A hospital bed (10) especially adapted for use by a woman giving birth is disclosed. The bed includes a base (11) on which a litter frame (12) is positioned. A lift assembly (14) attached to the base and is connected to a inner frame (50) located inside the litter frame. The lift assembly moves the inner frame and litter frame up and down. The litter frame is pivotally connected to the inner frame so that the litter frame can be selectively moved in the Trendelenburg position.

Over the years, the maternity bed on which a woman rests while giving birth has evolved into a useful aid for assisting in the birthing process. A maternity bed includes many of the elements of a conventional hospital bed. The bed has a base that forms the underlying support structure and a litter located above the base that serves as a support frame for the mattress on which the woman rests. Like many other hospital beds, a maternity bed is provided with a lift mechanism that raises and lowers the litter relative to the base. A maternity bed is further constructed so that the portion of the bed that supports the woman's upper body, referred to as the Fowler section, is able to pivot relative to the adjacent section, the seat section. The inclined Fowler section provides back support for the birthing mother so that she can be in an optimal position to facilitate delivery. A maternity bed is also usually provided with foot rests that are selectively positioned for the placement of the woman's feet. The foot rests and inclined Fowler section provide support for the mother so that she can generate muscle contractions along the birth canal that facilitate the delivery. A maternity bed is also usually designed so that the portion of the litter located anatomically below the seat section, referred to as the foot section, can be removed during the delivery process. The enables medical person to position themselves adjacent the open end of the birth canal so that they can provide the necessary assistance to the mother and child.
While current maternity beds have proved useful for facilitating the birthing process, they are not without some disadvantages. In a maternity bed, for example, it is desirable to design the lift mechanism so that the litter can be positioned both as close to the floor as possible and at normal, bed-height. This is because, as part of the delivery process, many women are encouraged to walk as much as possible prior to the commencement of the delivery in order to ease the delivery. The positioning of the bed close to the floor makes getting into and out of the bed a relatively easy task. Problems have arisen because a maternity bed should also be designed to pivot the litter into what is referred to as the Trendelenburg position. When the bed is in this position, the litter is oriented so that the woman's head and upper body are below her waist. It is desirable to pivot the bed into this position if, during the birthing process, the woman develops a cardiac condition and there is a need to ensure blood flow to the brain.
Beds have been provided with mechanisms that make it possible for both lift the litter and pivot it in the Trendelenburg position. However, many of these beds employ a manually actuated linkage for moving the litter into the Trendelenburg position. A disadvantage of this type of bed is that it requires medical personnel to spend time physically pivoting the litter; this takes away from the time available for attending to the woman. There have been attempts to provide beds with motor-driven systems for pivoting the bed into the Trendelenburg position. One disadvantage of these mechanisms is that the required numerous components. Still another disadvantage of some of these systems is that they operate in conjunction with the bed lift assembly and require the litter be lifted to its highest possible position before it can be pivoted into the Trendelenburg state. Clearly, a limitation associated with these beds is that if the litter is not already in full height position, time is lost having to properly position it before it can moved into the Trendelenburg position. The time lost having to raise the litter can, in some instances, be a factor in reducing the adverse effects the woman's medical condition.
Still another drawback of many maternity beds is that while they are provided with pivoting Fowler sections, the Fowler sections are not readily adjustable for women with varying body shapes and sizes. A relatively short woman, for example, may not be able to press her back against the Fowler even if it is in a fully inclined, almost upright, position. Furthermore, when a woman small in stature is positioned so that her back is against the Fowler section, the open end of her birth canal may not be positioned along the rear edge of the seat section, which is typically the optimal position for medical personnel to assist in the delivery process. In contrast, when the Fowler section is inclined, it may be difficult for a relatively tall woman to comfortably and safely be positioned so that her seat section rests firmly on the underlying mattress seat section.
Moreover, some maternity beds are designed so that in order to set their foot rests in position, it is necessary to flip-over and/or remove portions of the leg-and-foot section of the bed under which the foot rests are located. This may require repositioning and/or lifting of the woman's legs to gain access to the foot rests. Sometimes, having to move a woman's legs in order to be able to lift the foot-and-leg portions of a mattress in order to access the foot rests may require the attention of more than one individual. Furthermore, it is common practice to provide a maternity bed not only with foot rests but leg rests designed to hold the woman's legs open during the birthing process. Many of these leg rests are separate units that are installed by placement into complementary coupling mechanisms associated with the foot rests. The time required to place these leg rests in position likewise can sometimes divert medical personnel from more important tasks.
Still another limitation of some maternity beds is that the foot frame, the portion of the litter which supports the foot-and-leg mattress, may be difficult to quickly separate from the other sections of the litter. If there is a need to quickly access the woman's birth canal, medical personnel may lose some time in their efforts to separate this frame and mattress from the other elements of the bed.


A method of fabricating a turbomachine rotor disk is disclosed. In the method, a metal container is defined, made up of a plurality of parts that define between them at least one annular cavity, an insert made of composite material is positioned in the at least one cavity, the assembly is subjected to hot isostatic compacting, and a rotor disk is machined.

U.S. patent publication 2005/0166386 describes a method of fabricating an annular metal matrix reinforced by an annular insert of composite material. In that method, an annular groove is formed in a first annular metal part, a second annular metal part is formed that is suitable for constituting a cover for said groove, composite fiber turns are introduced into the groove, the cover is put into place, and the assembly is subjected to hot isostatic compression.
During that operation, the metal of the cover creeps into the cavity until all of the empty spaces between the turns have been filled.
It is known that such a hot isostatic compression operation is lengthy and expensive.
With the above-described prior method, it is not possible to make a metal matrix including an annular insert of considerable axial length.
In addition, with the prior method, making a drum of IBRs (a part that results from assembling a plurality of disks) assumes that welding is to be performed after each IBR has been individually fabricated. Such an operation carries risks, particularly since each IBR is expensive to make.
The invention enables this problem to be solved.

Method of fabricating a turbomachine rotor disk


A welding power source configured to receive an input power includes a plurality of components and supervising circuitry configurable in a plurality of modes. The plurality of components include power conversion circuitry and background power supply. The supervising circuitry is configured to distribute the input power to the plurality of components based at least in part on a mode of the plurality of modes. The plurality of modes include a welding mode configured to distribute the input power to the power conversion circuitry and to the background power supply. The plurality of modes also include a monitoring mode configured to distribute the input power to the background power supply, and to not distribute the input power to the power conversion circuitry.

The invention relates generally to welding systems, and, more particularly to welding power sources for reducing electromagnetic interference and power consumption.
Many types of welding power sources capable of providing a welding power from an alternating current (AC) or a direct current (DC) input power source have been developed. Typically, such welding power sources are configured to provide welding power to a torch for a welding process, such as a shielded metal arc welding (SMAW) operation, a tungsten inert gas welding (TIG) operation, a gas metal arc welding (GMAW) or metal inert gas welding (MIG) operation. Power conversion circuitry may convert the input power to welding power during the welding process. Welding power sources may also be configured to provide the input power to welding accessories and to other accessories. These welding accessories and other accessories may receive power from one or more power supplies within the welding power source. Unfortunately, the power conversion circuitry utilizes power and has power losses (e.g., heat, noise) whenever the power conversion circuitry is turned on. The power supplies also utilize power and have power losses when turned on, regardless of whether the power output is presently utilized by the welding accessories and other accessories. Moreover, some power supplies may cause electromagnetic interference when turned on. Reducing the electromagnetic interference with filter boards may add weight, bulk, and/or complexity to a welding power source.

Power source for reducing electromagnetic interference and power consumption


Memory devices, such as random access memory, are affixed to an electrical contact frame and coupled to signals lines on the contact frame which is, in turn, mounted on a top surface of an integrated circuit. The signal leads are coupled to electrical contact pads disposed on the top surface of the integrated circuit. The contact pads and signal leads transfer control and power signals between the integrated circuit and the memory devices.

One of the limitations of speed on a personal computer are the signal leads or traces on the motherboard that connect the microprocessor to memory devices such as random access memory. The length of the traces directly affects the speed at which signals can be exchanged between the microprocessor and the memory. Therefore, computer designers locate the memory as close to the microprocessor as possible within design constraints imposed by other components and the configuration of standard motherboards. As the complexity of personal computers increases and the size of the computer chassis decreases, the layout of the motherboard becomes a critical design limitation because of the clearances required between components on the motherboard, and between the motherboard and other integrated circuit boards in the chassis.
One solution to minimize the length of the traces has been to package the memory and the microprocessor together in the same assembly. However, doing so without radically modifying the configuration of the motherboard requires changing the die sizes of either the memory, the microprocessor, or both.
Therefore, there is a need for a combined microprocessor/memory assembly that minimizes the length of the traces without requiring changes to the die sizes of the microprocessor, the memory, or to the configuration of the motherboard.


The piezoelectric/electrostrictive properties and mechanical durability of a piezoelectric/electrostrictive ceramic can be improved. A piezoelectric/electrostrictive device has a laminated structure in which an electrode film, a piezoelectric/electrostrictive film, an electrode film, an piezoelectric/electrostrictive film, and an electrode film are laminated in the order mentioned on a thin portion of a substrate. The piezoelectric/electrostrictive films are ceramic films with a matrix of perovskite oxide that contains lead (Pb) as an A-site component and nickel (Ni), aluminum (Al), niobium (Nb), zirconium (Zr), and titanium (Ti) as B-site components. The piezoelectric/electrostrictive films are formed by firing as a unit the substrate that contains aluminum oxide and an intermediate coating film of perovskite oxide that contains components other than aluminum so that aluminum oxide is diffused from the substrate to the intermediate coating film.

