A puzzle assembly is shown and comprises a multiplicity of geared links that are arranged such that their turning axes are oriented along the edges of a polyhedral shape so that when a single link is turned, all links turn synchronously. In the assembly, there are two end positions of the geared links. In each end position, a set of link groups are formed, each of those groups corresponding to one face of the polyhedral shape so that each link group forms a circular track that is inscribed on that particular face. When the puzzle assembly is moved to a second end position, a new set of new link groups is formed corresponding to a different a different set of faces of the polyhedral shape. The puzzle assembly further comprises a number of “petal elements” equal to the number of geared links. The petals have a faceted form and a base piece that extends from that form for providing a sliding contact with the geared links. Each petal element is retained by a geared link. When the puzzle assembly is in one end position, a group of petals corresponding to a polyhedral face touch each other to form a pyramidal shape. Thus, one-half of their surfaces are exposed and one-half of their surfaces are hidden. When the puzzle assembly is “flipped”—the geared links are turned to their other end position—the petals recombine to hide the previously visible surfaces and to reveal the previously invisible surfaces. Importantly, in either end position, the group of petals corresponding to a polyhedral face may be twisted around the center point of that face, thereby changing the correspondence between the geared links and the petal elements.

Numerous puzzles are based on the principle of "recombination": manipulating pieces along constrained paths to reach a "solution state". A traditional example is the puzzle consisting of fifteen square pieces that can slide along their edges, held in place by a square tray whose sides are four times the length of the squares. As one attempts to move a piece to its desired location, one is forced to move other pieces out of the way which prevent one from achieving the solution directly.
A second famous example is "Rubik's Cube," whereby pieces are twisted around a cubic shape. Again, as one attempts to get certain pieces into a desired location, one is forced to move other pieces.


A safety architecture system includes, in one aspect, a first stage comprising a primary unit that generates primary data for performing normal system functionality; a secondary unit that generates secondary data for performing alternative system functionality; a primary safety gate coupled to the primary unit, with the primary safety gate providing the primary data as a primary output responsive to a determination of validity of the primary data; and a secondary safety gate coupled to the secondary unit, with the secondary safety gate providing the secondary data as a secondary output responsive to a determination of validity of the secondary data. The system also includes an output selector that is coupled to both the primary safety gate and the secondary safety gate of the first stage, with the output selector providing a system output responsive to the determinations of the validities of the primary data and the secondary data.

The complexity of unmanned vehicle software outpaces software-safety engineering techniques available today. Software-safety standards define processes to be employed when creating and validating software. While necessary, the processes prescribed by current standards may not be sufficient to ensure the safety of autonomous software within self-driving vehicles. In some cases, methods for advanced autonomy, such as machine learning, cannot readily be validated using traditional software testing methods. As a result, independent runtime invariant monitors have been used to firewall safety criticality into a small subset of the architecture, thus focusing resource-intensive software-safety engineering techniques away from complex autonomy software and onto much simpler monitoring components. But so far, such techniques have been most successfully deployed to unmanned vehicles that are remote-controlled or teleoperated. To date, it has not been clear how runtime invariant monitors could be most effectively used to mitigate safety risks posed by autonomous functions such as planning and control.

Safety architecture for autonomous vehicles


An aspect of the present invention reduces the effect of any noise present along with an input signal when sampling the input signal by charging each of several parallel connected capacitors for different time durations with at least some non-overlap. In an embodiment, such an approach is used in a switched capacitor amplifier circuit of an ADC. The capacitors in that embodiment start charging at the same time instance, but stop charging at different time instances due to the design of associated switches and control signals.

1. Field of the Invention
The present invention relates to integrated circuit design, and more specifically to a method and apparatus for reducing the effect of noise present along with an input signal when sampling the input signal.
2. Related Art
Sampling generally refers to capturing the strength of a signal at a time instance of interest. Capacitor circuits connected in parallel are often used to sample the voltage level of an input signal. One desirable feature of such sampling is that the effect of any noise present along with the input signal (on a path) be reduced/avoided when performing such sampling operations, as described with reference to an ADC.
FIG. 1 is a block diagram of a prior ADC used to illustrate the need to reduce the effect of any noise present along with an input when performing sampling operations. ADC 100 is shown containing sample and hold amplifier (SHA) 110, stages 120-1 through 120-S and digital error correction block 130. Each block is described below in further detail.
SHA 110 samples input signal received on path 134 and holds the voltage level of the sample for further processing. Each stage 120-1 through 120-S generates a sub-code corresponding to a voltage level of an analog signal received as an input, and an amplified residue signal as an input to a (any) next stage. Digital error correction block 130 receives sub-codes from various stages, and generates a digital code (on path 146) corresponding to the sample received on path 134.
FIG. 2 further illustrates the logical operation of each stage (described with reference to stage 120-1 only, for conciseness) according to a prior approach. Stage 120-1 is shown containing flash ADC 250, digital to analog converter (DAC) 260, subtractor 270 and gain amplifier 280. Flash ADC 250 (an example of a quantizer) converts a sample of an analog signal received on path 111 into a corresponding P-bit sub-code provided on path 256. DAC 260 converts the sub-code received on path 256 into corresponding analog signal (Vdac) on path 267.
Subtractor 270 generates a residue signal as the difference of sample 111 (Vi) and the analog signal received on path 267 (Vdac). Gain amplifier 280 amplifies the residue signal (Vi-Vdac), which is provided on path 112 as an amplified residue signal. The signal on path 112 is used to resolve the remaining bits in the N-bit digital code by the subsequent ADC stages.
Subtractor, DAC, and gain amplifier may be implemented using a capacitor network and an operational amplifier together operating as a switched capacitor amplifier. One prior switched capacitor amplifier implementing substracter 270, DAC 260, and gain amplifier 280 of stage 120-1 is described below with respect to FIGS. 3A and 3B.
FIG. 3A is an example switched capacitor amplifier illustrating combined implementation of DAC 260, subtractor 270, and gain amplifier 280 in one prior embodiment. FIG. 3B is a timing diagram depicting the sample and hold phases used in the operation of the circuit of FIG. 3A. The circuit diagram is shown containing op-amp 350, feedback capacitor 360, feedback switch 380 and circuit portions 301-1 through 301-2n. Circuit portions 301-1 is shown containing sampling capacitor 330-1, switch 310A-1, 310B-1 and 310C-1. The remaining circuit portions 310-2 through 310-2n may also contain similar components, and are not described in the interest of conciseness. Each component is described below in further details.
The circuit in FIG. 3A operates using two phase signals, shown as sampling phase clock 370 and hold phase clock 390. In the first phase (sampling phase 370) switches 310A-1 through 310A-2n are closed at time points 371 and the remaining switches 380, 310B-1 through 310B-2n, and 310C-1 through 310C-2n are kept open. As a result, each sampling (input) capacitor 330-1 through 330-2n is ideally charged (in duration between 371–372) to the voltage of input sample received on path 111 by time point 372.
In the second phase (between durations 391–392), feedback switch 380 is closed and switches 310A-1 through 310A-2n are kept open. Connections of switches 310B-1 through 310B-2n, and 310C-1 through 310C-2n are made such that the input terminals of each sampling capacitor 330-1 through 330-2n is connected either to Vref or to REFCM terminal, as determined from the output of flash ADC 250.
As a result, each of capacitors 330-1 through 330-2n transfers a charge proportional to the difference (residue) of input signal and the Vref or REFCM to feedback capacitor 360 (up to time point 392). The residue is amplified by op-amp 350 and provided as amplified residue signal to the next stage, as desired.
However, the input voltage provided on path 111 may contain various types of noise such as amplifier noise generated by SHA 110, noise generated by switches and other components, etc. Each sampling capacitor 330-1 through 330-2n samples the input signal along with the noise components present on path 111. The manner in which sampling capacitors sample both input signal and associated noise components is illustrated in FIG. 4.
FIG. 4 is a graph illustrating manner in which noise is sampled in addition to the analog input signal. The graph is shown containing sampling clock 370, input signal 430 and noise 450. Merely for illustration, the input signal and noise are shown as two separate signals. However, a cumulative signal (of input signal 430 and noise 450) is generally presented on path 111.
At time point 371, switches 310A-1 through 310A-2n are closed. As a result, the voltage on the sampling terminal of the capacitors (330-1 through 330-2n) starts increasing, and settles to the sampled input value (Vin) at time point 402. The input voltage remains a constant thereafter.
A noise signal (random) is shown varying randomly with respect to time and typically having zero mean value and a finite root mean square value. Due to the opening of switches at time point 372, each capacitor stores a (cumulative) voltage equaling the sum of settled input value (vin) and a noise value (with the root mean squared (RMS) value of the noise at the sampling time point).
Since each capacitor samples the noise between the same time points, the noise magnitudes sampled by the capacitors are correlated to each other (or same). As a result, the noise sampled by each sampling capacitor gets added at the input of the amplifier.
Accordingly, during hold phase (between time point 391 and 392), the amplified sum total of noise (sum of the noise sampled (N1) by all sampling capacitors 330-1 through 330-2n) is presented at the output of op-amp 350. Such noise propagation can cause an error in the residue signal and/or quantization, resulting in error in the sub-codes generated by various stages.
Therefore, what is needed is a method and apparatus for reducing the effect of noise present along with an input signal when sampling the input signal.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit (s) in the corresponding reference number.

