A process for determining 3-D data of at least one prepared jaw area, such as a prepared tooth stump, by mechanically scanning the jaw area and digitizing the measured values determined during the scanning. The jaw area is prepared with a dental instrument having positions which are optically measured during the preparation, and the 3-D data is determined from the positions of the dental instrument that are associated with the prepared jaw area.

The invention relates to a process for determining 3-D data of at least one prepared jaw area such as a prepared tooth stump by mechanical scanning of the jaw area and digitizing the measured values determined during the scanning.
A process for the production of a denture consisting of ceramic material can be gathered from EP-A-0 580 565. In it, a prepared tooth in the mouth of a patient can be optically or mechanically photographed in order to then produce the denture from the values determined in this manner and digitized by a milling machine.
Other processes provide that an impression is taken of the prepared jaw area, in particular a tooth stump, in order to produce a positive model that is scanned and digitized (EP-B-1 067 880).
All processes, whether a direct scanning in the patient's mouth, or a scanning of an impression require a completely or almost completely prepared jaw area in order to obtain the desired 3D data. In the case of a partially defective impression or not completely scanned jaw area there is then the possibility, as a function of the software used, of supplementing missing data or of removing obviously inappropriate data in order to avoid that the denture produced is defective.
The present invention is based on the problem of further developing a process of the initially cited type in such a manner that the 3-D data required for the production of the denture can be determined without expensive scanning processes or the production of a positive model being necessary.
In order to solve the problem the invention substantially provides that the jaw area, such as a tooth stump, to be prepared is prepared with a dental instrument whose positions are optically measured during the preparation and that the 3-D data is determined from the positions of the dental instrument that are associated with the prepared jaw area. The positional data of the dental instrument during the preparation of the jaw area is used for the determination of the final contour of the prepared jaw area. Therefore, it is not necessary that the jaw area is at first prepared and is subsequently scanned with a separate apparatus. This is time-consuming and expensive on account of the various apparatuses used. In contrast thereto, according to the invention the jaw area is tactilely scanned simultaneously with the preparation of the jaw area in order to make the required digitized measured values available after the conclusion of the preparation in order to be able to make a denture.
In order to make possible the determination of the position of the dental instrument, it is provided with optically effective markings that are detected by an optical sensor for the spatial determination of the position of the dental instrument. In particular, the dental instrument is a drill for preparing the jaw area.
In general, the dental instrument should consist of a handle such as a hand grip and of a replaceable insert such as, e.g., a drill. The handle should have markings so that one and the same handle can be used for different inserts or tools.
When an insert is replaced the different effective geometry of the inserts must be taken into account and a calibration is to be carried out.
In order to ensure an unambiguous determination of the position and therewith of the geometry, it is furthermore provided that the dental instrument is calibrated before the preparation by scanning a normal such as a sphere. These types of measures are sufficiently known from the technology for measuring coordinates in conjunction with the tactile measuring of workpieces so that these previously known measures are referred to and reference is explicitly made to them.
A further development of the invention that is to be emphasized provides that the positions of the dental instrument are determined taking into consideration any movement of the jaw area. In other words, the movement data of the dental instrument is offset against the movement data of the jaw in order to be able to calculate the 3-D data record.
To this end a position sensor arranged stationarily relative to the jaw area can be associated with the jaw area. The position sensor can comprise optically effective markings stationarily associated with the jaw area and can comprise an optical sensor that detects the movement of the markings. However, an inertial platform can also be used for determining positions whose data is offset with that of the optical sensor, by means of which the movements of the dental instrument are detected.
In particular, light sources such as LEDs or optical reflectors are used for the first and/or second optically effective markings. In the latter instance it is necessary that the reflectors are loaded with light in order to be able to detect the reflected light with the optical sensor such as a camera.
The 3-D data corresponding to the prepared jaw area is then processed in order to produce a denture by a software, in particular CAD software, which denture can fit on the jaw area, in order to then produce the desired denture by a CAM program from a blank, in particular consisting of porous and pre-sintered ceramic material. This basically takes place by milling. However, the denture can alternatively also be produced on the basis of the 3-D data in a building-up process such as rapid prototyping.
A further embodiment of the invention to be emphasized provides that the inner contour of the denture is determined and calculated from the 3-D data determined by the positional determinations of the dental instrument and that the outer contour is determined and calculated from determined digitized data and/or data taken from a library from scanning the jaw area surrounding the jaw area to be provided with the denture.
The teaching of the invention, the working of the jaw area and the simultaneous determination of the final contour in a single process have the advantage that measuring uncertainties during touching present regarding tactile measuring do not occur. As regards intraoral scanners, there is the advantage that no preparation edge must be exposed because it is frequently required during contactless scanning that the gum on the preparation boundary is pressed away by a thread. Translucency of the tooth or liquid in the jaw area are not a problem during the determination of the contour. Problematic gingiva is pressed away by the dental instrument during the preparation.
In particular, a rotating tool such as a drill is used as dental instrument in which the receptacle or handle of the rotating tool has at least three optical markings such as light-emitting diodes that are detected by a receiver in order to detect the spatial position of the tool in this manner. Due to the ability of the rotating tool to be replaced, it is necessary when using a new rotating tool that a calibration or teaching takes place on a normal such as a reference sphere.
According to the invention an outline is formed during the preparation that corresponds to the form of the prepared jaw area such as a tooth stump. The movement of the patient is additionally considered in order to avoid measuring errors.
In particular, the process of the invention is used to produce caps, a frame or an inlay. An exceedingly precise determination of contour takes place.
In contrast to the above, it is basically not necessary to take into account a possible relative movement of the jaw area to be prepared to the jaw itself since the cutting forces occurring during the preparation are so small that distortions of the measured values are excluded.
In order to initiate a measuring procedure the cutting in of the tool or, e.g., a power change of the tool can be used that occurs when the drill comes in contact with the jaw area to be prepared and the working begins.
In the case of a drill as dental instrument the movement of a rotating tool guided by the preparing person such as a dentist is detected. In order to detect the movements of the drill several optical markings such as LEDs are applied on it or on its holder. The calibration of the tip of the rotating tool to the optical marking takes place by touching a normal such as a reference sphere at several positions.
In order to detect the movement of the jaw a platform with at least three optical markings or an inertial platform is stationarily connected to the jaw. The sensor detecting the jaw movement can be fastened on a face leading to the jaw or in a bite block arranged between the lower and the upper jaw. The jaw movement can be detected by the optical sensor that determines the movement of the dental instrument. However, a separate sensor can also be used that stands in a stationary relationship to the optical sensor for the dental instrument.
In order to also digitize areas that are not prepared, it is provided that the dental instrument scans the areas of the jaw area such as at least one tooth and if required necessary parts of the jaw ridge, which areas are not provided for working in the course of the treatment phase. This yields data that can be used for the calculation of the outer contour of a denture to be produced.
Independently of the above, a further development provides that the preparation boundary is determined with a separate feeler or with an insert such as a feeler pin which insert can be provided with a dental instrument or its handle.
According to the invention a dental instrument used to prepare a jaw area is used at the same time as an oral scanner.
Further details, advantages and features of the invention result not only from the claims, the features to be gathered from them whether alone and/or in combination but also from the following description of preferred exemplary embodiments to be gathered from the drawings.

Method for determining 3-D data from at least one prepared maxillary area


A hydrophone-filter with the frequency response characteristics of a geophone utilizes a second order high pass filter wherein one capacitive element of the filter is the hydrophone itself. The filter includes an amplifier, wherein one input receives a biasing voltage from a resistive network, and the other input receives a signal provided by one or more hydrophones. The filter also includes one or more capacitive elements and one or more resistive elements. The natural frequency and slope of the filter depend upon the values of the capacitive elements of the circuit, including the capacitance of the hydrophones, as well as the values of the resistive elements of the circuit. Advantageously, the natural frequency of the hydrophone-filter remains constant even if the magnitude of the hydrophone's output changes.

