A method of manufacturing a non-woven fabric which is bulky caused by fiber-raised construction on the surface of a non-woven fabric includes adhering a non-woven web with its surface layer portion containing an easy-to-heat-melt component showing a property to be adhesive as heated to a smooth surface heated at the temperature for the easy-to-heat-melt component to show a property to be adhesive with the surface layer portion in contact with the smooth surface, and then raising the fibers of the non-woven web by peeling the non-woven fabric like web off the smooth surface so that a fiber-raised bulky state is generated, whereby a fiber-raised bulky structure is formed on the surface of the non-woven fabric.

1. Field of the Invention
The present invention relates to a method of manufacturing effectively and economically bulky non-woven fabric having a fluffy structure realized by fiber-raising process carried out during the processing of a non-woven fabric of relatively thin and having a relatively low density. Also, the present invention relates to such bulky non-woven fabric and composite absorbent material to be obtained by said method and absorbent products such as baby and incontinent diapers, feminine hygiene products and medical care products to be made by utilizing such non-woven fabric and composite absorbent material.
2. Related art
Bulky non-woven fabric is used in such uses as filling material, impregnated substrate, foamed substrate and the like as cushioning materials and in addition in many applications such as the top sheet for an absorbent product and a transfer layer and acquisition layer to reinforce an absorbent material.
A variety of methods have been proposed based on various technologies as ways to obtain bulky non-woven fabric of various kind commercially. Such methods are generally classified into six categories as follows:
(1) A method of forming web by means of carded method utilizing so-called bulky fiber such as hollow fiber or hollow bicomponent fiber having coarse denier and high resilience;
(2) A method of imparting a bulky structure by means of forming web consisting potently crimpable and heat shrinkable fibers and heat treating such web so that it becomes crimped and heat shrunk;
(3) A method of imparting a three-dimensional structure by means of continuously folding web oriented in the direction of X-Y like a carded web so that the web is oriented in the direction of Z axis, of then laminating and heat setting the web;
(4) A method of forming a fiber-raised structure by means of physically abrading the surface of non-woven fabric or of transplant;
(5) A method of obtaining bulky tow-like material by means of opening compressed crimped tow in an air stream; and
(6) A method of obtaining a foamed fibrous structure by means of combining a method of manufacturing foamed material such as polyurethane foam, polyethylene foam and cellulose foam with fiber web.
Many of these methods have already been proposed so far. These methods have in common the following two problems in handling such resultant bulky structure:
First, such a structure is bulky for its weight and as such is difficult to be made into a large package so that the cost of handling it in commercial or industrial scenes becomes high. In order to solve such problem, rather complicated operations are needed to wind up it as it is displaced like winding on a bobbin (which is called xe2x80x9cspoolingxe2x80x9d) or heap it as folded (which is called xe2x80x9cfestooningxe2x80x9d).
Second, the characteristic bulkiness of the structure achieved with effort may gradually be reduced as it is handled or further processed.
One of methods thought of in solving these two problems is bulking non-woven fabric in a line of its use when or immediately before it is used so that the resultant bulkiness can be utilized as it is achieved, which is generally called xe2x80x9cin-line bulkingxe2x80x9d.
A typical example of the in-line bulking as reported is that card web pressured and compressed in the shape of mat beforehand is fed continuously into a disposable diaper making machine so that the card web is opened and swollen to make cushion material for baby and incontinent disposable diapers. Alternatively, as reported, shrinkable non-woven fabric is fed as overfed continuously into a heat shrinking machine directly connected to a disposable diaper making machine to cause heat shrinkage corresponding to the amount of the overfeeding in the fabric to make it web material which is, as is made, used as acquisition layer in a baby disposable diaper. An important disadvantage of these solutions is that the equipment of realizing the solutions becomes necessarily complicated and at the same time the difference in speed between the bulking of non-woven fabric and the converting into a disposable diaper can hardly be made up for to synchronize the times.
The present invention has been completed through as the result of intensive research and study intended to overcome the above-mentioned disadvantages of the in-line bulking and to investigate how a compact and efficient process is realized to do so.
The present invention provides a method of bulking a non-woven fabric comprising the steps of:
adhering a non-woven web with its surface layer portion containing an easy-to-heat-melt component showing a property to be adhesive as heated to a smooth surface heated at the temperature for the easy-to-heat-melt component to show a property to be adhesive with said surface layer portion in contact with the smooth surface; and
peeling the non-woven fabric like web off said smooth surface so that a fiber-raised bulky state is generated by fiber-raising the fibers of said non-woven web; whereby a fiber-raised bulky structure is formed on the surface of said non-woven fabric.
In an aspect of the present invention, the adhering step may include a compressively adhering step where the non-woven web is compressively adhered onto the heated smooth surface.
The heated smooth surface may be formed into a cylinder-like shape and in this case, the compressively adhering step is achieved by means of more than one press roll for compressively adhering the non-woven web onto the cylinder-shaped heated smooth surface.
The present invention may include a further step that the non-woven web is preheated by having it pass through a hot air zone before it is introduced into the compressively adhering step.
In addition, the present invention may be provided with an post treatment step where the non-woven web through the fiber-raising step is cooled down so that the already formed fiber-raised structure is fixed.
A further additional step may be a pressing step where the non-woven web is pressed in part to an extent not substantially impairing the fiber-raised structure by pressing a heated roll with projections provided on the fiber-raised surface formed on the non-woven web.
The present invention also provides a method of bulking a non-woven fabric comprising the steps of:
obtaining a non-woven web by providing on the surface of a non-woven fabric a surface layer portion containing an easy-to-heat-melt component exhibiting a property to become adhesive as heated;
obtaining a compressed non-woven fabric by reducing the thickness of the non-woven web by compressing it in the direction of the thickness;
contacting said resultant compressed non-woven fabric with the surface of a roll heated at the temperature for said hot melt adhesive to develop a property to adhere or at higher temperatures and peeling said compressed non-woven fabric off the surface of the roll so as to raise the fiber of said non-woven web; and
stabilizing the fiber-raised bulky structure by subsequently cooling down the fiber-raised portion.
In the present invention, as non-woven web a compressed non-woven fabric can be used as obtained by having non-woven fabric in a dry state with its surface layer portion including an easy-to-heat-melt bicomponent fiber through a heated compression roll so that the thickness is reduced and then cooling it down.
Preferably, the non-woven web is that to be produced by a spun-laced method where a carded web of two layers composed of a surface layer portion mainly consisting of polyethylene terephthalate fiber and a back surface layer mainly consisting of cellulose fiber is formed, entangled integrally in a high pressure water stream and then dried to obtain the non-woven web.
Alternatively, the non-woven web may be such that with a spun bond of polyethylene terephthalate as the basis a mixed carded web of polyethylene/polyethylene terephthalate bicomponent fiber and cellulose fiber is entangled and combined in a high pressure water stream or that with cellulose fiber as the basis, a mixed carded web is entangled and combined in a high pressure water stream consisting of polyethylene/polyethylene terephthalate bicomponent fiber and polyethylene terephthalate fiber.
Another preferable non-woven web used in the present invention is three or four layer composite web consisting of a two-layered spun-bonded web mainly composed of polyethylene terephthalate fiber or polypropylene fiber and a one or two-layered melt-blown web disposed between the two layers of the two-layered spun-bonded web.
In the multi-layered composite web, so-called SMS, SMMS, it is preferable that the two layers of the two-layered spun-bonded web have different deniers, respectively, with the denier of the surface side (d1) being coarser than that of the backside (d2) and with the relation between the denier (d1) and the denier (d2) being
d1/d2xe2x89xa71.5.
More preferably, the two layers of the two-layered spun-bonded web have different apparent specific gravities with the apparent specific gravity of the surface side web (SG1) being higher than that of the backside web (SG2) and with the relation between the bulk specific gravity (SG2) and the bulk specific gravity (SG1) being
SG2/SG1xe2x89xa71.2.
As the fabric-like non-woven web, a spun-bonded or its laminated material whose main component is an easy-to-heat-melt bicomponent fiber can also be used.
In addition, the present invention provides a fiber-raised bulky non-woven fabric characterized in that a non-woven web with a surface layer portion existent on the surface containing an easy-to-heat-melt component having a property to become adhesive as heated is adhered to a smooth surface heated at the temperature at which said easy-to-heat-melt component exhibits a property to become adhesive with said surface layer portion in contact with said smooth surface and then peeled off said smooth surface to generate a fiber-raised bulky state whereby a fiber-raised bulky structure is formed on the surface of said non-woven web.
A preferable easy-to-heat-melt component is, for example, particle, suspension or emulsion of homo-polymer or copolymer of EVA, MA, MMA or PE or natural rubber or synthetic rubber latex.
The easy-to-heat-melt component showing adhesiveness as heated can be a hot melt adhesive.
The easy-to-heat-melt component can be a bicomponent fiber having a property to be easy to heat melt, and in the fiber-raising step a cooling step where the easy-to-heat-melt component is cooled down.
In case the easy-to-heat-melt component is a hot melt adhesive, the amount of added hot melt adhesive is preferably 0.5 to 10% by weight of the total weight of the non-woven web.
The thermal softening point of the hot melt adhesive is preferably at least 20xc2x0 C. lower than the temperature at which the fiber constituting the surface layer of the non-woven fabric starts to melt.
Alternatively, the easy-to-heat-melt component preferably contains a bicomponent fiber consisting of an easy-to-heat-melt high polymer showing a property to be adhesive at the time when it softens and melts and of relatively thermally stable high polymer component.
The content of the bicomponent fiber is preferably 20 to 100% by weight of the total weight of the non-woven web. The bicomponent fiber may be made of a sheath and core structure having a less-easy-to-heat-melt as the sheath and a relatively thermally stable component as the core.
In a further aspect of the present invention, there is provided a method of manufacturing a composite absorbent body comprising the steps of
adhering non-woven web with a surface layer portion existent on the surface containing an easy-to-heat-melt component having a property to become adhesive as heated to a smooth surface heated at the temperature at which said easy-to-heat-melt component exhibits a property to become adhesive with said surface layer portion in contact with said smooth surface;
peeling the non-woven web off said smooth surface to generate a fiber-raised bulky state so as to raise the fibers of said non-woven web; a step of forming non-woven web having a fiber-raised bulky structure on its surface;
applying a highly absorbent polymer in slurry to the fiber-raised bulky surface of the non-woven web obtained in the previous step used as a substrate to make a composite; and
removing dispersion medium out of said slurry so that the highly absorbent polymer is fixed in the non-woven web.
According to another aspect of the present invention is provided an absorbent product wherein on the surface of non-woven web are provided a non-woven web having a fiber-raised bulky structure on its surface and an absorbent body, said non-woven web being obtained through a adhering step of adhering non-woven web with a surface layer portion existent on the surface containing an easy-to-heat-melt component having a property to become adhesive as heated to a smooth surface heated at the temperature at which said easy-to-heat-melt component exhibits a property to become adhesive with said surface layer portion in contact with said smooth surface and a fiber-raising step of then peeling the non-woven web off said smooth surface to generate a fiber-raised bulky state, and said fiber-raised bulky non-woven fabric being disposed with fiber-raised surface having a cushion property facing said absorbent body and its smooth backside functioning as a topsheet in contact with the body of a wearer.
In such absorbent product the fiber-raised bulky non-woven fabric has preferably such a porous structure on the smooth backside as permit liquid to physically permeate.
According to still another aspect of the present invention is provided an absorbent product wherein a substrate consisting of non-woven web having a fiber-raised bulky structure on its surface and an absorbent body consisting of a highly absorbent composite where the substrate and a particulate highly absorbent polymer are integrated, said non-woven web being obtained through a adhering step of adhering non-woven web with a surface layer portion existent on the surface containing an easy-to-heat-melt component having a property to become adhesive as heated to a smooth surface heated at the temperature at which said easy-to-heat-melt component exhibits a property to become adhesive with said surface layer portion in contact with said smooth surface and a fiber-raising step of then peeling the non-woven web off said smooth surface to generate a fiber-raised bulky state.
In this absorbent product, the highly absorbent composite body can be used as the backsheet as provided with water impermeability with the non-woven web containing the easy-to-heat-melt component being liquid impervious and water resistance and with the highly absorbent resin made in an integral composite with the fiber-raised surface of the non-woven web.
The present invention provides a method of manufacturing an absorbent product comprising the steps of:
adhering non-woven web with a surface layer portion existent on the surface containing an easy-to-heat-melt component having a property to become adhesive as heated to a smooth surface heated at the temperature at which said easy-to-heat-melt component exhibits a property to become adhesive with said surface layer portion in contact with said smooth surface, a fiber-raising step of then peeling the non-woven web off said smooth surface to generate a fiber-raised bulky state, and
forming non-woven web having a fiber-raised bulky structure on its surface, and a step of incorporating the non-woven web obtained in the previous step into an absorbent product.
According to the present invention, since a non-woven web with a surface layer portion disposed on its surface containing an easy-to-heat-melt component having a property to be adhesive as heated is adhered to a smooth surface heated to a temperature at which the easy-to-heat-melt component becomes adhesive in contact with the surface layer portion, and peeled off the smooth surface so that a fiber-raised bulky state is generated, the non-woven web can be fed as being made bulky directly connected to a disposable diaper making machine so that the non-woven web as it is can be used as a component material of a diaper whereby the method of making a diaper can be simplified equipment-wise and process-wise and the speed of the diaper making line can be made higher.
In addition, bulky non-woven fabric to be obtained by the methods of the present invention can be advantageously used as topsheet for an absorbent article and as transfer and acquisition layers to reinforce an absorbent body in such a variety of uses as contain absorbent products like disposable baby and incontinent diapers, feminine hygiene articles and medical care products.

