A method and apparatus for cleaning the interior of a container or one or more objects suspended therein comprising generating a fluid vapor column by forming an air column having a direction of air flow. The air column is passed through a heating means, so as to heat the air, and then the cleaning fluid is injected into the air column against the direction of air flow. The fluid vapor column is then brought into contact with the interior of the container so that the vapor condenses on the interior of the container or on objects suspended therein.

In the past, the predominant cleaning method for cleaning the interior of pipes, tanks, and other containers employed the use of high pressure water systems. Such systems required workers to physically enter tanks containing hazardous residues. Because of the danger to workers, OSHA has strengthened regulations relating to confined entry (Occupational Safety and Health Standards, Part 1910, Subsection 146). These regulations now require such costly safety equipment and procedures that the market is eagerly searching for ways to adopt new cleaning systems which minimize or eliminate the need for workers to enter tanks. In addition, the large volume of water and waste material generated by these high pressure water systems must be handled and disposed of properly.
Accordingly, methods and apparatus for using solvent vapor to clean the interior surfaces of a container, such as a tank or objects suspended therein have been proposed. For example, U.S. Pat. No. 2,023,496 discloses a method whereby a liquid solvent or diluent is heated and then applied to oil-covered surfaces of a tank or vessel. The solvent acts to liquify the oily deposits so as to release the deposit from the interior surface of the tank. Similarly, U.S. Pat. No. 3,046,163 teaches a method of cleaning the interior of a tank holding oil, grease, crude petroleum products, coal tar products, resinous products, paints or plasticizers comprising the steps of first passing hot vapor of a chlorinated hydrocarbon solvent into the tank and condensing the vapor on the tank walls, thereby dissolving adhering dissolvable matter on the interior surfaces of the tank.
The efficiency and efficacy of the cleaning apparatus is dependent largely on the efficiency of the vapor forming process in the first instance, and additionally vapor concentration within the container being cleaned. However, the prior art vaporizing processes have been found to be inefficient due to the relatively inefficient mechanisms for forming the vapor such that quantities of solvent remained liquified, and hence unusable. In addition, prior methods generally produce relatively low concentrations of vapor in the air stream which is being used to clean the interior of the container.

System for cleaning the interior of tanks and other objects


A method to process credit card transactions, including obtaining available merchant account IDs allocated to a master merchant account at a credit card processor entity of a credit card transaction network, where the master merchant is authorized to set up merchant accounts based on the master merchant account and assumes merchant-side financial risks of the merchant accounts, receiving, after obtaining the available merchant account IDs, a request from a merchant to set up a merchant account, and assigning, in response to credit approval of the merchant, a merchant account ID selected from the available merchant account IDs to the merchant for setting up the merchant account, where a credit card transaction of the merchant is submitted, subsequent to assigning the merchant account ID, to the credit card processor entity for authorization based on the master merchant account, where the credit card transaction is tagged with the merchant account ID.

A merchant account is a type of bank account established under an agreement between an acceptor (i.e., a merchant accepting credit card payments) and a merchant acquiring bank for the settlement of credit card transactions. In some cases, a payment processor or independent sales organization (ISO) is also a party to the merchant agreement. Whether a merchant enters into a merchant agreement directly with an acquiring bank, or through an aggregator such as an ISO, the agreement binds the merchant to obey the operating regulations established by the credit card brands. On an average it takes a small business owner 30 days to set up a merchant account before they can start accepting credit card payments from their customers. This is mostly due to processing company policies and regulations.
Once the merchant account is set up and the merchant is ready to accept credit card payments. The cardholder presents the credit card as payment to the merchant and the merchant submits the transaction to the acquirer (acquiring bank). The acquirer verifies the credit card number, the transaction type and the amount with the issuer (i.e., card-issuing bank) and reserves that amount of the cardholder's credit limit for the merchant. An authorization will generate an authorization code, which the merchant stores with the transaction.
Authorized transactions are stored in "batches," which are sent to the acquirer. Batches are typically submitted once per day at the end of the business day. The acquirer sends the batch transactions through the credit card association, which debits the issuers for payment and credits the acquirer. Essentially, the issuer pays the acquirer for the transaction. Once the acquirer has been paid, the acquirer pays the merchant. The merchant receives the amount totaling the funds in the batch minus a fee. A chargeback is an event in which money in a merchant account is held due to a dispute relating to the transaction. Chargebacks are typically initiated by the cardholder claiming deficiencies in product or service received. In the event of a chargeback, the issuer returns the transaction to the acquirer for resolution. The acquirer then forwards the chargeback to the merchant, who must either accept the chargeback or contest it.

Pre-allocating merchant ID in a credit card processor entity system by a master merchant


Optical elements such as multilayered EUV mirrors are provided with protective capping layers of diamond-like carbon (C), boron nitride (BN), boron carbide (B4C), silicon nitride (Si3N4), silicon carbide (SiC), B, Pd, Ru, Rh, Au, MgF2, LiF, C2F4 and TiN and compounds and alloys thereof. The final period of a multilayer coating may also be modified to provide improved protective characteristics.