1. Field of Invention
The present invention relates to hydrophones employed in seismic exploration. More particularly, the invention relates to an improved hydrophone circuit that provides the electrical characteristics of a geophone by employing a second order high pass filter, wherein one capacitive element of the filter is a hydrophone.
2. Description of Related Art
Due to the increasing difficulty and cost of finding petroleum resources in the world today, exploration techniques are becoming more and more technologically sophisticated. For example, many have found crystal hydrophones to be useful in petroleum exploration. Basically, hydrophones are used to measure seismic waves created by a source such as an air gun or a dynamite charge, to obtain detailed information about various sub-surface strata of earth.
As shown in FIG. 1, a typical crystal hydrophone 100 includes a diaphragm 102, a crystal 104, and a housing 106 that is typically filled with a gas 107. The diaphragm 102, which has front and rear sides 102a, 102b, is made from a material such as Kovar.TM. or a Beryllium Copper compound, and is electrically connected to the crystal by a conductive epoxy 108. The crystal 104 is made from a material such as Lead Zirconium Titanate, and is silver-plated on its top 104a and bottom 104b to achieve better conductivity. The crystal 104 is initially polarized by applying a high-voltage electrical charge to the crystal 104. When the polarized crystal 104 experiences pressure resulting from a physical input such as sound, fluid pressure, or another type of pressure, it produces a voltage representative of the pressure experienced. The crystal 104 is electrically connected to electrical output leads 110, 112. To protect the crystal 104 from contaminants, and to maintain the crystal 104 in atmospheric pressure, the crystal 104 and the rear side 102b of the diaphragm 102 are sealed within the gas-filled housing 106. The housing 106 protects the crystal 104 and diaphragm 102, and facilitates mounting of the hydrophone 100.
The diaphragm 102 functions to vibrate in response to physical pressures it experiences. The physical deflection of the diaphragm 102 is transferred by the epoxy 108 to the crystal 104, deforming the electron structure of the crystal 104 and causing an electrical potential to be provided across the leads 110, 112.
Another apparatus that is also useful in petroleum exploration is the geophone. Geophones are commonly used to measure the motion of the earth's surface in response to seismic waves created by a seismic source, to obtain detailed information about various sub-surface strata in the earth.
As mentioned above, hydrophones and geophones are often used in petroleum exploration in conjunction with seismic equipment. In one example of such an application (FIG. 1B), a cable 150 including one or more hydrophones and one or more geophones is placed on the sea floor 154. Such a cable may be made up of cylindrical units 152, where each unit 152 includes a gimbaled geophone and a hydrophone. An example is the "ocean bottom cable" (OBC) system manufactured by Halliburton Geophysical Services; the OBC system utilizes six model SGH-2 hydrophone-geophone units, which are also manufactured by Halliburton Geophysical Services.
Seismic waves are produced by a seismic source 156 that is towed behind a ship; the seismic source 156 may comprise an air gun, a dynamite charge, or the like. The seismic source 156 produces a large explosion, creating seismic waves 160. The seismic waves 160 travel through water 162 and various layers of earth 164, and are reflected back to the cable 150 as upgoing incident waves 161. Each unit 152 detects and measures the incident waves 161 and creates a real-time record of the results. This record is typically stored in a recorder (not shown) that is linked to or contained within the cable 150. Records of this nature help geologists determine the makeup of the earth 164.
One problem with this arrangement, however, is surface ghost signals 166. Surface ghost signals 166 are produced by incident waves 161 that are reflected from the water's surface 168. At the wavelengths typically used for seismic signals, the surface 168 provides an effective mirror to reflect incident waves 161 and create downgoing surface ghost signals 166. Surface ghost signals 166 contain no additional information regarding the composition of the earth 164 or the possible petroleum deposits therein, and they interfere with the proper receipt and interpretation of the incident waves 161. Accordingly, it is desirable to eliminate the errors introduced by the surface ghost signals 166.
A hydrophone-geophone combination, in theory, is naturally suited to eliminate surface ghost signals. Generally, hydrophones detect pressure omnidirectionally, and geophones detect velocity, which is directional. Due to the relative strengths of the incident waves 161 and the surface ghost signals 166 at different depths, a hydrophone's output and a geophone's output will both vary with depth. For a seismic wave 161 of a given magnitude and frequency, a hydrophone's output will vary with depth sinusoidally (curve 180, FIG. 1C). Likewise, for the given seismic wave 161, a geophone's output will vary sinusoidally with depth (curve 182, FIG. 1C). The hydrophone and geophone outputs may be scaled by external circuitry or by a mathematical algorithm in a computer, so that their peak values have the same amplitude; for example, in FIG. 1C, the hydrophone and geophone outputs are scaled to a maximum peak amplitude of 1 and a minimum peak amplitude of -1. After such scaling, the sum of the hydrophone and geophone outputs will always be 1, irrespective of the depth at which the hydrophone and geophone are both located (curve 184, FIG. 1C). Therefore, in theory, a hydrophone output and a geophone output may be combined to effectively eliminate the influence of surface ghost signals 166.
One problem in applying this theory is that the frequency responses of hydrophones and geophones differ. Therefore, the hydrophone and geophone outputs will only complement each other as shown in FIG. 1C when the seismic wave 160 has a certain frequency. As a result, if the frequency of the seismic wave 160 were to change, the combined hydrophone-geophone output 184 would no longer be constant.
The difference between frequency responses of hydrophones and geophones will now be explained with reference to FIGS. 2-5. When an electronic amplifier 200 (FIG. 2) is utilized to amplify the output of a typical hydrophone 202, the frequency response of the hydrophone 202 (FIGS. 3A, 3B) resembles that of a single-pole high pass filter, since it exhibits a single pole and a 6 dB/octave slope at frequencies less than its natural frequency (f.sub.n). The amplifier 200 may comprise an operational amplifier. The hydrophone may be modeled as a voltage source 202a and a capacitor 202b in series; the capacitor 202b and resistance 204 provide the single pole, and hence the 6 dB/octave slope. The natural frequency of the hydrophone 202 depends upon the value of the internal resistance 204 (R) of the amplifier 200 and the capacitance (C) of the capacitor 202b; this relationship is shown in equation 1.0, below. ##EQU1##
In contrast to the hydrophone 202, the frequency response of a typical geophone resembles a double-pole high pass filter with a 12 dB/octave slope at frequencies less than its natural frequency (FIGS. 4A, 4B). The geophone's frequency response generally explained can be understood by considering the structure of a geophone. A typical geophone (not shown) includes a coil of wire that is positioned within a magnetic field and contained within a case. The coil is suspended by springs and tends to remain fixed in space due to its mass, while the case and magnetic structure vibrate with the motion of the earth's surface. The relative movement of the electrical coil within the magnetic field induces an electrical voltage across the coil, representative of the motion of the earth's surface. A damping resistor is connected across the coil to create a loop and thereby permit current to flow through the coil in proportion to the coil's velocity relative to the magnetic field. This flowing current has the effect of damping the coil's motion due to the force placed on the electrified loop by the magnetic field. This damping facilitates a more accurate representation of the seismic signals received by the hydrophone.
This mechanical system may be modeled as an electromechanical system, a typical application of which is shown in FIG. 4C. A geophone model 400 is electrically connected to a damping resistor 402, as discussed above, and an amplifier 404. The geophone model 400 includes a voltage source 406 to represent the velocity of the geophone case multipled by the transduction constant of the geophone. The model 400 also includes a capacitor 408 to represent the mass of the moving coil (i.e., C=aM). An inductor 410 is shown to represent the spring constant of the coil suspension (i.e., L=a/k). The model 400 also includes a first resistor 412 to represent the "coil form damping", i.e., the mechanical damping of the moving coil caused by eddy currents therein. A second resistor 414 represents the electrical resistance of the coil. The damping resistor 402, in combination with the input resistance of amplifier 404 and the coil resistance 414, is selected to electrically damp the geophone's response, as discussed above. In an exemplary embodiment, the damping resistor 402 is chosen to achieve 70% of critical damping. The geophone's natural frequency is calculated as shown in equation 2.0, below. ##EQU2## A geophone's frequency response, then, resembles a high pass second order electronic filter, since the geophone's equivalent circuit contains two impedance elements: the capacitor 408 and the inductor 410. Although the geophone model 400 acts like a resonant circuit, the output signal at the natural frequency is typically 3 dB lower than the asymptotic value due to the 70% damping provided by the damping resistor 402 in combination with the input resistance of the amplifier 404 and the coil resistance 414.
For the reasons explained above, hydrophones and geophones have different frequency response characteristics. Accordingly, hydrophones and geophones are not naturally suited to eliminate ghost signals 166 across the whole spectrum of desired frequency. To use a hydrophone with a geophone advantageously, the frequency response of the hydrophone must match the frequency response of the geophone. One approach to this problem has been to cascade the output of the op-amp 200 with a circuit 500 (FIG. 5) that includes a resistor 502 and a capacitor 504. However, the frequency response of such a circuit still differs from the frequency response of a geophone. Even though the addition of the capacitor 504 provides a second pole, the modified hydrophone circuit is still not a resonant circuit, and therefore the gain at the hydrophone's natural frequency is 6 dB down rather than 3 dB down.
Due to the limitations of this approach, some have used transformers in conjunction with hydrophones to obtain a frequency response that matches that of a geophone. Although a transformer may be advantageously used to bring the output of the hydrophone into conformance with that of a geophone at a particular output level of the hydrophone, there are a number of significant limitations. In particular, the magnitude and phase of the signal produced by the transformer-coupled hydrophone varies with the magnitude of the electrical output signal produced by the hydrophone, due to non-linearities of the transformer core. Furthermore, the natural frequency of the transformer-coupled hydrophone also varies with the magnitude of the electrical output signal provided by the hydrophone. FIG. 6 shows how the natural frequencies of two sample transformer-coupled hydrophones vary over a range of different hydrophone output amplitudes. The tests of FIG. 6 were conducted with an Oyo MP-24 transformer-coupled hydrophone. The use of a transformer to configure the output of a hydrophone to that of a geophone, then, is limited, since the hydrophone's output will not compliment the geophone's output for all amplitudes of the hydrophone's operating range.
This is more clearly illustrated in FIGS. 7 and 8, which show the frequency response of a conventional transformer-coupled hydrophone. In FIGS. 7 and 8, one sample curve was taken with a first seismic input, and the other sample curve was taken with a second seismic input ten times greater than the first.
In FIG. 7, the horizontal axis represents frequency in increments of 1 Hz. The vertical axis represents the magnitude of the transformer-coupled hydrophone's output. In particular, the voltage output of the transformer-coupled hydrophone was measured and compared to the voltage output of an arbitrarily selected, standard hydrophone with excellent low frequency response. In other words, the voltage output of the standard hydrophone was constant over the range of frequencies tested. The outputs of the standard hydrophone and the transformer-coupled hydrophone under test were compared using the formula of equation 3.0, below. ##EQU3## As seen in FIG. 7, the relative magnitude of the transformer-coupled hydrophone varied when the seismic input signal was increased.
In FIG. 8, the horizontal axis represents frequency in increments of 1 Hz. The vertical axis represents the phase of the transformer-coupled hydrophone's output, in degrees. FIG. 8 illustrates that the phase of the transformer-coupled hydrophone varied when the seismic input signal was increased.
In addition to the transformer-related problems mentioned above, transformers are not always as cost efficient as might be desired. Moreover, transformers are not always as free from distortion as some might require; transformers typically suffer from non-linearity due to power losses caused by hysteresis, eddy currents, "I.sup.2 R", and other inefficient characteristics.

