A high-frequency incision instrument for an endoscope is provided with a flexible sheath, and a rod electrode remotely operated to protrude from/retract into the distal end portion of the sheath. A stationary stopper provided at the distal end portion of the sheath and a movable stopper provided at the proximal end portion of the rod electrode, the movable stopper contacting the stationary stopper to define a maximum protruding amount of the rod electrode from the distal end of the sheath. A proximal end portion of the rod electrode is screw-engaged with a member to which the movable stopper is formed, and the rod electrode is rotatable so that screw-engaged amount of the proximal end portion of the rod electrode with respect to the member is changed, thereby a distance between the tip end of the rod electrode and the movable stopper being adjustable.

The present invention relates a high-frequency incision instrument for an endoscope. A high-frequency incision instrument for an endoscope is used for incision of in vivo mucosa and the like. The high-frequency incision instrument is generally inserted through an instrument channel of the endoscope. Typically, the high-frequency incision instrument is configured such that a rod electrode provided at a tip end portion of a flexible sheath is operated to protruded forward or retracted from the tip end of the sheath by an operating unit connected to the proximal end of the sheath.
Depth of the incision of the in vivo mucosa depends on a condition of a target portion and/or operational conditions of the high-frequency incision instrument, it is preferable that the depth is adjusted to be safe and optimum amount for the target portion by adjusting a protruding amount of the rod electrode. An example of such a configuration is disclosed in Japanese Patent Provisional Publication No. P2002-113016A (hereinafter, referred to as '016 publication).
According to the invention disclosed in '016 publication, stoppers configured to abut against each other are provided to the tip end of the sheath and the proximal end of the rod electrode, respectively, and a position of a cap member screwed onto the tip end of the sheath is adjusted so that the maximum protruding amount of the rod electrode with respect to the tip end of the sheath is restricted.
When in use, the high-frequency incision instrument is inserted through the instrument channel arranged inside an inserting section of the endoscope. Since the inserting section is bent inside a human cavity, the cap member screwed onto the sheath may be rotated when the high-frequency incision tool is inserted through such an instrument channel, and the adjusted condition of the protruding amount of the rod electrode may be changed. In the worst case, the cap may be disengaged from the sheath inside the human cavity.

High-frequency incision instrument for endoscope


According to one embodiment, a semiconductor element includes a first transistor section, a second transistor section, a contact region, and a capacitive element section. The first transistor section includes a first electrode, a second electrode, a first semiconductor region, a second semiconductor region, a third semiconductor region, the third semiconductor region, and the third semiconductor region being connected to the second electrode, and a third electrode. The second transistor section includes a fourth electrode, a fifth electrode, a fourth semiconductor region, a fifth semiconductor region, a sixth semiconductor region, and the sixth semiconductor region being connected to the fifth electrode, and a sixth electrode, the second transistor section being arranged adjacent to the first transistor section. The contact region includes a seventh electrode, electrically connecting the fifth electrode and the first electrode. The capacitive element section is connected between the second electrode and the fourth electrode.

There is a parasitic inductance in a wiring of a semiconductor device, and when a semiconductor element switches, an induction voltage will be generated, which is expressed by the product of the parasitic inductance and the current change rate (di/dt) at switching. Thus, a DC voltage of an electric power inverter circuit and the induction voltage will be applied to the semiconductor device. In order to enhance the reliability of the semiconductor device, it is important to reduce such a parasitic inductance as low as possible. Further, in order to downsize the semiconductor device, it is also important to scale down the semiconductor device.

Semiconductor device having a pair of transistors that are directly coupled and capacitively coupled


A system and method for performing stimulation operations at a wellsite having a subterranean formation with of a reservoir therein is provided. The method involves generating a plurality of quality indicators from a plurality of logs, and combining the plurality of quality indicators to form a composite quality indicator. The composite quality indicator may be combined with a stress log to form a combined stress and composite quality indicator, the combined stress and composite quality indicator comprising a plurality of blocks with boundaries therebetween. The method may further comprise identifying classifications for the plurality of blocks; defining stages along the combined stress and composite quality indicator based on the classifications; and selectively positioning perforations in select stages based on the classifications thereon.

The present disclosure relates to techniques for performing oilfield operations. More particularly, the present disclosure relates to techniques for performing stimulation operations, such as perforating, injecting, and/or fracturing, a subterranean formation having at least one reservoir therein. The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Oilfield operations may be performed to locate and gather valuable downhole fluids, such as hydrocarbons. Oilfield operations may include, for example, surveying, drilling, downhole evaluation, completion, production, stimulation, and oilfield analysis. Surveying may involve seismic surveying using, for example, a seismic truck to send and receive downhole signals. Drilling may involve advancing a downhole tool into the earth to form a wellbore. Downhole evaluation may involve deploying a downhole tool into the wellbore to take downhole measurements and/or to retrieve downhole samples. Completion may involve cementing and casing a wellbore in preparation for production. Production may involve deploying production tubing into the wellbore for transporting fluids from a reservoir to the surface. Stimulation may involve, for example, perforating, fracturing, injecting, and/or other stimulation operations, to facilitate production of fluids from the reservoir.
Oilfield analysis may involve, for example, evaluating information about the wellsite and the various operations, and/or performing well planning operations. Such information may be, for example, petrophysical information gathered and/or analyzed by a petrophysicist; geological information gathered and/or analyzed by a geologist; or geophysical information gathered and/or analyzed by a geophysicist. The petrophysical, geological and geophysical information may be analyzed separately with dataflow therebetween being disconnected. A human operator may manually move and analyze the data using multiple software and tools. Well planning may be used to design oilfield operations based on information gathered about the wellsite.

This patent is subject to a terminal disclaimer.

System and method for performing downhole stimulation operations


An an electronic circuit having improved protection against harsh environments, a preferred embodiment thereof including: a substrate 10 having a top surface 12; an electronic component 14 attached to the top surface of the substrate; a plastic and metal foil laminated barrier 16 having an outer periphery 18 thereabout, the outer periphery being sealably attached to the top surface 12 of the substrate so as to define a closed pocket 20 between the top surface 12 and the barrier 16 within which the electronic component 14 is enclosed; and a desiccant element 50. The desiccant element 50 includes: a case 51 having an internal chamber, an inlet orifice 58, and an outlet orifice 59, wherein the inlet and outlet orifices are each in communication with the internal chamber; a predetermined amount of desiccant material 53 contained within the internal chamber; a normally-open interior valve 54 situated between the inlet orifice 58 and the internal chamber; a normally-closed exterior valve 56 situated between the outlet orifice 59 and the internal chamber; and heating means 52 for selectably heating the desiccant material 53 preferably above a regeneration temperature thereof. The desiccant element 50 is situated such that at least the interior orifice 54 thereof is sealably enclosed within the closed pocket 20.

1. Field of the Invention
The present invention relates generally to electronic circuits, and more particularly to a method for protecting electronic circuits against harsh environments.
2. Disclosure Information
Many environments in which electronic circuits are used present harsh conditions which are detrimental to the performance and/or life expectancy of the circuit components. For example, in some automotive applications circuit components must be able to withstand severe vibrations, drastic temperature fluctuations (e.g., between -40.degree. C. and 125.degree. C.), corrosive and/or particle-laden exhaust fumes, high atmospheric moisture content, and so forth.
Various approaches are known for protecting electronic circuits from such harsh environmental conditions. One such approach is to provide a cover or housing of some sort around at least some portion of the circuit. Another approach is to pot the whole circuit or portions thereof in an epoxy, silicone, or other compound.
However, these and other previously known approaches often suffer from one or more drawbacks. For example, potting a circuit may protect it from gross exposure to water and other harmful fluids, but typically does not protect against gradual seepage of such fluids through the potting material and into the electronics over time. Likewise, providing a cover or housing over or about the electronics may suffer the same disadvantage. Furthermore, even if a cover or housing is generally well sealed against water penetration, over time moisture may nonetheless permeate into and accumulate in the interior of such covers or housings, which may detrimentally affect the functioning and/or useful life of the circuit.
It would be desirable, therefore, to provide some means for protecting an electronic circuit against the above-mentioned harmful environmental conditions without the aforementioned drawbacks.

Method for protecting electronic components


A lock mechanism for a faceplane infrastructure coupled externally from a faceplate of a modular device includes a locking bar, a locking bar engagement element, and a securing device. When the lock mechanism is assembled and in a locked state, the locking bar is housed within the modular device. Further, when the lock mechanism is assembled and in the locked state, the locking bar engagement element is fixedly coupled to a first portion of the faceplane infrastructure and removably engaged with the locking bar through an aperture in the faceplate of the modular device. Moreover, when the lock mechanism is assembled and in the locked state, the securing device locks the first portion of the faceplane infrastructure to the faceplate of the modular device.

Computing systems, such as server assemblies, include one or more electronic devices. For example, an electronic device may include a modular device. The modular device may be inserted into a frame and/or rack cabinet to form a part of a computing system. To facilitate communication, e.g., optical communication, within a modular device or between modular devices within the computing system, faceplane infrastructure may be used. Faceplane infrastructure includes infrastructure that is coupled external from a modular device, such as being coupled to a rack cabinet that holds the modular device. The faceplane infrastructure communicatively couples to the modular device through a faceplate of the modular device.