Lead nickel niobate (Pb(Ni1/3Nb2/3)O3)-lead zirconate (PbZrO3)-lead titanate (PbTiO3) (hereinafter referred to as "PNN-based") ternary piezoelectric/electrostrictive ceramics have high electric-field induced strains and, thus, are preferably used in actuators.
Further, as disclosed in Patent Document 1, adding aluminum oxide (Al2O3) to such PNN-based piezoelectric/electrostrictive ceramics has also been considered for the purpose of improving sintering properties, piezoelectric/electrostrictive properties, and the like.
Patent Document 1: Japanese Patent Publication No. 54-29718

Piezoelectric/electrostrictive ceramics and piezoelectric/electrostrictive device


A reception apparatus includes a detection unit that detects occurrence of a phase slip in phase estimation values of time-series received symbol data, and determines an inclination of the phase slip, a delay processing unit that generates first received signal data obtained by delaying received signal data obtained from the time-series received symbol data by one symbol time interval, a phase shift unit that generates second received signal data by performing phase shift according to the inclination, only in a period in which one symbol time interval elapses, on only the received signal data of a symbol time at which the occurrence of the phase slip is detected among pieces of the received signal data, and a remainder processing unit that derives a remainder of a difference between the second received signal data and the first received signal data.

In a digital communication system that executes M-ary phase shift keying (M-PSK), an unnecessary phase component corresponding to characteristics of oscillation units of a transmission apparatus and a reception apparatus may be generated in symbol data received by the reception apparatus (hereinafter, referred to as "received symbol data"). The reception apparatus may estimate the unnecessary phase component by a Viterbi and Viterbi (V&V) method of raising a complex amplitude of the received symbol data to an M-th power, and may remove the unnecessary phase component from the received symbol data (see Non Patent Document 1). An optical coherent communication system executes differential coding and differential decoding of the symbol data. In recent years, a technology for implementing the transmission apparatus and the reception apparatus as software by general-purpose processors such as a central processing unit (CPU) and a graphics processing unit (GPU) has been attracting attention due to high performance of the general-purpose processors (see Non Patent Document 2).

Receiving apparatus, receiving method and program

NIPPON TELEGRAPH AND TELEPHONE CORPORATION


A perforated tray without downcomer having only a small deviation between the opening ratio based on the diameter of a column and the actual opening ratio and a perforated tray column without downcomer formed by disposing such perforated trays without downcomer are provided. The perforated trays without downcomer are characterized by having a ratio of (A)/(B) in the range of 1.1-1.5, wherein A denotes the opening ratio found from the standard pitch between centers of holes and (B) denotes the opening ratio based on the diameter of a column.

1. Field of the Invention
This invention relates to a perforated tray column without downcomer formed by setting perforated tray without downcomers in place and a method for distillation by the use of the perforated tray column without downcomer. More particularly, this invention relates to a perforated tray column without downcomer equipped with in place such perforated tray without downcomers in order to effectively prevent the formation of a polymer of an easily polymerizable compound such as (meth)acrylic acid or a liquid containing such an easily polymerizable compound (hereinafter occasionally represented simply as "easily polymerizable compounds") and allow an easily polymerizable compound to be distilled stably for a long time and a method for performing the distillation by the use of the perforated tray column without downcomer.
2. Description of the Related Art
Concerning such easily polymerizable compounds as (meth)acrylic acid and esters thereof, the distilling and rectifying such an easily polymerizable compound in the presence of oxygen or a polymerization inhibitor with the object of preventing the compound from polymerization has been heretofore practiced widely on a commercial scale. It has been also known to employ for this distillation perforated tray without downcomers and a perforated tray column without downcomer formed of these trays.
The perforated tray without downcomers used in the perforated tray column without downcomer each have holes formed nearly uniformly throughout the entire surface except those holes for clamps and bolts which are used in fixing the trays in conjunction with support beams and support rings. Since these perforated trays without downcomer are fixed with clamps and bolts inside the perforated tray column without downcomer generally in a divided pattern, they give rise to portions having no hole by reason of construction. Thus, a discrepancy arises between an actual opening ratio of the perforated tray of the column and an opening ratio of holes per unit area of the perforated tray.
When a perforated tray column without downcomer formed by setting in place such perforated trays without downcomer as revealing this discrepancy in an unduly large magnitude is used in distilling (meth)acrylic acid, for example, it encounters the problem that the efficiency of separation in the operation of distillation is lowered as compared with a counterpart having a smaller discrepancy. When the discrepancy is large, the distillation of (meth)acrylic acid, for example, performed with the wireless perforated tray column formed by setting in place perforated trays without downcomer of this large discrepancy entails the problem that since the operation possibly forms a polymer, it must be suspended to allow artificial or chemical removal of the polymer from the column.
The present inventors have proposed in U.S. Pat. No. 6,214,174, as a means to prevent the formation of a polymer during the distillation of (meth)acrylic acid, for example, even when the discrepancy revealed by the column in use is large, a method for promoting the prevention of the polymerization by providing perforated tray support members with openings adapted to preclude stagnation of a liquid on the support members. They have proposed in European Patent No. 1,029,573A2 a method for preventing the polymerization by specifying the diameter of holes in a perforated tray without downcomer, the distance between the centers of holes, the thickness of perforated trays, the opening ratio of holes, and the interval between adjacent perforated trays thereby preventing a liquid and a gas from channeling and imparting improved dispersibility thereto.
They, however, have been unable to discover a means which is effective in decreasing the discrepancy itself which arises between an actual opening ratio of the perforated tray of the column and an opening ratio of holes per unit area of the perforated tray.

Perforated tray column without downcomer


A coin feeding device is provided comprising a base plate adapted for mounting predetermined coins on one end thereof, including a scraper for scraping the coins towards the other or opposite end of the base plate along a predetermined coin feeding path. The scraper comprises a main rotating body rotatably mounted on the base plate and includes a coin feeding wing unit or finger assembly extending radially outwardly from the main rotating body. The coin feeding wing unit or finger assembly is used for feeding the coins to the other or opposite end of the base plate while traveling along the coin feeding path by virtue of the rotation of the main rotating body. The coin-feeding device includes a movable engagement piece biased to force one of the coins against the main rotating body along the coin feeding path.

This invention relates to a coin feeding device, and more particularly, to such a device for properly feeding a plurality of coins and medals (hereinafter, "coins") to a chute communicating with the outside of the device.
Recently, demand for a coin feeding device has been increasing in various environments such as a gamehouse or a playhouse. Typical coin feeding device of the type described is disclosed in, for example, Japanese Patent Publication No. 63-36040 to the same applicant as the present invention. The coin feeding device comprises, a base plate, a scraper arrangement, a hollow cylindrical case, a coin feeding disc, an outlet, a coin counter, and a driving unit. A plurality of coins are mounted on one end of the base plate and delivered, one by one, by means of the coin feeding disc. The scraper arrangement scrapes the delivered coins from the coin feeding disc towards the other end of said base plate along a predetermined coin feeding path. More particularly, the scraper arrangement comprises a main rotating body and a coin feeding wing unit. The main rotating body is rotatably mounted on the base plate. The coin feeding wing unit or finger assembly has a plurality of wings or fingers which extend radially outwardly from the main rotating body. In this manner, the wings or fingers feed the coins to the other end of the base plate by means of rotation of the main rotating body. The coin counter is arranged besides the outlet to count the coin to be thrown out of the coin feeding device. The counter is operatively connected to an actuating lever and a switching roller. When the number of coins reaches a predetermined amount, electricity to the driving unit (e.g. an electric motor) is immediately interrupted. Simultaneously, rotation of a main rotating body is stopped by means of a damping device, as described in, for example, Japanese Utility Model Publication No. 63-49802 to the same applicant as the present invention. Thus, the predetermined number of coins are to be thrown out.
However, in the conventional coin feeding device as described above, the coins delivered to the outlet by the scraper arrangement continue to move due to its inertia force after the rotation of the main rotating body is stopped. As a consequence, when such inertia force is relatively large, the coin pushes the actuating lever aside and is thrown out of the device. That is, an overabundant coin is thrown out. On the other hand, in case where the inertia force is relatively small, the actuating lever is pushed back due to the returning force of a return spring attached to the actuating lever through the switching roller is actuated. This causes incorrect counting.
In particular, recent tendency of the coin feeding device demands reduction of the necessary time which is required for feeding a plurality coins staying in the game machine with respect to psychological desire of game players and managerial desire of playhouse managers. In order to satisfy such requirements, the rotation speed of the driving unit is increased. As a result, the above mentioned problems have been magnified because of the inertia force.
In order to solve the above mentioned problems, the applicant of the present invention had tried using a spring having a large spring constant as the aforementioned return spring. However, this only overcomes the problems regarding to the excessive feeding of the coin and incorrect counting for the thrown out coins. Other problems have been occurred such as destortion of the actuating lever because of the overloading thereon.
It is therefore an object of the present invention to provide a coin feeding device which perfectly avoid the excessive feeding of the coin and incorrect counting for the coins.
Other objects and advantages of the present invention will be clear as the description proceeds.


A method and apparatus are provided for performing an array DML operation. During the performance of the operation on a data item in the array, and if an error occurs, then error information is stored and the array operation continues by performing the operation on the next data item in the array. The error is used to create update input data for the DML operation, and the update input data can be supplied during run-time of the program.

