A combustor of a gas turbine combustion engine often includes several individual combustor cans. Within each can there are multiple swirlers which impart rotational movement to the air-fuel mixture flowing through it. A conventional configuration includes eight main swirlers and a central pilot swirler, where all swirlers have parallel axes. Compressed air flows, into each main swirler individually and into the central pilot swirler individually. Fuel is added to the air as it flows through the swirler, resulting in an air-fuel mixture flowing through each main swirler. Accordingly, in a configuration with eight main swirlers and a central pilot swirler, there are nine air-fuel mixture flows; one through each of the eight main swirlers, and one through the central pilot swirler. Each air-fuel mixture flows axially, centered on the same axis as the swirler through which it is flowing. A swirler then imparts a rotation to this axial flow, such that the air-fuel mixture exiting an individual swirler is flowing along the central axis of that swirler while simultaneously rotating around that central axis. Each of the main swirlers in this relevant configuration imparts a clockwise rotation to the air-fuel mixture flowing through it as viewed looking downstream, and the central pilot swirler imparts a counterclockwise rotation. Consequently, because each main swirler imparts a clockwise rotation to the air-fuel mixture flowing through it, the tangential velocities of the rotation of adjacent air-fuel flows will be opposite where the adjacent air-fuel flows meet. Friction in these areas where adjacent tangential fuel flows oppose each other results in shear and vortices.
The formation of oxides of nitrogen NOx is correlated to the temperature of combustion. Therefore, NOx emissions are reduced by reducing the temperature and size of the hot zones within the combustor. In the combustor configuration described above, the air-fuel flow through the pilot swirler runs relatively rich, i.e. a higher concentration of fuel in this mixture exists than exists in the main swirler flows. This provides a hot central flame to stabilize the overall combustor dynamics, which is necessary because the outer swirlers are unable to stabilize on their own due to the lean air-fuel mixture flowing through them. Thus, reducing NOx emissions in this configuration means reducing the size of the central pilot zone, and/or reducing the temperature of the air-fuel flow in the central pilot zone by reducing the amount of fuel in that air-fuel mixture. However, as the central pilot zone air-fuel flow (and associated temperature) is reduced, combustion dynamics (i.e. pressure oscillations) increase. These dynamic pressure oscillations can be harmful to the combustion chamber.
Dynamic pressure oscillations are associated with either the lean flammability limit of the air-fuel mixture, or fluctuations in the heat release rate of the combustion flame. Oscillations associated with the lean flammability limit are typically characterized by frequencies below 50 hertz. Oscillations associated with combustion flame heat release rate are typically associated with higher frequencies, and they and are often the limiting dynamic in the higher firing-temperature applications currently under development. High frequency pressure oscillations cause fluctuations in the heat release rate of the combustion flame, which is responsive to changes in pressure. A change in the heat release rate of the combustion flame produces pressure oscillations, and the feedback cycle repeats.
As a result, the ability to reduce NOx and CO emissions in the above described combustor configuration is limited by the need to minimize high frequency pressure oscillations. Accordingly, once the temperature of the central pilot zone is reduced to the point where combustion dynamics have reached a maximum safe level, NOx and CO emissions can not be reduced any more.
Conventional swirlers also have variable fuel-hole injection patterns to enable a center rich concentration of fuel in the air fuel mixture. Other patterns known in the art result in air-fuel mixtures where the fuel is either uniformly distributed throughout the air-fuel flow, or is concentrated in the outer portion of the air-fuel flow, result in high levels of combustion driven oscillations. However, because the fuel is concentrated in the center of the air-fuel flow, the peak temperature of the burn at the center of the flow is greater than the temperature of the burn of an evenly distributed air-fuel flow. This center-rich fuel configuration results in greater NOx and CO production, due to the exponential nature of NOx production with temperature.
Further, when main swirler flows have a center rich fuel configuration, complete combustion, which requires complete mixing of the central pilot flow and the main swirler flows, requires more time, resulting in a longer central flame, and yet further increased NOx and CO production.
Thus, there exists a need in the art to further reduce the temperature and/or size of the central pilot zone without increasing combustion dynamics, in an effort to reduce NOx and CO emissions.


Modern networks, such as access and aggregation networks, are moving towards Ethernet as the universal medium. However, Ethernet is not quite robust enough for carrier transport applications. Thus, a new variation termed “Carrier Ethernet” has been created. Carrier Ethernet is configured to provide Ethernet-based operations, administration, and maintenance (OAM). There are many variations of this type of Ethernet, for example Optical Transport Network (OTN) carriage of Ethernet is a form of carrier Ethernet. OTN can offer a form of tunneling, and in addition offers hardening features such as embedded forward error correction (FEC).
Referring to FIG. 1, an Ethernet frame 10 with Virtual Local Area Network (VLAN) tagging is illustrated in one instance of Carrier Ethernet. VLAN Tagging is defined in IEEE 802.1Q as a standard to allow multiple bridged networks to transparently share the same physical network link without leakage of information between networks (i.e. trunking). The Ethernet frame 10 in IEEE 802.1Q is not actually encapsulated. Instead, the EtherType value (for Ethernet II framing) in the Ethernet header is set to hex 8100, identifying this frame as an 802.1Q frame. Also, four extra bytes are added after the Ethernet header consisting of two-byte Tag Control Information (TCI). VLAN ID (VID) is a 12-bit field specifying the VLAN to which the frame 10 belongs. A value of “0” means the frame 10 does not belong to any VLAN (so that the 802.1Q header specifies only a priority), a value of “1” is used with bridges, and a value of hex FFF is reserved for implementation use; all other values can be used as VLAN identifiers, allowing up to 4093 VLANs.
VLAN tagging is a Media Access Control (MAC) option that provides three important capabilities not previously available to Ethernet network operators and users. First, it provides a quality-of-service (QoS) mechanism to expedite time-critical network traffic by setting transmission priorities for outgoing frames 10. Second, it allows stations to be assigned to logical groups to communicate across multiple LANs as though they were on a single LAN. For example, bridges and switches filter destination addresses and forward VLAN frames only to ports that serve the VLAN to which the traffic belongs. Finally, VLAN tagging simplifies network management and makes adds, moves, and changes easier to administer.
The VLAN header includes two fields: a reserved 2-byte type value, indicating that the frame is a VLAN frame, and a two-byte Tag-Control field 14 that contains both the transmission priority (0 to 7, where 7 is the highest) and a VLAN ID 12 that identifies the particular VLAN over which the frame is to be sent. The receiving MAC reads the reserved type value, which is located in the normal Length/Type field position, and interprets the received frame as a VLAN frame. If the MAC is installed in a switch port, the frame is forwarded according to its priority level to all ports that are associated with the indicated VLAN identifier. If the MAC is installed in an end station, it removes the 4-byte VLAN header and processes the frame in the same manner as a basic data frame. VLAN tagging requires that all network nodes involved with a VLAN group be equipped with the VLAN option.
Referring to FIG. 2, an Ethernet frame 20 for Provider Backbone Transport (PBT) according to IEEE 802.1ah is illustrated in another instance of Carrier Ethernet. PBT is a set of enhancements to Ethernet technology that allows the use of Ethernet as a carrier-class transport network. PBT uses the concepts of VLAN tagging as per IEEE 802.1Q, Q-in-Q as per IEEE 802.1ad and MAC-in-MAC as per IEEE 802.1ah (Provider Backbone Bridges (PBB)) but disables the concept of flooding/broadcasting and spanning tree protocol (SPT). The idea here is to use Ethernet for connection oriented purpose as is the case with present SDH/SONET transport by stripping down the complexity involved with the present Ethernet LAN. It simplifies the OAM, as in SDH/SONET world, by using additional extensions based on IEEE 802.1ag. It also provides extensions so as to provide path protection levels similar to the UPSR protection in SDH/SONET network.
In the Ethernet frame 20, the tunnel is encoded by the destination MAC address of the backbone egress switch (B-DA) as well as a 12-bit VLAN-tag (backbone tag, B-VID). PBT forms a topology of B-DA rooted trees and an independent sink-tree is configured for each <B-DA, B-VID> pair. Since no SPT algorithm has to be performed, the trees need not be spanning. Thus, up to 4096 different trees can be configured for one B-DA.
IEEE 802.1ad (Provider Bridges) is an amendment to IEEE standard IEEE 802.1Q-1998 (also known as Q-in-Q or Stacked VLANs), intended to develop an architecture and bridge protocols to provide separate instances of the MAC services to multiple independent users of a Bridged Local Area Network in a manner that does not require cooperation among the users, and requires a minimum of cooperation between the users and the provider of the MAC service. For example Q-in-Q can operate as follows: two VLAN tags are added to each customer Ethernet packet. The Ethernet VLAN tag includes both a 12-bit VLAN ID and a 3-bit priority tag. The inner VLAN is customer assigned, and the outer VLAN corresponds to the carrier's assignment of a tunnel in which customer traffic is carried. For example, multiple customer flows may be “clustered” into the outer VLAN. A part of the VLAN assignment can include a 3-bit p-bit priority marking per 802.1p. The VLAN assignment can indicate how the traffic is to be prioritized. Sometimes, the Ethernet packet priority is derived from the IP layer's DiffServ Code Point (DSCP) bits. The VLAN assignment can also indicate the shaping assigned to an Ethernet flow cluster.
In another example, PBT is used as a similar alternative to Q-in-Q except that two MAC addresses are used instead of two VLAN IDs. Each of these MAC addresses can be associated to a VLAN also, and as such has the priority markings. This is similar to the Q-in-Q except that the tunnel label field includes the MAC and that two MAC addresses are used instead of two VLANs. Another difference with PBT is that the management system normally assigns the MAC/VLAN labels along the tunnel path Ethernet switches. Once again, prioritization and clustering is done via the MAC+VLAN label.
Transport Multi-protocol Label Switching (T-MPLS) is an ITU-T defined network layer technology that uses a subset of the existing MPLS standards and is designed specifically for application in transport networks. T-MPLS offers a simpler implementation by removing features that are not relevant to connection-oriented packet-switched applications and adding mechanisms that provide support of critical transport functionality. For prioritization in T-MPLS, an MPLS shim header is used. In this scheme, the MPLS label is used to define a traffic engineered path for with the Ethernet frames must follow. The QoS can be explicit or implicit depending on the label implementation/policy.
Disadvantageously, all of the above described methods require prioritization to be marked in either the form of VLAN bits or MPLS labels, i.e. pre-determined or explicit. This leaves little flexibility in the grouping of individual Ethernet flows for the purpose of shaping and prioritization. For example, all Ethernet packets in one VLAN are treated with the priority of that VLAN.