Hewlett Packard Enterprise Development LP


A Reflective Semiconductor Optical Amplifier (RSOA) for compensating for light loss in an optical link, an RSOA module for improving polarization dependency using the RSOA, and a Passive Optical Network (PON) for increasing economical efficiency and practical use of a bandwidth using the RSOA are provided. The PON includes a central office comprising a plurality of optic sources transmitting a downstream signal and a plurality of first receivers receiving an upstream signal; at least one optical network terminal (ONT) including a second receiver receiving the downstream signal and an RSOA which receives the downstream signal, remodulates the downstream signal into the upstream signal, and transmits the upstream signal in loopback mode; and a remote node interfacing the central office with the ONT. The upstream signal and the downstream signal are transmitted between the remote node and the ONT via a single optical fiber. The remote node includes an optical power splitter at its port connected to the ONT.

1. Field of the Invention
The present invention relates to a Passive Optical Network (PON), and more particularly, to a Reflective Semiconductor Optical Amplifier (RSOA), an RSOA module having the RSOA, and a PON using the RSOA.
2. Description of the Related Art
Fiber To The Home (FTTH) technology for directly connecting a telephone switch to a home through optical fiber has been actively researched and developed worldwide in order to provide voice, data, and broadcast convergence services to subscribers and is expected to become popular within a few years. From the point of view of the characteristics of an optical network, it is most important to develop an optical signal transmission method having superior economical efficiency and mass productivity in developing the FTTH technology. Optical networks may be classified into a Passive Optical Network (PON) and an Active Optical Network (AON). The PON is currently being developed in the forms of an Asymmetric Transfer Mode (ATM)-PON, a B-PON, a G-PON and an E-PON. The AON is being developed into a form that connects local networks, each of which is composed of Ethernet switches, using optical fiber.
A Wavelength Division Multiplexing (WDM)-based FTTH network, that is, a WDM-PON, is a scheme in which the communication between a center office (CO) and subscribers is performed using a wavelength assigned to each subscriber. Such a WDM-PON is advantageous in that the WDM-PON can provide independent and high-capacity communication service to each subscriber, and has excellent security. Furthermore, in the WDM-PON, the modulation and demodulation of light are performed for each subscriber, unlike a Time Division Multiplexing (TDM) type, so that an optic source having low modulation speed and output and a receiver having narrow bandwidth can be employed.
However, since intrinsic wavelengths are respectively assigned to subscribers for communication with the CO, the WDM-PON has a limited wavelength band and interval, and thus, the number of subscribers is also limited. Moreover, although a transmission speed per wavelength is at least 1 Gbps, there is no content to be transmitted for which this high speed is appropriate.
From an economical point of view, the WDM-PON is more expensive since it requires a pair of optical transceiver modules for each subscriber, which are respectively installed in a subscriber's area and the CO. In addition, the WDM-PON requires optic sources having intrinsic wavelengths, the number of which is identical to the number of subscribers, so that an economical burden is imposed on subscribers and, therefore, implementation of the WDM-PON is difficult. From a maintenance point of view, the service provider is disadvantaged in that it must prepare different optic sources having different wavelengths for individual subscribers for installation and breakdowns. Accordingly, it is important to develop a low cost WDM-PON optic source and the provision of the same kind of wavelength-independent optic sources to all subscribers is necessarily required to implement the WDM-PON.
Meanwhile, a method of forming a WDM-PON that uses a Reflective Semiconductor Optical Amplifier (RSOA) and thus does not need independent seed light for an upstream signal (hereinafter referred to as a "seedless RSOA-based WDM-PON") and its applications have been suggested. In the operation of the seedless RSOA-based WDM-PON, an optical signal modulated into a downstream data output from the CO (hereinafter, referred to as a "downstream signal") is input to an RSOA at an optical network terminal (ONT) and the RSOA is operated in a gain-saturation region with respect to input optical signal power so that a difference between levels (i.e., level 0 and level 1) of the input optical signal is remarkably squeezed and the optical signal is remodulated into upstream data (hereinafter, referred to as an "upstream signal) and is transmitted to the CO.
In an RSOA structure, a usual SOA chip has a backside with a high-reflective (HR) coating facet and a front side with an anti-reflective (AR) coating facet. Light incident onto the front side is amplified while progressing in an active waveguide, is then reflected from the HR coating facet on the backside, and is then output through the front side. The RSOA structure may be classified into a weakly-index guided structure and a strongly-index guided structure according to the structure of a waveguide in the active region. The weakly-index guided structures include many kinds of waveguide structures, but a ridge waveguide structure is a typical structure. The strongly-index guided structure includes a planar buried heterostructure and a stripe buried heterostructure.
FIGS. 1A and 1B are horizontal and vertical cross-sections of a conventional RSOA 10 into which a passive spot-size converter is integrated. Referring to FIG. 1A, the RSOA 10 includes an active region 11, a p-type electrode 13 supplying current to the active region 11, and a passive spot-size converter 12. An HR coating facet 14a and an AR coating facet 14b are formed on both ends, respectively, of the RSOA 10. The AR coating facet 14b is an exit surface 14c for output light.
The passive spot-size converter 12 is formed using a material different from that of the active region 11 and is connected with the active region 11 using a butt-joint method. The passive spot-size converter 12 is inclined at a predetermined angle of θ with respect to a normal A of the exit surface 14c in order to improve an AR property. The predetermined angle of θ is in a range of 0 through 10 degrees.
Referring to FIG. 1B, an n-type electrode 15 is formed at the bottom of the RSOA 10. Accordingly, the current supplied by the p-type electrode 13 flows across the active region 11 to generate light and then flows into the n-type electrode 15.
The passive spot-size converter 12 increases the size of an optical mode generated to an appropriate range, thereby increasing the optical coupling efficiency between the RSOA 10 and optical fiber or other waveguides. A method of gradually decreasing an initial width Wactive of the active region 11 to an end width Wtaper of the passive spot-size converter 12, a method of gradually decreasing an initial thickness Hactive of the active region 11 to an end thickness Htaper of the passive spot-size converter 12, or a combination of them may be used to increase the size of the optical mode. Usually, the initial width Wactive is 0.8-1.5 μm; the initial thickness Hactive is 0.1-0.4 μm; the end width Wtaper is 0.1-0.5 μm; and the end thickness Htaper is 0.01-0.05 μm.
The performance of the passive spot-size converter 12 is usually evaluated based on a far-field angle. It is preferable that the far-field angle be 25 degrees or less in both of vertical and horizontal directions in order to increase the optical coupling efficiency between the passive spot-size converter 12 and optical fiber or other waveguides.
A length Lchip of the RSOA 10 may be 600-1500 μm but may be 1000 μm or less in order to realize a cheap TO-package. The active region 11 of the RSOA 10 may have a length Lactive of 200-600 μm.
FIG. 2 is a cross-section of the RSOA 10, taken along line I-I illustrated in FIG. 1A, and particularly, is a cross-section of the RSOA 10 having a planar buried heterostructure. Referring to FIG. 2, the RSOA 10 includes the active region 11 on an n-type substrate 16, a clad 18 including a lower clad 18a and an upper clad 18b respectively disposed below and above the active region 11, and the p-type electrode 13 and the n-type electrode 15 for supplying current to the active region 11. A planar buried heterostructure 11a is disposed on the top and bottom surfaces of the active region 11. The active region 11 and the planar buried heterostructure 11a form a waveguide. In addition, a current blocking layer 17 having a two-layer structure with a p-doped layer and an n-doped layer is disposed on the left and right sides of the active region 11 so that current from the p-type electrode 13 is supplied only to the active region 11.
Meanwhile, an ohmic contact layer 19a is disposed between the upper clad 18b and the p-type electrode 13, whereby an ohmic resistance between the upper clad 18b and the p-type electrode 13 is reduced. A passivation layer 19b may be disposed on a top surface of the ohmic contact layer 19a.
FIGS. 3A and 3B are horizontal and vertical cross-sections of an RSOA 10a into which a conventional active spot-size converter 12a is integrated. The RSOA 10a including the active spot-size converter 12a is almost the same as the RSOA 10 including the passive spot-size converter 12, with the exception of the form of an electrode and used materials. In detail, the active spot-size converter 12a is formed using the same material as the active region 11. Accordingly, the active spot-size converter 12a is formed by slanting the material of the active region 11 at an angle of θ with respect to a normal of the exit surface 14c without a butt-joint. Meanwhile, a p-type electrode 13a is formed for the active spot-size converter 12a. Other elements like the shape, the size and the far-field angle of the active spot-size converter 12a are the same as those of the passive spot-size converter 12.
The RSOA structure may be classified into a multiple quantum well structure and a bulk structure. Usually, an active region in an RSOA has an indium gallium arsenide phosphide (InGaAsP) bulk structure because it is not easy to reduce polarization-dependent gain (PDG) by controlling stress at a quantum well region in the multiple quantum well structure.
However, when the active region has the bulk structure, gain and saturation performance rapidly decreases when the temperature of the RSOA increases. Accordingly, a special temperature stabilizer is needed to use the bulk structure in a temperature range of 0-40 degrees or −20-60 degrees where communication systems are usually used. For this reason, the price of RSOA modules increases and the reliability thereof decreases. The active region may have the multiple quantum well structure to avoid these problems. However, as described above, when the multiple quantum well structure is used, it is necessary to precisely control polarization of light input to an RSOA by an optical link or to use unpolarized light due to a PDG problem.
Briefly, the multiple quantum well structure has excellent gain, saturation and temperature characteristics but has a PDG problem, while the bulk structure can reduce PDG when a tensile stress is appropriately applied during the growth of an active region but has poor gain, saturation and temperature characteristics.
Conventional methods of manufacturing an optical transceiver module or RSOA module using the above-described RSOA may be largely classified into an active alignment method and a passive alignment method. The RSOA installed within a TO-package or TO-CAN is aligned with optical fiber using the active alignment method and then fixed and packaged using laser welding. When the passive alignment method is used, the RSOA is aligned with an optical axis of a waveguide on a planar lightwave circuit (PLC) platform, aligned with optical fiber using a V-groove formed in the PLC platform, and fixed and packaged using an ultraviolet-curable or thermosetting epoxy. The passive alignment method enables easier alignment than the active alignment method, thereby being suitable for mass production, but is disadvantageous in that it needs expensive flip-chip bonding equipment and precise fabrication of a V-groove.