This present invention relates to databases and, more specifically, to methods and apparatus for reducing costs associated with manipulating data.
In a client-server architecture, the client (application program) relies on a server to perform some operations. In the context of database servers, the application program passes data to the server, the server stores the data, and the application program manipulates and retrieves the data by sending commands to the server.
Application programs typically interact with database servers using a query language such as the Structure Query Language (SQL). SQL is a powerful non-procedural language which serves as the industry standard for relational database management systems. Data Manipulation Language (DML) statements are SQL statements that retrieve or manipulate data in tables.
Frequently, database applications must manipulate large sets of records. For example, an application program APP1 may insert an array of data xe2x80x9cemployee_statsxe2x80x9d to a database server, where employee_stats consists of employee information for each of one thousand employees. Statements used to manipulate a series of records are referred to herein as array DML statements. The operations performed by database servers in response to array DML statements are referred to as array DML operations.
Various approaches may be used to pass data from an application program to a server. In one approach, APP1 passes employee_stats in the form of literal data (a xe2x80x9cliteralxe2x80x9d). A literal is a value written exactly as it is meant to be interpreted. A literal can be a number, a character, or a string. For example, in the expression,
Dept_Number=5
xe2x80x9cDept_Numberxe2x80x9d is a variable and xe2x80x9c5xe2x80x9d is a literal.
An application is able to pass literal data to the server only if the literal data is built into the code of the application program. Building literal data into an application program is known as hard coding. The drawback to hard coding is that the code of the application program needs to be changed and re-compiled each time there is a change to the literal data.
In another approach to providing data to a server, an application program passes data to a server using variables. For example, assume that APP1 uses an array xe2x80x9cINSERTxe2x80x9d statement to insert employee ID numbers into an array xe2x80x9cA( )xe2x80x9d. In database systems that support the Structured Query Language (SQL), such a statement may take the following form:
INSERT INTO A (e_id)
In this statement, xe2x80x9ce_idxe2x80x9d is a variable of data type number. In our example, xe2x80x9ce_idxe2x80x9d is a unique value used in identifying each employee. The array A( ) has a size of 1000, indicating that there are 1000 employee ID numbers. In response to this statement, the database server performs an INSERT operation 1000 times (one INSERT per row of the array). Each of the 1000 operations is referred to herein as a xe2x80x9cper-itemxe2x80x9d DML operation, because it only operates on a single item. Thus, a per-item DML operation means changing a single row of a given array.
Typically, a database server must perform a series of per-item DML statements in response to a single array DML statement. In one approach to handling array DML statements, the database server parses the INSERT statement before each per-item INSERT operation is executed in order to insert a row in array, A(1000). The database server parses the array DML statement to create an actual executable statement to perform the desired per-item operation on the data.
For example, the process of parsing involves passing the SQL statement, INSERT INTO A (e_id), from the user process to the database server (one round trip). During the parsing process, the database server, among other things, verifies that the SQL statement is syntactically and semantically valid, determines an execution plan for the statement, and allocates memory from a private region in memory (xe2x80x9cprivate SQL areaxe2x80x9d) to the verified SQL statement. Thus, parsing and execution is an expensive process because a roundtrip to the server is made each time a data manipulation language statement is to be parsed and executed and thus, the example above would result in 1000 roundtrips to the database server. However, the database may also allocate memory from a shared region in memory (xe2x80x9cshared SQL areaxe2x80x9d) to the verified SQL statement. The xe2x80x9cshared SQL areaxe2x80x9d is an area in memory used for processing subsequent occurrences of the same SQL statement. The database server parses a SQL statement only if a shared SQL area for an identical SQL statement does not exist. If a shared SQL area for an identical SQL statement exists, there is no need to completely parse the identical SQL statement again.
However, even in the case when the data manipulation language statement is parsed once but executed multiple times (i.e., only one roundtrip to the server is needed), there is another drawback when a failure occurs during the execution of an array DML statement. When a failure occurs, the performance of the array data manipulation operation is automatically aborted, even though the operation is incomplete. A new DML statement has to be re-issued in order to proceed with the operation. For example, assume that a failure occurs when performing the INSERT operation for the nth row in A(1000). An example of a failure is when the attempt to insert the nth row involves inserting a key value into a column that is subject to a uniqueness constraint, and the key value to be inserted matches a key value that already exists in the constrained column. Such an insertion attempt results in a xe2x80x9cUNIQUE KEY CONSTRAINT VIOLATIONxe2x80x9d. Assume that xe2x80x9cemployee IDxe2x80x9d is a unique value assigned to each employee and is stored in a unique key column of employee table. Thus, an attempt to insert a duplicate value in A(1000) would result in a Unique Key Constraint violation. In order to continue inserting values in the rest of the rows of A(1000), the INSERT statement must be re-issued, re-parsed and executed by the database server, resulting in at least an additional roundtrip to the database server. Thus, each failure that occurs during insertion of a row into A(1000) results in an additional roundtrip to the database server.
Based on the foregoing, there is a need for a method or mechanism for reducing the costs associated with manipulating data.
Techniques are provided for reducing the costs associated with manipulating data. According to one aspect of the invention, the techniques involve binding data by reference, performing data manipulation operation on a data item, and if an error occurs, then storing the error information and continuing the process by performing the operation on the next data item. In one feature, the error information is used to create corrective data for the data manipulation operation.

Method and apparatus for reducing costs associated with manipulating data


In a print system comprising a first printing unit for printing images on a first surface of a continuous sheet, a reading unit for reading an image, and a second printing unit for printing images on a second surface of the continuous sheet, in the case where the first printing unit prints a control image irregularly inserted between the images based on image data on the first surface of the continuous sheet, the first printing unit prints an identification mark which enables the control image to be identified on the first surface of the continuous sheet, and in the case where the reading unit reads an identification mark printed on the first surface of the continuous sheet, the second printing unit is caused not to print images based on image data in an area corresponding to the control image on the continuous sheet.

1. Technical Field
The present disclosure relates to a control apparatus, a control method, and a program.
2. Description of the Related Art
When printing is performed on continuous paper like roll paper, a method to use a plurality of printing apparatuses is known. In Japanese Patent Application Laid-Open No. 2008-149657, a first printing apparatus prints a plurality of control marks to be used for controlling print processing by a second printing apparatus for each image based on image data. Then, the second printing apparatus controls the print processing by reading the plurality of control marks. More specifically, a top of form (TOF) mark for adjusting a difference between print start positions on a front surface and on a back surface and a mark for adjusting a mismatch between print data printed on the front surface and print data printed on the back surface are described as the control marks. In addition, a color registration mark for adjusting color shift of print data printed on the front surface and the back surface and a post-processing mark indicating a position to be cut in a post-processing apparatus are described as other control marks.
However, the method described in Japanese Patent Application Laid-Open No. 2008-149657 performs print processing by setting a print output position of each mark based on sheet information. Therefore, for example, in the case of ink-jet method, printing cannot be performed if an irregular image pattern, such as a preliminary discharging pattern and a non-discharge monitoring pattern, is inserted.

Control apparatus, control method, and program


A method includes performing by a processor: receiving a plurality of power system phase angle measurements over a time interval from a plurality of phasor measurement units (PMUs) in a power system, generating a phase angle curve over the time interval based on the plurality of power system phase angle measurements, and detecting a sustained oscillation event in a power signal generated by the power system based on an envelope of the phase angle curve.

The present disclosure relates to power systems, and, in particular, to monitoring of power systems and frequency regulation of power systems.
The frequency of a power system may be affected by the balance between power generation and load consumption. Power consumption and/or power generation may both vary, which may result in the two rarely being precisely in balance. During normal operation, changes in frequency may be controlled by ancillary services that provide continuous, automatic frequency control through automatic generator control (AGC). However, severe electromechanical disturbances, such as generation trip and load reduction, can cause significant drops and/or increases in system frequency and may influence the dynamic behavior of a power grid. Therefore, it is generally desirable to prevent and/or reduce large deviations of the power system frequency from the nominal frequency during large disturbances and so as to improve the operational stability of power systems.
Modern power systems are progressively more interconnected on transmission networks and more interactive with distributed renewable power generation sources in distribution networks due to increasing power demand. This situation may create more technical challenges in the context of oscillations. Sustained oscillations have emerged as a threat to the operation stability of power grids worldwide. In addition the conventional poorly or negatively damped oscillations caused by insufficient system damping, there are forced oscillations caused by small and periodic external faults. The properties and behaviors of these two oscillations are well established in the literature. If the electromechanical eigenvalues of the power system are stable, the conventional oscillations will typically damp and the system will converge to a new stable status. These events may be called "natural oscillation" events. Actions can be taken to suppress the natural oscillations, such as installing a Power System Stabilizer (PSS), constructing new transmission lines, reducing gains of exciters on strongly related generators, etc. "Forced oscillation" refers to a type of system response to cyclic inputs often brought about by prime mover pressure pulsation, malfunction of a PSS, periodic load disturbances, etc. Forced oscillations generally respond to the disturbances quickly, and typically terminate immediately once the disturbances are withdrawn. Besides zero or negative damping natural oscillations and large magnitude forced oscillations, small cyclic input that coincides at a node nearby a weakly damped system node may result in resonance causing the generation of an output at a much larger magnitude than the input, which may be a threat to the stable operation of a power system.

Power system detection of sustained oscillations based on synchrophasor frequency measurements

University of Tennessee Research Foundation


In a lens module assembly method, a lens holder is placed in a receiver. The lens holder has a nest. A lens element is deposited in the lens holder. During the depositing, the lens element seats in the nest, if the lens element is in a forward-facing orientation. Entry of the lens element into the nest is interrupted, if the lens element is in a rearward-facing orientation.

Lens modules for one time use cameras and other optical devices are commonly made by assembling lens components, such as optical elements and aperture stops into a holder and attaching a retainer to hold the lens components in place. The assembly can be manual or automated. In both cases, mistakes can be made as to the orientation of individual optical elements. Such mistakes can occur during placement in the lens module or during an earlier step. For example, an individual lens element can have been positioned upside down in a rack or the like, which feeds an automated assembly tool. Once the lens module is assembled, it is not immediately apparent that one or more optical elements may have been reversed. Optical testing and other methods can be used to determine if the placement is correct. These methods tend to be cumbersome and add cost.
It would thus be desirable to provide improved lens module assembly methods and assembly intermediates, in which incorrect lens placement can be simply and easily prevented.

Lens module assembly method and assembly intermediate


According to various embodiments, a write control circuit configured to control writing to a memory cell by applying a writing current to the memory cell may be provided. The write control circuit may include: a current application circuit configured to apply the writing current to the memory cell; a determination circuit configured to determine whether writing to the memory cell is finished; and a stop writing circuit configured to cut off the writing current from the memory cell if it is determined that writing to the memory cell is finished.

