The invention relates to a process for the preparation of a supramolecular polymer comprising 1-50 4H-units, in which a 4H building block is reacted with a prepolymer, wherein a 4H building block comprises a 4H-unit and a reactive group according to Formula (I):4H-(L-Fi)r  (I)wherein 4H represents a 4H-unit, L represents a divalent, trivalent, tetravalent or pentavalent linking group, Fi represents a reactive group, and r is 1-4, is reacted with a pre-polymer comprising a complementary reactive group, wherein the reaction mixture comprising said 4H building block and said polymer comprises less than 10 wt. % of a non-reactive organic solvent, based on the total weight of the reaction mixture.

This invention relates to a process for the preparation of a supramolecular polymer comprising a 4H-unit that is capable of forming at least four H-bridges in a row, preferably with another 4H-unit, leading to physical interactions between different polymer chains. The physical interactions originate from multiple hydrogen bonding interactions (supramolecular interactions) between individual 4H-units or between a 4H-unit and another moiety capable of forming hydrogen bonds thereby forming self-complementary units, preferably comprising at least four hydrogen bonds in a row. Units capable of forming at least four hydrogen bonds in a row, i.e. quadruple hydrogen bonding units, are in this patent application abbreviated as "4H-units". Sijbesma et al. (U.S. Pat. No. 6,320,018; Science 278, 1601-1604, 1997; both incorporated by reference herein) discloses 4H-units that are based on 2-ureido-4-pyrimidones. These 2-ureido-4-pyrimidones in their turn are derived from isocytosines.
Telechelic polymers or trifunctional polymers have been modified with 4H-units (Folmer, B. J. B. et al., Adv. Mater. 12, 874-878, 2000; Hirschberg et al., Macromolecules 32, 2696-2705, 1999; Lange, R. F. M. et al, J. Polym. Sci. Part A, 37, 3657-3670, 1999; all incorporated by reference). However, these polymers are obtained by addition of solid reactants to chloroform or toluene solutions, which are both toxic organic solvents, and need prolonged reaction times of several hours in order to reach completion.
US 2004/087755, incorporated by reference, discloses polyurethane based polymers with 4H-units as end-cappers that can be used as hot melt adhesive. Example 4 in this patent discloses the preparation of supramolecular polyurethane polymers which are obtained by the bulk reaction of 6-methyl-isocytosine with 4,4′-methylene bis(phenyl isocyanate) (MDI) end-capped polyesters in the melt at 180° C., said reaction being performed in a Brabender mixer with a residence time of not more than 3 minutes. In this process it is preferred that the 6-methyl-isocytosine is added as a powder that is finely milled to a particular particle size to facilitate rapid and efficient conversion.
JP 2004250623, incorporated by reference, discloses polyester diols derived from poly(butanediol terephthalate) or polylactide that are reacted in the melt with a solid reactant comprising isocyanato functional 4H-unit, obtained by the reaction of a diisocyanate with 6-methyl-isocytosine. The reaction proceeds by kneading at 150° C. to 300° C., preferably at 160° C. to 250° C. and more preferably at 180° C. to 230° C. JP 2004250623 further discloses that it is desirable to perform the reaction above the melting point of the polymer. However, in order to control decomposition of the reactants and final products, the reaction is desirably performed at a temperature as low as possible, provided that the reactants are prevented to solidify as much as possible during the reaction. According to the examples, the reaction requires temperatures of 200° C. or higher and an excess of the isocyanato functional 4H-unit. Comparable functionalization of poly(butanediol terephthalate) and poly(butanediol isophthalate) with this isocyanato functional 4H-unit at temperatures above 180° C. are also disclosed by Yamauchi et al. (Macromolecules 37, 3519-3522, 2004; incorporated by reference). In both cases the excess of the 4H-unit in the synthesis has been removed using organic solvents (Soxhlet-extraction with methanol or precipitation from HFIP), thereby re-introducing the need of (toxic) organic solvents into the process. Moreover, the occurrence of side reactions with the isocyanate functional compound, like allophonate, biuret or isocyanurate formation, is eminent at the temperatures applied as is well known in the art (High Polymers Vol. XVI, Polyurethanes: chemistry and technology, Part 1, Ed.: J. B. Saunders and K. C. Frisch; J. Wiley & Sons, 1962; incorporated by reference).
Additionally, US 2010/0076147, incorporated by reference, discloses supramolecular polymers comprising 4H-units which are obtained by reactive extrusion in the melt at temperatures below 150° C. In order to be able to perform the melt processing, the 4H-units have been modified with e.g. C2-C20 alkyl chains on the heterocyclic ring structure in order to lower their melting point. Therefore, only specific, synthetically demanding, 4H-units can be used in this approach. Moreover, the 4H-unit is a powder at handling temperatures and needs relatively high processing temperatures (Examples 15-18 disclose reaction temperatures of 120° C. to 140° C. for the conversion into a supramolecular polymer.
Clearly, there is a need in the art for a process for the preparation of a supramolecular polymer containing a 4H-unit that does not require one or more organic solvents because of toxicological, ecological and economical reasons. Moreover, there is a need in the art for a bulk process that can be performed at temperatures below about 100° C. in which the different ingredients are formulated as liquids and can be dosed using known liquid-handling techniques in the art. There is also a need in the art for a broad range of liquid formulations comprising reactive 4H-units thereby facilitating essentially solvent-free processing of liquid reactants at moderate temperatures.

Process for the preparation of a supramolecular polymer


Shorting of a copper line with an adjacent line in a semiconductor device during chemical mechanical polishing may be prevented and thus reliability of the semiconductor device may be improved, when the semiconductor device includes a substrate, an interlayer insulating layer formed on the substrate and having a dual trench, and a copper line formed to fill the dual trench, wherein the dual trench includes a first trench inclined at a first angle with respect to the substrate, and a second trench connected to the first trench and inclined at a second angle that is smaller than the first angle with respect to the substrate.

Recently, as semiconductor integrated circuits have become more highly integrated and their speed of operation has become higher, metal lines in a semiconductor device have become narrower and multi-layered. As the widths of the metal lines become narrower, the resistance and capacitance of the metal lines increase, thereby causing signal delay. Therefore, copper, a metal having low resistance, is used as a material for forming the metal lines to decrease this signal delay.
However, since copper is difficult to etch, copper metal lines are usually fabricated by a damascene process in which copper is first filled in a trench formed on a substrate and then planarized via chemical mechanical polishing.
Such a conventional method of manufacturing a semiconductor device using the damascene process may be summarized as follows.
As shown in FIG. 1, an interlayer insulating layer 12 is first formed on a substrate 10. A trench T is then formed in the interlayer insulating layer 12 by a selective etching process. Subsequently, a copper layer 14A is formed such that the trench T is filled thereby.
As shown in FIG. 2, a copper line 14 may be formed by applying chemical mechanical polishing to the copper layer 14A to confine the copper to the trench T.
However, after the chemical mechanical polishing, a serration shape may be formed on a surface of the copper line, which may cause a short circuit between adjacent copper lines such as is shown in the example of FIG. 2. Therefore, as a result of employing such a conventional method, reliability and yield of the manufactured semiconductor devices may be deteriorated.
To clarify multiple layers and regions, the thickness of the layers are enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.

Semiconductor devices and methods of manufacturing the same


A liquid crystal material containing polymer network forming material is microencapsulated by a method utilizing an interfacial polymerization which creates a combination of polyurethane and polyurea polymers or melamine fromaldehyde or urea formaldehyde polymer which form the capsule walls surrounding the discrete liquid crystal droplets. The prepolymer of urethane acrylate and acrylate within the liquid crystal capsules is cured under UV light irradiation to form a web-like structure and induce the formation of polydomain configuration of nematic director. This allows to produce the display having faster switching property and showing significant lower threshold voltage.

