In one embodiment, a support member on an abrasive wheel has (a) an annular surface which fixedly supports (as by epoxy) a plurality of flaps in a partially overlapping relationship between successive flaps and (b) a central hole for receiving a mandrel which rotates the wheel. Each flap has on one of its surfaces abrasive particles facing outwardly from the annular surface. Each flap defines an acute angle with the annular surface and preferably extends at its opposite axial ends beyond the axial positions of support by such support surface to obtain a fixed positioning of the flaps relative to the support surface even at the axial positions beyond the axial ends of such annular surface. In a second embodiment, the flaps are disposed on the annular support surface in a tighter relationship than in the first embodiment so that each flap contacts adjacent flaps along a portion of its length. When the wheel is rotated with the flaps disposed adjacent a workpiece, the inner portions of the flaps provide an abrading action, partly because of their contact with one another, and the outer portions of the flaps provide a polishing action, partly because of their separation from one another. This polishing action is facilitated by the fact that (a) the flaps become separated from one another at their outer ends because of centrifugal action and (b) the grit on the flaps becomes progressively worn with progressive positions toward the outer ends of the flaps.

Abrasive wheels have been known for some time. In one type of abrasive wheel of the prior art, a plurality of abrasive flaps have been provided. Each flap has been coated on one side with abrasive particles. In certain embodiments of the prior art, the abrasive wheel has included a radially disposed disc for supporting the flaps.
In such embodiments of the prior art, the flaps have been attached to one surface of the disc so that each flap is disposed at an acute angle relative to the disc and in partially overlapping relationship to the adjacent flap in the plurality. In this relationship, a peripheral portion of each flap extends in an annular direction beyond the flap on which it is disposed. In this way, the progressive flaps define a complete ring.
When the wheel defined by the support disc and the flaps as discussed above rotates while disposed against a workpiece, the exposed portion of each flap abrades the workpiece. The abrasive wheel is advantageous because it is compact and strong and thus provides for a positive and controlled action on the workpiece.
The abrasive wheel discussed above is disadvantageous because it can be used only in a limited manner to abrade workpieces. This results from the disposition of the abrasive flaps on the disc such that the flaps are disposed in a substantially planar relationship on the disc. This limits the abrasive action of the abrasive wheel against workpiece surfaces which are exposed.
Abrasive wheels have also been known in the prior art where a support member has been provided with an annular surface defined by a constant radius at progressive positions on the surface. Abrasive flaps have been provided on this annular surface to abrade a workpiece surface. However, the abrasive flaps have been loosely disposed relative to one another on this annular surface. This loose relationship has limited the effectiveness of the flaps in abrading the workpiece surface. Furthermore, the axial widths of the flaps in such wheels have been limited to the axial widths of the members for supporting the flaps in such wheels.
The abrasive devices of the prior art have been limited in another important respect. They have been able to provide either an abrading action or a polishing action but have not been able to do both abrading and polishing. Abrading may be considered to constitute a coarser removal of material than polishing. It would be desirable for a device such as an abrasive wheel to provide both abrading and polishing actions.


A biosensor system is provided for detecting biological species such as bacteria, proteins, viruses, spores and DNA or RNA. The biosensor system may also be able to distinguish between Gram positive and Gram negative bacteria. In some embodiments, the analyte solution flows past a detector surface to a filter, which traps the analyte. The analyte is then washed back past the detector surface, thus increasing the number of analyte species that become attached to the surface. The detector may include an optical microresonator that is optically coupled via waveguides to a light source and an optical detector. One of the waveguides may be provided with a wavelength selective reflector to increase the amount of probe light coupled into the microresonator or to increase the fraction of the signal light detected by the optical detector.

The detection of biological species is an important analytical technique in several industries, including the food industry, environmental monitoring, and health care, e.g. for the prevention of post-surgical infection. For example, traditional methods of detecting bacteria require the culturing of microorganisms. While these methods provide a desired level of sensitivity, they require highly trained laboratory personnel and typically need days to obtain results.
Post-surgery infections constitute the most common infection for surgical patients. In many cases, bacteria still remain on the skin after the skin has been prepared for surgery. About 20% of the population have high bacteria counts on the skin, i.e. more than 1000 CFU cm−2 and represent those who are at greatest risk of infection. Accordingly, microbial detection is particularly important when preparing these patients for surgery. The bacteria on the skin are typically of the Gram positive type, and so it is important to be able to distinguish Gram positive bacteria. In other health care situations, it is important to differentiate between Gram negative and Gram positive bacteria, and to detect the total bacterial number from skin, wound, and body fluid (e.g., urine) samples. It is important also to be able to detect bacteria from environmental samples taken from food processing and clinical settings. The types of bacteria in these samples are typically Gram negative. Gram negative bacteria can be detected at very low concentration with a stable limulus amoebocyte lysate (LAL) reagent. The chromogenic substrate (p-nitroaniline) supplied with the commercial LAL changes from colorless to yellow in the presence of lipopolysaccharide (LPS) and is readily measured in a spectrophotometer. LAL cannot, however, distinguish between bacteria-surface bound LPS and free (soluble) LPS in solution. Free LPS is present in most environmental samples. It is either released under normal bacterial growth processes or from the dead gram-negative bacteria. The separation of soluble LPS from intact bacteria is a very challenging issue.

Systems and methods for biosensing and microresonator sensors for same


A light emitting element driving device of the present invention comprises at least one light emitting element and a power supply device for generating a driving current of the light emitting element. The power supply device has a step-up type DC-DC converter circuit. The step-up type DC-DC converter circuit has a soft-start function for gradually increasing the driving current at a rise of the driving current in generation of the driving current. Thus can be provided a light emitting element driving device which is capable of suppressing an inrush current to be generated at turn-on of the main power supply of the power supply device.

1. Field of the Invention
The present invention relates to a light emitting element driving device and can be applied to a light emitting element driving device which can operate a plurality of LEDs.
2. Description of the Background Art
As a light source for backlight of a liquid crystal display, a light emitting element such as an LED (Light Emitting Diode) is used. For the purpose of controlling visibility and suppressing an increase of the power consumption by lighting, a function of controlling the amount of light (hereinafter, referred to as "dimming function") is provided.
The LED has a characteristic of changing its emission wavelength in accordance with a current value to be inputted. Further, by performing a PWM (Pulse Wide Modulation) control of the inputted current, the above dimming function is controlled.
Therefore, by controlling the pulse width of the PWM control while keeping the current value supplied to the LED constant, brightness can be changed without changing the emission wavelength of the LED.
FIG. 4 is a block diagram showing a circuit configuration of an LED driving device under the PWM control in the background art.
As shown in FIG. 4, the LED driving device comprises a step-up type DC-DC converter circuit 101, a first switch element 102 and a resistor 103. The step-up type DC-DC converter circuit 101 is constituted of an inductance 104, a second switch element 105, a diode 106, a capacitor 107 and a control circuit 108. To an output portion of the step-up type DC-DC converter circuit 101, a plurality of LEDs 109 are connected in series.
Next, an operation of the LED driving device in the background art will be discussed.
A control signal generation circuit 110 outputs a control signal for turn-on from an OFF state. Then, the first switch element 102 is brought into conduction and the control circuit 108 serves to increase an output voltage Vo of the step-up type DC-DC converter circuit 101.
It is assumed that the output voltage Vo exceeds a total forward voltage Vf of the LEDs 109 connected in series. Then, from the capacitor 107, a current Io flows into the LEDs 109, the first switch element 102 and the resistor 103.
The control circuit 108 monitors a voltage drop Vp of the resistor 103. Further, in the control circuit 108, a reference voltage Vref is set in advance. The control circuit 108 controls the second switch element 105 to be turned off if the voltage drop Vp reaches the reference voltage Vref.
As discussed above, when the second switch element 105 is turned off, the output voltage Vo of the step-up type DC-DC converter circuit 101 decreases and the current Io flowing from the capacitor 107 toward the LEDs 109 and the like also decreases. When the current value Io decreases, the voltage drop Vp of the resistor 103 also decreases. If the voltage drop Vp becomes lower than the reference voltage Vref, the control circuit 108 controls the second switch element 105 to be turned on.
Thus, since turn-on and turn-off of the second switch element 105 are repeated under the control of the control circuit 108, a constant current flows in the LEDs 109.
It is assumed that a control signal for turn-off from the ON state is outputted from the control signal generation circuit 110 for dimming the LEDs 109. Then, the first switch element 102 is interrupted and the current Io flowing in the LEDs 109 and the like thereby sharply decreases. When the current Io decreases, the voltage drop Vp of the resistor 103 becomes lower than the reference voltage Vref and the control circuit 108 serves to increase the output voltage Vo of the step-up type DC-DC converter circuit 101.
In order to prevent an increase of the output voltage Vo, the second switch element 105 is turned off at the same time as the first switch element 102 is turned off. Then, the power supply from the step-up type DC-DC converter circuit 101 to the LEDs 109 is stopped, the voltage across the capacitor 107 is kept almost equal to the total forward voltage Vf of the LEDs 109. An input voltage Vi does not have a value enough to drive the LEDs 109.
Therefore, by turning off both the switch elements 102 and 105 at the same time, in effect, the power supply from the step-up type DC-DC converter circuit 101 to the LEDs 109 is stopped and the voltage across the capacitor 107 is kept almost equal to the total forward voltage Vf of the LEDs 109.
The conventional mainstream of light source for backlight is a power-saving type used for an indicator, a portable device or the like. Therefore, the voltage across the capacitor 107 can be kept by a small capacity.
In recent, however, a high power type light emitting element (such as an LED) which can be used for a light source for backlight of an illumination equipment or a large-scale liquid crystal display has been developed. The power consumed in the light emitting element thereby becomes larger than conventional one. With an increase of the power consumed in the light emitting element, there arises a necessity to increase the capacity of the capacitor 107.
The upsizing of capacity of the capacitor 107 increases an inrush current at turn-on of a main power supply of a light emitting element driving device. FIG. 5 shows generation of the inrush current. In FIG. 5, the upper stage shows an output signal waveform from the control signal generation circuit 110, and the lower stage shows a current waveform in the inductance 104. As discussed above, when the inrush current becomes too large, the circuit portions such as the second switch element 105 and the LED 109 may be broken.


