A flexible, raised snowplowable pavement marker having a top portion that readily deforms downwardly into a base portion when impacted by vehicular traffic or a snowplow blade. Markers installed in a cavity bored in pavement are anchored in place with grouts or alternatively within an annular ring mounting device. The marker body may be black in color to take advantage of solar activity in improving marker performance and longevity and may be vented to atmosphere to facilitate the downward deflection of the top portion of the pavement marker. A retroreflective sheeting is affixed to the marker so that the marker is highly visible to motor vehicle drivers at nighttime.

Raised pavement markers have evolved over the past sixty years and serve to delineate areas such as traffic lanes on pavement surfaces. Most pavement markers include some form of reflector to improve motorists' nighttime visual perception. The benefits of raised pavement markers include improved wet reflectivity wherein the markers delineate areas when precipitation on pavement surfaces reflects light from vehicle headlights obscuring markings painted on the pavement. Another benefit of raised pavement markings is improved nighttime visibility over long distances. This contributes to lower motorist visual stress, thus lower fatigue, yielding improved safety for nighttime driving.
Raised pavement markers have been installed at the pavement surface using a variety of fixation means including metal pins, nails, screws or alternatively an adhesive means. Such markers are shown in U.S. Pat. No. 1,802,940 (Cornelius), U.S. Pat. No. 4,088,416 (Taylor), and U.S. Pat. No. 4,717,281 (Shepherd et al.). The use of metal poses a threat because dislodgement of such components may result in increased hazards for vehicles. Metal pins and screws, once dislodged, could find their way into vehicle tires or they could, as the markers themselves, become projectiles on roadways when acted upon by vehicular traffic, particularly at high speeds. One sure method of dislodgement for these types of markers can be from the action of snowplows.
Raised pavement markers have been devised that address the action of snowplows. Such raised, snowplowable pavement markers usually require boring or cutting a cavity within the pavement surface for fixation means. In general, raised snowplowable pavement markers appear as three broad types in their construction:
a) rigid, non-articulated, non-deformable units that withstand substantial impact forces of snowplow blades at high speeds as shown in U.S. Pat. No. 4,147,447 (Heenan et al.), U.S. Pat. No. 4,577,992 (Jefferies) and U.S. Pat. No. 4,634,310 (Clarke). Although somewhat simplistic in their construction, these units typically employ cast metal bases to withstand high impact forces imparted to them by snowplows. Portions of the markers are disposed above the pavement surface and deflect snowplow blades off the pavement surface to protect the reflector mounted on the marker. Retroreflectors mounted on these units also are typically rigid in their construction. These markers although useful, present several difficulties for roadway maintenance operations. Plowblades and the vehicles to which they are attached can suffer considerable fatigue and damage as a result of the plowblade striking the cast metal surfaces at high speeds. The cast metal ramps on this type of pavement marker deflect plowblades upwards off the pavement surface. This can leave snow and ice on the pavement surface in the area immediately about and beyond the marker impact point. The plowblades upon returning to the road surface also may damage the road surface upon impact and can damage or destroy pavement markings resulting in increased pavement maintenance costs. Snowplow operators have experienced nausea from prolonged plowing operations on roadways employing such markers as the impact energy and loud noise transmitted to the plow vehicle enhances operator stress levels. At highway speeds, plow impact with markers can occur as often as once a second. Plowing in snowstorm conditions, in traffic, at high speed for many hours is stressful enough without this additional persistent distraction.
b) articulated units that are mechanical or employ compressible components to allow marker sections that are raised above the pavement to move or retract to survive impacts from snowplows and vehicle tires. Mechanical units such as shown in U.S. Pat. No. 4,140,418 (Holley) and U.S. Pat. No. 4,848,958 (Sheldon) employ metal components that ultimately may deteriorate from the effects of salt and sand materials used on pavements during snow and icing conditions. Although these types of marker are unlikely to impede pavement plowing operations, they require substantial open cavities in pavement to operate.
The cavities are problematic because they are likely to trap debris. Frozen water within the cavities may impede proper function of the units and lead to their destruction by snowplows. U.S. Pat. No. 5,302,048 (Paulos et al.) discloses a pavement marker that can have several of its components replaced, however, the marker employs elaborate mechanical components to provide such, and the impact energy required to deflect the marker top section is believed to be essentially of the same magnitude as that experienced with the rigid, non-deformable units thus presenting many of the road maintenance concerns associated with the rigid units. Further, maintenance of the marker may be difficult.
c) resilient, deformable units, that employ cavities in the pavement to situate and anchor the markers. Most involve a body structure that contains a reflector--although U.S. Pat. No. 3,890,054 (O'Connor) and U.S. Pat. No. 4,815,818 (Thomas) disclose arrays of resilient, fingerlike projections that are reflectorized. Deformable, resilient body types are disclosed in U.S. Pat. No. 4,297,051 (Robinson), U.S. Pat. No. 4,659,248 (Flanagan) and U.S. Pat. No. 5,069,577 (Murphy). Flanagan discloses a unit that resides totally below the pavement surface and would likely survive the action of snowplows but like the mechanical units of Holley and Sheldon, a substantial pavement cavity is required that may fill with debris or water, rendering the retroreflector imperceivable to vehicular traffic. Robinson and Murphy and U.S. Pat. No. 3,850,536 (Kone) employ a cavity cut into the pavement that is intended to accommodate the upper portion of the marker body when deformed by vehicular traffic and snowplow blades. Kone desires air, trapped within the market cavity, to assist in proper operation of the marker. Robinson suggests that with a suitable grout, the internal cavity is airtight and assists the marker in returning to its normal shape and attitude following deformation. The markers are anchored in the cavities in the pavement by capturing a skirt and flange portion of the marker body using suitable grouts. As the side walls or skirt portion of the marker bodies are integrally molded with the flexible top portions, there is potential for side wall deformation upon snowplow impact. Robinson makes provisions to strengthen or stiffen this portion of the marker body to prevent damage to the device upon plow impact.
Most snowplowable pavement markers in use today are rigid, non-deformable cast metal base type markers containing rigid cube corner retroreflectors that are adhesively bonded (usually epoxy) to the metal base. Such markers, as previously described and cited, are installed by cutting or boring a suitable cavity in the pavement to accept the lower portion of the metal base and then fixating the units in the cavity with a suitable epoxy, cement or similar rigid grout. Because of road closure time limitations, these grouts are usually fast setting/rapid cure type materials. Aside from any intended cavities within the marker bodies themselves, the entire cavity cut in the pavement typically is filled with the grout and the marker body material leaving no voids within the pavement.
Given that retroreflectors on raised snowplowable pavement markers are exposed to traffic and studded tires, tire chains, snowplows, road chemicals, and weather, they do not last forever. Reasonable lifetimes are on the order of 2 to 3 years. Efficient replacement of the retroreflectors poses problems in that if a retroreflector is easily removed for replacement, it is likely to become dislodged on impact by vehicular traffic or snowplows. Few published documents disclose details on maintenance or refurbishing methods, or go on to address the inevitable requirements when pavement resurfacing is required.