Resistive non-volatile memory (NVM) may have a write pulse width distribution for different cells. Clock controlled 'set' and 'reset' may have the same pulse width for all NVM cells. The pulse width may be desired to meet the worst case (longest pulse width) with margin. The cells with short "set/reset" pulse width may be over written, which may increase the resistance distribution and reduce endurance of the cells. Thus, there may be a need for an advanced writing scheme.

Write control circuits and write control methods

Agency for Science, Technology and Research


No wide bulk diamond wafer exists at present. A wide diamond-coated wafer is proposed instead of the bulk diamond wafer. Diamond is heteroepitaxially deposited on a convex-distorted non-diamond single crystal substrate by a vapor phase deposition method. In an early step, a negative bias is applied to the substrate. In the case of a Si substrate, an intermediate layer of .beta.-SiC is first deposited on the Si substrate by supplying a low carbon concentration material gas. Then the carbon concentration is raised for making a diamond film. The convex-distorted wafer is stuck to a holder having a shaft which is capable of inclining to the holder. The wafer is pushed to a turn-table of a polishing machine. The convex diamond wafer can fully be polished by inclining the holder to the shaft. A wide distorted mirror wafer of diamond is produced. Fine wire patterns can be made on the diamond mirror wafer by the photolithography.

This application claims a priority based on Japanese Patent Application No.6-165915 (165915/94) filed Jun. 24, 1994. Diamond has excellent physical and chemical properties. Current technology, however, cannot make a large diamond crystal yet. The ultra-high pressure synthesis method can produce bulk diamonds which are at large several millimeters in diameter. The diamond granules are too small to make devices thereby. There is no wide diamond crystal which has a wide area and can be safely called a wafer yet. Unfortunately, the Bridgman method, the Czochralski method or any other method cannot pull a thick diamond single crystal up from a melt unlike Si or GaAs. There is no effective method of growing a large diamond single crystal yet. The difficult of making a bulk crystal prevents from producing a bulk diamond wafer.
The use of a material in the electronics devices requires at least one inch diameter of a wafer. Furthermore 2 inch, 3 inch or 5 inch diameter wafers are desired for fabricating electronic devices on them. The applicability to the production line of devices demands less than 1 mm thickness of a wafer. Thus, the application of diamond to the device technology ardently requires a polycrystalline diamond wafer having a diameter of more than 1 inch and a thickness of less than 1 mm.
Further, a single crystal diamond wafer would be more convenient for making electronic devices of high quality. The feasible production of high quality single crystal wafers of Si or GaAs allowed the manufactures to make lots of Si or GaAs devices with stable performance.
Films of diamond can now be produced by a vapor phase synthesis method. The chemical vapor phase method produces a film of diamond on a pertinent substrate by heating the substrate in a reaction chamber, supplying a material gas to the reaction chamber, exciting the material gas, inducing a chemical reaction and depositing the result of the chemical reaction on the substrate. The material gas includes at least hydrogen gas and a hydrocarbon gas. In addition, boron-including gas, or nitrogen-including gas or other impurity gas is also supplied into the reaction chamber for changing the electric property or other properties by the impurity doping.
The chemical vapor deposition method is classified by the ways of exciting the material gas into a heat filament method, a microwave plasma CVD method, a radio-frequency plasma method, a DC plasma CVD method and so forth. Some method enables to make a wide diamond film. The speed of synthesis, however, is not fast. Thus, it is rather difficult to produce a thick diamond film by the method.
Nevertheless, there is not yet such a material as can be called a "diamond wafer" in the true meaning. The present technology Is still incapable of making a polycrystalline diamond wafer. Furthermore, nobody has succeeded in producing a single crystal diamond wafer.
Since no big bulk diamond can be produced yet, it is entirely impossible to make a homogeneous diamond wafer which consists only of diamond. A complex wafer may be produced even by the current technology by depositing a diamond film on a pertinent substrate. Since the diamond film is so thin that the substrate should remain for reinforcing the strength of the film. Thus, the complex wafer would consist of a diamond film and a substrate. If such a complex wafer of diamond were produced, the diamond film would be still polycrystalline. Thus the current technology is distanced far away from a single crystal diamond wafer. The single crystal diamond would be the most useful for all utilities. Since no big diamond bulk single crystal cannot be made at present, it is entirely impossible to make a monocrystalline diamond by homoepitaxy.
Some methods of heteroepitaxy were proposed by Japanese Patent Laying Open No.63-224225 (224225/1988), Japanese Patent laying Open No.2-233591 (233591/1990) and Japanese Patent Laying Open No.4-132687 (132687/1992).
They alleged that diamond single crystal films were heteroepitaxially grown on a SiC substrate, a Si substrate, a nickel substrate or a cobalt substrate.
Electronic devices or abrasion-resistant discs often make use only of a surface of a material. Thus, such a complex wafer may be useful to some extent. There is, however, no complex diamond wafer which is truly applicable for industrial purposes.


Compositions and methods are disclosed which employ PARIS proteins that are useful for suppressing proliferation of smooth muscle cells. Preferred PARISs are soluble proteins that are secreted by vascular smooth muscle cells, and include PARIS-1 (neuronal pentraxin 1), PARIS-2 (SBP (MIC-1, GDF-15), PARIS-3 (BTG2) and PARIS-4 (soluble fractalkine). Methods of preventing or treating restenosis by administering the new compositions are disclosed. Also disclosed are methods for treating patients undergoing angioplasty procedures, patients with atherosclerosis, and patients with other proliferative disorders, in order to suppress the growth of vascular smooth muscle cells or other cells that play a role in the particular proliferative disorder or condition. A method of screening mRNAs and identifying genes encoding PARISs is also disclosed.

1. Technical Field of the Invention
The present invention generally relates to compositions and methods for prevention of proliferative disorders, including restenosis, atherosclerosis and cancer. More particularly, the invention relates to compositions containing molecules secreted by cells and which are capable of inhibiting proliferation of those and/or other cells. The invention also relates to therapeutic methods employing such compositions.
2. Description of Related Art
Percutaneous transluminal coronary interventions ("PCI") such as angioplasty procedures are common practice today for relieving atherosclerotic blockage caused by fatty acid deposits in coronary arteries, whereby blood flow is restored in the affected arteries. A relatively common complication of angioplasty is restenosis, a renarrowing of the blood flow due to uncontrolled proliferation of smooth muscle cells at the angioplasty site. Post-angioplasty restenosis was first treated by balloon redilatation and, when stents became available1, by stent implantation2. However, close to 20% of patients developed restenosis within the stent ("in-stent restenosis")2, due to neointimal VSMC growth3. In-stent restenosis was initially treated by repeat angioplasty, rotational atherectomy, laser angioplasty, "stent-in-stent", and other techniques, but all of those procedures yielded suboptimal outcomes4. Brachytherapy has been investigated for preventing restenosis12,13 after primary angioplasty, however, at least 15% of patients treated with brachytherapy still develop restenosis, suggesting that the prevention of restenosis by brachytherapy is not entirely efficacious13. It has been reported that brachytherapy only moderately reduced the recurrence rate of in-stent restenosis (from 43.8% to 28.2%)5, at the expense of adverse radiation exposure both to patients and operators and of late-occurring, intralesional thrombosis.
Among a number of pharmacological interventions attempted, only a few preventive strategies, such as probucol6, trapidil7, cilostazol8, n-3 fatty acid (eicosapentaenoic acid)9, and folic acid combined with vitamin B12 and pyridoxine10, have been found acceptable. Even in the better trials, restenosis still developed in 17.9–24.2% of patients. When stent implantation was used to treat primary lesions in order to prevent restenosis, a significant number (18%) of patients who underwent stent implantation experienced restenosis nevertheless1,2,11. It has been reported that stents coated with sirolimus (also known as rapamycin) are more effective than conventional stents in a randomized, double-blind clinical trial55, and recently the FDA has approved a sirolimus-eluting coronary stent for angioplasty procedures to open clogged coronary arteries. Long-term effects and side-effect profiles of sirolimus have not been determined in a large clinical trail, however.
Although brachytherapy and sirolimus-eluting stents may effectively treat a selected group of patients with restenosis, those treatment modalities are likely to remain very expensive and exclusive. For example, the cost of sirolimus-eluting stents is estimated to be four times higher than that of conventional stents, while brachytherapy requires the involvement of radiation oncologists and nuclear physicists. It has been estimated that up to a million PCIs are being performed annually in North America alone14. A therapeutically viable, lower-cost treatment that can significantly reduce the risk of restenosis is greatly needed. It has been calculated that a treatment that reduces risk of restenosis by 25–33% risk reduction would save approximately $1,400–$2,000 per patient in hospital, procedural and professional fees, with a total savings in North America alone of $400–800 million a year15.

Composition and method for treatment and prevention of restenosis

The Board of Regents of the University of Texas System


A method for estimating a force exerted by a first body onto a second body including the steps of providing a motor having at least one detectable motor signal, wherein the motor is adapted to advance the first body into engagement with the second body, determining a first value for the motor signal prior to the first body engaging the second body, determining a second value for the motor signal after the first body engages the second body, and generating a force value based upon a comparison of the second value to the first value.

The low force level detection system and method relates to systems and methods for detecting force and, more particularly, systems and methods for detecting low force levels in electromechanical brake systems.
Electromechanical brake systems typically include a housing, a rotor, brake pads, an actuator/caliper and a motor. The actuator is adapted to drive the brake pads into engagement with the rotor, thereby clamping the rotor between the pads. The motor drives the actuator into engagement with the brake pads and the rotor. Therefore, the amount of force applied to the rotor by the brake pads is a function of the distance that the actuator is advanced by the motor.
Prior art systems attempt to detect the position of the actuator at the onset of force (i.e., the point of initial contact). Then, assuming that the brake system can be modeled as a spring, the braking force may be calculated using Hooke's law:F0=k(x0−xi)  (Eq. 1)wherein F0 is the braking force, k is the spring function of the system, xi is the position of the actuator at the onset of force and x0 is the position of the actuator at a subsequent time.
Such prior art systems attempt to detect the actual contact point. However, at the onset of force, the signal to noise level of the distinguishable signals is small and difficult to use. Therefore, such systems often encounter difficulty identifying the point at which contact is made and/or force is applied, thereby giving rise to inaccurate measurements of braking force.
Accordingly, there is a need for an improved system and method for estimating the contact force between two bodies.