A method of running a tubular string into or out of a wellbore includes the steps of moving the tubular string relative to the wellbore and making up or breaking a connection between a tubular joint and the tubular string when the tubular string is being moved relative to the wellbore.

With the evolution of top drive assemblies used in running oilfield tubulars into wellbores, recently developed top drives have been equipped with adaptors to grip casing, drill pipe, production tubing and other tubulars for lifting, lowering and rotating the tubular string in the wellbores, and have also included apparatus for torquing such joints together. Such prior art systems can generally be described as attaching a tubular joint into the tubular string, as the tubular string is being held by a spider at the drill floor level and using tongs on the drill floor to screw the joint into the held tubular string, or alternatively, as attaching a tubular joint into the tubular string while the string is being held in the spider at the drill floor and using the top drive to screw the tubular joint into the held string, or alternatively, as attaching a double or triple stand of tubulars using either of the above methods where the double or triple stands are assembled at a different location.

Frank's Casing Crew and Rental Tools, Inc.


A plurality of spring bases 50, 51 and 52 are provided to a tail edge side clamping base 76 independently. A pair of base convexes 51T are formed on both an upper surface and a lower surface of the spring base 51. A tension selecting part 70 comprising a first block 72 having a pair of block convexes 72T is provided at a position confronted with the spring base 51. The block convexes 72T and the base convexes 51T are contacted with each other by moving a lever 72L formed on an upper surface of the first block 72 when the plate 15 is fitted tightly on a cylinder surface of a plate cylinder 60 with low tension. The lever 72L is moved either in a direction of the arrow 100 or 101 when the plate 15 is fitted tightly on the cylinder surface of the plate cylinder 60 with high tension.

1. FIELD OF THE INVENTION
The present invention relates to structure of a clamping apparatus of a plate for a printing machine, and more specifically, to a clamping apparatus for a plate for a printing machine which can apply adequate tension to the plate depending on the materials of the plate.
2. DESCRIPTION OF THE PRIOR ART
Generally, in order to carry out printing with offset printing machines, an adequate amount of ink and dampening solution are supplied to a plate which is rolled around a plate cylinder and fitted thereon. A clamping apparatus is used for fitting the plate tightly on a cylinder surface of the plate cylinder. The plate is fitted on the cylinder surface of the plate cylinder to prevent a shear in printing or other failures in printing when the plate is not fitted tightly on the cylinder surface.
The structure and operation of conventional clamping apparatuses is described hereunder.
FIG. 13 is a sectional view showing a clamping apparatus 80 for fitting a plate on the cylinder surface of the plate cylinder. One edge (a leading edge side) of the plate 15 is clamped on the plate cylinder 30, and then the plate 15 is rolled around the cylinder surface of the plate cylinder 30. Thereafter, the other edge (a tail edge side) of the plate 15 is clamped by a clamping unit 20 provided on the tail edge side 35 of the plate cylinder 30. A plurality of adjustment bolts 22 are screwed into the clamping unit 20 in the same direction as a shaft of the plate cylinder 30. The clamping unit 20 is moved in the direction of arrow 200 as a result of pointed ends 22S of the adjustment bolts 22 contacting inner wall 30S of the tail edge side 35 when the adjustment bolts 22 are screwed into the clamping unit 20 to a certain depth.
In this way, the plate 15 clamped by the clamping unit 20 is pulled in the direction of the arrow 200 and the plate 15 is fitted on the cylinder surface of the plate cylinder 30. As indicated, the plate 15 is fitted tightly on the plate cylinder by screwing each of the adjustment bolts 22. On the contrary, each of the adjustment bolts is unscrewed in order to loosen the fixture of the plate 15 on the cylinder surface of the plate cylinder 30. The fixture of the plate 15 on the cylinder surface of the plate cylinder 30 is loosened as a result of moving the clamping unit 20 in the direction of arrow 300.
Further, there is conventional clamping apparatus which uses a plurality of coil springs between a side wall formed in the plate cylinder and the clamping unit instead of the adjustment bolts 22. The plate is fitted tightly on the cylinder surface of the plate cylinder by pulling the plate as a result of moving the clamping unit with spring force of the coil springs.
In addition, another conventional clamping apparatus is shown in FIG. 14. A clamping unit 40 is provided on the tail edge side of the plate cylinder 60, and the tail edge side part of the plate 19 is clamped by the clamping unit 40. A plurality of coil springs 45 are provided between the inner wall of the plate cylinder 60 and the clamping unit 40. The clamping unit 40 which clamps the plate 19 is pushed in the direction of arrow 150 by the spring force of the coil springs 45.
Also, a stopper 28 is provided on the plate cylinder 60, and a plurality of stopper screws 38 are screwed and pass through the stopper 28. Each of the stopper screws 38 is disposed in the same direction as the shaft of the plate cylinder 60. Pointed ends of the stopper screws 38 are contacted with the clamping unit 40. In other words, movement of the clamping unit 40 in the direction of the arrow 150 is restricted by the stopper screws 38 each of which is screwed into the stopper 28.
Each of the stopper screws 38 is loosened when the plate 19 is fitted tightly on the cylinder surface of the plate cylinder 60 by using the clamping unit 160. The plate 19 is fitted tightly on the cylinder surface of the plate cylinder 60 by pulling the plate 19 which is clamped by the clamping unit 40 as a result of moving the clamping unit 40 in the direction of the arrow 150 with the spring force of the coil springs 45 and the plate 19 can be fitted more tightly on the cylinder surface of the plate cylinder 60 with certain reliability by loosening each of the stopper screws 38.
On the other hand, each of the stopper screws 38 is screwed further in order to loosen the fixture of the plate 19 on the cylinder surface of the plate cylinder 60. By doing that, however, the fixture of the plate 19 on the cylinder surface of the plate cylinder 60 is loosened as a result of moving the clamping unit 40 in the direction of the arrow 190.
The conventional clamping apparatuses described above have the following problems to be resolved. Plates for printing machines are made of several different materials such as aluminum, resins, papers and so on. It is necessary to adjust tension for fitting these plates on the cylinder surface of the plate cylinder depending on the materials of the plates.
In the clamping apparatus 80 shown in FIG. 13, the moving distance of the clamping unit 20 can be adjusted by the amount of screwing done by each of the adjustment bolts 22. As a result, the tension applied to the plate 15 can be adjusted. Although the tension can be adjusted by the clamping apparatus, each of the adjustment bolts 22 has to be screwed on a one by one basis. In this way, adjustment of the tension takes much time and much work.
However, the tension applied to the plate can not be adjusted in conventional clamping apparatus which are equipped with coil springs instead of adjustment bolts 22. The coil springs can only apply uniform tension to the clamping unit. It is not possible for the clamping apparatus to apply tension to the clamping unit depending on the materials of the plates.
For instance, a plate which requires high tension for fitting can not be fitted tightly on the cylinder surface of the plate cylinder when coil springs having lower spring force than the tension required by the plate are provided to the clamping apparatus. Insufficient tension is applied to the plate. On the other hand, a plate which requires low tension for fitting may be damaged when coil springs having higher spring force than the tension required by the plate are provided to the clamping apparatus. Too much tension is applied to the plate.
Further, tension applied to the plate 19 can be adjusted in the clamping apparatus shown in FIG. 14 because the moving distance of the clamping unit 40 is adjusted by the amount of screwing done by each of the stopper screws 38. Although, the tension can be adjusted by the clamping apparatus, each of the stopper screws 38 has to be screwed on a one by one basis. In this way, adjustment of the tension to the plate 19 takes much time and much work similar to the clamping apparatus 80 shown in FIG. 13.

Clamping apparatus of a plate for a printing machine


In a fixing apparatus for fixing an optical connector to an optical cable having an optical fiber and wire members arranged around the optical fiber, the fixing apparatus includes first, second, and third holding members. The first holding member is adapted to be inserted between the wire member and the optical fiber. The second holding member is adapted to be disposed outside the wire members, the second holding member cooperating with the first holding member to tightly hold the wire members therebetween. The third holding member surrounding the second holding member and having an axial end portion adapted to be engaged with the second holding member in a rotation direction with respect to the optical cable. In addition, the third holding member has another axial end portion adapted to be connected to the optical connector.