Flexible raised pavement marker, mounting device and method

Minnesota Mining and Manufacturing Company


An electric field forming apparatus for a fryer includes an electrode which is disposed along an inner wall surface of an oil vat, and a power supply which supplies an alternating current at a frequency higher than a power line frequency to the electrode.

This invention relates to an electric field forming apparatus for use in a fryer for frying food. More particularly, it relates to an electric field forming apparatus for a fryer which applies a high voltage to an electrode disposed in an oil vat and generates an electric field in the oil vat. It also relates to a fryer which utilizes this electric field forming apparatus and to a method of frying food.
As described in Japanese Published Unexamined Patent Application 2001-95695, it has been proposed to dispose a flat electrode at the bottom of an oil vat of a fryer and to apply a high voltage to the electrode to form an electric field within the oil vat. Forming an electric field in an oil vat is said to provide benefits such as suppressing oxidation of oil in the vat, preventing contamination, and shortening the frying time. These benefits are thought to be primarily due to the electric field producing forced convention of oil in the oil vat, which promotes the transmission of heat to food and produces concentrated heating of the surface of the food. This results in rapid frying of the surface of the food and trapping of moisture within the food. Since moisture is prevented from flowing into the oil, an oxidation reaction between oxygen in the moisture and oil is prevented. It has also been proposed to detachably install a flat electrode parallel to a side wall of an oil vat (see Japanese Published Unexamined Patent Application No. 2004-41531).
However, the electric field forming apparatus described in Japanese Published Unexamined Patent Application 2001-95695 has a structure such that the bottom portion of an oil vat of a fryer is electrically charged by an electrode which extends over the entire bottom surface of the oil vat, so food which is placed into the oil vat adheres to the bottom inner surface of the oil vat. Convection of oil is insufficient in locations where adhesion of food takes place, so the effect of promoting uniform heat transmission by the electric field cannot be obtained. In particular, heating of the surface of food facing the bottom surface of the oil vat is delayed, and unfried portions end up forming in the food. In the electric field forming apparatus described in Japanese Published Unexamined Patent Application 2004-41531, a flat electrode is disposed parallel to a side wall of an oil vat, so the problem of adhesion of food to the bottom of the oil vat is avoided, but since the electrode extends along a vertical surface of the oil vat, the efficiency of the electrode is poor, and adequate heat convection to the underside of food cannot be produced. Namely, in order to obtain a uniform fried state, it is important to generate a strong electric field in the vicinity of the bottom of the oil vat, but with the electric field forming apparatus described in Japanese Published Unexamined Patent Application 2004-41531, the electrode spreads in the vertical direction along a side wall of the oil vat, so an electric field cannot be concentrated at the bottom portion of the oil vat, and the electric field which is generated cannot be effectively utilized. Therefore, the desired effect of applying an electric field to oil in an oil vat cannot be adequately obtained.

Electric field forming apparatus for a fryer


A gas re-use system for carbon fiber manufacturing processes based on hydrocarbon thermal decomposition. The system permits re-use of the output gas from the carbon fiber manufacturing process, a process based on the use of an industrial gas as the main raw material. The system can comprise a feedback pipeline provided with force and filtering means to raise the pressure from the reaction furnace output manifold to its input. There are also return and bleed lines operated separately to assure suitable pressure ranges at the same time both in the reaction furnace input area and extraction area.

