A gas detonation apparatus and method for powder coating a work piece. The present invention lies in the ability to preselect a discreet number of the detonation cells and the judicious selection of a suitable barrel diameter. The present invention employs an energy bleed system positioned in the downstream end of a combustion chamber of a detonation gun to bleed off unwanted energy from the combustion chamber leaving behind a discreet number of detonation cells. The detonation cells are then discharged into the barrel of the detonation gun. The barrel diameter is selected to match the total area of the discreet detonation cells selected. The effect is to discharge a discreet number of detonation cells into the barrel to preclude energy loss to the detonation cells from interference with reflected energy within the barrel itself. The present invention substantially increases the productivity of the detonation coating process.

Many industrial applications exist where materials are exposed to severe environmental conditions of heat, wear and corrosion. Spray coating processes utilizing powder coating materials offer high quality protection in some of these applications. A common method of spray coating is the detonation gun process. This process uses kinetic energy from the detonation of combustible mixtures of gases to deposit powdered coating materials on workpieces.
Typical coating materials used in conjunction with detonation gun in the spray coating process include powder forms of metals, metal-ceramic, ceramic, erosion resistant, thermal protection, electrically insulating, electrically conductive, and other coating materials. In addition powder forms of other materials can be utilized in conjunction with the detonation gun process for parts cleaning, hole drilling, making powders, and other conceivable applications.
A typical detonation gun functions in the following manner. A certain amount of a combustible gas mixture, oxygen and acetylene for example, is fed into a tubular combustion chamber have a closed end and an open end where it is subsequently ignited by a spark plug. The ignition of the gas brings about detonation and the formation of a shock wave. The shock wave travels down the combustion chamber to the open end which is attached to a tubular barrel. A suitable coating powder is typically injected into the barrel in front of the propagating shock wave and is subsequently carried out the open end of the barrel and deposited onto a substrate positioned in front of the barrel. The impact of the powder onto the substrate produces a high density coating with good adhesive characteristics. The process is repeated in a rapid fashion until the workpiece is coated to satisfaction. Between successive ignitions an inert gas, such as nitrogen, may be fed into the combustion chamber after the ignition to halt combustion and prevent backfire into the fuel and oxygen supply and to purge the barrel of combustion products.
The mechanics of detonation arc key to the operation of the detonation gun. Detonation produces shock waves that travel at supersonic velocities, as high as 4000 m/s, and elevated temperatures, as high as 3137.degree. C. Detonation in the detonation gun is controlled by the type of fuel used, such as propane, acetylene, butane, etc., the fuel and oxygen mixture ratio, the initial pressure of the gases in the combustion chamber, and the geometry of the combustion chamber. After ignition of the fuel and oxygen mixture deflagration produces an initial detonation wave front that increases the temperature and pressure within the combustion chamber which in turn propagates ignition of the combustible mixture throughout the combustion chamber. Given the correct combination of parameters, the detonation continues to propagate until all available fuel and oxygen is consumed. The detonation front moves toward the open end of the combustion chamber and into the barrel. It is of particular importance that the combustion chamber be of sufficient length, for the specific detonable mixture in use, to complete the transition from deflagration to detonation before entering the barrel or the detonation wave front may not be sustained within the barrel. It is also important in the operation of a detonation gun to produce as strong a shock wave as possible and direct it to the barrel as efficiently as possible so that a large amount of the kinetic energy of the detonation wave goes directly to carrying the powder out of the barrel and onto the substrate.
At a fixed moment in time the detonation wave front is made up of a system of individual stationary detonation cells. The behavior of detonation at the cell level is an important attribute in the control and operation of a typical detonation gun. The detonation cell is a multidimensional structure which includes both the detonation wave front and transverse detonation waves moving perpendicular to the detonation front. The frontal surface of a detonation cell consists of convex shaped mach wave. Behind the mach wave is a reaction zone where the chemical reactions take place that lead to detonation. At the edge of the cell transverse shock waves form at substantially right angles to the frontal surface of the detonation cell. The transverse waves have acoustic tails that extend from the aft edges of the transverse waves and define the aft edge of the detonation cell. The transverse waves move from cell to cell and reflect off of each other and off of any limiting structure such as the combustion chamber wall. Once detonation has been initiated the reaction continues in a fairly stable fashion. However, the detonation wave front structure can be negatively influenced by collisions with reflecting transverse waves and reflecting refracted waves from the detonation front while moving through the combustion chamber. These collisions diminish the intensity of the detonation cells and therefor lessen the amount of kinetic energy available to be transferred to the coating powder. This reduction in energy transferred to the coating powders translates into a reduction of the coatings produced in terms of density and adherence with the substrate. The residuum of detonation wave front moves from the combustion chamber into the barrel and out onto the workpiece.
The size of the detonation cell is another important attribute in the control and operation of a detonation gun. Cell size is a function of the molecular nature of the fuel, the initial pressure within the combustion chamber, and the fuel/oxygen ratio. The particular cell size for certain conditions can be determined experimentally. The width of a cell, Sc, is measured along the wave front between successive transverse waves. The length of a cell, Lc, is the perpendicular distance from a line tangent to the wave front measured to the intersection point of the acoustic tails from adjacent transverse waves. The typical ratio of cell width to cell length is Sc=0.6 Lc for the detonable gases under consideration. The physical parameters of a particular typical detonation gun, such as the geometry and operating pressures, are determined bv the cell size of a particular fuel and oxygen mixture.
The operating pressure within the combustion chamber is influenced by the behavior of the detonation cells. Prior to ignition the pressure within the combustion chamber is controlled by the fuel and oxygen supply pressures and the geometry of the combustion chamber. After ignition of the mixture the pressure within the combustion chamber increases and reaches a maximum when detonation occurs. As the detonation wave travels down the barrel and reaches the open end of the barrel a peak rarefaction pressure is measured within the combustion chamber. A positive pressure peak is then subsequently measured within the combustion chamber due to the presence of reflected waves from the detonation wave front.
In a typical detonation gun the coating powder, such as Amperit, is fed either directly into the barrel directly or into the combustion chamber and then carried into the barrel by inert gases ahead of the detonation wave. For example, a certain powder feeder utilizes a continues supply of air or inert gas to carry the powder fed from a continues source through a valve arrangement and finally into the gun. The operation of the valve is coordinated with the firing of the spark plug so that the powder and carrying gases are in position along the barrel to be properly effected by the detonation wave. Typically the valves are opened by mechanical means such as a cam and tappets or a solenoid. The disadvantage of these mechanisms is that they often limit the frequency at which the gun can fire because the valve must be opened far enough and long enough to permit the passage of the proper amount of powder through the valve. These mechanisms also pose reliability problems in that they have rapidly moving pieces and transport powders that tend to be abrasive in nature leading to gun life cycle and maintenance concerns. In addition, valves pose safety concerns in that a valve that leaks, sticks open or breaks gives an alternate and potentially harmful path for the detonation wave front to escape.
The rate at which a detonation gun deposits the coating powder on the workpiece is an important economic parameter in industrial applications. The deposition rate is controlled, and at times limited, by a variety of factors such as the type of fuel, the fuel supply system, the geometries of the combustion chamber and barrel, the powder feeder system, and the purging of the system between successive ignitions. Deposition rate is expressed as the ratio between the spray rate and spray spot square. The spray rate is stated in terms of the mass of coating powder utilized per unit time, typically Kg/hr, and typically ranges from 1 to 6 Kg/hr. Spray rate is obviously influenced to great extent by the rate at which the spark plug is ignited. In a typical detonation gun the spark plug is ignited at the maximum rate of 6 to 10 times per second. The spray spot square is the area coated by a single ignition of the gun and is roughly equal to the area of the barrel and is typically expressed as mm.sup.2. A typical industrial detonation gun has a deposition rate of about 0.001 to 0.02 Kg/mm.sup.2 -hr.
In the typical detonation gun the combustible fuels and oxygen are supplied in gas form either into a mixing chamber or directly into the combustion chamber itself through a series of valves. The combustible gases are supplied under pressure of about 1 to 3 Mpa from a continuous source to the valve system before being issued into the gun. The opening of the valve system is synchronized to properly proportion the gases and to prevent backfire. As discussed previously a valve system as employed in a typical detonation gun raises serious concerns about rate, reliability and safety.
An important characteristic affecting the quality of the coatings produced by the detonation gun is the supersonic velocities at which the shock waves travel. The shock waves carry the coating powders at such velocities and, therefore, the coatings that are produced achieve higher densities and better adhesive qualities than other spray coating methods. The velocity of the coating powder as it exits the barrel is influenced by, among other things, the type of fuel used, and the geometries of the combustion chamber and barrel. Typical detonation wave velocities for detonable gas mixtures lie between 1200 m/sec and 4000 m/sec with H.sub.2 --O.sub.2 at 2830 m/sec and CH.sub.4 --O.sub.2 at 2500 m/sec. The maximum achievable velocity in present detonation gun configurations is approximately 3000 m/sec.
The temperatures surrounding the operation of a detonation gun is yet another important characteristic affecting the quality of the coatings produced and concerning its use as an industrial coating apparatus. Typical adiabatic flame temperatures for detonable gas mixtures of concern range from 1947.degree. C. to 3137.degree. C. with H.sub.2 --O.sub.2 at 2807.degree. C. and CH.sub.4 --O.sub.2 at 2757.degree. C. It is often desirable to melt the coating powders before depositing them on the substrate and given the correct parameters these temperatures are high enough to melt certain powder coating materials. The temperature imparted to the powders is in part controlled by barrel geometry and in part controlled by active cooling of the barrel. These temperatures are high enough to melt most substrate materials, however, the discontinuous nature of the combustion within a detonation gun prevents the substrate from being adversely affected.
The use of non-combustible gases in the operation of a detonation gun also effects the quality of the coatings produced. There are three common uses of non-combustible gases in detonation gun operations: 1. As purging gases; 2. As powder carrier gases; and 3. As a control on the detonation process. Purging gases typically are inert gases and are used primarily to purge the combustion chamber between successive firings of the spark plug to arrest the combustion process. This is important in the typical detonation gun because the combustion chamber must be filled between successive firings of the spark plug with new amounts of combustible fuel and oxygen mixture through a series of valves. If combustion continued in the combustion chamber while the valves are opened it is possible that the combustion would continue into the fuel and oxygen supply and cause an explosion. One of the problems with using purging gases is that they mix with the combustible gases and lower the overall kinetic energy of the detonation because the inert gases are by their very nature non-combustible. Therefore the kinetic energy available for transferring to the coating powders is lessened and coating density and adhesion will be adversely affected. In addition, the purging gases mix with the coating powder and slightly alter the final composition of the coatings produced. Powder carrier gases, frequently compressed air, are typically used to transfer the coating powders from a reservoir to the barrel of the detonation gun in front of the detonation wave front. These gases also lessen the kinetic energy available for transfer to the coating powders because they lower the temperature and velocity of the detonation wave front. The effect on coating quality is evidenced by a lower density coating and poorer adhesion with the substrate. As a control on the detonation process inert gases are also mixed with the detonable gases. These are typically used in small amounts to control the temperature, velocity and chemical environment of the combustible products.
As an example of the closest prior art, U.S. Pat. No. 5,052,619 describes a barrel for a detonation projection device permitting the acceleration of the detonation of the fuel gas mixture, in order therefore to be able to use such gases as methane, butane or propane without having thereby to increase the barrel length, whereas the object of our Patent is to minimise detonation wave energy wastage inside the barrel and hence enhance the quality of the coating obtained.
The barrel of this U.S. Patent comprises a detonation initiator (1), a detonation combustion accelerator (3) and a detonation chamber (2), the combustion accelerator comprising a number of perforated discs (6, 7, 8, 9, 10, 11, 12, 13, 14, 15) concentric with the barrel, wherein the holes of each disc are partly closed by walls (17) to define a number of small holes (4) crossed by the combustion wave. These holes (4) are approximately equal in size to the detonation wave cells, the number of holes being provided to increase in the outward direction of the barrel, thereby to form a number of communication passages (5) between the detonation initiator and the detonation chamber.
Now, therefore, the gas mixture is ignited at the initiator and passes to the accelerator through the hole (16) in the first disc (6), with the unburned gases knocking against the walls (17), thereby for the flame to be accelerated, compression being generated right in front of the flame. The reflection of these waves by compression against the walls (17) causes a temperature rise which suffices to cause self-ignition of the mixture present in front of the flame, the combustion process being intensified as a result.


