1676.) Therefore, an increased expression of blood-brain barrier (BBB) disruption markers in cerebral ischemia may partially explain the syndrome of m-MCA infarction. The instant invention shows the association between plasma concentrations of MMP-9, c-Fn, excitatory amino acids (EAAs), and inflammatory molecules with the development of brain edema and subsequent m-MCA syndrome in patients with complete MCA infarction.
Results for mortality rate and functional outcome after hemicraniectomy in massive MCA infarction have been contradictory (for example see Schwab S, Steiner T, Aschoff A, Schwarz S, Steiner H H, Jansen O, Hacke W. Early hemicraniectomy in patients with complete middle cerebral artery infarction. Stroke. 1998; 29:1888-1893; Morley N C D, Berge E, Cruz-Flores S, Whittle I R. Surgical decompression for cerebral oedema in acute ischaemic stroke (Cochrane Review). In the Cochrane Library. 2003, Issue 3. Oxford, UK: Update Software; 2003.). This might be explained by the lack of reliable predictors of m-MCA infarction. Studies into the value of neuroimaging and clinical and biochemical markers of malignant brain edema have found few predictors to be sufficiently sensitive and specific as to be useful in clinical practice (Table 5). Clinical factors alone are not sufficient to identify patients with impending brain edema (for example see Kasner S E, Demchuk A M, Berrouschot J, Schmutzhard E, Harms L, Verro P, Chalela J A, Abbur R, McGrade H, Christou I, Krieger D W. Predictors of fatal brain edema in massive hemispheric ischemic stroke. Stroke. 2001; 32:2117-2123; Krieger D W, Demchuk A M, Kasner S E, Jauss M, Hantson L. Early clinical and radiological predictors of fatal brain swelling in ischemic stroke. Stroke. 1999; 30:287-292.). CT scan showed acceptable sensitivity in some studies but low specificity in identifying candidates for hemicraniectomy (for example see von Kummer R, Meyding-Lamade U, Forsting M, Rosin L, Rieke K, Hacke W, Sartor K Sensitivity and prognostic value of early CT in occlusion of the middle cerebral artery trunk. AJNR Am J Neuroradiol. 1994; 15:9-15; Berrouschot J, Sterker M, Bettin S, Koster J, Schneider D. Mortality of space-occupying ("malignant") middle cerebral artery infarction under conservative intensive care. Intensive Care Med. 1998; 24:620-623.). A recent approach has been to monitor biochemical markers and intracranial pressure (ICP) using a microdialysis probe inserted into the brain tissue (for example see Dohmen C, Bosche B, Graf R, Staub F, Kracht L, Sobesky J, Neveling M, Brinker G, Heiss W-D. Prediction of malignant course in MCA infarction by PET and microdialysis. Stroke. 2003;34:2152-2158.). However, this technique is complex, not widely available, invasive, and did not predict fatal outcome early enough for the successful implementation of invasive therapies because clinical deterioration often preceded the appearance of the analyzed biochemical markers and increased ICP. Promising results have been obtained with recent neuroimaging tests such as single-photon emission CT (for example see Berrouschot J et al. 1998), positron emission tomography of C-flumazenil (for example see Dohmen C et al. 2003), and diffusion-weighted MRI (for example see Oppenheim C, Samson Y, Manai R, Lalam T, Vandamme X, Crozier S, Srour A, Cornu P, Dormont D, Rancurel G, Marsault C. Prediction of malignant middle cerebral artery infarction by diffusion-weighted imaging. Stroke. 2000; 31:2175-2181. Thomalla G J, Kucinski T, Schoder V, Fiehler J, Knab R, Zeumer H, Weiller C, Rother J. Prediction of malignant middle cerebral artery infarction by early perfusion and diffusion-weighted magnetic resonance imaging. Stroke. 2003; 34:1892-1899.) in the prediction of m-MCA infarction within the suggested time window for hemicraniectomy. However these techniques evaluate infarct volume, the most reliable predictor of m-MCA, quickly and accurately but are unable to predict the development of massive brain edema directly as well as being very expensive as compared to the instant invention.
Accordingly, there is a present need in the art for a rapid, sensitive and specific differential diagnostic assay for the early detection and differentiation of EHG, m-MCA, and to identify patients who could benefit from aggressive therapies such as decompressive hemicraniectomy or hypothermia. Such a diagnostic assay would greatly increase the number of patients that can receive beneficial stroke treatment and therapy and in so doing reduce the costs associated with incorrect stroke diagnosis. Some content of this patent application was first published in the journal Stroke in its May 5 and Aug. 11, 2005, electronic issues, and thus we claim priority from these dates as well as the aforementioned dates.

