Rechargeable electrochemical cells, such as lithium batteries and asymmetric hybrid battery/supercapacitor systems, exhibiting exceptional specific capacity levels and stability over extended high-rate recharge cycling comprise nanostructure zero strain Li4Ti5O12 intercalation electrode material synthesized in a short duration process of annealing mixed TiO2 and Li-source precursor compounds at about 800° C. for a time of about 15–30 min which is not substantially longer than that required to effect maximum available reaction between the precursors, thereby substantially eliminating the growth of synthesized Li4Ti5O12 particles beyond nanostructure size. The process reduces by order of magnitude the time and energy required for synthesis of the active electrode material and fabrication of utilizing cell devices, and provides such nanostructure material which enables repeated, high-rate recharge cycling without loss of cell capacity or efficiency.

The present invention relates to rechargeable electrochemical energy storage systems, particularly to such systems comprising materials capable of reversibly taking up and releasing lithium ions as a means of storing and supplying electrical energy. More specifically, the invention relates to the synthesis and utilization of nanostructure lithium titanate as the active electrode component material of electrochemical cells capable of exhibiting high specific capacity at high recharge rates.
During the course of development of rechargeable lithium ion cells and the like, numerous materials capable of reversibly accommodating lithium ions have been investigated. Among these, occlusion and intercalation materials, such a carbonaceous and graphitic compounds, and transitions metal oxide spinels, have proved to be particularly well-suited to such applications. However, even while performing significantly well in high capacity recycling electrical storage systems, many of these materials exhibit detrimental properties which detract from the ultimate operation of rechargeable cell devices.
Notable among such shortcomings of active cell materials is the tendency toward physical expansion to a greater or lesser degree upon taking up the mobile ions, e.g., Li+ ions, which form the critical basis for the function of such systems. While the relatively minute size of Li+ ions, as compared to other mobile ion species of varying efficacy, minimizes to a great extent the physical strain upon the electrode material structure, there nonetheless often results from repetitive cycling effects a significant loss of electrochemical cell capacity, whether due to internal disruption of electrical continuity within the structure of the active compound or otherwise.
Extensive investigation into this so-called "electromechanical grinding" effect has revealed certain compounds which exhibit little or no physical expansion or flexing during the recharge cycling lithiation/delithiation process. Particularly notable in this respect is the lithium titanate defect spinel, Li4Ti5O12, reported by T. Ohzuku et al., J. Electrochem. Soc., 142, 1431 (1995), as a "zero-strain" insertion material. The reported test results of the efficacy of this material as an active counter-electrode component in a rechargeable lithium intercalation battery cell showed a remarkable capacity stability over extended cycling which indeed evidenced a low level of physical expansion nominally attributable to zero-strain ion insertion.
However, these promising capacity retention results were achieved at cycling rates of about C/3, i.e., at such low energy density as to require about 3 h to effect a complete charge or discharge operation, thereby allowing sufficient time to all but ensure thorough Li+ ion transfer to or from the active electrode material and provide an encouraging indication of a correspondingly high level of cell specific capacity. Such long charging periods are, unfortunately, impractical and unacceptable in the marketplace. Subsequent testing of similar Li4Ti5O12 material prepared in the manner of Ohzuku, that is, by 10–12 h, 750–800° C. annealing of a mixture of TiO2 and a thermolabile Li precursor, such as LiOH.H2O, at more acceptable cycling rates in excess of about 2C, i.e., at a charging energy density level sufficiently high to yield a full charge in ½ h, revealed that the otherwise promising zero-strain material could not maintain for any reasonable length of time a recharge capacity of more than about 50% of that initially exhibited at low cycling rates.
Attempts to improve recharge capacity of Li4Ti5O12 electrodes at higher cycling rates by reducing the particle size of this incorporated intercalation material were reported by Peramunage et al., J. Electrochem. Soc., 145, 2609 (1998). Such an approach would have appeared to have significant merit, since it could generally be observed that, while the rate at which an ion species, such as Li+, is capable of diffusing into a given host intercalation compound is a function of the molecular structure of such compound, the radial distance the ion must travel to complete intercalation throughout a host particle, i.e., the size of such particle, will determine the overall intercalation capability, or specific capacity, of a mass of the host compound. In such investigations, the authors utilized submicron-sized TiO2 and LiOH or Li2CO3 precursors in the process of Ohzuku (10 h anneal at 800° C.) to reportedly obtain submicron particles of Li4Ti5O12 material and thus substantially reduce the time required to provide thorough intercalation into the material. While some improvement in the recharge capacity of Li battery cells was shown by levels of 100–120 mAh/g at 1C to 1.2C cycle rates, significant capacities achieved at rates above 1.5C remained of borderline practicality.
Further investigations into the problem of high cycle rate recharge capacity of Li4Ti5O12 electrode materials have been undertaken here and have revealed that synthesized Li4Ti5O12 particles continue to enlarge during prolonged annealing, thus leading to detraction from any initial improvement in capacity at high cycling rates which the use of nanostructure precursor material particles might otherwise have provided. Resolution of this problem during the course of the present invention has resulted from the discovery of a process which yields consistent nanostructure Li4Ti5O12 product and provides such materials and electrochemical cells which exhibit remarkable improvement in high cycle rate capacity to the extent of many-fold increases in effective cycle rates. In addition, the invention provides a process for synthesizing such materials which realizes magnitude increases in economies of time and energy.

Nanostructure lithium titanate electrode for high cycle rate rechargeable electrochemical cell


A method and apparatus are provided for verifying authenticity of a data acquisition peripheral to be used, which has at least one identifier. The method includes: receiving the identifier by means of an authentication server, verifying, by the authentication server, an association of the identifier with a referenced authentic peripheral, delivering a decision of identification; and transmission, by the server, of the decision of identification.

The facility with which DAPs can be installed enables them to be adapted to novel uses, especially in various environments, for example environments without communications infrastructures. Payments by DAPs can thus be done through a private individual's smartphone or a merchant working outdoors, for example an artisan working in private homes or moving about in fairs or markets.
These novel possibilities of use, especially by nomadic merchants who are not known to their customers, raise a new problem of trust for their customers.
In addition, the hardware functions of these terminals are relatively basic and can be implemented at low cost. Consequently, such terminals are easy to make.
This explains the success of such terminals as well as the development of fraudulent solutions, aimed for example at obtaining confidential banking data from customers or aimed at obtaining debits of undue amounts.

Method for verifying authenticity, corresponding server, system and computer program


According to one embodiment of the invention, a non-transitory computer readable medium for configuring a noise floor of a network device based on the detection of a non-Wi-Fi signal is described. One embodiment of the non-transitory computer readable medium comprises instructions that detect a non-Wi-Fi signal, determine a noise floor based on at least one attribute of the non-Wi-Fi signal and configure the noise floor of the network device such that the network device receives signals with a signal strength above the noise floor value.

In recent years, Wireless Local Area Network (WLAN) technologies have emerged as a fast-growing market. Among the various WLAN technologies, Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard is the dominating technology and is frequently used for WLANs.
Devices within WLANs communicate wirelessly pursuant to the 802.11 standard with other devices within the WLAN to request, grant, provide, and/or receive access to network resources. However, wireless communication between a first set of devices may interfere with communication between another set of devices. In one example, a first set of devices communicating on a particular channel may cause interference for a second set of devices communicating on the same channel (or partially overlapping channels) if wireless signals, transmitted between devices in the first set of devices, reaches devices in the second set of devices.
Interference that affects wireless communication can come in many forms from sources operating in-band or out-of-band. There are different types of in-band and out-of band interference that may or may not be directly measurable at a narrow-band receiver. Interference may affect the ability of the network device to transmit and/or receive. In general, the receiver will be the most affected by out-of-band interference. Since transmit and receive paths are closely tied in Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (e.g., every directed frame sequence transmission requires the reception of an ACK or Block ACK), it may be difficult to pinpoint the problem in some cases. The Transmit (Tx) will be affected in different ways depending whether or not the in-band interference can be measured by the network device. For example, in IEEE 802.11 standards, when the measured in-band interference strength exceeds the Energy Detect Threshold (EDT), the ability of the network device to transmit will be affected. If the in-band interference is not directly measurable, then the transmissions may be corrupted.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.

Mitigating interference in wireless systems


A lens actuator includes a lens holder to support an objective lens and having a pair of first side surfaces in a tracking direction and a pair of second side surfaces in a tangential direction, a fixed magnet disposed to confront the second side surface and comprising four regions having approximately the same area and are magnetic, such that magnetic directions of the four regions are perpendicular to a plane including a focusing direction and the tracking direction but are in opposite directions between two mutually adjacent regions, a pair of tracking coils disposed between the second surface and the magnet and having centers located on an outer side of corresponding centers of the four regions in the tracking direction, a focusing coil disposed between the second surface and the magnet and having a center located on an outer side of corresponding centers of the four regions in the focusing direction, and a radial tilt coil disposed between the second surface and the magnet and having a center located on an outer side of corresponding centers of the four regions in the focusing direction.