Bulky non-woven fabric and method for manufacturing the same


A “peer-to-peer” hierarchical routing protocol—also referred to as Zone-based Hierarchical Link State Routing protocol (or “ZHLS”)—which incorporates location information into a novel “peer-to-peer” hierarchical routing approach. The network may be divided into non-overlapping zones. Aggregating nodes into zones conceals the detail of the network topology. Initially, each node knows its own position and therefore zone ID through a position determination unit, such as a Global Positioning System (GPS). After the network is established, each node knows the low level (node level) topology about node connectivity within its zone and the high level (zone level) topology about zone connectivity of the whole network. A packet may be forwarded by specifying the hierarchical address—zone ID and node ID—of a destination node in the packet header.

§ 2.1 Field of the Invention
The present invention concerns communicating information in a mobile ad hoc network. More specifically, the present invention concerns determining a state of a node in an ad hoc network, determining a topological state of the ad hoc network and/or using the determined node and network topology states to route (e.g., forward) communications to a destination node.
§ 2.2 Related Art
The present invention may be used in a mobile ad hoc network environment. Although mobile ad hoc networks are known to those skilled in the art, they are introduced in § 2.2.1 for the reader's convenience. Then, § 2.2.2 introduces known network architectures and routing protocols, as well as disadvantages and limitations of such known architectures and protocols as perceived by the inventors. Finally, § 2.2.3 introduces needs that have not been met by such known architectures and protocols.
§ 2.2.1 Mobile Ad Hoc Networks
As introduced above, the present invention may operate in the environment of a mobile ad hoc network. A mobile ad hoc network is a self-organizing and rapidly deployable network in which neither a wired backbone nor a centralized control is needed. Thus, a mobile ad hoc network is adaptable to the highly dynamic topology resulting from the mobility of network nodes and changing propagation conditions. The nodes of a mobile ad hoc network may communicate with one another over scarce wireless channels in a multi-hop manner. Thus, in addition to performing transmission and reception functions, the mobile nodes may perform a routing (e.g., data or message forwarding) function.
Having introduced mobile ad hoc networks, known network architectures and routing protocols are introduced in § 2.2.2 below.
§ 2.2.2 Network Architectures and Routing Protocols
Since the routing protocol to be used in an ad hoc network is typically affected by the network architecture, various network architectures are introduced first in § 22.214.171.124 below. There are two (2) basic categories of network architectures—flat and hierarchical. Each is introduced below.
§ 22.214.171.124 An Overview of Known Network Architectures Used in Mobile Ad HOC Networks
In hierarchical network architectures (See, e.g., the hierarchical spine routing protocol discussed in the articles: B. Das and V. Bharghavan, "Routing in Ad-Hoc Networks Using Minimum Connected Dominating Sets," IEEE ICC'97, June 1997; and B. Das, R. Sivakumar and V. Bharghavan, "Routing in Ad Hoc Networks Using a Virtual Backbone," IEEE IC3N'97, September 1997, pp. 1–20.), details of the network topology are concealed by aggregating nodes into clusters, aggregating clusters into superclusters, and so on (See, e.g., the article [4] G. S. Lauer, "Packet-Radio Routing," M. E. Steenstrup, editors, Routing in Communications Networks, Prentice-Hall, 1995, pp. 375–379.). Some nodes serve as "cluster heads" and "gateway nodes". In this way, control messages may only have to be propagated within a cluster. Thus, such hierarchical architectures are advantageous in that they reduce the storage requirements and communications overhead in large wireless networks. However, the cluster head nodes and gateway nodes have a greater computation and communication burden than other nodes. This complicates mobility management. Further, by concentrating critical functions at cluster head nodes and gateway nodes, network reliability can be greatly affected by the reliability of a few critical nodes. The failure of such nodes can lead to catastrophic failure of the network.
In flat network architectures, all nodes carry the same responsibilities. Thus, such architectures avoid catastrophic failures and spread computational and storage burdens more fairly. Unfortunately, however, flat network architectures use bandwidth resources inefficiently since control messages are propagated globally, throughout the network. This limits the scalability of flat network architectures.
Having introduced the basic types of network architectures which may be used in a mobile ad hoc network, various routing protocols which may be used in a mobile ad hoc network are introduced in § 184.108.40.206 below.
§ 22.214.171.124 An Overview of Known Routing Protocols and Schemes Used in Mobile Ad Hoc Networks
There are two (2) basic categories of routing protocols—proactive versus reactive. Each is introduced below.
In proactive routing schemes, nodes continuously maintain complete routing information of the network. In this way, when a node needs to forward a packet, the route is available ahead of time (hence the term "proactive"). This scheme therefore avoids delays that would otherwise occur in searching for a route. Unfortunately, however, in highly dynamic (i.e., rapidly changing) network topologies, proactive routing schemes require a significant amount of scarce wireless communications resources (or bandwidth) to maintain current and complete routing information.
Proactive protocols such as the link state routing protocol (also referred to as "open shortest path first") (See, e.g., the article, R. Perlman, Interconnections: Bridges and Routers, Addison-Wesley, 1992, pp. 149–152 and pp. 205–233.) and the distance vector routing protocol (also referred to as "Bellman-Ford") (See, e.g., the article, R. Perlman, Interconnections: Bridges and Routers, Addison-Wesley, 1992, pp. 149–152 and pp. 205–233.) were not designed to work in mobile networks (See, e.g., the article, J. P. Macker and M. S. Corson, "Mobile Ad Hoc Networking and the IETF," ACM Mobile Comput. and Commun. Rev., Vol. 2, No. 1, January 1998, pp. 9–14.) The inventors believe that these protocols do not converge fast enough for networks having a rapidly changing topology. Other distance vector routing protocols, such as the destination-sequenced distance vector routing protocol (See, e.g., the article, C. E. Perkins and P. Bhagwat, "Highly Dynamic Destination-Sequenced Distance-Vector Routing (DSDV) for Mobile Computers," ACM Comput. Commun. Rev., Vol. 24, No. 4, (ACM SIGCOMM'94) October 1994, pp. 234–244.) and the wireless routing protocol (See, e.g., the article, S. Murthy and J. J. Garcia-Luna-Aceves, "An Efficient Routing Protocol for Wireless Networks," ACM Mobile Networks and Applications J., Vol. 1, No. 2, 1996, pp. 183–197.) were proposed to eliminate counting to infinity and looping problems of the distributed Bellman-Ford algorithm.
In reactive schemes, nodes only maintain routes to active destinations. A route search is needed for every new destination. Examples of reactive protocols include the ad hoc on demand distance vector routing protocol (See, e.g., the article, C. E. Perkins, "Ad Hoc On Demand Distance Vector (AODV) Routing," Internet Draft, November 1997.), the temporally-ordered routing algorithm (See, e.g., the article, V. D. Park and M. S. Corson, "A Highly Adaptive Distributed Routing Algorithm for Mobile Wireless Networks," IEEE INFOCOM'97, Kobe, Japan, April 1997.) and the dynamic source routing protocol (See, e.g., the article, D. B. Johnson and D. A. Maltz, "Dynamic Source Routing in Ad Hoc Wireless Networks," T. Imielinski and H. Korth, editors, Mobile Computing, Kluwer, 1996.). Although communication/overhead is reduced when reactive schemes are used instead of proactive schemes, unfortunately, communications are delayed due to route searching. Also, an active route may be broken, causing the need for a subsequent route search. This problem is exacerbated in networks having rapidly changing topologies.
