Storage apparatus includes a supporting base (11) supporting silos (14) having a lower conical portion (15) and silo port (16) controlled by an outlet knifegate valve (17), and a charging port (20) controlled by an inlet knifegate valve (21). An upper portion (22) of the silo is closed by a domed top (18). The silo ports (16) are manifolded to a common outlet (not shown). A charge manifold (25) interconnects the respective upper charging ports (20) and connects the ports to the cuttings source conduit (26). A pressure/vacuum port (27) is connected via cycle control valve (30) to an ejector assembly (not shown) valved to be able to cycle between a vacuum phase and a pressure phase of about 16 psig using a compressed air source. Control means is selectively operable to control the outlet valve (17), inlet valve (21) and cycle control valve (30).

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the referenced prior art forms part of the common general knowledge in Australia.
The disposal of drill cuttings from rigs and platforms at sea has come under increasing regulation on environmental grounds. The challenge is to accumulate cuttings on board and tranship to shore for ultimate disposal. Typically drill cuttings are accumulated in generic crane-hoistable skips which are loaded on to boat or barge for transport ashore. The number of skips required is large due to lifting limitations. Cranes are weather-dependent in operation, meaning drilling must cease when cuttings capacity on board is reached. The large number of skips necessary is an encumbrance on deck space and skips may not be safe to stack.
One solution proposed has been to use bulk pneumatic silos to handle drill cuttings as is done with other bulk materials such as barite or cement. However, traditional silos are not usually suitable, as the unique and highly variable physical properties of drill cuttings in many cases limits the ability to adequately discharge these tanks.
Traditionally the challenge of discharging high moisture and viscous materials from bulk silos was solved by having high angle conical bottoms in pressure silos. While this approach has been proven to work in most cases, this approach creates limitations in the storage capacity of the tank in a set footprint. One solution proposed by Halliburton is to have a straight sided tank with a "honey comb base" (HCB™) comprising an array of high-angle polygonal pyramids or cones dividing flow into an array of invert-conical or polygonal-pryramid outlets. The HCB tank does not rely on a high angle conical bottom to ensure mass flow discharge and can hold approximately 20% more bulk material in the same footprint as a high angle conical bottomed silo. The disadvantage is that such large tanks cannot be subjected to pressure-and-vacuum cycles necessary for efficient charge and discharge.


A microprocessor is provided with an instruction fetch mechanism that simultaneously predicts multiple control-flow instructions. The instruction fetch unit further is capable of handling multiple types of control-flow instructions. The instruction fetch unit uses predecode data and branch prediction data to select the next instruction fetch bundle address. If a branch misprediction is detected, a corrected branch target address is selected as the next fetch bundle address. If no branch misprediction occurs and the current fetch bundle includes a taken control-flow instruction, then the next fetch bundle address is selected based on the type of control-flow instruction detected. If the first taken control-flow instruction is a return instruction, a return address from the return address stack is selected as the next fetch bundle address. If the first taken control-flow instruction is an unconditional branch or predicted taken conditional branch, a predicted branch target address is selected as the next fetch bundle address. If no branch misprediction is detected and the current fetch bundle does not include a taking control-flow instruction, then a sequential address is selected as the next fetch bundle address.

1. Field of the Invention
This invention relates to the field of microprocessors and, more particularly, to instruction fetching within microprocessors.
2. Description of the Related Art
Superscalar microprocessors achieve high performance by executing multiple instructions per clock cycle and by choosing the shortest possible clock cycle consistent with the design. On the other hand, superpipelined microprocessor designs divide instruction execution into a large number of subtasks which can be performed quickly. A pipeline stage is assigned to each subtask. By overlapping the execution of many instructions within the pipeline, superpipelined microprocessors attempt to achieve high performance. As used herein, the term "clock cycle" refers to an interval of time accorded to various stages of an instruction processing pipeline within the microprocessor. Storage devices (e.g. registers and arrays) capture their values according to the clock cycle. For example, a storage device may capture a value according to a rising or falling edge of a clock signal defining the clock cycle. The storage device then stores the value until the subsequent rising or falling edge of the clock signal, respectively. The term "instruction processing pipeline" is used herein to refer to the logic circuits employed to process instructions in a pipelined fashion. Although the pipeline may be divided into any number of stages at which portions of instruction processing are performed, instruction processing generally comprises fetching the instruction, decoding the instruction, executing the instruction, and storing the execution results in the destination identified by the instruction.
Superscalar microprocessors demand high memory bandwidth due to the number of instructions executed concurrently and due to the increasing clock frequency (i.e. shortening clock cycle) employed by the superscalar microprocessors. Many of the instructions include memory operations to fetch (read) and update (write) memory operands in addition to the operation defined for the instruction. The memory operands must be fetched from or conveyed to memory, and each instruction must originally be fetched from memory as well. Similarly, superpipelined microprocessors demand high memory bandwidth because of the high clock frequency employed by these microprocessors and the attempt to begin execution of a new instruction each clock cycle. It is noted that a given microprocessor design may employ both superscalar and superpipelined techniques in an attempt to achieve the highest possible performance characteristics.
Microprocessors are often configured into computer systems which have a relatively large, relatively slow main memory. Typically, multiple dynamic random access memory (DRAM) modules comprise the main memory system. The large main memory provides storage for a large number of instructions and/or a large amount of data for use by the microprocessor, providing faster access to the instructions and/or data then may be achieved from a disk storage, for example. However, the access times of modern DRAMs are significantly longer than the clock cycle length of modern microprocessors. The memory access time for each set of bytes being transferred to the microprocessor is therefore long. Accordingly, the main memory system is not a high bandwidth system. Microprocessor performance may suffer due to a lack of available memory bandwidth.
In order to relieve the bandwidth requirements on the main memory system, microprocessors typically employ one or more caches to store the most recently accessed data and instructions. Caches perform well when the microprocessor is executing programs which exhibit locality of reference, i.e., access data that has been recently accessed (temporal locality) or access data that is located near data that has been recently accessed (spatial locality). A memory access pattern exhibits locality of reference if a memory operation to a particular byte of main memory indicates that memory operations to other bytes located within the main memory at addresses near the address of the particular byte are likely. Generally, a "memory access pattern" is a set of consecutive memory operations performed in response to a program or a code sequence within a program. The addresses of the memory operations within the memory access pattern may have a relationship to each other. For example, the memory access pattern may or may not exhibit locality of reference.
When programs exhibit locality of reference, cache hit rates (i.e. the percentage of memory operations for which the requested byte or bytes are found within the caches) are high and the bandwidth required from the main memory is correspondingly reduced. When a memory operation misses in the cache, the cache line (i.e. a block of contiguous data bytes) including the accessed data is fetched from main memory and stored into the cache. A different cache line may be discarded from the cache to make room for the newly fetched cache line.
Instruction fetch units fetch blocks of instructions from an instruction cache for decoding and execution. The performance of a microprocessor is dependent upon keeping the instruction processing pipeline filled with the instructions of a program. Accordingly, the instruction fetch unit must predict the order of instruction within a program. Instructions of a program are typically executed sequentially. Control-flow instructions, however, cause instructions to be executed in a nonsequential order. For example, a branch instruction may cause program execution to jump to a nonsequential instruction address. In a pipelined microprocessor, a conditional control-flow instruction, such as a conditional branch instruction, may not be resolved at the time instructions are fetched from the instruction cache. Waiting for the branch instruction to be resolved would starve the pipeline and severely impact performance. In order to maintain optimum performance of the microprocessor, it is necessary to predict the instruction subsequent in program order to the control-flow instruction and dispatch that instruction into the instruction processing pipeline. Accordingly, the outcome and/or target address of a control-flow instruction must be predicted at the time of instruction fetching. For example, when a conditional branch is encountered, a prediction is made whether the branch instruction will be "taken" or "not taken." If the branch instruction is predicted "not taken," instructions sequential in program order to the branch instruction are fetched and conveyed into the instruction processing pipeline. If, however, the branch instruction is predicted "taken," the target address of the branch instruction is predicted and instructions at the target address are fetched and dispatched in the instruction processing pipeline. If the control-flow predictions are correct, the instruction processing pipeline is filled with instructions in the correct program order. If the control-flow predictions are incorrect, instructions within the instruction processing pipeline do not represent instructions in the program order. Those instructions must be flushed from the instruction pipeline and the correct instructions fetched and dispatched.
Correct prediction of control-flow instructions may be critical to the performance of a microprocessor. Changes in control-flow account for at least 15 to 20 percent of the instructions executed in a typical program sequence. As noted above, superscalar microprocessors execute multiple instructions per clock cycle. Accordingly, superscalar microprocessors fetch multiple instructions per clock cycle from the instruction cache to keep the instruction processing pipeline full. As parallelism increases, i.e., more instructions are executed per clock cycle, the probability of encountering multiple control-flow instructions per fetch cycle is increased. Unfortunately, instruction fetch units typically cannot detect and predict multiple control-flow instructions per clock cycle. Further, instruction fetch units typically cannot detect and predict multiple types of control-flow instructions per clock cycle. For example, a block of instructions may include a conditional branch instruction followed by a return instruction. If the conditional branch instruction is predicted "not taken," the instruction fetch unit typically is not capable of predicting the target address of the return instruction. Accordingly, instruction dispatch is typically stalled until a subsequent cycle, which may severely limit microprocessor performance.

