A flash microcontroller has a Static Random-Access-Memory (SRAM) buffer that stores several blocks of boot code read from a flash memory. The SRAM buffer also operates as a cache of flash data after booting is complete. Cache read and write hits use the SRAM cache rather than flash memory, while old cache lines and read misses access the flash memory. Both the external host and the microcontroller are booted from boot code buffered in the SRAM buffer. A boot-loader state machine reads the flash ID and programs flash parameter registers with timing parameters for the flash memory. The flash microcontroller uses a differential interface to the external host, with a differential transceiver and a differential serial interface. Frame, packet, and encoded clock processing is also performed by the serial interface.

Hard disks and other mass storage devices are being replaced or supplemented with solid-state mass storage such as flash memories. Flash memories use non-volatile memory cells such as electrically-erasable programmable read-only memory, (EEPROM), but are not randomly accessible at the byte level. Instead, whole pages or sectors of 512 bytes or more are read or written together as a single page. NAND flash memory is commonly used for data storage of blocks. Pages in the same block may have to be erased together, and limitations on writing may exist, such as only being allowed to write each page once between erases.
Program code is often stored in randomly-accessible memory such as a ROM or a NOR flash memory. Since NOR flash memory is byte-addressable, NOR flash can store code that can be executed. Byte-addressing is needed to execute code, since branch and jump instructions may have a target that is at a random location that must be fetched next. The target may be byte-addressable. Since boot routines execute instructions one at a time, rather than a whole page at a time, randomly-accessible memory is needed for boot-code execution.
Small portable devices such as personal digital assistants (PDA), multi-function cell phones, digital cameras, music players, etc. have a central processing unit (CPU) or microcontroller that must be booted just as a PC or host CPU must be booted. These small devices are often quite cost and size sensitive. Having a NOR flash or ROM may increase the size and cost of these portable devices.
NAND flash memory is less expensive than NOR flash memory, and thus preferable from a cost standpoint. NAND flash memory may already be present on some devices such as cell phones or music players as the primary mass storage memory. It is thus desirable to use NAND flash memory to store boot code.
Computers once required a complex series of steps to initialize and make them ready to run programs. Instructions for bootstrapping the computer were loaded into the computer after power-on, such as by manually toggling switches representing the 1's and 0's of bootstrap instructions on the front panel. The computer was brought from a dead state into a useful state, like lifting the computer up by its own bootstraps.
More recently, computers still execute a complex sequence of instructions after power-on to boot the computer and load its operating system (OS). The initial instructions may reside in a read-only memory (ROM), along with a personal computer's Basic Input-Output System (BIOS). The operating system such as Windows may be loaded from the hard disk, and when booting is complete the OS can execute user programs. Various system checks such as peripheral device and memory detection and sizing can be performed during booting.
Both the flash device and the host must be booted at some point in time. Typically, the host is booted from its hard disk before the flash device is inserted into the host. The flash device is then booted when power from the host reaches the flash device.
Cache memories are commonly used by host computers. A cache of the flash memory is desirable. Using this cache memory for booting both the flash-memory device and the external host is also desirable.
What is desired is a flash-memory microcontroller that is bootable from boot code stored in flash memory. It is further desired to boot both the flash microcontroller and the host. A flash microcontroller with a differential interface to the external host that is used to transfer boot code to the external host is also desired.

SRAM cache and flash micro-controller with differential packet interface


It is an object of the present invention to provide an effective technique to alleviate vibration in the electric hammer drill. According to the invention, representative electric hammer drill is provided with a body, a motor, a striker, a cylinder, first and second power transmitting mechanisms, a power switching mechanism, a mode changing mechanism, and a coupling mechanism. The mode changing mechanism is disposed on the upper surface of the body and can change between a hammer-drill mode and a hammer mode. The coupling mechanism is disposed between the mode changing mechanism and the power switching mechanism. The coupling mechanism extends along the peripheral surface of the cylinder and transmits the mode changing movement of the mode changing mechanism to the power switching mechanism by moving in the longitudinal direction of the cylinder. Because the mode changing mechanism is disposed on the upper surface of the body and the coupling mechanism extends along the peripheral surface of the cylinder to move in the longitudinal direction of the cylinder, the center of gravity of the electric hammer drill is positioned nearer to the axis of the cylinder, compared with the known art in which the components for the switching the operation modes are centralized in one area. As a result, operating vibration of the electric hammer drill is effectively alleviated.

1. Field of the Invention
The present invention relates to an electric hammer drill that can switch operation modes to perform predetermined processing works on a work-piece.
2. Description of the Related Art
A known electric hammer drill to switch between a hammer mode and a hammer-drill mode is disclosed in Japanese non-examined laid-open Patent Publication No. 2002-192481. In the known electric hammer drill, a piston is caused to reciprocate within a cylinder via a crank mechanism driven by a motor. Then, a striker is linearly driven via air spring and the striking movement is transmitted to the tool bit via an intermediate element. Further, a rotation transmitting mechanism is provided which transmits rotation of the motor from an intermediate shaft to the tool bit via the cylinder and a tool holder. A clutch mechanism is disposed in the rotation transmitting mechanism and is adapted to transmit rotation of the motor to the tool bit by engaging clutch claws and to prevent such transmission of rotation to the tool bit by disengaging the clutch claws. Further, a mode changing mechanism is provided which serves to switch the clutch mechanism between the state of transmitting rotation and the state of preventing the transmission of rotation. When the mode changing mechanism is switched to the hammer mode, the rotation of the tool bit is prevented so that an operation solely by a striking movement of the tool bit can be performed. When the mode changing mechanism is switched to the hammer-drill mode, rotation is transmitted to the tool bit so that an operation by a combined movement of striking and rotating can be performed.
Generally, in an electric hammer drill in which the cylinder and the motor are arranged within the tool body such that the respective axes run generally crossing to each other to form "L" shape, the center of gravity of the electric hammer drill is positioned below the axis of the cylinder and slightly forward of the axis of the motor. The user performs a predetermined operation by holding a handgrip on the opposite side of the tool bit, and a side handle. The greater the distance between the center of gravity and the axis of the cylinder, the larger the vibration in the longitudinal direction (the longitudinal direction of the cylinder) or in the vertical direction. In the known electric hammer, the intermediate shaft of the rotation transmitting mechanism that transmits rotation of the motor to the cylinder (the tool bit) is placed forward of the motor and below the cylinder. The clutch mechanism that serves to releasably transmit the rotation is placed on the intermediate shaft. Further, the mode changing mechanism that serves to switch the clutch mechanism between the engaged state and the disengaged state is placed near the clutch mechanism. Thus, the components for switching the operation modes of the tool bit are centralized in one area. In such a case, the weight of the lower part below the axis of the cylinder is further increased and the balance of weight is tipped. Thus, the center of gravity of the electric hammer drill is displaced farther downward away from the axis of the cylinder. Therefore, the known electric hammer is in difficulty to decrease operating vibration.


There is disclosed a method for performing channel assignment in a base station for a mobile communication system. Upon receipt of a request for assigning a channel to a mobile station, a base station transceiver system (BTS) generates a connect message including channel information, which indicates a Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi-orthogonal function (QOF) index. The BTS transmits the generated connect message to a base station controller (BSC). The BSC generates a connect ACK message for acknowledging the channel assignment-related information included in the connect message and transmits the generated connect ACK message to the BTS. Upon receipt of the connect ACK message, in the BTS assigns the channel that was acknowledged by the BSC to the mobile station.