Hydrophone circuit with electrical characteristics of a geophone


Compounds of the formula ##STR1## wherein the variables are defined in the specification; and acid addition and quaternary ammonium salts of formula (I) compounds are described. The compounds and their salts are soft anticholinergic/antisecretory agents especially useful as mydriatics and as antiperspirants.

1. Field of the Invention
The present invention relates to certain novel anticholinergic, mydriatic and antisecretory compounds as well as pharmaceutical and antiperspirant compositions containing the novel compounds and methods of treatment of animals and humans in need thereof.
2. Prior Art
Commercially available anticholinergic drugs such as atropine and scopolamine and their synthetic analogs all share a variety of undesirable side effects. In the elderly, excitement, agitation and drowsiness are frequently observed even in small doses. Dangerous central nervous system mediated psychotic reactions and behavioral disturbances have occurred in children after topical ocular administration. Ophthalmic use may also induce local side effects such as transient stinging, allergic lid reactions, follicular conjunctivitis, edema and photophobia. See Toxicology of Commercial Products, R. E. Gosselin et al, Eds. (Williams & Wilkins, Balt., 4th Ed., 1976) Sec. III, pp. 43-46.
Mydriatic agents are an important class of compounds that are used to dilate the pupil. Mydriasis is required during ophthalmic examinations, in order to provide for a more complete examination of the fundus, the vitreous and the periphery of the lens, and in various surgical procedures such as those reported by Freeman et al, American Intra-Ocular Society Journal 7:172-173 (1981) (e.g., vitrectomy, lens extraction, and intraocular lens implantation). Commercially available mydriatic drugs such as atropine, scopolamine, homatropine and their synthetic analogs all suffer from several disadvantages. Because the mydriasis induced by these agents causes blurred vision and is of a relatively long duration, i.e., several hours, it is necessary to virtually immobilize the patient after the ophthalmic examination until the mydriasis subsides and the patient can resume normal activities. Ophthalmic use of these agents may also induce local side effects such as transient stinging, allergic lid reactions, follicular conjunctivitis, edema and photophobia. See R. E. Gosselin et al supra.
One of the commonly known effects of antisecretory agents is inhibition of eccrine sweating and compensatory cutaneous flush. Systemically administered anticholinergics do generally decrease the secretion of the sweat glands, as well as saliva and that of other secretory glands. Based on these properties, it has been long investigated how one could safely use an antimuscarinic agent to inhibit local hyperhydration by topical application. Although a wide range of compounds have proved to be highly effective as antiperspirants when applied topically, it was concluded that they are in general not safe to use because of the well-known systemic effects of these drugs at a possible over-exposure. Side effects appear even at very low concentrations when highly potent anticholinergics are used.
It would be desirable to obtain practically exclusively locally acting agents, which is possible if the rate of penetration-absorption and the rate of in vivo destruction are well-balanced: if the latter is faster, no buildup and consequently no systemic effects due to the drug would be observed.
New drug design approaches can lead to novel, safer anticholinergic drugs with fewer side effects. One new approach that has shown promise is the soft drug design proposed by Bodor (Bodor, Chemtech, Jan. 28, 1984, pp. 28-38, and Bodor, in Design of Biopharmaceutical Properties Through Prodrugs and Analogs, ed. E. B. Roche, Washington, D.C., Academy of Pharmaceutical Sciences, 1977, pp. 98-135) and used to design and synthesize anticholinergic agents and other pharmacologically active classes of drugs. Previous soft ester analogs of anticholinergics were synthesized from cyclopentylphenylacetic acid, phenylacetic acid and branched aliphatic carboxylic acids. These soft drugs, also known as soft analogs, are described in U.K. Patent Application No. 7848850, filed Dec. 18, 1978 and published under U.K. Patent Application Publication No. 2010270A on Jun. 27, 1979, and in a related publication by Bodor et al, J. Med. Chem. 23, pp. 474-480 (1980). Nevertheless, it would be desirable to design yet other soft anticholinergic drugs, especially to design such drugs using the "inactive metabolite approach". According to this approach, an inactive metabolite (which could be hypothetical) is selected and reactivated by synthesizing an agent resembling the parent drug. The soft drug is designed with a molecular soft spot which should predictably metabolize back to the inactive starting metabolite in vivo in one step and without going through toxic intermediates.
It is an object of the present invention to provide such novel anticholinergic compounds which exhibit anticholinergic properties, which induce mydriasis and which also exhibit local antisecretory, especially antiperspirant, properties as well as pharmaceutical and antiperspirant compositions and methods of treatment embodying those compounds which are more effective and less toxic than those presently available.

Anticholinergic compounds, compositions and methods of treatment


An article comprising an electrodeposited aluminum alloy is described herein. The electrodeposited aluminum alloy comprises an average grain size less than approximately 1 micrometer. The electrodeposited aluminum alloy thickness is greater than approximately 40 micrometers. A ductility of the electrodeposited aluminum alloy is greater than approximately 2%.

Electrodeposited stable nano structured aluminum manganese alloys exhibit an exceptional combination of high hardness and tensile ductility. In addition to the combination of high hardness and tensile ductility, the alloys are approximately the same density as other aluminum alloys. This combination of high strength, ductility, and light weight make it an ideal structural material for applications such as armor, aircraft, sporting equipment, and other applications where a light weight high strength ductile material would be of benefit.

Articles comprising an electrodeposited aluminum alloys


A method of and device for removing a liquid from a resin of high melting point by means of a co-rotating twin extruder and an operation system of a liquid removal molding of a resin of high melting point by which a scaled down, highly effective, high performance and continuous stable operation of the device may be achieved.