Reflective semiconductor optical amplifier (RSOA), RSOA module having the same, and passive optical network using the same

Electronics and Telecommunications Research Institute


A multi-function printer includes a fuser unit which includes a heat roller and a pressure roller; a duct which is formed in a long shape in a direction along an axis of the heat roller, is disposed in the vicinity of the fuser unit along the axis of the heat roller, and is exhausted by an exhaust fan which is provided on one end side in a long-side direction; an exhaust port which is opened to a first side wall of the fuser unit side of the duct and causes the fuser unit and the duct to communicate with each other; and a planar filter which is attached to an inner wall surface of the duct and in which the surface of the filter is an irregular surface on which ditches and convex portions extending in a direction inclined to the long-side direction of the duct are alternately disposed in the long-side direction of the duct.

1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus.
2. Description of the Related Art
In an electrophotographic image forming apparatus, it is known that a plurality of kinds of chemical substances are discharged from an image forming apparatus during image forming. For example, as a representative of the discharged chemical substances, there is ozone generated when a photosensitive drum is charged, or toner dust generated during developing or fusing. In the related art, in order to not allow the generated chemical substances to be discharged outside the image forming apparatus, for example, a measure of providing a filter or the like is performed.
For example, in a volatile chemical substance collection device of an electronic apparatus disclosed in Japanese Patent Unexamined Publication No. 2009-282455, an electric field is generated in an atmosphere from an electric field generating collection member in an exhaust duct provided above a fuser unit, and volatile organic compounds (VOC) included in the atmosphere are drawn to the surface of the electronic field generating collection member by the operation of the electric field so as to be collected.
In an image forming apparatus disclosed in Japanese Patent Unexamined Publication No. 2011-180235, a duct which includes a take-in port for taking-in minute particles generated from a heat roller inside a fusing device is provided in the vicinity of the fusing device. An exhaust fan which generates a flow of air from the take-in port toward an outlet is provided in an expansion portion of the duct, and a first filter member is provided on the upstream side of the exhaust fan. The first filter member captures ultrafine particles (for example, siloxane) generated from a rubber layer configuring the fusing device. A shutter which closes a gap between the first filter member and the expansion portion is provided, and a control portion of the image forming apparatus switches a state where the shutter closes a first filter portion and a state where the shutter does not close the first filter portion according to a predetermined initial burst condition.
In an odor removing device of a multi-function image forming apparatus disclosed in Japanese Patent Unexamined Publication No. 2011-180283, a plurality of air passage portions for introducing air inside a housing are formed on a housing bottom portion. Each air passage portion is a cylindrical body in which an inner diameter of the upper portion side inside the housing is smaller than an inner diameter of the housing bottom portion, and an ozone decomposition filter including an ozone decomposition catalyst is disposed on an inner diameter surface of the cylindrical body. A waste liquid absorbing material is disposed on the bottom portion inside the housing, a deodorizing absorbent is disposed on an upper cover inside the housing, and an exhaust port of the air passing through a portion between the waste liquid absorbing material and the deodorizing absorbent is provided on the side surface of the housing.
However, in recent years, according to enhancement in consciousness with respect to worldwide environment protection, minute particles (for example, ultrafine particles (UFP) having a particle diameter less than or equal to 100 nm) different from ozone or the like occurring from an electrophotogrpahic image forming apparatus have become a problem.
As a structure which captures the ultrafine particles, for example, like the electronic apparatus disclosed in Japanese Patent Unexamined Publication No. 2009-282455, when the volatile chemical substance collection device which draws volatile organic compounds to the surface of the electric field generating collection member and collects the compounds is additionally provided, there is a problem in that the structure becomes complicated.
For example, as the image forming apparatus disclosed in Japanese Patent Unexamined Publication No. 2011-180235, when the structure in which the first filter member capable of capturing minute particles is provided on the upstream side of the exhaust fan and the exhaust gas permeates the first filter member is provided, the first filter member increases resistance when the air is transported, and thus, exhaust efficiency is decreased and the temperature inside the housing is increased. Accordingly, the output of the exhaust fan should be increased, and thus, there is a problem that noise is generated and running cost is increased.
For example, as the multi-function image forming apparatus disclosed in Japanese Patent Unexamined Publication No. 2011-180283, when the plurality of (for example, two in Japanese Patent Unexamined Publication No. 2011-180283) exclusive odor removing devices are additionally provided, the structure becomes complicated and, there is a problem that a cost of the apparatus is also increased.
The present invention is made for solving the above-described problems in the related art, and an object thereof is to provide an image forming apparatus which decreases amounts of emission of ultrafine particles and suppresses an increase of output of the exhaust fan by a simple structure.

Panasonic Intellectual Property Management Co., Ltd.


Systems and methods for implementing a lightweight checkpoint technique for resilience against soft errors are disclosed. The technique provides effective, safe, and timely soft error detection and recovery using software. In an exemplary aspect, resilience against data flow errors and control flow errors is provided in critical or mixed-critical applications in each basic block or at critical basic blocks. Verified register preservation is provided at each basic block, along with memory preservation checkpoints. In this manner, soft errors are quickly detected and addressed. The register and memory preservation further allows for safe re-execution from recoverable soft errors. Control flow errors can also be detected at the beginning and/or end of each basic block.

Soft errors or transient faults—caused by high energy particles that lead to an unexpected change in the transistor logic—have long been considered as the main reliability challenge for mission-critical applications, such as aviation. However, aggressive sub-nano transistor scaling (10 nm-7 nm) and near-threshold supply voltage are making modern digital circuits that we use in our everyday lives ever more susceptible to external noises. Now, even low-energy terrestrial particles like muons can cause soft errors. In fact, muon-induced soft errors are a major reliability challenge in both near-term and long-term microprocessor designs. Therefore soft error resilience is a must—even for safety-critical terrestrial applications.
Conventionally, hardware level soft-error resilience techniques have been employed in mission- and safety-critical systems, like spacecraft and enterprise systems. However, hardware solutions come with high costs owing to the need to redesign the system. Software approaches are attractive, as they can provide flexible and affordable solutions. They can be especially useful for mixed-critical systems, where flexible software techniques can provide reliability based on task requirements. For instance, in automobile applications where safety-critical tasks (e.g., braking) and non-critical tasks (e.g., entertainment systems) share an underlying microprocessor, software techniques are preferable as they can meet high-reliability requirements for critical tasks, while non-critical tasks get the best performance from the underlying microprocessor. Although existing software techniques can meet the reliability requirements for medium- and less-critical tasks, they do not provide high error resiliency (e.g., error detection and recovery) demanded by high-critical tasks.
An ideal error resilient scheme should provide complete, effective and timely recovery from soft errors. Some software-level fault tolerance techniques are incomplete, because they provide error detection and assume some sort of checkpoint/roll-back for recovery. Restarting an application from beginning is the simplest rollback recovery strategy. However, restarting is not applicable in many cases, such as long running, real-time and interactive applications. In addition, restarting is accompanied by high error recovery latency—expected recovery latency can be half of the application execution time. These problems can be alleviated by building full-system checkpoints (preserving the whole memory and register stats) during the execution of an application. However, to solve the problem of latent errors (errors which may happen before checkpointing and will be detected after checkpointing) frequent checkpoints are required, which impose unacceptable performance overhead on the system.
Software forward-recovery techniques which execute three versions of computations and perform majority-voting between the results can potentially solve the problem of latent errors in a more efficient way than frequent full system checkpointing. The recovery latency of voting-based techniques is small (˜10 machine instructions), but they cannot provide reliability demanded by high-critical applications mainly due to considerable single-points-of-failure introduced by voting. Moreover, coarse-grained forward-recovery schemes demand more than three times the memory overhead. However, since the memory subsystems are usually error-correcting-code (ECC) protected in many modern microprocessors, applying redundancy to memory is wasteful.
In-application fault tolerant techniques can potentially eliminate the need for full-system checkpointing and memory replication, while providing efficient and timely error handling by combining both error detection and recovery within the application itself. Unfortunately, existing in-application error tolerant schemes are significantly weaker than their underlying detection schemes, due to the vulnerability added by complex error recovery routines. In fact, some error tolerant schemes increase vulnerability over systems without the error tolerant schemes.