Cellular fibronectin as a diagnostic marker in stroke and methods of use thereof


An illustrative embodiment disclosed herein is an apparatus including a first loading tray configured to couple to a first wafer holding device holding a plurality of wafers. The first wafer holding device includes a first opening. The apparatus includes a second loading tray configured to couple to a second wafer holding device. The second wafer holding device includes a second opening. The apparatus includes a first motor coupled to the first loading tray and configured to rotate the first wafer holding device until the first opening faces the second opening to allow transfer of the plurality of wafers from the first wafer holding device to the second wafer holding device.

The present application relates to a method and an apparatus for semiconductor wafer transfer, and more specifically, to a method and an apparatus for semiconductor wafer transfer between a first wafer holding device and a second wafer holding device.
Traditionally, in order to transfer the wafers from a first pod or cassette to a second pod or cassette, the user transfers wafers one by one. This requires a large amount of time and manpower. In addition, during manual transfer, the wafers are not protected by the pod housing and are unavoidably exposed to air. Under such a situation, the wafers may be contaminated, damaged or otherwise scrapped due to the user mishandling the wafers.

Apparatus and method for transferring wafers

TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LIMITED


A substance in a condensed state, for example a powdered solid, is in continuous movement in the longitudinal direction (6) of a furnace (4, 5). A reactive gas mixture is brought into contact with the substance in the condensed state. A plurality of samples of the gaseous mixture are removed at a plurality of reference points (14) spaced apart from one another along the longitudinal direction (6) of the furnace (4, 5); each of the gas samples is analyzed outside the furnace to determine the composition of the gas mixture and for each point (14), the extent of a chemical reaction between the condensed substance and the reactive gas mixture is deduced from the composition of the gas mixture at each of the reference points (14). In particular, the apparatus comprises a sampling and injection rod (10) introduced into the furnace (4, 5) and disposed in its longitudinal direction (6). The invention is of particular application to modeling a rotary furnace (4, 5) for converting uranium oxyfluoride into uranium oxides and for controlling the conversion reaction in the furnace (4, 5).

