A system and method for enabling a network switch to transmit queued packets to a device when opened by the device, and thus to utilize the Fibre Channel Arbitrated Loop (FC-AL) in full-duplex mode when possible. The switch may include a plurality of queues each associated with a device on the FC-AL for queuing incoming packets for the device. The switch may determine a next non-empty queue, open the device associated with the queue, and send packets to the device. The device may send packets to the switch concurrently with receiving packets from the switch, thus utilizing the FC-AL in full-duplex mode. When a device opens the switch to transmit packets to the switch, the switch may determine if there are packets for the device in the queue and, if so, send packets to the device concurrently with receiving packets from the device, thus utilizing the FC-AL in full-duplex mode.

1. Field of the Invention
The present invention generally relates to the field of network switches. More particularly, the present invention relates to a system and method that allows a network switch coupled to an arbitrated loop such as an Fibre Channel Arbitrated Loop (FC-AL) to transmit queued packets to a device on the arbitrated loop when opened by the device, and thus to utilize the arbitrated loop in full-duplex mode when possible.
2. Description of the Related Art
In enterprise computing environments, it is desirable and beneficial to have multiple servers able to directly access multiple storage devices to support high-bandwidth data transfers, system expansion, modularity, configuration flexibility, and optimization of resources. In conventional computing environments, such access is typically provided via file system level Local Area Network (LAN) connections, which operate at a fraction of the speed of direct storage connections. As such, access to storage systems is highly susceptible to bottlenecks.
Storage Area Networks (SANs) have been proposed as one method of solving this storage access bottleneck problem. By applying the networking paradigm to storage devices, SANs enable increased connectivity and bandwidth, sharing of resources, and configuration flexibility. SANs are typically implemented using Fibre Channel devices and Fibre Channel switches. Fibre Channel is a serial data transfer architecture designed for mass storage devices and other peripheral devices that require very high bandwidth.
Fibre Channel defines three topologies, namely Point-to-Point, Arbitrated Loop, and Fabric. Fibre Channel Arbitrated Loop (FC-AL) has become the most dominant Fibre Channel topology. FC-AL is capable of connecting up to 127 ports in a single network without the need of a fabric switch (also referred to herein as a network switch). However, a network switch may be installed at a port of an FC-AL (typically port 0) to interface the FC-AL to other FC-ALs, fabrics, etc. in a SAN. In an FC-AL, unlike the other two topologies, the media is shared among the devices, limiting each device's access. Unlike token-passing schemes, there is no limit on how long a device may retain control of an FC-AL. This demonstrates the "channel" aspect of Fibre Channel. There is, however, an optional Access Fairness Algorithm, which prohibits a device from arbitrating again until all other devices have had a chance to arbitrate.
Like most ring topologies, devices in an FC-AL may be connected to a central hub or concentrator. The cabling is easier to deal with, and the hub can usually determine when to insert or de-insert a device. Thus, a "bad" device or broken fiber (e.g. fiber optic cable) won't keep the entire network down.
Before an FC-AL is usable, it must be initialized so that each port obtains an Arbitrated Loop Physical Address (AL_PA), a dynamically assigned value by which the ports communicate. The AL_PA is a 1-byte value used in the Arbitrated Loop topology used to identify Loop Ports (L_Ports). L_Port is a generic term for any Fibre Channel port that supports the Arbitrated Loop topology. During initialization, a Loop master is selected that will control the process of AL_PA selection. If a network switch is present on the FC-AL, it will become Loop master; otherwise, the port with the numerically lowest Port Name will be selected as Loop master. Ports arbitrate for access to the Loop based on their AL_PA. Ports with lower AL_PAs have higher priority than those with higher AL_PAs.
In an FC-AL, when a device is ready to transmit data, it first must arbitrate and gain control of the Loop. It does this by transmitting an Arbitrate primitive signal, which includes the Arbitrated Loop Physical Address (AL_PA) of the device. Once a device receives its own Arbitrate primitive signal, it has gained control of the Loop and can now communicate with other devices by transmitting an Open primitive signal to a destination device. Once this happens, there exists a point-to-point communications channel between the two devices. All other devices in between the two devices simply repeat (e.g. retransmit) the data.
Fibre Channel flow control is based on a credit methodology where a source port must have a positive credit before transmitting a packet. The scheme works as follows when connected to an arbitrated loop. An arbitrated loop port receives (and provides) a BB_CREDIT value from (to) each device that they login to. This BB_CREDIT value represents the number of buffers that the port will have available when a new circuit is established. A port is allowed to transmit (upon establishing a new circuit), the number of data frames defined by BB_CREDIT without receiving R_RDY primitives. However, the port must then wait until R_RDY primitives have been received that equal the number of data frames transmitted. The port may then transmit a data frame only if the port has received more R_RDY primitives than transmitted data frames.
Note that a value of 0 is allowed for BB_CREDIT that indicates that the port cannot transmit more data frames than R_RDY primitives received. When a port supplies a positive value of BB_CREDIT, the port is guaranteeing that BB_CREDIT buffers will be available when the circuit is established. For a nonzero value, this implies that the circuit will not be closed unless there are BB_CREDIT buffers available to ensure that if another circuit is established immediately, the port will not be short of buffers.
FIG. 1A is a block diagram illustrating an exemplary topology of a Fibre Channel Arbitrated Loop (FC-AL) 702 coupled to a network 700 (e.g. SAN) via network switch 710. The connection to network 700 is typically to an FC point-to-point, FC fabric, or another FC-AL, which in turn may link to other FC topologies or alternatively may be bridged to other data transports (e.g. Ethernet, SCSI) that together make up the SAN. Six devices, including network switch 710 and devices 712A–712E, are shown in the FC-AL 702. Data flows in only one direction on the FC-AL 702, as illustrated by the direction of the arrows connecting the devices in the loop. Data sent from one device to another device on the FC-AL 702 must pass through any and all devices between the two devices in the downstream direction. For example, if device 712C needs to send data to device 712E, the data is first passed to device 712D, which retransmits the data to device 712E. Also note that the network switch may have other connections that are not shown.
FIG. 1B is a flow diagram illustrating packet flow in an FC-AL 702, and shows a hub 714 used to interconnect the devices at port 0 through port 5. In this example, a network switch at port 0 couples the FC-AL 702 to the network 700. Note that data on the FC-AL 702 as illustrated in FIG. 1B may flow in only one direction on the FC-AL 702, as illustrated by the direction of the arrows connecting the devices to the hub 714. Data sent from one port to a second port on the FC-AL 702 must pass through any and all ports between the two ports in the downstream direction. For example, if port 0 needs to send data to port 3, it first arbitrates to gain control of the loop, then opens the device at port 3, and then transmits the data (through the hub 714) to port 1. The data is then retransmitted through the hub to port 2, and then finally to port 3, which receives the data (without retransmitting).
Referring again to FIG. 1A, only one device can gain control of and hold the FC-AL 702 at a time. A device first arbitrates for the FC-AL 702. When the device gains control of the loop, it opens a second device. The first device may then send frames of data (also referred to as packets) to the second device. In some instances, if the second device has packets for the first device, it may send the packets to the first device via FC-AL 702 after being opened by the first device and while receiving packets from the first device. When two devices are transmitting to each other simultaneously, the FC-AL is operating in full-duplex mode. When a first device is transmitting to a second device, and the second device is not transmitting, the FC-AL is operating in half-duplex mode. Obviously, for maximizing bandwidth utilization of the fibre, it is advantageous for the FC-AL 702 to operate in full-duplex mode as much as possible.
Network switch 710 serves as an interface between FC-AL 702 and network 700. Network switch 700 may receive FC packets from a device 712 on the FC-AL 702 that are destined for one or more devices on network 700, and then may retransmit the packets on network 700 to the one or more devices. Network switch 700 may also receive packets from a device on network 700 and then route the packets to the destination device 712 of the packets on the FC-AL 702.
In connecting to devices on the FC-AL 702, network switch 710 behaves similarly to the other devices 712 on the FC-AL. Switch 710 must arbitrate for the loop and, when it gains control, open a device 712 to transmit to. Likewise, a device 712 may open network switch 710 after gaining control of the loop. Since network switch 710 may have to wait to gain control of the FC-AL 702 to transmit packets to a device 712, or conversely may have to wait to transmit packets from a device 712 on FC-AL 702 to a device on network 700, network switch 710 typically includes buffer memory for storing packets waiting to be transmitted.
FIG. 2 is a data flow diagram illustrating a prior art network switch 710 opening a device 712N on an FC-AL. At 730, network switch 710 first arbitrates for and gains control of the FC-AL, and then opens device 712N to begin transmitting incoming packet(s) 720 to the device. Packets 720 may have been previously received by fabric 710 from a source device on network 700. When network switch 710 opens device 712N, the device may have data to send to switch 710. Device 712N may transmit the data to switch 710 in outgoing packet(s) 722 while receiving the incoming packet(s) 720 from switch 710. Thus, the FC-AL may be utilized in full-duplex mode when network switch 710 opens a device 712.
FIG. 3 is a data flow diagram illustrating a prior art network switch being opened by a device. At 732, device 712N on an FC-AL first arbitrates for and gains control of the FC-AL, and then opens the network switch 710 to begin transmitting outgoing packet(s) 722 to network switch 710.