First, second and third lighting devices each comprise a thermal conduction element, solid state light emitters and a reflective element. In the second device, the conduction element defines an opening; and the emitters and reflective element are mounted on a first side of the conduction element. In the third device, the conduction element defines an opening; a first portion of a first side of the conduction element is in contact with a contact region of a construction surface; and the emitters and reflective element are mounted on the first side. A fourth device comprises a conduction element and emitters; a first portion of a first side of the conduction element is in contact with a contact region of a construction surface; the emitters are mounted on a second portion of the first side of the conduction element; and a second side of the conduction element is exposed to ambient air.

A large proportion (some estimates are as high as twenty-five percent) of the electricity generated in the United States each year goes to lighting. Accordingly, there is an ongoing need to provide lighting which is more energy-efficient. It is well-known that incandescent light bulbs are very energy-inefficient light sources—about ninety percent of the electricity they consume is released as heat rather than light. Fluorescent light bulbs are more efficient than incandescent light bulbs (by a factor of about 10) but are still less efficient as compared to solid state light emitters, such as light emitting diodes.
In addition, as compared to the normal lifetimes of solid state light emitters, e.g., light emitting diodes, incandescent light bulbs have relatively short lifetimes, i.e., typically about 750-1000 hours. In comparison, light emitting diodes, for example, have typical lifetimes between 50,000 and 70,000. Fluorescent bulbs have longer lifetimes (e.g., 10,000-20,000 hours) than incandescent lights, but provide less favorable color reproduction.
Color reproduction is typically measured using the Color Rendering Index (CRI Ra) which is a relative measure of the shift in surface color of an object when lit by a particular lamp. CRI Ra is a modified average of the measurements of how the color rendition of an illumination system compares to that of a reference radiator when illuminating eight reference colors. The CRI Ra equals 100 if the color coordinates of a set of test colors being illuminated by the illumination system are the same as the coordinates of the same test colors being irradiated by the reference radiator. Daylight has a high CRI (Ra of approximately 100), with incandescent bulbs also being relatively close (Ra greater than 95), and fluorescent lighting being less accurate (typical Ra of 70-80). Certain types of specialized lighting have very low CRI Ra (e.g., mercury vapor or sodium lamps have Ra as low as about 40 or even lower).
Another issue faced by conventional light fixtures is the need to periodically replace the lighting devices (e.g., light bulbs, etc.). Such issues are particularly pronounced where access is difficult (e.g., vaulted ceilings, bridges, high buildings, traffic tunnels) and/or where change-out costs are extremely high. The typical lifetime of conventional fixtures is about 20 years, corresponding to a light-producing device usage of at least about 44,000 hours (based on usage of 6 hours per day for 20 years). Light-producing device lifetime is typically much shorter, thus creating the need for periodic change-outs.
Designs have been provided in which existing LED component packages and other electronics are assembled into a fixture. In such designs, a packaged LED is mounted to a circuit board or directly to a heat sink, the circuit board is mounted to a heat sink, and the heat sink is mounted to the fixture housing along with required drive electronics. In many cases, additional optics (secondary to the package parts) are also necessary.
The expression "light emitting diode" is used herein to refer to the basic semiconductor diode structure (i.e., the chip). The commonly recognized and commercially available "LED" that is sold (for example) in electronics stores typically represents a "packaged" device made up of a number of parts. These packaged devices typically include a semiconductor based light emitting diode such as (but not limited to) those described in U.S. Pat. Nos. 4,918,487; 5,631,190; and 5,912,477; various wire connections, and a package that encapsulates the light emitting diode.
In substituting light emitting diodes for other light sources, e.g., incandescent light bulbs, packaged LEDs have been used with conventional light fixtures, for example, fixtures which include a hollow lens and a base plate attached to the lens, the base plate having a conventional socket housing with one or more contacts which is electrically coupled to a power source. For example, LED light bulbs have been constructed which comprise an electrical circuit board, a plurality of packaged LEDs mounted to the circuit board, and a connection post attached to the circuit board and adapted to be connected to the socket housing of the light fixture, whereby the plurality of LEDs can be illuminated by the power source.
Although the development of light emitting diodes has in many ways revolutionized the lighting industry, some of the characteristics of light emitting diodes have presented challenges, some of which have not yet been fully met. For example, the emission spectrum of any particular light emitting diode is typically concentrated around a single wavelength (as dictated by the light emitting diode's composition and structure), which is desirable for some applications, but not desirable for others, (e.g., for providing lighting, such an emission spectrum provides a very low CRI Ra).
Traditional recessed light fixtures comprise a metal cylinder ("can") mounted into the ceiling using horizontal metal struts attached to the ceiling joints. Within the cylinder, mounted on an adjustable sliding plate, is light bulb socket into which a light bulb is inserted. Typically a 60 W incandescent light bulb or a 15 W compact fluorescent bulb is used. For example, a conventional recessed light fixture is depicted in FIG. 1.
Around the annulus of the bulb and extending downward to the lower inside edge of the cylinder is a baffle or reflecting cone. A cosmetic ring is placed around the bottom edge of the cylinder and extending outward to cover the area immediately surrounding the circular cutout in the ceiling and create an attractive edging around the light output aperture.
The position (height) of the bulb can be set such that the bulb is not directly visible to the people standing in the room and the light from the fixture is directed so that it principally illuminates an area below the fixture.
These fixtures are popular because they do not create significant glare (being recessed) and highlight objects situated below them.
The "cans" are generally required to be substantially airtight around the sides and top to prevent the loss of ambient heat or cooling from the room into the ceiling cavity through the fixture. As the lamp is mounted in the can, much of the heat generated by the light source is trapped within the can, because the air heated in the can rises and is trapped within the can. Special insulation is usually required around the can within the ceiling cavity to prevent fire.
The environment inside the can is not ideal for solid-state lighting. LEDs, for example, have significant energy and lifetime benefits over incandescent and fluorescent light sources—LEDs, however, do not operate well in high temperatures. LED light sources have operating lifetimes of decades as opposed to just months or 1-2 years for the others mentioned. An LED's lifetime is significantly shortened, however, if it operates at elevated temperatures. It is generally accepted that the junction temperature of an LED should not exceed 70 degrees C. if a lifetime of 100,000 hours is desired.
Efficient individual LED light sources typically provide between 3 and 50 lumens of light per source (LED die or lamp) depending on the size of the LED die. A typical recessed downlight using a 60 W incandescent bulb provides about 500 lumens of light, so it can be seen that to provide a similar amount of light from LEDs, multiple LED light sources would be required.
To provide a similar amount of light using "small die" (typically 300 square micrometers), approximately 200 die would be required, or, alternatively using large "power" die (typically approximately 1 square millimeter) 10-20 die would be required.
For the above and other reasons, efforts have been ongoing to develop ways by which solid state light emitters can be used in place of incandescent lights, fluorescent lights and other light-generating devices in a wide variety of applications. In addition, where light emitting diodes (or other solid state light emitters) are already being used, efforts are ongoing to provide light emitting diodes (or other solid state light emitters) which are improved, e.g., with respect to energy efficiency, color rendering index (CRI Ra), contrast, efficacy (lm/W), cost and/or duration of service.