In nuclear reactors, for example in pressurized water nuclear reactors, a fuel is used that can be constituted mainly of uranium oxide or of a mixture of uranium oxide and plutonium.
Nuclear fuel, which is enriched in fissile elements, for example in uranium-235 in the case of a fuel constituted by uranium oxide, is generally obtained by a process in which the final enrichment product is constituted by gaseous uranium hexafluoride UF6.
The UF6 is then converted into uranium oxide by oxidation using steam, for example.
Current processes producing the best results for converting uranium hexafluoride into uranium oxide are dry direct conversion processes which are conducted in apparatus comprising, in succession, a reactor provided with means for introducing UF6 and steam into a chamber of the reactor in which uranium oxyfluoride UO2F2 is formed from the UF6, and a rotary tube furnace in which the solid powdered uranium oxyfluoride UO2F2 is transformed into uranium oxide, the tube furnace being provided with heater means and means for introducing steam and hydrogen via the outlet portion of the rotary furnace as a counter-current to the powdered solid moving in the longitudinal direction of the furnace.
Uranium oxide powder principally constituted by the dioxide UO2 is recovered from the outlet of the rotary furnace, that powder then being conditioned in a conditioning unit before being used to produce sintered nuclear fuel pellets.
The process for transforming uranium oxyfluoride UO2F2 into uranium oxide is carried out by bringing a powdered solid into contact with a reactive gas mixture containing steam and hydrogen in particular.
Hydrofluoric acid HF is formed in the rotary furnace by oxidizing the sulfur oxyfluoride with steam.
The solid material circulating in the rotary furnace coming into contact with the reactive gas mixture is the seat of various chemical reactions that result in the formation of uranium oxide, and principally of the dioxide UO2; in particular, the chemical reactions indicated below occur:UO2F2+H2O→UO3+2HF3UO3→U3O8+½O2 U3O8+2H2→3UO2+2H2O
Thus, the composition of the continuously moving solid material in the furnace and the composition of the reactive gas mixture vary essentially in the longitudinal direction of the furnace along which the powdered solid material moves, with the gas mixture moving as a counter-current.
In order to control the chemical reactions in the furnace to the best possible extent, the heater elements of the furnace disposed at the periphery of the jacket of the rotary furnace are adjusted to obtain a regular temperature distribution in the longitudinal direction of the furnace.
However, that method of adjusting the temperature in the longitudinal axial direction of the furnace cannot effectively control the composition of the uranium oxides at the furnace outlet.
Adjusting the flow rates of the hydrogen and steam introduced via the outlet end portion of the rotary furnace cannot improve control of the conversion reactions in the furnace because the reactive gases are diluted in the furnace and because of the random nature of the distribution of the reactive gases obtained inside the furnace chamber.
Further, uranium dioxide UO2 can be produced from the oxide U3O8 via intermediate reactions during which different uranium oxides are obtained in accordance with the transformation sequence U3O8→U3O7→U4O9→UO2.
In general, no method is known for determining how the reactions between the reactive gas mixture and the oxyfluoride or uranium oxides moving along the rotary furnace are progressing in the longitudinal direction of movement of the substances inside the rotary furnace. Access to a graph of the progress of the reactions inside the rotary furnace would mean that the reactions could be manipulated to optimize the conversion process to obtain oxides with the desired composition at the furnace outlet.
In particular, in order to obtain green pellets with very high mechanical strength as measured by crush, microhardness or wear tests in which the uranium oxide powder is compressed, it has been observed that it is necessary to use oxide powders of a composition such that the atomic ratio of the oxygen over the uranium (O/U) is substantially higher than the ratios normally obtained with oxides from the outlet of a uranium oxyfluoride converting furnace, which oxides are constituted principally by uranium dioxide UO2.
To increase the O/U ratio, mixing certain proportions of particles of uranium dioxide UO2 obtained by dry conversion with particles of an oxide such as U3O8 has been proposed, for example. That method, which can increase the O/U ratio of the oxides used to produce fuel pellets, necessitates oxidizing the uranium oxide UO2 under perfectly controlled conditions in order to obtain the oxide U3O8, and then forming a homogeneous mixture of UO2 and U3O8 particles. Thus, that method of producing uranium oxide powders is complex.
Currently, no method is known that can control a reaction from an accurate determination of the progress of a chemical conversion reaction in a furnace to obtain uranium oxides at the furnace outlet with the desired composition, and in particular uranium oxides with a high O/U ratio, i.e., oxides with a mean formula of the type UO2+x, where x is relatively high (x in the range 0.03 to 0.7, preferably in the range 0.05 to 0.25).
More generally, when a chemical reaction is carried out between a substance in a condensed state, for example a solid powdered substance moving continuously in the longitudinal direction of a furnace, and a reactive gas mixture, no method is known for accurately determining the extent of the reaction at different points along the longitudinal direction of the furnace, and no method is known for controlling the reaction in the furnace from any such accurate determination.
An accurate determination of the extent of the reaction in the furnace must be carried out without opening the furnace and without risking the introduction of air into the furnace interior, since that would both completely falsify the measurements and analyses carried out, and would also modify the product being produced in the furnace. Thus, it is not possible to monitor the extent of the reactions by removing samples of the moving powdered substance at different points along the axis and inside the furnace chamber.

Method and apparatus for determining the progress of a uranium oxyfluoride conversion reaction in a furnace and for controlling the reaction

Societe Franco-Belge de Fabrication de Combustible-FBFC


An oil well drill pipe thread cleaning system uses mechanical brushes to clean the drill pipe, and a closed loop cleaning fluid system for continuously washing the drill pipe and the cleaning threads with solvent, an eductor is used to continuously suction dirty cleaning fluid from the drill pipe, and a source of compressed air powers the eductor, and the mechanical cleaner.