Reducing the effect of noise present along with an input signal when sampling the input signal


Disclosed is a microneedle for dental material delivery, the microneedle including a needle body portion; an active ingredient coating portion configured to coat the surface of the needle body portion, and including an active ingredient transferred to the skin tissue within a mouth; and a base portion configured to couple with the needle body portion, and to bend along a skin shape within the mouth, wherein the base portion includes at least one of polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethylmethacrylate (PMMA), ethylene vinyl acetate (EVA), polycaprolactone (PCL), polyurethane (PU), polyethylene terephthalate (PET), polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly lactide (PLA), poly lactic-co-glycolic acid (PLGA), and polyglycolide (PGA).

1. Field of the Invention
Example embodiments relate to a microneedle for dental material delivery and a method of manufacturing the microneedle, and more particularly, a microneedle for dental material delivery that may be attached to the gums having a curved surface and may deliver a dental material to an inside of the gums and a method of manufacturing the microneedle.
2. Related Art
In the dental treatment according to the related art, a transdermal drug composition method has generally employed a method of penetrating the skin within a mouth using a syringe. This method may cause pain and significant stress on a patient side.
In the recent times, research on a microneedle has been actively conducted as a new transdermal delivery method to outperform the above issue. In general, if the microneedle is a device for supplying the nutrition or facilitating the penetration of a medical substance by stimulating the skin or making a small hole on the skin using a small size of a needle, a type of the microneedle is not particularly limited. In general, the microneedle has a diameter of about 1 μm to about 100 μm.
When using the microneedle configured as above, the medical substance may be locally delivered to the cell or tissue without causing significant pain. Further, the microneedle may be effectively used to administer molecules, such as peptide, protein, oligonucleotide, DNA, etc., incapable of infiltrating into the biological membrane or to target-deliver the medical substance to a part hard to be treated and a specific portion or tissue of a body.
The microneedle may have four types, for example, a solid microneedle, a coating microneedle, a melting-type microneedle, a hollow microneedle.
Here, the melting-type microneedle employs a method in which, once the melting-type microneedle is applied to the skin, a microneedle material starts being melted and a medical substance contained therein is delivered to the skin. Using this microneedle, the medical substance may be delivered with a one-time administration and the microneedle does not remain and thus, the risk of pollution is absent.
Here, a relatively long period of time, for example, 10 minutes or more, is required to melt the melting-type microneedle due to the moisture in the skin after administration. Since an active ingredient contained in the microneedle is subject to the complete melting of the microneedle, a fixed amount of medical substance may not be readily delivered to the skin. In addition, the melting-type microneedle is to be manufactured based on molding. Thus, a relatively long manufacturing time is required and the active ingredient may vary due to a manufacturing temperature.
Meanwhile, the coating microneedle may be simply manufactured and may quickly deliver a medical substance since the surface of the coating microneedle is coated with the medical substance. However, the needle remains, which may cause pollution.
In general, the melting-type microneedle or the coating microneedle according to the related art is applied to the even skin and thus, may not be readily applied to the gums having an irregularly curved shape within the mouth.

Flexible microneedle for dental material delivery and method of manufacturing the same


Improved chewing gum formulations and bases, as well as methods of producing chewing gum and bases are provided. The chewing gum includes meadowfoam seed oils from the plant genus Limnanthes. Meadowfoam seed oils can be used in the base and/or gum as a plasticizer. In an embodiment, meadowfoam oil is added to sucrose-type gum formulations replacing a small or large quantity of other fats, oils, and waxes. A variety of base and chewing gum formulations including meadowfoam oil can be created and/or utilized pursuant to the present invention.

The present invention relates generally to chewing gum. More specifically, the present invention relates to improved formulations for chewing gum and bases.
Chewing gum generally consists of a water insoluble gum base and a water soluble portion along with flavors. The water soluble portion and flavors dissipate during chewing and the gum base is retained in the mouth throughout the chew.
The insoluble gum base generally comprises elastomers, resins, fats and oils, softeners, and inorganic fillers. Elastomers can include synthetic elastomers including polyisobutylene, isobutylene-isoprene copolymers, styrene-butadiene copolymers, polyvinyl acetate, polyisoprene, polyethylene, vinyl acetate--vinyl laurate copolymers, and combinations thereof. Natural elastomers that can be used include natural rubber.
The gum base can include elastomer plasticizers. Such elastomer plasticizers can include natural rosin esters, as well as other elastomer plasticizers. Additionally, the gum base can include fillers/texturizers and softeners/emulsifiers. Softeners are added to chewing gum in order to optimize the chewability and mouth feel of the gum. Softeners/emulsifiers that are typically used include tallow, hydrogenated tallow, hydrogenated and partially hydrogenated vegetable oils, cocoa butter, glycerol monostearate, glycerol triacetate, lecithin, and combinations thereof.
In addition to a water insoluble gum base portion, a typical chewing gum composition includes a water soluble portion and one or more flavoring agents. The water soluble portion can include bulk sweeteners, high intensity sweeteners, flavoring agents, softeners, emulsifiers, colors, acidulants, fillers, antioxidants, and other components that provide desirable attributes.


The disclosure relates to the treatment of rods made of metal, particularly to the method of reclamation of used standard length rods, such as pump rods already used in the mechanical deep-pumping extraction of oil, as well as to the product made with the help of the mentioned method. The method of remanufacturing of standard length rods includes the reheating of the rod body to a temperature favorable for the plastic treatment of the rod such as plastic deformation of the rod body under pressure. Such methods allow for the reclamation of rods of the desired geometric form and enhancement of the mechanical properties of the remanufactured rod. The technical outcome of the claimed invention consists in the reclamation of rods of the desired geometric form and enhancement of the mechanical properties of the remanufactured rod.

A sucker rod is a rigid rod used in the oil industry to join together the surface and downhole components of a reciprocating piston pump installed in an oil well. These rods are typically between 25 and 30 feet (7 to 9 meters) in length, and threaded at both ends.
Prior art discloses a method of hardening rods such as sucker rods with the help of a device with two heads that have the ability to clamp two ends of the rod in need of treatment or modification. See Russian patent RU 2082590. In this embodiment, typically one head turns uncontrollably with the rod treated along its longitudinal central line. Unfortunately, use of the aforementioned device can result in deformation of standard length sucker rods due to tension and torsion, even though cold working the rod's surface would improve the fatigue strength and the efficiency. Additionally another shortcoming of this known method lies in the fact that this device method will not reclaim the proper geometric shape of the rod and eliminate the inner stress in it, which deteriorates the quality of the remanufactured rod and its service life.
Additional methods of remanufacturing sucker rods for re-use is to eliminate the fatigue stress in the used rods by a method involving thermally treating the rods at a temperature between about 200° C. and about 650° C. for 15 to 30 minutes. It consists of normalization, upgrading or tempering, with reference to the material or rods remanufactured. After thermal treatment the rods are straightened while still hot to achieve the required straightness. Additionally, straightening while still hot allows for the removal of stress which can occur otherwise during the course of the straightening procedure.
Typically, in such implementation, the rods undergo shot peening. Shot peening is a cold working process used to produce a compressive residual stress layer and modify mechanical properties of metals. It entails impacting the surface of a metal with shot (round metallic, glass, or ceramic particles) with force sufficient to cause plastic deformation. The shot peening process used on the reclamation of sucker rods removes scale, localizes micro-cracks and improves fatigue strength.
However, the shortcomings of this aforementioned method lie in the fact that worn out or corrosion damaged rods still retain all outside geometrical form defects, even after thermal reclamation.
It would therefore be desirable to create a more efficient method for remanufacturing standard length rods such as sucker rods that would make it possible to improve the quality of the products and decrease defects as compared with the reclamation processes delivered by traditional methods.


A method for improving the communication of the human interface device, comprising reporting at least one interrupt input endpoint and at least one interrupt output endpoint to the host; specifying that the USB device has a report descriptor in the HID class descriptor; specifying an input report and an output report in the report descriptor; and receiving an instruction from the host through the bulk output endpoint by the USB device, and returning the result from the USB device to the host through the bulk input endpoint, in which the size of the data transferred between the USB device and the host each time is equal to that of the corresponding report to increase the communication speed of the Universal Serial Bus (USB) device, which is designed to work as an HID.