This invention relates to an apparatus for use in fixing or connecting an optical connector to an optical connector.
Japanese Unexamined Patent Application Publication (JP-A) No. H6-170949 (Patent Document 1) discloses a method of fixing a terminal end of a FRP (fiber-reinforced plastic) rod to a terminal fixture. The FRP rod is inserted into a hole of a conical member. The FRP rod and the conical member are adhered by an adhesive. The FRP rod and the conical member adhered to each other are fixed along a tapered portion of the terminal fixture. The conical member has a shape matching the shape of a tapered inner surface of the terminal fixture.
Japanese Patent (JP-B) No. 2590067 (Patent Document 2) discloses a cable retaining structure for fixing a terminal end portion of an optical cable. The cable retaining structure has a core metal having one end connected to a retainer. The core metal has an outer peripheral surface provided with a corrugated portion. Specifically, the outer peripheral surface is corrugated in a longitudinal direction of the cable to form two or more valley portions. The core metal has a center hole through which the cable is inserted. An armoring wire of the cable is deformed in conformity with a surface profile of the corrugated portion and laid along the outer peripheral surface of the core metal. Further, on the armoring wire, snap rings are attached at the valley portions of the corrugated portion.
In each of the patent documents 1 and 2, the FRP rod or the cable is not restricted in relative movement in a rotating direction and in an axial direction. In actual use, an external force is exerted in the rotating direction and in the axial direction in order to lay the FRP rod or the cable. Therefore, it is impossible to achieve reliable fixation of the FRP rod or a reliable cable retaining structure.
Further, in the patent documents 1 and 2, no disclosure is made of a structure for positioning the FRP rod or the cable in the axial direction when the FRP rod or the cable is connected to an optical connector.

Apparatus for tightly fixing an optical connector to an optical cable

Japan Aviation Electronics Industry, Limited


A thermoplastic blend composition is provided containing an aromatic polycarbonate and a hydroxy functional graft copolymer. The compositions exhibit reduced gloss and are useful as molding resins.

1. Field of the Invention
The present invention relates to blends of aromatic polycarbonate resin and ABS resin, and more particularly relates to low gloss aromatic polycarbonate/ABS blends containing an hydroxy functionalized graft copolymer.
2. Description of the Related Art
Blends of polycarbonate resin and ABS resin are known, see for example, German Patent 1,170,141--many polycarbonate resin/ABS resin blends however exhibit high levels of gloss while in various applications it is desired that the blends exhibit low surface gloss.

Low gloss polycarbonate blends obtained by using hydroxy functionalized graft copolymer


A handwashing medium which may be in liquid, cream, powder or spray form is provided with a detection agent such as an invisible fluorescent or phosphorescent additive, which combination is then rubbed onto one's hands using the individual's handwashing technique. The individual's hands are rinsed with water as in the normal handwashing fashion and the hands are then exposed to an activating agent such as an ultraviolet (UV) light source where the invisible detection agent is fluorescent. Areas missed during handwashing retain the fluorescent additive and are clearly visible due to fluorescence. In the case of a phosphorescent detection agent, an ultraviolet light source is not necessary as the phosphorescent detection agent will emit light on its own without any external light source in a reduced light environment. The method is useful in evaluating one's handwashing technique and in the teaching of proper hygiene. The invisible fluorescent or phosphorescent additive in a handwashing medium may also be used in determining patterns of body part contact such as contact with one's hands or feet in a given area by applying the invisible fluorescent or phosphorescent additive to a body part and either exposing the area to UV light or viewing the area of interest in reduced light to detect the presence of residue of the fluorescent or phosphorescent agent. The use of a phosphorescent additive in the handwashing medium may also be used in determining patterns of body part contact by viewing the area of interest in reduced light.

Cleanliness is essential for good health. The spread of infectious disease has reached epidemic proportions in many parts of the world. Even in the more technically advanced countries, the increase in the spread of contagious diseases, which in many cases is fatal to the victim, has reached an alarming level and has caused great fear and anxiety. Because of the nature of human beings and the manner in which they interrelate, contagious disease and illness is frequently transmitted by hand. It has been determined that some organisms live for 150 minutes on the skin. Because many patients can be handled in a 2 1/2 hour period, the risk of cross-infection is clearly great. The need for a high degree of cleanliness in certain environments such as hospitals, clinics, restaurants etc., is thus obvious. Great precautions are taken in these types of facilities to minimize the transfer of disease- causing microbes among people. In many cases, the transfer of disease is caused by improper cleaning such as of one's hands or by the improper or unauthorized handling of contaminated materials. Frequently, access to and the handling of contaminated materials or objects is inadvertent and the individual involved may not be aware that he or she has touched or been exposed to the source of contamination.
This invention addresses the aforementioned problems encountered in the prior art by providing a method which permits an individual to evaluate the effectiveness of his or her handwashing technique as well as to apprise the individual of his or her patterns of contact in a given area.


A slide member for use in an automotive vehicle. The slide apparatus includes a first slide member having a slidably contacting surface. Additionally, a second slide member is provided having a slidably contacting surface which is in slidable contact with the slidably contacting surface of the first slide member. In this slide apparatus, at least one of the slidably contacting surfaces of the first and second slide members is formed of a transferable water repellent material having a water repellency and a sufficient transferability to form a transferred film of the transferable water repellent material on at least the other slidably contacting surface.

This invention relates to improvements in a slide apparatus for use in an automotive vehicle, more particularly, to improvements in sliding characteristics in the slide apparatus which has a slide member manually operated or electrically operated under a condition conforming to manual operation which is especially such that a bearing pressure between slidably contacting surfaces of the slide member which slidably contact with an opposite member is not higher than 60 kg/cm2 and that a sliding speed is not higher than 300 mm/s. The slide member operated under the above condition includes a window regulator for a window glass operating apparatus, a guide rail of a slide door, a check link of a hinged door, a finisher of a seat belt, a cupholder, an ashtray, a hinge of a console, a hinge of a rear door, a gas-filled stay of the rear door, and the like.
There is an electrically operated window regulator for an automotive vehicle as an example of the slide apparatus. The window regulator usually includes an electric motor provided with a speed-reduction device such as a reduction gear and connected through the speed-reduction device with a drum. A wire is passed at its central portion on the drum and has opposite end portions which extend respectively through turn guides to be secured to a carrier plate. The carrier plate is a press-formed article formed of a sheet metal, and provided with a slider which is made of a plastic and slidably fitted to a guide rail. The carrier plate is fixed to a lower end side of the window glass. The guide rail is formed of pressed steel plate or sheet having a generally C-shaped cross-section. With the above arrangement, when the motor is rotationally driven, the wire passed on the drum is moved so that the carrier plate fixed to the wire is moved upward and downward together with the window glass.
In such a window regulator, a variety of devices are made to improve the sliding characteristics of the slider to the guide rail. For example, a technique is for lowering a sliding resistance by adding lubricants such as silicone oil, molybdenum disulfide or the like to a slidably contacting member of the slider in contact with the guide rail, as disclosed in Japanese Patent Provisional Publication No. 09-112125. Another technique is arranged such that a slidably contacting portion of the slider is in the shape of a roller which is in slidable contact with the guide rail, as disclosed in Japanese Patent Provisional Publication No. 2003-312254. A further technique is arranged such that the slider is provided with an elastic projecting piece which supplies lubricant to a slidably contacting surface of the guide rail while the elastic projecting piece slidably moves, as disclosed in Japanese Patent Provisional Publication No. 07-317432. A still further technique is arranged such that the slidably contacting surface of the slider in contact with the guide rail is formed with a groove to hold lubricant, as disclosed in Japanese Patent Provisional Publication No. 10-037586.


The present invention provides methods of treating arthritis. A sustained release composition comprising liposomes and one or more therapeutic agent or a pharmaceutically acceptable salt thereof is administered to a subject in need thereof. The liposomes may be in an aqueous suspension. The sustained release composition can be administered intraarticularly.

Osteoarthritis (OA) is the most common type of arthritis and a leading cause of disability. It is a non-inflammatory, degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone sclerosis, osteophyte formation, changes in the synovial membrane, and an increased volume of synovial fluid with reduced viscosity and hence changed lubrication properties.
Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease of unknown cause. Genetic, environmental, hormonal, immunologic, and infectious factors can play significant roles. The hallmark feature of this condition is persistent symmetric polyarthritis that affects the hands and feet, although any joint lined by a synovial membrane can be involved. This is due to the accumulation of and proliferation of inflammatory cells in the synovial lining, known as synovitis. Extra-articular involvement of organs such as the skin, heart, lungs, and eyes can be significant.
Intraarticular (IA) drug injection is an attractive treatment approach for treatment of arthritis, including OA and RA. The various steroid and hyaluronic acid formulations on the market are considered effective, but require frequent IA injections and provide only short-term symptomatic relief. Other crystal suspension formulations, which require large bore needles for IA injection are not suitable for treating small joints and can produce a crystal-induced synovitis. The available systemic treatments also have shortcomings, most notably side effects.
In view of the deficiencies outlined above, there is a need for methods for treating arthritis with less frequent IA injection and/or longer-term pain relief. The methods disclosed herein address this need as well as other important needs.

This patent is subject to a terminal disclaimer.

Pharmaceutical compositions for intraarticular delivery


A protection device 1 for a heat exchanger, comprising a grid 10 with an upstream surface 11 and a downstream surface 12, both located on opposite sides of the grid 10, the grid 10 being attachable to the heat exchanger 40 with attachment means 11 so that the downstream surface 12 can face a side of the heat exchanger 40, wherein the protection device 1 further comprises a shock absorber 20 attached to the grid 10 so that the shock absorber 20 least partly protrudes from the downstream surface 12 of the grid 10.

