Parallel tube type, gasoline powered, blower/vacuums with improved versatility are provided. In one possible feature, a flapper throttle adjacent to the housing for controlling the engine is pivotable from side-to-side with respect to an elongate handle. The elongate handle is sufficiently long to allow a plurality of gripping positions, while the flapper throttle is sufficiently long to allow the operator to access the flapper throttle from different gripping positions on the handle. In another possible feature, a pivotable lever throttle is provided at an interface of the handle forward portion and a transverse grip portion at the handle forward portion end. The lever throttle has a first end accessible to the operator when gripping the transverse grip portion, and a second end accessible to the operator when gripping the handle forward portion. In another possible feature, a blower/vacuum is provided with a rear handle that increases blower/vacuum versatility in that the operator has a plurality of gripping choices available to him.

Existing parallel tube type blower/vacuums are typically powered by an electric motor. The blower/vacuum has a housing with a motor disposed therein, and a fan assembly located at the housing and driven by the motor. An airflow tube connected to the housing forward end, in flow communication with the fan assembly, has a vacuum tube and a blower tube that are parallel and adjacent to each other. A handle is located adjacent to the housing for gripping by the operator.
With existing electric powered parallel tube blower/vacuums, the on/off switch for the electric motor is sometimes difficult for the operator to reach while gripping the blower/vacuum handle. However, this is not a problem because it is not necessary that the operator be able to reach the on/off switch while using an electric blower/vacuum.
However, in a gasoline powered parallel tube blower/vacuum, an operator may wish to adjust the engine throttle while operating the blower/vacuum. As such, existing electric powered parallel tube blower/vacuum designs cannot easily be modified into gasoline powered design having adjustable throttles that an operator may easily reach while gripping the handle.
Further, the handles on existing parallel tube blower/vacuums limit the versatility of the blower/vacuum because the handles are generally small and do not give an operator much choice as to where to place his hands when operating the blower/vacuum.
Although existing parallel tube blower/vacuums have been used in many applications that have been commercially successful, there is a need for gasoline powered parallel tube blower/vacuums that overcome the problems and limitations of the prior art.

Gasoline powered parallel tube blower/vacuum


The present invention provides a device including an article carry-in mechanism (1A) that transports an article (w) to a packaging position (P), an article carry-out mechanism (1B) that carries the article (w) away from the packaging position (P), and a relaying mechanism (1C) disposed between the article carry-in mechanism (1A) and the article carry-out mechanism (1B). The relaying mechanism (1C) receives and supports the transported article (w) from below in a center part of the article (w) in a direction of its width.

Examples of such a banding and packaging device are described in the patent documents 1 and 2 filed by the applicant of the present invention. As described in these documents, a piece of band-shaped film is held and transported by a film piece transporting mechanism to a predetermined position, released at the position, and then carried onto an article to be packaged. Then, the article and the piece of film attached to the article are vertically held together by an upper transport belt and a carry-in belt of an article transport apparatus and then transported to a packaging position.
In the device described in the patent document 1, a packaging position P is set to locate between the end of a carry-in belt 10 and the beginning of a carry-out belt 11, as schematically illustrated in the side view of FIG. 24. As illustrated with arrow A in the drawing, an article "w" and a piece of film (not illustrated in the drawing) attached to this article are vertically held together by the carry-in belt 10 and an upper transport belt 12 and then transported to the packaging position P. The transport of the article "w" by the carry-out belt 11 and the upper transport belt 12 is suspended when the article arrives at the packaging position P.
As schematically illustrated in the front view of FIG. 25, a film piece pressing mechanism is disposed at a position in the upper direction of the packaging position P. The film piece pressing mechanism is equipped with a pair of pressing members 42 used to press parts of the piece of film "f" downward that are hanging out from the left and right sides of the article "w". A film piece attaching mechanism is disposed at a position below the packaging position P. The film piece attaching mechanism is equipped with a pair of attaching members 62 that are allowed to move leftward and rightward.
As illustrated in FIG. 26, the pressing members 42 on the left and right sides move downward toward the article "w" at the packaging position P between the end of the carry-in belt 10 and the beginning of the carry-out belt 11, and both end sides of the piece of film "f" hanging out from the left and right sides of the article "w" are pressed downward by the pressing members 42 along the surfaces of the article "w" on its lateral sides.
After that, the attaching members 62 on the left and right sides move in the horizontal direction and arrives at positions for attaching the piece of film underneath the article "w", as illustrated in FIG. 27. Then, the piece of film "f" hanging downward from the article "w" is pressed by the attaching members 62 and thereby wound around the bottom surface of the article "w". Lastly, starched parts on both end sides of the piece of film are elastically pressed against and attached to the bottom surface of the article "w".
The article, after the piece of film "f" is wound around and attached to its bottom surface, starts to be transported by the carry-out belt 11 and the upper transport belt 12. The banding-completed article "w" is then carried out of the device.
Thus, when one end and the other of the film-attached article "w" are situated on the end of the carry-in belt 10 and the beginning of the carry-out belt 11, i.e., when the lateral and bottom surfaces of the article "w" are being exposed, both end sides of the piece of film "f" are pressed downward and then pressed against and attached to the bottom surface of the article "w". This is considered to be an efficient way of successfully banding and packaging target articles.


The residual level of monomer in a polymer may be reduced by passing a melt of the polymer through a devolatilizer column which contains an array of two or more trays having voids comprising from 15 to 50% of the surface of the tray which are offset so the voids in the upper tray are spaced over the solid areas of the tray below.

In the bulk or solution polymerization of one or more monomers, it is generally necessary to remove unreacted monomer, dimers, trimers, oligomers, and diluent if present from the resulting polymer. There are in theory and practice a number of processes for reducing the residual content of volatile material in the polymer melt.
In the technique to which the present invention relates, a polymer melt from the reactor is pumped by a gear pump or other suitable means to a heater (sometimes called a preheater) on top of a vertical vacuum chamber (i.e. devolatilizer). The heater is typically a shell and tube type heat exchanger. The polymer melt leaving the heater may be forced through many fine holes of a distributor showerhead. Typically the hole diameter ranges from 1/32 of an inch to 1/8 of an inch. The strands of polymer melt which are formed descend towards the bottom of the vacuum chamber (hence, the name, a falling strand devolatilizer). The showerhead extrudes the polymer melt as fine strands to lower the diffusion path distance. (The characteristic time for diffusion is defined by the equation .lambda..sub.D =.sup.r2 /D where .lambda..sub.D is the diffusion time, r is the radius of the strand and D is the diffusion coefficient.) The residual monomer and, if present, diluent, and dimers and trimers devolatilize out of the descending or falling polymer strands as they are exposed to the vacuum (and it is maintained) causing the polymer to foam. The polymer melt which collects at the base of the devolatilizer is then forwarded to the stranding and pelletization unit operations.
The preheater, showerhead distributor, and devolatilizer are maintained at an elevated temperature to reduce the viscosity of the polymer melt. The increase in temperature also increases the vapor pressure which increases the mole fraction of volatiles in the vapor phase (i.e. y.sub.i P=.delta..sub.i x.sub.i P.sub.i.sup.vap wherein y.sub.i is the mole fraction of the volatile component in the vapour phase; P is the system pressure; .delta..sub.i is the activity coefficient of the volatile component; x.sub.i is the mole fraction of the volatile component in the melt phase; and P.sub.i.sup.vap is the vapour pressure of the volatile component). This permits the bubbles of volatile material to diffuse or rise to the surface of the strands of polymer melt more rapidly. However, reducing the viscosity of the polymer melt increases the rate at which the polymer flows in the form of a strand to the bottom of the devolatilizer and correspondingly reduces the residence time of the polymer melt in the vacuum chamber. There is a need for a method to increase the residence time of the polymer melt in the falling strand vacuum chamber devolatilizer.
There are a number of devices which may be used to increase the residence time of a polymer melt in a vacuum chamber devolatilizer. Representative of such art are U.S. Pat. No. 3,694,535 issued Sep. 26, 1972 which teaches a single annular distributor device; U.S. Pat. No. 4,934,433 issued Jun. 19, 1990 which teaches a single "serpentine" distributor which replaces the conventional shell and tube heat exchanger in a falling strand devolatilizer, U.S. Pat. No. 5,118,388 issued Jun. 2, 1992 which discloses a single "candy scoop" distributor for a falling strand devolatilizer; and U.S. Pat. No. 5,069,750 issued Dec. 3, 1991 which teaches a single distributor tray for use in a falling strand devolatilizer. None of the above references teach an array of trays nor do they teach the type of tray which may be used in accordance with the present invention.
U.S. Pat. No. 3,747,304 issued Jul. 24, 1973 discloses a foam reduction means for treating hydrocarbon streams (typically oil or partially refined oil) in a separator drum to remove entrained vapor such as air. The separator drum is operated under pressure, rather than vacuum. While the drum contains an array of trays, the trays are designed to permit the liquid to flow from the tray and the foam to be retained upon the tray. The whole objective of U.S. Pat. No. 3,747,304 is to permit the liquid portion of the stream to flow as rapidly through the drum as possible while retaining the foam on the trays. The trays in the array according to the present invention do not contain an under flow weir to retain the foam and permit the non-foamed polymer to flow through the devolatilizer. The whole intent and essential feature of the design of the 304 patent teaches away from the subject matter of the present invention.
U.S. Pat. No. 3,886,049 issued May 27, 1975 is most intriguing. The patent discloses and claims a process for the recovery of aromatic monomer from polymers. In the process, a falling strand devolatilizer is used. However, there are no distributor trays in the vacuum chamber. Rather two vacuum chambers are used in series. More importantly there is a separator, downstream from the devolatilizer, to separate dimers and trimers from the aromatic monomer. The patent is interesting in that the patentee was likely aware of the art of the 304 patent but did not consider it useful in a devolatilizer and only used the art in the separation of the monomer from the heavy dimer/trimer organic phase. Clearly, although the art was available relating to the use of offset weirs in the refining and separation arts, the patentee of the 049 patent did not consider this art to be relevant to the devolatilization art field and particularly to the use of distributor trays in a falling strand devolatilizer.
The present invention seeks to provide a polymer devolatilizer tray and an array of devolatilizer trays which may be used in falling strand devolatilizers to improve the efficiency of the removal of monomer and diluent if present


Some embodiments include an integrated assembly having a pair of substantially parallel features spaced from one another by an intervening space. A conductive pipe is between the features and substantially parallel to the features. The conductive pipe may be formed within a tube. The tube may be generated by depositing insulative material between the features in a manner which pinches off a top region of the insulative material to leave the tube as a void region under the pinched-off top region.