Field of the Invention
The present invention relates to capping layers for optical elements, e.g. multilayer mirrors, for use with extreme ultraviolet (EUV) radiation. More particularly, the invention relates to the use of capping layers on optical elements in lithographic projection apparatus comprising:
an illumination system for supplying a projection beam of radiation;
a first object table provided with a mask holder for holding a mask;
a second object table provided with a substrate holder for holding a substrate; and
a projection system for imaging an irradiated portion of the mask onto a target portion of the substrate.
For the sake of simplicity, the projection system may hereinafter be referred to as the xe2x80x9clensxe2x80x9d; however, this term should be broadly interpreted as encompassing various types of projection system, including refractive optics, reflective optics, catadioptric systems, and charged particle optics, for example. The illumination system may also include elements operating according to any of these principles for directing, shaping or controlling the projection beam, and such elements may also be referred to below, collectively or singularly, as a xe2x80x9clensxe2x80x9d. In addition, the first and second object tables may be referred to as the xe2x80x9cmask-tablexe2x80x9d and the xe2x80x9csubstrate tablexe2x80x9d, respectively.
In the present document, the invention is described using a reference system of orthogonal X, Y and Z directions and rotation about an axis parallel to the I direction is denoted Ri. Further, unless the context otherwise requires, the term xe2x80x9cverticalxe2x80x9d (Z) used herein is intended to refer to the direction normal to the substrate or mask surface or parallel to the optical axis of an optical system, rather than implying any particular orientation of the apparatus. Similarly, the term xe2x80x9chorizontalxe2x80x9d refers to a direction parallel to the substrate or mask surface or perpendicular to the optical axis, and thus normal to the xe2x80x9cverticalxe2x80x9d direction.
Lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, the mask (reticle) may contain a circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto an exposure area (die) on a substrate (silicon wafer) which has been coated with a layer of photosensitive material (resist). In general, a single wafer will contain a whole network of adjacent dies which are successively irradiated via the reticle, one at a time. In one type of lithographic projection apparatus, each die is irradiated by exposing the entire a reticle pattern onto the die at ones; such an apparatus is commonly referred to as a wafer stepper. In an alternative apparatusxe2x80x94which is commonly referred to as a step-and-scan apparatusxe2x80x94each die is irradiated by progressively scanning the reticle pattern under the projection beam in a given reference direction (the xe2x80x9cscanningxe2x80x9d direction) while synchronously scanning the wafer table parallel or anti-parallel to this direction; since, in general, the projection system will have a magnification factor M generally  less than 1), the speed V at which the wafer table is scanned will be a factor M times that at which the reticle table is scanned. More information with regard to lithographic devices as here described can be gleaned from International Patent Application WO97/33205, for example.
Until very recently, lithographic apparatus contained a single mask table and a single substrate table. However, machines are now becoming available in which there are at least two independently moveable substrate tables; see, for example, the multi-stage apparatus described in International Patent Applications WO98/28665 and WO98/40791. The basic operating principle behind such multi-stage apparatus is that, while a first substrate table is at the exposure position underneath the projection system for exposure of a first substrate located on that table, a second substrate table can run to a loading position, discharge a previously exposed substrate, pick up a new substrate, perform some initial measurements on the new substrate and then stand ready to transfer the new substrate to the exposure position underneath the projection system as soon as exposure of the first substrate is completed; the cycle then repeats. In this manner it is possible to increase substantially the machine throughput, which in turn improves the cost of ownership of the machine. It should be understood that the same principle could be used with just one substrate table which is moved between exposure and measurement positions.
In a lithographic apparatus the size of features that can be imaged onto the wafer is limited by the wavelength of the projection radiation. To produce integrated circuits with a higher density of devices, and hence higher operating speeds, it is desirable to be able to image smaller features. While most current lithographic projection apparatus employ ultraviolet light generated by mercury lamps or excimer lasers, it has been proposed to use shorter wavelength radiation of around 13 nm. Such radiation is termed extreme ultraviolet (EUV) or soft x-ray and possible sources include laser plasma sources or synchrotron radiation from electron storage rings. An outline design of a lithographic projection apparatus using synchrotron radiation is described in xe2x80x9cSynchrotron radiation sources and condensers for projection x-ray lithographyxe2x80x9d, J B Murphy et al, Applied Optics Vol. 32 No. 24 pp 6920-6929 (1993).
Optical elements for use in the EUV spectral region, e.g. multilayered thin film reflectors, are especialy sensitive to physical and chemical damage which can significantly reduce their reflectivity and optical quality. Reflectivities at these wavelengths are already low compared to reflectors at longer wavelengths which is a particular problem since a typical EUV lithographic system may have nine mirrors; two in the illumination optics, six in the imaging optics plus the reflecting reticle. It is therefore evident that even a xe2x80x9csmallxe2x80x9d decrease of 1-2% in the peak reflectivity of a single mirror will cause a significant light throughput reduction in the optical system.
A further problem is that some sources of EUV radiation, e.g. plasma based sources, are xe2x80x9cdirtyxe2x80x9d in that they also emit significant quantities of fast ions and other particles which can damage otical elements in the illumination system.
Proposals to reduce these problems have involved maintaining the optical systems at very high vacuum, with particularly stringent requirements on the partial pressures of hydrocarbons which may be adsorbed onto the optical elements and then cracked by the EUV radiation to leave opaque carbon films.
It is an object of the present invention to provide optical elements, including multilayer mirrors, for use in lithographic projection apparatus using extreme ultraviolet radiation (EUV) for the projection beam, that are more resistant to chemical and physical attack.
According to the present invention, this and other objects are achieved in a lithographic projection apparatus comprising:
an illumination system for supplying a projection beam of radiation;
a first object table provided with a mask holder for holding a mask;
a second object table provided with a substrate holder for holding a substrate; and
a projection system for imaging an irradiated portion of the mask onto a target portion of the substrate; characterised by:
at least one optical element having a surface on which radiation of the same wavelength as the wavelength of said projection beam is incident and a capping layer covering said surface, said capping layer being formed of a relatively inert material.
The optical element may be a beam modifying element such as a reflector, e.g. a multilayer near-normal incidence mirror or a grazing incidence mirror, included in one of the illumination and projection systems: an integrator, such as a scattering plate: the mask itself, especially if a multilayer mask; or any other optical element involved in directing, focussing, shaping, controlling, etc. the projection beam. The optical element may also be a sensor such as an image sensor or a spot sensor;
The relatively inert material in particular should be resistant to oxidation and may be selected from the group comprising: diamond-like carbon (C), boron nitride (BN), boron carbide (B4C), silicon nitride (Si3N4), silicon carbide (SiC), B, Pd, Ru, Rh, Au, MgF2, LiF, C2F4 and TiN and compounds and alloys thereof.
The capping layer should have a sufficient thickness to protect the underlying optical element from attack, so that the capping layer is effecively xe2x80x9cchemically opaquexe2x80x9d, yet not be too thick so as to absorb too much of the incident radiation. To these ends, the capping layer may have a thickness in the range of from 0.5 to 10 nm, preferably from 0.5 to 6 nm and most preferably from 0.5 to 3 nm.
The capping layer may itself have a multi-layer structure, e.g. of two layers, with the outermost layer chosen both for improved chemical resistance and low refractive index at the wavelength of the projection beam to improve reflectivity or transmissivity.
A second aspect of the invention provides a device manufacturing method using a lithographic apparatus comprising
an illumination system for supplying a projection beam of radiation;
a first object table provided with a first object holder for holding a mask;
a second object table provided with a second object holder for holding a substrate; and
a projection system for imaging an irradiated portion of the mask onto a target portion of the substrate; said method comprising the steps of:
providing a mask containing a pattern to said first object table;
providing a substrate at least partially covered by a layer of energy-sensitive material to said second object table;
irradiating said mask and imaging irradiated portions of said pattern onto said substrate; characterised in that:
said lithographic projection apparatus comprises at least one optical element having a surface on which radiation of the same wavelength as the wavelength of said projection beam is incident and a capping layer covering said surface, said capping layer being formed of a relatively inert material.
In a manufacturing process using a lithographic projection apparatus according to the invention a pattern in a mask is imaged onto a substrate which is at least partially covered by a layer of energy-sensitive material (resist). Prior to this imaging step, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures, such as a post-exposure bake WEB), development, a hard bake and measurement/inspection of the imaged features. This array of procedures is used as a basis to pattern an individual layer of a device, e.g. an IC. Such a patterned layer may then undergo various processes such as etching, ion-implantation (doping) metallization, oxidation, chemo-mechanical polishing, etc., all intended to finish off an individual layer. If several layers are required, then the whole procedure, or a variant thereof, will have to be repeated for each new layer. Eventually, an array of devices will be present on the substrate (wafer). These devices are then separated from one another by a technique such as dicing or sawing, whence the individual devices can be mounted on a carrier, connected to pins, etc. Further information regarding such processes can be obtained, for example, from the book xe2x80x9cMicrochip Fabrication: A Practical Guide to Semiconductor Processingxe2x80x9d, Third Edition, by Peter van Zant, McGraw Hill Publishing Co., 1997, ISBN 0-07-0672504.
Although specific reference may be made in this text to the use of the apparatus according to the invention in the manufacture of ICs, it should be explicitly understood that such an apparatus has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms xe2x80x9creticlexe2x80x9d, xe2x80x9cwaferxe2x80x9d or xe2x80x9cdiexe2x80x9d in this text should be considered as being replaced by the more general terms xe2x80x9cmaskxe2x80x9d, xe2x80x9csubstratexe2x80x9d and xe2x80x9ctarget areaxe2x80x9d, respectively.


The present invention relates to a flue gas conditioning agent demand control apparatus for controlling a flow of conditioning agent for removal of entrained particles in a flue gas with an electrostatic precipitator having at least one charging electrode and at least one collecting electrode through the use of a signal determined from a rate of discharge of a charged electrode of the electrostatic precipitator.