Network switch 710 may have data queued for device 712N when opened by the device. However, when opened by device 712N, network switch 710 is not able to determine if it has queued data for the device 712, or to transmit the queued data to the device 712N concurrent with receiving outgoing packets 722 from the device. Prior art network switches, when operating in full duplex mode, may be blocked from sending data because data for another device on the loop is "blocking" access, thus limiting the efficiency of use of bandwidth on the FC-AL in full duplex mode.
Frame Ordering and Network Switch Performance on an Arbitrated Loop
An arbitrated loop may generally be defined as a set of devices that are connected in a ring topology as in the example FC-AL shown in FIG. 1A. The arbitrated loop protocol requires all devices on the loop to arbitrate for control of the loop. A device will arbitrate for control of the loop when it has data frames it wishes to send to another device on the loop. The device, when it wins arbitration, will then establish a connection to the device it wishes to transfer data. After all desired data frames are transferred, the loop is "closed". The device that controls the loop may then give up the loop for arbitration or open another device to transfer data frames. The following summarizes the arbitrated loop process:
a) Arbitrate for control of the loop.
b) Wait to win arbitration.
c) Open a connection with the destination device when arbitration is won.
d) Exchange data frames with the destination device.
e) Close the connection.
f) Release the loop for arbitration OR repeat steps c–e
The loop is utilized for transferring data only during step c). The remaining steps represent protocol overhead that tends to reduce the overall usable bandwidth on the arbitrated loop.
Prior art network switches typically have a single queue for holding frames to be output to the arbitrated loop. The order of frames on the queue determines the order in which frames are output to the arbitrated loop and hence the ordering of arbitration-open-close cycles which need to be performed. In some conditions, loop utilization may be less than optimal. For example, if there are frames in the queue for two or more devices and the frames from the devices are interleaved, the overhead for opening and closing devices may reduce the utilization of the loop bandwidth by an amount that may depend on average frame sizes and on the order of the frames on the queue.
For example, consider the case where the frames are ordered as shown in FIG. 4A. In this figure, the letters A and B represent frames on the queue for devices A and B on the loop. The ordering of frames in the queue of FIG. 4A forces the switch to transfer only one frame per each establishment of a connection. Processing of the frames may be as follows (assuming the switch holds the loop for an extended period of time before allowing arbitration to occur):
a) Arbitrate
b) Open Device A
c) Transfer Data Frame
d) Close Device A
e) Open Device B
f) Transfer Data Frame
g) Close Device B
h) Repeat b-d
i) Repeat e-g
j) Continue until queue empty or maximum time loop can be held occurs.
The loop utilization in this example may thus be less than optimal. The overhead for opening and closing devices may reduce the utilization of the loop bandwidth, for example, by 10–30% depending on average frame sizes.
FIG. 4B illustrates a more optimal frame ordering when compared to the frame ordering of FIG. 4A which may have reduced loop overhead since the switch may send multiple frames each time a device is opened or closed. However, the frame transmit scheduling logic used in network switches and other devices that carry IP (Internet Protocol) traffic are typically designed to generate traffic (e.g. packet or frame flow) with low jitter. As used herein, the term "jitter" relates to the transmission of frames from a source to a destination. "Low jitter" includes the notion of frames being transmitted and received in a steady flow, and implies that the temporal spacing between the frames at the receiver remains as constant as possible. Thus, prior art network switches typically use a low-jitter scheduling algorithm that attempts to interleave traffic from different sources as much as possible. This interleaving may result in the frames typically arriving at the network switch in a less than optimal ordering (e.g. more like FIG. 4A than FIG. 4B). Therefore, it may be desirable to implement a scheduling algorithm for a network switch specifically when interfacing an arbitrated loop such as an FC-AL with an IP network that carries low-jitter traffic.
Transfer Ready (XFER_RDY) Delay and Write Performance
In a Storage Area Network (SAN), a host bus adapter, e.g. a Fibre Channel host bus adapter, may be connected to a network switch performing a mixture of read/write transfers to multiple disk drives. Under some conditions, the write performance may be considerably lower than the read performance. While read performance under these conditions is typically as expected, write performance may be considerably less than expected. When only write operations are performed, the performance for the write operations is typically as expected. The reduced write performance during combined read and write operations may be the result of a large buffer within the network switch that causes the delivery of transfer ready (XFER_RDY) frames to be delayed when both write and read operations are being performed.
To understand the implication of delaying the delivery of XFER_RDY frames, it is necessary to understand the protocols for read and write operations by devices using FCP (Fibre Channel Protocol for SCSI). FCP uses several frame sequences to execute a SCSI command between the initiator of a command (the initiator) and the target of the command (the target). An example of an initiator is a host bus adapter such as a Fibre Channel host bus adapter and an example of a target is a storage device such as a disk drive. The initiator and target communicate through the use of information units (IUs), which are transferred using one or more data frames. Note that an IU may consist of multiple data frames but may be logically considered one information unit. The IUs for FCP may include, but are not limited to, the following:                FCP_CMND—The FCP_CMND IU is sent from an initiator to a target and contains either a SCSI command or a task management request to be executed by the target.        FCP_XFER_RDY—The FCP_XFER_RDY IU is sent from a target to an initiator for write operations and indicates that the target is ready to receive part or all of the data for a write command.        FCP_DATA—The FCP_DATA IU is sent from an initiator to a target for write commands and from targets to initiators for read commands. An FCP_DATA IU consists only of the actual SCSI command data.        FCP_RSP—The FCP_RSP IU is sent from a target to an initiator and contains the SCSI status, Sense information (if any), protocol status and completion status of task management functions.        FCP_CONF—The FCP_CONF IU is sent from an initiator to a target and provides confirmation that the initiator received the FCP_RSP IU. This IU is optional.
FIG. 5 shows an example of the processing of an FCP Read command. The initiator 200 sends the read command in an FCP_CMND IU to the target 210. When the target 210 has the data available, it returns the data to the initiator 200 in one or more FCP_DATA IUs. When all of the data has been transmitted, the target 210 sends an FCP_RSP IU with the command status information. The initiator 200 may optionally send an FCP_CONF IU to the target 210 indicating that the FCP_RSP IU was received. When an initiator 200 issues the read command, it must be prepared to receive all of the data indicated by the command (i.e. buffer(s) must be available for the returned data).
FIG. 6 shows an example of an FCP write command. The initiator 200 sends the write command to the target 210 in an FCP_CMND IU. The target 210 responds with an FCP_XFER_RDY IU indicating the data it is ready to accept. The initiator 200 then sends the data to the target in a single FCP_DATA IU. After all of the data requested by the target 210 has been transferred, the target 210 will either send another FCP_XFER_RDY IU requesting additional data or send an FCP_RSP_IU containing the command status information. The initiator 200 may optionally send an FCP_CONF to the target 210 indicating that the FCP_RSP IU was received. (Note that the FCP_DATA IU may consist of multiple data frames but is logically considered one information unit.)
Preferably, when an initiator 200 issues a write command, the FCP_DATA IU can be returned as soon as the initiator 200 receives the FCP_XFER_RDY IU from the target 210. If an initiator 200 is performing overlapping write commands (i.e. there are multiple outstanding write commands), it can maintain a constant flow of FCP_DATA IU frames as long as it has received at least one XFER_RDY IU for which it has not yet transmitted the data. However, if the FCP_XFER_RDY IU is delayed, the initiator 200 will not maintain a constant flow of output data when it is waiting for an XFER_RDY IU to transmit data.
When only write operations are performed, the XFER_RDY IU see little delay because only FCP_RSP and FCP_XFER_RDY IUs are being sent from the targets to the initiator. The FCP_RSP IUs have little effect on the FCP_XFER_RDY latency because only one FCP_RSP IU is received per SCSI command and the FCP_RSP IUs are small. However, when read and write operations are performed simultaneously, the initiator 200 will also be receiving FCP_DATA IU from the target(s) 200. For typical SCSI commands (e.g. 8K byte to 64 Kbyte commands), there can be a lot of FCP_DATA frames waiting in network switch queues to be forwarded to the initiator 200. Thus, the XFER_RDY IU may be significantly delayed due to queuing of data frames by network switches. Thus, write performance can be degraded significantly when performing a combination of read and write commands. In larger networks, write performance may be degraded when XFER_RDY IUs are delayed due to other traffic, therefore the write performance degradation may not be limited to instances where an initiator 200 is performing both read and write operations.
FIG. 7 illustrates how XFER_RDY IUs can be delayed due to network switch queuing. The amount of switch queuing 300 may affect the latency of XFER_RDY IUs being returned to an initiator 200. Network switches with small amounts of buffer memory (i.e. small queues 300) may experience fewer problems than network switches with larger amounts of buffer memory (i.e. larger queues 300) because the XFER_RDY IUs may be delayed less within a switch with a small queue 300. Prior art Fibre Channel switches typically have small amounts of buffer memory and therefore this problem may not appear in these switches. Network switches that support multiple network protocols may be more susceptible because they contain more buffering to support the other protocols. For example, a network switch that supports Fibre Channel and Ethernet may have buffering for 512 frames per port while prior art Fibre Channel-only switches may have buffering for only 16 to 32 frames.