Generally, a USB device works with a driver, which provides a data transfer channel from the application to the device. However, to develop an error-free driver is very complicated. Any problem with the driver might lead to a system crash. For this reason, the operating system is designed to provide built-in drivers to some typical USB devices, such as the Human Interface Device (HID) like mouse and keyboard. Therefore, if the non-typical USB devices, such as the USB Key, are designed as a human interface device, they can directly utilize the built-in drivers of the operating system, eliminating the complexity of design of drivers and related risks.
For the HID driver of the operating system, there are two approaches to access to the hardware device: Control Transfers and Interrupt Transfers, as defined by the USB Specification. Both Control Transfers and Interrupt Transfers are designed to best support trickle data transfers. The USB device as a human interface device cannot conduct bulk and high-speed data communication. When working on bulk data, the USB device as a human interface device cannot perform high-speed communication because the capacity of Interrupt Endpoint Buffers is not large enough.
In the USB Specification, Bulk Transfers are defined for bulk and high-speed data communication. Generally, the capacity of the buffers for Bulk Transfers is relatively large in the chip used by the USB device. But the HID class device cannot use the communication means of Bulk Transfers.
The chip with a USB interface has circuitries for various data transfer means inside. Each data transfer means corresponds to a circuitry, which is also referred to as "endpoint". The endpoint that supports control transfers is named as the control endpoint. The endpoint that supports interrupt transfers is named as the interrupt endpoint. The endpoint that supports bulk transfers is named as the bulk endpoint.
When connected to a host, the USB device sends a set of data to the host. The set of data declares the type of the device and the supported data transfer means. The host recognizes the USB device through the descriptor (i.e. the set of data). Each descriptor contains the information of a device or one of its components. All USB peripherals must respond to the request for standard USB descriptors. The host requests the descriptor to the device through control transfers during enumeration.
The descriptors referenced by the present invention are:                The interface descriptor. It defines an interface between a USB device and a host, and indicates if the device is a human interface device and has any endpoint other than the control endpoint etc. The endpoint descriptor. It is required only if the device has any endpoint other than the control endpoint. It indicates the type of the endpoint, the address of the endpoint in the chip, the size of the endpoint's buffer, and the interval of the host's access to the endpoint.        The HID class descriptor. It is required only if the device is defined as a human interface device. It indicates the version number of the USB protocol supported by the device. It also indicates that if the device has private descriptors and the feature limitation to the private descriptors.        The report descriptor. It is required only if the device is defined as a human interface device. It indicates how the data is to be organized during the communication between the device and the host.

Method for improving the communication of the human interface device


A backlight for a display screen, an electronic device and a method of operating a backlight are described. A backlight includes a light guide, a lead frame, and at least one visible light-emitting diode (LED) and at least one infrared (IR) LED on the lead frame. The backlight includes at least one light entry face and a light exit face. The lead frame includes a first lead and a second lead isolated from each other. The at least one visible LED is optically coupled to one of the at least one light entry face and includes a counter electrode contacted by the first lead and an electrode contacted by the second lead. The at least one IR LED is optically coupled to one of the at least one entry face and includes a counter electrode contacted by the second lead and an electrode contacted by the first lead.

Optical imaging may be used for identification purposes based on biometric principles, for example optical iris and face identification. Biometric identification typically requires a dedicated light source. Light sources providing illumination in the IR range have been found to beneficial for identification, as IR light is able to reveal biometric features that cannot be detected by visible light. At the same time, an active IR light source may be invisible to the user, such that the user is not distracted by the lighting device for identification.
Systems for optical identification may also be integrated into mobile devices such as mobile phones. In mobile devices, the available space for each electronic element is highly restricted. Recently, there is a tendency to maximize the area of a display screen in mobile devices, such as the touchscreen of mobile phones. In some mobile devices, the display screen covers practically an entire face of the mobile device, significantly reducing or eliminating a bezel of the display screen.
Typically, only a small "notch" is left on the corresponding face of the mobile device for other devices than the display screen, e.g. cameras for visible light and IR light, a flash light as well as the IR lighting device for identification. In mobile device design, there is the need to further increase the coverage of the display screen by reducing the size of the notch, e.g. such that the display screen covers the entire face, optionally only with a camera remaining in the notch at a corner of the display screen. Hence, it is desirable to configure the IR lighting device such that only very little available space for the display screen is consumed at the face of the mobile device.
In principle, it is possible to arrange the IR lighting device at an edge or the back side of the mobile device and to use light guides to redirect the light provided by the IR lighting device around the display screen and towards the front side of the mobile device. However, the efficiency of such arrangements is typically rather low. At the same time, still a significant amount space at the front face is consumed by the light guides, reducing the available size of the display screen.

Lighting device for backlighting of display screen


Compositions and methods for the manufacture of electrodes for fuel cells. The compositions and methods are particularly useful for the manufacture of anodes and cathodes for proton exchange membrane fuel cells, particularly direct methanol fuel cells. The methods can utilize direct-write tools to deposit ink compositions and form functional layers of a membrane electrode assembly having controlled properties and enhanced performance.