This invention relates to a system for treating particulate-laden boiler flue gas with a conditioning agent to improve the removal of particulate matter by electrostatic means, and, more particularly, relates to a conditioning agent demand control apparatus used in controlling a flow of conditioning agent.
The increasing demand for electrical power has forced electrical utilities to burn increasing quantities of fossil fuels such as coal. However, electric utilities face increasing environmental standards that are imposed upon their operation. To reduce air pollutants, electrical utilities generally use a flue gas treatment system intended to remove the majority of the particulate matter in the gas effluent. A flue gas treatment system generally comprises an electrostatic means, such as an electrostatic precipitator, and a conditioning agent source for introducing a conditioning agent into the flue gas stream.
An electrostatic precipitator generally comprises at least one set of electrodes disposed within the flue gas stream path and positioned in the flue conduit. A transformer and rectifier apply DC (direct current) high voltage power to charging electrodes to produce a high voltage field between a charging electrode and a collecting electrode. Entrained particles travelling in the flue gas stream are charged and attracted to the collecting electrode in the electrostatic precipitator.
The efficiency of an electrostatic precipitator in removing particulate matter from the boiler flue gas is dependent, in part, upon the electrical resistivity of the entrained particulate matter in the boiler flue gas. The entrained particulate matter expelled from a boiler fired with low sulfur coal, i.e., coal having less than 1 percent sulfur, has been found to have a resistivity of approximately 10.sup.13 ohms/cm. It has been determined that efficient removal of particulate matter by electrostatic precipitation occurs when the particulate matter resistivity is approximately 10.sup.8 ohms/cm. Therefore, to obtain effective use of an electrostatic precipitator, the resistivity of the entrained particulate matter from low sulfur content coals must be reduced.
Electrical utilities have long used conditioning agents introduced into the flue gas stream prior to entry into the electrostatic precipitator to reduce the resistivity of the entrained particles. Various chemicals, such as water, anhydrous ammonia, and various ammonia-bearing solutions, sulfuric acid, sulfur trioxide and phosphoric acid, have been used as conditioning agents. Controlling the flow of the conditioning agent has been approached in a variety of ways.
U.S. Pat. No. 2,864,456 discloses an automatic control for electrostatic precipitators which varies both the electrostatic precipitator voltage and the supply of a conditioning agent, such as water, for conditioning particles to be removed by the electrostatic precipitator and to maintain an optimum sparking rate for efficient particle removal.
U.S. Pat. No. 3,523,407 discloses a method of improving the electrostatic precipitation of particles from a flue gas by adding preselected amounts of ammonia and water to the flue gas.
U.S. Pat. No. 3,665,676 discloses a system to condition the particles of boiler flue gas by the use of a salt solution such as a solution of ammonium sulfate or ammonium bisulfate. The salt solution is injected into the flue gas prior to entering the electrostatic precipitator and the system includes a metering means for controlling the amount of conditioner injected into the flue gas. U.S. Pat. No. 3,665,676 indicates that, if desired, conventional automatic controls can be provided to open the metering means when the flue gas reaches the desired operating temperature or to close it should the temperature fall below operating temperature. In addition, automatic controls can also be made to open the metering means to provide the amount of conditioner needed in proportion to the volume of gas to be conditioned.
U.S. Pat. No. 3,689,213 discloses a process for treating flue gas in which gaseous sulfur trioxide is generated in the immediate vicinity of the point of use as required by the quantity of fossil fuel being burned per unit time and is then introduced into the flue gas at a predetermined rate to facilitate fly ash removal by an electrostatic precipitator.
U.S. Pat. No. 3,772,178 discloses a system for the production of sulfur trioxide for flue gas conditioning including means to deliver a source of sulfur such as sulfuric acid to a vaporizer in proportion to the amount of flue gas from the boiler measured in terms of the electrical output generated at a particular time. As the production of flue gas changes in the boiler system, the proper ratio of acid to flue gas is automatically maintained by a control responsive to a signal coming from a boiler capacity index gauge to control the volume of sulfur trioxide being produced.
U.S. Pat. No. 3,993,429 discloses a system in which the temperature of operation of the catalytic converter is controlled by providing a second flow of air to be mixed with the output of the sulfur burner, detecting the temperature of the mixture of the second flow of air and the gases leaving the sulfur burner and varying the temperature of the air in the second flow of air to maintain a desired operating temperature for the catalytic converter. U.S. Pat. No. 3,993,429 further discloses that SO.sub.3 flue gas conditioning systems can operate by sensing the rate of coal combustion and varying the rate of flow of sulfur into a sulfur burner in response to the rate of coal combustion.
U.S. Pat. No. 4,770,674 discloses a system for conditioning flue gas for an electrostatic precipitator, including equipment for converting sulfur into sulfur trioxide. The disclosed systems of U.S. Pat. No. 4,770,674 include a sulfur burner to produce oxidized sulfur, a catalytic converter to convert the oxidized sulfur to sulfur trioxide, and means to control sulfur and air inputs to the sulfur burner. Various inputs to the control means are disclosed, including the outlet temperature of the catalytic converter and such operating parameters of the exhaust stage of the system as the output temperature of the exhaust gas from the precipitator, the flow rate of the exhaust gas, the power delivered to or the speed of, an induced draft fan, if any, the opacity of the exhaust gas within the stack, and the power dissipated by the precipitator.
U.S. Pat. No. 4,779,207 discloses a system for preconditioning flue gas for electrostatic precipitation. The system of U.S. Pat. No. 4,779,207 includes a source of an SO.sub.3 conditioning agent, a means for controllably adding the conditioning agent to the flue gas, a means for detecting the input power level of the electrostatic precipitators and control means for monitoring the input power level and controlling the amount of conditioning agent added to the gas to substantially maintain input power to the electrostatic precipitator to predetermined levels.
A controller commercially available from Castlet (Electronic Engineers) Ltd., of 14 Crofton Drive, Lincoln, England, can control an electrostatic precipitator by detecting the presence of deleterious back ionization and intermittently applying voltage to the charging electrodes of the precipitator to minimize back ionization. The Castlet controller detects back ionization by interrupting the applied charging voltage at its peak value and comparing, after a preset time, the actual charging electrode voltage with a programmed charging electrode voltage to identify excess charging electrode decay rate indicative of back ionization. The Castlet controller uses the difference in actual and programmed charging electrode voltage to determine a rate of application of voltage to the charging electrodes in an effort to optimize precipitator operation in the presence of conditions of back ionization.
U.S. Pat. No. 5,032,154 discloses, among other things, a system which provides direct, automatic control of the opacity of the effluent of a coal-fired boiler to maintain minimal opacity of the flue gas effluent passing from the boiler into the atmosphere. Systems of U.S. Pat. No. 5,032,154 provide a controlled flow of an agent, such as sulfur trioxide, to the boiler flue gas to condition its particulate matter for removal by electrostatic means, monitor precipitator power, and the opacity of the boiler flue gas after it leaves the electrostatic particle-removal means, and vary the controlled flow of conditioning agent to hunt and operate at conditioning agent flow rates determined from flue gas opacity alone or combined with precipitator power.
Other conditioning systems are shown, for example, in U.S. Pat. Nos. 3,686,825; 3,993,429; 4,042,348; 4,466,815; 4,533,364; and 4,624,685.

Flue gas conditioning agent demand control apparatus

Wilhelm Environmental Technologies, Inc.


An instrument guiding device featuring a base having an aperture for a catheter; one or more legs disposed on the base; a first plate and a second plate each extending upwardly from the base perpendicularly to each other, the second plate is pivotally attached to the base; a guide component having an inner channel adapted to receive the catheter, the first end of the guide component is pivotally attached to the second plate, the guide component can be pivoted toward sides of the second plate; a first scale disposed on the first plate, a second scale disposed on the second plate; reference markers on the second plate and on the guide component; and a temporary attachment means for holding the second plate in place with respect to the first plate and for holding the guide component in place with respect to the second plate.

A ventriculostomy is the insertion of a catheter into a ventricle of the brain. They are generally performed to monitor and/or manage intracranial pressure, to obtain cerebrospinal fluid (CSF) specimens, and/or to administer medications into the nervous system.
An example of a procedure for performing a ventriculostomy may include creating a burr hole in the skull (e.g., 11 cm above the nasion and 3 cm lateral of the midline), opening the dura, introducing a catheter with a stiffening stylet through the burr hole, and advancing the catheter freehand using external landmarks as a guide. If the procedure is successful, the CSF should flow. If the procedure is unsuccessfully, the catheter must be removed and the procedure attempted again using a modified trajectory. The present invention features an instrument guiding device that may be used to help insert a catheter into the brain ventricle.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.


Pharmaceutical compositions of 4-hydroxy tamoxifen, particularly compositions suitable for percutaneous administration, are useful in methods for treating and preventing breast cancer. When percutaneously administered to a patient's breasts, 4-hydroxy tamoxifen concentrates locally, and exerts an anti-estrogenic effect. In patients with breast cancer, this effect reduces tumor tissue proliferation. In patients at risk for developing breast cancer, the anti-estrogenic effect prevents breast tumor formation.

The present invention relates to the treatment and prevention of breast cancer with 4-hydroxy tamoxifen (4-OHT).
Breast cancer constitutes a significant health problem for women in the United States and throughout the world. Despite advances in detection and treatment of the disease, breast cancer remains the second leading cause of cancer-related deaths in women, affecting more than 180,000 women in the United States alone each year. For women in North America, the life-time odds of getting breast cancer are one in eight.
No universally successful method for preventing or treating breast cancer currently exists. Management of the disease relies on a combination of early diagnosis (through routine breast screening procedures) and aggressive treatment, which may include one or more of a variety of treatments such as surgery, radiotherapy, chemotherapy and hormone therapy. These therapies are dangerous, toxic, costly, and often ineffective, especially in the treatment of metastatic disease.
The most commonly prescribed hormonal medication for breast cancer is tamoxifen. It works by blocking the effects of estrogen, which promotes the growth of breast cancer cells. As a treatment for breast cancer, tamoxifen slows or stops the growth of cancer cells that are already present in the body, and helps prevent recurrences and the development of new cancers. Taking tamoxifen for 5 years reduces the risk of recurrence by about half in patients with estrogen receptor positive cancers. Tamoxifen also decreases the incidence of breast cancer involving the opposite breast (contralateral) in both premenopausal and postmenopausal women. Moreover, tamoxifen has recently been found to reduce the incidence of breast cancer in women at high risk of developing this disease.
In spite of its benefits, tamoxifen has significant drawbacks. Its action potentially impacts on every estrogen receptor bearing cell in the body, and, as both an agonist and antagonist, tamoxifen provokes a wide range of systemic effects. These effects increase the risk of endometrial cancer, endometrial hyperplasia and polyps, deep vein thrombosis and pulmonary embolism, changes in liver enzyme levels, and ocular toxicities, including cataracts. Additionally, patients treated with oral tamoxifen reported having hot flashes, vaginal discharge, depression, amenorrhea, and nausea (Ibis, 2002; Fentiman 1986, 1988, 1989).
Due to tamoxifen's drawbacks, some cancer researchers have proposed using 4-hydroxy tamoxifen, a metabolite of tamoxifen, for breast cancer. In in vitro studies, 4-hydroxy tamoxifen inhibits the growth of both normal and cancerous breast cells (Nomura, 1985; Malet, 1988, 2002; Charlier, 1995). Additionally, transdermally delivered 4-hydroxy tamoxifen exhibits an anti-tumor effect on human breast tumors grown subcutaneously in mice (U.S. Pat. No. 5,904,930).
Limited experiments in humans have shown that percutaneously administered 4-hydroxy tamoxifen can concentrate in local breast tumors, with very little systemic distribution (Mauvais-Jarvis, 1986). However, the most extended reported study of this sort, in which patients were treated for three weeks, showed that breast tissue concentrations of 4-hydroxy tamoxifen administered percutaneously remained lower than those observed after oral tamoxifen treatment (Pujol, 1995). Accordingly, the researchers concluded that they could not propose percutaneous 4-hydroxy tamoxifen as an alternative tamoxifen treatment.
Importantly, none of the reported studies regarding 4-hydroxy tamoxifen in humans has evaluated an anti-tumor effect. This failure leaves wide open the most important question—whether percutaneously administered 4-hydroxy tamoxifen actually exerts any effect on breast cancer in humans. Therefore, a strong need still exists for breast cancer treatments and prophylactics that provoke few systemic side effects.