Method and apparatus for scheduling packet flow on a fibre channel arbitrated loop


The disclosure is directed to a carbonylation process for producing acetic acid which includes separating a vapor product stream from a carbonylation reactor to produce a crude acid product comprising acetic acid comprising lithium cations and contacting the crude acetic acid product with a cationic exchanger in the acid form within a first treatment device to produce an intermediate acid product; and contacting the intermediate acetic acid product with a metal-exchanged ion exchange resin having acid cation exchange sites within a second treatment device to produce a purified acetic acid. Embodiments directed to operation of a treatment device comprising a plurality of sampling ports are also disclosed.

Acetic acid production by carbonylation includes continuously reacting methanol and carbon monoxide in the presence of a catalyst in a reactor. The reaction mixture present in the reactor comprises a transition metal, which may be a Group 9 metal, which may be iridium and/or rhodium, and may further include one or more solvents, water, various stabilizers, co-catalysts, promoters, and the like. Reaction mixtures known in the art may comprise acetic acid, methyl acetate, methyl iodide, hydrogen iodide, a hydrogen iodide promoter, and the like.
A complex network of interdependent equilibria involving liquid acetic acid reaction components exists in the reactor, which include those directed to the formation of acetic acid, as well as those directed to the formation of various impurities which are also produced in the reactor. Impurities which may be present in acetic acid include permanganate reducing compounds (PRCs) such as acetaldehyde. Accordingly, acetic acid processes disclosed in the art may further include various purification processes and control schemes wherein impurity formation is minimized and/or impurities produced are removed from the process or converted into product acetic acid.
Various impurities present in the produce acetic acid are difficult to remove. There is a need to control and monitor purification systems in various aspects of an acetic acid production process.


A shrink-fit coupling includes a discontinuous ring between a ceramic stub shaft of a turbine rotor and an inner diameter r2 of a metallic shaft which typically supports a compressor rotor. If the materials for the ceramic stub shaft and the discontinuous ring are pre-determined and the radius of the ceramic stub shaft is also given, then the inner radius r2 of the shaft should be chosen by the equation: r2=(CTE1−CTE2)/(CTE3−CTE2) r1.

The present invention relates to a coupling, and more particularly to a compressive stress coupling arrangement having a third material between a ceramic component and a metal component.
Turbine inlet temperature strongly influences the thermal efficiency of a gas turbine: higher turbine inlet temperature generally leads to thermally more efficient gas turbines. However, higher turbine inlet temperature requires temperature and oxidation resistant materials such as ceramics. These components include ceramic turbine rotors that are typically attached to a metal shaft such that power is transmitted from the turbine rotor to a compressor rotor.
Connecting the ceramic turbine rotor to the metal shaft requires particular structural arrangements as ceramics thermally expand less than metals. The difference in thermal expansion results in thermal stress that may lessen the connection between the ceramic rotor and the metallic shaft. To maintain an effective joint between the rotor and the shaft, various brazing, shrink-fit compliant intermediate layers as well as mechanical clamp structures have been employed.
Accordingly, it is desirable to provide a shrink fit coupling for coupling a ceramic member to a metal member that is capable of transmitting torque at relatively high temperatures.

Shrink-fit stress coupling for a shaft of differing materials


A step prismatic retro-reflector includes a main reflective corner having a shared reflective surface of a geometric single plane, a virtual step surface coming into contact with the shared reflective surface at a right angle, and a plurality of sub reflective corners. Each reflective corner has a pair of independent reflective surfaces coming into contact with each other at a right angle, and arranged along the step surface, wherein the retro-reflector elements are arranged to be alternated such that a corner ratio (l/w) of the sub reflective corners is 1.5 or more, a corner orientation of the main reflective corner deviates at an angle of 10 degrees or more with respect to a point of tangency of an incident plane, a reflection orientation thereof deviates at an angle within 10 degrees, and the corner orientations thereof deviate in the opposite direction to each other.

Retro-reflectors are installed or attached to various types of traffic safety facilities such as various types of traffic signs, pavement markers, delineators, and traffic tripods, or items such as safety clothing, automobiles, bicycles, hats, and shoes, of which the visibility needs to be ensured at night, and the retro-reflectors may improve visibility of these items by retro-reflecting incident light, which enters from a front side, toward a light source that emits the light.
As the retro-reflectors applied to these items in the related art, retro-reflectors provided with glass beads or cube corners have been often used. Since the retro-reflectors in the related art have different retro-reflection characteristics varying depending on incident angles of incident light, the retro-reflectors have advantages and disadvantages.
For example, retro-reflection efficiency of the retro-reflector using the glass beads is uniform regardless of incident angles, but the retro-reflector using the glass beads has problems in that retro-reflection efficiency is low overall, and a reflection function deteriorates in a case in which water is attached to the surface of the retro-reflector.
Further, the retro-reflector using the cube corners in the related art has high retro-reflectivity for light having a small incident angle, that is, front light, but rapidly degrades brightness for lateral light having a large incident angle, such that a range of incident angles within which retro-reflection is enabled, that is, retro-reflection visibility is very narrow. Moreover, it is very difficult to design and change a direction of retro-reflection visibility in order to mainly retro-reflect light having a large incident angle.
To solve the problems, the present applicant has developed 'Retro-Reflection Unit and Retro-Reflector (Korean Patent Application No. 10-2006-7038)' which have a complex total-reflection prismatic retro-reflective structure in which reflective surfaces, which are orthogonal to each other, are arranged, in a steplike manner, on a reflective surface of two reflective surfaces which are orthogonal to each other, such that overall retro-reflectivity is high, and particularly, a direction of a main reflection orientation, which is defined as an incident direction in which retro-reflectivity is highest, may be very easily changed without limitation on an angle with respect to a normal direction of an incident plane during a design process.
However, the retro-reflection unit of the retro-reflector includes two reflective surfaces (a shared reflective surface and a step portion), such that there is a problem in that retro-reflection is enabled only for incident light within a particular incident angle range, and thus a retro-reflection range is very narrow. For example, in a case in which the retro-reflector is developed for front light, very high retro-reflection efficiency is implemented for incident light having an incident angle of zero (0) degree, but in a case in which an incident angle becomes 10 degrees or more, the incident light penetrates the shared reflective surface such that a retro-reflection function of some retro-reflection units is degraded, and as a result, there is a problem in that retro-reflection performance is low for lateral light, and in a case in which the retro-reflector is developed for lateral light, there is a problem in that retro-reflection efficiency is very low for front light with compared to lateral light. Accordingly, since the retro-reflector of Korean Patent Application No. 10-2006-7038 has a very narrow reflection range, there is a problem in that applicability to front light or lateral light is restricted.

Step prismatic retro-reflector with improved wide-angle performance


An acupuncture needle and delivery system that facilitates the sanitary insertion and handling of the acupuncture needle in all orientations, and that does not impede the performance of the various post-insertion procedures of the sort commonly used by acupuncture practitioners. In a fully assembled pre-use state, the device includes an acupuncture needle having a filiform shaft and an enlarged head portion, an insertion tube accommodating at least the filiform shaft of the acupuncture needle to protect the filiform shaft from contamination, a stabilization sleeve slidably engaging the outer surface of the insertion tube, and retainer means for releasably securing the acupuncture needle within the insertion tube.

