An oxide superconductor element, produced by forming a damaged region on a substrate surface by the Ga.sup.+ focusing ion beam method and then depositing an oxide superconductor thin-film over it, is characterized in that a NdBa.sub.2 Cu.sub.3 O.sub.7-y (0.ltoreq.y.ltoreq.0.5) oxide superconductor is used in a tunnel junction having a tunneling barrier region with weak superconductivity.

1. Field of the Invention
The present invention relates to a Josephson element employing an oxide superconductor operating at below the temperature of liquid nitrogen, and to a process for its production.
2. Description of the Related Art
The creation of Josephson junctions, which are the basis of superconducting electronic devices, involves the use of multiple thin-films, and the superconducting coherence length at their interface is an important parameter. Since all oxide superconductors have low carrier concentrations compared to normal metals, the superconductive characteristics are subtly influenced by the crystalline structure and composition. Therefore, damaged layers are produced by defects at junction interfaces. In such cases, a short coherence length makes it impossible to achieve satisfactory junction characteristics. All superconductors with a high Tc (critical temperature), however, have short coherence lengths. In addition, the quantum phenomenon of the tunneling effect is highly dependent on the geometry of the junction interface. This has meant low reproducibility of the characteristics of Josephson junctions of oxide superconductors. On the other hand, a major advantage of Josephson junctions is low power consumption, and this has been very advantageous for the integration of multiple elements. The homogeneity (reproducibility) of element characteristics thus becomes essential for realizing design performance. In addition, the fact that Josephson junctions have no amplification function necessitates a narrow distribution of element characteristics for realizing circuit performance. This has led to continuous active research for improving the reproducibility of Josephson junctions. One thing that has been learned is that Josephson junctions may be achieved relatively easily by forming plane-configured junctions which allow the a-axis direction, having a relatively long coherence length, to be oriented perpendicular to the junction surface (Japanese Unexamined Patent Publication (Kokai) No. 6-151986).
According to a known process, after preliminary treatment of the (100) surface of a single crystal substrate, such as MgO, SrTiO.sub.3, etc., which may include formation of a groove, amorphization and roughening, a YBCO or BSCCO film is formed, and the treated region is made into a tunneling barrier region. Japanese Unexamined Patent Publication (Kokai) No. 4-152686 discloses formation of a groove 0.2 .mu.m wide and 0.1 .mu.m deep in a MgO (100) single crystal substrate by photo etching (Ar sputtering), followed by formation of a BSCCO film by RF magnetron sputtering to create a tunneling Josephson junction. Japanese Unexamined Patent Publication (Kokai) No. 4-155875 discloses excimer laser irradiation of a MgO or SrTiO.sub.3 (100) single crystal substrate for melting and resolidification to amorphize a 1 .mu.m width, followed by formation of a YBCO or BSCCO film by sputtering. Finally, Japanese Unexamined Patent Publication (Kokai) No. 4-132278 discloses rough finishing of the entire surface of a MgO or SrTiO.sub.3 (100) single crystal substrate with diamond powder, coating an approximately 1 .mu.m width with a resist, and melting of the other sections by Ar ion milling to flatten them, followed by formation of a YBCO film.
With the methods disclosed in the above-mentioned publications, however, it is still difficult to control the critical current value, and it has not been possible to provide sufficient reproducibility for integration. In the case of planar junctions, the barrier layer is roughly the same substance as the thin-film, and the critical current value is highly dependent on the cross-sectional area of the junction. Consequently, it is believed that any irregularities in the quality of the thin-film will lead to variations in the characteristics of the barrier layer or the lateral characteristics during patterning, thus eventually resulting in poor reproducibility. Particularly when a YBCO thin-film is deposited by the pulse laser method, particulates are generated and reside in the junction surface, thus lowering the critical current value.
The present invention relates to a Josephson element which employs a superconductor, and specifically it provides a Josephson element employing a NdBa.sub.2 Cu.sub.3 O.sub.7-y thin-film for the purpose of preventing the generation of particulates by the use of the NdBa.sub.2 Cu.sub.3 O.sub.7-y thin-film which has excellent surface flatness and homogeneity, in order to improve the reproducibility of critical current densities of plane-configured Josephson junctions, thus opening the door to integration of Josephson junctions.

Josephson element having a NdBa.sub.2 Cu.sub.3 O.sub.7-y superconductor thin-film wiring pattern

International Superconductivity Technology Center


Apparatus and methods for dynamically rendering transparent ink strokes, in some situations such that the rendered ink stroke has transparency similar to physical ink while it is being drawn. For example, the ink stroke may be dynamically rendered as a stroke having uniform transparency while it is being drawn. Only the new ink segment that has most recently been added to the stroke may be drawn, and areas of the new ink segment that overlap older segments of the ink stroke may be frozen, or excluded from being repainted.

The term "digital ink" refers to one or more strokes that are recorded from a pointing device, such as a mouse, a stylus/pen on a digitizer tablet, or a stylus/pen on a display screen integrated with a digitizer tablet (e.g., a touch-sensitive display screen). As used herein, the term "ink" is shorthand for digital ink. Also, the term "pen" and "stylus" are used generically and interchangeably. Each stroke may be stored as one or more ink packets, in which each ink packet may contain coordinates (x, y) corresponding to the position of the pointing device. For example, a user may move a pen along a touch-sensitive display screen of a computer system so as to draw a line or curve, and the computer system may sample the coordinates (x, y) along the trajectory of the pen tip position over time (or on any other interval as known in the art) as the user moves the pen. These coordinates represent points along the curve or line and are stored as ink packets.
Ink may be either transparent or non-transparent, as used herein. Ink that is transparent means that the ink does not fully conceal the background behind it when displayed on a display or printed on a printer. Ink that is not transparent completely conceals or occludes the background behind it. Non-transparent ink may also be referred to as opaque ink. For instance, FIG. 1 shows ink strokes 101, 102, and 103. Ink strokes 102 and 103 each overlay ink stroke 101, but ink stroke 103 completely conceals its background, including the portion of ink stroke 101 that it overlays (i.e., the portion of ink stroke 101 that is a background behind ink stroke 103). Thus, ink stroke 103 is considered opaque. In contrast, ink stroke 102 allows some of ink stroke 101, as well as some of the white background, to show through where ink stroke 102 overlays ink stroke 101. Thus, ink stroke 102 is considered transparent. Ink can be of any transparency and still be considered transparent. Current graphics interfaces are capable of applying transparent paint with a prescribed degree of transparency. For example, ink may be 50% transparent, which means that 50% of the background is concealed, or ink may be 25% transparent, which means that 75% of the background is concealed. A transparent ink stroke can be analogized with a piece of glass, such as colored glass, in which objects behind the glass can be seen. A non-transparent ink stroke can be analogized with a brick wall that hides everything behind it.
It is often desirable to render a transparent ink stroke dynamically while the ink stroke is being drawn, in other words, to draw the ink stroke on the display screen while the pointing device moves and adds new points to the ink stroke or strokes. One way to accomplish this is to erase the entire screen and redraw everything on the screen each time a new point is added to the ink stroke. This is an imperfect solution, however, since in practice there is typically a short time interval between ink points, and repeatedly clearing and redrawing the screen uses massive amounts of processing power, not to mention causing the screen to flicker. A way to reduce the redrawing time would be draw each new segment of an ink stroke as it is drawn. The problem with this is that the transparencies of the overlapping portion of ink segments are reduced in an unexpected and unintended manner. The effect of redrawing transparent ink is shown in FIG. 2, where the darker circles of an ink stroke 200 represent the overlapping start and end points of the segments. These overlapping areas are darker because they are each drawn twice—once when a segment ending with a particular point is drawn, and again when the next segment beginning with the same point is drawn—thereby reducing the transparency at the overlap. The result is an unintentionally non-uniform ink stroke. This is analogous to repeatedly making a glass window thicker, thereby making objects on the other side of the glass more difficult to see by making the window darker. The variable transparency of the rendered ink is unexpected to the user who would expect transparent ink to be rendered as transparent physical ink as applied to paper and/or over other ink.
There is also a need for providing various artistic features not provided by current systems, such as dynamically rendering ink responsive to variable width, pressure, speed, and angle of the pen.

Dynamic rendering of ink strokes with transparency


A delta query technique transmits only latest changes to data of objects from a server to one or more clients in response to a client query (request) to access the object data. A global counter is maintained for all of the objects served by the server. Every time the data of an object changes, a value of the global counter increments (updates) and the updated global counter value is then assumed (“inherited”) by that object. In addition, the global counter is updated when a client issues a request to access one or more objects. If the data of the objects has changed since the last time the client accessed the objects, the server responds with the latest object data and the updated global counter value. Notably, each client maintains a local counter having a value that, upon receipt of the latest object data, is modified to reflect the updated global counter value.