This application claims the benefit of Japanese Patent Applications No.2002-294609 filed Oct. 8, 2002 and No.2003-138918 filed May 16, 2003, in the Japanese Patent Office, the disclosures of which are hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to, and more particularly to lens actuators, optical pickup units and optical disk apparatuses, and more particularly to a lens actuator which turns an objective lens about a center axis along a focusing direction, about a center axis along a tracking direction and about a center axis along a tangential direction, an optical is pickup unit which uses such a lens actuator, and an optical disk apparatus having such an optical pickup unit.
2. Description of the Related Art
A description will be given of an example of a conventional lens actuator, that is, an objective lens driving unit for an optical disk apparatus, by referring to FIG. 1. FIG. 1 is a perspective view showing the example of the conventional lens actuator.
This example of the conventional lens actuator shown in FIG. 1 uses a single cylindrical coil as a focusing drive coil and two flat coils as tracking drive coils. An objective lens holder 2 holds an objective lens 1, and the objective lens holder 2 is resiliently supported by four wire springs 4 which are drawn out from a fixed member 3 which is provided on a substrate 7. A single cylindrical focusing drive coil 5 and two flat tracking drive coils 6 are provided around the objective lens holder 2. The focusing drive coil 5 and the two tracking drive coils 6 are wound in mutually perpendicular directions. The wire springs 4 are drawn out from the substrate 7 via the fixed member 3, and also function as conductor lines by being electrically connected to the coils 5 and 6 via solder portions 8 at ends of the wire springs 4. Magnets 10, each supported on a corresponding yoke 9, sandwich the objective lens holder 2, so that magnetic poles of the magnets 10 confront each other. Each magnet 10 is fixed to the corresponding yoke 9 via a gap, so that magnetic flux from the magnets 10 penetrate a driving portion of the coils 5 and 6.
The objective lens holder 2 is moved by applying a control current to each of the coils 5 and 6, and the objective lens 1 can be moved in a focusing direction (Z-axis direction) and in a tracking direction (Y-axis direction).
However, there are demands to further increase the recording density of optical disks. Consequently, as a beam spot of light used is made smaller and a numerical aperture (NA) of the objective lens becomes larger, a tilt tolerance of the objective lens becomes more severe. In the case of the conventional lens actuator shown in FIG. 1 employing a drive motor structure, the tilt that occurs when the objective lens 1 makes focusing and tracking operations introduces a big problem.
In other words, in the conventional optical disks such as the compact disk (CD), the wavelength of a laser beam used by an optical pickup is approximately 780 nm, and a track pitch of the optical disk is approximately 1.6 μm. Since the recording density on such an optical disk is relatively low, an optical inclination of the optical pickup with respect to the optical disk surface, that is, the tilt of the objective lens with respect to the optical disk surface, has a relatively large tolerance. For this reason, if the parts of the optical disk apparatus are manufactured with a precision to satisfy the designed manufacturing tolerance and assembled with a precision to satisfy the designed assembling tolerance, the assembled parts are positioned with a satisfactory precision which would not adversely affect the tilt, and the tilt does not become a problem.
However, in optical disks which have been developed recently, such as a digital versatile disk (DVD), the recording density is considerably increased compared to that of the CD. Hence, the wavelength of the laser beam used by the optical pickup in this case is approximately 650 nm, and the track pitch of the optical disk (DVD) is approximately 0.74 μm. As a result, the tilt of the optical pickup, particularly the objective lens, must be suppressed to approximately one-half that of the CD, and there are demands to satisfy such severe conditions.
For example, a Japanese Laid-Open Patent Application No.2001-34974 proposes an objective lens driving unit in which a center of each of two focusing drive coils in the tracking direction approximately matches a center of a magnetic field distribution in the tracking direction, so that a change in a driving force during a tracking operation is approximately the same for the two focusing drive coils. In addition, by making an absolute value of a moment about an axis in a jitter direction small, the tilt associated with focusing and tracking operations is considerably suppressed to such an extent that would satisfy the severe conditions demanded by high-recording-density optical disks such as the DVD.
On the other hand, an actuator which is used for active control must employ a movable mechanism which reduces, as much as possible, lost motion due to non-linearity or the like. For this reason, a Japanese Patent No.2856176 proposes a spring support structure for supporting a lens actuator which requires high-precision control.
In order to realize portable equipments and the like, there are demands in the field of recording and/or reproducing apparatuses to reduce the size, thickness and weight of the structure. Since the optical pickup is provided within the recording and/or reproducing apparatus, there are thus demands to further reduce the size, thickness and weight of the optical pickup and the actuator structure provided on the optical pickup for moving the objective lens.
In addition to the above described demands to reduce the size, thickness and weight of the recording and/or reproducing apparatus, there are also demands to increase the data processing speed and to reduce the cost of the apparatus. In order to meet such demands, it is necessary to reduce the size and weight of the structure of the movable section of the actuator, and to realize the actuator for active control, which generally is an expensive assembly, by a relatively simple structure. Moreover, the structure must enable easy assembly, and it is essential from the point of view of reducing the cost to take measures so that the characteristics are maintained and the generation of defective parts is prevented.
The above described demands to reduce the size, thickness and weight, increase the data processing speed, reduce the cost, and improve the performance are not only applicable to the field of the recording and/or reproducing apparatus, but also similarly applicable to other fields. In apparatuses related to optical disks, there are demands to realize a high-density recording and reproduction, high-quality recording and reproduction, and high-speed recording and reproduction. As described above, much progress is being made in the field of high-density recording and reproduction, and the progress is expected to accelerate when the wavelength of the laser beam is reduced and the NA of the objective lens is increased. But as a consequence, there is a new problem in that the signal deterioration becomes large with respect to the tilt of the objective lens.
In order to cope with this new problem, it is necessary to carry out an active drive correction in a roll direction which was conventionally for passive use, that is, in a radial tilt direction. However, an actuator which can be driven along three axes, that is, in the focusing direction, the tracking direction and the radial tilt direction, will become expensive because it is already difficult to mass produce the actuators which can be driven along two axes at a low cost.
Accordingly, there is a proposed arrangement which divides the focusing drive motor into two which are connected in parallel, so as to form a focusing drive motor portion and a radial tilt motor portion which are driven in the same phase and opposite phases. But in this case, the phase control of the two motor portions becomes complex. On the other hand, there is another proposed arrangement which provides, in addition to the actuator which can be driven along two axes, a joint member which joins the movable section and the fixed section and functions as a radial tilt actuator. But in this case, it is productionwise and costwise essentially the same as additionally providing an actuator which can be driven along a single axis.
A most easily conceivable structure is to provide additional coils for radial tilt on the actuator which can be driven along two axes. However, this conceivable structure requires magnets to be provided on the fixed section and the coils to be provided on the movable section, and the need to additionally provide such parts makes the assembling process more complex and increases the cost of the apparatus. Furthermore, the need to additionally provide such parts inevitably increases the number of required parts and makes the structure of the movable section complex, and may even deteriorate the characteristics of the actuator.

Lens actuator, optical pickup unit and optical disk apparatus


Pulse Width Modulation (PWM) techniques, often used to reduce the power dissipation in polyphase motors, chop the current in the coils of the motor at their peak current levels, to achieve maximum torque, to allow rapid accelerations, and to reduce the power dissipated in the chip to a level proportional to the duty cycle. During the time the current is switched off, the current which has been established in the coils of the motor is allowed to be dissipated. Accordingly, when the switching transistors of the active coils are turned off during PWM mode chopping, a non-rectifying ground return path is provided for flyback energy in the active driving coil. This non-rectifying ground return path is provided by switching transistors in parallel with flyback diodes, operated in a form of synchronous rectification. This gives an alternate current path for the coil current to reduce the voltage drop across the diodes, and thereby reduce the power dissipation and heat in the chip.

1. Field of the Invention
This invention relates to improvements in circuitry for driving polyphase motors, and more particularly to improvements in circuitry for driving polyphase motors in a PWM mode in which the power dissipation requirements of the circuitry is reduced.
2. Description of the Prior Art
Pulse Width Modulation (PWM) techniques, often used to reduce the power dissipation in polyphase motors, chop the current in the coils of the motor at their peak current levels, to achieve maximum torque, to allow rapid accelerations, and to reduce the power dissipated in the chip to a level proportional to the duty cycle. In the past, during this Chopping, the transistors which control the current to the currently active coils of the motor, are switched on and off in a network of switching transistors. During the time the current is switched off, the current built up in the coils is allowed to be dissipated through fly back diodes in parallel with the transistors associated with the active coils. Nevertheless, a voltage drop still exists across the fly back diodes, as the coil current flows through them to dissipate power in the form of heat. This heat, of course, creates a problem which needs to be controlled.

Synchronous rectification method for reducing power dissipation in motor drivers in PWM mode


An endoscope is disclosed that provide selection of each illumination mode of four different illumination modes, with one of the four different illumination modes being a mode which sequentially transmits very narrow wavelength ranges at three different wavelength regions within the visible spectrum.

Endoscope apparatuses wherein a scope is inserted into a coelom in order to observe portions of the alimentary canal such as the esophagus, the stomach, the small intestine, and the large intestine, or into the trachea and the lungs for observing images on a TV monitor screen are commonly utilized. Recently, the use of illumination light of specific wavelength ranges for observing in vivo tissue has started to become popular. For example, an endoscope apparatus has been proposed for more easily identifying lesions that are difficult to discern with normal observation light which utilizes the phenomenon that in vivo tissue emits fluorescence when illuminated by light of specific wavelengths. Furthermore, attempts have been made to gather detailed information of lesions by utilizing the light absorbance properties and the light scattering properties of in vivo tissues to light of different wavelength ranges. For example, Japanese Laid Open Patent Application H08-140929 discloses an apparatus which can switch between providing an ordinary color image observation and a fluorescent image observation of a lesion. At the tip of the endoscope are installed one image sensing chip that detects ordinary color images and a separate image sensing chip that detects fluorescent light images.
As another example, Japanese Laid Open Patent Application 2001-170009 discloses an apparatus which can switch between providing an ordinary color image observation and the observation of blood vessel structure at various depths from the surface of a lesion. In this apparatus, a light source unit is used which provides different illumination light for the two kinds of observations.
As another example, Japanese Laid Open Patent Application 2000-41942 discloses an apparatus which can switch between providing ordinary color image observation verses infrared image observation of a lesion. In this apparatus as well, a light source unit is used which provides different illumination light for the different kinds of observations. This endoscope apparatus can provide two kinds of observations using different specialized infrared illuminations as well as provide an ordinary color image observation. However, when performing a precise diagnosis or treatment of a lesion by combining three kinds of observations, three kinds of endoscope apparatuses have to be prepared. Because of this, there is a shortcoming in that it is troublesome to have to change the endoscope apparatus every time the kind of special light observation is changed, and such a procedure increases the time required for such an endoscopic examination. Also disclosed in this prior art example is a device for performing individual special light observations effectively and efficiently. However, there is no mention of a method and apparatus for diagnosing a lesion state correctly within a short period of time by combining special light observations. Namely, there is no disclosure of a device which allows the state of a lesion to be immediately determined without taking a pathological sample and having it examined in detail, after which a decision may be made for treatment.