Low force level detection system and method


Embodiments relate to an apparatus for adjusting channel quality indicator measurements of a channel between a client device and a serving device within a wireless communication system. The apparatus includes a controller adapted to receive, from the client device, a first information and, when the client device is in a handover zone, a second information. The controller is further adapted to transmit according to a switching sequence either the first information alone or the first information together with the second information. The apparatus also includes an adjustment function entity adapted to receive the first information together with the second information and adapted to adjust the first information based on the second information by modifying it or keeping it unchanged. The first information is related to the CQI measurements, while the second information is related to a handover (HO).

In current radio access technologies, the communication systems automatically adapt their transmission to their propagation channel. As those channels are highly unstable, frequent feedbacks are performed through channel quality indicator (CQI) measurements performed on the transmitted data in the downlink. These measurements, which are performed at the user equipment (UE) device, are then transformed into a single scalar value, which is fed back to the base station (BS) in order to adjust and select, for example, the appropriate modulation and coding scheme (MCS) used to serve the concerned UE device. The computation of the CQI is based on the signal-to-interference-plus-noise ratio (SINR), which takes different degradation terms, such as propagation path-loss, shadowing, fast fading and random inter-cell interference factors, into consideration.
This interference can usually be regarded as a noise mainly caused by the use of inter-cell interference coordination schemes. Nevertheless, this assumption does not hold anymore when the UE device gets closer to the cell edge. In fact, in these overlapping regions, the interference component due to the transmission of neighboring base stations becomes almost equivalent to the useful signal received from the serving base station and aimed at the considered UE device.
In these circumstances, the SINR is highly affected by the interference component. However, the perceived interference level highly depends on the load of the neighboring base stations, which is related to the requested traffic of their attached UE devices as well as their respective schedulers. As a result, the reported CQI at a given time slot N can be drastically different from the CQI at a later time N+1.
Moreover, there is always a delay between the instant when the measurements are performed and the instant when they are actually used in the network at the BS level. Due to this delay, the network performance can be prejudicially affected. In this regard, the document entitled: Z. Shen, J. G. Andrews and B. L. Evans, "Short range wireless channel prediction using local information", in Proceedings IEEE Asilomar Conference on Signals, Systems and Computers, vol. 1, pp. 1147-1151, Nov. 9-12, 2003, Pacific Grove, Calif., USA, discloses a capacity loss up to 17% at a Doppler frequency of 10 Hz due to delayed channel state information (CSI) measurements.
Given the above statements, the performance loss is even more important at the cell edge and the usage of the CQI that has been fed back at a time slot N would become obsolete at a later time slot N+1. This might highly underestimate the interference and thus lead to a transmission failure (e.g., a call drop) or, conversely, lead to an over estimation of the interference component, thereby drastically reducing the achievable rate.
Such a problem has been widely addressed in the prior art and the common solutions point towards the CQI prediction and its target usage such as the adaptive modulation and coding (AMC) design optimization. In general, the proposed solutions consider a set of observations as an input. Based on these input observations collected up to an instant N, an extrapolation is carried out in order to estimate the potential values at the next instants N+1, . . . , N+L, where L is the prediction horizon value.
However, all these solutions only consider as input the CQI as reported by the attached UE devices, whereas there is an extra information that is available at the BS and can be potentially helpful to better assess the channel quality. This additional information is fed back by the UE device during a handover (HO) procedure and is related to the channel quality through a measurement of the reference signal received power (RSRP) and/or the reference signal received quality (RSRQ). Unlike the CQI, these channel quality indicators (RSRP, RSRQ) are independently computed and performed on signals that are not affected by the random interference since the measurements are achieved on control channels.

Method and apparatus for adjusting channel quality information (CQI) considering handover


An adjustable support structure for a panel computer includes: a cradle having a slide slot at a middle section, at least two fastening slots placed at a bottom surface of the slide slot, and at least two pairs of positioning holes separately corresponding to the fastening slots are placed on two side walls of the slide slot. The back end of the support prop is optionally pushed against one of the fastening slots in the cradle; therefore, the cradle, the back support and the support prop which form a triangularly linked structure. The elastic unit can be pressed to drive the two positioning tabs to leave the positioning holes, so that the support prop can slide along the parallel track until the back support is at a desired leaning angle.

1. Field of the Invention
The present invention relates to an adjustable support structure, and more particularly, to an adjustable support structure for a panel computer.
2. Description of the Related Art
Currently, desktop computers and notebook computers have been gradually replaced by panel computers, as panel computers are easier to carry, are touch-controlled and utilize digital ink.
Generally, user simply holds the panel computer when using it. However, the user is usually sitting down when using the panel computer, and if the panel computer has no support element for itself, it can only be placed upon a table, which limits the viewing angle for the user.
A prior art support for the panel computer comprises a cradle, a shelf, and a supporting arm, which are all pivoted with respect to each other to hold the panel computer at a particular angle. However, this prior art support has the problem that when the user wants to pack the support, the cradle, the shelf, and the supporting arm cannot be packed in a stable configuration, which is inconvenient for portability. Furthermore, the prior art does not provide different viewing angles for the panel computer, and so the user may be unable to find a satisfactory viewing angle.
Therefore, it is desirable to provide an adjustable support structure for a panel computer to mitigate and/or obviate the aforementioned problems.

Adjustable support structure for a panel computer


Shielding gas mechanisms for arc welding systems are shown and described. The shielding gas mechanisms each include a gas sensor configured to read and provide a measurement of the shielding gas and a shut-off mechanism configured to stop power to a welding gun when the measurement of the shielding gas falls below a minimum effective level. In some examples, the gas sensor is coupled to the gas line proximal to an inlet of a wire feed unit. In some other examples, the gas sensor is coupled to the gas line proximal to an outlet of the wire feed unit. In even other examples, the gas sensor is coupled to the welding gun.

The present disclosure relates generally to shielding gas mechanisms for arc welding systems. In particular, arc welding systems including gas pressure sensing and automatic shut-off mechanisms are described.
Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and a base material to melt metal at a desired welding point of a work piece. Arc welding systems generally use a shielding gas mechanism to provide a shielding gas (i.e., inert or semi-inert gas) in order to protect the welding region of a work piece during a welding operation. Specifically, the shielding gas protects the welding point from oxygen and water vapor. Thus, insufficient shielding gas can lead to porous welds, weak welds, and/or cause splatter, which can increase the working time by requiring additional clean up.
Known shielding gas mechanisms are not entirely satisfactory for the range of applications in which they are employed. For example, existing shielding gas mechanisms include hoses that may undergo kinking and/or damage, thereby stopping or slowing the flow of gas. Further, hose fittings may degrade with use or loosen causing gas leaks. In addition, in conventional shielding gas mechanisms, the gas supply can run low or run out without alerting the user that the gas flow is stopped or insufficient to provide effective shielding.
Thus, there exists a need for shielding gas mechanisms that improve upon and advance the design of known shielding gas mechanisms. Examples of new and useful shielding gas mechanisms relevant to the needs existing in the field are discussed below.


An exposure apparatus illuminates a mask with exposure light emitted from an illumination optical system and projects a mask pattern image that is formed when the exposure light passes through the mask onto a photosensitive substrate. The illumination optical system includes an optical element for making the intensity distribution of exposure light emitted from the light source uniform, and aperture stops are interchangeably positioned directly behind the optical element. The illumination optical system additionally includes an adjusting mechanism that adjusts the positions and the inclination of the optical element and the aperture stops in the direction along the optical axis in directions perpendicular to the optical axis, and with respect to the inclination from the optical axis. Thus, the positional relationship between the optical element and the aperture stops can be kept constant, and as a result, the exposure accuracy of an exposure apparatus can be improved.

This invention relates to an exposure apparatus and, more particularly, to a projection exposure apparatus including an adjustable holder mechanism that controllably adjusts positions of an optical element and a plurality of aperture stops relative to each other and to the optical axis.
When manufacturing, for example, a semiconductor integrated circuit or liquid crystal substrate using a lithography technique, a resist film formed on a sample substrate is exposed into a predetermined pattern. In this exposure process, a projection exposure apparatus is generally used.
A projection exposure apparatus illuminates a reticle (mask), on which a prescribed circuit pattern is formed, with illumination light emitted from a light source. When the illumination light passes through the reticle, an image of the reticle pattern is formed. The reticle pattern image is projected through a projection optical system onto the resist film on the sample substrate. Thus, the resist film is exposed into the prescribed circuit pattern.
Recently, in connection with this type of projection exposure apparatus, many proposals have been made to make uniform an intensity distribution of illumination light that is guided to the reticle. For example, it has been proposed to provide an optical element called a fly-eye lens in the optical path of illumination light between the light source and the reticle. Japanese patent application laid-open No. 5-175100 discloses aperture stops positioned directly behind the fly-eye lens in an interchangeable manner, and one of the aperture stops is selected as necessary to chance the illumination condition of illumination light guided to the reticle.
However, in the prior art, even if a fly-eye lens is provided in the illumination optical system, which extends from the light source to the reticle, and even if interchangeable aperture stops are positioned immediately after the fly-eye lens, there is no consideration given to the positional relationship between the fly-eye lens and the aperture stop.
In recent years, improved exposure accuracy is demanded as the exposure pattern becomes smaller. To this end, it becomes necessary to maintain the stability of the positional relationship between the fly-eye lens and the aperture stop.


The present invention relates to a method for nucleic acid replication and novel artificial base pairs.