A storage system is a computer that provides storage services relating to the organization of information on writeable persistent storage devices, such as disks. The storage system may include a software component that functions as a server to manage and maintain up-to-date (current) information about the system. The information maintained by the server can be modeled as a set of objects, each of which contains a set of properties. Objects may be added or removed from the system, and the values of their properties may change over time.
The storage system may be further configured to operate according to a client/server model of information delivery to thereby allow many clients to access the objects served by the system. In this model, the client may comprise a software component, such a graphical user interface (GUI) process, executing on a computer that "connects" to the storage system over a computer network, such as a point-to-point link, a shared local area network, a wide area network that may span long distances or a virtual private network implemented over a public network, such as the Internet. Each client may request the services of the server by issuing object access queries or requests to the storage system.
In response to a client issuing a request to access (e.g., read) the data of one or more objects, the server may send a latest image of the data for all of the objects. Depending on the number and type of objects, this could represent a substantial amount of data that consumes a substantial amount of resources (e.g., processor, memory and/or storage) on the storage system and on the network (bandwidth). In the latter case, the available bandwidth in the network may be limited and its usage may be expansive, while the latency of the network may be high (especially for long distances). Each client may disconnect and reconnect (either shortly thereafter or after a long pause), or never reconnect. Often the server may not know whether or when the client may reconnect. A disconnection may not necessarily be an orderly one, and may include an unplanned outage in the network, a failure in the client, etc.
Armed with the latest image of the object data, the client constructs a local copy of the information, including all existing objects and their relationships in the system, and may display this information to a user via, e.g., an associated GUI display. In response, the user may perform various filtering and navigation operations on the information in a local, high-responsiveness fashion, without requiring interaction with the server. The user typically expects the displayed information to be current, such that if new objects are is added (e.g., by a different client) or changed, the client reflects such additions or changes in a timely manner (e.g., 10 seconds). Accordingly, a basic implementation could be for the client to query the server, e.g., on the order of every 10 seconds, for the entire information about the objects and their structural properties. Since the number of objects is large, this would lead to excessive and impractical network utilization.
Since the server manages and maintains all information, some systems are configured such that the server performs most of the logic needed for each client to interact with its user. The server may even dictate the manner in which the information is presented on the display associated with the client. Although such configurations may lead to efficient network utilization, they may also overload the server with GUI related operation processing that may, in turn, cause a scalability bottleneck. Furthermore, various GUI operations may be slow and/or lengthy due to inherent network latency, resulting in adverse (degraded) user interaction/responsiveness.
A different approach may offload such operation processing from the server to the client. Typically, this requires that the server propagate some portion of its managed information to the client via the network. The advantages of this approach include offloading of the processing effort and, for various operations, potentially faster responsiveness for a client user. Often, the client's local copy of the information is not fully up-to-date; however, this may be acceptable as long as the currency of the copy is reasonable. A disadvantage of this approach is the typically higher network utilization required to propagate the information to the client. This is particularly prominent in cases where the client requires certain information related to the entire managed system, and where the entire system's information is large.
Some systems address the issues described above by enabling the server to propagate only changes (delta) information to each client. To that end, these systems typically maintain a queue of information changes for each client and stream (transmit) that information to the client. The disadvantage of this approach is that the queues may grow in size. Furthermore, if a client disconnects, the server may either maintain the queues in the event the case the client reconnects or eventually destroy (cancel) the queues. If a client reconnects after a long pause, and its queues were cancelled, then synchronization is of the entire information from the server to the client is required.


Disclosed is a device made of a soft, flexible elastomer with freely movable members for use as a vibration dampener on an archery bow limb. Upon release of an arrow from an archery bow, the damper members reactively contact and rebound against the bow limb. The device can be installed on a mount to attach to both solid limb and split limb bows at the same general location on both the top and bottom limbs to greatly reduce the duration of vibration, the amount of hand shock and perceived noise generated upon release of an arrow from an archery bow.

Archery bows generate excessive noise when fired due to the considerable amount of vibration of the archery bow limbs. Other bow limb vibration dampeners position the greater mass of the elastomer device at the end furthest from the mount. This allows the greater mass of the device to wiggle and jiggle in free space without making contact with the bow limb. Although these devices were effective in reducing vibrations in older bows, they are not as effective when attached to newer bows that have a generally parallel limb arrangement. This is due to the unique forces placed on the bow limbs upon the release of an arrow from an archery bow. The reason that more manufactures have started using this parallel limb mounting arrangement is because it has been observed that hand shock, vibration and noise are reduced.
There exist a need for more modern compound bows with parallel and non-parallel limbs to place the elastomer dampening device closer to the surface of the archery bow limb to allow symmetric and asymmetric rebounding of the device against the surface of the bow limb. It has been observed that the actions of the device upon firing an arrow from an archery bow will greatly reduce the duration of vibrations, hand shock and perceived noise in the archery bow.


The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.

Fuel cells have been proposed as a power source for many applications. So-called PEM (proton exchange membrane) fuel cells [a.k.a. SPE (solid polymer electrolyte) fuel cells] potentially have high energy and low weight, and accordingly are desirable for mobile applications (e.g., electric vehicles). PEM fuel cells are well known in the art, and include a "membrane electrode assembly" (a.k.a. MEA) comprising a thin, proton transmissive, solid polymer membrane-electrolyte having an anode on one of its faces and a cathode on the opposite face. The membrane-electrode-assembly is sandwiched between a pair of electrically conductive elements which serve as current collectors for the anode and cathode, and contain appropriate channels and/or openings therein for distributing the fuel cell's gaseous reactants over the surfaces of the respective anode and cathode catalysts. The channels/openings for the reactants are often referred to as "flow channels". A plurality of individual cells are commonly bundled together to form a PEM fuel cell stack.
PEM fuel cells are typically H.sub.2 --O.sub.2 fuel cells wherein hydrogen is the anode reactant (i.e., fuel) and oxygen is the cathode reactant (i.e., oxidant). The oxygen can either be in a pure form (i.e., O.sub.2), or air (i.e., O.sub.2 admixed with N.sub.2). The solid polymer membranes are typically made from ion exchange resins such as perfluoronated sulfonic acid. One such resin is NAFION.TM. sold by E. I. DuPont deNemeors & Co. Such membranes are well known in the art and are described in U.S. Pat. No. 5,272,017 and 3,134,697, and in Journal of Power Sources, Volume 29 (1990), pages 367-387, inter alia. The anode and cathode themselves typically comprise finely divided carbon particles, very finely divided catalytic particles supported on the internal and external surfaces of the carbon particles and proton conductive resin intermingled with the catalytic and carbon particles. One such membrane electrode assembly and fuel cell is described in U.S. Pat. No. 5,272,017 issued Dec. 21, 1993 and assigned to the assignee of the present invention.
The hydrogen used in the fuel cell can be derived from the reformation of methanol or other organics (e.g., hydrocarbons). Unfortunately, the reformate exiting the reformer contains undesirably high concentrations of carbon monoxide which can quickly poison the catalyst of the fuel cell's anode, and accordingly must be removed. For example, in the methanol reformation process, methanol and water (as steam) are ideally reacted to generate hydrogen and carbon dioxide according to the reaction: EQU CH.sub.3 OH+H.sub.2 O.fwdarw.CO.sub.2 +3H.sub.2
This reaction is accomplished heterogeneously within a chemical reactor that provides the necessary thermal energy throughout a catalyst mass and actually yields a reformate gas comprising hydrogen, carbon dioxide, carbon monoxide, and water. One such reformer is described in U.S. Pat. No. 4,650,727 to Vanderborgh. Carbon monoxide (i.e., about 1-3 mole %) is contained in the H.sub.2 -rich reformate/effluent exiting the reformer, and must be removed or reduced to very low nontoxic (i.e., to the anode) concentrations (i.e., less than about 20 ppm) to avoid poisoning of the anode by adsorption onto the anode catalyst. The unreacted water serves to humidify the fuel gas and prevent drying of the MEA.
It is known that the carbon monoxide, CO, level of the reformate/effluent exiting a methanol reformer can be reduced by utilizing a so-called "shift" reaction. In the shift reactor, water (i.e. steam) is injected into the methanol reformate/effluent exiting the reformer, in the presence of a suitable catalyst, to lower its temperature, and increase the steam to carbon ratio therein. The higher steam to carbon ratio serves to lower the carbon monoxide content of the reformate according to the following ideal shift reaction: EQU CO+H.sub.2 O.fwdarw.CO.sub.2 +H.sub.2
Some CO survives the shift reaction and remains in the reformate. Depending upon the reformate flow rate and the steam injection rate, the carbon monoxide content of the gas exiting the shift reactor can be as low as 0.5 mole %. Any residual methanol is converted to carbon dioxide and hydrogen in the shift reactor. Hence, shift reactor effluent comprises hydrogen, carbon dioxide, water and some carbon monoxide.
The shift reaction is not enough to reduce the CO content of the reformate enough (i.e., to below about 20 ppm). Therefore, it is necessary to further remove carbon monoxide from the hydrogen-rich reformate stream exiting the shift reactor, and prior to supplying it the fuel cell. It is known to further reduce the CO content of H.sub.2 -rich reformate exiting the shift reactor by a so-called "PROX" (i.e., preferential oxidation) reaction effected in a suitable PROX reactor and can be either (1) adiabatic (i.e. where the temperature of the catalyst is allowed to rise during oxidation of the CO), or (2) isothermal (i.e. where the temperature of the catalyst is maintained substantially constant during oxidation of the CO). The PROX reactor comprises a catalyst bed operated at temperatures which promote the preferential oxidation of the CO by injecting controlled amounts of air into the effluent from the shift reactor to consume the CO without consuming/oxidizing substantial quantities of the H.sub.2. The PROX reaction is as follows: EQU CO+1/20.sub.2 .fwdarw.CO.sub.2
Desirably, the O.sub.2 required for the PROX reaction will be about two times the stoichiometric amount required to react the CO in the reformate. If the amount of O.sub.2 is substantially less than about two times the stoichiometric amount needed, insufficient CO oxidation will occur. On the other hand, if the amount Of O.sub.2 exceeds about two times the stoichiometric amount needed, excessive consumption of H.sub.2 results. Consumption of the H.sub.2 raises the temperature of the gas, which in turn causes the formation of CO by the reaction of H.sub.2 with CO.sub.2, known as the reverse gas-shift reaction. Hence, careful control of the amount of air injected in the PROX reaction is essential to control the CO content of the reformate feed stream to the fuel cell. The PROX process is described in a paper entitled "Methanol Fuel Processing for Low Temperature Fuel Cells" published in the Program and Abstracts of the 1988 Fuel Cell Seminar, Oct. 23-26, 1988, Long Beach, Calif. and in U.S. Pat. No. Vanderborgh et al 5,271,916, inter alia.
Whether an adiabatic or isothermal PROX reaction, a controlled amount of O.sub.2 (i.e., as air), is mixed with the reformate exiting the shift reactor, and the mixture passed through a suitable PROX catalyst bed known to those skilled in the art. To control the air input rate, the CO concentration in the gas exiting either the shift reactor or the PROX reactor is measured, and based thereon, the O.sub.2 concentration needed for the PROX reaction adjusted. However, sensitive, real time, CO sensors have not heretofore been available, and accordingly system response to CO concentration variations has been slow. This is particularly troublesome in dynamic systems where the flow rate, and CO content, of the H.sub.2 -rich reformate vary continuously in response to variations in the power demands on the fuel cell system. Since the amount of O.sub.2 (e.g., air) supplied to the PROX reactor must vary on a real time basis in order to accommodate the varying power demands on the system, there is a need for a rapid response CO sensor to continuously monitor the CO in the reformate stream and therefrom (1) maintain the proper oxygen-to-carbon monoxide concentration ratio in the PROX reactor, and/or (2) divert the reformate stream away from the fuel cell until the CO content thereof falls within acceptable levels.