Instruction fetch mechanism with simultaneous prediction of control-flow instructions


A heating device for use in an internal combustion engine having an intake defining a passage is disclosed. The intake includes an opening in communication with the passage. The heating device includes a one-piece housing having a mounting flange portion and a first leg portion positioned substantially parallel to and spaced apart from a second leg portion. The mounting flange is adapted to mount to the intake and cover the opening. The heating element is coupled to the one-piece housing and positioned between the first and second leg portions. The heating element is positioned in a heat transfer relation with the passage to thereby heat air flowing through the passage.

The invention generally relates to an apparatus for heating the air/fuel mixture entering the cylinders of an internal combustion engine. More particularly, the invention relates to an electric heater having a one-piece housing adapted for mounting to the air intake system of an engine.
The air/fuel mixture entering the cylinders of an internal combustion engine is commonly heated to increase fuel economy and responsiveness to starting as well as to decrease pollutant discharge. One type of intake heating device generally includes a housing or frame disposed between a fuel delivery device and an air intake manifold. Another type of intake heating device is mounted within an open cavity of an intake manifold. After this second type of heating device is mounted on the intake, the heater and intake subassembly is subsequently mounted to an engine. In the aforementioned devices, current is passed through a heating coil or grid to increase the temperature of the surrounding air as it passes into a combustion chamber of the engine.
While the aforementioned heaters generally address cold starting and fuel economy issues, other concerns remain. For example, access to the prior art heaters is obtained only after the intake manifold is removed from the engine. Retro-fitting an existing vehicle not originally equipped with a heater is similarly difficult. In addition, prior art heaters have been specifically constructed to package within a given geometry and function only with a certain power system. As a result, many heater components were proliferated in order to meet varying customer needs. Furthermore, many prior heater designs exhibit unsatisfactory vibration resistance. These heaters may not continue to properly function after being fitting to a vehicle and subjected to repeated impact loading due to road inputs as the vehicle is used.
Accordingly, in view of the above concerns as well as the manufacturer's ever present desire to reduce manufacturing costs and complexity, a need exists for a robust air heater having a one-piece housing that may be installed within a vehicle intake air system without removing the intake manifold.


The present invention relates to a condensing heat exchanger and a boiler/water heater including the same and, more particularly, to a condensing heat exchanger, which can increase a contact area between water and a combustion gas having high temperature and improve efficiency by passing a combustion gas, generated from a combustion chamber, through a plurality of exhaust pipes and which can be fabricated in a small and compact size, and a boiler/water heater including the same.

As energy is recently increasingly used worldwide, supplementary problems, such as environmental pollution, are frequently generated. In order to solve the problems, eco-friendly alternative energy is being developed worldwide.
Since to change chemical energy now being used all at once is difficult, much research is being carried out in order to improve efficiency of devices that use energy as one option for solving problems, such as environmental pollution and research for economic effects resulting from reduced maintenance costs is also being carried out.
As part of the research, various types of high-efficiency heat exchangers are being proposed in order to improve the heat transfer efficiency of gas devices, such as a boiler for heating and a water heater.
In order to improve the heat exchanger efficiency, a method of increasing a heat transfer area by adding a plurality of heat exchange roots is chiefly used. In this case, there is a problem in that the volume of a heat exchanger is increased. Furthermore, there is a problem in that a loss of water pressure is increased because a channel between a water inlet port and a water outlet port is increased due to the added heat exchange roots.
Furthermore, in a low-efficiency heat exchanger, there is no problem in the generation of condensate water, but in a high-efficiency heat exchanger, there is a problem in that condensate water is generated and the generated condensate water deteriorates heat exchange efficiency.
In particular, a conventional one path condensing heat exchanger is problematic in that volume is increased on the basis of a direction where water flows. Furthermore, a conventional two-path condensing heat exchanger is problematic in that a manufacturing process is complicated because a fluid passage has to be formed by plural times of welding processing and the lifespan of the condensing heat exchanger is reduced due to corrosion.

Condensing heat exchanger and boiler/water heater including the same


A computer program product and to a method for compensating thermal errors in a mechanical process, the mechanical process in particular provided by a mechanical device such as a coordinate measuring machine, a tooling machine or an articulated robot arm. Thermal errors arise due to thermal disturbances affecting the mechanical process, wherein thermal disturbances may arise from environmental influences affecting the mechanical process or from internally generated changing temperature distributions.

General mechanical processes are susceptible to errors arising from thermal disturbances; such errors may be caused by thermal gradients across the mechanical process and/or by errors arising from a changed base value of temperature, for example. Depending on the exact nature of such thermal disturbances, it is difficult to predict the potentially subtle influences of the thermal disturbances on the outcome of the mechanical process. One way to mitigate such potentially detrimental influences is by way of a careful calibration of the mechanical process, wherein the calibration provides information about thermal errors for specific evolutions of the mechanical process. Different evolutions of the mechanical process which are not calibrated cannot be compensated by such a naive method.
Information about the evolution of the mechanical process can be obtained via sensors, wherein sensors are in particular embodied as thermal sensors (such as resistance temperature detectors (RTDs), thermocouples, thermistors, semiconductor sensors, infrared sensors or thermal cameras) or as mechanical sensors (such as strain gauges), attached to or integrated into the mechanical device realizing the mechanical process, or via sensors providing information from the vicinity of the mechanical device. Such sensor readings may then provide diagnostic information. The optimal number of sensors to be used as well as their location/type for providing thermal error information usable for deriving thermal error compensation values is a difficult problem in general.
Mechanical processes are to some extent related to one another, in particular if the mechanical devices realizing the mechanical processes are similar. In some cases, a large amount of data might be available for a particular mechanical process, while a scarcer supply of data might exist for a different mechanical process. Often it is desirable, however, to be able to apply equally good thermal error compensation methods for both mechanical processes.

Advanced thermal compensation of mechanical processes


An overhead cam engine system comprises a rotating overhead exhaust cam rail comprising a plurality of exhaust lobes. A first switching roller finger follower actuates a first exhaust valve, and is configured to switch between a first lift profile and a second lift profile. A second switching roller finger follower is coupled to actuate a second exhaust valve, and is configured to switch between a third lift profile and a fourth lift profile. The third and fourth lift profile are different than the first and second lift profile. An actuation assembly is connected to switch the first switching roller finger follower and the second switching roller finger follower to select between at least three exhaust lift modes to open and close the first exhaust valve and the second exhaust valve using combinations of the first, second, third and fourth lift profiles.

Systems for type II (overhead cam, "OHC") engines can suffer from complex systems when attempting to permit multiple modes of operation. It is difficult to synchronize solutions with the overhead cam rail. So, such engines can be restricted to only one mode of variable valvetrain operation such as a normal mode and either cylinder deactivation or early intake valve closing. However, it is desired to offer all three modes using the existing cam rail.


Data is obtained at a data storage system. Codewords are generated from the obtained data. The codewords are computed using a folded code and each codeword comprises symbols. The codewords are stored on an array of disks associated with the data storage system in accordance with a codeword symbol mapping that is specified by at least one parameter of the folded code used to generate each codeword.

The increasing amount of data available in digital format requires developing appropriate data storage systems. In many cases, the amount of data to be stored exceeds the capacity of a single disk drive. Furthermore, the reliability of a single drive may not be sufficient for a particular application. This motivates the development of redundant disk arrays such as, for example, a Redundant Array of Independent Disks or RAID. The size of such arrays may vary from a few disks to a few thousand disks. Such arrays employ some kind of error/erasure correcting codes, which provide the redundancy needed to recover the data if one or more of the disks fail.
However, in many cases, a disk remains operational, while only a few blocks on the disk become unreadable. These unreadable blocks are typically discovered when some other disk fails, and the data on remaining disks is being read in order to re-calculate the data on the failed disk. The need to be able to cope with such latent media errors is a main rationale for developing RAID architectures with many parity disks (e.g., RAID-7.3). However, the need to allocate additional parity disks significantly increases the cost of data storage systems.

Folded codes for correction of latent media errors


A circuit and method for compensating sigma-delta modulators in A/D and D/A converters is disclosed. Circuits according to the invention use a low-resolution Sigma-Delta encoded version of the signal to inexpensively encode quadratic and cubic compensation terms. These circuits can encode quadratic and cubic compensation signals with acceptably low quantization noise without requiring the use of expensive multi-bit multipliers to compute the square or cube of the signal. The method includes providing a binary word Q or a binary word C (or both) representing the desired amount of quadratic or cubic compensation to apply. Because the encoded quadratic and cubic signals have only one or a few bits, they can be multiplied by Q and C without the use of expensive multi-bit multipliers and applied to the modulator input or output to provide a compensated result.