The present invention relates to a gas re-use system for carbon fiber manufacturing processes based on hydrocarbon thermal decomposition.
The system can relate to or provide for the re-use of gas stemming from the carbon fiber manufacturing process, a process based on the use of an industrial gas as the main raw material.
There can be a feedback pipeline having a force and filtering means to raise the pressure from the reaction furnace output manifold to the input. There are, in turn, return and bleed lines operated independently that assure suitable pressure ranges at the same time both in the reaction furnace feed area and in the extraction area.
This system can have a control means that makes use of mass controllers to adjust the supply of raw materials and the supply of residual gas to keep the gases entering the reaction furnace constant in suitable proportions.
There can be a check made such that the residual gas is practically the same as that of the gas used as raw material.
Carbon nanofibers are filaments of submicron vapour grown carbon fiber (usually known as s-VGCF) of highly graphitic structure which are located between carbon nanotubes and commercial carbon fibers, although the boundary between carbon nanofibers and multilayer nanotubes is not clearly defined.
Carbon nanofibers have a diameter of 30 nm-500 nm and a length of over 1 m.
There is scientific literature available describing and modelizing both the physicochemical characteristics of nanofiber and the generation process at microscopic level from the carbon source used in its production.
These models have been created in most cases on the basis of laboratory experiments making use of controlled atmospheres combined with electron scanning or transmission microscopes
Carbon nanofibers are produced on the basis of catalysis by hydrocarbon decomposition over metal catalytic particles from compounds with metallic atoms, forming nanometric fibrillar structures with a highly graphitic structure.
There are studies, such as those of Oberlin [Oberlin A. et al., Journal of Crystal Growth 32, 335 (1976)], in which the growth of carbon filaments over metallic catalytic particles is analysed by electron transmission microscope.
On the basis of these studies, Oberlin proposed a growth model based on the diffusion of carbon around the surface of the catalytic particles until the surface of the particles is poisoned by an excess of carbon.
He also explained that deposition by carbon thermal decomposition is responsible for the thickening of the filaments and that this process takes place together with the growth process and is therefore very hard to prevent.
For this reason, once the growth period has finished, for instance by poisoning of the catalytic particle, the thickening of the filament is maintained if the pyrolysis conditions continue to exist.
Afterwards, other growth models were put forward that have been considered in the light of experimental data and starting from different simplifying hypotheses that give rise to results to match up to a greater or lesser extent with the observations obtained in the laboratory.
Metal catalytic particles are formed of transition metals with an atomic number between 21 and 30 (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn), between 39 and 48 (Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd), or between 73 and 78 (Ta, W, Re, Os, Ir, Pt). It is also possible to use Al, Sn, Ce and Sb, while those of Fe, Co and Ni are especially suitable.
Different chemical compounds may be used as a source of catalytic metal particles for the continuous production of carbon nanofibers, such as inorganic and organometallic compounds.
There is a significant jump with regard to production method and means from laboratory results to the production of industrial quantities of nanofiber in acceptable conditions from the engineering and economic cost point of view.
On an industrial scale, the ways of preparing metal catalytic particles for feeding into the reaction furnace may be classified in two groups: with substrate and without substrate.
In the former case, when the metal particles are added as substrate, fibers are obtained whose application calls for them to be aligned, as is the case of the use of electron emission sources for microelectronic applications.
In the latter case, also known as floating catalyst, the reaction occurs in a certain volume without the metal particle being in contact with any surface, with the advantage that the nanofibers produced do not have to be separated from the substrate afterwards.
It is very highly improbable that the carbon nanofibers will grow directly from the initial carbon source. It is believed that the filaments appear from side products generated from the thermal decomposition of the initial carbon source.
Some authors state that for light hydrocarbons below C16 any of them may be used without the quality of the nanofiber obtained being dependant on the hydrocarbon selected.
Carbon nanofibers are used for making charged polymers giving rise to materials with enhanced qualities, such as resistance to stress, modulus of elasticity, electrical conductivity and thermal conductivity. Other applications are, for instance, their use in tires in partial replacement of carbon black, or in lithium ion batteries, as carbon nanofibers are readily collated with lithium ions.
When considering the nanofiber growth models, it has been considered that deposition due to carbon thermal decomposition is responsible for the thickening of the filaments produced together with the growth process and that this thickening is maintained if pyrolysis conditions continue to exist. Consequently, in an industrial furnace, thickening continues if the nanofiber is kept in the reactor.
The dwell time of the fibers in the reactor is very important as the longer the dwell time, the larger the diameter of the fibers produced. The dwell time depends on multiple variables connected with the reaction, including the temperature of the furnace, the sizes of the tubes, the pressure gradient, and others. It is advisable to keep the whole system below atmospheric pressure to prevent leaks; however, for their operation the control system and the mass controllers need to work above atmospheric pressure.
The manufacture of nanofibers of this type in industrial processes has been addressed by means of techniques such as that described in the U.S. Pat. No. 5,165,909 incorporated herein by reference, in which use is made of a vertical reactor operating at around 1100° C.
The fiber obtained in this furnace has a diameter between 3.5 and 70 nanometres and a length between 5 and 100 times the diameter.
Regarding the inner structure of the fiber obtained by this procedure, the fiber is made up of concentric layers of ordered atoms and a central area that is either hollow or contains disordered atoms.
The reaction furnace used in this patent is supplied at the top mainly with CO used as the gas with carbon content, a catalyst compound with iron content, and all this in the presence of hydrogen as the diluent gas.
A ceramic filter is situated after the reaction furnace for separating the residual gas and the fiber obtained.
This patent uses a gas residual gas treatment line with a feedback line that comprises a compressor and a small bleed valve, a chemical potassium hydroxide filter to remove the carbon dioxide, and a supply input for enriching the residual gas with carbon monoxide.
The resultant flow divides into two branches: three quarters go to a heat exchanger and from there to the bottom of the furnace to prime the ceramic filter, and the remaining quarter goes to reaction furnace input.
In contrast, the invention can relate to a system for the recirculation of residual gas to the supply, which enables the residual gas from the process to be recirculated and monitors both the feed gases and the pressures required at the reaction furnace input and output.
The special configuration of the system based on the installation of a feedback line leads to a considerable reduction in contamination due to re-use of residual gas.
The result is a lowering of the cost of production through use of less raw material due to the re-use of process output gas.

Gas re-using system for carbon fiber manufacturing processes


Transition support rings for joining tubular segments of different inner cross-sectional dimensions to make segmented liners for use in a fluidized bed reactor (FBR) for making polysilicon-coated granulate material are disclosed. Segmented liners comprising the transition support rings and fluidized bed reactors including segmented liners are also disclosed.