A rotational force transmitting device includes: an inertia wheel connected to an output gear; a spindle coupled freely rotatable to the center of the front surface of the inertia wheel; a power transmitting eccentric body extended vertically with respect to the rotary shaft of the spindle; an insert pin inserted into a guide hole, a position restoring spring inserted into the guide hole, for elastically supporting the insert pin in a backward direction; and a balance weight coupled rotatably to the rear surface of the inertia wheel, the balance weight rotating with the centrifugal force generated by the rotation of the inertia wheel to push the insert pin forward to allow the insert pin and the power transmitting eccentric body to be engaged with each other.

FIG. 1 is an exploded perspective view showing a conventional centrifugal clutch power transmission mechanism, which is disclosed in Korean Utility Model Registration No. 0237307 (entitled "electrical screw driving tool"), and an operation principle of the conventional centrifugal clutch power transmission mechanism will be described below.
If a motor does not operate or rotates at a low speed, a lever 17 is pushed to the right side in the drawing through the operation of a spring 8, and an elevating rod 16 connected with the lever 17 through a cam 18 is moved down and escaped from a concave groove 23 of a wing 20. In this state, a spindle 7 is coupled freely rotatable to an inertia wheel 5, and therefore, even though the inertia wheel 5 rotates, the spindle 7 does not rotate. If the rotational speed of the motor reaches a given speed or more, the centrifugal force applied to a starter 10 mounted on the inertia wheel 5 exceeds the elastic force of the spring 8, and accordingly, the starter 10 is moved outward to pull the lever 17, so that the elevating rod 16 is moved up by the operation of the cam 18 and engaged with the concave groove of the wing 20 on the top end periphery thereof, thus hitting and rotating the spindle 7. If substantially large resistance occurs during the rotation to cause the rotational speed of the motor to be decreased, the centrifugal force applied to the starter 10 is not sufficient to allow the starter 10 and the lever 17 to be returned to their original position by the operation of the spring 8, and thus, the elevating rod 16 is moved down by the operation of the cam 18 and escaped from the concave groove 23, thus stopping the rotation of the spindle 7. If the rotational speed of the motor reaches the regulation speed again, the above-mentioned process is carried out again to generate torques needed for mounting/demounting bolts or nuts.
The conventional power transmitting mechanism using the centrifugal force does not immediately transmit the rotational force of the motor to the spindle 7 during the initial operation due to the gaps among the starter 10, the lever 17, the cam 18, and the elevating rod 16, and the elevating rod 16 collides against the concave grove 23 of the wing 20 during the upward movement and thus moved down. After that, the elevating rod 16 is moved up again by the operations of the starter 10, the lever 17, and the cam 18. The downward and upward movements are repeatedly carried out (which is called "chattering"), thus decreasing the transmission efficiency of the rotational force.
Furthermore, the starter 10, the lever 17, the cam 18, and the elevating rod 16 are connected to one another through complicated articulated structures, thus increasing the manufacturing cost and decreasing the durability of the product.
Moreover, separate shock absorbing means is not suggested so that the shock and vibration generated during the working are totally transmitted to a user.


The light alloy wheel assembly for motor vehicles includes a rim for mounting a tire, a wheel hub for fixing the wheel assembly to a motor vehicle axle hub, a disc or spokes connecting the wheel hub and the rim, a false hub to be fixed on the vehicle axle hub and to allow fixing thereon of the wheel hub, and bolt/bore/seat arrangements for tightening and centering the false hub on the vehicle axle hub. A number of centering pins are provided on the false hub, with a corresponding number of bores on the wheel hub. A central threaded pin is formed on the false hub, a corresponding central bore is formed in the wheel hub, a nut is provided for screwing on the threaded pin, and a striker seat for the nut is formed on the flange around the central bore. Such a wheel assembly permits mounting of a single-nut wheel on the axle hub of a motor vehicle.

It is known that light alloy wheels are not always the first equipment of an automobile. Indeed, very often alloy wheels are mounted in replacement of the standard steel wheels. There is also a rather broad market, especially for high-performance cars, in which the original light alloy wheels are replaced with others of a more refined design.
The maker of alloy wheels must therefore provide his products to meet the dimensional requirements imposed by the various automobiles.
In addition to the two basic dimensions consisting of the diameter and width of the wheel, a measurement which must be taken into consideration with the greatest attention is the distance between the striker surface of the wheel on the hub and the median plane of the wheel. Even for the same diameter and width, wheels of different cars often differ in said distance.
To meet the various requirements, the wheel maker is thus forced to provide and keep in store a very broad range of wheels. This is particularly costly for large-diameter wheels designed for high-performance sports cars. In this case, the design refinement of the cars makes it necessary for practically each car type to have its specific wheel. In addition, each wheel has a rather high value. Finally, the quantities of such cars in existence and hence the market for their wheels are of course very limited.
There is thus the problem of providing a wheel assembly which can be used on several automobiles.
There are known (FR-A-1549438, GB-A-2080745) adapters which permit mounting the spare wheel of a motor vehicle on the hub of a trailer having couplings different from those of the automobile. These adapters comprises an intermediate disc with bores designed for fixing on the studs of the trailer hub and with studs designed for fixing of the motor vehicle wheel.
There is also known (GB-A-577095) a wheel for agricultural tractors provided in two parts, i.e. an external part made in various sizes and forms to be able to carry various tires or special rims, and an internal portion which can also be made in various sizes and forms suited for mounting on different hubs. The two parts are coupled together by means which ensure their interchangeability.
In addition, among light alloy wheels, wheels whose design resembles the single-nut wheels used in competition, i.e. wheels having a single central fixing nut in place of the normal four or five nuts, are much more appreciated due to their sporty appearance. Naturally these are not truly single-nut wheels. Indeed, their central `nut` is merely a shaped cap covering the normal fixing nuts.

Light alloy wheel assembly for an automobile


A thin film transistor (TFT) having improved characteristics, a method for fabricating the same, and an organic light emitting display device (OLED) including the same. The TFT is constructed with a substrate, a semiconductor layer disposed on the substrate and including a channel region, source and drain regions, a gate insulating layer disposed on the semiconductor layer, a gate electrode disposed on the gate insulating layer and corresponding to the channel region, an interlayer insulating layer disposed on the gate electrode, and source and drain electrodes electrically connected to the source and drain regions of the semiconductor layer. The channel region is made from polycrystalline silicon (poly-Si), and the source and drain regions are made from amorphous silicon (a-Si). The polycrystalline silicon of the channel region is formed by crystallizing amorphous silicon using Joule's heat generated by the gate electrode.

1. Field of the Invention
The present invention relates to a thin film transistor (TFT), a method for fabricating the TFT, and an organic light emitting display device (OLED) constructed with the TFT, and more particularly, to a TFT which is fabricated using Joule's heat to improve its characteristics, a method for fabricating the TFT, and an OLED constructed with the TFT.
2. Description of the Related Art
In recent years, much attention has been paid to flat panel display devices (FPDs) that can overcome the problems faced by contemporary heavy and large-sized display devices such as a cathode ray tube (CRT) display. The FPDs may be a liquid crystal display device (LCD), an organic light emitting display device (OLED) or a plasma display panel (PDP).
The FPDs are typically constructed with a thin film transistor (TFT), which is required to operate at high speed in response to a given signal and is required to exhibit uniform characteristics over the entire substrate of the TFT. In order to satisfy these requirements, it is most important to control the characteristics of a semiconductor layer of the TFT.
The semiconductor layer is typically constructed by crystallizing amorphous silicon (a-Si) into a polycrystalline silicon (poly-Si) layer. The crystallization of the semiconductor layer may be performed using a solid phase crystallization (SPC) process, an excimer laser annealing (ELA) process, a metal induced crystallization (MIC) process or a metal induced lateral crystallization (MILC) process. Specifically, the SPC process includes a step of annealing an a-Si layer for several to several tens of hours at temperatures below 700° C. where a glass substrate used in the TFT may be undesirably deformed. The ELA process includes a step of partially heating an a-Si layer to reach a high temperature in a short time by irradiating excimer lasers on the a-Si layer. The MIC process includes a step of bringing a metal such as nickel (Ni), palladium (Pd), gold (Au) or aluminum (Al) into contact with an a-Si layer, or a step of injecting the metal into the a-Si layer to induce a phase change of the a-Si layer into a poly-Si layer. The MILC process includes a step of sequentially inducing the crystallization of an a-Si layer while laterally diffusing silicide obtained by a reaction between a metal and silicon.
Since the SPC process involves annealing a substrate at a high temperature for a long period of time, the substrate may be seriously damaged. Also, the ELA process requires expensive laser apparatuses and a high maintenance fee. Further, both the MIC and MILC processes consume too much time in order to crystallize an a-Si layer into a poly-Si layer.