1. Field of the Invention
The present invention relates generally to a CDMA (Code Division Multiple Access) mobile communication system, and in particular, to a method for providing 4 quasi-orthogonal functions (QOF), which are used in association with 256 Walsh codes in a forward link, in a base station transceiver system (BTS) and a base station controller (BSC).
2. Description of the Related Art
Existing IS-95A/B CDMA communication systems spread a radio channel with a Walsh function. However, as the IS-2000 standard introduces new channels to the forward and reverse links, the existing conventional communication system lacks the necessary amount of Walsh codes to maintain orthogonality between channels
Accordingly, there is a need for a method for increasing the number of the channels, without decreasing the orthogonality between the existing channels. For the IS-2000 forward link, several methods have been proposed. One method is to define a quasi-orthogonal function (QOF) necessary for the mobile station thereby to assign 4 times the channels as compared with the case when the existing Walsh function is used, and another method is to expand the existing Walsh function which can generate 64 Walsh codes, so as to generate 256 Walsh codes. The quasi-orthogonal function (QOF) is commonly applied to IS-2000 forward channels, such as the fundamental channel (FCH), the dedicated control channel (DCCH) and the supplemental channel (SCH). However, existing base stations can only support 64 Walsh code channels.
Now, reference will be made to the types of the channels used in the IMT-2000 (International Mobile Telecommunications 2000) standard. IMT-2000 includes UMTS (Universal Mobile Telecommunication Service) and CDMA-2000/IS-2000.
Every channel is divided into a physical channel and a logical channel. The logical channel is established over the physical channel, and several logical channels can be established on a single physical channel. If the physical channel is released, the logical channel established over the physical channel is automatically released. It is not necessary to establish another physical channel in order to establish a certain logical channel. When a physical channel to be established for a logical channel is already established for another logical channel, the only required operation is to assign this logical channel to the previously established physical channel.
The physical channel can be divided into dedicated channels and common channels according to its characteristics. Dedicated channels are exclusively used for communication between the BTS and a particular mobile station (MS), and include a fundamental channel (FCH), a dedicated control channel (DCCH) and a supplemental channel (SCH). The fundamental channel is used to transmit voice, data and signaling signals. Such a fundamental channel is compatible with TIA/EIA-95-B. The dedicated control channel is used to transmit data and signaling signals. The dedicated control channel supports a discontinuous transmission (DTX) mode in which data is only transmitted when the upper layer generates transmission data. Because of this property, the dedicated control channel is suitable for effectively providing a packet service. The supplemental channel is used to transmit large amounts of data.
In addition to the dedicated channels stated above, the physical channel includes a common channel which is used in common by the base station and several mobile stations. A physical channel for the forward link transmitted from the BTS to the MS is called a paging channel, and a physical channel for the reverse link transmitted form the MS to the BTS is called an access channel. These common channels are compatible with IS-95B.
The logical channels to be assigned on the above physical channels include a dedicated signaling channel (dsch) and a dedicated traffic channel (dtch). The dedicated signaling channel can be assigned to the fundamental channel and the dedicated control channel, which are physical channels. The dedicated traffic channel can be assigned to the fundamental channel, the dedicated control channel and the supplemental channel. The dedicated signaling channel is used when the base station and the mobile station exchange a control signal. The dedicated traffic channel is used when the base station and the mobile station exchange user data.
The common logical channel to be assigned on the common physical channel is divided into a common signaling channel (csch) used to transmit control signal, and a common traffic channel (ctch) use to transmit user data. The common logical channels are assigned on the paging channel for the forward link, and are assigned on the access channel for the reverse link.
FIG. 1 shows a structure of a general mobile communication system. More specifically, FIG. 1 shows a reference model of a 3G IOS (Interoperability Specifications) for a digital air interface between a mobile switching center (MSC) and a base station, and between base stations in the common mobile communication system.
Referring to FIG. 1, between MSC 20 and BSC 32, a signal is defined as an A1 interface and user information is defined as an A2/A5 (circuit data) interface. An A3 interface is defined to connect a target BS 40 to a frame selection/distribution unit (SDU) function block 34 of a source BS 30 for soft/softer handoff between base stations. The signaling and user traffic between the target BS 40 and the SDU function block 34 of the source BS 30 are transmitted through the A3 interface. An A7 interface is defined for signal exchange between the target BS 40 and the source BS 30, for soft/softer handoff between the base stations. In the CDMA mobile communication system, a wired communication link between the base station 30 and the base station 40, and between the base station 30 and the MSC 20, is comprised of a forward link transmitted from the MSC 20 to the base station 30, a reverse link transmitted from the base station 30 to the MSC 20. Generally, a wired bi-directional line connected between the MSC 20 and the base station 30 carries the forward and reverse links. The MSC 20 includes a call control and mobility management block 22 and a switching block 24. Further, the MSC 20 is connected to a data network such as the Internet through an interworking function (IWF) block 50. The wired line exists over all the interfaces in the RAN, e.g., MSC-BSC, BS-BS, BSC-BTS, BSC-Target BTS and so on.
FIG. 2 shows a procedure for exchanging signals between the BTS and the BSC (more specifically, the SDU function block in the BSC, BSC-SDU) according to the prior art. The operation can be performed either between the BSC 32 (or BSC-SDU 34) and the BTS 36 in the source BS 30, or between the BSC 42 and the BTS 44 in the target BS 40. FIG.2 is independent of types of the required physical channel, i.e., DCCH, FCH, SCH or whatever. That is, the invention in this document can be applied to all types of physical channels.
Referring to FIG. 2, the BTS determines forward and reverse channels to be established with the MS and then generates a signaling message (more specifically, a connect message) necessary for channel establishment, in step 201. The generated signaling message includes a frame selector (or channel type) and channel information. The detailed operation of step 201 will be described later with reference to FIG. 3. The BTS sends the generated connect message to the BSC in step 203. Upon receipt of the connect message, the BSC analyzes the received connect message to check the channel assigned to the MS, and generates a connect ACK message to be transmitted to the BTS, in step 205. The detailed operation of receiving the connect message will be described later with reference to FIG. 4. The BSC sends the generated connect ACK message to the BTS in step 207. The connect ACK message includes information for acknowledging establishment of the channel requested by the BTS. The BTS then assigns the acknowledged channel to the MS in step 209.
Summarizing the operation of FIG. 2, the BTS generates the connect message including information about a channel to be assigned to the MS and sends the generated connect message to the BSC. Upon receipt of the connect message, the BSC processes the received connect message, generates the connect ACK message for acknowledging channel assignment and sends the generated connect ACK message to the BTS. The BTS then assigns the acknowledged channel to the MS.
FIG. 3 shows a detailed procedure for transmitting the connect message according to the prior art. This operation is performed when the BTS transmits the connect message to the BSC-SDU when it is required to assign a channel to the MS. The structures of the connect message transmitted from the BTS to the BSC-SDU are shown in FIGS. 5A and 5B.
Referring to FIG. 3, the BTS determines in step 301 whether the channel to be assigned to the MS is a supplemental code channel (SCCH). SCCH is the IS-2000 defined name corresponding to IS-95B SCH (Supplemental Channel). IS-2000 is on the evolution path of IS-95A/B. IS-2000 also has the IS-95 A/B channels in order to maintain backward compatibility. It is determined in step 301 that the channel to be assigned to the MS is SCCH, the BTS sets (designates) in step 303 the frame selector (or channel type) in the connect message, whose structure is shown in FIGS. 5A and 5B, to IS-95B SCCH, so as to enable the BSC to recognize that the channel to be assigned is an IS-95B channel, and then designates a Walsh code with 6-bit channel information. Thereafter, in step 305, the BTS ignores an information element overlapped due to establishment of the IS-95A/B fundamental channel in the connect message, whose structure is shown in FIGS. 5A and 5B. Cell Information, Extended Handoff Parameters in the A3 Connect Information element are overlapped with those in the same Connect message used when IS-95 A/B FCH is newly established. IS-95B SCCH establishment procedure follows the IS-95 A/B FCH establishment procedure. IS-95B SCCH has to be established in parallel to IS-95A/B FCH under the same cell. The BTS fills all other information elements to complete the connect message, and then transmits the connect message to the BSC. Here, in a handoff (HO) situation, the BTS fills all the handoff-related information element.
If it is determined in step 301 that the channel to be assigned to the MS is not SCCH, the BTS designates in step 307 the frame selector (or channel type) in the connect message shown in FIGS. 5A and 5B to the fundamental channel, so as to enable the BSC to recognize that the channel to be assigned is an IS-95B fundamental channel, and then designates a Walsh code with 6-bit channel information. Thereafter, in step 309, the BTS fills all the information elements in the connect message of FIGS. 5A and 5B to complete the connect message, and then transmits the connect message to the BSC. Here, in the handoff (HO) situation, the BTS fills all the handoff-related information element.
FIG. 4 shows a procedure for receiving the connect message according to the prior art. This operation is performed when the BSC-SDU receives the connect message for requesting channel assignment, transmitted from the BTS, and generates a connect ACK message for the connect message.
Referring to FIG. 4, the BSC-SDU receives the connect message for requesting channel assignment from the BTS in step 401. In step 401, the BSC-SDU analyzes the received connect message, and examines the establishment-requested channel in the message of FIGS. 5A and 5B and an identifier of a traffic channel between the BTS and BSC. The BSC-SDU assigns the traffic channel between the BSC and BTS, corresponding to the radio channel, in step 403. As a result, channel connection among BSC-BTS-MS is completed. Further, in step 405, the BTS-SDU fills all the information elements of the connect ACK message shown in FIG. 6 and transmits it to the BTS.
A simplified structure of the connect ACK message shown in FIG. 6 will be described with reference to Table 1 below.
The connect message shown in Table 1 is an A3 message transmitted when the target BS 40 initiates or adds one or more A3 user traffic connections to the SDU 34 of the source BS 30. The A3 message includes the following information.
Message Type II: an information element indicating A3/A7 message type.
Call Connection Reference: an information element for uniquely defining a call connection over all zones. This value is always maintained during call connection over every handoff.
Correlation ID: an information element used to correlate a request message with a response message for the request message.
SDU ID: an information element for identifying a specific SDU instance in one SDU node.
A3 Connect Information: an information element used to add one or more cells to one new A3 connection or existing A3 connection. This information element field is shown in Table 2 below, and 4th to (jxe2x88x921)th octets of Table 2 include Cell Information Record fields of Table 3 below.
Table 3 shows a message including air interface channel information for the cells attached to one call leg, and each field is defined as follows.
Length: the number of octets of the elements following a Length field.
Cell Identification Discriminator: a value used to describe the formats following a Cell Identification field according to cells.
Cell Identification: identification of the cells relating to A3 connection.
Reserved: this value is set to xe2x80x9800000xe2x80x99.
New Cell Indicator: a field indicating whether a corresponding cell is a cell newly added to A3 traffic connection in the present procedure or a cell which previously exists in A3 connection.
PWR_Comb_Ind: a power control symbol combining indicator. The BTS sets this field to xe2x80x981xe2x80x99, if a forward traffic channel relating to the corresponding pilot transmits the same bits as closed-loop power control subchannel bits of a previous pilot in this message. Otherwise, the BTS sets this field to xe2x80x980xe2x80x99. When this record occurs first in this element, the BTS sets this field to xe2x80x980xe2x80x99.
Pilot_PN: this field includes a PN sequence offset corresponding to the related cell and is set in a unit of 64 PN chips.
Code_Chan: this field includes a code channel index corresponding to the related cell. The BTS sets a value used on the forward traffic channel in connection with a designated pilot to one of 0 to 63.
A simplified structure of the connect ACK message shown in FIG. 6 will be described with reference to Table 4 below.
The connect ACK message of Table 4 is an A3 message for transmitting A3-CDMA Long Code Transition Directive results performed on the A3 signaling interface from the target BS 40 to the SDU 34 of the source BS 30. Further, an A3 CDMA Long Code Transition Directive Ack message for the A3 CDMA Long Code Transition Directive of Table 4 is shown in Table 5 below.
The A3 CDMA Long Code Transition Directive Ack message of Table 5 includes the following information elements.
Message Type II: an information element indicating an A3/A7 message type.
Call Connection Reference : an information element for uniquely defining a call connection over all zones. This value is always maintained during call connection over every handoff.
SDU ID: an information element for identifying a specific SDU instance in one SDU node.
PMC Cause: an information element indicating failed results of A3/A7 message.
Cell Information Record (Committed, Uncommitted): a Cell Information Record field of Table 3 is used, as it is. This is an information element including air interface channel information for the cells attached to one call leg. When successful, this field is set to xe2x80x98Committedxe2x80x99, and when failed, this field is set to xe2x80x98Uncommittedxe2x80x99. This field is used together with the PMC Cause field.
Problems of the existing channel assignment method will be described based on the foregoing descriptions.
As described with reference to Tables 1 to 5, in the conventional 3G IOS radio channel information, the quasi-orthogonal function (QOF) specified in the CDMA-2000 standard is not defined. Further, only 64 Walsh codes of 0 to 63 are supported for the code channels. Thus, when the base station does not support the quasi-orthogonal function (QOF) which is necessary for the mobile station, the 3G forward radio channel cannot be assigned in the mobile station. Therefore, it is necessary to define a message field which can support the quasi-orthogonal function (QOF) and 256 Walsh codes for the radio channel information in the existing 3G IOS.
It is, therefore, an object of the present invention to provide a method for expanding existing 64 supportable Walsh codes to 256 Walsh codes and supporting a quasi-orthogonal function (QOF) for a forward channel in a base station of a mobile communication system.
To achieve the above objects, there is provided a method for performing channel assignment in a base station for a mobile communication system. Upon receipt of a request for assigning a channel to a mobile station, a base station transceiver system (BTS) generates a connect message including channel information indicating a Walsh code to be used for a channel to be assigned to the mobile station, out of 256 Walsh codes, and information indicating a quasi-orthogonal function (QOF) index, and transmits the generated connect message to a base station controller (BSC). The BTS generates a connect ACK message for acknowledging the channel assignment-related information included in the connect message and transmits the generated connect ACK message to the BSC. Upon receipt of the connect ACK message, in the BTS assigns a channel acknowledged by the BSC to the mobile station.