This document provides methods and materials related to treating orthostatic hypotension and/or postural tachycardia syndrome. For example, methods and materials for using a composition containing 3,4-diaminopyridine, 4-aminopyridine, or both to treat patients with orthostatic hypotension, postural tachycardia syndrome, or both orthostatic hypotension and postural tachycardia syndrome are provided.

1. Technical Field
This document relates to methods and materials involved in treating orthostatic hypotension or postural tachycardia syndrome. For example, this document relates to methods and materials involved in using a composition containing 3,4-diaminopyridine, 4-aminopyridine, or both to treat patients with orthostatic hypotension, postural tachycardia syndrome, or both orthostatic hypotension and postural tachycardia syndrome.
2. Background Information
Orthostatic hypotension is a disabling condition characterized by inability to maintain adequate blood pressure (BP) in the upright position resulting in lightheadedness and syncope. It occurs frequently in central (multiple system atrophy) and peripheral (autonomic neuropathies, pure autonomic failure) autonomic disorders and is associated with troublesome supine hypertension. The postural tachycardia syndrome (POTS) is also a heterogenous condition characterized by symptomatic excessive orthostatic tachycardia. Treatment options for both disorders are limited and often associated with intolerable side effects including aggravation of supine hypertension.

Methods and materials for treating orthostatic hypotension or postural tachycardia syndrome

Mayo Foundation for Medical Education and Research


Common mode ferrite bead is provided for suppressing EMI/RFI. The bead includes a ferrite body of substantially rectangular configuration with top and bottom surfaces, first and second end surfaces and first and second side surfaces. Six apertures pass entirely through the body from the first end surface to the second end surface. Grooves may be provided in bottom surface. Two conductors are provided through the body such that each of the conductors passes through each of three of the apertures through the body. The opposed ends of the conductors are bent to fit in the grooves in the bottom surface of the body. These ends of the respective conductors define contact which can be soldered to conductive pads on a circuit board.

1. Field of the Invention.
The subject invention relates to a high frequency common mode ferrite bead for surface mounting on a circuit board.
2. Description of the Prior Art.
Ferrites are widely used as attenuators or suppressors of unwanted signals in electrical circuits. When the problem of EMI/RFI arises in a circuit, the first step is to isolate the source. The second step is to diminish its output to an acceptable level without destroying the necessary information being transmitted at other frequencies.
The prior art has included ferrite suppressors that are inserted into a circuit containing useful signals as well as noise or interference. The desired signals will pass through while the undesired energy will be attenuated. This is accomplished through the impedance of the ferrite which is frequency sensitive. Direct and low frequency currents see only the conductor, and are unimpeded. The high frequency energy couples with the ferrite and impedance is developed which has inductive and resistive components. When a line is passed through a ferrite core, low frequency energy is transmitted with little loss, whereas higher frequency energy encounters the inductive reactance caused by the real part of the complex permeability of the ferrite. The inductive reactance reduces the conducted EMI current and introduces an insertion loss. At still higher frequencies, where the real part of the permeability of the ferrite material decreases and the inductive reactance falls, the lossy characteristics dominate and the resistive componet of the impedance assumes the main role of providing the insertion loss for dissipating the unwanted energy.
Ferrite suppressors have taken many forms in the prior art. A significant number of very desirable ferrite suppressors are sold by Fair-Rite Products Corp., the assignee of the subject application. For example, Fair-Rite part #2744041447 is identified generally by the numeral 10 in FIGS. 1 and 2. The prior art ferrite surface mount bead 10 of FIGS. 1 and 2 includes a generally rectangular ferrite body 12 having top and bottom surfaces 14 and 16, first and second end surfaces 18 and 20 and first and second side surfaces 22 and 24. Two rectangular slots 26 and 28 extend entirely through the ferrite body 14 from the first end 18 to the second end 20 at a position midway between the top and bottom surfaces 14 and 16 and equally spaced from the respective side surfaces 22 and 24. These slots are connected by a narrower slot that is designed to limit the sidewise movement of the conductive strips 30 and 32 that pass through the slots 26 and 28 respectively. Used as a common mode choke, the source and return electrical currents are conducted in opposite directions on these strips. Any direct or low frequency current, which would be equal, create magnetic fields that are equal and opposite, and therefore cancel, resulting in a net zero magnetic field. Any common mode, meaning in-phase signals travelling on both conductors, will be attenuated by the characteristics of the ferrite since the magnetic fields created by the signal would not cancel. The ends of the respective conductive strips 30 and 32 are folded around the respective end faces 18 and 20 of the ferrite body 14 and into abutting face-to-face engagement with the bottom surface 16 thereof. These end faces may then be electrically and mechanically mounted to conductive pads on the surface of a circuit board. Common-mode surface mount beads as shown in FIGS. 1 and 2 have proved to be very effective.
Fair-Rite Products Corp. also sells a ferrite bead identified as part #2943666681 and indicated generally by the numeral 34 in FIG. 3. The bead 34 includes a cylindrical ferrite body 36 having a total of six apertures passing therethrough substantially parallel to the axis of the cylinder. Two conductive wires are threaded through the apertures such that each wire passes through three of the six apertures. In particular, each wire will enter the ferrite core at one end, will pass entirely to the opposed end and reverse directions. The wire will reverse directions again at the original end and will continue back to the opposed end. The wires from the suppressor shown in FIG. 3 will be bent away from an axial direction and down toward a surface board where the wires may be mounted in conductive through holes or may otherwise soldered into connection with conductive regions on a circuit board. The prior art bead 34 is not designed for surface mount applications.
Another prior art ferrite bead is shown in U.S. Pat. No. 5,455,552 which issued to Metsler on Oct. 3, 1995 and is assigned to Steward, Inc. The bead shown in U.S. Pat. No. 5,455,552 includes a generally rectangular ferrite body with two parallel slots extending therethrough. Two conductors of generally U-shape are arranged parallel to one another such that one leg of each conductor passes through each of the two slots in the ferrite body. These conductors continue through the ferrite body and are mounted in conductive through holes of a circuit board. However, when employed as a common mode choke, the magnetic fields created are complex, do not completely cancel, and the close proximity of the conductors to each along with the dielectric constant of the ferrite material that is greater than that of air that results in severe degradation of the attenuative characteristics of the device above about 100 MHz.
It is an object of the subject invention to provide a ferrite common mode bead intended for surface mount applications and exhibiting very high impedance over a very wide frequency range.


In an evaluation circuit for evaluating an output signal of a magnetoresistive sensor (1) for rotational speed measurement, in which the evaluation circuit performs an offset compensation of the sensor signal and comprises a comparator (4) which receives the offset compensated sensor signal and compares it with a reference voltage, a reliable identification of the output signal of the sensor after switching on the arrangement is ensured in that, in an initial mode, the value of the reference voltage is selected in dependence upon the temperature, the temperature dependence being approximated to that of the sensor signal, in that a control unit (6) is provided which, in the initial mode, consecutively checks whether the sensor signal is present, triggers the offset compensation only after the presence of said signal, subsequently checks whether the comparator (4) supplies an output signal, and changes over to a control mode only after the presence of said signal, in which control mode the temperature dependence of the reference voltage is switched off and, instead, the reference voltage is adjusted to approximately 40% of the maximum amplitude of the offset-compensated sensor signal.