Liquid crystal materials are widely used in making liquid crystal displays for high content information flat panel devices, specifically for personal computers, projectors and televisions. Such devices usually require relatively low power and have a satisfactory response time, and are relatively economical. The property of liquid crystals enabling use, for example, in visual displays, is the ability of liquid crystals to transmit light on one hand, and to scatter light and/or absorb light, on the other, depending upon the alignment (or lack thereof) of the liquid crystal structure with respect to a prescribed input, such as an electrical field.
The conventional liquid crystal displays including twisted nematic, supertwisted nematic, thin film transistor twisted nematic and ferroelectric liquid crystal displays are prepared by filling liquid crystal materials directly into the liquid crystal display cells. These devices operate on the principal of light polarization. Due to the method in which the devices operate they suffer from reduced optical efficiency and require backlighting in order to achieve a good brightness on the display.
Currently there are three categories of liquid crystal materials, namely cholesteric, nematic and smectic types. The invention of the present application relates in the preferred embodiment described below to use of either a nematic, cholesteric, smectic A, or ferroelectric (chiral smectic C*) liquid crystal material or to a combination of liquid crystal types. The various characteristic of the cholesteric, nematic and smectic types of liquid crystal material are described in the prior art.
For many years, a class of new liquid crystal materials has been manufactured by treating such materials with a polymeric material to form a polymer dispersed liquid crystal for use in the manufacture of displays or other devices. U.S. Pat. No. 3,872,050, issued to Benton, relates to a polyurethane/liquid crystal dispersion system, in which cholesteric liquid crystal is dispersed as discrete naked aggregates in a polyurethane film. U.S. Pat. No. 4,101,207, issued to Taylor, relates to a liquid crystal/polymer film which is formed by: 1) casting a polymer solution containing liquid crystal, or 2) mixing liquid crystal with a polymerizable monomer or prepolymer followed by polymerization. More recently, these technologies have been improved further by the use of more suitable liquid crystal and polymeric binder materials to fabricate the electronic displays and light shutters, for example. These technologies basically include three distinct methods, an emulsion method, a phase separation method and a microencapsulation method.
An example of an emulsion method is disclosed in U.S. Pat. No. 4,435,047, issued to Fergason. The encapsulated liquid crystal droplets, which are dispersed in a polyvinyl alcohol film, are opaque in the off state. However, they become transparent when an electric field is applied. The liquid crystal/polymer film called nematic curvilinear aligned phase (NCAP) film is prepared by emulsifying liquid crystal material, generally a nematic type liquid crystal material, in aqueous polyvinyl alcohol. The emulsion is drawn down on an indium-tin oxide coated substrate, which is then laminated by another indium-tin oxide film after drying. This liquid crystal/polymer film based on a light scattering does not require the polarizers to function. However, this manufacturing process permits contamination by the impurities which are contained in the process' water and dispersing agents (e.g. polyvinyl alcohol or latex) to be transmitted to the liquid crystal material. In the Drzaic article, Journal of Applied Physics, Volume 60, NO. 6, Sep. 15, 1986, at pages 2142-2148, it is reported that an aqueous based NCAP system is an interpenetrating network of liquid crystal in a polymer matrix, rather than an encapsulated liquid crystal. Furthermore, U.S. Pat. No. 4,707,080, issued to Fergason, relates to a plurality of liquid crystal volumes which are interconnected. In addition, U.S. Pat. No. 5,216,530, issued to Pearlman et al, relates to the encapsulation of a smectic phase liquid crystal in a polymer matrix (known as NCAP). See also Drzaic et al articles, SID 90 Digest, at pages 210-213.
EP 0238 626 relates to a phase separation method utilized to obtain a light modulating material. The material is prepared from an isotropic solution of liquid crystal and prepolymer, which can be a monomer or a mixture of a monomer and an oligomer. Under an ultraviolet or an electron beam irradiation, the liquid crystal droplets segregate from the insoluble polymer matrix. The liquid crystal droplets are then located in cavities within a continuous polymer matrix layer.
WO 85/04262 relates to liquid crystal droplets which are dispersed in an epoxy resin to form a new light modulating material. The film produced also exhibits an opaque characteristics in the off state, while exhibiting a clear characteristic when an electrical field is applied.
U.S. Pat. Nos. 3,499,702 and 3,551,026 relates to the incorporation of pleochroic dyes in liquid crystal materials, in order to enhance contrast. This is accomplished by the fact that pleochroic dyes align parallel to nematic liquid crystal director and respond to an electric field in a liquid crystal like manner.
In the Drzaic et al article, SID 92 Digest, at pages 571-574, it is reported that a dichroic based liquid crystal film prepared by NCAP technology demonstrates that there are possible applications, in portable high information density displays, without the requirement of backlighting. However, the device's useful life time is dependent upon capability of finding a dichroic dye with a long period of stability and the liquid crystal material's charge holding capability. The dichroic based NCAP film suffers problems due to the fact that the dye is exposed to moisture, air and ionic impurities existing in polymeric binder. As a result, dichroic dyes suffer stability problems.
For the polymer dispersed liquid crystal (PDLC) manufactured by a phase separation method, the liquid crystal material is dissolved in polymeric resin and placed between two indium-tin oxide coated substrates and is irradiated by ultraviolet light or electron beam in order to cure the resin. The liquid crystal material used in a PDLC may be either nematic, cholesteric or ferroelectric. See Crooker et al article, SID 90 Digest, at pages 214-216; Yang et al article, SPIE Liquid Crystal Displays and Applications, Volume 1257, 1990, at pages 60-67; Molsen et al article, SID 92 Digest, at pages 773-775; and Zyryanov et al article SID 92 Digest, at pages 776-777, for example, The optical films prepared by this method suffer some drawbacks as well. For instance, one of these drawbacks is the component in the system of liquid crystal/polymer are mutually soluble and can not be completely separated during phase separation. This causes a decrease in the liquid crystal/polymer film contrast, which specifically effect the dichroic based PDLC. This is due to the fact that only dye dissolved in the liquid crystal droplets can exhibit the dichroic properties for the guest-host effect.
U.S. Pat. No. 5,585,947, relates a method for making liquid crystal composite which has an interfacial material disposed between liquid crystal and encapsulating medium.
U.S. Pat. No. 4,100,103 relates a capsule wall is formed by the condensation of melamine-formaldehyde in the presence of a negatively-charged, carboxylsubstituted, linear aliphatic hydrocarbon polyelectrolyte material dissolved in the capsule manufacturing vehicle. This method has been used to encapsulate the inner phase materials such as a mixture of dye dissolved in oily material. There is no examples describing the microencapsulation of liquid crystal for an electronic display application where the refractive index of the capsule wall should be closely matched with the liquid crystal and the binder material.
U.S. patent application Ser. No. 08/827,574 filed by Hsu, discloses the microencapsulation method for adjusting the capsule wall refractive index by an interfacial polymerization of polyurethane/polyurea or polyurea structures and there also exists a highly cross-linked structure within the polymer film. Further, the capsule wall may be manufactured so as to be transparent, in order to be more suitable for use in an electronic display application.
The liquid crystal/polymer film preparation methods described in the prior art are all relates to the formation of monodomain liquid crystal configuration within the liquid crystal droplets or microcapsules. The liquid crystal director aligns in four major configurations e.g. radiant, bipolar, axial and toroidal (concentric) according to the liquid crystal and wall surface interaction (wall surface anchoring situation). The creation of scattering from liquid crystal/polymer film is basically due to the mismatch of the refractive index between liquid crystal material (n.sub.o and n.sub.e) and polymeric binder (n.sub.p) in the off state. On the other hand, the liquid crystal/polymer film should be transparent in the on state.
In the De Baets et al article, Journal of the SID, 1/2 1993, at pages 189-193, it relates to the development of a polymer-network liquid crystal display (PNLCD) by curing a mixed solution of liquid crystal and UV-curable acrylic monomer and photoinitiator in a conventional display cell at a slightly higher temperature than the nematic-to-isotropic transition temperature of the solution. The PNLCD shows a fast switching speed and high transmission at low operating voltage,
In the Wu et al article, SID 92 Digest at pages 583-586, it is reported that a sub-micron size droplet network is formed within PDLC droplets by incorporating a PVF thermoplastic and prepolymer resin in liquid crystal. The prepared PDLC film showed extremely fast switching time at a high threshold turn-on voltage (about 70 volts).
According to the present invention, the operating voltage reduction, and the optical efficiency improvement may be achieved by formation of cross-linked web-like structure (polymer network) within liquid crystal microcapsules. The web-like structure induces the disclination of liquid crystal alignment and formation of multidomain (polydomain) liquid crystal configuration. The web-like structure is a three-dimensional polymer network randomly oriented in a liquid crystal within a micro-capsule. The liquid crystal molecules form a continuous layer within the micro-capsule.

Microencapsulated liquid crystal having multidomains induced by the polymer network and method


A method for detecting address rotation by a device in a communication network includes receiving, at a first time, a first message transmitted by the device, receiving, at a second time, a second message transmitted by the device, and processing the first message to determine a first sequence number and a first transmitter address. The method also includes processing the second message to determine a second sequence number and a second transmitter address, determining that the second transmitter address is different from the first transmitter address, determining a time gap between the first time and the second time, and determining, based, in part, on the time gap, a sequence threshold value. The method further includes determining a sequence difference between the first sequence number and the second sequence number, determining that the sequence difference is less than the sequence threshold value, and providing an indication of address rotation by the device.

The present invention relates generally to computer networking techniques. More particularly, the invention provides methods and systems for intrusion (attack) detection for local area networks with wireless extensions. The present intrusion detection can be applied to many computer networking environments, e.g. environments based upon the IEEE 802.11 family of standards (WiFi), Ultra Wide Band (UWB), IEEE 802.16 (WiMAX), Bluetooth, and others. It will be appreciated that applications extend to other computer networking techniques.
Computer systems have proliferated from academic and specialized science applications to day-to-day business, commerce, information distribution and home applications. Such systems can include personal computers (PCs) to large mainframe and server class computers. Powerful mainframe and server class computers run specialized applications for banks, small and large companies, e-commerce vendors, and governments. Personal computers can be found in many offices, homes, and even local coffee shops.
The computer systems located within a specific local geographic area (e.g., an office, building floor, building, home, or any other defined geographic region (indoor and/or outdoor)) are typically interconnected using a Local Area Network (LAN) (e.g. the Ethernet). The LANs, in turn, can be interconnected with each other using a Wide Area Network (WAN)(e.g., the Internet). A conventional LAN can be deployed using an Ethernet-based infrastructure comprising cables, hubs switches, and other elements.
Connection ports (e.g., Ethernet ports) can be used to couple multiple computer systems to the LAN. For example, a user can connect to the LAN by physically attaching a computing device (e.g., a laptop, desktop, or handheld computer) to one of the connection ports using physical wires or cables. Other types of computer systems, such as database computers, server computers, routers, and Internet gateways, can be connected to the LAN in a similar manner. Once physically connected to the LAN, a variety of services can be accessed (e.g., file transfer, remote login, email, WWW, database access, and voice over IP).
Using recent (and increasingly popular) wireless technologies, users can now be wirelessly connected to the computer network. Thus, wireless communication can provide wireless access to a LAN in the office, home, public hot-spot, and other geographical locations. The IEEE 802.11 family of standards (WiFi) is a common standard for such wireless communication. In WiFi, the 802.11b standard provides for wireless connectivity at speeds up to 11 Mbps in the 2.4 GHz radio frequency spectrum; the 802.11g standard provides for even faster connectivity at about 54 Mbps in the 2.4 GHz radio frequency spectrum; and the 802.11a standard provides for wireless connectivity at speeds up to 54 Mbps in the 5 GHz radio frequency spectrum. The standards such as 802.11n provide even higher connectivity speeds.
Advantageously, WiFi can facilitate a quick and effective way of providing a wireless extension to an existing LAN. To provide this wireless extension, one or more WiFi access points (APs) can connect to the connection ports either directly or through intermediate equipment, such as WiFi switch. After an AP is connected to a connection port, a user can access the LAN using a device (called a station) equipped with WiFi radio. The station can wirelessly communicate with the AP.
The application of wireless communication to computer networking can introduce additional security exposure. Specifically, the radio waves that are integral to wireless communication often cannot be contained inside or outside the physical space bounded by physical structures, such as the walls of a building. Because of this signal penetration, unauthorized users, who could be using their wireless devices in a nearby street, parking lot, or building, could launch security attacks on the wireless networks. Moreover, several weak points in the IEEE 802.11 MAC standards have been recently discovered which make such wireless networks easy target for denial of service (DOS) attacks. See for example, a paper by Bellardo and Savage entitled, "802.11 Denial-of-Service Attacks: Real Vulnerabilities and Practical Solutions" published in the 12th USENIX Security Symposium in August 2003, for discussion on deauthentication, disassociation and virtual carrier sense DOS attacks. Other types of DOS attacks such as authentication flood, association flood and EAPOL START flood can also be launched on the 802.11 wireless networks. In the DOS attack, an attacker sitting in street, parking lot, or neighboring premises can bring down the wireless network of an organization. This can cause significant loss of productivity.
Conventional techniques can be used for detecting such attacks with varying degrees of success. For example, certain principles of conventional threshold crossing/flooding/anomaly detection can be applied to this problem in a naïve manner. Certain examples of threshold crossing/flooding/anomaly detection techniques can be found in U.S. Pat. No. 6,321,338 to Porras et al. entitled "Network surveillance." However such naïve application is rife with problems such as false alarms, impracticality of threshold tuning and others as described throughout the present specification and more particularly below.
From the above, techniques for improving security in wireless networks, and in particular the ability to accurately detect security attacks without causing false alarms, are highly desired.