Nucleic acids are amplified and act as catalysts and ligands through complementarity of A-T(U) and G-C base pairs. However, unlike 20 different amino acids in natural proteins, natural nucleic acids are composed of nucleotides consisting of only 4 different bases. This number limit restricts the functions of DNA and RNA molecules. Unnatural base pair systems provide a resolution to this problem because they increase the types of nucleic acid bases to allow expansion of genetic information (Non-patent Documents 1-5). Unnatural base pairs are required to have highly specific complementarity which allows site-specific incorporation of special nucleotide analogs into DNA and RNA through polymerase-catalyzed reactions. If this requirement is achieved, current genetic engineering technology, which is limited by the number of naturally-occurring bases, can be replaced with a novel technology using unnatural base pair systems.
The first attempt to create unnatural base pairs was made by Benner et al (Non-patent Documents 6-7). They developed some unnatural base pairs, including isoguanine-isocytosine (isoG-isoC) and xanthosine-diaminopyrimidine, based on different hydrogen bonding patterns than those of natural base pairs. Recently, these unnatural base pairs have been applied to PCR amplification (Non-patent Documents 8-9) and sequence analysis (Non-patent Document 10) of DNA fragments containing these base pairs. However, the fidelity is relatively not high and/or complicated procedures are required. In addition to these problems, 2-aminopyrimidine analogs such as isoC and diaminopyrimidine are not recognized as substrates by T7 RNA polymerase. Thus, these base pairs are of limited use.
Subsequently, Kool et al. synthesized hydrophobic bases having shapes similar to those of natural bases, but lacking the ability to form a hydrogen bond during base pairing (Non-patent Documents 11-12). These hydrophobic bases were selectively recognized by DNA polymerases, suggesting that geometric shape complementarity between paring bases is more important during replication, rather than hydrogen bonding interaction. Recently, a series of hydrophobic base pairs have been developed by Romesberg et al. and introduced into DNA in a complementary manner by the action of the Klenow fragment of E. coli-derived DNA polymerase I (Non-patent Documents 13-15). However, these hydrophobic bases did not conform to shape complementarity during replication, and their non-selective introduction through enzymatic reactions occurred between hydrophobic bases (Non-patent Document 14). Moreover, there is no report of these hydrophobic base pairs functioning during transcription.
By combining the ideas of hydrogen bonding pattern and shape complementarity, the inventors of the present invention developed unnatural base pairs between 2-amino-6-(2-thienyl)purine (s) and 2-oxopyridine (y) (Non-patent Documents 16-17) as well as between 2-amino-6-(2-thiazolyl)purine (v) and y (Non-patent Document 18). The bulky substituents at the 6-position of s and v efficiently prevented undesirable base pairing (non-cognate pairing) with a natural base, and a substrate (nucleoside 5′-triphosphate) of y or modified y was introduced in a site-specific manner into RNA opposite s or v in the template by the action of T7 RNA polymerase. This specific transcription is available for practical use as a means for developing functional RNA molecules (Non-patent Documents 19-21), but the selectivity of s-y and v-y base pairings during replication is not notably higher than that during transcription (Non-patent Documents 16 and 18).
To solve the problems stated above, there is a demand for a novel artificial base pair showing excellent efficiency and selectivity during replication and transcription (for design of functional nucleic acids) or during all of replication, transcription and translation (for design of functional proteins).
The following documents are listed as reference documents, the entire contents of which are incorporated herein by reference.                Patent Document 1: WO2001/005801        Patent Document 2: WO2004/007713        Patent Document 3: WO2005/026187        Patent Document 4: Japanese Patent Application No. 2005-226492
Non-patent Document 1: Benner, S. A., Burgstaller, P., Battersby, T. R. & Jurczyk, S. in The RNA World (eds Gesteland, R. F., Cech, T. R. & Atkins, J. F.) 163-181 (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1999).
Non-patent Document 2: Henry, A. A. & Romesberg, F. E. Beyond A, C, G and T: augmenting nature's alphabet. Curr. Opin. Chem. Biol. 7, 727-733 (2003).
Non-patent Document 3: Moser, M. J. & Prudent, J. R. Enzymatic repair of an expanded genetic information system. Nucleic Acids Res. 31, 5048-5053 (2003).
Non-patent Document 4: Bergstrom, D. E. Orthogonal base pairs continue to evolve. Chem. Biol. 11, 18-20 (2004).
Non-patent Document 5: Benner, S. A. & Sismour, A. M. Synthetic biology. Nat. Rev. 6, 533-543 (2005).
Non-patent Document 6: Piccirilli, J. A., Krauch, T., Moroney, S. E. & Benner, S. A. Enzymatic incorporation of a new base pair into DNA and RNA extends the genetic alphabet. Nature 343, 33-37 (1990).
Non-patent Document 7: Switzer, C. Y., Moroney, S. E. & Benner, S. A. Enzymatic recognition of the base pair between isocytidine and isoguanosine. Biochemistry 32, 10489-10496 (1993).
Non-patent Document 8: Sismour, A. M. et al. PCR amplification of DNA containing non-standard base pairs by variants of reverse transcriptase from Human Immunodeficiency Virus-1. Nucleic Acids Res. 32, 728-735 (2004).
Non-patent Document 9: Johnson, S. C., Sherrill, C. B., Marshall, D. J., Moser, M. J. & Prudent, J. R. A third base pair for the polymerase chain reaction: inserting isoC and isoG. Nucleic Acids Res. 32, 1937-1941 (2004).
Non-patent Document 10: Ahle, J. D., Barr, S., Chin, A. M. & Battersby, T. R. Sequence determination of nucleic acids containing 5-methylisocytosine and isoguanine: identification and insight into polymerase replication of the non-natural nucleobases. Nucleic Acids Res. 33, 3176-3184 (2005).
Non-patent Document 11: Morales, J. C. & Kool, E. T. Efficient replication between non-hydrogen-bonded nucleoside shape analogs. Nat. Struct. Biol. 5, 950-954 (1998).
Non-patent Document 12: Kool, E. T., Morales, J. C. & Guckian, K. M. Mimicking the structure and function of DNA: Insights into DNA stability and replication. Angew. Chem. Int. Ed. 39, 990-1009 (2000).
Non-patent Document 13: McMinn, D. L. et al. Efforts toward expansion of the genetic alphabet: DNA polymerase recognition of a highly stable, self-pairing hydrophobic base. J. Am. Chem. Soc. 121, 11585-11586 (1999).
Non-patent Document 14: Wu, Y. et al. Efforts toward expansion of the genetic alphabet: optimization of interbase hydrophobic interactions. J. Am. Chem. Soc. 122, 7621-7632 (2000).
Non-patent Document 15: Ogawa, A. K. et al. Efforts toward the expansion of the genetic alphabet: Information storage and replication with unnatural hydrophobic base pairs. J. Am. Chem. Soc. 122, 3274-3287 (2000).
Non-patent Document 16: Fujiwara, T., Kimoto, M., Sugiyama, H., Hirao, I. & Yokoyama, S. Synthesis of 6-(2-thienyl)purine nucleoside derivatives that form unnatural base pairs with pyridin-2-one nucleosides. Bioorg. Med. Chem. Lett. 11, 2221-2223 (2001).
Non-patent Document 17: Hirao, I. et al. An unnatural base pair for incorporating amino acid analogs into proteins. Nat. Biotechnol. 20, 177-182 (2002).
Non-patent Document 18: Mitsui, T., Kimoto, M., Harada, Y., Yokoyama, S. & Hirao, I. An efficient unnatural base pair for a base-pair-expanded transcription system. J. Am. Chem. Soc. 24, 8652-8658 (2005).
Non-patent Document 19: Kimoto M. et al. Site-specific incorporation of a photo-crosslinking component into RNA by T7 transcription mediated by unnatural base pairs. Chem. Biol. 11, 47-55 (2004).
Non-patent Document 20: Moriyama, K., Kimoto, M., Mitsui, T., Yokoyama, S. & Hirao, I. Site-specific biotinylation of RNA molecules by transcription using unnatural base pairs. Nucleic Acids Res. 33, e129 (2005).
Non-patent Document 21: Kawai, R. et al. Site-specific fluorescent labeling of RNA molecules by specific transcription using unnatural base pairs. J. Am. Chem. Soc. in press.
Non-patent Document 22: Matray, T. J. & Kool, E. T. A specific partner for abasic damage in DNA. Nature 399, 704-708 (1999).
Non-patent Document 23: Doublié, S., Tabor, S., Long, A. M., Richardson, C. C. & Elenberger, T. Crystal structure of a bacteriophage T7 DNA replication complex at 2.2 Å resolution. Nature 391, 251-258 (1998).
Non-patent Document 24: Kiefer, J. R., Mao, C., Braman, J. C. & Beese, L. S. Visualizing DNA replication in a catalytically active Bacillus DNA polymerase crystal. Nature 391, 304-307 (1998).
Non-patent Document 25: Morales, J. C. & Kool, E. T. Functional hydrogen-bonding map of the minor groove binding tracks of six DNA polymerases. Biochemistry 39, 12979-12988 (2000).
Non-patent Document 26: Mitsui, T. et al. An unnatural hydrophobic base pair with shape complementarity between pyrrole-2-carbaldehyde and 9-methylimidazo[(4,5)-b]pyridine. J. Am. Chem. Soc. 125, 5298-5307 (2003).
Non-patent Document 27: Morales, J. C. & Kool. E. T. Minor groove interactions between polymerase and DNA: More essential to replication than Watson-Crick hydrogen bonds? J. Am. Chem. Soc. 121, 2323-2324 (1999).
Non-patent Document 28: Hirao, I. et al. A two-unnatural-base-pair system toward the expansion of the genetic code. J. Am. Chem. Soc. 126, 13298-13305 (2004).
Non-patent Document 29: Tae, E. L., Wu, Y., Xia, G., Schultz, P. G. & Romesberg, F. E. Efforts toward expansion of the genetic alphabet: Replication of DNA with three base pairs. J. Am. Chem. Soc. 123,7439-7440 (2001).
Non-patent Document 30: Petruska, J. et al. Comparison between DNA melting thermodynamics and DNA polymerase fidelity. Proc. Natl. Acad. Sci. USA 85, 6252-6256 (1988).
Non-patent Document 31: Goodman, M. F., Creighton, S., Bloom, L. B. & Petruska, J. Biochemical basis of DNA replication fidelity. Crit. Rev. Biochem. Mol. Biol. 28, 83-126 (1993).
Non-patent Document 32: Kimoto, M., Yokoyama, S. & Hirao, I. A quantitative, non-radioactive single-nucleotide insertion assay for analysis of DNA replication fidelity by using an automated DNA sequencer. Biotechnol. Lett. 26, 999-1005 (2004).
Non-patent Document 33: Ohtsuki, T. et al. Unnatural base pair for specific transcription. Proc. Natl. Acad. Sci. USA 98, 4922-4925 (2001).
Non-patent Document 34: Mitsui, T., Kimoto, M., Sato, A., Yokoyama, S. & Hirao, I. An unnatural hydrophobic base, 4-propynylpyrrole-2-carbaldehyde, as an efficient pairing partner of 9-methylimidazo[(4,5)-b]pyridine. Bioorg. Med. Chem. Lett. 13, 4515-4518 (2003).
Non-patent Document 35: Cha, R. S. & Thilly W, G. in PCR Primer (eds Dieffenbach, C. W. & Dveksler, G. S.) 37-51 (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1995).
Non-patent Document 36: Himeno, H., Hasegawa, T., Ueda, T., Watanabe, K. & Shimizu, M. Conversion of aminoacylation specificity from tRNATyr to tRNASer in vitro. Nucleic Acids Res. 18, 6815-6819 (1990).
Non-patent Document 37: Bedouelle, H. Recognition of tRNATyr by tyrosyl-tRNA synthetase. Biochimie 72, 589-598 (1990).
Non-patent Document 38: Mulder, B. A. et al. Nucleotide modification at the γ-phosphate leads to the improved fidelity of HIV-1 reverse transcriptase. Nucleic Acids Res. 33, 4865-4873 (2005).
Non-patent Document 39: Mitsui, T., Kitamura, A., Kimoto, M., To, T., Sato, A., Hirao, I. & Yokoyama, S. An unnatural hydrophobic base pair with shape complementarity between pyrrole-2-carbaldehyde and 9-methylimidazo[(4,5)-b]pyridine. J. Am. Chem. Soc. 125, 5298-5307 (2003).
Non-patent Document 40: Mitsui, T., Kimoto, M., Sato, A., Yokoyama, S. & Hirao, I. An unnatural hydrophobic base, 4-propynylpyrrole-2-carbaldehyde, as an efficient pairing partner of 9-methylimidazo[(4,5)-b]pyridine. Bioorg. Med. Chem. Lett. 13, 4515-4518 (2003).
Non-patent Document 41: De Roos, K. B. & Salemink, C. A., Deazapurine derivatives. V, A new synthesis of 1- and 3-deaza-adenine and related compound. Recueil. 88, 1263-1274 (1963).
Non-patent Document 42: Rolland, V., Kotera, M. & Lhomme, J. Convenient preparation of 2-deoxy 3,5-di-O-p-toluoyl-a-D-erythro-pentofuranosyl chloride. Synthetic Commun. 27, 3505-3511 (1997).
Non-patent Document 43: Ludwig, J. & Eckstein, F. Rapid and efficient synthesis of 5′-O-(1-thiotriphosphates), 5′-O-triphosphates and 2′,3′-cyclophosphorothioates using 2-chloro-4H-1,3,2-benzodioxaphosphorin-4-one. J. Org. Chem. 54, 631-635 (1989).
Non-patent Document 44: Stevens, J. D., Ness, R. K. & Fletcher. Jr, H. G. Syntheses with partially benzylated sugars. XI. Studies on the synthesis of the anomeric 5,6-dimethyl-1-D-ribofuranosylbenzimidazole (Ribazoles). Comparison of the condensation of 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide and 2,3,5-tri-O-benzoyl-D-ribofuranosyl chloride with 5,6-dimethylbenzimidazole. J. Org. Chem. 33, 1806-1810 (1968).
Non-patent Document 45: Kovacs, T. & Otvos, L. Simple synthesis of 5-vinyl- and 5-ethynyl-2′-deoxyuridine-5′-triphosphates. Tetrahedron Lett. 29, 4525-4528 (1988).
Non-patent Document 46: Ti, G. S., Gaffney, B. L. & Jones, R. A., Transient protection: Efficient One-Flask Syntheses of Protected Deoxynucleosides. J. Am. Chem. Soc. 104, 1316-1319 (1982)
Non-patent Document 47: Stumber, M., Herrmann, C., Wohlgemuth, S., Kalbitzer, H. R., Jahn, W. & Geyer, M. Synthesis, characterization and application of two nucleoside triphosphate analogues, GTPγNH2 and GTPγF. Eur. J. Biochem. 269, 3270-3278 (2002).
Non-patent Document 48: Knorre, D. G., Kurbatov, V. A. & Samukov, V. V. General method for the synthesis of ATP gamma-derivatives. FEBS Lett. 70, 105-108 (1976).
Non-patent Document 49: K. J. Morgan and D. P. Morrey. Nitropyrrole-I, The preparation and properties of 2- and 3-nitropyrrole, Tetrahedron, 22, 57-62, 1966.