The invention relates to an evaluation circuit for evaluating an output signal of a magnetoresistive sensor for rotational speed measurement, in which the evaluation circuit performs an offset compensation of the sensor signal and comprises a comparator which receives the offset-compensated sensor signal and compares it with a reference voltage.
Such evaluation circuits are marketed, for example, by Philips. They are used for processing the output signals from magnetoresistive sensors in anti-blocking systems for motor vehicles. These sensors supply signals which are dependent on the rotational speed of the wheels of the vehicle. They have an offset compensation which is intended to eliminate the DC component in the possibly amplified output signal of the sensor. The offset-compensated signal is processed by means of a comparator which essentially ensures that interference signals are eliminated. To this end, the comparator compares the offset-compensated sensor signal with a reference voltage.
After such an arrangement has been switched on, there is the problem that neither the temperature nor the distance between the sensor and the magnetized disc whose rotational speed is measured by means of the sensor are known. Therefore, the amplitude of the sensor signal is not known either. This involves the risk that, for example, in a vehicle which is standing still, interference modulation occurring in the output signal of the sensor is interpreted as a sensor signal and that both the offset compensation and the adjustment of the reference voltage are carried out with reference to this interference modulation. In that case, a control mode would already start, although the vehicle is not moving. This is unacceptable.
It is an object of the invention to improve the arrangement described above to such an extent that, after switching on, it is reliably adjusted only to actual sensor output signals rather than to possible interference signals.
According to the invention, this object is solved in that in an initial mode, the value of the reference voltage is selected in dependence upon the temperature, the temperature dependence being approximated to that of the sensor signal, in that a control unit is provided which, in the initial mode, consecutively checks whether the sensor signal is present, triggers the offset compensation only after the presence of said signal, subsequently checks whether the comparator supplies an output signal, and changes over to a control mode only after the presence of said signal, in which control mode the temperature dependence of the reference voltage is switched off and, instead, the reference voltage is adjusted to approximately 40% of the maximum amplitude of the offset-compensated sensor signal.
The invention is based on the recognition that the problem described above is based on the fact that a control unit in the arrangement does not know the temperature on the side of the sensor. In fact, its output signal is greatly dependent on temperature, i.e. the amplitude clearly decreases with an increasing temperature. When the arrangement is switched on and attempts to evaluate a sensor signal, the control unit does not know which temperature prevails. This problem becomes even more serious because the distance between the sensor and a sensor wheel scanning the sensor magnetically is neither known but that this distance also has a considerable influence on the amplitude of the sensor output signal. The result of this overall problem is that the output amplitude of the sensor may be very different but that simultaneously the cause (temperature or distance) after switching on is not known. Consequently, this involves the risk that the evaluation circuit performs both the offset compensation and the adjustment of the reference voltage at which the comparator operates with reference to a modulation signal having a small amplitude and being actually an interference signal. This may also be triggered, for example, by small vibrations of the sensor wheel when the vehicle is standing still, which vibrations may be particularly caused by the engines.
The arrangement according to the invention obviates this in that it changes, in an ordered manner, from an initial mode to a control mode.
The reference voltage is chosen to be such that it is also temperature-dependent. The type and value of the temperature dependence is chosen to be similar to that of the sensor. Thus, with a changing temperature, the value of the reference voltage and the amplitude of the sensor output signal are approximately proportional to each other.
This property is utilized by a control unit which initially checks in an initial mode whether a sensor signal is present. To this end, a possibly amplified and possibly analog/digitally converted output signal of the sensor is checked instead of the output signal of the comparator. Only when such a sensor signal is present does the control unit start the offset compensation. A DC component which may be present in the output signal of the sensor is then eliminated. When an adjustment of this offset compensation has taken place, it is subsequently checked whether the comparator supplies an output signal. This check is important because, based on the temperature-dependent selection of the reference voltage, the comparator only supplies an output signal when the output signal of the sensor actually has such a value in dependence upon the temperature that it is certainly a sensor signal and not an interference modulation. This is achieved in response to the temperature dependence of the reference voltage whose value is adjusted in dependence upon the temperature to the expected amplitude of the sensor signal. Only when the comparator supplies an output signal may it be assumed that it is a regular sensor signal. The control unit then changes over to a control mode in which the reference voltage is no longer chosen to be temperature-dependent but in which the reference voltage is adjusted to approximately 40% of the maximum amplitude of the offset-compensated control signal. Now, a direct coupling of the value of the reference voltage with the actual amplitude of the sensor signal takes place.
As a result, it is achieved by means of this arrangement according to the invention that, due to the temperature dependence of the reference voltage and the evaluation of the output signal of the comparator of the control unit, information is provided on the presence of an actual sensor signal at a given temperature. This is achieved in that the comparator only supplies an output signal when the sensor itself actually supplies an output signal.
The arrangement according to the invention obviates separate use of a temperature sensor which would involve additional costs and additional components.
In an embodiment of the invention as defined in claim 2, it is advantageous that the arrangement triggers the initial mode particularly after switching on the sensor and/or the evaluation circuit, because it is exactly at this moment that the actual cause of the value of the amplitude of the sensor is initially unknown.
The evaluation of the output signal of the comparator, which may be basically an analog signal, can be digitally evaluated, as described in accordance with a further embodiment of the invention as defined in claim 3. This means that it can only be checked in the simplest case whether such a signal is present or absent. The value of the signal then does not play any role. Thus, a simple yes/no decision can be taken.
The temperature dependence of the reference voltage in the initial mode can be generated relatively easily by means of a current mirror circuit which is known in the IC technique and supplies the desired voltage variation upon a changing temperature.
These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Evaluation circuit for a magnetoresistive sensor


The invention relates to a circuit arrangement for switching high-voltage signals with low-voltage signals, particularly for driving a semiconductor memory arrangement, comprising a low-voltage logic device for generating a low-voltage signal with a first predetermined logic level and with a second predetermined logic level, comprising a latch for receiving and latching the low-voltage signal and for outputting an output signal with a voltage dependent on the logic level of the received low-voltage signal, comprising a level shifter for increasing the value of the voltage of the latched low-voltage signal to a voltage of a high-voltage signal, as a result of which the voltage of the output signal output essentially rises to the voltage of the high-voltage signal, the latch exhibiting one or more high-voltage transistors.