Method and system for detecting address rotation and related events in communication networks


This invention relates to compounds, pharmaceutical compositions, and methods of using compounds of the formula: ##STR1##. A is O or S; PA1 R is C.sub.1 -C.sub.10 straight or branched chain alkyl, C.sub.2 -C.sub.10 straight or branched chain alkenyl, C.sub.2 -C.sub.10 straight or branched chain alkynyl, aryl, heteroaryl, carbocycle, or heterocycle; PA1 D is a bond, or a C.sub.1 -C.sub.3 straight or branched chain alkyl, C.sub.2 -C.sub.3 straight or branched chain alkenyl, C.sub.2 -C.sub.3 straight or branched chain alkynyl, wherein any of the carbon atoms of said alkyl, alkenyl, or alkynyl of D are optionally replaced with oxygen, nitrogen, or sulfur; and PA1 X is aryl, heteroaryl, carbocycle, or heterocycle.

1. Field of the Invention
The present invention relates to inhibitors of the nucleic enzyme poly(adenosine 5'-diphospho-ribose) polymerase ["poly(ADP-ribose) polymerase" or "PARP", which is also sometimes called "PARS" for poly(ADP-ribose) synthetase or "PART" for poly (ADP-ribose) transferase]. More particularly, the invention relates to the use of PARP inhibitors to prevent and/or treat tissue damage resulting from cell damage or death due to necrosis or apoptosis, neural tissue damage resulting from ischemia and reperfusion injury, neurological disorders and neurodegenerative diseases; to prevent or treat vascular stroke; to treat or prevent cardiovascular disorders; to treat other conditions and/or disorders such as age-related macular degeneration, AIDS and other immune diseases, arthritis, atherosclerosis, cachexia, cancer, degenerative diseases of skeletal muscle involving replicative senescence, diabetes, head trauma, immune senescence, inflammatory bowel disorders (such as colitis and Crohn's disease), muscular dystrophy, osteoarthritis, osteoporosis, chronic and acute pain (such as neuropathic pain), renal failure, retinal ischemia, septic shock (such as endotoxic shock), and skin aging; to extend the lifespan and proliferative capacity of cells; to alter gene expression of senescent cells; or to radiosensitize hypoxic tumor cells.
2. Description of the Prior Art
Poly(ADP-ribose) polymerase ("PARP") is a type of enzyme located in the nuclei of cells of various organs, including muscle, heart and brain cells. Several structural variants or isoforms of PARP enzymes have been isolated in various species and tissue types, and all of these enzymes are capable of PARP activity which consists of ADP-ribosylation. Babiychuk et al., "Higher Plants Possess Two Structurally Different Poly(ADP-Ribose) Polymerases", (1998) Plant Journal 15:635-645. Smith et al., "Tankyrase, a Poly(ADP-Ribose) Polymerase at Human Telomeres", Science 282:1484-1487 (1998). These structurally-variant forms of PARP enzymes are all referred to herein as PARP. Furthermore, the compounds of the present invention would be expected to inhibit the PARP activity of any and all enzymes which can perform ADP-Ribosylation. These PARP enzymes, collectively referred to as PARP, play a physiological role in the repair of strand breaks in DNA. Once activated by damaged DNA fragments, PARP catalyzes the attachment of up to 100 ADP-ribose units to a variety of nuclear proteins, including histones and PARP itself. While the exact range of functions of PARP has not been fully established, this enzyme is thought to play a role in enhancing DNA repair.
During major cellular stresses, however, the extensive activation of PARP can rapidly lead to cell damage or death through depletion of energy stores. Four molecules of ATP are consumed for every molecule of NAD (the source of ADP-ribose) regenerated. Thus, NAD, the substrate of PARP, is depleted by massive PARP activation and, in the efforts to re-synthesize NAD, ATP may also be depleted.
It has been reported that PARP activation plays a key role in both glutamate- and NO-induced neurotoxicity, as shown by the use of PARP inhibitors to prevent such toxicity in cortical cultures in proportion to their potencies as inhibitors of this enzyme (Zhang et al., "Nitric Oxide Activation of Poly(ADP-Ribose) Synthetase in Neurotoxicity", Science, 263:687-89 (1994)); and in hippocampal slices (Wallis et al., "Neuroprotection Against Nitric Oxide Injury with Inhibitors of ADP-Ribosylation", NeuroReport, 5:3, 245-48 (1993)). The potential role of PARP inhibitors in treating neurodegenerative diseases and head trauma has thus been known. Research, however, continues to pinpoint the exact mechanisms of their salutary effect in cerebral ischemia, (Endres et al., "Ischemic Brain Injury is Mediated by the Activation of Poly(ADP-Ribose) Polymerase", J. Cereb. Blood Flow Metabol., 17:1143-51 (1997)) and in traumatic brain injury (Wallis et al., "Traumatic Neuroprotection with Inhibitors of Nitric Oxide and ADP-Ribosylation, Brain Res., 710:169-77 (1996)).
It has been demonstrated that single injections of PARP inhibitors have reduced the infarct size caused by ischemia and reperfusion of the heart or skeletal muscle in rabbits. In these studies, a single injection of the PARP inhibitor, 3-amino-benzamide (10 mg/kg), either one minute before occlusion or one minute before reperfusion, caused similar reductions in infarct size in the heart (32-42%). Another PARP inhibitor, 1,5-dihydroxyisoquinoline (1 mg/kg), reduced infarct size by a comparable degree (38-48%). Thiemermann et al., "Inhibition of the Activity of Poly(ADP Ribose) Synthetase Reduces Ischemia-Reperfusion Injury in the Heart and Skeletal Muscle", Proc. Natl. Acad. Sci. USA, 94:679-83 (1997). This finding has suggested that PARP inhibitors might be able to salvage previously ischemic heart or skeletal muscle tissue.
PARP activation has also been shown to provide an index of damage following neurotoxic insults by glutamate (via NMDA receptor stimulation), reactive oxygen intermediates, amyloid .beta.-protein, n-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its active metabolite N-methyl-4-phenylpyridine (MPP.sup.+), which participate in pathological conditions such as stroke, Alzheimer's disease and Parkinson's disease. Zhang et al., "Poly(ADP-Ribose) Synthetase Activation: An Early Indicator of Neurotoxic DNA Damage", J. Neurochem., 65:3, 1411-14 (1995). Other studies have continued to explore the role of PARP activation in cerebellar granule cells in vitro and in MPTP neurotoxicity. Cosi et al., "Poly(ADP-Ribose) Polymerase (PARP) Revisited. A New Role for an Old Enzyme: PARP Involvement in Neurodegeneration and PARP Inhibitors as Possible Neuroprotective Agents", Ann. N. Y. Acad. Sci., 825:366-79 (1997); and Cosi et al., "Poly(ADP-Ribose) Polymerase Inhibitors Protect Against MPTP-induced Depletions of Striatal Dopamine and Cortical Noradrenaline in C57B1/6 Mice", Brain Res., 729:264-69 (1996).
Neural damage following stroke and other neurodegenerative processes is thought to result from a massive release of the excitatory neurotransmitter glutamate, which acts upon the N-methyl-D-aspartate (NMDA) receptors and other subtype receptors. Glutamate serves as the predominate excitatory neurotransmitter in the central nervous system (CNS). Neurons release glutamate in great quantities when they are deprived of oxygen, as may occur during an ischemic brain insult such as a stroke or heart attack. This excess release of glutamate in turn causes over-stimulation (excitotoxicity) of N-methyl-D-aspartate (NMDA), AMPA, Kainate and MGR receptors. When glutamate binds to these receptors, ion channels in the receptors open, permitting flows of ions across their cell membranes, e.g., Ca.sup.2+ and Na.sup.+ into the cells and K.sup.+ out of the cells. These flows of ions, especially the influx of Ca.sup.2+, cause overstimulation of the neurons. The over-stimulated neurons secrete more glutamate, creating a feedback loop or domino effect which ultimately results in cell damage or death via the production of proteases, lipases and free radicals. Excessive activation of glutamate receptors has been implicated in various neurological diseases and conditions including epilepsy, stroke, Alzheimer's disease, Parkinson's disease, Amyotrophic Lateral Sclerosis (ALS), Huntington's disease, schizophrenia, chronic pain, ischemia and neuronal loss following hypoxia, hypoglycemia, ischemia, trauma, and nervous insult. Recent studies have also advanced a glutamatergic basis for compulsive disorders, particularly drug dependence. Evidence includes findings in many animal species, as well as, in cerebral cortical cultures treated with glutamate or NMDA, that glutamate receptor antagonists block neural damage following vascular stroke. Dawson et al., "Protection of the Brain from Ischemia", Cerebrovascular Disease, 319-25 (H. Hunt Batjer ed., 1997). Attempts to prevent excitotoxicity by blocking NMDA, AMPA, Kainate and MGR receptors have proven difficult because each receptor has multiple sites to which glutamate may bind. Many of the compositions that are effective in blocking the receptors are also toxic to animals. As such, there is no known effective treatment for glutamate abnormalities.
The stimulation of NMDA receptors, in turn, activates the enzyme neuronal nitric oxide synthase (NNOS), which causes the formation of nitric oxide (NO), which more directly mediates neurotoxicity. Protection against glutamate neurotoxicity mediated through the NMDA receptors has occurred following treatment with NOS inhibitors. See Dawson et al., "Nitric Oxide Mediates Glutamate Neurotoxicity in Primary Cortical Cultures", Proc. Natl. Acad. Sci. USA, 88:6368-71 (1991); and Dawson et al., "Mechanisms of Nitric Oxide-mediated Neurotoxicity in Primary Brain Cultures", J. Neurosci., 13:6, 2651-61 (1993). Protection against glutamate neurotoxicity mediated through NMDA receptors can also occur in cortical cultures from mice with targeted disruption of NNOS. See Dawson et al., "Resistance to Neurotoxicity in Cortical Cultures from Neuronal Nitric Oxide Synthase-Deficient Mice", J. Neurosci., 16:8, 2479-87 (1996).
It is known that neural damage following vascular stroke is markedly diminished in animals treated with NOS inhibitors or in mice with NNOS gene disruption. Iadecola, "Bright and Dark Sides of Nitric Oxide in Ischemic Brain Injury", Trends Neurosci., 20:3, 132-39 (1997); and Huang et al., "Effects of Cerebral Ischemia in Mice Deficient in Neuronal Nitric Oxide Synthase", Science, 265:1883-85 (1994). See also, Beckman et al., "Pathological Implications of Nitric Oxide, Superoxide and Peroxynitrite Formation", Biochem. Soc. Trans., 21:330-34 (1993). Either NO or peroxynitrite can cause DNA damage, which activates PARP. Further support for this is provided in Szabo et al., "DNA Strand Breakage, Activation of Poly(ADP-Ribose) Synthetase, and Cellular Energy Depletion are Involved in the Cytotoxicity in Macrophages and Smooth Muscle Cells Exposed to Peroxynitrite", Proc. Natl. Acad. Sci. USA, 93:1753-58 (1996).