Some routing protocols or schemes are basically hybrids of the proactive and reactive schemes. One example of such a hybrid routing protocol is referred to as the zone routing protocol (or "ZRP") (See, e.g., the articles: M. R. Pearlman and Z. J. Haas, "The Performance of the Zone Routing Protocol in Reconfigurable Wireless Networks," IEEE J. Select. Areas Commun., Vol. 17, No. 8, August 1999, pp. 1395–1414; Z. J. Haas and M. R. Pearlman, "The Performance of Query Control Scheme for the Zone Routing Protocol," ACM SIGCOMM'98, Vancouver, Canada, 1998; and Z. J. Haas, "The Zone Routing Protocol (ZRP) for Ad Hoc Networks," Internet Draft, November 1997.).
Other ad hoc routing protocols have been discussed (See, e.g., the articles: M. Gerla and J. T. Tsai, "Multicluster, Mobile, Multimedia Radio Network," ACM Wireless Networks, Vol. 1, No. 3, 1995, pp. 255–265; D. J. Baker, A. Ephremides and J. A. Flynn, "The Design and Simulation of a Mobile Radio Network with Distributed Control," IEEE J. Select. Areas Commun., Vol. SAC-2, No. 1, January 1984, pp. 226–237; A. Ephremides, J. E. Wieselthier and D. J. Baker, "A Design Concept for Reliable Mobile Radio Networks with Frequency Hopping Signaling," Proc. IEEE, Vol. 75, No. 1, January 1987, pp. 56–73; and J. Sharony, "An Architecture for Mobile Radio Networks with Dynamically Changing Topology Using Virtual Subnets," ACM Mobile Networks and Applications J., Vol. 1, No. 1, 1996, pp. 75–86.).
In the zone routing protocol (ZRP), each node proactively maintains the topological information within its routing zone (e.g., within a predefined distance) only. Thus, the zone routing protocol (ZRP) is proactive within a zone. For routing outside a node's routing zone, the zone routing protocol (ZRP) employs "bordercasting". "Bordercasting" exploits the structure of the routing zone by allowing a node to send messages to nodes on the boundary of its routing zone (such nodes may be referred to as "peripheral nodes") and by preventing non-peripheral nodes from accessing the messages. Routes are efficiently discovered by bordercasting a route query to all the source's peripheral nodes. These peripheral nodes, in turn, bordercast the query to their peripheral nodes if the destination node is not within the respective routing zones of the peripheral nodes, and so on. Once the destination node is found, a route reply is echoed back to the source node. Thus, the zone routing protocol (ZRP) is reactive with respect to destination nodes beyond a source node's zone. The routing path, which includes a list of peripheral nodes between the source and destination nodes, is stored in the header of a packet(s) or cached in the queried peripheral nodes. Unfortunately, any change in the peripheral nodes gives rise to the need to discover another route.
Other articles of interest may include: L. Kleinrock and F. Kamoun, "Hierarchical Routing for Large Networks: Performance Evaluation and Optimization," Computer Networks, Vol. 1, No. 3, 1977, pp. 155–174; J. Behrens and J. J. Garcia-Luna-Aceves, "Hierarchical Routing Using Link Vectors," IEEE INFOCOM'98, San Francisco, Calif., March 1998; UCLA Parallel Computing Lab, Maisie User Manual Release 2.2, December 1995; J. Short, R. Bagrodia, L. Kleinrock, "Mobile Wireless Network System Simulation," Proc. ACM Mobile Commun. Network. Conf., Berkeley, Calif., November 1995; and M. Joa-Ng, "Routing Protocol and Medium Access Protocol for Mobile Ad Hoc Networks," Ph.D. dissertation, Department of Electrical Engineering, Polytechnic University, Brooklyn, 1999.
§ 2.2.3 Unmet Needs
In view of the foregoing, there is a need for an improved routing protocol for used in ad hoc networks. The routing protocol should use less bandwidth than purely proactive routing schemes, should provide faster route determination that purely reactive routing schemes, and should better adapt to changing network topology as well as incur less location search overhead than hybrid routing schemes.

Methods and apparatus for routing in a mobile ad hoc network


An improved rim for a mouthpiece for a plurality of non-French horn labrosone brass musical instruments. The improved rim has a rim width having a predetermined width measurement as a smallest width dimension taken of an outer edge, a crown, and an inner edge of the improved rim, where the rim width can be a same width as a playing surface of the improved rim, where the playing surface is a width of the improved rim engaged by a musician's lips. Also provided are improved rims removably or permanently affixed to the mouthpiece.

Field of the Invention
The present invention pertains to the field of mouthpieces for non-French horn labrosone brass musical instruments, specifically an improved mouthpiece rim for brass instruments such as tubas, trumpets, euphoniums, and trombones.
Background Art
A musical brass instrument produces sound by the sympathetic vibration of air. A sympathetic vibration is a harmonic phenomenon wherein a formerly passive vibratory body responds to external vibrations to which it has a harmonic likeness, and in the case of a brass instrument such as a trumpet, sound is produced by sympathetic vibration of air in a tubular resonator, for instance, a trumpet mouthpiece, in sympathy with the vibration of the player's lips. Brass instruments are thus also referred to as labrosones, literally meaning "lip-vibrated instruments".
The player's ability to control the sound produced by the instrument thus is critically dependent on the player's embouchure control, specifically, the agility and flexibility of the player's lips engaging the mouthpiece of the instrument, which depends at least partially on the physical characteristics of the mouthpiece rim with which the player's lips engage.
Historically, the French horn was the first musical instrument in the brass family of instruments to be used consistently by composers in the early 1700s in orchestras, and its mouthpiece was apparently copied and repeated for all succeeding orchestral brass family instrument mouthpieces by expanding its relative size based on the different sized instruments. This resulted in a homogenous look for brass instrument family mouthpieces, but unfortunately, a resized French horn mouthpiece for a tuba, for instance, results in a mouthpiece with a fat and unwieldy rim that causes the tubaist to lose essential agility and flexibility. Non-French horn playing musicians, such as tubaists and trombonists, all suffer from the shape and size of the mouthpiece rims for those instruments: the French horn mouthpiece shape is truly only suitable for the French horn mouthpiece itself. The configuration of mouthpiece rims for brass instruments other than for French horns thus are apparently more a function and result of history and visual appeal rather than actual performance enhancement value to the players of those instruments.
What is needed is an improved mouthpiece rim for non-French horn labrosone brass instruments whose shape and size maximizes playing agility, and flexibility, and reduces to the lowest possible degree the lips dragging, sticking, or catching on the rim. Additionally, the improved rim provides a more suitable container for the player's lips, as opposed to mashing them down or unduly pressing on them.

Mouthpiece rim for non-french horn labrosone musical brass instruments


The present invention is a process for reversibly absorbing acid gases, such as CO.sub.2, H.sub.2 S, SO.sub.2, HCN and the like from gas mixtures. The gas mixture containing one or more of these acid gases is contacted with a hydrated salt of the composition EQU A.sub.x.sup.m+ B.sub.y.sup.n-.rH.sub.2 O. wherein A.sup.m+ is a cation, B.sup.n- is the conjugate base of a weak acid having a pKa corresponding to an ionization constant of the acid greater than 3 as measured in dilute aqueous solution, m and n are independently integers from 1-4, x and y are integers such that the ratio of x to y provides a neutral salt and r is any number greater than zero up to the maximum number of moles of water which can be bound to the salt. The salt hydrate reversibly absorbs the acid gas from the gas mixture.