1. Field of the Invention
The present invention relates to a method for the selective growth of an epitaxial layer on source/drain areas.
2. Description of the Related Technology
In semiconductor fabrication a hard mask (HM) is applied in order to protect part of the wafer from etching the other part of the wafer. The hardmask usually has to be removed afterwards. Typically an etch resistant material is employed for the hardmask.
When considering a process flow for fabricating a CMOS FET transistor, a gate stack is formed, which is capped with a silicon oxide (2) and with spacers (4)(see FIG. 1(A)). Spacers (4) around the gate are typically in Si nitride. The full encapsulation is of vital importance, as it protects the gate during epitaxial growth. Further processing steps are depicted in FIG. 1. In a first step either a single layer hardmask (5) is deposited (FIG. 1(B.1)) or a hardmask stack, which cannot be etched during source/drain etching (in FIG. 1(B.2) a two-layer stack (5, 6) is shown). Next a first area is opened up comprising a source and drain (S/D) and a gate stack (FIG. 1(C)). The hardmask (5) is etched selectively towards Si oxide (used to cap the gate) and Si nitride (used for the spacers) of the first area and also selectively to the hardmask on top of a second area of the substrate (1). If the hardmask etching is not performed in a sufficiently selective way, an accurate control of the lost amount of Si oxide/Si nitride is required. In the following step (FIG. 1(D)) a source/drain (S/D) silicon etch is performed selectively towards Si oxide and Si nitride. The etch rate depends on the amount of exposed Si. A part of the hardmask (5) is consumed by a break through (BT) etch. Next an epitaxial layer is grown. During the epitaxial growth a selective growth towards the hardmask in the second area is required. The epitaxial growth is only selective towards Si oxide and Si nitride. Finally the hardmask is removed on the second area (FIG. 1(E)). Note that the hardmask cannot be removed before the epitaxial layer has grown as it should protect (at least the second area on) the wafer. In the state of the art approach the hardmask on the second area is removed afterwards by an etching step, which causes field oxide loss. A possible solution exists in providing an additional protective mask on the first area, which clearly would increase the complexity.
Silicon nitride is the typical material for spacers (4). Si nitride cannot be applied for the hardmask (5), as during hardmask removal it would remove the spacers (4) as well. An alternative would be the use of Si oxide. However, Si oxide is not an appropriate material either, as Si oxide may be used on top of the gate. When using a Si oxide hardmask, one would have to remove the hardmask very carefully in order not to damage the oxide capping layer on top of the gate (in order to protect the gate during the epitaxial growth). Using a Si oxide hardmask, the extra oxide on top of the second area must be removed, which increases field loss on the first area, as the latter ‘sees’ the double removal of the oxide layer. An option would be to use lithography and etch only on the second area, which increases complexity.
In the state of the art solutions it is neither possible to use poly-silicon as the hardmask material. The poly-Si hardmask would have to be removed before the epitaxial growth, as it does not allow such epitaxial growth in a selective way. The epitaxial layer will cover the whole wafer and not only fill the S/D areas of the first area. However, it would be desirable and advantageous to have a poly-Si hardmask, as it would allow etching selectively towards nitride and oxide (e.g. towards an oxide gate capping layer or towards the field oxide), which would put less strain.
It is thus desirable to provide a method for selective epitaxial growth of S/D areas that overcomes the drawbacks of the prior art solutions.


Electrical cables are commonly supplied to an electrical junction box for connecting the cable to electrical fixtures or other electrical cables. The cables generally pass through an opening in the wall of the electrical box and are secured in place by a suitable clamp. Conventional cable clamps generally clamp the cable between the clamping plate and a side wall or bottom wall of the electrical box. This type of clamping arrangement generally relies on the smooth surface of the wall of the electrical box that does not adequately grip the cable.
Cable clamps are produced which are able to accommodate metal armor cable and plastic sheath cables. These devices include a stop member for the metal sheath to prevent the metal sheath from extending into the electrical box. Various clamping devices are known for clamping the electrical cable. Many of these cable clamps are mounted to the cable and then inserted into the opening in the electrical box so that at least a portion of the clamp projects outwardly from the outer surface of the electrical box.
One example of an electrical cable clamp is disclosed in U.S. Pat. No. 4,316,999 to Nattel which discloses an electrical wiring box and cable clamp where the cable clamp is attached to the wall of the electrical box. The cable clamp is a flexible member that overlies the opening in the electrical box bottom edge of the leg portions including upwardly turned flanges. The bottom wall of the electrical box includes ridges or score lines for engaging the nonmetallic cable.
U.S. Pat. No. 4,922,057 to Ross discloses an electrical box having a flexible flat retaining member attached to the inner face of the side wall of the electrical box. As shown in FIG. 2, the flat retaining member flexes to grip the surface of the cable passing through the opening in the electrical box.
U.S. Pat. No. 4,724,282 to Troder discloses a nonmetallic electrical box having a flexible metal cable retaining member attached to the inner face of the electrical box. The retaining member flexes when the cable is passed through the opening to grip the cable.
U.S. Pat. No. 4,277,641 to Bauer et al. discloses a nonmetallic electrical box having a cable clamp member that is inserted into the cavity of the electrical box. The cable clamp member includes an outer frame and a flexible flap. The flexible flaps bend upon insertion of the electrical cable through the opening in the frame to grip the cable.
U.S. Patent Publication No. 2012/0024596 to DiLillo et al. discloses a plastic cable clamp adapted for mounting in one of the openings in the electrical box. The cable clamp includes one or more flexible members capable of clamping the nonmetallic cable. In one embodiment, the cable clamp includes flexible legs that can bend inwardly upon insertion of the cable to grip the outer surface of the cable.
While the prior cable clamps and connectors are generally suitable for the intended use, there is a continuing need in the industry for improved cable clamps and connectors.


With the advent of the Internet has come the opportunity for the print media industry to publish “on-line” rather than producing and distributing traditional paper based publications. On-line publishing has a number of advantages. From the consumer's point of view, information is available on demand, information can be navigated via hypertext links, information can be searched, and information can be automatically personalized. From the publisher's point of view, the costs of printing and physical distribution are eliminated and the publication becomes more attractive to advertisers as it can be targeted to specific demographics and linked to product sites.
On-line publication also has disadvantages. Computer screens are inferior to paper. At the same quality as a magazine page, a SVGA computer screen displays only about a fifth as much information. Both CRT's (Cathode Ray Tubes) and LCD's (Liquid Crystal Displays) have brightness and contrast problems, particularly when ambient light is strong. Ink on paper, being reflective rather than emissive is both bright and sharp in ambient light. Accordingly, people have a natural preference to read newspapers, magazines, catalogues, brochures and other publications in a bound paper based format.
Known digital printers, and in particular digital inkjet printers, do not make any provision for binding together the pages of printed media. Such an arrangement would conveniently provide for bound document production in the small office/home office (SOHO) environment. This would also permit some of the existing drawbacks of on-line publication to be addressed. However, in the SOHO environment space is often at a premium. Therefore, any provision for automatically binding separate pages into a bound document must not add a significant amount of extra space over that occupied by the printer.