Heat exchangers interact with a fluid circulation loop in order to generate heat exchange between the outside air of the motor vehicle directed to pass through these heat exchangers and the fluid. It may be a coolant fluid, a refrigerant fluid or a gaseous fluid such as an intake air flow for an internal combustion engine.
These heat exchangers may consist of radiators, condensers or supercharged air coolers. In these heat exchangers, several tubes are stacked on top of each other with heat dissipating elements arranged in-between. The fluid circulates inside the tubes and participates in heat exchange with the outside air which passes through the dissipating elements of the heat exchanger.
These heat exchangers are conventionally arranged on the front face of motor vehicles in order to capture the outside air, ahead of the engine which is placed in the engine compartment of the motor vehicle.
The frontal position of these heat exchangers exposes the heat exchanger which is closest to the front face of the motor vehicle to the projection of debris or gravel which are on the road and which can damage or even pierce the tubes inside which the fluid circulates. More specifically, the tubes of the heat exchanger arranged closest to the front face of the motor vehicle are generally arranged transversally to the running direction of the motor vehicle in a flat and horizontal arrangement. As a result, the tubes of this heat exchanger located closest to the front face of the motor vehicle are exposed to the projections of debris or gravel at their edges facing the front face of the vehicle.
In order to protect these heat exchangers, it is known to place in front of them a protective grid capable of retaining the gravel or any other projectile and thus preventing shocks on the tubes of the heat exchangers. It is known for example to arrange a protective grid ahead of the heat exchanger(s) of the motor vehicle, by clipping this protective grid onto the heat exchanger.
However, additional elements such as protective grids may under specific circumstances apply shocks to the heat exchanger, for example upon being hit by debris, or during normal lifecycle operation. Consequently, instead of protecting the heat exchanger, they may actually be a source of damage themselves. Additionally, protective grids may produce noise when vibrating. Driving comfort of vehicle passengers as well as the rest of traffic participants is then lowered.
Thus, one of the aims of the present invention is to reduce or eliminate the abovementioned disadvantages.


The inkjet printer head includes heating elements and ejection nozzles. Each of the heating elements has a heating resistor which is energized by application of an electric current so that a part of ink which is located in proximity to the heating resistor is boiled to form a bubble. The expansion of the formed bubble causes the ink to be ejected as a droplet through each of the ejection nozzles. Each of said heating elements has no protective film disposed between the heating resistor and the ink in which the bubble is to be formed. A thickness of said heating resistor is in a range of from 2 μm to 5 μm.

This invention relates to an inkjet printer head capable of thermal inkjet printing in which ink is heated to boil by applying an electric current to heating elements and ink droplets are ejected by the expanding force of bubbles formed in the ink.
One of the inkjet printers commonly used today are those capable of thermal inkjet printing in which ink is heated to boil by applying an electric current to heating elements and ink droplets are propelled and ejected by the expanding force of bubbles formed in the ink.
In order to heat the ink in thermal inkjet printing, an electric current needs to be applied to the heating elements for only a very brief period, so the printer head can be constructed in a comparatively simple design and precise printing is yet possible. In addition, the heating elements can be arranged on the substrate on a large scale and at high density. Because of these advantages, thermal inkjet printers are suitable for use not only at homes but also in commercial applications such as textile printing and on-demand printing where continuous printing is performed.
A disadvantage of the thermal inkjet printer head is that the heating elements are prone to be damaged by cavitation that occurs from the extinction of bubbles formed in order to eject ink droplets. In order to prevent this problem, the resistors in the heating elements are commonly protected by superposing an anti-cavitation coat. However, this is not desirable from the viewpoint of the need to achieve very rapid, almost instantaneous, transfer of heat from the heating elements to the ink since the protective coat placed between each heating resistor and the ink slows down the heating of the ink.
JP 9-174848 A proposes a heating element that does need to have a protective coat placed between the heating resistor and the ink in which bubbles are to be formed.
In JP 9-174848 A, thin-film resistors of a Ta—Si—O ternary alloy system having a thickness of 0.1 μm (1000 Å) with the constituent elements defined at proportions within a specified range are used as resistors in heating elements to enable the fabrication of an inkjet printer head that can be energized by application of as many as 108 impulses without being destroyed due to cavitation.
JP 2000-168088 A describes a thermal inkjet printer head that has a two-layered Ta—Si—O film about 7000 Å thick, with a self-oxidizing protective layer formed on top in a thickness of 100–500 Å. The head claims high durability against both cavitation damage and electrolytic corrosion.
As already mentioned, the thermal inkjet printers manufactured today are required to find use not only at homes but also as long-lived and highly durable commercial printers capable of continuous operation as in textile printing and on-demand printing. For use at homes, it has been necessary that the printer should be capable of withstanding the application of at least 108 impulses before the heating elements in the head become no longer operative. However, commercial printers that need to have better durability than home printers are required to use heads with much longer lives than those used on the home printers, for example, heads that can withstand the application of 1010 impulses.
However, the life of the heating elements proposed in JP 9-174848 A is only about 108 impulses and by no means exceeds 1010 impulses. Hence, the technology disclosed in JP 9-174848 A has the problem that it cannot manufacture an inkjet printer head that can withstand the application of 1010 impulses. The thermal inkjet printer head proposed in JP 2000-168088 has the same problem and its cycle life does not exceed 1010 impulses.


A method for determining the thickness of a layer of insulation comprises the steps of: contacting a top surface of a portion of the layer of insulation, compressing the portion of the layer of insulation until a predetermined compressive load is achieved, measuring a distance through which the top surface is moved during the compressing step, and determining the thickness of the layer of insulation based on the measured distance. Apparatus is provided for performing the method.

ASTM standard C167-98 specifies standard methods for measuring the thickness and density of blanket or batt thermal insulation. The standard specifies use of a depth gage such as gage 600 shown in FIG. 6. The depth gage 600 has a clear plastic disk 610 of about 76 mm (3 inches) attached near or at a top end of a pin 620 having sufficient length for the material to be measured. The disk 610 is aligned perpendicular to the pin 620. A friction device is used to fix the disk to the pin. For example, the disk 610 may have a hub 612 with a female threaded sleeve 614 to receive a set screw 616. The set screw 616 can be advanced to engage a side surface of the pin 620. The pin 620 has a sharpened point 620p.
To use the depth gage 600, the disk is placed at the top end of the pin 620, as shown. The pin 620 is pushed into and through the insulation (not shown in FIG. 6), until the pin contacts a hard surface below the insulation. The set screw 616 is then loosened, so that the disk 610 can be freely lowered relative to the pin 610, until the disk contacts the top surface of the insulation. The contact is detected visually, by looking through the clear plastic disk. The set screw 616 is then tightened, and the gage 600 is removed. The distance between the bottom surface of disk 610 and the point 620p of pin 620 is the thickness of the insulation. A graduated rule (not shown) is placed against the disk 610, parallel to the pin. The distance is measured visually, by looking at where the point 620p lies along the rule.
The precision of the measurement method described above is limited by the precision of the rule, and the accuracy of the measurement is limited by any variation in the angle from which the test person views the pin 620 and rule while taking a reading. Also, during the initial step of contacting the insulation with the disk, the weight of the disk and any force inadvertently exerted by the test person may result in compression of the insulation, further reducing the accuracy of the measurement.
An improved method and apparatus for measuring insulation depth is desired.

Method and apparatus for determining insulation thickness


Hair removal by using an Alexandrite laser emitting energy between 0.2-40 joules per pulse to provide an energy fluence between 15 and 70 joules per centimeter square and having a pulse duration of between 100 microseconds and 10 milliseconds. A scanner may be used to direct the laser beam on the tissue. The skin in the area to be irradiated may be shaved prior to exposure to laser treatment and may be also covered by a protective substance serving as a heat sink.