Prior art CO.sub.2 absorbent systems generally fall into one of two categories: (1) amines or (2) aqueous salt solutions.
A variety of amines, mostly alkanolamines, are used as CO.sub.2 absorbents; see Hydrocarbon Processing, 57-80 (April 1988). Primary and secondary amines, such as monoethanolamine (MEA) and diethanolamine (DEA), react with CO.sub.2 to form carbamates in accordance with the following reaction: EQU 2RNH.sub.2 +CO.sub.2 .revreaction.RNHCO.sub.2.sup.- +RNH.sub.3.sup.+
Since carbamates are relatively stable, heating is required to regenerate the CO.sub.2 -free absorbent. Typical heats of reaction of amines with CO.sub.2 are relatively high, 10-20 kcal/mole CO.sub.2. Tertiary amines, such as triethanolamine (TEA) and methyldiethanolamine (MDEA), cannot form carbamates. Such amines generate hydroxide in aqueous solutions and hydroxide subsequently reacts with CO.sub.2 to give HCO.sub.3.sup.- and/or CO.sub.3.sup.2-. The heats of reaction of CO.sub.2 with tertiary amines are less than those of primary and secondary amines and less energy is needed to desorb CO.sub.2 from tertiary amine solutions.
Recently, the use of sterically hindered amines as CO.sub.2 absorbents was reported by Nirula, S. C.; Ashraf, M. SRI International Report No. 180 (1987). Due to steric hinderance at the amine nitrogen, the resulting carbamate is less stable than that of an unhindered amine, resulting in absorption capacities and rates greater than those of conventional amines. Conventional amines have capacities of only 0.5 mole CO.sub.2 /mole amine except at quite high pressures. Two moles of amine are necessary to form one mole of carbamate. Since the carbamate is stable, hydrolysis to HCO.sub.3.sup.- and protonated amine does not occur readily. By contrast, the unstable carbamate of a hindered amine is readily hydrolyzed and a maximum capacity of 1.0 mole CO.sub.2 /mole amine can be obtained.
The absorption of CO.sub.2 using aqueous solutions of strongly alkaline salts has been practiced for over 50 years and numerous reviews of the subject are available, see Encyclopedia of Chemical Processing and Design McKetta, J. J. Editor Vol. 6, p 292-310 (1978). The most commonly used salts are sodium and potassium carbonate, phosphate, borate, arsenite, and phenolate. The common use of potassium carbonate at relatively high temperatures for both absorption and desorption led to the hot potassium carbonate or hot pot process (HPC) in the early 1950s. The addition of activators or catalysts to enhance the rates of absorption and desorption and of corrosion inhibitors followed.
Several processes have been developed which use aqueous potassium carbonate with added activators (e.g. alkanolamines) and corrosion inhibitors. In one well known process, the Giammarco-Vetrocoke process, activators such as glycine, arsenic trioxide, and selenous acid are used. The Alkazid process uses aqueous solutions of potassium methylaminopropionate or, in some cases, sodium phenolate. The SRI International report cited above also teaches the use of sterically hindered amines as activators for potassium carbonate solutions. In all of the above aqueous salt processes, a strongly alkaline salt results in a high concentration of hydroxide. Reaction of CO.sub.2 with hydroxide leads to bicarbonate and/or carbonate. CO.sub.2 is desorbed by decomposition of bicarbonate which, at high hydroxide concentrations, requires heating.
Processes using strongly alkaline amino acid salts have also been reported. Amino acid salts can also react with CO.sub.2 to form carbamates. Guyer and Purner, Helv. Chim. Acta 21, 1337-1345 (1938), evaluated solutions of the sodium and potassium salts of glycine and alanine as CO.sub.2 absorbents. CO.sub.2 desorption required heating. U.S. Pat. No. 3,042,483 describes the use of concentrated aqueous solutions of salts of amino acids as CO.sub.2 absorbents. In particular, salts of taurine and substituted taurines, glycine, alanine, and sarcosine are claimed as absorbents. Each absorbent is either a primary or secondary amine capable of carbamate formation. Heat is required for desorption. German Pat. No. 2,605,618 describes the use of aqueous solutions of potassium methylaminopropionate to absorb CO.sub.2 from air. The absorbent is regenerated by steam stripping. South African Pat. No. 7,603,420 reports the use of aqueous solutions of alkali metal salts of N-dialkylaminomonocarboxylic acids as CO.sub.2 absorbents between 20.degree. and 60.degree. C. CO.sub.2 is removed under reduced pressure and, optionally, heating. Japanese Pat. No. 61-101244 describes the preparation of an absorbent consisting of an alkali metal salt of N-methylalanine support on a porous material (e.g. alumina). The supported salt is capable of absorbing CO.sub.2 in closed spaces, apparently via hydrolysis and formation of K.sub.2 CO.sub.3. The absorbent is regenerated by heating up to 200.degree. C. with no reported salt decomposition.
A number of reports have been written describing the solubility of CO.sub.2 in aqueous solutions of weakly alkaline salts. The solubility of CO.sub.2 in aqueous solutions of the sodium salts of succinic, oxalic, and malonic acids, potassium chromate, potassium fluoride, borax, ammonium molybdate, and others were determined to obtain equilibrium constants of weak acids. As reported in Solubilities of Inorganic and Metal-Organic Compounds, Linke, W. F. Editor, Vol. I (1958), the CO.sub.2 solubilities are somewhat greater than those of aqueous solutions containing neutral salts. For example, at 30.degree. C. the solubility of CO.sub.2 in 1.19M KF is 0.14M versus that in water, 0.032M. Fr. Pat. No. 1130145 describes the use of aqueous solutions of K.sub.2 HPO.sub.4 to absorb CO.sub.2 and H.sub.2 S. The absorbent was regenerated by blowing with an inert gas or by application of a slight vacuum. Fr. Pat. No. 1135262 describes the use of weakly basic salt solutions as absorbents. A salt containing the anion, A, of a weak acid is used and the following reaction occurs: EQU NaA+CO.sub.2 +H.sub.2 O.revreaction.AH+NaHCO.sub.3
1.5M solutions of Na.sub.2 HPO.sub.4 and Na.sub.2 CrO.sub.4 are cited as examples. Desorption of CO.sub.2 does not require heating. The first addition to this patent, addition No. 68,830 describes the use of 1.5M aqueous solutions of alkali metal and ethanolamine salts containing various anions, among them, sulfite, malate, succinate, and malonate. The best results were obtained for acids which results in pH of 4-5 and salts with pH of 9-10. In the second addition to the above patent, addition No. 71,112, a variation using aqueous potassium chromate is described where slight heating (to 50.degree. C.) is used for desorption. The above patents and additions also appeared as Brit. Pat. No. 831532.
Ger. Pat. No. 1177619 describes the use of aqueous solutions of alkali salts of heteropoly acids, where one is a weak acid and the other is a weak to medium strong acid, as CO.sub.2 absorbents. The absorbent can be regenerated by treating with air at 30.degree. C.
The kinetics of the reaction of CO.sub.2 with aqueous Na.sub.2 CrO.sub.4 has been investigated by R. Vaikunrm, et al. Ind. J. Tech. 16 379-383 (1978). The reaction generates HCO.sub.3.sup.- and Cr.sub.2 O.sub.7.sup.2- and is second order in chromate. Belton et al. J. Inorg. Nucl. Chem. 43, 614-615 (1981) reported that the reaction of CO.sub.2 with solid Na.sub.3 PO.sub.4 .cndot.11H.sub.2 O results in the apparently irreversible formation of Na.sub.2 HPO.sub.4 .cndot.7H.sub.2 O and NaHCO.sub.3.
U.S. Pat. Nos. 4,235,607 and 4,239,510.sup.27 describe a method for purification of natural gas by removal of CO.sub.2. The absorbent is sea water and the separation apparatus is constructed near the ocean floor. CO.sub.2 rich sea water is simply discharge without regeneration.
U.S. Pat. No. 4,472,283 reports that retardation of the loss of CO.sub.2 from circulating water can be obtained by addition of less than 50 ppm of quaternary ammonium salts of chloride or bromide. The addition of such salts, however, appears to have no effects on the solubility of CO.sub.2 in water.
Seel, et al. in Angew. Chem., Vol. 67 No. 1. pp 32-33 (1955) report the formation of adducts of SO.sub.2 with anhydrous salts such as (CH.sub.2).sub.4 NF, KF, NaF and RbF.

Use of salt hydrates as reversible absorbents of acid gases


An electric system includes a local power controller and solar panel system that includes a plurality of solar modules on one or more branch circuits. A method for commissioning the electric system includes an installer using a commissioning device to send and receive information from a remote system and the local power controller performing an automatic self-test of the electric system. The results of the self-test may be packaged with photographs and measurements of the electric system and sent to a remote system where an inspector can inspect the electric system remotely. After receiving approval by the inspector, the local power controller may automatically activate each branch circuit of the electric system and thus enabling the electric system to generate electricity.

Photovoltaic (PV) cells, commonly known as solar cells, are devices for conversion of solar radiation into electrical energy. Generally, solar radiation impinging on the surface of, and entering into, the substrate of a solar cell creates electron and hole pairs in the bulk of the substrate. The electron and hole pairs migrate to p-doped and n-doped regions in the substrate, thereby creating a voltage differential between the doped regions. The doped regions are connected to the conductive regions on the solar cell to direct an electrical current from the cell to an external circuit. When PV cells are combined in an array such as a PV module, the electrical energy collected from all of the PV cells can be combined in series and parallel arrangements to provide power with a certain voltage and current.
In addition to PV modules, PV module systems include additional hardware. Such hardware may include inverters, power meters, and PV module system controllers. When these PV modules and additional hardware are installed at a site (e.g., the roof of a building, a field, a carport, etc.) in many jurisdictions the system must be commissioned and approved by an inspector prior to operation. It may be advantageous to use portions of the PV module system to automate portions of the commissioning and inspection process and also facilitate communication with the inspector.