This patent is subject to a terminal disclaimer.

Percutaneous composition comprising 4-hydroxy tamoxifen


In accordance with the teachings of the present invention, a method and apparatus is presented for registering a mobile IP node with a home agent. A self-selection method is implemented in a home agent. When a home agent receives a registration request from the mobile node, the self-selection method enables each home agent to independently and randomly generate a value that falls within a range of numbers. Each range of numbers is referred to as a bin. In addition, each home agent is associated with at least one of bin. If the value falls within the bin, the home agent associated with the bin responds to the registration request. In addition, home agents are uniformly selected relative to other home agent on the network; therefore, implementing the self-selection method performs load balancing in the network.

1. Field of the Invention
This invention relates to communication networks.
2. Description of the Prior Art
The modern Internet includes an interconnection of both wireless and wireline networks. In the case of wireless networks, mobile nodes, such as a mobile telephone, require a mechanism for maintaining contact and registration with the network as the mobile node moves through different access and attachment points in the network. In addition, as the mobile node moves to different access and attachment points, the network needs to be able to properly identify and forward calls to the mobile node.
To facilitate this process network protocols, such as the Internet Protocol (IP) version 6 (i.e., Ipv6), promulgated by the Internet Engineering Task Force have been established. Ipv6 or "mobile IP," as it is often referred to, is intended to enable mobile nodes to move from one attachment point in a network to another attachment point in the network. As such, mobile IP is a communication protocol, which enables the mobile node to communicate from different attachment points and serves as a mechanism for the network to identify and communicate with the mobile node as the mobile node moves to different attachment points in the network.
Mobile IP is designed for use across homogeneous medias as well as heterogeneous media. For example, mobile IP facilitates attachment from one Ethernet segment to another as well as attachment from an Ethernet segment to a wireless Local Area Network (LAN), etc.
A number of architectural components have been defined in the mobile IP protocols, such as Request For Comments (RFC) 3344, published August 2002 by the Internet Engineering Task Force. Notable components include a mobile node, a home agent, and a foreign agent. A mobile node is defined as a host or router that changes its point of attachment from one network or sub-network to another. A mobile node may change its location without changing its IP address. The mobile node may continue to communicate with other Internet nodes from different locations using its constant IP address, assuming connectivity to a point of attachment is available.
A home agent is defined as a router on a mobile node's home network, which tunnels datagrams for delivery to the mobile node when the mobile node is away from home and maintains current location information on the mobile node. A foreign agent is a router on a mobile node's visited network, which provides routing services to the mobile node while registered. The foreign agent detunnels and delivers datagrams to the mobile node that were tunneled by the mobile node's home agent. For datagrams sent by a mobile node, the foreign agent may serve as a default router for registered mobile nodes. As defined in RFC 3344, when the mobile node is away from home, it registers its "care of address" with its home agent. Depending on its method of attachment, the mobile node will register either directly with its home agent or through a foreign agent, which forwards the registration to the home agent.
In addition, RFC 3344 defines a dynamic home agent discovery procedure, in which a mobile node discovers a home agent during the registration process. RFC 3344 refers to this discovery process as "dynamic home agent address resolution."
In the first step of the dynamic home agent address resolution procedure, the mobile node sends a mobile IP registration request message with a home agent field located in the registration request message set to the network broadcast address of its home network. The receiving home agents on the home network send registration reply messages to the mobile node with an error code 136. In the registration reply messages, the home agents insert their unicast IP address in the home agent field. In the second step of the process, the mobile node selects one home agent and sends a new registration request message to that home agent with the home agent field in the registration request message set to the unicast IP address of a specific home agent.
This conventional registration process is inefficient in wireless networks. In addition, the current method of registration includes a number of shortcomings. For example, 1) a mandatory double roundtrip is required to accomplish registration with the conventional registration process; 2) all the home agents receiving the initial registration request message must respond with an error code 136. The overhead to carry these registration reply messages from a variable number of home agents may become significant over a wireless network link and use the limited radio resources that are available in a wireless network; 3) prior to the completion of the registration process, the mobile node and the applications running on the mobile node cannot start to use other intended services, the resulting delay may be critical for certain services; 4) the processing overhead for the mobile node is high when too many home agents respond to the initial registration request message; and 5) there is no control over which home agent the mobile node chooses for registration; as a result, it is difficult for a network operator to perform load balancing in the network.
Thus, there is a need for a new method and apparatus for performing registration in a mobile IP environment. There is a need for a method of reducing the roundtrip communication required by the current mobile IP registration process. There is a need for a method of minimizing the use of valuable radio resources in the current mobile IP registration process. There is a need for a method of reducing the delay in the current mobile IP registration process. There is a need for a method of reducing the processing overhead of the mobile node when registering with a home agent. There is a need for a mobile IP registration process that facilitates load balancing in the network.

Dynamic home agent method and apparatus for mobile internet protocol


A device for slidably positioning a power tool accessory. The geometry of the device is that of a specially modified channel with the interior opposed surfaces of the two legs of the channel being sloped like a truncated wedge. Sections of the sides of the device are partially separated from the main body so as to permit them to spring outwardly under pressure imparted by wedging members so as to cause the sprung sections to either move towards, or frictionally engage surfaces within guiding slots in a major surface of the power tool (e.g., table saw). The wedging members are controlled by conventional machine screws which permit a continuous range of adjustment.

As is well known to those skilled in the art, certain power tools require precision guiding of work pieces therein in order to produce desired geometries, tolerances and configurations. Thus, for example, conventional power driven equipment such as table saws, router tables and the like have included at or on guiding surfaces one or more longitudinally disposed slots adapted for mated fitting with guiding members that thereby may be guided rectilinearly. In addition, in certain uses, provision must be made to lock the guiding member in a desired position within the guide slot while providing for its ready release. The geometries of the guiding members must be closely correlated with the dimensions of the slots so as to avoid binding, wobble or other tracking errors. The dimensions of such slots often conform to industry-wide standards, albeit within a broad range of tolerances. Dimensional variations within this tolerance range from manufacturer to manufacturer, and from machine to machine often result in a poor fit between a particular guide member and a given slot, thus producing unacceptable occurrences of the aforementioned tracking errors.
To accomplish the foregoing, there have previously been proposed a variety of configurations including the formation of the guiding member in an extended longitudinal geometry that fits within the guiding slots. Due to the aforementioned variations in slot dimensions, it was typically necessary to machine the guiding member to exacting tolerances in order to produce a customized fit between the guide member and a particular guide slot in an effort to reduce tracking errors. In addition to being relatively expensive to manufacture, such a custom guide member would also become one of a kind, and could not be readily transferred to another machine whose guide slots differed in geometry from those to which it had previously been fitted. In many cases, the guide member was constructed from wood, which was chosen for its low cost, widespread availability, and its relative ease of fabrication on readily available and inexpensive woodworking equipment. This, however, imposed an additional limitation brought about by the dimensional instability typical of most woods which is caused by variations in ambient temperature and humidity. Thus, under one set of atmospheric conditions, such a wooden guide member might very well fit perfectly in its intended guide slot, whereas under a different set of weather conditions it might bind or wobble excessively.
As mentioned previously, certain uses require that the guide member be disengageably locked within the guide slot for stationary applications. Since the aforementioned custom fitted guide members have no provision for such a locking action, they could not be used for these purposes. Other proposals exist to accomplish this locking operation, but they typically are usable for this purpose only, and cannot be used for those applications mentioned previously which require a close tolerance rectilinear movement of the guiding member along its associated guide slot. Additionally, some of these other proposals include levers or similar elements disposed above or below the guide member to disengageably lock the member in the guide slot. Such extensions potentially interfere with the full use of the equipment, or limit its use to a single application.
In view of the foregoing, it is apparent that there has continued to be a need for an improved positionable guiding member which singly can operate with a high degree of alignment accuracy over a wide range of guide slot geometries, while also providing the capability of being disengageably locked at any position in such guide slots. Additionally, the need continues to exist for such a guiding member which also embodies simplicity of operation, does not encroach upon equipment working surfaces, and is relatively inexpensive and simple to manufacture.


Disclosed are holders for supporting a burnable substrate such as a mosquito coil. They have an ash tray, a mounting post coupled to the ash tray and moveable between a storage position wherein both an outward part and an inward part of the mounting post are adjacent the ash tray and an erected position where the mounting post is suitable to support the burnable substrate, and a locking bracket linked to the ash tray which is suitable to retain the mounting post in the erected position when that is desired. In some forms multiple such coils and holders are housed in a compact kit.