(1). Field of the Invention
The present invention relates to a method of removing liquids from water containing resin of high melting point over 200.degree. C., and more particularly to a monitoring system for removing liquids from the high melting point resin by melt-kneading in a co-rotating twin screw extruder for removing the water component with extrusion, and method and apparatus as well as molding thereof.
(2). Background Information
Generally, resin materials produced in a polymer manufacturing process of thermoplastic resins or ground materials produced in a recycling process of the waste plastic products (hereinafter simply referred to as resin materials) contain a relatively large quantity of liquid so that a liquid removing process is required to remove the water component at the end of each process.
Hitherto, in a manufacturing process of ABS (acrylonitrile butadiene styrene) resins for example, a flow drying oven and the like have conveniently been used. ABS latex manufactured by an emulsion polymerization may be obtained as a slurry which contains a large quantity of liquid after coagulation and water washing. As a method of removing liquids, the slurry is supplied into a centrifugal dehydroextruder for obtaining a water containing powder or a wet cake containing water in the range of 30%-40%. The water containing powder is dried until the water content reaches 1% by heat energy using a drying pipe and a flow drying oven to avoid compounding by an extruder in the final process, a vent-up and a blowing phenomenon in a granulation process.
In the drying process, the approximately 30%-4% water component of the powder or cake is vaporized by consuming large quantities of heat energy and time. The powder of lower water content in almost dried state is associated with a risk of dust explosion so that the device as a whole needs to be isolated from oxygen with a hot nitrogen gas and a larger scale of the facility.
A resin material of approximately 1% water content is supplied to a co-rotating twin screw extruder for the ultimate dryness followed by compounding and granulating.
For a scale down version of the device, a method of removing liquids by means of a co-rotating twin screw extruder has been proposed. A water removing system of this type generally comprises a squeeze process and a vaporization process.
In the liquid removing method of the squeeze type as illustrated in FIG. 9, for example, a co-rotating twin screw extruder 10 is mounted with a co-rotating twin screw 14 in a barrel 12 and provided with a material feeding section (or port) 16 to which is supplied a mixture of a water containing powder 30a, a pellet 30b and a process adjuvant 30c of the resin material 30 from which liquids are previously removed by a centrifugal hydroextruder 32. It is proposed to provide such structure so that the resin material within the mixture is squeezed at the liquid removing screw portion (not shown) of the screw 14 so that the resin material is mold-extruded as a solid from a delivery (outlet) 18.
ABS water containing powder 30a of water content of 30%-40% reduced by the centrifugal hydroextruder 32 is supplied to the material feeding section 16 at the uppermost stream of the co-rotating twin screw extruder 10 together with other materials such as SAN (styrene and acrylonitrile copolymer) pellet 30b and the process adjuvant 30c. The material supplied to the material feeding section 16 is conveyed effectively to the lower stream without retention by the twin screw 14 having a self-cleaning finction. The material being conveyed is squeezed by a liquid removing screw portion 24 comprising a kneading block and a reverse-flighted screw provided in the twin screw 14, whereby the material is elastically or plastically deformed for reduction of the specific volume of the material so that the water component in the material is removed as a liquid.
The liquid separated flows in reverse through the screw channel against the upper stream of the liquid removing screw portion 24 along a pressure gradient directing from a maximum pressure point of the liquid removing screw portion to the material feeding section 16 and is discharged from a delivery 20 (water removing screen) provided between the upper stream of the liquid removing screw 24 and the material feeding section 16. At this section, approximately 30%-90% of the entire water component in the resin material is separated and discharged, and approximately 10%-70% of the remaining water component is separated and vaporized through vent holes 22a, 22b and 22c of the vent portion provided at the lower stream of the liquid removing screw, and is finally vaporized through the vent hole 22c and the resin is extruded from the delivery 18.
According to the liquid removing method of the aforementioned type, a certain quantity of water is removed from the resin material in the form of liquid without vaporization so that water vaporization energy effectiveness may be improved. Since the wet material is used, a risk of dust explosion may be avoided without any particular device for sealing oxygen with minimized scale of a facility. Further, in accordance with the liquid removing method of this type, continuation of the manufacturing process, simplification of the multi-stage processes and drastic rationalization of the manufacturing process may be achieved.
In the liquid removing method of the squeeze process as proposed in FIG. 10, for example, a method of removing the liquid is similar to the aforementioned system but a method of discharging the liquid is different. Namely, in the former method of the squeeze process, a separated liquid is flowed in reverse and discharged from the liquid removing screen located in the upper stream of the liquid removing screw portion. In the process shown in FIG. 10, however, to separate and evaporate water the liquid removing portion 34 is provided with a discharge port 35 at a portion where the resin material is compressed and with a vent staffer means 36 to prevent a material from flowing out the discharge port. Other structures are the same as those of the liquid removing method as hereinbefore described.
The liquid removing method free of water reverse flow may expand the operational conditions and this method is well tolerated to a recycling process of the waste plastics.
Further, another liquid removing method of the vaporization process has been proposed as illustrated in FIG. 11 where SAN pellet and water containing ABS powder are supplied into the twin extruder 10 from different places.
Namely, to remove the liquid SAN (styrene and acrylonitrile copolymer), a pellet 30b is supplied to the extruder 10 for quick melting, to which preheated water containing ABS powder 30a with the process adjuvant are added by means of a side feeder 37 having a preheating means in the middle portion of the extruder. Thus, the water component is steamed by an enthalpy of the molten SAN so that the separated and vaporized steam is discharged from the vent holes 22a, 22b and 22c of the vent portion 22.
Accordingly, in the liquid removing method of the type as hereinbefore described, the wet material is also used to avoid any risk of the dust explosion without necessitating any facility to isolate oxygen and to minimize an arrangement. A residual monomer value obtained after devolatilization from the vent hole 22c is better than that of the liquid removing method of the squeeze process as hereinbefore described and the liquid removing method of this type is well tolerated in the case where a material of two components, for example, containing ABS diluted by SAN is adopted.
In the aforementioned conventional liquid removing method of the squeeze process, however, a melting point, a glass transition point or a heat distortion temperature is extremely high as compared with a boiling point of water, and when liquid is removed from the solid resin material of more than 10% water content by means of the co-rotating twin extruder, more power is required as compared with that of the material of low melting point such as ABS. Namely, according to the conventional liquid removing method, a water containing material is squeezed by a propelling force of the screw at the squeeze liquid removing screw comprising a kneading block and/or a reverse-flighted screw provided in the extruder in order to remove liquid by an elastic or plastic deformation. The materials of low melting point such as ABS have the melting points which are similar to or lower than the boiling point of water so that they are elastically or plastically deformed at a relatively lower temperature and pressure by a minimized energy of the screw for the material and a smaller power of the extruder.
Materials of high melting points such as engineering plastics, however, have a melting point, a glass transition point or a heat distortion temperature that is extremely higher than the boiling point of water and may not conveniently be elastically or plastically deformed. For convenient deformation, a temperature of the material at the squeeze liquid removing screw portion may be elevated, notwithstanding that a heat energy may not be supplied to satisfy the necessary evaporation latent heat. Accordingly, it is inevitable to increase the pressure of the squeeze liquid removing screw portion to an extremely high level by applying a large quantity of energy from the screw to the material resulting in an expansion of the power supply. In the co-rotating twin screw extruder where the screw torque is limited on account of the mechanical strength, a large power is required to remove the liquid with reduction of the processing capacity and deterioration of the energy effectiveness losing advantages described hereinbefore.
For example, when resins of high melting points are subjected to the liquid removing procedure without using any particular screw for increasing the pressure at the squeeze liquid removing screw portion or any other means necessary for increasing the power, water is not discharged from the discharge port and a flake up phenomenon occurs to flow the material up from the vent portion at the lower stream. To remove the liquid from the resins of high melting points using such a conventional liquid removing method results in loss of the advantages of liquid removal molding by means of the twin screw extruder which purports to provide an improvement in the energy effectiveness with worthlessness as an industrial facility.
The aforementioned conventional liquid removing method of the vaporization process is effective to the materials containing more than two components of a combination of the water containing materials with other resins but is not applicable to the engineering plastics containing of essentially one component and having a high melting point.
The liquid removing method of this kind stands on an energy balance between water containing materials and other materials. Generally, an evaporation latent heat is greater than an enthalpy of molten resin, and the liquid remove molding method may not be carried out because of loss of the energy balance when water content of the resin material is increased on account of increments of the water content and mixing ratio of the water containing materials, and in this situation, a flake-up phenomenon appears to fly up the material from the vent portion at the lower stream. According to the heat balance of the ABS liquid remove molding method, the water content of the resin material is generally limited to the range of 8%-10%.
The conventional liquid removing method is not applicable to the liquid remove molding of the engineering plastics of essentially one component and even if applicable, the scope of the application is extremely limited because of the energy balance.

Device and monitoring system for removing liquid from high melting point resin by means of co-rotating twin screw extruder


A method of operating a base station in a wireless communication system supporting frequency and quadrature-amplitude modulation (FQAM) is provided. The method includes receiving channel quality information and non-Gaussian information for a data region from a mobile station, and determining a MCS level on the basis of the channel quality information and the non-Gaussian information.