Method of fabricating a thin film transistor using joule heat from the gate electrode to form a crystallized channel region


A system and method for vehicle assembly may include a vehicle body sensing unit sensing positions of vehicle bodies conveyed at regular intervals along a vehicle body convey line, a tool sensing unit disposed on a fastening tool for assembling parts to a vehicle body and sensing movement displacement of the fastening tool with respect to an origin of the fastening tool, a tool controller that transmits a fastening torque value of a predetermined part to the fastening tool in accordance with the movement displacement of the fastening tool and records an accumulated value of the movement displacement of the fastening tool, and a main controller that stores a result value of fastening the part, corresponding to a vehicle number of the vehicle body, on the basis of the accumulated value of the movement displacement of the fastening tool and positional information of the vehicle body.

Field of Invention
The present invention relates to a vehicle assembly system. More particularly, the present invention relates to a joint guarantee system for vehicle assembly that can manage joint history of parts of a vehicle in an assembly line where the parts are assembled to a vehicle body, and a control method of the same.
Description of Related Art
In general, vehicle makers assemble tens of thousands of parts through a large vehicle number of welding and assembly processes in all of mass production processes to produce vehicles. In particular, most of the works made in a designing process of the processes of producing a finished vehicle is a fastening process that fastens various parts to a vehicle by, using fasteners such as bolts and nuts.
The fastening process impacts the quality index of the vehicle such as durability or the degree of comfort of the finished vehicle, which the consumers feel, so it is required to thoroughly manage the joint history of the parts for the vehicle body. However, although the importance of managing the joint history of parts for a vehicle body is recognized in the art, management of joint history with a high practical effect has not been made by technical limitations.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Joint guarantee system for vehicle assembly and control method of the same


Methods and apparatus for supporting instance ordering selection policies (ISOPs) for network-accessible resources are disclosed. A system includes a plurality of resource instances of a provider network, and a resource manager. The resource manager assigns an ISOP to be used to respond to instance acquisition requests of a specified type from a particular client. In response to a request of the specified type from the client, the resource manager determines, based at least in part on the ISOP, an order in which a plurality of resource groups (such as a set of instances reservations of the client, or an instance marketplace accessible to multiple clients) is to be examined to obtain an instance for the client. Starting with a first resource group, the resource manager examines each resource group until an instance matching instance selection criteria specified in the request is found.

Many companies and other organizations operate computer networks that interconnect numerous computing systems to support their operations, such as with the computing systems being co-located (e.g., as part of a local network) or instead located in multiple distinct geographical locations (e.g., connected via one or more private or public intermediate networks). For example, data centers housing significant numbers of interconnected computing systems have become commonplace, such as private data centers that are operated by and on behalf of a single organization, and public data centers that are operated by entities as businesses to provide computing resources to customers. Some public data center operators provide network access, power, and secure installation facilities for hardware owned by various customers, while other public data center operators provide "full service" facilities that also include hardware resources made available for use by their customers. However, as the scale and scope of typical data centers has increased, the tasks of provisioning, administering, and managing the physical computing resources have become increasingly complicated.
The advent of virtualization technologies for commodity hardware has provided benefits with respect to managing large-scale computing resources for many customers with diverse needs, allowing various computing resources to be efficiently and securely shared by multiple customers. For example, virtualization technologies may allow a single physical computing machine to be shared among multiple users by providing each user with one or more virtual machines hosted by the single physical computing machine, with each such virtual machine being a software simulation acting as a distinct logical computing system that provides users with the illusion that they are the sole operators and administrators of a given hardware computing resource, while also providing application isolation and security among the various virtual machines. Furthermore, some virtualization technologies are capable of providing virtual resources that span two or more physical resources, such as a single virtual machine with multiple virtual processors that spans multiple distinct physical computing systems. As another example, virtualization technologies may allow data storage hardware to be shared among multiple users by providing each user with a virtualized data store which may be distributed across multiple data storage devices, with each such virtualized data store acting as a distinct logical data store that provides users with the illusion that they are the sole operators and administrators of the data storage resource.
In many environments, operators of provider networks that implement different types of virtualized computing, storage, and/or other network-accessible functionality allow customers to reserve or purchase access to resources in any of several different resource acquisition modes. For example, a customer may reserve a virtual compute resource instance for a relatively long duration, such as one year or three years, or a customer may purchase resources for shorter terms on an ad-hoc basis as needed. In some cases resource instances may also be sold in one or more marketplaces where the pricing varies based on supply and demand. For some types of long-term resource reservations, customers may typically pay an upfront free for making the reservation, and in addition may have to pay usage-based fees for periods when the reserved resource is activated. In many cases, customers may make long-term reservations for some expected level of workload for each of several application types, and may rely on using (potentially more expensive) on-demand instances or dynamically priced instances (e.g., in a spot market) if and when the workload of any of the application types increases beyond the expected level. However, especially for accounts with large numbers of reserved instances and large numbers of active users of the network-accessible resources who may not have a big-picture view of the account's resource assets, situations may arise where users attempt to acquire additional resource instances (e.g., in the spot marketplace) without being aware of the fact that at least some of the additional workload for which they are acquiring the additional resources may be handled more economically.
While embodiments are described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that embodiments are not limited to the embodiments or drawings described. It should be understood, that the drawings and detailed description thereto are not intended to limit embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include," "including," and "includes" mean including, but not limited to.

Instance selection ordering policies for network-accessible resources


An improved user experience is provided for passengers of a transportation vessel, such as an airplane. A passenger's experience is enhanced by allowing the passenger to enjoy media provided by an entertainment device without ambient noise. When the passenger requests accesses to a media item through the entertainment device, a microphone in the entertainment system generates an ambient noise signal based on captured ambient noise. A noise cancellation device generates a predictive noise cancelling signal based on the ambient noise signal. To generate the predictive noise cancelling signal, the noise cancellation device inverts the ambient noise signal and applies a predictive phase shift to the signal based on an estimated distance between the microphone and the passenger's ears. The noise cancelling signal is mixed with audio of the media item.

1. Field
The embodiments disclosed herein relate generally to active noise cancellation. More specifically, the embodiments disclosed herein are directed towards the cancellation of ambient noise in transportation vessels.
2. Description of the Related Art
Commercial transportation vessels designed to carry passengers often include entertainment systems. For example, many airlines operate airplanes that include displays mounted on the back of each seat, allowing passengers to watch movies. However, the noises generated by the airplane (e.g., airplane jet engines and aerodynamic noises) and the passengers make it difficult to enjoy the entertainment even when wearing headphones.

Aircraft predictive active noise cancellation


A micromachined hot-wire anemometer having fast response times and higher sensitivities than conventional hot-wire anemometers is provided by micromachining doped polysilicon wires carried on silicon supports cantilevered from a substrate including one or more insulating layers disposed between said substrate and supports. The micromachined polysilicon hot-wire anemometer is fabricated using surface micromachining techniques.. A shear stress sensor is micromachined to define a thin diaphragm over a cavity defined in a substrate underlying the diaphragm. The cavity is evacuated, sealed, and a thermistor disposed over the diaphragm. The thermistor is thus thermally insulated from the substrate and provides a low profile shear stress sensor for measuring flow rates in boundary layers above a flow surface.