Channel assignment method for a base station in a mobile communication system


A row crop harvesting device for mounting on the forward end of a combine, the row crop harvesting unit having closely spaced individual row harvesting units to facilitate retrieval of downed crop and use on closely-spaced crops. The present invention is particularly applicable to corn harvesting units that include a gear housing which is part of and supports the individual row harvesting units, which individual row harvesting units are adjustable transverse to the forward end of the combine to allow adjustment for crop row spacing. The present invention allows closer spacing of the individual row harvesting units by offsetting certain components of the row harvesting units on alternate row harvesting units.

This invention relates to a row crop harvester adapted to be mounted on the forward end of a combine or similar mechanized harvesting machine. More particularly, the invention relates to a row crop harvester with increased density of individual harvesting units on the structure to facilitate increased percentage of recovery of crop from down crops and the like, and, also to enable effective harvesting of closely-planted rows of crops.
Agricultural harvesting machines, such as combines, are fitted on their forward end with a variety of row crop harvesting devices or headers, such as a corn head. A typical row crop harvester, comprises a plurality of individual row harvesting units (row units) each separated by a plurality of row crop dividers. As the combine moves through a field planted with a row crop, adjacent crop dividers define areas into which the crop being harvested is drawn by a gathering structure associated with each of the individual row units. The gathering structures typically comprise gathering chains or serpentine gathering belts to urge the crop further into the individual row units where a cutting mechanism or snapping rollers separate the desirable portion of the crop from other portions of the plant. The harvested crop is urged rearward toward the combine by action of the combine moving forward through the crop and the motion of the gathering chains urging the crop rearwardly toward a laterally disposed auger, which further urges the crop toward the intake to the separator portion of the combine. Typical row crop header units are disclosed in U.S. Pat. Nos. 3,808,783 and 3,759,021, each of which is incorporated herein by reference. A variety of row crop dividers also exist, such as those disclosed in U.S. Pat. No. 5,195,309, which is incorporated herein by reference.
For discussion purposes, features of the corn head will be examined, although it will be apparent that features of this invention are applicable to other crops. Individual corn collecting units (referred to herein as row units or harvesting units), such as those in a 40 Series John Deere corn head, typically comprise a pair of gathering chains, each chain disposed around a rearward chain gear drive and a forward idler chain gear. The chains extend forwardly from the platform of the combine and are configured in the same plane to form generally parallel lines of chains arranged to urge cornstalks rearwardly into the header. Located immediately below the gathering chains is a pair of snap rollers, configured to pull corn plants downwardly between the rollers so as to separate corn ears from the corn stalks. The individual row units are mounted to the frame of the header and typically are driven from a common power shaft that extends parallel to the header auger. Historically, harvesting units have been set up to be, within certain limits, adjustable so that the individual row units can be located to take best advantage of the crop row placement in the field. Generally, the row units are arranged so that each row unit is dedicated to each row of crop. In the past, typically the corn crop row spacing has been kept at nominally 30 inches between rows. This allowed for pest and weed control and provided optimal growing conditions for the cultivars available.
More recent developments in seed technology, fertilizer availabilities, pest and weed control are allowing corn crops to be planted in narrower rows to make better use of the available farmland. These rows have become as narrow as 15 inches. Traditional corn harvesting equipment cannot generally be adjusted to accommodate these narrower rows, however. The typical problem involved is that the return side of the gathering chains of adjacent individual row units interfere with each other when the units are placed in close proximity, generally preventing placement significantly closer than 30 inch spacing.
In addition, the close spacing of individual row units facilitates lifting and retrieval of downed crops. Generally, corn and similar crops are allowed to dry for a period of time in the fields prior to harvesting to minimize crop damage due to spoilage and the need for mechanical drying. However, late season storms can topple portions of the crop creating what is called a "downed crop" condition. In this instance, the individual stalks of corn are lying across the rows and entangled with one another. Further, the stalk can be essentially lying on the ground. A typical wide row harvester approaching a downed crop has a tendency to lift portions of the downed crop with the stalk upside down in an inverted U-shape such that, when pulled into the widely spaced crop gathering units, the ears of the plant pass below the snap rollers and are forced down with the rejected silage, thus reducing an ultimate crop yield. Narrower spacing of the individual crop units tends to lift the downed crop in a configuration which is less likely to reject useful ears of corn. Further, the narrow spacing ensures more structures for picking the corn ears so that the random nature of the downed crop can be more easily dealt with.


An oven includes a conveying interior for moving produce through the oven and a gas fired heat source for cooking the produce conveyed through the oven. The conveying interior preferably comprises a rotating drum with a conveying spiral extending inwardly from an inner wall of the rotating drum. The rotating drum may further be sloped downward to facilitate progress of the produce through the oven, and the time spent in the oven may be controlled by controlling the rotating rate of the drum. The gas fired heat source may comprise a thermostatically controlled burner residing under the drum.

The present invention relates to ovens and in particular to a gas fired continuous feed oven.
Salsa has become a very popular garnishment for a variety of Mexican food and various corn chips. In particular, many salsa users prefer fire roasted salsas. One of the most important steps in producing a high quality fire roasted salsa is cooking the salsa ingredients, and in a production environment, the salsa ingredients are preferably cooked in a continuous feed oven (i.e., an oven in which the produce being cooked is continuously fed into the oven and is cooked as it moves through the oven.) Known continuous feed ovens use steam to cook the salsa ingredients, but the steam cooking does not provide the desired characteristics in the cooked salsa ingredients.
There is thus a need for a gas fired continuous feed oven suitable for cooking salsa ingredients.


In a wireless communications system, a subscriber unit transmit power is determined. Thereafter, a power margin is determined by subtracting the subscriber unit transmit power from a maximum transmit power. In response to a current communication mode of the subscriber unit, a predetermined power margin requirement for the current communication mode, and the current power margin, a communication mode quality is estimated. Either the power margin or communication mode quality may be indicated at the subscriber unit, or reported to the infrastructure of the wireless communications system. In response to an unsatisfactory power margin or communication mode quality, the infrastructure may make adjustments to improve service.

For many wireless communication system operators, maintaining and optimizing the communications system performance is a constant challenge. Factors that affect communication system performance include placement of transmitters or receivers, adjustment of antennas, and the selection of various software parameters that control almost every aspect of the communications system operation. Wireless communication system operators frequently wish to optimize range or coverage area of the communication system, the capacity or number of users that may be served by the system, and the bandwidth efficiency or amount of data that may be transported in a unit of time.
For communication systems that are full-duplex, the operator must be concerned with optimizing two wireless channels or links: an uplink and a downlink, which may also be referred to as a forward channel and a reverse channel. In some systems, the forward channel and the reverse channel are separated in frequency such that the characteristics or quality of one channel is not necessarily the same as those of the other channel. Therefore, the task of optimizing the wireless communications system may include simultaneously optimizing both wireless links. In some communication systems, this may be made more difficult by the fact that metrics and measurement techniques exist for one link and not the other. Furthermore, various modes of operation in the subscriber unit may depend upon the quality of one link independent of the quality of the other. For example, in some systems, such as a code division multiple access (CDMA) system that uses power control in the subscriber units, the system capacity is more sensitive to the proper control of the reverse link than the control of the forward link. Therefore, when such a communication mode depends upon the quality of the link that is not measured in the communications system, erroneous assumptions about the quality of a link may be made, which may lead to assumptions as to whether or not certain other modes of operation are available to a subscriber unit.
Therefore, a need exists for an improved method and system for estimating a communication mode quality in a wireless communication system.