To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a 'Beyond 4G Network' or a 'Post LTE System'.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
In general, a signal processing procedure for wireless communication includes channel coding, modulation, frequency up-conversion, and transmission in a transmitting side. In accordance therewith, signal processing in a receiving side includes frequency down-conversion, demodulation, and channel decoding. Herein, the demodulation in the receiving side includes a procedure of calculating a per-bit or per-symbol decoding metric.
To generate the decoding metric, it is necessary to premise a specific probability distribution for an interference and noise signal. The conventional technique assumes a Gaussian distribution for an interference signal to perform decoding with a low complexity. Therefore, a quadrature amplitude modulation (QAM)-series modulation scheme is primarily used in order for the interference signal to be similar to a Gaussian signal to the maximum extent possible.
However, it is generally known that a channel which assumes a non-Gaussian distribution has a greater channel capacity than a channel which assumes the Gaussian distribution. Therefore, if decoding is performed properly, the channel which assumes the non-Gaussian distribution can have a higher decoding performance in comparison with the channel which has the Gaussian distribution.
Accordingly, there is a need to develop a modulation scheme which allows an interference signal to be similar to the non-Gaussian distribution to the maximum extent possible, and as a result, a frequency-QAM (FQAM) scheme is proposed. The FQAM method is a hybrid modulation scheme in which the QAM scheme is combined with a frequency shift keying (FSK) scheme, and has advantages of the QAM scheme having a high spectral efficiency and the FSK scheme allowing an interference signal to have a non-Gaussian distribution.
However, since the FQAM is a new technique proposed recently, a channel quality information feedback scheme different from the conventional scheme is required. A method has been conventionally used in which a signal to interference plus noise ratio (SINR) value is calculated on the basis of channel estimation using a pilot, the calculated SINR value is transmitted by quantizing it through a determined scheme, a modulation and coding scheme (MCS) level is determined on the basis of the calculated SINR value, and an MCS index corresponding to the determined MCS level is transmitted. That is, in a channel quality information feedback of a wireless communication system using the conventional QAM scheme, channel information other than the SINR value has not been used to determine the MCS level.
Since a non-Gaussian distribution for an interference signal is assumed in the wireless communication system using the FQAM scheme, it is difficult to determine an accurate MCS level when only the SINR is simply used, which causes a performance deterioration.

Apparatus and method for channel quality information feedback in wireless communication system using frequency quadrature amplitude modulation


A method for producing a pulley assembly intended primarily for use with the endless drive belt of a vehicle accessories drive system is provided. The method involves placing a circular metal insert having an axis and an outer substantially flat circumferential surface extending radially from the axis on a locating means, located inside a mold cavity and positioned around the outside circumference of the metal insert, for positioning the metal insert inside the mold cavity before molding and for maintaining the roundness of the metal insert during molding, and molding a plastic annular body about the metal insert. A pulley assembly produced by this method is also provided. The method of producing the pulley assembly may include modifying the outer flat circumferential surface of the metal insert prior to molding the plastic annular body about the metal insert, for clamping, structurally bonding, and resisting relative rotation between the plastic body and the metal insert.

The present invention relates generally to the field of pulleys such as may be used with the endless drive belt of a vehicle accessories drive system, and a method for producing the pulley. More particularly, the invention relates to i method of producing a pulley assembly, in which a plastic outer pulley body is molded about a metal insert by utilizing a locating means for positioning the metal insert inside the mold cavity, to maintain the roundness of the metal insert inside the plastic outer pulley body during molding and to ensure the concentricity of the belt engaging portion of the plastic outer pulley body relative to the round metal insert. Specifically, the invention relates to a method of producing a pulley assembly, in which a plastic outer pulley body is molded about a metal insert by utilizing a locating means for positioning the metal insert inside the mold cavity, and including a locking means on the outer flat circumferential surface of the metal insert to resist relative rotation between the plastic outer pulley body and the metal insert.
Pulleys are commonly used in vehicle accessory drive systems. Various vehicle accessories such as the power steering pump, alternator, air conditioning pump and water pump are operated by a single endless drive belt driven by a pulley connected to the engine crankshaft and linked to driven pulleys operatively associated with the accessories. This system is referred to as a "serpentine" drive belt system. Driving a number of accessories, particularly with a serpentine drive belt, requires careful handling of the belt to ensure proper placement of the belt on the driven pulleys operatively associated with the accessories. Precise location of the belt frequently calls for the use of idler pulleys. In addition, to prevent slippage of the belt, a constant load must be maintained on the endless drive belt system. The use of a tensioner assembly, complete with a tensioner arm attached to a tensioner pulley, helps maintain a load or torque on the endless drive belt system. Idler and tensioner pulleys are typically manufactured from steel, but the steel is expensive, heavy and can be difficult to form into a satisfactory pulley construction. These pulleys are also manufactured from nylon, but the nylon does not have good dimensional stability and the nylon pulley experiences excessive wear during operation.
Pulleys formed of plastic and metal are not new, per se; prior art plastic belt-driven pulleys with metal inserts exist of the type in which a plastic outer pulley body is both molded on and supported on a metal disc. U.S. Pat. Nos. 4,473,363 and 4,468,210 illustrate examples of the plastic outer pulley body molded on a metal disc in a one-step process. U.S. Pat. Nos. 4,913,688 and 5,476,423 illustrate examples of a two-step assembly process wherein first the plastic outer pulley body is molded and then the metal insert is placed into the already molded pulley body.
A number of plastic pulleys with metal inserts are manufactured by the one-step molding process. In the case of a pulley assembly manufactured by a compression molding process, a plastic ring shaped perform is heated until pliable, then cavity molded about the metal insert. A simple way to locate the metal insert within the mold cavity is a single locating pin positioned within the center hole of the metal disc. If the metal insert is a bearing assembly, preserving the concentricity or roundness of the metal bearing is of great importance. Because of the high pressure involved in the compression molding process, the use of a single locating pin through the center of the bearing has been found to result in loss of concentricity of the bearing within the plastic body of the pulley, rendering the bearing unacceptable. Issues that exist with a bearing that is out of round include shortened bearing life at high RPM and possible noise generation.
Traditionally, when producing a pulley by the one-step process of compression molding the plastic body about the metal insert, the outer periphery of the metal insert is physically altered (or upset). Examples include utilizing a metal insert with projections on its outer periphery, such as radially extending scallops, as described in U.S. Pat. No. 4,473,363, or with a knurl applied thereto, as described in U.S. Pat. No. 4,468,210. The outer periphery of the metal insert is altered (or upset) for the purpose of resisting relative rotation between the metal insert and the plastic outer body.
Many pulleys are also produced by the two-step manufacturing process. U.S. Pat. No. 4,913,688 illustrates an example of attaching the metal insert to the plastic outer pulley body after the body has been molded; to assist the bonding of the plastic to the metal, an adhesive, such as epoxy, is applied between the metal and plastic, after the plastic outer pulley body has been molded as a separate piece. U.S. Pat. No. 5,476,423 illustrates first molding a plastic outer pulley body, and while the plastic is still above 38.degree. C. (100.degree. F.), positioning a bearing within the plastic body and cooling the assembly, to allow the plastic body to shrink around and fix the bearing in place. The adhesive bonding method as well as the shrinkage method of attaching the metal insert to the plastic pulley body does overcome the risk of a loss of concentricity of the round metal insert (or bearing), but introduces other problems. The process of bonding with an adhesive presents clean-up and environmental problems. And the method of utilizing the plastic shrinkage to hold the metal insert in place does not, in practice, sufficiently lock the metal insert to the plastic body.
The need remains, particularly in the area of the endless drive belt of a vehicle accessories drive system, for a plastic pulley with a metal insert that may be manufactured easily and successfully by a process which maintains the roundness of the metal insert.

Method of producing a plastic pulley with a metal insert


P-channel MOSFET devices are used as reprogrammable fuse or antifuse elements in a memory decode circuit by utilizing anomalous hole generation. An applied negative gate bias voltage is sufficiently large to cause tunnel electrons to gain enough energy to exceed the band gap energy of the oxide. This causes energetic hole-electron pairs to be generated in the silicon substrate. The holes are then injected from the substrate into the oxide, where they remain trapped. A large shift in the threshold voltage of the p-channel MOSFET results. The device can subsequently be reset by applying a positive gate bias voltage. Various circuits incorporating such fuse or antifuse elements are also disclosed.