Zhang et al., U.S. Pat. No. 5,587,384 issued Dec. 24, 1996, discusses the use of certain PARP inhibitors, such as benzamide and 1,5-dihydroxy-isoquinoline, to prevent NMDA-receptor mediated neurotoxicity and, thus, treat stroke, Alzheimer's disease, Parkinson's disease and Huntington's disease. However, it is has now been discovered that Zhang et al. may have been in error in classifying neurotoxicity as NMDA-receptor mediated neurotoxicity. Rather, the in vivo neurotoxicity present is more appropriately classified as glutamate neurotoxicity. See Zhang et al. "Nitric Oxide Activation of Poly(ADP-Ribose) Synthetase in Neurotoxicity", Science, 263:687-89 (1994). See also, Cosi et al., Poly(ADP-Ribose)Polymerase Inhibitors Protect Against MPTP-induced Depletions of Striatal Dopamine and Cortical Noradrenaline in C57B1/6 Mice", Brain Res., 729:264-69 (1996).
It is also known that PARP inhibitors affect DNA repair generally. Cristovao et al., "Effect of a Poly(ADP-Ribose) Polymerase Inhibitor on DNA Breakage and Cytotoxicity Induced by Hydrogen Peroxide and .gamma.-Radiation," Terato., Carcino., and Muta., 16:219-27 (1996), discusses the effect of hydrogen peroxide and .gamma.-radiation on DNA strand breaks in the presence of and in the absence of 3-aminobenzamide, a potent inhibitor of PARP. Cristovao et al. observed a PARP-dependent recovery of DNA strand breaks in leukocytes treated with hydrogen peroxide.
PARP inhibitors have been reported to be effective in radiosensitizing hypoxic tumor cells and effective in preventing tumor cells from recovering from potentially lethal damage of DNA after radiation therapy, presumably by their ability to prevent DNA repair. See U.S. Pat. Nos. 5,032,617; 5,215,738; and 5,041,653.
Evidence also exists that PARP inhibitors are useful for treating inflammatory bowel disorders. Salzman et al., "Role of Peroxynitrite and Poly(ADP-Ribose)Synthase Activation Experimental Colitis," Japanese J. Pharm., 75, Supp. I:15 (1997), discusses the ability of PARP inhibitors to prevent or treat colitis. Colitis was induced in rats by intraluminal administration of the hapten trinitrobenzene sulfonic acid in 50% ethanol and treated with 3-aminobenzamide, a specific inhibitor of PARP activity. Inhibition of PARP activity reduced the inflammatory response and restored the morphology and the energetic status of the distal colon. See also, Southan et al., "Spontaneous Rearrangement of Amino-alkylithioureas into Mercaptoalkylguanidines, a Novel Class of Nitric Oxide Synthase Inhibitors with Selectivity Towards the Inducible Isoform", Br. J. Pharm., 117:619-32 (1996); and Szabo et al., "Mercaptoethylguanidine and Guanidine Inhibitors of Nitric Oxide Synthase React with Peroxynitrite and Protect Against Peroxynitrite-induced Oxidative Damage", J. Biol. Chem., 272:9030-36 (1997).
Evidence also exists that PARP inhibitors are useful for treating arthritis. Szabo et al., "Protective Effects of an Inhibitor of Poly(ADP-Ribose)Synthetase in Collagen-Induced Arthritis," Japanese J. Pharm., 75, Supp. I:102 (1997), discusses the ability of PARP inhibitors to prevent or treat collagen-induced arthritis. See also Szabo et al., "DNA Strand Breakage, Activation of Poly(ADP-Ribose)Synthetase, and Cellular Energy Depletion are Involved in the Cytotoxicity in Macrophages and Smooth Muscle Cells Exposed to Peroxynitrite," Proc. Natl. Acad. Sci. USA, 93:1753-58 (March 1996); Bauer et al., "Modification of Growth Related Enzymatic Pathways and Apparent Loss of Tumorigenicity of a ras-transformed Bovine Endothelial Cell Line by Treatment with 5-Iodo-6-amino-1,2-benzopyrone (INH.sub.2 BP)", Intl. J. Oncol., 8:239-52 (1996); and Hughes et al., "Induction of T Helper Cell Hyporesponsiveness in an Experimental Model of Autoimmunity by Using Nonmitogenic Anti-CD3 Monoclonal Antibody", J. Immuno., 153:3319-25 (1994).
Further, PARP inhibitors appear to be useful for treating diabetes. Heller et al., "Inactivation of the Poly(ADP-Ribose)Polymerase Gene Affects Oxygen Radical and Nitric Oxide Toxicity in Islet Cells," J. Biol. Chem., 270:19, 11176-80 (May 1995), discusses the tendency of PARP to deplete cellular NAD+ and induce the death of insulin-producing islet cells. Heller et al. used cells from mice with inactivated PARP genes and found that these mutant cells did not show NAD+ depletion after exposure to DNA-damaging radicals. The mutant cells were also found to be more resistant to the toxicity of NO.
Further still, PARP inhibitors have been shown to be useful for treating endotoxic shock or septic shock. Zingarelli et al., "Protective Effects of Nicotinamide Against Nitric Oxide-Mediated Delayed Vascular Failure in Endotoxic Shock: Potential Involvement of PolyADP Ribosyl Synthetase," Shock, 5:258-64 (1996), suggests that inhibition of the DNA repair cycle triggered by poly(ADP ribose) synthetase has protective effects against vascular failure in endotoxic shock. Zingarelli et al. found that nicotinamide protects against delayed, NO-mediated vascular failure in endotoxic shock. Zingarelli et al. also found that the actions of nicotinamide may be related to inhibition of the NO-mediated activation of the energy-consuming DNA repair cycle, triggered by poly(ADP ribose) synthetase. See also, Cuzzocrea, "Role of Peroxynitrite and Activation of Poly(ADP-Ribose) Synthetase in the Vascular Failure Induced by Zymosan-activated Plasma," Brit. J. Pharm., 122:493-503 (1997).
Yet another known use for PARP inhibitors is treating cancer. Suto et al., "Dihydroisoquinolinones: The Design and Synthesis of a New Series of Potent Inhibitors of Poly(ADP-Ribose) Polymerase", Anticancer Drug Des., 7:107-17 (1991), discloses processes for synthesizing a number of different PARP inhibitors. In addition, Suto et al., U.S. Pat. No. 5,177,075, discusses several isoquinolines used for enhancing the lethal effects of ionizing radiation or chemotherapeutic agents on tumor cells. Weltin et al., "Effect of 6(5H)-Phenanthridinone, an Inhibitor of Poly(ADP-ribose) Polymerase, on Cultured Tumor Cells", Oncol. Res., 6:9, 399-403 (1994), discusses the inhibition of PARP activity, reduced proliferation of tumor cells, and a marked synergistic effect when tumor cells are co-treated with an alkylating drug.
Still another use for PARP inhibitors is the treatment of peripheral nerve injuries, and the resultant pathological pain syndrome known as neuropathic pain, such as that induced by chronic constriction injury (CCI) of the common sciatic nerve and in which transsynaptic alteration of spinal cord dorsal horn characterized by hyperchromatosis of cytoplasm and nucleoplasm (so-called "dark" neurons) occurs. See Mao et al., Pain, 72:355-366 (1997).
PARP inhibitors have also been used to extend the lifespan and proliferative capacity of cells including treatment of diseases such as skin aging, Alzheimer's disease, atherosclerosis, osteoarthritis, osteoporosis, muscular dystrophy, degenerative diseases of skeletal muscle involving replicative senescence, age-related macular degeneration, immune senescence, AIDS, and other immune diseases; and to alter gene expression of senescent cells. See WO 98/27975.
Large numbers of known PARP inhibitors have been described in Banasik et al., "Specific Inhibitors of Poly(ADP-Ribose) Synthetase and Mono(ADP-Ribosyl)-Transferase", J. Biol. Chem., 267:3, 1569-75 (1992), and in Banasik et al., "Inhibitors and Activators of ADP-Ribosylation Reactions", Molec. Cell. Biochem., 138:185-97 (1994).
However, the approach of using these PARP inhibitors in the ways discussed above has been limited in effect. For example, side effects have been observed with some of the best-known PARP inhibitors, as discussed in Milam et al., "Inhibitors of Poly(Adenosine Diphosphate-Ribose) Synthesis: Effect on Other Metabolic Processes", Science, 223:589-91 (1984). Specifically, the PARP inhibitors 3-aminobenzamide and benzamide not only inhibited the action of PARP but also were shown to affect cell viability, glucose metabolism, and DNA synthesis. Thus, it was concluded that the usefulness of these PARP inhibitors may be severely restricted by the difficulty of finding a dose that will inhibit the enzyme without producing additional metabolic effects.
The inventors have now discovered that select ortho-diphenol compounds can inhibit PARP activity and can treat or prevent tissue damage resulting from cell damage or death due to necrosis or apoptosis and/or can ameliorate neural tissue damage, including that following focal ischemia and reperfusion injury. Generally, inhibition of PARP activity spares the cell from energy loss, preventing irreversible depolarization of the neurons and, thus, provides neuroprotection. While not wishing to be bound thereby, it is thought that PARP activation may play a common role in still other excitotoxic mechanisms, perhaps as yet undiscovered, in addition to the production of free radicals and NO.
Certain related compounds have been disclosed for medical treatments and other uses. However, these compounds are structurally distinguishable and directed to uses which emphasize their toxic characteristics. Compounds that are used primarily as synthetic intermediates in the preparation of compounds for: treating hyperlipemia in U.S. Pat. No. 5,719,303 to Yoshida et al. "Phosphinic Acid Derivatives"; treating plant nepovirus in "Inhibition of Tomato Ringspot Virus by Flavenoids", by Malhotra et al, (1996) Phytochem. 43:1271-1276; inhibiting fibrosis in Japanese Patent 92JP-0098635 to Kyota et al. "Fibrosis-inhibiting Agents Containing Gallate Esters"; treatment of hypertension in European Patent 86EP-194046 to Hargreaves et al. "Dihydropyridine Alkanolamines and Their Use"; bronchodilation in U.S. Pat. 4,336,400 to Minatoya et al. "3-(Hydroxy or Hydroxymethyl)-4-Hydroxy-alpha (Aminomethyl)Benzyl Alcohols and Methods of Use"; treating snakebite in U.S. Pat. No. 4,124,724 to Agoro, "Crystalline Caffeic Acid Derivatives and Compositions for Treating Snakebite"; and bronchodilation in "Esters of N-tert-butylarterenol: Long-acting New Bronchodilators with Reduced Cardiac Effects", by Tullar et al, (1976) J. Med. Chem. 19:834-838.
Other related, but structurally distinct compounds for unrelated uses include: PCT Publication WO9720944 by Banister et al., "Melanin Production"; "(+)-Catechin: Benzoyl Protection of OH Groups and NMR Study of Products", by Marek et al, (1997) Chem. Pap. 51:107-110; "Decomposition of Polyurethane Foams Derived from Condensed Tannin", by Ge et al, (1996) Mokuzai Gakkaishi 42:776-781; "Cinnamic Acid Derivatives", Yamaguchi et al, (1996) Sekiyu Gakkaishi 39:273-278; Japanese Patent JP03088882 to Kanba et al., "Weather Resistant Water-Based Fluoropolymer Coating Compositions"; "A DTA Study of Phenols: III Polyhydroxyphenols and Naphthols", by Buckman et al, (1991) J. Therm. Anal. 37:79-94; and U.S. Pat. No. 3,904,671 to Minatoya et al. "(Aminohydroalkyl) Catechol Diesters".
Accordingly, there remains a need for compounds capable of acting as PARP inhibitors, pharmaceutical compositions containing the same and methods of using the same that produce more potent and reliable effects, particularly with respect to treatment of tissue damage resulting from cell death or damage due to necrosis or apoptosis, and less side effects.