Method and system for estimating a communication mode quality in a wireless communications system


Provided are compositions and methods for stimulating an immune response against Mycobacterium avium subspecies paratuberculosis (MAP). The compositions include a recombinant polypeptide that contains from its N-terminus to C-terminus a C-terminal fragment of MAP protein Map3527, a Map1519 protein amino acid sequence, followed by an N-terminal portion of Map3527. The method comprises administering the composition to an animal in an amount effective to stimulate an immunological response against MAP bacteria. The method is of benefit to any animal susceptible to MAP infection, but is particularly beneficial for ruminants.

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease (JD), which causes chronic granulomatous enteritis in ruminants. Clinically affected animals develop chronic diarrhea and progressive weight loss that eventually results in death, while subclinically infected animals mainly have decreased production of milk. JD is of tremendous economic importance to the worldwide dairy industry, causing major losses due to reduced production and early culling of animals with estimates of 20% of U.S. dairy herds affected and costs of $220 million per year to the dairy industry (Wells, et al. 2000. J. Am. Vet. Med. Assoc. 216: 1450-1457). Cattle are most susceptible to infection with this organism within the first 6 months of life, but disease typically does not become evident until 3 to 5 years of age. Infection occurs by ingestion of contaminated manure, colostrum, or milk from infected cows (Sweeney, 1996. Vet. Clin. N. Am. Food Anim. Pract. 12:305-312). Fetal infection also occurs, particularly in pregnant cows with advanced disease (Sweeney, et al. 1992. Am. J. Vet. Res. 53:477-480). Moreover, the significance of MAP has increased significantly because of its potential role as a causative agent of Crohn's disease in people (Chamberlin, et al. Aliment Pharmacol Ther 2001; 15(3):337-46; Naser S A, et al. Mol Cell Probes 2002; 16(1):41-8).
The currently approved JD vaccine for field use is an oil suspension of a killed strain of MAP, which has significant limitations. Primarily, the efficacy of this vaccine is questionable with varying results in different vaccination trials Another concern is the interference of whole cell bacterins with diagnostic testing, since vaccinated animals have false positive reactions for tuberculosis and paratuberculosis). Thus, the demand for improved vaccines is on the rise, but they need to be potent and at the same time should not interfere with the diagnosis of tuberculosis and JD. To achieve this goal, several approaches have been tried, which include recombinant vaccines, DNA vaccines and subunit vaccines 13; Shin S J, et al. Infect Immun 2005; 73(8):5074-85). However, there continues to be a need for the development for improved MAP vaccines.

Compositions for eliciting an immune response against


Disclosed are a method of manufacturing a graphene-carbon nanotube nanostructure which includes mixing graphite, a catalytic metal, and an ionic liquid, and then radiating microwaves on the mixture, and a graphene-carbon nanotube nanostructure manufactured using the method.

(a) Field of the Invention
A graphene-carbon nanotube nanostructure and a method of manufacturing the same are disclosed.
(b) Description of the Related Art
In general, various electronic devices such as a display device, a light emitting diode, a solar cell, and the like transmit light and display an image or generate electricity, and thus require a transparent conductive layer for transmitting the light. This transparent conductive layer is widely formed by using indium tin oxide (ITO).
However, since the indium tin oxide becomes expensive and less economical due to increasing consumption of indium, and particularly, the transparent conductive layer including the indium has a chemical and electrical defect, a transparent conducting material for replacing the indium tin oxide is required.
As for this transparent conducting material, carbon nanotubes are being researched. Carbon nanotubes are a carbon material having a diameter of several nanometers and thus have high conductivity.
The carbon nanotubes may be formed in a chemical vapor deposition (CVD) method. For example, the carbon nanotubes may be vertically raised by supplying a carbon source gas to a substrate on which a metal catalyst is dispersed, and then heat-treating it at a high temperature.
However, the chemical vapor deposition method of raising the carbon nanotubes requires a high temperature of greater than or equal to about 500° C., and thus may require a complicated process and a higher cost as well as including a limited kind of substrate.

Graphene-carbon nanotube nanostructure and method of manufacturing same

KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY


A system and method for extracting facts from documents. A fact is extracted from a first document. The attribute and value of the fact extracted from the first document are used as a seed attribute-value pair. A second document containing the seed attribute-value pair is analyzed to determine a contextual pattern used in the second document. The contextual pattern is used to extract other attribute-value pairs from the second document. The extracted attributes and values are stored as facts.

The internet provides access to a wealth of information. Documents created by authors all over the world are freely available for reading, indexing, and extraction of information. This incredible diversity of fact and opinion that make the internet the ultimate information source.
However, this same diversity of information creates a considerable challenge when extracting information. Information may be presented in a variety of formats, languages, and layouts. A human user may (or may not) be able to decipher individual documents to gather the information contained therein, but these differences may confuse or mislead an automated extraction system, resulting in information of little or no value. Extracting information from documents of various formats poses a formidable challenge to efforts to create an automated extraction system.


A method for producing a plate of steel which is resistant to abrasion and whose chemical composition includes, by weight: 0.24%≦C<0.35%; 0%≦Si≦2%; 0%≦Al≦2%; 0.5%≦Si+Al≦2%; 0%≦Mn≦2.5% 0%≦Ni≦5%; 0%≦Cr≦<5% 0%≦Mo≦1%; 0%≦W≦2%; 0.1%≦Mo+W/2≦1%; 0%≦B≦0.02%; 0%≦Ti≦1.1%; 0%≦Zr≦2.2%; 0.35%<Ti+Zr/2≦1.1%; 0%≦S≦0.15%; N<0.03%, optionally up to 1.5% of copper; optionally at least one element selected from Nb, Ta and V at contents such that Nb/2 +Ta/4+V≦0.5%; optionally at least one element selected from among Se, Te, Ca, Bi, Pb at contents which are less than or equal to 0.1%; and the balance being iron and impurities resulting from the production operation. The chemical composition further complying with the following relationships: C*=C−Ti/4−Zr/8+7×N/8≧0.095% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8 with: K=0.5 if B≧0.0005% and K=0 if B<0.0005%.

The present invention relates to an abrasion-resistant steel and its production method.
Steels are known which have a high level of abrasion resistance and whose hardness is approximately 600 Brinell. These steels contain from 0.4% to 0.6% of carbon and from 0.5% to 3% of at least one alloy element, such as manganese, nickel, chromium and molybdenum and they are quenched in order to have a completely martensitic structure. However, these steels are very difficult to weld and cut. In order to overcome these disadvantages, it has been proposed, in particular in EP 0 739 993, that a less hard steel be used for the same purposes, the carbon content of which is approximately 0.27% and which has a quenched structure containing a large quantity of residual austenite. However, these steels are still difficult to cut or weld.

This patent is subject to a terminal disclaimer.

Method for making an abrasion resistant steel plate and plate obtained


A system and method for modulating the sound pressure that is output from an audio transducer is disclosed. In one embodiment, the method includes receiving an audio signal and placing the audio signal across a voice coil of the transducer. In addition, a voltage is applied across a field coil of the transducer, the field coil being separate from the voice coil. And the voltage that is applied across the field coil is adjusted so as to modulate the sound pressure output from the audio transducer.

Since the inception of the electric guitar, guitarists have created overtones by overdriving amplifiers, and many guitarists use these overtones as a stylized element of their music. In particular, many musicians deliberately turn up a vacuum tube amplifier to the point where distortion (e.g., clipping) is clearly audible in the output signal. This distortion may range from a slight added "edge" with some increase in sustain, up to a thick fuzzy sound whose tonality is almost unrecognizable as that of the input signal. Although the overdriving of amplifiers is predominantly used with an electric guitar, some have also used it with the bass guitar or even a keyboard.
These artists, however, face the dilemma of either being able to preserve these overtones in their music or being able to adjust the volume of the output amplifier to lower levels where the overtones are not produced. Guitarists, for example, often times must sacrifice these desired overtones because the volume at which their amplifiers produce these overtones in simply too loud for small clubs, recording studios, townhouses or apartments.
Many circuit designs and additional components have been created in an attempt to simulate the overtones that occur when an amplifier is overdriven without actually overdriving the amplifier. For example, commercial devices have been developed and sold that either change or add circuitry in the path which the audio signal travels. More specifically, devices have been developed that generate signals that attempt to replicate the overtones that are created when an amplifier is overdriven. These replications, however, typically do not provide the same quality of overtones that are naturally produced by an overdriven amplifier.
Alternatively, many modern guitar amplifiers have a preamplifier stage, which can be made to distort heavily and the final output volume can be controlled by changing the gain on the later stage(s) of amplification. This approach, however, only introduces class A-type distortion from the preamplifier and does not enable the distortions created by an overdriven output stage, which many artists are most interested in, to be introduced into the audio signal.
Moreover, even when a tube amplifier is not overdriven, there are inherent distortions created when a tube amplifier drives a transducer, and many musicians desire to maintain these distortions as well. Accordingly, a method and an apparatus are needed to overcome the shortfalls of present technology.