Treatment of skin with lasers have been the subject of study since the early 1960s. A variety of lasers have been used in dermatologic practice. Different lasers are primarily distinguished by a wavelength of the light produced, measured in nanometers, such as the XeF excimer (351 nm), argon (488 nm, 514 nm), ruby (694 nm), Nd:YAG (1060 nm), and CO.sub.2 (10,600 nm) lasers.
Photothermolysis of skin has been demonstrated using dye laser pulses and Q-switched ruby laser pulses. It has been found that radiation from Q-switched ruby lasers deeply penetrates the epidermis and dermis. It has also been found that application of ruby red laser energy can cause depigmentation of the skin as well as significant follicular damage to the extent that the hair will fall out.
The Q-switched ruby laser has been used for the treatment of tattoos, pigmented lesions, and conventional ruby lasers have been used to treat epidermal and dermal pigmented lesions. Studies based on experimentation with Q-switched ruby lasers, as well as other lasers, have reported skin depigmentation and temporary hair loss.
The use of lasers for non-invasive hair removal has been disclosed in U.S. Pat. No. 5,059,192, issued Oct. 22, 1991 to Nardo Zaias, entitled METHOD OF HAIR DEPILATION. This patent teaches the use of a pulsed ruby laser as the preferred embodiment. The ruby laser radiation (694 nm wavelength) penetrates deep into tissue and is relatively well absorbed by melanin to cause thermal damage to dark, melanin rich hair shafts and follicles.
U.S. Pat. No. 5,226,907, issued Jul. 13, 1993 to Nikoli Tankovich, entitled HAIR REMOVAL DEVICE AND METHOD and U.S. Pat. No. 5,425,728, issued Jun. 20, 1995 to Nikoli Tankovich, entitled HAIR REMOVAL AND METHOD teach the use of a CO.sub.2 pulse laser and a Nd:YAG laser, among other types of lasers, to effect hair removal in conjunction with light absorbing oil used to stain hair.
The Nd:YAG laser is limited to relatively low energy levels at affordable commercial production costs. It is effective only for highly absorptive hairs, usually stained for this purpose. Energy levels adequate for hair removal with bare hairs makes it impractical to use an Nd:YAG laser.
Large pulsed ruby lasers are capable of delivering very high energy levels--as high as 40 J. As a result, they can attain the energy fluences of 15-70 J/cm.sup.2 necessary for hair removal. However, ruby lasers can be fired only at a very low repetition rate--approximately 1 pulse per second (pps). This limits the benefit of using a scanner such as that described in U.S. Pat. No. 5,411,502 to Eliezer Zair and the computerized pulsed generator (CPG) scanner, commercially available from Coherent Inc. of California, USA. This low repetition rate is too low to cover large treated areas as legs and hands in a reasonable time. A 10.times.30 cm.sup.2 area (one leg) would require some 1200 pulses, each pulse covering an area of 0.25 cm.sup.2 (typical for hair removal with a 5 Joules laser). Assuming a repetition rate of 1 pps, this leads to 20 minutes for a single leg, or over 1 hour for two legs and two hands. This considerably limits the number of patients treatable for hair removal with the expensive laser.
Another drawback of pulsed ruby lasers is their limited pulse time duration. Ruby lasers operated in their free running modes can usually attain a maximum time duration of 300-1000 microseconds. Extending the pulse duration to 1-10 milliseconds is almost impractical. On the other hand, it would be desirable to operate ruby lasers at pulse durations of 1-10 milliseconds in most cases of hair removal because of hair follicle diameters being of over 100 microns.
A third drawback of ruby lasers is their size due to their low efficacy. A 5 Joules, 1 pps ruby laser may typically be of 150 cm.times.70 cm.times.70 cm size. A 25 Joule laser may weigh over 400 kilograms.
U.S. Pat. No. 5,290,273, issued Mar. 1, 1994 to Oon Tan, entitled LASER TREATMENT METHOD FOR REMOVING PIGMENT CONTAINING LESIONS FROM THE SKIN OF A LIVING HUMAN and U.S. Pat. No. 5,217,455, issued Jun. 9, 1993 to Oon Tan, entitled LASER TREATMENT METHOD FOR REMOVING PIGMENTATIONS, LESIONS, AND ABNORMALITIES FROM THE SKIN OF A LIVING PERSON, teach the use of an Alexandrite laser instead of a ruby laser to treat pigmentation, lesions and skin abnormalities. Both teach that before and after irradiation, the area irradiated should be checked for the presence or absence of adhexac (skin appendages) such as hairs. If a hair loss condition is observed, then the energy density from the laser radiation should be decreased for subsequent treatments. The pulse duration is 10-300 nanoseconds.
Skin treatment employing laser based systems, usually pulsed laser based systems is well known in the art. Such laser based systems are used inter alia for cutaneous vascular lesions treatment and for hair removal, the latter application being described for example in U.S. Pat. Nos. 5,059,192 to Zais and 5,226,907 to Tankovich.
As is also well known in the art, the operation of laser based systems for cutaneous treatment is more effective when the tissue is cooled. Examples for prior art devices for cooling the skin during laser treatment are U.S. Pat. No. 5,057,104, U.S. Pat. No. 5,282,797 and U.S. Pat. No. 5,486,172 to Chess specifically designed for cutaneous vascular lesions treatments and U.S. Pat. No. 5,344,418 to Ghaffari.
A major disadvantage of prior art laser based systems for cutaneous treatment is that the operation of the laser is not visible to the physician carrying the treatment, thus he can not be sure that the laser covered the entire area to be treated. This results in an inhomogeneous treatment of the skin, such as an inhomogeneous removal of hair from the patient skin in the case of hair removal treatment.

Hair removal by selective photothermolysis with an alexandrite laser


The invention relates to a method and a device for contrast enhancement for display devices. A high-contrast representation of optical signals and/or symbols is achieved by providing a light-absorbing and/or light-deflecting background which is dark in comparison to the symbol or signal to be displayed and thus highlights said symbol or signal. The following invention enables a high-contrast representation of optical signals and symbols by the provision of a dark, light-absorbing background.

Optical displays are often hard to view in bright surroundings. For the purpose of counteracting this and heightening the contrast between the display and the surroundings, the light efficiency of the means must be increased which entails that more energy is consumed. Another possibility consists in the provision of shielding elements which are intended to shield the display from extraneous light incident on it. As a rule, such shielding means restrict the viewability of the display or shield it only insufficiently from incident extraneous light, such as, e.g., sunlight. Shielding the display from variable extraneous light, e.g. with a moving incident angle, often turns out to be difficult.
DE-T-693 26 611 discloses a device for preventing a false light phenomenon in a signal lamp, said device being provided between a light source and a cover lens and comprising a pair of complex spherical lenses in a specific arrangement and a shielding element positioned between said pair of lenses and having light-transmitting holes.


A ferrule and method are presented that fuses optical fibers, capillaries and the like to ferrules while reducing deformation of the fused component and the ferrule and minimizing stresses within the assembly. Reduced deformation and stress is accomplished by providing high contact angles in a symmetrical, short section of fusion in fusing the component carried by the ferrule to the ferrule. It is particularly applicable to hermetic terminations of polymer clad fiber optics where irregular glass fusion joints cause irregular light leakage at the fiber launch but benefits are significant when used for other fiber and capillary architectures as well.

U.S. Pat. No. 4,185,883 (Chown et al.) discloses an optical fiber coupling element that includes a glass sleeve secured to a length of optical fiber. The optical fiber is placed in the glass sleeve, and the sleeve is heated so that it collapses around the fiber to hold the fiber in place.
U.S. Pat. App. No. 20020110332 (Clarkin et al.) discloses a ferrule presenting a preferentially "softenable" substance within the bore for reducing fusion temperatures and thus reducing distortion of the ferrule and element fused within.
U.S. Pat. No. 6,282,349 (Griffin) discloses a fiber fused in a ferrule.
It is often desirable to employ a ferrule in joining optical components together or when incorporating optical components into other devices. A ferrule is a piece of material (glass, ceramic, polymer, metal or composite) having one or more holes into which components such as optical fibers or capillaries may be inserted, offering added support to the fiber/capillary as well as increased structural strength and facilitate alignment of the fiber/capillary with another, similarly terminated component.
In most cases, adhesives secure components carried within ferrules but adhesives can be problematic in many applications due to the difference in chemical and physical properties of the adhesives with respect to the fiber and ferrule. Adhesive terminated fibers in ferrules are not truly hermetic and are labile to elevated temperatures and certain chemicals. In some applications, it is desirable to provide a fiber-in-ferrule (or capillary-in-ferrule) that may be immersed within solutions of extreme pH, solvents that degrade adhesives, vacuum or elevated pressure and temperature environs. In many, more routine applications it is desirable to provide a seal to prevent migration of gasses or other contamination from the environment into a package intended to isolate an active device, e.g., a semiconductor laser. A ferrule may also act to redirect overfill energy in fibers used in a high power coupling application such as a industrial welding and medical laser delivery systems. Where a fiber must pass through a bulkhead, e.g., from a monitor to within a chemical reaction process stream, chemical and thermal resistance may be critical in maintaining the system seal.
In all cases, it is important to minimize stress induced by thermal expansion mismatches between the ferrule, the carried optical fiber or capillary element and any other materials (polymer adhesives, solders, etc.). The stresses generated by thermal expansion mismatch can degrade optical and mechanical performance of the overall package. By directly fusing fiber or capillary within ferrules made of like material, thermal expansion mismatch stresses are eliminated. Residual physical stresses and strains do remain in traditional packages, however, due to the extremely low contact angles in the fusion region. As is generally known in the scientific glassblowing community, low contact angles in welds are extremely susceptible to failure due to these residual stress concentrations. While post-fusion annealing can reduce the stresses in the weld, considerable stress generally remains and, in the case of fiber and capillary terminations, true post-fusion annealing is rarely possible due to the local presence of thermally labile materials (fiber and capillary polymer coatings, strain relief materials, etc.).
It has been known in the art to seal fibers to ferrules by several methods including adhesives, soldering of metallized fibers and ferrules or by swaging material around the fiber. Many attempts have been made to seal terminations by fusing a fiber together with the ferrule. While generally successful in cases where fiber or capillaries are not doped or employ dopants that do not radically alter thermal properties of the glass or easily diffuse throughout the glass at elevated temperatures, attempts with doped core fiber such as that used in telecom/datacom applications and polymer clad fiber have had limited success. Seals generally fail to hold, or the fiber and/or the ferrule fails, particularly when fiber and ferrule are of differing materials, coupling efficiencies are poor where core dopants diffuse under heating and where polymer clad fibers—necessarily bare of polymer near the fusion, leak into the ferrule at points of contact therein. Where each is made substantially of similar glasses, fusing tends to distort tiny telecom fiber cores to such an extent that the fiber's optical characteristics are changed. This distortion is primarily due to asymmetric, low contact angle stresses in the fusion seal and generally lengthy and poorly reproducible fusion regions. In the case of single mode or polarization maintaining fibers, the fiber geometry is crucial to its proper operation. It is extremely difficult to maintain uniformity of stresses and dimensions during a fusing operation and, due to the small diameter of both core and cladding (and in the case of polarization maintaining fibers, the precise stress distributions within the core composite structures), such difficulty renders the practice of fusion terminations for these type fibers impractical.
Even in cases where fusion has proven viable, e.g., so-called "Specialty Fiber" (fiber for power and spectrum transmission as opposed to data) terminated within quartz and silica ferrules, the residual stress within the structure of the fiber and the ferrule, which may lead to premature failure. Moreover, in the case of providing a preferentially softenable material as an interface between a telecom-type fiber and ferrule, asymmetric stresses due to low contact angles and non-centrosymmetric, extended fusion regions remains and the potential for premature failure remains.
Finally, for lower cost, higher Numerical Aperture (NA) specialty fiber where polymer claddings are employed instead of fluorine doped silica claddings, contact between the bare glass core and the ferrule, in both fused and non-fused regions, must be kept to a reproducible minimum. While the input face may be reproducibly located in space for reproducible fusion thickness (where the nascent core dimension is lost in the fusion to the larger glass ferrule) as the fiber in free space is clad efficiently by air, additional points of contact between the bare core and glass are sites of light leakage and must be avoided. A competing requirement is that the space between the glass ferrule bore and the fiber core must be kept to a minimum in order to maintain concentricity and axial alignment of the fiber within the ferrule. The invention disclosed herein addresses these conflicting requirements, facilitating a low cost, high energy and hermetic termination for polymer clad silica fiber.