1. Field of Invention
The present invention relates to methods for manufacturing membrane electrode assemblies useful in proton exchange membrane and direct methanol fuel cells, including compositions useful for the deposition of the various layers in the membrane electrode assemblies. The methods enable rapid production of the membrane electrode assemblies and layers used therein. The present invention also relates to membrane electrode assemblies, including the gas and fluid distribution layers used therein, as well as proton exchange membrane and direct methanol fuel cells produced by the method.
2. Description of Related Art
Fuel cells are electrochemical devices that are capable of converting the energy of a chemical reaction into electrical energy without combustion and with virtually no pollution. A typical fuel cell includes a stack of membrane electrode assemblies (MEAs). Generally, MEAs comprise an anode, a cathode and a solid or liquid electrolyte disposed between the anode and the cathode. Different types of fuel cells are categorized by the electrolyte used in the fuel cell, the five main types being alkaline (including metal-air fuel cells), molten carbonate, phosphoric acid, solid oxide and proton exchange membrane (PEM) or solid polymer electrolyte fuel cells (PEFCs). A particularly preferred fuel cell for portable applications, due to its compact construction, power density, efficiency and operating temperature, is a proton exchange membrane fuel cell (PEMFC) which can utilize methanol directly without the use of a fuel reformer. This type of fuel cell is referred to as a direct methanol fuel cell (DMFC). Other liquid fuels may also be used in a liquid fueled fuel cell including formic acid, formaldehyde, ethanol and ethylene glycol. DMFCs are related to PEMFCs because both types employ a proton exchange membrane and oxygen as an oxidant on the cathode, but they are different in that DMFCs utilize liquid methanol as the fuel on the anode whereas a PEMFC utilizes a gas feed containing hydrogen. The hydrogen feed for a PEMFC can originate from a reformed methanol fuel feed as well as other fuel sources such as methane or propane. DMFCs are attractive for applications that require relatively low power because the anode achieves the combined function of "reforming" the methanol directly into hydrogen ions that can be delivered to the cathode through the PEM. This avoids the need for a separate methanol reforming system thereby reducing the size, and potentially the cost, of the overall system.
A DMFC is comprised of membrane electrode assemblies (MEAs). A cross-sectional view of a typical MEA is illustrated in FIG. 1 (not to scale). The MEA 100 comprises a PEM 102, an anode 104 and a cathode 110, and anode and cathode fluid distribution layers 106 and 112. The anode and cathode each include an electrocatalyst layer 120 and 122 which sandwich the PEM. The gas or fluid distribution layers, 106 and 112, typically include a carbon-based substrate and each layer is located next to its respective electrode. Bipolar plates 108 and 114 are disposed between the anode and cathode of sequential MEA stacks and comprise current collectors and flow fields, 116 and 118, for directing the flow of incoming reactant fluid to the appropriate electrode. Two end plates (not shown), similar to the bipolar plates, are used to complete the fuel cell stack.
The bipolar plates serve as electrically conductive separator elements between two adjacent MEAs, and (1) have reactant distributing grooves on both external faces thereof, (2) conduct electrical current between the anode of one MEA and the cathode of the adjacent MEA in the stack, and (3) in most cases, have internal passages which are defined by internal heat exchange faces and through which coolant flows to remove heat from the stack. Bipolar plates are often fabricated from graphite which is lightweight, corrosion resistant and electrically conductive in the PEM fuel cell environment. In certain cases, bipolar plates may also be fabricated from metals including expanded metals, metal foams and porous metal sheets. Bipolar plates are also gas impermeable to prevent mixing of the two reactants, which would lead to direct oxidation of the methanol. Bipolar plates are described in more detail in, for example, U.S. Pat. No. 5,776,624 by Neutzler and U.S. Pat. No. 6,255,012 by Wilson, et al, which are incorporated herein by reference in their entirety.
During operation of the DMFC, methanol is supplied to the anode and oxygen (air) is supplied to the cathode to create the reactants necessary to operate the fuel cell. Methanol flows through the flow fields 116 of bipolar plate 108, through the anode fluid distribution layer 106 and to the anode electrocatalyst layer 120, where it is oxidized. Oxygen flows through the flow fields 118 of bipolar plate 114 through the cathode fluid distribution layer 112, and to the cathode electrocatalyst layer 122 where the oxygen molecules are reduced to oxygen ions. Electrons from the oxidized methanol are routed to the cathode 110 through an external circuit 130 connecting the bipolar plates 108 and 114 to produce electrical current. Protons from the oxidized methanol pass from the anode to the cathode through the PEM 102 and recombine with the electrons and ionized oxygen to form water. Carbon dioxide is produced at the anode and is removed through the exhaust of the cell. The foregoing reactions can be written as follows:Anode: CH3OH+H2O→CO2+6H++6e−  (1)Cathode: 6H++6e−+ 3/2O2→3H2O  (2)Overall: 2CH3OH+3O2→2CO2+6H2O+energy  (3)
Although the theory behind fuel cell operation has been known for over 100 years, there has been difficulty producing commercially viable fuel cells due to technological barriers, and also due to the availability of more cost-effective energy sources such as petroleum. However, devices using petroleum products, such as the automobile, produce significant pollution and may eventually become obsolete with the depletion of petroleum resources. As a result, there is a need for an alternative means for producing energy. Fuel cells are a promising alternative source of energy in that they are relatively pollution-free and utilize hydrogen, a seemingly infinite fuel source.
Among the critical issues that must be addressed for the successful commercialization of fuel cells are cell cost, cell performance and operating lifetime. For stationary applications, improved power density is critical. For automotive applications, high voltage efficiencies are necessary. In terms of cell performance and operating lifetime, it is important that the fuel cell be constructed to minimize kinetic, ohmic and mass transport losses within individual MEAs. A major technical challenge is enabling the efficient transport of methanol, water, oxygen, carbon dioxide, protons and electrons to and from the relevant locations in the MEA. The efficient transport of these reactants and by-products will increase both the cell performance and the operating lifetime of the fuel cell. Most current manufacturing methods are not capable of forming structures that enable all around efficient transport of reactants and by-products within the MEA.
Aside from optimizing the cell performance by improving the aforementioned transport characteristics of the MEA, the successful commercialization of fuel cells depends on producing MEAs at a reasonable cost. The ideal MEA manufacturing process is one that rapidly and continuously produces MEAs having good transport characteristics, and with reduced manufacturing down-time and reduced capital costs associated with the MEAs. One way to decrease capital costs, without decreasing cell performance, is to place the required materials only where needed within the MEA structure, especially the expensive catalyst materials.
Fuel cells operate most efficiently when the electrocatalytically active sites are in direct contact with both the PEM and the supply fuel. This location within the electrode is known as the three-phase interface. Most conventional methods for manufacturing MEAs cannot deposit catalyst and other materials in predetermined locations to increase the catalyst utilization. As a result, an unnecessarily large amount of catalyst is deposited. Depositing the catalyst in relation to other materials such that the catalyst is located only in the areas where the three-phase interface (discussed below) occurs would decrease the capital cost of the MEA without sacrificing performance.
There are many different methods for producing the layers of an MEA including physical vapor deposition, screen printing, dry powder lamination, spraying, extrusion (a.k.a., slot die), electrostatic printing, and dry powder vacuum deposition. However, there are many drawbacks to these manufacturing methods. Many of the processes are laboratory methods, which cannot be used in full-scale manufacturing processes. Many of the processes are slow and require significant amounts of down-time to change patterns. Many of the processes cannot directly deposit materials on flexible or low-temperature surfaces such as thin polymer membranes. Many of the processes cannot precisely control the volume or concentration of the deposited materials on selected microscopic areas of the substrate and many of the processes cannot deposit the materials on the substrate in a pattern or cannot deposit patterns with a small line width. As a result, controlled gradients in composition, concentration or porosity within layers are difficult to fabricate. Many of the processes are not compatible with all of the required materials which results in the use of different deposition methods during the fabrication of the MEA. This increases the number of deposition steps, which in itself is inefficient and may lead to alignment errors within the MEA and lead to unnecessary handling and breakage of fragile components such as the thin PEM.
Lamination is well-known in the art and in the context of MEA manufacture refers to a process where two components, e.g., a PEM and an electrode, are bonded together using heat, pressure and/or an adhesive. U.S. Pat. No. 6,197,147 by Bonsil et al. discloses a laminating process for producing MEAs. The process comprises laminating an ion-conductive membrane, a catalytically active substance and a gas permeable electron conductive material. It is disclosed that the membrane and/or conductive material can be contacted with a compound such as hexachloroplatinic acid, which is then reduced to form platinum metal.
Decalcomania is generally defined as a process for transferring designs printed on a specially prepared transfer substrate to materials such as glass or metal. In the context of MEA assembly, the designs are the deposition patterns used to create the various layers of the MEA which are then transferred to a MEA substrate, such as a PEM, gas or fluid distribution layer or bipolar plate. In practice, an ink composition is deposited onto a blank cartridge, herein referred to as a transferring substrate. The transferring substrate and the MEA substrate are then sandwiched together and pressed in a heated environment. The heat cures the ink to the substrate thereby releasing it from the transferring substrate and depositing it on the substrate. The transferring substrate is then removed by peeling it from the deposited ink layer.
U.S. Pat. No. 5,211,984 by Wilson discloses a method of producing MEAs by decalcomania. An ink composition comprising a supported platinum catalyst and a proton conducting polymer is painted on a release blank to form a thin film decal. The decal is then transferred to the surface of a PEM using a heat press.
Decalcomania and lamination are advantageous in that they can deposit materials on fragile surfaces and are relatively simple to operate. Lamination also provides a high throughput. However, decal and lamination methods cannot produce fine patterns or gradients in composition without additional processing. Moreover, aligning the various MEA layers can be difficult.
U.S. Pat. No. 6,187,467 by Zhang et al. discloses the manufacture of electrodes using sequential impregnation and printing. First, a proton conducting polymer is impregnated onto a surface of a substrate, such as carbon fiber paper. The impregnation may be accomplished using a variety of techniques such as dipping the substrate into a solution comprising the proton conducting polymer. An electrocatalyst is then applied to the impregnated substrate. It is disclosed that the electrocatalyst can be applied to the substrate in the form of an aqueous ink including a proton conducting ionomer in solution by any known method including spraying, screen printing and ink-jet printing.
International (WIPO) Publication No. WO 0205365 by Gascoyne et al. discloses an ink composition useful in fabricating the anode of a PEMFC. The ink comprises a liquid medium, which may be aqueous or organic, one or more electrocatalyst, one or more proton-conducting polymer and one or more water retaining materials. It is disclosed that the ink may be applied to a substrate by any variety of methods known in the art such as filtration, vacuum deposition, spray deposition, casting, extrusion, rolling, printing or decal transfer. The substrate may be either the fluid distribution layer or the PEM.
Methods to produce MEAs using ink compositions containing carbon particles and zero-valent Pt compounds have been disclosed by Starz et al. in U.S. Pat. No. 6,500,217. This patent discloses a process for applying electrode layers to the front and back of a polymer electrolyte membrane strip.
Ink-jet deposition of platinum sols has been disclosed by Shah et al. (Langmuir, 1999, Vol. 15, pp. 1584-1587) for use as a catalyst in electroless copper deposition for microelectronic applications.
U.S. Pat. No. 5,672,439 by Wilkinson et al. discloses an MEA for a DMFC wherein crossover of the liquid methanol from the anode to the cathode is reduced. To reduce crossover, catalyst particles that promote the oxidation of the methanol in the anode can be concentrated on a surface of the anode.
U.S. Pat. No. 6,024,848 by Dufner et al. discloses an electrochemical cell such as a PEMFC. The cell can include a bi-layer for enhancing the transport of fluids within the cell. The bi-layer is in contact with an electrode and includes a hydrophobic phase of carbon black and a hydrophobic polymer, as well as a hydrophilic phase including a mixture of carbon black and a proton exchange resin. The bi-layer can be formed by a filter transfer process.
U.S. Pat. No. 6,156,449 by Zuber et al. discloses a catalyst layer, such as in a PEMFC, which includes a proton-conducting polymer, electrically conductive carbon particles and fine particles of a precious metal such as platinum. The layer is formed from an ink composition that includes carbon particles and at least one organic precious metal complex compound in a solution of the ionomer. The composition is applied and dried wherein the complex compounds are thermally decomposed during drying to form precious metal particles.
There is a need for a manufacturing process which can rapidly and economically produce MEAs with the aforementioned transport characteristics. That is where: methanol is transported within the MEA directly to the active sites within the electrocatalyst layer but away from the PEM to prevent cross-over; electrons are transported quickly from the anode electrocatalyst layer to the electrically conductive portions of the anode bipolar plate; water is transported through the anode and PEM quickly to deliver methanol to the active sites, maintain the hydration of the PEM and prevent back-pressure on the PEM; and CO2 is transported out of the anode in its dissolved state to prevent the removal of the methanol fuel.
It would be advantageous to provide an MEA manufacturing process which is capable of depositing all desired materials on fragile or durable substrates in a desired pattern and in a desired concentration. It would be advantageous to provide a single deposition method which is capable of depositing all materials in desired patterns and concentrations. It would be advantageous to provide an MEA manufacturing process which is capable of depositing materials quickly and without substantial changes in materials or downtime. The MEA manufacturing process for a DMFC should be able to construct liquid diffusion electrodes for the DMFC anode and gas diffusion electrodes for the cathode. The design elements of the DMFC gas diffusion cathode can also be incorporated into the design of a gas diffusion anode and therefore used for other types of fuel cells including PEMFC.

Method of producing membrane electrode assemblies for use in proton exchange membrane and direct methanol fuel cells


Offset cartridge microphones are provided that include multiple unidirectional microphone cartridges mounted in an offset geometry. Various desired polar patterns and/or desired steering angles can be formed by processing the audio signals from the multiple cartridges, including a toroidal polar pattern. The offset geometry of the cartridges may include mounting the cartridges so that they are immediately adjacent to one another and so that their center axes are offset from one another. The microphones may have a more consistent on-axis frequency response and may more uniformly form desired polar patterns and/or desired steering angles by reducing the interference and reflections within and between the cartridges.