System, method and apparatus for adjusting an output of a transducer


Compressed audio data for 5.1 channels stored in the DVD-ROM 11A is read by the AC-3 decoder 12 of a pseudo multi-channel stereo play-back apparatus and, after expansion, stored temporarily in a buffer 13, channel by channel. Among stored audio data stored in the buffer 13, audio data for left and right channels and for a front center channel are then subjected to the phase transformation. Audio data for left and right front channels are mixed with the phase transformed audio data by first and second mixing circuits 21 and 22 and mixed audio data are converted into analog audio signals by first and second D/A converters. The apparatus is capable of pseudo reproduction of the multi-channel audio signals stored in a recording medium such as a DVD-ROM by two channel play-back with an excellent sound effect which is not obtainable by usual two-channel play-back systems.

1. Field of the Invention
This invention relates to a two channel pseudo play-back apparatus for pseudo reproduction of a multi-channel audio output, and particularly relates to a two channel pseudo play-back apparatus in a personal computer for pseudo reproduction by two channel speakers of multiple channel audio outputs from, for example, DVD-ROMs.
2. Background Art
Conventionally, in a personal computer loaded with a reproducible sound board of sound or music, it was standard to use two channels for outputting an audio output of the medium for playing back.
Examples of reproducible mediums of sound or music in a personal computer include CD-ROM or CD-I (Compact Disc-Interactive). In the play-back of CD-I, there is a system which is capable of obtaining particular sound effect by processing audio signals for right and left channels, as disclosed in Japanese Patent Application, First Publication No. Hei 2-261213. This apparatus is provided with a function for producing particular sound effects using a four-channel mixing circuit and this apparatus comprises a digital audio processing portion containing a four-times over sampling type digital filter, and outputs two channel audio signals using the four channel mixing circuit by individually processing digital audio data for the L channel and the R channel.
Recently, attention has been attracted to an audio data signal system for digital video discs (hereinafter called DVD), which is a high efficiency coding system of AC-3 developed by Dolby Research Institute in the United States. This AC-3 is capable of playing back 5.1 channels of surrounding sounds. The number of channels in this AC-3 system is defined as two right and left front channels, one front center channel, two rear channels, and a low band channel (0.1 channel) for driving a super woofer.
For such audio data of 5.1 channels are reproduced by a personal computer with two audio output channels, two methods are known as described hereinafter.
A stereo play-back apparatus using the first method is described hereinafter with reference to FIG. 4. The first method comprises the steps of reading compressed digital audio data from a digital video disc-read only memory (DVD-ROM) 11 which stores the compressed audio data, and expanding the compressed data into 5.1 channel audio data by a decoder 12 of the AC-3, and storing expanded data temporarily in a buffer 13 composed of a plurality of buffers 131 to 136. Subsequently, among digital audio data stored in the buffer 13, digital audio data (FR and FL) for the left and right front channels are converted into analog audio signals by respective D/A converters constituted by a left D/A converter (L) and a right D/A converter (R), and thus converted analog signals are output into the audio signal output lines for playing back by left and right speakers 17 and 18.
A stereo play-back apparatus using the second method is described hereinafter with reference to FIG. 5. The same reference numerals are used in FIG. 5 for the same elements as those of FIG. 4, and explanations of the same elements are omitted. The stereo play-back apparatus using the second method comprises the same steps as those described referring to FIG. 4, that is, reading compressed digital audio data from the DVD-ROM, expanding the compressed data into digital signals for 5.1 channels using the AC-3 decoder 12, and storing the expanded data temporarily in the buffer 13. The steps are followed by mixing audio data for 3.1 channels containing the left front channel (FL), left rear channel (RL), the front center (FC), and a super woofer (SU) using a left mixing circuit (L) 18, converting the mixed data into analog data using a left D/A converter (L) 15, outputting the analog data into the left audio outputting line for play-back of the sound by a left speaker 19. Similarly, the audio data for 3.1 channels containing the right front channel (FR), right rear channel (RR), the front center channel (FC), and the super woofer (SU) are mixed using a right mixing circuit (R) 19, the mixed data are converted into an analog signals using a right D/A converter (R) 15, and the analog signals are output to a right outputting line for play-back using a right speaker 17.
In the first method, since audio data for only two channels consisting of the left and right channels (FL and FR) from among 5.1 channels are output, it is not expected to take advantage of the surround effect of the DVD. The second method is able to produce audio quality which is superior to that of the first method by mixing all of the audio data for the 5.1 channels. However, the surround effect of the second method is still inferior to that reproduced by the play-back apparatus for DVD.
Therefore, it is an object of the present invention to provide a pseudo stereo play-back apparatus with two channel speakers, which is capable of playing back a superior surround effect which is not obtainable using a usual two-channel play-back apparatus by processing the multiple channel audio outputs from a recording medium such as DVD-ROM for the two channel audio outputting apparatus.
Another object of the present invention is to provide a pseudo stereo play-back apparatus with two channel speakers, which is capable of playing back a superior surround effect which cannot be obtained with the usual two channel audio output apparatus by pseudo reproduction of the multiple channels by a two channel audio apparatus from a recording medium containing multiple channel audio outputs.

Pseudo multi-channel play-back apparatus


Systems and methods are provided for graphically configuring leads for a medical device. According to one aspect, the system generally comprises a medical device and a processing device, such as a programmer or computer, adapted to be in communication with the medical device. The medical device has at least one lead with at least one electrode in a configuration that can be changed using the processing device. The processing device provides a graphical display of the configuration. In one embodiment, the graphical display graphically represents, illustrates or displays the lead(s), the electrode(s), a pulse polarity, and a vector. According to another aspect, the method generally comprises receiving information for a medical device having at least one lead with at least one electrode in a configuration, and presenting a graphical representation of the configuration on a display. According to other aspects, a device and a computer-readable medium encoded with a software program for providing a graphical display of a lead configuration for an implantable medical device are also provided herein.

Medical devices, including cardiac stimulus devices such as implantable cardiac pacemakers and implantable cardioverter defibrillators (ICDs), are surgically implanted within a patient and have one or more electrical leads that conduct signals to and receive signals from the patient's heart. Each electrical lead has at least one electrode. Electrode types include ring, tip, and coil electrodes. Tip electrodes are positioned at the tip of the lead, and ring electrodes are bands positioned along the length of the lead. Coil electrodes are exposed conductor coils positioned along the lead, and are often used as part of a defibrillator to disperse a strong signal throughout the heart. Several of these electrode types may be placed on a single lead, and several of these leads may be placed in or around an organ such as the heart. Additionally, each of the electrodes may be configured to transmit or conduct a signal or pulse, or to receive or sense a signal. As such, the lead(s) with the electrode(s) are in a configuration with respect to their position and their electrical character or nature. The electrical character of the electrode(s) may be changed, and one method for changing the configuration is through programming.
A programming device or programmer communicates with the device. One communication method uses a telemetry link that enables commands and data to be non-invasively transmitted and received between the programmer and the device. During a programming operation, a user sets programmable parameters, including those parameters that relate to the configuration of the electrode(s), to values that cause the medical device to work in an optimum way for a particular patient. There are a number of reasons for which it is desirable to change the configuration. One reason is that the appearance of an electrogram (ECG, EGM) and the detection of intrinsic heart signals can be improved by changing the sensing configuration for a particular patient. Another reason is that the anode usually drifts slightly over time in its threshold voltages and thus requires more power to deliver the same pacing pulse. Reprogramming or reconfiguring the pacemaker to switch over and pace from the cathode rather than the anode can reduce the power requirements. Yet another reason is that the pacing electrode may have been placed near or on top of a diaphragm nerve such that the patient hiccups at each pacing pulse. Changing the pacing pulse resolves this situation. The list of reasons given above are nonexclusive as one skilled in the art would recognize that other reasons exist.
As medical devices provide more leads, electrodes per lead, and programming parameters for the leads, programming a configuration tends to become more complicated and confusing. Due to discrepancies in the terminology and procedures used in the medical field between doctors, clinical engineers or other users, there may be problems in connecting a textual term such as "unipolar" or "bipolar" with the placement of the leads and the actual pacing and sensing vectors between the electrodes on the leads.
Therefore, there is a need in the art to provide a system and method for graphically configuring leads of medical devices.

System and method for graphically configuring leads


An electrophotographic photoreceptor is provided that in excellent in the electrical characteristics such as the charging property, the sensitivity and the responsiveness, the oxidizing gas resistance such as the ozone resistance and the nitrogen oxide resistance, and the electrical durability such that even after repetition use the foregoing excellent electrical characteristics are not deteriorated. A photosensitive layer of an electrophotographic photoreceptor contains an amine compound represented by the general formula (1).