Ortho-diphenol compounds, methods and pharmaceutical compositions for inhibiting parp


A temperature adjusting valve includes, a first member made of a first material having a first coefficient of thermal expansion, a second member made of a second material having a second coefficient of thermal expansion that is in operable communication with the first member, and a flow passageway at least partially defined by a distance between a first surface of the first member and a second surface of the second member, the first coefficient of thermal expansion and the second coefficient of thermal expansion are selected such that a flow area of the flow passageway changes in response to changes in temperature of at least one of the first member and the second member the distance also is adjustable independently of temperature changes of the first member and the second member.

Some turbine pump assemblies employ speed control valves to adjust mass flow of gases that determine the rotational speed of the turbine pump assembly. While such speed control valves work well for the purpose for which they were designed, industry is always receptive to systems and methods that provide additional features and controls.

Temperature adjusting valve, a turbine pump assembly and method of adjusting flow through a valve


A filtering apparatus comprises a housing having a blood inlet and a blood outlet as well as a vent which are formed protrudingly from the housing. A filtering element is provided inside the housing to partition the inside of the housing into a first space and a second space. The filtering element is made from a porous material folded to have a plurality of pleats, the pleated material being arranged to form a hollow truncated cone with the pleats radiating outward. The opening at the top portion of the filtering element is sealed with a filling material. The filling material has a bottom surface that includes a central portion which protrudes into the second space, and this allows a pleat intersecting portion at the outer circumference of the bottom surface to have an inclined surface with respect to the horizontal. Preferably, the outermost diameter of the filtering element gradually increases in the direction from the top portion of the filtering element to the bottom portion thereof, so as to form the shape of a hollow truncated cone. More preferably, a vertical cross section of this conical shaped filtering element reveals a trapezoid with the top and bottom portions thereof forming flat horizontal surfaces.

1. Field of the Invention
This invention relates to a filtering apparatus, and in particular to a blood filtering apparatus for separating and removing air bubbles and foreign substances from the blood being filtered.
2. Description of the Prior Art
In blood treatment systems in which blood removed from a patient is treated and then returned back to the patient, a filtering apparatus (blood filter) has been employed in the blood flow return line for separating and removing air bubbles and foreign substances from the blood.
These filtering apparatuses are generally referred to as blood filters or bubble traps. In this type of blood filter, a filtering material formed into a pleated shape has been employed to obtain a large filtering surface area, as is mentioned for example in Laid-Open Patent Publications Nos. 1-148265 and 1-148266.
In these prior art blood filters, as is stated for example in Laid-Open Patent Publication No. 1-148265, there is a housing, and in the blood filtering portion of the lower section of the housing, there is provided a filtering material made from a porous material that has been folded to form a plurality of pleats. This filtering material is rolled up within the housing so as to have a cylindrical shape with the pleats radiating outwardly therefrom. Then the open top end of the filtering material is sealed by forming a non-permeable portion obtained from the hardening of a potting material poured across such opening, and this is done in such a way that the interior surface of the non-permeable portion that faces towards the inside of the filtering material is formed as a flat, horizontal surface. Further, the blood outlet that is formed in the lower section of the housing communicates with the interior space of the filtering material.
When these blood filters are primed, the priming fluid enters from the blood outlet and fills up the interior space of the filtering material. At this time, by utilizing the pressure difference between the interior and exterior of the filtering material, any air bubbles existing in the priming fluid are discharged to the outside.

Filtering apparatus with a pleated filtering element embedded in a filling material


According to one embodiment, a cavity with a cavity mode which is coupled to physical systems includes a spherical mirror and a plane mirror. The spherical mirror is provided at a birefringent crystal including the physical systems. The plane mirror is provided at the birefringent crystal opposite to the spherical mirror. The birefringent crystal has a first refractive index to light polarized in a first direction parallel to a polarization direction of the cavity mode on an optical axis of the cavity and a second refractive index to light polarized in a second direction parallel to the optical axis, the second refractive index being different from the first refractive index. A cavity length of the cavity and a mode waist radius of the cavity mode satisfy a specific condition.

In recent years, much effort has been made to research quantum computers based on coupling between a cavity and physical systems arranged in the cavity. In such a quantum computer, the physical systems which couple to a common cavity mode of the cavity are used as qubits (quantum bits). The quantum computer executes calculation by resonating the qubits with the common cavity mode to generate an interaction between the qubits, and in that state, optically manipulating the qubits. For the quantum computer, there has been a demand to increase the success probability of optical manipulation of the qubits referred to as quantum gate operation.


The present invention relates to a support apparatus or accessory capable of attaching to an article, such as a ladder via mating and locking of a primary attachment member connected to the support and a complementary secondary attachment member securable to the ladder. In a preferred form, the support is an adjustable length support for levelling a ladder on an uneven surface. The adjustable length support comprises a fixed component and a moveable component that moves relative to the fixed component to thereby adjust a length of the adjustable length support. The moveable member is securable at a desired length by a securing means.

It may be necessary to adjust a length of an article, such as a ladder, when the ladder is located on uneven or on an incline surface. Use of a ladder on such a surface may pose a danger to a person climbing the ladder. In some situations it may be possible to level the contacting surface, for example, if the surface is dirt or gravel. However, levelling a dirt or gravel surface may be time consuming and unstable.
In some situations the surface may not easily be levelled, for example concrete surfaces including steps. In the past, placing wood blocks or other objects as spacers under a ladder leg have been used to adjust the length of one ladder leg to thereby level the ladder. However, using such temporary means tend to be unstable and may be unsafe as the blocks could shift relative to the ladder causing the ladder and user to fall. To overcome this problem, ladders and apparatus for adjusting ladders to be level on uneven or sloping surfaces have been developed.
A levelling apparatus attachable to a ladder to overcome the problems associated with temporary levelling means is described in PCT/AU02/00080. The described levelling apparatus comprises a tubular housing through which an inner leg telescopically moves to thereby adjust the extended length of the inner leg. The tubular housing is attachable to the ladder via a rod that extends at least partially through a rung of the ladder. Although this levelling apparatus provides a means for levelling a ladder, attaching and removing the levelling apparatus from a ladder can be time consuming. Accordingly, a user may leave the levelling apparatus attached to the ladder when not in use, which can lead to damage to the levelling apparatus, for example during transport and storage. Also, leaving the levelling apparatus attached to a ladder requires individual levelling apparatus for each ladder. This can be expensive, in particular in a situation where a person or company has multiple ladders.