High energy fiber terminations and methods


The method of the present invention generates print data to be supplied to a printing module, which ejects ink to form dots on a printing medium. This method includes a dot data generation step of generating dot data, which represent a dot formation in respective pixels, according to pixel values of given video data with regard to the respective pixels. The dot data generation step includes the step of generating the dot data, such that a dot formation with respect to at least part of the pixel values in a pixel belonging to an end area located on an end of the printing medium is different from the dot formation in a pixel belonging to a middle area located in a middle of the printing medium, so as to prevent adhesion of ink to the printing module.

1. Field of the Invention
The present invention relates to a printing technique of ejecting ink droplets to print an image on a printing medium, and more specifically to a printing technique of printing to ends of printing paper.
2. Description of the Related Art
Printers that eject inks from nozzles on a print head have widely been used as the output device of the computer. Some known printers have been developed to implement printing to ends of printing paper, as disclosed in Japanese Patent Laid-Open Gazette No. 2002-103586. One proposed method attaining rimless printing uses an ink absorption material set in grooves of a platen to absorb ink ejected outside the printing paper.
This proposed method, however, may cause problems, such as fouling of the printing device with misted ink or solid ink retention in the ink absorption material.

Printing with varied dot-recording rate with respect to each printing region


A facility for performing employing multiple frequencies in a secure distributed hierarchical convergence network is described. The facility receives a signal in a first frequency, converts the received signal to an internal representation, applies a business rule to the converted signal, and, when the business rule indicates that the signal should be transmitted in a second frequency, causes the internal representation of the signal to be translated to a second frequency and transmitted in the second frequency.

In the land mobile radio (LMR) communication environment LMR networks conventionally use a single frequency range to transmit and receive radio signals. There exists many types of LMR networks using many transport and modulation schemes carrying different types of formatted information in the radio wave. The most basic are analog information and currently the most advanced are P25 & Tetra standards-based digital transmissions. LMR networks generally carry half duplex or multi channel duplex voice communications. Additionally, the digital based LMR networks are capable of carrying low bandwidth data.
Commercial wireless carrier networks use commercial frequency ranges to carry full duplex voice and packet data. The U.S. military makes use of other frequency areas in various low band and high band ranges carrying a variety of voice and data transmissions. The frequency ranges are separate from the public safety, government and commercial ranges so that the transmissions have minimal radio interference with each other. Additionally, multiple modulation schemes and transports exist between wireless carriers and vary greatly on military bands. Add to this the public broadband frequency allocations for 802.11 and other publicly available spectrum areas and the spectrum chart break down is fragmented in no particular order with a large number of incompatible modulation schemes and transports making it very difficult for specific voice and data applications using separate frequencies and networks to interoperate, as is illustrated in FIG. 1. FIG. 1 further illustrates GSM with SMS with full-duplex voice, UHF LMR analog with full channel voice with no transport layer, 800 MHz LMR P25 with narrow band voice, and military band for voice.
This stove piped frequency and transport arrangement has never been ideal but now there is an urgent need by the government and military with a compelling business case for commercial communication companies to be able to interoperate and communicate between frequencies and disparate networks using both existing and next generation equipment.

Secure, distributed hierarchical convergence network


Integrated circuits suitable for high-performance applications, especially mixed signal products that have analog and digital sections, are fabricatable from a semiconductor structure having two levels of buried regions. In a typical embodiment lower buried regions of opposite conductivity types are situated along a lower semiconductor interface between a semiconductive substrate and an overlying lower semiconductive layer. Upper buried regions of opposite conductivity type are similarly situated along an upper semiconductor interface between the lower semiconductive layer and an overlying upper semiconductive layer. The upper semiconductive layer contains P-type and N-type device regions in which transistor zones are situated. The semiconductor structure is normally configured so that at least one of each of the P-type and N-type device regions is electrically isolated from the substrate. Complementary bipolar transistors can be integrated with complementary field-effect transistors in the structure.

Semiconductor devices made according to CMOS technology employ complementary insulated-gate field-effect transistors ("FETs"). An advantage of CMOS devices is that insulated-gate FETs individually occupy relatively small chip area and, when arranged in complementary configurations, consume little power. CMOS devices commonly use a power supply voltage of 5 V, especially in digital applications.
A mixed signal integrated circuit is a semiconductor device that contains analog and digital sections. Traditional CMOS technology is generally not suitable for high-quality mixed signal devices due to crosstalk (noise) which occurs between the analog and digital sections. In crosstalk, the effect of actions taking place in one part--e.g., the digital section--of the mixed signal device is partially transmitted through the device substrate and can detrimentally affect actions taking place in another part--e.g., the analog section--of the device. Also, many mixed signal devices need to operate at voltages much greater than 5 V. Accordingly, traditional 5-V CMOS technology is not suitable for high-voltage mixed signal applications.
Bipolar transistors are often combined with FETs to improve overall performance. Bipolar transistors generally respond fast. In addition, bipolar transistors provide readily controllable current gain and high transconductance, both of which are advantageous. Integrating bipolar transistors and FETs into a single integrated circuit permits the high-speed and current-gain features of bipolar transistors to be combined with the low power consumption and high packing density of FETs.
An integrated circuit made according to BiCMOS technology typically combines NPN transistors with complementary insulated-gate FETs. Some BiCMOS devices also contain PNP transistors. In this case, BiCMOS is sometimes referred to as CBiCMOS where the first "C" indicates that complementary bipolar transistors are provided.
The performance improvements available with BiCMOS technology make it attractive for mixed signal integrated circuits, especially those used in high-voltage applications. In high-voltage BiCMOS, some of the transistors handle low-voltage tasks and are not generally suited for high-voltage operation, while other transistors are specially designed to operate at high voltage.
Kosiak et al, U.S. Pat. No. 4,918,026, discloses a method of fabricating high-voltage complementary insulated-gate FETs for a BiCMOS process. The high-voltage FETs in Kosiak et al differ from (standard) low-voltage FETs in that the drains of the high-voltage devices include lightly doped portions which extend under thick portions of the gate dielectric layers. Kosiak et al reports that their high-voltage FETs can tolerate a 30-volt source-drain voltage without incurring avalanche breakdown.
In Kosiak et al, the sources and drains of high-voltage P-channel FETs are formed in N wells provided in a P-type substrate. As a result, the high-voltage P-channel FETs are not resistively connected to the substrate. However, the sources and drains of high-voltage N-channel FETs are formed directly in the P-type substrate. Substantial crosstalk can thus occur between N-channel FETs in one part of the structure and N-channel FETs in another part of the structure.
Mosher et al, U.S. Pat. No. 5,256,582, discloses a CBiCMOS structure that utilizes three epitaxial layers: (a) a lower N-type epitaxial layer, (b) an intermediate P-type epitaxial layer, and (c) an upper N-type epitaxial layer. A P-type buried region lies along the interface between the P-type epi and the lower N-type epi. P-type and N-type buried regions lie along the interface between the upper N-type epi and the P-type epi. An N-type plug, created by implanting an N-type semiconductor dopant into the P-type epi and then thermally driving the implanted dopant, extends fully through the P-type epi to connect the two N-type epis.
Both low-voltage and high-voltage transistors are available in the CBICMOS structure of Mosher et al. However, it takes 10 hours for Mosher et to drive the N-type plug through the P-type epi. This is a very long time for a commercial fabrication process. It is desirable to have a semiconductor technology which substantially avoids crosstalk, can handle both low-voltage and high-voltage operations, and is suitable for production-scale fabrication.
In addition, a semiconductor technology that combines different types of transistors is difficult to optimize for all the transistors. For example, an integrated circuit having only vertical NPN transistors can be fabricated on a P-doped substrate that helps isolate the NPN transistors from each other. Likewise, an N-type substrate can be conveniently used to achieve transistor isolation in a circuit having only vertical PNP transistors. However, in a circuit that integrates both NPN and PNP transistors, neither a P-type nor an N-type substrate will provide isolation for all the transistors. Further isolation is necessary.
Additional doped regions can be used to provide further PN-junction isolation. But, the capacitances associated with the additional PN junctions reduce transistor speed. Thus, there is also a need for a semiconductor technology which allows NPN and PNP transistors to be integrated with each other and with their FET counterparts, is not highly complex, and provides low capacitances and high transistor speeds while allowing transistors to be isolated from one another.

Semiconductor structure having two levels of buried regions


A high voltage level shifter having a cost effective design that saves chip architecture and power. The high voltage level-shifter includes a resistor connected between a first node and a first power supply rail. An inverter couples to receive an input signal to provide an inverted input signal. A first circuit portion couples to receive the inverted input signal and connects between the first power supply rail and a second power supply rail for converting a high voltage signal into a low voltage signal. The first circuit portion includes a first clamp circuit, wherein the first circuit portion is biased through the first clamp circuit and the first node. A second circuit portion couples to receive the input signal and connects between the first power supply rail and a second power supply rail for converting a low voltage signal into a high voltage signal. The second circuit portion includes a second clamp circuit, wherein the second circuit portion is biased through the second clamp circuit and the first node. The second circuit portion provides a first internal bias for the first circuit portion and the first circuit portion provides a second internal bias for the second circuit portion. This high voltage level-shifter provides level shifting a low voltage signal (<5V) to a high voltage signal (˜40V), with no static power dissipation while still protecting all devices.