Automated commissioning and inspection for PV systems


A method for producing a nitride semiconductor device. The method comprises providing a substrate made of a material other than a nitride semiconductor. The material has a hexagonal crystal structure. An upper face of the substrate has at least one flat section. The method further comprises growing a first nitride semiconductor layer on the upper face of the substrate. The first nitride semiconductor layer is made of monocrystalline AlN. The first nitride semiconductor layer has an upper face that is a +c plane. The first nitride semiconductor layer has a thickness in a range of 10 nm to 100 nm. The method further comprises growing a second nitride semiconductor layer on the upper face of the first nitride semiconductor layer. The second nitride semiconductor layer is made of InXAlYGa1-X-YN (0≦X, 0≦Y, X+Y<1). In an initial stage of growing the second nitride semiconductor layer, micronuclei are formed in multiple locations on the upper face of the first nitride semiconductor layer such that a plurality of upside-down hexagonal pyramid-shaped or upside-down hexagonal frustum-shaped recesses separate the micronuclei above the at least one flat section of the upper face of the substrate. After the initial stage of growing, further growth is performed to reduce a size of the recesses until the recesses are substantially eliminated. The further growth is performed such that the recesses are substantially eliminated before a thickness of the second nitride semiconductor layer grows to 800 nm. The second nitride semiconductor layer is grown to have an upper face with at least one flat section.

1. Field of the Invention
The present disclosure relates to a nitride semiconductor device and a method for producing the same.
2. Description of Related Art
A conventional process for producing nitride semiconductor devices involves forming a buffer layer made of a nitride, such as AlN, which moderates lattice constant mismatch, on a sapphire substrate or the like, and further stacking a gallium nitride-based semiconductor by metalorganic chemical vapor deposition. Japanese Patent Application Publication No. 2006-080378 and Japanese Patent Application Publication No. 2013-065849, for example, each discloses a process for stacking, as buffer layers, a first buffer layer made of high carbon concentration AlN and a second buffer layer made of low carbon concentration AlN, and further stacking a defect-reducing layer made of undoped GaN for reducing crystal defects by metalorganic chemical vapor deposition. Japanese Patent Application Publication No. 2009-081406 discloses a process for forming a buffer layer made of AlN on a sapphire substrate by sputtering, and further stacking an undoped GaN layer as an underlayer by metalorganic chemical vapor deposition.

Nitride semiconductor device and method for producing the same


A method for selectively adjusting the duration of vacuum application to various stations of an insertion machine which ultimately inserts insertion material into an envelope.

This invention pertains to a method of operating insertion machines, and in particular such machines wherein a vacuum is used at various machine stations to ultimately insert material into an envelope.
U.S. Pat. No. 2,325,455 to A. H. Williams relates to a multi-station inserter which performs numerous functions including extracting an envelope from an envelope supply station and transporting it to an inserting station where the envelope is opened. The machine also extracts pieces of insert material from one or more insertion supply stations and transports the aggregate material so extracted to the inserting station where it is inserted into the envelope.
The inserter described above provides a pneumatic mechanism for handling insertion material at each insertion supply station. In this regard, a pair of vacuum cups at each station applies suction to a lowermost piece of vertically stacked material at the station in order to deflect the lowermost piece for extraction by a gripper jaw. Each pair of vacuum cups for each insertion supply station is ultimately connected to a single control valve which simultaneously governs the transmission of the vacuum through the pairs of vacuum cups at each insertion supply station. In this respect, the control valve is operated once during each operating cycle of the inserter machine.
In an analogous manner, the inserter provides a similar pneumatic mechanism at the envelope supply station to engage successive envelopes. A second similar control valve is also timed to the machine operating cycle; and applies a vacuum to similar vacuum cups at the envelope supply station to engage a selected envelope.
In addition to the above-described inserter features, pneumatic means are also provided at the inserting station to draw front and back portions of each envelope away from one another in order to open the envelopes for reception of the aggregate insertion material. In this regard, vacuum cups are positioned above and below the plane of travel of the envelope at the inserting station; and, a third valve, timed with the operating cycle of the machine, operates the vacuum cups to open and close the envelope at the inserting station.
As indicated above, the vacuum supply is turned on or off at particular points, or increments, in the machine's operating cycle. These points are typically expressed in degrees of the machine's rotational cycle, each full cycle being 360.degree.. The vacuum may be applied to each particular type station only during a range of degrees, or a "window," which corresponds to an appropriate stage in the inserting machine.
Since all the insertion supply stations are governed by a single valve, it follows that all of the insertion supply stations have the same vacuum timing. This is true regardless of the number or nature of such stations.
In operating in the above-described manner it often would be advantageous to vary the vacuum timings. For example, in the case of the insertion supply stations it would generally be economical to change the timing from station to station depending on the characteristics of the insertion material being handled at the respective stations. By way of illustration, heavier insertion material stacked at one station may require a longer vacuum duration than lighter material stacked at another station. Other material characteristics which may prompt variable vacuum timing include the degree of material warpage and flexibility. Also, the relative conditions of the operating environment, such as the degree of humidity, may have an impact on the desirable duration of vaccum timing.
In the past it has been possible to vary vacuum timings for all the insertion supply stations collectively by having a mechanic internally adjust the timing of the appropriate control valve. Of course, all the supply stations connected to the valve would be uniformly affected by this change in the valve timing. Moreover, it is unfortunate that a machine operator is not able to make the timing adjustments, but, instead is dependent upon the availability and skill of a mechanic to make the mechanical adjustments to the valve.
Accordingly, an object of this invention is to provide a timing control system to selectively vary the application of vacuum to individual stations of an insertion machine.
An advantage of this invention is the capability for an operator to externally select the variable vacuum application for individual stations without the need for internal structural adjustment by a mechanic.
A further advantage of this invention is the conservative and economical use of a vacuum in an inserter depending on the variable operating considerations for different stations of the machine.


In some embodiments, a cluster computing system notifies a host system that a first path to a resource in the cluster computing system is optimized and that a second path to the resource is non-optimized. The resource is owned or managed by a first computing node of the cluster computing system. The first path includes the first computing node. The second path includes a second computing node and an intra-cluster connection between the second computing node and the first computing node. A disruption in the intra-cluster connection, which prevents communication between the first and second computing nodes via the intra-cluster connection, is identified. During a time period in which the disruption exists, the host system is notified that the first path is optimized and that the second path is unavailable, and input/output operations between the host system and the resource via the first path are continued.

Clustered computing systems can be used to reliably store data, host applications, and otherwise provide reliable storage. In a clustered computing system, two or more cluster nodes are connected in a distributed architecture, where the cluster nodes operate in a coordinated manner to respond to requests from host systems (e.g., end-user computing devices, external distributed computing systems, etc.). In a clustered computing system used to implement a distributed storage system, each cluster node may be a storage controller that is used to manage physical or logical storage volumes. Two or more cluster nodes are communicatively coupled to form a cluster. Each of the nodes in the cluster can communicate with the other nodes in the cluster.
A clustered architecture allows convenient scaling through the addition of more cluster nodes, which are capable of communicating with each other. In some cases, a storage cluster may present a single system image of stored data to hosts and administrators. For example, from the perspective of the host system that accesses a distributed storage area network ("SAN") environment, a given cluster may appear as a single logical unit, which can be identified by a logical unit number ("LUN"). The host system is not aware of the existence of logical sub-units of the distributed LUN (e.g., nodes in the cluster represented as the LUN). Thus, if a data operation in the SAN involves access to a particular logical sub-unit, this data operation and the actual location of the data is transparent to the host system.
However, as the number of nodes increases, maintaining a consistent single cluster configuration across the cluster nodes of the cluster becomes a challenge, since management and control operations may be performed on multiple nodes simultaneously. Thus, the consistency of the cluster configuration may be negatively impacted if communications between cluster nodes experiences intermittent failures.
For example, communication problems within a cluster can cause nodes that have lost connectivity with the rest of the cluster to become unresponsive. This can result in one or more partitions of the cluster. A partition is a condition in which not all of the nodes in a cluster can communicate with one other. For example, a node in a subset (i.e., a partition) of the nodes may only be able to communicate with other nodes in the subset. Nodes within a partition can maintain connectivity between each other. But the nodes within a first partition cannot be accessed via nodes of a second partition. This can result in a "split brain" configuration, in which one or more nodes in a cluster may operate autonomously from other nodes rather than all cluster nodes operating in a coordinated manner.
In some cases, a quorum-based fencing algorithm can be used to reduce the negative impacts associated with a split-brain configuration. For example, a "quorum" of nodes (i.e., a partition having the largest number of nodes in communication with one another) can be selected as the "active" partition. Out-of-quorum nodes can be fenced by preventing host systems or other devices from accessing resources (e.g., logical storage units) that are owned or managed by the out-of-quorum nodes. But using a quorum-based procedure for selecting an active partition may not properly account for certain in-use resources being owned or managed by an out-of-quorum node. For example, from the perspective of a host system, the fenced node whose access is blocked (i.e., the out-of-quorum node) may still have active logical interfaces that have been used by the host system to access a logical storage unit. The host system therefore expects to be able to access data from one or more logical storage unit owned by the fenced node. Thus, existing quorum-based solutions may reduce the availability of cluster-managed resources to host systems.
With respect to these and other considerations, improvements are desirable for managing the availability of resources in a distributed storage environment or other clustered computing system that has experienced a partition or other intra-cluster communication disruption.