Conferencing environments, such as boardrooms, video conferencing settings, and the like, can involve the use of microphones for capturing sound from audio sources. The audio sources may include human speakers, for example. The captured sound may be disseminated to an audience through loudspeakers in the environment, a telecast, a webcast, telephony, etc. The types of microphones and their placement in a particular environment may depend on the locations of the audio sources, physical space requirements, aesthetics, room layout, and/or other considerations. For example, in some environments, the microphones may be placed on a table or lectern near the audio sources. In other environments, the microphones may be mounted overhead to capture the sound from the entire room, for example. Accordingly, microphones are available in a variety of sizes, form factors, mounting options, and wiring options to suit the needs of particular environments.
The types of microphones that can be used for conferencing may include boundary microphones and button microphones that can be positioned on or in a surface (e.g., a table). Such microphones may include multiple cartridges so that the microphones have multiple independent polar patterns to capture sound from multiple audio sources, such as two cartridges in a single microphone for forming two separate polar patterns to capture sound from speakers on opposite sides of a table. Other such microphones may include multiple cartridges so that various polar patterns can be formed by processing the audio signals from each cartridge. These types of microphones are versatile since they are configurable to form different polar patterns as desired without the need to physically swap cartridges. For these types of microphones, while it would be ideal to co-locate the multiple cartridges within the microphone so that each cartridge detects sounds in the environment at the same instant, however, it is not physically possible. As such, these types of microphones may not uniformly form the desired polar patterns and may not ideally capture sound due to frequency response irregularities, and interference and reflections within and between the cartridges.
Typical polar patterns for microphones and individual microphone cartridges can include omnidirectional, cardioid, subcardioid, supercardioid, hypercardioid, and bidirectional. The polar pattern chosen for a particular microphone or cartridge may be dependent on where the audio source is located, the desire to exclude unwanted noises, and/or other considerations. In conferencing environments, it may be desirable for a microphone to have a toroidal polar pattern that is omnidirectional in the plane of the microphone with a null in the axis perpendicular to that plane. For example, a microphone with a toroidal polar pattern that is positioned on a table detects sound in all directions along the plane of the table but minimizes the detection of sound above the microphone, e.g., towards the ceiling above the table. However, existing microphones with toroidal polar patterns may be physically large, have a high self-noise, require complex processing, and/or have inconsistent polar patterns over a full frequency range, e.g., 100 Hz to 10 kHz.
Accordingly, there is an opportunity for microphones that address these concerns. More particularly, there is an opportunity for microphones including multiple unidirectional microphone cartridges that can reduce interference between the cartridges, more uniformly form desired polar patterns, form a toroidal polar pattern, are relatively small and compact, and have a relatively low self-noise.


An ultra-small angle X-ray scattering measuring apparatus includes a detector for detecting X-rays emitted from a sample, an X-ray collimating mirror arranged between the X-ray real focus and the sample, a monochromator arranged between the X-ray collimating mirror and the sample and an analyzer arranged between the sample and the detector. The X-ray collimating mirror includes a pair of X-ray mirrors that are arranged orthogonally relative to each other. The X-ray mirrors are multilayer film mirrors and their X-ray reflection surfaces are paraboloidal. The interplanar spacing of lattice planes of each of the multilayer films is continuously changed along the paraboloid so as to meet the Bragg's condition. The monochromator and the analyzer are formed by using a channel-cut crystal. The analyzer is driven to rotate for scanning around a 2θ-axial line and diffracted rays reduced to a spectrum by the analyzer are detected by the detector.

1. Field of the Invention
This invention relates to an X-ray small angle scattering measuring apparatus for measuring scattered rays emitted from a sample in a small angle region. In particular, the present invention relates to an ultra-small angle X-ray scattering measuring apparatus that can suitably be employed to measure scattered rays within such an ultra-small angle region that the angle of 2θ-diffraction is defined as 2θ≦0.08°.
2. Description of the Related Art
The X-ray small angle scattering method is known as a technique of determining the sizes and the shapes of crystal particles in the inside of a substance by observing X-ray scattering in a small angle region of 2θ-diffraction angle, e.g. 0°≦2θ≦5°. Slit type X-ray small angle scattering measuring apparatuses have been known as apparatuses which realize the X-ray small angle scattering method. Some kinds of slit type X-ray small angle scattering measuring apparatuses have been known, such as an X-ray small angle scattering measuring apparatuses employing an optical system that has three slits and an X-ray small angle scattering measuring apparatuses employing a Kratky U-slit.
Japanese Patent Laid-Open Publication No. 2001-356197 discloses an exemplar 3-slit type X-ray small angle scattering measuring apparatus. The disclosed X-ray small angle scattering measuring apparatus is adapted to limit divergence (or spreading) of X-rays entering a sample by means of the first and second slits to form parallel X-rays and obtain scattered rays in a small angle region from a sample by irradiating the sample with the parallel X-rays. The third slit exerts the effect of eliminating scattered rays emanated from the first and second slits. An X-ray small angle scattering measuring apparatus that employs the Kratky U-slit can realize a resolution higher than the 3-slit type X-ray small angle scattering measuring apparatus by controlling divergence of X-rays by means of the Kratky U-slit that is a block-shaped member.
Meanwhile, there has been an increasing demand, or desire, for clearly capturing scattered rays in an ultra-small angle region (2θ≦0.08°) in order to analyze the aggregate structure of a higher order of molecules of a polymer material such as plastic and rubber. In principle, it may be possible to analyze such an aggregate structure to meet the demand by measuring X-ray small angle scattering by means of a 3-slit type X-ray small angle scattering measuring apparatus or an X-ray small angle scattering measuring apparatus employing the Kratky U-slit. In reality, however, it is not possible to meet the demand for analyzing such an aggregate structure by means of an X-ray small angle scattering measuring apparatus of either type. The reason is that it is difficult for both the 3-slit type and the Kratky U-slit type X-ray small angle scattering measuring apparatuses to narrow the divergence angle of X-rays entering a sample, while maintaining the intensity of the X-rays to a high level, so that it is not possible to clearly remove the background in an ultra-small angle region and hence capture scattered rays from the sample in the ultra-small angle region.
X-ray small angle scattering measuring apparatuses employing a Bonse-Hart optical system have been known as X-ray small angle scattering measuring apparatuses designed to obtain information on scattered rays in an ultra-small angle region. As shown in FIG. 12A of the accompanying drawings as an example, such a device has a structure in which a monochromator 101 formed by using a channel-cut crystal is arranged between a sample S and an X-ray source 102 and an analyzer 103 also formed by using a channel-cut crystal is arranged between the sample S and an X-ray detector 104.
In FIG. 12A, reference symbols X, Y and Z indicate three-dimensional directions. The Z-direction is the direction perpendicular to the plane of FIG. 12A. In a measuring operation, as the analyzer 103 is driven to rotate for scanning around the axial line X0 of the analyzer 103 itself (so-called 2θ-rotation), it is possible to observe the change in the intensity I of scattered rays that corresponds to the change of 2θ-angle as shown in FIG. 12B. The 2θ-direction is the direction of rotation around the axial line X0 that is perpendicular to the XY plane. The XY plane is a plane that includes the optical axis X1 of X-rays extending from the X-ray source 102 to the X-ray detector 104 and orthogonal relative to the axial line X0 of 2θ-rotation. The XY plane may also be referred to as equatorial plane. The direction perpendicular to the equatorial plane that extends in the Z-direction may be referred to as latitudinal direction.
In an ultra-small angle X-ray scattering measuring apparatus employing a Bonse-Hart optical system, a parallel X-ray beam is formed not by partly removing X-rays emitted from the X-ray source 102 by means of a slit or slits, but by causing X-rays to be diffracted (namely be reflected) by the channel-cut crystal 101. At this time, the channel-cut crystal 101 also performs monochromatization that converts an X-ray beam containing X-rays of different wavelengths to a monochromatic (e.g. Kα1) X-ray beam. Therefore, the aforesaid ultra-small angle X-ray scattering measuring apparatus may irradiate a sample with a parallel and monochromatic X-ray beam. Further, with use of the analyzer 103, the precise monochromatic X-ray beam is directed to the X-ray detector 104. Thus, the ultra-small angle X-ray scattering measuring apparatus employing a Bonse-Hart optical system has been said to be capable of measuring scattered rays generated by the sample S in an ultra-small angle region.
However, the inventor of the present invention conducted an experiment and found that it was not possible to accurately capture scattered rays from a sample in an ultra-small angle region even by using a Bonse-Hart optical system. The reason for this is that divergence (namely spreading) of X-rays can not be limited in the latitudinal direction that is perpendicular to the equatorial plane, while the resolution in intra-equatorial-plane directions can be maintained high, e.g., to about 0.002° because divergence (or spreading) of X-rays can be limited in the equatorial plane by means of a monochromator and an analyzer. Note that the equatorial plane means the plane in which the X-ray detector is driven to move for scanning in order to capture scattered rays from a sample, and further means the plane in which the analyzer crystal 103 is driven to rotate in 2θ-rotation. When divergence (spreading) of X-rays is not limited in the latitudinal direction, a smearing phenomenon arises resulting in failing to accurately capture the pattern of scattered rays emitted from a sample.
A smearing phenomenon may also be referred to as a blurring/staining phenomenon that can arise when a plurality of Debye rings that are formed due to scattered rays from a sample are found one on the other in the X-ray detection region of the X-ray detector and stains the Debye rings that have been actually captured and makes them unclear. Now, a smearing phenomenon will be described in greater detail below by referring to FIGS. 13A and 13B of the accompanying drawings.
A smearing phenomenon appears when the width of X-rays entering a sample is sufficiently broader than the Debye rings of scattered rays arising from the sample. FIG. 13A schematically illustrates how incident X-rays R0 enter the sample S to produce scattered rays R1. Scattered rays R1 include a plurality of Debye rings D that are found one on the other. The width W0 of the incident X-rays R0 is sufficiently broader than the Debye rings forming scattered rays R1.
In FIG. 13A reference symbols X, Y and Z depict a three-dimensional space. The X-ray detector is driven to rotate in a manner of a 2θ-rotation around the Z-axis to detect scattered rays R1. In other words, the XY plane is an equatorial plane and the Z-direction that is perpendicular to the XY plane is the latitudinal direction. FIG. 13A illustrates a phenomenon observed in an ultra-small angle region (e.g., 2θ≦0.08°). The width W0 is so small that it may be contained in the X-ray optical axis of a wide-angle diffractometer, which may be a powder X-ray diffractometer.
From the viewpoint of ideal observation, the detection region A0 of a zero-dimensional X-ray detector such as an SC (scintillation counter) is supposed to detect a single Debye ring. If such is the case, a scattering pattern (Gaussian distribution pattern) A that is attributable to a single Debye ring is detected in FIG. 13B. However, when scattered rays R1 include a plurality of Debye rings D that are found one on the other, the detection region A0 detects those large number of Debye rings so that a scattering pattern B as indicted by symbol B in FIG. 13B that is attributable to a plurality of Debye rings is detected. In other words, when a smearing phenomenon occurs, significant peak information that indicates the sizes and the shapes of crystal particles that are present in a sample is buried in the background that arises due to a large number of Debye rings produced according to a broad X-ray beam width and hence cannot be detected.
With a Bonse-Hart optical system as shown in FIG. 12A, divergence (spreading) of X-rays in intra-equatorial-plane directions (namely intra-XY-plane directions) may be controlled by means of monochromator crystals. Therefore, it may be safe to assume that the influence of a smearing phenomenon in intra-equatorial-plane directions does not adversely affect the results of observation. However, since divergence (spreading) of X-rays is not controlled in the latitudinal direction (Z-direction), the sample S is irradiated with X-rays having broad width in the latitudinal direction to probably give rise to a smearing phenomenon. Then, it may not be possible to accurately capture the pattern of scattered rays in an ultra-small angle region due to the smearing phenomenon.
In FIG. 12A, a technique of narrowing the X-ray beam width in the latitudinal direction (Z-direction) by means of a slit or slits may be conceivable, for the purpose of dissolving the smearing phenomenon in the latitudinal direction. It may appear that Debye rings overlapping with each other within an ultra-small angle region (2θ≦0.08°) are reduced in number by means of such a technique so that the pattern of scattered rays may be accurately captured. However, the intensity of X-rays is made too weak to make it no longer possible to accurately observe X-rays when a slit is employed to control the width of an X-ray beam.