The present invention relates to burnable insect control substrates (e.g. mosquito coils), holders for supporting them when they are burning (and thereby dispensing an air treatment chemical such as a repellent), and kits that include multiple such substrates, multiple such holders, and a compact container therefor.
Burnable substrates such as mosquito coils and incense coils are designed to provide sustained air treatment chemical release when burnt. They burn very slowly (because they are often designed to last overnight, or a significant portion thereof). As a result, they are susceptible to being inadvertently extinguished if they are positioned directly on a supporting surface such as a table. Thus, mosquito coils are often supported mostly or only at their center, such as by being impaled on a centrally positioned holder post. See e.g. U.S. patent application publication 2002/0124459 and U.S. Pat. No. 8,146,875.
While such holder posts reduce the incidence of premature extinguishing, ashes from such coils/substrates may drop down onto the supporting surface underneath such holders. This presents a somewhat messy appearance, and may limit where the holder stand is placed (e.g. if a support table is made of a particularly delicate material). As such burnable coil holders have been developed in which the stand is used with some form of ash tray. See U.S. Pat. Nos. 3,796,002 and 6,389,739. However, typical such ash tray included assemblies are not particularly compact, and as a result have an increased shipping cost, an increased material cost, and/or take up more retail shelf space than is optimal.
There have therefore been attempts to create slab-like holders where a tang of the slab can pivot up from a compact shipping position to a use/support position (so that the slab is very compact until use, and part of the holder acts like an ash tray even after the tang is pivoted up). However, the tang relies on material characteristics to keep it vertical. As a result, when the mosquito coil or similar substrate is being mounted on the tang the tang can tend to bend back down out of the desired supporting position.
Yet another problem is that when such coils are used outdoors (e.g. in a typical patio area) the repellent coverage of a single coil may not be sufficient to achieve adequate protection for somewhat larger size areas such as patio areas. It may therefore be desired to sometimes use multiple such coil/stand devices simultaneously, positioned in an array. Transporting multiple such devices to such an area, in one trip, can be somewhat awkward.
Accordingly, a need still exists for an improved mosquito coil/burnable substrate and holder, and improved kits containing such devices.


Method for etching organic low-k dielectric using ammonia, NH3, as an active etchant. Processes using ammonia results in at least double the etch rate of organic low-k dielectric materials than processes using N2/H2 chemistries, at similar process conditions. The difference is due to the much lower ionization potential of NH3 versus N2 in the process chemistry, which results in significantly higher plasma densities and etchant concentrations at similar process conditions.

Integrated circuits use dielectric layers, which have typically been formed from silicon dioxide, SiO2, to insulate conductive lines on various layers of a semiconductor structure. As semiconductor circuits become faster and more compact, operating frequencies increase and the distances between the conductive lines within the semiconductor device decrease. This introduces an increased level of coupling capacitance to the circuit, which has the drawback of slowing the operation of the semiconductor device. Therefore, it has become important to use dielectric layers that are capable of effectively reducing the coupling capacitance levels in the circuit.
In general, the capacitance in an integrated circuit is directly proportional to the dielectric constant, k, of the material used to form the dielectric layers. As noted above, the dielectric layers in conventional integrated circuits have traditionally been formed of SiO2, which has a dielectric constant of about 4.0. Dielectric layers formed of SiO2 do not reduce the coupling capacitances sufficiently to levels required for increasing device densities and operating frequencies. In an effort to reduce the coupling capacitance levels in integrated circuits, the semiconductor industry has engaged in research to develop materials having a dielectric constant lower than that of SiO2, which materials are suitable for use in forming the dielectric layers in integrated circuits. To date, a number of promising materials, which are sometimes referred to as "low-k materials", have been developed. Many of these new dielectrics are organic compounds. In the specification and claims, the definition of a low-k material, is a material with a dielectric constant less than 3.
Low-k materials include, but are specifically not limited to: benzocyclobutene or BCB; Flare™ manufactured by Allied Signal® of Morristown, N.J., a division of Honeywell, Inc., Minneapolis, Minn.; one or more of the Parylene dimers available from Union Carbide® Corporation, Danbury Conn.; polytetrafluoroethylene or PTFE; and SiLK®. One PTFE suitable for IC dielectric application is SPEEDFILM™, available from W. L. Gore & Associates, Inc, Newark, Del. SiLK®, available from the Dow® Chemical Company, Midland, Mich., is a silicon-free BCB.
During semiconductor wafer processing, features of the semiconductor device are defined in the wafer using well known patterning and etching processes. In these processes a photoresist (PR) material is deposited on the wafer and then is exposed to light filtered by a reticle. The reticle is generally a glass plate that is patterned with exemplary feature geometries that blocked light from propagating through the reticle.
After passing through the reticle, the light contacts the surface of the photoresist material. The light changes the chemical composition of the photoresist material such that a developer can remove a portion of the photoresist material. In the case of positive photoresist materials the exposed regions are removed, and in the case of negative photoresist materials the unexposed regions are removed. Thereafter the wafer is etched to remove the underlying material from the areas that are no longer protected by the photoresist material and thereby define the desired features in the wafer. Low-k organic polymers in general can be etched by oxidation (e.g. oxygen-based) or reduction (e.g. hydrogen-based) chemical processes.
The etching of organic low-k dielectrics may be advantageously accomplished in a dual-frequency capacitively-coupled (DFC) dielectric etch system. One such is Lam® Research model 4520XLE™, available from Lam® Research Corporation, Fremont Calif. The 4520XLE™ system processes an extremely comprehensive dielectric etch portfolio in one system. Processes include contacts, vias, bilevel. contacts, borderless contacts, nitride and oxide spacers, and passivation.
Advanced etch systems like the 4520XLE™ perform several processes in the same system. By performing many different semiconductor fabrication steps in a single system, wafer throughput can be increased. Even further advanced systems contemplate the performance of additional steps within the same equipment. Again by way of example, but not limitation, Lam® Research Corporation's Exelan™ and Exelan-HP™ systems are dry etch systems capable of performing many process steps in a single apparatus. Exelan™ enables hardmask open, inorganic and organic ARC etch, and photoresist strip to be performed in situ with a single chamber. This system's extensive process portfolio includes all dual damascene structures, contacts, vias, spacers, and passivation etch in doped and undoped oxides and low-k dielectrics required in the sub-0.18 micron environment. Of course, the principles enumerated herein may be implemented in wide variety of semiconductor fabrication systems, and these principles specifically contemplate all such alternatives.
As used herein, the term in situ refers to one or more processes performed on a given substrate, such as a silicon wafer, in the same piece of semiconductor fabrication equipment without removing the substrate from the equipment.
As discussed, the etching of organic low-k dielectrics may be accomplished using oxygen-based or hydrogen-based etching processes. Each of these is, however, less than ideal.
Hydrogen-based etching processes, e.g.: N2/H2 processes, are less than ideal for etching organic low-k dielectrics, particularly for etching the high-density features required in current sub-0.18 micron devices. This is true for a number of reasons. First, current N2/H2 processes offer generally slow etch rates and poor profile control of the etched features: bowing and re-entrant etch profiles are particular problems. Another problem relates to high aspect ratio features having differing sizes, which features are etched concurrently.
The etching of high aspect ratio trenches, sometimes referred to as HART, into low-k materials is becoming increasingly important for micro- and nano-engineering. One example is in the case of comb-driven structures, trench capacitors, and trench isolation for vertical transistors. The aspect ratio, AR, is defined as the depth of the trench divided by its width. Currently, one of the most commonly implemented techniques for etching HART's is dry reactive ion etching, or RIE.
When etching HART's with RIE it is observed that the etch rate is dependant on time and the mask opening. In general, smaller trench openings are etched more slowly than those that are wider. Accordingly, large features etch at a faster rate than small features. This effect is known as Aspect Ratio Dependent Etch (ARDE) or "RIE lag". Known N2/H2 etch processes incur not only significant RIE lag, but more importantly, also exhibit etched profile angle dependence on feature size.
Another problem with known N2/H2 chemistries is that they have generally poor selectivity with respect to the oxides and nitrides commonly used as hard masks during etching. This means that the hard mask that should provide accurate feature definition is itself etched away fairly quickly during dielectric etch by the N2/H2 etch chemistry.
Another problem with N2/H2 plasmas is that in general they are stable only over fairly narrow ranges of pressure and power as a result of the high ionization potential of N2.
Finally, etching of organic low-k dielectrics with known N2/H2 processes is slow. This leads to reduced wafer throughput and increased cost of ownership of processing equipment for the integrated circuit manufacturer.
The slow etch rates obtainable by N2/H2 processes is often overcome using oxidative processes, most especially utilizing oxygen, O2 and a diluent such as nitrogen, N2. O2/N2 etch systems tend to possess much faster etch rates than N2/H2 systems, but are especially prone to bowing and can degrade the dielectric constant of the low-k dielectric. More troubling, they introduce a significant new problem, especially when utilized in conjunction with the manufacture of integrated circuit devices that incorporate copper.
Copper is currently being implemented as an interconnect material in favor of prior aluminum interconnect technologies. Copper offers several important advantages over aluminum. The higher conductivity of copper simplifies interconnect routing. This reduces the number of interconnect levels from 12 to 6, which removes upwards of 200 process steps and has a direct impact on device yield. Chips with copper interconnects operate with less power at a given frequency than chips with aluminum interconnects. Accordingly, copper interconnect technology enables devices with significantly higher performance for mobile applications. Finally, for very small features, the interconnect delay for copper and low-k materials is approximately one-half that of aluminum and SiO2. Copper interconnects are accordingly preferred for very small features because it provides speed enhancement with no sacrifice of device reliability.
Where copper in such devices is exposed to the etching environment, the use of an oxygen plasma often results in damage to the copper lines by generating copper-containing residue, which may deposit on the trench and via sidewalls causing copper contamination of the dielectric materials. Eventual migration of the copper to the transistor level of the device leads to failure of the device due to copper poisoning.
Many current integrated circuit fabrication technologies utilize a photoresist stripping step following one or more of the patterning steps used to form the features in the wafer. If a methodology could be found which not only completed a dielectric etch step, but simultaneously removed the photoresist from the surface of the wafer, a process step, that of the separate photoresist strip, could be eliminated. This of course would result in lower process times and higher throughput.
From the foregoing, a low-k etch process which implements higher etch rates than previous N2/H2 processes while avoiding the problems associated with prior N2/H2 processes would be very desirable.
It would also be very desirable to avoid the previously discussed problems with RIE lag, etch rate, and especially profile control.
It would moreover be very desirable to provide an etching process which exhibits a much higher degree of selectivity between the organic low-k dielectric and the hard mask required to form features through the dielectric. It would also be advantageous if the etch process could minimize the effect of "micro-masking" at the bottom of the etched feature. Micro-masking occurs when the etch process etches away a portion of the hard mask and subsequently re-deposits elements of the etched hard mask at the bottom of etched features.
It would be very advantageous if a dielectric etch process could be implemented which achieved the previous advantages while enabling a more stable etch plasma over a wider band of pressure and power operations than current N2/H2 processes.
In order to maintain a high wafer throughput, what is also desirable is that the methodology be capable of being performed in situ within the fabrication equipment utilized to form the wafer.
Finally, it would be very desirable if these advantages could be implemented using existing integrated circuit manufacturing equipment.
These and other features of the present invention will be described in more detail in the section entitled detailed description of the preferred embodiments and in conjunction with the following figures.

