An improved nozzle assembly for servo-controlled fuel injectors is provided which includes a needle valve control device including a rate shaping control device for effectively producing a predetermined time varying change in the flow rate of fuel injected into the combustion chamber during an injection event so as to reduce emissions. The rate shaping control device includes an injection control valve positioned along a drain circuit connected to a control volume positioned at one end of the needle valve element. The injection control valve includes an actuator for controlling the flow of fuel through the drain circuit to variably control the rate of movement of the needle valve element between the open and closed positions so as to provide the desired shaping to the flow rate of fuel into the combustion chamber. The injection control valve may include a control valve element positioned in the control volume adjacent the needle valve element for cooperating with the needle valve element to control the drain flow of fuel through the drain circuit during the injection event. The needle valve element may include a valve surface wherein positioning of the control valve member relative to the valve surface controls drain flow through the drain circuit. The valve surface may be either a flat valve surface or a conically shaped surface for positive abutment by the control valve member, or alternatively, the needle valve element and the control valve member may be of the spool-type.

In most fuel supply systems applicable to internal combustion engines, fuel injectors are used to direct fuel pulses into the engine combustion chamber. A commonly used injector is a closed-nozzle injector which includes a nozzle assembly having a spring-biased nozzle valve element positioned adjacent the nozzle orifice for resisting blow back of exhaust gas into the pumping or metering chamber of the injector while allowing fuel to be injected into the cylinder. The nozzle valve element also functions to provide a deliberate, abrupt end to fuel injection thereby preventing a secondary injection which causes unburned hydrocarbons in the exhaust. The nozzle valve is positioned in a nozzle cavity and biased by a nozzle spring to block fuel flow through the nozzle orifices. In many fuel systems, when the pressure of the fuel within the nozzle cavity exceeds the biasing force of the nozzle spring, the nozzle valve element moves outwardly to allow fuel to pass through the nozzle orifices, thus marking the beginning of injection. In another type of system, such as disclosed in U.S. patent application Ser. No. 686,491, now U.S. Pat. No. 5,676,114, filed Jul. 25, 1996, entitled Needle Controlled Fuel System With Cyclic Pressure Generation and commonly assigned to the assignee of the present invention, the beginning of injection is controlled by a servo-controlled needle valve element. The assembly includes a control volume positioned adjacent an outer end of the needle valve element, a drain circuit for draining fuel from the control volume to a low pressure drain, and an injection control valve positioned along the drain circuit for controlling the flow of fuel through the drain circuit so as to cause the movement of the needle valve element between open and closed positions. Opening of the injection control valve causes a reduction in the fuel pressure in the control volume resulting in a pressure differential which forces the needle valve open, and closing of the injection control valve causes an increase in the control volume pressure and closing of the needle valve. U.S. Pat. No. 5,463,996 issued to Maley et al. discloses a similar servo-controlled needle valve injector.
Internal combustion engine designers have increasingly come to realize that substantially improved fuel supply systems are required in order to meet the ever increasing governmental and regulatory requirements of emissions abatement and increased fuel economy. It is well known that the level of emissions generated by the diesel fuel combustion process can be reduced by decreasing the volume of fuel injected during the initial stage of an injection event while permitting a subsequent unrestricted injection flow rate. As a result, many proposals have been made to provide injection rate control devices in closed nozzle fuel injector systems. One method of controlling the initial rate of fuel injection is to spill a portion of the fuel to be injected during the injection event. For example, U.S. patent application Ser. No. 376,417, now U.S. Pat. No. 5,647,536, filed Jan. 23, 1995, entitled Injection Rate Shaping Nozzle Assembly for a Fuel Injector and commonly assigned to the assignee of the present application discloses a closed nozzle injector which includes a spill circuit formed in the needle valve element for spilling injection fuel during the initial portion of an injection event to decrease the quantity of fuel injected during this initial period thus controlling the rate of fuel injection. A subsequent unrestricted injection flow rate is achieved when the needle valve moves into a position blocking the spill flow causing a dramatic increase in the fuel pressure in the nozzle cavity. However, the needle valve is not servo-controlled and, thus, this nozzle assembly does not include a control volume for controlling the opening and closing of the needle valve. Moreover, the rate shaping nozzle assembly does not permit the rate to be selectively varied.
U.S. Pat. No. 5,133,645 to Crowley et al. discloses a common rail fuel injection system having two common rails serving respective banks of injectors. Fuel is supplied to each rail by a respective cam-operated reciprocating plunger pump. Each injector includes a nozzle element positioned in a spring cavity which receives high pressure fuel from the common rail via a check valve. The spring cavity is also connected, via an orifice, to a pressure control volume positioned above the nozzle element. A solenoid operated control valve opens to connect the control volume to drain thereby initiating injection as fuel flows from the nozzle cavity through the orifice to drain, and closes to terminate injection. U.S. Pat. No. 4,249,497 to Eheim et al. discloses a fuel injection system wherein fuel injection is controlled by controlling the differential pressure across a nozzle valve element using a single valve which opens to direct fuel to drain so as to start injection and closes to end injection. However, these references fail to disclose a means for achieving injection rate shaping.
U.S. Pat. No. 5,176,120 to Takahashi discloses a fuel injection system including a cam-operated fuel pump for supplying high pressure fuel to a common rail serving an injector. The injector includes a needle valve movable under the influence of differential fuel pressures as controlled by a solenoid-actuated valve. The system provides a control unit for achieving different fuel injection rates. However, the control unit must vary the pressure in the common rail to vary the fuel injection rate. When a lower common rail pressure is desired, the common rail fuel pressure is gradually lowered by the slow incremental extraction of fuel for injection without the addition of fuel to the rail. As a result, this system is incapable of quickly varying the pressure in the common rail to achieve a desired corresponding injection pressure and injection rate. Moreover, injection rate of each injector cannot be controlled independently. In addition, this system only permits two injection rate shapes thus limiting the effectiveness of the system. Also, the servo-controlled needle valve and actuator valve assembly is unnecessarily complex.
U.S. Pat. No. 2,959,360 to Nichols discloses a fuel injector nozzle assembly incorporating passages in the nozzle assembly for diverting the fuel from the nozzle assembly. Specifically, Nichols discloses a nozzle valve element having an axial passage formed therein for diverting fuel from the nozzle cavity into an expansible chamber formed in the nozzle valve element. A plunger is positioned in the chamber to form a differential surface creating a fuel pressure induced seating force on the nozzle valve element to aid in rapidly seating the valve element. The Nichols reference does not suggest the desirability of controlling the rate of injection.
Although some systems discussed hereinabove create different stages of injection, further improvement is desirable. None of the above discussed references disclose a fuel injector incorporating a simple, cost effective rate shaping device for a servo-controlled needle valve which minimizes the complexity of the nozzle assembly while effectively controlling emissions by controlling the rate of fuel injection.

Injection rate shaping nozzle assembly for a fuel injector


In magneto-optical recording medium, on a transparent substrate of polycarbonate resin, an SiN film having the thickness of 600 to 800 .ANG. and surface roughness Rmax of at most 10 nm is formed. On the SiN film, a GdFeCo reading layer having the thickness of 800 to 1200 .ANG. with Gd content of 30 to 36 at. % and Co content of 12 to 50 at. % is formed. On the reading layer, a TbFeCo recording layer of which Co content is 10 to 16 at. % is formed. The recording layer is a perpendicular magnetization film, and the reading layer is an in-plane magnetization film. At the time of reading, the reading and recording layers are heated, and the direction of magnetization of the recording layer is transferred to the reading layer only in the prescribed heated area. Information can be read only from the transferred portion, and thus a super resolution effect is obtained. When Kerr rotation angle .theta..sub.K is measured for the light reflected from the reading layer while the temperatures of the reading and recording layers are elevated, .theta..sub.K is approximately in proportion to Cth power of the elevated temperature t, wherein C is at least 8.0.