1. Field Of The Invention
The present invention relates to oil well drill pipe cleaning and more particularly relates to an improved method and apparatus for the cleaning of oil well drill, pipe threads wherein an improved solvent based cleaning and filtration system features a continuous closed loop flow system that continuously filters hydrocarbons, scale, rust and the like from the solvent, as generated during the mechanical cleaning of the drill pipe threads.
2. General Background
In the drilling of oil wells, a plurality of lengths of drill pipe are connected end to end and slowly extended down into the earth forming what is called in the industry a drill string. Drill strings can be thousands of feet in length and typically are lengths of cylindrical pipe having an open ended bore which is also cylindrical. At the ends of these lengths of pipe there are provided threads which include external threads on one joint and a corresponding connecting portion on the next joint which includes internal threads. These threaded end portions of drill pipe are often referred to as "pin" and "box" end portions.
The cleaning of drill pipe must be done on a regular basis because the environment of oil well drilling subjects the drill pipe to accumulations of drilling mud, soil and other formation material, rust, scale and the like.
One prior art method of cleaning drill pipe is through the use of an abrasive rotary wire brush machine which is powered by a rotary device such as an air powered drill. A shroud has been used to encapsulate the end of the drill pipe so that the removed scale, rust, dirt, drilling mud, hydrocarbons and the like are captured by the shroud and so that the material that is removed from the drill pipe does not pose a threat to the operator of the power tool which is used to remove the drill pipe. The shroud simply catches scale, rust and the like and prevents that material from flying through the air and hitting the operator in the eyes or face.
The use of a solvent increases the effectiveness of the mechanical action of the wire brush, but generates significant particulate matter including rust, scale, tar, drilling mud and the like which renders the solvent dirty and less effective as well as a pollution problem requiring disposal.

Blasting and filtration system for use with oil well drill pipe


A buoy is provided for storing a line connected to an underwater object, having a hollow casing formed of resilient plastics material and having two side portions each with bearings. A reel for carrying the line has shaft portions rotatable in the bearings. The reel is a buoyant hollow body also formed of flexible plastics material and is provided with a fluid inlet for inflation from an axially collapsed state, in which the reel and its shaft portions can be fitted between the side portions, to an inflated state wherein the shaft portions are rotatably held in the bearings.

1. Field of the Invention
The present invention provides improvements in buoys especially buoys useful for lobster fishing, of the general type described in our U.S. Pat. No. 4,778,422 which issued Oct. 18, 1988. In this prior patent, a buoy was provided having a casing with two side portions connected together and with a reel rotatably mounted between the side portions and carrying a length of line connectable at its outer end to a lobster pot or other article, so that the line could be entirely contained within the buoy until the lobster pot or other article was deployed. Stowage of the line in this way prevented entanglements which were a common problem with the simple buoys and coils of line previously used in lobster fishing.
2. Prior Art
One feature of the buoy described in the aforesaid patent was that a central portion of one end of the reel was accessible through an aperture in the adjacent casing side portion, and this end of the reel shaft had a non-circular configuration adapted to be engaged by winding means such as a handle. The handle was removable when not in use. Another feature of this prior buoy was that the line was connected to the reel by a swivel link rotatable within a transverse bore in the reel so that when the line was fully paid out from the reel the buoy was free to rotate without causing entanglements.
Although it has been useful, the buoy of U.S. Pat. No. 4,778,422 did not prove sufficiently sturdy to be acceptable to all lobster fishermen; it could be broken by rough usage. Also, it was relatively expensive to manufacture. The present invention provides an improved buoy which overcomes these shortcomings of the previous design of buoy.

Buoy for storing line connected to underwater object

South Ohio, Yarmouth County, Nova Scotia


A beam shaping device (1; 31) comprising first (3; 33) and second (4; 37) optically transparent substrates, a liquid crystal layer (2; 36) sandwiched there between, and first (5; 34) and second (6; 35) electrodes arranged on a side of the liquid crystal layer (2; 36) facing the first substrate (3; 34). The beam shaping device (1; 31) is controllable between beam-shaping states, each permitting passage of light through the beam-shaping device in a direction perpendicular thereto. The beam shaping device (1; 31) is configured in such a way that application of a voltage (V) across the first (5; 34) and second (6; 35) electrodes results in an electric field having a portion essentially parallel to the liquid crystal layer (2; 36) in a segment thereof between neighboring portions of the electrodes (5, 6; 34; 35) and extending substantially from the first substrate (3; 34) to the second (4; 35) substrate. In this way a relatively high refractive index gradient can be obtained across short distances, which enables a very efficient beam shaping. The electric field can be achieved by utilizing electrodes provided on one side of the liquid crystal layer, in a so-called in-plane configuration. The device can be used in an autostereoscopic display device, for switching between 2D and 3D modes.