Acupuncture is gaining wide acceptance as a medical treatment for a variety of health conditions, and has become widely integrated into health care systems throughout North America. By way of general overview, acupuncture involves the insertion of a filiform needle (at least the shaft of which is typically constructed of medical grade stainless steel) to a target depth below the dermis of the skin at a predetermined sensitive point, and the performance of various additional procedures selected to stimulate a positive change in the health condition of a patient. These additional procedures may, for example, involve heating the needle with a heat source (commonly known as "moxibustion"), applying electrical stimulation to the needle, such as by attaching the needle to a milliamp or microamp stimulator, and/or the use of various manual manipulative techniques such as thrusting, angling and vibrating the needle.
To minimize patient discomfort, the acupuncture needle is typically first quickly "set" through the dermal layer of the patient's skin, and then further inserted through the skin into the body of the patient to a target depth of up to several centimeters, depending upon the application and on the region of the body being treated. In many cases, the acupuncture treatment may be preformed on a recumbent patient that has been positioned so as to facilitate the practitioner's access to the predetermined sensitive point. However, in some instances, such as when patients have circulatory or neurological limitations, this is not possible and the acupuncture needle must be set and inserted horizontally, or even from below.
Great care must be taken to maintain sterility of the acupuncture needle throughout the entire acupuncture treatment process in order to protect both the patient and the practitioner from possible contamination, and acupuncture needle delivery techniques have accordingly evolved over the years from simple free hand insertion and manipulation to the use of insertion tube-assisted delivery systems intended to assist with the maintenance of sanitary conditions (and in some instances to facilitate consistent setting of the acupuncture needle). As is discussed further below, the use of an insertion tube surrounding the needle shaft facilitates sanitary pre-use initial handling and setting of an acupuncture needle by a practitioner. Once the needle has been set, the insertion tube is generally discarded in order to permit the further insertion and manipulation of the needle at the target depth.
Additional sanitary challenges often arise, however, during the further insertion and manipulation of the acupuncture needle at the target depth, particularly in situations where the practitioner is inserting the needle into scarred, dense, or fibrous tissue (such as in intra-articular insertions in, for example, the knee). In these situations and others, such as where, for example, the needle has a thickness of 0.22 mm or less and a needle length is 35 mm or shorter, or a thickness of 0.22 mm or greater and a length that is 50 mm or longer, the needle is prone to bowing or bending during further insertion and manipulation.
Any such bowing or bending interferes with the practitioner's ability to accurately insert and manipulate the needle, and requires the practitioner to attempt to compensate by initiating time consuming and/or difficult compensatory movements. In many cases, suitable compensation for the bowing or bending of the needle is not easily achievable, and in some cases may not be achievable at all by even the most skilful practitioner unless the practitioner stabilizes the shaft of the needle using a cotton swab or simply his/her fingers. These stabilization techniques compromise the sterility of the needle, and increase the risk of infection.
To address this need for stabilization (and the resulting potential for contamination), acupuncture needle assemblies and delivery systems that additionally provide a grip element have been proposed. However, all known acupuncture needle assemblies and delivery systems that additionally provide a grip element to facilitate stabilization of the needle during insertion and manipulation fail to adequately address the need for such stabilization when the needle is inserted horizontally or from below the predetermined sensitive point, or fail to adequately accommodate the performance of various stimulative procedures. In addition, many of the known needle assemblies and delivery systems are relatively difficult to manufacture and to use.
By way of example, U.S. Pat. No. 5,624,460 to Yoo describes an acupuncture needle assembly that includes a "guide pipe" (i.e. an insertion tube) and a paper, rubber or foamed resin "grip pipe" that is located within the guide pipe and that immediately surrounds the needle shaft about 3-5 mm from the end portion of the needle head. As with a conventional insertion tube-assisted delivery system, the guide pipe facilitates the sanitary pre-use initial handling and setting of the needle, and is discarded once the needle has been set. A practitioner may then grasp the grip pipe to stabilize the needle during the acupuncture stimulus, and use the grip pipe to withdraw the needle from the patient after use.
However, since the Yoo grip pipe is formed of paper, rubber or foamed resin, and since it immediately surrounds the shaft of the needle, which has an internal diameter that is smaller than that of the handle or upper "grip portion" of the needle itself, the Yoo grip pipe cannot readily be removed from the needle during use, and would accordingly impede procedures requiring a practitioner to heat or electrify the needle. For example, the moxibustion technique known as "sparrow pecking" requires a practitioner to heat the acupuncture point and needle with an external heat source to stimulate circulation and immune function. It is important in performing this technique to bring the heat source to the point were the heat is intense but tolerable in a "coming and going" process (i.e. in a "pecking" manner), and to achieve this the heat source must be brought as close as possible to the needle and to the skin to generate a strong heat reaction. Since the Yoo grip pipe is immediately associated with the needle shaft and cannot readily be removed, it may have an insulatory effect between the needle and the heat source (and may itself melt or burn if brought too close to the heat source), and thereby limit the effectiveness of this type of procedure. Additionally, in some scenarios, the treatment target depth may require the needle to be inserted up to 90% or so of it's overall length. Since the Yoo needle assembly does not provide for removal of the grip pipe during use, the grip pipe also limits the depth to which a practitioner may insert the Yoo needle.
Published U.S. patent publication Ser. No. 11/292,025 to Teichert et al. (U.S. Patent Publication No. 2007/0129744), the disclosure of which is hereby fully incorporated by reference, describes an acupuncture needle guide assembly that comprises an acupuncture needle with a shaft and a needle handle, a guiding tube (i.e. an insertion tube) accommodating the acupuncture needle before use and providing guidance for setting the acupuncture needle, a holding tube being arranged within the guiding tube and providing a cover for the needle shaft, and a destructible or detachable connector fixing the holding tube between the needle handle and an inner wall of the guiding tube until the connector is removed or broken. The holding tube has an inner diameter that is greater than the diameter of the needle shaft, and preferably has an inner diameter that is greater than the outer diameter of the needle handle in order to permit the holding tube to be removed from the needle after insertion thereof into the body. In use, the assembly is first positioned on the skin of the patient to be treated, and the acupuncture needle is then released by removing or breaking the connector. Upon removal or destruction of the connector, the holding tube drops down the shaft of the needle towards the tip thereof under the effect of gravity, and is manually gripped by the practitioner after the guiding tube is withdrawn to facilitate stabilization during the further insertion and manipulation of the needle.
Although the "loose" fit of the holding tube vis-à-vis the needle of the Teichert et al. assembly permits the holding tube to be removed during use and thereby addresses some of the shortcomings of the Yoo assembly, the inability of a practitioner to control the position of the holding tube after the connector is removed or broken, but prior to removal of the guiding tube, makes it generally unsuitable for use in horizontal orientations, or in situations where the needle must be set and inserted from below the predetermined sensitive point.
There accordingly exists a need for an improved acupuncture needle and delivery system that facilitates the sanitary insertion and handling of the acupuncture needle in all orientations, and that does not impede the performance of the various post-insertion procedures of the sort that are commonly used by acupuncture practitioners to stimulate a positive change in the health condition of a patient. Since the need for stabilization of the needle shaft is situation dependant, provision of an improved acupuncture needle and delivery system in which the implementation of the stabilizing feature is optional and does not commit the practitioner to a predefined insertion process would also be beneficial.


The present invention refers to a sealable device for temporary or permanent surgical placement through a bone to provide a passage into a cavity or internal anatomic site in a mammal. The sealable device comprises two preferred embodiments: in the first one the device comprises two members, the first one provides a passage through the bone, and the second one, which is movable, is used as a stopper means for the first member, and in the second embodiment, a third removable member is added, which may be connected with said second end of said first member so that the device is affixed to the bone it runs through. The device can be used, for example, for diagnostic purposes, for topical in situ therapy, of medical treatment or for viewing into the cavity. The cavity may be, for instance, the sinus maxillaris. If so, the temporary or permanent placement of the device is carried out via the canine fossa or the lower meatus.