1. Field of the Invention
The present invention relates to Sigma-Delta Digital-to-Analog (D/A) and Analog-to-Digital (A/D) converters. More particularly, the present invention relates to low-cost methods to compensate for quadratic and cubic errors in Sigma-Delta D/A and A/D converters.
2. The Prior Art
The Sigma-Delta modulator forms the basis for many modern Analog-to-Digital (A/D) and Digital-to-Analog (D/A) converter topologies. In one fairly common implementation of a D/A converter, a digital Sigma-Delta modulator takes in a relatively high-resolution but highly over-sampled digital input signal and converts it to a one-bit highly over-sampled digital output signal. The pulse density, or duty factor, of the one-bit output represents the signal. This one-bit signal is fed to a one-bit D/A converter which, by virtue of its simplicity, is generally lower in cost than a higher-resolution D/A converter.
Because the resolution of the digital signal is drastically lowered by the sigma-delta modulator, a large amount of quantization noise is added to the signal. However, due to the well-known frequency-shaping operation of the sigma-delta modulator, the quantization noise is added largely in frequency bands not occupied by the desired signal, and can thus be filtered away, leaving just the desired analog signal at the output of the converter.
The performance of the Sigma-Delta converter can be similar to that of a much higher resolution conventional converter. For example, a Sigma-Delta D/A converter comprising a one-bit modulator and a one-bit D/A and an output filter can have similar performance in many respects to a 16-bit conventional (e.g., R-2R ladder) D/A converter.
In a one-bit Sigma-Delta A/D converter, the Sigma-Delta modulator is mostly analog. An analog-input comparator and a one-bit D/A converter in the feedback loop of the modulator provide the interface between the analog and digital domains.
Practical Sigma-Delta D/A and A/D converters may exhibit Integral Non-Linearity (INL) errors for many reasons. One such reason includes errors due to Inter-Symbol Interference (ISI). This occurs where like digital symbols do not have a like effect in the analog domain because symbols are not completely independent of each other, and are influenced by the history of other recent symbols. For example, the DC result of converting the one-bit sequence of digital symbols "010010" to analog may be slightly different than the result from the sequence "001100," even though the average pulse density for the two sequences is the same, because in one case the two "1" bits are back-to-back and in the other case they are not. Often, this difference will exhibit itself primarily as a second-order (or quadratic) non-linearity of the D/A (or A/D) output.
Besides ISI, there are many other possible root-causes of INL including, for example, inherent component effects, such as the resistance sensitivity to an applied voltage of a resistor. When a sine wave is applied to a converter with INL, harmonic distortion products result.
Previous designs to compensate quadratic or cubic non-linearities generally required the use of multipliers either in the analog or digital domain. For instance, the input number to a Sigma-Delta D/A converter might be multiplied by itself (i.e., squared) and then multiplied by a compensation coefficient, and then added to the original input, in order to pre-compensate a non-linearity that occurs in the analog portion of the D/A converter (e.g., due to ISI). In this case, two multiply operations were required. Generally for a cubic compensation, three multipliers would be required, and for simultaneous quadratic and cubic compensation, a total of four multipliers would be used. Such an arrangement is shown in FIG. 1. Multipliers, whether implemented in the analog or digital domain, are relatively expensive components.

Quadratic and cubic compensation of sigma-delta D/A and A/D converters


In general, in one aspect, the invention relates to a method for accessing encrypted data by a client. The method includes receiving from the client by a server client information derived from a first secret wherein the client information is derived such that the server can not feasibly determine the first secret. The method also includes providing to the client by the server intermediate data, which is derived responsive to the received client information, a server secret, and possibly other information. The intermediate data is derived such that the client cannot feasibly determine the server secret. The method also includes authenticating the client by a device that stores encrypted secrets and is configured not to provide the encrypted secrets without authentication. After the authenticating step, the method also includes providing the encrypted secrets to the client. The encrypted secrets 5 are capable of being decrypted using a third secret that is derived from the intermediate data.

FIG. 1 shows a prior art system 100 in which a user 3 stores secrets 5 on a remote server computer 10, where the term secrets is used broadly to mean any data or information that the owner wishes to keep private. The user 3 accesses the secrets 5 using a client computer 15 that is connected to the server computer 10 via a data or telecommunications network 20, such as the Internet. Storage of the secrets 5 on the server 10 allows the user 3 to access the secrets 5 from any client computer connected to the network 20.
To help prevent the secrets 5 from being obtained by others, the secrets 5 are typically encrypted. Encrypting the secrets 5, for example, by use of a key 24, prevents someone who has access to the secrets 5 from learning the secrets 5, for example, by compromise of the server or by observing the user's communications with the server 10 over the network 20. The encryption of the secrets 5 can be performed according to various known techniques including symmetric encryption in which the same decryption key 24 is used for both encryption and decryption, and/or asymmetric encryption, in which different keys are used for encryption and decryption respectively.
As the number of possible values from which a key 24 might be chosen (the "key space") is increased by changing the encryption implementation, it becomes increasingly more difficult for an attacker to try every possible decryption key 24. At some point, the number of possible of keys is so great that an encrypted secret 5 cannot feasibly be decrypted by trying each possible key 24. This is referred to as a strong encryption, because the large key space makes the encryption stronger. For example, a key that is chosen from the set of all known English words is much weaker than a key that is chosen from the set of all 1024-bit numbers. An encryption and/or decryption key 24 that is selected from a large key space is typically cumbersome for a user 3 to employ, however, because long sequences of characters are difficult for humans to remember. Users 3 may be inclined to write down such sequences, thereby making the key available to an attacker. To ease the memory burden on users 3, shorter decryption keys 24 are frequently used, with the disadvantage that it may be feasible for a party that has access to the encrypted secrets 5 to decrypt the encrypted secrets 5 by trying every possible key.

System and method for increasing the security of encrypted secrets and authentication


A system includes a circuitry that provides for psychoacoustic frequency range extension for a speaker. The circuitry generates quadrature components from an audio channel, and generates rotated spectral quadrature components by applying a forward transformation that rotates a spectrum of the quadrature components from a standard basis to a rotated basis. In the rotated basis, the circuitry isolates components of the rotated spectral quadrature components at target frequencies, and generates weighted phase-coherent harmonic spectral quadrature components by applying a scale-independent nonlinearity to the isolated components. The circuitry generates a harmonic spectral component by applying an inverse transformation that rotates a spectrum of the weighted phase-coherent harmonic spectral quadrature components from the rotated basis to the standard basis. The circuitry combines the harmonic spectral component with frequencies of the audio channel outside of the target frequencies to generate an output channel, and provides the output channel to the speaker.

The bandwidth of loudspeakers, headphones, and other acoustic actuators is often limited to a sub-domain of the bandwidth of the human auditory system. This is most often a problem in the low frequency region of the audible spectrum, roughly 18 Hz to 250 Hz. It is desirable to modify an audio signal to produce the impression of frequencies beyond the bandwidth of a physical driver. Beyond simply extending the frequency response of the driver, depending on the application, it may be desirable to increase the perception of certain subbands without increasing the amount of physical energy present in those subbands. For example, it may be desirable to use psychoacoustic impressions to decrease the stress on a driver, or to improve power consumption characteristics of a device.

Nonlinear adaptive filterbanks for psychoacoustic frequency range extension


A polymer-electrode including (a) a substrate having a conductive working surface; and (b) a polymer layer on the conductive working surface. The polymer layer has a plurality of microfluidic reaction openings distributed throughout the layer. An oligonucleotide probe can be attached to the polymer layer and is available to capture target nucleic acid. A soluble mediator can diffuse freely and transfer electrons from the preselected base in the hybridized nucleic acid to the conductive working surface of the substrate. An electronic signal generated from the electron transfer reaction is detected and quantitated.