Many electronic products use memory devices to store data. Non-volatile memory, such as electrically programmable read-only memory (EPROM) and electrically-erasable programmable read-only memory (EEPROM), are extensively used for storing data in, for example, computer systems. EPROM and EEPROM typically comprise a large number of memory cells having electrically isolated gates, referred to as floating gates. Data is stored in the memory cells in the form of charge on the floating gates. Charge is transported to or removed from the floating gates by program and erase operations, respectively.
Another type of non-volatile memory is flash memory. Flash memory is a derivative of EPROM and EEPROM. Although flash memory shares many characteristics with EPROM and EEPROM, the current generation of flash memory differs in that erase operations are performed in blocks. Flash memories have the potential of replacing hard storage disk drives in computer systems. The advantages would be replacing a complex and delicate mechanical system with a rugged and easily portable small solid-state non-volatile memory system. There is also the possibility that, given their very high potential densities, flash memories might be used to replace DRAMs if certain improvements in operating speed, e.g., in the erase operation, were realized.
A typical flash memory device comprises a memory array that includes a large number of memory cells arranged in row and column fashion. Each memory cell includes a floating gate field-effect transistor capable of holding a charge. The cells are usually grouped into blocks. Each of the cells in a block can be electrically programmed on a random basis by charging the floating gate. The charge can be removed from the floating gate by a block erase operation. The data in a cell is determined by the presence or absence of the charge in the floating gate.
Programmable address decode circuits and buffers are needed in conjunction with the memory array to allow faulty rows and/or columns of the array to be replaced by functional redundant rows and/or columns. An example of a redundancy repair scheme is shown in U.S. Pat. No. 5,324,681, issued to Lowrey on Jun. 28, 1994. Another is provided in U.S. Pat. No. 4,051,354, issued to Choate on Sep. 27, 1997. Another is provided in U.S. Pat. No. 5,327,380, issued to Kersh III on Jul. 5, 1994.
With the increasing array density of successive generations of flash memory devices, the desirability of incorporating other functions, such as programmable address decode logic, into the chip also increases. Any successful incorporated technology, however, must be cost competitive with the existing alternative of combining separate chips at the card or package level, each being produced with independently optimized technologies. Any significant addition of process steps to an existing flash memory technology in order to provide added functions, such as high speed logic, static random access memory (SRAM), or EEPROM, becomes rapidly cost prohibitive due to the added process complexity cost and decreased yield. Accordingly, there is a need to provide additional functions on a flash memory chip with little or no modification of the optimized process flow.
Programmable address decode circuits conventionally employ one time programmable (OTP) switches. Fuses and antifuses, present in peripheral circuits, are one method for constructing address decode logic. The fuse or antifuse integrally combines the functions of a switching element, which makes the interconnection, and a programming element, which stores the state of the switching element, i.e., either "off" (a blown fuse) or "on" (an unblown fuse).
Fusible elements are employed in integrated circuits to permit changes in the configuration of the integrated circuits after fabrication. For example, fusible elements can be used to replace defective circuits with redundant circuits. Memory devices are typically fabricated with redundant memory cells. The redundant memory cells may be enabled with fusible elements after fabrication to replace defective memory cells found during a test of fabricated memory devices.
One type of fusible link that can be used is a standard polysilicon fuse. The fuse comprises a polysilicon conductor approximately 0.5 μ thick that is fabricated on the integrated circuit such that in its normal state there is a complete electrical path through the fuse. To program the fuse, a high power laser is used to open the electrical path by evaporating a portion of the polysilicon. The laser can be used to open selected polysilicon fuses in an integrated circuit to change its configuration. The use of polysilicon fuses, however, is attended by several disadvantages. Polysilicon fuses must be spaced apart from each other in an integrated circuit such that when one of them is being opened by a laser, the other polysilicon fuses are not damaged. A bank of polysilicon fuses therefore occupies a substantial area of an integrated circuit. As integrated circuits continue to be fabricated with high density circuitry, the need for more fusible links also increases. In addition, polysilicon fuses cannot be opened once an integrated circuit is placed in an integrated circuit package, or is encapsulated in any manner.
Another type of fusible link that has been used in integrated circuits is the antifuse. An antifuse comprises two conductive terminals separated by an insulator or a dielectric, and is fabricated as an open circuit. In this respect, the antifuse is electrically opposite of the fuse. To program the antifuse, a high voltage is applied across its terminals to rupture the insulator and form an electrical path between the terminals. One type of antifuse that is commonly used in integrated circuits is an oxide-nitride-oxide (ONO) antifuse. A typical ONO antifuse has a layer of nitride sandwiched between two layers of oxide, where the bottom layer of oxide is in contact with polysilicon and the top layer of oxide is also in contact with polysilicon. The ONO sandwich is a dielectric such that the unprogrammed antifuse functions as a capacitor. To program the ONO antifuse, a large potential is applied across the dielectric such that the dielectric is ruptured and the two polysilicon layers are shorted together.
Antifuses have several advantages that are not available with fuses. A bank of antifuses takes up much less area of an integrated circuit because they are programmed by a voltage difference that can be supplied on wires connected to the terminals of each of the antifuses. The antifuses may be placed close together in the bank, and adjacent antifuses are not at risk when one is being programmed. Antifuses can also be programmed after an integrated circuit is placed in an integrated circuit package, or encapsulated, by applying appropriate signals to pins of the package. This is a significant advantage for several reasons. First, an integrated circuit may be tested after it is in a package, and may then be repaired by replacing defective circuits with redundant circuits by programming selected antifuses. A generic integrated circuit may be tested and placed in a package before it is configured to meet the specifications of a customer. This reduces the delay between a customer order and shipment. The use of antifuses to customize generic integrated circuits also improves the production yield for integrated circuits because the same generic integrated circuit can be produced to meet the needs of a wide variety of customers.
Despite these advantages, the use of antifuses in integrated circuits is limited by a lack of adequate circuitry to support the programming and reading of the antifuses. In addition, another disadvantage with ONO antifuses is that they are fabricated with separate, extra steps when an integrated circuit is fabricated.
Conventional fuses and antifuses also share a number of significant drawbacks that limit their usefulness. One such significant drawback is that neither fuses nor antifuses are reprogrammable. Rather, they are one time programmable devices, making them difficult to test and unsuitable for a large class of applications where reprogrammability is desirable or required. Fuses and antifuses suffer from the further disadvantage of not being fabricated according to the flash memory process flow.
Micron Technology, Inc. taught in U.S. Pat. No. 5,324,681, which issued to Lowrey et al. on Jun. 28, 1994, that one time programmable (OTP) memory cells formed as MOSFETs could be used to replace laser/fuse programmable memory cells for applications such as OTP repair of DRAMs using redundant rows and columns of DRAM memory cells and OTP selection of options on a DRAM (such as fast page mode (FPM) or extended data out (EDO)). One of the key advantages of that capability is the ability to program the OTP memory cells after the DRAM memory chip is packaged, a decided advantage over previous solutions. However, the invention in the Lowrey patent still has the disadvantage of single time programmability.
Another approach to solving the programmable switching problem is described in U.S. Pat. No. 5,764,096, which issued to Lipp et al. on Jun. 9, 1998. U.S. Pat. No. 5,764,096 provides a general-purpose nonvolatile, reprogrammable switch, but does not achieve the same using the commonality in the basic DRAM cell structure. Thus, the Lipp patent does not achieve the desired result of providing nonvolatile memory functions on a DRAM chip with little or no modification of the DRAM process flow.
Still another alternative to programmable interconnects, e.g., logic switching circuits, uses a metal oxide semiconductor field effect transistor (MOSFET) as the switching element. The MOSFET is controlled by the stored memory bit of a programming element. Most commonly, this programming element is a dynamic random access memory (DRAM) cell. Such DRAM based field programmable gate arrays (FPGAs) are reprogrammable and use a DRAM process flow, but have a disadvantage in that the programming of the switching elements is lost whenever power is turned off. A separate, nonvolatile memory cell must be used to store the programmed pattern on power down, and the FPGA must be reprogrammed each time the device is powered back up. This need again increases the fabrication complexity and requires significant additional chip surface space.
Accordingly, a need continues to exist for fuse and antifuse elements that can be reprogrammed and that are compatible with MOSFET memory technology. Such elements should be capable of being fabricated on a MOSFET memory chip with little or no modification of the MOSFET memory process flow.

Programmable fuse and antifuse and method thereof


The present invention relates to a process for producing a chitosan-containing soft capsule. The process includes the steps of rendering chitosan a powder; adding the chitosan powder, powder comprising an organic acid and a salt thereof, and an emulsifier to an oil or fat; stirring the resultant mixture so as to suspend the powders, to thereby obtain a gel-like stock; and feeding the gel-like stock and a gelatin solution for coating into an automated encapsulation machine, to effect encapsulation of the stock with gelatin.