Endoscope that provides selection of each illumination mode of four different illumination modes


A head case accommodates an axially movable suction nozzle that holds an electric component on a chip by suction at its center. At least four jaws, which are disposed around the center axis of the suction nozzle and adapted to move parallel to the bottom plate of the head case through guide slots radially extending with respect to the same axis, are attached to the bottom plate. Two each of the facing jaws on both sides of the axis are coupled together by means of links and always urged toward the suction nozzle by springs. While expanding rods actuated by pistons open the jaws, the suction nozzle picks up the electric component on a chip by suction. When released on completion of the pick-up, the jaws urged by the springs move an equal distance toward the axis of the suction nozzle parallel to the surface of the bottom plate to squarely hold the four sides of the electric component on a chip, with its center thus held in alignment with the axis of the suction nozzle.

This invention relates to apparatus for placing in position on printed circuit boards electronic elements that are taken out of a series of equally spaced packing recesses provided along the length of a tape.
Chip Electronic elements widely used for surface packaging are supplied to users with a reeled base tape having recesses of conforming size to contain individual elements that are provided at equal intervals along the length of the base tape and covered with a detachable cover tape.
A packaging apparatus that uses such component chips supplied in the packing recesses on a tape have an air-cylinder-driven sprocket whose teeth engage with the perforations of the base tape to feed forward the tape and a take-up reel that is intermittently driven by an air cylinder to remove the cover tape away from the base tape so that one chip after another is exposed in the desired position.
A nozzle connected to a vacuum source sucks the exposed chip in position to take it out of the packing recess, with the nozzle and the chip thus removed being then jointly carried to the desired position on a printed circuit board.
Component chips of this type have leads at given points of their packages to establish connection with external circuits. To establish an electric connection with the printed pattern on a circuit board, therefore, each chip must be oriented in conformance therewith. To meet this requirement, the chucks according to U.S. Pat. No. 4,135,630 and Japanese Provisional Utility Model Publication No. 78288 of 1987 have a chip position corrector at the tip of a nozzle that adjusts the direction and position of a chip sucked thereby over a given angle with respect to the reference position of the nozzle.
FIG. 15 shows an example of the chucks just mentioned which comprises a vertically movable suction nozzle 300 positioned at the center and surrounded by four adjustable jaws 306 which are rotatably mounted on pivots 302 and turned by an external drive unit 304.
When brought in contact with a chip surrounded by the tips of the expanded jaws 306 (as indicated by the double-dot-dash line in the figure), the suction nozzle 300 draws the chip to the tip thereof. Then the tips of the jaws 306 come in contact with the chip drawn to the suction nozzle 300 when they are turned thereto by means of the drive unit 304, whereupon the orientation of the chip is changed in conformance with the position and direction of the jaws 306. The adjustment of the chip posture according to the position and direction determined by the jaws 306 permits positioning each chip in exact agreement with the circuit pattern printed on the board.
Now that the jaws 306 turn about the pivots 302 when grasping a chip, the suction nozzle 300 inevitably moves axially. Besides, the long distance between the tips of the jaws and the pivots on which they turn causes a considerable play at the grasping tips of the jaws. Such axial movement and play make the holding of component chips of ultra-small sizes of the order of one millimeter square and the correction of their position and direction extremely difficult.

Chuck for positioning chip electronic elements


A magnetic recording head and a method of manufacturing the same. The magnetic recording head includes a stack containing a main pole and a return pole. The stack includes a first magnetic layer having a groove formed therein; an insulating layer covering a surface of the groove; and a second magnetic layer pattern filling the groove covered with the insulating layer.

1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a data recording apparatus and a method of manufacturing the same and, more particularly, to a magnetic recording head and a method of manufacturing the same.
2. Description of the Related Art
Magnetic recording media can be classified into longitudinal magnetic recording media and perpendicular magnetic recording media according to whether magnetization is longitudinal or perpendicular to a surface of a recording medium. As the demand for recording media with higher data recording density increases, increasing attention is being directed toward perpendicular magnetic recording media. Because a magnetic recording medium is very closely related to a magnetic recording head, as attention toward perpendicular magnetic recording media increases, attention toward a magnetic recording head used in writing data on a perpendicular magnetic recording media is also increasing. A main pole and a return pole in a magnetic recording head are used in writing data directly on a magnetic recording medium. Thus, the stability and excellence of a magnetic recording head are closely related to the return pole and the main pole and, in particular, the main pole.
FIG. 1 illustrates the relationship between a selected track 12 on which a magnetization pattern, that is, bit data is written and a rectangular main pole 10 used in a conventional magnetic recording head when a skew angle of the main pole 10 is 10°. Referring to FIG. 1, when the bit data is written on the selected track 12, a portion 10a of the main pole 10 deviates from the selected track 12.
FIG. 2 is a magnetic force microscopy (MFM) image of a bit data recorded on a perpendicular magnetic recording medium using the conventional magnetic recording head including the main pole 10 shown in FIG. 1. Reference numeral 14 in FIG. 2 indicates a magnetization pattern recorded on a periphery of the track 12 by the portion 10a of the main pole 10 deviating from the track 12 while a magnetization pattern is recorded by the main pole 10 of the magnetic head on the track 12. When a magnetization pattern is recorded on a track adjacent to the track 12, a wrong magnetization pattern is recorded on the track adjacent to the track 12 by the magnetization pattern 14. To prevent this problem, it is desirable to have the magnetization pattern 14 not to be recorded on a track adjacent to the track 12 while a magnetization pattern is recorded on the track 12. Thus, there is a need for a novel main pole not affecting recording on a track adjacent to a main track on which a magnetization pattern is recorded. FIG. 3 illustrates one of main poles introduced to satisfy this requirement. While the main pole 10 illustrated in FIG. 1 is rectangular, a main pole 18 illustrated in FIG. 3 has a trapezoidal shape tapering end to end. The main pole 18 is formed by removing a portion of the rectangular pole 10 illustrated in FIG. 1.
More specifically, when the main pole 10 is used to write a magnetization pattern on an inner track located interior to the track 12, a case opposite to that illustrated in FIG. 1 appears. That is, as the skew angle changes in the opposite direction, the portion 10a of the main pole 10 that was originally exposed outside the track 12 is then located within the inner track on which a magnetization pattern will be recorded while a lower portion of the main pole 10 that was originally located within the track 12 is then located outside the inner track 12.
To prevent unnecessary magnetization patterns from being recorded on a track other than a selected track, it is necessary to remove the portion 10a of the main pole 10 located outside the track 12 as well as the portion of the main pole 10 deviating from another selected track located interior to the track 12 when a magnetization pattern is recorded on the other selected track at a different skew angle.
Reference numeral 16a in FIG. 3 indicates a removed portion of the main pole 18 corresponding to the portion 10a of the main pole 10 exposed outside the track 12 when the main pole 10 shown in FIG. 1 having the skew angle of 10° writes a magnetization pattern on the track 12. Also, reference numeral 16b in FIG. 3 indicates a removed portion of the main pole 18 corresponding to the portion of the main pole 10 exposed outside the inner track when the main pole 10 shown in FIG. 1 is used to write a magnetization pattern on the inner track.
FIG. 4 illustrates a magnetization pattern recorded on a selected track 12 using the main pole 18 of FIG. 3. As is evident from FIG. 4, a magnetization pattern with alternating black and white lines is recorded on a selected track 12 only, not on a periphery of the track 12.
FIG. 5 illustrates a change in erase band width with respect to the geometrical shape of a main pole contacting a magnetic recording medium and a skew angle.
Referring to FIG. 5, when a portion of the main pole facing the magnetic recording medium has a rectangular shape (indicated by ▴), the erase band width increases as a skew angle increases. On the other hand, when the portion of the main pole is trapezoidal (indicated by ●), the erase band width does not increase as the skew angle increases.
FIGS. 6-9 illustrate a process of manufacturing a main pole and a return pole in a conventional magnetic recording head.
Referring to FIG. 6, an insulating layer 22 is formed on a NiFe magnetic layer 20 that will be used as a return pole. A photoresist pattern 24 is formed on the insulating layer 22 and defines a region where a main pole will be formed. Using the photoresist pattern 24 as a mask, the defined region of the insulating layer 22 is etched to form a groove 26 in the insulating layer 22 as illustrated in FIG. 7.
Referring to FIG. 8, a magnetic layer 28 is formed on the insulating layer 22 in which the groove 26 has been formed and fills the groove 26. The magnetic layer 28 is formed of a magnetic substance with high saturation magnetic flux density Bs. Referring to FIG. 9, a top surface of the magnetic layer 28 is polished until the insulating layer 22 is exposed to form a magnetic layer pattern 28a filling the groove 26. The magnetic layer pattern 28a is used as the main pole. An arrow in FIG. 9 indicates a direction in which a recording medium moves.
FIGS. 10-12 illustrate a method of manufacturing a conventional magnetic recording head with side shields on either side of a main pole in order to reduce the effect of a magnetic field generated by the main pole on adjacent tracks.
Referring to FIGS. 10 and 11, an insulating layer 22 is formed on a magnetic layer 20. Then, a photoresist pattern 30 is formed on the insulating layer 22 and defines a first region R1 in which a main pole will be formed and second and third regions R2 and R3 where side shields will be formed. Using the photoresist pattern 30 as a mask, a magnetic layer 32 is formed on the insulating layer 22 using an electroplating method. Referring to FIG. 12, the photoresist pattern 30 is then removed to form first through third magnetic layer pattern 32a through 32c. The first magnetic layer pattern 32a is used as the main pole while the second and third magnetic layer patterns 32b and 32c are used as side shields to prevent a magnetic field generated by the main pole 32a from extending to adjacent tracks.
Because the main pole 28a in the conventional magnetic recording head manufactured according to the steps illustrated in FIGS. 6-9 is formed using a photo process and an etching process, it is difficult to precisely control a distance between the main pole 28a and the return pole 20. Furthermore, for the conventional magnetic recording head manufactured using the method illustrated in FIGS. 10-12, in which the distance between the main pole 32a and one of the side shields 32b and 32c is determined by the photoresist pattern 30, the distance is eventually determined by the resolution of an exposure system used. Thus, it is also difficult to precisely control the distance between the main pole 32a and one of the side shields 32b and 32c.