The present invention relates to electrodes for detecting nucleic acid hybridization and to the method of detecting nucleic acids utilizing such electrodes. The electrodes may also be used for detection of proteins.
The detection of nucleic acid hybridization at solid surfaces has been used for the identification of infectious organisms in clinical specimens (Spargo, C. A. et al., (1993), Molecular and Cellular Probes 7, 395-404; Martin, W. J. (1994) Infectious Diseases. In The Polymerase Chain Reaction (K. B. Mullis, F. Ferre and R. A. Gibbs, eds.), pp. 406-417. Berkhauser, Boston), the quantitation of mRNA for gene expression analysis (Schena, M., et al., (1995). Science 270, 467-470), and the sequencing or resequencing of genomic DNA on high-density "chip" arrays (Chee, M., et al., (1996) Arrays. Science 274, 610-613). Presently, these efforts involve the attachment of a fluorescent label to the target nucleic acid, which is then hybridized with a probe-modified surface and detected after washing the unhybridized DNA away from the solid surface. Since detection of photons is required to signal hybridization, analysis of high-density arrays labeled in this manner requires high-resolution fluorescence microscopes. Alternatively, indirect detection of hybridization can be accomplished using sandwich assays where the surface-bound hybrid is subsequently hybridized to an additional signal probe that carries one or more fluorescent labels or enzymes that convert a non-fluorescent substrate to a fluorescent one (Spargo, C. A. et al., (1993), Molecular and Cellular Probes 7, 395-404). By attaching multiple enzymes to the signal probes, large signal amplification can be achieved (Holodniy, M. et al., (1995). J. Virology 69, 3510-3516); however, the preparation of these multiple enzyme systems is complex.
The patents of Heller (U.S. Pat. Nos. 5,532,129; 5,565,322; 5,605,662; and 5,632,957) disclose the use of an electrode with a permeation layer which is an agarose gel placed on the electrode. A potential is applied to the electrode that brings probe or target DNA to the reaction site on the electrode. Because of the high voltages required, there is a strong possibility of electrooxidation of the probe, target and other components of the solution. The gel protects the system so that excessive levels of target DNA do not accumulate and so that the DNA oxidation is minimized.
Labeled proteins and soluble mediators have been used to detect protein-protein interactions. For example, the patent of Weetall (U.S. Pat. No. 5,066,372) discloses a support layer on a working electrode that is porous to mediator and to which protein can be immobilized. See also U.S. Pat. Nos. 4,945,045 of Hill, 4,545,382 of Higgins, and 5,378,628 of Gratzel. The instant invention differs from these references in that it utilizes guanine as a electron donor to drive the electron transfer reaction rather than utilizing an enzyme oxidation reaction.
The paper of Wang et al. (Wang et al., (1997), Anal. Chem. 69, 4056-4059), describes a membrane-covered carbon electrode for analysis of oligonucleotides in the presence of polymeric nucleic acids. The purpose of the membrane is to exclude the polymeric DNA, while small molecules can pass through the membrane for electroanalysis by the carbon electrode. The membrane is not used for attachment of probes and the membrane-covered electrodes do not offer discrimination at the sequence level.
The parent applications, whose entire specifications, drawings, and claims are specifically incorporated herein by reference, disclose, among other inventions, sequencing and methods of qualitatively and quantitatively detecting nucleic acid hybridization.
Such inventions represent a major advance in the art and provide oxidation-reduction complexes which function in a catalytic manner without the addition of an enzyme or fluorescent label, provide for a catalytic current to give the concentration of guanine, or alternate base, in a manner useful for determining the presence or absence of a target, and provide for extremely accurate testing.
Although a major advance, the prior inventions rely on electrodes that are not entirely suitable for measuring the oxidation-reduction reaction. The invention herein provides electrodes coated with a polymer material (a) to which oligonucleotide probes can be covalently attached; (b) in which the soluble mediator can diffuse freely and dock with immobilized DNA; (c) for which no additional electrochemical current is generated at potentials between 0 and +1.3 V (vs a Ag/AgCl reference electrode); and (d) at which the immobilized oligonucleotide probe is available to capture target nucleic acid. In addition, the polymer coating should preferably not adsorb protein or other non-targeted nucleic acid material in biological samples, unlike previously developed electrodes that utilize nylon or nitrocellulose films that have significant affinity for protein and non-complementary nucleic acid. Adsorbed protein, non-targeted nucleic acid, and other biological material contribute to the undesirable background signal and may inhibit proper capture of targeted nucleic acid.
The distinguishing feature of the approach of the invention is that the unlabeled target DNA is differentiated from the synthetic probes by modulation of the electron-transfer reactivity. In the use of the polymer-electrode of the invention, instead of differentiating duplex and single-stranded DNA (as in ethidium bromide fluorescence (Waring, M. J., (1965). J. Mol. Biol. 13, 269), we differentiate probe and target. The importance of this difference is that our assay is not dependent on bringing double-stranded DNA to the electrode. Thus, the invention is equally well suited for detection of single- or double-stranded DNA. More importantly, single-stranded RNA, which is of particular interest in identifying unamplified genomic RNA from viruses such as HIV or Hepatitis C, in detecting ribosomal RNA from bacteria, or in quantitating cellular MRNA for gene expression analysis, may also be detected. For the studies described here, the probes are attached to the membrane via the endogenous exocyclic amines of the nucleobases, as has also been done for direct attachment to glassy carbon electrodes (Millan, K. M. et al., (1994), Anal. Chem. 66, 2943-2948; Millan, K. M. & Mikkelsen, S. R. (1993). Anal. Chem. 65, 2317-2323). Membranes behave similarly with synthetic oligonucleotides to which an alkyl amine linker is appended, which can provide for greater hybridization efficiency and specificity.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.

Polymer-electrodes for detecting nucleic acid hybridization and method of use thereof

The University of North Carolina at Chapel Hill


An image capture device electronically captures and selects a desired text portion. A visible light image is projected onto text on a document to enable a user to position the light image relative to the desired text portion. At least some of the text is captured in accordance with a position of the light image. A text selector selects the desired text portion from the captured text.

Using a known type of camera device, for example as described in International Patent Application Publication Number WO 01/01332, text can be captured by holding a tip of the device flat in contact with a surface of a text document so that an opening of the camera covers the entire height of the text, pressing a trigger of the device and, keeping the trigger pressed, moving the device so as to scan the desired text. The trigger is released to stop scanning. To function effectively, the device must be moved in contact with the document surface.
EP-A-1022608, assigned to Hewlett-Packard Company, discloses a camera that projects a pattern of visible light onto an object to be photographed to indicate the area of the object within view of the camera. The device is for framing whole documents, and is not for indicating desired portions of text within documents.
U.S. Pat. No. 4,514,063 uses a light pattern to delimit the capture area in a copy stand. It does not have application in hand held devices for indicating desired portions of text within documents.
Bar-code scanners are known which project light primarily to enable them to sense reflected light data pertaining to the bar-code indicia. Such devices are not useful for capturing desired text constituting a portion of a text document.
An object of the invention is at least to mitigate or to overcome at least one drawback of at least one of the above-mentioned known devices.

Image capture device and method of selecting and capturing a desired portion of text

Hewlett-Packard Development Company L.P.


An apparatus and method for rapid real time imaging with wavefield energy using a C.P.U. programmed to process data derived from wavefield energy that has been transmitted and scattered by an object so as to reconstruct a wavefield image of the object. Electronic signals are propagated and are transduced into wavefield energy waves which in turn are propagated toward the object. Detectors detect the wavefield energy waves scattered by the object. The detected wavefield energy waves are then electronically processed and input into a high-speed digital computer which may comprise a C.P.U. and/or a C.P.U. in combination with an array or parallel processor. Data is also prepared and input to the computer representing the incident field and the computer then reconstructs a high-quality image of the object having high spacial resolution and including actual properties of the object. The media in which the object is embedded may be fluid or solid, homogeneous, or layered (such as stratigraphic layering, or ocean velocity layers, or layering of composites in nondestructive imaging applications), or may consist of porous material (either sedimentary deposits or composites in nondestructive testing).

A portion of the disclosure of this patent application contains material to which a claim of copyright protection is made. The copyright owner(s) has/have no objection to the facsimile reproduction by any one of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but reserves all other rights in the copyrighted work. Appendices A-L, L1, M1, M1, M2, and M3, referred to herein, may be found in the microfiche appendices attached hereto. The microfiche appendices is comprised of one microfiche sheet for each of the Appendices A-L, L1, M1, M1, M2 and M3, for a total of seventeen (17) sheets.
1. Field of the Invention
This invention related to an apparatus and method for imaging in either homogeneous, or layered, or porous media. The media may be fluid or solid, the imaging energy may be electromagnetic, elastic (seismic-like energy) or acoustic (sound/ultrasound energy). Furthermore, the ambient media (in which the object to be imaged is embedded) may have layering (such as stratigraphic layering, or ocean velocity layers, or layering of composites in nondestructive imaging applications) or consist or porous material (either sedimentary deposits or composites in nondestructive testing).
2. The Prior Art
It has long been known that elastic, electromagnetic or acoustic waves in homogeneous and layered environments in the frequency range of a fraction of a cycle per second up to hundreds of millions of cycles per second and higher can be propagated through many solids and liquids. Elastic waves are waves that propagate through solids, and have components of particle motion both parallel (longitudinal, or pressure, wave) and perpendicular (shear wave) to the direction of propagation of the wave energy itself. In contrast to this, acoustic waves are those waves that generate particle motion that is exclusively parallel to the propagation of wave energy. Electromagnetic waves have components of variation of field strength solely in the direction perpendicular to the direction of propagation. All of these types of waves may be used to image the acoustic longitudinal wavespeed and absorption, the electromagnetic wavespeed and absorption, the shear wavespeed, and the density of the material through which the wave energy has travelled.
It is also known that scattering is produced not only by spatial fluctuations in acoustic impedance, which is the product of mass density times wavespeed, but also by independent fluctuations in electromagnetic permeability, permittivity and conductivity, elastic compressibility, shear modulus, density, and absorption. These lead to variations in phase speed (which is the speed of propagation of fronts of constant phase) and in impedance (for the electromagnetic case, the ratio of the electric to the magnetic field strength). The net property of an object which describes the phenomenon of scattering in a given modality, is called the "scattering potential".
Other imaging methods have been applied to one or the other modality, or restricted to acoustic or elastic media, the method described in this patent is applicable to any type of wave motion, whether electromagnetic, elastic (including shear wave effects) or acoustic (scalar approximation valid in liquid and gases). Furthermore, the ambient media may have some forms of structure (layering) or microstructure (porosity) relevant to the medical, geophysical, or nondestructive imaging applications envisioned for this technology. In the prior art the presence of this layering or porosity has greatly diminished the effectiveness of the imaging program. The method of this patent minimizes the obscuring effect of such structures in the ambient media. In addition, we have made several changes to the previous U.S. Pat. No. 4,662,222 that significantly extend the applicability and speed of our algorithm. These changes are described, in part, below:
As discussed in U.S. Pat. No. 4,662,222, by one of the present authors, these principles can be used to image scattering bodies within a given medium. Some definitions will clarify the procedures and methods used:
The direct or forward scattering problem is concerned with a determination of the scattered energy or fields when the elastic or electromagnetic properties of the scattering potential are known.
The inverse scattering problem, by contrast, consists in the use of scattered electromagnetic, elastic, or acoustic waves to determine the internal material properties of objects embedded in a known (ambient) medium. An incident wave field is imposed upon the ambient medium and the scatterer. The scattered field is measured at detectors placed a finite distance from the scattering objects. The material parameters of the scatterer are then reconstructed from the information contained in the incident and scattered fields. In other words, as defined herein, acoustic or electromagnetic imaging using inverse scattering techniques is intended to mean electronic or optical reconstruction and display of the size shape, and unique distribution of material elastic or electromagnetic and viscous properties of an object scanned with acoustic, electromagnetic or acoustic energy, i.e., reconstruction of that scattering potential which, for a given incident field and for a given wave equation, would replicate a given measurement of the scattered field for any source location.
The description of prior art summarized in U.S. Pat. No. 4,662,222 (referred to as "the previous Patent") is also relevant here. It is sufficient to say here, that the use of the conjugate gradient algorithms discussed in the previous patent brought the attainment of inverse scattering into a practical reality. Previous to that U.S. Pat. No. (4,662,222), only linear approximations to the full inverse scattering problem were amenable to solution, even with the aid of modern high speed digital computers. The resolution achievable with the inverse scattering methods described in the previous patent was far superior to any ultrasound imaging in medicine previous to that time,

Apparatus and method for imaging with wavefields using inverse scattering techniques


A process for forming diffused region less than 20 nanometers deep with an average doping dose above 1014 cm−2 in an IC substrate, particularly LDD region in an MOS transistor, is disclosed. Dopants are implanted into a source dielectric layer using gas cluster ion beam (GCIB) implantation, molecular ion implantation or atomic ion implantation resulting in negligible damage in the IC substrate. A spike anneal or a laser anneal diffuses the implanted dopants into the IC substrate. The inventive process may also be applied to forming source and drain (S/D) regions. One source dielectric layer may be used for forming both NLDD and PLDD regions.