1. Field of the Invention
The present invention relates to soft capsules which encapsulate chitosan therein (hereinafter may be referred to as "chitosan soft capsules"). The chitosan soft capsules of the present invention are advantageously used for controlling blood pressure of hypertensives. The present invention also relates to a process for producing the soft capsules.
2. Background Art
Hypertension; in particular, essential hypertension having no underlying disease, induces lethal diseases of organs such as the heart, brain, and kidneys. Therefore, daily control of blood pressure to a normal state is a key to curing diseases induced by hypertension. A variety of antihypertensive drugs have been developed and employed for treating hypertension. However, such drugs induce adverse side effects such as headache, drowsiness, cough, and depression. Therefore, patients taking such drugs during treatment become de-energized or feel weak, and may suffer degraded quality of life (QOL).
Extensive studies have been carried out for reducing blood pressure without use of conventional drugs. One such study is application of chitosan.
Presently it is well known that chitosan has an antihypertensive effect and that hypertension is caused by excess intake of salt. See, for example, OKUDA et al., Journal of Traditional Medicine 11, 198-205, 1994 (Hideo KATO, Tomoko TAGUCHI, Hiromichi OKUDA, Mari KONDO, and Minoru TAKARA).
In the above journal, OKUDA et al. describe that in the digestive tract chitosan captures chloride ions (Cl.sup.-) originating from salt contained in ingested food and excretes the ions into feces, to thereby exhibit an action for reducing blood pressure. Briefly, Cl.sup.- in blood activates an angiotensin-converting enzyme (ACE) which acts to elevate blood pressure, whereas chitosan promotes excretion of chloride ions (Cl.sup.-) into feces, to thereby suppress transfer of Cl.sup.- into blood and reduce blood pressure. A test conducted by OKUDA et al. revealed that intake of chitosan powder in an amount of 5 g per day suppresses human hypertension caused by a high-salt diet.
However, the present inventors have observed that intake of an aqueous solution of cuttlefish-chitosan containing chitosan in an amount as small as 20 mg is effective in reducing blood pressure of hypertensives (see Tests 1 through 5 described below). According to the calculation described by OKUDA et al. the amount of salt captured by 20 mg of chitosan is about 6 mg, and the capture of salt in such a small amount is unlikely to reduce blood pressure. Thus, the present inventors considered that the mechanism of inhibiting Cl.sup.- -intake attributed to chitosan is not a direct capture but involves inhibition of the Cl.sup.- absorption process, such as Cl.sup.- channeling. When channeling-like inhibition occurs, chitosan should manifest its action in an aqueous solution state, and administration of solid state chitosan would provide only poor inhibition efficiency.
In their test, OKUDA et al. administered solid chitosan derived from a crab in an amount as large as 5 g to human subjects. However, daily intake of such a large amount of chitosan from food or drugs is not realistic. As mentioned above, it was previously found that a small amount of chitosan was expected to provide an antihypertensive effect so long as it is used in the form of an aqueous solution. Along this line, studies on preparing an aqueous solution of chitosan have been carried out, and a patent application has been filed (Japanese Patent Laid-Open Publication No.110634/1997).
Briefly, there has been developed a method in which cuttlefish-chitosan having a deacetylation degree of 75% or more is dispersed in an aqueous alkali solution for hydration and an organic acid in an amount of 0.01-5 wt. % is added to the dispersion to thereby form a neutral solution.
In view of the foregoing, the present inventors have conducted a test, in which 1% aqueous solution of cuttlefish-chitosan in a volume of 1-3 ml (equivalent to 10-30 mg of chitosan) was administered to five hypertensive patients, and reduction of blood pressure was observed.
Test for an Effect on Reduction of Blood Pressure Induced by 1% Aqueous Solution of Cuttlefish-Chitosan (pH 5.5-6.0)
Case 1. Age 68, Female
When the subject took 2-3 ml of the cuttlefish-chitosan aqueous solution three times daily, systolic pressure was reduced from 180 mmHg to 150 mmHg. Thereafter, the dose was reduced to 2 ml or less twice daily and the administration was continued. Systolic pressure stabilized at 150 mmHg.
Case 2. Age 72, Male
When the subject took 5 ml of the cuttlefish-chitosan aqueous solution at one dose together with a cup of onion-infused wine, systolic pressure was drastically reduced from 190-200 mmHg to 160 mmHg. The reduction in blood pressure was so drastic that the dose of the solution was reduced to 2 ml and the administration was continued. Thereafter systolic pressure was gradually reduced from 180 mmHg to 170 mmHg and then to 160 mmHg, where it stabilized.
Case 3. Age 57, Male
When the subject took 3 ml cuttlefish-chitosan aqueous solution at one dose together with a cup of black mushroom broth, 2-3 times per day, systolic pressure was reduced from 180 mmHg to about 150 mmHg.
Case 4. Age 51, Male
When the subject took the cuttlefish-chitosan aqueous solution at a dose of 1 ml and five droplets of mixed propolis twice daily, systolic pressure was reduced from 170 mmHg to 150-155 mmHg.
Case 5. Age 46, Female
When the subject took the cuttlefish-chitosan aqueous solution at a dose of 2 ml twice daily, and the administration was continued, systolic pressure was gradually reduced from 150 mmHg to 130-135 mmHg.
In consideration of the above results, application of the cuttlefish chitosan aqueous solution to pharmaceuticals and health food has been studied. However, the cuttlefish-chitosan aqueous solution employs glutamic acid as an organic acid and sodium glutamate, and provides such bad taste that daily intake of the solution as such is difficult. Thus, encapsulation of the solution has also been studied. However, encapsulation of an aqueous solution is difficult in that capsules per se dissolve in water.

Chitosan-containing soft capsule and process for producing the same


Apparatus and methods operate to disable a dynamically biased apparatus and a dynamic bias current source providing dynamic bias current to the apparatus at the beginning of a static bias startup period shortly after power-on. The dynamically biased apparatus is then gradually enabled in a static bias mode of operation during the static bias startup period. Following the end of the static bias startup period, operation of the dynamically biased apparatus in a dynamic transconductance mode is gradually enabled during a dynamic bias startup period. Such startup sequence operates to prevent damaging in-rush currents in a system employing the dynamically biased apparatus in a feedback control loop.

Linear amplifiers are used in a variety of applications, including, e.g., audio, video, and power supplies. Linearity between the amplifier input signal and the output signal enables the faithful reproduction of analog information presented at the amplifier input. A key metric associated with linearity and amplifier quality is slew rate, often expressed as volts per second (millivolts per microsecond, etc.). Slew rate is a measure of the maximum rate of change of the information signal at a particular point within the amplifier. A poor slew rate may result in a distorted output, as fast-changing portions of the information signal are delayed in time relative to other portions of the signal.
One application for which amplifier slew rate may be particularly important is that of regulating the output voltage of a switching DC-DC voltage converter. A switching DC down-converter (known in the art as a "buck" converter) alternately makes and breaks a circuit path between the converter DC supply input and an energy conversion inductor. During the ON state, the inductor stores energy in a magnetic field as current flows through the inductor. During the OFF state, the collapsing magnetic field generates current at the converter output. The inductor thus integrates the switched waveform to create an output voltage waveform proportional to the duty cycle of the active-state switched waveform. A filter capacitor is typically used to smooth the voltage waveform at the converter output.
To maintain a voltage set-point at the output of a DC-DC converter as load current demand changes, the output voltage level may be monitored and fed back to a circuit controlling the switching duty cycle. The slew rate of the DC-DC converter feedback circuit may be particularly important in applications requiring tight voltage regulation. For example, modern processors typically employ hundreds of millions of transistors. The on/off state of each transistor contributes to the overall instantaneous current load presented to the DC power supply. The latter current load may be quite high and may change substantially within a few microseconds. And, low-voltage operation associated with today's microprocessor technology presents an additional challenge to DC power supply regulation requirements, given that small supply voltage variations may represent a significant percentage of a processor's operating voltage margin.
The slew rate of an error amplifier situated in the feedback loop associated with a DC-DC converter may be improved through the use of dynamic biasing techniques. Signals applied to the differential inputs of the error amplifier typically include a reference voltage and a voltage divided sample of the converter output. The feedback error signal appears at the output of the error amplifier. Some error amplifiers use a "dynamic bias" current circuit to provide a variable current source as the error signal. The magnitude of the current source is proportional to the magnitude of the difference between the reference voltage and the converter output sample voltages appearing at the error amplifier differential inputs.
An additional challenge for DC-DC converter design is the instantaneous and possibly indeterminate state of voltage regulation-determining components when power is switched on to the converter. Power-handling components should be protected against in-rush currents during the switch-on period.

Dynamic bias soft start control apparatus and methods


A reciprocating pump includes an open-bottomed barrel adapted for attaching to the lower end of a production tubing string; a seating assembly having a cylindrical bore and adapted for mounting to a seating nipple at the upper end of the barrel; and a plunger assembly adapted for attaching to the lower end of a sucker rod string. The plunger assembly includes concentric upper and lower plunger sections interconnected by a double-valve, ported valve cage. The plungers are sized for sealing reciprocating engagement within, respectively, the bore of the seating assembly and the bore of the pump barrel. The lower plunger and the ported valve cage define a production chamber within the pump barrel. The upper plunger has ports allowing fluid flow from the tubing into the production chamber. Optionally, the upper plunger and the barrel may be provided with flush ports facilitating flushing of the pump to eliminate vapor lock.