1. Field of the Invention
The present invention relates to an electrophotographic photoreceptor that is used to form an image according to an electrophotography process and image forming apparatus providing the same
2. Description of the Related Art
In electrophotographic image forming apparatus used frequently as copy machines and printers, a surface of an electrophotographic photoreceptor (hereinafter simply referred to as photoreceptor as well) is charged uniformly by a charging unit, the surface is exposed to form an electrostatic latent image corresponding to image information, the electrostatic latent image is developed with fine particles called toner to form a toner image that is a visible image, a formed toner image is transferred on a toner receiving material such as transfer paper and fixed, and thereby an image is formed on the toner receiving material.
An electrophotographic photoreceptor is formed by laminating a photosensitive layer including a photoconductive material on an electrically conductive substrate. As a photoconductive material of the electrophotographic photoreceptor, so far, inorganic photoconductive materials such as selenium (Se), cadmium sulfide (CdS) and zinc oxide (ZnO2) have been used. However, since there are problems of toxicity and so on in these inorganic photoconductive materials, in recent years, electrophotographic photoreceptors that use an organic photoconductive material (hereinafter in some cases referred to as organic photoreceptor) that is nontoxic, excellent in the film forming property and wide in a material selection range have been actively developed.
As the organic photoreceptor, a functionally-separated photoreceptor in which a charge generation function and a charge transport function, respectively, are carried out by different substances is used. The functionally-separated photoreceptor is roughly divided into a single layer photoreceptor that has a photosensitive layer in which a charge generating substance that has the charge generation function and a charge transporting substance that has the charge transport function are dispersed together in a resin that is called a binder resin and has the binding property; and a laminate type photoreceptor that has a photosensitive layer in which a charge generation layer in which a charge generating substance is dispersed and a charge transport layer in which a charge transporting substance is dispersed are laminated.
The laminate type photoreceptor has advantages in that a photosensitive layer can be easily designed and an electrophotographic photoreceptor excellent in the sensitivity and stability can be relatively readily prepared; accordingly, the laminate type photoreceptor forms a main stream of the organic photoreceptors. Furthermore, the single layer photoreceptor, since the photosensitive layer is formed of a single layer, in comparison with the laminate type photoreceptor, is higher in the productivity, can be manufactured at lower manufacturing costs, and, since a positive charge process in which at charging ozone that is a hazardous material is generated with difficulty can be used, is being put into practical use.
As performance required for an electrophotographic photoreceptor in an image forming process, the superiority in the electrical characteristics such as the charging property, the sensitivity and the responsiveness can be cited. Furthermore, in the image forming apparatus, since the image forming process is repeated many times, the photoreceptor is demanded to be stable in the electrical characteristics and excellent in the electrical durability even in repetition use.
However, existing photoreceptors have disadvantages in that the electrical durability is insufficient and when the photoreceptors are repeatedly used, the fatigue and deterioration such as a decrease in the charging potential, an increase in the rest potential and deterioration of the sensitivity are caused to induce deterioration of image quality, resulting in being incapable of using over a long term.
Regarding reasons for the fatigue and deterioration of the photoreceptor, several factors can be cited. Among these, an influential factor is in that oxidizing gases such as ozone, nitrogen oxides, chlorine oxides, and sulfur oxides that are emitted from a corona discharge type charging device (herein after referred to as corona discharger) that is used as charging means when a photoreceptor is charged in the image forming process greatly damage a photosensitive layer. It is considered that the oxidizing gases react with a charge transport material to generate ion pairs that accompany electron transfer or are absorbed by the charge generation material to induce a decrease in the charging potential, an increase in the rest potential, deterioration of the sensitivity, and deterioration of the resolution power owing to a decrease in the surface resistance. As a result, the image quality is remarkably deteriorated and the lifetime of the photoreceptor is shortened.
In order to overcome the problem of the fatigue and deterioration of the photoreceptor due to the oxidizing gases, an idea is proposed in that the oxidizing gases generated from a corona discharger is efficiently evacuated and replaced by an inert gas to a photosensitive layer, and thereby an adverse affect of the oxidizing gases on the photoreceptor is suppressed. However, in order to evacuate the oxidizing gases, an evacuation unit has to be newly disposed in the image forming apparatus. However, a problem causes that a process as a whole and a system becomes complicated.
Furthermore, in order to suppress the fatigue and deterioration of the photoreceptor from occurring owing to the oxidizing gases, a particular compound is added to a photosensitive layer. It is proposed to add, for instance, an anti-oxidant such as a hindered phenol compound (Japanese Unexamined Patent Publication JP-A 62-105151 (1987)) and an aromatic amine compound such as N,N′-diphenyl-p-phenylene diamine (Japanese Unexamined Patent Publication JP-A 63-216055 (1988)); and a light stabilizer such as a hindered amine compound (Japanese Unexamined Patent Publication JP-A 63-18355 (1988)) and a benzotriazole compound to a photosensitive layer. Here, the hindered phenol compound is a phenol compound that has a bulky substituent group such as a side chain-like alkyl group, cyclo-alkyl group, aryl group or heterocyclic group in an ortho-position of a phenolic hydroxy group. Furthermore, the hindered amine compound is an amine compound in which a hydrogen atom of an amino group is substituted with a bulky substituent group such as a side chain-like alkyl group, cyclo-alkyl group, aryl group or heterocyclic group.
Furthermore, in different related art, it is proposed to add a trialkyl amine compound (Japanese Unexamined Patent Publication JP-A 63-4238 (1988)), a t-amine compound having a particular structure such as 2-(N,N-dibenzylamino) ethanol (Japanese Unexamined Patent Publication JP-A 03-172852 (1991)) and the like to a photosensitive layer.
The photoreceptors disclosed in the JP-A Nos. 62-105151, 63-216055, 63-18355, 63-4238 and 03-172852 have problems as shown below. Even though compounds disclosed in JP-A Nos. 62-105151, 63-216055, 63-18355, 63-4238 and 03-172852 are used, the fatigue and deterioration of the photoreceptor due to the oxidizing gases such as ozone and nitrogen oxides cannot be sufficiently suppressed from occurring; that is, after the repeated use thereof, the decrease of the charging potential and the increase of the rest potential are generated. Furthermore, when the compounds disclosed in JP-A Nos. 62-105151, 63-216055, 63-18355, 63-4238 and 03-172852 are added to a photosensitive layer, the deterioration of the sensitivity and the deterioration of the electrical characteristics such as the increase of the rest potential owing to the deterioration of the responsiveness are caused; accordingly, there is a problem that from the beginning of use, practically sufficient sensitivity and responsiveness cannot be obtained.

Electrophotographic photoreceptor and image forming apparatus providing the same


A bracing apparatus for bracing a flexible pipe extending between a fire sprinkler header pipe and a sprinkler and for holding the sprinkler in a desired location, a flexible piping system having the bracing apparatus, and a method of installing a sprinkler of a sprinkler system having the bracing apparatus. The bracing apparatus has first mounting members that attach to a flexible pipe, and a stiffener bar that extends between the first and second mounting members.

1. Field of the Invention
The present invention relates to fire sprinkler systems, and in particular to a flexible piping system for a ceiling tile fire sprinkler installation.
2. Brief Description of the Prior Art
Fire sprinkler systems carry a fire suppressing agent, commonly water, from a source into a building through a network of pipes. The piping network operates under pressures as high as 150-200 psi, and transient pressures can be even higher. Thus, the network must be sufficiently supported so that the components of the system are not compromised due to the fluctuations in pressure. Typically, the network of piping for fire sprinkler systems is located within the building or infrastructure above the ceiling, typically a drop ceiling, or ceiling tiles, and the sprinkler ends protrude through holes formed in the ceiling tiles. The sprinkler ends are connected to fire sprinkler distribution headers (sprinkler pipes) by means of rigid metal pipe and associated fittings. During construction or installation, the distribution header is installed. The metal pipe connections from the distribution header to the sprinkler, and the sprinklers themselves, are installed at a later time, usually after the ceiling support system is in place and the openings are formed in the ceiling tiles. Once the ceiling grid system is in place and the location of the tiles and openings are known, the fire sprinkler installation crew then returns to size the rigid pipe connections from the header to the sprinkler. The sprinklers are then installed. This method slows installation in that the sprinkler installation crew must fit and install the distribution header and estimate locations of the branch pipe connections. At this point, they must wait until the ceiling support system and tiles are in place before they can complete installing the connecting pipes and sprinkler fittings. Another drawback associated with having to wait until ceiling installation is complete is that pressure testing cannot be done until the complete system, and thus the ceiling, is installed, making it more difficult to isolate and repair leaks in the distribution system.
It is recently known in the art to use flexible pipe to distribute the flow from the distribution header to the sprinkler fitting. However, these systems require adequate support, usually from the ceiling tile support grid system, for the sprinkler fittings to stay in place during pressure variations in the system.

Fire sprinkler flexible piping system, bracing apparatus therefor, and method of installing a fire sprinkler


An apparatus for mounting and adjusting a satellite antenna in the azimuth and elevational planes. The present invention provides a base having a longitudinal axis adaptable to adjustably receive a mounting pole. A rotational mount is rotatably connected to the base and has a longitudinal axis extending at an acute angle relative to the longitudinal axis of the base. A satellite antenna support is adaptable to receive a satellite antenna, and the satellite antenna support is adjustably coupled to the rotational mount for adjustment about a rotational axis wherein the rotational axis is substantially perpendicular to the longitudinal axis of the rotational mount. A first adjustment mechanism is coupled to the base and the rotational mount for providing fine azimuth adjustment of the satellite antenna. A second adjustment mechanism is coupled to the rotational mount and the satellite antenna support for \providing fine elevational adjustment of the satellite antenna.