Pyrolytic decomposition of silicon-bearing gas in fluidized beds is an attractive process for producing polysilicon-coated granular material, such as polysilicon or polysilicon-coated germanium, due to excellent mass and heat transfer, increased surface for deposition, and continuous production. An issue in many fluidized bed reactors is the formation of large bubbles within the bed in the main reaction zone under certain conditions.
An unwanted effect of large bubbles, particularly in gas-solid systems, is that they can cause the bed to bounce violently up and down as they lift a significant fraction of the bed, then drop it suddenly. This pressure oscillation can interfere with proper operation of the bed by causing the gas velocity rate to vary, which may be harmful to optimum productivity. The pressure oscillation also causes mechanical stress to the reactor structure and any directly connected support equipment. Furthermore, large bubbles can cause the bed material to surge upward in the reactor in a phenomenon known as "slugging." Slugging can cause ejection of at least a portion of the bed from the reactor or damage internal reactor components.
Slugging is a significant problem when bubbles reach a diameter close to the inner cross-sectional dimension of the reaction chamber. Varying the diameter of fluidized bed reactor's reaction chamber such that a narrower section is included in the reaction zone tends to reduce the amount of slugging in the fluidized bed. The varying inner cross-sectional dimensions affect the velocity of upward gas flow in the reaction chamber. A first velocity at the point of gas introduction produces bubbles having a first average size, while a second, different velocity higher up in the reaction chamber favors bubbles having a second average size. The inner cross-sectional dimension of the reaction chamber can be varied over its length to prevent or minimize the occurrence of bubbles having a size sufficient to disrupt fluidization, which may result in slugging that ejects at least a portion of the bed from the reactor and/or damages internal reactor components. A liner of varying inner cross-sectional dimension can be formed by joining liner segments of differing inner cross-sectional dimensions and inserted into the FBR reaction chamber to reduce slugging. However, a need exists for a component suitable for joining the liner segments to produce the liner.

Segmented liner and transition support ring for use in a fluidized bed reactor


The present disclosure is directed to surface-modified particles and to methods of making and using the same. The surface-modified particles comprise a particle core and a coating associated with the particle core, wherein the particle core comprises an active agent, the coating comprises a surfactant having formula I, and the surface-modified particle has an average size from about 1 nm to about 2,000 nm:

Field of the Disclosure
The disclosure relates generally to compositions comprising coated particles and to methods of making and using such compositions for targeted drug delivery.
Brief Description of Related Technology
Nanoparticles (including nanospheres) and microparticles (including microspheres) referred to herein collectively as "particles," are solid or semi-solid particles having a diameter from about 1 nm to about 10,000 nm (10 microns), preferably from about 1 nm to about 2,000 nm (2 microns). Such particles can be formed from a variety of materials, including proteins, synthetic polymers, polysaccharides, nucleic acids, small molecules, and combinations thereof, and have been used in many different applications, primarily separations, diagnostics, and drug delivery.
Compositions comprising such particles have been found to be useful for drug delivery. For example, U.S. Patent Publication No. 2006/0073199 discloses that particles comprising an active agent can be formulated as aqueous suspensions, and stabilized against aggregation and particle growth by providing surfactant coatings on or about the particles.
There is an on-going need for development of compositions comprising particles and methods for making and using same, particularly in delivering drugs of interest.

Compositions and methods for drug delivery


A Protection Primary state is newly defined. When the traffic route is switched by a ring interworking function, while APS is in operation, a protection primary node is caused to restore the service path.

1. Field of the Invention
This invention relates to a ring interconnection network system formed by connecting a plurality of ring networks with a self-healing function to each other, node equipment and network management equipment and a path setting method used in the system. This type of network architecture is known as Ring Interconnection or Ring Interworking, which has been described in, for example, ITU-T (Telecommunication Standardization Sector of ITU) Recommendation G. 842 distributed by the ITU (International Telecommunication Union).
2. Description of the Related Art
A traffic self-healing method that is completed in a ring network has been described in ITU-T Recommendation G. 841. In this recommendation, this type of self-healing method is referred to as APS (Automatic Protection Switching).
In Annex A to the recommendation, measures to avoid failures known as Transoceanic Applications have been described. By the Transoceanic Applications, the communication path can be detoured to the shortest route that avoids the fault segment. This makes it possible to shorten the transmission distance of the path, which enables switching with less impact to be realized in a system with a long distance between nodes (or a large delay in transmission).
On the other hand, in ITU-T Recommendation G. 842, a method of interconnecting a plurality of ring networks has been described. In this recommendation, a method of restoring the traffic in a ring interconnection network system has been explained.
Recommendation G. 842, however, has explained only a failure avoiding method using a so-called non-Transoceanic method that avoids a failure. Therefore, Recommendation G. 842 has not disclosed a failure avoiding method using the above-described Transoceanic method.
This prevents operators who offer node equipment from becoming multi-vendors, which means that it is difficult to meet the needs of today's carrier operators. Furthermore, when the APS function according to Recommendation G. 841 Annex A and the interworking function according to Recommendation G. 842 operate independently, the communication can be disconnected or the traffic can be misconnected. Therefore, any measure to deal with this problem must be taken as soon as possible.
Furthermore, when the interworking function according to Recommendation G. 842 is realized, the following problem is encountered. In a network system, there is provided network management equipment to provide monitoring control of the system. In a conventional system taking no account of interconnection, the network management equipment can be regarded as each of the ring networks being an independent one. In this case, the network management equipment has only to manage the paths existing only in each ring network.
However, a system with an interconnection function has such paths as are set over a plurality of ring networks. Therefore, the network management equipment must manage such paths as well.
In such a situation, to grasp the path configuration, the operator has no choice but to combine manually the results of path management performed on a ring network basis in the conventional system. This takes a lot of time and labor for the operator to do it.
Furthermore, the path restoration process in such a ring interconnection network system is complex. This makes it more difficult for the operator to grasp the state of each path. For this reason, there is a need to improve the human-machine interface of the network management equipment and increase the convenience of the system operation.
As described above, a failure avoiding method using the Transoceanic method has not been provided in the ring interconnection network system. As a result, if switching by the Transoceanic method is effected in this type of system, there is a possibility that the line will be disconnected or the traffic will be misconnected.
Furthermore, since managing the paths requires a lot of time and labor in the conventional network management equipment, there is a need to decrease the required time and labor and improve the convenience of the system operation.