Lightweight checkpoint technique for resilience against soft errors

Arizona Board of Regents on Behalf of Arizona State University


Embodiments of the present invention are directed to apparatus and methods for converting carbon dioxide and/or methane into higher alkanes and hydrogen gas in a single reaction chamber using a catalyst and microwave radiation.

There are widespread concerns regarding the increase in carbon dioxide concentration in the atmosphere and the association of such concentration to climate change. The increase in concentration of carbon dioxide in the atmosphere has led to the imposition of new limitations on key sources of carbon dioxide. In parallel, major international efforts have begun to search for a viable solution to the large amounts of carbon dioxide that are produced, and will continue to be created by industry in the near future. In the U.S. alone, 6 billion tons of carbon dioxide are produced annually, and will continue to be produced in the foreseeable future.
It would be desirable to produce methods and apparatus for consuming carbon dioxide to remove the gas from the atmosphere to reduce its effect on climate change. It would also be desirable to produce methods and apparatus to convert the low value and widely-available natural gas into higher value hydrocarbons as a feedstock to oil refineries as a replacement to imported oil.

Process and apparatus for converting greenhouse gases into synthetic fuels


An optical recording/reproducing apparatus has a laser diode and a semiconductor integrated circuit device for driving the laser diode. The semiconductor integrated circuit device has a driver circuit for producing a drive current to be supplied to a laser diode in accordance with an input signal representative of a laser beam power varying depending on a relative speed between a magneto-optical disk and a spot of a laser beam emitted by the laser diode on the optical disk. The driver circuit has a non-linear first operation range and a substantially linear second operation range subsequent to the first operation range. For a linear operation of the driver circuit, a level shifter circuit is connected to the driver circuit for applying a shift voltage to the driver circuit with a result that an excess output current is produced by the driver circuit even when the input signal is non-existent. To prevent supply of the excess output current to the laser diode, a current suppressing circuit is provided for supplying a suppression current to the driver circuit.

The invention relates to a an optical recording/reproducing apparatus having a laser diode driver and, more particularly, to a technique effective for use in a magneto-optical recording and reproducing apparatus of a light modulating type.
With respect to a rewritable optical disk, reference may be made to "Nikkei Electronics", Nikkei McGraw-Hill, Inc., No. 440, pages 115-142, Feb. 8, 1988. In a light modulation type disk, among such rewritable optical disks, a temperature of a recording layer of the disk is raised to a temperature near a Curie temperature by heat of a laser beam and "1" and "0" are recorded (written) on a recording magnetic medium in terms of the direction of an auxiliary magnetic field. To read out data recorded on the optical disk, use is made of the Kerr effect such that when the laser beam is reflected from the disk surface, a plane of polarization is rotated and changed depending on a direction of the magnetization of the disk.
In the magneto-optical disk recording and reproducing apparatus of the light modulation type, it is necessary to raise the temperature of the recording layer of the disk to a temperature near the Curie temperature as mentioned above. Since the magneto-optical disk rotates at a constant speed, relative moving speeds of a laser beam spot on inner side tracks and outer side tracks differ. Namely, since the relative moving speed of the beam spot is high for the outer side tracks of the disk, it is necessary to enhance the laser beam power in order to raise the temperature of the recording layer to the Curie temperature. On the other hand, since the relative moving speed of the beam spot is low for the inner side tracks, it is sufficient to set a laser beam for raising the temperature of the recording layer to the Curie temperature to rather a weak power. For this purpose, it will be necessary to accurately control a drive current of the laser diode in accordance with track address information of the disk.
A technique is disclosed in JP-A-53-61984 (laid-open on Jun. 2, 1978) in which a drive current of a light emitting device is controlled by supplying a current from a second current source to a first current source for supplying a drive current to a light emitting diode.

Optical recording/reproducing apparatus having laser diode driver capable of a linear operation responsive to an input signal representative of a laser beam power varying depending on a magneto-optical disk-laser beam spot relative speed


The present disclosure relates to a method and an apparatus for controlling a drive current of a display panel, an electronic device, and a storage medium. A standard drive current of the display panel is calculated based on the power function of the display panel. An actual drive current is detected in a working process of the display panel, and it is determined whether the actual drive current exceeds the standard by comparing the actual drive current with the standard drive current. The actual drive current is regulated if the actual drive current exceeds the standard.

With the progress of various technologies, OLED screens are becoming more and more widely used because OLED screens do not require any backlight, are high in contrast, thin in thickness, wide in viewing angle, fast in response speed, applicable to flexible panels, wide in operating temperature range, simpler to construct and manufacture, and so forth.
It is to be noted that the above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore, it may contain information that does not form the related art that is already known to a person of ordinary skill in the art.

Method and apparatus for controlling drive current of display panel, electronic device, and storage medium


A foundry sand binder composition and method of manufacturing cast metal objects by casting molten metal into a mold cavity formed of sand held in a predetermined mold configuration by a binder comprising a plurality of sodium bentonite clays. A blend of two or more sodium bentonite clays obtained from different areas as a foundry sand binder synergistically and unexpectedly improves the foundry sand used as a mold cavity for casting metal objects by unexpectedly improving one or more of the following foundry sand properties beyond the level of either of the blended sodium bentonites alone: green compressive strength; hot compressive strength; dry compressive strength; wet tensile strength; flowability; surface finish; activation speed and shakeout.

Green sand molding is the production of molded metal objects from tempered molding sand and is the most diversified molding process used to cast ferrous as well as non-ferrous metal castings. Green sand molding is favored by foundrymen because it is economical and permits both quality and quantity production, particularly for smaller castings. Castings as large as three to four tons are made successfully in green sand molds; however, as molds become larger, more time is required for the making and assembling of mold parts. Consequently, other types of molding are generally favored for the larger castings. The rapid collapsibility of green sand molds makes them much less resistant to the normal contraction of the castings while metal solidification takes place, thus minimizing problems of stresses and strains. Green sand is defined as a water tempered molding sand mixture with plasticity. A green sand mold used for casting steel usually consists of silica sand, a clay binder, and/or an organic binding agent mulled together with temper water. Other useful foundry sands include chromite, zircon and olivine sands.
One or more binders mixed with the silica sand are essential to maintain the sand in a predetermined mold configuration. One of the most commonly employed green sand binders is clay, such as a water-swellable sodium bentonite clay or a low swellable calcium bentonite clay. The amount of the clay binder that is used together with the sand generally depends upon the particular type of sand used in the mixture and the temperature of firing. Silica sand grains expand upon heating. When the grains are too close, the molding sand moves and expands causing the castings to show defects such as "buckles" (a deformity in the casting resulting from excessive sand expansion), "rat tails" (a rough, irregular depression that appears on the surface of a casting or a minor buckle), and "scabs" (a breaking away of a portion of the molding sand when hot metal enters the mold). To overcome this harmful expansion, more clay is added to the sand mixture since the clay contracts upon firing thereby compensating for the expansion of the silica sand grains. In green sand molding, the reproducibility of the dimensions obtained on the casting are the result of such factors as shrinkage, changes in dimensions of mold cavity, hardness of mold, stability of molding sand, mechanical alignment of flask and maintaining a fixed temperature.
Clays have been blended in the past in an attempt to achieve acceptable combinations of permeabilities, green compression strengths and dry compression strengths in the molding sand mixture or composition. Toward this end, it is known to mix a sodium bentonite with a calcium bentonite or a kaolinite clay in an attempt to achieve the high dry compression strength of the sodium bentonite clay together with the high green compression strengths of the calcium bentonite clay and the low permeability of the kaolinite clay. See Foundry Sand Practice by Clyde A. Sanders, 6th Edition, 1973, pp. 585-590. To date, however, a plurality of various sodium bentonite clays, each having particular desirable characteristics, have not been blended for the purpose of providing a binder to a foundry sand. Quite surprisingly, it has been found that when a mixture of sodium bentonites is used as a binder in the preparation of a foundry sand, synergism results with respect to green compressive strength; hot compressive strength; dry compressive strength; flowability; surface finish; activation speed; and/or shake-out. One or more of these properties are better in the blend than each of the sodium bentonites, prior to blending.

Sodium bentonite clay binder mixture for the metal casting industry


An apparatus and method are provided for arbitrating access to a set of resources that are to be accessed in response to requests received at an interface. Arbitration circuitry arbitrates amongst the requests received at the interface in order to select, in each arbitration cycle, at least one next request to be processed. Each request identifies an access operation to be performed in response to the request, the access operation being selected from a group of access operations. Further, each access operation in the group has an associated scheduling pattern identifying timing of access to the resources in the set when performing that access operation. In response to a given request being selected by the arbitration circuitry, access control circuitry controls access to the set of resources in accordance with the associated scheduling pattern for the access operation identified by that request. Ordering circuitry determines, for different combinations of requests, an associated ordering of those requests, where the associated ordering is determined taking into account the associated scheduling pattern of each access operation in the group. The arbitration circuitry may employ a bandwidth aware arbitration scheme where a multi-arbitration operation is iteratively performed. Each performance of the multi-arbitration operation comprises sampling the requests currently received at the interface, and employing the ordering circuitry to determine, based on the sampled requests, an order in which the sampled requests should be selected. Then, during each arbitration cycle, at least one next request to be processed is selected from amongst the sampled requests based on the determined order, until each sampled request has been selected.