1. Field of the Invention
The invention relates to the field of microelectromechanical systems (MEMS), and in particular to micromachined anemometers.
2. Description of the Prior Art
A hot-wire anemometer is a thermal transducer which is capable of sensing point flow velocity by means of temperature variations using a heated resistive wire which is a nonzero temperature coefficient of resistance. When the electrically heated wire is placed in flow of fluid, heat is taken away by flow-induced forced convection. Depending upon the operational mode used, e.g. constant current or constant temperature, either the resistance or the voltage output drop across the wire is then a function of the flow velocity.
Conventional hot-wire anemometers have been used for flow velocity measurements for more than 80 years. The conventional structure is a metal wire, welded or soldered between two metal needles, which are molded to a probe body. The wire is usually made of platinum or tungsten and is typically 5 microns in diameter and 1 millimeter in length. The wire typically has a resistance of 10 to 30 ohms at room temperature and requires 10 to 40 milliamps of current to operate. Conventional anemometers are usually hand-assembled, thus making it difficult and expensive to incorporate them into large arrays for simultaneous velocity distribution measurements. Also, since the wire diameter is difficult to control with good repeatability, the anemometer probes are essentially noninterchangeable without recalibrating the anemometer system.
Since the spatial resolution of the anemometer for flow velocity distribution measurements is determined by the anemometer's dimensions, it is advantageous if the wire size could be reduced. This would reduce power consumption and thermal interference to the flow and increase frequency response. In fact, many prior art anemometer designs have been demonstrated using either surface or bulk micromachining technologies. See, Y. C. Tai et al., "Polysilicon Bridge for Anemometer Application," Digest Tech Papers, Transducers '85, Philadelphia, Pa., Jun. 4-7, 1985 at 354-57; H. Rahnamai et al., "Pyroelectric Anemometers: Preparation of Velocity Measurements," Sensors and Actuators, Volume 2, at 3-16 (1981); M. Stenberg et al., "A Silicon Sensor for Measurement of Liquid Flow and Thickness of Fouling Biofilms," Sensors and Actuators, Volume 13 at 203-21 (1988); B. W. Van Oudheusden et al., "Integrated Silicon Flow Direction Sensor, " Sensors and Actuators, Volume 16, at 109-19 (1989); and R. Kersjes et al., "An Integrated Sensor for Invasive Blood-Velocity Measurement," Sensors and Actuators, Volume 37-38 at 674-78 (1993).
Interestingly, however, these anemometers are either bulk micromachined chip-size devices or wires on top of chips. No one has been able to simulate the features of a conventional hot-wire, that is a wire free-standing in space without anything nearby so that good thermal isolation is achieved. As a result, the prior art anemometers are not direct replacements for conventional hot-wire anemometers.
Therefore, what is needed is a new type of micromachined anemometer that is capable of performance simulation of conventional hot-wire anemometers, but with a greatly reduced wire size, improved spatial resolution, improved device sensitivity, and improved frequency response.
In order to modify a surface to reduce drag or to control vortices within the boundary layer above the surface, sensors must be able to provide flow field information having a spatial resolution of the order of 100 microns and a frequency response of greater than a kHz. Shear stress sensors previously used exploit either a direct or indirect method for shear stress detection. In the direct method, a tangential force on a surface floating balance gives a direct measurement to the shear stress. In the indirect method, shear stress is extracted from other physical measurands that are indirectly related to shear stress such as Preston tubes, Stanton tubes and hot-wire/film surface mounted sensors. These conventional shear stress sensors, however, can only be hand-made, one at a time, and therefore ill-adapted for use in a system where thousands of uniform sensors are required.
In response, the prior art has developed micromachined surface floating balance for direct shear stress measurements. Sensitivity is 52 microvolts/Pa for gas sensing and 13.7 microvolts per volt-kPa for liquid sensing have been reported using a piezo resistive readout. Flow sensors based on heat transfer principles have also been demonstrated in micromachined sensors using free-standing beams, free-standing diaphragms and low thermal conductivity layers such as polyimid. Unfortunately, none of these devices are adaptable for use in large array vortices control within a boundary layer.
Therefore, what is needed some type of shear stress sensor adaptable for use in large arrays for vortice control within a boundary layer.

Micromachined hot-wire shear stress sensor

The Regents of the University of California


Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI.

Data storage devices are used in a variety of applications to store and retrieve user data. The data are often stored to internal storage media provisioned within a data storage device housing.
The storage media can take a variety of forms, such as one or more rotatable discs accessed by an array of data transducers supported by a moveable actuator. The transducers are configured to be hydrodynamically "flown" a selected distance from the media to form a head-disc interface (HDI). As will be appreciated, certain types of disturbances at the HDI, such as intermittent or continuous contact between the transducers and the media, can adversely affect storage device performance.

Head-disc interface (HDI) modal response monitoring


Memory allocation to multiple computing units is disclosed. A static offset for each computing unit is determined, and a portion of memory is allocated for each computing unit, and remapped into a contiguous logical region that is addressable by a pointer plus the static offset. The portion of the memory is dynamically passed out to each computing unit as the computing units need memory. Upon the initial contiguous memory being completely passed out to the computing units, a number of physically non-contiguous sections of memory are mapped into another logically contiguous section of memory. A portion of this logically contiguous section of memory is allocated for each computing unit, and is addressable by a pointer plus the static offset that was previously determined. The portion of the logically contiguous section of memory can be dynamically passed out to each computing unit as the computing units need memory.

Within a typical single-processor computing environment, memory is dynamically allocated as it is needed by the processor. That is, when the processor needs memory for whatever reason, it can request and receive an allocation of memory in the amount that is desired. Memory allocation within multiple-processor computing environments is, however, more difficult. Memory may be shared by all the processors, and specific portions of the memory may be local to one of the processors but remote to the other processors. Therefore, it is desirable to allocate duplicates of memory, or one memory location for each processor, rather than having all the processors share the same allocation of memory. It is noted that local memory is accessed more quickly than remote memory. The local memory of a given processor is remote memory to the other processors.
One approach to allocating memory within a multiple-processor computing environment is to allocate a large section of local memory for each processor at boot time, and then dynamically pass out the memory as needed. For static allocations, the simplest technique is to group all per-processor variables together, and then allocate a copy of that group for each processor at boot time within memory that is local to the processor. Each processor needs only maintain a single offset to locate its copy of a given variable within its local memory.
For example, if there are five kilobytes of static per-processor data, the system may choose to allocate five kilobytes of memory per processor at boot time using standard dynamic allocation techniques, by allocating memory for each processor that is within the range of memory closest to that processor—in other words, local memory to each processor. Each processor then stores an offset between the static area and the allocated per-processor data, so that the processor can find its copy of the static area within its own local memory with a simple offset from the static area.
Such an addressing scheme, however, can be problematic after boot time, once all of the initially allocated memory has been passed out to the processors. This is because additional allocations of memory may be difficult to accomplish for the same addressing scheme of a general pointer plus an offset specific to each processor to be employed. For instance, available memory may be fragmented or otherwise limited, such that reproducing the exact same layout between allocations for each processor is at best difficult, and more than likely impossible.
This problem can be solved by allocating memory for all the processors from a single contiguous section of memory, so that the same pointer plus per-processor offset can be used. However, the memory allocated to each processor is no longer local to the processor by which it is used. To allocate memory to each processor that is local to each processor, more complicated and complex addressing schemes may have to be used, which can add undesired overhead and difficulty to the memory allocation process. A common solution is to generate a new table of offsets for each processor with each allocation, which is wasteful and requires an extra memory load to de-reference every different per-processor pointer.

International Business Machines Corporation


In accordance with an embodiment, a method of operating a switched-mode power supply includes synchronously rectifying a current in a secondary side of the switched-mode power supply by detecting a voltage drop of a secondary winding of a transformer and activating a semiconductor switch coupled to the secondary winding when the voltage drop is detected. The method also includes determining a digital signal transmitting the digital signal to a controller coupled to a primary winding of the transformer by switching the semiconductor switch in accordance with the digital signal.

Power supply systems are pervasive in many electronic applications from computers to automobiles. Generally, voltages within a power supply system are generated by performing a DC-DC, DC-AC, and/or AC-DC conversion by operating a switch loaded with an inductor or transformer. One class of such systems includes switched mode power supplies (SMPS). An SMPS is usually more efficient than other types of power conversion systems because power conversion is performed by controlled charging and discharging of the inductor or transformer and reduces energy lost due to power dissipation across resistive voltage drops.
A SMPS usually includes at least one switch and an inductor or transformer. Some specific topologies include buck converters, boost converters, and flyback converters, among others. A control circuit is commonly used to open and close the switch to charge and discharge the inductor. In some applications, the current supplied to the load and/or the voltage supplied to the load is controlled via a feedback loop.
One application of an SMPS is a charger for a lithium ion battery. Since lithium-ion batteries are prone to damage if an upper voltage limit is exceeded, it is common to charge the battery with a constant current until the output voltage reaches a target voltage. As result, such a battery charger may utilize a SMPS that is configured to provide a constant current. Because such battery chargers may convert AC current from a wall socket to a DC current, flyback converters that use a transformer are commonly used to provide galvanic isolation from the AC mains to the battery being charged.

System and method for a switched-mode power supply


The invention provides new androstene derivatives having anti-inflammatory activity, pharmaceutical compositions containing them, and methods of administering them to warm-blooded animals in the treatment of inflammation. The active compounds are alkyl 17.alpha.-dichloroacetoxy-11.beta.-hydroxyandrosta-1,4-dien-3-one-17.beta. -carboxylates and related androstenes.

