An introducer assembly includes a valve having a first end and an opposite second end; a sheath fixedly secured to and extending axially from one of the first and second ends of the valve; a dilator extending through the valve and sheath; and a lock knob rotatable between locked and unlocked positions to releasably axially lock the tool relative to the sheath without causing corresponding rotation of the tool therewith.

Field
The invention relates to an introducer sheath assembly for medical procedures and, more particularly, a locking mechanism for releasably axially locking an introducer sheath and a surgical implement inserted through the introducer sheath.
Discussion
Introducer sheath assemblies are used in a wide variety of minimally invasive and conventional surgical procedures, such as endoluminal delivery of surgical implements. Introducer sheath assemblies typically include an introducer sheath and valve for controlling leakage while accessing the introducer sheath with surgical implements, such as endoprosthetic devices, dilators, guidewires and the like. Introducer sheath valves generally rely on contact between a resilient elastomeric sealing body and a surgical implement inserted through the introducer sheath valve to form a desired fluid tight seal. It remains desirable to provide a mechanism for locking an introducer sheath and surgical implement without disrupting the seal between the introducer sheath valve and surgical implement.

Introducer sheath assembly having a locking dilator


A technique is presented for minimizing crosstalk between adjacent differential signal pairs in communications. A backplane embodiment wherein the backplane includes a plurality of differential signal line pairs, is presented. A first differential signal line pair can include a first differential signal line and a second differential signal line. The backplane can have the first differential signal line connected between first and second vias. The second differential signal line can be connected between third and fourth vias. A third signal line can be connected between fifth and sixth vias. The first via can be spatially adjacent to the fifth via such that a signal on the third signal line is coupled to the first differential signal line and the fourth via can be spatially located adjacent to the sixth via such that a signal on the third signal line is coupled to the second differential signal line.

This invention relates to systems and techniques that are used to enhance the performance of data communication systems employing differential signaling techniques; and more particularly, in one aspect, to enhance the performance of data communication systems, using differential signaling, implemented in wired type environments such as microstrip, stripline, printed circuit board (for example, a backplane), and integrated circuit (IC) package.
Communications systems are continuing to increase the rate at which data is transmitted between devices. The increase in data rate presents a challenge to maintain, enhance or optimize the ability to recover the transmitted signal and thereby the information contained therein. In general, increasing the rate of transfer of data tends to adversely impact the fidelity of the communications.
In the context of communications systems employing differential signaling, the layout of the signal path in, for example, a backplane or printed circuit board environment, may impact the ability of the receiver to recover the transmitted information. Conventional systems tend to layout the signal paths of differential signal pairs in a manner that minimizes or eliminates skew (relative time delay) between the differential signal pair. As such, conventional systems tend to layout signal paths so that differential signal pairs are transmitted on paths having the shortest and equal lengths. In this way, the contribution to skew (of a differential signal pair) as a result of the signal path layout in a backplane or printed circuit board environment is minimized or substantially eliminated.
For example, with reference to FIGS. 1 and 2A,2B, 2C, a conventional data communications system typically includes a layout or routing of differential signal pair 2 such that signal paths 4 and 4′ are equal (and the shortest) lengths. Similarly, differential signal pair 6 may be transmitted on signal paths 8 and 8′, which are also equal in length. As such, the layout of the signal paths is unlikely to introduce additional skew between the respective signal pairs 2 and 6. (See, for example, U.S. Pat. Nos. 6,249,544 and 6,252,904). This is significant because the receiver employs the difference between the signals of the differential signal pairs, sampled at a particular time, in order to recover the transmitted information.
While conventional systems avoid certain debilitating affects on the fidelity of the differential signal as a result of skew between the differential signal pair, such systems tend to experience significant coupling or crosstalk from adjacent signals (for example, inductive and/or capacitive coupling) which adversely impacts the ability of the receiver to recover the transmitted information. For example, with continued reference to FIG. 1, the signal transmitted on signal path 4 is likely to experience cross coupling, at the vias or connector pins, between the signal on signal path 8. Similarly, the signal transmitted on signal path 4′ is likely to experience cross coupling, at the vias or pins, between the signal on signal path 8′.
Conventional systems often address such crosstalk using circuitry, additional insulation materials to "shield" the signals, and/or intricate layout techniques. (See, for example, U.S. Pat. Nos. 6,266,730, 6,420,778, 6,449,308, and 6,570,944 and U.S. Patent Application Publication 2003/014375). Such conventional crosstalk reduction techniques may be quite complicated to implement as well as expensive. In this regard, systems that employ crosstalk reduction circuitry tend to consume power and space/area, for example, on the die or printed circuit board. Further, conventional systems that employ additional materials to "shield" the signals and/or complicated layout techniques are often expensive, and/or the layout techniques may be quite complicated and susceptible to manufacturing tolerances, which are often quite strict.
There is a need for a system and technique that overcomes the shortcomings of one, some or all of conventional systems. In this regard, there is a need for an improved crosstalk reduction or management technique that is less complicated and expensive than conventional circuitry and techniques and that overcomes one, some or all of the shortcomings of conventional systems.

Crosstalk reduction for a system of differential line pairs


A method for implementing visualization of public welfare activities includes: displaying to a target user a map of a geographic region for carrying out a public welfare activity in response to the target user's selection, wherein the map comprises a first geographic location associated with a first icon indicating that the public welfare activity has been carried out at the first geographic location and a second geographic location associated with a second icon indicating that the public welfare activity is able to be carried out at the second geographic location; when a relationship exists between the target user and a public welfare activity participant user that has carried out the public welfare activity on the map, displaying on the map user information of the public welfare activity participant user; updating the second icon to be a first icon in response to the target user's selection on the second icon.

With the rapid development of Internet technologies, more and more public welfare activities have been carried out through the Internet. In addition to carrying out public welfare behavior to help others and the society, online public welfare activities may further help public welfare activity initiators to garner users and increase user traffic.
However, existing technologies enabling users to carry out online public welfare activities provide a relatively poor sense of reality, and users often cannot truly feel that they have participated in public welfare activities. Therefore, it is desirable to provide a more effective solution enabling users to carry out online public welfare activities with a stronger sense of reality.

Method and apparatus for visualization of public welfare activities


An apparatus for inserting an expander ring into an inner circumferential groove of a split piston ring includes a first magazine for storing a stack of piston rings; and a second magazine for storing a stack of expander rings. The second magazine has a discharge end and a longitudinal axis coinciding with a longitudinal axis of the expander ring stack. There are further provided a device for displacing a piston ring from the first magazine into axial alignment with the longitudinal axis of the second magazine at the discharge end thereof; a spreader device for radially outwardly spreading the piston ring positioned at the discharge end; and a pusher for pushing an expander ring from the second magazine parallel to the longitudinal axis into the piston ring spread-open by the spreader device.

This invention relates to an apparatus for the automatic installation of expander rings into a circumferential ring groove of split piston rings, particularly oil scraping piston rings. The piston rings and the expander rings are stored in separate magazines and may be dispensed individually therefrom.
The preparation of piston rings requires a significant number of different, mutually coordinated processes. In case of large numbers of piston rings to be prepared, the output is dependent from the working speed of the individual processes. For treating the running faces, the piston rings are, for example, polished in a polishing (lapping) sleeve. The discontinuous piston ring exerts a radially outwardly directed force so that it engages the inner circumferential surface of the polishing sleeve with a defined inherent stress which depends from the ring geometry. Based on such a geometry, in some piston rings the inherent stress is insufficient for providing a satisfactory treatment of the running faces. For this reason, in piston rings having only a slight inherent stress, expander rings are inserted into the inner ring groove. Since such a process is conventionally performed manually, the manufacturing costs are very significantly increased.
German Offenlegungsschrift (application published without examination) 24 40 996 discloses an apparatus for installing split safety rings into ring grooves of cylindrical workpieces. The safety rings to be installed are stored in a stacked state in a magazine and are individually ejected therefrom for insertion on a spreader mandrel. The installation of spreader rings into piston rings, however, cannot be performed with such an apparatus.

Apparatus for the automatic installation of expander rings into split piston rings


A power supplying apparatus is disclosed, in which an under voltage lock out function is not performed for instantaneous voltage dip even in case that a reference under voltage detection voltage is set at high level. The power supplying apparatus comprises an under voltage detector generating an under voltage lock out signal by detecting voltage dip of an input power and performing an under voltage protection function, wherein the under voltage detector delays the input power for a delay time, which is set, to generate the under voltage lock out signal.