It is well known that transistors in advanced integrated circuits (ICs) are shrinking with each new fabrication technology node, as articulated by Moore's Law. For example, at the 32 nanometer technology node, it is desired to form doped regions in transistors such as source and drain extensions which are less than 10 nanometers deep with average doping densities above 1021 cm−3. Formation of heavily doped shallow regions is problematic because anneals sufficient to repair damage to the IC substrate cause dopants to diffuse deeper than desired.

Formation of shallow junctions by diffusion from a dielectric doped by cluster or molecular ion beams


The invention generally relates to a shopping cart that could have: (i) a slidably movable lower container; (ii) a telescoping container; (iii) dual handles; (iv) a stand having a number of holders and a writing surface formed therein; (v) a wheel having a brake coupled thereto; (vi) a generally A-shaped frame; and/or (vii) a retractable child seat assembly.

Shopping carts are known in the art and generally include a frame, a main container, wheel assemblies and a handle for pushing the cart. The average shopper is buying more fresh produce than in years past, yet many shopping carts remain essentially the same with one main container. The main container typically has a limited size child seat assembly that is used in most cases to transport a child or a shopper's personal belongings. Shoppers without children often place fragile items, such as produce, in the child seat assembly in order to protect the produce from heavier items.
The majority of the produce is placed inside the main container due to the limited size of the child seat assembly. Such placement causes the shopper to risk damage to the produce or to constantly relocate the produce to prevent damage as heavier items are placed in the main container. Also, most grocery stores are designed so the shopper begins shopping in the produce department. While the produce department may make the store look more appealing by stimulating the senses of shoppers, the layout also increases the risk of produce being crushed by heavier items placed in the main container as the shopper moves through the remaining aisles of the grocery store.
The shopping cart is also oftentimes difficult to maneuver throughout the grocery store when many shoppers are in the store as well. The shopping cart is additionally hard to move around the grocery store when the aisles are closely spaced together. The shopping cart is also tricky to steer in various directions due to the dimensions of the main container and the wheel base.
Accordingly, a need exists in the art for shopping carts that have additional containers.
A need also exists in the art for shopping carts that have greater maneuverability.


A craft-mounted repeater system processes signal properties (e.g., signal strength) between terrestrial (ground-based) wireless networks and mobile users that are aboard crafts (e.g., airplanes and/or ships) equipped to allow the user's mobile communications device to communicate at departure and at arrival of the craft. An onboard craft-mounted non-translating in-band only repeater system is a provided that increases the terrestrial mobile network signal levels inside the aircraft or ship to allow passengers to communicate with a terrestrial cellular communications system.

There are tremendous advances being made to equip transportation systems (e.g., airplanes and ships) with base stations such that mobile cellular users can continue to communicate using wireless communications devices. Typically these craft-mounted base stations form picocells that utilize satellite or other wireless backhaul networks as communication links with terrestrial networks to complete the voice and/or data call. In the case of aircraft, these picocells can be switched on once the aircraft has reached a safe cruising altitude, and turned off when the aircraft is on final landing approach or at other designated times.
A main concern with these craft-mounted base stations is the potential for interference with terrestrial mobile networks and other licensed spectrum bands while in-flight. Although the use of cell phones while airborne is currently prohibited, that may be changing. Government oversight agencies such as the FCC (Federal Communications Commission) and FAA (Federal Aviation Administration) are currently considering allowing the capability of operating cell phones while the aircraft is airborne. Additionally, airlines and the aircraft manufactures are considering increasing the capability of aircraft to be electromagnetically shielded to/from other terrestrial wireless networks. Shielding of the aircraft would in principle reduce (or attenuate) signal levels originating from inside the aircraft, such as from mobile cellular telephones, and thus potentially reduce the level of interference to the terrestrial wireless networks.
Herein is a problem with such craft-mounted systems for the terrestrial wireless operator. It is fairly common today for many wireless customers to desire to use cell phones onboard aircraft, for example, to make last minute calls prior to being told to discontinue the use of all electronic devices. These calls can be extremely important to the terrestrial wireless operators. As the aircraft or ship, for example, is parked at the terminal or dock, and prior to commencing travel, mobile users should not be prohibited from utilizing the terrestrial mobile networks.
If the aircraft or ship is equipped with the additional shielding, the mobile device of the user can have difficulty establishing and maintaining a call with the terrestrial base station that serves the airport or shipping dock due to the additional signal attenuation presented by the aircraft/ship shielding mechanism. Compounding the problem is the difficulty, if not outright prohibition, in zoning additional towers around airports and docks to address the needs of such implementations. Thus, there is a substantial unmet need in the art for an improved craft-mounted system for mobile communications.

Terrestrial repeater system for use with craft-mounted base stations


An improved process for making vinyl aromatic/allylic alcohol copolymers is disclosed. Gradual addition of a free-radical initiator during the course of the polymerization results in a substantial increase in the polymer yield obtained compared with the yield from conventional processes in which all of the free-radical initiator is charged initially. High yields are obtained when the monomer mole ratios are adjusted to produce styrene-allyl alcohol copolymers having a hydroxyl number in the 50-150 mg KOH/g range. Copolymers made by the process are valuable coating resins.

Vinyl aromatic/allylic alcohol copolymers are well known (see U.S. Pat. Nos. 2,630,430, 2,894,938, and 2,940,946). Copolymers of styrene and allyl alcohol (SAA copolymers) are resinous polyols that are particularly useful for polyesters, fatty ester emulsions, alkyd and uralkyd coatings, melamines, and polyurethanes. Styrene-allyl alcohol copolymers can be made in a batch process by charging a reactor with styrene, allyl alcohol, and a free-radical initiator, and heating the mixture at a temperature effective to polymerize the monomers (usually 100.degree.-300.degree. C.).
While SAA copolymers having relatively low hydroxyl contents (hydroxyl number=50 to 150 mg KOH/g) are known (see, e.g., U.S. Pat. No. 2,894,938, Example 1), the utility of these polymers was previously thought to be rather limited (see U.S. Pat. Nos. 5,444,141 and 2,940,946). Those skilled in the art believed that a higher concentration of SAA hydroxyl groups was needed for sufficient crosslinking and good coating properties.
We recently described a process for making vinyl aromatic/allylic alcohol copolymers (U.S. Pat. No. 5,444,141). The process is well-suited for making SAA copolymers having hydroxyl numbers within the range of about 180 to 280 mg KOH/g, the range generally recognized as commercially valuable. Commercially available resins include "SAA 100" (hydroxyl number=200 mg KOH/g) and "SAA 101" (hydroxyl number=260 mg KOH/g) resinous polyols. We demonstrated that yields of these SAA copolymers improve significantly when the free-radical initiator is gradually added to the reaction mixture. We reported polymer yields of 30-40% for products having hydroxyl numbers of 180-280 mg KOH/g.
In U.S. Pat. No. 5,444,141, we said that the yield of SAA copolymer can be increased, "but only at the expense of making a product having higher styrene content, lower hydroxyl number, etc., a product that lacks utility for most of the targeted end-use applications."
For some coating applications, however, hydroxy-functional resins with lower hydroxyl numbers are actually an advantage. Some coating components are incompatible with SAA copolymers that have a high content of hydroxyl groups. Low hydroxyl content can also be an advantage in reducing the amount of relatively expensive crosslinking agent (e.g., polyisocyanate) required.
In sum, an improved process for making vinyl aromatic/allylic alcohol copolymers, especially styrene-allyl alcohol copolymers, is needed. Coating applications that could benefit from a low hydroxyl group content resin are evolving, and suitable resins are needed for these applications. A process for making the resins is therefore also of interest. Preferably, the process would be easy to perform, would use conventional equipment, and would be cost-effective. A preferred process would give favorable yields of SAA copolymers having hydroxyl numbers within the 50 to 150 mg KOH/g range.

Process for making vinyl aromatic/allyl alcohol copolymers


A cylinder pressure sensor of the annular insert type disposed within an access well to measure the flexure of a first wall relative to a second wall along a response axis has low-cost components thereof requiring only simple sequential assembly in axial stacked fashion providing contaminant protection and electrical shielding of the sensing element.