The present technique relates to an apparatus and method for arbitrating access to a set of resources.
A device within a system may be arranged to have an interface for receiving requests from other entities within the system. The device may have a set of resources that are accessed in response to the requests. Each request may identify an access operation to be performed, and exactly which resources within the set of resources need to be accessed, and the order in which those resources need to be accessed, will depend on the access operation specified by that request.
Arbitration circuitry will typically be provided to arbitrate between the various requests received at the interface. Once a given request has been selected, then performance of its associated access operation will cause resources from the set of resources to be accessed over a number of clock cycles. This can cause some issues in subsequent arbitration cycles, since it may be the case that in some instances none of the requests pending at the interface can be selected in a particular arbitration cycle, since selection of such a request would cause contention for access to one or more of the resources.
In some situations, this may not be problematic, since it may be the case that the arbitration circuitry is merely seeking to select higher priority requests in favour of lower priority requests, so as to reduce the latency of those higher priority requests, and is not concerned with the overall throughput of requests. However, in some instances there are workloads that need to be performed within the system that require a high sustainable bandwidth, and hence the series of requests defining such a workload would desirably be handled in a manner which reduced any wasted cycles where requests could not be selected by the arbitration circuitry. It would hence be desirable to provide an arbitration scheme that allows for the bandwidth to be improved, i.e. for the volume of requests that can be handled in a given time to be improved.

Apparatus and method for arbitrating access to a set of resources


A communication system makes throughput preferable by reducing wireless frame collision which occurs when a plurality of control stations cannot recognize one another. When a wireless communication device that is operating as a dependent station of a first control station detects a second control station, DEVice operates as a dependent control station. Accordingly, the second control station is changed to a dependent station or a dependent control station.

1. Field of the Invention
This invention relates to a control technique of a communication network.
2. Description of the Related Art
Various wireless communication systems are under developing and are gradually going to become common. For example, as a relatively short-ranged wireless communication system, a wireless LAN (Local Area Network) system is generally widespread.
On the other hand, as a more short-ranged (e.g., 10 m or less) wireless communication system, a WPAN (Wireless Personal Area Network) system is being developed. That can connect consumer apparatus (e.g., computer peripheral apparatus, digital camera, digital video camera or the like) with a printer or a cellular phone.
At present, for the WPAN, a standard is being drawn as a group of IEEE802.15 standards. Specifications for a network topology configuration or a media access protocol are defined in IEEE802.15.3 standard.
Compared with a wireless LAN, the WPAN may be characterized in that each of wireless communication devices dynamically (autonomously) forms a network according to surrounding circumstances or an executing condition of an application. For example, in an infrastructure mode of the wireless LAN, a predetermined wireless communication device called an access point controls each terminal device. To the contrary, in a wireless network in the WPAN (hereinafter called a piconet), a control station called a PNC (Piconet Coordinator) controls a media access of each terminal device (child station), but a predetermined wireless communication device does not necessarily become a PNC. The WPAN wireless communication device is classified as a device with a PNC function and a device without a PNC function. Any device with a PNC function actually generates a piconet and controls it as a PNC.
FIG. 14 is a sequence diagram representing a procedure of generating a piconet in the WPAN. Each of DEV1 and DEV2 in the figure is a WPAN wireless communication device with a PNC function. DEV1 which is powered on (S1401) scans available frequency channels in order (S1402). That is for determining whether a WPAN piconet has been present or not. A PNC of a piconet periodically transmits a beacon frame. Thus, if DEV1 can detect the beacon frame, it can determine that a piconet is present. If a piconet is present, DEV1 will participate in the piconet.
If a piconet is not present at this moment, DEV1 with a PNC function determines that it needs to be a PNC. DEV1 selects an optimum channel from available frequency channels (S1403). Then, DEV1 generates a new piconet by starting periodic transmission of beacon frame in the selected channel (S1404).
When DEV2 is powered on next to DEV1 (S1411), DEV2 scans frequency channels for a certain time period in the same manner as DEV1 (S1412). DEV2 detects a operating piconet of DEV1 as DEV2 receives a beacon frame from DEV1 (S1413). DEV2 transmits a request for participation command to DEV1, which is a control station of a piconet (S1414). In response to the request for participation, DEV1 returns an admission of participation command to DEV2 (S1415). The admission of participation command includes a device identifier newly allocated to DEV2 by DEV1.
With operation above, one of a plurality of wireless communication devices autonomously becomes a control station and creates a WPAN piconet. Thereafter, when a new wireless communication device is powered on, it participates in a piconet in the same procedure as DEV2.
The TDMA (Time Division Multiple Access) system is adopted as a media access method in a WPAN. Generally, in the TDMA system, a terminal device which needs to reserve a data channel requests a control station to allocate a communication band in advance.
FIG. 15 is a diagram showing a principle of the TDMA system in a WPAN. The abscissa indicates time. A superframe 1501 starts with a beacon frame 1502 that is periodically transmitted by a PNC. Each superframe 1501 is divided into time slots 1503 each of which becomes an available time period to be used by each terminal device in wireless communication.
A communication band available for a terminal device is reserved as a time slot on a time axis like this. In each of time slots, only a terminal device which is designated as a transmitting terminal can transmit a wireless frame. A starting time of the time slot and the length of the time slot are indicated in a beacon frame from a control station. In such a time slot, a source device (Source) and a destination terminal device (Destination) are designated.
With the WPAN, a child station (dependent station) participating in a piconet can hierarchically generate a dependent piconet. In such a case, the wireless communication device that generated the dependent piconet behaves as a control station in the dependent piconet. On the other hand, said wireless communication device operates as a child station in a parent piconet. Such a wireless communication device is called a dependent control station or a dependent PNC. As the parent piconet and the dependent piconet are synchronized with each other, wireless frames that are transmitted by different devices never collide with each other in theory.
On the other hand, a plurality of piconets which are independent of each other operate asynchronously in time. Therefore, a wireless signal asynchronously arrives from each piconet at a region in which communication cover-areas of the piconets overlap one another. Accordingly, collision of wireless frames may occur. In an access protocol by the TDMA, such a frame collision degrades data transfer throughput.
As mentioned above, operation of a parent piconet and operation of a dependent piconet are synchronized with each other so that such degradation of throughput can be avoided.
FIG. 16 is a diagram showing a configuration of a parent piconet and a dependent piconet. In FIG. 16, PNC1 is a control station of a parent piconet 1601 and contains a plurality of wireless communication devices. Although DEV2 among the plurality of wireless communication devices becomes a child station in a parent piconet, it has a role of PNC2 as it operates as a control station in a dependent piconet 1602.
FIG. 17 is a diagram showing operation timing for a parent piconet and a dependent piconet. In FIG. 17, a superframe of the parent piconet 1601 is managed by beacon frame 1502 which is periodically transmitted from PNC1. If a time slot which can be used by the dependent piconet 1602 is allocated in the superframe, PNC2, which is a dependent PNC at a starting point of the time slot, transmits beacon frame 1702. A child station in the dependent piconet 1602 operates being synchronized with the beacon frame 1702. Therefore, a wireless frame of the parent piconet 1601 and a wireless frame of the dependent piconet 1602 never collide with each other. Here, a time slot of the dependent piconet 1602 is indicated in the beacon frame 1502 of the parent piconet 1601. Each time slot in a superframe in the dependent piconet 1602 is indicated in the beacon frame 1702 of the dependent piconet 1602.
The Japanese Patent Application Laid-Open 2000-288813 proposes a technique in which a slave station that was not able to receive synchronized signals from a master station changes from a slave mode to a master mode.
The Japanese Patent Application Laid-Open 2004-146883 proposed a method for a plurality of control stations to receive beacon frames one another and avoid collision of wireless frames by adjusting lengths of superframes one another.
In order to further improve data throughput, a network topology needs to be optimized as much as possible.
When a wireless communication device dynamically and autonomously creates a piconet, it can use a function of generating a piconet and a dependent piconet function mentioned above. But no specific algorithm for constructing an optimum network topology by using the functions has been provided yet.
FIG. 18 is a diagram showing a network configuration that causes frame collision among piconets. In the figure, a first wireless communication device 1801 that is operating as a control station forms a first piconet 1810. The first piconet 1810 contains a second wireless communication device 1802 that is operating as a child station.
When a third wireless communication device 1803 is powered on near the first piconet 1810, it first detects whether a piconet is present or not in the vicinity. The third wireless communication device 1803 can receive a wireless frame transmitted from the second wireless communication device 1802. But as the third wireless communication device 1803 is placed at a distant from the first wireless communication device 1801, i.e., a control station of the first piconet 1810, it cannot receive a beacon frame transmitted from the first wireless communication device 1801.
In this case, as the third wireless communication device 1803 determines that it has no piconet to participate in the vicinity, it becomes a control station itself and generates an independent piconet 1820. As the first piconet 1810 and the independent piconet 1820 operate independently and asynchronously, at a place where cover areas of both of the piconets overlap (the place of the second wireless communication device 1802), frames transmitted from the two piconets may collide with each other. It is needless to say that data throughput is reduced, if frame collision occurs.
Briefly speaking, if a plurality of control stations which cannot recognize the others' presence are present, and if a child station which can communicate with the control stations is present, throughput may be reduced to the child station.
According to the Japanese Patent Application Laid-Open 2000-288813, as a plurality of master stations asynchronously transmit beacon frames in the same manner, the above-mentioned problem cannot be solved.
The Japanese Patent Application Laid-Open 2004-146883 assumes that control stations can communicate with one another, the above-mentioned problem cannot be solved either.
The present invention intends to solve at least one of such problems or the other problems. The other problems can be understood through the entire of the specification.