1. Field of the Invention
The present invention relates to a power supplying apparatus and a display apparatus including the same.
2. Discussion of the Related Art
Generally, a power supplying apparatus rectifies an alternating current voltage and converts the alternating current voltage to a direct current voltage, or provides a direct current voltage required for various apparatuses (for example, display device and light emitting diode) by boosting or decompressing an alternating current voltage to a direct current voltage.
FIG. 1 is a diagram illustrating a power supplying apparatus of the related art.
Referring to FIG. 1, the power supplying apparatus of the related art includes a direct current-to-direct current converter 10, an under voltage detector 20, and a switching controller 30.
The direct current-to-direct current converter 10 converts an input power Vin to a direct current voltage and outputs the converted voltage. The direct current-to-direct current converter 10 includes an inductor L, a diode D, a switching element Psw, and a capacitor C. The direct current-to-direct current converter 10 converts the input power Vin to the direct current voltage in accordance with switching of the switching element Psw based on a pulse width modulation signal SPWM supplied from the switching controller 30. In other words, if the switching element Psw is turned on, a current flows to the inductor L by means of the input power Vin, whereby energy is accumulated in the inductor L. If the switching element Psw is turned off, the energy accumulated in the inductor L is added to the input power Vin, is rectified by the diode D, and is planarized by the capacitor C, whereby the energy is output as an output voltage Vout.
The under voltage detector 20, as shown in FIG. 2, generates an under voltage lock out signal UVLO of a high state and supplies the generated under voltage lock out signal to the switching controller 30 only if the voltage of the input power Vin is less than a reference under voltage detection voltage Vref_UVLO, thereby preventing a circuit, to which the input power Vin is supplied, from being operated in error.
The switching controller 30 generates a pulse width modulation signal SPWM by receiving the output voltage Vout fed back from the direct current-to-direct current converter 10, and uniformly controls the output voltage Vout of the direct current-to-direct current converter 10 by using the pulse width modulation signal SPWM only if the under voltage lock out UVLO signal of low state is supplied from the under voltage detector 20.
Meanwhile, according to the power supplying apparatus of the related art, if load is increased instantaneously and instantaneous voltage dip of the input power Vin occurs during inrush current, the under voltage lock out UVLO signal of high state is generated by the under voltage detector 20, whereby the under voltage lock out function may be performed. In order to prevent the circuit, to which the input power Vin is supplied, from being operated in error, during abnormal voltage dip of the input power Vin, the under voltage lock out function should be performed. However, in the display apparatus, etc., it may be preferable for stable operation that instantaneous voltage dip of the input power Vin is disregarded.
In this respect, in the power supplying apparatus applied to the display apparatus, the reference under voltage detection voltage Vref_UVLO is lowered so that the under voltage lock out function may not be performed during instantaneous voltage dip of the input power Vin, whereby the voltage range of the input power Vin is increased.
However, if the reference under voltage detection voltage Vref_UVLO for the under voltage lock out function is lowered to increase the voltage range of the input power Vin, the input current needs to be increased as the input power Vin is lowered. For this reason, as shown in FIG. 3, since the input current of each of the switching element Psw, the inductor L and the diode D is increased in accordance with the change of the input power Vin, a problem occurs in that a chip size of the integrated circuit IC is increased and current rating of each of the switching element Psw, the inductor L and the diode D should be enhanced. In order to solve this problem, if the reference under voltage detection voltage Vref_UVLO for the under voltage lock out function is increased, the under voltage lock out function is performed even in case of instantaneous voltage dip.
Accordingly, it is required that the under voltage lock out function should not be performed for instantaneous voltage dip even in case that the reference under voltage detection voltage Vref_UVLO is set at high level.

Power supplying apparatus and display apparatus including the same


A speed transferring system includes an input shaft having a first input gear and a second input gear, a middle shaft having a slidable engaging member which includes a first middle gear, a second middle gear and a third middle gear. The first, second and third middle gears are connected with each other. An output shaft has a first output gear and a second output gear. A shaft driven by a motor has a shifting device which retains the first middle gear so as to alternately engage the engaging member with the first input gear, the second input gear, the first output gear and the second output gear.

1. Field of the Invention
The present invention relates to speed transferring system and, more particularly, to an improved speed transferring system for a lathe with stopping a driving engine of the lathe.
2. Brief Description of the Prior Art
Lathes include two main types, one of which includes a conventional driving motor driving a shaft which has a chuck disposed to the shaft, and the other of which includes a servo motor to drive the shaft. When changing speed levels of the lathe, the driving motor of the former type has to be stop so as to completely stop the shaft and then ped control rods are shifted to change gears arrangements in a gear box connected to the driving motor such that when restarting the driving motor, the shaft will rotate at a desired speed. The servo motor of the latter type does not need to be stopped when changing the speed levels. However, an output of the servo motor is transmitted by belts so that it cannot produce a large torque. In addition, the servo motor is very expensive. Therefore, changing the speed levels of the former type of the lathe takes a lot of time and the latter type of the lathe costs too much and produces only a small torque.
The present invention intends to provide an improved speed transferring system for a lathe to mitigate and/or obviate the above-mentioned problems.


A conditional e-coupon distribution method distributes e-coupon predefined by sellers to mobile users only if the number of mobile users requesting such e-coupons equals or exceeds a threshold. The method receives a request to browse e-coupons from a mobile user. The method receives the location of the mobile user and determines a plurality of sellers local to the mobile electronic device and a plurality of corresponding e-coupons available from the local sellers. The method receives a request for a particular e-coupon from a seller and authorizes the provision of said e-coupon to the mobile user. At the end of a processing cycle, the mobile user receives the requested e-coupon if all conditions, such as a period of time and threshold, have been met. A computer-usable medium having computer-readable program code embodied therein allows for storage of the method.

Today, there exist a few techniques for distribution of electronic coupons (e-coupons) to potential customers. A seller of a service or product can distribute mass email messages with e-coupons attached to or within the message. The seller then hopes that at least some of the potential customers who receive the messages will redeem the e-coupons included. Additionally, a seller can post an e-coupon on a web site, whether or not owned by the seller, and hope that a potential customer will see the e-coupon and choose to redeem it. Similar techniques exist for targeted distribution of coupons to attract potential customers who live local to a seller. For example, local restaurants or stores can attempt to attract customers on web pages local to a particular city. A city newspaper may have a website and these local sellers can post e-coupons on the site with the same hope of a customer seeing the e-coupon and choosing to redeem it.
Yet these and other techniques tend to be expensive to sellers and highly inefficient in attracting potential customers. The mass emails and e-coupon distribution carry a fixed cost based upon a hope that a potential customer exists. A seller must pay the website provider in order to put its e-coupons on the website, without any assurance at all that the e-coupons will be requested and redeemed by customers. Even existing location-aware wireless targeted advertising methods have a cost to transmit an advertisement when a mobile customer is around a particular store. A need exists to allow for distribution of an e-coupon when a desired profit margin for the seller has been statistically guaranteed.
Generally, potential customers choose a particular type of service or product and then seek to find the service or product based upon some need, whether such need is based on cost, ease of acquisition, location, or some other factor. Customer service can be enhanced if an e-coupon service were provided based upon an initial inquiry from the customer. In such an example, a seller has a substantially increased opportunity to ensure that an e-coupon is redeemed because the customer initiates the desire for the e-coupon rather than a random e-coupon being sent to a customer.
However, a seller needs additional safeguards to ensure that distributed e-coupons will be redeemed not only at a high probability, but also at an economic advantage to the seller. A seller wants to issue e-coupons so that a larger number of potential customers will redeem the e-coupons, because the seller has no economic incentive when one or a few customers actually redeem the e-coupons. Additionally, a seller needs to ensure that the distribution of e-coupons does not become economically ineffective by continually distributing e-coupons that are not redeemed.
In addition to business concerns, there are privacy concerns and technical issues often left unresolved in wireless targeted advertising and distribution systems. Privacy concerns have emerged from FCC requirements that wireless service providers must be able to identify the locations of cellular phone users making emergency calls after Oct. 1, 2001. The concern stems from the worry that wireless service providers will turn the FCC requirement into a source of profit. In particular, the wireless service providers could release the location information of mobile users to anyone wiling to pay for such information, including individuals or others who will mishandle this information.
Technical issues also exist from the standpoint of wireless service providers. In order for a participating seller to send a targeted advertisement to mobile users at a right time and in a right place, the location information of the mobile users must be accurate and monitored closely. To do so, all mobile devices must frequently send location data to the network, and thus cause significant uplink signaling traffic that may eventually overflow the network. The situation could get even worse if the location identification methods are network-based or network-assisted because they consume significant computing resources from the network.
Therefore, a need exists to allow for distribution of e-coupons to potential customers based upon an initial desire from the customer and an assurance for a seller to make extra profits in a statistical sense. Privacy concerns and technical issues also need to be addressed in order to promote location-aware mobile commerce in an optimal manner.

This patent is subject to a terminal disclaimer.

E-coupon service for location-aware mobile commerce which determines whether to supply requested e-coupons based on the number of requests received in a processing cycle, and a threshold number of requests required to make expected returns from redeemed coupons greater than advertising fees


A lens sheet, transmission screen, and a rear projection display are provided. The lens sheet includes fly-eye lens elements periodically arranged on one side of a transparent base, wherein the lens elements are composed of a UV-curing type resin, and the storage elastic modulus at a reference temperature of 25° C. and a frequency of 1031 6 Hz, in a master curve obtained from measurement of dynamic viscoelasticity of the resin, ranges from 1×107 Pa to 1×109 Pa.