Typical "sucker rod" pumps are positive displacement pumps used to pump fluids from wells. These pumps are typically located in the wellbore below the liquid level of the fluid to be pumped. The pump has an elongate cylindrical barrel connected to the lower end of a string of production tubing (which extends upward to the wellhead), plus a hollow piston (also referred to as a plunger) which reciprocates up and down within the pump barrel and in sealing engagement with the inner wall of the barrel. The plunger is connected to the lower end of a string of sucker rods extending to the surface within the production tubing, with the upper end of the sucker rod string being connected to a surface-located pumping unit (such as the well-known "horsehead" or "walking beam" pump jack), which reciprocates the rod string and the plunger.
The barrel of the sucker rod pump has an inlet check valve (comprising a standing ball and seat, and alternatively referred to as a "standing valve") at its lower end, and an outlet check valve (comprising a travelling ball and seat, and alternatively referred to as a "travelling valve") disposed within the plunger. Formation fluids flow into the wellbore and thence into the pump barrel through the standing valve when fluid pressure is sufficient to unseat the ball in the standing valve. Downward movement of the plunger through the fluid above the standing valve forces the ball in the travelling valve open, thus allowing fluid to flow through the travelling valve and into a region of the barrel above the plunger. During the plunger's downstroke, the standing valve is closed and thus prevents fluids from flowing back into the wellbore. When the plunger begins its upstroke, the ball in the travelling valve becomes seated due to the weight of the fluid column now overlying the travelling valve, and the fluid column is therefore lifted upward by the plunger. At the same time, the upward movement of the plunger draws additional fluids from the wellbore into the barrel through the standing valve, and the pumping cycle begins again when the plunger begins its next downstroke.
These pumps have proven to be mechanically sound and reliable, but they do encounter pumping problems. When the fluid being pumped is near its flash point temperature, it will partially vaporize when it is drawn into the barrel. Any vapor or gas drawn into the barrel through the standing valve must be compressed to the pressure of the production tubing on the plunger downstroke before the travelling valve will open and allow fluids out of the pump. In other words, the pressure built up in the barrel during the plunger downstroke must overcome the hydrostatic load acting on the travelling ball due to the fluid column above the plunger, or else the travelling valve will not open. However, the compressibility of any gas in the barrel makes it more difficult to build up sufficient pressure in the barrel, and this problem worsens as the amount of gas in the barrel increases.
The pressure drop that is often increased by pressure differentials through the standing valves in conventional sucker rod pumps is partially responsible for "gas locking" and for problems achieving satisfactory fluid flow into the pump when such pumps are used to pump viscous fluids (such as heavy oil). There are many types of standing cages (i.e., cages for standing valves) designed to reduce the pressure differential across the standing valve. The volume of gas or vapor within the pump can be great enough that the full downward stroke of the plunger will not produce sufficient pressure in the pump barrel to force the travelling valve open. When this happens, the pump is said to be gas-locked (or, alternatively, "vapor locked"). Pumps used to pump crude oil containing significant amounts of lighter fractions will be particularly prone to vapor locking. When an oil field is subject to a steam flood, a mixture of oil and condensate near its flashing point is produced, which also can vapor-lock a pump.
When a pump is vapor-locked, it is typically shut in for a period of time, or, alternatively, fluid is introduced into the wellbore with a "flush-by" service rig. During the shut-in period, the gas will have a chance to escape through check valves, and the pump can cool due to the absence of the heat of compression and frictional heat created by the plunger sliding up and down within the pump barrel. The vapor lock will eventually break, allowing pumping to be continued. The use of mechanical impact or tapping bottom to solve vapor lock is unacceptable.
Conventional sucker rod pumps are also often used to lift viscous or "heavy" oils, and in such conditions the standing valves can impede efficient pump performance and production, because the restricted area around and through the ball and seat of the standing valve can limit the amount of fluid that can be drawn into the pumping chamber. Similar concerns can arise when a conventional pump is being reciprocated at high speeds. The fluid cannot completely fill the pumping chamber due to frictional drag caused by the restrictive standing valve, which acts as a choking point limiting the volume of fluid allowed into the pumping chamber. A further problem commonly arising when pumping viscous fluids using conventional pumps is that solids contained in the produced fluid often contaminate the ball and seat of the standing valve, causing the pump to cease operation.
It is common practice, when a conventional sucker rod pump becomes plugged with solids from the wellbore, to use a specialized service rig called a "flush-by unit" to clean out the pump so that it can be put back into service. The flush-by unit will lift the pump out of the seating nipple or remove the plunger and standing valve. At this stage, clean fluid is pumped down the production tubing in an effort to remove contaminating solids from the tubing string and pump components. These operations cost money in terms of both the flush-by unit and lost production time.
When conventional sucker rod pumps are employed to pump viscous wells, or wells in which wellbore deviations cause frictional drag (such as in horizontal wells), the sucker rod string may be unable to fall fast enough for satisfactory oil production to be realized. Various devices and pumps have been used in the past to increase downstroke loads in order to increase downstroke speed (i.e., strokes per minute) and thereby mitigate the frictional drag problem in deviated wellbores. However, with the increasingly common use of directional drilling to drill horizontal and other non-vertical wellbores, slower downstroke speeds continue to be a problem that limits production.
For the foregoing reasons, there is a need for a well pump which is capable of pumping volatile fluids and is resistant to gas/vapor-locking, and which will not "fluid pound" (a term well understood in the art). There is a further need for a well pump that can facilitate flushing action to remove contaminating solids from the pump without the need for a flush-by unit. In addition, there is a need for a well pump that has no standing valve, such that there is no pressure drop through the inlet valve. Furthermore, there is a need for a well pump that that is less prone to reduced downstroke speed when operating in a deviated wellbore.


A system design support system is disclosed, which handles specifications at system level, e.g., a specification of software executed by a computer, specification of hardware implemented by combining semiconductor devices and the like, a specification of an incorporated system implemented by combining software and hardware, and a specification of a business process such as a workflow. This apparatus searches for an advertisement in accordance with an query specification. The apparatus also creates a communication procedure between the query specification and a specification of an advertisement part obtained by a search.

1. Field of the Invention
The present invention relates to design support for hardware such as a computer and electronic device, software, and a system including a combination of hardware and software.
2. Description of the Related Art
Recently, a system specification description language for describing a specification at system level without discrimination between hardware and software has been developed. With this development of the language, an environment for consistent specification description from a specification at system level to specified software or hardware specifications based on the same specification format has been improving. A rapid prototyping tool (Rapid or BetterState) is known, which provides a design environment in an upstream stage of system design while checking a system specification. See "Rapid-plus, White Paper", http://www.e-sim.com/pdf/whtpaper.pdf as a reference for Rapid.
A characteristic feature of such a rapid prototyping tool is that system analysis and design can be seamlessly and quickly performed by using hierarchical state transition diagrams. From the viewpoint of specification design at system level at which a specification implementation method is not clear, this tool has a merit of allowing efficient design by hierarchically combining interrupt execution, sequential execution, and parallel execution.
In order to efficiently perform system design in an upstream stage of design, i.e., a stage where no architecture is determined, a technique of forming a specification at system level into parts and reusing them is indispensable. With a system specification language, the contents (operation) of a system can be described according to a formal specification description rule instead of a natural language. However, no mechanism has been provided, which searches the contents of a specification part on the basis of a specification description at system level so as to reuse it.
The techniques of forming software into parts in the conventional software engineering provide parts designed in detail, i.e., so-called parts at implementation level, and provide users with API (Application Programming Interface) function specifications of parts. The techniques of part formation in consideration of reuse can be used for only predetermined architectures. For example, JavaBeans in a program described in the Java language defines a specification for part formation in a Java execution environment, and hence parts can be reused only within the range of this defined part formation specification. See "Java programming JavaBeans—component framework", Science, (Dec. 1, 1997), ISBN: 4781908624 as a reference for JavaBeans.
According to such conventional techniques associated with formation of software parts, descriptions and classification indexes (indexes) of parts are provided in advance in a natural language, and part search and reuse are realized by searching for parts. However, these technique are not configured to realize part search and reuse in consideration of the contents of software other than those in a natural language.
Demands have arisen for a mechanism for forming a specification at system level, which is created in a system specification description language in the above manner, into parts and reusing them.

Method and computer program product for realizing a system specification which is described in a system description language