Use of ammonia for etching organic low-k dielectrics


A liquid crystal display including upper and lower substrates facing each other, electrodes and alignment layers sequentially disposed on and between the upper and lower substrates, a liquid crystal layer interposed between the alignment layers, and a spacer for controlling the distance between the upper and lower substrates, wherein an ion-absorbing material layer coats the spacer. Since an adverse phenomenon caused by generation of ions or contaminants in a liquid crystal cell is prevented, the reliability of the liquid crystal display is improved. Blurriness is prevented from occurring on a displayed picture due to a change in the alignment characteristic of the liquid crystal material. Also, crosstalk and deterioration of contrast are prevented by suppressing a decrease in the specific resistance of the liquid crystal material.

1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a reliable liquid crystal display which exhibits excellent contrast and excellent picture quality, irrespective of a change with the passage of time, and which can prevent crosstalk.
2. Description of the Related Art
Liquid crystal displays are light-reflecting devices which receive light from an external source to display an image, and play an important role in the field of display devices because they consume little electric power compared to other devices, are able to be manufactured in various sizes, and are capable of displaying various patterns.
A general liquid crystal display has upper and lower substrates facing each other, upper and lower electrodes and an alignment layer sequentially disposed on each substrate, and a liquid crystal layer between the alignment layers.
In the aforementioned liquid crystal display, the alignment of liquid crystals varies according to application of an external voltage. External light applied to the liquid crystal display is shielded or transmitted according to a change in the alignment of liquid crystals. That is to say, if a voltage is applied to the liquid crystal display, an electric field is formed at the liquid crystal layer. As a result, liquid crystals are aligned in a predetermined direction, and external light applied to the liquid crystal display is shielded or transmitted, thereby creating an image on the screen of the liquid crystal display.
However, as time passes, contaminants such as dust and ions are generated at the alignment layers or sealing member of the liquid crystal display, which may deteriorate contrast characteristics of the liquid crystal display and cause crosstalk. Also, the alignment characteristic of liquid crystals varies, causing blurry areas on a picture.
In more detail, in the case of using polar liquid crystals having a high dielectric constant, a polar liquid crystal material partially dissolves the sealing member so that ions are generated at the interface between the liquid crystal layer and the sealing member, thereby lowering the purity of the liquid crystal material.
Also, the alignment layer is mainly formed by a rubbing method in which a thin film made of an organic polymer such as polyimide is formed on a substrate and hardened, and then the resultant product is rubbed with a specific cloth to control the orientation of liquid crystal molecules. However, fine particles or cellulose may be separated from the specific cloth to produce contaminants. Also, the thin-film transistor may be damaged by static electricity generated during rubbing, thereby deteriorating the performance of the liquid crystal display.
It is an object of the present invention to provide a reliable liquid crystal display which exhibits excellent contrast and excellent picture quality, irrespective of a change with the passage of time, and which can prevent crosstalk.
Accordingly, to achieve the above object, there is provided a liquid crystal display liquid crystal display including upper and lower substrates facing each other, electrodes and alignment layers each sequentially formed on the upper and lower substrates, a liquid crystal layer interposed between the alignment layers respectively formed on the upper and lower substrates, and a spacer for controlling the distance between the upper and lower substrates, wherein an ion-absorbing material coated layer is formed on the surface of the spacer.


A method and apparatus for achieving a fluid tight seal of a fluid coupling having an axis, wherein a spring interposed between a coupling nut and an inner member of a first coupling element is compressed when the coupling nut is engaged with a second coupling element and rotated in a tightening direction such that complementary sealing surfaces between the first and second coupling elements are axially pre-loaded to achieve a fluid tight seal. A fluid tight seal is dependent on the axial compression of the spring, indicated by the axial location of the coupling nut with respect to the inner member and second coupling element, and is visually indicated by the rotational relationship of the coupling nut and the second coupling element.

Coupling systems for interconnecting lines, particularly fluid conveying lines, must provide reliable service even in adverse operating conditions. For example, the couplings for fluid lines associated with the hydraulic, fuel, or other systems of aircraft are subjected to vibration, temperature extremes, axial loading and a variety of other difficult operating conditions. Reliably insuring such couplings are properly connected is essential to safe operation as failure of such couplings or their improper installation could lead to catastrophic results.
Shown in FIG. 1 is a typical fluid coupling 8 comprising a coupling element 9 having a ferrule 10 with a frustoconical seat 11, which acts as a sealing surface, and a second coupling element 12 comprising a ferrule with a complementary sealing surface, depicted as a ball nose surface 13. Coupling elements 9 and 12 are joined together by a coupling nut 14 on the first coupling element 9 being threaded onto threads of the second coupling element 12 and tightened, transmitting axial forces from the coupling nut 14 through a load bearing surface 15 to the complementary sealing surfaces 11 and 13. This axial compression forces these complementary sealing surfaces together to achieve a pre-load of one surface against the other such that the surfaces will remain fluid tight through the operational environment of the fluid coupling. Thread torque is conventionally used as a measure of whether an appropriate compressive pre-load of the sealing surfaces to achieve the fluid-tight seal has been reached, and also as a measure that the threaded surfaces are sufficiently engaged to prevent loosening. Loosening of an engaged and torqued coupling is also accomplished by the use of lockwire and other apparatus, such as disclosed in co-pending application Ser. No. 07/815,998, now U.S. Pat. No. 5,188,398, Redundantly Locked Fluid Coupling, to Parimore, et al. incorporated herein by reference. While it is important for the coupling elements to be tightened sufficiently to form a fluid-tight seal, it is also essential that the elements not be overtightened. Overtightening of a coupling can lead to not only weakening and failure of the threads of either coupling element, but also to plastic deformation of either the seat or mating sealing surface, or both.
The problem of applying the proper amount of axial pre-load to mating coupling elements has been addressed by providing assembly personnel with torque wrenches designed for a given coupling. However, this solution often produces less than desired results in practice. It is not unusual for a mechanic or other assembler to employ the wrench or other tool at hand, rather than search for the torque wrench designed for a given coupling. This results in an unreliable estimate of the amount of torque and the potential for either overtightening and failure of the coupling or undertightening and a potential loosening and leakage of the coupling elements. Even if the appropriate torque wrench is employed, proper seating pre-load to assure a leak-free joint is not guaranteed. A torque wrench measures the amount of torque applied to a coupling. The torque wrench does not measure the amount of axial seating pre-load a joint receives. It is this axial seating load that assures a leak-free joint. Torque vs. axial seating pre-load is a function of many variables. With today's couplings it is possible, with damaged threads for example, to torque a fitting to the proper torque range and still not achieve the proper seating pre-load.
In addition to torque not being a reliable measure of axial seating pre-load, aircraft threaded connections are subjected to vibration and other operating conditions which make such connections susceptible to loosening after a period of time, thus no longer providing a fluid-tight connection. In many coupling designs, such loosening of the coupling elements cannot be visually detected and maintenance personnel often check on the integrity of the coupling connection by taking the coupling apart and then retightening it with the appropriate torque wrench or other means. This can increase the time and cost of maintenance particularly in instances where the coupling elements have not in fact become loosened and could have been left intact.