The present application relates to a lens sheet which is preferable for use as, for example, a transmission type screen for a rear projection television set, to a transmission type screen using the lens sheet, and to a rear projection type display using the transmission type screen.
In recent years, there has been a rapid spread of rear projection television sets (rear projection type displays) in which picture light modulated by a liquid crystal display, a digital mirror device or the like is displayed by projecting onto a transmission type screen while being enlarged by projection means such as a projection lens. In use of the rear projection television set, the picture light is transmitted through a screen to form an image in the vicinity of the front surface of the screen, and the image-forming picture light is recognized by a viewer from the front side of the system.
The transmission type screen for the rear projection television set has two sheet-like members which are disposed proximate to each other, with an appropriate spacing therebetween. One of the sheet-like members is a lenticular lens sheet having a lens array on the rear side thereof, and the other is a Fresnel lens which is formed with a Fresnel lens on the front side thereof and disposed to face the rear side (lens-formed surface) of the lenticular lens sheet.
The lenticular lens sheet has a structure in which a lens layer formed of a UV-curing type resin is laminated on a transparent plastic base of polyethylene terephthalate or the like. On the other hand, the Fresnel lens sheet is generally composed of a glass or an injection molded body of a transparent synthetic resin material such as an acrylic resin, a polycarbonate resin, etc.
Meanwhile, in the rear projection television screen, if the spacing between the two sheet-like members is too large, the formed image would be blurred to be a double image, and the picture would be distorted or become obscure. Therefore, it is ideal that the lenses of the sheet-like members are in contact with each other at central portions thereof.
In view of this, one or both of the sheet-like members, for example the lenticular lens sheet is preliminarily formed in a cambered state. The lenticular lens sheet in the cambered state is laid on the Fresnel lens sheet serving as the other sheet-like member, then a pressure is so exerted that the peripheral edge portions of the lenticular lens sheet is laid just on the peripheral edge portions of the Fresnel lens sheet, and the peripheral edge portions of both the sheets are fixed. With the peripheral edge portions of both the sheet-like members fixed integrally, the spacing between the lenticular lens sheet and the Fresnel lens sheet can be prevented from being too large.
However, the pressing of the lens-formed surfaces of the lenticular lens sheet and the Fresnel lens sheet against each other may lead to deformation of the lens elements on the lenticular lens sheet side. The deformation of the lens elements, if occurred, would lead to a change or changes in optical characteristics, whereby the optical path of the outgoing light may be changed, the image formed may be blurred, and the picture may be distorted or become obscure.
Besides, even in the case where the contact pressure between the lens elements is not so strong as to cause deformation of the lenticular lens sheet, upon a situation where vibration is continuingly applied to the system, as for example during transportation, the induced contact between the lens elements may cause friction and marring on the surface of the lenticular lens sheet, and the image displayed may be turned into a double or triple image due to the mars.
In order to solve such a problem, there have been made various proposals as to improvements in the resin composition constituting the lenticular lens sheet. It has been found, however, that the performances obtained according to the proposals are insufficient for the performance required of the fly-eye lens (one of lenticular lenses) attracting attention in recent years.
To be more specific, Japanese Patent Laid-open No. 2005-49795 describes a lens sheet composed of a thermoplastic resin wherein universal hardness, compressive modulus, and dissipation factor are specified. However, since a thermoplastic resin is used, this configuration is unsatisfactory from the viewpoint of precise shape reproduction and thermal strain. Besides, in Japanese Patent Laid-open No. 2003-313445 and JP-A-2005-503578, a resin composition for an optical element is disclosed which has a specified creep deformation coefficient and a specified compressive modulus. However, these indices have been unsatisfactory in terms of correspondence with the deformation in the case where a low level of pressure is exerted for a long period of time.
On the other hand, Japanese Patent Laid-open No. 2003-84101 discloses a technique of determining the relationship between the dissipation factor of a resin composition and temperature and specifying a range of peak width. However, this is also insufficient in terms of correspondence with the deformation in the case where a low level of pressure is applied for a long period of time. Further, Japanese Patent Laid-open No. 2001-228549 discloses a lens sheet which has a specified dissipation factor of dynamic viscoelasticity and a specified coefficient of dynamic friction. However, these indices pertain to frictional wear, and it is impossible to define the correspondence thereof with the deformation in the case where a low level of pressure is exerted for a long period of time.
In the case of a cylindrical lens conventionally used as a lenticular lens, the portions of contact thereof with a Fresnel lens are a plurality of line form portions. On the other hand, in the case of a fly-eye lens, the portions of contact are a plurality of spot form contact portions, and the area of contact is smaller. Therefore, the pressure exerted on the lens element is greater in the case of the fly-eye lens than in the case of the cylindrical lens. Accordingly, the pressure resistance and mar resistance performances required of a fly-eye lens are higher than those required of a cylindrical lens. However, it has been found as a result of the present inventors' research that the physical properties disclosed in Patent Documents described above cannot insure long-term properties as well as short-term properties.

Lens sheet, transmission type screen, and rear projection type display


A rotating vacuum heat treatment equipment, applicable for heat treatment of rare earth permanent magnetic devices, hydrogen pulverization of rare earth permanent magnetic alloy, and heat treatment of mechanical electronic components, mainly comprises: a vacuum unit, a gas cooling device, and a vacuum furnace, wherein an insulating layer is provided in the vacuum furnace, a heater is provided in the insulating layer, a rotating cylinder is provided in the heater, a nozzle, connected with pipelines of the gas cooling device, is provided on the insulating layer, and cooled gas is sprayed to the rotating cylinder via the nozzle.