1. Field of the Invention
The present invention relates to a magneto-optical recording medium including an exchange coupling magnetic layer essentially consisting of a recording layer and a reading layer, which attains high density recording by transferring the direction of magnetization in the recording layer to the reading layer for reading, and to manufacturing method thereof.
2. Description of the Background Art
A magneto-optical recording medium has attracting attention as a recording medium which is rewritable and having large storage capacity and high reliability. It has come to be used as a computer memory, for example. However, as the amount of information increases and the device is made smaller, recording/reading technique with higher density has been desired.
The technique for recording and reading with high density includes techniques related to the apparatus for recording and reading, and techniques for the medium. The former techniques include an optical super resolution technique for obtaining a convergence spot exceeding diffraction limit of laser beam, and a technique for making shorter the wavelength of the laser beam. The latter techniques include narrowing the pitch of the medium, and improvement of the reading resolution by using magnetic multi-layered films. The technique for improving the reading resolution by using a magnetic multi-layered film includes a technique in which the state of the recording layer is selectively transferred to the reading layer and the state of the reading layer is read, utilizing the fact that temperature distribution of the laser spot has Gaussian distribution. In a magneto-optical recording medium used for the optical super resolution technique, a recording layer which is magnetized in a direction perpendicular to the disc surface has been generally used. As a substrate for the medium, generally, a glass substrate has been used.
In NIKKEI ELECTRONICS 1993, 7.5 (No. 585) pp. 163-170, a magneto-optical disc including a magnetic film consisting of a reading layer and a recording layer is disclosed. The conventional magneto-optical disc disclosed in this paper will be described. FIG. 1 shows the structure of the disclosed medium. On a glass substrate 101, an APN dielectric layer 102 having the thickness of 80 nm, a GdFeCo reading layer 103 having the thickness of 40 nm, a DyFeCo recording layer 104 having the thickness of 40 nm, an APN dielectric layer 105 having the thickness of 20 nm, and a protective layer 107 are formed in this order. In the magneto-optical disc, the magnetic material of which the recording layer is formed is magnetized in the perpendicular direction and records information. Meanwhile, the reading layer is formed of a magnetic film in which in-plane magnetization occurs at room temperature and perpendicular magnetization occurs at high temperature. The principle of reading from a magneto-optical disc using such an in-plane magnetic film as the reading layer is as shown in FIG. 2. When the magneto-optical disc is irradiated with laser beam 17, intensity of the laser spots has Gaussian distribution. Therefore, temperature distribution of the magnetic film also tends to have Gaussian distribution, as shown in the figure. Since the magnetic material of which the direction of magnetization changes from in-plane to perpendicular direction when the temperature exceeds 120.degree. C. is used as the reading layer, only the area 13a of reading layer 13 where the temperature exceeds 120.degree. C. because of laser beam 17 is magnetized in the perpendicular direction, in accordance with the direction of magnetization of the corresponding portion of recording layer 14. Thus, the information of recording layer 14 is transferred to reading layer 13, enabling reading of the information in recording layer 14. Reading of information from the transferred portion is realized, utilizing Kerr effect. Kerr effect refers to the effect that when light is reflected from a magnetic body, the plane of polarization of the reflected light is rotated. In the magneto-optical disc, the rotation angle is read as an output signal. As shown in FIG. 3A, when reading layer 103 which is in the state of perpendicular magnetization is irradiated with light, the Kerr rotation angle on the plane of polarization becomes maximum. Meanwhile, as shown in FIG. 3B, when reading layer 103 in the state of in-plane magnetization is irradiated with light, there is hardly a rotation of the plane of polarization. Referring to FIG. 2, at the center of the spot of laser beam 17 where temperature is high, magnetization of reading layer is perpendicular, and at other portions, magnetization is in-plane. Therefore, at the center of the spot, the aforementioned Kerr effect occurs, while at other portions, Kerr effect does not occur. Therefore, only the signal at the center of the spot can be detected, and other portions are masked by in-plane magnetization. As shown in FIG. 2, the area where the threshold value 120.degree. C. is exceeded can be made smaller than the laser spot diameter. Accordingly, information of the area which is smaller than the laser spot diameter can be read, which means that a higher recording density is possible. Such an effect is referred to as magnetically induced super resolution (MSR). As to writing of information to the recording layer, when a portion of the recording layer which has been heated to a temperature not lower than Curie temperature by the laser beam comes to be off the laser beam and the temperature thereof becomes lower than Curie temperature, it is magnetized in the direction of an external magnetic field. Recording of information by perpendicular magnetization is performed in this manner. In magnetic field modulation recording with continuous irradiation, the medium is continuously irradiated with the laser beam at the time of recording. Meanwhile, in laser pulse magnetic field modulation recording, pulse laser is emitted, and the cycle of heating to at least Curie temperature and cooling is repeated in an instant during recording.
SPIE Vol. 1316 Optical Data Storage (1990)/271-277 discloses a method of high density magneto-optical recording using magnetic field modulation and pulsed laser irradiation. In the magneto-optical disc disclosed in this paper, a TbFeCo recording layer having Curie temperature of 180.degree. C. is formed on a glass substrate.
The method of detection for MSR includes a center aperture detection (CAD), a front aperture detection (FAD) and a rear aperture detection (RAD). In the CAD, information of the recording layer is read through the reading layer at the central portion of the laser beam spot irradiated for heating. In the FAD, as shown in FIG. 4A, a portion 110a in front of the disc proceeding direction is masked at the laser beam spot 110, and other portions are opened. In the RAD, as shown in FIG. 4B, a portion 110b in front of the disc proceeding direction of the laser beam spot 110 is opened and other portions are masked. JJAP Series 6 Proc. Int. Symp. on Optical Memory, 1991, pp. 203-210 discloses a structure of a magnetic film for the MSR disc utilizing the FAD and RAD. In the MSR disc using the FAD disclosed in this paper, a GdFeCo read out layer having the thickness of 30 nm and having the Curie temperature of at least 300.degree. C., a TbFeCoAl switching layer having the thickness of 10 nm and the Curie temperature of about 140.degree. C., and a TbFeCo recording layer having the thickness of 40 nm and the Curie temperature of about 250.degree. C. are stacked. In the MSR disc using the RAD, a GdFeCo read out layer having the thickness of 30 nm and the Curie temperature of at least 300.degree. C., a TbFeCoAl subsidiary layer having the thickness of 10 nm and the Curie temperature of about 140.degree. C., a GdFeCo intermediate layer having the thickness of 15 nm and the Curie temperature of about 250.degree. C., and a TbFeCo recording layer having the thickness of 40 nm and the Curie temperature of about 250.degree. C. are provided.
In the magneto-optical disc in which the direction of magnetization of the recording layer is transferred to the reading layer at the time of reading, the transfer characteristic is of critical importance. It is desired that the transfer is performed quickly at a prescribed temperature attained by heating. However, the conventional magneto-optical disc still has a room for improvement in the transfer characteristic. In the conventional magneto-optical disc of the CAD method, there is a possibility of conversion from in-plane magnetization perpendicular magnetization in the reading layer in a relatively wide temperature range of several tens to about 100.degree. C. Such a transfer in a wide temperature range causes much reading noises results in an insufficient MSR effect. The wider the area of the reading layer magnetically influenced by the recording layer at the time of reading, the lower the mask effect, and it becomes more difficult to clearly read the information recorded with high density. In addition, the transfer temperature of the magnetic film much depends on various conditions for forming the film. Therefore, it is relatively difficult to form a magnetic film having a definite threshold value for the transfer with good reproductivity.
In order to heat the recording layer and the reading layer at the time of recording to a temperature not lower than the Curie temperature, conventionally, it was necessary to increase laser power. When heating is not sufficient, a carrier to noise ratio (CNR) of the recording signal is degraded. Further, in order to align the direction of magnetization of the not sufficiently heated reading layer to the direction of the external magnetic field, it is necessary to apply a large magnetic field. In this case also, the CNR of the recording signal is degraded. Further, in magnetic field modulation recording, it is desired that a smaller magnetic field be applied.
When the Curie temperatures of the recording layer is low and the difference between the Curie temperatures of the recording layer and the reading layer is large, sometimes a part of the magnetization of the reading layer prematurely turns to the in-plane direction when the transfer of the direction of magnetization of the reading layer to the recording layer starts during the process of cooling at the time of recording. Such a phenomenon causes noises in the signal to be transferred from the reading layer to the recording layer, degrading the CNR of the recording signal.
In the technique where the state of the recording layer is transferred to the reading layer for reading, it is desired that the temperature distribution of the reading layer heated by the laser spot should have a desired distribution. The reason for this is as follows. When the temperature distribution deviates from the desired distribution, noises caused by random magnetization directions increase, and further, crosstalk noises increase which derive from reading of the state of a portion other than the center of laser spot (that is, a peripheral portion which should have lower temperature). In a transparent type magneto-optical recording medium in which light is transmitted through the magnetic layer, heat accumulation caused by the laser spot irradiation is negligible. Meanwhile, in a magneto-optical recording medium in which the laser beam reflected from a magnetic layer having the thickness of at least 400 .ANG. is detected, the heat accumulation affects the temperature distribution of the reading layer. Therefore, in the reflection type magneto-optical recording medium, the aforementioned noises are increased. Further, in the conventional magneto-optical recording medium, when recording is performed with the medium being irradiated with the laser beam of a constant intensity, the heated area in the recording layer has been larger than the laser spot. As a result, the recording spot becomes larger, making it difficult to increase the density in recording.
When glass is used as the substrate, the following problems are experienced.
a) The magneto-optical recording medium becomes heavy. PA1 b) There is a possibility of breakage when one erroneously drops the medium. PA1 c) The medium cannot withstand a high speed rotation. PA1 d) Surface polishing of the substrate requires much cost. PA1 e) It is difficult to form a guiding groove used for tracking the laser beam directly thereon.
An object of the present invention is to provide a magneto-optical recording medium of the type in which the direction of magnetization of the recording layer is transferred to the reading layer at the time of reading, which has a superior transfer characteristic, and low noises in reading and which attains a high MSR.
Another object of the present invention is to provide a technique for obtaining a magneto-optical recording medium which has a superior transfer characteristic and low reading noises and which can attain a high MSR, with high reproductivity.
A further object of the present invention is to provide a magneto-optical recording medium which allows recording even with a small magnetic field applied and which can be preferably applied to the magnetic field modulation technique.
A still further object of the present invention is to provide a magneto-optical recording medium which is capable of recording with a good CNR and reading with a good CNR.
A still further object of the present invention is to provide a magneto-optical recording medium in which a heat accumulation can be suppressed to a negligible level, and hence noises are reduced.
A still further object of the present invention is to provide a magneto-optical recording medium in which the uniformly heated area in recording and reading can be made smaller, thereby enabling high density recording and reading.
A still further object of the present invention is to provide a magneto-optical recording medium which is easy to handle, on which a guiding groove used for tracking the laser beam can be directly formed and which is relatively inexpensive.