Patterned features are commonly utilized in integrated assemblies. In some example applications, the patterned features may be conductive features utilized as interconnects, and/or utilized to bring suitable voltage (e.g., VDD, VSS, etc.) to integrated circuitry. It is becoming increasing difficult to fabricate patterned features with increasing levels of integration due to the tight spacings available for the patterned features. It would be desirable to develop new methods for forming patterned features and to develop new architectures utilizing the patterned features.

Methods of forming conductive pipes between neighboring features, and integrated assemblies having conductive pipes between neighboring features


Accessory components aid in preventing loss of a pager of the type that emits an audible and/or visual signal in response to radio signals and which has a clip member pivoted to the pager housing for attaching the pager to another article and a clip tensioning spring which acts to pivot the member towards the housing. In the preferred form, one such component positions an auxiliary spring between the housing and clip member to supplement the force of the pager tensioning spring and enables adjustment of the auxiliary spring force to compensate for a weakened tensioning spring. Another component emits a perceptible signal when the clip member is pivoted outward from the housing to detect accidental dislodgment or theft of the pager.

Pagers enable rapid alerting of persons of the need to contact others at a distant location or to perform some act such as returning to a particular site. In most instances this requires that the person carry the pager from place to place. To reduce the risk of loss, pagers typically have a clip member that is pivoted to the pager housing and a tensioning spring urges the member towards a wall of the housing. This allows the pager to be clipped to any of various articles that accompany the user of the pager such as a carrier case, a belt, a pocket or other portion of the person's clothing.
The clip is helpful but loss of pagers remains a common occurrence. The clip tensioning spring tends to weaken after extended use at which time various movements of the person carrying the pager can easily dislodge the device and the person may not be immediately aware of the loss. Pagers are also attractive to thieves who may be able to unclip and remove the device without the owner being aware of the occurrence.
Thus more effective measures for reducing the risk of losing a pager by inadvertent dislodgment or surreptitious theft would be highly beneficial to the owners of such devices.
The present invention is directed to overcoming one or more of the problems discussed above.


A releasable hitch having a T-shaped body portion including a horizontal member perpendicularly joined to a vertical member is disclosed. The vertical member has opposing side walls, one of which is bisected by an upwardly sloping channel disposed above the horizontal member. The vertical member additionally comprises a horizontally disposed bore disposed the horizontal member. A bolt is fitted for rotational and longitudinal motion within the horizontally disposed bore. The bolt includes a cylindrical shaft having an externally threaded portion at one of its ends and two semicircular flanges, defining a slot therebetween, at the other end thereof. A C-shaped hook is pivotally secured to the semicircular flanges and has a free end adapted for engagement with the lateral channel. A spring, coiled about the cylindrical shaft and acting upon the bolt, normally biases the free end of the hook within the channel. A nut threadably secured to the externally threaded portion of the cylindrical shaft is provided for adjusting the tensile force required to extract the free end of the hook from the channel.

1. Field of the Invention
The present invention relates generally to a fastening device having a safety release feature for use in hitching pack animals together.
2. Description of the Related Art
Devices including means for automatically releasing two bodies joined by a cord have been proposed in prior patents. While commonly including spring-biased hooks, many of these devices are of complex and costly construction. Further, they are often difficult to reset, requiring a high degree of manual dexterity or strength to position the hooks for subsequent release. By way of example, those devices known to the inventor are described below.
U.S. Pat. No. 544,568, issued Aug. 13, 1895 to Louis J. DeSailly et al, provides a safety hook for use in stables. The hook itself pivots upon the end of a bolt disposed within a cylindrical body. A series of alternatingly positioned steel cups fitted upon the bolt biases the hook against the body in its unreleased position. Upon the application of a sufficient tensile force, the steel cups are compressed and somewhat flattened, thereby allowing the upper end of the hook to be released from a catch extending outwardly from the body.
U.S. Pat. No. 602,569, issued Apr. 19, 1898 to Donald L. Turner, shows a releasing device comprising a pivoting clutch mechanism releasably secured within a tubular housing. The clutch mechanism includes two cylindrical jaws adapted to engage a ball disposed at the end of a spring biased eyebolt. Two of the housing's tubular elements are threadably connected allowing the spring tension upon the eyebolt to be varied. A set screw permits the spring tension to be fixed and prevented from varying. Thus, upon application of a force sufficient to overcome the spring's pull, the clutch may be withdrawn from the housing and the device separated into two component parts.
U.S. Pat. No. 675,453, issued Jun. 4, 1901 to George F. Sturgess, describes a coupling device for use with bicycles. The device includes a tether or cord for transmitting tensile force from one bicycle to another for towing purposes. A C-shaped spring clip is provided for securing one end of the tether to a bicycle. When a sufficient tensile force is applied thereto, the spring clip will automatically release from its supporting surface preventing harm to the riders.
U.S. Pat. No. 2,452,796, issued Nov. 2, 1948 to Ole M. Skibsted, discloses self-releasing rope hitch used when towing a plow behind a tractor. The hitch includes a circular link retained against a metal strap by a spring biased jaw member. The biasing means for the jaw member include a spring disposed upon a threaded bolt. Rotation of a nut at the end of the bolt adjusts the force imparted by the spring against the jaw member.
U.S. Pat. No. 4,186,690, issued Feb. 5, 1980 to John J. Seiler, teaches the use of a safety clip in an animal grooming tethering device. The clip includes two generally resilient parallel arms connected to one another at one end and having their free ends bent inwardly toward one another in a V-shaped configuration. A band, slidable on the arms, is provided to adjust the clip to release a tether at a predetermined force.
None of the above inventions, taken either singly or in combination, is seen to describe the instant invention as claimed.


An air deflector is positioned relative to the through bore in the pole piece of the motor structure of a speaker such that the flow of air entering and leaving a cavity overlying the voice coil and pole piece is directed along a flow path which passes in thermal communication with at least a portion of the inner surface of the former of the voice coil opposite the wire winding on the outer surface of the former.