This invention relates to internal combustion engine cylinder pressure sensors, more particularly a non-intrusive sensor of the "annular insert" type which measures flexure of a first wall defining in part a cylinder relative to a second relatively rigid wall of an internal combustion engine housing component. Such a sensor is disclosed in U.S. Pat. No. 4,969,352 to Sellnau and assigned to the assignee of the present invention. In the disclosure of that patent such a Sensor finds particular utility when mounted in a spark plug access well.
It is known in the field relating to internal combustion engines to utilize cylinder pressure sensors for monitoring and controlling various processes, among them being combustion knock, misfire and associated combustion dilution and combustion phasing. Delivery of fuel and exhaust gas recirculation and timing of ignition may then be optimized accordingly. In order for cylinder pressure sensing to find its way into the mainstream of commercial automotive applications, it must be cost effective. Advances to making pressure sensing cost effective have been made as shown in Sellnau wherein simple modifications to pre-existing engine head features provide necessary mounting provisions for non-intrusive sensors. Another way to advance cost effectiveness is by reducing piece price. This is especially true where multiple sensors (i.e. one per cylinder) are to be used in a single vehicle. Therefore, innovative designs which reduce piece price by simplifying manufacturing and assembly are highly favored.
Sellnau '352 shows a sensor having a castellated lower portion effective to allow axial compressive forces to act on a trapped sensing element while bypassing torsional loads around the load sensing element. Another approach accomplishing the same is also shown wherein an integral axial extension from the major portion of the annular insert extends downward therefrom and is bent in an outward flange arrangement to trap the sensing element between the flange portion and the major portion of the annular insert. Such arrangements accomplish the objective of bypassing torsional loads around the sensing element, however, they also leave the sensing element and electrical connections exposed to infusion of such common deleterious materials as oil, road salt and water. Additionally, such arrangements are relatively complex and costly and may not be necessary where the sensing element can sufficiently cope with the torsional loads expected. It is desirable to simplify sensor packaging and ensure that the sensing element and electrical connections are adequately shielded from electromagnetic interference and sealed against contaminant infusion.
In order to obtain a signal from such a sensor it is necessary to electrically couple to the sensing element. One approach shown in related art cylinder pressure sensors provides for electrical coupling to each of two sides of a piezoelectric sensing element by electrodes or metal traces attached thereto, thereby requiring at least two sensor leads and providing an engine ground-isolated sensor with a differential signal. Reducing the number of lead wires and simplifying electrical coupling to a single-ended configuration would reduce failure modes, increase reliability and may decrease the complexity of overall engine dress wiring. Also, the sensor signal would not be subject to stray capacitive effects precipitated by engine ground noise. For these reasons, it is desirable to simplify electrical coupling including reducing the number of lead wires.
It is possible in such an arrangement that significant noise may be induced upon the high impedance sensor from the high voltage ignition system. This is particularly true where a spark plug access well is the location of choice for such a sensor. It is therefore desirable to reduce noise induced upon the pressure sensor by the high voltage ignition system components proximate thereto.


There is a self heating light comprising a body and a cover. Disposed inside of the body is a circuit board, a light element, a heat transfer device, a temperature sensor, a heating element, a power contact, and a switch. The switch is configured to switch power between the heating element and the light depending on a predetermined temperature of determined by the temperature sensor inside of the body of the light.

At least one embodiment of the invention relates to a headlight that transfers all or much of the heat generated by the LED Light Engine to the front of the headlight, and dissipates such heat to the environment using a finned circular heatsink located in front of the light, such heat is used to melt ice or snow build up, and or evaporate moisture normally deposited in front of the headlight by unusual of severe weather conditions. Imbedded Heat pipes are used to transfer the heat from the LED Light Engine to the finned circular heatsink, allowing the headlights to normally illuminate the front of the vehicle under extreme weather conditions, during dub-zero temperatures and high wind conditions, an imbedded heater inside the front heatsink can generate additional heat and maintain the lens above freezing temperatures, free of ice, snow and moisture, always maintaining the lens with clear visibility and always allowing for maximum light output. Headlights for vehicles such as trains, trucks, airplanes, boats, cars or other vehicles are subject to illumination obstructions such as moisture, ice and snow.


A phase shift mask has phase shift portions of both Levenson type and Halftone type. At the phase shift portion of Levenson type, formed are first and second light transmitting regions and transmitting exposure light of different phases, as well as a shading region constituted by a stacked structure of a semi-shading shifter film and a shading film. At the phase shift portion of Halftone type, a third light transmitting region where a surface of a quarts substrate is exposed, and a fourth light transmitting region having the semi-shading shifter film on the surface of the quartz substrate are provided. A phase shift mask, a method of manufacturing the phase shift mask and a method of forming a pattern using the phase shift mask can thus be obtained in which a highly precise alignment mark is unnecessary, a process for manufacturing is simple, and a defect can easily be removed.