The invention relates to a circuit arrangement for switching high-voltage signals by means of low-voltage signals, particularly for driving a semiconductor memory arrangement and to a method for switching high-voltage signals by means of low-voltage signals, particularly for driving a semiconductor memory arrangement.
EEPROMs (Electrically Erasable Programmable Read Only Memories) or EAROMs (Electrically Alterable ROM), so-called flash memories, are known in various embodiments from the prior art. EEPROM/flash memories are generally divided into rows, so-called word lines, and columns, so-called bit lines, each intersection of bit lines and word lines representing one memory cell.
FIG. 7 shows a circuit diagram of a section from a cell array 1, comprising two word lines WLn, WLn−1, and two bit lines BLm, BLm+1′ of an electrically erasable and then reprogrammable read only memory (EEPROM) according to the prior art.
Each intersection of a word line WLn, WLn−1 with a bit line BLm, BLm+1 comprises a memory cell 2 as shown, for example, in FIG. 8.
Each memory cell 2 comprises two transistors, namely a cell transistor 4 and a select transistor 3, the drain of the cell transistor 4 being connected to the source of the select transistor 3. Whereas the select transistor 3 is a conventional NMOS transistor of the enhancement type, the NMOS cell transistor has an electrically variable threshold voltage Uth. For this purpose, the cell transistor 4 comprises a so-called tunnel window 5 via which charges for changing the threshold voltage Uth can be supplied to a floating gate FG4 of the cell transistor 4.
Each word line WLn, WLn−1 comprises two control lines, namely a drive line CGLn, CGLn−1 for the so-called control gates CG4 of the respective cell transistors 4 of a respective word line WLn, WLn−1, and a drive line SGLn, SGLn−1 for the so-called select gates SG3 of a respective select transistor 3 of a respective word line WLn, WLn−1.
Each bit line BLm, BLm+1 likewise comprises two control lines, namely a drive line Sm, Sm+1 for the sources S4 of the respective cell transistors 4 of a respective bit line BLm, BLm+1, and a drive line Dm, Dm+1 for the respective drains D3 of the respective select transistors 3 of a respective bit line BLm, BLm+1.
Each memory cell can be selected by a suitable drive via the corresponding four associated drive lines. For example, the memory cell 2 in FIG. 7 can be driven via a corresponding circuit of the drive lines CGLn, SGLn of the n-th word line WLn and the drive lines Sm+1, Dm+1 of the m+1-th bit line BLm+1.
Each selected memory cell can be operated in three operating modes, namely the read mode, the erase mode and the program mode.
In the read mode, a memory cell is selected by applying a positive voltage of, for example, +1.8 volt to the select gate of the select transistor. The read mode results from the voltages applied to the source of the cell transistor, to the drain of the select transistor and to the control gate of the cell transistor of, in the exemplary embodiment, 1.2 volt, 0 volt and 1.8 volt.
In the erase mode, a memory cell is selected by applying a high positive voltage of in this case 18 volts to the control gate of the cell transistor.
Selection in the program mode occurs by applying 0 volt to the source of the cell transistor, −8.4 volts to the control gate of the cell transistor, +10 volts to the select gate of the select transistor and +6.6 volts to the drain of the select transistor. This circuit application simultaneously specifies the program mode.
All of the operating states can be seen in the table representation according to FIG. 9.
In FIG. 7, the voltage values in each case associated with the corresponding read mode (top), erase mode (in the center), program mode (bottom) are specified above the respective drive lines CGLn, SGLn, SGLn−1, CGLn−1, Sm, Dm, Sm+1, Dm+1. The values specified result in the memory cell identified by the reference symbol 2 being exclusively selected in all operating modes.
From the prior art, a multiplicity of circuit arrangements for driving the control gates of the cell transistors and the select gates of the select transistors with the voltages with relatively high values in the erase and program mode are known. A comparatively elaborate circuit arrangement is known, for example, from U.S. Pat. No. 5,265,052. A simpler circuit arrangement is described in the documents JP 06338197 A and DE 197 14 658 C2.
The drive to the select gates and control gates of the cell and select transistors, respectively, in a cell array with the aid of the circuit arrangements described in the two last-mentioned documents will firstly be described by means of drawing FIGS. 3 and 6.
FIG. 3 shows a circuit arrangement of a control gate driver 7 according to the prior art for driving the control gate CG4 of a cell transistor 4 and a corresponding drive line CGL. The control gate driver 7 according to the prior art consists of a low-voltage logic with low-voltage transistors 16 and a high-voltage unit with high-voltage transistors 15. The low-voltage section with the low-voltage transistors 16 comprises a word line decoder 10 and a low-voltage read driver 9.
The high-voltage section with the high-voltage transistors 15 consists of a high-voltage decoupling transistor 8 and a high-voltage latch 6. The HV decoupling transistor 8, in this case an NMOS transistor, comprises a gate G8, via which the high-voltage latch 6 can be separated from the low-voltage read driver 9. The high-voltage latch 6 consists of two series-connected inverters I1, I2, which in each case exhibit a PMOS transistor MP1, MP2 and an NMOS transistor MN1, MN2, the output of the second inverter I2, forming the output of the latch 6, being fed back to the input of the first inverter I1 via a feedback line RL. The source terminals of the respective transistors MP1, MP2 and, respectively, MN1, MN2, are in each case connected to one another via corresponding circuit nodes KP1 and KN1, respectively, and connected to a corresponding positive high-voltage supply HVP and negative high-voltage supply HVN, respectively.
Although the fundamental operation of the circuit arrangement is described in DE 197 14 658 C2, the operation of the control gate driver 7 will be explained by means of table 1 specified below.
TABLE 1notV(CON)V(HVP)V(HVN)selectedselectedErasevboost→0 Vvread→vpp0 V01Programvboost→vread→0 V0 V→10vprognvprognReadvboostvread0 V11The Read ModeThe Read Mode is Initiated as Follows:
The voltage vboost is present at the terminal CON, the voltage vread is present at terminal HVP and the terminal HVN is at 0 volt. This state is retained for as long as it is intended to read from the cell.
Erase Mode
The Erase Mode is Initiated as Follows:
Before erasing, vboost is present at the terminal CON, vread is present at the terminal HVP and 0 volt is present at terminal HVN. The HV latch is brought into the desired state by the low-voltage logic 10 via the low-voltage driver 9. Then the connection from the HV latch 7 to the NV driver 9 is separated by lowering the voltage at the gate terminal CON to HVN=0 volt. After that, the voltage at the positive high-voltage supply HVP is ramped up to the erase voltage vpp. After the erase time has elapsed, the voltage at terminal HVP is lowered back to the read voltage vread and the connection to the NV driver 9 is restored by raising the voltage at the gate terminal CON to the boost voltage vboost.
Program Mode
The Program Mode is Initiated as Follows:
Before programming, the boost voltage vboost is present at terminal CON, the read voltage vread is present at the high-voltage supply terminal HVP and 0 volt is present at the high-voltage supply terminal HVN. The high-voltage latch (HV latch) 7 is brought into the desired state by the low-voltage logic 10 via the low-voltage driver 9. Then the connection from the HV latch 7 to the NV driver 9 is separated by dropping the voltage at the control terminal CON to HVN=initially 0 volt. After that, the voltages at the negative high-voltage terminal HVN and at the control terminal CON are ramped to the negative programming voltage vprogn. After the programming time has elapsed, the voltage at terminal HVN is increased again to 0 volt. After that, the connection to the NV driver 9 is restored by ramping up the voltage at the terminal CON to the boost voltage vboost.
As can be seen from the above explanations, the control gate word line CGL in a flash EEPROM is operated    a) with low voltage levels (e.g. 0 volt and 2 volts) in the read mode,    b) with high voltage levels (e.g. 0 volt and 18 volts) in the erase mode,    c) with high voltage levels (e.g. −12 volts and 0 volt) in the program mode,the low-voltage logic section 16 having to be separated from the high-voltage section 15 in the erase and program mode.
To separate the low-voltage section 16 from the high-voltage section 15 and to reconnect them, the high-voltage transistor 8 is required which is driven with the so-called boost voltage vboost. To provide this boost voltage vboost requires a charge pump. For this charge pump, an area must be provided on the semiconductor chip and, as well, an operating current for operating this charge pump and a control logic are required. To switch from the disconnected state to the read mode, the charge pump requires a certain time until it has reached its maximum output voltage. The flash EEPROM can only be read out after this time has elapsed.
Similar disadvantages occur if the operation of a so-called select gate driver 17 according to the prior art is considered as is shown, for example, in FIG. 6.
FIG. 6 shows a circuit arrangement of a select gate driver 17 according to the prior art for driving the select gate SG4 of a cell transistor 4 and a corresponding drive line SGL. The select gate driver 17 according to the prior art consists of a low-voltage logic with low-voltage transistors 26, and a high-voltage unit with high-voltage transistors 25. The low-voltage section with the low-voltage transistors 26 comprises a word line decoder 20 and a low-voltage read driver 19.
The high-voltage section with the high-voltage transistors 25 consists of a high-voltage decoupling transistor 18 and a high-voltage latch 21. The HV decoupling transistor 18, again an NMOS transistor, comprises a gate G18 via which the high-voltage latch 21 can be separated from the low-voltage read driver 19. The high-voltage latch 21 consists of two series-connected inverters I1, I2, in each case exhibiting a PMOS transistor MP1, MP2, and an NMOS transistor MN1, MN2, the output of the second inverter I2 forming the output of the latch 21 being fed back to the input of the first inverter I1 via a feedback line RL. The source terminals of the respective transistors MP1, MP2 and, respectively, MN1, MN2 are in each case connected to one another via corresponding circuit nodes KP1 and KN1, respectively, and are connected to a corresponding positive high-voltage supply HVP and ground GND (terminal 22).
Although the fundamental operation of the circuit arrangement is described in DE 197 14 658 C2, the operation of the select gate driver 17 will be explained here, too, by means of the table 2 specified below.
TABLE 2Logic level at sgi  voltage at SGLnotV(CON)V(HVP)selectedselectedErasevboostvread1   vdd1   vddProgramvboost → 0 Vvread → vpp0   0 V1   vppReadvboostvread0   0 V1   vddThe Read ModeThe Read Mode is Initiated as Follows:
At terminal CON, the voltage vboost is present and at terminal HVP the read voltage vread is present. As long as no reading takes place, 0 volt are present at sgi and SGL. If it is intended to read from the relevant word line, the voltage at sgi is raised to the read voltage VRead for a short time by the NV driver and then lowered again to 0 volt. Via the low-resistance connecting transistor 18, the voltage at SGL follows the voltage at sgi.
Erase Mode
The Erase Mode is Initiated as Follows:
At terminal CON, the voltage vboost is present and at terminal HVP the voltage vread is present. The logic level is 1 and thus vread is also present at SGL. This state is retained as long as erasing is taking place.
Program Mode
The program mode is initiated as Follows:
Before programming, the boost voltage vboost is present at terminal CON and the read voltage vread is present at terminal HVP. The HV latch 17 is brought into the desired state by the low-voltage logic 20 via the low-voltage driver 19. Then the connection from the HV latch 17 to the NV driver 19 is separated by lowering the voltage at CON to 0 volt. After that, the voltage at HVP is ramped to the voltage vboost. After the programming time has elapsed, the voltage at HVP is dropped again to 0 volt. After that, the connection to the NV driver 19 is restored by ramping up the voltage at CON to vboost.
As can be seen from the above, the driving of a select gate word line SGL in an EEPROM is characterized by the fact that it is operated    a) very rapidly with low voltage levels (e.g. 0 volt and 2 volts) in a read mode, and    b) with high voltage levels (e.g. 0 volt and 10 volts) in a program mode,the low-voltage logic section 26 having to be separated from the high-voltage section 25 in the program mode.
If a high-voltage transistor 18 is used for separating the low-voltage logic and the read amplifier from the high-voltage latch 21, a so-called boost voltage vboost is again needed. To generate this voltage, a separate charge pump is again necessary.

Circuit arrangement and method for switching high-voltage signals by means of low-voltage signals


Techniques for increasing the thermal efficiency of high temperature combustion sources such as glass and other process furnaces are disclosed. These techniques include one or more of the steps of co-firing of a carbonaceous solid fuel or heavy fuel oil with the primary fuel in the primary combustion zone such that the co-fired fuel is cracked and thereby generates a high number density of carbonaceous particles sufficient to improve soot radiation; providing enhanced mixing of first burnout air with the flue gas in a first burnout zone; and promoting instability of boundary layer gases adjacent refractory packings.