Loudspeakers generally comprise a frame, a motor structure, a diaphragm, a lower suspension and an upper suspension. In one common type of speaker, the motor structure includes a permanent magnet mounted between a top plate and a back plate, a pole piece centrally mounted on the back plate and a voice coil axially movable with respect to the pole piece. The voice coil includes a hollow, cylindrical-shaped former having an outer surface which receives a winding of wire.
One end of the diaphragm is connected to the upper suspension, which, in turn, is mounted to the upper end of the frame. The lower suspension is connected at one end to the frame at a point between its upper and lower ends. The free ends of the diaphragm and lower suspension are mounted to the outer surface of the former of the voice coil and support it within the magnetic gap formed between the pole piece and top plate of the motor structure such that the former of the voice coil is concentrically disposed about the pole piece. In some speaker designs, a dust cap is mounted to the diaphragm in a position overlying the voice coil and pole piece to protect them from contaminants. This forms a dust cap cavity between the dust cap, diaphragm, the voice coil and pole piece. In alternative designs, the upper end of the voice coil is connected directly to the diaphragm, thus eliminating the need for a dust cap but nevertheless forming an internal or dust cap cavity in the area directly above the voice coil and pole piece.
In the course of operation of a speaker of the type described above, electrical energy is supplied to the voice coil causing it to axially move relative to the pole piece within the magnetic gap of the motor. The diaphragm, upper suspension and lower suspension all move as a unit with the excursion of the voice coil. A pervasive problem associated with speaker operation involves the build up of heat produced in the wire winding of the voice coil, and by its axial movement, which is radiated to surrounding surfaces, particularly the top plate. Both the voice coil and top plate become quite hot during speaker operation which can reduce the power handling of the speaker, and increase power compression, i.e. a reduction in acoustic output due to temperature-related voice coil resistance.
A variety of designs have been employed in the prior art to address the problems associated with heat build up in speakers. One approach has been to create a flow of cooling air in thermal communication with the voice coil, such as disclosed, for example, in U.S. Pat. No. 5,042,072 to Button, U.S. Pat. No. 5,357,586 to Nordschow et al. and U.S. Pat. No. 5,426,707 to Wijnker. Speaker designs of this type generally include a pole piece formed with passages which provide a flow path for the transfer of cooling air from outside of the speaker into and out of the dust cap cavity described above. An air flow through these passages is created in response to movement of the diaphragm with the excursion of the voice coil. When the diaphragm moves in one direction, air is drawn from outside of the speaker, along the passages in or along the pole piece, and then into the dust cap cavity. Movement of the diaphragm in the opposite direction creates a flow out of the dust cap cavity along the reverse flow path.
In the Button U.S. Pat. No. 5,042,072, the pole piece of the motor is formed with a series of circumferentially spaced, longitudinally extending grooves or channels. Each channel extends radially inwardly from the outer surface of the pole piece toward its center, and from the top end of the pole piece to its bottom end including in the area of the magnetic gap between the pole piece and top plate. The purpose of the radial channels in the pole piece is to direct a flow of air along the voice coil as the air passes in and out of the dust cap cavity. Although it is contemplated that at least some of the air flow contacts the voice coil in this design, because the radial channels in the pole piece are oriented parallel to the voice coil along the longitudinal axis of the pole piece a limited amount of the cooling air actually impinges directly against the voice coil. Additionally, the formation of a number of radial channels in the pole piece reduces its mass in the area of the magnetic gap. This increases the reluctance of the magnetic path between the pole piece and top plate resulting in a decrease in motor strength which can adversely impact the acoustic performance of the speaker.
U.S. Pat. No. 5,357,586 to Nordschow employs a pole piece including a central through bore forming an annular wall defining a hollow interior. An aerodynamically-shaped insert is mounted within the central bore of the pole piece by a series of fins or spacers, thus forming longitudinally extending channels between the insert and the wall. Additionally, the wall of the pole piece is formed with a number of transverse bores extending between its outer surface and the central bore. In response to movement of the voice coil and diaphragm in one direction, air from outside of the speaker is drawn into the central bore of the pole piece, through its transverse bores, along the exterior surface of the pole piece into the magnetic gap between the pole piece and top plate, and then through bores formed in the voice coil into the dust cap cavity. Movement of the diaphragm in the reverse direction causes a flow of air out of the cavity through the voice coil bores, and then predominantly through the central bore of the pole piece along the channels formed by the fins of the aerodynamically-shaped insert.
Although the intention in the '586 patent is to cool the voice coil, it is unlikely that any effective cooling occurs with this design. The magnetic gap between the pole piece and top plate is exceedingly small, particularly considering that the voice coil is located therein, and no appreciable amount of air flow can be created through the magnetic gap without using a design such as described in the '072 Button patent wherein longitudinal channels are formed in the pole piece to provide a flow path between the pole piece and the top plate. The '586 patent does not include a pole piece with longitudinal channels along its exterior surface, but instead attempts to force a flow of air from the transverse bores in the pole piece through the magnetic gap, and, hence, along the outer surface of the voice coil. Additionally, the flow of air in the reverse direction noted above is for venting purposes only and does not result in the movement of cooling air along or adjacent to the wire winding of the voice coil.
The '707 patent to Wijnker is similar to Nordschow et al. in that it includes, in one embodiment, a pole piece formed with a central bore and a number of transverse bores extending through the wall of the pole piece. The transverse bores in the Wijnker patent are employed to create a flow of air from outside of the speaker, into the central bore of the pole piece and then out the transverse bores to discharge ports formed in the back plate of the speaker. No cooling air passes from the transverse bores, along the voice coil and into and out of the dust cap cavity. Alternative embodiments of the Wijnker patent disclose a flow path into and out of the dust cap cavity, but employ a pole piece formed with a through bore and no transverse bores and wherein an attempt is made, as in Nordschow et al., to force air to flow within the magnetic gap between the top plate and pole piece.
The deficiencies of such prior designs have been addressed to some degree in U.S. Pat. No. 6,243,479 to Proni and U.S. Pat. No. 6,535,613 to Ssutu. Each of these patents discloses a speaker having a motor which employs a pole piece formed with a bore. Structure is provided for directing a flow of air entering and exiting the pole piece bore(s) into contact with the inner surface of the voice coil in an area opposite the wire winding located on the outer surface of the voice coil. In the Ssutu design, the pole piece is formed with a through bore and an air deflector is inserted within the through bore at the top end of the pole piece. Air entering and exiting the dust cap cavity of the speaker as a result of axial movement of the voice coil and diaphragm contacts the air deflector and is directed against the inside surface of the voice coil opposite the wire winding to enhance cooling of the wire winding and top plate.
The Proni patent discloses a number of alternative embodiments, some where the pole piece is formed with a through bore and others in which the pole piece has an axial bore extending from the top end of the pole piece toward its bottom end. In most versions, the top end of the bore in the pole piece is closed by an insert, and transverse vent holes are formed in the side wall of the pole piece which intersect the axial bore or the central through bore therein. The axial bore or through bore, and the vent bores, cause air entering and exiting the dust cap cavity to flow directly against at least a portion of the interior of the former of the voice coil for cooling. Neither the Ssutu nor Proni design attempts to force a flow of air through the magnetic gap of the speaker. Instead, the cooling air is directed along the inner surface of the former of the voice coil to assist in cooling the wire winding on its opposite surface.


A model generation machine may form all or part of a network-based system. The model generation machine may generate an item model (e.g., a 3D model of the item) based on a set of images of an item and based on a product model (e.g., a 3D model of a product of which the item is a specimen). The item may be available for purchase from a seller. The model generation machine may access the set of images, as well as a descriptor of the item. Based on the descriptor, the model generation machine may identify the product model. Accordingly, the model generation machine may generate the item model from the identified product model and the accessed set of images.

A product may be manufactured by a manufacturer and available for purchase from a seller. For example, the product may take the form of a good, such as a physical item that has a three-dimensional (3D) shape. For example, a product may be a particular model of digital camera or a specific model of a car. The seller may be the same as the manufacturer, or the seller may be distinct from the manufacturer. An item may be a specimen (e.g., an individual instance) of the product, and multiple items may constitute multiple specimens of the product. Accordingly, a seller may seek to merchandise one or more items as specimens of the product.
In merchandising an item, the seller may use a network-based system to present information referencing the item to a user of the network-based system (e.g., a potential buyer of the item). Examples of network-based systems include commerce systems (e.g., shopping websites), publication systems (e.g., classified advertisement websites), listing systems (e.g., auction websites), and transaction systems (e.g., payment websites). Examples of information referencing the item include a product information document, a product review, a comment concerning the item, a view item page, a search result, an advertisement, a recommendation, a suggestion, an auction listing, a wish list, or any suitable combination thereof.

This patent is subject to a terminal disclaimer.

Item model based on descriptor and images


An e-fuse device disclosed herein includes an anode and a cathode that are conductively coupled to the doped region formed in a substrate, wherein the anode includes a first metal silicide region positioned on the doped region and a first conductive metal-containing contact that is positioned above and coupled to the first metal silicide region, and the cathode includes a second metal silicide region positioned on the doped region and a second conductive metal-containing contact that is positioned above and conductively coupled to the second metal silicide region. A method disclosed herein includes forming a doped region in a substrate for an e-fuse device and performing at least one common process operation to form a first conductive structure on the doped region of the e-fuse device and a second conductive structure on a source/drain region of a transistor.