1. Field of Invention
The present invention belongs to a field of mechanical equipment, and especially relates to a field of rotating vacuum heat treatment equipments, which are applied in heat treatment of neodymium-iron-boronrare earth permanent magnetic devices, hydrogen pulverization of neodymium-iron-boronrare earth permanent magnetic alloy, heat treatment of small-sized mechanical electronic components.
2. Description of Related Arts
A neodymium-iron-boron rare earth permanent magnetic device has alloy comprising R, Fe, B, and M, wherein R refers to one or more rare earth elements,
Fe refers to element Fe,
B refers to element B,
M refers to one or more elements selected from the element group consisting of Al, Co, Nb, Ga, Zr, Cu, V, Ti, Cr, Ni, and Hf.
A method for producing the neodymium-iron-boron rare earth permanent magnetic device is as follows.
1. Alloy Smelting Process
Smelting method of the alloys comprises an ingot casting process, which comprises heating raw materials of the neodymium-iron-boron rare earth permanent magnetic alloy to be an alloy in a molten state under a condition of vacuum or protective atmosphere; and then pouring the alloy in the molten state into a water-cooled mould under the condition of vacuum or protective atmosphere to form an alloy ingot. Preferably, the ingot casting process comprises moving or rotating a mould while pouring, in such a manner that an ingot thickness is 1˜20 mm. Preferably, an alloy smelting method comprises a strip casting process, which comprises heating and melting an alloy, and pouring the molten alloy on a rotating roller with a water cooling device via a tundish, wherein the molten alloy becomes an alloy slice after cooled by the rotating roller, a cooling speed of the rotating roller is 100-1000° C./S, and a temperature of the cooled alloy slice is 550-400° C. Preferably, the alloy smelting method comprises cooling the alloy slice again by collecting the alloy slice with a rotating cylinder after the alloy slice leaves a rotating copper roller. Preferably, the alloy smelting method comprises cooling the alloy slice again by collecting the alloy slice with a turntable after the alloy slice leaves a rotating copper roller, wherein the turntable is below the copper roller, and an inert gas cooling device with a heat exchanger and a mechanical stirring device are provided above the turntable. Preferably, the alloy smelting method comprises preserving heat of the alloy slice by a secondary cooling device after the alloy slice leaves the rotating copper roller and before the alloy slice is cooled again, wherein a period of heat preserving is 10˜120 min, and a temperature of heat preserving is 550˜400° C.
2. Coarsely Pulverization Process
Coarsely pulverizing method of the alloy mainly comprises two methods, i.e., mechanical pulverization and hydrogen pulverization. The mechanical pulverization comprises pulverizing the alloy ingot smelted into particles having a grain diameter less than 5 mm with a pulverizing equipment, such as jaw crusher, hammer crusher, ball mill, rod mill, and disc mill, under a protection of nitrogen. Generally, the alloy slice is not pulverized by the jaw crusher and the hammer crusher. Coarseparticles obtained by a previous process are directly milled into fine particles having a grain diameter less than 5 mm by the pulverizing equipment, such as the ball mill, the rod mill, and the disc mill under the protection of nitrogen.
Another producing method of this process is hydrogen pulverization, which comprises: displacing the alloy slice or the alloy ingot obtained by the previous process into a vacuum hydrogen pulverization furnace, which is evacuated and filled with hydrogen, in such a manner that the alloy in the vacuum hydrogen pulverization furnace absorbs the hydrogen, wherein a temperature of hydrogen adsorption is usually less than 200° C., and a pressure of hydrogen adsorption is usually 50˜200 KPa; after absorbing the hydrogen, evacuating the vacuum hydrogen pulverization furnace again and heating the vacuum hydrogen pulverization furnace to dehydrogenate the alloy, wherein a temperature of dehydrogenation is usually 600˜900° C.; and cooling the particles after dehydrogenation, under the condition of vacuum or protective atmosphere, wherein the protective atmosphere is embodied as an argon protective atmosphere.
Preferably, the hydrogen pulverization method comprises: displacing the alloy ingot or the alloy slice into the rotating cylinder, which is evacuated and then filled with hydrogen, in such a manner that the alloy absorbs the hydrogen; stopping filling the rotating cylinder with hydrogen until the alloy is saturated with hydrogen; keeping the state for more than 10 minutes; evacuating the rotating cylinder, then heating the rotating cylinder while rotating the rotating cylinder to dehydrogenate the alloy under the condition of vacuum, wherein the temperature of dehydrogenation is usually 600˜900° C.; and cooling the rotating cylinder after dehydrogenation.
Preferably, the hydrogen pulverization method relates to a method for producing rare earth permanent magnetic alloy continuously and its equipment. The equipment comprises a hydrogen adsorption chamber, a heating dehydrogenation chamber, a cooling chamber, chamber-isolating valves, a charging basket, a transmission device, a evacuating device; wherein the hydrogen adsorption chamber, the heating dehydrogenation chamber and the cooling chamber are respectively connected via the chamber-isolating valves, the transmission device is provided in upper portions of the hydrogen adsorption chamber, the heating dehydrogenation chamber and the cooling chamber, the charging basket is hanged on the transmission device, materials in the charging basket is transported into the hydrogen adsorption chamber, the heating dehydrogenation chamber and the cooling chamber in turn along the transmission device. When the equipment is working, the alloy ingot or the alloy slice is fed in the charging basket hanged on the transmission device, and the charging basket carrying the alloy ingot and the alloy slice is transported to the hydrogen adsorption chamber, the heating dehydrogenation chamber and the cooling chamber in turn, in such a manner that the alloy ingot and the alloy slice is processed with hydrogen adsorption, heating and dehydrogenation, and cooling in turn. Then the alloy is stored in a storage drum under the condition of vacuum or protective atmosphere.
3. Milling Process
A method for producing alloy powder comprises milling by a jet mill. The jet mill comprises: a feeder; a milling chamber, wherein a nozzle is provided in a lower portion thereof, and a sorting wheel is provided in an upper portion thereof; a weighing system for controlling a powder weight and a feeding speed in the milling chamber; a cyclone collector; a powder filter; and a gas compressor. Working gas is embodied as nitrogen, and a pressure of compressed gas is 0.6˜0.8 MPa. When the jet mill is working, the powder obtained by the previous process is fed into the feeder of the jet mill firstly. The powder is added into the milling chamber under controlling of the weighing system. The powder is grinded by high-speed airflow sprayed by the nozzle. The powder grinded rises with the airflow. The powder meeting a milling requirement enters into the cyclone collector to be collected via the sorting wheel, and the coarse powder not meeting the milling requirement goes back to the lower portion of the milling chamber, under an effect of centrifugal force, to be grinded again. The powder entering into the cyclone collector is collected in a material collector in a lower portion of the cyclone collector as a finished product. Because the cyclone collector cannot collect all of the powder, a few fine powder is discharged with the airflow. This part of fine powder is filtered by the powder filter, and collected in a fine powder collector provided in a lower portion of the powder filter. Generally, a weight ratio between the fine powder and the whole powder is less than 15%, and a grain diameter of the fine powder is less than 1 μm. This part of powder has a rare earth content higher than an average rare earth content of the whole powder, so this part of powder is easy to be oxygenated, and is thrown away as waste powder. Preferably, an oxygen content in the atmosphere is controlled less than 50 ppm. This part of fine powder and the powder and the powder collected by the cyclone collector are added into a two-dimensional or three-dimensional mixing machine to mix with each other, and then compacted into compacts in a magnetic field under the protective atmosphere. A mixing period is generally more than 30 minutes, and the oxygen content in the atmosphere is less than 50 ppm. Preferably, a fine powder collector is provided between the cyclone collector and the powder filter, for collecting the fine powder discharged with the airflow from the cyclone collector. 10% of the fine powder can generally be collected. This part of the fine powder and the powder collected by the cyclone collector are added into the two-dimensional or three-dimensional mixing machine to mix with each other, and then compacted into compacts in the magnetic field under the protective atmosphere. Because of having a high content of rare earth, the fine powder is very suitable to be used as a rare-earth-rich phase in crystal boundaries, in such a manner that a magnetic performance is increased. To increase the magnetic performance, preferably, alloys of various compositions are respectively smelted according to the above processes, and the alloys are respectively milled into powders. Then the powders are mixed, and compacted in the magnetic field.
4. Compaction Process
Compaction of neodymium-iron-boron rare earth permanent magnets is most different from compaction of common powder metallurgy in compaction under an oriented magnetic field, so an electromagnet is provided on a press. Because neodymium-iron-boron rare earth permanent magnetic powder tends to be oxygenated, some patents proposed that an environmental temperature while compaction was required to be controlled between 5° C. and 35° C., a relative humidity was required to be 40%-65%, and an oxygen content was required to be 0.02-5%. To prevent the powder from being oxygenated, preferably, a compacting equipment comprises a protecting box, wherein gloves are provided on the protecting box, and the powder is processed with magnetic compaction under a protective atmosphere. Preferably, a cooling system is provided in a magnetic space in the protecting box, and a temperature of a magnetic space can be controlled. Moulds are displaced in a microthermal space which has a controllable temperature. The powder is compacted into compacts in a controlled temperature, and the temperature is controlled between −15° C. and 20° C. Preferably, the compacting temperature is less than 5° C. An oxygen content in the protecting box is less than 200 ppm, preferably, 150 ppm. An oriented magnetic field intensity in a chamber of the mould is generally 1.5-3 T. The magnetic field is oriented in advance before magnetic powder is compacted into the compacts, and the oriented magnetic field intensity remains unchanged while compaction. The oriented magnetic is embodied as a constant magnetic field, or a pulsating magnetic field, i.e., an alternating magnetic field. To decrease a compacting pressure, isostatic pressing is processed after the magnetic compaction, and then the material is fed into a sintering furnace to be sintered after the isostatic pressing.
5. Sintering Process
The sintering process is after the compaction process. The sintering process is finished in a vacuum sintering furnace, and under the condition of vacuum or protective atmosphere. A protective gas is embodied as argon. A sintering temperature is 1000-1200° C. A heat preservation period is generally 0.5-20 hours. Argon or nitrogen is used to cool the material after heat preservation. Preferably, a sintering equipment comprises a valve and a transferring box with gloves provided in front of the vacuum sintering furnace. The compacts processed with compaction are transported into the transferring box under the condition of protective atmosphere. The transferring box is filled with the protective gas. Under the condition of protective atmosphere, outer packings of the compacts are removed, and the compacts are fed into a sintering box. Then the valve between the transferring box and the sintering furnace is opened. The sintering box carrying the compacts is transported into the vacuum sintering furnace to be sintered by a transport mechanism in the transferring box. Preferably, a multi-chamber vacuum sintering furnace is used for sintering. Degasification, sintering, and cooling are respectively finished in different vacuum chambers. The transferring box with gloves is connected with the vacuum chambers via the valve. The sintering box passes through the vacuum chambers in turn. To increase the coercivity of magnets, the compacts are processed with aging process once or twice after sintering. An aging temperature of a first aging process is generally 400-700° C. A higher temperature of a second aging process is generally 800-1000° C., and a lower temperature of the second aging process is 400-700° C. The compacts are processed with machining and surface treatment after aging.
With expanding of application market of neodymium-iron-boron rare earth permanent magnetic materials, a problem of shortage of rare earth resources becomes more and more serious. Especially in fields of electronic components, energy-saving and controlling motors, auto parts, new energy automobiles, wind power, etc., more heavy rare earth is required to increase coercivity. Therefore, how to reduce a usage amount of the rare earth, especially the usage amount of the heavy rare earth, is an important topic in front of us. After exploration, we develop a rotating vacuum heat treatment equipment applicable for producing a neodymium-iron-boron rare earth permanent magnetic device having a high performance.

Rotating vacuum heat treatment equipment

China North Magnetic & Electronic Technology Co., LTD


A spring structure for a weight scale is described which is assembled from four extruded aluminum parts. The structure readily lends itself to the addition of a platform for placing weights and its deflection resulting from a weight is essentially invariant to the location of the weight on the platform. The sensor which converts deflection of the structure into an electrical signal includes two conducting plates, attached to the structure, which constitute a variable capacitor. The variable capacitor is part of a self-excited oscillator circuit which yields a frequency which is accurately related linearly to the value of the weight. Means are provided for distorting one of the capacitor plates to provide further improvement of invariance to weight location on the platform.

Electronic weighing scales typically present the value of a weight on an electronic digital display. The latter is convenient to read and potentially capable of reading with high accuracy.
Electronic weighing scales are commercially available for a wide variety of applications; employed for weighing small weights (less than 1 gram) as well as for applications involving weights exceeding many tons. The sensor which converts the value of the weight to an electrical signal can either sense the deflection of a spring structure by an added weight, or alternatively can sense the strain in a relatively stiff spring structure by the added weight.
An important aspect of the design of the spring structure and its associated sensor is the elimination of variations of apparent weight related to the weight location on the weighing platform. This weighing error is typically reduced or eliminated in commercial designs by employing a cantilevered spring structure.
Commercial sensors for transforming spring deformation into an electrical signal are of two types depending upon whether strain or deflection of the spring structure is being sensed. Sensors employed in prior designs utilizing deflection of the spring structure are typically either the variable differential transformer or variable capacitance means; the typical sensor for measuring strain in the spring structure is the conventional strain gauge.


An apparatus for holding open a door or similar member for a predetermined time period includes a suction mechanism coupled to the door and the door frame. The suction mechanism includes an adjustable valve to provide a controlled flow of air to release the suction. The mechanism includes an arm having a suction cup at one end and a suction plate pivotally connected to the arm for engaging the suction cup when the door is in the open position. The suction mechanism is attached to the inner surface of the door and the necessary relative motions of parts achieved by an articulated connecting rod and suction cup pad assembly are pivotally attached to the adjacent door frame. The articulated assembly permits the face of the suction cup and its target to be parallel to the door in the open and closed positions. The arm is connected to a spring loaded mounting assembly so that the door""s maximum opening limitation is dictated by the spring closing mechanism or other motion limiting device.