Topical or other local application of potent glucocorticoids can produce severe toxic effects such as Cushingoid features, pituitary-adrenal suppression, skin atrophy, immunosuppression and inhibition of wound healing. Other kinds of toxic responses, including allergies and cataracts, have resulted from long term use of drugs of this type.
Ophthalmic application of glucocorticosteroids presents additional problems. The protective mechanisms built into the eye allow only small amounts of doses applied to the eye to reach the target sites within the eye; generally, over 90 per cent of the total dose will find its way into the general circulation. This in turn leads to serious systemic side effects of the type described above. Moreover, there is a more serious and specific side effect when these drugs are used in the eye, which is an increase in intraocular pressure (IOP). Corticosteroid-induced chronic or acute glaucoma has in fact been reported since the early 1960's. Generally, the corticosteroid is needed only topically to control the inflammation. However, the absorbed steroid is responsible for the serious side effects noted above. It is believed that the effect of the corticosteroid on the aqueous outflow pathway and adjacent tissue glycosaminoglycans (GAG's) is important in the development of glucocorticoid-induced ocular hypertension.
There is therefore a serious need for potent local anti-inflammatory steroids which lack systemic activity and consequently do not produce the serious systemic side effects associated with drugs of this class.
The natural glucocorticosteroids and many of their marketed derivatives are .DELTA..sup.4 and .DELTA..sup.1,4 pregnenes having 21-hydroxy substituents. There are, however, a number of anti-inflammatory .DELTA..sup.4 and .DELTA..sup.1,4 androstenes described in the literature. Thus, Anner et al, U.S. Pat. No. 3,636,010, patented Jan. 18, 1972, describes esters of .DELTA..sup.4 and .DELTA..sup.1,4 -16.alpha.-methyl-6.alpha.,9.alpha.-difluoro-11.beta.,17.alpha.-dihydroxy- 3-oxo-androstadiene-17-carboxylic acid having "good anti-inflammatory and thymolytic activity." Thymolytic activity is, however, an indication of systemic activity.
In the 1970's and early 1980's several patents have issued describing androstene derivatives which have been purported to have more desirable ratios of anti-inflammatory activity to undesirable side effects. These include British Patent Specification No. 1,384,372; Phillipps et al U.S. Pat. No. 3,828,080; Phillipps et al U.S. Pat. No. 3,856,828; Phillipps et al U.S. Pat. No. 4,093,721; UK Patent Application GB 2,014,579; Edwards U.S. Pat. No. 4,188,385; Alvarez U.S. Pat. No. 4,198,403; and Edwards U.S. Pat. No. 4,263,289. The .DELTA..sup.4 and .DELTA..sup.1,4 3-oxoandrostene derivatives of these patents may bear various substituents at the 6, 9, 11 and 16 positions and typically possess a 17.alpha.-hydroxy or 17.alpha.-alkanoyloxy substituent. The 17.beta.-grouping is variously a carboxylic acid alkyl ester, a carboxylic acid haloalkyl ester or a thiocarboxylic acid alkyl ester. In British Patent Specification No. 1,578,243 and its U.S. counterpart, Kalvoda et al U.S. Pat. No. 4,285,937, there are also described androstadiene-17-carboxylic acids and their esters. The Kalvoda et al compounds are represented in the '937 patent as novel esters of androstadiene 17-carboxylic acids of the formula ##STR1## wherein R' represents a free hydroxyl group or a hydroxyl group which is esterified with a carboxylic acid having not more than 7 carbon atoms, R" represents a methyl group in the .alpha.- or .beta.- position or the methylene group, R is H or Cl, each of X and Y represents a hydrogen, chlorine or fluorine atom, with the proviso that at least one of these substituents is one of these halogens, when R is Cl, and that Y is only Cl or F and X only Cl, when R is H and that the androstadiene-17-carboxylic acid ester group does not contain more than 11 carbon atoms. These compounds are said to have pronounced anti-inflammatory action coupled with remarkedly low systemic side effects and to be especially suitable for dermatological use. The esters of the steroid 17-carboxylic acids are derived from alcohols containing 1 to 10 carbon atoms of the aliphatic, araliphatic and heterocyclic type which are unsubstituted or substituted by chlorine, fluorine, bromine, hydroxyl, lower alkoxy or lower alkanoyloxy; these alcohols are said to include the lower alkanols (methanol, ethanol, isopropanol etc.). The 17-ester group can also be chloromethoxycarbonyl, fluoromethoxycarbonyl or 2-chloro or 2-fluoroethoxycarbonyl. The esterified hydroxy group R' is said to be derived from a saturated or unsaturated C.sub.1 -C.sub.7 carboxylic acid which is unsubstituted or substituted by halogen atoms, hydroxyl or lower alkoxy groups; named as examples of R' are formyloxy, acetoxy, propionyloxy, butyryloxy, valeryloxy, diethylacetoxy, caproyloxy, chloroacetoxy, chloropropionyloxy, oxypropionyloxy or acetoxypropionyloxy. However, the only specific compound in which the 2-position is unsubstituted which is disclosed by Kalvoda et al is methyl 9.alpha.-chloro-6.alpha.-fluoro-11.beta.-hydroxy-16.alpha.-methyl-3-oxo-17 .alpha.-propionyloxyandrosta-1,4-diene-17-carboxylate. Indeed, all of Kalvoda et al's specific compounds are 17.alpha.-propionyloxy compounds. In view of the fact that Kalvoda et al's compounds are expected to hydrolyze in vivo to release the acid from which the 17.alpha.-ester is derived, it is not surprising that the acid preferred by Kalvoda et al for derivatizing the 17.alpha.-hydroxyl is propionic acid, which is known to have an LD.sub.50 in rats of only 4.29 g/kg orally. Acetic acid, which is also basically non-toxic, has an LD.sub.50 in rats of 3.53 g/kg orally. In contrast, the oral LD.sub.50 in rats of chloroacetic acid is 76 mg/kg, which is relatively quite toxic.
More recently, soft steroids have been developed in an effort to provide compounds having potent anti-inflammatory activity with minimal systemic activity. These compounds include .DELTA..sup.4 and .DELTA..sup.14 17.alpha.-alkoxy-11.beta.-hydroxy-3-oxoandrostenes optionally bearing various substituents at the 6,9 and 16-positions and related 11-substituted compounds which are esters or thioesters of 17.beta.-carboxylic acids. These 17.alpha.-ethers are described in Bodor U.S. Pat. No. 4,710,495. Preferred compounds are taught to be the haloalkyl esters of 17.alpha.-alkoxy-11.beta.-hydroxyandrost-4-en-3-one-17.beta.-carboxylic acids.
Another series of soft steroids which are described as having potent anti-inflammatory activity with minimal systemic activity are the 17.alpha.-carbonates of Bodor U.S. Pat. No. 4,996,335. These compounds include as preferred embodiments haloalkyl 17.alpha.-alkoxycarbonyloxy-11.beta.-hydroxyandrost-4-en-3-one-17.beta.-ca rboxylates and the corresponding .DELTA..sup.14 compounds, optionally bearing 6.alpha.- and/or 9.alpha.-fluorine and 16.alpha.- or 16.beta.-methyl substituents. One of these compounds is chloromethyl 17.alpha.-ethoxycarbonyloxy-11.beta.-hydroxyandrosta-1,4-dien-3-one-17.bet a.-carboxylate, also known as loteprednol etabonate, for which clinical development has been completed and which is awaiting final FDA approval.
Nevertheless, there remains a serious need in this art for new anti-inflammatory steroids which have potent local anti-inflammatory activity while having minimal or non-existent systemic activity.


A catheter for treatment of chronic total occlusions includes an occlusion breach device, a catheter body made of a temperature-dependent softening, shape-memory, thermoplastic polymer having a first flexible state and a second stiff state. The catheter body has a heat transfer conduit and a conduit for slidably receiving the breach device. A heat-transferring device selectively changes a temperature of the heat transfer conduit to, thereby, change stiffness of the catheter body between the two states. To treat a CTO with the catheter, it is warmed above the glass-transition temperature and below the melting-temperature to make the catheter flexible. The catheter has a shape when inserted at the occlusion site and is cooled to, thereby, stiffen. Breaching of the occlusion is assisted with the stiff catheter. The catheter is removed by warming the polymer. Also provided is a method for manufacturing such a selectively stiffening catheter.

1. Field of the Invention
The present invention relates to a catheter, especially a catheter for treatment of acute, sub-acute, or chronic total occlusions ("CTOs"), in particular, the catheter facilitates crossing CTOs of the coronary or peripheral vasculature, and methods for manufacture and use of the catheter.
2. Description of Related Prior Art
Catheters for treating chronic total occlusions exist in the prior art. For example, U.S. Pat. No. 6,800,085 to Selmon et al. (hereinafter "Selmon") describes a catheter system for treatment of occluded blood vessels.
The prior art catheters, however, are not able to circumnavigate vasculature in a flexible state and, when ready to treat a vessel occlusion, to become fixed in the vasculature so that virtually all of the force acting upon the occlusion is used against the occlusion instead of on the catheter to displace the catheter proximally. Accordingly, it would be beneficial to provide a catheter that has the ability to change its flexibility state from flexible and soft to hard and rigid upon the command of the user.

Catheter for treatment of total occlusions and methods for manufacture and use of the catheter


The invention provides methods, kits, and compositions for enhancing synthesis of DNA involving a carboxylate ion-supplying substance that is effective in promoting DNA synthesis in enzymatic DNA synthesis reactions. The invention further provides a thermostable DNA polymerase-related factor derived from Thermococcus species, which has an activity to promote the DNA synthesis activity of DNA polymerase or which binds to DNA polymerase.