1. Field of the Invention
Generally, the present disclosure relates to the manufacture of semiconductor devices, and, more specifically, to various methods of making an e-fuse for use on integrated circuit products and the resulting e-fuse device.
2. Description of the Related Art
The fabrication of advanced integrated circuits, such as CPU's, storage devices, ASIC's (application specific integrated circuits) and the like, requires the formation of a large number of circuit elements in a given chip area according to a specified circuit layout. Field effect transistors (NMOS and PMOS transistors) represent one important type of circuit element that substantially determines performance of such integrated circuits. During the fabrication of complex integrated circuits using, for instance, MOS technology, millions of transistors, e.g., NMOS transistors and/or PMOS transistors, are formed on a substrate including a crystalline semiconductor layer. A field effect transistor, whether an NMOS or a PMOS device, is a planar device that typically includes a source region, a drain region, a channel region that is positioned between the source region and the drain region, and a gate structure positioned above the channel region. The gate structure is typically comprised of a very thin gate insulation layer and one or more conductive layers that act as a conductive gate electrode. In a field effect transistor, the conductivity of the channel region, i.e., the drive current capability of the conductive channel, is controlled by applying an appropriate voltage to the gate electrode.
For many early device technology generations, the gate structures of most transistor devices were made using silicon-based materials, such as a silicon dioxide and/or silicon oxynitride gate insulation layer, in combination with a polysilicon gate electrode. However, as the channel length of aggressively scaled transistor devices has become increasingly smaller, many newer generation transistor devices employ gate electrode structures comprised of a so-called high-k gate insulation layer (k value of 10 or greater) and a gate electrode structure comprised of one or more metal layers, i.e., high-k/metal gate structures (HK/MG). Transistor devices with such an HK/MG structure exhibit significantly enhanced operational characteristics as compared to the heretofore more commonly used silicon dioxide/polysilicon (SiO2/poly) configurations.
One well-known processing method that has been used in recent years for forming a transistor with a high-k/metal gate structure is the so-called "gate last" or "replacement gate" technique. In general, the replacement gate process involves forming a basic transistor structure that includes a sacrificial or "dummy" gate insulation layer, a sacrificial or "dummy" gate electrode, sidewall spacers and source/drain regions in the substrate. The sacrificial gate insulation layer is typically made of silicon dioxide and the sacrificial gate electrode is typically made of polysilicon. After certain high-temperature process operations are performed, e.g., after the source/drain anneal process is performed to activate the implanted dopant materials and to repair any damage to the lattice structure of the substrate, the sacrificial gate electrode and the sacrificial gate insulation layer are removed to thereby define a gate cavity between the spacers where the "replacement gate", i.e., the high-k dielectric/metal gate structure, will be formed.
In modern integrated circuits, a very high number of individual circuit elements, such as field effect transistors in the form of CMOS, NMOS, PMOS elements, resistors, capacitors and the like, are formed on a single chip area. In addition to the large number of transistor elements, a plurality of passive circuit elements, such as capacitors, resistors and the like, are typically formed in integrated circuits that are used for a plurality of purposes, such as for decoupling.
Due to the reduced size of circuit elements, not only the performance of the individual transistor elements may be increased, but also their packing density may be improved, thereby providing the potential for incorporating increased functionality into a given chip area. For this reason, highly complex circuits have been developed which may include different types of circuits, such as analog circuits, digital circuits and the like, thereby providing entire systems on a single chip (SoC). Furthermore, in sophisticated micro-controller devices, an increasing amount of storage capacity may be provided on a chip with the CPU core, thereby also significantly enhancing the overall performance of modern computer devices.
For a variety of reasons, the various circuit portions may have significantly different performance capabilities, for instance with respect to useful lifetime, reliability and the like. For example, the operating speed of a digital circuit portion, such as a CPU core and the like, may depend on the configuration of the individual transistor elements and also on the characteristics and performance of the metallization system coupled to the CPU core. Consequently, the combination of the various circuit portions in a single semiconductor device may result in a significantly different behavior with respect to performance and reliability. Variations in the overall manufacturing process flow may also contribute to further variations in the performance capabilities between various circuit portions. For these reasons, in complex integrated circuits, frequently, additional mechanisms are used so as to allow the circuit itself to adapt or change the performance of certain circuit portions to comply with the performance characteristics of other circuit portions. Such mechanisms are typically used after completing the manufacturing process and/or during use of the semiconductor device. For example, when certain critical circuit portions no longer comply with corresponding device performance criteria, adjustments may be made, such as re-adjusting an internal voltage supply, re-adjusting the overall circuit speed and the like, to correct such underperformance.
In computing, e-fuses are used as a means to allow for the dynamic, real-time reprogramming of computer chips. Speaking abstractly, computer logic is generally "etched" or "hard-coded" onto a silicon chip and cannot be changed after the chip has been manufactured. By utilizing an e-fuse, or a number of individual e-fuses, a chip manufacturer can change some aspects of the circuits on a chip. If a certain sub-system fails, or is taking too long to respond, or is consuming too much power, the chip can instantly change its behavior by blowing an e-fuse. Programming of an e-fuse is typically accomplished by forcing a large electrical current through the e-fuse. This high current is intended to break or rupture a portion of the e-fuse structure, which results in an "open" electrical path. In some applications, lasers are used to blow e-fuses. Fuses are frequently used in integrated circuits to program redundant elements or to replace identical defective elements. Further, e-fuses can be used to store die identification or other such information, or to adjust the speed of a circuit by adjusting the resistance of the current path. Device manufacturers are under constant pressure to produce integrated circuit products with increased performance and lower power consumption relative to previous device generations. This drive applies to the manufacture and use of e-fuses as well.
Prior art e-fuses come in various configurations. FIGS. 1A-1B depict illustrative examples of some forms of prior art e-fuses. FIG. 1A is a plan view of a very simple e-fuse 10 comprised of conductive lines or structures 12 having a reduced-size metal line 14 coupled to the conductive structures 12. The e-fuse 10 may sometime be referred to as a "BEOL" type e-fuse as it is typically made using the materials used in forming various metallization layers in so-called Back-End-Of-Line activities.
FIG. 1B is a cross-sectional view of another type of e-fuse 15 that extends between two illustrative metal layers, M2 and M3, formed on an integrated circuit product. In general, the e-fuse 15 is comprised of schematically depicted conductive lines 16, 18 that are formed in the metallization layers M2, M3, respectively. A reduced-size metal structure or via 20 is conductively coupled to the conductive lines 16, 18. The e-fuse 15 may sometimes be referred to as an "I" type e-fuse due to its cross-sectional configuration. In some very early device generations, e-fuses were comprised of structures that included polysilicon line-type features as part of the e-fuse. The polysilicon line-type features for the e-fuses (i.e., a "poly fuse" or an "RX fuse") were typically patterned at the same time as was the polysilicon gate electrodes for the various transistor devices. A metal silicide material was typically formed on such poly fuses
All of the above-described e-fuses typically worked by passing a sufficient current though the e-fuse such that, due to resistance heating, some portion or component of the e-fuse ruptured, thereby creating an open electrical circuit. Some types of e-fuses, such as BEOL e-fuses, require a relatively high programming current, e.g., about 25 mA or higher. Such a high programming current is generally not desirable for e-fuses, as such a high programming current will require a relatively larger programming transistor, which means increased consumption of valuable space on the chip. Moreover, a higher programming current degrades the sensing margin for sensing circuits that are used to determine whether or not the e-fuse is programmed, i.e., blown.
The present disclosure is directed to various methods of making an e-fuse for use on integrated circuit products and the resulting e-fuse device.

Methods of forming an e-fuse for an integrated circuit product and the resulting e-fuse structure


The subject disclosure is directed towards making cube data highly available and efficient to access by separating the read cube server from the processing cube server, on different physical machines. The read cube server may be mirrored, and the write cube server may be mirrored. When the primary read cube server is not operational (e.g., has failed) or is having its read cube synchronized, the read queries are handled by the mirror read cube server. When a processing cube server (or its write cube) is not operational, its mirror processing cube server takes over and performs cube processing operations via its mirror write cube.

A data cube, such as a Microsoft® SQL Server Analysis Services cube, is a three-dimensional (or higher) database structure for storing and presenting data. Users of such a cube want their data to be highly available, with minimum interruptions in the event of hardware or software faults. However, there was heretofore not any consistent way to ensure highly available cubes, including highly available cubes in which data access remains efficient, even in heavy traffic.


A method and apparatus as described herein provide a novel modification to any iterative FEC decoder method that can improve FER performance in the error floor region. Many iterative FEC methods, such as commonly used LDPC decoders, have error floors where the performance of the decoder does not improve below a certain threshold. Error Floors are caused by trapping sets from which traditional methods cannot escape. With Stochastic Floor Mitigation, according to embodiments of the present disclosure, noise is strategically added to the operations occurring during decoding resulting in significantly improved error floor performance.

Low Density Parity Code (LDPC) decoders are current generation iterative soft-input forward error correction (FEC) decoders that have found increasing popularity in FEC applications where low error floor and high performance are desired. LDPC decoders are defined in terms of a two-dimensional matrix, referred to as an H matrix, which describes the connections between the data and the parity. The H matrix comprises rows and columns of data and parity information. Decoding an LDPC code requires solving the LDPC code according to the H matrix based on a two-step iterative method. Soft-decoding the code causes convergence of the solved code with the true code; convergence is achieved over a number of iterations and results in a corrected code with no errors.
A category of LDPC codes, known as quasi-cyclic (QC) codes, generates an H matrix with features that improve the ease of implementing the LDPC encoder and decoder. In particular, it is possible to generate a QC-LDPC H matrix where some rows are orthogonal to each other. These orthogonal rows are treated as a layer, and rows within a layer can be processed in parallel, thus reducing the iterative cost of the decoder. It is advantageous to reduce the number of iterations necessary to decode an LDPC code.
LDPC codes typically have an error floor in terms of frame error rate (FER) performance as shown in FIG. 1. In the example shown in FIG. 1, the FER performance of the decoder follows ideal waterfall performance 10 until the error floor region of the code is approached. At this point, the real decoder performance 12 begins to diverge from ideal 10, eventually reaching a condition where the FER performance only improves slowly as the input BER is reduced.
Such error floors are caused by trapping sets where the decoder can no longer determine the correct solution method that will lead to eliminating the remaining errors even when given an infinite number of decode iterations. Such trapping sets are typically near code words containing a small number of errors compared to the real solution. A trapping set can be defined by a fixed number of failing check nodes, optionally plus or minus 1 in an oscillating pattern.
Error floors are present in most every LDPC code (or other code), even those employed in many communications standards. For many systems this error floor issue is accepted so long as the error floor of the H matrix used is below the requirement for the communication standard. For example, for a mobile wireless communication system, there are fading conditions that can periodically render a given link un-usable; such a communication system must be able to deal with high frame error rates and still be effective. In such a standard an error floor of 1e-5 would be acceptable, any losses at this point would not be noticed due to the inherent noise floor in the medium.
In the present disclosure, the error floor itself is defined as the FER at which the FER waterfall plot of the code diverges nearly horizontally from the ideal waterfall plot. Many communications standards have much lower error floor requirements, some at FER=1e-8 or FER=1e-10 and even lower. The difficulty of finding an H matrix exhibiting a given error floor increases exponentially with each decadal drop in the required error floor.
In some cases the exact trapping set or sets of a given H matrix can be dealt with using custom-built changes to the convergence methods of the decoder in question. Such custom methodic enhancements are expensive to generate, difficult to determine and ultimately only deal with a few of the trapping sets in any given H matrix.
Improvements in forward error correction approaches error floor mitigation are desirable.

Error correction code decoder with stochastic floor mitigation

Microsemi Storage Solutions (U.S.), Inc.


A novel optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-substituted pentane expressed by the formula ##STR1## wherein R.sup.1 represents a halogen atom or cyano group and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms, and a process for producing the above compound are provided, the compound being preferably usable as an intermediate for preparing a HMG-CoA reductase inhibitor and the process being practiced under mild conditions and with a high yield.