The present invention is directed generally to an apparatus for holding a door or similar member in an open position for a predetermined period of time, after which the door is returned to the closed position. More particularly, the invention is directed to a delayed action suction operated device for holding a door in an open position for a selected period of time.
Doors and gates are often provided with an automatic closing assembly for maintaining the door in a closed position. The automatic door closing apparatus are typically spring operated, pneumatically operated or hydraulically operated systems. Although many of these automatic door closing systems close the door at a controlled rate, these devices generally do not have a system for holding the door in an open position.
In an effort to control the closing operation of the automatic door closing assembly, various devices have been proposed to hold the door in an open position for a predetermined period of time. For example, U.S. Pat. No. 4,053,961 discloses a suction cup that is attached to the back of a door. The suction cup is positioned so that the suction cup mates with an adjacent wall when the door is open. The suction cup is allowed to leak to release the suction and allow the door to close. The suction cup can be provided with small holes to allow the controlled flow of air into the suction cup. Alternatively, the mating wall can be provided with holes to allow air to flow into the suction cup. A disadvantage of this device is that the suction cup relies on the adjacent wall for the operation of the door holding assembly. Therefore, this assembly cannot be used in situations where there is no adjacent wall.
Another example of a device for holding a door in an open position is disclosed in U.S. Pat. No. 3,042,958. This device includes a suction cup coupled to the back side of a door which mates with a complementing suction cup mounted on a wall. This device has the disadvantage of requiring a suction cup mounted directly to the wall, thereby damaging the wall. In addition, the suction cup mounted to the wall must be precisely located to mate with the suction cup on the door to ensure proper operation of the assembly.
Still another example of a device for holding a door in an open position is disclosed in U.S. Pat. No. 5,293,666 to Armstrong. This device includes a suction mechanism for holding a door in an open position for a period of time. The assembly is mounted between the door and the door jamb and includes a suction cup mounted to the door and a plate for mating with the suction cup. The plate is mounted to engage the suction cup when the door is open and to hold the door in the open position. A valve can be provided in the plate to control the release of the vacuum in the suction cup to release the suction and allow the door to close. In this device, the plate is oriented substantially perpendicular to the plane of the door and extends outwardly from the door throughout the operation of the assembly. The suction cup has a center axis oriented generally parallel to the door and perpendicular to the mating plate. A disadvantage of this assembly is the orientation of the suction cup and the plate which extend outwardly from the door a depth at least equal to the diameter of the suction cup. The average space between a storm door and an exterior door of a house is generally about 2.5 inches. This space limits the size of the suction cup that can be used to hold the door in an open position when the suction cup is oriented along an axis parallel to the door.
Although the above-noted devices have exhibited some success, there is a continuing need in the industry for an improved delayed door holding device.
The present invention is directed to an apparatus for holding a door or other member in an open position for a predetermined period of time. More particularly, the invention is directed to a delayed action suction operated device for holding a door in an open position against the force of a door closing mechanism.
Accordingly, a primary object of the invention is to provide a suction operated device for holding a door in an open position.
Another object of the invention is to provide a delayed action door holding device having a dimension to fit within the space between an exterior door and a storm door.
A further object of the invention is to provide a delayed action door holding device that is mounted to the door and to the door jamb for holding the door in an open position against the force of an automatic door closing assembly.
Still another object of the invention is to provide a delayed action door holding device having a suction cup and a mating surface for the suction cup where the mating surface and the suction cup are oriented in a plane generally parallel to the door when the door is in an open and closed position.
Another object of the invention is to provide a delayed action door holding device having a first arm pivotally connected to a door jamb and a second arm pivotally connected to the first arm and to the door where the first arm includes a suction cup and the second arm includes a mating surface for coupling to the suction cup.
Still another object of the invention is to provide a delayed action door holding device having a mounting bracket for mounting the device to a door jamb where the bracket is spring biased to allow the door to open beyond a predetermined point without damaging the device.
The objects and advantages of the invention are basically attained by providing an apparatus for retaining a movable member in a fixed position for a predetermined period of time. The apparatus comprises a first arm having a suction cup coupled thereto. A plate is pivotally coupled to the first arm which has a surface for mating with the suction cup. The plate is pivotable by movement of the member between a first position spaced from the suction cup and a second position contacting and temporarily attaching to the suction cup and holding the movable member in the fixed position.
The objects and advantages of the invention are further attained by providing an apparatus for temporarily holding a pivotally mounted door in an open position. The apparatus comprises a first arm having a first end for pivotally coupling to a door frame and also having a second end. A second arm has a first end for pivotally coupling to a door and a second end pivotally coupled to the second end of the first arm. The second arm is pivotable with respect to the first arm between a first position when the door is in a closed position and a second position when the door is in an open position. A suction cup is positioned to temporarily hold the second arm in the second position and to hold the door in the open position.
The objects and advantages of the invention are also attained by providing an apparatus for temporarily holding a member in a first position for a period of time. The member is pivotally coupled to a support. The apparatus comprises a first arm having a first end pivotally coupled to the support and having a second end. A second arm has a first end pivotally coupled to the member and a second end pivotally coupled to the second end of the first arm. The second arm is pivotable between a first position and a second position by pivotal movement of the member with respect to the support. A coupling member for temporarily holding the second arm in the second position is provided.
The objects advantages and salient features of the invention will become apparent from the following detailed description in conjunction with the annexed drawings which form a part of this original disclosure.


Agrochemical compositions are described which contain a carboxylic acid salt of dodecylguanidine and a compatibility agent for slowing down the dissociation reaction of the carboxylic acid salt of dodecylguanidine in an aqueous medium. Also, the formation of anionic dodecylguanidine is suppressed or prevented. The ratio of the dodecylguanidine acetate to that of the compatibility agent in the agricultural compositions is below 5.0, preferably between 3.0 and 0.5, more preferably equals 1.4.

Relative to certain crops, such as apples and cherries, it is desirable to effect spraying of both an insecticide and fungicide simultaneously because of the simultaneous appearance of the pests which are to be destroyed. In this respect, tank mixing two or more pesticides and/or fertilizers is a convenient way to reduce labour and equipment use. In addition, adjuvants may be added.
Tank mixing chemicals is a convenient way to reduce labour and equipment use, it offers flexibility and may increase pesticide effectiveness. However, an incompatible mix can cause equipment damage, downtime, damage to desirable plants and chemical ineffectiveness. Incompatible mixes can result from chemical or physical incompatibility. Chemical incompatibility occurs when one or more of the chemicals changes properties. Physical incompatibility causes the formation of lumps or gels. The chemicals do not disperse properly and settle out of suspension. Incompatibility can also take the form of foams, stratification in the tank, colour changes and bubbles.
Dodecylguanidine acetate, known as dodine, is a fungicide recommended for the control of a number of major fungal diseases on cash crops such as apples and bananas. It is known in the art that dodine is incompatible with some pesticides and/or additives.
For instance, in U.S. Pat. No. 3,452,931 it was disclosed that dodine and a material known under the trademark Glyodin are immiscible and therefore cannot be mixed before spraying. An agricultural sprayer was disclosed which is capable of the simultaneous but separated application of dodine and Glyodin. Whereas this liquid sprayer offers a solution to the compatibility issue of dodine, it is desirable that an applicator would not have to resort to special equipment.
There remains a need in the art for providing further solutions that resolve the incompatibility of dodine with tank mix partners.
The present invention aims to resolve or ameliorate at least some of the problems mentioned above. In particular, the invention thereto aims to provide a compatibility agent for dodine that resolves the incompatibility of dodine in a tank-mix.

Agrochemical formulations containing a compatibility agent


An apparatus, system, and method for producing electro-chemically activated water wherein (1) a dilute aqueous salt solution is first delivered through a preliminary reactor which has an anode element and a cathode element but does not have a membrane element positioned between the anode and the cathode and (2) the product from the preliminary reactor is then delivered through an activation reactor having a membrane element positioned between the anode and cathode elements thereof.