Method of manufacturing a magnetic recording head


A curable composition is disclosed and comprises the following components.. (A) 100 parts by weight of a oxypropylene polymer having a polymer main chain containing a repeating unit represented by the following formula ##STR1## and having at least one group containing a silicon atom bonded to a hydroxyl group and/or a hydrolyzable group and capable of crosslinking by forming a siloxane bond, wherein Mw/Mn thereof is not more than 1.6 and the number average molecular weight is at least 6,000,. (B) from 1 to 200 parts by weight of a filler having a BET specific surface area of not higher than 10 m.sup.2 /g, and. (C) from 0.1 to 20 parts by weight of a curing catalyst, said composition containing substantially no plasticizer.

Oxyalkylene series polymers each having a reactive silicon group are disclosed in JP-A-52-73998 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), U.S. Pat. No. 3,971,751, etc., and a typical example thereof is a polymer represented by the following formula; EQU X".sub.3 Si(oxypropylene polymer)SiX".sub.3
wherein X" represents a hydrolyzable group such as a methoxy group, etc.
A oxyalkylene series polymer having a reactive silicon groups cures by forming a siloxane bond (Si--O--Si) between the polymer molecules by function of moisture in air at room temperature to obtain a rubbery cured material.
Since the cured products exhibit excellent elongation properties, strength, adhesion, etc., the material is used as a sealant, adhesives, so on. The polymer may be used in a form of a composition by mixing with a filler to save material cost. The composition, however, is liable to substantially increase in viscosity, accordingly, a plasticizer is technically essential to be incorporated into the composition.
On the other hand, use of the plasticizer has various problems due to evaporation and shifting the material. For instances, the problems include softening of the composition due to shifting the material to the substrate, causing cracks of the products, softening of a paint when the paint is coated over the products, contamination of the products due to adhesion, and also lowering of the adhesive property and the flexibility of coating with the passage of time, etc.

Curable composition based on oxypropylene polymer

Kanegafuchi Kagaku Kogyo Kabushiki Kaisha


A name space registry manages name space data within a computer operating system including configuration and initialization data. The registry provides access to the configuration information by means of an application program interface (API) for programs which can operate with the name space registry. Backward source-code compatibility is provided for older applications by maintaining configuration and initialization files that the older applications use to store configuration and initialization data under their traditional file names and with the traditional contents. Thus the older applications can directly access these files. The registry provides newer programs access to these configuration and initialization files through API program calls.

A conventional personal computer comprises a processor whose actions are controlled and coordinated by means of programs stored in main memory. For example, such programs may consist of operating system programs and application programs. The main memory is typically "volatile" and requires external electrical power to maintain its storage capability so that the programs in the main memory are erased whenever the electrical power is turned off or the computer is "powered down".
The computer is generally provided with additional non-volatile mass storage, typically in the form of magnetic media such as a "hard" or "floppy" disks on which relatively permanent copies of the programs can be stored. When the computer is initially turned-on or "powered up", or when an application program is loaded, some process or method must be used to both load the programs from the non-volatile mass storage into the volatile main memory and configure the programs to work with the hardware which comprises the computer.
The phrase commonly used to denote the process of loading and initializing both the operating system and the application programs is "bootstrapping" the computer or simply "booting" the computer or the application program. A boot process is a sequence of steps which are performed during the booting procedure. During the boot process, various set up parameters are usually determined by reading the contents of one or more "configuration" or "initialization" files containing a list of selected programs, definitions and parameters which are used to initialize the operating system or application program.
On earlier versions of operating systems, the configuration files were given specific, predefined names and the programs searched for these names when booted. For example, on personal computers that use the MS-DOS.RTM. operating system developed and sold by Microsoft Corporation, Redmond, Washington, the operating system definitions and the system commands are kept in two login files that work in tandem. System definitions are normally placed in a disk file which is named CONFIG.SYS and system commands are placed in disk batch file named AUTOEXEC.BAT. During the booting process, the computer will first load the device drivers and the system definitions specified in the CONFIG.SYS file and run the programs in the AUTOEXEC.BAT file. Once execution of the system commands in the AUTOEXEC.BAT file have been completed the system is ready for operation.
Operating systems also store data in files and memory locations, which data is provided to other programs, such as application programs. In general, a location in operating system stores data, and from which it provides this data to application programs,device drivers, and other programs is called herein a "repository." Repositories can include disk files, such as the CONFIG.SYS file, and memory wherein data on a floating-point processor is stored.
Programs and operating systems use the data that is stored in the repositories. For example, The MS-DOS operating system also stores, in memory, environment variables that it finds in the AUTOEXEC.BAT file. Application programs can then retrieve the contents of the environment variables and alter their own behavior based on these contents. For example, a word processing program can use the contents of the TEMP variable to locate scratchpad space on disk for temporary files.
Various application programs and system components can also read their own configuration and initialization files when they start up. For example, the WINDOWS.TM. program developed and sold by the Microsoft Corporation, Redmond, Washington is a well-known graphic interface program which has its own initialization files. When this program starts, it reads five initialization files, some of which contain parameters that specify the appearance of a user interface, a list of application programs to start automatically, and the size and location of a swap file.
Configuration and initialization files pose problems because they are difficult to maintain. For example, some operating systems such as the MS-DOS operating system referred to above use user-defined configuration files in that changes to the file are generally made by the user directly on the file in order to change the basic system configuration. User-defined configuration files require that the user know what hardware is resident on the system and also know how to edit the login files in order to properly inform the system of the presence of the hardware.
Developers of prior art installation and configuration procedures have attempted to overcome these problems by providing automatic procedures that updated the configuration and initialization files. These procedures reduced the risk of introducing errors because no human interactions were involved. For example, some operating systems automatically detect, and store data about, the presence and amount of various hardware resources, such as memory, disks, and floating-point processors, that are available on a computer. These latter operating systems relieve the user of the responsibility of actually manually editing the configuration file. Many other automatic application installation procedures also create application-specific initialization and configuration files.
However, there are still other problems. Some of these latter prior art systems, such as the OS/2.RTM. operating system developed and sold by the International business Machines Corporation, Boca Raton, Fla., use configuration and initialization files, e.g. OS2.INI, which contain binary data and cannot be updated with a traditional text editor.
Even ASCII text configuration and initialization files are difficult to maintain with a traditional text editor because text editors do not check syntax. A user or system administrator can thus introduce syntax errors or "pathological" interactions amongst entries in these files. Further, text editors do not check for missing critical sections. Hence, it is possible for a user or system administrator to create a configuration or initialization file from which the system or an application will not start.
These ad hoc solutions create other problems because of the wide variety of configuration and initialization files they create on many computers. Sometimes related data is stored in two or more files and in several directories. For example, the MS-DOS operating system typically requires entries in both CONFIG.SYS file and in AUTOEXEC.BAT file in order to use CD-ROM hardware devices.
In addition, many of the configuration and initialization files, particularly those that relate to applications programs, are poorly documented. This poses problems for operating system and application developers. They must learn the location, syntax and semantics of each of these files because no common format exists for these files.
Developers of some prior art operating system software, such as WINDOWS NT.RTM., have attempted to impose a uniform structure on the data stored in the various repositories by providing "name space" services. A name space is a collection of all the data that an operating system manages. A name space service, or "registry," stores and organizes the data into a hierarchy, much like the objects in an object oriented programming system. Each piece of data has a name and a class and can optionally have one or more values associated with it. A registry is generally accessed by a predefined set of functions or function calls called an application program interface (API) and stores all the data formerly stored in the various repositories, e.g. memory locations and files, such as CONFIG.SYS. Programs, via calls to a registry API, can request, add, modify and delete data in a name space. With a single name space service API, one documentation standard can be used by both users and application programmers.
Automatic application installation procedures call a name space service API to register the installation of application software, check for the existence of prerequisite hardware and/or software components, and, when appropriate, locate and remove superseded versions of an application.
However, the use of a single name space service poses problems for developers and users of "older" application programs and automatic installation procedures. "Older" applications and procedures are ones that assume the existence of, and directly access, configuration and initialization files with predefined names such as CONFIG.SYS. Since these names are generally coded into the program, these older application programs and procedures must be rewritten to make calls to a new API in order to run with prior art systems that provide a name space service. This problem is significant because many older applications exist and users and system administrators are reluctant to upgrade to operating systems that provide a single name space service if they cannot use their existing application programs. Forcing application developers to rewrite existing applications to use a name space server API and forcing users and system administrators to buy updated application programs is expensive, wasteful and impedes the movement to more modern and robust operating systems.

Name space registry with backward compatibility for older applications

International Business Machines Corporation


A server capable of rotating and accessing storage devices accommodated therein includes a server chassis, a motherboard, a power supply module, two racks, and a system cooling module. The server chassis includes two side plates and an accommodating space between the two side plates. The power supply module is disposed in the accommodating space and arranged corresponding to the motherboard. The racks are arranged parallel to each other and detachably connected to the server chassis. A pivot structure and a handle for operating the rack are disposed at the rack near the motherboard. The rack is rotatable with respect to the server chassis by means of the pivot structure. The system cooling module is disposed adjacent to the rack. At least one cord passage is provided between the system cooling module and each of the side plates.