1. Field of the Invention
This invention relates to a novel optically activate substance, preferably usable as an intermediate for preparing HMG-CoA reductase inhibitor, known as a remedy for high cholesterol blood disease, and a process for producing the same.
2. Description of the Related Art
The HMG-CoA reductase inhibitor has been noted as a remedy for high cholesterol blood disease, and a number of its homologues have been synthesized and active research of its pharmaceutical activity has been carried out. As one area of researches, a pyrrole derivative of the following formula (7) has been disclosed in U.S. Pat. No. 4,681,893 (Bruce D. Roth et al): ##STR2##
Further, an effective process for producing the compound of the formula ( 7 ) has been disclosed in U.S. Pat. No. 5,003,080 (Donald E Butler et al). The literature of the prior art shows that when the following compounds of the formulas (8) and (9) are treated with 10% hydrochloric acid, the compound of the formula (7) can be easily prepared: ##STR3## Further, it is also shown that the other preparation fragment (9) is prepared by catalytically reducing the following nitrile compound (10) at 0.degree. to 70.degree. C.: ##STR4##
However, the process for producing the nitrile compound (10), disclosed in the above literature of the prior art is commercially inferior. Namely, the disclosed process for producing the nitrile compound (10) consists of the following steps:
Firstly, an alkyllithium, iodine and CO.sub.2 in this order are reacted with 1,6-heptadiene-4-ol (11) to generate an iodide (12) in the reaction system, followed by treating it with an alkali or alkaline earth hydroxide or carbonate to prepare an epoxide (13). ##STR5##
An alkali metal cyanide is reacted with the epoxide to open the oxirane ring, followed by ketalization to obtain (14), oxidizing it with ozone at -20.degree. to -78.degree. C. to obtain an aldehyde (15), further oxidizing it with Jones reagent to obtain a carboxylic acid (16), and esterifying it with an alkyl halide in the presence of 1,8-diazabicyclo[5,4,0]-7-undecene (DBU) to obtain (17). ##STR6##
However, the above processes have the following commercial disadvantages:
1. In the preparation of (12), it is necessary to use an alkyllithium which is difficult to deal with. PA1 2. In the preparation of (15), it is necessary to carry out ozone oxidation at low temperatures (-20.degree. to -78.degree. C.). PA1 3. In the preparation of (16), it is necessary to use Jones reagent containing harmful chromic acid. PA1 1. An optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-substituted pentane expressed by the formula ##STR8## wherein R.sup.l represents a halogen atom or cyano group and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms. PA1 2. A process for producing an optically active erythro-1-alkanoyloxy-2 ,4-O-isopropylidene-2,4-dihydroxy-5-halogenopentane which process comprises reacting an ester with meso-1,2,4,5-pentanetetraol expressed by the formula ##STR9## in the presence of a lipase to prepare a meso-1,5-alkanoyloxy-2,4-dihydroxypentane expressed by the formula ##STR10## wherein R.sup.3 represents an alkyl group of 1 to 10 carbon atoms; ketalizing the compound ( 3 ) to prepare a meso-1,5-dialkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxypentane expressed by the formula ##STR11## dealkanolizing the compound (4) to prepare meso-2,4-O-isopropylidene-l,2,4,5-pentane tetraol expressed by the formula ##STR12## reacting an ester with (5) in the presence of a lipase to prepare an optically active erythro-l,alkanoyloxy-2,4-O-isopropylidene-1,2,5-pentanetriol expressed by the formula ##STR13## wherein R.sup.2 represents an alkyl group of 1 to 10 carbon atoms, and halogenating it, to prepare an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-halogeopentane expressed by the formula ##STR14## wherein R.sup.1 represents a halogen atom and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms. PA1 3. A process for producing an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-cyanopentane, which process comprises reacting an ester with meso-1,2,4,5-pentanetetraol expressed by the formula ##STR15## in the presence of a lipase to prepare a meso-1,5-alkanoyloxy-2,4-dihydroxypentane expressed by the formula ##STR16## wherein R.sup.3 represents an alkyl group of 1 to 10 carbon atoms; ketalizing the compound (3) to prepare a meso-1,5-dialkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxypentane expressed by the formula ##STR17## dealkanolizing the compound (4) to prepare meso-2,4-O-isopropylidene-l,2,4,5-pentane tetraol expressed by the formula ##STR18## reacting an ester with (5) in the presence of a lipase to prepare an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,5-pentanetriol expressed by the formula ##STR19## wherein R.sup.2 represents an alkyl group of 1 to 10 carbon atoms, halogenating it, to prepare an optically active alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-halogenopentane expressed by the formula ##STR20## wherein R.sup.1 represents a halogen atom and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms, and cyanizing it, to prepare an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-cyanopentane expressed by the formula ##STR21## p10 wherein R.sup.1 represents a cyano group and R.sup.2 represents an alkyl .group of i to 6 carbon atoms. PA1 4. A process for producing an optically active erythro-1- alkanoyloxy-2,4-O-isopropylidene-1,2,5-pentanetriol expressed by the formula ##STR22## wherein R.sup.2 represents an alkyl group of 1 to 6 carbon atoms, which process comprises reacting an ester with meso-2,4-O-isopropylidene-l,2,4,5-pentanetetraol expressed by the formula ##STR23## in the presence of a lipase. 5. A process for producing a meso-1,5-dialkanoyloxy-2,4-dihydroxypentane expressed by the formula ##STR24## wherein R.sup.3 represents an alkyl group of 1 to 10 carbon atoms, which process comprises reacting an ester with meso-1,2,4,5-pentanetetraol expressed by the formula ##STR25## in the presence of a lipase. 6. A process for producing an optically active erythro-3,5-O-isopropylidene-3,5,6-trihydroxy-hexanoate, which process comprises reacting an ester with meso-1,2,4,5-pentanetetraol expressed by the formula ##STR26## in the presence of a lipase to prepare a meso-1,5-alkanoyloxy-2,4-dihydroxypentane expressed by the formula ##STR27## wherein R.sup.3 represents an alkyl group of 1 to 10 carbon atoms; ketalizing the compound (3) to prepare a meso-1,5-dialkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxypentane expressed by the formula ##STR28## dealkanolizing the compound (4) to prepare meso-2,4-O-isopropylidene-1,2,4,5-pentane tetraol expressed by the formula ##STR29## reacting an ester with (5) in the presence of a lipase to prepare an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-1,2,5-pentanetriol expressed by the formula ##STR30## wherein R.sup.2 represents an alkyl group of 1 to 10 carbon atoms, halogenating it, to prepare an optically active alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-halogenopentane expressed by the formula ##STR31## wherein R.sup.1 represents a halogen atom and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms, and cyanizing it, to prepare an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-cyanopentane expressed by the formula ##STR32## wherein R.sup.1 represents a cyano group and R.sup.2 represents an alkyl group of 1 to 6 carbon atoms, and converting the cyano group into an alkoxycarbonyl group, to prepare an optically active erythro-3,5-O-isopropylidene-3,5,6-Trihydroxyhexanoate expressed by the formula ##STR33## wherein R.sup.4 represents an alkyl group of 1 to 6 carbon atoms.
Furthermore, according to this preparation route, while it is possible to separately prepare an erythroform substance and a threo-form substance, it is impossible to prepare an optically active substance. Thus, the final product prepared through the preparation route is a racemic substance. A pyrrole derivative having a physiological activity as HMG-CoA reductase inhibitor is only 2R-transform substance expressed by the formula (7), and optical isomers have no activity.
The above U.S. Pat. No. 5,003,080 also discloses preparation of an optically active substance. Namely, the above optically active nitrile compound (10) is prepared through the following route:
A carboxylic acid (19) derived from isoascorbic acid (18) according to a known method has one more carbon atom increased, using carbonyldiimidazole and a half ester of malonic acid, to prepare (20), followed by removing the protective group to obtain an alcohol (21).
This alcohol is stereoselectively reduced with triethylborane or methoxydiethylborane and then with sodium borohydride, at -78.degree. to -110.degree. C. preferably -100.degree. C., to obtain a diol (22), followed by protecting the hydroxyl groups with acetonide to obtain the above nitrile compound ( 10 ) . ##STR7##
However, the above process cannot be regarded as a commercially advantageous process, since conversions of the isoascorbic acid (18) into the carboxylic acid (19) requires a number of steps and reduction of the alcohol (21) requires an extremely low temperature (because no steroselectivity is exhibited at high temperatures).
Thus, a novel optically active compound equivalent to optically active nitrile compound (10) or easily convertible into (10), and a process for producing a novel optically active compound easily convertible into (10) under mild reaction conditions and commercially advantageously, have been required.
The present inventors have made extensive research in order to solve the above-mentioned problems, and as a result, have found a novel and useful optically active compound, i.e. an optically active erythro-1-alkanoyloxy-2,4-O-isopropylidene-2,4-dihydroxy-5-substituted pentane (1) of the present invention, equivalent to or easily converted into an optically active nitrile compound (10) as a raw material for preparing a pyrrole derivative (7) which is one of HMG-CoA reductase inhibitors, and a suitable and simple process for producing the compound of the present invention (1); thus the present invention has been completed.
As apparent from the foregoing, the object of the present invention is to provide the above-mentioned novel compound and a process for producing the same.