The present invention relates to implantable systems that include medical devices (e.g., stents, vascular grafts, stent grafts) that function as a carrier for eukaryotic cells (e.g., genetically engineered endothelial cells). Such cells are capable of producing and releasing a therapeutic agent (e.g., tissue-type Plasminogen Activator) for on-demand localized treatment of conditions such as coronary artery disease. The cells or the device carrying them release the therapeutic agent upon the application of a stimulus (e.g., electrical stimulus).
Coronary Artery Disease (CAD) affects 1.5 million people in the USA annually. About 10% of these patients die within the first year and the rest suffer from myocardial infarction and develop related symptoms, such as arrhythmias, CHF, and mechanical complications (e.g., aneursym, thrombus formation, pericarditis). During CAD, formation of plaques under the endothelial tissue narrows the lumen of the coronary artery and increases its resistance to blood flow, thereby reducing the O2 supply. Injury to the myocardium (i.e., the middle and thickest layer of the heart wall, composed of cardiac muscle) fed by the coronary artery begins to become irreversible within 0.5-1.5 hours and is complete after 6-12 hours, resulting in a condition called myocardial infarction. If the ischemia due to stenosis of the coronary artery lumen could be reduced by increasing the blood circulation to the myocardium, the major cause of most of the heart disease would be eliminated.
Current and proposed treatments for coronary artery disease typically focus on pharmacological approaches and surgical intervention. For example, angioplasty, with and without stents, is a well known technique for reducing stenosis. Systemically administered drugs (e.g., anticoagulants) are also commonly used, however, such drugs become diluted, which can reduce their potency by the time they reach the remote site. Furthermore, systemic administration can be deleterious because it can lead to complications as a result of the high dosages required upon administration to allow for dilution that occurs during transport to the remote site. Therefore, localized delivery of therapeutic agents is preferred. Local delivery is advantageous in that the effective local concentration of delivered drug is much higher than can normally be achieved by systemic administration.
Stents have been used as delivery vehicles for therapeutic agents (i.e., drugs). Intravascular stents are generally permanently implanted in coronary or peripheral vessels. Stent designs include those of U.S. Pat. Nos. 4,733,655 (Palmaz), 4,800,882 (Gianturco), or 4,886,062 (Wiktor). Such designs include both metal and polymeric stents, as well as self-expanding and balloon-expandable stents. Stents are also used to deliver a drug (e.g., antiplatelet agents, anticoagulant agents, antimicrobial agents, antimetabolic agents) at the site of contact with the vasculature, as disclosed in U.S. Pat. No. 5,102,417 (Palmaz) and in International Patent Application Nos. WO 91/12779 (Medtronic, Inc.) and WO 90/13332 (Cedars-Sanai Medical Center), for example. Anticoagulant substances such as heparin and thrombolytic agents have also been incorporated into a stent, as disclosed, for example, in U.S. Pat. Nos. 5,419,760 (Narciso, Jr.) and U.S. Pat. No. 5,429,634 (Narciso, Jr.). Stents have also been used to deliver viruses to the wall of a lumen for gene delivery, as disclosed in U.S. patent application Ser. No. 08/746,404, filed Nov. 8, 1996 (Donovan et al.).
Stents seeded with autologous endothelial cells (Dichek, et al., Circulation, 80, 1347-1353 (1989)) are disclosed as a method for delivering recombinant protein over time to the vascular wall. The concentration of secreted protein produced by the endothelial cells that is required to treat the surrounding vascular tissue can be significantly higher than could be tolerated if delivered systemically. However, in order to be effective, it is not only necessary to release a high dose of the drug, but it is also necessary to achieve controlled release, e.g., immediately after an occlusion. Thus, it would be desirable to control the release of such cellular components into the surrounding tissue when needed (i.e., on demand). The present invention provides such a system.
Many of the following lists of patents and nonpatent documents disclose information related to the local delivery of therapeutic agents using medical devices, such as stents. Others are directed toward stent designs and other medical devices as well as genetically engineered cells, for example.
All patent and nonpatent documents listed in Table 1 are hereby incorporated by reference herein in their respective entireties. As those of ordinary skill in the art will appreciate upon reading the Summary of the Invention, Detailed Description of Preferred Embodiments, and Claims set forth below, many of the systems, devices, and methods disclosed in these documents may be modified advantageously by using the teachings of the present invention.
The present invention provides implantable systems that include delivery devices having a carrier and eukaryotic cells associated therewith, optionally within a containment vehicle. Such cells are capable of producing at least one therapeutic agent (i.e., drug), which is released from the delivery device upon the application of a stimulus (e.g., electrical stimulus) for on-demand (i.e., when needed) localized treatment of conditions such as coronary artery disease or cerebral vascular occlusion, for example. The cells are referred to herein as xe2x80x9cdrug-elutingxe2x80x9d cells.
Release of the therapeutic agent from the delivery device is stimulated by a variety of methods, including electrical stimulation, which can be used to create an electrical field or mechanical stimulus, for example. This can be accomplished by direct action on the cells, such as by stimulating the cellular membrane to release the cellular products contained therein. Alternatively, this can be accomplished by activating the cellular products such that upon release they will function as therapeutic agents. This can also be accomplished by stimulating a microscopic containment vehicle that contains the cells, such as by stimulating a synthetic membrane of the containment vehicle, to release the cells and/or their cellular products.
Thus, an object of the present invention is to provide a system and method for the treatment (including prevention) of coronary artery disease, for example, by producing and delivering locally a therapeutic agent, such as an anticoagulant. Significantly, the local dosage can be controlled and provided on demand without worrying about the systemic effects. Furthermore, the local dosage can be administered prior to significant physiological damage occurs to the patient.
In a preferred embodiment, the present invention provides an implantable system that includes: a delivery device comprising a carrier for carrying eukaryotic cells that produce at least one therapeutic agent; a stimulating element for stimulating the release of the therapeutic agent from the delivery device; and a sensing element for monitoring at least one physiological property of a patient in which the system is implanted and communicating with the stimulating element to stimulate the release of the therapeutic agent from the delivery device.
In another embodiment, an implantable system includes a delivery device comprising an intraluminal stent, which includes a lumen-wall contacting surface, a lumen-exposed surface, a first polymer composition covering at least a portion of the stent (preferably, at least a portion of the lumen-exposed and the lumen-wall contacting surfaces), and endothelial cells associated with the first polymer composition covering, wherein the endothelial cells produce at least one therapeutic agent. The implantable system further includes an electrical stimulating element for stimulating the release of the therapeutic agent from the delivery device, and a sensing element for monitoring at least one physiological property of a patient in which the system is implanted and communicating with the electrical stimulating element to stimulate the release of the therapeutic agent from the delivery device.
The present invention also provides a method of local delivery (as opposed to systemic delivery) of a therapeutic agent. The method involves simply implanting an implantable system described above. Once implanted into a patient, the therapeutic agent is released from the delivery device when the sensing element detects a predetermined level of a physiological property (e.g., a certain pH or level of blood flow or blood gases) and communicating with the stimulating element to trigger the release.
A method of making an implantable system for local delivery of a therapeutic agent is also included within the scope of the present invention. The method includes: providing a delivery device comprising a carrier and eukaryotic cells associated therewith that produce at least one therapeutic agent; providing a stimulating element for stimulating the release of the therapeutic agent from the delivery device; providing a sensing element for monitoring at least one physiological property of a patient in which the system is implanted; and connecting the stimulating element and sensing element such that they communicate with each other to stimulate the release of the therapeutic agent from the delivery device when implanted in the body of a patient and the sensing element detects a predetermined level of a physiological property. Preferably, the step of providing a delivery device includes: providing a carrier; isolating eukaryotic cells from a patient; culturing the eukaryotic cells; delivering nucleic acid of a desired therapeutic agent to the eukaryotic cells to form genetically engineered eukaryotic cells; and contacting the carrier with the genetically engineered eukaryotic cells.
In an alternative embodiment, the present invention provides implantable systems as described above without the sensing element. In such systems, the patient in which the system is implanted activates the stimulating element when desired (i.e., on demand). Typically, this occurs when the patient detects a change in a physiological condition (e.g., angina) and communicates with the electrical stimulating element to trigger release of the therapeutic agent. The patient can communicate with the electrical stimulating element to activate it using radio frequency, infrared, or acoustic pulses.


1) Field of the Invention
This invention relates to new antibacterial spirocyclic 6-amido-carbapenems and to a process for their synthesis through new intermediates.
2) Brief Description of Disclosures in the Art
Carbapenem antibiotics, particularly imipenem, (see U.S. Pat. Nos. 3,950,377 and 4,194,047) are well known for treating a broad spectrum of gram negative and gram positive bacterial infections. ##STR2##
1-.beta.-Methylcarbapenems, as described in the reference Heterocycles, 1984, Vol. 21, pp. 29-40 by D. H. Shih, F. Baker, L. Cama and B. G. Christensen, are extremely useful and effective broad spectrum antibiotics, useful against a wide variety of bacteria including gram-positive bacteria such as S. aureus, Strep. sp., B. subtilis, and gram negative bacteria such as E. coli, Shigella sp., Enterobacter sp., Klebsiella sp., Proteus, Serratia and Pseudomonas sp.
However, all of the above antibacterial carbapenems utilize 6-substituents other than amido or substituted amido which are the 6-substituents of choice in penicillin, e.g. ##STR3## or the cephalosporins, e.g. ##STR4##
6-Amidocarbapenems and penams are known in the art as exemplified in the following references: U.S. Pat. No. 4,260,627; U.S. Pat. No. 4,206,219; U.S. Pat. No. 4,217,453; U.S. Pat. No. 4,218,459; U.S. Pat. No. 4,218,463; U.S. Pat. No. 4,277,482; and U.S. Pat. No. 4,298,741 to Merck & Co., Inc. which describe 1H-6-amidocarbapenems and 1-methyl 6-aminocarbapenems; BE 887,618 and U.S. Pat. No. 4,347,355 to Abbott which describe 1,1-diloweralkyl-6 -amidocarbapenems; EPO Publication No. 040,494 and U.S. Pat. No. 4,348,264 to Pfizer which describes 1-hydroxy, acetoxy or 1,1-oxo-carbapenems with 6-position conventional penicillin sidechains; EPO Publication Nos. 634,443 and 073,100 and U.S. Pat. No. 4,407,815 to Beecham which describe 1-H-6-amidocarbapenems and penams; Japanese Kokai 58 174 382 to Sanraku Ocean Co. Ltd. which discloses 6-phthalimido-2-SR carbapenems; and EPO Publication No. 045,198 to Takeda Chem. Ind. Ltd. which discloses 1-alkyl-1-alkoxycarbonyl, cyano or COR-substituted-6-aminocarbapenems.
Literature articles relating to 1-H-6-amidocarbapenems discussing problems in ring closures and ester deblocking reactions include: Tetrahedron Letters, 1982, 23 (15), 1545-1548; Tetrahedron Letters, 1982, 23 (50), 5339-5342; L. C. Blaszczak, Eli Lilly Co. Report "Joint Great Lakes and Central Regional Meeting", Western Michigan University, May 23-24, 1984; J. Chem. Soc., Perkins Trans. I, 1982, 2123-2129; Helv. Chim. Acta. 1982, 65, 1378-1384; J.A.C.S., 1982, 104, 4262-4264; Chem. Pharm. Bull. 31 2578 (1983); N. Narisada et. al. 176th ACS National Meeting, Miami, Fla. 1978.; and Nouv. J. Chim. 7 691 (1983).
The assignee herein has been responsible for more recent work with 6-amidocarbapenems. U.S. Ser. No. 213,579, filed Jun. 30, 1988, discloses novel 6-amido-1-methyl-2-(substituted thio)-carabapenems. Also, U.S. Ser. No. 213,398, filed Jun. 30, 1988, discloses novel 6-amido-1-methyl-carbapenems. Further, assignees docket No. 17660 filed the same date herewith discloses novel 6-amido-1-methylcarbapenems. Each class of compounds exhibits antibacterial activity.
New antibacterial compounds are constantly being searched for to enhance the potency and decrease the side effects of current existing carbapenem antibiotics. Thus far, spirocyclic 6-amido carbapenems have not been disclosed in the art.