1. Field of the Invention
The present invention is directed to apparatus and methods for increasing the thermal efficiency of high temperature combustion sources such as glass and other process furnaces. More particularly, although not exclusively, the present invention is directed to methods and apparatus for enhancing fuel efficiencies of regenerative furnaces and as well as for reducing the fuel penalty that is associated with the use of gas reburning for NO.sub.X control with respect to the same.
2. Technology Review
The combustion of fossil fuels, especially coals and heavy oils, produces a significant amount of NO.sub.X which ultimately participates in the formation of smog and acid rain. This problem is exacerbated in the case of certain combustion sources such as glass furnaces, cement and ceramic kilns, and steel reheat furnaces which operate at extremely high temperatures. Such high temperature combustion sources produce even greater levels of NO.sub.X.
Currently, increasingly stringent air quality regulations impose requirements on glass manufacturing and other industries to reduce such NO.sub.X emissions. A number of technologies to reduce NO.sub.X emissions have been developed in response to such air quality regulations. A brief discussion of these technologies may be helpful to an understanding of the nature of the present invention.
Two technologies that have achieved generally moderate NO.sub.X reductions of approximately 40% to 50% at relatively low cost are low NO.sub.X burners and oxygen enriched air staging. These technologies offer good cost effectiveness (e.g., $400/ton of abated NO.sub.X), but don't always meet stringent air quality regulations. These technologies also exhibit a small fuel penalty, typically on the order of 2% to 5%.
Two other technologies, that are capable of achieving 85% to 90% reductions in NO.sub.X, are selective catalytic reduction and oxy-fuels. These technologies, however, suffer from high capital costs and high operating costs, respectively. Oxy-fuels exhibit poor cost effectiveness (typically $2500 per ton of abated NO.sub.X). Further, selective catalytic reduction is poorly suited to glass furnaces because the alkalis, that are present in the exhaust gas, can rapidly poison the catalyst.
Two other NO.sub.X reduction technologies, that have been effective in achieving up to 60% NO.sub.X reductions, are combustion modification techniques such as staged combustion and reburning. Gas reburning can be applied to high temperature combustion sources such as glass furnaces and can achieve NO.sub.X reduction levels similar to oxy-fuel, but with a cost effectiveness similar to low NO.sub.X burners and oxygen enriched air staging.
Reburning is a controlled process that uses fuel to reduce oxides of nitrogen that are collectively referred to as NO.sub.X. These oxides include NO (nitric oxide), NO.sub.2 (nitrogen dioxide), and N.sub.2 O.sub.4 (dinitrogen tetroxide), and N.sub.2 O (nitrous oxide). In the reburning process, a fraction of the total fuel, typically an amount of fuel yielding between 10% to 20% of the total heat input, is injected above the main heat release zone to produce an oxygen deficient reburning zone. The combustion of reburning fuel forms hydrocarbon radicals which react with nitric oxide to form molecular nitrogen, thus reducing NO.sub.X. This process occurs best in the at very low oxygen. Subsequently, burnout air is injected downstream of the reburn zone to combust the remaining fuel fragments and convert the exiting HCN and NH.sub.3 species to either NO or NO.sub.2.
Previous studies have shown that 60% to 80% reduction in NO.sub.X emissions can be achieved with natural gas reburning and that most of the reduction occurs in the reburning zone. NO.sub.X reduction in the burnout zone, via the HCN and NH.sub.3 species from the reburning zone, is minimal because of the high burnout temperature (2200.degree.-2400.degree. F.) and the presence of an excessive amount of carbon monoxide ("CO", above 2% at 0.9 stoichiometry).
The overall reburning process can be divided conceptually into three zones as follows:
Primary Zone: The primary or main heat release zone normally accounts for approximately 80 percent of the total heat input to the system and is operated under fuel lean conditions. The level of NO.sub.X exiting this zone is defined to be the input to 7 the reburning process. If sufficient residence time is not provided, unburned fuel fragments may leave this zone and enter the reburning zone. PA1 Reburning Zone: The reburning fuel is injected downstream of the primary zone to create a fuel rich, NO.sub.X reduction zone. Reactive nitrogen enters this zone from two sources: the primary NO.sub.X created in the main heat release zone and the fuel nitrogen, if any, in the reburn fuel. These reactive nitrogen species react with the hydrocarbon fragments formed during the partial oxidation of the reburning fuel, primarily CH species, to produce intermediate species such as HCN and NH.sub.3. Additionally, some nitrogen is converted to N.sub.2 and some is retained as NO. If the reburning fuel is a solid such as coal, nitrogen may also leave this zone as char nitrogen. PA1 Burnout Zone: In this final zone, air is added to produce overall lean conditions and to oxidize all of the remaining fuel fragments. The total fixed nitrogen species (TFN=NH.sub.3 +HCN+NO+char nitrogen) will be either oxidized to NO.sub.X or reduced to molecular nitrogen. PA1 (a) co-firing a heavy fuel oil or solid carbonaceous fuel with the primary fuel in the primary combustion zone such that the co-fired fuel is cracked and thereby generates a high number density of carbonaceous particles sufficient to improve soot radiation; PA1 (b) introducing the reburn fuel into the reburn zone at or near sonic speeds; PA1 (c) enhancing the mixing of first burnout air with the flue gas in a first burnout zone; and PA1 (d) promoting instability of boundary layer gases adjacent to the refractory packing. PA1 (a) mixing a reburning fuel with combustion emissions in a gaseous reburning zone such that the reburning zone is substantially oxygen deficient; PA1 (b) passing the resulting mixture of reburning fuel and combustion emissions into a first burnout zone; PA1 (c) introducing burnout air into the first burnout zone such that the carbon monoxide concentration in the first burnout zone is reduced to a level below about 500 ppm; PA1 (d) enhancing the mixing of first burnout air with the flue gas in a first burnout zone; PA1 (e) advancing the resulting mixture from the first burnout zone to a second burnout zone having a temperature in the range from about 1300.degree. F. to about 1900.degree. F.; and PA1 (f) introducing a second stream of burnout air into the second burnout zone, said second stream of burnout air including a reducing agent capable of providing a source of nitrogenous reducing species thereby reducing the nitrogen oxides in the combustion emissions. PA1 (a) mixing a reburning fuel with combustion emissions in a gaseous reburning zone such that the reburning zone is substantially oxygen deficient; PA1 (c) introducing burnout air into the first burnout zone such that the carbon monoxide concentration in the first burnout zone is reduced to a level below about 500 ppm; PA1 (d) advancing the resulting mixture from the first burnout zone to a second burnout zone having a temperature in the range from about 1300.degree. F. to about 1900.degree. F.; PA1 (e) introducing into the second burnout zone a reducing agent capable of providing a source of nitrogenous reducing species thereby reducing the nitrogen oxides in the combustion emissions; and PA1 (f) advancing the second stream of burnout air and the combustion emissions to a bed of refractory packing, the bed of refractory packing having a surface adapted to promote the tripping of the boundary layer gases proximal to it.
It will be understood, however, that the introduction of gas reburn fuel downstream of the primary combustion zone represents a potentially significant increase in operating costs over other available NO.sub.X reduction technology.
Another, more advanced technique for NO.sub.X reduction, which is capable of obtaining NO.sub.X reduction of up to 90%, is "advanced gas reburn." Advanced gas reburn technology represents a synergistic combination of gas reburn technology with selective non-catalytic reduction. The techniques for advanced gas reburn are set forth in U.S. Pat. No. 5,139,755 (hereinafter the "'755 patent") which is incorporated by reference herein. Advanced gas reburn provides a significant incremental improvement in NO.sub.X control over conventional gas reburn and other combustion modification techniques, with only a minimal fuel efficiency penalty (approximately $600 per ton of abated NO.sub.x) (which is similar to most other NO.sub.X reduction methods using combustion modification techniques).
The advanced gas reburn process has wide application to high temperature pyroprocessing and melting operations which employ direct fired combustion and furnace equipment. Such equipment is typically used in the manufacture of glass, refractory and steel products, and high temperature hydrocarbon (cracking) processes. Best results are typically obtained where post-combustion temperatures are in the range of 2200.degree. to 2900.degree. F.
In the case of glass furnaces, recovery regenerators or recuperators are commonly used to minimize thermal energy loss. Most large glass furnaces have staged regenerators where cavities exist. In the case of retro-fit advanced gas reburn, reburn fuel and burnout air are provided in a first cavity that is connected to the melting tank. A second or additional cavity, having a preferred temperature window of between 1650.degree. and 1900.degree. F., is provided downstream of the first cavity. The selective non-catalytic reducing agent, and burnout air, are introduced in the second cavity.
It will be understood, however, that the use of advanced gas reburn will nonetheless exhibit a potentially significant fuel penalty that is associated with the introduction of reburn fuel. While regenerators may be able to recapture 50% of this thermal energy loss, the remaining energy is lost. It will be therefore be understood that what is needed in the art are methods for optimizing reburning processes to thereby reduce the aforesaid fuel penalty to a minimum and to maintain the second cavity temperature in the preferred range.
It will also be understood that high temperature process furnaces and the like operate with substantial thermal inefficiencies. It will therefore be understood that it is desirable to minimize thermal inefficiencies that are associated with high temperature combustion sources. This would serve to further minimize the overall operating costs and hence reduce the aforesaid fuel penalty that is associated with reburning processes.
Such apparatus and methods are disclosed and claimed herein and comprise a number of control processes that may be used for optimization of gas reburn technology.

Heat transfer enhancements for increasing fuel efficiency in high temperature furnaces


The present disclosure provides a method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C2+), comprising introducing methane and an oxidant (e.g., O2) into an oxidative coupling of methane (OCM) reactor. The OCM reactor reacts the methane with the oxidant to generate a first product stream comprising the C2+ compounds. The first product stream can then be directed to a separations unit that recovers at least a portion of the C2+ compounds from the first product stream to yield a second product stream comprising the at least the portion of the C2+ compounds.

The modern refining and petrochemical industry may make extensive use of fractionation technology to produce and separate various potentially desirable compounds from crude oil. The conventional fractionation technology may be energy intensive and costly to install and operate. Cryogenic distillation has been used to separate and recover hydrocarbon products in various refining and petrochemical industries.

This patent is subject to a terminal disclaimer.

Methods and systems for performing chemical separations


A switch control apparatus for controlling a switch is provided, the switch control apparatus including: a sequence memory for recording a sequence pattern, which includes open/close instruction data which instruct the switch thereon to open/close; an address control module for sequentially retrieving each of the open/close instruction data of the sequence pattern from the sequence memory; and an open/close state storage module for storing an open/close state instructed by changed open/close instruction data, when the open/close instruction data retrieved by the address control module is changed, wherein the open/close state stored by the open/close state storage module is provided to the switch such that the switch opens or closes in response to the open/close state.

1. Field of the Invention
The present invention relates to a switch control apparatus, a semiconductor testing apparatus, and a machine readable medium storing thereon a generating program. More particularly, the present invention relates to a switch control apparatus, a semiconductor testing apparatus, and a machine readable medium storing thereon a generating program for controlling timing of opening and closing a switch.
2. Description of the Related Art
A number of semiconductor switches are provided in a circuit used for a semiconductor testing apparatus. Order and timing of opening and closing the switches are predetermined and if opening and closing are conducted against the order and timing, sometimes the semiconductor testing apparatus or a semiconductor under test is broken down. For example, if a number of switches are open all at once, sometimes the semiconductor under test is damaged by spike voltage.
Therefore, conventionally, for each semiconductor switch, a technique to provide a sequence circuit which is a logic circuit for controlling timing of opening and closing of the semiconductor switch is used.
However, in case of frequently repeat of opening and closing of the switch being required, a logic circuit constituting the sequence circuit becomes complicated. Further, for every testing apparatus for performing a different testing, an exclusive sequence circuit should be prepared. Further, when it is required to maintain the position of the switch to be opened or closed for a while after a testing is started, even if it is a case where the switch same is to be controlled about the same examination, a different kind of control is sometimes required according to an open/close state predetermined before the testing is started. Thus, sometimes the sequence circuit becomes more complicated.
Accordingly, it is an object to make a program for writing sequence of instructing open or close of a switch on a sequence memory and make the contents of a testing easily changed by rewriting the sequence memory, without composing a sequence circuit by a logic circuit.