Ring interconnection network system, node equipment, network management equipment, and path setting method


A multilayer ceramic capacitor may include: an active part including a plurality of first and second internal electrodes; upper and lower cover layers; and first and second external electrodes including head parts and band parts. When a thickness of the upper or lower cover layer is defined as C, a width of a margin portion of the ceramic body in a width direction is defined as M, a cross-sectional area of the ceramic body in a width-thickness direction is defined as Ac, a cross-sectional area of the active part in a width-thickness direction in a portion thereof in which the first and second internal electrodes are overlapped with each other in a thickness direction is defined as Aa, and a width of the band part of the first or second external electrode is defined as B, 1.826≦C/M≦4.686, 0.2142≦Aa/Ac≦0.4911, and 0.5050≦C/B≦0.9094 may be satisfied.

The present disclosure relates to a multilayer ceramic capacitor and a board having the same mounted thereon.
A multilayer ceramic capacitor, one of multilayer chip electronic components, is a chip-shaped condenser mounted on printed circuit boards of various electronic products such as display devices, for example, liquid crystal displays (LCDs), plasma display panels (PDPs) and the like, as well as computers, smartphones, mobile phones, and the like, to charge and discharge electricity therein.
Since such a multilayer ceramic capacitor (MLCC) has advantages such as a small size, high capacitance, ease of mounting, or the like, such a multilayer ceramic capacitor may be used as a component in various electronic devices.
The multilayer ceramic capacitor may have a structure in which a plurality of dielectric layers and internal electrodes having different polarities are alternately stacked while being interposed between the dielectric layers.
Since the dielectric layer has piezoelectric and electrostrictive properties, a piezoelectric phenomenon occurs between the internal electrodes when a direct current (DC) or alternating current (AC) voltage is applied to the multilayer ceramic capacitor, such that vibrations may be generated.
These vibrations may be transferred to a board on which the multilayer ceramic capacitor is mounted through external electrodes of the multilayer ceramic capacitor, such that the entirety of the board is a sound radiating surface to generate a vibration sound, noise.
The vibration sound may be within an audio frequency range of 20 to 20,000 Hz, which may cause listener discomfort and is referred to as an acoustic noise.
Recently, a degree of the acoustic noise has become an important factor determining quality of the multilayer ceramic capacitor.
In accordance with an increase in capacitance of the multilayer ceramic capacitor, a mechanical deformation amount of dielectrics may be inevitably increased. Therefore, various methods for solving this problem have been attempted.
Among these methods, a method of controlling an acoustic noise by controlling an amount of solder used to bond the board and the multilayer ceramic capacitor to each other has been disclosed.
However, in this method, bonding strength between the board and the multilayer ceramic capacitor is decreased by an amount in which the solder is decreased, and it is difficult to expect a large decrease in the acoustic noise even in a case in which an amount of the solder is decreased.
As another method, a method of changing an internal structure of the multilayer ceramic capacitor is present.
However, in the method of changing an internal structure of the multilayer ceramic capacitor, generally, a size or a form itself of a product is mainly changed, such that an appropriate method of mounting the multilayer ceramic capacitor needs to be separately introduced.
As another method, a method of controlling a direction in which the multilayer ceramic capacitor is mounted is present.
However, in the method of controlling a direction in which the multilayer ceramic capacitor is mounted, it is necessary to separately align the direction in which the multilayer ceramic capacitor is mounted, such that a separate preprocess may be required.
Meanwhile, in the multilayer ceramic capacitor, external electrodes are formed on the sintered ceramic body and then a process for sintering the external electrodes is performed.
Here, stress may occur during the sintering process, and radiating cracks may occur due to the stress.

Multilayer ceramic capacitor and board having the same mounted thereon


An orthopedic device and method for correcting angular deformation of a bone structure having a growth plate. The device includes first and second hinge members connected together at a hinge joint. The device is adapted for mounting the orthopedic device to the bone structure with the pivot joint positioned over the growth plate. Alignment of the pivot joint with the growth plate promotes asymmetric growth of the growth plate to thereby correct the angular deformation.