Floor care appliances such as upright vacuum cleaners have long been known in the art to be useful in cleaning dirt and debris from floors and the like. Generally such vacuum cleaners are not suited for use by individuals with disabilities that restrict them to movement in a wheelchair. The present invention relates to a vacuum cleaner particularly adapted for use by such individuals.


When making a housing for an electronic device for use in outdoor environments, an important consideration is that the housing should be able to cope with large differences in temperature. That is, the housing should be adapted to both cold and hot environments. Much focus is hence needed on insulation and power consumption, and from a economical and environmental perspective it is desirable to keep power consumption at a low level.
Protective housings for electronic devices for outdoor environments usually have a single sealed shell for the purpose of protecting the electronic devices inside the shell. Heat in the shell generated by the electronic device can easily be conducted through the shell if the external air temperature is low. However, when the external temperature is high or the shell is heated by solar radiation, the internal temperature will rise due to the generated heat from the electronic device and the external heat. A solution to such a problem may be to arrange a sunshade or adding a shell outside the sealed shell.
Conventional double shell housings for electronic devices use air between the shells to prevent the external heat to reach into the inner shell. A ventilation opening is typically provided in the outer shell, and provide a natural convection of the air if the inside of the inner shell is heated by the electronic device to a higher temperature than the external temperature. Another way is to manufacture shells in a heat conducting material so as to facilitate transmission of heat, which is generated by the electronic device, to the outside in order to keep the internal temperature down.
Likewise, in conventional double shell housings, the air between the shells may be useful in cold environments, as the air between the shells is applied as an insulation to maintain a convenient tempered environment inside the inner shell around the electronic device.
In such double shell housings using natural convection and an opening in the outer shell, however, there is a problem with a non-effective heat transportation both from the inside of the inner shell and also between the inner and outer shell.
EP 0746 192 A1 addresses this problem by using a plurality of fans provided between an inner and an outer shell, where the inner shell is hermetically sealed and the outer shell has bimetal valves for support of circulation with the environment outside the outer shell. However, EP 0746 192 A1 has a drawback, in that the fans and any electronics connected to the fans will be exposed to the outside environment. If the outside environment is cold and damp, this will lead to damages to the fans and any connected electronics.
In U.S. Pat. No. 4,984,089 an outdoor surveillance apparatus is disclosed which support movement of a camera assembly. The apparatus is adapted to low and high temperature by use of a heater and multiple fans which are regulated by thermostats.
U.S. Pat. No. 4,419,716 disclose a sealed vapor proof housing with a system for isolating an electrical device from ambient atmosphere. Heat is transferred by use of a fan and that the housing made of metal consists of a multiple number of heat exchange fins.


In recent years, machine-learning approaches for data analysis have been widely explored for recognizing patterns which, in turn, allow extraction of significant information contained within a large data set that may also include data consisting of nothing more than irrelevant detail. Learning machines comprise algorithms that may be trained to generalize using data with known outcomes. Trained learning machine algorithms may then be applied to predict the outcome in cases of unknown outcome, i.e., to classify the data according to learned patterns. Machine-learning approaches, which include neural networks, hidden Markov models, belief networks and kernel-based classifiers such as support vector machines, are ideally suited for domains characterized by the existence of large amounts of data, noisy patterns and the absence of general theories. Support vector machines are disclosed in U.S. Pat. Nos. 6,128,608 and 6,157,921, both of which are assigned to the assignee of the present application and are incorporated herein by reference.
Many successful approaches to pattern classification, regression, clustering, and novelty detection problems rely on kernels for determining the similarity of a pair of patterns. These kernels are usually defined for patterns that can be represented as a vector of real numbers. For example, the linear kernels, radial basis function kernels, and polynomial kernels all measure the similarity of a pair of real vectors. Such kernels are appropriate when the patterns are best represented in this way, as a sequence of real numbers. The choice of a kernel corresponds to the choice of representation of the data in a feature space. In many applications, the patterns have a greater degree of structure. This structure can be exploited to improve the performance of the learning system. Examples of the types of structured data that commonly occur in machine learning applications are strings, such as DNA sequences, and documents; trees, such as parse trees used in natural language processing; graphs, such as web sites or chemical molecules; signals, such as ECG signals and microarray expression profiles; spectra; images; spatio-temporal data; and relational data, among others.
For structural objects, kernels methods are often applied by first finding a mapping from the structured objects to a vector of real numbers. In one embodiment of the kernel selection method, the invention described herein provides an alternative approach which may be applied to the selection of kernels which may be used for structured objects.
Many problems in bioinformatics, chemistry and other industrial processes involve the measurement of some features of samples by means of an apparatus whose operation is subject to fluctuations, influenced for instance by the details of the preparation of the measurement, or by environmental conditions such as temperature. For example, analytical instruments that rely on scintillation crystals for detecting radiation are known to be temperature sensitive, with additional noise or signal drift occurring if the crystals are not maintained within a specified temperature range. Data recorded using such measurement devices are subject to problems in subsequent processing, which can include machine learning methods. Therefore, it is desirable to provide automated ways of dealing with such data.
In certain classification tasks, there is a priori knowledge about the invariances related to the task. For instance, in image classification, it is known that the label of a given image should not change after a small translation or rotation. In a second embodiment of the method for selecting kernels for kernel machines, to improve performance, prior knowledge such as known transformation invariances or noise distribution is incorporated in the kernels. A technique is disclosed in which noise is represented as vectors in a feature space. The noise vectors are taken into account in constructing invariant kernel classifiers to obtain a decision function that is invariant with respect to the noise.


This invention relates to fluid flow rate measurements. More specifically, this invention relates to determining fluid flow rates using measured motor speed and torque parameters.
Measurement of fluid flow through pipes and pumps is well known in the art. One method of determining fluid flow rates is to install gears, vanes, paddle wheel, turbines, etc., in the flow channel and determine fluid flow rate by the speed at which these devices turn. A second method is by measuring the differential pressure across a dedicated flow obstruction, such as a venturi, orifice plate, annubar, pitot tube, etc., and applying the well-known Bernoulli""s principle to obtain a velocity and, consequentially, a fluid flow rate. As an example of this principle, U.S. Pat. No. 5,129,264, entitled xe2x80x9cCentrifugal Pump with Flow Measurement,xe2x80x9d issued Jul. 14, 1992, to Lorenc, and assigned to the same assignee herein discloses using differential pressure and pump speed to measure fluid flow rates. Still other methods of fluid flow rate measurement employ electrical/magnetic or sonic measurement means. For example, Mag Meters determine fluid flow rates by measuring the change in a magnetic field caused by the velocity of the fluid flowing therethrough. Sonic devices use acoustical pulses, i.e., Sonar, and Doppler principles to measure fluid flow rates. Other non-intrusive methods measure the torque a variable speed electrical motor delivers to a pump by installing a torque shaft between the motor and pump. The motor or pump is then calibrated and a motor kilowatt input/Motor Brake Horsepower Output (BHP) calibration table is developed. Accordingly, knowledge of the kilowatt input value can be used to determine the output horsepower. However, this calibration is needed at several speeds and requires several different sized torque shafts.
Thus, current methods for determining fluid flow rates necessitate intrusion into, or require access to, the enclosures transporting the fluid. In some systems, such as caustic systems having lined pumps, intrusion is prohibited.
Hence, there is a need for a simple, accurate and reliable method for determining fluid flow rates without intruding into the fluid flow or having access to the enclosures transporting the fluid.
The present invention determines a fluid flow rate through a pump by first determining two flow rate values from a plurality of characterizing flow rate values corresponding to two known speed values selected from a plurality of known characterizing speed values at a known motor torque. The first one of the two known speed values is selected greater than a measured pump speed and a second one of the two known speed values is selected less than the measured pump speed. The fluid flow rate is then determined as being proportional to the two determined flow values at the known speed values and the pump speed.