Ultra-small angle x-ray scattering measuring apparatus


Example embodiments presented herein are directed towards a base station, and corresponding method therein, for determining a control timing configuration. The control timing configuration provides a subframe timing for configuring PUSCH and uplink HARQ-ACK control timing for a cell serving a user equipment in a multiple cell communications network. The user equipment is served by a TDD based cell and a FDD based cell. Example embodiments are also directed towards a user equipment, and corresponding method therein, determining the control timing configuration discussed above.

Long Term Evolution Systems
Long Term Evolution (LTE) uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink direction and a Discrete Fourier Transform (DFT)-spread OFDM in the uplink direction. The basic LTE downlink physical resource can thus be seen as a time-frequency grid, where each resource element corresponds to one OFDM subcarrier during one OFDM symbol interval. In the time domain, LTE downlink transmissions may be organized into radio frames of 10 ms, with each radio frame consisting of ten equally-sized subframes of length Tsubframe=1 ms.
Furthermore, the resource allocation in LTE is typically described in terms of resource blocks, where a resource block corresponds to one slot, e.g., 0.5 ms, in the time domain and 12 subcarriers in the frequency domain. A pair of two adjacent resource blocks in time direction, e.g., 1.0 ms, is known as a resource block pair. Resource blocks are numbered in the frequency domain, starting with 0 from one end of the system bandwidth.
The notion of virtual resource blocks (VRB) and physical resource blocks (PRB) has been introduced in LTE. The actual resource allocation to a user equipment is made in terms of VRB pairs. There are two types of resource allocations, localized and distributed. In the localized resource allocation, a VRB pair is directly mapped to a PRB pair, hence two consecutive and localized VRBs are also placed as consecutive PRBs in the frequency domain. On the other hand, the distributed VRBs are not mapped to consecutive PRBs in the frequency domain, thereby providing frequency diversity for data channel transmitted using these distributed VRBs.
Downlink transmissions are dynamically scheduled, i.e., in each subframe the base station transmits control information regarding which terminals data is transmitted and upon which resource blocks the data is transmitted, in the current downlink subframe. This control signaling is typically transmitted in the first 1, 2, 3 or 4 OFDM symbols in each subframe and the number n=1, 2, 3 or 4 is known as the Control Format Indicator (CFI). The downlink subframe also contains common reference symbols, which are known to the receiver and used for coherent demodulation of, e.g., the control information.
From LTE Release 11 and onwards, the above described resource assignments may also be scheduled on the enhanced Physical Downlink Control Channel (EPDCCH). For 3GPP Release 8 to 3GPP Release 10, only Physical Downlink Control Channel (PDCCH) is available.
PDCCH Search Space
LTE defines so-called search spaces, which describe the set of CCEs the terminal is supposed to monitor for scheduling assignments/grants relating to a certain component carrier. A search space is a set of candidate control channels formed by CCEs on a given aggregation level, which the terminal is supposed to attempt to decode. As there are multiple aggregation levels, corresponding to one, two, four, and eight CCEs, a terminal has multiple search spaces. In each subframe, the terminals will attempt to decode all the PDCCHs that can be formed from the CCEs in each of its search spaces. If the CRC checks, the content of the control channel is declared as valid for this terminal and the terminal processes the information (scheduling assignment, scheduling grants, etc.). Each terminal in the system therefore has a terminal-specific search space at each aggregation level.
In several situations, there is a need to address a group of, or all, terminals in the system. To allow all terminals to be addressed at the same time, LTE has defined common search spaces in addition to the terminal-specific search spaces. A common search space is, as the name implies, common, and all terminals in the cell monitor the CCEs in the common search spaces for control information. Although the motivation for the common search space is primarily transmission of various system messages, it may be used to schedule individual terminals as well. Thus, it may be used to resolve situations where scheduling of one terminal is blocked due to lack of available resources in the terminal-specific search space. More important, the common search space is not dependent of user equipment configuration status. Therefore, the common search space may be used when the NW needs communicate with the user equipment during user equipment reconfiguration periods.
PUCCH
If the mobile terminal has not been assigned an uplink resource for data transmission, the L1/L2 control information, e.g., channel-status reports, Hybrid-ARQ acknowledgments, and scheduling requests, is transmitted in uplink resources, e.g., resource blocks, specifically assigned for uplink L1/L2 control on 3GPP Release 8 PUCCH. These resources are located at the edges of the total available cell bandwidth. Each such resource consists of 12 "subcarriers", e.g., one resource block, within each of the two slots of an uplink subframe. In order to provide frequency diversity, these frequency resources are frequency hopping on the slot boundary, i.e., one "resource" consists of 12 subcarriers at the upper part of the spectrum within the first slot of a subframe and an equally sized resource at the lower part of the spectrum during the second slot of the subframe or vice versa. If more resources are needed for the uplink L1/L2 control signaling, e.g., in case of very large overall transmission bandwidth supporting a large number of users, additional resources blocks can be assigned next to the previously assigned resource blocks.
Carrier Aggregation
The LTE Release 10 standard has recently been standardized, supporting bandwidths larger than 20 MHz. One important requirement on LTE Release 10 is to assure backward compatibility with LTE Release 8. This should also include spectrum compatibility. That would imply that an LTE Release 10 carrier, wider than 20 MHz, should appear as a number of LTE carriers to an LTE Release 8 terminal. Each such carrier may be referred to as a Component Carrier (CC). In particular for early LTE Release 10 deployments it may be expected that there will be a smaller number of LTE Release 10 capable terminals compared to many LTE legacy terminals. Therefore, it is necessary to assure an efficient use of a wide carrier also for legacy terminals, i.e., that it is possible to implement carriers where legacy terminals may be scheduled in all parts of the wideband LTE Release 10 carrier. The straightforward way to obtain this would be by means of Carrier Aggregation (CA). CA implies that an LTE Release 10 terminal may receive multiple CC, where the CC have, or at least the possibility to have, the same structure as a Release 8 carrier.
The number of aggregated CC as well as the bandwidth of the individual CC may be different for uplink and downlink. A symmetric configuration refers to the case where the number of CCs in downlink and uplink is the same whereas an asymmetric configuration refers to the case that the number of CCs is different. It is important to note that the number of CCs configured in a cell may be different from the number of CCs seen by a terminal: A terminal may for example support more downlink CCs than uplink CCs, even though the cell is configured with the same number of uplink and downlink CCs.
During initial access a LTE Release 10 terminal behaves similar to a LTE Release 8 terminal. Upon successful connection to the network a terminal may, depending on its own capabilities and the network, be configured with additional CCs in the UL and DL. Configuration is based on RRC. Due to the heavy signaling and rather slow speed of RRC signaling, it is envisioned that a terminal may be configured with multiple CCs even though not all of them are currently used. If a terminal is configured on multiple CCs this would imply it has to monitor all DL CCs for PDCCH and PDSCH. This implies a wider receiver bandwidth, higher sampling rates, etc., resulting in high power consumption.
To mitigate the above problems, LTE Release 10 supports activation of CCs on top of configuration. The terminal monitors only configured and activated CCs for PDCCH and PDSCH. Since activation is based on Medium Access Control (MAC) control elements, which are faster than RRC signaling, activation/de-activation may follow the number of CCs that are required to fulfill the current data rate needs. Upon arrival of large data amounts multiple CCs are activated, used for data transmission, and de-activated if not needed anymore. All but one CC, the DL Primary CC (DL PCC), may be de-activated. Activation provides therefore the possibility to configure multiple CC but only activate them on a need basis. Most of the time a terminal would have one or very few CCs activated resulting in a lower reception bandwidth and thus battery consumption.
Scheduling of a CC is done on the PDCCH via downlink assignments. Control information on the PDCCH is formatted as a Downlink Control Information (DCI) message. In Release 8 a terminal only operates with one DL and one UL CC, the association between DL assignment, UL grants and the corresponding DL and UL CCs is therefore clear. In LTE Release 10 two modes of CA needs to be distinguished. The first case is very similar to the operation of multiple Release 8 terminals, a DL assignment or UL grant contained in a DCI message transmitted on a CC is either valid for the DL CC itself or for associated (either via cell-specific or UE specific linking) UL CC. A second mode of operation augments a DCI message with the Carrier Indicator Field (CIF). A DCI containing a DL assignment with CIF is valid for that DL CC indicted with CIF and a DCI containing an UL grant with CIF is valid for the indicated UL CC.