The conventional server system mainly has electronic devices such as the motherboards, the storage devices, and the power supply installed in a casing. The interior space of the casing is usually divided into a plurality of insertion spaces which are provided to accommodate multiple storage devices arranged in an array. The most common storage device includes a hard disk drive (HDD) or a solid state drive (SSD), etc. However, due to the demand of calculation ability and massive data storage, the server needs to accommodate more storage devices in a very limited casing space. Therefore, the structure and configuration of the casing also needs to be changed correspondingly.
In order to increase the quantity of the storage devices, the casing of the conventional server is provided with racks arranged parallelly to receive the storage devices. Since it is not easy to pull out or replace and service the storage devices in rack near the motherboard, a simple flexible element is fixed, by screws, to a side wall of the rack, so that the rack is rotatable with respect to the casing. In the conventional server, the storage devices are stacked horizontally in the insertion spaces of the rack, and the quantity of the storage devices is too limited to satisfy the demand. If increasing the quantity of the storage devices, the flexible element on the rack is not able to provide sufficient torque to support the rack and allow its rotation to a certain angle.
Accordingly, the inventor made various studies to improve and solve the above-mentioned problem, on the basis of which the present invention is accomplished.

Server capable of accessing and rotating storage devices accommodated therein


Transgenic non-human mammals over-expressing MHCI in skeletal muscle are provided herein, as are methods of using these transgenic non-human mammals for screening candidate compounds for treating type 2 diabetes, and methods for altering the ratio of MHCI to MHCII in a subject.

Approximately 17 million people in the United States, or 6.2% of the population, have diabetes. Diabetes is a disease in which the body either does not produce or does not properly use insulin, a hormone that regulates blood glucose levels. The cause of diabetes is not known, although both genetics and environmental factors such as obesity and lack of exercise appear to play roles.
The two most common types of diabetes are type 1 diabetes and type 2 diabetes. Type 1 diabetes [formerly called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes] develops when the body's immune system destroys pancreatic beta cells, the only cells in the body that make insulin. This form of diabetes usually strikes children and young adults, who require exogenous insulin to survive. It is estimated that 5–10% of Americans diagnosed with diabetes have type 1 diabetes.
Approximately 90–95% of Americans who are diagnosed with diabetes have type 2 diabetes [formerly called non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes]. Type 2 diabetes usually begins as insulin resistance, a disorder in which the cells do not use insulin properly. As the need for insulin rises, the pancreas gradually loses its ability to produce insulin. Type 2 diabetes is associated with obesity, family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, physical inactivity, race/ethnicity, and older age.
Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are considered to be prediabetic conditions. IGT is a condition in which the blood glucose level is elevated (between 140 and 199 mg/dL in a 2-hour oral glucose tolerance test), but is not high enough to be classified as diabetes. IFG is a condition in which the fasting blood glucose level is elevated (between 110 and 125 mg/dL after an overnight fast) but is not high enough to be classified as diabetes. Studies suggest that IGT and IFG may be reversible. With an increasingly aged population, however, IGT and development of type 2 diabetes are emerging as major worldwide public health problems. The cause of age-related impaired glucose tolerance remains to be defined.

Transgenic animals with increased slow-twitch muscle fibers and methods of using such animals

Mayo Foundation for Medical Education and Research


Patients susceptible to or suffering from disorders, such as central nervous system disorders, which are characterized by an alteration in normal neurotransmitter release, such as dopamine release (e.g., Parkinsonism, Parkinson's Disease, Tourette's Syndrome, attention deficient disorder, or schizophrenia), are treated by administering a 1-aza-2-(3-pyridyl)bicyclo[2.2.1]heptane, a 1-aza-2-(3-pyridyl)bicyclo[2.2.2]octane, a 1-aza-2-(3-pyridyl)bicyclo[3.2.1]octane, a 1-aza-2-(3-pyridyl)bicyclo[3.2.2]nonane, a 1-aza-7-(3-pyridyl) bicyclo[2.2.1]heptane, a 1-aza-3-(3-pyridyl)bicyclo[3.2.2]nonane, or a 1-aza-7-(3-pyridyl)bicyclo[3.2.2]nonane. The compounds can exist as individual stereoisomers, racemic mixtures, diastereomers and the like.