Magneto-optical recording medium and manufacturing method thereof


A nuclear fuel element includes a core comprising a fissile element and an additional element. A protective structure surrounds the core and comprises at least a first material surrounding the nuclear fuel. The first material comprises the fissile element and the additional element and comprises a greater than stoichiometric amount of the additional element. An outer portion of the nuclear fuel element comprises a metal. Related nuclear fuel elements, and related methods are also disclosed.

As the global population increases, the demand for energy is expected to continue to increase. Methods of energy production include coal gas filed power plants, natural gas energy production, renewable energy (e.g., wind, wood, solar, hydroelectric, biofuels), and nuclear power generation, among other methods. Nuclear energy production may be advantageous due to reduced pollution relative to other forms of energy production due to relatively low cost, stable load of energy, and minimal emissions.
Nuclear power generation includes the use of nuclear reactions in a nuclear reactor core to provide power. The nuclear reactions may include fission of enriched uranium to generate power. The enriched uranium may be provided to the nuclear reactor core in the form of fuel pellets, which may be disposed in fuel rods that are, in turn, disposed in the nuclear reactor core.
The fuel rods are often surrounded by a cladding material to physically separate the nuclear fuel from an external environment, such as from thermal transfer fluids (e.g., water) that are used to drive, for example, turbines for power generation. Unfortunately, during use and operation of the nuclear reactor, the cladding materials may be exposed to excessing temperatures, pressures, and other environments that may facilitate corrosion of the cladding materials. When the cladding material corrodes, the fuel pellets within the fuel rods may be exposed to the thermal transfer fluids (e.g., coolants). However, exposure of the fuel pellets to the thermal transfer fluids may result in dissolution or erosion of the fuel pellets, reducing the effectiveness of the nuclear fuel.

Nuclear fuel elements including protective structures, and related method of forming a nuclear fuel element


Methods, systems and devices are described for a direct-sequence spread-spectrum communication scheme that increases the number of users by utilizing a plurality of closely spaced orthogonal carriers that produce overlapping spectra. A method includes overlapping a plurality of direct-sequence spread-spectrum signals using carrier frequencies that are orthogonally spaced relative to a bit rate. The methods, systems and devices provide advantages because they can accommodate an increase in the number of normalized users and can optimize the loading of users across multiple frequency channels.

1. Field of the Invention
The invention relates generally to the field of communications. More particularly, the invention relates to spread-spectrum communications.
2. Discussion of the Related Art
In standard direct-sequence spread-spectrum (DSSS) methods, each doubling of the number of users in a given frequency channel decreases the reliability by 3 dB due to code interference. In the typical DSSS systems, carrier separation is based on the chip rate as discussed in the following patent summaries.
A technique for utilizing orthogonal frequency spacing to enhance communication efficiency is disclosed in Natali, U.S. Pat. No. 5,623,487, "Doubly Orthogonal Code and Frequency Multiple Access Communication System" the entire contents of which are hereby expressly incorporated by reference herein for all purposes. Natali discusses orthogonal code division multiple access (OCDMA) radio communication systems having at least one base station and a plurality of remote subscriber terminals, the a method of reducing the sensitivity of OCDMA to access noise due to time base error and multi-path delay spread comprising: (1) reducing the size of the orthogonal signal set on a single carrier, and (2) providing additional carriers with orthogonal frequency spacing for additional subscriber capacity. The orthogonal frequency spacing of Natali is based on the spread-spectrum chip rate as discussed in the following excerpt. "The modulated carrier frequency is selected from one of N frequencies which are orthogonal over a RW (Radamacher-Walsh) chip interval, i.e. the carrier frequencies are spaced by the RW chipping rate. The composite signal is up-converted to the appropriate frequency band for transmission."
A similar technique is disclosed in Kondo, et al., U.S. Pat. No. 5,521,937, "Multicarrier Direct Sequence Spread System and Method," the entire contents of which are hereby expressly incorporated by reference herein for all purposes. Kondo discloses an orthogonal frequency spacing based on the chip rate as discussed in the following excerpt: "The M carriers are designed to be orthogonal to each other. That is,∫OT cos(ωit+φi)cos(ωjt+φj)dt=0 for i≠j  , (Eq. 1)where T is the bit duration, and ωi and ωj are different carrier frequencies for i≠j. Orthogonality is achieved by choosing
                                          ω            i                    =                                                    m                                                  π                  T                                            +                                                (                                      i                    -                    1                                    )                                                n                                                                      4                                                                                π                                    T                                                      =                                          m                                                  π                  T                                            +                                                (                                      i                    -                    1                                    )                                                                                4                                                                                π                                                        T                    c                                                                                ,                            (                  Eq          .                                                    2                )            where m is an integer, n is the number of chips per bit [that is, the rate at which the bits of the data signal d(t) are chopped into chips], and Tc is the chip duration."
Another technique that uses chip-rate frequency spacing to achieve orthogonality is disclosed in Schilling, U.S. Pat. No. 5,274,665, "Polyopoly Overlapping Spread Spectrum Communication System and Method," the entire contents of which are hereby expressly incorporated by reference herein for all purposes. Schilling discloses a system such as discussed in the following excerpt: "The carried signal of the second transmitter station is shifted in frequency from the carrier signal of the first transmitter station by the chip rate of the message-chip-code signals. The carrier signal of the third transmitter station is shifted in frequency from the carrier signal of the first transmitter station by twice the chip rate of the message-chip-code signals, etc."
A problem with these technologies is user interference due to channel overcrowding. As the number of users increases, this problem is exacerbated.
Modern spread-spectrum communication systems, both CDMA and FDMA, are reaching the limit of user saturation in populated urban areas. The usual solutions of allocating more bandwidth with a multiplicity of standards and frequency channels are unattractive due to the hardware cost to the vendor and the proliferation of specialized consumer units required. To take a particular example, consider the Industrial, Scientific, and Medical (ISM) band of 902 to 928 MHz that is commonly used for unlicensed communications, the standard U.S. IS-95 cellular telephone bands of 824–849 MHz (transmit) and 869–894 MHz (receive), or the PCS bands from 1850–1910 MHz (transmit) and 1930–1990 MHz (receive). A typical ISM vendor will choose a 915-MHz carrier for DSSS or frequency-hopping spread-spectrum (FHSS) CDMA (code-division multiple-access) channels. Each user is assigned a pseudo-random code such that (few) users active on the same carrier frequency have little probability of interfering with one another. The code itself is unambiguous to decode, allowing effective and noise-free transmission of digital information (usually) at baud rates consistent with high-quality voice communication.
Since these codes appear to be random, one interferes with another by appearing as random noise. If two users are transmitting at the same power level (as seen by a receiver) using one of the same signals or codes, the ability to decode the desired signal in an error-free manner will degrade by 3 dB. If the number of interferers is doubled to 2 (three transmissions on the same channel), the effective signal-to-noise degradation will be by 6 dB. In a similar manner, for each doubling of users that generate noise-like random signals as far as decoding a particular signal is concerned, the ability to detect and use the desired signal will degrade by an additional 3 dB.
A simplistic solution to this problem is to allocate a new frequency channel once the previous one has reached capacity as defined by a certain level of inter-user interference. The drawbacks to this simplistic approach are twofold: (1) such allocations must be coordinated with the services presently extant and (2) the particular band is soon full; e.g., the 915-MHz ISM band can only support 14 such channels if the chipping rate is 1 MHz.
Other solutions to relieve this overcrowding have been known for many years and are discussed in such texts as the one by Dixon(1) and Peterson(2) under the rubric "hybrid methods." The central idea of these solutions is to frequency hop between DSSS channels. The standard discussion of hybrid FDMA/CDMA systems is from the processing-gain standpoint. Various authors have correctly and consistently pointed out that the increase in processing gain to be expected from any such hybrid system is approximately 3 dB in a typical case.
What is missing in these prior art discussions that start with a predetermined number of users and frequency-hop channels is a method that accommodates a probabilistic or deterministic increase in the number of users normalized to a standard bandwidth (bits/sec/Hz, for example). What is needed, therefore, is an approach that accommodates an increase in the number of normalized users.
What is also missing in these prior-art discussions are methods for optimizing the loading or equalization of the users across multiple, closely spaced frequency channels within the allocated band. What is also needed, therefore, is an approach to optimizing the loading or equalization of the users across multiple, closely spaced frequency channels within the allocated band.
Heretofore, the requirements of accommodating an increase in the number of normalized users and optimizing the loading of users across multiple, closely spaced frequency channels have not been fully met. What is needed is a solution that addresses both of these requirements.

Hybrid spread-spectrum technique for expanding channel capacity


A slide rail assembly for a rack system is installed to a chassis. The chassis includes a first chassis and a second chassis. The slide rail assembly includes an outer rail and an inner rail. The inner rail is movably connected to the outer rail. The first chassis of the chassis is installed to the inner rail, and the second chassis of the chassis is movably connected to the inner rail. The second chassis is movable relative to the first chassis to adjust the total length of the chassis.