Many integrated circuits, such as display drivers, require a combination of high-voltage driving capability (an output voltage swing up to 100V or more) and a digital control using standard 5V CMOS logic. Hence, complex level-shifting circuits are needed to convert the 5V control signals into the desired high-voltage output waveforms. Moreover, in many of those applications, the system is battery-powered and very severe constraints are put on the power consumption of the level-shifters. One application where both high-voltage driving capability and low power consumption are required in the design of driver chips is in automotive applications.
Level shifters, in general, are utilized in a circuit to transition from a low voltage signal to a high voltage signal. In the alternative, a level shifter may be used to transition from a high voltage signal to a low voltage signal. Level shifters are commonly used for multi-rail or multi-power supply designs, where multiple rails or multiple power supplies exist and numerous signals reference these multiple rails or power supplies. These signals interact with various logic blocks that operate on different power supplies. Thus, every time a high voltage signal is transferred to a low voltage block, the signal must be level-shifted. Similarly, in the alternative, when a low-voltage signal is transferred to a high voltage block, the signal must be level-shifted.
Most of the circuits in the automotive electronic systems are high voltage circuits. High voltage level shifters, however, are large. In addition, when there are a lot of signals that need to be level-shifted, it becomes very difficult to incorporate large level shifters in a system's design. Thus, to date, there has been no way of designing around the affects of incorporating high voltage level shifters in a system. In particular, high-voltage signals in a electronic system leads to high-voltage components which are larger than low-voltage components. Secondly, another deficiency of high-voltage level-shifters is that they are slow. Primarily, because the high-voltage components are large, these components cannot be switched as fast as low-voltage components.
Referring to known a high-voltage level-shifter 10 as is displayed FIG. 1, a low-voltage input signal IN1 is level-shifted to an high voltage output signal Out1. Transistors, MN1 and MN2, provide the level shifting function to shift a voltage applied at the input signal node IN1 to a signal at the output node Out1. Transistors, MP1 and MP2, protect the drain-to-source voltage Vds and gate-to-source voltage Vgs of transistors, MP4 and MP3. Diodes, D2 and D1, only provide protection for the gate-to-source voltage Vgs of transistors, MP2 and MP1. A high voltage reference HVref1 is applied to gate of transistors, MP2 and MP1, such that the source of each transistor, MP2 and MP1, will not go one gate-to-source voltage Vgs above the HVref1 signal. This design for a high voltage level-shifter is troublesome in that it requires a large and complex circuit to provide a high voltage reference HVref1.
FIG. 2 shows the another known level-shifter 20 that is self-biased, wherein a low-voltage input signal IN2 is level shifted to an high voltage output signal Out2. Transistors, MN3 and MN4, are switched on and off to provide the level-shifting feature of level-shifter 20. Transistors, MP6 and MP5, protect the drain-to-source voltage Vds and gate-to-source voltage Vgs of transistors, MP8 and MP7. As shown, a current source I1 is pulled through two reverse bias Zener diodes, D4 and D3, which have a 6.5V breakdown voltage for this particular technology. Those skilled in the art would recognize that even if a Zener diode has a 13V breakdown voltage, the only requirement is that the breakdown voltages of diodes, D4 and D3, must correspond with the vgs of transistors, MP5 and MP6. Diodes, D4 and D3, provide the high voltage reference signal which is applied to each gate of transistors, MP5 and MP6, such that the source of each transistor, MP5 and MP6, will not go one gate-to-source voltage Vgs above the high voltage reference signal.
The difference between the design of high voltage level-shifter 20 and the design of the level-shifter 10 in FIG. 1 is the way in which the high voltage reference signal HVref1 is generated. This approach, however, requires the external current source I1.
Thus, there exists a need for a self-biased high voltage level shifter that provides level shifting a low voltage signal (<5V) to a high voltage signal (˜40V), with no static power dissipation while still protecting all devices. Furthermore, there exists a need for a simple, yet, cost-effective design that does not require an external current source.
The present invention is directed to overcoming, or at least reducing the effects of one or more of the problems set forth above.


A fuel cell system installed in a fuel-cell movable body. The system includes a fuel cell for generating electric power using reaction gases; a plurality of sensors for measuring states of the fuel cell; an abnormal state detecting device for detecting an abnormal state of at least one of said plurality of sensors; a substitution possibility determining device for determining whether there are one or more substitution sensors from among said plurality of sensors, each substitution sensor outputting a signal value used for setting a substitutional value for a signal value output from the sensor whose abnormal state has been detected; and a predetermined operation control device for operating the fuel cell in a predetermined operation state when the abnormal state of the sensor is detected by the abnormal state detecting device and it is determined by the substitution possibility determining device that there is no substitution sensor.

1. Field of the Invention
The present invention relates to a fuel cell system.
Priority is claimed on Japanese Patent Application No. 2005-177592, filed Jun. 17, 2005, the content of which is incorporated herein by reference.
2. Description of the Related Art
In a known fuel cell system having a plurality of sensors for detecting operation states of a fuel cell, when a specific sensor (e.g., an air flow rate sensor, a hydrogen inlet pressure sensor, or a cooling water inlet pressure sensor) has an abnormal state, a substitutional value with respect to a signal value output from the sensor in the abnormal state is computed based on a signal value output from another sensor (e.g., an air temperature sensor, a hydrogen outlet pressure sensor, or a cooling water outlet pressure sensor) in a normal state, and the operation of the fuel cell is continued in accordance with the computed substitutional value (see, for example, Japanese Unexamined Patent Application, First Publication No. 2004-179127).
In the fuel cell system relating to the above conventional technique, the fuel cell is operated in accordance with signal values output from the plurality of sensors, and only a substitutional value for the signal value output from a sensor in the abnormal state is computed based on a signal value output from another sensor in the normal state. Therefore, if the sensor necessary for computing the substitutional value enters an abnormal state, it is difficult to continue the operation of the fuel cell. For example, when the fuel cell system is provided for supplying electric power to a driving source of a vehicle, it may be difficult to run the vehicle.
In addition, if redundant or excessive sensors are provided for computing a substitutional value for a target sensor, the structure of the fuel cell system is complicated, thereby increasing the cost necessary for implementing the structure.

Fuel cell system for setting predetermined operation state when substitutional value control is impossible


An exhaust gas recirculation (EGR) system for use in a four-stroke, internal combustion, compression-ignition engine having at least one engine cylinder, at east one combustion chamber, at least one intake valve and a crankshaft. The EGR system includes at least one exhaust gas intake valve that is opened during at least a portion of an engine intake stroke when the exhaust gas pressure is greater than the pressure of gas in the combustion chamber, thus allowing exhaust gas to flow into the combustion chamber to establish internal EGR. A cam-operated intake rocker arm assembly has the form of both a first class lever and a second class lever. The first class lever directly communicates motion of the intake rocker arm assembly to open the intake valve, and the second class lever communicates motion of the intake rocker arm assembly through a hydraulic transfer assembly to open the exhaust gas intake valve.

1. Field of the Invention
This invention relates to exhaust gas recirculation (EGR) systems, and more particularly to EGR systems that draw a portion of exhaust gases through valves back into combustion chambers of four-stroke, internal combustion, compression-ignition engines.
2. Background Art
Exhaust gas recirculation (EGR) is a known approach to reducing diesel engine emissions. In typical internal combustion engines, fuel is mixed with air and ignited in a combustion chamber. Air comprises roughly 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases. Fuel and oxygen take part in combustion and, at sufficiently high temperatures, normally inert nitrogen reacts with the oxygen to form nitric oxide (NO). Upon being released into the atmosphere, nitric oxide readily oxidizes to form toxic nitrogen dioxide (NO2). This can be photochemically decomposed by sunlight to form nitric oxide and atomic oxygen, and the latter can initiate a reaction to form ozone.
Temperature has the greatest influence on the rate of formation of nitric oxide from atmospheric nitrogen. The reduction of combustion temperatures in an engine generally reduces the production of oxides of nitrogen (NOx), and combustion temperatures can be reduced by the presence in combustion chambers of a portion of exhaust gases produced during a previous cycle of the engine.
There are three common methods for ensuring the presence of exhaust gases. The first includes an external EGR system that routes a portion of exhaust gases from an engine's exhaust manifold to an engine's intake manifold. In this method, the exhaust gases are mixed with intake air before being drawn into the engine's combustion chambers through its intake valves. The second method retains a portion of the exhaust gases from a previous cycle within the engine's combustion chambers. The third method includes an internal EGR system that draws a portion of the exhaust gases from a previous cycle back into the engine's combustion chambers through its exhaust valves. The present invention represents a novel device for drawing exhaust gases into combustion chambers through valves controlled by intake rocker arms.

Internal EGR for an internal combustion engine


Gel plugs that can be stored in a sealed condition and delivered individually to an electrophoresis gel as standards for electrophoretic separations are retained in a cartridge that is cleanly breakable into individual sections, each section retaining a gel plug of predefined dimensions with standard solute mixtures embedded in the plug. The separation of any single section from the cartridge exposes opposing edges of the gel plug which permits the user to insert an implement into the section interior and to urge the plug out of the section and into a well of an electrophoresis gel. All manipulations are performed without any need for contact between the user and the gel.