Method for nucleic acid replication and novel artificial base pairs

Abstract: The method of the present invention for nucleic acid replication is characterized in that a deoxyribonucleoside 5′-triphosphate, in which the hydroxyl group of phosphoric acid at the γ-position is substituted with a group selected from the group consisting of an amino group, a methylamino group, a dimethylamino group, a mercapto group and a fluoro group, is used as a substrate during replication reaction. The novel artificial base pairs of the present invention are characterized in that 7-(2-thienyl)-imidazo[4,5-b]pyridine (Ds) or an analog thereof forms a base pair with pyrrole-2-carbaldehyde (Pa) or an analog thereof.


A cooking medium filter system determines a quality of a cooking medium. The cooking medium filter system includes a filter container, a filter medium, a pump, a sample chamber, and a controller. The filter container receives the cooking medium from a cooking vessel. The filter medium is disposed in the filter container and removes contaminants from the cooking medium. The pump conveys the cooking medium along a filter path from the filter container to the cooking vessel. The sample chamber is disposed in the filter path downstream from the filter medium. The sample chamber includes an electrode disposed therein. The sample chamber receives therein a quantity of the cooking medium that is sufficient to immerse the electrode therein. The controller controls operations of the filter pump and controls the electrode to measure a property of the cooking medium that is associated with the quality of the cooking medium.

1. Field of the Invention
The present invention relates generally to oil quality measurement and more specifically to systems and methods for single-sensor oil quality measurement.
2. Description of Related Art
When preparing food in a fryer, the quality of the cooking medium (e.g., the oil) may impact the quality of the food that is cooked by the fryer. As the cooking medium is used to cook food, particles of food may contaminate the cooking medium. The flavor characteristics of each of these food products may become infused to a greater or a lesser degree in the cooking medium. This infusion may adversely affect food quality. Moreover, upon heating the cooking medium, the cooking medium may undergo chemical reactions (e.g., hydrolysis, oxidation, and polymerization). These degradations may cause products such as free fatty acids, hydroperoxides, and polymerized triglycerides. Moreover, degradation may reduce the viscosity of the cooking oils, which also may decrease performance. In many instances, such degradation of the cooking medium does not become apparent to the human eye until a late stage of degradation. Thus, there is a need to measure the quality of the cooking medium, which directly correlates to its suitability for use in cooking.
One method of measuring the quality of cooking medium uses an electrode sensor immersed in the frying medium. The electrode is energized with an excitation voltage signal, and the resulting current flows from the energized electrode through the cooking medium to a ground. The measured value of this current corresponds to the cooking medium quality (e.g., the suitability of the cooking medium for use during cooking) Nevertheless, known electrode systems are not suitable for use in an open fryer. First, the construction materials must withstand cooking oil temperatures up to 450 degrees Fahrenheit (230 degrees Celsius). Second, the electrode must resist mechanical damage from cleaning and operator equipment abuse. Thus, the electrode must be sufficiently unaffected by contamination from suspended food particles, as well as from long-term varnishing by exposure to hot cooking medium.
In addition to the above problems, for use in a commercial fryer, known electrodes are not small enough to mount in the cooking vessel below the cooking medium level without interfering with the fry baskets or other mechanical features of the cooking vessel. Additionally, readouts from the electrodes must be sufficiently shielded such that they are sufficiently unaffected by the proximity of grounded metal objects in the cooking vessel (e.g., the fry baskets). Thus, the electrode must be small, but if the electrode is too small, then the electrode may not be capable of generating sufficient signal gain to generate an output signal of sufficient magnitude to resolve cooking medium quality differences with an adequate signal to noise ratio, Cooking media may have very high resistance, so the electrode current is very small, requiring a large circuit gain to create a usable signal.
Known electrodes use, for example, an interdigitated pattern of conductors deposited on a ceramic or a fiberglass substrate. These conductors have very small spacing. Such electrodes are too fragile for use in a commercial fryer. Additionally, such electrodes are too susceptible to contamination from food particles entering the small conductor spacing. Further, known electrodes, such as those described above, do not comply with food safety regulations.
Moreover, known systems for measurement of food cooking oil quality use, for example, a sensor in each vat of a fryer with multiple vats. In the known systems, the oil quality is monitored continuously. Further, in the known systems, the sensor is near the top of the vat but below a minimum level of oil required for proper operation of the known systems. This location reduces the risk of trapping contamination in the electrode gaps. In other known systems, each sensor is placed near the bottom of each vat, such that each sensor is fully immersed in the oil. In addition, in the known systems, the cooking media surrounding the sensor in each vat may be stationary or may engage in a negligible amount of motion related to convection, pressure, or other phenomena, such that the electrode is exposed to a static electric field and the current flow in the cooking media is steady. Further, the temperature of the cooking media at the electrode may be the desired cooking temperature and the measured conductivity does not have to be adjusted to compensate for a temperature difference.