1. Field of the Invention
The present invention relates to the game apparatus, and more particularly to the game apparatus with attachable game pieces played on the outer surfaces of the three-dimensional game structure.
2. Description of Related Art
Various board-type racing games have been developed in the past. U.S. Pat. No. 6,883,803 B1 issued to Barry on Apr. 26, 2005 discloses a two-dimensional tourist game board. U.S. Pat. No. 4,182,516 issued to Gill on Jan. 8, 1980 discloses a two-dimensional sailboat racing game. U.S. Pat. No. 3,871,656 issued to Selness on Mar. 18, 1975 discloses a two-dimensional sailing game apparatus. These games are two-dimensional planer games and did not suggest three-dimensional movement for game pieces on the three-dimensional game structure. The present invention is to produce a game in which the player can be challenged to race and capture the opponent's game piece on the transformable three-dimensional game structure.
The three-dimensional game apparatus which incorporate the concept of tic-tac-toe or checker type of games have been developed in the prior art wherein a series of two-dimensional playing surfaces are vertically arranged one above the other. So that game piece can be moved or arranged on a two-dimensional playing surface as well as between the playing surfaces. One such game apparatus is disclosed by Mahoney U.S. Pat. No. 3,464,701 on Sep. 2, 1969, wherein a series of horizontally disposed playing boards are vertically supported in parallel spaced relationship by a box-shaped frame.
U.S. Pat. No. 3,623,729 issued to Wetherell on Nov. 30, 1971 discloses a three-dimensional board game apparatus. U.S. Pat. No. 3,656,755 issued to Thompson on Apr. 18, 1972 discloses a three-dimensional checker game apparatus. U.S. Pat. No. 4,129,303 issued to Flagg on Dec. 12, 1978 discloses a cubic game board. Another three-dimensional game apparatus of the tic-tac-toe type is constructed with rods joined together to form a grid pattern in the shape of a cube. A three-dimensional tic-tac-toe game is played by arranging game pieces on selected horizontal runs of the grid pattern. A game apparatus of this type is disclosed by Green in U.S. Pat. No. 3,606,333 on Sep. 20, 1971.
Even though the prior art's innovations may be suitable for the specific individual purposes to which they address, they would not be comparable for the purposes of the present invention as heretofore described.


1. Field of the Invention
The present invention relates to a paint bucket comprised of an open-top-end container having a lid with attachment brackets disposed on a rear face of the lid to retain paint applicating implements thereagainst and wherein the paint bucket has a slot in a top edge thereof for the passage of a paint roller connecting rod whereby a wet roller may be stored inside the container to prevent drying thereof.
2. Description of Prior Art
It is known in the prior art to provide paint buckets having a ribbed wall surface formed with the bucket whereby to remove excess paint from a roll applicator brush rolled thereagainst. This is disclosed in U.S. Pat. No. 2,988,767. However, with such buckets there is a need to remove paint from the bucket in order to use the ribbed side wall as the paint in the bucket, when full, conceals this ribbed side wall. It is therefore necessary to have another bucket to store paint while the bucket with the flat ribbed wall is utilized. U.S. Pat. No. 2,983,938 also discloses a paint bucket wherein a roller-type paint applicator is inserted within the container, which is filled with paint, through a small cylindrical orifice and then withdrawn therefrom and during this withdrawing process a plurality of circumferential serrations will be in doctoring contact with the peripheral surface of the roller brush to remove excess paint. The purpose of this device is to eliminate the need to use paint pans which need to be constantly refilled due to their small capacity size. It also eliminates the need to clean the paint pan.
There is, however, another need for storing wet paint applicating implements, such as rollers or paint brushes, to prevent them from becoming dry when there is a pause in the applicating of paint for a substantial period of time. When wet paint implements are left uncleaned and exposed to air they dry out. This need to prevent wet paint implements from drying also eliminates the need to have to clean the paint implements each time there is a lengthy pause. Often paint implements have to be left wet for a substantial length of time.
There is a further need to provide a paint bucket which will also serve as a paint tray but without having to remove paint from within the bucket for access to a ribbed surface of the paint bucket whereby excess paint from a roller-type paint applicator can be removed.


1. Field of the Invention
The present invention relates to an optical output control circuit of a semiconductor laser for constantly setting the optical output of the semiconductor laser irrespective of ambient temperature.
2. Description of the Related Art
FIG. 4 shows an optical output control circuit of a conventional semiconductor laser. A reference voltage Vref is applied to the base of a transistor 42 for flowing a modulating electric current to the semiconductor laser 41, and its emitter is connected to the emitter of a transistor 43 having a base to which a pulse signal for modulation is inputted. These two emitters are connected to the collector of a transistor 44, and an operational amplifier 45 is arranged between the base and the emitter of the transistor 44. The voltage of an emitter resistor 46 of the transistor 44 is inputted to the operational amplifier 45. Further, negative feedback is applied to an inversion input terminal (−) of the operational amplifier 45 by a thermistor 47. A non-inversion input terminal (+) of the operational amplifier 45 is connected to the ground by a thermistor 48.
In the above construction, the transistors 42 and 43 are alternately turned on/off by a continuous pulse signal so that the modulating electric current is flowed to the semiconductor laser 41. Further, since the thermistors 47, 48 are connected to the operational amplifier 45, the semiconductor laser 41 is operated such that the modulating electric current flowed to the semiconductor laser 41 is increased correspondingly with a rise in temperature. Thus, the optical output is constantly set even when the semiconductor laser 41 is reduced in efficiency.
Further, one portion of the optical output of the semiconductor laser 41 is detected by a light receiving element 50. The detected voltage is inputted to an optical output control circuit 51. The optical output control circuit 51 operates a transistor 52 for flowing a bias electric current to the semiconductor laser 41 such that the optical output of the semiconductor laser 41 is constant irrespective of the ambient temperature. Namely, if the detected voltage is reduced by a reduction in efficiency of the semiconductor laser 41 caused by the rise in temperature, the optical output control circuit 51 controls the operation of the transistor 52 so as to compensate for this reduction in the detected voltage so that the bias electric current is increased (see Patent Literature 1).
[Patent Literature 1]
Japanese Unexamined Published Patent Application No. H5-259563 (FIG. 1)
The level of the optical output outputted from the semiconductor laser 41 is determined by a sum of the bias electric current and the modulating electric current. Therefore, if the pulse signal for modulation is continuously inputted in the above construction, the modulating electric current and the bias electric current are changed dependently on temperature. Accordingly, the optical output level is controlled by the optical output control circuit 51 such that the optical output level is constant at all times. However, when the pulse signal for modulation is inputted in a so-called burst shape, no modulating electric current is flowed to the semiconductor laser 41 in a period in which no pulse signal for modulation is inputted. Accordingly, no electric current is flowed to the light receiving element 50 so that the optical output control circuit 51 increases the flow electric current to the semiconductor laser 41 to a maximum. As this result, there is a problem of destroying the semiconductor laser 41. Accordingly, no semiconductor laser can be used in the burst mode in the conventional construction.


Not applicable.
The present invention relates to a marine or other recreational vehicle receptacle for receiving and storing a marine shower. The marine shower may or may not accommodate a hot-cold water mixing valve as required by the consumer.
While the invention has multiple uses readily apparent to those skilled in the art it will be described primarily for use in connection with the marine industry.
Marine showers are most often mounted in the transom of a boat or in the cockpit coaming of a boat and in modern day boat designs these transoms and coamings comprise a multitude of surfaces with orientations from vertical to horizontal and therebetween. These orientations require different shower head receptacle designs and when a mixing valve is required a still further design is needed. Thus multiple items must be kept in inventory in order to accommodate all requirements.
A shower receptacle designed for a vertical surface will not be useful for a horizontal surface and a receptacle adapted for a straight shower handle will not accommodate a Euro-style handle with a projecting on-off lever. When a hot-cold water mixing valve is desired a further receptacle is needed to accommodate the valve. Some prior art designs feature the shower wand and hot and cold water valves in one box but this requires a large opening to be cut in the boat transom with its attendant disadvantages.
The disadvantages and limitations of the prior art devices are obviated by the present invention.
An object of the present invention is to provide a shower head receptacle adapted to be mounted on surfaces having different angles of orientation.
A further object of the present invention is to provide a shower head housing or receptacle for receiving either a straight or Euro-style shower wand or handle.
A still further object of the present invention is to provide a receptacle with a lid which is relatively easy to manufacture.
Another object of the present invention is to provide a receptacle which can accommodate various shower heads or wands as well as a hot and cold water mixing valve as the case may be.
Another object of the invention is to provide a receptacle for a shower head and a receptacle for a mixing valve in side by side relation with a single cover for both receptacles.
Other objects, advantages and features of the present invention will become apparent to those skilled in the art from the following detailed description which with referencess to the accompanying drawings discloses a preferred embodiment of the invention.