Location-based resource availability management in a partitioned distributed storage environment


A pull down roof rack comprising a pair of parallel fixed rails secured to the roof of a vehicle, the fixed rails including a front fixed rail and a rear fixed rail, the rails adapted to extend from side to side of the vehicle each with a slot in its upper surface with rollers rotatable therein, and with their upper surfaces extending above the upper surfaces of the rail, each rail having lateral projections constituting bearing surfaces; two pair of movable rails slidable supported in pairs on the fixed rails and movable in pairs between a storage position where the movable rails are totally overlying the fixed rails and a loading position wherein the movable rails are slid outwardly from the center of the fixed rails, each movable rail having an upper surface, downwardly extending side surfaces and inwardly extending bearing surfaces located above and below the lateral projections of the fixed rails; and one pair of cross rails coupling each pair of movable rails, each pair of cross rails including a laterally exterior cross rail and a laterally interior cross rail.

1. Field of the Invention
The present invention relates to pull down utility roof rack and more particularly pertains to a roof rack which may be pulled down from the vehicle for easy loading.
2. Description of the Prior Art
The use of vehicle roof racks is known in the prior art. More specifically, roof racks heretofore devised and utilized for the purpose of transporting articles are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
The prior art discloses various types of roof racks for the transportation of articles on vehicles. Note U.S. Pat. No. 4,630,990 to Whiting wherein adjustability and removability is provided for a roof rack. A series of patents including U.S. Pat. Nos. 4,948,024 to Warner; 4,134,509 to Clement and 4,024,971 to Rohrer all disclose roof racks wherein movement thereof is effected by forward and rearward movement with respect to the vehicle. Lastly, lateral motion of a roof rack is disclosed in U.S. Pat. No. 4,887,750 to Dainty. According to that disclosure, however, straps in clamps associated with the sides of the vehicle are utilized with convenience being relatively limited as compared with the simplicity and reliability of the present invention.
In this respect, the roof rack according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of facilitating loading and unloading.
Therefore, it can be appreciated that there exists a continuing need for a new and improved roof rack which can be moved from the roof of a vehicle for easy loading and unloading. In this regard, the present invention substantially fulfills this need.


A twin-axle rail-bogie which incorporates a steering mechanism for positively steering one or both of the axles of the rail-bogie in proportion to the rotation of the frame of a structure supported by this rail-bogie. Steering is achieved by slidably mounting one of the axle end supporting assemblies onto the chassis of the bogie so that this assembly is longitudinally slidable and thus causes the one axle having one of its ends connected thereto to pivot forwards or rearwards out of its normal transverse position relative to the transversally opposite supporting assembly which holds the other end of the one axle and then acts as a pivot. An operating arm attached to the frame near the one supporting assembly is used for moving via a linking mechanism the one supporting assembly in such a direction as to cause the one axle held by this supporting assembly to pivot in the same direction but at an angle smaller than and proportional to the frame with respect to the chassis of the bogie.

The present invention is concerned with an improvement to the basic structure of a twin-axle rail-bogie.
More particularly, the invention is concerned with the incorporation of a steering mechanism to a twin-axle rail-bogie for steering one or both of the axles of this rail-bogie in proportion to the rotation of the frame of a structure supported by this rail-bogie. Such a supported structure may, in practice, be the platform of a conventional wagon or the front or rear end of a semi-trailer when the rail-bogie is adapted for hooking with semi-trailers to form a train for riding on rails.


An instruction-programmable processor, such as a digital signal processor, having a level one program cache memory and instruction buffer subsystem, is disclosed. The subsystem includes a loop cache subsystem that includes a branch cache register file for storing instruction opcodes corresponding to a sequence of fetch addresses beginning with a base address. If the fetch address issued by the instruction fetch unit is a hit relative to the loop cache subsystem loop cache control logic disables reads from program data RAM in favor of accesses to the branch cache register file. The branch cache register file can be loaded with opcodes beginning with each backward branch that is a miss relative to the branch cache register file and can be loaded with opcodes beginning with backward branches that are a miss relative to the branch cache register file and that have been executed twice in succession.

This invention is in the field of integrated circuits, and is more specifically directed to microprocessor and digital signal processor architecture.
As is well known in the art, advances in integrated circuit manufacturing technology, and in circuit design and architecture, have enabled the widespread deployment of instruction-programmable logic devices in a wide range of electronic systems. The scope of modern digital systems ranges in size from hand held systems, such as wireless telephones and personal digital assistants (PDAs), to large-scale computer systems, and ranges in functionality from embedded control devices to supercomputing applications. The programmable logic devices included in such systems may be general purpose devices, such as microprocessors, or devices that are particularly suited for certain types of instruction execution, such as digital signal processors (DSPs); for purposes of the following description, devices of these types will be referred to generically as central processing units, or CPUs.
As is fundamental in the art, CPUs are implemented in connection with random access memory (RAM) for the storage of data operands and results, and also for the storage of the program instructions that direct the desired data processing. In relatively large and complex systems, the necessary memory resources require the use of external RAM (relative to the CPU), considering that on-chip memory resources are necessarily quite limited. Of course, the use of external memory generally results in reduced performance because of the overhead operations that are required for external memory access, and because of bandwidth limitations in the communication of data between external memory and the CPU. Additionally, the power consumed in the use of external memory is typically much greater than that required by on-chip memory in the CPU, primarily due to inter-chip signal driving requirements.
As a result, many modern microprocessor and DSP architectures now utilize cache memory systems to improve the performance and reduce the power consumption of the overall system. Fundamentally, cache memories are implemented by way of small high-speed memories that are "closer" to the CPU both physically (i.e., on-chip, or connected by way of a special short range bus such as a "backside" cache bus) and logically (i.e., not requiring the use of general interface circuitry, bus mastering, and the like). The cache memory stores data and instruction codes for which the CPU has a relatively high likelihood of accessing, based on certain assumptions. For example, many cache memories rely on an assumption that data operands and instruction opcodes are often accessed in sequence, in which case the associated CPU loads cache memories in blocks (i.e., cache lines) based upon a fetched memory address. Accesses to cache are typically carried out by the CPU comparing the memory address of a data operand or instruction to be fetched with the addresses of the current entries in the cache, to determine whether the target of the fetch may be retrieved from the cache or must instead be accessed from the external memory. Many strategies for the storage, access, and updating of cache memories, as well as the arrangement of cache memories into multiple levels, are well known in the art.
Many modern CPU architectures, particularly those of the Harvard architecture class in which data and program memory are separate from one another, include separate cache memories for data and instructions. Indeed, the term Harvard architecture is now often used in connection with CPUs having a single main memory but having separate data and instruction caches. This separation of data and instruction caches takes advantage of the different data paths, and perhaps different points in the instruction pipeline, by way of which instructions and data operands are fetched, thus providing efficient cache usage, at least at a lower level (e.g., level 1 cache).
Even with the provision of a separate instruction cache, the determination of which instructions are to be stored in the instruction cache may vary, in efforts toward maximizing the cache "hit" rate (i.e., the percentage of fetches made from the cache). Of course, a high cache hit rate will improve the performance of the CPU and the power efficiency of the system. Other factors beside cache hit rate are important in this regard, however; for example, significant power dissipation may result from frequent reloading of the cache from memory.
By way of background, prior CPUs include a "repeat block" instruction in their instruction set, in response to which the CPU loads an instruction loop buffer with the indicated block. An example of such a prior CPU is the 320C54x family of digital signal processors available from Texas Instruments Incorporated.
Another conventional approach for utilizing an instruction cache is described in U.S. Pat. No. 5,579,493, in which the program being executed by the CPU includes a "repeat" instruction that identifies a module of the program that is to be repetitively executed. In this U.S. Pat. No. 5,579,493, the repeated block of instructions is stored in an instruction buffer, permitting fetches of the identified instructions from the instruction buffer rather than from memory, thus saving power. However, this approach also requires the use of a special instruction (the "repeat" instruction), which of course renders the use of the feature non-transparent to the programmer.
By way of further background, another conventional instruction cache approach is described in U.S. Pat. No. 4,626,988. This approach stores each fetched instruction in an instruction fetch look-aside buffer. Upon execution of a loop, the instruction fetch unit enters a loop mode, in which instructions are fetched from the buffer. However, each fetched instruction must be stored in the buffer, in preparation for possible loop mode entry.