The movement of particles in a liquid flowing in a duct is controlled by an ultrasonic standing wave having nodal fronts at a small angle to one pair of side walls of the duct. As the liquid flows along the duct, particles responsive to the acoustic energy are held on the oblique nodal fronts and are carried along these by the flow so that they also move towards one side wall. Particles in the vicinity of that one side wall are swept from the nodal fronts by the liquid drag forces. At the duct exit the particles will therefore tend to be concentrated in that portion of the liquid flow that passes nearer said one wall.

This invention relates to the use of ultrasonic wave energy for the manipulation of particulate material in a liquid medium.
It is known that the acoustic forces from an ultrasonic standing wave acting on particles suspended in a liquid can attract individual particles to the nodes or the antinodes of a standing wave. For the purposes of the present invention it is immaterial whether the attraction is to the nodes or to the antinodes and to simplify the following description these zones of attraction will be referred to only as the nodes or the nodal fronts. Since a similar mechanism is operative for such particles as may be attracted to the antinodes, this alternative is accordingly included within the scope of the invention.
It has been proposed that these mechanisms in an ultrasonic standing wave can be employed to manipulate particulate material. For example in our European patent application No. 147032 (84.307496.4) there is described how two axially opposed ultrasonic transducers can establish a standing wave to control the movement of particles in a coaxial column of liquid interposed between the transducers, and how, by displacing the standing wave along its axis, it is possible to move the particles along the column under the influence of the standing wave.
Such a system has a number of limitations, not least being those arising from the effects of attenuation on the ultrasonic energy in its passage through the medium. This limits the effective length of the standing wave in the column before acoustic streaming weakens unduly the attachment of particles to the nodes. An alternative proposal, in our PCT application WO85/01892(PCT/GB84/00368) can avoid that problem but relies on establishing an appropriate degree of non-uniformity of the acoustic energy density in the nodal fronts of a standing wave, which can lead to complexity in the design and operation of such a system.
The present invention seeks to provide an apparatus and method that permits particles in a liquid medium to be controlled in a relatively simple manner and without being unduly limited by acoustic streaming effects.

National Research Development Corporation


A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a first amplification stage having a first hetero bipolar transistor of which collector output is detected; a second amplification stage which is prior to the first amplification stage and which has a second hetero bipolar transistor in which the detection result is reflected; a first resistor provided between a collector of the second hetero bipolar transistor and a power supply; and a protection circuit which is connected between a collector of the first hetero bipolar transistor and the collector of the second hetero bipolar transistor, detects output from the collector of the first hetero bipolar transistor, and reduces a voltage of the collector of the second hetero bipolar transistor in accordance with the detected output.

1. Field of the Invention
The present invention relates to a radio-frequency power amplifier using a transistor, and particularly to a radio-frequency power amplifier including a protection circuit.
2. Description of the Background Art
A radio-frequency power amplifier of a mobile communication terminal such as a mobile phone includes a multistage amplifier using, for two to three stages, transistors made of compound semiconductors. Further, in recent years, as a device for an amplifier, a hetero bipolar transistor (hereinafter referred to as an "HBT") capable of single power supply operation is mainly used. The HBT has the advantage of having higher power density per unit area than that of a field effect transistor and thus being reducible in size, but also has the problem of having lower ruggedness at the time of load mismatch than that of the field effect transistor.
The ruggedness at the time of load mismatch will be described below. Mobile communication terminals of a GSM (Global System for Mobile Communications), which is the world's currently most common mobile phone communication system, and some mobile communication terminals of a UMTS (Universal Mobile Telecommunications System), which has recently started to become common, do not use an isolator for stabilizing the load impedance of a radio-frequency power amplifier, due to reducing the mobile communication terminals in size and the like. Consequently, when a termination condition of an antenna changes, a load condition of the radio-frequency power amplifier also changes.
FIG. 21 is a general diagram showing a dynamic load line and a safe operating area at the time of load mismatch, of the HBT. In FIG. 21, Ic represents a collector current and Vc represents a collector voltage. In FIG. 21, when the load condition changes, the dynamic load line changes significantly. Then, the HBT is destroyed when the dynamic load line of the HBT goes beyond the safe operating area, i.e., reaches a thermal destruction area or a breakdown-voltage destruction area. More specifically, the HBT is thermally destroyed when the dynamic load line exceeds a thermally safe operating limit, and the HBT is breakdown-voltage-destroyed when the dynamic load line exceeds a breakdown voltage limit.
FIG. 22 is a diagram showing the dynamic load line at the time of load mismatch, of a final-stage HBT which is included in a multistage amplifier and to which the collector voltage exceeding a rated value is applied (hereinafter referred to as an "overvoltage condition") due to the change of a power supply voltage and the like. As shown in FIG. 22, in an overvoltage condition, the dynamic load line shifts in the direction of increasing the voltage (Vc) and breakdown-voltage destruction is caused. To prevent such destruction at the time of load mismatch in the overvoltage condition from occurring, a method is proposed for limiting the input power to a final-stage HBT, by incorporating a protection circuit which senses the collector voltage of the final-stage HBT and reduces the base voltage of a first-stage HBT in the overvoltage condition (see Japanese Laid-Open Patent Publication No. 2005-64658).
FIG. 23 is a diagram showing the dynamic load line of the first-stage HBT which is included in the multistage amplifier and of which the base voltage is reduced by the above-described protection circuit. As shown in FIG. 23, the base voltage is reduced, whereby the dynamic load line of the first-stage HBT shifts in the direction of reducing the collector current (Ic). Consequently, the output power of the first-stage HBT is reduced, and thus the power inputted to the final-stage HBT is reduced. FIG. 24 is a diagram showing the dynamic load line at the time of load mismatch, of the final-stage HBT, in the case where, in the overvoltage condition, the base voltage of the first-stage HBT is reduced by the protection circuit and thus the input power to the final-stage HBT is reduced. As shown in FIG. 24, the input power to the final-stage HBT is reduced, whereby the dynamic load line of the final-stage HBT becomes smaller. Consequently, the dynamic load line of the final-stage HBT does not go beyond the safe operating area, thus it is possible to prevent the final-stage HBT from being destroyed.
However, the method disclosed in Japanese Laid-Open Patent Publication No. 2005-64658 has the following problem. FIG. 25 is a diagram showing the dynamic load line of the first-stage HBT of which the base voltage is reduced by the protection circuit and to the base of which a radio-frequency signal exceeding the rated power is then inputted. As shown in FIG. 25, when the radio-frequency signal exceeding the rated power is inputted to the base of the first-stage HBT (hereinafter referred to as "at the time of excessive input"), the dynamic load line of the first-stage HBT shifts in the direction of increasing the collector current and also becomes larger due to the increase of the input power thereto. That is, the output power of the first-stage HBT is increased. This results from a phenomenon that the base voltage of the first-stage HBT is increased due to a voltage swing of the radio-frequency signal inputted thereto. FIG. 26 is a diagram showing the dynamic load line at the time of load mismatch, of the final-stage HBT, in the case where the dynamic load line of the first-stage HBT shifts in the direction of increasing the collector current in FIG. 25. Since the output power of the first-stage HBT cannot be reduced when the first-stage HBT is at the time of excessive input (see FIG. 25), the input power to the final-stage HBT is not reduced. Therefore, as shown in FIG. 26, the dynamic load line at the time of load mismatch, of the final-stage HBT becomes larger, and as a result, the final-stage HBT is destroyed when the dynamic load line goes beyond the safe operating area. As described above, in the method disclosed in Japanese Laid-Open Patent Publication No. 2005-64658, when the base of the first-stage HBT is at the time of excessive input, the output power of the first-stage HBT cannot be reduced even if the base voltage of the first-stage HBT is reduced by the protection circuit, and thus the final-stage HBT may be destroyed.
FIG. 27 is a diagram showing, in a two-stage power amplifier employing the method disclosed in Japanese Laid-Open Patent Publication No. 2005-64658, the output power of a final-stage HBT, in the case where the radio-frequency signal of the rated power is inputted to the base of a first-stage HBT and in the case where the radio-frequency signal exceeding the rated power is inputted thereto. Note that: the operating frequency of the two-stage power amplifier is 0.9 GHz; regarding the device size of the first-stage HBT, the emitter area is 200 um2; regarding the device size of the final-stage HBT, the emitter area is 800 um2; the collector voltage (Vc) of the first-stage HBT is 1.8 V (fixed); the rated collector voltage of the final-stage HBT is 3.5 V; and the input/output impedance of the two-stage power amplifier is matched to 50 Ω by an input/output /interstage matching circuit. As shown in FIG. 27, when the input power (Pin) to the first-stage HBT is 0 dBm, the output power of the first-stage HBT is reduced in the overvoltage condition in which the collector voltage (Vc) of the final-stage HBT exceeds the rated collector voltage of 3.5 V. As a result, the output power (Pout) of the final-stage HBT is reduced. However, it is indicated that when the input power (Pin) to the first-stage HBT is +5 dBm (in an excessive input condition), the output power of the first-stage HBT is not reduced. As a result, in the overvoltage condition in which the collector voltage (Vc) of the final-stage HBT exceeds the rated collector voltage of 3.5 V, the output power (Pout) of the final-stage HBT is increased.