Optically active 1-5-disubstituted-2,4-o-isopropylidene-2,4-dihydroxypentane and a process for producing the same


A head rest apparatus comprises a sole stay, a head rest main body movably supported on the sole stay, a guide rod fixed in the head rest main body, a rail disposed in the head rest main body and fixed on the sole stay, a guide member slidably supported on the guide rod and the rail, a screw rotatably supported in the head rest main body, a nut supported on the rail and engaged with the screw, a cushion disposed between the rail and the nut, and a motor connected to the screw or the nut. A load imparted to the head rest main body is absorbed by the sliding movement of the guide member and the distortion of the cushion.

1. Field of the Invention
This invention relates to a head rest apparatus, and more particularly to a head rest apparatus including a driving mechanism for moving a head rest main body by a nut and a screw.
2. Description of the Related Art
A head rest apparatus is disclosed in Japanese Utility Model Laid Open Publication No. 2(1990)-61233 published without examination on May 8, 1990.
This head rest apparatus includes a stay means fixed on a seat back, a head rest main body movably supported on the stay means in the vertical direction, a bracket disposed in the head rest main body and fixed to the stay means, a screw fixed in the head rest main body, a nut rotatably supported on the bracket and engaged with the screw, and a motor disposed in the head rest main body and connected to the nut for moving a head rest. The head rest main body is moved relative to the seat back in response to the movement of the screw by the nut which is in turn rotated by the motor. Therefore, a position of the head rest main body is adjusted relative to the seat back.
However, in the conventional structure as mentioned above, if a force is applied excessively to an engaged portion between the nut and the screw, the engaged portion will be damaged, thereby disturbing further smooth relative movement between the nut and the screw, which leads to a malfunction of the height adjustment of the head rest apparatus.


Method for determining a sequence of audio pieces, comprising receiving a set of audio pieces, and determining the sequence of audio pieces by arranging audio pieces from the set in an order; wherein a position of a respective audio piece within the order is determined based on a user's personal profile, the user's personal profile includes rules descriptive of the user's preferences, the rules relating to attributes including meta data attributes and/or acoustic parameters of audio pieces, and wherein the position of the respective audio piece is determined depending on one of the attributes of the respective audio piece according to one of the rules.

An embodiment of the invention relates to a method for determining a sequence of audio pieces. Further embodiments relate to a music playback device and to a system for personalized playlist arrangement and stream selection.
Nowadays, a multitude of large music databases exist, and it is known to provide users with music pieces selected in accordance with their likings. Supposing however that not only the selected music pieces, but also a manner of arranging the music pieces has an influence upon a user's acceptance, there is a need for methods for arranging playlists or streams for enhancing the user's pleasure and agreement.
It is therefore an object of the invention to provide a method for arranging a given set of audio pieces so as to enhance a user's pleasure with and agreement to the arrangement.
This object is solved by a method, a music playback device and server according to the independent claims.
Further details of the invention will become apparent from the consideration of the drawings and the ensuing description.

Personalized playlist arrangement and stream selection


Dopant activation in heavily boron doped p.sup.+ --Si is achieved by applying electric current of high density. The p.sup.+ --Si was implanted by a 40 KeV BF.sup.2+ at an ion intensity 5.multidot.10.sup.15 ions per cm.sup.2 and annealed at 900.degree. C. for 30 minutes to obtain a partial boron activation according to conventional processing steps. To obtain additional activation and higher conductivity, current was gradually applied according to the invention to a current density of approximately 5.times.10.sup.6 A/cm.sup.2 was realized. The resistance of the p.sup.+ --Si gradually increases and then decreases with a precipitous drop at a threshold current. The resistance was reduced by factor of 5 to 18 times and was irreversible if an activation current threshold was reached or exceeded. The high-current-density-dopant activation occurs at room temperature.

1. Field of the Invention
The invention relates to the field of semiconductor processing and in particular to activation of ion implanted dopants.
2. Description of the Prior Art
Ion implantation is widely use to dope silicon for making shallow junction devices. The host lattice damage caused by ion implantation must be repaired by annealing in order to activate the dopant and to recover carrier mobility. Post implantation annealing, which is typically undertaken at 800.degree.-1000.degree. C. for 30 minutes, or rapid thermal annealing, at 1100.degree. C. for one second, is typically performed for lattice damage repair subsequent to dopant ion implantation. However, in heavily-doped silicon, such as silicon having 10.sup.20 ions per cm.sup.3 or more, these annealing procedures are incapable of achieving complete activation of the dopants. This failure of complete activation has been an unsolvable and perplexing problem for researchers in this field beginning from the 1960s to continuing to the present. While raising the temperature to provide higher temperature annealing is capable of also realizing better activation of dopants, annealing at these higher temperatures increases the thermal budget and broadens the junctions which are formed, which in the case of small devices results in an unacceptable broadening.
Moreover, as device processing rules decrease below the length of a wavelength used in the photolithographic patterning, it becomes necessary to maintain the shallow junction depths in proportion to the reduction in the lateral dimensions in order to maintain operability of the device. Moreover, as the device junctions and channels become smaller, signal strength decreases with decreasing current densities so that if an attempt is made to keep signal strengths at levels normally required within integrated circuits, current densities within the doped channels dramatically increase requiring increased conductivities to avoid overheating and to meet the performance requirements.
Therefore, what is needed is some means whereby conductivity of semiconductor material may be substantially increased without the use of high temperature annealing or other processes which would tend to broaden junctions or be subject to other defects of the prior art.

Dopant activation of heavily-doped semiconductor by high current densities

The Regents of the University of California


A method of making a plurality of flexible containers (12/112/212) comprising the steps of manufacturing a plurality of bag structures (13/113/213), separately manufacturing a plurality of valves (10/110/210), aligning the valves (10/110/210) with openings (24/124/224) in the bag structures (13/113/213), and securing the aligned valves (10/110/210) to the bag structures (13/113/213). Each valve (10/110/210) comprises a vent layer (30/130/230) which is pervious with respect to expected gasses and a sealed passageway is formed between the vent layer (30/130/230) and the container (12/112/212) when the valve (10/110/210) is secured to the bag structure (13/113/213).

Food bags are commonly used by consumers and industries to store food for later use or consumption. A standard food bag construction comprises a pair of rectangular side panels made from a thermoplastic material and joined together along side seams, a bottom seam, and a top seam. The side and bottom seams usually are permanent seals (e.g., heat sealed) and the top seam can be re-closeable.
Food bags are often used to store food for freezing whereby such bags are frequently referred to as freezer bags. A major complaint surrounding the use of freezer bags stems from what has come to be called "freezer burn;" that is, the dehydration that occurs when food is stored in the low humidity atmosphere of a freezer. Freezer burn can cause a complex deterioration of food quality involving undesirable texture changes, followed by chemical changes such as degradation of pigments and oxidative rancidity of lipids. Taste, aroma, mouth feel, and appearance all can be ruined.
The elimination of air from the interior cavity of the freezer bag is known to dramatically decrease freezer burn. To this end, air release valves and/or special bag constructions have been used to minimize air within the bag. However, these solutions can substantially complicate (and slow-down) the bag-making process, and/or can significantly increase production costs.


A system for heating a stator segment includes a first frame member, a plurality of arms extending radially from the first frame member, and a heater releasably connected to each arm. The system further includes a biasing element for biasing each heater away from the first frame member.

Compressors are widely used in industrial and commercial operations. For example, a typical commercial gas turbine used to generate electrical power includes a compressor at the front, one or more combustors around the middle, and a turbine at the rear. A casing generally surrounds the compressor to contain a working fluid flowing through the compressor, and alternating stages of rotating blades and stationary vanes inside the casing progressively impart kinetic energy to the working fluid to produce a compressed working fluid at a highly energized state. Each rotating blade may be releasably connected to a rotor located along an axial centerline of the compressor, and each stator vane may be attached to a stator segment. For example, six stator segments may circumferentially surround the rotor, with three stator segments in each half of the casing. The casing may include a hook fit slot that extends circumferentially around the casing for each stage of stator vanes, and the stator segments may releasably slide into the hook fit slots.
Periodically, the stator vanes and stator segments in the compressor must be removed and/or replaced. Doing so typically requires at least partial removal of the casing surrounding the compressor to provide access to the stator vanes and stator segments. With the rotor still in place, however, access is somewhat restricted, and particular care must be taken to ensure that removal of the stator vanes and stator segments does not result in collateral damage to the rotor, casing, or adjacent rows of rotating blades. For example, a cutting tool may be manually inserted around the rotor to individually cut each stator vane, and once all stator vanes have been cut from a particular stator segment, the stator segment may be removed from the hook fit slots in the casing.
Occasionally, however, corrosion, creep, and/or other plastic deformation of the hook fit slots and/or stator segments prevent the stator segments from readily sliding out of the casing. For example, the stator segments may be constructed from carbon steel, and moisture from condensation, water washes, and other environmental factors may product corrosion that makes it extremely difficult to remove the stator segments from the hook fit slots. Rapid heating and cold water quenching of the stator segments is a very effective method to loosen the corrosion and remove the stator segments. However, the current method to heat the stator segments uses a torch or other open flame that may inadvertently damage the adjacent components and presents a fire hazard if exposed to rotor dams temporarily installed to protect the rotating blades. In addition, a single torch has a limited surface area for heating the stator segments, requiring several hours to heat a single stator segment. Therefore, an improved system and method for heating a stator segment would be useful.