Support apparatus or accessory for a ladder


A three-dimensional universal unit for movable structures includes first and second coupling members. Each coupling member includes two opposing side surface parts, an end face part connected to form a right angle with one end face of each side surface part, a coupling/uncoupling device provided on the two side surface parts and end surface part of the first coupling member and operating independently, a permanent magnet provided on the two side surface parts and end face part of the second coupling member, and a linking part disposed between the two side surface parts of each coupling member. The universal unit further includes a linking member that rotatably links the linking parts of the two coupling members and a drive apparatus that rotationally drives the two coupling members relative to the linking member.

1. Field of the Invention
This invention relates to a universal unit that can form three-dimensional structures of arbitrary shape by means of automatic self-configuration, and more concretely to a three-dimensional universal unit for movable structures that is suited to utilization in three-dimensional structures of arbitrary shape to be erected in outer space or other extreme environments, consisting of a plurality of universal units of identical structure which are coupled to each other and these couplings can be changed, released or recoupled without outside assistance, thereby forming the desired three-dimensional structure by itself.
2. Description of the Prior Art
When various types of work are necessary in extreme environments such as outer space, planetary exploration, deep sea or inside nuclear reactors where work by humans is difficult or undesirable, this work must be performed using robots. It has been envisioned that such robots would form various structures by coupling together a plurality of assembly units of identical structure, or by changing, releasing or recoupling the couplings among the assembly units. Such robots would typically couple, release, change or recouple the units with outside assistance. However, if such structures are in the aforementioned extreme environments or confined spaces or the like where outside assistance is difficult to obtain, it is difficult to couple, release, change or recouple the units. Regarding this technical topic, the present inventors have already developed a multi-function module used to constitute equipment (JP-B-8-1575).
The structures formed by means of these multi-function modules used to constitute equipment have a two-dimensional shape, and the modules, each equipped with an information processing unit, can be coupled to each other by electromagnetic force and the positions of the couplings can be changed or repulsive force can be generated to release the couplings, so by successively changing the relationship among couplings with the adjacent modules, it is possible to change the two-dimensional shape of the entire structure. Therefore, starting from an initial shape when coupled into an arbitrary two-dimensional shape, it is possible to change the relationship among couplings to make it into a structure having the target two-dimensional shape. This apparatus is constituted such that an upper-layer member, middle-layer member and lower-layer member with a plurality of central axisymmetric protruding arms at equal intervals are coaxially stacked, where the upper-layer member and lower-layer member are in the same phase around the central axis, while the middle-layer member is in the opposite phase. In addition, the protruding arms of the upper-layer member and lower-layer member are coupled at a distance at which the protruding arms of the middle-layer member of another module can be inserted between them, and an attracting or repelling coupling/uncoupling mechanism is provided between the protruding arms of opposing upper-layer members and lower-layer members and the protruding arms of middle-layer members of other modules, while an information processing apparatus is connected to each protruding arm and transmitters and receivers are provided in order to perform communication with other modules that are coupled by means of the coupling/uncoupling mechanism. However, if the shape is changed in only two dimensions, its applications are markedly limited, since a three-dimensionally arbitrary shape is required for a general structure.
In order to meet these needs, the present inventors have further developed a three-dimensional universal unit proposed in U.S. Pat. No. 5,988,845 and JP-A-10-110893.
With the aforementioned three-dimensional universal unit proposed by the present inventors, the modules used to constitute equipment which can be formed into an arbitrary two-dimensional shape without outside assistance as proposed above have evolved to a constitution such that they can be assembled into an arbitrary three-dimensional shape, so a plurality of universal units of identical structure can be coupled or these couplings can be released or changed, and thus the desired three-dimensional structure can be self-configured.
However, the aforementioned proposal describes constructing a structure at limited lattice points, and it is difficult to construct machines that have active components such as robot arms, hands or walking machines. In addition, the modules have a complex structure, making them very difficult to manufacture and expensive, there are many areas of mechanical friction and the number of components is large so the probability of failure becomes higher, among other problems.
The present invention was accomplished in consideration of the above problems and one object thereof is to provide a three-dimensional universal unit for movable structures that has a simple structure and can easily form machines having active components, that operates reliably in long-term usage and that can be manufactured inexpensively.
In order to achieve the aforementioned object, the three-dimensional universal unit for movable structures according to this invention comprises first and second coupling members, each of which comprises two opposing side surface parts, an end face part connected to form a right angle with one end face of each side surface part, a coupling/uncoupling device provided on the two side surface parts and end face part of the first coupling member and which operates independently, a permanent magnet provided on the two side surface parts and end face part of the second coupling member, and a linking part disposed between the two side surface parts of each coupling member; a linking member that rotatably links the linking parts of the two coupling members; and a drive apparatus that rotationally drives the coupling members relative to the linking member.
The coupling/uncoupling device comprises a top plate, a base plate disposed movably opposite to said top plate, a permanent magnet secured upon the base plate, a compression coil spring disposed between the base plate and the top plate that continuously pushes the two apart, and a shape memory spring disposed between the base plate and the top plate, wherein the shape memory spring takes two positions: a short first shape that does not contact one of the base plate and the top plate when the base plate is separated furthest from the top plate; and a long second shape that pushes in a direction separating the base plate and top plate when the base plate is closest to the top plate.
The compression coil spring may comprise a conical coil spring adapted to the attraction characteristics of the permanent magnet.
The drive apparatus that rotationally drives the coupling members may be provided on the side of the linking member.
Electrodes that are secured in the interior of the coupling members and that extend to the surface of the top plate may be provided.
As described above, the universal unit according to the present invention consists of two coupling members of a simple structure that are easily configured and a linking member that links the two coupling members. Accordingly, it can operate reliably in long-term usage and can be manufactured inexpensively.
The above and other objects and features of the invention will become apparent from the following description made with reference to the appended drawings.

Three dimensional universal unit for movable structure

Agency of Industrial Science and Technology

Ministry of International Trade and Industry


A safety brake of the type for use in hoist. As a hoist cage descends or ascends faster than a predetermined safety speed, a corresponding high speed motion is transmitted to a main shaft of the safety brake through a input pinion gear connected to the main shaft for engagement with a vertical rack attached to a hoist tower. Movable braking disks are attached to the main shaft for rotation therewith. Fixed braking disks are interleaved with the movable disks. Such high speed motion causes a dog retained in the main shaft to centrifugally move outwardly to engage the drum. The actuator assembly connected to the drum acts to cause the drum to move against the fixed and movable braking disks.

Hoists have been widely used to hoist workmen and materials on building construction work sites. A typical hoist includes a hoisting tower constructed of lattices of steel angle iron, and a lift cage or platform equipped to be vertically movable along the hoisting tower. The lift cage is guided by rollers along a vertical path provided in the hoisting tower and is driven by motors having pinions engaging with vertical racks attached to the tower along the vertical path.
In such a rack and pinion drive system, there are usually provided safety brakes to stop a cage when it exceeds a predetermined speed. A particular safety brake generally has an input pinion gear in engagement with the rack. In the event that the input gear rotates faster than a predetermined rate, the safety brake starts to operate stopping its input gear to provide a braking force to the cage.
U.S. Pat. No. 4,258,832, to Thorp, discloses a safety brake in which a centrifugal control assembly is connected to an input pinion gear engaging a vertical rack of a hoist, and a dog of the control assembly is positioned inside a drum of a brake assembly. When the dog is thrown outwardly by centrifugal force, it engages an internal tooth of the drum and simultaneously a tab of an actuator so that the drum and the actuator are both operatively connected to the input pinion gear for rotation. Movable braking disks are attached to the drum for rotation therewith. The movable braking disks are interleaved with the fixed braking disks which are non-rotatably but slidably fixed to a housing of the safety brake. The actuator rotates a ball screw and a nut of the ball screw moves axially to compress slidably fixed braking disks against the rotating braking disks to effect a braking force until the cage is stopped.
Although this patent apparatus presented an advance in the art, it was not without any drawbacks. Since the movable disks are attached to the drum, they do not rotate until the drum is operatively connected to the main shaft. Those movable disks are therefore required to be lubricated. Such lubrication disadvantageously acts to reduce friction between the movable and fixed disks when compressed to each other, which friction produces a braking force.
The present invention provides a further advancement in the art, as will be fully explained below.


Fire barrier composition particularly applicable as an acoustic panel-fire wall structure in aircraft, capable of withstanding a 2,000.degree. F. flame temperature, comprising incorporating a silica-containing material such as silicic acid or the reaction product of silicic acid and maleic anhydride, into a resin, particularly a polyimide resin. The resulting silica-containing resin, e.g. silicic acid-filled polyimide, is then applied to a substrate such as graphite fiber or glass cloth, to form a composite structure, which is then cured. The resulting cured composite when subjected to high temperature, e.g. a 2,000.degree. F. flame temperature, forms silicon carbide and/or silicon nitride, in situ, which stabilizes any char that forms.