DCI messages for downlink assignments contain among others resource block assignment, modulation and coding scheme related parameters, HARQ redundancy version, etc. In addition to those parameters that relate to the actual downlink transmission most DCI formats for downlink assignments also contain a bit field for Transmit Power Control (TPC) commands. These TPC commands are used to control the uplink power control behavior of the corresponding PUCCH that is used to transmit the HARQ feedback.
In LTE Release 10, the transmission of PUCCH is mapped onto one specific uplink CC, the UL Primary CC (UL PCC). Terminals only configured with a single DL CC, which is then the DL PCC, and UL CC, which is then the UL PCC, are operating dynamic ACK/NACK on PUCCH according to 3GPP Release 8. The first Control Channel Element (CCE) used to transmit PDCCH for the DL assignment determines the dynamic ACK/NACK resource on 3GPP Release 8 PUCCH. Since only one DL CC is cell-specifically linked with the UL PCC no PUCCH collisions may occur since all PDCCH are transmitted using different first CCE.
Upon reception of DL assignments on a single Secondary CC (SCC) or reception of multiple DL assignments, a PUCCH format (which is referred to as CA PUCCH herein) that can carry the HARQ-ACK of multiple serving cells should be used. A DL SCC assignment alone is untypical. The eNB scheduler should strive to schedule a single DL CC assignment on the DL PCC and try to de-activate SCCs if not needed. A possible scenario that may occur is that eNB schedules terminal on multiple DL CCs including the PCC. If the terminal misses all but the DL PCC assignment it will use Release 8 PUCCH instead of CA PUCCH. To detect this error case eNB has to monitor both the Release 8 PUCCH and the CA PUCCH.
In LTE Release 10, the CA PUCCH format is based on the number of configured CC. Configuration of CC is based on RRC signaling. After successful reception/application of the new configuration a confirmation message is sent back making RRC signaling very safe.
CA PUCCH Transmission Scheme
In this application, CA PUCCH refers to means of transmitting HARQ-ACK of multiple serving cells in the UL. For Rel-10 LTE, CA PUCCH can be embodied in one of the following two approaches. The first method is based on the use of PUCCH format 3 that is based on DFTS-OFDM. The multiple ACK/NACK bits are encoded to form 48 coded bits. The coded bits are then scrambled with cell-specific (and possibly DFTS-OFDM symbol dependent) sequences. 24 bits are transmitted within the first slot and the other 24 bits are transmitted within the second slot. The 24 bits per slot are converted into 12 QPSK symbols, DFT precoded, spread across five DFTS-OFDM symbols and transmitted within one resource blocks (bandwidth) and five DFTS-OFDM symbols (time). The spreading sequence is user equipment specific and enables multiplexing of up to five users within the same resource blocks. For the reference signals cyclic shifted CAZAC sequences, e.g., computer optimized sequences, may be used.
The second CA PUCCH method is called channel selection. The basic principle is that the user equipment is assigned a set of PUCCH format 1a/1b resources. The user equipment then selects one of resources according to the ACK/NACK sequence the user equipment should transmit. On one of the assigned resources, the user equipment would then transmit a QPSK or BPSK. The eNB detects which resource the user equipment used and which QPSK or BPSK value the user equipment fed back on the used resource and combines this into a HARQ response for associated DL cells. A similar type of mapping including a bundling approach is also done for TDD as in the FDD, in case the user equipment is configured with channel selection.
Time Division Duplex
Transmission and reception from a node, e.g., a terminal or user equipment 501 and base station 401 in a cellular system such as LTE, may be multiplexed in the frequency domain or in the time domain (or combinations thereof). Frequency Division Duplex (FDD) as illustrated to the left in FIG. 1 implies that downlink and uplink transmission take place in different, sufficiently separated, frequency bands. Time Division Duplex (TDD), as illustrated to the right in FIG. 1, implies that downlink and uplink transmission take place in different, non-overlapping time slots. Thus, TDD can operate in unpaired spectrum, whereas FDD requires paired spectrum.
Typically, the structure of the transmitted signal in a communication system is organized in the form of a frame structure. For example, LTE uses ten equally-sized subframes of length 1 ms per radio frame as illustrated in FIG. 2.
In case of FDD operation, illustrated in the upper section of FIG. 2, there are two carrier frequencies, one for uplink transmission (fUL) and one for downlink transmission (fDL). At least with respect to the terminal in a cellular communication system, FDD may be either full duplex or half duplex. In the full duplex case, a terminal may transmit and receive simultaneously, while in half-duplex operation, the terminal may not transmit and receive simultaneously. The base station is capable of simultaneous reception/transmission though, e.g., receiving from one terminal while simultaneously transmitting to another terminal. In LTE, a half-duplex terminal is monitoring/receiving in the downlink except when explicitly being instructed to transmit in a certain subframe.
In case of TDD operation, illustrated in the lower section of FIG. 2, there is only a single carrier frequency and uplink and downlink transmissions are always separated in time also on a cell basis. As the same carrier frequency is used for uplink and downlink transmission, both the base station and the mobile terminals need to switch from transmission to reception and vice versa. An essential aspect of any TDD system is to provide the possibility for a sufficiently large guard time where neither downlink nor uplink transmissions occur. This is required to avoid interference between uplink and downlink transmissions. For LTE, this guard time is provided by special subframes, e.g., subframe 1 and, in some cases, subframe 6, which are split into three parts: a downlink part (DwPTS), a guard period (GP), and an uplink part (UpPTS). The remaining subframes are either allocated to uplink or downlink transmission.
TDD allows for different asymmetries in terms of the amount of resources allocated for uplink and downlink transmission, respectively, by means of different downlink/uplink configurations. In LTE, there are seven different configurations as shown in FIG. 3. It should be appreciated that a DL subframe may mean either DL or the special subframe.
To avoid severe interference between downlink and uplink transmissions between different cells, neighbor cells should have the same downlink/uplink configuration. If this is not done, uplink transmission in one cell may interfere with downlink transmission in the neighboring cell and vice versa. Hence, the downlink/uplink asymmetry may typically not vary between cells, but is signaled as part of the system information and remains fixed for a long period of time.
PUSCH Scheduling and PHICH Timings
The PUSCH scheduling timing and the corresponding HARQ feedback PHICH timing are described extensively in 3GPP Technical Specification 36.213. A basic summary is provided below for discussing the example embodiments presented herein.
For TDD UL/DL configurations 1-6 and normal HARQ operation, the user equipment shall upon detection of a PDCCH/ePDCCH with uplink DCI format and/or a PHICH transmission in subframe n intended for the user equipment, adjust the corresponding PUSCH transmission in subframe n+k, with k given in Table 8-2 of TS 36.213 (reproduced in Table 1 below), according to the PDCCH/ePDCCH and PHICH information. For FDD, k=4.
TABLE 1k for TDD configurations 0-6TDD UL/DLsubframe number nConfiguration01234567890464616464244344444454677775
For TDD UL/DL configuration 1-6, if a user equipment is configured with one serving cell, or if the user equipment is configured with more than one serving cell and the TDD UL/DL configuration of all the configured serving cells is the same, an HARQ-ACK received on the PHICH assigned to a user equipment in subframe i is associated with the PUSCH transmission in the subframe i-k as indicated by the following Table 8.3-1 of TS 36.213 (reproduced below). For FDD, k=4.
TABLE 2k for TDD configurations 0-6TDD UL/DLsubframe number iConfiguration01234567890747414646266366646656664746
For TDD, if the user equipment is configured with one serving cell, or if the user equipment is configured with more than one serving cell and the TDD UL/DL configuration of all the configured serving cells is the same, for PUSCH transmissions scheduled from serving cell c in subframe n, the user equipment shall determine the corresponding PHICH resource of serving cell c in subframe n+kPHICH, where kPHICH is given in Table 9.1.2-1 of TS 36.213 (reproduced in Table 3 below). For FDD, kPHICH=4.
TABLE 3kPHICH for TDDTDD UL/DLsubframe index nConfiguration0123456789047647614646266366646656646647
Within the downlink control information (DCI) transmitted to the user equipment via PDCCH/ePDCCH for scheduling PUSCH, there is a transmit power control (TPC) command. For a PUSCH transmission at subframe i, the TPC command from subframe i−KPUSCH should be incorporated. For TDD UL/DL configurations 1-6, KPUSCH is given in Table 18.104.22.168-1 of TS 36.213 (reproduced in Table 4 below). For FDD, KPUSCH=4.
TABLE 4KPUSCH for TDDTDD UL/DLsubframe number iConfiguration01234567890——674——6741——64———64—2——4————4——3——444—————4——44——————5——4———————6——775——77—

This patent is subject to a terminal disclaimer.