This invention relates to correcting angular bone deformities, and more particularly to an orthopedic device and method for correcting angular deformities of the lower extremities, such as genu varus and genu valgus conditions.
Angular bone deformities of the lower extremities are typically characterized by abnormal angulations of the lower leg in relation to the thigh. For example, genu varum is characterized by an abnormal outward bowing of the leg resulting in bowlegs, while genu valgum is characterized by an inward bowing of the leg and is commonly referred to as knock-knees. Under normal conditions, the femur and tibia meet at a tibial-femoral angle of approximately 5-12 degrees of valgus. A greater angle results in a genu valgus condition while a lesser angle results in a genu varum condition. Either of these conditions in one or both legs may result in improper load distribution on the knee joint, causing swelling, knee pain, loss of stability, subluxation, increased joint arthritis, and other conditions that restrict one's lifestyle.
Angular bone deformities in young children can be caused by the following conditions, which are by no means exhaustive: Blount disease, Cerebral Palsy, Larsen's Syndrome, dysplastic disorders, rickets, chronic inflammatory arthritis, neuromuscular causes of hypotonia and fractures.
Various procedures have been developed for treating genu varum and genu valgum in young patients, such as children and adolescents that have not reached full growth. One such procedure is known as cuneiform or wedge osteotomy in which a wedge-shaped section of bone is surgically removed to allow realignment of the bone. The wedge cut made by the surgeon should not completely sever the tibia so that a bridge of residual bone is intact to effectually serve as a hinge for reduction of the wedge-shaped gap that remains following removal of the bone wedge. The depth of the wedge is critical in that if the wedge is too shallow, thus rendering the bridge too wide, the resulting wide fulcrum results in over stressing of the medial cortex during wedge compression, causing fracture of the bone bridge. If the wedge is too deep (the residual bone bridge is too narrow) the residual bone bridge, if not completely severed, may lack sufficient strength to provide medial stability to the reduced osteotomy. Reduction of the wedge-shaped gap allows realignment of the bone, and correction of the loading patterns of the leg. Bone plates are then installed to secure the reshaped bone, at least through the healing process. Although this technique has proven widely successful for adults that have no other recourse or for severe deformities that cannot be corrected by any other means, it is preferable to use less invasive procedures for children and adolescents that have not reached their full stature.
One less invasive procedure for treating the valgus and varus conditions of children or adolescents still in the growth stage includes damaging or destroying one half of the physis or growth plate of the distal femur or proximal tibia by scraping or cutting, with the premise that the undamaged portion will continue to grow in an asymmetric manner to affect the angulation of the lower extremity. However, this technique involves destruction of one half of the growth plate and therefore not a viable option for all patients.
Another less invasive procedure is known as hemiepiphyseal stapling. The principal steps of this procedure are as shown in FIGS. 1A-1C. For a genu valgus condition, a staple 10 is driven into the lateral side 15 of the distal femur 12 about the distal femur physis or growth plate 18. For a genu varus condition, the staple 10 would alternatively be driven into the medial side 22 of the distal femur 12 about the growth plate 18. Other locations for stapling may include the lateral or medial sides of the proximal tibia 24. The staple 10 has two prongs 14, 16 that straddle the distal femur growth plate 18 and a cross member 20 that extends between the prongs 14, 16. Typically, the prongs are oriented perpendicular to the cross member 20. Depending on the age and amount of angular deformity, more than one staple may be used. Ideally, the staple 10 with its prongs 14, 16 promote asymmetric growth on the medial side of the growth plate 18, while inhibiting growth on the lateral side of the growth plate 18 as shown by growth lines 26 and growth distance 28 in FIG. 1B, to thereby reduce the initial tibial-femoral angle a1 (FIG. 1A) to a more acceptable angle a2 (FIG. 1B)
Although hemiepiphyseal stapling is, in some instances, advantageous over other techniques, it suffers from numerous drawbacks. For optimal bone angle correction, growth of the physis should be inhibited on one and unrestricted on the opposite side. However, since the staple 10 must have prongs 14, 16 of sufficient length to ensure firm anchorage into the distal femur, more of the physis may be restricted from growth than desired, leading to less bone angle correction. By way of example, if the prongs extend approximately ⅓ distance into the bone, than approximately ⅓ of the physis will be restricted from growth due to prong resistance. If the stapling procedure is performed toward the end of the growth cycle (13-15 years of age for girls and 16-17 years of age for boys) and does not produce the desired results, then more invasive procedures, such as wedge osteotomy as described above, may have to be performed.
In addition, the staple itself must be inserted with extreme caution, and always in conjunction with radiography to ensure that the ends of the prongs are sufficiently spaced from the growth plate to prevent its damage. Moreover, the dense fibrous tissue (known as the perichrondial ring of LaCroix) that surrounds, anchors and supports the physis during the growth phase may become permanently damaged by the cross member 20 if the staple 10 is inserted too far into the bone.
It would therefore be desirous to provide an orthopedic implant and method for correcting angular bone deformity which minimizes or eliminates the deficiencies of the prior art devices and techniques. It would be further desirous to provide the orthopedic implant and method which promotes asymmetric growth of the growth plate without damaging fibrous tissue by means of a pivotal motion of one part of the device relative to another.

Orthopedic method for correcting angular bone deformity


An integrated circuit device and method. A substrate having contacts has a plurality of capacitors thereon. A plurality of fusible links selectively connect the plurality of capacitors to one another and selected ones of the capacitors to the contacts. In this manner, for example, the capacitance value can be adjusted to tune an antenna mounted on the substrate during testing of the integrated circuit device.

With certain integrated circuit devices, such as radio frequency (RF) devices, impedance matching to an antenna is required to achieve the desired performance. For instance, a tuning process is required for RF identification devices (RFID) to achieve the desired operating distance. However, due to typical underlying manufacturing processes of semiconductor wafers, a certain variation and consequently a deviation in the RF-output impedance of the device is encountered. To match the antenna impedance, discrete passive components are required. During test processes for such RF devices, different results can be obtained depending on the variance of those discrete components. A further optimization to match the antenna impedance, such as would be required for RFID devices, does not take place during the component manufacturing processes.
With known processes, such RF components typically are not tuned until they are mounted on a printed circuit board (PCB) as part of a larger system. Tuning processes at a system or board level is difficult and expensive. For instance, in systems on PCBs a tunable capacitor (for example, cermet trimmer) is mounted on the PCB for this purpose. Alternatively, when manufacturing devices such as RF-IDs, the wafer manufacturing process is kept in a narrow process window to keep the variations as low as possible. Unfortunately, this also adds complexity and cost to manufacturing processes.
For these and other reasons, there is a need for the present invention.

Integrated circuit device including tunable substrate capacitors


The present invention relates to methods for space-time coding and decoding in a wireless communication system with multiple antennas including: generating an orthogonal matrix according to signals to be transmitted; generating a coefficient matrix corresponding to the orthogonal matrix according to channel status information received; and generating a transmission matrix according to the orthogonal matrix and the coefficient matrix; performing a weight-combination for received signals according to channel status information in a receiver; and obtaining estimations of transmitted signals corresponding to the received signals by performing detection for the received signals. The present invention also provides apparatuses for space-time coding and decoding. By applying the present invention, the bit error rate of a system is reduced and bit error performance of the system is improved. And the transmission rate of the system is increased remarkably when there are more than one complex signals to be transmitted.