The present invention relates to steam turbines and more particularly to a steam turbine cover for minimizing or eliminating solid particle erosion of bucket tenons and to improve sealing efficiency.
In conventional steam turbines, bucket covers are typically attached to the buckets by peening the tenon projecting from the end of the bucket and through an aperture in the bucket cover. This peening operation results in a projecting bulb or knob on the outside diameter of the cover. This raised knob or projection can be eroded by solid particles in the steam path. As a result, the cover may become loose, crack or separate from the buckets. Also, the raised knob or projection, resulting from peening the tenon, substantially prevents the application of one or more labyrinth seal teeth along the outside face of the cover, particularly on units with large differential expansion between the stationary and rotating components.
In another cover-to-bucket design, the knob or projection of the peened tenon is disposed below the outer surface or outer diameter of the cover. While that configuration enabled the application of sealing teeth configurations to the cover, it is limited to straight tooth or flat surface geometry. Under certain conditions, solid particles may become trapped within the confines of the recess and between the walls defining the recess and the tenon. These trapped particles tend to erode the tenon knob or projection very quickly and have been shown, in certain circumstances, to essentially cut through the tenon.
Another bucket/cover design includes the integral formation of the bucket and cover. While this design incorporates the necessary sealing options, i.e., application of one or more labyrinth seal teeth, and also minimizes or eliminates the concern for solid particle erosion, the integral bucket/cover combination is costly to manufacture and complex. Accordingly, there has arisen a need for a bucket/tenon/cover design that both eliminates or minimizes solid particle erosion, as well as affords sealing efficiencies without complexity or excessive costs.
In accordance with a preferred embodiment of the present invention, there is provided in a steam turbine, a plurality of buckets mounted on a rotating component, e.g., a rotor, and a plurality of covers mounted on the tips of the buckets, the buckets having tenons peened to secure the buckets to the covers. At least one recess is preferably formed in the outer cover surface to form a profiled surface and at least one tooth projects either radially outwardly from the profiled surface or radially inwardly from the registering stationary component. In a preferred embodiment hereof, the profiled surface includes at least one recess defined at least in part by the tenon. In another preferred embodiment, the profiled surface includes a tooth projecting from the outer surface of the cover toward the stationary component and including at least part of the tenon. It will be appreciated that the recess or the tooth each formed, at least in part, by the tenon extend in a circumferential direction about the cover. To form this preferred configuration, the outer surface of the cover is machined such that the tenon forms part of the recess or the labyrinth tooth, as applicable.
In a preferred embodiment according to the present invention, there is provided in a steam turbine having a plurality of buckets rotatable about an axis and a stationary component surrounding the buckets, a seal between the buckets and the stationary component, comprising a cover mounted on a radial outer end of at least one bucket and having an opening, one bucket having a tenon projecting from the outer end of one bucket and extending into the cover opening, an outer surface of the cover and an outer end surface of the tenon forming a profiled surface in opposition to the stationary component with contiguous surfaces of the tenon end and the cover lying flush with one another, the profiled surface including at least one of a recess formed in the profiled surface and a tooth projecting radially outwardly of the profiled surface.
In a further preferred embodiment according to the present invention, there is provided in a steam turbine having a plurality of buckets rotatable about an axis and a stationary component surrounding said buckets, a seal between the buckets and the stationary component, comprising a plurality of covers mounted on radial outer ends of the buckets arranged in an annular array thereof with one or more buckets being secured to each cover, each cover having at least one opening and each bucket having a tenon projecting from the outer end thereof into the opening, an outer surface of each cover and an outer end face of each tenon forming a profiled surface in opposition to the stationary component with contiguous surfaces of the tenon end faces and the outer cover surface lying flush with one another.
In a further preferred embodiment according to the present invention, there is provided in a steam turbine having a plurality of buckets rotatable about an axis and a stationary component surrounding the buckets, a seal between the buckets and the stationary component, comprising a plurality of covers mounted on radial outer ends of the buckets arranged in an annular array thereof with one or more buckets being secured to each cover, each cover having at least one opening and each bucket having a tenon projecting from the outer end thereof into the opening, an outer surface of each cover and an outer end face of each tenon forming a profiled surface in opposition to the stationary component with contiguous surfaces of the tenon end faces and the outer cover surface lying flush with one another, the profiled surface including at least one recess, the profiled surface including a tooth projecting radially outwardly thereof.


FIG. 8 shows a conventional nozzle through which air can be pumped into a cushion (not shown) from a pump (not shown). The cushion includes a tube and a valve installed in the tube. A thread is formed on an internal face of the tube.
The nozzle comprises a housing 100, a tube 200 and a tubular seal 300. The housing 100 comprises an annular portion and a cylindrical portion 120 extending from the annular portion. A thread 122 is formed on the annular portion of the housing 100.
The tube 200 includes a first section inserted through the annular portion of the housing 100, a second section put in the housing 100 and an annular flange 210 formed between the first and second sections of the tube 200 for abutment against the annular portion of the housing 100. The first section of the tube 200 is inserted in a pipe 400 leading to a pump (not shown). A thread 212 is formed on the first section of the tube 200 for engagement with the thread 122 formed on the annular portion of the housing 100. A ferrule 420 is put around the pipe 400 in order to keep the first section of the tube 200 in the pipe 400. Pushers 220 are formed at the second section of the tube 200. The pushers 220 leave the second section of the tube 200 open.
The tubular seal, 300 is put around the second section of the tube 200. The tubular seal 300 defines a big hole 320 and a small hole 340 communicated with the big hole 320. A portion of a tubular lip 140 is screwed in the cylindrical portion 120 of the housing 100. A thread 142 is formed on an internal face of the tubular lip 140.
To pump air, a user rotates the housing 100 so as to rotate the tubular lip 140 in order to engage the thread 142 of the tubular lip 140 with the thread formed on the tube of the cushion. Now, the valve of the cushion is pushed by the pushers 220 so that air flows through the tube of the cushion. The user rotates the tube 200. Because of the engagement of the thread 212 with the thread 122, the tube 200 is moved towards the tube of the cushion. The tubular seal 300 will also be moved to the tube of the cushion and seal the same. The pressurized air can be pumped into the cushion from the pump. However, much air has escaped from the cushion after the valve installed in the tube of the cushion is pushed by the pushers 220 before the tube of the cushion is sealed by the tubular seal 300. In addition, it takes quite some time to rotate the tube 200 in order to use the seal 300 to seal the tube extending from the cushion.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.


Games played on tablet computers typically rely on the touch screen interface of the tablet device to interact with the user.


1. Field of the Invention
This invention relates to technology of manufacturing a semiconductor device. More especially, this invention relates to a set of masks, a method of generating mask data and a method for forming a pattern.
2. Description of the Related Art
In recent years, with the trend toward higher integration of large scale integrated circuits (LSIs), there has been a demand for finer circuit patterns of LSIs. As examples, for a transistor in a microprocessing unit (MPU), an application specific integrated circuit (ASIC), a system LSI, or the like, there is a demanded for a pattern to be delineated with fine line widths of 100 nm or less.
As a method for forming a pattern with fine line widths, there is a known method in which a resist pattern with fine line widths is formed using a positive alternating phase shift mask (Levenson-type phase shift mask) where phase contrasts of adjacent openings are shifted from each other by 180 degrees, and any unnecessary part of the resist pattern is removed using a trim mask. Moreover, as another method for forming a pattern with fine line widths, a method has been studied in which isotropic etching is performed after the formation of a resist pattern, thereby slimming the line widths of the resist pattern.
Here, for example, as to a pattern of a memory cell of a SRAM or the like which coexists with a logic circuit, demand for the pattern have fine space widths in addition to fine line widths in order to reduce the circuit space. In the case of using a positive alternating phase shift mask (Levenson-type phase shift mask), it is required to form fine space widths when a trim mask is used. However, the resolution of a trim mask is low, and it is therefore difficult to form fine space widths in a resist pattern. Moreover, in the case of performing isotropic etching after the formation of a resist pattern, the space widths between the lines of the resist pattern are increased when the line widths of the resist pattern are slimmed. Therefore, it is difficult to delineate a circuit pattern which has fine line widths and fine space widths at the same time.


In this type of installation, the ladles containing the molten metal coming from the steel plant are brought near to the casting installation by means of a transport carriage or a travelling crane and are placed above a tundish, into which the molten metal pours via a taphole. The molten metal subsequently passes from the tundish to the bottomless mold, where the continuous strip of metal, namely a slab or a bar, is formed.
In order to make it easier to replace the ladles and reduce the downtime as much as possible, an appliance called a "ladle turntable" is often used as a ladle support.
Such appliances are known. They comprise at least one arm extending in an overhung manner from a barrel mounted rotatably about a vertical axis on a stationary base, for example the supporting stand of the installation. Each arm can support a ladle and, as a result of rotation, move it from a charging and discharging position into a casting position above the tundish.
The turntable is often equipped with two diametrically opposite arms, so that, while one ladle located above the tundish pours the steel which it contains, the previously emptied ladle can be removed from the other arm in order to replace it with a new full ladle.
In general, the taphole closed by means of a spout is extended downwards by a casting pipe, the function of which is to protect the jet of steel between the ladle and tundish from contact with the air and therefore from oxidation.
The protective devices are generally either a refractory pipe attached or retained under the ladle or a skirt made of asbestos or similar material, in which an inert atmosphere is maintained.
Because the ladle is brought above the tundish and then emptied as a result of the rotation of the arm of the support about its vertical axis, it was thought expedient to equip the ladle supports with lifting devices which make it possible to release the casting pipe during changes of ladles or tundishes. Lifting is also necessary when, in order to unblock the spout closing the taphole, it is necessary to blow into it, by means of a lance, pressurized oxygen which burns the steel solidified in the spout orifice.
The known devices for lifting the ladle-supporting arms can be of the hydraulic or the electromechanical type.
In devices of the mechanical type, lifting is brought about by means of elements of the winch and block and tackle, screws and nuts, connecting rod or crank type. These devices are heavy and bulky, and they sweep across a large space through the rotation of the turntable, thus creating dangerous zones at the workstations. Furthermore, they generally comprise a certain number of joints and guides which are exposed to the splashes of steel, and which therefore require frequent and difficult maintenance.
Moreover, the guides projecting above the arms require a greater lifting height on the crane and therefore a proportionate building height.
In devices of the hydraulic type, lifting is brought about by means of jacks. These devices are simpler and generate fewer stresses than the mechanical devices.
In this case, the lifting of the ladle is controlled by at least one hydraulic jack bearing on the supporting arm, the latter being mounted pivotally on the barrel about a horizontal axis.
The ladle is equipped with two journals engaging into suspension members which allow actuation by means of the travelling crane, and which rest on bearing parts formed at the end of the supporting arm and often having the form of a trapezoidal cup, into which fit the lower parts, of corresponding forms, of the suspension members. Thus, if the bearing parts are fastened rigidly to the end of the supporting arms, the pivoting of these during lifting determines a change of orientation of the supporting members and consequently an oscillation of the ladle about its journals. Consequently, it is often considered preferable to provide the bearing parts on two supporting stays connected to the barrel by means of an articulated system constituting a deformable parallelogram, of which they form an outer side moveable parallel to itself. For this purpose, each supporting stay is articulated about horizontal axes, respectively on the end of the supporting arm and on a connecting rod parallel to the supporting arm and articulated on the base, the vertex of the deformable parallelogram being formed by the respectively stationary and moveable axes of articulation of the supporting arm and of the retaining connecting rod respectively on the base and on the two supporting stays.
In such arrangements, which are described, for example, in EP-A-0,206,169 or FR-A-2,234,946, the lifting force is exerted on the supporting arm, which is therefore subjected to bending, and the force required from the jack is greater than the weight of the charge. For this reason, in order to support the articulated assembly more effectively during lifting, the latter is generally produced by means of two set-apart and synchronized jacks, each acting on one side of the supporting arm.