This invention relates to thermal insulation materials having high fire resistance and low thermal conductivity, and is particularly concerned with resin compositions and composites, particularly polyimide resins and composites formed therewith, incorporating substances in the resin to substantially increase fire resistance, and which are particularly applicable as an acoustic panel-fire wall structure in aircraft.
In order to reduce aircraft weight, thereby saving fuel, it is desirable to use graphite-resin composites in as many areas as possible. One location for use of such composites is the engine nacelle; and one application in that area is the acoustic panel. However, this area is also in the hot zone. Thus, in addition to serving as an acoustic panel, it must also serve as a fire barrier between the hot zone of the engine and the outer region, which contains fuel lines, hydraulic lines, electrical components, etc. Furthermore, there is an FAA requirement that any fire barrier used in the engine nacelle must be capable of withstanding a 2,000.degree. F. flame for 15 minutes.
Thus, using graphite-polyimide as the composite, a structural component is available that has good strength, is light weight and has some fire resistance, in that the polyimide will not burn at low flame temperatures. However, at 2,000.degree. F. flame conditions, the polyimide will burn and decompose to form a relatively stable char. This char, however, will allow heat to pass through to the backside and decompose the resin. This, in turn, creates a hazard due to the possibility of the decomposition products igniting, thereby starting a fire, even though the parent polymer (polyimide) will not readily burn. Therefore, a need exists for a non-burning resin that has good stability and low thermal conductivity.
Various ways have been suggested to effect protection of the acoustic panel-fire wall structure. One approach is to use a titanium face shield over the panel, thereby preventing a fire from getting through. Another approach is to use a high silica glass fabric face shield, or a silicone rubber impregnated high silica glass fabric. In the first instance, use of titanium does not help in weight reduction over use of graphite-polyimide composite. In the second approach, the high silica glass fabric or silicone-rubber impregnated high silica glass fabric also offers some protection, but it again necessitates the use of an extra barrier over the acoustical panel.
It is therefore necessary that some substance be incorporated into the polyimide that will give direct protection to the polyimide by being non-burning, have a low thermal conductivity, and be a char stabilizer. As mentioned above, there may be employed either a face shield of titanium, glass fabric or silicone-rubber impregnated glass fabric. Another alternative is to incorporate hydrated aluminum oxide directly into the polyimide for fire protection. Each of these methods is satisfactory, but suffers from limitations, such as increase in weight, e.g. in the case of titanium, removal of the water of hydration from the hydrated aluminum oxide, i.e., the water is known to come off at around 350.degree. F., which is the cure temperature of the polyimide, and the like.
Examples of the prior art relating to the present invention are set forth below.
U.S. Pat. Nos. 3,356,525 and 3,644,135 are directed to coating or impregnating carbon fibers or cloth with various metal carbides obtained by reacting carbon-containing materials or polymers with various metals.
U.S. Pat. Nos. 3,523,056 and 3,604,257 are directed to the production of glass cloth impregnated with a polyimide resin.
U.S. Pat. No. 3,642,681 discloses a coating composition containing a polysilicic acid component.
A number of patents including, for example U.S. Pat. No. 3,079,273, disclose formation of various silicon carbide articles.
Accordingly, one object of the invention is to provide resin compositions and composites having high fire resistance and low thermal conductivity. Another object is the provision of compositions and composites of the above type having utility as a fire barrier, and particularly applicable as an acoustic panel-fire wall structure in aircraft, capable of withstanding high temperature, e.g. a 2,000.degree. F. flame temperature. A still further object is the provision of resin compositions, particularly polyimide compositions and composites, such as polyimide-glass fabric composites or laminates, having incorporated therein a substance which substantially increases the fire resistance of the resin and reduces its thermal conductivity, and functions to stabilize the resin or resin char, at high temperatures, e.g. a 2,000.degree. F. flame temperature.

Fire barrier compositions and composites


A printer includes LED heads and head controllers. Each head controller transfers items of data to a corresponding head over a set of common buses. The LED head has a receiver activated by a corresponding head selecting signal. In one configuration, the common buses may include a selector bus over a data bus. Image data and a group of signals are alternately transferred over the data bus, the group of signals including a latch signal for latching the image data into a corresponding head and a strobe signal for driving a corresponding head in accordance with the image data. The selector signal allows the receiver to direct the image data and the group of signals into separate data paths. In another configuration, the control signals may further include an image clock and a control clock. The common buses may include an image clock bus, a control clock bus, and a data bus over which the image data and the group of signals are alternately transferred, the image data being attended by the image clock and the group of signals being attended by the control clock. In still another configuration, the image data may include a train of image data in which first image data and second image data appear alternately. One receiver receives the first image data on the rising edges of the image clock and another receiver receives the second image data on the falling edges.

1. Field of the Invention
The present invention relates to printers and facsimile machines, and more particularly to a printer where multiplexed print data is transferred from control circuits to corresponding one of a plurality of print heads via a common bus line.
2. Description of Related Art
An electrophotographic color printer incorporates a series of print engines of the same construction. Each print engine operates for a corresponding one of yellow, magenta, cyan, and black images. Such a system is referred to as tandem system. An LED array illuminates a photoconductive drum to form an electrostatic latent image of a corresponding color on the surface of the drum. The electrostatic latent image is then developed with a corresponding colored toner into a colored toner image. The colored toner image is then transferred to a print medium. As the print medium passes through the series of print engines, yellow, magenta, cyan, and black toner images are transferred one over the other on the print medium, thereby producing a full color image.
However, a tandem system requires a large number of interface cables which increase manufacturing cost. For example, a control circuit generates image data for each color and transfers the image data to a corresponding LED print head. Therefore, in order to communicate image data and associated control signals, a total of four sets of cables are connected between the respective LED print heads and the circuit board on which the control circuits are built.
A large number of cables necessarily increases the number of connectors and the number of pins of LSIs that connect cables, and therefore requires large circuit boards. This increases the total cost of the printer. In addition, a large number of wires radiate more noise, and therefore requires some measure for addressing increased noise radiation.
The aforementioned problems exist not only in a printer having a plurality of LED heads but in thermal transfer type printers, ink jet type printers and the like having a plurality of print heads.


A faucet comprising a spout, a passageway, an electrically operable valve; a first manual valve; a first manual handle; and a bypass. The passageway conducts water flow through the spout. The electrically operable valve is disposed within the passageway. The first manual valve disposed within the passageway in series with the electrically operable valve. The first manual handle that controls the first manual valve. The bypass has a first end above the electrically operable valve, relative to the water flow, and a second end below the electrically operable valve, such that a portion of the water flow bypasses the electrically operable valve.

1. Field of the Invention
The present invention relates generally to the field of automatic faucets. More particularly, the present invention relates to an automatic faucet having a restricted flow state.
2. Description of the Related Art
Automatic faucets have become popular for a variety of reasons. They save water, because water can be run only when needed. For example, with a conventional sink faucet, when a user washes their hands the user tends to turn on the water and let it run continuously, rather than turning the water on to wet their hands, turning it off to lather, then turning it back on to rinse. In public bathrooms the ability to shut off the water when the user has departed can both save water and help prevent vandalism.
One early version of an automatic faucet was simply a spring-controlled faucet, which returned to the "off" position either immediately, or shortly after, the handle was released. The former were unsatisfactory because a user could only wash one hand at a time, while the latter proved to be mechanically unreliable.
One solution was the hands-free faucet. These faucets employed a proximity detector and an electric power source to activate water flow without the need for a handle. In addition to helping to conserve water and prevent vandalism, hands-free faucets had additional advantages, some of which began to make them popular in homes, as well as public bathrooms. For example, there is no need to touch the faucet to activate it; with a conventional faucet, a user with dirty hands may need to wash the faucet after washing their hands. In public facilities non-contact operation is more sanitary. Hands-free faucets also provide superior accessibility for the disabled, the elderly, and those who need assisted care.
Other kinds of automatic faucets employ touch-control, in which water flow can be toggled by tapping a part of the faucet, such as a button or the spout.
Because one function of automatic faucets is to save water by shutting off the water flow when it is not immediately needed (without requiring the user to manually turn it off and then on again), it is possible for the user to become confused about the state of the faucet. With a strictly manual faucet, the user uses the presence or absence of a water stream to determine whether the faucet is on. With an automatic faucet, however, the absence of a water stream does not indicate whether the faucet has been manually closed, or whether the electrically operable valve is closed and the manual valve is open.
This uncertainty can have several undesirable effects. For example, it can result in inadvertent activation of water flow, as one may approach or put items in the sink area for certain activities when water flow is not desired. This can be especially problematic with faucets that have a proximity sensor, since water flow can be initiated when the user places a hand or other object in the path of the proximity sensor. Also, in certain applications conservation of power is desirable, making it desirable to turn off the automatic faucet functions. In these applications a user may forget or overlook the fact that the faucet is still in an automatic operation mode due to the absence of water flow. Most of these problems can be especially problematic for users unfamiliar with the automatic faucet's operation, such as visitors, or even new adopters.
Thus, what is needed is an automatic faucet that provides users conspicuous and intuitively obvious feedback to distinguish between a manual off state and an automatic off state. The present invention is directed towards meeting these needs, among others.


Coated cemented carbide inserts, particularly useful for milling of cast iron, methods for making the inserts, and methods of their use are disclosed. The inserts are characterized by a composition of the substrate of about 5-7 wt % Co, about 0.05-2.0 wt % total amount of the metals selected from the group consisting of Ti, Nb,Ta and combination thereof, and balance WC with a coercivity (Hc) of 1 about 4-19 kA/m and an S-value of about 0.81-0.96. The coating comprises a homogeneous layer of (TixAl1-x)N, where x is between about 0.25 and about 0.50 with a crystal structure of NaCl type and a total thickness of between about 1.0 and about 5.0 μm as measured on the middle of the flank face.