1. Field of the Invention
The present invention relates to a phase shift mask, a method of manufacturing the phase shift mask and a method of forming a pattern using the phase shift mask. The invention more particularly relates to a phase shift mask provided with phase shift portions of Levenson type and Halftone type, a method of manufacturing the phase shift mask and a method of forming a pattern using the phase shift mask.
2. Description of the Background Art
As higher integration and miniaturization have been achieved in a semiconductor integrated circuit, miniaturization of a circuit pattern formed on a semiconductor substrate (hereinafter simply referred to as a wafer) has also been proceeded.
As a basic technique for generating the pattern, photolithography is widely known among others. Although various development and improvement have been made in the field, dimension of the pattern has still become smaller, and requirement for improved resolution of the pattern has also become stronger.
According to the photolithography technique, a mask (original) pattern is transferred to a photoresist coating a wafer, and underlying film to be etched is patterned using the photoresist. At the time of the transfer, the photoresist is developed. Through the development process, the photoresist of the type in which a portion exposed to light is removed is called a positive type, while the type in which a portion not exposed to light is removed is called a negative type photoresist.
Resolution limit R (nm) in the photolithography employing the demagnification exposure method is represented as EQU R=k.sub.1 .multidot..lambda./(NA)
where .lambda. is wavelength (nm) of the light used, NA is numerical aperture of a lens and k.sub.1 is a constant dependent on the resist process.
As can be appreciated from above equation, in order to improve the resolution limit R to obtain a fine pattern, the values K.sub.1 and .lambda. should be smaller, and the value NA should be larger. In other words, what is required is to reduce the constant dependent on the resist process as well as to shorten the wavelength and to increase NA. However, improvement of light source or the lens is technically difficult, and depth of focus .delta. (.delta.=k.sub.2 A .lambda./(NA).sup.2) of light might become shallower by shortening the wavelength and increasing NA, thus causing deterioration of the resolution.
In view of this, studies of miniaturization of the pattern by improving not the light source or the lens but the photomask are proceeded. Lately, a phase shift mask has been attracting much attention as a photomask allowing improvement of the resolution of the pattern. The structure and principle of such a phase shift mask will be hereinafter described in comparison with an ordinary photomask. The description below will be directed to a phase shift mask of the Levenson type and that of the Halftone type.
FIGS. 10A, 10B, and 10C respectively show a cross section of a mask, electric field on the mask, and light intensity on a wafer when an ordinary mask is used. With reference to FIG. 10A, the ordinary photomask is structured to have a metal mask pattern 103 formed on a glass substrate 101. The electric field on such an ordinary photomask is pulse modulated spacially by metal mask pattern 103 as shown in FIG. 10B.
Referring to FIG. 10C, if the pattern has smaller dimension, exposure light transmitted through the photomask extends into a non-exposed region (a region where transmission of the exposure light is blocked by metal mask pattern 103) on the wafer due to the diffraction effect of the light. The light is thus directed to a region not to be exposed on the wafer, resulting in deterioration of contrast of light (difference of light intensity between an exposed region and a non-exposed region on a wafer). The resolution is degraded and transfer of a fine pattern becomes difficult.
FIGS. 11A, 11B, and 11C respectively show a cross section of a mask, electric field on the mask, and light intensity on a wafer when a phase shift mask of Levenson type is used. With reference to FIG. 11A, an optical member called phase shifter 105 is provided on an ordinary photomask.
More specifically, chromium mask pattern 103 is formed on glass substrate 101 to provide an exposure region and a shading region, and phase shifter 105 is formed at every other exposure region. Phase shifter 105 has a function of shifting the phase of the transmitted light by 180.degree..
Referring to FIG. 11B, in the electric field on the mask generated by the light transmitted through the phase shift mask, the phases are alternately inverted by 180.degree. since phase shifters 105 are provided at every other exposure region. As described above, adjacent exposed regions have opposite phases of light, so that beams of light cancel each other out due to the interference of light in the portions where light beams of opposite phases are overlapped.
As a result, as shown in FIG. 11C, the intensity of the light becomes weak in the boundary portion between the exposed regions, then sufficient difference of light intensity between the exposed region and the non-exposed region on the wafer can be obtained. The improvement of the resolution is thus possible to allow the transfer of a fine pattern.
FIGS. 12A, 12B, and 12C respectively show a cross section of a mask, electric field on the mask, and light intensity on a wafer when a phase shift mask of the Halftone type is used. With reference to FIG. 12A first, the phase shift mask of the Halftone type is also provided with an optical member called phase shifter 106 as the phase shift mask of the Levenson type described above.
Optical member 106 is deposited on only a semi-transparent film 103 on glass substrate 101. Phase shifter 106 and semitransparent film 103 thus constitute a double layered structure. Phase shifter 106, as described above, has a function of shifting the phase of the transmitted light by 180.degree., and semitransparent film 103 has a function of attenuating the intensity of the exposure light without blocking it completely.
Referring to FIG. 12B, since the double layered structure of phase shifter 106 and semitransparent film 103 is provided, phases of the electric field on the mask are alternately inverted by 180.degree., and intensity of one phase becomes smaller than that of the other phase. As a result, the phase of light is shifted by 180.degree. by transmission through phase shifter 106, and the intensity of light is attenuated by transmission through semitransparent film 103 such that a prescribed thickness of the film of the photoresist is left after development. Phases of light are reversed at exposure regions adjacent to each other, so that light is canceled out at a portion where the light beams of opposite phases overlap.
As a result, as shown in FIG. 12C, light intensity can be reduced at an edge portion of the exposed pattern since phases are reversed at the edge portion of the exposed pattern. Accordingly, difference of the light intensity of the exposure light transmitted through semitransparent film 103 and not transmitted therethrough increases at corresponding regions, and resolution of a pattern image can be enhanced.
There are various types of the phase shift mask, including the Levenson type and the Halftone type. The phase shift mask of the Levenson type is known to be effective for a densely formed line/space pattern. The mask is also effective for producing an isolated dark line. More specifically, an isolated dark line of high resolution can be obtained by increasing width Ln and La of light transmitting regions and decreasing width Ls of the shading region sandwiched between the light transmitting regions in FIG. 11.
However, it is difficult to produce an isolated bright line using the phase shift mask of the Levenson type. In FIG. 11, an isolated bright line can be generated by increasing width Ls of the shading region and decreasing the width La (or Ln) of the transmitting region sandwiched between the shading regions. However, there is no interference of exposure light transmitted through transmitting portions adjacent to each other, so that high resolution cannot be obtained when an isolated bright line is to be formed.
On the other hand, according to an exposure method using the phase shift mask of the Halftone type described above, resolution of an isolated bright line can be improved. Therefore, if the masks of these two types can be fabricated on a same mask substrate, densely formed lines, an isolated bright line, and an isolated dark line of high resolution can simultaneously be obtained.
A mask structure and a method of manufacturing the mask structure for achieving the effect above are proposed in Japanese Patent Laying-Open Nos. 7-168342 and 6-123961. Phase shift masks disclosed in the Japanese Patent Laying-Open Nos. 7-168342 and 6-123961 are hereinafter described as a first conventional example and a second conventional example, respectively.
FIG. 13 is a cross sectional view schematically showing a structure of a phase shift mask according to the first conventional example. With reference to FIG. 13, a transparent substrate 201 is provided with a trench 201a, providing first and second light transmitting regions Tn and Ta having phases of light shifted by 180.degree. to each other. Between the first and the second light transmitting regions Tn and Ta, a semi-shading region S is produced by forming a semi-shading film 203 which covers a sidewall of trench 201a.
In a phase shift mask 210, a phase shift effect of the Halftone type is obtained by providing semi-shading film 203 having a width Ls greater than a prescribed dimension, and a phase shift effect of the Levenson type is achieved by providing semi-shading film 203 having the width Ls smaller than a prescribed dimension. By appropriately setting the width Ls of semi-shading film 203, both of the phase shift portion of the Levenson type and that of the Halftone type can be produced on the same mask.
A method of manufacturing the phase shift mask is hereinafter described.
FIGS. 14-17 are schematic cross sectional views showing a method of manufacturing the phase shift mask according to the first conventional example, following the order of process steps. With reference to FIG. 14, a chromium film 205 is deposited on a surface of a quartz substrate 201 and a resist pattern 207 is formed on chromium film 205. Chromium film 205 is patterned by anisotropic etching using resist pattern 207 as a mask. Resist pattern 207 is thereafter stripped.
Referring to FIG. 15, quartz substrate 201 is anisotropically etched using chromium film pattern 205 as a mask. A shifter pattern is transferred onto the substrate by providing trench 201a on the surface of quartz substrate 201. Chromium film pattern 205 is thereafter removed.
With reference to FIG. 16, the entire surface of quartz substrate 201 is exposed by the removal of chromium film pattern 205.
Referring to FIG. 17 next, a chromium film 203 is formed on the entire surface and a resist pattern 209 is formed on chromium film 203. Chromium film 203 is anisotropically etched using resist pattern 209 as a mask. Chromium film 203 is thus patterned exposing the first and second light transmitting regions while being left on the semi-shading region sandwiched between the first and second light transmitting regions. Resist pattern 209 is thereafter stripped and phase shift mask 210 illustrated in FIG. 13 is completed.
FIG. 18 schematically shows a cross section of a structure of the phase shift mask according to the second conventional example. With reference to FIG. 18, a phase shift mask 310 is provided with a phase shift mask portion of the Levenson type and that of the Halftone type. An etching stop film 303 is provided on an entire surface of a quartz substrate 301.
At the phase shift portion of the Levenson type, a shift layer 305 divided into a plurality of pieces is formed on etching stop film 303. A shading film 307 is formed on an edge portion of phase first layer 305 such that it partially exposes the surface of phase shift layer 305.
On the other hand, at the phase shift portion of the Halftone type, phase shift layer 305 divided into a plurality of pieces is formed on etching stop film 303. Semi-shading film 309 is provided such that it covers an entire surface of phase shift layer 305.
As clearly illustrated in FIG. 18, both of the phase shift portion of the Levenson type and that of the Halftone type are fabricated on the same mask.
A method of manufacturing the phase shift masks will be described.
FIGS. 19-23 are cross sectional views schematically showing the method of manufacturing the phase shift mask according to the second conventional example, following the order of process steps. First with reference to FIG. 19, etching stop film 303, phase shift layer 305, and shading film 307 are successively formed on quartz glass substrate 301. A resist pattern 311a is deposited on shading film 307. Shading film 307 is anisotropically etched using resist pattern 311a as a mask. Resist pattern 311a is thereafter removed.
Referring to FIG. 20, a plurality of pieces of shading film 307 separated from each other on phase shift layer 305 are formed at the phase shift portion of the Levenson type through this etching.
Referring to FIG. 21, semi-shading film 309 is formed to cover the entire surface of shading film 307 and phase shift layer 305.
Referring to FIG. 22, a resist pattern 311b having a prescribed shape is deposited on semi-shading film 309. Semi-shading film 309 and phase shift layer 305 are successively etched using resist pattern 311b as a mask. Resist pattern 311b is thereafter stripped. With reference to FIG. 23 next, a resist pattern 311c is further formed such that it covers the phase shift portion of the Halftone type. Semi-shading film 309 of the phase shift portion of the Levenson type is etched using resist pattern 311c as a mask and thereafter removed, thereby completing phase shift mask 310 shown in FIG. 18.
According to the first and the second conventional examples described above, a phase shift mask provided with a phase shift portion of the Levenson type and that of the Halftone type can be obtained.
However, in the first conventional example, the formation and patterning of semi-shading film 203 are carried out after the formation of trench 201a as shown in FIG. 17. In order to ensure satisfactory function of a phase shift mask of the Levenson type, semi-shading film 203 should be formed to exactly cover a sidewall of trench 201a which is a boundary portion of the regions having different light phases from each other. A problem of this example is that a highly precise alignment between semi-shading film 203 and an underlying shifter pattern is required when semi-shading film 203 is patterned.
In the second conventional example, phase shift layer 305 and semi-shading film 309 should be formed separately at the phase shift portion of the Halftone type as shown in FIGS. 19 and 21. A problem in this example is that the number of film formation steps increases and the process of manufacturing becomes complex, resulting in higher cost of manufacturing.
In the step of manufacturing a mask, a defect must be removed after patterning each film. However, in the second conventional example, removing the defect becomes difficult because of the increased number of film formation steps.
Furthermore, in the first conventional example, chromium film 203 is formed after the formation of the shifter pattern at quartz substrate 201 as shown in FIG. 16. When the shifter pattern is formed at quartz substrate 201 or after the formation, it is highly likely that a foreign matter is trapped in trench 201a. If chromium film 203 is formed having the foreign matter trapped as shown in FIG. 17, chromium film 203 could be broken due to the foreign matter. This leads to a problem that chromium film 203 tends to have a defect.
In the second conventional example, semi-shading film 309 is formed after the patterning of shading film 307 as shown in FIGS. 20 and 21, so that semi-shading film 309 is also likely to have a defect as in the first conventional example.

Phase shift mask, method of manufacturing phase shift mask and method of forming a pattern using phase shift mask


Insulating oil in electric power generation, transmission and distribution equipment such as circuit breakers, regulators, phase shifters, tank diverter switches and capacitor banks for respectively separated phases of a plural phase transmission or distribution line is filtered for removal of accumulated water, carbon particles and other contaminants by filters in oil circuits respective to each phase in the plurality. Each oil circuit respective to each circuit breaker includes a respective filter and circulation pump. However, all pumps in the plural phase power system, for example, are driven by the same motor and drive line whereby a fluid condition or circulation interruption of one oil circuit that requires termination of pump operation in the one oil circuit terminates the pump operation in all oil circuits. Pump motor power is preferably drawn from an energy source that may be independent of that served by the transmission and/or distribution power source.