Instruction-programmable processor with instruction loop cache


An electrophotographic photosensitive member has, in this order, a support, a photosensitive layer and a protective layer. The thickness d (xcexcm) of the protective layer, the universal hardness Hu-1 (N/mm2) of the protective layer, and the universal hardness Hu-2 (N/mm2) of the photosensitive layer after peeling off the protective layer satisfy the following expression (1):

1. Field of the Invention
This invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.
2. Related Background Art
Electrophotographic photosensitive members are repeatedly put to means for charging, exposure, development, transfer, cleaning and charge elimination. An electrostatic latent image formed upon charging and exposure is made into a toner image by the use of a fine-particle developer called a toner. This toner image is further transferred to a transfer medium such as paper by a transfer means, where the toner of the toner image is not all transferred, but partly remains on the surface of the photosensitive member.
The remaining toner (residual toner) is removed by a cleaner, or, on account of the advancement of cleanerless techniques in recent years, the residual toner is collected by what is called a cleaning-at-development system in which any independent cleaning means is not provided and the residual toner is collected through a developing means.
Electrophotographic photosensitive members, to which electrical and mechanical external forces as stated above are directly applied, are also required to have durability to such forces. Stated specifically, they are required to have durability to the occurrence of surface wear and scratches due to friction and durability to the deterioration of surface layer that is caused by adhesion of active substances such as ozone and NOx generated at the time of charging.
To meet such requirements imposed on electrophotographic photosensitive members, it has been attempted to provide protective layers of various types. In particular, protective layers composed chiefly of resins have been proposed in a large number. For example, as disclosed in Japanese Patent Application Laid-open No. 57-30846, a protective layer is proposed which is formed of a resin to which a metal oxide is added as conductive particles so that its resistance can be controlled.
Such conductive particles are dispersed in the protective layer of an electrophotographic photosensitive member chiefly in order to control the electrical resistance of the protective layer itself to prevent residual potential from increasing in the photosensitive member as the electrophotographic process is repeatedly used. It is known that suitable resistance values of protective layers for electrophotographic photosensitive members are 1010 to 1015 xcexa9xc2x7cm. In respect of abrasion wear due to repeated used, it is advantageous for the mass ratio of the mass (P) of conductive particles to the mass (B) of binder resin, P/B, to be smaller, i.e., for the binder resin to be in a larger quantity than the conductive particles.
Meanwhile, in a protective layer containing a charge-transporting material, the mass ratio of the mass (D) of charge-transporting material to the mass (B) of binder resin, D/B, is about 2/1 to 1/2, in order for the layer to have a low residual potential. In general, its residual potential can be made smaller by making the value of D/B larger, but this may cause a great abrasion for the film of a protective layer, or, when a curable resin is used, the curing of the curable resin may be inhibited.
As stated above, in recent years studies are being made on how to improve the performance of electrophotographic photosensitive members with resort to protective layers. However, compared with the thickness of usual photosensitive layers which is tens of xcexcm, the thickness of protective layers is usually as small as a few xcexcm. Thus, in order to maintain the like durability, it is, of course, necessary for the protective layers to be more kept from being scratched and abraded. Accordingly, studies are being made on protective layers the resin of which is replaced with a curable resin, and efforts are made on how to make the layer harder and less abrasive. However, with progress of studies actually made taking note of only the hardness, it has been realized that although the layer is hard, it tends to be scratched to have a poor durability after all, or although it is not so hard, it is well balanced with abrasion wear to bring about an improvement in durability in total.
Too low hardness also makes the abrasion wear worse as a matter of course. Especially when continuing to use a layer having not so high hardness in spite of the use of a curable resin, black dots may occur if a reverse development system is used. Such black dots differ from black dots having ever come into question, and are caused neither by simple injection of holes from the support nor by generation of holes due to heat or electric field generated from a charge generation layer even at the initial stage. This has become apparent as a result of studies made by the present inventors. The real cause of such black dots has not been regretfully elucidated, but it has been realized at least that the black dots occur after extensive operation on thousands to tens of thousands of sheets when a photosensitive member is used which has the photosensitive layer and the protective layer on a conductive support and also that they occur when the protective layer has a specific hardness.
An object of the present invention is to provide an electrophotographic photosensitive member which has a surface layer free of cracks and having a superior durability to the occurrence of surface wear and scratches, does not cause black dots upon running (or extensive operation) which are inherent in the electrophotographic photosensitive member having the above protective layer, and can maintain a high-grade image quality; and also to provide a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
To achieve the above object, the present invention provides an electrophotographic photosensitive member comprising a support, and a photosensitive layer and a protective layer which have been formed on the support in this order;
a thickness d (xcexcm) of the protective layer, a universal hardness Hu-1 (N/mm2) of the protective layer, and a universal hardness Hu-2 (N/mm2) of the photosensitive layer as measured after the protective layer is peeled off satisfying the following expression (1):
5.8xc3x97d+Hu-2xe2x89xa6Hu-1xe2x89xa6xe2x88x922.45xc3x97d2+44.4xc3x97d+Hu-2xe2x80x83xe2x80x83(1).
The present invention also provides a process cartridge comprising an electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means;
the electrophotographic photosensitive member and at least one means being supported as one unit and being detachably mountable on the main body of an electrophotographic apparatus; and
the electrophotographic photosensitive member comprising a support, and a photosensitive layer and a protective layer which have been formed on the support in this order;
a thickness d (xcexcm) of the protective layer, a universal hardness Hu-1 (N/mm2) of the protective layer, and a universal hardness Hu-2 (N/mm2) of the photosensitive layer as measured after the protective layer is peeled off satisfying the following expression (1):
5.8xc3x97d+Hu-2xe2x89xa6Hu-1xe2x89xa6xe2x88x922.45xc3x97d2+44.4xc3x97d+Hu-2xe2x80x83xe2x80x83(1).
The present invention still also provides an electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging means, an exposure means, a developing means and a transfer means;
the electrophotographic photosensitive member comprising a support, and a photosensitive layer and a protective layer which have been formed on the support in this order;
a thickness d (xcexcm) of the protective layer, a universal hardness Hu-1 (N/mm2) of the protective layer, and a universal hardness Hu-2 (N/mm2) of the photosensitive layer as measured after the protective layer is peeled off satisfying the following expression (1):
5.8xc3x97d+Hu-2xe2x89xa6Hu-1xe2x89xa6xe2x88x922.45xc3x97d2+44.4xc3x97d+Hu-2xe2x80x83xe2x80x83(1).

Electrophotographic photosensitive member, and process cartridge and electrophotographic apparatus having the electrophotographic photosensitive member

Abstract: Also disclosed are a process cartridge and an electrophotographic apparatus which have the above electrophotographic photosensitive member.


A method and apparatus for recovering the timing frequency in a modulated data signal receiver containing a timing frequency generator, by demodulating a received signal with the aid of carriers which are shifted by 90.degree. in phase relative to one another to form two demodulation products, forming the sum of the squares of the two demodulation products, and determining changes in the value of that sum with respect to time to provide characteristic values which determine the adjustment criterion for the timing frequency generator.

The present invention relates to derivation, or recovery, of the timing frequency, or symbol rate, in modulated data signal receivers in which demodulation is effected with the aid of two carriers which are shifted by 90.degree. relative to one another.
The receiver timing frequency can be recovered by various different procedures. For example, by means of a criterion obtained from a received signal, resonators can be excited or control loops can be corrected. A process for stepped synchronization with controllable divider chains is described in German Pat. No. 1,287,609 in which use is made of a phase control loop which is advantageous when dealing with brief losses of clock pulse information since the clock pulse generation continues with a high degree of precision if quartz oscillators are used. However, phase control loops, and even resonators, require for their control a criterion which indicates the desired phase position of the clock pulse. A technique for achieving this is described by R. D. Gitlin and F. J. Hayes in Timing Recovery and Scramblers in Data Transmission, THE BELL SYSTEM TECHNICAL JOURNAL, Vol. 54, No. 3, March 1975, at pp. 569-593. In the method described therein, the timing frequency is acquired from the envelope of the received signal. This process, however, is very expensive as it requires additional filters. Furthermore, when operating with nearly identical carrier and timing frequencies, the beat frequency must be converted in order to obtain the envelope curve. In addition, this process is highly sensitive to noise and distortions.
In the German periodical "Nachrichtentechnische Fachberichte", [Communication Engineering Reports], Vol. 37, 1969, Datenuebertragung [Data Transmission] VDE Verlag, Berlin, at pp. 271-279, in an article entitled "A Four-Phase Modem for 2400 Bits per Second" by J. Haas, there is described a method in which the timing frequency is derived directly from the demodulated signals. This method works well only if applied with differentially coherent demodulation. If coherent demodulation is effected by means of a recovered carrier, the control circuit may become dependent on the timing frequency and the carrier, which will lead to reduced adjustment speeds.


A vehicle proximity annunciator device reduces an occurrence of a pop noise without an additional circuit changing an output of a power amplifier. A capacitor is located between a connection point connecting multiple resistances generating a reference voltage and a ground terminal. The capacitor causes a rise-up time of the reference voltage to delay at a start of power supply to a power source terminal. A sound emission signal is increased at substantially a same level of the reference voltage so that a variation of a differential voltage between the reference voltage and the sound emission signal falls in a pre-determined range.

An electric vehicle, which is equipped with only an electric motor as driving source, emits a significantly low traveling sound when traveling at a low speed. Similarly a hybrid vehicle, which is equipped with an electric motor and an internal combustion engine as driving sources, also emits a significantly low traveling sound when traveling at a low speed only with driving power of the electric motor. Accordingly, a pedestrian or other person may not notice proximity of such a vehicle.
In consideration of this, a vehicle proximity annunciator device equipped in such a low noise vehicle is used practically, for example, as described in JP-A-2012-17071. The vehicle proximity annunciator device generates an annunciation sound signal of which a frequency changes according to a vehicle speed and emits an annunciation sound based on the annunciation sound signal to the outside of the vehicle to notify a pedestrian and the like around the vehicle of existence of the vehicle.
The vehicle proximity annunciator device as described above begins to operate when the vehicle proximity annunciator device is supplied with electric power via an ignition (IG) power supply of a vehicle battery according to an operation of a starter switch and the like. When the vehicle proximity annunciator device begins to operate, a pop noise such as a pop and the like is generated in a speaker causes a reduction of commercial value.


According to an example aspect of the present invention, there is provided a method for tracking and determining the position of an object, the method comprising determining a primary position indication based on signals received from an external positioning system and using said primary position indication to determine a first position of said object, recording acceleration data of a cyclically moving object using inertial sensor signals or accelerometer sensor signals and integrating said acceleration data over a selected period of time to determine a tilting of said cyclically moving part of the object relative to a horizontal plane, recording direction data of said moving object based on measuring an external magnetic field of the cyclically moving part of the object using a magnetometer sensor to determine an orientation of said cyclically moving part relative to the external magnetic field, computing the velocity of said moving object in any direction based on said inertial sensor signals or accelerometer sensor signals, determining a secondary position indication of said object based on said first position, said direction data and said velocity data, and using said secondary position indication to determine a second position of said object.