Active beam shaping is useful for various applications ranging from general lighting to special lighting applications, such as a video flash in which the zoom function of the camera is coupled to the beam width control function of an active optical element. Liquid crystal optics would appear to be suitable for this purpose. The alignment orientation of liquid crystal molecules in a liquid crystal cell can be controlled by applying an electric field thereto. This reorientation of the liquid crystal molecules results in a refractive index gradient, which leads to a light ray passing through the liquid crystal cell being redirected. Hereby, the direction and/or shape of a light beam can be controlled electrically.
One application of beam shaping devices of particular interest is in the field of autostereoscopic display devices, which include a display panel having an array of display pixels for producing a display and an imaging arrangement for directing different views to different spatial positions. It is well known to use an array of elongate lenticular elements which are provided extending parallel to one another and overlying the display pixel array as the imaging arrangement, and the display pixels are observed through these lenticular elements.
In an arrangement in which, for example, each lenticule is associated with two columns of display pixels, the display pixels in each column provide a vertical slice of a respective two dimensional sub-image. The lenticular sheet directs these two slices and corresponding slices from the display pixel columns associated with the other lenticules, to the left and right eyes of a user positioned in front of the sheet, so that the user observes a single stereoscopic image. The sheet of lenticular elements thus provides a light output directing function.
In other arrangements, each lenticule is associated with a group of four or more adjacent display pixels in the row direction. Corresponding columns of display pixels in each group are arranged appropriately to provide a vertical slice from a respective two dimensional sub-image. As a user's head is moved from left to right, a series of successive, different, stereoscopic views are perceived creating, for example, a look-around impression.
The above described device provides an effective three dimensional display. However, it will be appreciated that, in order to provide stereoscopic views, there is a necessary sacrifice in the horizontal resolution of the device. This sacrifice in resolution is unacceptable for certain applications, such as the display of small text characters for viewing from short distances. For this reason, it has been proposed to provide a display device that is switchable between a two-dimensional mode and a three-dimensional (stereoscopic) mode.
One way to implement this is to provide an electrically switchable lenticular array. In the two-dimensional mode, the lenticular elements of the switchable device operate in a "pass through" mode, i.e. they act in the same way as would a planar sheet of optically transparent material. The resulting display has a high resolution, equal to the native resolution of the display panel, which is suitable for the display of small text characters from short viewing distances. The two-dimensional display mode cannot, of course, provide a stereoscopic image.
In the three-dimensional mode, the lenticular elements of the switchable device provide a light output directing function, as described above. The resulting display is capable of providing stereoscopic images, but has the inevitable resolution loss mentioned above.
In order to provide switchable display modes, the lenticular elements of the switchable device can be formed as a beam shaping arrangement of an electro-optic material, such as a liquid crystal material, having a refractive index that is switchable between two values. The device is then switched between the modes by applying an appropriate electrical potential to planar electrodes provided above and below the lenticular elements. The electrical potential alters the refractive index of the lenticular elements in relation to that of an adjacent optically transparent layer.
A more detailed description of the structure and operation of the switchable device can be found in U.S. Pat. No. 6,069,650.
The known use of switchable liquid crystal materials for switchable 2D/3DD displays uses a replica technique to form the lens shapes, which are then filled with liquid crystal material. This process is not compatible with the other processing steps associated with the LCD fabrication process, and therefore adds significantly to the cost of producing the display device.
A more general example of liquid crystal optics is disclosed in JP 07-043656, where a light beam coupler is arranged to align a light beam to a selected optical fiber and to adjust the beam spot size. In the coupler, a liquid crystal layer is provided between transparent substrates. One of the substrates is provided with a ground plane, and the other substrate is provided with a number of individually controllable electrodes. By varying the potential of the electrodes in relation to the ground plane a light beam passing through the coupler is aligned to hit a selected optical fiber.
Although being capable of deflecting a light beam a short distance, the device disclosed in JP 07-043656 appears unsuitable for more macroscopic beam shaping applications, where a large beam divergence and/or convergence is typically desired.


The arrangement of focus-detecting sensors for autofocus in multipoint range finding and the arrangement of light detection sensors for focus detecting regions are optimized. Further, the chip area and power consumption are reduced. Light detection sensors are provided on the sensor chip in a manner such as to be disposed between focus-detecting sensors provided on the same sensor chip.