1. Fields of the invention
The present invention relates to a slide rail assembly for use in a rack system, and more particularly, to a slide rail assembly which has an adjustable length and allows a chassis to move along its adjusted length.
2. Descriptions of Related Art
To facilitate the examination and maintenance of rack-type servers in a computer system, the conventional chassis for the rack-type servers usually has slide rails installed on two sides thereof and are connected to posts of a rack by support members which are connected to the slide rails such that the servers can be easily pulled out from the rack.
U.S. Pat. Nos. 7,137,512, 6,574,100, 6,930,886 and 6,948,691have disclosed related techniques of rack systems and are incorporated herein by reference.
The related prior art usually modularizes different electronic components of a server into different modules, such as to arrange a CPU module, a hard disk module, and a power supply module, etc. in a chassis, and connects those different modules by cables to facilitate the examination and maintenance of the servers. For example, a module, such as the CPU module, can be removed from the chassis after the cables connected between the different modules are removed. However, due to the narrow and limited space of the chassis and the complication of the cables, the removal of the cables is not easy, and this brings a lot of difficulties for the workers.
The present invention intends to provide a slide rail assembly for a rack system, wherein the length of the slide rail assembly is adjustable such that the installation or removal of the cables of the servers is facilitated.


A monolithically integrated bipolar transistor has an SOI substrate, a collector region in the SOI substrate, a base layer region on top of and in contact with the collector region, and an emitter layer region on top of and in contact with the base layer region, wherein the collector, base layer, and emitter layer regions are provided with separate contact regions. Further, a region of an insulating material, preferably an oxide or nitride, is provided in the base layer region, in the emitter layer region, or between the base and emitter layer regions, wherein the insulating region extends laterally at a fraction of a width of the base and emitter layer regions to reduce an effective width of the bipolar transistor to thereby eliminate any base push out effects that would otherwise occur.

1. Field of the Invention
The present invention generally relates to the field of integrated circuit technology, and more specifically the invention relates to a monolithically integrated bipolar transistor on an SOI (Silicon-On-Insulator) substrate.
2. Description of Related Art
Bipolar transistors in SOI technologies using thin silicon layers are often designed by means of a vertical emitter-base structure and a lateral collector structure, see e.g. U.S. Pat. No. 5,087,580 to Eklund, and J. Cai et al., Vertical SiGe-Base Bipolar Transistors on CMOS-Compatible SOI Substrate, p. 215 in Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting.
Depending on the geometry, this design may be limited by base push out effects, also called the Kirk effect, as shown by Q. Ouyang et al., A Simulation Study on Thin SOI Bipolar Transistors with Fully or Partially Depleted Collector, p. 28 in Proceedings of the 2002 Bipolar/BiCMOS Circuits and Technology Meeting. The base push out is strongly affected by the oxide layer of the SOI substrate beneath the transistor. In a standard transistor the base push out would just continue down towards the collector. However the oxide interface prevents all transport and the entire collector layer becomes flooded with carriers, giving a slower transport. This is seen as a hook in a Gummel plot and as a dip in the transition frequency, fT.
As pointed out by Q. Ouyang et al., a common manner to reduce the base push out is to shrink the emitter width or to increase the doping concentration in the collector region. However, the shrinking of the emitter may be prevented by the minimum feature sizes allowable by the lithography of the particular fabrication process used.


Disclosed is a method for interfacing in a communication system. The method includes receiving an event, which should be processed using information managed by a second system providing a second service, from a first system providing a first service; and performing an interface so that the second system performs an operation corresponding to the event by using the information.

1. Field of the Invention
The present invention relates to an apparatus and a method for interfacing in a communication network, and in particular, to an apparatus and a method for interfacing between a mobile communication system and an Internet service/content providing system.
2. Description of the Related Art
In general, mobile communication systems are being developed today to provide a wider variety of services to Mobile Stations (MSs). For example, mobile communication systems research is being directed toward delivering a wider variety of services, such as Internet service and content, to the MSs. In this case, the Internet services and content are typically provided by an Internet service/content providing system.
Currently, the mobile communication system and the Internet service/content providing system are independently operated. As such, the mobile communication system cannot use the Internet service/content-related information managed by the Internet service/content providing system, and the Internet service/content providing system cannot use mobile communication-related information managed by the mobile communication system. Therefore, the mobile communication system is limited in the services that can be provided by the mobile communication system because the mobile communication system cannot use the Internet service/content-related information managed by the Internet service/content providing system as described above. On the other hand, the Internet service/content providing system is also limited in the services that can be provided by the Internet service/content providing system because the Internet service/content providing system cannot use mobile communication-related information managed by the mobile communication system as described above.

Apparatus and method for interfacing in a communication system


A protection circuit board resulting in a compact battery pack having a higher capacity than a conventional battery pack of the same size, a battery pack including the protection circuit board and a method of fabricating the protection circuit board includes: a first lead terminal disposed on a first side of the protection circuit board; and a first aperture for exposing the first lead terminal to a second side of the protection circuit board. The battery pack also includes: a bare cell including an electrode terminal; a second lead terminal arranged over the electrode terminal; and a protection circuit board electrically connected to the second lead terminal and the bare cell, and having an aperture for exposing the second lead terminal arranged the first side of the protection circuit board to the second side of the protection circuit board.

1. Field of the Invention
The present invention relates to a protection circuit board, a battery pack including the protection circuit board and a method of fabricating the protection circuit board, and more particularly, the present invention relates to a protection circuit board which can realize a compact battery pack and a higher capacity than a conventional battery pack having the same size by changing electrical connections between a bare cell and a protection circuit board, a battery pack including the protection circuit board and a method of fabricating the protection circuit board.
2. Description of the Related Art
In recent times, various compact handheld electronic/electrical devices, such as cellular phones, notebook computers, camcorders, and so on, have been widely developed and produced. The handheld electronic/electrical devices include a battery pack installed therein to operate the devices without a separate power source. Battery packs may be classified into nickel-cadmium (Ni—Cd) batteries, nickel-metal hydride (Ni-MH) batteries, and lithium (Li) batteries. A battery pack using a secondary (rechargeable) battery is generally used in consideration of economic efficiency.
Among the types of batteries, the lithium ion secondary battery is widely used for the handheld electronic/electrical devices due to an operating voltage three times higher and a higher energy density per unit weight than the Ni—Cd battery and the Ni-MH battery. Lithium ion secondary batteries may be classified into Li ion batteries using a liquid electrolyte and Li polymer batteries using a polymer electrolyte depending on the kind of electrolytes, or may be classified into a cylindrical, rectangular or pouch type batteries, depending on the shape thereof.
Generally, a battery pack includes a bare cell which can be charged or discharged, and a protection circuit board electrically connected to the bare cell.
The bare cell is formed by accommodating an electrode assembly including a positive electrode plate, a negative electrode plate and a separator disposed therebetween, and an electrolyte in a can, and sealing the can with a cap assembly including an electrode terminal electrically connected to either the positive electrode plate or the negative electrode plate.
The positive or negative electrode plate which is not electrically connected to the electrode terminal is electrically connected to a cap plate of the cap assembly or to the can, which thus serves as a terminal, and the electrode terminal is electrically insulated from the cap plate and the can.
The protection circuit board is electrically connected to the electrode terminal of the bare cell, and to the cap plate or the can, thereby controlling voltage or current during charging/discharging of the bare cell to prevent an overvoltage or overcurrent in the bare cell.
The battery pack is fabricated by arranging an electrode assembly into an opening on one side the can. The electrode assembly includes a positive electrode plate and a negative electrode plate formed by applying a positive electrode active material and a negative electrode active material to a positive electrode collector and a negative electrode collector and a separator formed between the positive electrode plate and the negative electrode plate and then stacking and winding them.
Then, a cap assembly is attached to the open side of the can, an electrolyte is injected into the can through an electrolyte injection hole of the cap assembly, and the electrolyte injection hole is sealed, thus completing the bare cell.
Subsequently, a first lead plate and a second lead plate respectively electrically connected to an electrode terminal and a cap plate or a can of the bare cell, are electrically connected to third and fourth lead plates, which are electrically connected to the protection circuit board, and a space formed due to the electrical connection between the first to fourth lead plates is filled using resin, thereby preventing an occurrence of an electrical short-circuit between the bare cell and the protection circuit board, thus completing the battery pack.
To electrically connect a bare cell to a protection circuit board, in the conventional battery pack, first and second lead plates electrically connected to the bare cell were electrically connected to third and fourth lead plates electrically connected to the protection circuit board using a soldering process or a welding process, such as resistance welding. Also, a specific-sized space should be maintained between the bare cell and the protection circuit board for smooth welding. Thus, the space between the bare cell and the protection circuit board could not be smaller than a predetermined amount.
Also, in order to prevent an occurrence of electrical short-circuits due to moving of the bare cell and the protection circuit board, the space between the bare cell and the protection circuit board is filled in. However, defects may occur in the filling process, or the bare cell or the protection circuit board may be misplaced, thereby making electrical connection therebetween unstable.

Protection circuit board, battery pack including the protection circuit board and method of fabricating the protection circuit board


An improved fragrance dispenser, domestic appliance, such as a vacuum cleaner, including such a fragrance dispenser, and cartridge for such a fragrance dispenser is provided in which the dispenser includes a housing portion through which an air discharge passage interconnecting an upstream side of the housing portion and a downstream side of the housing portion extends, and a cartridge carrying a fragrant substance and having vents for allowing air to pass for entraining fragrance from said cartridge, wherein the cartridge is removably mounted and rotatably adjustable about an axis of rotation between at least a first position and a second position, at least a portion of at least one of the vents being obstructed by a housing portion if the cartridge is in the first position and being open if the cartridge is in the second position. The cartridge is removable in a direction transverse to the axis of rotation, and the dispenser includes means adapted for engaging and releasing the housing portion in a direction transverse to the axis of rotation. The cartridge contains a granular fragrance carrier substrate.