Electro-chemically activated (ECA) water is produced from dilute dissociative salt solutions by passing an electrical current through the solution to produce catholyte and/or anolyte products. The catholyte, which is the solution exiting the cathodal chamber of the activation reactor cell, is an anti-oxidant which typically has a pH in the range of from about 8 to about 13 and an oxidation-reduction potential (ORP) in the range of from about −200 mV to about −1100 mV. The anolyte, which is the solution exiting the anodal chamber, is an oxidant which typically has a pH in the range of about 2 to about 8, an ORP in the range of from about +300 mV to about +1200 mV or more, and a Free Available Oxidant (FAO) concentration of ≦300 ppm by weight.
During the electrochemical activation of aqueous saline solutions, various oxidative and reductive species can be present, for example: HOCl (hypochlorous acid); ClO2 (chlorine dioxide); OCl− (hypochlorite); Cl2 (chlorine); O2 (oxygen); H2O2 (hydrogen peroxide); OH− (hydroxyl); and H2 (hydrogen). The presence or absence of any particular reactive species in the solution is predominantly influenced by the derivative salt used and the final solution pH. So, for example, at a pH of 3 or below, HOCl tends to convert to Cl2, which increases the toxicity level of the product. At a pH of below 5, low chloride concentrations tend to produce HOCl, but high chloride concentrations typically produce Cl2 gas. At a pH above 7.5, hypochlorite ions (OCl−) are typically the dominant species. At a pH of greater than 9, the oxidants (chlorites and hypochlorites) tend to convert to non-oxidants (chloride, chlorates and perchlorates) and active chlorine (i.e. defined as Cl2, HOCl and ClO−) is typically lost due to conversion to chlorate (ClO3−). At a pH of 4.5-7.5, the predominant species are typically HOCl (hypochlorous acid), O3 (ozone), O22− (peroxide ions) and O2− (superoxide ions).
For this reason, anolyte will typically predominantly comprise species such as ClO; ClO−; HOCl; OH−; HO2; H2O2; O3; S2O82− and Cl2O62−, while catholyte will typically predominantly comprise species such as NaOH; KOH; Ca(OH)2; Mg(OH)2; HO−; H3O2−; HO2−; H2O2−; O2−; OH− and O22− The order of oxidizing power of these species is: HOCl (strongest)>Cl2>OCl− (least powerful). Therefore, anolyte can have a much higher antimicrobial and disinfectant efficacy in comparison to that of catholyte, or of commercially available stabilized chlorine formulations used at the recommended dosages.
The anolyte and catholyte solutions will typically be produced by electro-chemically activating a dilute aqueous saline solution comprising in the range of from about 1 to about 9 grams of salt per liter of water. The salt can be any inorganic salt. The salt will preferably be non-iodated sodium chloride (NaCl) or potassium chloride (KCl).
Prior to use, the electro-chemically activated anolyte product will typically be diluted with water. The diluted anolyte solution will typically comprise at least 50 parts by volume of non-activated water per 50 parts by volume of concentrated anolyte. More typically, the diluted anolyte solution will have a water-to-anolyte volume ratio of at least 60:40. In each case, the parts by volume ratio of water to concentrated anolyte will typically not be greater than 98:2, will more typically not be greater than 95:5, will more typically be in the range of from about 94:6 to about 60:40, and will most typically be in the range of from about 93:7 to about 65:35.
One type of reactor cell 1 used in the art for producing electro-chemically activated water solutions is depicted in FIG. 1. The reactor cell 1 is a flat plate reactor cell which comprises: a negatively charged cathodal plate 7 positioned within a container 2 on one side thereof; a positively charged anodal plate 6 positioned in the container 2 opposite the cathodal plate 7; a ceramic membrane 5 which is positioned within the container 2 between the cathode 7 and the anode 6; an anodal flow chamber 3 formed in the container 2 between the ceramic membrane 5 and the anodal plate 6; and a cathodal flow chamber 4 formed in the container 2 between the ceramic membrane 5 and the cathode 7.
Another type of reactor cell 11 used in the art for producing electro-chemically activated water solutions is depicted in FIG. 2. The reactor cell 11 is a cylindrical cell which comprises: a negatively charged outer cathodal cylinder 17; a positively charged, coaxial anodal rod 16 which extends through the cathodal cylinder 17; a coaxial cylindrical ceramic membrane 15 which is positioned within the cathodal cylinder 17 between the interior wall of the cathodal cylinder 17 and the exterior surface of the anodal rod 16; a cylindrical cathodal flow chamber (annulus) 14 formed between the ceramic membrane 15 and the cathodal cylinder 17; and a cylindrical anodal flow chamber (annulus) 13 formed between the ceramic membrane 15 and the anodal rod 16.
The anodal rod 16 will typically be formed of titanium and will be coated with an oxide of a platinum group metal such as iridium or ruthenium. The cathodal cylinder 17 will typically be formed of titanium.
The operation of the plate-type reactor cell 1 depicted in FIG. 1 or the cylindrical reactor cell 11 depicted in FIG. 2 can be varied significantly depending upon the particular solution properties desired. In one aspect, the properties of the electro-chemically activated product solution(s) can be varied by changing the flow rate of the aqueous saline solution through the reactor cell and/or by changing the amount of electrical current applied to the dilute saline solution. In addition, the product solutions and solution properties can also be altered by changing the flow pattern of the dilute aqueous saline solution through the reactor cell such that (1) the saline solution is delivered through the anodal chamber and the cathodal chamber in co-current flow; (2) the saline solution is delivered through the anodal chamber and the cathodal chamber in countercurrent flow; (3) a portion of the catholyte recovered from the cathodal chamber is recirculated through the anodal chamber; and/or (4) all of the catholyte recovered from the cathodal chamber is recirculated through the anodal chamber.
By way of example, in one application, it is known in the art that electro-chemically activated anolyte solutions can be added to foods, water, beverages, or pharmaceuticals, or can be used as disinfectants, purification agents, odor neutralization agents, flavor neutralizing agents, or for other purposes in food, water, beverage, and pharmaceutical processing systems. Prior to being diluted with water, the concentrated anolyte solutions used in these applications will typically be neutral or only slightly acidic solutions having a pH in the range of from about 5 to about 7.5, an oxidation-reduction potential (ORP) of at least +400 mV, a free available oxidant (FAO) content of ≦300 ppm by weight and a free available chlorine content (FAC) of 30-200 ppm by weight. These anolyte solutions will more preferably have a pH in the range of from about 6 to about 7.3 and will most preferably have a pH in the range of from about 6.5 to about 7.2. In addition, these anolyte solutions, in undiluted form, will most preferably have an ORP of at least +600 mV.
An example of a procedure used in the art for producing a slightly acidic or pH neutral anolyte product of this type using either a plate-type reactor cell 1 as depicted in FIG. 1 or a cylindrical reactor cell 11 as depicted in FIG. 2 involves the steps of: separately harvesting a concentrated catholyte solution from the cathodal flow chamber; reintroducing at least some of the catholyte solution into the anodal flow chamber, preferably in the absence of any fresh water; and manipulating the flow rate, the hydraulic flow configuration, and the pressure and temperature of the catholyte through the anodal chamber as needed so as to produce an anolyte solution that is characterized in that it predominantly includes the species HOCl (hypochlorous acid), O3 (ozone), O22− (peroxide ions) and O22− (superoxide ions), and has a Free Available Oxidant (FAO) concentration of ≦300 ppm by weight.
Unfortunately, however, one shortcoming of this procedure for producing a highly effective yet neutral to slightly acidic anolyte which is safe for human consumption is that a significant amount, or sometimes substantially all, of the catholyte is consumed by recirculation through the anodal flow chamber. Thus, oftentimes, very little or substantially none of the catholyte product can be independently harvested for other uses.
Another shortcoming of this procedure is that a significant amount of the chloride ions in the dilute brine feedstock are not converted during the electro-chemical activation process. The presence of a higher concentration of unreacted chloride ions in the anolyte product is viewed as presenting an increased risk of corrosion which could shorten the life of the reactor components and coatings.
Moreover, chlorides are already present in most water sources and the addition of any further chloride load can create concerns, for example, for beverage producers and other users of stainless steel processing equipment. In many cases, the original equipment manufacturer will not guarantee equipment which is exposed to chloride levels of greater than 55 ppm, and in some cases even less.
Unfortunately, to reduce the residual chloride content and increase the FAC levels of these anolyte products using a traditional prior art reactor system configuration, it would be necessary to use a high brine concentration, a very low flow rate, and an increased amount of electrical current. This would result in premature failure of the reactor system due to coating failure, and would also significantly reduce the amount of anolyte product produced.

Method for electro-chemical activation of water


An acoustic wave filtering apparatus includes an acoustic wave propagating substrate for supporting propagation of acoustic waves and a plurality of acoustic wave filters for filtering an electrical signal. Each of said plurality further comprises an input for supplying electrical input signals, an input unidirectional acoustic wave transducer for converting electrical signal energy into acoustic energy, an output unidirectional acoustic wave transducer for converting acoustic signals to electrical signals, and an output for combining and delivering electrical output signals to external electrical apparatus.

Acoustic wave filters comprise a class of frequency selection components having the advantages of small size, light weight, and large out-of-band signal rejection.
Periodic or quasi-periodic acoustic wave transducer structures are employed for achieving acousto-electric and electro-acoustic energy conversion required in surface acoustic wave filters. The bandwidth of an acoustic wave transducer (and filter) is inversely proportional to the length of the acoustic wave transducer.
A first problem which all acoustic wave filters incur is that such structures typically provide efficient energy conversion, but also impose bandwidth limitations on the frequency response of the completed acoustic wave filter.
A second problem which many acoustic wave transducers suffer is "ripple" or nonuniformity of the pass-band frequency response of the completed filter due to what is termed "triple-transit" distortion of the filter response. Triple transit distortion results from acoustic reflections within an acoustic wave filter, which occur when a propagating acoustic wave impinges upon, for example, a simple, bi-directional acoustic wave transducer. Such transducers are often preferred because they are easily manufactured using a single photolithography step, by techniques which are very similar to those employed to fabricate semiconductor-based integrated circuit devices, as is well known in the art.
The triple transit distortion level can be minimized by increasing the pass-band insertion loss of the acoustic wave filter, without increasing the filter's fabrication complexity.
However, this approach requires large filter insertion losses in order to satisfy many system specifications for filter pass-band insertion loss uniformity. These losses are often deliberately introduced into acoustic wave filters in order to ameliorate triple-transit induced effects. In turn, these large filter insertion losses necessitate either pre- or post-filter gain, effected via amplifiers. Such amplifiers require power, occupy space, and impose weight requirements which are inconsistent with many applications for low-power, hand-portable communications equipment, wherein acoustic wave filters find substantial application.
What is needed are means and methods for achieving wide bandwidth acoustic wave filters. What is further needed are means and methods for providing wide bandwidth acoustic wave filters also having low pass-band insertion loss, low triple transit spurious response, strong rejection of out-of-band signals, and single level photolithographic process fabrication requirements.

Low loss wide bandwidth parallel channel acoustic filter


The invention relates to a method for producing pure melamine by preparing a melamine melt, which is obtained in a high pressure process and from which the reaction gases are removed. Said method is characterized in that the melamine melt is quenched by water with a purity in excess of 95 wt. %, that NH3 and CO2 are subsequently removed from the obtained melamine solution and that alkali is added to said melamine solution and the mixture is then left to rest, whereby pure melamine is obtained by crystallization. Thus a melamine can be obtained with the same quality as that produced in known comparative methods, using smaller quantities of alkali.