1. Field of the Technology
The present invention relates to wireless communication technologies, and more particularly, to methods and apparatuses for space-time coding and decoding.
2. Background of the Technology
Along with the development of wireless communication technologies, a wireless communication system is expected to support higher communication quality and a higher data rate. In the wireless communication system, time and frequency resources are limited, so that a Multiple Input Multiple Output (MIMO) system is developed. And extensive attention is paid to the MIMO system which provides remarkable improvement in channel capacity.
Diversity techniques are generally adopted in MIMO systems for achieving better signal transmission quality. However, since size of a mobile terminal is limited and there is not enough space for multiple antennas to ensure independence of communication channels, receiver diversity can not be implemented in downlink channels. Base stations are capable of processing multiple transmission antennas, so that space-time coding technologies are usually adopted for implementing transmission diversity in the wireless communication system with multiple antennas.
At present, a Space-Time Block Code (STBC) has become a main technology adopted for implementing transmission diversity, because the STBC has relatively low complexity to implement.
However, bit error rates (BERs) of systems remain high when conventional STBC algorithms are adopted. Therefore, receiver performance of the systems is poor and development of the wireless communication systems with multiple antennas is limited.
Further, when signals to be transmitted in a system are at least two complex numbers, the transmission rate of the system is relatively low.
Taking the STBC for two antennas as an example, a transmission matrix is:
      (                                        x            1                                                x            2                                                            -                          x              2              *                                                            x            1            *                                )
Here, x1 and x2 respectively indicate two signals to be transmitted in a base station, and * indicates a conjugate operation.
FIG. 1 shows a structure of an STBC algorithm. Detailed descriptions of the algorithm are shown as follows.
In Time Period 1, x1 is transmitted to Mobile Terminal via Antenna 1 and x2 is transmitted to Mobile Terminal via Antenna 2 in Base Station, and signals received by the Mobile Terminal are:r1=h1x1+h2x2+n1
In Time Period 2, −x*2 is transmitted to Mobile Terminal via Antenna 1 and x*1 is transmitted to Mobile Terminal via Antenna 2 in Base Station, and signals received by Mobile Terminal are:r2=−h1x*2+h2x*1+n2
Here, h1 indicates a parameter of a flat fading channel from Antenna 1 to Mobile Terminal and h2 indicates a parameter of a flat fading channel from Antenna 2 to Mobile Terminal, i.e. channel status information, rm and nm respectively indicate the signals and Additive White Gaussian Noise (AWGN) received by Mobile Terminal in Time Period m (m=1,2).
The receiver computes signals to be tested, i.e. {circumflex over (x)}1 and {circumflex over (x)}2, as follows:{circumflex over (x)}1=h*1r1+h2r*2 {circumflex over (x)}2=h*2r1−h1r*2
Finally, Mobile Terminal may respectively perform detection for the original signals sent by Base Station, i.e., x1 and x2, according to the maximum likelihood rule.
The STBC algorithm is further explained with reference to a system with four antennas. A transmission matrix is:
      [                                        x            1                                                x            2                                                x            3                                                x            4                                                            -                          x              2                                                            x            1                                                -                          x              4                                                            x            3                                                            -                          x              3                                                            x            4                                                x            1                                                -                          x              2                                                                        -                          x              4                                                            -                          x              3                                                            x            2                                                x            1                                                            x            1            *                                                x            2            *                                                x            3            *                                                x            4            *                                                            -                          x              2              *                                                            x            1            *                                                -                          x              4              *                                                            x            3            *                                                            -                          x              3              *                                                            x            4            *                                                x            1            *                                                -                          x              2              *                                                                        -                          x              4              *                                                            -                          x              3              *                                                            x            2            *                                                x            1            *                                ]    ,
Here, x1, x2, x3 and x4 respectively indicate four signal stobe transmitted in a base station, and * indicates a conjugate operation.
Signals received by a mobile terminal in 8 consecutive time periods are as follows:r1=h1x1+h2x2+h3x3+h4x4+n1 r2=−h1x2+h2x1−h3x4+h4x3+n2 r3=−h1x3+h2x4+h3x1−h4x2+n3 r4=−h1x4−h2x+h3x2+h4x+n4 r5=h1x*1+h2x*2+h3x*3+h4x*4+n5 r6=−h1x*2+h2x*1−h3x*4+h4x*3+n6 r7=−h1x*3+h2x*4+h3x*1−h4x*2+n7 r8=−h1x*4−h2x*3+h3x*2+h4x*1+n8
Here, hm indicates a parameter of a flat fading channel from a antenna m (m=1, 2, 3, 4) in a base station to the mobile terminal, and rm and nm respectively indicate the signals and Additive White Gaussian Noise received by the mobile terminal in the time period m(m=1, 2, 3, 4, 5, 6, 7, 8).
The system with four antennas computes the four signals to be tested, i.e. {circumflex over (x)}1, {circumflex over (x)}2, {circumflex over (x)}3, {circumflex over (x)}4, as follows:{circumflex over (x)}1=h*1r1+h*2r2+h*3r3+h*4r4+h1r*5+h2r*6+h3r*7+h4r*8 {circumflex over (x)}2=h*2r1−h*1r2−h*4r3+h*3r4+h2r*5−h1r*6−h4r*7+h3r*8 {circumflex over (x)}3=h*3r1+h*4r2−h*1r3−h*2r4+h3r*5−h4r*6−h1r*7−h2r*8 {circumflex over (x)}4=h*4r1−h*3r2+h*2r3−h*1r4−h4r*5−h3r*6−h2r*7−h1r*8
It can be seen that, when signals to be transmitted are complex numbers and the number of antennas is larger than two in an MIMO system, the transmission rate of the system is half of the transmission rate of a Single Input Single Output (SISO) system, thus the transmission rate of the MIMO system is reduced.
Therefore, when the conventional STBC algorithm is adopted in the system, the bit error rate of the system is high. Further, the transmission rate of the system is low when signals to be transmitted are more than one complex numbers.