The invention relates to a fragrance dispenser comprising a housing portion through which an air discharge passage interconnecting an upstream side of said housing portion and a downstream side of said housing portion extends, and a cartridge carrying a fragrant substance and having vents for allowing air to pass for entraining fragrance from said cartridge, wherein the cartridge is removably mounted and rotatably adjustable about an axis of rotation between at least a first position and a second position, at least a portion of at least one of said vents being obstructed by said housing portion if said cartridge is in said first position and being open if said cartridge is in said second position.
The invention further relates to a domestic appliance, such as a vacuum cleaner, including a fragrance dispenser according to the invention.
The invention also relates to a fragrance dispensing cartridge carrying a fragrant substance and having vents for allowing air to pass for entraining fragrance from said cartridge and including retaining means for removably engaging a housing portion for mounting the cartridge in a position such that it is rotatably adjustable about an axis of rotation between at least a first position and a second position.

Fragrance dispenser, domestic appliance including such a fragrance dispenser, and cartridge for such a fragrance dispenser


A method for testing power switches using a logic gate tree, the method includes providing a logic gate tree electrically connected to a plurality of power switches, each output node of the plurality of power switches being electrically connected to a corresponding input node of a logic gate of the logic gate tree; applying a pattern of control signals to the plurality of power switches for controlling on-off states of the plurality of power switches; and determining whether an output voltage signal of an output node of the logic gate tree matches a predetermined value corresponding to the pattern of control signals.

1. Field of the Invention
The present invention relates to a method for testing power switches using a logic gate tree, and more particularly, to a method for testing embedded power switches of an integrated circuit using a logic gate tree.
2. Description of the Prior Art
As related technology keeps improving, integrated circuits become more powerful and smaller, and lower power consumption becomes a basic requirement of the integrated circuits correspondingly. Therefore, ways to control or decrease leakage current inside the integrated circuit is of key importance.
Please refer to FIG. 1, which shows an integrated circuit 100 of the prior art utilizing MOS transistors M1, M2, M3 as power switches to control current flows i1, i2, i3 inside the integrated circuit 100. Because the MOS transistors M1, M2, M3 are capable of switching large amounts of power, the MOS transistors M1, M2, M3 are installed between a power source 140 and corresponding functional circuits 110, 120, 130 of the integrated circuit 100. When the functional circuit 110, 120, 130 is working, the MOS transistor M1, M2, M3 is turned on to provide a path for the current flow i1, i2, i3 from the power source 140 to the functional circuit 110, 120, 130. On the other hand, when the functional circuit 110, 120, 130 is idle, the MOS transistor M1, M2, M3 is turned off to block the current flow i1, i2, i3 from the power source 140 in order to decrease leakage current in the functional circuit 110, 120, 130.
In the prior art, the method for verifying function of the MOS transistors M1, M2, M3 is performed by measuring leakage current at the output nodes B of the MOS transistors M1, M2, M3 one by one. For example, the MOS transistor M1 is turned on and then off (the other MOS transistors M2, M3 are turned off) to measure leakage current at the output node B of the MOS transistor M1. Thereafter, the MOS transistor M2 is turned on and then off (the other MOS transistors M1, M3 are turned off) to measure leakage current at the output node B of the MOS transistor M2. Finally, the MOS transistor M3 is turned on and then off (the other MOS transistors M1, M2 are turned off) to measure leakage current at the output node B of the MOS transistor M3. Therefore, each leakage current of the MOS transistors M1, M2, M3 can be detected to determine whether the MOS transistors M1, M2, M3 work functionally.
However, measuring leakage current level is time consuming, and sometimes the leakage current may be too small to be sensed such that it may cause an error judgment. Moreover, the prior art must measure each leakage current of the MOS transistors one at a time, which is inefficient.

Method and apparatus for testing power switches using a logic gate tree


A plant watering container assembly comprising a bottom container section having side and bottom walls defining a water reservoir, and a top container section removably connected to said bottom container section. The top container section includes an integrally formed funnel-shaped section having a side wall extending downwardly toward said reservoir and defining a conical opening for receiving a side wall of a potted plant, and further having an integrally formed annular bottom wall defining at its radially inner edge a central opening through which a watering wick can pass downwardly into the reservoir. In the event the container is tipped or turned, water in the container reservoir is trapped in an annular chamber defined by the wall of the funnel and the top and bottom container sections, thereby precluding water passing outwardly through the central opening of the funnel-shaped section.

The present invention relates as indicated to a plant watering container, and more particularly to a container which can be partially filled with water prior to shipping and is able to accommodate tilting or tipping of the container without spillage during transportation.
There are numerous plant watering systems for systematically supplying water or nutrient-enriched water from a reservoir to the bottom of a pot by capillary action. Many plant species, for example, African violets, clearly prefer bottom watering. Top water tends to result in overwatering of the plant, whereas bottom watering, if properly performed, tends to provide a consistent and adequate supply of moisture to the growing media for the plant without the adverse effects or potential for overwatering.
In standard approximately 4" pots, bottom watering of African violets was provided for in U.S. Pat. Nos. 4,343,109 and 4,434,577, issued to Reinhold Holtkamp, Sr. In each of those patents, a water absorbing pad was positioned between the pot and a support member, with the pad including a tab portion extending into a water reservoir for transmitting water by capillary action through the pad into the bottom of the pot. Although such arrangements perform very satisfactorily for pots 4" or larger in diameter, they are not designed for miniaturized pot containers.
Pot miniaturization has developed for numerous species, including African violets. Miniaturized pots, approximately 1.25" up to 2.25" in pot diameter at the top thereof, have been very popular with consumers, and special African violet breeding programs have been developed to miniaturize plants for these pots in such a manner that the plants are proportional in every respect to plants much larger. These miniaturized pots present special problems for bottom watering, and special containers for that purpose have been designed and have achieved considerable commercial success and acceptance. U.S. Pat. Nos. 4,996,792 and 5,111,614, also issued to Reinhold Holtkamp, Sr., disclose watering containers which comprise separate but interengageable upper and lower container sections. The lower section defines a water reservoir, with the upper container section being formed with a central opening to receive and support the miniature pot. The plant is watered by means of a wick which extends from the growing media in the pot downwardly into the water reservoir whereby water is transferred by capillary action up into the growing media to provide moisture for the plant.
In U.S. Pat. Nos. 4,996,792 and 5,111,614, a central opening is formed in the top wall of the upper container section, and the miniature pot is formed with an annular flange which engages the portion of the top wall surrounding and defining the central opening. One or more watering wicks are provided, with the lower end of the or each wick extending into the water reservoir, and the upper end of the wick engaging and being retained by a wick holding device which extends upwardly through an opening in the bottom wall of the pot into the growing media. Various wick holding and insertion devices have been devised for that purpose, with two such devices being disclosed in U.S. Pat. Nos. 4,932,159 and 5,193,305.
Although miniature potted plants and watering containers can be separately supplied to the wholesaler or retailer, it is desirable to assemble the plant with the container. Similarly, although water can be added to the container by the wholesaler or retailer, it is more desirable to provide the water supply at the time of assembly so as to ensure satisfactory watering of the plants during transportation and during handling of the plants and containers for display. This requires that the wick and wick holding device be inserted in the growing media in the pot, and that the wick extend downwardly into the water reservoir when the plant pot and container are assembled. This not only ensures adequate watering during the shipping and handling process, but eliminates the time-consuming need for the recipient, e.g. a retailer, to assemble the wick with the pot, the pot with the container, and to make certain that adequate water is added to the reservoir. Pre-assembly and watering permits the retailer to immediately display the plants and containers while the plant is in optimum condition. This is critically important to the marketing effort.
Although pre-assembling and watering does provide several advantages as noted above, there are also potential problems. With previous containers, it was very important that the container and potted plant be kept generally upright. Tilting or entirely tipping the container onto its side could result in the pot being separated from the upper container section, with the plant itself possibly being separated from the pot. The tipping also caused water in the reservoir to leak outwardly of the upper container section if the water in the reservoir was filled above a fairly low level. Since numerous plants and containers are normally shipped in a single shipping container, the tilting, or tipping of the containers onto their sides, could result in the damage or loss of the entire shipment, or require at the very least replacement of those plants damaged during shipment.
The plant watering system of the invention disclosed in my pending application Ser. No. 08/352,078 attempts to solve the leakage problem resulting from turnover by providing in the upper container section a downwardly directed funnel-shaped wall complementary to the shape of the side wall of the pot and surrounding the same when the pot is mounted in the upper container section. The funnel-shaped wall is open at its bottom and extends downwardly below the bottom wall of the pot. This arrangement provides a continuous annular wall positioned much closer at its bottom to the vertical axis of the container, as a result of which greater amounts of water can be stored in the reservoir before leakage occurs if the container is tipped on its side.
Another arrangement designed to overcome the problem of leakage resulting from tipping of pre-assembled, watered containers is disclosed in U.S. Pat. No. 5,491,929. The container assembly disclosed therein comprises upper and lower halves rigidly secured together. The upper half is formed with a re-entrant structure comprised of a side wall which is conical or funnel-shaped and complemental to the angularity of the outer walled surface of the pot to be supported by the container. The side wall of the re-entrant structure is open at the top thereof to receive the pot flange, and also at the bottom thereof. In the preferred form disclosed, the height of the conical wall is less than the side wall of the pot which it supports, and the vertical dimension of the conical wall is substantially less than one half the vertical dimension of the assembled container halves. This greatly limits the depth of water in the reservoir which can be accommodated during transportation and shipping, while still being able to preclude leakage of water in the event the container is fully tipped on its side. Although the patentee contemplated a longer conical re-entrant wall, it is clearly recognized and described that with such longer wall structure, substantially less water can be accommodated in the reservoir before spilling out over and through the conical re-entrant wall and consequently outwardly of the container.
A further described feature of the container illustrated in U.S. Pat. No. 5,491,929 is the bonding of the two container halves in order to provide a container that will not leak through the connecting joint. Ultrasonic bonding is described as being preferred, although chemical or mechanical techniques could be employed. Although such bonding provides the desired advantage of leakage avoidance during shipping and handling, it has the distinct disadvantage of precluding separation of the container halves or sections by the retailer or ultimate consumer. As a result, in order to replenish the water supply, the pot must be removed from its supported position. Since the conical re-entrant wall tightly frictionally receives the pot, it is potentially difficult to remove the pot without damaging the plant. Moreover, rigidly connecting the container halves results in significant aesthetic and sanitary disadvantages. Algae and dirt particles frequently are present in the reservoir water thereby discoloring the same. Since there is no direct access to the bottom container half except through the open lower end of the re-entrant wall, the reservoir walls are cleaned very infrequently, and then with great difficulty.