The present invention relates to a grommet constructed and arranged to make a blind connection between a primary panel and a secondary panel. More specifically, the grommet of the present invention may be laterally secured to a pin extending from the undersurface of the primary panel.
The present invention can best be summarized as a side mounting grommet that comprises a body having an aperture formed entirely therethrough and a head that extends laterally from its upper end and which acts to limit the depth of insertion of the body into a bore that is formed into a panel. Both the body and the head have a slot formed therethrough that communicates with the aperture formed through the body. This slot allows the grommet to be addressed laterally to a pin that extends from the underside of a primary panel such that the pin is received within the aperture.
A detent structure formed within the aperture of the body extends into the aperture and is constructed and arranged to engage a flat or depression formed near the base of the pin such that once the pin is seated within the aperture of the grommet""s body, the pin may not easily be withdrawn longitudinally from the bore. At least one retaining mechanism on the exterior surface of the body of the grommet acts to retain the grommet, and the pin that has been pre-assembled therewith, within a bore formed in a secondary panel. Typically, the connection made between the primary and secondary panels is considered xe2x80x9cblindxe2x80x9d, i.e., the pre-assembled pin and grommet are not visible as they are being inserted into the bore formed through the secondary panel.
One advantage of the grommet of the present invention is that it may be disassembled for the purposes of repair or replacement of the panels or related structures. To facilitate this, the cooperative bearing surfaces of the depression formed in the pin and/or the bearing surfaces of the detent structure may be constructed and arranged to impose a predetermined withdrawal force upon the grommet. Forming an angled or curvilinear surface on one or both of the detent structure and depression will allow one or both of these structures to be biased or elastically deformed such that the pin may be removed longitudinally from the aperture in the grommet body. The withdrawal force required to remove the pin longitudinally from the body may be larger or smaller than the force required to remove the body of the grommet from the bore formed in the secondary panel when the grommet and pin are received therein.
To further facilitate the disassembly of the grommet of the present invention, the head of the grommet may be provided with release apertures that allow a user to pry or bias the retaining mechanism(s) that retain the grommet body in the bore in the secondary panel inwardly such that the grommet body may be removed from the bore.
The present invention also comprises a method of creating a blind connection between a primary and a secondary panel. The process begins with the step of providing a pin on the underside of the primary panel. This pin may be formed integral with the panel in a molding operation or it may be adhered or mechanically secured thereto after the primary panel has been manufactured. A grommet having a body constructed as described herein is then assembled with the pin by addressing a longitudinal slot in the grommet body to the pin and forcing the grommet body onto the pin such that the pin is received and retained within the aperture formed through the body of the grommet. Once the grommet and pin have been pre-assembled, the grommet, with the pin received therein, is inserted into a bore formed through the secondary panel until the retaining structures on the grommet body engage the secondary panel, thereby securing the primary panel to the secondary panel. Disassembly of the primary and secondary panel is undertaken by first applying a withdrawal force to the pin. Note that this withdrawal force is typically applied by prying the primary panel away from the secondary panel but may be applied directly to the pin itself where a suitable tool can be addressed thereto. Once the pin has been withdrawn from the grommet body, the retaining structures are accessed through the release apertures formed in the head of the grommet body and biased away from the bore in the secondary panel to a degree that allows the grommet body to be removed from the bore.
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.


Various collaborative communications platforms exist, such as unified telephony systems, that may allow users of the system to communicate with one another for various purposes. For example, such systems may support multi-party communications, such as conference calls, web-conferences, virtual meetings, and the like. As is sometimes the case, one or more parties on a call may do most of the talking, with other parties participating in a more passive or listening role. In some such circumstances, the speaking parties may not be aware of changes in circumstances of other participants on a call, which can lead to confusion, for example, if a response, or other input is solicited from generally passive or listening party on the call. For example, such a passive or listening party may have become distracted from participation in the call, but due to their passive role on the call, the other participants may not be aware of the change in circumstance.


When making a CMOS device that includes metal gate electrodes, it may be necessary to make the NMOS and PMOS gate electrodes from different materials. A replacement gate process may be used to form gate electrodes from different metals. In that process, a polysilicon layer, bracketed by a pair of spacers, is removed to create a trench between the spacers on both NMOS and PMOS gate areas simultaneously. The trench is filled with a first metal. Then, the first metal layer is removed from either the NMOS or PMOS gate area and replaced with a second metal that differs from the first metal.
The replacement gate process requires the polysilicon and metal layers to be formed on a dielectric layer. The dielectric layer serves as an etch stop layer and prevents significant numbers of ions from reaching the channel when ions are implanted into the polysilicon layers. The dielectric layer may, for example, comprise silicon dioxide or a high-k dielectric layer.
U.S. Pat. No. 7,160,767 to Brask, et al. (“Brask”), provides a method for making a semiconductor device that includes metal gate electrodes, wherein such method includes replacing polysilicon layers with metal layers without damaging the channel region. However, Brask also has disadvantages. For example, the Brask method includes a large number of steps and is otherwise complex, such as its required removal of two different dummy gates, its deposition of two different high-K dielectric layers, and its performance of two different CMP processes. The Brask method is also disadvantageous in that gate height is lost due to the requirement for two different CMP processes. The complex and lengthy method taught by Brask is also very expensive. Brask also requires thick layers of precious metals, which are expensive to obtain. Moreover, the Brask method results in a metal gate plagued by internal seams, gaps or voids which, when not sufficiently filled, results in excessively high gate resistance.


This invention is concerned with a method and system for tenderizing meat. A standard technique for improving the flavor of meat is to soak meat before cooking in a marinade. When meat is placed in a liquid marinade, the flavor is enhanced due to the absorption of some of the marinate liquid into the meat. Others have suggested enhancing the effect of marination by including enzymes.
To speed up and to augment the process of the absorption of a marinade by meat, others have suggested placing the marinade in a closed container in which the meat is placed and subjecting the container to pressure--the concept being to utilize fluid pressure to force more of the marinade into the meat. Still others have suggested placing meat in a closed container containing liquid marinade and subjecting the container to a vacuum on the basis that a vacuum will cause the marinade to penetrate more deeply into the meat. U.S. Pat. No. 2,525,581 includes the concept of placing meat in a liquid within a vessel and altering the pressure applied to the meat during a marination process for more effective penetration of the marinade.
While forcing a marinade into meat achieves the goal of improving, or at least changing, the taste of the meat after it has been cooked, marination alone does not dramatically effect how tender the meat will be when cooked.
When the strength of connective tissue is great and of substantial quantity, or the muscle tissue is strong and is not broken down in the cooking process, meat can be "tough", that is, difficult to chew. Accordingly, it has long been an objective of processors of meat to find ways of enhancing the tenderness and the flavor thereof.
Examples of the work done by others to improve the tenderness, texture or flavor of meat are exemplified by the following United States patents:
(a) U.S. Pat. No. 4,818,550 teaches applying a vacuum to draw marination into the meat but does not teach rapid variation of a high vacuum to achieve tenderization; PA1 (b) U.S. Pat. No. 2,043,392 relates to tenderizing meat but in this method a dilute aqueous solution of a proteolytic enzyme is pumped through the vascular system of the meat; PA1 (c) U.S. Pat. No. 2,509,299 relates to a method of preserving food in which the food is placed is a syrup composition including a bleach and subjecting the composition while in the syrup to an elevated fluid pressure and freezing the food while subjected to the elevated pressure; PA1 (d) U.S. Pat. No. 2,881,080 is for tenderizing meat by applying an aqueous enzyme solution and then subjecting the meat to sound wave energy; PA1 (e) U.S. Pat. No. 5,200,223 is a process for treating meat by subjecting the meat to thin jets of liquid to penetrate the meat in which the jets are applied in short bursts; and PA1 (f) U.S. Pat. No. 5,328,403 subjects meat to shock waves generated by an explosive charge to tenderize the meat.
While all of these previously disclosed methods of enhancing the tenderness and flavor of meat have merit to one degree or another, nevertheless, none adequately address the problem of economically and expeditiously tenderizing meat by breaking down excessive connective and muscle tissue. Particularly none have taught the concepts to effectively tenderize meat with the opportunity at the same time to marinate the meat to produce a superior flavor when the meat is cooked.
For further background information concerning the treatment of meat, see the following additional United States patents:
______________________________________ PATENT NO. INVENTOR TITLE ______________________________________ 2,525,581 Bierman Apparatus For Treating Food Material 2,742,367 Apparatus and Method For Curing Meats 3,370,959 Method of Flavoring Poultry Meat 3,663,233 Method of Tenderizing, Curing and Cooking A Meat Product 4,036,122 Apparatus For Treating Meat, More Particularly Ham Meat 5,057,332 Apparatus and Process For Marinating Foodstuffs ______________________________________
Of the known prior art references, U.S. Pat. No. 2,525,581 appears to be the most closely related to the present invention.