System and method for heating a stator segment


A programmable gate array (PGA) according to the present invention includes a plurality of state machine logic blocks and a plurality of error detecting logic blocks. Each state machine logic block of the plurality of state machine logic blocks produces a respective state with the plurality of state machine logic blocks in combination producing a system state. The plurality of state machine logic blocks are interconnected to execute logic programmed logic functions, such functions employed by a system within which the PGA resides. The error detecting logic blocks are interconnected to detect errors in the system state and to produce an error signal upon detection of an error in the system state. The error signal serves to reset operation of the plurality of state machine logic blocks. The plurality of state machine logic blocks may be one-hot encoded wherein, during non-error states, only one of the states produced by the plurality of state machine logic blocks is logic high. In such case, the plurality of error detecting logic blocks detects an error in the system state when more than one of the states produced by the plurality of state machine logic blocks is logic high or when none of the plurality of state machine logic blocks is in a logic high state. In producing the error signal, the plurality of error detecting logic blocks may be connected in a multi-level hierarchy.

1. Technical Field
This invention relates generally to digital circuitry and more particularly to a system and associated method of operation in a programmable gate array for detecting error conditions in the programmable gate array, the system and associated method providing high speed error detection with minimized overhead.
2. Related Art
The use of state logic within digital systems is well known. Many modern integrated circuits use some form of state logic to execute their specific functions. Circuitry using state logic includes, for example, microprocessors, digital signal processors, application specific integrated circuits, micro-controller units and various other digital circuits. State logic typically includes state machines and combining logic. State machines may include registers, latches and other circuits employed to represent one or more state bits. The combining logic interconnects the state machines and intercouples inputs to execute desired state machine logic. External inputs are provided to the combining logic per a state machine logic design while outputs are derived from the state bits and output per the state machine logic design.
In many applications, for example in the communications industry, programmable gate arrays are used within communication system elements to execute particular state machine logic. In many applications, the programmable gate arrays are field programmable so that they may be easily reprogrammed as required. Field programmable gate arrays ("FPGAs") are used in, for example, switching systems, switching equipment, mobile terminals, radio control circuitry, and various other elements that may reside within such communication systems.
FIG. 1 generically illustrates a FPGA 100 that may be employed within various communication system elements. The FPGA 100 includes a plurality of logic blocks 102 connected via routing resources 104A and 104B to, in combination, execute programmed logic, which may include state machine logic. Each of the logic blocks 102 receives inputs 106A and 106B and produces outputs 112A and 112B. The inputs 106A and 106B may be either inputs received externally from the FPGA 100 or outputs of other logic blocks 102. Further, outputs 112A and 112B may be outputs provided external to the FPGA 100 or provided as inputs to other logic blocks 102.
Each of the logic blocks 102 may include, for example, lookup tables (LUTs) 108A and 108B and registers 110A and 110B. Each of the registers 110A and 110B produces one or more state bits. In combination, these state bits represent a state of the logic block 102 while, in combination, the states of the logic blocks 102 produce a system state. The LUTs 108A and 108B receive the inputs 106A and 106B, respectively, and execute logic functions to produce either inputs to the registers 110A and 110B or the outputs 112A and 112B, based upon the programming of the multiplexing elements 107A and 107B. Programmed in a bypass mode, the multiplexing elements 107A and 107B bypass outputs from the LUTs 108A and 108B to the outputs 112A and 112B. In such a bypass mode, the logic block 102 executes only combinational logic without producing state bits. In a non-bypass mode, outputs from the LUTs 108A and 108B route via the multiplexing elements 107A and 107B to the registers 110A and 110B to produce the state bits. The LUTs 108A and 108B, the multiplexing elements 107A and 107B and the routing resources 104A and 104B are programmed at startup or reset so that the FPGA 100 performs a desired logic operation which may include state machine logic operation. Due to its reprogrammable construction, the FPGA 100 may be reprogrammed as required without removing the FPGA 100 from its host system.
During normal operations, the FPGA 100 executes it programmed state machine logic without error. However, in the presence of noise and other system anomalies, operation of the FPGA 100 may become disrupted. During such disruption, the FPGA 100 may enter an erroneous system state. Such erroneous system state causes the outputs 112A and 112B produced by the FPGA to also be erroneous, potentially disrupting operation of the host system. Thus it is desirable to determine when an erroneous state or states are entered by the FPGA so that the FPGA may be reset to a known valid state and to commence operation therefrom.
Some prior art FPGAs incorporated error detection methodologies that were incorporated into the state machine logic. However, these FPGAs used a binary encoded method for implementing the state machine logic, such programming being inherently slow. Thus, with the error detection functions, the FPGAs failed to provide satisfactory performance.
Thus, in speed sensitive applications, FPGAs may be programmed to implement state machine logic using one-hot encoding. In one-hot encoding, the plurality of logic blocks 102 operate in cooperation such that only a single one of the state bits of the system state is logic high at any time. Further, in one-hot encoded operation, the overall speed of operation of the FPGA increases significantly as compared to the speed of binary encoded state machine logic implemented in FPGAs. However, in one-encoding, the number of erroneous states, as compared to the number of erroneous states in a binary encoded state machine, increases significantly. For example, in a ten state programmable gate array, there are 1,014 undefined states. To detect such large number of undefined states using conventional techniques wherein error logic is programmed along with operating logic would decrease the speed of operation to such an extent so as to defeat the purpose of one-hot encoding.
Thus, there is a need in the art for a system and associated methodology that expeditiously determines whether a one-hot programmed gate array and other gate arrays is properly operating and to initiate a reset upon detection of an erroneous operating condition.

System and method for covering illegal states in a programmable gate array


A system and method of using multiple processors to perform video compression is provided. A video sequence is partitioned into subsequences and processing assignments for the subsequences are distributed among a plurality of processors. A picture type is then determined for each picture in each subsequence and the encoding complexity of each picture is modeled, based on the picture type. Based on the modeling, a number of bits is allocated to each picture. Each picture is then compressed in accordance with the bits allocated. Another aspect provides for encoding of pictures in a video sequence using dynamic modeling of the encoding complexity of future pictures in the video sequence. Bits are allocated to the encoding of a current picture in the video sequence based on the dynamic model. The current picture is then encoded based on the bits allocated.

A. Field of the Invention
The present invention relates to the field of data compression and, more particularly, to systems and techniques for compressing digital motion video signals.
B. Related Art
Technological advances in digital transmission networks, digital storage media, Very Large Scale Integration devices, and digital processing of video and audio signals are converging to make the transmission and storage of digital video economical in a wide variety of applications. Because the storage and transmission of digital video signals is central to many applications, and because an uncompressed representation of a video signal requires a large amount of storage, the use of digital video compression techniques is vital to this advancing art. In this regard, several international standards for the compression of digital video signals have emerged over the past decade, with more currently under development. These standards apply to transmission and storage of compressed digital video in a variety of applications, including: video-telephony and teleconferencing; high quality digital television transmission on coaxial and fiber-optic networks as well as broadcast terrestrially and over direct broadcast satellites; and in interactive multimedia products on CD-ROM, Digital Audio Tape, and disk drives.
Several of these standards involve algorithms based on a common core of compression techniques, e.g., the CCITT (Consultative Committee on International Telegraphy and Telephony) Recommendation H.120, the CCITT Recommendation H.261, and the ISO/IEC MPEG-1 standard (ISO/IEC JTC1/SC2/WG11 MPEG 91/74 MPEG Video Report Draft, CD-11172, 1991) and and MPEG-2 Standard (ISO/IEC 13818-2, 1994).
The MPEG standards have been developed by the Moving Picture Experts Group (MPEG), part of a joint technical committee of the International Standards Organization (ISO) and the International Electrotechnical Commission (IEC). The MPEG committee has been developing standards for the multiplexed, compressed representation of video and associated audio signals. The standards specify the syntax of the compressed bit stream and the method of decoding, but leave considerable latitude for novelty and variety in the algorithm employed in the encoder.
The MPEG-1 standard was developed for use in compressing progressive video. A progressive video sequence is a sequence in which each frame represents a scene as it is viewed at a discrete time instance. By contrast, for interlaced video, a field--every other line on the screen--is captured periodically. For interlaced video, at alternating time instances the top and bottom field on a screen is refreshed. At any given time, data from two fields--a frame--can be seen.
The MPEG-2 standard, can be used to compress either interlaced video, progressive video, or a mixture of progressive and interlaced video: the encoder specifies whether each frame is progressive or interlaced.
By today's yardstick, compressing a video sequence into high quality MPEG bit stream is a computationally intensive task. The video compression process is sequential in nature, i.e., there are many temporal dependencies. These dependencies arise primarily from the need to do motion estimation and the need to stay within the specified bit-rate constraints, i.e., rate control. As a result of these dependencies, it is difficult to use multiple processors to parallelize (and hence speed up) the compression process.
One conventional method of performing MPEG-1 compliant video compression is to parallelize the compression at the macroblock level, i.e., each processor compresses a macroblock. While superior to pure sequential processing, this fine grain of parallelism leads to significant communication overheads among processors and between the processors and the shared memory.

Video compression using multiple computing agents

International Business Machines Corporation


A dishwasher includes a cabinet having an opening, a door provided to open/close the cabinet opening, a washing chamber member provided in the cabinet and forming a washing chamber facing the opening, a washing nozzle provided facing in a certain direction of the washing chamber, a circulation pump coupled to the washing nozzle, the bottom portion of washing chamber and an external drain outlet, a driving source provided outside the washing chamber, a power transmission mechanism provided at a corner on one side in cabinet behind and outside the washing chamber, and a control circuit controlling the circulation pump and driving source. By the power transmitting mechanism, a dish washing basket placed in the washing chamber is rotated. Since the power transmitting mechanism is placed in a corner behind the washing chamber, the dishwasher can be made smaller.