A heat dissipating lamp is provided. The lamp includes a reflector, a lens cover, a support structure interposed between the reflector and the lens cover, and an LED mounted to the support structure. The lens cover includes a portion adjacent a peripheral edge of the reflector. The support structure includes a bridge.

The present invention relates generally to illumination devices. It finds particular application in conjunction with illumination devices employing multiple light emitting diodes ("LEDs") and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.
Most automotive lamps use incandescent filaments to generate light. The light can be reflected off a simple mirror-type reflector. LEDs have been replacing incandescent filaments as a light source, because LEDs are more efficient and longer lasting.
LEDs are small efficient light sources, but to emit a sufficient amount of light, especially in an automotive lamp, a plurality of LEDs need to be grouped together. Pointing the LEDs toward the field where illumination is desired can appear to an onlooker as a group of bright dots. A reflector is provided in the lamp to direct and scatter the light so that the lamp does not look like a plurality of lighted dots.
LEDs operate at high temperatures. High operating temperatures degrade the performance of LED lighting systems. Also, high-powered LEDs can have very wide light emission angles, some approaching or exceeding 180°. Existing LED reflector/thermal systems either collect a much smaller cone angle of light or fail to provide a thermal path for heat convection.
Accordingly, it is desirable to design a lamp that collects the majority of light emitted by an LED and directs it toward a desired target. It is also desirable to position the LED such that light reflected by the reflector does not strike the LED resulting in additional heat being directed toward the LED. It is also desirable to provide a suitable thermal path for cooling the lamp.

LED luminaire with thermally conductive support


Method and apparatus for reclaiming sand from a foundry sand containing, inter alia, a clay binder by cooling the foundry sand to a temperature at or below -40.degree. C. (-40.degree. F.) followed by separation of the sand from the binder while the sand is maintained at a temperature at or below 0.degree. C. (32.degree. F.). Foundry sands with clay binders have a water content to 1% to 15% by weight prior to being cooled.

The present invention pertains to reclaiming foundry sand, be it green sand or sand used in molded cores for reuse or safe disposal.
In the production of certain types of metal castings, large or small, e.g. aluminum, iron or steel, the casting mold is prepared by the application of suitable binders or adhesives to specifically sized aggregates such as silica sand, specialty sands or synthetic sands. The adhesives most commonly used include natural clays activated by water and inorganic and organic resins cured by various catalysts, such as acids, bases or heat activation. In the founder's lexicon, the term "green sand" refers to sand that is bonded with a mixture of clay and water. Water is added in specified amounts to activate the fine ground clay which has been mixed with the specially prepared aggregate, sand. This homogeneous mixture of sand which has been coated with water activated clay is then applied to patterns using pressure, vibration or other means of compaction to form the container or "mold" into which molten metal is poured to form the casting.
Alternatively to clay/water adhesives, the use of synthetic organic and inorganic resins are commonly used to prepare molds capable of withstanding the regors of the metal casting process. In the preparation of resin bonded sand molds, washed and dried aggregates such as silica sand, lake sand, synthetic aggregates, specialty sands such as olivene, chromite and Zircon sands are mixed with resins in mullers, batch mixers or continuous mixers to coat the aggregate particles with the resins. Curing or hardening of the resin films or adhesives which coat the sand grains can be achieved in a wide variety of methods including, catalysis, heat, or through the use of gases or vapors. Some resin systems employed can also be autocatalytic or self setting.
The terminology "green sand" describes the natural state of clay/water activated adhesives since it is similar to green ware in ceramics or wood, where the term green means that the ceramic has not been fired or dried in a kiln or oven. In the case of wood, the wood has not been subjected to a drying operation to reduce its moisture content. In addition to sand, the aggregates, which can be silica, zircon, chromite, olivine, ceramic or synthetic, and the clay binder, which can be western bentonite, southern bentonite or other clays such as fire clay, the foundry sand may also contain additives such as cereal, in the form of corn, milo, wheat and rye flours, cellulose in the form of finely ground wood flour, oat hulls, rice hulls and ground nut shells, carbon in the form of seacoal, (low sulfur coal), gilsonite, lignite and polymers or chemicals, such as water, or polymers, wetting agents, soda ash and iron oxide to name a few.
The foundry process also includes the use of bonded aggregates to produce cores or shaped sand necessary to form the internal passages or surfaces. The same sand that is used to make the mold can also be used to make cores which are placed in the mold to achieve hollows, slots, passages, holes and the like in the finished castings. Cores are generally made from new sand since the presence of contaminates such as clays, fines, water or organic and inorganic materials interfere with the adhesives bonding mechanism chemically or physically. Synthetic sands may also be employed to impart special characteristics to the cores when they are exposed to the casting process. Again, as in the production of resin bonded molds, adhesives or resins are coated on washed and dried specifically sized aggregates which are cured through a variety of methods described above for molding with resin systems. Examples of no bake binders are furan and phenolic/acid cured systems, phenolic/ester cured systems, alkyd oil urethanes, alumina phosphate, and silicate/ester mixtures. Examples of cold box binders are acrylic epoxy SO2, (free radical or acid cured), furan SO2, phenolic urethane amine cured systems, ester cured alkaline phenolics, sodium silicate CO2 and phenolic CO2 cured systems. Examples of heat cured binders are hot box-furan and phenolic resins, warm box-furan and phenolic, shell, core oil and aluminate silicates.
In the manufacture of castings, after the molten metal is poured into the mold and solidification has occurred, the mold is subjected to "shake-out". Shake-out refers to the separation of the sand from the casting(s). The casting is then sent to various finishing operations and the sand is subject to either reclamation, reuse or disposal.
The most prevalent foundry molding method used is the green sand process followed by chemically bonded no-bake molding. Green sand molding without insertion or use of cores allows the mixture of sand, cereal, clay, water, seacoal, etc. to be reactivated through the addition of new clay, water and additives in mixers or mullers. However, new sand must be added to replace the sand lost in the casting process since handling, high temperatures and fracturing of the sand can occur.
In the case of castings which have internal passages or those which are hollow, the use of cores adds sand to the system or green sand which dilutes the clay bonded sand. Again, additions of clay, water, seacoal etc. must be made to maintain the desired properties of the green sand system.
Since most castings made in green sand systems and no-bake or chemically bonded molding require cores, the ability to reclaim the used or spent sand would be extremely desirable. In the past, disposal of foundry sand in a landfill site was one way of disposing of the sand after the shake-out operation. However, because of the ever changing environmental rules and regulations and the increasing costs for acquisition, preparation and delivery of new sand, efforts have been focused on the reclamation and reuse of sand and aggregates used in the casting process.
Attempts to reclaim sand for use within the foundry have not been successful for a variety of reasons. While green sand can be reprocessed for re-use in clay bonded molding sand, the reclamation of clay bonded sand has not been successful for a variety of physical and chemical reasons. These include alterations to grain fineness number, particle size distribution, contamination, moisture, changes in pH or acid demand value, and surface area changes to name a few.
Attempts to reclaim bentonite or clay bonded systems have included attrition, washing and thermal treatment. The most prevalent method of reclaiming sand values from foundry sand is through the application of mechanical treatment, thermal treatment or combinations of both. Thermal units typically employ infrared or gas fired thermal sources. In the traditional process for green sand reclamation, the ionic bond of clay systems is deactivated by calcination of the clay. The calcined clay, known as dead clay, can then be stripped from the sand by mechanical means, e.g. by high energy pneumatic stripping which impacts a stream of sand on a target and mechanically blasts the clay particles from the sand grain, or by imparting energy in the form of attrition, scrubbing or subjecting the particles to mechanical treatment.
Physical abrasion of the agglomerated and individual sand grains does not remove all of the adhesives from the sand particles since the irregular shapes on the sand surface do not always unlock the entrapped clay or resin particles. This, combined with the fact that the mechanical stripping results in a change in the particle size distribution of the sand so that the particle size distribution must be readjusted with the addition of new sand additions to maintain the desired size distribution. Too fine or coarse particle distribution results in inferior molding properties and can produce adverse affects upon the castings produced, such as, gas related and metal penetration defects.
Thermal reclamation of green sand or resin bonded sands typically operate at temperatures in excess of 1600 degrees F. (871.degree. C.) for bentonite bonded and inorganic bonded sands and in excess of 900.degree. F. for organic based adhesive systems. The process of thermal reclamation includes both heating and cooling followed by mechanical stripping, sand cooling and classification of the sand for reblending or rebonding. The overall process can result in a sand fraction that may not meet original specifications and a waste stream of silica fines and dead clay, all of which must be disposed of in a landfill or by other environmentally acceptable means.
A second type of reclamation is the use of mechanical attrition to mechanically breakdown the lumps or agglomerated sand particles into individual sand grains when resins or adhesives are used in place of clay bonded systems. Although mechanically reclaimed sand can be used in most chemically bonded systems, the returned or reclaimed sand typically contains residues of resin and carbonaceous materials which interfere with rebonding of the sand or produce undesirable casting conditions. The presence of residuals not removed by mechanical reclamation increase the fineness of the sand which typically requires greater levels of binder additions to maintain equivalent strength for handling and pouring. In addition, the higher levels of adhesives in the system can contribute to casting defects.
In a thermal process it is typical that about 1 million Btu's of energy be consumed per ton of reclaimed sand. In addition to the heat energy, energy must be expended to cool and classify the sand as well as to provide for whatever environmental regulations require. In many instances, thermally treated sand may require additions of chemicals to alter the pH and acid demand value of the sand to make it suitable for reuse in the core production area or in chemically bonded systems.
Thermal processes work well on most chemically bonded sands, but as stated above, do not work as well on clay bonded systems. Numerous schemes have been used to provide exposure of the sand to the source of heat, such as rotary kilns, fluidized beds and mechanical stirring. All of the thermal reclamation systems are sensitive to sand composition, binders and the amount of metallic oxides present in the sand, regardless of how the sand is heated. Thermal reclamation units require periodic relining and extensive environmental regulations govern their use. For example, calciners have been classified as fluid bed incinerators rather than reclaimers, thus requiring the operators to respond to different and more stringent environmental rules and regulations. It is estimated that, on average, to construct and verify operability of a thermal reclamation system will cost an operator about 500 thousand dollars per ton of capacity per hour of operation.
Additional discussions of foundry sands, binder systems and additives can be found in a series of papers published in AFS Transactions of the American Foundry Society. These are "If it's Black, Why do they scall it Green Sand" by D. F. Hoyt, AFS Transactions 1995, Vol. 103, Pages 353-369 (#95-100), "Scanning Electron Microscope and Sand-Binder Studies: A 25-Year Review" by R. H. Toeniskoetter, AFS Transactions 1995, Vol. 103, Pages 477-486 (#95-144), "Sand Reclamation Project: Saginaw Malleable Iron Plant, GM Powertrain Group" by D. J. Couture, R. L. Havercroft and L. L. Stahl, AFS Transactions 1995, Pages 783-790 (#95-141), "Evaluation of Reclaimed Green Sand for Use in Various Core Processes" by S. E. Clark, C. W. Thoman, R. H. Sheppard, R. Williams and M. B. Krysiak, AFS Transactions 1994 Vol. 102, Pages 1-12 (#94-02) and "Thermal Reclamation The Evidence Against It" by D. S. Leidel, AFS Transactions 1994, Vol 102, Pages 443-453 (94-10).
Ashland Chemical Company has collected thirteen additional papers in a re-print publication titled Sand Binder Systems under the cover Foundry Management & Technology (1996).
Therefore, there is a need for yet another method of reclaiming foundry sand.