1. Field of the Invention
The present invention relates to a photosensor for detecting the focus, a focus detecting device, and an image pickup apparatus.
2. Description of the Related Art
When the focus of an object at the same distance is detected with a phase-difference focus detecting device, the focus detection result varies (defocusing) in accordance with the wavelength because of chromatic aberration of an imaging optical system.
For this focus detecting device in which the focus detection result varies, for example, Japanese Patent Publication No. 1-45883 proposes a technique of detecting and correcting the variation in the focus detection result due to the difference of the light source by using a light-receiving section that detects the light source. In this focus detecting device, a signal corresponding to the infrared region and signals of other wavelength regions are detected, the defocus amount is calculated, and defocusing is corrected on the basis of the defocus amount.
Japanese Patent No. 2555681 proposes a focus detecting device in which first and second photodiodes for detecting the color temperature are disposed adjacent to a base portion and a reference portion of a focus-detecting photodiode array on the same chip. In this focus detecting device, the photodiode array and the first and second photodiodes receive almost the same object image.
Japanese Patent Laid-Open No. 2004-272238 discloses a focus detecting device in which a plurality of focus-detecting photoreceptors are provided corresponding to a plurality of optical systems and in which monitoring photoreceptors are provided adjacent to the focus-detecting photoreceptors.
In the technique disclosed in Japanese Patent Publication No. 1-45883, a photoreceptor that obtains a photoelectric signal indicating infrared light and a photoreceptor that obtains a photoelectric signal indicating light with other wavelengths are provided near photoreceptors that detect the focus of a light beam received from an imaging optical system that forms an object image. However, this publication does not describe the arrangement of the photoreceptors for a plurality of focus detecting fields. Japanese Patent 2555681 teaches that the photodiodes for detecting the color temperature are provided adjacent to the photodiode array, but does not describe the arrangement for a plurality of focus detecting fields.
In the focus detecting device disclosed in Japanese Patent Laid-Open No. 2004-272238, a monitoring photoreceptor is provided for each focus detecting photoreceptor. However, with the increase in number of distance measuring fields of the focus detecting device, the number of focus-detecting photoreceptors increases, and the number of monitoring photoreceptors increases in proportion thereto. Consequently, the sizes of the sensor circuit and the sensor are increased.


The invention concerns a gas tight drift chamber of an ion mobility spectrometer with ring electrodes separated by insulating rings. In order to simplify the construction and to improve the mechanical and electrical stability, the ring electrodes have a z-shaped cross section, into which the insulating rings with the rectangular cross sections are fitted. Electrodes and insulating rings are connected is in a gas-tight manner. The high voltage divider consists either of individual SMD resistors which are soldered or vapor deposited to the outside or of a highly resistively coated ceramic rod.

Such a drift chamber is for example known from U.S. Pat. No. 4,777,363.
Ion mobility spectrometers (IMS) are generally used to detect the presence of materials in a surrounding, e.g. of harmful substances in the atmosphere. The possibilities extend from a pure alarm function in the presence of a known harmful substance, e.g. a chemical warfare agent, via the identification of an unknown substance to a quantitative determination of the concentration.
Typical IMS comprise an ionization source, a reaction cell, a drift chamber, e.g. in the form of a tube, an entrance grid between the reaction region and the drift region, and an ion detector. The spectrometers at atmospheric pressure, where the average path length of the gas molecules within the drift chamber is small compared to the chamber dimensions. Usually, a carrier gas, generally dry air, is introduced into the spectrometer together with the sample gas or vapour. The carrier gas which contains the sample is fed via an inlet onto the ionization source, resulting in a partial ionization of the molecules of the carrier gas and the sample. The ionization source consists generally of tritium or .sup.63 Ni. Additional charges are transferred by means of impact from molecules of the carrier gas to sample molecules, or quasi-molecule ions are formed. Within the reaction region usually an electrical potential gradient is present, so that the charged mixture is moved towards the injection grid. The grid is charged electrically and blocks the transfer to the drift chamber under normal conditions. However, for short times this potential is periodically reduced, so that a number of sample ions reaches the drift chamber in a pulse-like manner. Here an approximately constant electrical drift field, i.e. a constant potential gradient, is present, which moves the ions along the cell axis towards a detector electrode, which is located at the end of the drift chamber opposite to the injection grid and which collects the charge of the ions. The time of arrival of the ions with respect to the pulse-like opening of the injection grid depends on the mobility of the detected ions. Light ions are more mobile than heavy ones and reach the detector earlier. This effect is used to characterize the ions. The pulse-like opening of the grid can be repeated periodically to increase the signal-to-noise-ratio or to perform a quasi-contenuous measurement.
The drift chamber of the known spectrometer is part of a cylindrically shaped tube with an injection grid said grid separating a reaction region containing a .sup.63 Ni source from the drift region. The actual drift tube comprises a multitude of metal rings ranging from the injection grid to the detector electrode at the opposite end of the drift region and which are separated by insulating rings. The stack of metal and insulating rings is compressed along the axis and fixed by axial rods. Via a resistor network electrical potentials may be applied to the injection grid and to the metal rings from a 3000 volt high voltage source, resulting in an axial electrical field of 221 volts per centimeter inside the drift chamber. In alternatively described embodiments of the cell, this cell is hermetically sealed from the outside by O-rings between the metal rings or the rings are arranged outside a tube made from glass or "TEFLON". In a further embodiment the electronics to drive the spectrometer is arranged on a flexible printed circuit which is wrapped around the drift chamber.
GB-A1 2 217 103 discloses electrode rings in the form of copper bands which are glued onto the outside of an IMS drift chamber made from a non-conductive material, particularly glass.
In U.S. Pat. No. 4,390,784 a drift chamber made from ceramics or glass is described which is continuously coated on its inside with a resistive coating, to produce the constant axial electrical field.
U.S. Pat. No. 4,633,083 discloses an IMS drift chamber with a multitude of stainless steel electrode rings with a T-shaped profile, which are separated by insulating glass rings.
In particular with regard to an IMS for mobile, e.g. military, application as a series product, despite known spectrometers, there is still a need for a robust, reliable apparatus with a gas-tight drift chamber which is simply and cost effectively produced.