Nicotine has been proposed to have a number of pharmacological effects. See, for example, Pullan et al., N. Engl. J. Med. 330:811 (1994). Certain of those effects may be related to effects upon neurotransmitter release. See for example, Sjak-shic et al., Brain Res. 624:295 (1993), where neuroprotective effects of nicotine are proposed. Release of acetylcholine and dopamine by neurons upon administration of nicotine has been reported by Rowell et al., J. Neurochem. 43:1593 (1984); Rapier et al., J. Neurochem. 50:1123 (1988); Sandor et al., Brain Res. 567:313 (1991) and Vizi, Br. J. Pharmacol. 47:765 (1973). Release of norepinephrine by neurons upon administration of nicotine has been reported by Hall et al., Biochem. Pharmacol. 21:1829 (1972). Release of scrotonin by neurons upon administration of nicotine has been reported by Hery et al., Arch. Int. Pharmacodyn. Ther. 296:91 (1977). Release of glutamate by neurons upon administration of nicotine has been reported by Toth et al., Neurochem. Res. 17:265 (1992). Confirmatory reports and additional recent studies have included the modulation, in the central nervous system (CNS), of glutamate, nitric oxide, GABA, takykinins, cytokines and peptides (reviewed in Brioni et al., Adv. Pharmacol. 37:153 (1997)). In addition, nicotine reportedly potentiates the pharmacological behavior of certain pharmaceutical compositions used for the treatment of certain CNS disorders. See Sanberg et al., Pharmacol. Biochem. & Behavior 46:303 (1993); Harsing et al., J. Neurochem. 59:48 (1993) and Hughes, Proceedings from Intl. Symp. Nic. S40 (1994). Furthermore, various other beneficial pharmacological effects of nicotine have been proposed. See, for example, Decina et al., Biol. Psychiatry 28:502 (1990); Wagner et al., Pharmacopsychiatry 21:301 (1988); Pomerleau et al., Addictive Behaviors 9:265 (1984); Onaivi et al., Life Sci. 54(3):193 (1994); Tripathi et al., J. Pharmacol. Exp. Ther. 221:91 (1982) and Hamon, Trends in Pharmacol. Res. 15:36.
Various nicotinic compounds have been reported as being useful for treating a wide variety of conditions and disorders. See, for example, Williams et al., Drug News & Perspectives 7(4):205 (1994); Arneric et al., CNS Drug Rev. 1(1):1 (1995); Arneric et al., Exp. Opin. Invest. Drugs 5(1):79 (1996); Bencherif et al., J. Pharmacol. Exp. Ther. 279:1413 (1996); Lippiello et al., J. Pharmacol. Exp. Ther. 279:1422 (1996); Damaj et al., J. Pharmacol. Exp. Ther. 291:390 (1999); Chiari et al., Anesthesiology 91:1447 (1999); Lavand'homme and Eisenbach, Anesthesiology 91:1455 (1999); Holladay et al., J. Med. Chem. 40(28): 4169 (1997); Bannon et al., Science 279: 77 (1998); PCT WO 94/08992, PCT WO 96/31475, and U.S. Pat. No. 5,583,140 to Bencherif et al., U.S. Pat. No. 5,597,919 to Dull et al., U.S. Pat. No. 5,604,231 to Smith et al. and U.S. Pat. No. 5,852,041 to Cosford et al. Nicotinic compounds are particularly useful for treating a wide variety of CNS disorders. Indeed, a wide variety of compounds have been reported to have therapeutic properties. See, for example, Bencherif and Schmitt, Current Drug Targets: CNS and Neurological Disorders 1(4): 349 (2002); Levin and Rezvani, Current Drug Targets: CNS and Neurological Disorders 1(4): 423 (2002); O'Neill et al., Current Drug Targets: CNS and Neurological Disorders 1(4): 399 (2002); U.S. Pat. No. 5,1871,166 to Kikuchi et al., U.S. Pat. No. 5,672,601 to Cignarella, PCT WO 99/21834 and PCT WO 97/40049, UK Patent Application GB 2295387 and European Patent Application 297,858.
CNS disorders are a type of neurological disorder. CNS disorders can be drug induced; can be attributed to genetic predisposition, infection or trauma; or can be of unknown etiology. CNS disorders comprise neuropsychiatric disorders, neurological diseases and mental illnesses; and include neurodegenerative diseases, behavioral disorders, cognitive disorders and cognitive affective disorders. There are several CNS disorders whose clinical manifestations have been attributed to CNS dysfunction (i.e., disorders resulting from inappropriate levels of neurotransmitter release, inappropriate properties of neurotransmitter receptors, and/or inappropriate interaction between neurotransmitters and neurotransmitter receptors). Several CNS disorders can be attributed to a deficiency of choline, dopamine, norepinephrine and/or serotonin. Relatively common CNS disorders include pre-senile dementia (early-onset Alzheimer's disease), senile dementia (dementia of the Alzheimer's type), micro-infarct dementia, AIDS-related dementia, Creutzfeld-Jakob disease, Pick's disease, Parkinsonism including Parkinson's disease, Lewy body dementia, progressive supranuclear palsy, Huntington's chorea, tardive dyskinesia, hyperkinesia, mania, attention deficit disorder, anxiety, dyslexia, schizophrenia, depression, obsessive-compulsive disorders and Tourette's syndrome.
Senile dementia of the Alzheimer's type (SDAT) is a debilitating neurodegenerative disease, mainly afflicting the elderly, characterized by a progressive intellectual and personality decline, as well as a loss of memory, perception, reasoning, orientation and judgment. One feature of the disease is an observed decline in the function of cholinergic systems, and specifically, a severe depletion of cholinergic neurons (i.e., neurons that release acetylcholine, which is believed to be a neurotransmitter involved in learning and memory mechanisms). See, for example, Jones et al., Intern. J. Neurosci. 50:147 (1990); Perry, Br. Med. Bull. 42:63 (1986); and Sitaram et al., Science 201:274 (1978). It has been observed that nicotinic acetylcholine receptors, which bind nicotine and other nicotinic agonists with high affinity, are depleted during the progression of SDAT. See Giacobini, J. Neurosci. Res. 27:548 (1990) and Baron, Neurology 36:1490 (1986). As such, it would seem desirable to provide therapeutic compounds that either directly activate nicotinic receptors in place of acetylcholine or act to minimize the loss of those nicotinic receptors.
Certain attempts have been made to treat SDAT. For example, nicotine has been suggested to possess an ability to activate nicotinic cholinergic receptors upon acute administration and to elicit an increase in the number of such receptors upon chronic administration to animals. See, for example, Rowell, Adv. Behav. Biol. 31:191 (1987) and Marks, J. Pharmacol. Exp. Ther. 226:817 (1983). It also has been proposed that nicotine can act directly to elicit the release of acetylcholine in brain tissue, to improve cognitive functions, and to enhance attention. See Rowell et al., J. Neurochem. 43:1593 (1984); Sherwood, Human Psychopharm. 8:155 (1993); Hodges et al., Bio. of Nic. Edit. by Lippiello et al., p. 157 (1991); Sahakian et al., Br. J. Psych. 154:797 (1989); and U.S. Pat. No. 4,965,074 to Leeson and U.S. Pat. No. 5,242,935 to Lippiello et al. Other methods for treating SDAT have been proposed, including U.S. Pat. No. 5,212,188 to Caldwell et al. and U.S. Pat. No. 5,227,391 to Caldwell et al., European Patent Application No. 588,917 and PCT WO 96/30372. Another proposed treatment for SDAT is COGNEX®, which is a capsule containing tacrine hydrochloride, available from Parke-Davis Division of Warner-Lambert Company, which reportedly preserves existing acetylcholine levels in patients treated therewith.
Parkinson's disease (PD) is a debilitating neurodegenerative disease, presently of unknown etiology, characterized by tremors and muscular rigidity. A feature of the disease appears to involve the degeneration of dopaminergic neurons (i.e., which secrete dopamine). One symptom of the disease has been observed to be a concomitant loss of nicotinic receptors which are associated with such dopaminergic neurons, and which are believed to modulate the process of dopamine secretion. See Rinne et al., Brain Res. 54:167 (1991) and Clark et al., Br. J. Pharm. 85:827 (1985). It also has been proposed that nicotine can ameliorate the symptoms of PD, as discussed in Smith et al., Rev. Neurosci. 3(1):25 (1992).
Certain attempts have been made to treat PD. One proposed treatment for PD is SINEMET CR®, which is a sustained-release tablet containing a mixture of carbidopa and levodopa, available from The DuPont Merck Pharmaceutical Co. Another proposed treatment for PD is ELDEPRYL®, which is a tablet containing selefiline hydrochloride, available from Somerset Pharmaceuticals, Inc. Another proposed treatment for PD is PARLODEL®, which is a tablet containing bromocriptine mesylate, available from Sandoz Pharmaceuticals Corporation. Another method for treating PD and a variety of other neurodegenerative diseases has been proposed in U.S. Pat. No. 5,210,076 to Berliner et al.
Tourette's syndrome (TS) is an autosomal dominant neuropsychiatric disorder characterized by a range of neurological and behavioral symptoms. Typical symptoms include (i) the onset of the disorder before the age of 21 years, (ii) multiple motor and phonic tics although not necessarily concurrently, (iii) variance in the clinical phenomenology of the tics, and (iv) occurrence of quasi-daily tics throughout a period of time exceeding a year. Motor tics generally include eye blinking, head jerking, shoulder shrugging and facial grimacing; while phonic or vocal tics include throat clearing, sniffling, yelping, tongue clicking and uttering words out of context. The pathophysiology of TS presently is unknown, however it is believed that neurotransmission dysfunction is implicated with the disorder. For further discussion, see Calderon-Gonzalez et al., Intern. Pediat. 8(2):176 (1993) and Oxford Textbook of Medicine, Weatherall et al., eds., p.218 (1987).
It has been proposed that nicotine pharmacology is beneficial in suppressing the symptoms associated with TS. See Devor et al., The Lancet 8670: 1046 (1989); Jarvik, Brit. J. of Addic. 86: 571 (1991); McConville et al., Am. J. Psychiatry 148(6): 793 (1991); Newhouse et al., Brit. J. Addic. 86: 521 (1991); McConville et al., Biol. Psychiatry 31: 832 (1992); and Sanberg et al., Proceedings from Intl. Symp. Nic. S39 (1994). It also has been proposed to treat TS using HIALDOL®, which is haloperidol available from McNeil Pharmaceutical; CATAPRES®, which is clonidine available from Boehringer Ingelheim Pharmaceuticals, Inc., ORAP®, which is pimozide available from Gate Pharmaceuticals; PROLIXIN®, which is fluphenazine available from Apothecon Division of Bristol-Myers Squibb Co.; and KLONOPIN®, which is clonazepam available from Hofformann-LaRoche Inc.
Attention deficit disorder (ADD) is a disorder that affects mainly children, although ADD can affect adolescents and adults. See Vinson, Arch. Fam. Med. 3(5): 445 (1994); Hechtman, J. Psychiatry Neurosci. 19(3): 193 (1994); Faraone et al., Biol. Psychiatry 35(6): 398 (1994) and Malone et al., J. Child Neurol. 9(2): 181 (1994). Subjects suffering from the disorder typically have difficulty concentrating, listening, learning and completing tasks; and are restless, fidgety, impulsive and easily distracted. Attention deficit disorder with hyperactivity (ADHD) includes the symptoms of ADD as well as a high level of activity (e.g., restlessness and movement). Attempts to treat ADD have involved administration of DEXEDRINE®, which is a sustained release capsule containing dextroamphetamine sulfate, available from SmithKline Beecham Pharmaceuticals; RITALIN®, which is a tablet containing methylphenidate hydrochloride, available from Ciba Pharmaceutical Company; and CYLERT®, which is a tablet containing premoline, available from Abbott Laboratories. In addition, it has been reported that administration of nicotine to an individual improves that individual's selective and sustained attention. See Warburton et al., Cholinergic Control of Cognitive Resources, Europsychobiology, Mendlewicz et al., eds., p. 43 (1993) and Levin et al., Psychopharmacology 123:55 (1996).
Schizophrenia is characterized by psychotic symptoms including delusions, catatonic behavior and prominent hallucinations, and ultimately results in a profound decline in the psychosocial affect of the subject suffering therefrom. Traditionally, schizophrenia has been treated with KLONOPIN®, which is available as a tablet containing clonezepam, available from Hoffmann-LaRoche Inc.; THORAZINE®, which is available as a tablet containing chlorpromazine, available from SmithKline Beecham Pharmaceuticals; and CLORAZIL®, which is a tablet containing clozapine, available from Sandoz Pharmaceuticals. Such neuroleptics are believed to be effective as a result of interaction with the dopaminergic pathways of the CNS. In addition, a dopaminergic dysfunction possessed by individuals suffering from schizophrenia has been proposed. See Lieberman et al., Schizophr. Bull. 19:371 (1993) and Glassman, Amer. J. Psychiatry 150:546 (1993). Nicotine has been proposed to be effective in modulating neurotransmitter dysfunction associated with schizophrenia. See Merriam et al., Psychiatr. Annals 23:171 (1993) and Adler et al., Biol. Psychiatry 32:607 (1992). See also Freedman et al., Proc. Natl. Acad. Sci. 94:587 (1997).
It would be desirable to provide a useful method for the prevention and treatment of a condition or disorder by administering a nicotinic compound to a patient susceptible to or suffering from such a condition or disorder. It would be highly beneficial to provide individuals suffering from certain disorders (e.g., CNS diseases) with interruption of the symptoms of those disorders by the administration of a pharmaceutical composition containing an active ingredient having nicotinic pharmacology which has a beneficial effect (e.g., upon the functioning of the CNS), but does not provide any significant associated side effects. It would be highly desirable to provide a pharmaceutical composition incorporating a compound that interacts with nicotinic receptors, such as those that have the potential to affect the functioning of the CNS. The present invention provides such compounds, compositions and methods.
There exist subtypes of nAChRs in both the central and peripheral nervous systems, but the distribution of subtypes is heterogeneous. For instance, the subtypes which are predominant in vertebrate brain are α4β2, α7, and α3β2, whereas those which predominate at the autonomic ganglia are α3β4 and those of neuromuscular junction are α1β1δγ and α1β1δε (see for instance Dwoskin et al., Exp. Opin. Ther. Patents 10: 1561 (2000) and Schmitt and Biencherif, Annual Reports in Med. Chem. 35: 41 (2000)). A limitation of some nicotinic compounds is that they elicit various undesirable pharmacological effects because of their interaction with nAChRs in peripheral tissues (for example, by stimulating muscle and ganglionic nAChR subtypes). It would be desirable to have compounds, compositions and methods for preventing and/or treating various conditions or disorders (e.g., CNS disorders), including alleviating the symptoms of these disorders, where the compounds exhibit nicotinic pharmacology with a beneficial effect on the CNS nAChRs (e.g., upon the functioning of the CNS), but without significant associated effects on the peripheral nAChRs (compounds specific for CNS nAChRs, without significant effects on cardiovascular and/or skeletal muscle receptor sites). The present invention provides such compounds, compositions and methods.

Pharmaceutical compositions and methods for effecting dopamine release


The present invention relates to polynucleotide and polypeptide molecules for stanniocalcin-2, a novel member of the stanniocalcin family. The polypeptides, and polynucleotides encoding them, modulate electrolyte homeostasis. The present invention also includes antibodies to the stanniocalcin-2 polypeptides.