Method for cold reclamation of foundry sand containing clay

American Metalcasting Services Int'l Inc.


The disclosure generally relates to a multimode imaging apparatus for simultaneously obtaining multiple wavelength-discriminative spectral images of a sample. In one embodiment, the apparatus includes an image selector having a rotator assembly, the rotator assembly housing a first plurality of optical components, the image selector adapted to receive a illuminating photons having a first wavelength and direct the illuminating photons to the sample, the image selector adapted to receive illuminating photons interacted with the sample and selectively direct said interacted photons to one of a plurality of detection sources; a microscope turret housing a second plurality of components, the microscope turret adapted to receive illuminating photons having a second wavelength and direct the photons to the sample; the microscopic turret adapted to receive illuminating photons interacted with the sample and selectively direct said interacted photons to one of a plurality of detection sources; wherein substantially all of the interacted photons are selectively directed one of a plurality of detection sources to form multiple wavelength discriminative spectral images of the sample simultaneously.

Spectroscopic imaging combines digital imaging and molecular spectroscopy techniques, which can include Raman scattering, fluorescence, photoluminescence, ultraviolet, visible and infrared absorption spectroscopies. When applied to the chemical analysis of materials, spectroscopic imaging is commonly referred to as chemical imaging. Instruments for performing spectroscopic (i.e. chemical) imaging typically comprise an illumination source, image gathering optics, focal plane array imaging detectors and imaging spectrometers.
In general, the sample size determines the choice of image gathering optic. For example, a microscope is typically employed for the analysis of sub micron to millimeter spatial dimension samples. For larger objects, in the range of millimeter to meter dimensions, macro lens optics are appropriate. For samples located within relatively inaccessible environments, flexible fiberscope or rigid borescopes can be employed. For very large scale objects, such as planetary objects, telescopes are appropriate image gathering optics.
For detection of images formed by the various optical systems, two-dimensional, imaging focal plane array (FPA) detectors are typically employed. The choice of FPA detector is governed by the spectroscopic technique employed to characterize the sample of interest. For example, silicon (Si) charge-coupled device (CCD) detectors or CMOS detectors are typically employed with visible wavelength fluorescence and Raman spectroscopic imaging systems, while indium gallium arsenide (InGaAs) FPA detectors are typically employed with near-infrared spectroscopic imaging systems.
Spectroscopic imaging of a sample can be implemented by one of two methods. First, a point-source illumination can be provided on the sample to measure the spectra at each point of the illuminated area. Second, spectra can be collected over the an entire area encompassing the sample simultaneously using an electronically tunable optical imaging filter such as an acousto-optic tunable filter (AOTF) or a liquid crystal tunable filter ("LCTF"). Here, the organic material in such optical filters are actively aligned by applied voltages to produce the desired bandpass and transmission function. The spectra obtained for each pixel of such an image thereby forms a complex data set referred to as a hyperspectral image which contains the intensity values at numerous wavelengths or the wavelength dependence of each pixel element in this image. Simplified imaging methods using Fiber array spectral translators (FAST) or reduced dimensional optical coupling devices can also be used to obtain lower resolution chemical imaging by segmenting pixels of the image for spectral analysis and analysis of the imaged data set and possible recombination for image analysis purposes.
The ability to improve discrimination testing of inks, stains, fibers and cloth as well as to improve visualization of fingerprints and thin layer chromatography plates are critical to the forensic analysis. Similarly, improved discrimination of irregularities, lesions or cellular objects or pathogens in biomedical or pathology applications is also critical. Such testing often requires obtaining the spectrum of a sample at different wavelengths. Conventional spectroscopic devices operate over a limited ranges of wavelength due to the operation ranges of the detectors or tunable filters possible. This enables analysis in the Ultraviolet (UV), visible (VIS), near infrared (NIR), mid infrared (MIR) wavelengths and to some overlapping ranges. These correspond to wavelengths of about 180-380 nm (UV), 380-700 nm (VIS), 700-2500 nm (NIR) and 2500-25000 nm (MIR). Thus, to obtain a comprehensive spectral analysis over a broad range of wavelengths more than one spectroscopic device must be applied. In other words, a first spectral image of the sample is obtained in a first mode followed by a second image of the sample obtained at a second detection mode.
Conventional methods are time-consuming and often impractical where several spectral images are required simultaneously. The sample position and condition may be changed between the first analysis or a later analysis thereby lessening the ability to precisely correlate the spectra obtained at different wavelength ranges. There is a need for a multi-mode imaging device capable of obtaining multiple wavelength-discriminative spectral images of a sample.

Method and apparatus for a microscope image selector


The present application discloses a method and apparatus for extracting association rules from data having two or more numeric attributes and a true-false attribute, and for presenting the rules in an easily understandable form. The method comprises the steps of: (i) storing numbers u(i,j) and v(i,j) of data in each pixel whose true-false attribute is true, so as to correspond to each pixel in a plane; (ii) inputting a condition .theta.; (iii) segmenting from the plane a rectilinear region S of the pixels to maximize the equation ##EQU1## ;and (iv) outputting data included in the segmented rectilinear region S. The invention also allows regions to be derived which satisfy a desired support maximization rule, confidence maximization rule, optimized entropy rule, and optimized interclass variance rule.