Fuel gas (G) is supplied via a pipe to a pre-combustion chamber of an internal combustion engine. The pre-combustion chamber is formed inside a chamber body which is received in a cavity of the engine body, while the pipe is received in a passageway of the engine body which communicates with the cavity. A seal which may be made from an elastomer comprises a wall defining an interior space opening through the wall at first, second and third openings. A first portion of the wall defining the first and second openings is arranged in the cavity so that the chamber body can be inserted through the openings into the interior space of the seal, while a second portion of the wall comprising the third opening is received in the passageway so that the pipe can be inserted into the interior space of the seal via the third opening. The pipe is sealed in fluid communication with the pre-combustion chamber via an inlet in the chamber body by sealing regions of the seal.

Gas engines are often fitted with a pre-combustion chamber in fluid communication with the combustion chamber. Fuel gas is supplied directly to the pre-combustion chamber where it is ignited to detonate the main charge in the combustion chamber.
The fuel gas may be supplied via a pipe which extends through a passageway in the engine body (typically the cylinder head) to a cavity in the cylinder head in which a chamber body defining the pre-combustion chamber is housed.
It is necessary to seal the pipe in fluid communication with the pre-combustion chamber to prevent the fuel gas from leaking.
In one conventional arrangement, the fuel gas supply pipe is sealed to the chamber body within the cylinder head by means of a metal sealing tube arranged between the outlet end of the pipe and the inlet orifice of the chamber body, with metal-to-metal interference contact all around its circumference at each end of the tube.
This requires accurate dimensional and surface quality control and so is a technically demanding and expensive solution.
Care is also required to exactly align the inlet orifice of the chamber body with the pipe, and to avoid unseating the chamber body in the cavity of the cylinder head by the sealing force which is applied to the tubular seal by axial compression of the pipe.
There may also be difficulty in remaking the seal satisfactorily after maintenance.
In another conventional arrangement, the fuel gas supply pipe and the chamber body are sealed to the cylinder head, each by means of a separate group of O-ring seals, so that an inner end region of the passageway in the cylinder head in which the fuel gas supply pipe is installed forms a conduit for conveying the fuel gas from the outlet end of the fuel gas supply pipe to the inlet orifice of the pre-combustion chamber.
The O-rings are relatively soft and so care must be taken to avoid damaging them during installation by abrasion against the material of the cylinder head as they are inserted together with the chamber body or fuel gas supply pipe into the respective passageway or cavity of the cylinder head.
Moreover, since the cylinder head may be made from a relatively more porous material than the gas inlet pipe and the chamber body, its porosity must be carefully controlled to avoid leakage of the fuel gas through the cylinder head into the ambient environment or coolant passages.

Seal and method for a fuel gas supply to a pre-combustion chamber