Maintaining electrolyte homeostasis is critical for preserving a cell's ability to interact with other cells and transduce signals that are mediated by changes in the environment. The levels of Ca.sup.++ and P.sub.i in extracellular fluid is tightly regulated, and excitability of nerve and muscle are dependent upon ion concentration. In vertebrates parathyroid hormone (PTH), active metabolites of vitamin D and calcitonin have been identified as regulators of plasma levels of Ca.sup.++ and P.sub.i. PTH stimulates the mobilization of Ca.sup.++ and P.sub.i from bone into plasma. In the kidneys, PTH decreases the urinary excretion of Ca.sup.++ and stimulates excretion of P.sub.i. P.sub.i reabsorption is reduced by decreasing the Na.sup.++ -dependent P.sub.i transport into the renal proximal tubule. Calcitonin is a hormone released by the thyroid that lowers Ca.sup.++ and P.sub.i levels in the blood to maintain the equilibrium when serum levels are elevated. Calcitonin is believed to counteract hypercalcemia by inhibiting osteoclast-mediated bone resorption. However, the role of calcitonin as regulator of transient influcuations in serum calcium levels or promotion of bone mineralization has not been demonstrated. In addition, there are no known regulators of transient changes P.sub.i levels in mammals, other than PTH, which only promotes P.sub.i excretion, thereby suggesting that our understanding and identification of factors involved in the calcium and phosphate homeostasis is incomplete.
In fish, the environment can be either hypertonic (seawater) or hypotonic (fresh water) and is the primary source for Ca.sup.++ and P.sub.i, unlike terrestrial vertebrates whose uptake of Ca.sup.++ and P.sub.i are diet dependent. Some fish migrate to and from seawater and fresh water and have had to develop mechanisms to adapt to these radical changes in electrolyte concentrations. Stanniocalcin (also known as Stc, CS protein, teleocalcin or hypocalcin) is a homodimeric glycoprotein hormone secreted by endocrine glands found on the kidneys of bony fish called the corpuscles of Stannius (Stannius, H. Arch. Anat. Physiol. 6:97-101, 1839 and Wagner, G., in Biochemistry and Molecular Biolocy of Fishes, eds. Hochachka and Mommsen, Elsevier Science, Amersterdam, Vol 2, Chap. 21, pp. 419-434, 1993). The secretion of stanniocalcin in fishes is stimulated in response to rising plasma Ca.sup.++ levels (Wagner et al., Mol. Cell Endocrinol. 79:129-138, 1991) whereupon it acts to reduce Ca.sup.++ uptake by the gills (Wagner et al., Gen. Comp. Endocrinol. 63:481-491, 1986) and increase P.sub.i reabsorption by the kidneys (Lu et al., Am. J. Physiol. 36:R1356-R1362, 1994) with the net result being restoration of normal calcium levels.
Stanniocalcin has been identified and isolated from several species of fish, such as Australian eel (Auguilla australis; Butkus et al., Mol. Cell. Endocrinol 54:123-134, 1987), rainbow trout (Oncorhynchus mykiss; Lafeber et al., Gen. Comp. Endocrinol. 69:19-30, 1988), coho salmon (Oncorhynchus kisutch; Wagner et al., Mol. Cell. Endocrinol. 90:7-15, 1992), and sockeye salmon (Oncorhychus nerka; Wagner et al., Gen. Comp. Endocrinol. 72:237-246, 1988. Studies using both in vivo and in vitro systems, show that in response to increased excellular Ca.sup.++ levels, Stc is released. Stc reduces plasma Ca.sup.++ concentration by inhibiting Ca.sup.++ absorption across the intestine (Sundell et al., J. Compl Physiol. B, Biochem Sys. Environ. Physiol. 162:489-495, 1992) and Ca.sup.++ transport across the gills (Wagner et al., ibid., 1988). In vivo, the rapid equilibration that occurs even when presented with massive increases in Ca.sup.++ suggests that there may be additional pathways involved that have not yet been elucidated.
Human stanniocalcin has recently been discovered (Chang et al., Mol. Cell. Endocrinol. 112:241-247, 1995 and Olsen et al. WO 95/24411). The human protein is 247 amino acids, of which 214 amino acids constitute the mature polypeptide. It is believed that the first 33 amino acids represent a prepro region, consistent with Stc from fish, where the polypeptide is synthesized as a larger molecule and processed during secretion from the Corpuscles of Stannius. The human stanniocalcin discovered had a high degree of homology to the Australian eel; 119 identical amino acids in a 195 amino acid overlap (61% identity) and to coho salmon, 118 amino acids in a 204 amino acid overlap resulted in 57% identity. Eel and coho salmon Stc contain 15 and 12 cysteines respectively, while the human Stc has 11 cysteines. The spacing of the cysteines is highly conserved between all three proteins.
Human stanniocalcin mRNA was found to be most abundant in ovary, prostate and thyroid as a 4 kb transcript (Chang et al., Mol. Cell. Endocrinol. 112:241-247, 1995). The 4 kb band was also seen in kidney, bone marrow, thymic stromal cells (Olsen et al., Proc. Natl. Acad. Sci. USA 93:1792-1796, 1996) and many other tissues, but no signal was found in brain, liver, spleen, peripheral blood leukocytes and adrenal medulla. In addition, a 2 kb transcript was identified with a probe designed to a 1 kb N-terminal portion of the molecule but was not seen with a probe containing C-terminal sequence (Chang et al., ibid., 1995). Isolation of human stanniocalcin has been reported from an early stage lung cDNA library (Olsen et al., WO 95/24441). Sera from normal humans was immunoreactive with salmon Stc antibodies. Analyses by immunocytochemistry suggested that cells in the human kidney tubules contained Stc-like proteins (Wagner et al., Proc. Natl. Acad. Sci. USA 92:1871-1875, 1995).
Human stanniocalcin mRNA levels have been shown to increase in the presence of increasing amounts of excellular Ca.sup.++ in an immortalized liver fibroblast cell line SUSM-1, T98G human glioblastoma cell line and normal human foreskin fibroblasts (Chang et al., ibid., 1995).
Because of the anti-hypercalcemic activity of stanniocalcin, members of the family, particularly human polypeptides will be very valuable in the understanding and treatment of diseases caused by electrolyte disorders. The present invention provides such polypeptides for these and other uses that should be apparent to those skilled in the art from the teachings herein.


Asymmetrically strengthened glass articles, methods for producing the same, and use of the articles in portable electronic device is disclosed. The asymmetrically strengthened glass articles include glass articles having a deeper compressive stress layer in a thicker portion of the glass article. Using a budgeted amount of compressive stress and tensile stress, asymmetric chemical strengthening is optimized for the utility of a glass article. In some aspects, the strengthened glass article can be designed for reduced damage, or damage propagation, when dropped.

The cover window and display for small form factor devices are typically made of glass. Glass, although transparent and scratch resistant, is brittle and prone to impact failure. Providing a reasonable level of strength in these glass parts is crucial to reducing the likelihood of glass part failure, and hence device failure.
Chemical strengthening has been used to increase the strength of glass parts. Typical chemical strengthening relies on a uniform and symmetric increase of the compression stress over the entire surface of the glass part. Such strengthening processes have proven effective at reducing some level of failure in glass parts. However, there continues to be significant pressure on forming thinner glass for use in small form factor devices, where symmetric chemical strengthening is insufficient to prevent impact failure in a reliable fashion.
As such, while conventional chemical strengthening is effective, there is a continuing need to provide improved and alternative ways to strengthen glass, particularly, thin glass.


A link established between a first network element that supports connection-oriented links, and a second network element that supports packet-oriented links, by establishing a connection-oriented link between the first network element and a gateway unit, and a packet-oriented link between the second network element and the gateway unit. A first link protocol that is associated with the first network element, and a second link protocol that is associated with the second network element are used. The first link protocol and the second link protocol differ by an information element that contains an address for the packet-oriented link between the second network element and the gateway unit.

Radio communication systems are used for transmitting information, speech or data, with the aid of electromagnetic waves over a radio interface, also called an air interface, between a sending and a receiving radio terminal. Radio communication systems can be subdivided into a core network in which payload and signaling data of a plurality of terminals is transported over long distances on wires and via which a connection can be implemented to a fixed communication network, and into a Radio Access Network (RAN) via which the data received from the terminals is converted into a format suitable for the transmission in the core network and vice versa, the form of data received by the core network is adapted to radio transmission and forwarded to the relevant radio terminal, within the send area in which the terminal involved is located.
Radio communication systems of the first and second generation are currently in use around the world and, because of the great demand for mobile communication, are coming up against the limits of their capacity. The emerging capacity problems are to be resolved by the third-generation radio communication systems. One of the third-generation radio communication systems which shows the greatest promise of success is the Universal Mobile Telecommunication System (UMTS) that was specified by the standardization body 3GPP (Third Generation Partnership Project) (see for example: B. Walke, Mobilfunknetze und ihre Protokolle (Mobile radio networks and their protocols), Volume 1, P. 385-387, Teubner Verlag 2000).
Data is transmitted circuit switched in the UTRAN access network specified for UMTS in accordance with the ATM procedure. In this case the data which is to be transmitted over a connection is subdivided into ATM cells. The timing of ATM cells for a number of connections is interleaved and the cells are transmitted over the same physical connection. The connection channel in this case remains the same for the duration of the transmission. An overview of the ATM method is for example to be found in: B. Walke, Mobilfunknetze und ihre Protokolle (Mobile radio networks and their protocols), Volume 2, Chapter 8, Page 255 to 290, Teubner-Verlag 1998.
The demands on mobile communications are being paralleled by the increased demand for high bandwidth worldwide data communications. This data is communicated over the Internet according to the IP (Internet protocol) procedure. In this case data packets are transported over packet-oriented connections, i.e. connectionless, between the users. With packet-oriented transmission there is a free choice of connection channel between the users only for the transmission of the relevant data packet. A subsequent data packet can be routed via another channel. It is thus possible that the order in which the data packets are received differs from the order in which they were sent.
There is an increasing demand to be able to also transmit large volumes of data by mobile communication with a high bandwidth. An IP-based radio communication network has therefore been proposed (see for example: 3GPP, IP Transport in UTRAN Work Task Technical Report, in 3GPP TR 25.933 2001), in which connections are made using the IP procedure.