1. Field of the Invention
The present invention relates to a dishwasher for washing dishes by jetting washing water. More specifically, the present invention relates to a dishwasher for washing dishes by jetting water to a dish washing basket which contains dishes and is rotated.
2. Description of the Background Art
A conventional dishwasher is disclosed in Japanese Utility Model Laying-Open No. 62-183393. The conventional dishwasher includes, referring to FIG. 41, a washing tank 101, a turntable 101 provided in washing tank 101, a container rack 102 for placing dishes on turntable 100, a water jet pipe 103 for jetting water, provided on an inner surface of washing tank 101 and having a nozzle formed over height direction of container rack 102, and a driving apparatus 104 provided below washing tank 101 for rotating turntable 100.
The dishwasher operates in the following manner. Dishes are placed on turntable 100. While turntable 100 is rotated by driving apparatus 104, water is jetted out from water jet pipe 103 to the dishes, and the dishes are washed.
In such a conventional dish washer, the driving apparatus for rotary driving the turntable is arranged below the turntable. This makes the dishwasher higher and larger. Further, in a conventional dishwasher, arrangement of water jet pipe for jetting water, water inlet and so on has not been well considered, and therefore a space in the box is not well utilized.
Most of commercially available dishwashers use a rotating nozzle and not a turntable such as described above. A control circuit for a dishwasher using a rotary nozzle is disclosed, for example, in Japanese Patent Laying-Open Nos. 7-289492 and 7-303592. The control circuit of the conventional dishwasher includes electric parts such as a pump, heater, and a fan connected parallel to a power source through switches.
It has been described in Japanese Utility Model Laying-Open No. 6-11665 that drying finish of dishes is improved when a rinsing agent is dropped into the washing tank after washing. The rinsing agent helps draining after rinsing, and thus prevents water marks on the dishes after drying.
Further, Japanese Utility Model Laying-Open No. 4-100931 discloses a business use dishwasher having a function of easy demonstration for sales promotion.
Of the dishwashers, one washing dishes using a turntable is more advantageous than the one in which jet nozzle rotates, in that articles or dishes can be washed more uniformly. However, conventionally, the technique necessary for using the turntable has not been sufficiently considered, and therefore advantages of the turntable type apparatus have not been fully exhibited. Specifically, a display portion showing set operation or process which is being done is not provided on a control panel, and therefore the user cannot have sufficiently detailed information of the process of dish washing. Therefore, the conventional dishwasher has poor operability. Further, conventionally, failure in operation by some cause cannot be well addressed, especially failure or difficulty derived from the use of the turntable has not been well addressed. When there is a malfunction in the turntable driving system, for example, it is difficult to access the defective portion for repair. In other words, the serviceability is poor. Further, family use dishwashers do not have any demonstration function. This makes sales activity difficult at shops. Further, if a family use dishwasher were provided with demonstration function, the demonstration function might have been mistaken as a failure as the dishwasher operates in a different manner if the user started the demonstration function unknowingly.

Dishwasher for washing dishes by rotating a dish washing basket and dish washing basket therefor


A slide hinge is connected a cover to a base of a portable electronic device and has a stationary bracket, two pivot members, a sliding bracket and two torsion springs. The pivot members are mounted rotatably on the sliding bracket and are mounted to the base. The sliding bracket is mounted slidably on the stationary bracket and is mounted to the cover. The torsion springs are connected between the stationary bracket and the sliding bracket and each torsion spring multiple looped segments. The torsion springs with the looped segments provide an excellent resilient force to position the stationary bracket in one edge of the sliding bracket and therefore stably hold the cover in opened or closed positions without inadvertently sliding relative to the base.

1. Field of the Invention
The present invention relates to a hinge, and more particularly to a slide hinge that is used in a portable electronic device and has an excellent positioning function.
2. Description of Related Art
Portable electronic devices such as cellular phones and personal data assistant (PDA) are designed to be compact and light for handholding and carriage.
Conventional portable electronic devices have a base, a cover, an inputting interface and a liquid crystal display (LCD). The cover is connected movably to the base. The inputting interface may be a keyboard and is mounted on the base. The LCD is mounted on the cover and may be overlapped on the cover to change the portable electronic device into a compact configuration.
The portable electronic devices are classified into a sliding type and pivoting type depending on the way the cover mounted on the base.
A sliding type portable electronic device mounts the cover slidably on the base with springs selectively positioning the cover on opened or closed positions. However, the springs have insufficient forces to securely position the cover so that the cover easily slides inadvertently.
To overcome the shortcomings, the present invention provides a slide hinge to mitigate or obviate the aforementioned problems.


A tableted household cleaning composition for cleaning glass and other hard surfaces and methods for making and using the same are disclosed. The cleaning composition is in tablet form and includes an acidic component selected from the group consisting of carboxylic acids, their salts and mixtures thereof; a basic component selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates and mixtures thereof; and polyvinyl alcohol.

The present invention relates to household cleaning compositions and, in particular, to household cleaning compositions in tableted form for use in cleaning glass and other hard surfaces.
Liquid and powdered products for cleaning glass and other hard surfaces are known in the art and are available in the marketplace. The liquid cleaning products generally contain water, thus making them heavy. Similarly, powdered products generally have a high-bulk capacity, which also results in a bulky product. Moreover, liquid and powdered cleaning products require a great deal of storage space.
Cleaning compositions in tablet form, like that of the present invention, have several advantages over such liquid and powdered products. Because they are compressed and contain no water, tablets are lightweight and have a low-bulk capacity. Their small size makes for more economical shipping and storage.
Surprisingly, it has been found that a household cleaning composition that effectively cleans glass and other hard surfaces can be prepared by combining an acidic component, a basic component and polyvinyl alcohol in a tablet. The polyvinyl alcohol replaces most of the surfactants found in other tableted cleaners. The polyvinyl alcohol also provides a reduction in surface tension, so as to allow for easier wiping, and stabilizes the tableted cleaner. The tableted cleaner of the present invention dissolves quickly, resulting in a product with little or no streaking.

Tableted household cleaner comprising carboxylic acid, BI carbonate and polyvinyl alcohol


A process for preparing a tetra-substituted aminobiphenol macrocyclic ligand having the structure (I), comprising the step of treating a precursor compound having the structure (II) with a compound having the structure R6-L where L represents a leaving group (hereinafter compound (III)) in the presence of a base.

The present invention relates to an improved process for the production of tetraaminobiphenol macrocyclic ligands, in particular, tetraaminobiphenol macrocyclic ligands for use in the production of bimetallic catalysts employed in copolymerization reactions.
The invention relates in particular to an improved process for the production of tetraaminobiphenol macrocyclic ligands in which each of the amino moieties of the macrocyclic ligand is substituted, for example alkylated or allylated.
The invention further relates to novel tetraaminobiphenol macrocyclic ligands.
It is disclosed in Hodgkin, Polymer Science: Part A: Polymer Chemistry Edition, Vol. 24, 3117-3127 (1986), that a Mannich reaction between p-cresol, and N,N′-dimethylethylenediamine and formaldehyde yielded a tetramethylaminobiphenol macrocyclic ligand. The process is as shown in outline below.

In this method there is no alkylation step carried out on the macrocyclic ligand and therefore no risk of alkylating the phenol moieties. However, the process has disadvantages. The macrocycle is formed in low yields as a by-product to the linear polymeric products that were the target of Hodgkin et al. There is no indication that any other macrocyclic product could be made; but if this method were possible for different substituents of the amine groups it would be necessary to run a new Mannich reaction for each macrocyclic ligand.
Direct alkylation of a tetraaminobiphenol macrocyclic ligand is described in Chen et al., CrystEngComm, 2013, 15, 5168-5178. In this reference it is stated that a tetraaminobiphenol macrocyclic ligand (3 mmol) was reacted with ethylchloroacetate (6 mmol) and potassium carbonate (24 mmol) in dimethylformamide under reflux for 20 hours. Following filtration and evaporation the residue was hydrolysed with sodium hydroxide to give the desired tetracarboxylic acid ligand. The reaction scheme is shown in outline below:

It is stated in the Chen reference that the tetracarboxyaminobiphenol ligand H6L was obtained in 65% yield. However this yield is not possible: only two equivalents of ethylchloroacetate were used, per one equivalent of the tetraaminobiphenol macrocyclic ligand H2L′. It will be appreciated that the tetraaminobiphenol macrocyclic ligand of interest in the Chen reference has four N-sites and two phenolic moieties, all of which are potential sites for reaction. Thus the theoretical maximum of the yield of the tetracarboxyaminobiphenol ligand is 50%; and this would assume no other products; for example no mono-carboxy ligand, no di-carboxyaminobiphenol ligand, no tri-carboxyaminobiphenol ligand, and no alkylated phenol ligands of any sort. It may be noted here that alkylation of phenol moieties under basic conditions is commonplace and is described in chemistry textbook. One literature example (from many) is Facile Synthesis of Alkyl Phenyl Ethers Using Cesium Carbonate, Lee et al, Synthetic Communications, 25(9), 13671370 (1995) which describes a "highly efficient" alkylation method of phenols using alkyl halides/cesium carbonate/acetonitrile. For Chen to choose to use such a low amount of the alkylating agent—two mole equivalents when the target product has 4 moles of the carboxylate substituent—may indicate a desire to avoid competing reactions, such as alkylation of the phenol groups.

Process for the production of tetraaminobiphenol macrocyclic ligands; and novel tetraaminobiphenol macrocyclic ligands