The importance of accurately aligning a communication antenna relative to the associated signal source with which the antenna is positioned to communicate is well known. Such alignment is necessary for both land-based and satellite-based signal transmission systems. In either installation, it is important that the antenna be aligned along at least two axes. The first axis is that of the horizontal orientation of the antenna, or azimuth. The azimuth motion is typically directed to the points of the compass, i.e., north, east, south, west. The second axis of movement is that of the vertical orientation, or elevation. The elevation orientation moves up and down, that is, goes from the horizon to the zenith (directly overhead). Thus, it is well established that the ability to assemble, mount, and align a satellite antenna with the fewest manual adjustments and the most efficiency is a great advantage.
Ultimately, the precise alignment of a satellite antenna is a critical function. In order to facilitate alignment, electronic devices, such as those that measure the strength of the signal to the antenna, have been designed for use during the antenna installation. It is, however, necessary that the antenna be coarsely aligned with its designated signal source, such as a satellite, before such electronic devices that measure the strength of the signal to the antenna can be utilized. A coarse alignment of the antenna is thus necessary in order to first obtain a signal for subsequent dual axis tuning of the antennas in the azimuth and elevational orientations.
Once a coarse alignment of the satellite antenna is obtained, primary alignment or fine tuning of the satellite antenna occurs when the antenna is orientated and precisely positioned relative to a detected antenna signal strength. Although many designs have been created to aid in the primary adjustment of the satellite antenna, such designs are expensive, complex, cumbersome, and often difficult to use.
Typically, tuning of the satellite in the azimuth plane occurs with the azimuth plane lying in a direction substantially perpendicular to the axis of the base structure or mounting pole supporting the satellite antenna. Based on this structure, the azimuth adjustment range is reduced as the elevation angle increases to 90°. However, based on population demographics, the majority of satellite installations require an elevation range extending between 20–60° above the horizon. Thus, the azimuth adjustment range of the satellite antenna is not maximized by an azimuth plane perpendicular to the base or mounting pole of the satellite antenna.
Therefore, it would be desirable to provide a method and apparatus for mounting and adjusting a satellite antenna that was inexpensive, simple, quick, and accurate in detecting a strong signal. In addition, it would also be desirable to provide a method and apparatus for mounting and adjusting a satellite antenna that utilized a greater range of azimuth adjustment that corresponded to the largest population demographic.

Apparatus for mounting and adjusting a satellite antenna


A semiconductor memory device comprises an array of electrically rewritable memory cells which are arranged in a matrix, erasing section for applying an erasing voltage to the memory cells to effect erasing, and writing section for applying a writing voltage to the memory cells to effect writing, wherein in the erasing section and writing section, either MOS transistors to which a voltage higher than the erasing voltage and writing voltage is applied or MOS transistors which transfer a voltage higher than the erasing voltage and writing voltage contain MOS transistors which are in a weak inversion state or an inversion state with their substrate bias voltage, gate voltage and source voltage at 0 V.

1. Field of the Invention
This invention relates to a semiconductor memory device, such as an electrically rewritable nonvolatile semiconductor memory device (EEPROM), and more particularly to an EEPROM that writes and erases the data into and from memory cells by tunnel current.
The invention further relates to such a high-voltage switching circuit as is used in the semiconductor memory device, and more particularly to a voltage switching circuit that uses only NMOS transistors (n-channel MOS transistors).
2. Description of the Related Art
One known type of EEPROMs is a NAND-cell EEPROM capable of high integration. In this type of EEPROM, a plurality of memory cells are connected in series in such a manner that their source and drains may be shared by adjacent cells and these series-connected cells are treated as one unit and connected to a bit line. The memory cells generally have an FETMOS structure in which a charge storage layer (a floating gate) and a control gate are laminated together. The memory cell array is formed by integrating cells in a p-type substrate or p-well. The drain side of a NAND cell is connected to a bit line via a select gate and the source side is connected to a common source line via a select gate. The control gates of the memory cells are arranged consecutively in the row direction and serve as word lines.
The NAND-cell EEPROM operates as follows. The data is written, starting at the memory cell farthest from the bit line (i.e., the memory cell on the source line side). A high voltage V.sub.ppW (=about 18 V) is applied to the control gate of the selected memory cell, an intermediate voltage of V.sub.m10 (=about 10 V) is applied to the control gates of the memory cells closer to the bit line than the selected one and their select gates on the drain side, and 0 V or an intermediate voltage of V.sub.m8 (=about 8 V) is applied to the bit line according to the data.
When 0 V is applied to the bit line, the voltage is transferred to the drain of the selected memory cell, causing electrons to be injected into a charge storage layer. This causes the threshold voltage of the selected memory cell to shift in the positive direction. This state is assumed to be "0", for example. When V.sub.m8 is applied to the bit line, electron injection virtually does not take place and consequently the threshold voltage does not change and remains negative. This state is assumed to be "1" and the erased state. The data is written simultaneously into the memory cells sharing the control gate.
The data is erased in blocks simultaneously from all of the memory cells in the selected NAND cell. All of the control gates in the selected NAND cell block are set at 0 V and the p-well is set at 20 V. At this time, with the high voltage applied to the p-well, the select gate, bit line, and source line are also set at 20 V. This causes the electrons in the charge storage layer to be discharged into the p-well in all of the memory cells in the selected NAND cell block, causing the threshold voltage to shift in the negative direction. All of the control gates of the memory cells in the NAND-cell blocks not to be erased are set at 20 V. High voltages necessary for writing and erasing are generated at the charge pump circuit.
The data is read by setting the control gate of the selected memory cell at 0 V and the control gates and select gates of the other memory cells at a power-supply voltage Vcc (e.g., 3 V), and sensing whether or not current flows through the selected memory cell. To achieve this, the threshold voltage of the memory cell after writing must be Vcc or less.
Since such a NAND-cell EEPROM uses a wide voltage range of 0 V to Vpp (up to 20 V), transistors dealing with a voltage range of 0 V to V.sub.m10 (up to 10 V) (hereinafter, abbreviated as Vm-route transistors) and high-withstand-voltage transistors handling a voltage range of 0 V to Vpp (hereinafter, abbreviated as Vpp-route transistors) are needed. The reason for this is that a circuit to which only a voltage of V.sub.m10 or less is applied is composed of Vm-route transistors of a relatively small size, thereby suppressing the circuit area and only the transistors to which Vpp is applied are determined to be Vpp-route transistors.
This type of device, however, has the following problem.
When n-channel and p-channel MOS transistors are used as Vpp-route transistors, the number of types of transistor increases and production cost rises. When, for example, only n-channel MOS transistors are used as Vpp-route transistors and constitute a circuit, the power-supply voltage cannot be made low because of a decrease in the voltage transfer efficiency due to the threshold voltage of the transistors. Furthermore, when a circuit is composed of, for example, n-channel MOS transistors with a low threshold voltage, acting as Vpp-route transistors, leakage current in the transistors increases the drawn current in the stand-by condition or prevents the high voltage Vpp from being stepped up from the power supply voltage.
Still furthermore, since the writing voltage and erasing voltage are generated internally at the charge pump circuit, variations in production are liable to have an adverse effect on the devices and variations in the threshold voltage after the data has been written into the memory cell must be restricted within a specific range.
Additionally, the above-described semiconductor memory device is provided with a high-voltage switching circuit that switches the high voltage between the selected mode and the unselected mode. With the high-voltage switching circuit, a high voltage is applied to the source of an n-channel MOS transistor (hereinafter, referred to as an NMOS transistor) and a gate voltage is applied to its gate, depending on whether it is in the selected or unselected mode. Specifically, in the selected mode, the gate of the NMOS transistor is applied with the stepped-up voltage, or a high voltage raised from the power supply voltage, the output (drain) is supplied with a boosted voltage higher than the high voltage by at least the threshold voltage of the NMOS transistor so as to achieve complete transfer. In the unselected mode, the gate is applied with the ground.
With the high-voltage switching circuit, although the magnitude of the high boosted voltage required depends on the threshold voltage of the NMOS transistor, the boosted voltage must be made as low as possible to improve the reliability of the transistor. Therefore, the threshold voltage of the NMOS transistor must be made as low as possible. Use of transistors with a low threshold voltage would result in a poorer cut-off characteristic, increasing a leakage current from the high voltage when the high voltage is not transferred. Specifically, even when the output and the gate of the NMOS transistor are grounded, the transistor is not cut off, permitting the input or a leakage current from the high voltage to increase. In this way, because the high voltage is obtained by stepping up the power-supply voltage, as the leakage current increases, a desired high voltage cannot be output.

Semiconductor memory device and high-voltage switching circuit


Disclosed are systems, methods, and computer-readable storage media to select content to present to a user are disclosed. In one aspect, a method includes determining a content consumption rate of the user, and selectively presenting content to the user based on the content consumption rate. The content consumption rate may be determined based on a number of media content presented to the user over a period of time. If the number is above a threshold, a first type of content may be presented, while if the number is below (or equal) to the threshold, a second type of content, or in some aspects, no content, may be presented. After the selective presentation, additional content may be presented regardless of the content consumption rate.

Social network members demonstrate diversity in their usage of the various features available to them. Some members utilize the social features extensively, exchanging messages and corresponding frequently on a one on one basis with other members. Some other members may utilize the social network to obtain news or other information, without fully utilizing the social networking features. Methods and systems to adapt to how users utilize these social networks are therefore desirable.

Selecting content for high velocity users


A link for connecting a chain. The link has a first outer chain plate, a first pin, a second pin, and a second outer chain plate. The first outer chain plate has two circular holes. The pin has, at a first end, an enlarged flat head and, at a second end, a dome head near which a groove extends so as to form a neck. The second outer chain plate has a circular hole and a hole consisting of a relatively small semicircular hole overlapping partially with a relatively large semicircular hole. In a plant, the first pin is (a) inserted through a hole of the first outer chain plate, holes of two inner chain plates, and the circular hole of the second outer chain plate and (b) riveted at both heads to thereby combine these elements conventionally. The second pin is inserted through the other hole of the first outer chain plate and the enlarged flat head thereof is secured to the first outer chain plate. A bike rider can (a) insert the dome head of the second pin through holes of other two inner chain plates, (b) move the dome heads toward each other, whereby the dome head of the second pin is permitted to be inserted through the relatively large semi-circular hole, and (c) release the second pin to thereby permit the neck to be received in the relatively small semicircular hole.