1) Field of the Invention
The Application relates to a process for the preparation of pure melamine according to claim 1.
2) Description of the Related Art
In the high-pressure processes for the preparation of melamine, in general urea melt and optionally gaseous ammonia are reacted without the presence of a catalyst, for example at temperatures between 325 and 450° C., preferably between 350 and 425° C., and pressures between 50 and 250 bar to give liquid melamine and off gas. The reaction off gas mainly comprises ammonia and carbon dioxide, with small amounts of gaseous melamine. In addition to unconverted urea, the liquid crude melamine also contains byproducts, such as, for example, melem, melam and further condensation products of melamine, which are undesired in the end product and therefore have to be separated off. The melamine byproducts are separated from melamine by utilizing the known fact that the byproducts hydrolyze with water, preferably in the presence of alkalis, to give oxoaminotriazine compounds, such as ammeline and ammelide. During the subsequent melamine crystallization, these are kept in solution so that the pure melamine crystallizes out selectively. In these melamine processes, the melamine melt from the high pressure part is worked up in a downstream low pressure part in the presence of water.
According to U.S. Pat. No. 3,132,143, for example, the reaction mixture from the high pressure synthesis reactor, consisting of the melamine melt and the off gas, is fed to a quencher in which the mixture is brought into contact with an aqueous solution saturated with ammonia and carbon dioxide, at from 100 to 200° C. and from 10 to 35 bar for from 10 to 60 min. On contact with the cool quench solution, the melamine is absorbed therein while the major part of the off gas is separated off. For the degradation of the byproducts, the melamine solution is allowed to reside for from 20 to 50 min, the NH3 and CO2 contained is then removed with the aid of steam and, after addition of alkali-containing mother liquor and filtration of insoluble products, the melamine crystallizes out.
A disadvantage of this process is the fact that the melamine off gas is separated from the melamine only in the quencher and is thus obtained at a low pressure level and in a state which is not anhydrous. Since the off gas mainly comprises NH3 and CO2, considerable amounts of CO2 are introduced into the wet part of the plant. CO2 which has already been separated off is even recycled into the melamine process via the CO2-containing quench liquid, with the result that the CO2 content of the melamine solution is increased and hence the pH of the solution is reduced. This is disadvantageous in particular for the byproduct degradation preferably taking place in the alkaline range during the residence in the quencher, since this takes place slowly and incompletely under these conditions. The total CO2 is stripped from the melamine solution only in the steam stripper of the wet part. This is also very energy-consumptive.
WO 00/29393 A1 or WO 03/045927 A1 describes melamine preparation processes in which the melamine melt is separated from the reaction off gas in the high pressure reactor itself. The off gas is obtained in anhydrous form and at high pressure and is recycled into the urea plant. The melamine melt fed for further working-up accordingly already contains a CO2 content reduced by the proportion of off gas. Subsequently, the CO2 dissolved in the melamine melt is removed from the melt, for example by passing through NH3. The melamine melt pretreated in this manner is then fed to the quencher, in which the melamine melt is converted into a melamine suspension or solution by contact with an aqueous, alkali-containing solution. In order to accelerate the byproduct degradation and to keep oxoaminotriazine compounds formed thereby, ammeline and ammelide, in solution, NaOH is added to the melamine solution before it is allowed to reside for byproduct degradation. Dissolved NH3 still present is then stripped out and the melamine finally crystallizes out. A disadvantage of these processes is the fact that considerable amounts of CO2 are still present in the melamine suspension or solution discharged from the quencher. Said amounts arise because of incomplete CO2 removal in the high pressure part and as a result of hydrolytic decomposition of unconverted urea and melamine byproducts in the quencher. The total CO2 present must be neutralized by adding NaOH. Only on further addition of NaOH does the pH increase. A high pH is required for rapid byproduct degradation during the subsequent residence of the melamine solution. This results in very large amounts of NaOH for the desired high melamine purity with low byproduct contents, which amounts are undesired for economic and logistical reasons.
It was accordingly the object to provide a melamine process which has a reduced NaOH consumption in combination with the same energy characteristics of the plant and the same quality of the end product melamine.

AMI-Agrolinz Melamine International GmbH


Exhaust capture and containment are enhanced by means of automatic or manual side skirts, a sensitive breach detector based on interference effects, a combination of vertical and horizontal edge jets, and/or corner jets that are directed to the center diagonally from corners. Associated control functions are described.

Exhaust hoods are used to remove air contaminants close to the source of generation located in a conditioned space. For example, one type of exhaust hoods, kitchen range hoods, creates suction zones directly above ranges, fryers, or other sources of air contamination. Exhaust hoods tend to waste energy because they must draw some air out of a conditioned space in order to insure that all the contaminants are removed. As a result, a perennial problem with exhaust hoods is minimizing the amount of conditioned air required to achieve total capture and containment of the contaminant stream.
Referring to FIG. 1A, a typical prior art exhaust hood 45 is located over a range 40 or other cooking source. The exhaust hood 45 has a recess 25 with at least one vent 20 (covered by a filter also indicated at 20) and an exhaust plenum 20 and duct 10 leading to an exhaust system (not shown) that draws off fumes 35. The exhaust system usually consists of external ductwork and one or more fans that pull air and contaminants out of a building and discharge them to a treatment facility or into the atmosphere. The recess 25 of the exhaust hood 45 plays an important role in capturing the contaminant because heat, as well as particulate and vapor contamination, are usually produced by the contaminant-producing processes. The heat causes its own thermal convection-driven flow or plume 35 which must be captured by the hood within its recess 25 while the contaminant is steadily drawn out of the hood. The recess creates a buffer zone to help insure that transient, or fluctuating, surges in the convection plume do not escape the steady exhaust flow through the vent.
It is desirable to draw off as little air from the conditioned space as possible. There are various problems that make it complicated to simply adjust the exhaust flow rate so that just enough air is withdrawn as needed to ensure all of the fumes are captured and drawn out by the hood. One problem is unpredictable cross drafts in the conditioned area. Employees might use local cooling fans or leave outside doors open. Or rapid movement of personnel during busy periods can create air movement. These drafts can shift the exhaust plume 35 sideways causing part of it to leave the suction zone of the hood allowing some of the fumes to escape into the occupied space.
Another problem is variations in the volume generation rate, the temperature and corresponding thermal convection forces, and phase change in the fumes. Generally exhaust hoods are operated at exhaust rates that correspond to the worst-case scenario. But this means they are overdesigned for most conditions. There is an on-going need for mechanisms for minimizing the exhaust rate while maintaining capture and containment of fumes.
One means for reducing the effect of cross-drafts is the use of side skirts 30 as shown in FIG. 1B. Side skirts 30, which are simple metal plates, may be affixed at the ends of an exhaust hood 46 as illustrated allowing workers to access a cooking appliance 40 from a front edge 36 of the appliance 40 without interference from the skirts 30. The skirts 30 reduce the sensitivity of the plume of fumes 35 to cross-drafts by simply blocking cross-drafts. Although only one is shown, a skirt 30 is implied on an opposite side of the hood 46 perpendicular to the line of sight of the elevation drawing.
FIGS. 1A and 1B illustrate hoods ("backshelf") that are normally located against a wall. Another type of hood is illustrated in FIG. 2 which is called a canopy hood 60. This type of hood can have mirror image exhaust outlets as indicated at 21 (with filters also indicated at 20) or it can have an asymmetrical configuration. The canopy style hood 60 allows workers 5 to approach multiple sides of an appliance 41 such as one or more ranges. The canopy style hood is particularly susceptible to cross-drafts because of its open design.
In addition to minimizing the exhaust rate while providing capture and containment, there are many opportunities in commercial kitchens to recycle otherwise wasted energy expended on conditioning air, such as using transfer air from a dining area to ventilate a kitchen where exhaust flow rates and outdoor air ventilation rates are high. In such systems, the space conditioning or heating, ventilating and air-conditioning (HVAC) systems are responsible for the consumption of vast amounts of energy. Much of the expended energy can be saved through the use of sophisticated control systems that have been available for years. In large buildings, the cost of sophisticated control systems can be justified by the energy savings, but in smaller systems, the capital investment is harder to justify. One issue is that sophisticated controls are pricey and in smaller systems, the costs of sophisticated controls don't scale favorably leading to long payback periods for the cost of an incremental increase in quality. Thus, complex control systems are usually not economically justified in systems that do not consume a lot of energy. It happens that food preparation/dining establishments are heavy energy users, but because of the low rate of success of new restaurants, investors justify capital expenditures based on very short payback periods.
Less sophisticated control systems tend to use energy where and when it is not required. So they waste energy. But less sophisticated systems exact a further penalty in not providing adequate control, including discomfort, unhealthy air, and lost patronage and profits and other liabilities that may result. Better control systems minimize energy consumption and maintain ideal conditions by taking more information into account and using that information to better effect.
Among the high energy-consuming food preparation/dining establishments such as restaurants are other public eating establishments such as hotels, conference centers, and catering halls. Much of the energy in such establishments is wasted due to poor control and waste of otherwise recoverable energy. There are many publications discussing how to optimize the performance of HVAC systems of such food preparation/dining establishments. Proposals have included systems using traditional control techniques, such as proportional, integral, differential (PID) feedback loops for precise control of various air conditioning systems combined with proposals for saving energy by careful calculation of required exhaust rates, precise sizing of equipment, providing for transfer of air from zones where air is exhausted such as bathrooms and kitchens to help meet the ventilation requirements with less make-up air, and various specific tactics for recovering otherwise lost energy through energy recovery devices and systems.
Although there has been considerable discussion of these energy conservation methods in the literature, they have had only incremental impact on prevailing practices due to the relatively long payback for their implementation. Most installed systems are well behind the state of the art.
There are other barriers to the widespread adoption of improved control strategies in addition to the scale economies that disfavor smaller systems. For example, there is an understandable skepticism about paying for something when the benefits cannot be clearly measured. For example, how does a purchaser of a brand new building with an expensive energy system know what the energy savings are? To what benchmark does one compare the performance? The benefits are not often tangible or perhaps even certain. What about the problem of a system's complexity interfering with a building operator's sense of control? A highly automated system can give users the sense that they cannot or do not know how to make adjustments appropriately. There may also be the risk, in complex control systems, of unintended goal states being reached due to software errors. Certainly, there is a perennial need to reduce the costs and improve performance of control systems. The embodiments described below present solutions to these and other problems relating to HVAC systems, particularly in the area of commercial kitchen ventilation.