During milling of various materials with coated cemented carbide cutting tools, the cutting edges are regarded as being worn according to different wear mechanisms. Wear types, such as chemical wear, abrasive wear and adhesive wear, are rarely encountered in a pure state, and complex wear patterns are often the result. The domination of any of the wear mechanisms is determined by the application, and is dependent on properties of the machined material, applied cutting parameters, and the properties of the tool material. The machinability of cast irons can vary considerably between the various groups but also within a certain group. Small variation in the chemical composition or the micro-structure, related to the casting technique, can have significant influence on the tool life.
In general, the different cast irons are very demanding when it comes to wear resistance and therefore chemical vapor deposition (CVD)-coated inserts have been commonly used. However, in some applications these inserts do not have the combination of edge toughness and wear resistance needed.
EP 1205569 discloses a coated milling insert particularly useful for milling of grey cast iron with or without cast skin under wet conditions at low and moderate cutting speeds and milling of nodular cast iron and compacted graphite iron with or without cast skin under wet conditions at moderate cutting speeds. The insert is characterised by a WC—Co cemented carbide with a low content of cubic carbides and a highly W-alloyed binder phase and a coating including an inner layer of TiCxNy with columnar grains followed by a layer of κ-Al2O3 and a top layer of TiN.
EP 1655391 discloses coated milling inserts particularly useful for milling of grey cast iron with or without cast skin under dry conditions at preferably rather high cutting speeds and milling of nodular cast iron and compacted graphite iron with or without cast skin under dry conditions at rather high cutting speeds. The inserts are characterised by a WC—Co cemented carbide with a low content of cubic carbides and a highly W-alloyed binder phase and a coating including an inner layer of TiCxNy with columnar grains followed by a wet blasted layer of α-Al2O3.
What is needed is a coated cutting tool with enhanced performance for wet or dry milling of cast irons. The invention is directed to these, as well as other, important needs.


A method performed by a nuclear medicine diagnosis apparatus includes reconstructing a first image from first measurement data obtained by detecting a pair of radioactive rays emitted from a measurement target; reconstructing a second image from second measurement data obtained by detecting a single radioactive ray emitted from the measurement target; and generating a final image based on the first image and the second image.

1. Field of the Invention
An aspect of this disclosure relates to an image processing method, a nuclear medicine diagnosis apparatus, and a storage medium.
2. Description of the Related Art
Positron Emission Tomography (PET) is a technology for obtaining diagnostic images of the inside of a subject such as a human body or an animal. A PET apparatus can visualize the distribution of a radioactive isotope (RI) injected into the body of a subject.
In a diagnostic method using a PET apparatus, a test agent labeled (or marked) by a radioactive isotope that emits positrons is introduced into the body of a subject by, for example, injection or inhalation. The test agent introduced into the body is accumulated in a specific part of the body due to metabolism. The radioactive isotope labeling the test agent emits positrons, each emitted positron and a surrounding electron combine with each other and are thereby annihilated, and as a result, two gamma rays are emitted in opposite directions.
In a diagnosis method using a PET apparatus, the two gamma rays are detected and the detection results are processed by a computer to obtain distribution image data indicating the distribution of the radioactive isotope in the subject, and the subject is diagnosed based on a diagnostic image reconstructed from the distribution image data.
A gamma ray (radiation) detector for PET is implemented, for example, by a scintillation detector (e.g., bismuth germinate (BGO) or lutetium orthosilicate (LSO)). A scintillation detector can be manufactured at comparatively low costs. However, because a scintillation detector converts an incident gamma ray into light and converts the light into an electric signal using a photomultiplier tube, the resulting signal may be degraded during the conversion processes due to the spatial resolution and energy resolution.
On the other hand, a semiconductor detector can convert a gamma ray directly into an electric signal. For example, a semiconductor detector made of cadmium telluride (CdTe) has a higher spatial resolution and a higher energy resolution compared with a scintillation detector. However, a semiconductor detector made of cadmium telluride (CdTe) is less sensitive and more expensive than a scintillation detector.
Japanese Laid-Open Patent Publication No. 2008-232641, for example, discloses a method where Compton scattering is detected, and a gamma ray occurrence position detected by counting the coincidence at a pair of detectors (two-detector coincidence) is corrected based on the detected Compton scattering. Also, Japanese Laid-Open Patent Publication No. 2008-522168 discloses a method for reconstructing a cone from Compton scattering data by determining true events and accidental events. In a coincidence detection method, two or more sets of detection data obtained at a pair of detectors and having substantially the same gamma ray incident time are determined to be valid, sets of detection data having different gamma ray incident times are determined to be invalid, and image reconstruction is performed using the valid detection data to obtain a diagnostic image.
Here, to improve the sensitivity of a semiconductor detector, it is necessary to increase the volume of a semiconducting crystal such as a CdTe crystal. However, increasing the volume of a semiconducting crystal such as a CdTe crystal increases the costs of a semiconductor detector.
Also, the related-art methods disclosed in JP 2008-232641 and JP 2008-522168 are for correcting coincidence counting events. For example, in JP 2008-232641, the deviation of gamma rays from the 180 degree directions due to angular deviation is measured based on the principle of the Compton camera and an image is reconstructed taking into account the deviation; and in JP 2008-522168, a cone is reconstructed from Compton scattering data. Accordingly, the related-art methods do not increase the total number of valid events usable for reconstructing an image and therefore do not make it possible to obtain an image at high sensitivity.

Image processing method, nuclear medicine diagnosis apparatus, and storage medium


A synthetic jet actuator and a method for optimizing a synthetic jet actuator to meet operating requirements and physical constraints may include estimating dimension and a resonance frequency of an air cavity of the synthetic jet actuator, and using the estimated resonance frequency to the estimate dimensions of a piezoelectric actuator of the synthetic jet actuator. Individual simulations of the air cavity and piezoelectric actuator, and a coupled simulation may be performed using the estimated dimensions, and the dimensions may be revised and simulations re-executed to match the resonance frequencies of the air chamber and the piezoelectric actuator. The method maybe yield a synthetic jet actuator having a resonance frequency of the piezoelectric actuator that is approximately equal to a quarter-wavelength resonance frequency of the air cavity.

In recent years, active flow control has been used to increase the aerodynamic efficiency of machines having air flow over a surface, in particular vehicles such as airplanes. Adverse fluid flows generated over aerodynamic surfaces can buffet and fatigue downstream structures exposed to the flows, and the flows can affect efficiency by increasing drag or resistance over the surface. In one version of active flow control, jets of air are blown into the path of the adverse fluid flows to mix with the flows and cause the air to flow more smoothly over the aerodynamic surfaces and reduce the drag and resistance over the surfaces or increase the lift force generated by the surfaces. In many cases, such active flow control can be implemented in existing vehicle designs without needing significant changes thereby directly reducing the operating cost of the vehicle or other machine.
One device for creating jets of air in active flow control is a synthetic jet actuator that forms a so called synthetic jet flow by moving air back and forth through a small opening of the device. Synthetic jet actuators typically have a housing in the shape of a hollow box or cylinder with a resonant chamber therein and an orifice or nozzle opening through one of the side or end walls. At least one wall of the synthetic jet is formed from a flexible membrane that can deflect inwardly and outwardly to alternately decrease and increase the volume in the resonant chamber and expel and draw in air through the opening. Deflection of the membrane may be caused by a piezoelectric actuator that responds to an applied electric field.
The piezoelectric actuator may include a piezoceramic plate or disk having a surface facing and rigidly attached to a corresponding surface of the membrane. The actuator may have a single piezoceramic disk attached to a surface of the membrane, or two piezoceramic disks with each disk being attached in a similar manner to one of the opposing surfaces of the membrane. In alternative arrangements, a piezoelectric strain amplification structure, such as that shown in U.S. Pat. No. 8,937,424, issued to Griffin et al. on Jan. 20, 2015, and entitled, "Strain Amplification Structure and Synthetic Jet Actuator," may be implemented to cause the membrane to deflect inwardly and outwardly.
A synthetic jet actuator works most efficiently and produces a maximum synthetic jet output when the structural dynamics of the piezoelectric actuator couple with the fluid dynamics and acoustics of the synthetic jet actuator. Early designs of synthetic jet actuators included generally spherical air cavities that were generally similar to the traditional spherical Helmholtz resonators. In these designs, the resonance frequency of the spherical air cavity could be approximated accurately using the Helmholtz resonance equation for vented spheres of air as follows:
                              f          H                =                              v                          2                            π                                                                    A                                                V                  0                                                                  L                  eq                                                                                (        1        )
Where fH is the Helmholtz resonance frequency, v is the speed of sound in a gas which is approximately 343 m/s (approximately 1125 ft/s) at 20° C. (68° F.) and at sea level, A is the cross-sectional area of the neck or opening, VO is the static volume of the air cavity, and Leq is the equivalent length of the neck with end correction according to the equation Leq=Ln+0.6d, where Ln is the actual length of the neck and d is the hydraulic diameter of the neck.
Over time, synthetic jet actuators have been developed that have varying air cavity geometries, such as cubic air cavities and cylindrical air cavities. However, current design methods continue to use the Helmholtz resonance equation for estimating the resonance frequency of the non-spherical air cavities. The Helmholtz resonance equation provides a starting point for designing modern synthetic jet actuators, but the equation is a less accurate predictor of the resonance frequencies of non-spherical air cavities than spherical air cavities. In view of this, a need exists for improved design processes for coupling the structural dynamics of the piezoelectric actuators with the fluid dynamics and acoustics of the geometries of the synthetic jet actuators in which they are implemented.

Piezoelectric actuators optimized for synthetic jet actuators


The disclosed computer-implemented method for anonymizing log entries may include (1) detecting a data pattern in a group of log entries documenting events performed by at least one process executing on at least one device, (2) identifying, in the data pattern, at least one data field in the log entries that contains variable data, (3) evaluating the data field containing variable data to determine whether the data field contains sensitive data, and (4) in response to determining whether the data field contains sensitive data, applying a data-anonymization policy to the data field to anonymize the log entries. Various other methods, systems, and computer-readable media are also disclosed.

System operation logs, such as security system logs, often contain valuable data about the operation of information systems. For example, system administrators may monitor security logs to verify that security systems are operating properly, diagnose operation or performance problems, identify system weaknesses, identify the source of security threats, and/or perform forensic analysis of security breaches. Administrators may also mine security log entries to discover new types of security threats. In addition, data analysts may mine system operation logs to analyze user behavior and/or system performance.
However, system operation logs frequently include sensitive information, such as personally identifying information (PII) or infrastructure-related information (such as network addresses or server names). Unfortunately, this information may enable an attacker to map an internal network and search for vulnerabilities. Log information may also expose work schedules, personal relationships, or other information that may be used in social engineering attacks. As such, if left unprotected, a security log may be the source of information used in a targeted threat. Accordingly, the instant disclosure identifies and addresses a need for additional and improved systems and methods for anonymizing log entries.

Systems and methods for anonymizing log entries