1. Field of the Invention
This invention resides in the materials and equipment used in performing slab gel electrophoresis, and particularly in the use of standards for facilitating the analysis of solute mixtures separated by electrophoresis.
2. Description of the Prior Art
One of the most effective, convenient, economical, and commonly used methods of analyzing biochemical mixtures in the investigations done in clinical and research laboratories is slab gel electrophoresis, a technique which allows a series of samples to be analyzed simultaneously and the results detected on a qualitative basis by direct visual observation or on a quantitative basis by instrumentation. For these reasons, slab gel electrophoresis is widely used for analyzing protein mixtures in cell lysates and other biological samples, nucleic acid mixtures in DNA sequencing operations, and any of the wide variety of analyses of this sort that are commonly performed by biologists and biochemists. The two-dimensional shape of a slab gel makes it useful in horizontal pulsed-filed electrophoretic separations, such as the CHEF® system of Bio-Rad Laboratories, Inc., Hercules, Calif., USA, and in two-dimensional electrophoretic separations, where the slab gel serves as the second dimension of the separation, following a linear first dimension separation which is typically performed by isoelectric focusing in an immobilized pH gradient (IPG) strip gel. These are only examples; other applications of slab gel electrophoresis will be readily apparent to the skilled biochemist.
Analyses of protein or other solute mixtures by slab gel electrophoresis are helped considerably by the use of standards which may consist of mixtures of proteins, nucleic acid fragments, or whatever type of species is appropriate to the analysis, each mixture having a known composition for separation in the same gel alongside the samples to be analyzed, providing a comparison by which the components of the sample can be identified. These standards can assume a variety of forms. Paper standards for example are often used in when electrophoresis is performed in vertically oriented slab gels, i.e., when the gel is oriented such that the direction of migration is vertical, and gel plug standards are often used when the slab gel is oriented such that the direction of migration is horizontal. In each case, the standard is commonly loaded onto the slab gel in a position adjacent to the samples to be analyzed. When the gel is the second dimension of a two-dimensional separation, the first-dimension gel strip is placed along one edge of the gel and the standard is placed along the same edge at one end of the gel strip.
Among the various standards that are commercially available are precast gel plugs of Bio-Rad Laboratories, Inc. A set of plugs of agarose that contain DNA size markers embedded in the agarose are available from this supplier under the product name "DNA Size Marker, H. wingei" (Catalog No. 170-3667). To use this product, the user cuts a plug to the desired dimensions with a razor blade and then inserts the cut plug into the slab gel with a flat-bladed implement referred to as a "spatula." The use of these plugs thus involves individual handling of the plugs by the user which makes the procedure susceptible to user error and the possible loss of gel plug material. The same supplier also supplies plug kits that include plastic molds to enable one to cast one's own standard-containing agarose plugs in the laboratory. These kits are available under the product names "CHEF Mammalian Genomic DNA Plug Kit" (Catalog No. 170-3591), "CHEF Bacterial Genomic DNA Plug Kit" (Catalog No. 170-3592), and "CHEF Yeast Genomic DNA Plug Kit" (Catalog No. 170-3593). The casting of these plugs by the user adds to the tasks that the user must perform and, like the preformed plugs, requires the handling of individual pieces of gel material by the user.
Among the other standards of the prior art are those of New England Biolabs, Inc., Beverly, Mass., USA. The New England Biolabs standards consist of modified syringes filled with agarose with standards embedded in the agarose. These standards are sold under the product names "Yeast Chromosome PFG Marker" (Catalog No. NO345S), "Lambda Ladder PFG Marker" (Catalog no. NO340S), and "Low Range PFG Marker" (Catalog No. NO350S). To use these standards, the user depresses the syringe plunger to extrude the agarose containing the embedded standards, then slices off the desired amount for insertion in the gel. Similarly to the products described in the preceding paragraph, this entails the handling of a bare plug by the user.
These and other limitations of the prior art are addressed by the present invention.

Device for storage and delivery of standards for gel electrophoresis


Several embodiments of electrical circuit devices and systems with clock distortion calibration circuitry are disclosed herein. In one embodiment, an electrical circuit device includes an electrical circuit die having clock distortion calibration circuitry to calibrate a clock signal. The clock distortion calibration circuitry is configured to compare a first duty cycle of a first voltage signal of the clock signal to a second duty cycle of a second voltage signal of the clock signal. Based on the comparison, the clock distortion calibration circuitry is configured to adjust a trim value associated with at least one of the first and the second duty cycles of the first and the second voltage signals, respectively, to calibrate at least one of the first and the second duty cycles and account for duty cycle distortion encountered as the clock signal propagates through a clock tree of the electrical circuit device.

Clock signals are used to coordinate actions of electrical circuits in electrical circuit devices. In some devices, these signals can be single-ended clock signals where a signal is transmitted by a voltage and is referenced to a fixed potential (e.g., a ground node). In such devices, one conductor carries the clock signal while another conductor carries the reference potential. Other electrical circuit devices can use a differential clock signal that employs two complementary (e.g., inverse) voltage signals to transmit one information signal. A receiver in such devices extracts information by detecting the potential difference between the complementary voltage signals. Each complementary voltage signal is carried by its own conductor, which means that differential-signaling often requires more wires than single-ended signaling and, thus, more space. Despite this disadvantage, differential signaling has many benefits over single-ended signaling. For example, because the two voltage signals have equal amplitude and opposite polarity relative to a common-mode voltage, return currents and electromagnetic interference generated by each signal are balanced and cancel each other out, which is an advantage especially noticeable at high frequencies. This, in turn, also reduces crosstalk to other nearby signals. In addition, electromagnetic interference or crosstalk introduced by outside sources is often added to each voltage signal, so the magnitude of the interference or crosstalk is reduced when a receiver takes a potential difference between the two signals. Furthermore, differential signaling provides a more straightforward logic state determination procedure, allows for more precise timing, and maintains an adequate signal-to-noise ratio at lower voltages. Even so, neither type of clock signaling is immune to duty cycle distortion.
A duty cycle of a clock signal is a ratio of the pulse time of the clock signal to its cycle period. A duty cycle of a clock signal can become distorted due to a variety of sources, including amplifiers that make up a clock tree, large propagation distances between amplifier stages of the clock tree, and/or parasitic conductor capacitance. Distortion of the duty cycle skews timing margins defined by the clock signal in electrical circuit devices. As a result, an electrical circuit using the distorted clock signal can have smaller timing windows in which to transfer and/or process data, which could lead to reduced pulse widths, data errors, and unreliable circuit performance. As input/output speeds increase (e.g., as the cycles of a clock signal are reduced), it also becomes increasingly more challenging to reduce duty cycle distortion, meaning that the consequences of duty cycle distortion at high input/output speeds are even more apparent. In addition, electrical circuits at different locations (e.g., on different electrical circuit dies) can experience varying degrees of duty cycle distortion of a clock signal due to differing sources of distortion located along the corresponding clock branches of a clock tree that define the clock signal pathways. Thus, it is desirable to mitigate duty cycle distortion of a clock signal at points along the clock signal pathways closest to electrical circuits, especially as input/output speeds increase.

Internal clock distortion calibration using DC component offset of clock signal


A solution is provided wherein only primary keys are used as meta-data to construct many-to-many relationships between table, resulting in amore robust, efficient database structure. Once tables of user-specific data are bound to the database as meta-data using their primary keys, the system may automatically ensure the handling of the records as related units. This eliminates the traditional heavy-weight dependence on foreign key relationships.

A relational database stores data in a number of disparate tables, each of which is linked or related to another table. A table is organized by rows and columns, each row or record containing the same columns or fields. A conventional flat-file database would store all the data in a single table, but the relational model allows for maximum flexibility for querying the data. Data need only be brought together for a particular query, so the structure of the database contains no assumptions about what sort of queries may be required in the future. Another powerful feature of the relational model is that each data item appears only in a single place in the tables and thus only needs to be updated in one place when it changes.
In the relational model, each table has a primary key, which is a field or combination of fields that uniquely identifies each record in the table. The primary key provides a means to distinguish one record from all others in the table.
When a field in one table matches the primary key (or a candidate key) of another table, the field is referred to as a foreign key. The foreign key is the anchor on the many side of a one-to-many or many-to-many relationship, much as the primary or candidate key is the anchor on the one side of this relationship. A foreign key is a linchpin used to ensure that invalid data is not entered into a table. It also prevents a user from deleting or updating in a way that might leave orphan rows.
There are several different classes of relationships possible using a relational model. The first is a one-to-one relationship. Two tables are related in a one-to-one relationship if, for every row in the first table, there is at most one row in a second table. True one-to-one relationships seldom occur in the real world. This type of relationship is often created to get around some limitation of the database management software rather than to model a real-world situation. For example, one-to-one relationships may be necessary in a database when there is a need to split a table into two or more tables because of security or performance concerns. Tables that are related in a one-to-one relationship share the same primary key.
A second type of relationship is a one-to-many relationship. Two tables are related in a one-to-many relationship if, for every row in a first table, there can be zero, one, or many rows in a second table, but for every row in the second table there is exactly one row in the first table. The one-to-many relationship is also referred to as a parent-child or master-detail relationship.
A third type of relationship is a many-to-many relationship. Two tables are related in a many-to-many relationship when, for every row in a first table, there can be many rows in the second table, and for every row in the second table, there can be many rows in the first table. Many-to-many relationships can't be directly modeled in the typical relational database, and therefore these types of relationships must be broken into multiple one-to-many relationships. A third table, known as a linking table, may then be utilized to model the relationships between the two tables.
Regardless of the type of relationship used, past relational models utilized foreign keys for the "many" side of the relationship (except for one-to-one of course). These foreign keys, however, must be constantly managed to ensure that no errors occur in the storage of the data. This wastes both computing power and memory space. Additionally, the traditional heavy-weight dependence on foreign key relationships causes tables to have database enforced key constraints, which limits the ability of a user to easily add new tables or permutations.
What is needed is a solution that eliminates the traditional heavy-weight dependence on foreign key relationships in order to allow users to add new tables or permutations without restrictions.