1. Field of the Invention
The present invention relates generally to electric power transmission and distribution devices. More particularly, the invention relates to apparatus and methods for protecting a dielectric oil insulating medium used with phase switching equipment, circuit breakers, regulators, phase shifters, tank diverter switches, similar switchgear and capacitor banks for generating, transmitting and/or distributing plural phase electric power.
2. Description of Related Art
Electrical power load control and switching regulation devices for plural phase electric power generation, transmission and distribution devices such as circuit breakers, load regulators, phase shifters, tank diverter switches and similar switch gear, are often immersed in a specially compounded oil having dielectric properties for purposes of insulation, arc isolation and cooling. On occasion, these devices generate extremely high operating temperatures. Although the oil will not burn in the absence of atmosphere or oxygen, small portions will directly decompose under the intense heat of electrical arcing. This is especially true for circuit breakers, regulators and similar switchgear wherein mechanical contact switches are routinely closed and opened with a high potential difference standing at the switch contacts. As mechanical switch contact is closed or opened, brief arcing occurs. Such arcing transforms the oil by decomposition into elemental carbon which remains in the oil as suspended particles of graphite. An accumulation of suspended graphite particles will often reduce the dielectric value and hence, the insulating capacity of the oil.
Under other service circumstances and mechanisms, a dielectric oil system may also accumulate dissolved and entrained water. Water, particulate carbon and other accumulated contaminates in an oil system reduce the dielectric value of the oil and, hence, the effectiveness of the dielectric fluid to protect the internal components of the electrical apparatus.
Fortunately, contaminates such as water and carbon particles may be effectively removed from a system by filtration. Such filtration often takes the form of an external fluid circulation loop that includes a pump, a motor and a canister filter. Conduits channel a circulating flow stream of the dielectric oil between an equipment reservoir in which the electrical equipment is immersed and the filter/pumping equipment. This circulation may be continuous or intermittent.
For plural, two or three phase transmission or distribution of electrical power, each phase is carried on a separate line conduit. Regulating the power, therefore, includes individual capacitors, circuit breakers or regulators respective to each phase of the transmission. Each of these capacitors, circuit breakers or regulators may be physically positioned within a tank that confines an immersion quantity of dielectric fluid. In restatement, there is an insulating oil tank for each phase of the system. A three phase power system, therefore, has three tanks to hold three respective insulating oil reservoirs that immerse three respective switchgear devices.
A respective fluid circulation loop is preferably provided for each tank to maintain the fluid in that tank, exclusively. Hence, for the three switchgear tanks in a three phase power system, there are three respective fluid circulation loops. Each circulation loop includes a separate filter and pump respective to that circulation loop. This separation of fluids is essential to continuing load and equipment analyses of each phase since the accumulation rate and type of contaminates respective to the fluid of each phase is instructive of service needs.
When it is necessary to terminate a fluid circulation loop for one insulating oil tank respective to one power phase, whether automatically or manually, a typical operating procedure may terminate insulating oil circulation about the loops of all tanks. Although termination of all circulation loops in the event of maintenance or repair to one circulation loop is preferable, the procedure is not an absolute necessity. Normally, the circulation pumps respective to each tank in a circulation loop are driven by respective motors and connecting drive lines. Consequently, it is possible to terminate each circulation loop, selectively and individually. However, finding the volumetric space for three pumps and three motors within the permissible confines of a control cabinet becomes a challenge.
It is one objective of the present invention, therefore, to provide a system of separate circulation loops for the insulating oil in each switchgear immersion tank respective to a plural phase electrical power system wherein the circulation of insulating oil in each of the two or more circulation loops is impelled by a respective pump but that all pumps of the several circulation loops are driven by a common drive line that is controlled by a common power source.
Also an objective of the present invention is a unit of three separate pumps respective to each of three dielectric fluid circulation loops wherein all three pumps are driven by the same motor and drive line.

Oil filtration system for plural phase power equipment tanks


A battery pack includes a secondary battery including a plurality of cell blocks, a measuring section, a charge and discharge control switch, a protection circuit, and a memory. The measuring section detects a voltage, a current, and an internal resistance, of the secondary battery. The controller monitors the voltage and the current of the secondary battery and outputs a request signal indicative of a charge condition to charge the secondary battery in accordance with the charge condition which is set. The protection circuit monitors voltages of the plurality of cell blocks. The memory registers an initial internal resistance of the secondary battery. The controller calculates a deterioration coefficient by a ratio of the internal resistance detected by the measuring section to the initial internal resistance registered in the memory, and changes the charge condition in accordance with the deterioration coefficient.

The present application relates to a battery pack, a method of charging a secondary battery, and a battery charger. More particularly, the application relates to a battery pack, a method of charging a secondary battery, and a battery charger, which control a charge condition in accordance with the deterioration coefficient of a secondary battery.
A combination of constant-current charge and constant-voltage charge (constant-current constant-voltage method) is known as a method of charging a secondary battery. This charging method will be described with reference to FIG. 9, on which the abscissa represents charging time and the ordinate represents cell voltage and charging current. In FIG. 9, the region indicated by arrows a and b (hereinafter referred to as a "region a-b") is the range of constant-current charge, and the region indicated by arrows c and d (hereinafter referred to as a "region c-d") is the range of constant-voltage charge. The arrow I indicates charging current, and the arrow V indicates cell voltage. A power supply section for charging performs the operation of constant-current control in the region a-b, and performs the operation of constant-voltage control in the region c-d.
As shown in FIG. 9, during the region a-b, the constant-current charge is performed by a predetermined current value, and then the cell voltage rises. In this example, the charging current is maintained at, for example, 3300 mA. When the charging proceeds, so that the cell voltage reaches a predetermined voltage value, for example, 4100 mV, switching takes place from constant-current charge to constant-voltage charge. During the region c-d, the charging current is gradually lowered, and the cell voltage rises toward the output voltage (e.g. 4200 mV) of the power supply section. Thereafter, the charging is completed when the charging current becomes smaller than a predetermined value (a current value at end-of-charge).
The secondary battery gradually deteriorates with increasing the number of charge and discharge cycles, where each cycle consists of charge, and discharge and pause, as described above. The secondary battery deterioration has been determined by the count of charge and discharge cycles, the actual discharge amount, or charging time. For example, in the method using the count of charge and discharge cycles, the number of charge and discharge cycles is calculated by using charging amount or discharging amount, and a deterioration coefficient is obtained from the number of charge and discharge cycles. When the actual discharging amount is used, a deterioration coefficient is obtained from the actual discharging amount and a design capacity value by using a calculation equation: Deterioration coefficient=Design value capacity/Actual discharging amount.
Japanese Unexamined Patent Application Publication No. H11-174136 discloses the method including the steps of measuring the effective resistance in a battery pack and determining the deterioration thereof by the measured value. When the effective resistance is used, the deterioration can be determined in a short time.

Battery pack, method of charging secondary battery and battery charger


A macro lens comprises first to third lens groups having positive powers and an aperture stop disposed the first and second lens groups. The first lens group, aperture stop and second lens group remain fixed with respect to one another and movable as one unit relative to the third lens group for focusing. The third lens group is stationary with respect to an image plane of the macro lens.

1. Field of the Invention
The present invention relates to a macro lens having an exit pupil at a long distance for use with TV cameras with a color separation optical system, and, more particularly, to a macro lens which can form a sharp image of a subject located in a subject distance range from an infinite distance to the closest distance at which an image magnification is of approximately 1/3.
2. Description of Related Art
In order to produce fine quality close-up pictures, macro lenses typically have at least two groups of lens elements and are designed to move both the lens groups along the optical axis, changing an axial air spacing distance between the two lens groups. Such a macro lens is known from, for instance, Japanese Unexamined patent Publication No. 48-38,138.
In an attempt to decrease thrust movement of lenses or lens groups at very close focusing distances, some macro lenses of this kind are designed to cause a complicated relative movement of these lens groups along the optical axis so as to change an axial air spacing between each adjoining lens groups. Such a macro lens is known from, for instance, Japanese Unexamined patent Publication No. 58-186,714.
Both the macro lenses described in the above publications are designed for use with picture cameras and nothing is considered concerning a location of an exit pupil of the macro lens. Accordingly, the macro lenses are unavailable to color TV cameras having color separation optical systems which require a lens with an exit pupil located far away from an image plane of the lens. That is, as is well known to those skilled in the art, such a color separation optical system has a dichroic prism applied with an interference layer for separating light according to wavelengths. Since a macro lens having an exit pupil located at a relatively short distance from an image plane causes a principal ray to enter into the interference layer of the dichroic prism at greatly different incident angles depending upon image heights, color separation takes place differently according to lateral distances of principal rays from the optical axis due to a difference in optical path of the interference layer. If a principal ray is in parallel with the optical axis, in other words, if an exit pupil is located at infinity, the principal ray enters into the interference layer at a same incident angle independently from lateral distances of a principal ray from the optical axis, and color separation occurs with same characteristics. Although the allowable range of incident angle is slightly different according to dichroic prisms used in TV camera optical systems, it can be generally said that an incident angle of a principal ray less than one (1) degree is allowable.
An incident angle Ad of a principal ray is generally defined for an image having a height h by the following equation: EQU Ad=tan.sup.-1 h/f
where f is the focal length of a lens.
If a TV camera has a 2/3" image plane whose diagonal size is 11.0 mm. and whose aspect ratio is 3:4, a lateral height of an image is 3.30 mm. Accordingly, the focal length f is 189.0 mm. for an incident angle (Ad) of a principal ray of one (1) degree. Consequently, in order for a principal ray to enter the dichroic prism at an incident angle within one (1) degree, the focal length f must be longer than 189.0 mm. On the other hand, a thrust movement of lens X from an infinity focusing distance is defined for a magnification M by the following equation: EQU X=M.times.f
Accordingly, if the magnification M is 1/3, the thrust movement of lens X is 63.0 mm., which makes the overall length of the lens large.