Switch control apparatus, semiconductor device test apparatus and sequence pattern generating program


A reception apparatus includes: a reception unit for receiving the scrambled content, the scrambled content being scrambled so that a predetermined unit of scrambled content is descrambled using a descrambling key corresponding to the predetermined unit of scrambled content, and at least one piece of storage information in which a list including all descrambling keys used for descrambling the scrambled content is embedded; storage unit for storing the received scrambled content and the storage information; list extraction unit for extracting the list from the stored storage information; descramble processing unit for extracting the predetermined unit of scrambled content from the stored scrambled content, extracting a descrambling key corresponding to the predetermined unit of scrambled content from the extracted list, and descrambling the extracted predetermined unit of scrambled content using the extracted descrambling key; and reproduction unit for reproducing the predetermined unit of descrambled content in the descrambled order.

(1) Field of the Invention
The present invention relates to a storage service in the digital broadcast or the like, whereby received scrambled content is stored and then descrambled as required. More specifically, the present invention relates to technology for improving performance of the service in some particular reproduction modes.
(2) Description of the Related Art
In the current pay satellite digital broadcast system, a viewer contracts with a broadcast provider to pay some amount of charges to the broadcast provider for viewing programs on selected channels.
Since a broadcasting satellite broadcasts on a number of channels, programs on the channels for which a viewer does not make subscribing contracts are also broadcast to the viewer. The receiver owned by the viewer, then, confirms the presence/absence of the subscribing contract for each channel and receives only programs on the channels allowed to be viewed. Such technology for selecting channels to receive programs thereon is called Conditional Access (abbreviated as "CA").
On the other hand, the transmitter scrambles content including audio and visual data of a pay broadcast program to be broadcast one each channel, where content per predetermined unit is scrambled with a scrambling key different for each predetermined unit of contents. The transmitter, then, sequentially transmits the scrambled content accompanied with an Entitlement Control Message (ECM) containing this scrambling key and the scrambling key for content in the successive predetermined unit. This ECM is encrypted so as to be interpreted only by the receivers owned by subscribers to the channel.
Note that the scrambling key used for scrambling data functions as a descrambling key as well for descrambling the data.
Each receiver comes with an IC card used for the receiver only, to which an identifying number associated with the subscriber is assigned. The IC card has a CPU and a memory within it to store contract conditions and software for executing CA processes. The data relating to the CA processes is completely digitized and contained in the IC card, which makes unauthorized viewing difficult and therefore provides high levels of security.
Meanwhile, the service called a "storage service" is scheduled to become operational targeted for those who have not yet subscribed to a channel so that, once storing scrambled content with ECM in the recording media in the receivers owned by them, they pay some amount of charges for viewing the content to become subscribers, which enables them to decode the ECMs so as to reproduce the stored scrambled content.
In such a service, when reproducing content in the normal reproduction mode, the receiver acquires content in the first predetermined unit, and decodes the accompanied ECM to extract the scrambling keys for content in the first and the second units. Then, the receiver descrambles the content in the first unit using the scrambling key exclusive to the content. As for the content in the second unit or later, the receiver sequentially descrambles content in each unit using the scrambling key obtained in the process for the preceding unit.
However, when reproducing content by the storage service in the particular reproduction modes such as a fast-forward reproduction mode and a fast-reverse reproduction mode, the receiver cannot descramble content in each unit using the scrambling key obtained in the process for the preceding unit, because the order of the reproduction becomes different from that in the normal reproduction mode. Therefore, the receiver has to, each time acquiring content in a predetermined unit, decode the accompanied ECM to obtain a scrambling key and descramble the scrambled content using the key, which makes it difficult to realize a sufficient performance level of the particular reproduction modes, such as fast-forward speed.

Broadcast apparatus and reception apparatus for providing a storage service by which scrambled content is stored and descrambled using scrambling key list

Matsushita Electric Industrial Co., Ltd.


An apparatus and method are disclosed that enable a private branch exchange to determine that a voice mail system has answered a call, without some of the disadvantages in the prior art. The private branch exchange—or, generally-speaking, a data-processing system—infers that the voice mail system has answered a call by timing key events or by noting some of indications that are received from another system, or both. Subsequently, the private branch exchange drops the voice mail system from the call, thereby minimizing the non-enterprise voice mail system's handling of calls that are originated to an on-premises terminal.

FIG. 1 depicts a schematic diagram of a telecommunications system in the prior art. Telecommunications system 100 comprises:                i. the Public Switched Telephone Network,        ii. private branch exchange 102,        iii. telecommunications terminals 103-1 and 103-2,        iv. telecommunications terminals 110-1 and 110-2, and        v. telecommunications terminal 111;all of which are interconnected as shown.
The Public Switched Telephone Network (i.e., element 101) is a complex of telecommunications equipment that is owned and operated by different entities throughout the World. In the United States of America, for example, the Public Switched Telephone Network (or "PSTN") comprises an address space that is defined by ten digits, and, therefore, comprises 10 billion unique addresses or "telephone numbers." The Public Switched Telephone Networks in other countries are similar.
The Public Switched Telephone Network provides telecommunications service to telecommunications terminals 110-1, 110-2, and 111. Telecommunications terminals 110-1, 110-2, and 111 can be either wireline terminals or wireless terminals, or a combination of both.
Private branch exchange 102 is capable of switching incoming calls (e.g., from terminal 111, etc.) from the Public Switched Telephone Network via one or more transmission lines to terminals 103-1 and 103-2. Private branch exchange 102 is also capable of handling outgoing calls from terminals 103-1 and 103-2 to the Public Switched Telephone Network via one or more transmission lines.
Private branch exchange 102 is capable of also extending an incoming call (e.g., from terminal 111, etc.) to a telephone number of an "off-premises" terminal in the Public Switched Telephone Network, in addition to switching the same incoming call to an "on-premises terminal" within the enterprise area (e.g., an office building, etc.) that is served by exchange 102. Terminals 103-1 and 103-2 are considered to be on-premises terminals with respect to private branch exchange 102, while terminals 110-1 and 110-2 are considered to be off-premises terminals.
To accomplish the switching of an incoming, enterprise-related call to one of on-premises terminals 103-1 and 103-2, and the extending of the call to one of off-premises terminals 110-1 and 110-2, private branch exchange 102 maintains a table that correlates the off-premises telephone number to the on-premises, private branch exchange (PBX) extension. Table 1 depicts a table that illustrates the correlation.
TABLE 1PBX Extension-to-PSTN Number DatabaseOn-PremisesTelecommunicationsPrivate BranchTelecommunicationsTerminalExchange ExtensionNetwork Number103-1732-555-0102, x11201-555-1236103-2732-555-0102, x12908-555-3381. . .. . .. . .
As an example, a caller at terminal 111 who wishes to reach the PBX user of terminal 103-1 dials the PBX number (i.e., 732-555-0102). Private branch exchange 102 receives the incoming call, including the extension number (i.e., x11). Using information stored in memory and similar to what is shown in Table 1, private branch exchange 102 determines that the call is also to be extended to off-premises telephone number 201-555-1236, associated with terminal 110-1. The off-premises number corresponds to the off-premises terminal (e.g., a cellular phone, a home phone, etc.) that belongs to the PBX user of terminal 103-1. The idea behind transmitting the call to both terminal 103-1 and 110-1 is that if the PBX user is not reachable at his office phone (i.e., terminal 103-1), then maybe he is reachable at a phone that is outside of the office (i.e., terminal 110-1).
One problem that can occur, however, is that the extended call might ultimately be routed to a voice mail system (i.e., a non-enterprise system) that is not associated with private branch exchange 102. For example, if private branch exchange 102 attempts to reach cellular terminal 110-1, the cellular voice mail system of cellular terminal 110-1 might instead answer the call. Consequently, some calls that are made to the PBX user might go to the non-enterprise voice mail system. Meanwhile, other calls that are made to the PBX user might still go to the PBX voice mail system (i.e., the enterprise system), such as when the PBX user disables the call-extending feature when the feature is not needed. It is undesirable for enterprise-related calls to end up in the non-enterprise voice mail system because it burdens the PBX user with having to retrieve voice mail from multiple systems. Also, when accessing the non-enterprise voice mail system, the PBX user is inconvenienced with having to sort out the personal calls that were made directly to the user's off-premises terminal from the enterprise-related calls that were routed from the PBX.
What is needed is a technique to minimize the handing of enterprise-related calls by non-enterprise voice mail systems, without some of the disadvantages in the prior art.

Detecting a voice mail system answering a call


Systems, methodologies, media, and other embodiments associated with color measuring are described. One exemplary system embodiment includes a spectrophotometer, one or more light sources for illuminating an interior of the spectrophotometer, and a digital camera configured at a port of the spectrophotometer and being configured to measure light components from a sample. In the present invention, segmentation logic is provided for the spectrophotometer that is configured to employ computational image segmentation to characterize specular reflection from a sample and to characterize a selected patch or portion from the test sample, such as a selected color in a multicolor pattern. In accordance with the present invention, the spectrophotometer and the included digital camera may be color-characterized in situ.