The signal from a GPS (Global Positioning System) sensor or other satellite-based navigation system located in a device carried by a person on the wrist or elsewhere on the body, has a very small bias error, i.e. a systematic error, but contains a great deal of noise. At a measurement frequency of 1 Hz with the person walking or running, the noise in a purely GPS-based speed measurement can be in the order of 20-30%, compared to the pure GPS signal.
Direction or speed data measured and estimated from sensors carried directly on the body of a person, contains usually less noise. However, large bias errors may be present in these measurement signals.
Sensor fusion means that first and second sensors may be based on different operating principles, but they are measuring the same physical variable. For example, horizontal speed can be measured using a satellite-positioning sensor or an acceleration sensor. Sensors that can be used in sensor fusion may be, for example, a GPS sensor, a magnetometer (compass), and acceleration sensors. With such sensors, the acceleration, speed and direction of a moving object may be measured and displayed on a mobile device, for example on the display of a wristop computer, a mobile telephone or any other portable device.
It is known from GB 2497153 to measure first and second physical variables with first and second sensors respectively, and to determine an estimate of a target variable by measuring a first physical variable. An error estimate is determined by measuring a second physical variable, and the estimate of the target variable is filtered with a strength that depends on the error estimate. However, during a loss of satellite signals, as may be the case in shadow areas such as in tunnels, backyards and mountain areas, where only a weak or non-detectable positioning signal strength exists, a satellite-based measurement may not be available at all.
Therefore, there is a need for a positioning system that delivers accurate and uninterrupted position data and other data derivable therefrom, under all circumstances. In view of the foregoing, it would be beneficial to provide a method and a system for tracking and determining the position of an object, which method and system are capable of providing uninterrupted position data and other data derivable therefrom.

Method and system for tracking and determining a position of an object


A cell structure for electrolyzer units and fuel cells, comprising an electrolyte-permeable diaphragm, one metallic, electrolyte-permeable electrode respectively on either side of the diaphragm, an electrically conductive bipolar cell partition respectively which bounds the cell, one electrically conductive structure respectively between the electrode and the cell partition which acts as an elastic spacer and current supply, and a frame construction which encloses the cell on the circumference side. The diaphragm is constructed as a flat plate, with layer-type electrodes resting directly on it and integrally connected with it. The cell partitions are constructed of sheet metal, if necessary, with spacers. The spaces between the electrodes and the cell partitions are at least partially filled with lamellar structures which are axially and perpendicularly fluid-permeable and rest against the electrodes. The lamellar structures consist of a plurality of wall elements which are arranged at a narrow distance and have interposed spacers.

The present invention relates to a cell structure for a plurality of electrolyzer units and fuel cells which are electrically and geometrically connected in series, particularly for the evolution of hydrogen and oxygen or for operation with hydrogen and oxygen.
The characteristic elements of such cells are a central diaphragm, electrodes on both sides of the diaphragm, bipolar cell partitions and elastically flexible spacers between the electrodes and the cell partitions. (There is also, of course, a frame which is of less interest in the present context.) The conditions in the boundary layers of adjacent elements (that is, mechanical connections, electrical contacts, possible relative movements, fluidic transitions, starting points for corrosion, etc.) are of great significance for the electrochemical and mechanical characteristics of the cell and thus of the electrolyzer unit and of the fuel cell, because they affect in particular its efficiency and the service life. For the purpose of obtaining a structure which is mechanically or structurally as simple, sturdy and durable as possible, while the cell voltages for a given current density are as low as possible, a preference exists for the so-called zero gap arrangement, in which the electrodes rest directly against the diaphragm, without any gap and without any spacers.
As disclosed in German Patent Document DE-OS 32 24 556, the diaphragm may consist of a metal netting coated with oxide ceramics, which affords relatively good stability characteristics. Moreover, German Patent Document DE-PS 37 43 354 teaches that the electrodes may consist of porously coated, catalytically activatable perforated plates, metal nettings or expanded metal elements. Where such electrode units are combined with a metal-netting-supported diaphragm, the risk exists, among others, that, as a result of frictional events, local overloading or corrosive events, the metal netting in the diaphragm can become partially exposed, which may lead to a shorting of the electrodes.
The best solution for the foreseeable future for a zero gap configuration seems to be a combination of the electrodes with the diaphragm to form an integral unit (EDE-plate=Electrode-Diaphragm-Electrode plate), which permits the diaphragm to be constructed in an unsupported manner (that is, without any inner metal nettings, etc.). The integration of these three functional elements takes place during manufacturing. The diaphragm is made from a ceramic blank, onto which the electrodes are applied in powder or paste form, by means of sintering or reductive sintering in the manner known to those skilled in the art. German Patent Document DE-OS 32 24 555 and the related European Published Patent Applications 0 297 315 and 0 297 316, for example, address the manufacture of such EDE-units.
In such EDE-composites, the electrodes virtually take over the support of the interposed diaphragm. Moreover, in tests it has been found that such EDE-plates can provide high current densities at low cell voltages and moderate cell temperatures.
In the spaces required, among other things, for electrolyte storage, between the electrodes of the EDE-plate and the bipolar cell partitions (that is, in the anode and cathode spaces), electrically conductive spacers are arranged which contact and center the EDE-plate. Preferably, elastically flexible elements, such as corrugated sheets, sheet metal strips or metal wool are used. It is also possible to mold the spaces into the cell partitions; for example, as naps which project axially to both sides. Such a construction is disclosed, for example, in European Patent Document EP-OS 0 340 820, albeit not for a zero-gap arrangement, but rather for a micro-gap arrangement with a narrow distance between the electrodes and the diaphragm, which is produced by additional non-conductive spacers in the electrodes.
Another known electrode structure having a zero-gap arrangement, but without forming a unit with the diaphragm, is composed of a lamellar structure in the form of a plurality of straight sheet metal strips arranged vertically and perpendicular to the diaphragm, at a narrow distance from one another, with interposed spacers. The prestressed zigzagging spacers are also made of sheet metal strips, and are disposed between the straight sheet metal strips. The spacers are arranged such that their zigzagging front edges contact the diaphragm along the whole electrode height. The distance between the straight sheet metal strips is dimensioned such that, while the number of layers is as small as possible, a sufficient circulation of fluids, such as the electrolyte is still possible. Because of the spacer arrangement, the main delivery direction extends horizontally, and perpendicular to the diaphragm. However, because of the contacting conditions between the parts, a perpendicular flow of the electrolyte or of the generated or fed gas is also possible. In addition, the gas generated by electrolysis can rise substantially unimpaired in the anode or cathode space kept free by spacers between the electric and the cell partition.
A disadvantage of this type of electrode, however, lies in the necessary filigree, high-expenditure structure. Moreover, tests with such electrodes have indicated that they are inferior to other zero gap arrangements with porous electrodes, particularly of the EDE-unit, in that they require higher cell voltages to achieve a given current density. Another disadvantage is the relatively intensive substance transport due to the delivery effect (electrolyte circulation, gas transport) in the spaces between the lamellae.
It is therefore an object of the present invention to provide a cell structure for electrolyzer units and fuel cells having a zero-gap arrangement, which permits a still higher efficiency, more favorable operating conditions and a longer service life.
This object is achieved according to the invention, in which a zero-gap arrangement with a plate-shaped diaphragm and electrolyte-permeable electrodes on both sides, is combined with a lamellar structure which fills out the electrode space at least partially and rests against the electrode, the lamellar structure being designed in the manner of the described electrode. The lamellar structure according to the invention has several functions. It serves as a mechanical spacer; that is, as a spring-elastic support of the electrodes and the diaphragm, which provides an optimal introduction and distribution of force. It also forms an electrical connection between the electrode and the cell partition, with a favorable current distribution and contact; and it promotes electrolyte circulation and gas transport by means of its delivery effect.
Tests of electrolyzer units having such combination of the zero-gap arrangement and the lamellar structure have shown that, in comparison to known EDE-units with spacers, given current densities and gas generation rates are reached with still lower cell voltages and significantly lower cell temperatures. In other words, the invention reduces the electric or chemical energy requirement, and improves the operating conditions as a whole, which has a positive effect in many respects. In an embodiment without additional spacers, the bipolar cell partitions can be constructed in a particularly simple and low-cost manner as flat plates made of sheet metal.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Cell structure for electrolyzer units and fuel cells


Apparatus and a corresponding method for processing a received data item comprising a received sequence number are provided. A set of sequence number entries are stored as an array and data item processing circuitry performs an access to only a selected entry in the array in dependence on the received sequence number. Each possible sequence number maps only to a single entry in the array. The access comprises performing an atomic check and update operation on a stored sequence number in the selected entry and the update comprises storing the received sequence number in the selected entry when the received sequence number is larger than the stored sequence number in the selected entry. Since only the selected entry in the array is accessed, the blocking of the array whilst the access is made is limited only to the selected entry and multiple concurrent accesses to the array can be made, allowing the process to readily scaled out to multiple parallel processes.

In a receiver which receives data items it may be necessary to ensure that an individual data item is only received once. As such the receiver may be provided with the capability to detect duplicate (also known as "replayed") data items, wherein the receiver makes reference to an identifier, such as a sequence number, associated with each data item, in order to determine if a newly received data item has in fact already been received by the receiver. In order to provide this functionality the receiver therefore needs to maintain a window of past sequence numbers against which a newly received sequence number can be checked.