The present invention relates to an electrically erasable and programable random access read only memory (hereinafter called as an EEPROM).
A conventional EEPROM is disclosed in U.S. Pat. No. 4,901,320 (Literature I) or Japanese laid open publication 64-59693 (Literature II). Literature I relates to an error correction principle and its method, whereas Literature II relates to an EEPROM operable with low voltage and low current. An EEPROM circuit with high liability has recently been demanded. In other words, it has been desired to achieve an EEPROM circuit having relatively longer life time and less failure which can operate with low voltage and low current and can detect its failure.


This invention relates to variable area exhaust nozzles for gas turbine engines and, more particularly, to sealing means for nozzle flaps of turbojet engines.
The exhaust nozzle of a gas turbine engine, such as a turbojet or turbofan engine, has as its purpose a transformation of the pressure and thermal energy of the combustion discharge into velocity, with the forward thrust of the engine being directly proportional to the increase in velocity of the gas from the entrance of the engine to the exit plane of the nozzle. In high performance engines and, in particular, in engines having some sort of thrust augmentation such as an afterburner, it has been found desirable to cause a variation of nozzle flow area to maintain high engine performance under a wide range of operating conditions. For example, it is desirable to provide a larger nozzle flow area during a take-off mode of operation than during a cruise mode. In addition to the function of maintaining the exhaust gas temperature within allowable limits, variable area exhaust nozzles may be employed to bring about noise, thrust and fuel economy benefits. One means for varying the nozzle flow area is by the so-called iris mechanism wherein a plurality of concentrically disposed movable members or flaps are pivotably supported about the nozzle axis. One of the problems associated with such an arrangement is the need to maintain effective sealing between the flaps as the flaps are adjusted to vary the nozzle flow area. Therefore, it is desirable to provide an exhaust nozzle whose area can be flexibly varied between minimum and maximum positions while maintaining a circumferentially continuous aerodynamic structure throughout the entire range.
Early method of locating seals with respect to exhaust nozzle flaps relied entirely on a combination of bolts and spectacles wherein, when the nozzle was in the closed position the seals were relatively free to move in the circumferential direction, and when the flaps moved toward the open position, the position of the seals was still not positively enough controlled so as to maintain circumferential sealing integrity around the entire nozzle periphery. Some of the problems encountered were those of dimensional stack-up, limited seal overlap within the circumferential envelope, and misalignment due to nozzle sag on or near the horizontal plane. These problems caused nozzle leakage and seal "blow-out", thereby resulting in decreased nozzle efficiency.
Recent methods of effecting positive placement of seals within exhaust nozzles employ a combination of linkage pairs interconnecting the flaps to the seal wherein an axial track is located on the seal for the purpose of varying the effective lengths of the links. Such an arrangement has been recognized as being somewhat complex and requiring an excess number of moving parts which are susceptible to wear and malfunction.
Accordingly, a primary object of the present invention is to provide an improved seal arrangement for a jet engine variable exhaust nozzle flap.
Another object of this invention is the provision in a variable exhaust nozzle for the maintaining of circumferential sealing integrity throughout the range of nozzle areas.
Yet another object of the present invention is the provision for maintaining a variable area exhaust nozzle seal in a centered relationship between adjacent flaps during all modes of nozzle operation.
These objects and other features and advantages become more readily apparent upon reference to the following description when taken in conjunction with the appended drawings.


This invention relates to the field of hermetic ceramic substrates for microelectronic applications. More particularly, this invention relates to protective surface layers for providing hermeticity and corrosion protection.
In the microelectronics environment, there is a need for high density, high strength packaging to provide interconnection between semiconductor devices and connection from the devices to the electrical power supply. The electrical properties which are desirable include a highly conductive medium in a highly insulative carrier medium having a low dielectric constant. Thermally, the package must withstand not only the operating environment but also the thermal excursions encountered during the processing and fabrication of the part.
Mechanically, it is preferable to have a substrate package which can withstand chip and pin joining stresses and stresses related to interconnecting with the next level of packaging.
The packaging should also be hermetic to prevent degradation of any of the desired properties due to adverse environmental effects. In particular, corrosion of any of the metallurgies used in the package is a real concern if not adequately protected from ambient moisture and deleterious ionic contaminants.
Boss et al. U.S. Pat. No. 4,880,684, the disclosure of which is incorporated by reference herein, discloses the present day state of the art for the bottom surface of a ceramic substrate. Thus, there is a capture pad, a polymeric sealing and stress relief layer followed by an I/O (conventional nomenclature meaning "input/output") bonding pad. Thereafter, the I/O pin is brazed to the I/O bonding pad.
It has recently been discovered by the present inventors, however, that there is a concern with the structure disclosed by Boss et al. The I/O bonding pad is typically made from a plurality of layers of metallic material. The present inventors have found the presence of corrosion at this I/O bonding pad during reliability testing which has led to premature failure of the I/O pad structure. While not wishing to be held to a particular theory, it is believed by the present inventors that the corrosion of the I/O bonding pad occurs by a galvanic corrosion mechanism wherein the less noble metals become anodic to the more noble metals in the presence of a suitable electrolyte such as water. At the edges of the I/O bonding pad, the different metals of the pad are exposed together to the environment which thus allow these deleterious corrosion cells to form.
It has thus been proposed by the present inventors to apply a protective coating to the bottom surface of the ceramic substrate after the pins have been attached to protect the edges of the I/O bonding pads.
Various solutions have been proposed to protect electronic substrates from the effects of corrosion.
Bakos et al. U.S. Pat. No. 4,048,356, the disclosure of which is incorporated by reference herein, discloses in general the application of a hermetic topsealant for the active areas of an integrated circuit device.
Darrow et al. U.S. Pat. No. 4,233,620, the disclosure of which is incorporated by reference herein, discloses the application of an epoxy material to the surface of a substrate having electrically conductive pins protruding therefrom and to the sides of the substrate so as to hermetically seal the backside of the substrate containing a chip in a cap. Such arrangements wherein epoxy is applied are typically not reworkable, a disadvantage for many ceramic substrates such as those contemplated by the present inventors wherein reworkability is a necessity. Additionally, epoxies are not suitable for the substrates contemplated by the present inventors because epoxies are brittle which could lead to their cracking. Manifestly, such cracking destroys any advantage epoxies may have as a barrier material. The poor thermal stability of epoxies is yet another disadvantage.
Dalencon U.S. Pat. No. 4,360,559, the disclosure of which is incorporated by reference herein, discloses the application of a protective varnish to a printed circuit card, including the weld area of the pins.
Harris U.S. Pat. No. 4,427,715, the disclosure of which is incorporated by reference herein, discloses an inorganic passivation layer such as polysilicon glass or vapox overlapping the edge of the bonding pad that is applied prior to the bonding operation. The patent is directed to a structure for TAB bonding pads on semiconductor chips that is aimed at preventing the cracking of the chip during the thermo-mechanical bonding process.
Clark et al. U.S. Pat. No. 4,592,944, the disclosure of which is incorporated by reference herein, discloses a polymeric coating over the top surface of substrates for corrosion protection, insulation, etc. The corrosion protection is directed at the top surface thin film circuitry and solder connections.
Notwithstanding the numerous solutions and disclosures proposed by those familiar with electronic substrates, there still remains a very real need to solve the problem discovered by the present inventors, namely, the corrosion of the I/O bonding pad due to corrosive effects.
Accordingly, it is an object of the present invention to solve the problem of I/O bonding pad corrosion by providing a protective layer over the I/O bonding pads to insulate them from the deleterious effects of corrosion.
This and other objects of the invention will become apparent to those skilled in the art after referring to the following description considered in conjunction with the accompanying drawings.


The present invention relates to the driving of a floppy disk and, more particularly, to the driving of a tunnel erase type floppy disk.
A conventional tunnel erase type floppy disk comprises a read/write (R/W) head and a pair of erasing heads positioned to the rear of the read/write head. The pair of erasing heads are operated for erasing both sides of data recorded by the read/write head, so that a non-data record area is provided between the tracks to assure compatibility.
Normally, because the record tracks are arranged to be coaxial, the outer portions of the record disk move more slowly than the inner portions of the disk. Each of the tracks contain an identification (ID) field for storing address information, a data field for storing data, and a gap. If while recording data into the floppy disk the read/write head and the pair of erasing heads are simultaneously operated and the track is improperly aligned, the pair of erasing heads may erroneously erase the data in the ID field, and may not conduct a tunnel erasure of the data field. Therefore, conventionally, the pair of erasing heads are operated as being delayed at a predetermined time after the read/write head is energized.
Because the outer tracks of the disk move more slowly than the inner tracks of the disk, a common predetermined delay time is not suitable for all the tracks.
Due to the usage of a common delay time, it may be difficult to delay the ON condition of each of the pair of erase heads at a satisfactory time with respect to all of the tracks.


The present invention relates to the pumping art, and, more specifically, concerns a new and improved construction of hose pump containing movable pressure elements.
In the case of hose pumps, a hose is rhythmically compressed in sections for the purpose of conveying a fluid medium. To this end the hose pump is either equipped with one or a number of squeeze rolls, arranged at a rotatable body, and a hose arranged at a circular arcuate-shaped surface, or with a number of adjacently arranged punches which are moved to-and-fro by cams and a flat or planar counter element. Conveying of the fluid medium is accomplished either by the rotating squeeze rolls or by successive contact of the punches against the counter element, so that the hose is continuously pressed in a peristaltic movement.
Experience has shown that the hose of such type hose pumps are exposed to large loads and subjected to pronounced mechanical wear. This wear is attributable to the continuously identical deformation of the hose, i.e. the hose is always compressed together at the same region, and the additional tensional load of the hose by the rotating squeeze rolls, or by the additional loading by virtue of the edges of the punches.