Problems associated with acute or chronic diseases in cavities or internal anatomical sites in the body, for which it is sometimes necessary to enter via a bone are known in medicine. The sinus maxillaris is an example of a cavity where much too often rhinosinus diseases occur, which require medical and/or surgical treatment. The problem, in these cases, is the passage into the cavity, either for diagnostic purposes, or for topical treatment in situ, as well as medical treatment, or observation and evaluation.
There are known in current medicine certain devices for temporary insertion related to sinus cavities.
Using "SinoJet.TM." from ATOS MEDICAL company, it is possible to insert a silicone rubber tube via the lower meatus. Its insertion is carried out by a special puncturing or driving means, similar to a trigger. Insertion is fast, by pressing on and breaking tissues. Therefor, the only feasible path for this device is the lower meatus. While this tube may be inserted under a certain degree of control, the possibility that it be introduced too deep into the sinus maxillaris, thus causing undesired effects, cannot be ruled out. The tube may be kept in place for a few days as a means to be in contact with the sinus maxillaris in the lower meatus, but it is not designed or intended to be inserted permanently or for long periods of time and it is not sealable. At its forward end, the tube is in the shape of a truncated arrow with a pair of fins on either side, and its rear end is beadless. This tube allows for irrigation or flushing of the sinus maxillaris, but because of its small inner diameter it is impossible to look into the sinus maxillaris, since it does not allow for insertion of any direct vision optical instrument through it.
"Rains Frontal Sinus StentTM", sold by Smith+Nephew ENT, is a silicone rubber device designed solely for temporary insertion into de frontal sinus. Following frontal sinus endoscopic surgery, the tube is inserted exclusively for the purpose of preventing a surgical complication or natural reclosure of the opening in the frontal recess. The tube will maintain a surgical opening cut through the ostrum of the frontal sinus for 7 to 14 dais after surgery. The device has a hollow stem, and at its forward end it is provided with a head or bulb which, upon insertion into the frontal sinus, it keeps the tube within the cavity. While it is supposed to be self-fastening, it does not allow for an accurate control of its advancing or keeping the tube in place within the frontal sinus. This device is not designed for permanent placement, it is not sealable, it cannot be used to inject or remove any solutions from the frontal sinus nor does it allow for insertion of direct viewing optical instruments through its lumen.
"Shikani Middle Meatal Antrostomy Stent (SMMAS).TM." sold by Micromedics, Inc., is designed to be inserted following functional endoscopic surgery of the sinus maxillaris. The above device, SMMAS, is introduced via an antrostomy made in the middle meatus, by means of a Ferris-Smith forceps. The device is kept in place temporarily for 10 to 14 days after surgery, after which it is readily removed via the nasal fossa. It has a sole purpose: preventing adhesions from being formed by adjacent tissues through connection of same between the middle ethmothurbinate and the nasal side wall. The above device is made of a soft material, such as silicone rubber, it has two fins at its forward end which prevent the device from undesirably slipping out of the opening, and at its rear end it has a bead that prevents both the middle ethmothurbinate and the nasal side wall from attaching one another, and the undesirable advance of the device into the cavity of the sinus maxillaris. The device SMMAS is not sealable and its use is intended for a short period of time, with insertion only through the middle meatus.
There are known, in prosthetic and implant medicine devices to be affixed to a bone. These devices generally comprise one or several components, for a reliable attachment of the same to the bone, because prostheses attached to a bone will generally have to bear a heavy load, whether it is a prosthesis or a dental implant, a lockscrew in a limb, an artificial joint or the like. Therefore, it is required a reliable attachment, which provides for an unlimited and more secure use of the prosthesis. The components are substantially solid, and they may be generally attached to a bone by means of threads, since this combination insures a better attachment.
Generally, devices are solid or partially hollow. The latter may be provided with a stopper system, but they cannot provide a passageway through their lumen between two different anatomical sites, for one of their ends is closed.
There are also hollow devices which, after being inserted through a bone, define a passageway between two different anatomical sites, but which lack an internal stopper system, leaving both of the above histic surfaces in permanent open connection.

Hollow sealable device for temporary or permanent surgical placement through a bone to provide a passageway into a cavity or internal anatomic site in a mammal

Virrey Olaguer y Feliu 2970 6th Floor "B"


A cooling system is provided in which an integrated controller 10 controls the compressor for compressing a refrigerant and at least one constituent device which is a separate device from the compressor and that constitutes a refrigerant circulation circuit together with the compressor. The integrated controller 10 has a control data generation unit 16 that controls the compressor using a compressor sensor for detecting a first physical value, which is a physical value of the refrigerant at the time of normal operations, and an abnormality detection unit 13 for detecting an abnormality of the compressor sensor. The control data generation unit 16 controls the compressor using a constituent device sensor for detecting a second physical value that is a physical value having a close correlation with the first physical value in place of the compressor sensor when the abnormality was detected by the abnormality detection unit 13.

1. Field of the Invention
The invention relates to a cooling system utilizing a compressor for compressing a refrigerant and a constituent device that constitutes a refrigerant circulation circuit together with the compressor, a control device, and a control program.
2. Description of Related Art
As a cooling system utilizing a refrigerant circulation circuit that circulates a refrigerant, an air conditioning system of an indoor space such as stores, and refrigeration and freezer system that refrigerates and freezes merchandizes within showcases installed at stores have been widely used in the past. The refrigerant circulation circuit utilized in such systems includes a compressor for compressing the refrigerant and a constituent device which is a separate device from the compressor that constitutes the refrigerant circulation circuit together with the compressor. Here, the constituent device is, for example, a heat exchanger of the air conditioning system and a showcase and a condenser of the refrigeration and freezer system.
It is common that the compressor has a sensor for detecting a suction pressure (or suction temperature etc.) of the compressor and the compressor is controlled according to the sensor value outputted by the sensor. Because of this, in a case that an abnormality such as a breakdown occurs to the sensor provided at the compressor, the compressor becomes uncontrollable.
As a technology to handle when an abnormality occurred to the sensor provided at the compressor, a cooling system such as described in Japanese Laid-Open No. 2002-188874 (Claim 1, FIG. 1) was proposed. In particular, at the cooling system described in Japanese Laid-Open No. 2002-188874, total of four sensors, that is, a suction pressure sensor, suction temperature sensor, discharge pressure sensor, and discharge temperature sensor are provided at the compressor.
When an abnormality occurred to one of the above four sensors in the cooling system of Japanese Laid-Open No. 2002-188874, the sensor value of the sensor in which the abnormality occurred is supplemented using the sensor values outputted by the remaining three sensors.
However, because it is necessary that a number of sensors are provided at the compressor in the cooling system of Japanese Laid-Open No. 2002-188874, the size of the compressor system was increased and its control became complex.
Also, the technique described in Japanese Laid-Open No. 2002-188874 cannot be applied to a case in which only one sensor is provided at the compressor, and therefore, in such a case, there was a problem that the operation of the compressor could not be continued appropriately when an abnormality occurred to the sensor provided at the compressor.

Cooling system, control device, and control program


A golf club is composed of a tapered shaft, a grip fastened at one end of the shaft, and a head fastened at another end of the shaft. The shaft is reinforced by a ridged structure consisting of at least two ridges extending along the direction of the longitudinal axis of the shaft.

The conventional golf club is composed of a tapered shaft and a head fastened to the small diametrical end of the shaft. The hand grip is located at the large diametrical end of the shaft. Whenever a golf club is swung to hit the ball, the midsection of the shaft and the small end contiguous to the head are greatly exerted on by a force torque capable of causing the shaft to curve due to the application of force between the ball-hitting position of the head and the axis of the golf club. In other words, when a golf club is at work, the golf club must be able to withstand the force causing the golf club to curve and the torque causing the golf club to twist. In order to reinforce the tapered golf club of a fiber composite material, the conventional wisdom places the emphasis on the arrangement of the fiber braids making up the golf club.
In general, there are two conventional ways of reinforcing a golf club. As shown in FIG. 1, a golf club 10 is provided with a small protruded section 12. On the other hand, a golf club 15 is provided with a large protruded section 16, as shown in FIG. 2. The protruded sections 12 and 16 are basically similar in construction, with the only difference being that they are different in length. The protruded portions 12 and 16 have a cross section conical in shape, with the diameter of the cross section being gradually diminished towards both ends of the golf club. Such protruded portions of the conventional golf clubs as described above are effective in reinforcing the golf clubs; nevertheless they are integral parts of the golf clubs such that they are limited in design to give an added mechanical strength to the golf clubs. In addition, the golf clubs 10 and 15 of the prior art are not cost-effective in view of the fact that the formation of the protruded sections 12 and 16 calls for the additional amount of material. Moreover, the protruded sections 12 and 16 make the golf clubs 10 and 15 heavier.


There is provided a field device for downloading a new software through a field bus from a host system and replacing a current software which is currently executed with the new software. The field device includes: a history information generation and management section which generates and stores history information of the current software when the new software is downloaded from the host system.