Node and method for uplink scheduling and hybrid automatic repeat request timing


A hubcap vent plug is disclosed which includes a plug body having inlet vent structure for accommodating air flow into a bearing chamber during wheel end pressurization, outlet vent structure for accommodating gaseous flow out of the bearing chamber during wheel end depressurization, a first one-way check valve operatively associated with the inlet vent structure, a second one-way check valve operatively associated with the outlet vent structure, and an annular seal member mounted on the plug body for sealingly engaging the periphery of a reception port formed the end wall of the hubcap.

1. Field of the Invention
The subject invention relates to a vehicle hubcap, and more particularly, to a vented plug for use with a hubcap assembly installed on the wheel end of a heavy duty trailer or truck.
2. Background of the Related Art
In tractor and trailer wheel end axle assemblies, particularly those employed on large trailers and semi-trailers and tractors, the wheel is mounted on a fixed axle or spindle for rotation thereabout. The hub of the wheel defines a lubricant chamber about the end of the spindle in association with the wheel bearings. A quantity of lubricant is maintained in the lubricant chamber or wheel housing to continuously bath the bearings. A hubcap is used to enclose the lubricant chamber and, for maintenance purposes, the hubcap is oftentimes provided with a transparent end wall to readily observe the lubricant chamber.
Since the operation of a truck or trailer results in the heating of the fluid lubricant with the wheel housing, it has been found desirable to ventilate the wheel housing and provide for pressure equalization between the lubricant chamber and the surrounding atmosphere. It has also been found that water and foreign matter may be injurious to the wheel bearings. Therefore, provisions must be made to prevent such contaminates from entering the lubricant chamber by way of the ventilating features.
The subject invention provides a novel plug dimensioned and configured for reception in the end wall of a hubcap which includes features for ventilating the wheel housing while preventing the egress of fluid lubricants from the lubricant chamber and the ingress of water and foreign matter into the lubricant chamber.


A maskable data output buffer includes an output stage receiving data signals from a data coder. The signals output from the data coder are normally complementary data signals corresponding to complementary data input signals. However, in response to receiving a mask signal, the data coder forces the output signals to be other than complementary. The output stage normally generates a data output signal corresponding to the complementary data input signals. However, when the data input signals are other than complementary, the output of the output stage assumes a high impedance condition. Since the timing of the high impedance condition is determined from the data signals themselves, the timing of the mask operation is inherently properly timed to the output of the data from the data output buffer.

Output buffers are commonly used in memory devices, such as dynamic random access memories ("DRAMs"), to supply data from a location in a memory array to one or more data bit terminals of the memory device during a memory read operation. The data bit terminal is commonly referred to as the "DQ" terminal. When a memory location storing a value of logic "1" is read, the output buffer receives complimentary logic "1" and logic "0" signals at respective DATA and DATA* input terminals and applies a logic "1" signal (which may be 3.3 volts or 5 volts, for example) to the DQ terminal. When a memory location storing a value of logic "0" is read from a memory location, the output buffer receives complimentary logic "0" and logic "1" signals at respective DATA and DATA* input terminals and applies a logic "0" signal to the DQ line. Although the prior art output buffers will be described as being a component of a DRAM, it will be understood that they are also used in devices other than DRAMs, such as in static random access memories ("SRAMs").
As output buffers have developed in speed and capability, they have been designed to perform additional functions. One of these functions is a data mask operation in which the data output terminal of the output buffer is switched to a high impedance or "tri-state" condition responsive to a data mask signal, known as a "DQM" signal. During this tri-state condition, the output buffer does not output any signal at the DQ terminal.
The conventional approach to masking a data signal output by a data output buffer is to apply the DQM signal to an active low enable input of an output buffer 10, as illustrated in FIG. 1. The DQM signal is applied to the enable output buffer 10 through a register 12 that is enabled by a clock ("CLK") signal. Thus, the DQM signal is registered to the edge of the CLK signal, although the DQM signal may be delayed to some degree in being coupled out of the register 12 to the output buffer 10. Similar, and often longer, delays may occur in coupling the DATA and DATA* signals to the output buffer 10.
During a normal read operation, the DQM signal is a logic "0" thereby enabling the output buffer 10. As a result, the output buffer 10 applies a data output signal to the DQ terminal that correspond to the complimentary DATA and DATA* inputs to the output buffer 10.
With reference to FIG. 2, when a masked data read operation is to occur, a logic "1" DQM signal is applied to the enable input of the output buffer 10. As is conventional, the output buffer operates with a read latency, which may be 2 clock cycles as shown in FIG. 2. In a latency of 2, an active DQM signal is applied to the output buffer 10 approximately 2 clock pulses before the data to be masked are applied to the DATA and DATA* input of the output buffer 10. Thus, the output buffer 10 is disabled approximately 2 clock pulses after DQM goes high. As a result, the output buffer 10 passes the first two bits of data, but its output is tri-stated during the third bit of data. Thus, during the time that DATA2 and DATA2* are applied to the output buffer 10 and the output buffer would otherwise output a corresponding DQ signal on the DQ terminals of the output buffer 10, the DQ terminal of the output buffer 10 becomes essentially open circuited. (The DATA* signal has been omitted from FIG. 2 since it is simply the compliment of DATA).
The above-described conventional approach to performing a masked data read operation is satisfactory if the DQM signal is properly synchronized with the DATA and DATA* signals. Under these circumstances, the output buffer 10 is disabled as illustrated in FIG. 2 in a manner in which the entire DATA2 signal is masked, but no part of either DATA1 or DATA3 is masked. However, in practice, particularly at higher operating speeds, the DQM signal is often not well synchronized to the DATA and DATA* signals. If an active high DQM signal is applied to the output buffer 10 too late relative to the DATA and DATA* signals, then the trailing part of the data bit prior to the desired data bit will be masked, and the trailing part of the desired data bit will not be masked. With reference to FIG. 3, the output buffer 10 is disabled after the DQM signal goes high with the same latency delay shown in FIG. 2. However, the DATA and DATA* signals are applied to the output buffer 10 later than as shown in FIG. 2. As a result, the trailing portion of the DQ1 bit is improperly masked, and the trailing portion of the DQ2 bit is improperly not masked. Under these circumstances, the DQ1 bit may be present for less than the output hold time t.sub.OH specified for a memory device using the output buffer 10. Furthermore, the output buffer 10 may fail to mask the DQ2 bit so that it is read by a processor (not shown) or other device performing the read operation. Although the problem illustrated in FIG. 3 has occurred because of an excessive delay in applying the DATA and DATA* signals to the output buffer 10, the same problem occurs if the DQM signal is applied with insufficient delay (i.e., to early), or any combination of the DATA and DATA* signals applied too late and the DQM signal applied too early.
A problem similar to that illustrated in FIG. 3 occurs if the DQM signal is applied to the output buffer 10 too late, the DATA and DATA* signals are applied to early, or any combination of the two. With reference to FIG. 4, the output buffer 10 is once again disabled after the DQM signal goes high with the same latency delay shown in FIGS. 2 and 3. However, the DATA and DATA* signals are applied to the output buffer 10 earlier than as shown in FIG. 2. As a result, the leading portion of the DQ2 bit is improperly not masked, and the leading portion of the DQ3 bit is improperly masked. Under these circumstances, the DQ3 bit may be present for less than the output hold time t.sub.OH specified for a memory device using the output buffer 10. Furthermore, the output buffer 10 may once again fail to mask the DQ2 bit so that it is read by a processor (not shown) or other device performing the read operation.
Although both of the above-described problems could theoretically be solved by precisely synchronizing the DQM signal to the DATA and DATA* signals as they are applied to the output buffer 10, in practice it is not possible to synchronize the signals to each other with adequate precision. Furthermore, the delays are difficult to predict and may vary with time with different memory devices and with different systems using the memory devices, thus making it impractical to synchronize the signal to each other by imposing a compensating delay on either the DQM signal or the DATA and DATA* signals. There is thus a need for an output buffer that is capable of precisely masking the entire portion of a desired data bit without masking any portion of adjacent data bits.

Output buffer having inherently precise data masking