Consider the following problem about customers of a bank: what their floating deposit balances and their age must be so that the number of people having a time deposit balance of two million yen or more is 20% or more of the total number? The floating deposit balance and age are integers which are continuous numeric values, while the time deposit balance of two million yen or more is a classification of not less than two million yen or less than two million yen. The time deposit balance therefore has a true-false attribute. Similarly, a true-false attribute may represent, for instance, a question such as "Does the customer have a credit card?" or "is the customer male?" If such a query can be solved, the bank can easily find out, for instance, who it should send a new product advertisement to in order to efficiently conduct its business.
Conventionally, studies on the fast extraction of a rule (association rule) to represent a correlation between true-false attributes have been made in the field of data mining. These methods are described, for instance, in "Mining Association Rules Between Sets of Items In Large Databases," R. Agrawal et at., Proc. of the ACM SIGMOD Conference on Management of data, May 1993, and in "Fast Algorithms For Mining Association Rules," R. Agrawal et al., Proc. of the 20th VLDB Conference, 1994.
Furthermore, the following conventional techniques for determining rules between two-term numeric data are also known in the art.
1. Techniques of searching for a straight line in a plane that optimally approximates a set of points to find a strong linear correlation: These include, for example, least squares methods, recurrent center methods, etc. A drawback of these methods is that only a linear correlation can be found. Also, their accuracy is low if each data is predicated using the linear correlation and the absolute value of the correlation coefficient is 0.5 or less. Their usefulness is therefore limited.
2. Techniques for finding squares, rectangles, or circles or ellipses containing much data for the area thereof on a two-dimensional plane to find a weak global correlation: An example of these techniques is one using a calculation geometry algorithm, which generally has a long calculation time. For instance, a time more than O(M.sup.3) may be required for circles. O(M.sup.3) means that a calculation time of order M.sup.3 is required, where M represents the number of data. Further, a correlation region to be taken out is limited to only those having a fixed shape. However, there are not many cases in which a proper coverage is provided by a fixed shape.
3. Techniques for dividing a plane into a square mesh, and extracting pixels containing much data: The extracted pixels are often not connected, but exist apart from each other. It is therefore difficult to detect them as rules.
The above approaches also have a drawback of being difficult to distinguish meaningful rules from those that are meaningless. Generally, whether a correlation is practically meaningful often must be determined by a person. In the first two groups, meaningful correlations are easy to overlook since only special correlations can be taken out. In the third group, a person cannot find any rule by looking at the output.
Other methods include one for dividing a plane into a square mesh, and segmenting a region containing much data, which is in connection with pixels and x-monotone. (See, for example, "Data Mining Using Two-dimensional Optimized Association Rules: Scheme, Algorithms, and Visualization," Takeshi Fukuda et al., Proc. of the ACM SIGMOD Conference on Management of Data, pages 13-23, June 1996). The x-monotone means that it is convex in the column direction, but not in the row direction. Although this method can take out a correlation having a certain meaning at high speed, it often segments a complicated region which dramatically varies in the vertical direction, and thus it is difficult for a person to grasp by looking which portion has a strong correlation. Further, there is a disadvantage that the shape of a segmented region largely depends on how square meshes are given (i.e., how data is distributed to each pixel), because the region is x-monotone.

Method and apparatus for deriving association rules from data and for segmenting rectilinear regions

International Business Machines Corporation


Techniques for implementing a log message buffering system are disclosed. To this end, a computer implemented method includes receiving log messages. The computer implemented method also includes associating log messages with items of work and organizing the received log messages according to the items of work. Each item of work contains one or more log messages. The computer implemented method also includes outputting organized log messages according to items of work to a logging subsystem.

Many of today's software applications which are being run on a computer system include a logging feature such as the Syslog utility provided by the GNU C library. This utility is utilized in conjunction with many operating systems, such as IBM's Z/OS, Unix, AIX and the like. Like most logging facilities, the Syslog utility is a heterogeneous network logging feature which provides one or more systems with the ability to store and process debug, trace, and error messages into a single data repository. A Syslog repository allows a system administrator or software developer to isolate problems with the system. Many applications which utilize a logging feature such as the Syslog facility simply write messages to the logging feature at the time a debug or trace point or error occurs in the system. In other words, log messages are written to a log in the order they are produced, sequentially one after another. For example, a software application may produce five log messages during its initialization and three log messages during the process of shutting itself down. If the application is started and then immediately stopped, eight log messages are written to the log in time order.
Internally, many of today's software applications are multilayered, meaning that the successful completion of a function performed at a particular layer of the application is dependent on the successful completion of a lower or higher layer. By way of example, consider an Internet Key Exchange (IKE) daemon supplying encryption keys to an internet protocol security communication (IP/SEC) stack. An IKE daemon is a software application which implements Requests for Comments (RFCs) 2407, 2408, and 2409. In particular, the IKE daemon provides two levels of keys for establishing a secure network communication path and securing the data exchange over the secure network communication path between two endpoints. The purpose of the first level or phase one is to create valid encryption keys for a limited time for the IP/SEC stack to establish the secure network communication path. Once the secure network communication path is established, the second level or phase two creates valid encryption keys to be used by the IP/SEC stack to encrypt the data between the two endpoints.
In the case of an IKE daemon, an endpoint, by way of a software application, will request a secure connection to send its data securely to another endpoint. In this example, phase two will be requested by the endpoint to secure the endpoints' data for transmission to the other endpoint. However, phase two must request a secure connection to be established from phase one. Consequently, phase one begins establishing a secure connection with the other endpoints. Once this connection is established, phase two begins generating keys to encode the endpoints data. The initial reporting of debug or trace messages and error messages or collectively referred to herein as log messages are typically from within the phase one and phase two portions of the software application. In the example above, the order of log messages to a Syslog repository could include phase two initialization messages, followed by phase one initialization, establishment, and completion messages, followed by phase two establishment and completion messages. As a result, the sequential outputting of messages in the software application makes the arrangement of messages in the Syslog facility difficult for a software developer to trouble shoot problems in phase two due to the interspersing of phase one messages. Furthermore, since the data of outputted log messages within a phase or between phases is typically not associated, each outputted log message typically becomes too large in order to provide enough useful information. Consequently, the Syslog file becomes cluttered and unorganized for the software developer to readily isolate the reported problem. Additionally, by sequentially outputting log messages when they occur, information which would be useful to be outputted with a particular log message during trouble isolation may not be available until after the particular message was logged. For example, the code section which contains a call to Syslog subsystem may not have access to the additional information or perhaps the information is not known until after the call to Syslog subsystem is invoked.
One prior approach to extracting useful information from the outputted log messages is to develop a software application to interpret the outputted log messages. However, this approach does not reduce the redundant information outputted in the log file which is typically significant. Such large outputted log files may cause network problems when being transmitting from a customer's site where a problem arises and the service engineer's site where trouble isolation is typically done.

Apparatus and methods for a message buffering system

International Business Machines Corporation


An imaging apparatus includes a print engine having a print zone. A print media feed system transports a sheet of print media in a media feed direction along a media feed path through the print zone. The print media feed system includes a plurality of exit rollers positioned across a width of the media feed path. Each of a plurality of pressure rollers engages a respective one of the plurality of exit rollers to define a plurality of exit nips. A support structure mounts the plurality of exit rollers and the plurality of pressure rollers. The support structure positions the plurality of exit nips in an arrangement to define a transverse path across the width of the media feed path in the direction transverse to the media feed direction, the transverse path having a central portion and elevated portions on each side of the central portion.

1. Field of the Invention
The present invention relates to an imaging apparatus, and more particularly, to an exit roller system for an imaging apparatus.
2. Description of the Related Art
An imaging apparatus, such as a multifunction device or printer, may include an ink jet print engine that forms an image on a sheet of print media, such as paper, by ejecting ink from a plurality of ink jetting nozzles of an ink jet printhead to form a pattern of ink dots on the sheet of print media. Such an ink jet print engine typically includes a reciprocating printhead carrier that transports one or more ink jet printheads across the print medium along a bi-directional scanning path defining a print zone of the printer. Typically, the mid-frame provides media support at or near the print zone. A sheet feeding mechanism is used to advance the print medium sheet in a media feed direction through the print zone between scans in the main scan direction, or after all data intended to be printed with the print medium at a particular stationary position has been completed. One such sheet feed mechanism includes a feed roller, also sometimes referred to as an index roller, and a corresponding pinch roller arrangement located upstream of the print zone, and an exit roller and corresponding pressure roller arrangement, such as a plurality of star wheels, located downstream of the print zone.
A common problem in ink jet printers is the occurrence of print artifacts due to poorly maintained printhead-to-print medium gap. When feeding multiple media types (i.e., plain paper, glossy paper, transparencies, envelopes, etc.) a trade off is often made by increasing this gap to avoid the printhead scraping the paper. This results in increased defects from misdirected nozzles and more poorly formed drops, and places a higher requirement on printhead performance to achieve the desired level of print quality.

Exit roller system for an imaging apparatus


A combustion control apparatus for an internal combustion engine having an exhaust gas purifier in an exhaust passage, includes a controller that controls supply of fuel and air to the engine. The controller is configured to produce preliminary combustion at or near compression top dead center and main combustion after an end of the preliminary combustion under a predetermined condition based on a condition of the exhaust gas purifier. The controller is further configured to determine a target intake air quantity by adding an increase correction to the target intake air quantity based on a torque correction value and determine a target fuel injection quantity by calculating the target fuel injection quantity from an actual air quantity and a target air/fuel ratio. A combustion control method is also provided.

The present invention relates to a combustion control apparatus and method for an internal combustion engine.
It is heretofore known a diesel engine fuel injection system in which a fuel injector splits injection of fuel into three separate shots at or near compression top dead center of each cylinder when it is required to promote activation of catalyst as disclosed in Japanese Unexamined Patent Publication No. 2000-320386.

Combustion control apparatus and method for internal combustion engine