1. Technical Field
The present disclosure relates to a field device whose software is replaced through a field bus and a field device software update system using the field device and, more particularly, relates to implementation of history information management of software.
2. Related Art
In recent years, in order to improve function distribution intended for process improvement, in a process control system of industrial automation, an additional function such as expansion of a self-diagnosis function has also been demanded for a field device including a sensor (e.g., a flowmeter or a thermometer), an actuator, and a controller making up a control loop of feedback control. Since a conventional field device has rich functions and thus a bug is likely to occur, software or firmware installed in the field device is replaced (updated) using the communication function of a field bus (see e.g., JP-A-2005-173747).
FIG. 7 is a block diagram to show a configuration example of a field device and a process control system using the field device in a related art. In FIG. 7, a field device 1 incorporating an analog input function block AI and a PID function block PID is connected to a field bus 2 for FOUNDATION Fieldbus (registered trademark), serial transmission or the like. Plural field devices (not shown) are connected to the field bus 2.
The field device 1 is made up of a sensor 11 for measuring a process amount, a communication section 12 for conducting data communications with a different field device or any other device through the field bus 2, a computation control section 13 for controlling the functions of the field device 1 and replacing software or firmware, and a storage section 14 having program storage areas 14A and 14B for storing software, firmware or a program of a computation portion for converting a measurement signal from the sensor into an output signal.
Software of the field device 1 can be replaced with new software to upgrade the function of the existing software or solve a problem.
Any other field device (not shown) is connected to the field bus 2 and a host 3 is connected to the field bus 2 through an I/O unit and a bus (not shown). The host 3 is a host system of DCS, including software transfer means for downloading or transferring software to a field device.
In the configuration, the field device 1 receives data of new software from the host 3 through the field bus 2 and stores the received new software in the storage area 14B where operating software is not stored.
After the data is downloaded, the field device 1 is restarted and operates the new software stored in the storage area 14B. This means that the operating software is rewritten in the field device 1.
Thus, in the related-art field device, the software or firmware installed in the field device can be replaced using the communication function of the field bus.
However, in the related-art field device, history information as to what revision the software which previously operated has undergone cannot be known although software can be replaced.
Also, in the related-art field device, the revision of the software which previously operated cannot be grasped and thus it is hard to restore the operation of the field device to the operation of the previous revision software if a defect occurs.
Further, in the related-art field device, the revision of the software which previously operated cannot be grasped and thus the circumstances and the progress of a plurality of software products installed so far are not known and the defects of the software which occurred in the past cannot be investigated.
Further, in the related-art field device, the revision of the software which previously operated cannot be grasped and thus if a defect occurs, it is not easy to restore the operation of the field device to the operation of the previous revision software. Accordingly, it takes time in maintenance of the software, and the whole process control system is affected.

Field device and field device software update system therewith


Approaches for using a physically unclonable function (PUF) are described. A selector map is used to indicate stable and unstable bits in a PUF value that is generated by a PUF circuit. The stable bits of the PUF value generated by the PUF circuit may be selected for use by an application, and the unstable bits ignored.

A system's identity may be established and authenticated based on the unique physical properties of the system. In some applications, physically unclonable functions (PUFs) embodied in integrated circuits (ICs) are used to exploit the unique physical characteristics of a system for purposes of authentication. Each instance of the IC will have slightly different physical characteristics due to the random variation in an IC fabrication process. A PUF circuit uses the physical characteristics to generate an identifier value, for example a binary number, which differs from one integrated circuit to the next due to the different physical characteristics of each manufactured device. These identifier values may be used to uniquely identify the integrated circuit, as a key for encryption and decryption, or for other purposes. Examples of circuits used to implement PUFs include delay circuits and ring oscillators, memory circuits, and cross-coupled latches. The terms PUF circuit and PUF may be used interchangeably herein.
PUFs may operate according to a challenge-response protocol. The input to a PUF is the challenge, and the output from the PUF is the response. The slight variations between instances of the PUF circuits in different systems result in the separate instances providing different responses to the same challenge. In addition to identification and authentication, PUF circuits may be used to generate volatile secret keys.
Helper data is sometimes used to compensate for instability in a PUF circuit. Since a PUF circuit relies on a physical property of a device, a PUF value may not remain stable as the device and PUF circuit age. Since a changed PUF value may prevent authentication or communication, helper data in the form of error-correcting codes (ECGs) may be used to correct generated PUF values to the expected PUF value. While the helper data is useful in maintaining the viability of the PUF over the life of the device, the helper data may also reveal information about the PUF value. In addition, the helper data may be large and may create storage issues.

Physically unclonable function and helper data indicating unstable bits


Disclosed herein are delayed reaction threshold temperature indicators and methods of making and activating the same, the delayed reaction threshold temperature indicators including a first substrate, first and second layers, and a housing secured to the substrate. The first layer includes a first reactant and an optional meltable polymer, and the second layer includes a meltable polymer and a second reactant. The meltable polymer is configured to keep the first and second reactants from interacting with each other. When exposed to temperatures at and/or above a desired threshold for a period of time, the meltable polymer melts and allows the first and second reactants to come into contact with each other, thereby producing a visual change in appearance.

Many vaccines, drugs, foodstuffs and other products are temperature-sensitive, or perishable, and can lose quality with time at rates that are influenced by ambient temperatures. Time-temperature indicators are known which can provide a simple visual indication of the cumulative historical exposure of a host product to heat or exposure to a peak temperature for even a short period of time. The visual indication can be used to provide a signal of when a product may have lost quality or freshness.
Known time-temperature indicators can provide a color change at a predetermined threshold or end point to indicate possible loss of quality or freshness of the host product. The color change can be displayed in a suitable label, or the like, to be read optically, for example, visually by a human viewer. The color change can be chromatic or achromatic or provided by another visually detectable optical parameter change. The temperature-response parameters of the time-temperature indicator can be correlated with a deterioration characteristic of the host product to coordinate the color change appropriately with the likely condition of the host product.
Also, certain perishable products, for example, vaccines and sensitive medications as well as some foodstuffs and other products including some industrial products can have their quality or safety compromised by relatively brief exposures to a temperature in excess of a predetermined threshold.
Some known time-temperature and threshold indicators employ dye-sublimation technology (U.S. Publication No. 2014/0119402), metal etching (U.S. Pat. No. 9,448,182), gel-based technology (U.S. Pat. Nos. 7,940,605, 8,562,208, and 9,182,292), spiropyrans and UV energy (International Publication No. WO 2005/075978), meltable granules (U.S. Pat. No. 6,602,594), and linear diffusion (U.S. Pat. No. 9,234,806).
Notwithstanding the foregoing proposals for cumulative and threshold temperature indicators, it would be desirable to have a relatively simple threshold indicator having enhanced response characteristics, such as a delayed response, a simple method of manufacture, and a minimal space requirement.

Activatable temperature indicator with time delay


A feedwater heater (10) for a steam generator communicating feedwater through an external heat exchanger (12), a deaerator (14) that allows the use of carbon steel feedwater tubes, a first heater (16), an evaporator section (18) and steam drum (17) for communicating a portion of the feedwater in the form of steam to the deaerator (14), and a second heater (20).