1. Field of the Invention
The present invention generally relates to color measuring devices and more specifically to systems, methods, computer-readable media, and other devices associated with measuring of color of a sample under test using a spectrophotometer or other color measuring device.
2. Description of the Related Art
A specular (mirror-path, or gloss) component of light reflecting from a material sample is often different in color from the body-reflection (perhaps matte) component. For example, in dielectric materials, the specularly-reflected light has the same relative spectrum as that of the incident illumination. Characterizing the color of a sample through a spectrophotometer (for example, an instrument based on an integrating sphere) can be designed to separate the specular from the matte component of reflection. That task is not difficult for smooth samples: Standard practice with integrating spheres simply uses a closable port that excludes or includes the light within a small incidence angle of the mirror path to the exit port of the device (the port through which the reflected light is recorded by the spectrophotometer). However, for rough samples (and particularly for textiles) such practice does not truly separate out the specular component: The specular reflection arises from elsewhere on the sphere than the specular port. Characterizing the geometry of the specular component of reflection through means other than the simple opening or closing of a hole in the integrating sphere may be useful.
A user may wish to measure the reflectance properties of a sample of material in an industrial "batch" and compare those properties with a standard sample. The "batch" may incorporate the material in a pattern (e.g., a textile pattern), whereas the standard is ensured to be calorimetrically uniform over its entire surface. A spectrophotometer can give accurate reflectance values for a sample that is spatially uniform (such as a calibrating tile). However, it is difficult to measure the reflectance spectrum of a part of a patterned material. The sample port of the spectrophotometer must be sized and shaped specifically for the part of the material specimen that is to be measured. Such adaptation may produce its own artifacts of measurement (e.g., depth of the mask next to the small area reduces the illumination to that area).
An integrating-sphere spectrophotometer can have several automatic mechanisms that determine the aperture of the sample port, whether the sample port door is open or closed, and the position of the sample. All these mechanisms are quite expensive in current implementations. Also, the spectrophotometer by itself does not allow viewing and adjustment of the sample once the sample is readied for measurement.


A method for target device discovery on a network is disclosed. The method includes multicasting a signal from a master initiator over the network. A unicast is received from a new target recently connected to the network where the new target is passive when no multicast signal from the master initiator is received. Then the new target is added to a list of targets connected to the network. The method concludes by sending out a next multicast to other initiators where the next multicast includes information regarding the adding of the new target to the network.

1. Field of the Invention
This invention relates generally to data communication, and more particularly to protocols for efficiently identifying peripheral devices on a network while reducing data congestion and decreasing device recognition time on the network.
2. Description of the Related Art
The art of networking computers has evolved over the years to bring computer users a rich communication and data sharing experience. Typically, in a network, numerous devices may be connected to a computer to maximize computing power and efficiency. As is well known, new levels of sophisticated communication technologies enable users to share information across both large and small networks. Most of the world's computers communicate via computer networks by communicating data from one node to another node utilizing various data transport protocols. One typical type of protocol utilizing networks for data transmission is TCP/IP. TCP/IP is a set of protocols developed to allow cooperating computers to share resources across a network. TCP (the "transmission control protocol") is responsible for breaking up a message into variable length segments, reassembling them at the other end, resending anything that gets lost, and putting things back in the right order. IP (the "internet protocol") is responsible for routing individual segments. Utilizing such protocols as IP, computer networks may transfer data from one node to another.
As a high level overview, take an exemplary data file that is selected for communication over a network using the TCP protocol. Initially, the TCP protocol will break up the data file into a plurality of variable length segments. Each variable length segment is then packaged with an associated TCP header. An IP header will also be added to the beginning of the packet. The packets are now transmitted over the network, where each packet may potentially travel a different path (e.g., through a plurality of routers and the like) in their journey to a destination. At the destination, the TCP protocol is charged with receiving the packets.
For example, TCP/IP may be utilized in a data storage network for the sending and receiving of data with a SCSI host adapter and a typical NIC. To do this, network interface cards (NICs) with initiators are often utilized to communicate data and peripheral device information throughout the network. NICs may generally connect a computer or other type of node to a network. NICs are typically a circuit, an ASIC, or a host adaptor card that are often utilized in Ethernet or token ring networks. Initiators generally are located within a NIC and originates an input/output command over a network, bus, etc.
Unlike general communication networks, which assume that all attached devices are peers and that any given device will want to communicate with only a small subset of other devices, storage networks are hierarchical, with a few initiators in communication with many targets, and with targets in communication only with initiators, or with other targets under the control of an initiator. Typically, this storage viewpoint requires that initiators be able to locate all the targets, and be able to communicate with many or all of them.
Problematically, present methods to manage and determine the peripheral devices connected to the network have high data transmission overhead and often requires an additional directory agent to keep track of all of the peripheral devices. In addition, frequent use of broadcasting in the prior art can cause congestion in switch based networks. Typically large networks have many targets and numerous initiators. In addition, large networks have a directory that is generally set up by network administrators. Large networks also generally require a network administrator to assign IP addresses to devices on the network so a directory agent may keep track of them. Furthermore, in the process of setting up directories, network administrators must often decide on the scope of each directory such as geographic extent or types of devices. In such a configuration, targets may register their existence and addresses with the directory agent, and initiators or hosts may then communicate with the directory agent and poll all of the targets to determine the existence of every peripheral device connected to the network. Therefore, every initiator generally polls all directory agents at certain intervals to determine the target connection. This arrangement can cause data transfer congestion. Unfortunately frequent polling generally occurs in an attempt to obtain quick discovery of targets, but the resulting network congestion can create the degradation of target discovery and reduction in the speed of target recognition due to packet dropping. Consequently, polling occasionally means new devices take a long time to be "found" by the initiators.
For example, although new targets will often broadcast a signal to state to the network that it exists and is connected to the network, if a directory is present, as is usually the case in large networks, the directory registers the device and it will only broadcast once. This may be good for bandwidth, but also means that some initiators may not "see" the target's broadcast (dropped packets) so even if they are listening for such broadcasts to find out if a new target has joined the network, they tend to miss its joining and will not find out till they are polled. Therefore, target recognition speed may be severely hampered, and in some circumstances, target recognition may not occur.
Unfortunately, in small networks, directory agents are generally not utilized so all of the initiators on the network tend to poll extremely often so they can find all of the targets on the network. Regrettably, such numerous pollings create excess data traffic on the network and therefore decrease available bandwidth. Furthermore, targets themselves attempt to broadcast that they are connected onto the network thereby increasing data congestion even more. In addition, because small networks typically do not have a network administrator who can perform tasks such as, for example, assigning IP addresses to targets, such networks do not generally operate in a centralized and organized manner because there is no entity to assist in the organization and centralization of network connections and configurations. Even medium size systems tend to need directories to keep the initiator polling overhead from getting too large which entails once again to have a network administrator to look over the network.
For example, at startup of a small network, initiators typically broadcasts a query of all of the targets to determine what devices may be connected to the network. At the same time, targets may broadcast signals throughout the network in an attempt to notify initiators of their existence. In such a configuration, initiators generally broadcasts signals to communicate with the targets. Once again, this creates excess data transmissions and network congestion. Therefore, in typical peripheral device discovery, the network becomes congested with the initiators and targets all trying to communicate to each other without any sort of organization. In essence, initiators and targets are involved in a "free for all" in an attempt to communicate with each other. This results in excessive data transmission and dramatically lowers the network's ability to transmit data.
Furthermore, when a new target such as a peripheral device is added to a network, the peripheral device generally sends a broadcast signal throughout the network indicating that the peripheral device is connected to the network. By the broadcast signal, the peripheral device communicates its existence to all of the initiators located on the network. Unfortunately, in a typical network, when a target such as a peripheral de ice is attached, the signal broadcasted throughout the network creates data traffic within the network thus slowing down data being transferred between the other peripheral devices and an initiator. This problem becomes progressively worse as multiple targets are added to the network. In addition, broadcasts may not reach all of the initiators due to congestion caused packet drops. Thus, some initiators may not find out about the new devices for quite some time thus detrimentally contributing to lengthened device recognition times.
In view of the foregoing, there is a need for a target discovery and management protocol that removes the data congestion produced by prior art device discovery protocols. There is also a need for an initiator recognition protocol that is optimized for storage and enables fast and efficient utilization in local area networks, wide area networks, and over the Internet.

Device discovery methods and systems implementing the same


A panorama display application shows objects from a spreadsheet such as charts in primary screen of a mobile device adjoined by left and right virtual screens. The application overlays interaction controls such as sort and filter functions on the object. The application also provides additional interaction controls for the object on the left virtual screen and associated objects links on the right virtual screen. The application may expose the additional interaction controls and the associated objects links by overlaying portions of the virtual screens on the primary screen. The application fluidly shifts content from virtual screens to the primary screen subsequent to detected user action on the overlaid portions.

Computer applications interact with human beings through user interfaces. While audio, tactile, and similar forms of user interfaces are available, visual user interfaces through a display device are the most common form of user interface. With the development of faster and smaller electronics for computing devices, smaller size devices such as handheld computers, smart phones, tablet devices, and comparable devices have become common. Such devices execute a wide variety of applications ranging from communication applications to complicated analysis tools. Many such applications render visual effects through a display and enable users to provide input associated with the applications' operations.
Screen size and utilization are ongoing concerns in mobile device platforms. Screen sizes in mobile devices are limited due to minimalist approach most modern solutions provide to fulfill customer demand. There is substantial technical challenge to providing a display capable of desktop computer resolutions in a mobile device. Even when feasible, providing a desktop computer resolution in a mobile device leads to tiny fonts and diminished usability. Duplicating most features of a desktop application including controls and fine details of a displayed object is a great challenge to surmount. Most modern solutions provide mobile applications with diminished features compared to desktop counterparts. Other solutions try to fit large desktop based menu structures into smaller screen size of mobile devices with diminished returns on usability.

Managing objects in panorama display to navigate spreadsheet