Reduced frame collision wireless communication system having communication device mode switching


A collision preventing system for vehicles comprising a road surface friction coefficient judgement circuit for judging a friction coefficient of a travel road surface on the basis of a detection value detected by a wheel speed detector, and for outputting a judgement signal, when determination is made that the friction coefficient is equal to or less than a predetermined value, a first comparator adapted to deliver a first brake control signal indicative of a command to continuously operate each brake when there is a high possibility of collision, a second comparator adapted to deliver a second brake control signal indicative of a command to perform a pumping braking when there is a lower possibility of collision than that of the first brake control signal, and a changing-signal outputting circuit for outputting a changing-signal indicative of a command to change the operation control mode for each brake in response to the delivery of the judgement signal from the road surface friction coefficient judgement circuit when the second brake control signal is delivered form the second comparator. With this arrangement, it is possible to conduct the pumping braking at a stage prior to the full braking, and to obtain an appropriate braking force in accordance with the friction coefficient which is determined during the pumping braking. This avoids conveyance of a vague braking feeling to a driver.

1. Field of the Invention
This invention relates to a collision preventing system for vehicles, including a detector for detecting an operational parameter between a subject vehicle and a contrast obstruction for judging the possibility of collision of the subject vehicle against the contrast obstruction, so that a brake is operated on the basis of a detection value detected by the detector.
2. Description of the Prior Art
Such collision preventing systems are conventionally well-known, for example, from Japanese Patent Publication No. 4700/86.
In the above prior art systems, each of the brakes is automatically operated when there has arisen a possibility of collision of the subject vehicle against a contrast obstruction, e.g., against a vehicle in front. However, the friction coefficient of the road surface is not taken into consideration and for this reason, a desired reduction in speed cannot be obtained on a road surface having a low friction coefficient, such as a snowy road or an iced road, even if full braking is applied. In addition, a vehicle driver cannot feel or sense automatic braking beforehand and, therefore, if such automatic braking is suddenly applied so as to avoid a collision, it imparts to the driver an impermissible braking feeling.


The invention relates to the technical field of oil and gas drilling, and discloses an amphiphilic block polymer ultralow-permeability agent and an intelligent temporary plugging type water-based drilling fluid. The ultralow-permeability agent contains a structural unit provided by styryl hydrophobic monomer, maleic anhydride and acrylamide; the drilling fluid contains two or more of water, sodium bentonite, Pac-Lv, the ultralow-permeability agent, calcium carbonate, one-way plugging agent, white asphalt and barite which are stored in a mixed manner or independently stored. When the amphiphilic block polymer provided by the invention is used as the ultralow-permeability agent of the intelligent temporary plugging type water-based drilling fluid, the self-adaptive characteristic is realized; according to the amphiphilic block polymer, temporary plugging layer gaps formed in pore and throats by plugging materials in drilling fluid can be fully filled under the condition that the sizes and the distribution of the pore and throats of reservoirs are not required to be clear, so that the permeability of temporary plugging layer is greatly reduced, ultralow-permeability is realized, and the amphiphilic block polymer is weak in tackifying effect, has gel-improving effect and can improve the rheological property of the drilling fluid.

When a reservoir is drilled, the invasion of the solid phases and the liquid phases in the drilling fluid inevitably causes reservoir damage, even "kills" the reservoir, resulting in the failure of drilling and development of oil and gas reservoir.
The temporary plugging drilling fluid can quickly form a temporary plugging layer with low permeability when the reservoir is drilled, the invasion of the drilling fluid can be avoided to the maximum extent, and the temporary plugging drilling fluid is a very ideal reservoir protection drilling fluid, but the plugging material in the temporary plugging drilling fluid must strictly match the reservoir requirements, and particularly the softening point and the particle size of the deformable filling particles must strictly match the reservoir temperature and the reservoir pore and throat size, so that a compact temporary plugging layer with low permeability can be formed.
However, in most cases, the reservoir properties are complex, and the pore and throat size and distribution cannot be accurately known, so that blindness exists in the selection of the filling particles, and the formulation design of the temporary plugging drilling fluid and the performance of the drilling fluid are seriously influenced.

Amphiphilic block polymer ultralow-permeability agent and intelligent temporary plugging type water-based drilling fluid


Disc assay devices and methods for the detection and enumeration of microorganisms are disclosed. The devices and methods include a plurality of discs attached to a substrate and a reflector on one surface of each of the discs to reflect electromagnetic energy of selected wavelengths after the energy has passed through the disc. The reflector may be useful to improve the accuracy of detection and/or enumeration of target microorganisms on the assay devices. A system for detecting and/or enumerating target microorganisms on disc assay devices is also provided.

This invention relates to disc assay devices, systems, and methods of use for culturing biological samples to detect and/or enumerate microorganisms present within the samples.
The detection and enumeration of microorganisms is practiced in numerous settings, including the food-processing industry (testing for the contamination of food by microorganisms such as E. coli and S. aureus), the health care industry (testing of patient samples and other clinical samples for infection or contamination), environmental testing industry, the pharmaceutical industry, and the cosmetic industry.
Growth-based detection and enumeration of microorganisms is commonly practiced using either liquid nutrient media (most probable number analysis (MPN)) or semi-solid nutrient media (agar petri dishes). Enumeration using the liquid MPN method is typically achieved by placing serial 10-fold dilutions of a sample of interest in replicate sets of tubes containing selective media and chemical indicators. The tubes are incubated at elevated temperature (24-48 hours) followed by examination for growth of organisms. A statistical formula, based on the volume of sample tested and the number of positive and negative tubes for each set, is used to estimate the number of organisms present in the initial sample.
This method of performing MPN analysis has several disadvantages. It is labor intensive because of the multiple diluting and pipetting steps necessary to perform the analysis. In addition, in practice it is only practical to use replicate sets of about three to five tubes for each dilution. As a result, the 95% confidence limits for an MPN estimate for microbial concentration are extremely wide. For example, a three tube MPN estimate of 20 has 95% confidence limits ranging from 7 to 89.
In contrast to the method described above, a direct count of viable microorganisms in a sample can be achieved by spreading the sample over a defined area using nutrient media containing a gelling agent. The gelling agent (agar) prevents diffusion of the organisms during incubation (24-48 hours), producing a colony in the area where the original organism was deposited. There is, however, a limit to the number of colonies that can fit on a given area of nutrient media before fusion with neighboring colonies makes counting difficult. This usually necessitates performing several dilutions for each sample. In addition, the classes of chemical indicator molecules that can be used for identifying individual types of microorganisms present within a mixed population are limited to those that produce a product that is insoluble in the gelled media.
In some of these processes, the detection or enumeration of a microorganism is determined by detecting an electromagnetic signal, e.g., fluorescence, emitted by an indicator substance in response to excitation (where the indicator substance is activated by presence of the microorganism to be detected). The excitation may be provided in the form of electromagnetic energy from, e.g., a laser. One potential problem with known assay devices is that the electromagnetic energy used for excitation may also excite other materials present in the substrate or other portions of the device, causing them to emit an electromagnetic signal similar to that emitted by the desired indicator. For example, where the assay is formed on a polymeric substrate that fluoresces in the same or similar wavelength regions as the indicator, a relatively high background electromagnetic signal can be produced by the substrate that reduces the signal-to-background ratio. A lower signal-to-background ratio can make accurate detection or enumeration of the desired microorganism more difficult.
The invention provides devices and methods for the detection and enumeration of microorganisms. The devices and methods include a plurality of discs attached to a substrate and a reflector proximate one surface of each of the discs to reflect electromagnetic energy of selected wavelengths after the energy has passed through the disc. The reflector may be useful to improve the accuracy of detection and/or enumeration of target microorganisms on the assay devices. A system for detecting and/or enumerating target microorganisms on disc assay devices is also provided.
One advantage of the devices and methods of the present invention is that the reflectors proximate each of the discs may reflect the excitation energy directed at the discs after it has passed through the discs. As a result, the effective path length of the excitation energy through the discs is doubled as compared to assay devices in which the excitation energy is not reflected after passing through the discs. That increased path length may improve the accuracy of the detection and/or enumeration of microorganisms by effectively increasing the intensity of the excitation energy.
Another potential advantage of the devices and methods of the invention is that the reflectors may improve the signal-to-background ratio during detection and/or enumeration of target microorganisms. In some instances, the reflectors preferably reduce or prevent transmission of the excitation energy to the underlying substrate. In other instances, the reflectors may reduce or prevent the transmission of electromagnetic energy from, e.g., the substrate, that is similar to the electromagnetic signal energy emitted by, e.g., an indicator substance, in response to the excitation energy. In either case, with the reflectors in place, the electromagnetic signal energy emitted from the assay device may more accurately indicate the presence of the target microorganisms, rather than the underlying substrate or other portions of the device.
The signal-to-background ratio may be further improved if the reflectors are also reflective for the electromagnetic signal energy generated as a result of the presence of the target microorganisms within or on the discs. If the reflectors are located on the side of the discs opposite the detector, at least a portion of the electromagnetic signal energy that is emitted in the direction of the reflectors may be reflected back towards the detector, thereby potentially increasing the intensity of the emitted signal energy. Increases in emitted signal energy intensity may improve detection accuracy and, in some instances, may also allow for detection of the target microorganisms after shorter incubation periods.
With respect to the excitation/detection systems of the present invention which include reflective walls, one potential advantage is that the reflectivity of the walls may improve uniformity in excitation of the assay devices being sampled.
In one aspect, the present invention provides a microorganism culture device including a substrate; a plurality of liquid-retaining discs attached to the substrate, wherein each of the plurality of discs has first and second opposing surfaces; and a reflector proximate the first surface of each of the plurality of discs, wherein electromagnetic energy of selected wavelengths is reflected from the reflector after passing through the disc.
In another aspect, the present invention provides a method of detecting at least one target microorganism by providing a disc assay device including a substrate; a plurality of liquid-retaining discs attached to the substrate, each of the plurality of discs having first and second opposing surfaces; and a reflector proximate the first surface of each of the plurality of discs; and wherein at least one of the discs further includes growth media, an indicator substance, and a target microorganism; directing excitation energy at the disc assay device; and detecting signal energy emitted from each of the plurality of discs including the target microorganism in response to the excitation energy; wherein at least a portion of the signal energy is reflected by the reflector.
In another aspect, the present invention provides a method of manufacturing a disc assay device by providing a substrate; locating a plurality of liquid-retaining discs on the substrate, each of the plurality of discs having first and second opposing surfaces; and providing a reflector proximate the first surface of each of the plurality of discs, wherein electromagnetic energy of selected wavelengths is reflected from the reflector after passing through the disc.
In another aspect, the present invention provides a system for detecting target microorganisms on a disc assay device, the system including at least one excitation source emitting electromagnetic excitation energy of selected wavelengths; a detection chamber including at least one wall, wherein the at least one wall reflects a significant portion of the electromagnetic excitation energy incident thereon; and a detector arranged within the detection chamber to detect electromagnetic signal energy emitted from the assay device in response to the electromagnetic excitation energy.
These and other features and advantages of the invention will be described in connection with illustrative embodiments of the invention below.
As used herein, the term xe2x80x9cmicroorganismxe2x80x9d includes all microscopic living organisms and cells, including without limitation bacteria, mycoplasmas, rickettsias, spirochetes, yeasts, molds, protozoans, as well as microscopic forms of eukaryotic cells, for example single cells (cultured or derived directly from a tissue or organ) or small clumps of cells. Microorganisms are detected and/or enumerated not only when whole cells are detected directly, but also when such cells are detected indirectly, such as through detection or quantitation of cell fragments, cell-derived biological molecules, or cell by-products.