The invention relates in general to steam generators or boilers and more particularly to a feedwater heater and feedwater heating process for a heat recovery steam generator.
Natural gas represents a significant fuel to produce of electrical energy in the United States. It burns with few emissions, and is available throughout much of the country. Moreover, the plants which convert it into electrical energy are efficient and, in comparison to hydroelectric projects and coal-fired plants, they are relatively easy and inexpensive to construct. In the typical plant, the natural gas burns in a gas turbine, causing the rotor of the turbine to revolve and power an electrical generator to which the rotor is connected. Turbine exhaust gases—essentially air, carbon dioxide and steam—leave the gas turbine at about 1200° F. (649° C.) and are a significant source of energy. To harness this energy, the typical combined cycle, gas-fired, power plant also has a heat recovery steam generator (HRSG) through which the hot exhaust gases pass to produce steam which powers a steam turbine which, in turn, powers another electrical generator. The exhaust gases leave the HRSG at temperatures as low as 150° F. (66° C.).
The steam turbine and the HRSG operate within a loop that also contains a condenser and a feedwater pump. The steam generated by the HRSG passes through the turbine and then into the condenser where it is condensed back into liquid water. The pump delivers that water to the HRSG at about 100° F. (38° C.) or perhaps a lower temperature. The water enters the HRSG at a feedwater heater or economizer which elevates its temperature for subsequent conversion into steam within an evaporator and superheater that are also part of the HRSG.
Often the feedwater requires deaeration with a deaerator to remove dissolved gases from the feedwater to prevent corrosion of the system. Feedwater entering a deaerator needs to be approximately 20° F. below the deaerator operating temperature for proper operation. The temperatures shown in FIG. 1 are merely illustrative as the temperatures can vary depending on the application.
Generally, feedwater heaters have tubes produced from costly high alloy material to withstand the dissolved gases in feedwater, such as a high oxygen concentration. Therefore, it would be advantageous to remove the dissolved gases from the feedwater so that feedwater heater tubes can be produced using more economical materials, such as carbon steel.
The exhaust gas in an HRSG includes carbon dioxide and water in the vapor phase, but also includes traces of sulfur in the form of sulfur dioxide and trioxide. Those sulfur compounds, if combined with water, produce sulphuric acid which is highly corrosive. As long as the temperatures of the heating surfaces remain above the acid dew point temperature of the exhaust gas, SO2 and SO3 pass through the HRSG without harmful effects. But if any surface drops to a temperature below the acid dew point temperature, sulphuric acid will condense on that surface and corrode it.
Dew point temperatures vary depending on the fuel that is consumed. For natural gas, because of the sulphuric acid content the temperature of the heating surfaces should not fall below about 140° F.
Generally, an HRSG comprises a casing having an inlet and an outlet and a succession of heat exchangers-namely a superheater, an evaporator, and a feedwater heater arranged in that order within the casing between the inlet and outlet.
Such heat exchangers for an HRSG can have multiple banks of coils, the last of which in the direction of the gas flow can be a feedwater heater. Surfaces vulnerable to corrosion by sulphuric acid do exist on the feedwater heater. The feedwater heater receives condensate that is derived from low-pressure steam discharged by the steam turbine, and elevates the temperature of the water. Then the warmer water from the feedwater heater flows into one or more evaporators that convert it into saturated steam. That saturated steam flows on to the superheater which converts it into superheated steam. From the superheater, the superheated steam flows to the steam turbine.
In this process, by the time the hot gas reaches the feedwater heater at the back end of the HRSG, its temperature is quite low. However, that temperature should not be so low that acids condense on the heating surfaces of the feedwater heater.
Generally, in the above-discussed process, most HRSGs produce superheated steam at three pressure levels-low pressure (LP), intermediate pressure (IP) and high pressure (HP). An HRSG can thus have a superheater and also can have what are termed an LP Evaporator, an HP Economizer, and an IP Economizer. The feedwater heater typically discharges some of the heated feedwater directly into an LP evaporator.
A feedwater heater, or preheater, in a steam generator extracts heat from low temperature gases to increase the temperature of the incoming condensate before it goes off to the LP evaporator, HP economizer, or IP economizer. Multiple methods have been used to increase the temperature of the condensate before it enters any part of the preheater tubes within the gas path (e.g., recirculation pump, external heat exchanger). These methods are used to prevent the exhaust gas temperature from dropping below the acid dew point and causing sulphuric acid corrosion.
An overall illustration of a system which features use in a heat-recovery steam generator (HRSG) appears in U.S. Pat. No. 6,508,206 B1 (hereafter "'206 Patent"). FIG. 4 of the '206 Patent illustrates an arrangement with a superheater 18 located at the farthest position upstream. FIG. 4 of the present application generally refers to members such as a superheater and IP Economizer as upstream coils UC.
FIG. 3 of the present application shows a layout perspective similar to that shown in FIG. 3 of the '206 Patent. FIG. 3 of the present application discloses a gas turbine G that discharges hot exhaust gases into an "HRSG", which extracts heat from the gases to produce steam to power a steam turbine S. The gas turbine G and steam turbine S power the generators E that are capable of producing electrical energy. The steam turbine S discharges steam at a low temperature and pressure into a condenser CN, where it is condensed into liquid water. The condenser CN is in flow connection with a condensate pump CP that directs the water back to the HRSG as feedwater. That water can pass through an external water-to-water heat exchanger EWTWEX that is located outside of the casing CS, and thus is external to the internal exhaust gas flow path through the HRSG duct.
The HRSG has a casing CS within which are heat exchangers. Hot gases, such as discharged from a gas turbine, enter the casing CS and pass through a duct having an inlet IN and an outlet OT. During such process, that gas passes through heat exchangers.
The casing CS of the HRSG generally will have a floor F, a roof R, and sidewalls that extend upwardly from the floor F to the roof R. The heat exchangers are positioned within the casing CS. The floor F and roof R extend between the sidewalls so that the floor F, sidewalls and roof R help to form the internal duct of the casing CS of the HRSG, through which the exhaust gas passes.
Generally, the heat exchangers comprise coils that have a multitude of tubes that usually are oriented vertically and arranged one after the other transversely across the interior of the casing CS. The coils are also arranged in rows located one after the other in the direction of the hot gas flow depicted by the arrows in FIGS. 3 and 4 of the present application. The tubes contain water in whatever phase its coils are designed to accommodate. The length of the tubes can be as great as 80' tall.
Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.


The invention provides a stage system comprising a stage (ST) which is movable in respect of a reference structure. One of the stage and the reference structure comprises a reflective surface (REFS). An optical position sensor (IF1) is arranged at the other one of the stage and the reference structure and is configured to determine a position of the reflective surface relative to the optical position sensor. An optical shape sensor (IF2) is configured to determine a shape of the reflective surface. The stage system further comprises a position measurement controller configured to derive a stage position of the stage from the position of the reflective surface relative to the optical position sensor and from the shape of the reflective surface as determined by the optical shape sensor.

A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may, for example, project a pattern (also often referred to as "design layout" or "design") of a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) provided on a substrate (e.g., a wafer).
As semiconductor manufacturing processes continue to advance, the dimensions of circuit elements have continually been reduced while the amount of functional elements, such as transistors, per device has been steadily increasing over decades, following a trend commonly referred to as 'Moore's law'. To keep up with Moore's law the semiconductor industry is chasing technologies that enable to create increasingly smaller features. To project a pattern on a substrate a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features which are patterned on the substrate. Typical wavelengths currently in use are 365 nm (i-line), 248 nm, 193 nm and 13.5 nm. A lithographic apparatus, which uses extreme ultraviolet (EUV) radiation, having a wavelength within a range of 4 nm to 20 nm, for example 6.7 nm or 13.5 nm, may be used to form smaller features on a substrate than a lithographic apparatus which uses, for example, radiation with a wavelength of 193 nm.
In a lithographic apparatus a movable stage may be applied, such as a substrate support that holds the substrate or a mask support that holds the mark. An accuracy of positioning of such a stage may translate into a projection accuracy, e.g. an overlay accuracy of the patterns to be projected onto the substrate. The stage may be positioned by a positioner, e.g. comprising one or more actuators. The position of the stage may be controlled making use of one or more position sensors, such as optical position sensors. Examples of such optical position sensors are an interferometer and an encoder. The optical position sensor may make use of a reference, such as a mirror. For example, the interferometer may make use of a reflecting surface onto which an interferometer beam is reflected. For example, a measurement head of the interferometer may be arranged stationary, whereby a distance to a reflecting surface of the stage is measured using the interferometer beam. As another example, a measurement head of an encoder and/or interferometer may be arranged at the stage. A stationary encoder grid may be applied as a reference for the encoder. The encoder grid may form a reflective surface. Likewise, in the case of an interferometer, an interferometer measurement head may be arranged at the stage and may cooperate with a stationary reflective surface to perform position measurement.


A support robot and control system having a support arm providing at least one degree of motion. The support robot includes a support arm supporting mechanism connected to the support arm and providing at least two degrees of motion. The support arm optionally includes a biomimetic actuator connectable to an end effector, a telescoping section operatively connected to the biomimetic actuator, and a tensile force transmitting member connected to an actuator. The actuator is capable of moving the biomimetic actuator towards and away from the actuator via the tensile force transmitting member. The support arm further includes an inflatable outer cover at least partially encasing the telescoping section and the tensile force transmitting member.

Modern assembly lines and/or automobile assembly or repair processes still rely on tasks performed by technicians. Automation has significantly reduced the number of tasks performed by technicians; however, a number of tasks cannot be effectively or efficiently performed by automated systems due in part to an automated system's lack of ability to respond flexibly to changes in the assembly process and/or to perform certain complex tasks. Thus, the need for technicians in an assembly and/or repair environment still exists. However, there remains an unmet need to improve efficiency and worker safety when completing certain tasks. Automation may be especially useful in transporting or manipulating an object and/or assembly to improve the efficiency of tasks performed by technicians, for example. While manipulators for transporting loads such as robot arms exist, their complexity, high cost, and relatively low load carrying capacity compared to complexity and cost provides a need for a simpler solution that allows for increased load carrying capacity. Further, there remains an unmet need for a collaborative robot and/or system that is safe for technicians and would not cause injury if the robot and/or system were to come into contact with the technician. Further advantages will become apparent from the disclosure provided below.