The present invention relates to methods and compositions for the prevention and treatment of cancer, inflammatory diseases and disorders or deficiencies of the immune system. The methods of the invention comprise administering a CD40 binding protein that potentiates the binding of CD40 to CD40 ligand.

CD40 is a cell surface phosphorylated glycoprotein that is expressed on a variety of cell types, including B cells, B cell malignancies, follicular dendritic cells, basal epithelial cells, and carcinomas. CD40 binds CD40 ligand ("CD40L"). CD40L is expressed on activated T cells during inflammation and cancer (Younes et al., 1998, Br. J. Haematol. 100:135-141; for areview see Grewal and Flavell, 1998, Annu. Rev. Immunol. 16:111-135). The interaction of CD40 with CD40L results in B cell activation and proliferation of normal B cells; however CD40-mediated signaling in B cell-derived tumor lines can result in activation-induced cell death. The strength of the activation signal is key to activation-induced tumor cell death (Grafton et al., 1997, Cell. Immunol. 182:45-56). Therefore, compositions and methods for increasing receptor-ligand interaction and strength of activation signal between CD40 and CD40L would be of great value in treating disease.
2.1 CD40 and CD40 Ligand
CD40 is a member of the TNF receptor superfamily. This family includes TNFrII, CD40, CD30, LMP-1, LTBr, ATAR, OX-40 and 4-1BB receptors. CD40 is constitutively expressed on B-lymphocytes, macrophages and dendritic cells and is induced by cytokine activation on fibroblasts, endothelial cells and epithelial cells (Van Kooten and Banchereau, 1997, Curr. Opin. Immunol., 9: 330-337). CD40 has also been shown to be highly expressed on many human carcinomas including lung, bladder, gastric, breast and ovarian cancers (Stamenkovic et al., 1989, EMBO J. 8:1403-1410).
The ligand for CD40 is a membrane protein that is expressed on activated T cells. Receptor binding of CD40L results in CD40 multimerization, the generation of activation signals (for antigen presenting cells such as dendritic cells, monocytes and B cells) and the generation of growth and differentiation signals (for cytokine-activated fibroblasts and epithelial cells). CD40 signals are transduced from the multimerized receptor via recruitment of a series of TNF receptor-associated factors ("TRAFs") (Kehry, 1996, J. Immunol. 156:2345-2348). Subsets of TRAFs interact differentially with TNF family members, including CD40, to provide stimuli to a wide variety of downstream pathways. TRAF1 and TRAF2 are implicated in the modulation of apoptosis (Speiser et al., 1997, J. Exp. Med. 185:1777-1783; Yeh et al., 1997, Immunity 7:715-725). TRAFs 2, 5, and 6 participate in proliferation and activation events, including NF-kB and c-Jun N-terminal kinase activation. In normal B cells, binding of CD40 recruits TRAF2 and TRAF3 to the receptor complex and induces down-regulation of other TRAFs (Kuhune et al., 1997, J. Exp. Med. 186: 337-342). The effects of CD40 binding are also dependent on membrane density (De Paoli et al., 1997, Cytometry 30:33-38). Importantly, unlike the proliferative response seen with normal primary B cells, CD40 binding on neoplastic B cells can result in growth inhibition and activation-induced cell death (Funakoshi et al., 1994, Blood 83:2787-2794). Thus, CD40 activation in the context of different cell types, transformation, resident TRAFs and co-stimuli can induce responses ranging from activation and proliferation to growth inhibition and apoptosis.
2.2 Anti-CD40 Antibodies
With at least one exception, the anti-CD40 monoclonal antibodies ("mAbs") described to date are of three general classes: (1) those that block CD40/CD40L interaction by at least 90% and have anti-neoplastic properties (Armitage et al., U.S. Pat. No. 5,674,492; Fanslow et al., 1995, Leukocyte Typing V, Schlossman et al., eds., 1:555-556); (2) those that antagonize signaling through CD40 (deBoer et al., U.S. Pat. No. 5,677,165); and (3) those that deliver a stimulatory signal through CD40 but do not increase the interaction between CD40 and CD40L, e.g., G28-5, (Ledbetter et al., U.S. Pat. No. 5,182,368; PCT Publication WO 96/18413).
One mAb, CD40.4 (5C3) (PharMingen, San Diego, Calif.), has been shown to increase the interaction between CD40 and CD40L by approximately 30-40% (Schlossman et al., eds., 1995, Leukocyte Typing V: White Cell Differentiation Antigens 1:547-556).
Armitage et al. (U.S. Pat. No. 5,674,492) describes methods using CD40 binding proteins, including mAb HuCD40-M2, that are capable of binding CD40 and inhibiting the binding of CD40 to CD40L, for preventing or treating disease characterized by neoplastic cells expressing CD40.
DeBoer et al. (U.S. Pat. No. 5,677,165) describes anti-CD40 mAbs that, being free of significant agonistic activity, bind to CD40 on the surface of B-cells, and block B-cell activation. An essential feature of U.S. Pat. No. 5,677,165 is that upon binding of the anti-CD40 mAb to human CD40 on the surface of normal human B cells, the growth or differentiation of normal human B cells is inhibited.
Ledbetter et al. (U.S. Pat. No. 5,182,368) describes a ligand, G28-5, that binds to the B cell surface antigen Bp50 (now designated CD40) and stimulates activated B cells to traverse the cell cycle such that B cell proliferation is augmented. However, G28-5 does not enhance activation of B cells in the presence of CD40L, and does not potentiate CD40/CD40L interaction.
S2C6 is an anti-CD40 mAb that was prepared against a human bladder carcinoma (Paulie et al., 1984, Cancer Immunol. Immunother. 17:165-179). S2C6 binds to the CD40 receptor expressed on a variety of cell types including B-lymphocytes, endothelial and epithelial cells. S2C6 has been shown to have specificity toward neoplastic urothelium and B cell-derived malignant lymphocytes. Reactivity with a prostatic carcinoma cell line, HS, and weak reactivity with a melanoma has also been shown (Paulie et al., 1984, Cancer Immunol. Immunother. 17:165-179). Studies have suggested the utility of S2C6 as a diagnostic marker for B cell malignancies (Paulie et al., 1984, Cancer Immunol. Immunother. 17:165-179; Paulie et al., 1985, Eur. J. Cancer. Clin. Oncol. 21:701-710). In addition to detecting B cell malignancies, S2C6 has been shown to deliver strong growth-promoting signals to B lymphocytes (Paulie et al., 1989, J. Immunol. 142:590-595).
S2C6 has agonistic activity on human peripheral B cells as demonstrated by its ability to stimulate primary B cell proliferation in a dose dependent manner (Paulie et al., 1989, J. Immunol. 142:590-595).
Although competition studies have shown that G28-5 and S2C6 bind the same or proximal epitopes, the antibodies have been determined to be functionally different based primarily on the stated magnitude of stimulation achieved by either mAb on previously stimulated tonsillar B cells (Clark and Ledbetter, 1986, Proc. Natl. Acad. Sci. USA 83:4494-4498; Ledbetter et al., U.S. Pat. No. 5,182,368). One hundred times more S2C6 compared to G28-5 was required to achieve tonsillar B cell activation under the specific conditions tested (Ledbetter et al., U.S. Pat. No. 5,182,368).
There is a need in the art for therapeutics with increased efficacy to treat or prevent cancer, activate or augment the immune system or treat or prevent an immune deficiency or disorder, a need provided by the present invention.
Citation or identification of any reference herein shall not be construed as an admission that such reference is available as prior art to the present invention.

Methods for the treatment of cancer using anti-CD40 antibodies


Various embodiments described herein provide systems and methods for improved performance for power amplifiers, particularly GaN power amplifiers. According to some embodiments, a power amplifier (e.g., GaN power amplifier) utilizes an adaptive closed loop control of the drain current of the power amplifier to achieve improved performance for the power amplifier.

1. Field of the Invention(s)
The present invention(s) relate to power amplifiers, and more particularly, some embodiments relate to systems and methods for improved power amplifier performance.
2. Description of Related Art
The radio frequency (RF) power amplifiers and devices using Gallium Nitride (GaN) have benefits over other technologies such as gallium arsenide (GaAs). For example, GaN-based power amplifiers have exceptional power density (i.e., increased power per square millimeter of die) and exceptional power efficiency characteristics. Unfortunately, one of the challenges of using GaN-based power amplifiers is controlling the quiescent current (Iq) of such power amplifiers over a period of time. FIG. 1 provides a chart depicting the drift of the quiescent drain current (Idq) of an example GaN power amplifier over time. Such drift impacts certain systems, because as the quiescent drain current (Idq) of a GaN power amplifier changes, so does the performance of the GaN power amplifier. One solution to this is a "burn-in" procedure, whereby a GaN power amplifier is energized until the quiescent drain current (Idq) of the GaN power amplifier stabilizes. The "burn-in" procedure, however, is time consuming, it is difficult to tell how much time will be required for Idq stabilization (as it is difficult to predict the drift of the quiescent drain current over long periods of time), and a GaN power amplifier cannot be biased at a constant drain current for its drain current varies according with its RF power output.

Systems and methods for biasing amplifiers with adaptive closed loop control