The DNA amplification technique represented by polymerase chain reactions (PCR); Nature, vol. 324 (6093), 1986, pp.13-19) is a well-known technique in the field of molecular biology. Detection, analysis, transcription or amplification of nucleic acids by the PCR technique is one of the most important operations in modern molecular biology and is especially important in gene expression studies, diagnosis of infectious agents or hereditary diseases, cDNA production, analysis of retroviruses, etc.
Since DNA amplification performance depends on the performance of the DNA polymerase used, various DNA polymerases have been searched for in nature or improved. For example, PCR was originally performed using insufficiently thermostable DNA polymerases derived from mesophiles such as E. coli. However, since PCR is performed under highly stringent conditions, i.e., themocycling at temperatures in the range of about 23° C. to about 100° C. many times, the success rate (probability with which object DNA is successfully amplified) was low. It is now, however, common practice to utilize highly thermostable thermophile-derived DNA polymerases.
One of the important performances required of DNA polymerases is "elongation rate". A typical method of determining DNA elongation rate comprises performing a DNA synthesis reaction in a buffer using DNA prepared by annealing of M13 single-stranded DNA (1.6 μg) and complementary primer(s) (16 pmole) as a template and using KOD, Pfu, Deep Vent, Taq or like various DNA polymerases (5U) (as an enzyme), followed by calculating the DNA elongation rate from the relationship between the reaction time and the size of DNA synthesized.
For example, the DNA elongation rate of KOD polymerase is 105 to 130 bases/second, that of Pfu polymerase is 24.8 bases/second, that of Deep Vent polymerase is 23.3 bases/second, and that of Taq polymerase is 61.0 bases/second (Takagi, M. et al.: Characterization of DNA polymerase from Pyrococcus sp. KOD1 and its application to PCR; Appl. Environ. Microbiol. 63, 4504-45410, (1997)).
"Fidelity" is another important performance required of DNA polymerases. One example of a method for evaluating the DNA synthesis fidelity of DNA polymerase is using a ribosomal protein S12 (rpsL) gene associated with streptomycin resistance. Streptomycin is an antibiotic that inhibits protein synthesis in prokaryote. This antibiotic binds to bacterial 30S ribosomal RNA (rRNA) to inhibit initiation complex for protein synthesis formation reactions and cause the misreading of genetic code. Streptomycin-resistant strains have a mutation at the ribosomal protein S12 locus. This mutation is known to produce pleiotropic effects such as inhibiting suppressor tRNA from reading the stop codon to enhance translation fidelity of the ribosome. Thus, when PCR amplification is carried out using rpsL gene as a template, a mutation is introduced with a certain probability. When the mutation occurs at the amino acid level, the rpsL protein structure is changed so that streptomycin cannot act on 30S ribosomal RNA (rRNA). Therefore, when the amplified plasmid DNA is used to transform E. coli, the more mutations introduced, the higher the frequency of streptomycin-resistant strain appearance.
The plasmid pMol 21 (described in Journal of Molecular Biology (1999) 289, 835-850) is a plasmid containing rpsL gene and ampicillin resistant gene. A primer set for PCR amplification (one of the primers is biotinylated and has a MluI restriction site introduced therein) is designed on the ampicillin resistant gene of the plasmid pMol 21 to amplify the full-length plasmid by PCR using a thermostable DNA polymerase. The obtained PCR product is purified using streptavidin beads and cut out using the restriction enzyme MluI, followed by ligating the ends using DNA ligase to transform E. coli. The transformant is inoculated into two types of plate media, i.e., one containing ampicillin, and the other containing both ampicillin and streptomycin. The ratio of numbers of colonies appearing on the two plate media is calculated to determine the fidelity or correctness of DNA synthesis (Kunkel, Journal of Biological Chemistry, vol. 260, 1985, pp.5787-5796).
When PCR product fidelity of Taq DNA polymerase is determined by the above method of determining DNA synthesis fidelity, the mutation rate was 4% or more. In the case of a DNA polymerase capable of exhibiting 3′-5′ exonuclease activity when used alone, the mutation rate was 0.05 to 1%. When using a mixed enzyme of an enzyme not having 3′-5′ exonuclease activity such as Taq DNA polymerase and an enzyme having 3′-5′ exonuclease activity, the mutation rate was 2 to 4%. The mutation rate achieved by KOD DNA polymerase was 0.1% or less. This DNA polymerase is the most suitable enzyme for obtaining high-fidelity PCR products.
To what length the target DNA can be amplified (hereinafter referred to as "long-PCR performance") is also an important requirement of DNA polymerases.
DNA polymerases, kinds of thermostable (or heat-resistant) DNA polymerases, are roughly classified into Pol I-type enzymes represented by Taq DNA polymerase and Tth DNA polymerase, and α-type enzymes represented by Pfu DNA polymerase. Generally, Pol I-type enzymes achieve high DNA elongation rates but have poor fidelity because of the lack of 3′-5′ exonuclease activity. In contrast, α-type enzymes, which possess 3′-5′ exonuclease activity, have high fidelity but achieve low DNA elongation rates. Thus, although the two types of DNA polymerases have excellent properties in "elongation rate" and "fidelity", respectively, neither have both.
With the purpose of combining the merits of both types of enzymes, Proc. Natl. Acad. Sci. USA, vol.91, 1994, pp.2216-2220 describes a technique utilizing a mixed type enzyme prepared by mixing two kinds of thermostable enzymes. This enzyme mostly comprises a Pol I-type enzyme, which is considered to mainly perform DNA biosynthesis, while the α-type enzyme merely proofreads base errors.
Japanese Patent Publication No. 3112148 describes KOD DNA polymerase, a single enzyme (α-type enzyme) having both excellent "elongation rate" and "fidelity".
A method using HindIII-digested λDNA labeled with 3H at the 3′ end as a substrate and measuring the rate of 3H release under the optimal temperatures for each polymerase is known as a typical method of evaluating 3′-5′ exonuclease activity. More specifically, using a HindIII-digested λDNA fragment having [3H] TTP incorporated therein as a substrate, for example, the DNA fragment and a polymerase are left in a buffer solution (20 mM Tris-HCl pH 6.5, 10 mM KCl, 6 mM (NH4)2SO4, 2 mM MgCl2, 0.1% Triton X-100, 10 μg/ml BSA) under the optimal conditions for the polymerase and the [3H]TTP release rate is determined. The substrate DNA is prepared by adding 0.2 mM of dATP, dGTP, dCTP and [3H] TTP to 10 μg of HindIII-cleaved λDNA and extending the 3′ end with Klenow polymerase, followed by phenol extraction and ethanol precipitation to recover the DNA fragment and further purification by removal of the released mononucleotides using a spun column (product of Clontech).
To improve DNA amplification performance, various studies have been conducted to improve the composition of DNA synthesis reaction solutions. Examples of tested buffers include Tris, Tricine, bis-Tricine, HEPES, MOPS, TES, TAPS, PIPES, CAPS, etc. Examples of tested salts include potassium chloride, potassium acetate, potassium sulfate, ammonium sulfate, ammonium chloride, ammonium acetate, magnesium chloride, magnesium acetate, magnesium sulfate, manganese chloride, manganese acetate, manganese sulfate, sodium chloride, sodium acetate, lithium chloride, lithium acetate, etc. Examples of tested additives include DMSO, glycerol, formamide, betaine, tetramethylammonium chloride, PEG, Tween 20, NP40, ectoine, polyols, E. coli SSB protein, phage T4 gene 32 protein and BSA, etc (Published Japanese Translation of PCT International Publication of Patent Application No. H9(1997)-511133, U.S. Pat. No. 5,545,539, International Publication No. WO 96/12041, U.S. Pat. No. 6,114,150, WIPO Publication No. WO 99/46400, Nucleic Acids Research, vol. 23, 1995, pp.3343-3344, and Nucleic Acids Research, vol. 28, 2000, p.70).
However, the above reagents are not effective for all DNA polymerases. Effectivity depends on the enzyme. Therefore, different reaction solution compositions have been investigated for different enzymes, and optimal reaction buffer solutions for individual enzymes have been recommended. It has been considered impossible to achieve a higher amplification efficiency than commercially co-packaged buffer solutions.
With the recent advances in biotechnology, the required performance levels in DNA amplification, especially PCR, of "elongation rate", "fidelity" and "long-PCR performance" have been raised ever upwards. In particular, DNA amplification fidelity has become more important in that successful elucidation of the entire human genome sequence has shifted the focus of study from mere detection of genes or analysis of their differences to analysis of the functions of genes or proteins encoded by the genes.
Therefore, the establishment of a DNA amplification method achieving these requirements has been desired, but none of the prior art is satisfactory for practical use in all the requirements "elongation rate", "fidelity" and "long-PCR performance".

Compositions for enhancing DNA synthesis, DNA polymerase-related factors and utilization thereof


A synchronizing method in a mobile radio system which operates with Time Division Multiple Access (TDMA) but which lacks global time reference for all base stations and mobiles in the system. The inventive method is intended for ciphered transmission of data and speech in accordance with a given ciphering key (E2). When handing-over a call, the ciphering synchronism is lost. In accordance with the method, subsequent to hand-off (the time t.sub.2), the take-over base station (BS2) signals non-ciphered information (S1) to the mobile (MS) disclosing the number of frames (R1-R13) which shall pass until ciphering can again be commenced, calculated from a given frame (R1). Call information is transmit the following frame (R2), this information now being ciphered with the aid of a ciphering key (E1) different to the original key. This other ciphering key consists of a periodic bit sequence having a period which is equal to one frame interval.

1. Field of the Invention
The present invention relates to a synchronizing method in a mobile radio system which lacks a global time reference, i.e. a system which lacks a time reference that is common to all mobiles and base stations in the system. More specifically, although not exclusively, the present invention relates to a method of synchronizing a random bit flow which is superimposed cryptically on the normal traffic flow during call transmission or data transmission between the base stations and the mobiles. The present invention can be applied solely to a so-called TDMA-system, i.e. a mobile radio system in which calls are transferred in frames and time slots by means of time multiplexing.
2. Description of Prior Art
It is desirable in mobile radio systems, and in TDMA-systems in particular, to be able to maintain the security of calls so as to prevent unauthorized persons from setting-up and making calls over the network. In order to meet this requirement, it has been suggested that the calls are ciphered; see for instance EP-A-273289.
Calls between a base station and a mobile are ciphered by processing the speech message in a scrambler, which functions to convert the speech signals into a random sequence in accordance with a given key. For instance, the speech signals can be superimposed with a random sequence of bits of relatively long duration (several minutes). In this case, the cipher key consists in the knowledge of the total bit pattern of the sequence and also knowledge of the time at which the sequence was commenced. An authorized subscriber can plug into a circuit module in the apparatus which stores this sequence and said starting timepoint, and is thus able to decode incoming calls.
Some TDMA mobile radio systems lack a global time reference, i.e. means in the mobile telephone exchange which contains a clock common to the overall system and operative to produce the same time reference for all base stations and mobiles in the system. The purpose of such a common time reference is to enable the mobiles and the base stations to be synchronized with one another in certain frames and time slots when synchronizing from signalling or data/speech signals falls away for some reason or other. When transferring (hand-off) a call from one radio channel to another radio channel, synchronization between the mobile and its base station may be los, since a brief interruption will occur during the actual transmission or switching of the call. If the call is also ciphered, a further problem can occur as a result of fall-off of the synchronism of the actual ciphering key concerned, thereby rendering deciphering impossible.
These problems also occur when setting up ciphered calls, although said problems are most pronounced during "hand-off".