Radio communication system and method for operating


A convertible burner for gas-fueled cigarette pocket lighters for use with flint and wheel ignition, the burner including a burner body having a central gas fuel passageway and an air inlet channel in fluid communication with the central passageway and may have a plurality of integrally formed passageways around the periphery of the burner body. An air control structure in the form of a collar is movable to a first position with respect to the burner body to close the air inlet channel and form a post-mix burner for flint and wheel ignition, and to a second position with respect to the burner body to admit air via the air inlet channel to form a pre-mix burner after ignition. The relative movement can be longitudinal or peripheral, and the peripheral movement can be circumferential. In one embodiment, the collar surrounds and is immediately adjacent to the air inlet channel.

There are two primary types of gas-fueled pocket lighters presently available. The first type of gas-fueled device utilizes a post-mix burner. Post-mix burners pull oxygen for combustion from the air surrounding the gas outlet. This combustion type is characterized by a low velocity, low temperature yellow flame sometimes referred to as a traditional or lazy flame.
A second type of gas-fueled device is a pre-mix burner. This type of burner pulls oxygen for combustion through holes in the base of the burner and combines the oxygen and fuel prior to combustion. This combustion type is characterized by a high velocity, blue flame. These burners, by virtue of their improved efficiency, provide higher flame temperatures, and more complete combustion. The devices are commonly referred to as blue flame, torch flame, or invisible flame, lighting devices.
There are two primary ignition systems that are typically used with gas-fueled cigarette or pocket lighters. The first type is the flint and wheel ignition mechanism. A hardened striking wheel is rotated against a flint made of a pyrophoric material. The engagement of the striking wheel with the flint produces a spark that ignites the fuel as it leaves the gas outlet. Another type of ignition system is piezoelectric. In this type of ignition system, a high voltage charge is generated when a crystal is struck. A spark is created when this charge jumps across a preset gap between an electrical contact and the gas nozzle (which is constructed of a conductive material). This spark ignites the gas as it leaves the nozzle.
The pre-mix burners offer advantages over post-mix burners including better efficiency of combustion, higher heat, and higher velocity, which makes the flame more stable and less likely to be blown out by the wind. The flint and wheel type ignition offers some advantages over piezoelectric ignition systems including being more reliable and consistent, and less costly to produce. Attempts to combine the pre-mix burner with flint and wheel ignition have met the following difficulties. Because of the velocity of the pre-mix burner, it is difficult to ignite the air/fuel mixture with flint and wheel type ignition systems. Also, the dust and debris generated by the flint and wheel ignition system has a tendency to accumulate and clog the air orifices and the gas orifice on the pre-mix burner.
To overcome the above drawbacks, devices have been developed to incorporate a dual i.e., separate burner approach in combination with the flint and wheel ignition. These devices generally offer the following features. First, the device can provide both a post-mix and a pre-mix flame from the same device or lighter, but using separate burners. Some of these devices utilize a flint and striking wheel and others use piezoelectric ignition. In addition, some devices ignite one burner and then utilize the existing flame to ignite the other burner. The dual burner approach suffers from drawbacks including increased complexity, and therefore increases the cost with an adverse effect on reliability. Accordingly, what is needed is a gas operated pocket lighter that combines a single burner capable of operating as a pre-mix burner along with the flint and wheel ignition system.


The present invention provides a print control technique for printing a plurality of documents more flexibly. A document list obtaining unit in an MFP (Multi Function Peripheral) obtains a document list DL of a plurality of documents to be printed. The document list DL is described by, for example, the XML (extensible Markup Language) or the like. A style sheet obtaining unit obtains a style sheet ST corresponding to the document list DL from a style sheet storing unit or the like. A converting unit converts the document list DL to a printing list PL of a predetermined format by using the tag in the document list DL on the basis of the style sheet ST. On the basis of the printing list PL, a printing instruction unit uses the document data obtained by a document data obtaining unit and outputs a printing instruction to a printer unit. The printer unit continuously prints the plurality of documents onto sheets on the basis of the printing instruction.

1. Field of the Invention
The present invention relates to a print control technique for printing a plurality of documents.
2. Description of the Background Art
Conventionally, at the time of printing a plurality of documents, a document list in a predetermined format of a plurality of documents to be printed is generated (for example, see Japanese Patent Application Laid-Open No. 2000-318254).
Concretely, a print control unit analyzes the document list of the predetermined format and gives a printing instruction to a printing engine (printing output unit) so as to automatically and sequentially print the plurality of documents. By the instruction, the printing engine can continuously print the plurality of documents and output the resultant printed documents. At the time of printing a plurality of documents, therefore, the operator can save time and effort to designate the next document to be printed each time printing of one document is finished.
However, since such a document list has to be adapted to only one predetermined format, there is a problem in that the creator of a document list does not have freedom. In other words, due to this constraint, the document list is not easy to use.

Print control apparatus, method and program using a tag of a document list for printing a plurality of documents in various formats


The present invention relates to a method for preparing polyarylene sulfide with a reduced free iodine content. More specifically, the method for preparing polyarylene sulfide includes: (a) polymerizing reactants including a diiodo aromatic compound and a sulfur compound to form a polyarylene sulfide; and (b) maintaining the polyarylene sulfide product at 100 to 260° C. for heat-setting. The preparation method of the present invention effectively reduces the free iodine content of the polyarylene sulfide to prevent potential corrosion of facilities for the subsequent process and improves the properties of the polyarylene sulfide product such as thermal stability, so the method can be usefully applied to industrial fields in regard to the preparation of polyarylene sulfide.

(a) Field of the Invention
The present invention relates to a method for preparing polyarylene sulfide and, more particularly, to a method for preparing polyarylene sulfide having a low iodine content and enhanced properties.
(b) Description of the Related Art
As a typical engineering plastic, polyarylene sulfide has recently been in considerable demand as a material for high temperature and corrosive environments and electronics products due to its excellence in thermal resistance, chemical resistance, flame resistance, and electrical insulation properties. Polyarylene sulfide is primarily used for computer parts, automotive components, protective coatings against corrosive chemicals, industrial chemical resistant fabrics, and so forth.
The only polyarylene sulfide that is commercially available is polyphenylene sulfide (hereinafter, referred to as "PPS"). The current industrial synthesis process for PPS involves a reaction of p-dichlorobenzene (hereinafter, referred to as "pDCB") and sodium sulfide in a polar organic solvent such as N-methyl pyrrolidone. This process is known as "Macallum process", which is disclosed in U.S. Pat. Nos. 2,513,188 and 2,583,941. Among several polar solvents suggested in the prior art, the mostly used one is N-methylpyrrolidone. The process uses dichloro aromatic compounds as a reactant and yields sodium chloride as a byproduct.
The PPS produced in the Macallum process has a molecular weight around 10,000 to 40,000 and a low melt viscosity less than 3,000 poise. For higher melt viscosity, PPS is usually subjected to the curing process including application of heat below the melting temperature Tm and exposure to oxygen. During the curing process, the melt viscosity of PPS can be raised to a level required for general PPS uses through reactions such as oxidation, cross-bonding, or polymer chain extension.
The PPS obtained in the conventional Macallum process, however, has some fundamental disadvantages as follows.
Firstly, the use of sodium sulfide as a supply of sulfur needed in the polymerization reaction leads to a large amount of metal salt such as sodium chloride as a byproduct in the polymer product. The residual metal salt is contained in the polymer product to several thousand ppm even after the polymer product is washed out, not only to raise the electrical conductivity of the polymer but also to cause corrosion of the processing machinery and problems during spinning of the polymer into fibers. From the standpoint of the manufacturer, the use of sodium sulfide as an ingredient material ends up with the 52%-yield of sodium chloride as a byproduct with respect to the weight of the added material, and the byproduct, sodium chloride, is not economical but wasteful even when recycled.
Secondly, the properties of the polymer product are adversely affected during the curing process. For example, oxygen-driven oxidation and cross-bonding reactions turn the polymer product darker with more brittleness in the aspect of mechanical property.
Thirdly, like all the polymer products of solution polymerization, the final PPS product is prepared in a very fine powder form that relatively lowers the apparent density, causing inconvenience in carrying and some problems during the processing of the PPS into desired goods.
Beside the Macallum process, some other processes have been proposed in U.S. Pat. Nos. 4,746,758 and 4,786,713 and other related patents. These patents suggest that polyarylene sulfide can be prepared by directly heating diiodo compounds and solid sulfur rather than dichloro compounds and metal sulfide used in the existing process without using any polar solvent. This method consists of two steps, iodization and polymerization: the iodization step involves a reaction of aryl compounds and iodine to form a diiodo compound, and the polymerization step includes a reaction of the diiodo compound and solid sulfur to yield polyarylene sulfide having a high molecular weight. During the reaction, there occurs production of iodine in vapor form, which iodine is collectible and reused to react with the aryl compounds again. Hence, the iodine substantially acts like a catalyst in the reaction.
This method can solve the problems with the conventional processes. First, iodine yielded as a byproduct does not raise the electrical conductivity of the polyarylene sulfide product as metal salts usually do, and can be easily collected from the reactants to readily make its content in the final product lower than the content of metal salts in the conventional processes. The collected iodine is reusable in the iodization step, reducing the quantity of waste almost to zero. Second, the polymerization step using no solvent provides the polyarylene sulfide product in the pellet form like the conventional polyester product, avoiding a problem with the product in the powder form according to the prior art. Finally, this method raises the molecular weight of the final polyarylene sulfide product far more than the conventional processes and thus eliminates a need for the curing process that leads to inferior properties of the product.
This process however has two main disadvantages. First, the residual iodine in the molecular state is so corrosive to adversely affect the processing machinery when it is contained in the final polyarylene sulfide product even in a minute amount. Second, the use of solid sulfur in the polymerization step causes introduction of disulfide bonds in the final polyarylene sulfide product to deteriorate the thermal properties of the product including melting temperature.
Consequently, there is a need for studies to develop a method for effectively preparing polyarylene sulfide that not only considerably lowers the content of iodine causing corrosion of machinery but also provides excellent properties such as thermal resistance, chemical resistance, and mechanical strength.

Method for preparing polyarylene sulfide with reduced free iodine content