The present invention relates to a chain connector.
The present inventor's co-pending U.S. application Ser. No. 07/680,905 filed Apr. 5, 1991 teaches a novel link for connecting a chain consisting of a plurality of conventional links including two terminal links each having two inner chain plates. The novel link has a first outer chain plate, two pins, and a second outer chain plate. The first outer chain plate has two circular holes. Each pin has, at a first end thereof, an enlarged flat head and, at a second end thereof, a flat head near which a groove extends to thereby form a neck. The second outer chain plate has two holes each consisting of a relatively large semicircular hole partially overlapping with a relatively small semicircular hole. A distance between centers of the relatively large semicircular holes is less than a distance between the pins, while a distance between centers of the two relatively small semicircular holes is the same as the distance between the pins.
To assemble a chain, (a) the flat head of each pin is inserted through circular holes of the first outer chain plate and of the inner chain plates of each terminal link of the chain; (b) the first outer chain plate is bent to thereby move the flat heads of the pins toward each other, thereby allowing each head to be inserted through each relatively large semicircular hole; and (c) the first outer chain plate is released, whereby each neck is received in each relatively small semicircular hole. When used, the chain is subject to a tension to thereby urge each neck to be received in each relatively small semicircular hole, thereby firmly connecting the chain.
The present inventor's co-pending U.S. application Ser. No. 07/816,429 filed Dec. 31, 1991 discloses a chain consisting of links as taught in the above-mentioned application. Therefore, the length of the chain is easily adjustable because each link could be disengaged therefrom without any tools.
A major problem of the above-mentioned application is that it is difficult to bend the pins and to maintain the outer chain plate in position at the same time. The present invention is intended to solve this problem.


A 60 degree bump placement layout for an integrated circuit power grid is provided. This layout improves integrated circuit performance and reliability and gives an integrated circuit designer added flexibility and uniformity in designing the integrated circuit. Further, a patterned bump array for a top metal layer of an integrated circuit having a plurality of 60 degree bump placement structures is provided.

A typical computer system includes at least a microprocessor and some form of memory. The microprocessor has, among other components, arithmetic, logic, and control circuitry that interpret and execute instructions necessary for the operation and use of the computer system. FIG. 1 shows a typical computer circuit board (10) having a microprocessor (12), memory (14), integrated circuits (16) that have various functionalities, and communication paths (18), i.e., buses and wires, that are necessary for the transfer of data among the aforementioned components on the circuit board (10).
Integrated circuits (16) and microprocessors (12), such as the ones shown in FIG. 1, are electrically connected, i.e., xe2x80x9cmounted,xe2x80x9d to the circuit board (10) via chip packages. A chip package houses semiconductor devices in strong, thermally stable, hermetically-sealed environments that provide a semiconductor device, e.g., an integrated circuit, with electronic connectivity to circuitry external to the semiconductor device.
FIG. 2 shows a typical chip package assembly. In FIG. 2, an integrated circuit (20) is mounted onto a chip package (22), where an active side (24) of the integrated circuit (20) is electrically interfaced to the chip package (22). Specifically, the integrated circuit (20) has bumps (26) on bond pads (also known in the art as xe2x80x9clanding padsxe2x80x9d) (not shown) formed on the active side (24) of the integrated circuit (20), where the bumps (26) are used as electrical and mechanical connectors. The integrated circuit (20) is inverted and bonded to the chip package(22) by means of the bumps (26). Various materials, such as conductive polymers and metals (referred to as xe2x80x9csolder bumpsxe2x80x9d), are commonly used to form the bumps (26) on the integrated circuit (20).
As discussed above with reference to FIG. 2, the bumps (26) on the integrated circuit (20) serve as electrical pathways between components within the integrated circuit (20) and the chip package (22). Within the integrated circuit (20) itself, an arrangement of conductive pathways and metal layers form a means by which components in the integrated circuit (20) operatively connect to the bumps (26) located on an exterior region of the integrated circuit (20). To this end, FIG. 3a shows a side view of the integrated circuit (20). The integrated circuit (20) has several metal layers, M1-M8, surrounded by some dielectric material (28), e.g., silicon dioxide. The metal layers, M1-M8, are connected to each other by conductive pathways (30) known as xe2x80x9cvias.xe2x80x9d Vias (30) are essentially holes within the dielectric material (28) that have been doped with metal ions. Further, those skilled in the art will understand that although FIG. 2 shows only eight metal layers and a particular amount of vias, integrated circuits may have any number of metal layers and/or vias.
Circuitry (not shown) embedded on a substrate of the integrated circuit (20) transmit and receive signals and power via the metal layers, M1-M8, and the vias (30). Signals that need to be transmitted/received to/from components external to the integrated circuit (20) are propagated through the metal layers, M1-M8, and vias (30) to the top metal layer, M8. The top metal layer (also referred to and known as xe2x80x9cpower gridxe2x80x9d), M8, then transmits/receives signals and power to/from the bumps (26) located on the active side (24) of the integrated circuit (20). With respect to the power and energy needed by the integrated circuit (20), power is delivered to the integrated circuit (20) from external sources through the bumps (26) and metal layers, M1-M8. The top metal layer, M8, on the integrated circuit (20) acts as an interface between the integrated circuit (20) and the external sources/signals of power.
FIG. 3b shows a top view of the integrated circuit (20) shown in FIG. 3a. The top metal layer, M8, as shown in FIG. 3b, has a number of parallel regions, otherwise known as xe2x80x9cmetal bars.xe2x80x9d These metal bars alternate between bars connected to VDD and regions connected to Vss. Such a configuration helps reduce electromagnetic interference. The top metal layer, M8, is configured such that it is orthogonal with the metal layer below, M7, as shown in FIG. 3b. Further, bumps (26) on the top metal layer, M8, are arranged in a non-uniform fashion with some areas of the top metal layer, M8, having larger numbers of bumps (26) than other areas.
According to one aspect of the present invention, an integrated circuit having a top metal layer that has a first metal bar and a second metal bar comprises a first bump disposed on the first metal bar, a second bump disposed on the first metal bar, and a reference bump disposed on the second metal bar, where the first bump and the second bump are positioned such that an angle between a line from the reference bump to the first bump and a line from the reference bump to the second bump has a value substantially equal to 60 degrees.
According to another aspect, an integrated circuit having a top metal layer that has a first metal bar and a second metal bar comprises a first bump disposed on the first metal bar, a second bump disposed on the first metal bar, and a reference bump disposed on the second metal bar, where the first metal bar and the second metal bar are positioned such that an angle between a line from the reference bump to the first bump and a line from the reference bump to the second bump has a value substantially equal to 60 degrees.
A patterned bump array for a power grid of an integrated circuit comprises a reference bump disposed on a first metal bar, a first bump disposed on a second metal bar, and a second bump disposed on a second metal bar, where the first bump, the second bump, and the reference bump are arranged such that an angle between a line from the reference bump to the first bump and a line from the reference bump to the second bump has a value substantially equal to 60 degrees.
According to another aspect, a bump layout for a power grid of an integrated circuit comprises a reference bump disposed on a first metal bar, a first bump disposed on a second metal bar, and a second bump disposed on a second metal bar, where the first metal bar and the second metal bar are arranged such that an angle between a line from the reference bump to the first bump and a line from the reference bump to the second bump has a value substantially equal to 60 degrees.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.


A process for producing a 1,2-diol through the reaction of an olefin with hydrogen peroxide. The process is highly efficient and highly selective and catalyst recovery and reuse are easy. It does not use any strong acid or strong base causative of apparatus corrosion. The process for producing a 1,2-diol is characterized by reacting an olefin with hydrogen peroxide in the presence of a polymer having a sulfo group.

Methods of producing a 1,2-diol by reacting an olefin with an aqueous hydrogen peroxide solution in formic acid or acetic acid to synthesize an epoxide and then by hydrolyzing the epoxide have been known for a long time (Organic Syntheses, Coll. Vol. 3, 217-219 (1955), J. Am. Chem. Soc., 67, 1786-1788 (1945), etc.) The methods require multi-step operations after the reactions, such as removing the solvent, reacting with an aqueous sodium hydroxide solution, and neutralizing with hydrochloric acid.
Another method of producing a 1,2-diol from an olefin via an epoxide by using peracetic acid as an oxidizing agent has been known (JP-A-4-41449). However, the method has problems such as corrosion of a reaction vessel, treatment of by-product acetic acid, etc.
In view of overcoming the problems by using an appropriate catalyst, methods of producing a 1,2-diol from an aqueous hydrogen peroxide and an olefin in one step using a tungsten complex catalyst have been reported (J. Chem. Soc., 1949, 2988-3000, J. Am. Oil Chem. Soc., 44, 316-320 (1967), Tetrahedron Lett., 29, 823-826 (1988), etc.) However, since the diol thus produced can be further oxidized, a ketone or a carboxylic acid is inevitably generated as a by-product.
Though attempts have been made to improve the 1,2-diol selectivity by tuning the reaction conditions (EP 146374; Synthesis, 1989, 295-297, etc.), the methods use highly-toxic benzene as a solvent and require complicated operations for isolating the product such as extraction using a 30% aqueous sulfuric acid solution and neutralization using a base.
Reactions between an olefin and an aqueous hydrogen peroxide using a solid catalyst such as TS-1 and MCM-41, which can be easily removed by filtration and reused, have recently been reported (J. Cat., 145, 151-158 (1994); Chem. Commun., 1998, 325-326; J. Cat., 189, 40-51 (2000), etc.) Though these reactions provide improved methods with respect to the operations, the reactions form a large amount of an epoxide or a ketone in addition to the desired 1,2-diol product, resulting in poor yield and low selectivity of the 1,2-diol. Thus, the development of a method capable of producing a 1,2-diol with high efficiency and high selectivity by a simple operation, using a catalyst that is easily recovered and reused without using a strong acid and a strong base causing the corrosion of a reaction vessel, has been strongly demanded.

National Institute of Advanced Industrial Science and Technology