Synchronizing method in a mobile radio system


The present invention provides a compressor capable of arranging a refrigerant discharge port regardless of the location of a separation chamber. In this compressor, a separation tube is pressed in through an opening of the separation chamber, and by engaging a regulating ring with an engagement groove provided in the inner wall of the separation chamber, the movement of the separation tube in the anti-insertion direction is regulated. Therefore, unlike the conventional compressor, a refrigerant discharge pipe for regulating the movement of the separation tube in the anti-insertion direction need not be connected to the upper part of the separation tube, and the refrigerant discharge port can be arranged freely regardless of the location of the separation section.

(i) Field of the Invention
The present invention relates to a compressor used to compress a refrigerant for, for example, a vehicular air conditioner.
(ii) Description of the Related Art
Conventionally, a compressor of this type includes a compressor body, a compression section for compressing a refrigerant sucked into the compressor body, and a separation chamber for separating a lubricating oil, which is contained in the refrigerant discharged from the compression section, from the refrigerant. Thereby, the refrigerant compressed together with the lubricating oil in the compression section in the compressor body is separated into refrigerant and lubricating oil in the separation chamber, and the separated refrigerant is discharged to the outside of the compressor body.
Also, the separation chamber is provided with a separation tube in the vertically extending separation chamber having a circular cross section, and is configured so that the refrigerant containing the lubricating oil is caused to flow in the tangential direction of the inner wall in the upper part of the separation chamber and is swirled along the inner wall. Thereby, the lubricating oil contained in the refrigerant adheres to the inner wall of the separation chamber and is separated from the refrigerant, and the separated refrigerant flows in the separation tube and is discharged to the outside of the compressor body.
However, in the conventional compressor, a pipe serving as a refrigerant discharge port is connected to the upper part of the separation chamber, and the separation tube is fixed by the end portion of the pipe. Therefore, since the location of the refrigerant discharge port is limited to the upper part of the separation chamber, the degree of freedom of the arrangement of refrigerant discharge port may be restricted.

This patent is subject to a terminal disclaimer.

Compressor including separation tube engagement mechanism


A single-and double-effect absorption refrigerator comprising a drum including both a preliminary low-temperature regenerator having a low-temperature heat source and a condenser, a piping for low-concentration liquid absorbent extending from an absorber to the preliminary low-temperature regenerator through the pump for low-concentration liquid absorbent, a piping for intermediate-concentration liquid absorbent having a pump for intermediate-concentration liquid absorbent and extending from the preliminary low-temperature regenerator to a high-temperature regenerator, and a pipe for liquid absorbent connecting a part of the piping for intermediate-concentration liquid absorbent provided on a drawing side of the pump for intermediate-concentration liquid absorbent to a pipe for high-concentration liquid absorbent extending from a low-temperature regenerator to a low-temperature heat exchanger.

1. Field of the Invention
The present invention relates generally to an absorption refrigerator and more particularly to a single-and double-effect absorption refrigerator comprising a drum including both a preliminary low-temperature regenerator with a low-temperature heat source and a condenser.
2. Background Art
Japanese examined patent application publication SHO.61-13546 discloses a prior-art single-and double effect absorption refrigerator. A refrigeration-cycle system of this absorption refrigerator comprises a high-temperature regenerator with a high-temperature heat source as a heating source, a low-temperature regenerator, a condenser, an evaporator, an absorber, a low-temperature heat exchanger and a high-temperature heat exchanger. The condenser has an auxiliary regenerator or generator with a low-temperature heat source as a heating source. The top of the auxiliary regenerator has a pipe for low-concentration liquid absorbent connected thereto. The bottom of the auxiliary regenerator has a pipe for high-concentration liquid absorbent connected thereto.
This prior-art absorption refrigerator involves problems in that the size of a drum including the auxiliary regenerator, the low-temperature regenerator and the condenser is large and in that this absorption refrigerator must have both the drum for the auxiliary regenerator, for the low-temperature regenerator and for the condenser instead of a drum for a condenser and for a low-temperature regenerator of a conventional double-effect absorption refrigerator and an additional system piping the elements of this absorption refrigerator and in that single-and double-effect operational modes must be switched by means of operating a control valve and a shut-off valve provided intermediate the piping system. Thus, the structure of this prior-art single-and double-effect absorption refrigerator and the switching between the single-and double-effect operational modes thereof must be complicated.

Single-and double-effect absorption refrigerator


A system for metering and dispensing single and plural component liquids and solids as described herein. The dispensing system has a microprocessor-based control system and progressive cavity pumps which provide a very accurate control of component ratios, shot sizes, flow rates and dispense durations. The system has numerous feedback components for accurately controlling the pressure, flow rates, fluid levels and amounts of fluids dispensed. Where a valved nozzle is used, the pressure in the flow system is used to control the pumps rather than the valve. Such a system may be used as a sprayer with compressed air added. Drum rams are associated with the supply drums and the progressive cavity pumps may be placed on the drum ram. Maintenance of a steady state in the system is accomplished with back and forth movement of the pump, with compensation for pressure changes. Absolute rotational position of the pump can be monitored when a set pressure is maintained, to diagnose system conditions. A high flow system uses ball valves and a releasably coupled manifold. A mold charging system uses pressure to control the pumps which are cycled on and off to avoid overpressurizing the mold. The rate of pressure increase is used to control the rate of flow from the pumps as the mold approaches completion of the charge, again to avoid overpressurizing the mold. A signal controlled by a timer can indicate elapsed time as a warning that material within the mixer conduit is hardening to a condition such that flow cannot be reinitiated.

Systems for mixing and dispensing singular and multi-component materials are well known in the art. An almost infinite variety of substances may be dispensed. Many materials are packaged through dispensing in a fluid or semifluid state. Paint is sprayed, molds are pressure charged with materials, and electronic devices are potted. A variety of means for distributing such materials are available. Where plural components are involved, such systems typically include pumping mechanisms for pumping and metering separate materials in a prescribed ratio to a mixing device that thoroughly mixes these materials together. The mixed composition then flows out of a dispensing nozzle directly to the surface or point of application where the composition is desired.
When a curable composition is desired, two or more suitable materials are mixed to interact with each other to create a flowable, curable composition which will set or harden to a non-flowable state. The time required for a curable composition to harden is referred to as the "cure" time and often is a short period of time. Such resulting curable compositions have been used, for instance, as adhesives, sealants and potting materials in a wide variety of industrial applications and for the creation of useful objects.
Production environments can impose limitations on how a dispensing device should operate. For example, in a production environment, it is desirable for the curable composition to cure as rapidly as possible so that subsequent production operations can be performed on the production item without having to wait a significant time for curing to occur.
Further, production requirements often include the need to dispense a precise amount of a properly constituted composition. A deviation in the actual ratio of the constituent materials dispensed may alter the strength, viscosity, cure time and/or other properties and attributes of the composition. Thus, a dispensing system should dispense the desired ratio and quantity of constituent materials as accurately as possible. In many cases, the desired ratio is expressed as a function of the weight or mass of two constituent components. Nonetheless, the two constituent components are generally supplied to the mixer by volumetric metering pumps which control the volumetric ratio of the two components, rather than their weights or masses. The volumetric ratio fails to account for any changes in density and changes in mass that may occur when the components are subjected to temperature or pressure change.
Also, production items often move along a production line at a set speed. Therefore, the flow rate of the dispensed composition should be kept or maintained as constant as possible so that the time required to dispense the proper amount of composition onto or into the production item remains constant.
An assembly line operation may further require that the composition be dispensed intermittently because the composition is applied to production items that are separated spatially and temporally. Dispensing compositions intermittently may cause a loss of flow control and/or ratio control. During the first few seconds of dispensing a composition, a transient imbalance phenomenon may arise from the elasticity of materials in the dispensing system and/or changing pressures caused by cycling the dispenser. When pressure changes, the volume of stored material between the mixer and the pump changes. In other words, changes in pressure may introduce an error into the weight or mass ratio of the constituent components because a higher pressure results in a component taking less volume than the component would otherwise take, or in an expansion or shrinkage of the hoses, fittings and tubes. The loss of control may result in inaccurately dispensed quantities or ratio of materials. This loss of flow control can occur separately or in addition to the loss of ratio control. A loss of ratio control occurs when the transient imbalance phenomenon causes the dispensing system to dispense too much or too little of one constituent material, thereby resulting in an improperly constituted end product. In other words, even if the ratio control is not lost during the early stage of dispensing a composition, the flow control may be lost. Therefore, it is desirous to control both the ratio of constituent materials and the flow rate of dispensing of the resulting composition.
Dispensing machines may be used to create various types of compositions. A dispensing machine may be required to dispense two or more constituent materials to form a first composition and then switch to dispense either the same constituent materials in a different ratio or other constituent materials to form a second composition. Thus, it is desirable for a dispensing machine to change what materials are dispensed, the quantities of materials dispensed and/or the ratio of constituent materials while maintaining the ability to control accurately the quantity, ratio, flow rate and other dispensing criteria. Current dispensing systems fail to satisfy these needs and require users to shut down the dispensing machine and go through a lengthy calibration cycle in order to adjust the machine to the viscosity and/or other properties of the constituent materials.
Some dispensing systems include vats capable of holding large amounts of a constituent material. Motor-driven agitators are placed inside the vat to maintain the material homogeneity. One system is illustrated in U.S. Pat. No. 5,857,589 the disclosure of which is incorporated herein by reference. This system employs progressive cavity pumps and provides a system upon which the present disclosure is based.

Method and apparatus for dispensing liquids and solids