Reflective disc assay devices, systems and methods


A system and method of providing financial services to children provides a child-friendly user-interface that includes an age-appropriate integrated financial services account statement having links to multimedia files providing information on or related to specific assets listed in the statement. The system and method of the invention may also be used as a convenient way of giving gifts to a child, and as a portal to a variety of child-related services and products.

1. Field of the Invention
This invention generally relates to the field of electronic commerce, and in particular to a third generation business-to-business-to-consumer (B2B2C) content management and delivery infrastructure for the fragmented financial services industry.
More specifically, the system and method of the invention serve to create an interface between existing providers of financial services such as banking and brokerage services and children and teenagers (hereinafter referred to collectively as "children"). The interface includes a simple, "kid-friendly" bank statement that provides a fun and educational way of accessing the financial services while educating children and teenagers about money and personal finance, encouraging savings, and providing a convenient way of providing gifts of money or securities, and that may include additional educational features, or links to additional educational features, such as a dialog box through which answers to specific questions concerning finance or financial services may be obtained. The "kid-friendly interface" thus serves as an intermediary between one or more financial service providers and the child, or between the one or more financial services providers and an adult who wishes to make a gift to the child, and in addition may be adapted to serve as a portal through which the child may access a variety of child-related services and vendors, and through which vendors and service providers having products of interest to children may offer targeted information, educational, and promotional materials.
2. Description of Related Art
At present, youth accounts provided by financial services companies are aimed at adult use, i.e., they hold a child's money, but do not provide the child with the ability or incentive to access the account. This lack of financial knowledge on the part of young people and, perhaps more importantly, the incentive to learn more about finance and savings is a serious problem in the United States and other developed countries.
One of the most difficult concepts for a child to grasp is the concept that money is not an inexhaustible resource which magically appears in a parent's wallet or purse, or upon presentation of a credit or debit card, whenever a purchase needs to be made. In today's relatively affluent society, appreciation for the value of work and savings is diminishing, even while the concept of money becomes ever more abstract. The result is a generation less prepared than any previous generation to face the inevitable ups and downs of the economy, or to accumulate wealth in a way that benefits themselves and society as a whole.
Children who use computers to access the Internet and whose families make purchases on-line are even more likely to view money as intangible because of the manner in which such purchases are completed. Upon deciding to the purchase the product, the parent simply types in a number or, in some cases, simply indicates a desire to charge an account whose number has previously been stored, and a few days later the desired product appears at the child's doorstep. Even if the child understands that there is some relationship between the purchase and the fact that his or her parents leave for work in the morning, the child will seldom grasp the exact nature of the relationship.
While materials for teaching children about money and encouraging savings certainly exist, both on and off the Internet, for every call to financial responsibility, there are 10,000 calls to purchase a product or service. Finance, as an educational topic, cannot compete with the attractions of contemporary marketing. Currently available educational materials, such as the "Board Game For Teaching Fundamental Aspects Of Personal Finance, Investing And Accounting" described in U.S. Pat. No. 6,032,957, have a relatively limited appeal in comparison with the multimedia attractions of the various child-oriented ".com" websites. A website that educated children about personal finance and that could compete with other child-oriented websites would clearly be of benefit not only to children visiting the website, but also to society in general.
Of course it is marketing and not education that pays for the Internet, and few sophisticated websites, and in particular those including multimedia, can be maintained without marketing, which would seem to be contradictory in a website that sought to encourage savings. Nevertheless, any website that seeks to provide an educational service, including those that seek to teach fundamentals of finance, must at the same time find a way to attract revenue. To be successful, any website must in general offer benefits both to users of the site and to underwriters of the website, i.e., the website must educate in a way that attracts users to the site, and that in turn attracts those who wish to sell to those users. In the case of a website that seeks to educate children about personal finance by providing financial services to children, an additional source of revenue is essential since children are unlikely to have accounts as large as those owned by adults.
Systems and methods for providing financial services over the Internet are of course well-known. Numerous websites are set up to provide banking and/or brokerage services to adults, including one proposed site described in U.S. Pat. No. 5,953,710, which enables a parent to manage a custodial credit card account on behalf of a child. Among the activities that can be carried out on these sites are the viewing of account statements and the gathering of financial information, as well as purchases and sale of securities, transfers of funds between accounts, and payment of bills. However, none of websites are structured in such a way that would make them suitable for providing financial services to children in a commercially viable manner.
The task of attracting children to a website is especially difficult because of the great variation between what attracts children of different ages. A thirteen-year-old will not have the same interests as an eight-year-old or a four-year-old. Yet if a financial services website is to be successful, it must be able to hold the interest of all age groups, from the youngest to those ready to open accounts on adult financial services websites.
The lack of websites directed to providing financial services to children leaves an enormous gap between those who seek to market to children and those who wish to teach children about savings and earnings. Piggy banks, allowances, and passbook savings accounts which can hardly compete with the contrary message provided by most child-oriented ".com" sites. Lectures by parents and teachers are no substitute for hands-on experience, and yet because children cannot enter into legally binding contracts, and because the revenues generated by individual child accounts are likely to be small in comparison with the cost to an individual financial services provider of managing the site, there is currently little immediate incentive for financial services providers to provide a site which assists parents and others in teaching children about money and finance by enabling the child to actively participate in managing a real bank or brokerage account.
While it would be impractical for an individual financial services provider to set up a website directed towards children, it is just as impractical to set-up a new bank or brokerage for that purpose. As a result, any website that seeks to provide financial services to children would need to be able utilize existing financial services providers, and preferably multiple financial services providers, including banks, brokerage houses, mutual fund providers, and even insurance companies. Convenient and practical ways must be found not only to offer financial services to children in an attractive, educational, and commercially viable manner, but also to serve as an intermediary between child-customers and existing financial services providers such as banks and brokerage houses.
In summary, there is a need for an Internet-based system of encouraging savings and of teaching children about money and personal finance that can compete with other child-oriented Internet sites, and that can meet the following requirements:
(i) the system must offer an interface that provides information necessary to manage an account, and preferably information on personal finance and financial services in general, and yet that also incorporates the technological bells and whistles to compete with conventional non-financial service providers and encourage use of the system,
(ii) the system must provide a revenue stream that is not dependent on the value of financial services provided, and
(iii) the system must include the ability to interface not only with children but also with existing financial services providers.
The present invention is intended to meet these requirements by using a novel account statement that serves as an education tool, as a way of attracting users, as a medium through which marketers may promote products and services, and as an intermediary between the users and existing financial services providers.