An active control method of accelerator pedal effort comprises steps to actively vary pedal effort. When a vehicle having a controllable pedal effort accelerator pedal runs, the active control method can actively vary the accelerator pedal effort according to an accelerator position sensor operation percentages selected by a driver, thereby improving the accelerator pedal manipulation efficiency of the driver.

FIG. 1 illustrates an organ type of accelerator pedal, as an example of related art vehicle accelerator pedals. The related art accelerator pedal includes a pedal arm housing 1 securely mounted to a frame panel placed below a driver's seat, and a pedal arm 2 with one end rotatably connected to the pedal arm housing 1. A pedal bracket 3 is securely mounted to a floor panel placed below the driver's seat. A pedal pad 4 with one end rotatably connected to the pedal bracket 3 is coupled to the pedal arm 2 by ball joint.
A spring plate 5, located in the pedal arm housing 1, is combined with an end of the pedal arm 2. An end of a spring 6, in the pedal arm housing, is held by the spring plate 5 and another end of the spring 6 is held by the pedal arm housing 1.
When the pedal arm 2, according to the related art accelerator pedal, is rotated around a hinge shaft 7, the spring 6 is elastically compressed and forms a pedal effort of the pedal pad 4.
However, the above-mentioned related art accelerator pedal uses a spring having a predetermined elastic modulus as the spring 6 to meet the safety laws and regulations, and thus the pedal effort of the related art accelerator pedal cannot be changed if the spring 6 is not changed. Further, in the related art accelerator pedal, accelerator pedal effort of a vehicle cannot be varied according to APS operation percentages when the vehicle is being driven, thus inconveniencing the driver.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and should not be construed as being included in the related art that is already known by those skilled in the art.

Active control method of accelerator pedal effort


A binary encoding method notably but not exclusively for the encoding of data elements designed to be represented sequentially, according to a preestablished order, for example in counters, inducing a uniform or substantially uniform mean changing rate for each of the binary elements, the data elements being encoded on two distinct fields of binary elements, a reference field and a permutation field, and the sequence of binary elements assigned to the permutation field undergoing a permutation as a function of the value contained in the reference field.

1. Field of the Invention
The field of the invention is that of binary encoding, namely the representation of data of any nature by means of binary elements 0 or 1.
The invention relates notably but not exclusively to the encoding of data designed to be shown sequentially in a pre-established order.
More generally, the invention can be applied in a preferred way when it is necessary to encode data elements which, on an average, appear a substantially equal number of times.
A particular example of application is thus the encoding of a counter for which the data elements to be encoded are integers or whole numbers from 0 to n-1. Besides, counters can always be reduced to this case since, for this purpose, it is enough to number the data elements to be represented from 0 to n-1 in the order in which they appear. The invention can be applied both to simple, systematically incremented counters and to counters that can be sometimes incremented and sometimes decremented.
The invention can be used notably when implementing memories of the type sensitive to wear. This is the case, for example, of E2PROM memories such as those contained in microprocessor cards.
However, it is clear that the invention can be applied to the encoding of any type of data, irrespectively of the type of system and/or data processing and storage media used.
2. Field of the Invention
There are already many known methods for the binary encoding of whole numbers. The method most frequently used consists in representing this whole number by its binary decomposition into a number system using base two. This method is often known as standard binary encoding or natural binary encoding. In another well-known method, each digit of the decomposition of this whole number, in a system using base ten, is represented by the decomposition of this digit into a number system using base two. Four binary elements are then needed to encode each digit of the decomposition in the base ten system. There are again several types of binary encodings, corresponding to specific applications or needs.
Thus, in certain applications, it is desirable that the encoding method used should be such that when changing from one whole number to the next whole number, or to the preceding whole number, the number of binary elements that change value is as small as possible on an average, the ideal being 1. Standard binary encoding falls far short of this ideal, since the average number is equal to about 2.
Satisfactory approaches to this minimum change constraint have long existed. These approaches are known as minimum-change codes and are described, for example, in W. R. Bennet & J. R. Davey, Data Transmission, New York, McGraw Hill, 1965. The Gray codes constitute a particular example of minimum-change codes. They are notably described in the U.S. patent published on Mar. 17 1953 under No. 2,632,058.
The Gray codes have proved to be particularly valuable and are much used owing to the simplicity of their construction and the simplicity of the conversions between these codes and the standard binary code and because the number of binary elements used is equal to the number of binary elements used in the standard binary encoding, said number being as small as possible.
However, it is sometimes also desirable for all the binary elements to change value, on an average, as much as one another, i.e. it is desirable for the change to be uniform. Gray encoding does not have this property since a binary element of low significance changes a number of times equal to half the whole numbers to be encoded at each cycle of a counter while the binary element of high significance changes only once.
The constraint of uniform changing of the binary elements arises, for example, in a crucial way in the case of E2PROM type memories. For, in these memories, since the number of instances of changing possible for each binary element is limited (for example it is in the range of some thousands) it is advantageous to distribute the changings homogeneously among all the binary elements, thus enabling the lifetime of the components to be prolonged.
There is no encoding that is truly effective with respect to this particular constraint.

Binary encoding method with substantially uniform rate of changing of the binary elements and corresponding method of incrementation and decrementation


The specification describes an optical fiber grating package with means for controllably adjusting the strain in the optical fiber grating count. The package is provided with two threaded members with different thread counts so that when both members are simultaneously turned axial displacement results, and the magnitude of the displacement is determined by the difference between the axial displacement of the two threads.

Techniques for forming Bragg gratings directly in the core of optical fibers have enabled a simple low cost manufacturing technology for optical filters, laser mirrors, wavelength division multiplexers and demultiplexers, chirped gratings for dispersion compensation, etc. The gratings in all of these devices have a very critical grating period .LAMBDA. which essentially determines the operating frequency of the system in which the grating is installed according to the relationship: EQU .lambda.=2.LAMBDA.n
where .lambda. is the effective resonant wavelength of the grating, .LAMBDA. is the period of the grating, i.e. the spacing between refractive index shifts, and n is the average refractive index. Both during manufacture, and in the service environment of the optical system in which the grating is used, environmental changes such as temperature affect both .LAMBDA. and n. The grating period, .LAMBDA., varies with mechanical strains on the optical fiber. Strains can be internal in the optical fiber itself, or can result from mechanical stresses produced in the fiber typically from differential thermal expansion of the elements in the package containing the optical fiber grating. Strains can also be introduced purposely, either during production of the fiber, or by design of the grating package. In the latter case, the strain can be a static strain, fixed by the structure of the package, or can be dynamic in the sense that the package is provided with means for adjusting the strain either as a manufacturing step, or in the use environment, to vary the effective resonant wavelength of the grating.
The ability to adjust strain in a fiber grating can be used to advantage either to change the resonant frequency of the grating or to preserve the resonant frequency of the grating by compensating against unwanted effects of temperature. Changing the resonant frequency is a useful expedient in the final stages of grating manufacture, or can be used as a device or system adjustment in, for example, WDM devices to add or subtract channels.
The relationship between strain in the fiber and the properties of the fiber is given by: EQU .DELTA..lambda.=.lambda.(1-P.sub.E).epsilon.
where .DELTA..lambda. is the change in the grating center wavelength, .lambda. is the signal wavelength, P.sub.E is the photoelastic constant (typically .about.0.22 for silica fibers), and .epsilon. is the strain in the fiber. Because the grating spacing is very small, these adjustments are typically very sensitive, with small strains in the fiber producing a significant shift in the resonant frequency of the grating.
Because of these and other considerations a variety of device packages have been designed to control strains in the optical fiber of fiber grating devices. Some of these are passive and depend on choice of packaging materials to minimize the effects of differential thermal expansion between the package and the fiber, or to compensate for temperature induced changes in the fiber itself. A typical prior art passive temperature compensating package is described by G. W. Yoffe et al, "Passive temperature-compensating package for optical fiber gratings", Applied Optics, Vol. 34, No. 30, Oct. 20, 1995, pp. 6859-6861. This paper also describes an active strain adjustment to set the strain of the fiber to the desired initial value. The active adjustment is realized by having one of the ends of the package fixed to the fiber but threaded to the rest of the package so that relative axial movement occurs between the fixed ends holding the fiber when the threaded portion is rotated. The degree of axial movement resulting from turning the threaded member is determined by the pitch of the thread. For a fine pitch thread of 80 threads per inch each turn of the threaded member produces an axial movement of 316 microns. For a package 40 mm in length, a single turn of the threaded adjustment member produces a strain in the fiber of close to 1.0%, well beyond the working strength of the fiber. Partial turns of the threaded member may provide useful adjustments in limited applications but this mechanism overall is undesirably coarse for most applications.
Other schemes for actively controlling the strain in an optical fiber grating have been proposed which provide better precision. For example, piezoelectric elements have been used to modulate the strain in the fiber in response to electrical signals. These devices are effective but costly. Similar packaging approaches using electrostrictive or magnetic strain control are also effective but are complex and prone to failure.