Telescoping support robot and methods of use thereof


A method, a software product, and an apparatus to determine time offsets to use with a local synchronization clock in a wireless device that can act as a plurality of (virtual) APs, each having a different network identifier. The offsets provide for the wireless device the time to transmit frames that include a broadcast-buffered indication for a particular (virtual) AP identified by a MAC address of a plurality of MAC addresses supported by the wireless device. The broadcast-buffered indication for a particular MAC address indicates that there is broadcast/multicast data buffered in the wireless device. The method is arranged such that the frames containing the broadcast buffered indication for each access point of the wireless device are transmitted by the wireless device at times spread substantially evenly, interleaved with other broadcast frames not containing broadcast buffered indications.

The present invention relates to wireless networks, and in particular to a method and apparatus to determine times for transmission of frames by a wireless device capable of supporting a plurality of MAC addresses such that the wireless device can function as a plurality of access points in a wireless network.
Wireless networks, in particular wireless local area networks (WLANs) such as those conforming to the IEEE 802.11 standard are becoming widely used. In a wireless network that acts in infrastructure mode, one wireless device acts as an access point (AP)—also called a base station—to a set of client stations, and all communication to and from a client station via the access point to which the client is associated.
Multiple BSSID Wireless Devices as Virtual Access Points
A new feature being developed for wireless devices is the ability for a single wireless device to act as multiple "virtual" access points, each for a different infrastructure wireless network. Thus, a single wireless device can act as an access point, also called a base station for a plurality of infrastructure networks. Each infrastructure network is identified by a network identifier. In the language of the IEEE 802.11 standard, each infrastructure network is called a basic service set (BSS), and the network identifier is a basic service set identifier (BSSID). For an AP, the BSSID is the MAC address of the AP. Thus, a single wireless device can have a plurality of MAC addresses.
An AP indicates its availability by broadcasting beacon frames. For a wireless device to act as more than a single AP, that is, to act as a multiple BSSID AP (MBSSID-AP) device, the wireless device needs to be able to broadcast multiple beacons spread across a beacon period, each beacon indicating that the broadcasting device has a different BSSID.
To a client station, an MBSSID-AP appears to be several distinct co-located APs.
Power Save Mode in WLANS
It is known for a wireless client of an infrastructure WLAN to work in power save mode, wherein the AP of the client notes which client is in "sleep" ("power save") mode, and buffers packets for clients in sleep mode. An indication by an AP to one or more particular clients that data is buffered for the client(s), called a traffic indication map element (TIM) in the case of the IEEE 802.11 standard, is used to make it possible for the AP to announce which client stations have data buffered. The TIM is sent with every beacon from the AP. Client stations that are in power save mode periodically wake up and listen for beacons. Thus, an AP broadcasts frames containing indications to particular client(s) that data is buffered for the client(s) in the AP.
A client receiving a TIM interprets the TIM to determine if unicast and multicast traffic is buffered on the AP for the client. A client station, once it determines that unicast data is buffered at the AP, transmits a short poll frame (a PS-Poll) to the AP, and the AP of the client station responds with the corresponding buffered unicast data, or acknowledges receipt of the poll and sends the buffered unicast data at a later time.
If the TIM indicating that data is buffered is sent during a contention-free period (CFP), a contention-free pollable client station operating in sleep mode does not send the short PS-Poll frame, but rather remains active until the buffered data is received, or until the CFP ends.
In addition to unicast traffic for a client station, there may be broadcast or multicast traffic buffered for client stations. On the AP side, if any client station is in sleep mode, the AP buffers all broadcast and multicast traffic. Once in a while, the AP broadcasts a frame—a beacon frame—that includes an indication that broadcast or multicast traffic is buffered in the AP. We call such an indication a broadcast-buffered indication. In the case of the IEEE 802.11 standard, the indication is called a delivery traffic indication map element (DTIM). Thus, an AP once in a while transmits a beacon containing a DTIM. The AP then delivers any multicast or broadcast traffic that is buffered to all clients immediately following transmission of the DTIM-containing beacon.
Recall a TIM identifies the client stations for which traffic is pending and buffered in the AP, and this is coded in a partial virtual bitmap. In addition, the TIM contains an indication of whether multicast/broadcast traffic is buffered. While an AP sends a TIM with every beacon, a DTIM rather than an ordinary TIM is transmitted within a beacon every period called a DTIM period. After transmitting a DTIM, an AP sends out any buffered broadcast or multicast traffic using normal frame transmission rules.
Thus, unicast traffic is obtained by the client via a PS-Poll, and multicast traffic destined to the clients in the BSSID is transmitted at the DTIM beacon boundary.
In an 802.11 WLAN, a timing synchronization function (TSF) keeps the timers for all stations in the same infrastructure network synchronized. The AP is the timing master and performs the TSF. Each station maintains a local TSF timer. Each client station's TSF timer keeps running even when stations are sleeping.
Power Save Mode for Virtual APs in a Device Supporting Multiple BSSIDs
With a single wireless device able to act as different APs for different sets of client stations, e.g., a single device having multiple BSSID's, problems arise if the individual beacon DTIM periods overlap between different infrastructure networks. As an example, consider the case of a single wireless device acting as the virtual AP of four BSSs. The wireless device thus has four corresponding BSSIDs, each with a DTIM period. Suppose the DTIM period was 2. The following describes what would be the default transmission order of the beacons:
Denote by B(n) a regular beacon frame for the device acting as AP with a BSSID denoted n, n=1, 2, 3, or 4, and denote by D(n) a beacon frame containing a DTIM for the wireless device acting as AP with the BSSID n, n=1, 2, 3, or 4. Then the sequence of transmitting beacons would be:
B(1) B(2) B(3) B(4) D(1) D(2) D(3) D(4)
This is undesirable because there is a cluster of DTIM beacons happening one after the other. Suppose, for example, that power save client stations are associated to all four "virtual" APs, i.e., with all four of the BSSIDs supported by the wireless device. After each DTIM beacon, all the multicast traffic that needs to be transmitted is so transmitted at the respective DTIM beacon boundary. If there is high priority traffic in another of the BSSIDs, such high priority traffic would be affected.
Thus there is a need in the art for a method for a wireless device to broadcast DTIM beacons for one BSSID in a manner such that traffic in other BSSIDs supported by the wireless device is unlikely to be affected in the case that the single wireless device acts as multiple APs, each with a different BSSID.

Determining broadcast message transmit times for a wireless device having a plurality of WLAN MAC addresses


A wireless power supply device comprises a transmitting coil assembly and a receiving coil assembly. The transmitting coil assembly includes a first ferrite core having a receiving chamber with an opening and a transmitting coil disposed in the receiving chamber of the first ferrite core. The receiving coil assembly is adapted to be moved into the receiving chamber through the opening of the receiving chamber and located at a predetermined position in the receiving chamber. The receiving coil assembly is electromagnetically coupled with the transmitting coil assembly.

In the prior art, an electric energy for controlling and driving parts of an electrical apparatus is mainly transmitted by electrical wires connected to an external power source or a built-in battery. Internal power of the electrical apparatus is transmitted by the physical connections of electrical wires. The electrical wires may be physically worn and damaged by some of the movable parts of the electrical apparatus, leading to safety problems and reducing the life of the electrical apparatus. The electrical apparatus must therefore undergo frequent maintenance.
A wireless power supply device has recently been used in an electrical apparatus to overcome the problems associated with physical connections of electrical wires. The wireless power supply device coupling coils achieve contactless electric energy transmission among parts of the electrical apparatus. The movable parts of the electrical apparatus are not limited to the location of the electrical wires and may be positioned at any suitable location due to the wireless power supply device, avoiding the problems caused by the physical connections of electrical wires. Moreover, the structural design of the electrical apparatus is more flexible, and the aesthetic feeling and functions of the electrical apparatus may be improved, especially as it relates to household electrical appliances.
The wireless power supply device generally comprises a transmitting coil and a receiving coil electromagnetically coupled with the transmitting coil. The transmitting coil is disposed in a metal case to ensure the electrical apparatus has an aesthetically pleasing appearance. If the metal case is close to the transmitting coil, an alternating magnetic field, generated by the transmitting coil, may induce an eddy current in the surface of the metal case. As is well known to those in the art, the eddy current effect means the power of the electrical system is wasted in the heating of the metal case, which reduces the efficiency and stability of the electrical system. The inductance of the transmitting coil and the receiving coil, as well as the mutual inductance between the transmitting coil and the receiving coil, are affected, and the original matching between the transmitting coil and the receiving coil may become invalid, causing the electrical system to function abnormally.
In order to reduce the eddy current effect, it is normally required to keep a distance between the metal case and the receiving coil of at least 6 mm, requiring an increased size of the metal case and the electrical apparatus and increasing the difficulty of designing an aesthetically pleasing electrical apparatus.

Wireless power supply device and electrical apparatus