Systems and methods for single-sensor oil quality measurement


Generating and frequency tuning of modulated high current electron beams and a specific efficient, high current, frequency-tunable device for generating intense radio frequency (RF), microwave electromagnetic fields in a rectangular waveguide. Current multiplication of a modulated seed electron beam is created by an energetic electron beam impacting a thin foil surface. The transmissive-electron-multiplier foils also mitigate both space charge expansion and improve beam propagation effects, by shorting of the radially directed electric field at the axial location of the foil(s). Foil thinness and intensity of the exit fields provide for a multiplication process occurring in a fraction of an RF period. Also included are both a self-excited microwave generator and an amplifier, using a temporally modulated laser to generate a modulated seed electron beam that is amplified. Methods to tune the oscillator are described that allow tunability over a full waveguide band.

1. Field of the Invention (Technical Field)
The invention relates to microwave generation and more particularly to a resonant frequency (RF) generator that operates at low impedance, amplifies the current to increase the RF output power, allows tuning the frequency of the apparatus, and a method to allow operation as an amplifier
2. Background Art
The efficient generation of microwaves from modulated electron beams requires electron beam velocity spectrums with low ratios of perpendicular energy to axial energy. Devices which violate this criteria pay a large price in terms of efficiency. For example, the virtual cathode oscillator (D. J. Sullivan, "High Power Microwave Generation using a Relativistic Electron Beam in a Waveguide Tube," U.S. Pat. No. 4,345,220, 17 Aug. 1982) has a very high ratio of E-perpendicular/E-parallel at the nominal axial location of the virtual cathode, potentially exceeding unity. Due to challenges in extracting usable RF power from such beams the practical efficiency of this device, a few percent typically, is poor, and no efficient means of harnessing the high modulated currents, often exceeding a few 10s kA at voltages of order 500 kV, has been developed.
A highly efficient device for modulating electron beams is known as the Split Cavity Oscillator, as described in U.S. Pat. No. 5,235,248. While this device has a high ratio of E-perpendicular/E-parallel at its exit port, this ratio is substantially reduced with acceleration, of the modulated electron beam to voltages of order MV. Post-acceleration of a spatially modulated electron beam, as a means to lock in a spatial modulation while substantially increasing axial kinetic energy and thus reducing E-perpendicular/E-parallel, has been used for many years. As far back as 1940 Haeff and Nergaard described post-acceleration in their Inductive Output Amplifier device, as shown in "A wide-band inductive-output amplifier," A. V. Haeff and L. S. Nergaard, Proc. of the IRE, vol. 28, pp. 126–130, March 1940. With post-acceleration, the SCO modulated beam kinetic energy can be converted to RF electromagnetic fields quite efficiently, exceeding 50%. However, virtual cathode formation limits the attainable current, due to space charge limitations in the modulating cavity of the device.
The operation of the prior art transit time oscillator (TTO), split cavity oscillator (SCO), and post accelerated split cavity oscillator (PASCO) are next briefly described in order to enable a distinction between previous techniques and the new methods described in the present invention.
The geometry of the TTO microwave oscillator is depicted in FIG. 1. Its operation relies on the interaction of a direct current (DC) electron beam 10 and the field of a cavity formed by a cylindrical pill box with perfectly conducting walls. The DC electron beam is often produced by a thermionic or field emission cathode 12. The geometry of the cavity is such that the time of flight 18 across the cavity 20 and the interaction of the beam 10 with the oscillating axial electric field associated with the cavity's axially symmetric mode 22 produce a spatially modulated electron beam 14. The spatially modulated electron beam 14 is converted to an electromagnetic wave 16; this conversion process is depicted symbolically in FIG. 1 since the details of the extraction/conversion process vary depending on the device and/or application. The operation of the TTO is described in detail in "The Split Cavity Oscillator: a high power e-beam modulator and microwave source," B. Marder, et al., pg. 312, IEEE Trans. Plasma Sci., vol. 20, 1992. This device is an extremely inefficient oscillator, a problem that is addressed by the SCO.
The geometry of the SCO microwave oscillator is depicted in FIG. 2. Its operation also relies on the interaction of a direct current (DC) electron beam 40 and the field of a cavity 41. In this case the cavity 42 is formed by a cylindrical pill box cavity with an intermediate electrically conducting septum 44 (placed exactly midway across the pill box) that extends part ways across the interior of the cavity 42, as shown in FIG. 2. Distinct from the operation of the TTO, the SCO operates according to a well known energy instability that exists between the electron beam 40 and the cavity 42, and an externally applied field is not required, as described in "The Split Cavity Oscillator: a high power e-beam modulator and microwave source," B. Marder, et al., pg. 312, IEEE Trans. Plasma Sci., vol. 20, 1992. Again, the DC electron beam 40 is often produced by a highly inefficient thermionic or field emission cathode 46. As with the TTO, the geometry of the SCO cavity is such that the time of flight across the cavity 48 and the interaction of the beam with the Pi-mode of the cavity's oscillating electric field cavity produce a spatially modulated electron beam 50. The SCO geometry and resulting electromagnetic field mode structure permits the axial length 48 of the cavity to be much shorter than the axial length of the TTO oscillator 18. Finally, the spatially modulated electron beam 50 is converted to an electromagnetic wave 52 as depicted symbolically in FIG. 2. Note that cathode 46 must produce the entire charge of electron beam 40, and consequently, operation at high powers requires that cathode 46 be capable of producing high current densities at high voltages. This often results in short cathode lifetimes, and pulse shortening due to gap closure caused by plasma drift across the anode-cathode gap, as shown in "Results of research on overcoming pulse shortening of GW class HPM sources," K. Hendricks, et al., pg. 81, Digest of Technical Papers, International Workshop on High Power Microwave Generation and Pulse Shortening, Edinburgh, Scotland, 1997. The main disadvantage of the SCO is the large axial velocity spread, and the substantial unwanted perpendicular velocities of the electrons that exit the cavity, leading to poor beam-to-RF power conversion efficiencies. The SCO is described in U.S. Pat. No. 5,235,248. However, this prior art patent describes an apparatus with a very specific geometry (cylindrical pill box with an electrically conducting septum placed exactly midway along the axial length of the cavity) that operates at a single frequency. No capability to adjust the frequency of operation of the device is disclosed or implied in the prior art patent.
The geometry of the PASCO microwave oscillator is depicted in FIG. 3. Its operation to produce a spatially modulated electron beam 60 is equivalent to the SCO described above. However, once the spatially modulated electron beam 60 is produced, the PASCO uses an accelerating screen or grid 62 at a high relative potential, typically 100's of kV or more, to accelerate the electron beam to relativistic velocities 64, i.e., close to the speed of light. This greatly reduces the relative axial velocity spread intrinsic to the SCO and represents a major improvement for potential high power and high efficiency operation. The relativistic spatially modulated electron beam 64 is then converted to an electromagnetic wave 66 as depicted in FIG. 3. This technique results in a more tightly velocity-modulated beam, while maintaining excellent spatial bunching allowing more efficient beam-to-RF extraction. The main disadvantages of the PASCO are: (1) the device has an inherent limitation on total current due to space charge depression in the modulating cavity, which ultimately can lead to virtual cathode formation, but at more modest current levels, reduces modulation efficiency; and (2) the PASCO is a fixed frequency device, in that there is no ability to tune its frequency while maintaining axisymmetry.
Post-acceleration of an electron beam for high power and high efficiency operation is described in U.S. Pat. No. 5,101,168. However, this patent describes methods that were well known prior to the patent's application date. As an example, post-acceleration of an electron beam was described by Haeff and Nergaard, "A wide-band inductive-output amplifier," A. V. Haeff and L. S. Nergaard, Proc. of the IRE, vol. 28, pp. 126–130, March 1940. Furthermore, post-acceleration of an electron beam was described by Preist and Shrader, "The Klystrode—an unusual transmitting tube with potential for UHF," D. H. Preist and M. B. Shrader, Proc. of the IEEE, vol. 70, no. 11, pp. 1318–1325, November 1982.
The present invention, a Current Amplified, Tunable, Post Accelerated, Modulator (CATPAM) apparatus uses techniques of the well known transit time oscillator (TTO) as described in "Interchange of energy between an electron beam and an oscillating electric field," J. Marcum, Journal of Applied Physics, vol. 17, January, 1946, a split cavity oscillator (SCO) shown in 'The Split Cavity Oscillator: a high power e-beam modulator and microwave source," B. Marder, et al., pg. 312, IEEE Trans. Plasma Sci., vol. 20, 1992, and the post accelerated split cavity oscillator (PASCO) (the PASCO is also known as the Reltron described in "Super RELTRON theory and experiments," R. Miller, et al., pg. 332, IEEE Trans. Plasma Sci., vol. 20, 1992, in conjunction with unique techniques to operate at low impedance, amplify the current to increase the RF output power, tune the frequency of the device, and a method to allow operation as an amplifier, as opposed to just an oscillator. The disclosed apparatus spatially modulates a direct current (DC) electron beam using instabilities associated with device geometry and transit time effects; or, it directly generates a spatially modulated electron beam using laser-induced electron emission. It then amplifies the resulting electron beam (current), accelerates the spatially modulated beam to relativistic velocities, and converts the kinetic energy of the spatially modulated relativistic electron beam to electromagnetic fields at microwave frequencies. In addition, methods are disclosed that allow the device to be tuned to a desired operating frequency while maintaining nominal axisymmetry. None of the prior art teaches or implies these novel features.

Method and apparatus for generation and frequency tuning of modulated, high current electron beams