System and method for providing financial services to children and teenagers


A movable holding bracket is provided for attachment to a fastening tool having a nosepiece for driving a fastener, the holding bracket configured for holding overlapping portions of two members to be fastened to one another, the bracket including a fixed portion configured for attachment to a workpiece contact element of the tool, and a movable portion movably attached to said fixed portion. A holding arm is attached to the movable portion and defines a gap configured for holding the overlapping portions of the two members for insertion of a fastener driven from the tool nosepiece.

Fastening tools that use combustion, compressed gas, and other driving forces to shoot fasteners from a barrel and into a work surface are known. Other fastening tools such as power drills and screwdrivers are also known. Such tools can be used, for example, to fasten two members to one another. The two members may be, for example, metal construction framing members such as metal studs and tracks. Metal framing (typically steel) offers advantages compared to wood when used as framing materials related to strength, cost, resistance to shrinkage and warping, resistance to insect damage, resistance to combustion, and others. Metal framing has become very popular for these and other reasons.
Typical metal framing applications often include generally "U"-shaped metal tracks running in the horizontal direction and attached to underlying and overhead substrates which in some cases are concrete floors and ceilings. Vertical studs then connect the upper and lower track members to provide a framing skeleton. Construction panels such as wallboard, paneling or other planar facing material are then attached to this framing structure. The vertical stud may be attached to the horizontal track using a fastener such as a screw, rivet, nail, or the like. The fastener may be inserted using a fastening tool.


The present invention is a battery powered, portable microprocessor based early warning alarming smoke detector. It provides the user two different time limited unattended alarms, as well an alarm for a tipped smoke detector; an alarm for a bumped smoke detector; an alarm based on nearby or lower elevation smoke by either of the two smoke detection devices; and a low power alarm. It offers “full protection” for most of the likely scenarios encountered by residential users that could result in a fire. Since the device is microprocessor controlled, the timing intervals and magnitude of the different alarm notifications can be preprogrammed as well as the sensitivity of the smoke detector devices.

The present invention relates to a device capable of both preventing and detecting residential fires and more particularly, to a microprocessor based battery powered, portable early fire detection and prevention device.
Cooking fires are one of the leading causes of residential fires and related injuries. Often, to avoid false alarms, most smoke detectors are not recommended for use in the kitchen. The lack of smoke detectors in such close proximity to the oven or range is one of the leading factors in the rapid spread and destruction of kitchen fires. Additionally, cigarette related fires are commonplace and rank as the leading cause of fire deaths for senior citizens and children under eight years old in the United States. It is well documented that many of the cigarette related fires stem from a lit cigarette that is knocked from an ashtray, a lit cigarette that burns unattended and shortens until it tips from the ashtray, or a person who falls asleep while smoking. Although early warning smoke detectors are commonplace in most residences, their proximity to the source of the smoke is directly related to the amount of time available to rectify the situation before it gets out of hand. Furthermore, many smokers prefer to disable their ceiling mounted smoke detectors if they smoke indoors as the hot rising smoke particles continually set off the alarms, and ceiling mounted smoke detectors are difficult to disarm.
The present invention offers true "full protection" for a variety of scenarios, and since it is portable, is easy to disarm. Its portability allows it to be moved to locations of temporary interest, ie a smoking room at a party, a BBQ, an ironing room, a crafts room etc. This is something not likely to be one if one has to get out a ladder to remove the existing smoke detector from a ceiling or stairwell location. Bumping or tilting the device beyond a pre-set angle initiates a continual, audible notification until the situation is remedied. The device also warns the user of a low battery condition. Since the device is microprocessor controlled, the timing intervals and magnitude of the different alarm notifications can be preprogramed as well as the sensitivity of the smoke detectors.
Henceforth, a "full protection" alarming portable early fire detection and prevention device would fulfill a long felt need in the industry. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems and accomplish this.

Microprocessor operated, portable early fire detection and prevention device


A shield for a screen of an image display device comprises a substrate including a pair of opposing faces, an anti-static coating on each of the opposing faces and an outer coating on each of the anti-static coatings, opposite the substrate. The shield is mounted in spaced apart relation from a screen of an image display device. The outer coating preferably is softer than the screen but harder than the case of the display.

Image display devices are widely used for displaying information. Liquid crystal displays (LCD) are widely used as image display devices. For example, LCDs are used in laptop computers, among other reasons because they are thin.
Image displaying devices including LCDs include a screen on which image information is visibly displayed for viewing. The screen is directly exposed to external environments and therefore may be damaged.
Accordingly, it is known to provide a shield to protect the screen from being damaged by static electricity, scratches and other causes. For example, U.S. Pat. No. 5,132,588 to Warman entitled Viewing Screen Protective Shield discloses a protective shield that is readily removable and replaceable and which is secured to the associated screen.
Unfortunately, portions of this protective shield may not completely adhere to the surface of the screen, thereby generating visible bubbles which may stain the screen and degrade the external appearance thereof. Protective shields may also be easily scratched, which may also degrade the external appearance of the screen. Static electricity may also cause dirt or dust to adhere to the surface of the protective shield.

Image display devices including image display screen shields


A method of removing at least one oxide from a surface of a body of semiconductor material is disclosed. The method includes arranging the body in a vacuum chamber and maintaining a temperature of the body in the vacuum chamber within a predetermined range, or substantially at a predetermined value, while exposing said surface to a flux of indium atoms. Corresponding methods of processing an oxidized surface of a body of semiconductor material to prepare the surface for epitaxial growth of at least one epitaxial layer or film over said surface, and methods of manufacturing a semiconductor device are also disclosed.

A wide variety of techniques for the manufacture of semiconductor devices and semiconductor structures are known. These include, for example, techniques in which a layer, film, or some other body of material is formed over a body of semiconductor material. For numerous reasons it may be desirable to remove oxides from the surface of the body of semiconductor material before the body of material is formed over it. A general problem is how to remove such oxides without detrimentally affecting the semiconductor body surface. More specific problems will be appreciated from the following discussion.
Ex-situ pattering of GaAs substrates, combined with molecular beam epitaxy (MBE) regrowth, provides a technique for the wafer scale production of new designs of three-dimensional devices. However, to exploit fully the length scales available through MBE growth, and achieve patterning in all three-dimensions, it is necessary to regrow active layers in close proximity to the patterned interface. The production of a clean, smooth regrowth interface is therefore essential. Conventionally, cleaning of a GaAs surface prior to MBE growth is achieved by thermal desorption of oxide layers. Such cleaning requires temperatures in excess of ˜580° C. and an As overpressure, but can have limited effectiveness. This is because, at high temperatures, the most stable surface oxide, Ga2O3, reacts with the host substrate through the reaction Ga2O3+4GaAs→3Ga2O↑+2As2 (or As4)↑ to form the more volatile oxide Ga2O. Thermal cleaning of the GaAs surface, therefore, tends to result in a pitted surface owing to GaAs removal from the substrate. Such surface pits are considered to be the cause of the formation of macroscopic 'mounds' during the epitaxial growth of GaAs, and require planarization with a GaAs buffer layer of typically ˜0.5 μm thickness. This issue must be addressed to achieve the high quality interfaces required for fabricating nanostructures through regrowth on patterned substrates.
Recently, both hydrogen-assisted cleaning and gallium-assisted oxide desorption have been shown to reduce pit formation significantly, leading to flat, unpitted and oxide-free surface. This has led to the growth of site-controlled quantum dots (QDs) on patterned substrates, with reasonably good optical properties. Hydrogen-assisted cleaning allows gallium oxides to be removed at lower temperatures, ˜400° C., without surface pitting. However, this method is known to lead to Fermi-level surface pinning and possible degradation of the surface if the hydrogen dose is not precisely controlled. In addition, surface contamination could be introduced during the hydrogen-assisted cleaning process, if extreme care is not taken. Gallium-assisted desorption removes native GaAs surface oxide at temperatures above ˜420° C., in the absence of an arsenic flux, through the reaction Ga2O3+4Ga→3Ga2O. Compared with hydrogen-assisted cleaning, gallium-assisted desorption has the practical advantage that the desorption can be carried out in the growth chamber, with the oxide removal being monitored in-situ by reflection high-energy electron diffraction (RHEED). Furthermore, there is no requirement for additional apparatus, such as a hydrogen source and associated turbomolecular pump, or a dedicated cleaning chamber. However, the technique is very sensitive to the precise amount of oxide on the surface. Sub-monolayer precision of the gallium flux is required to remove the oxides effectively, but avoid droplet formation and the infill of pre-patterned holes. This is a direct consequence of the lower vapour pressure of gallium, compared with the underlying GaAs substrate—any excess gallium will re-evaporate more slowly than the decomposition of the underlying GaAs substrate even for substrate temperatures as high as 650° C.

Oxide removal from semiconductor surfaces using a flux of indium atoms