Method and apparatus for space-time coding and decoding


A multiphase zero-volt switching, zero volt switch resonant DC-DC regulator includes: a zero-volt switch zero volt switch; a DC output voltage means; a variable resonant circuit; a synchronous rectifier; and a sensing circuit. The sensing circuit senses a DC output voltage at the DC output of the regulator. The regulator uses the resonant circuit in conjunction with the sensing circuit to provide a substantially constant DC output voltage at a fixed frequency. If the sensing circuit senses a change in the DC output voltage, then a resonant frequency of the regulator is changed by the variable resonant circuit. This allows the oscillator of the regulator to maintain a fixed frequency, thus ensuring the availability of zero-volt switching over the full range of operation. The regulator also has the advantages of low power loss, reduced ripple, and a very fast transient response time.

The present invention relates to power sources, and more particularly to DC-DC regulators.
DC-DC regulators are well known in the art. FIG. 1. illustrates a conventional DC-DC regulator. The conventional DC-DC regulator 100 is a variable frequency resonant DC-DC regulator. The regulator 100 comprises a pull-pull driver 102 with a Voltage Controlled Oscillator (VCO) 124, a zero-current switch 104 (ZCS) with switching transistors 126 and 128, a resonant circuit 130 with transformer 106 (TI) and a capacitor 108 (C2), a synchronous rectifier 132, a sensing circuit 134 with resistors 112 and 114 and an error amplifier 116, and an opto-coupler 118 with a diode 120 and a transistor 122.
The DC output voltage is sensed by R1112 and R2114 and fed to the error amplifier 116. The error amplifier 116 compared the DC output voltage against VREF. The output of the error amplifier 116 drives a current proportional to the error voltage through the opto-coupler diode 120 of the opto-coupler 118, which then develops a voltage across the transistor 122 of the opto-coupler 118. This variable voltage so developed is applied to the VCO 124 which changes the frequency of the push-pull driver 102.
To maintain a constant DC output voltage, the conventional DC-DC regulator 100 changes the frequency of the push-pull driver 102 to maintain zero current switching (ZCS) operation. However, this prevents the push-pull transistors of the ZCS from operating in ZCS mode over the full range of operations. This may result in the loss of zero-current switching, high dissipation in the regulator, and unpredictable behavior due the wide range of frequencies.
Accordingly, there exists a need for an improved DC-DC regulator. The improved DC-DC regulator should maintain a substantially constant DC output voltage without changing the frequency of the oscillator. The present invention addresses such a need.
A multiphase zero-volt switching (ZVS) resonant DC-DC regulator includes: a zero-volt switch (ZVS); a DC output voltage means; a variable resonant circuit; a synchronous rectifier; and a sensing circuit. The sensing circuit senses a DC output voltage at the DC output of the regulator. The regulator uses the resonant circuit in conjunction with the sensing circuit to provide a substantially constant DC output voltage at a fixed frequency. If the sensing circuit senses a change in the DC output voltage, then a resonant frequency of the regulator is changed by the variable resonant circuit. This allows the oscillator of the regulator to maintain a fixed frequency, thus ensuring the availability of zero-volt switching over the full range of operation. The regulator also has the advantages of low power loss, reduced ripple, and a very fast transient response time.

Multiphase zero-volt-switching resonant DC-DC regulator

International Business Machines Corporation


A device for reading data from or writing data to magnetic storage media, the device comprising a head having a plurality of read/write elements for reading data from or writing data to magnetic storage media in respective tracks, and a plurality of servo elements for reading servo code from the media in respective bands different from the data tracks, the read/write elements and servo elements being arranged such that a plurality of the tracks operated on by the read/write elements are disposed between two servo bands operated on by two of the servo elements.

With increased computerization, more and more sensitive and valuable information is being generated and stored. The need for storage capacity is increasing. Higher capacity backup tapes are demanded.
One method for storing information on magnetic tape uses what is a known as "helical scan" technology. Helical scan tape systems cause information to be recorded in stripes that are diagonal relative to the length of a tape. The helical scan systems use a rotating drum head operating on a slowly driven tape, for high capacity. The tape is wrapped around the rotating drum.
Another method for storing information on magnetic tape uses what is known as "linear recording" technology. Linear recording tape systems cause information to be recorded in multiple parallel tracks that extend in the direction of the length of the tape. Linear recording systems use a stationary head operating on tape that is driven past the head at a speed that is typically much faster than the speed used by helical scan tape systems. With linear recording systems, multiple read/write elements can be employed in a head and can simultaneously operate on the tape.
Continuing advances in magnetic storage technology provide for constantly increasing data storage densities. The more tracks that can be fit across the width of a tape, the more information that can be stored on a tape. Thus, there is a push to increase the number of tracks across the width of a tape and to reduce the width of each track. Increasing the number of tracks or reducing the width of a track makes accurate positioning of read/write elements, and issues of tape wander more important. Therefore, servo systems are desirable in linear drive systems.
Servo systems employ information or patterns recorded along a track of the tape to accurately position read/write elements relative to data on the tape. The servo information can be used to accurately position heads relative to the length of the tape (e.g., when searching for a desired position along the length of the tape, such as the start of a file) as well as relative to the width of the tape.
Thus, servo patterns on a tape have a characteristic that changes across the width of the tape. Dual frequency servo schemes are known, in which a pattern is written with one frequency on one side of the servo track, and at a different frequency at the other side of the track. Thus, as a servo element passes over the servo track, lateral position can be determined.
Various servo systems are known in the art. For example, U.S. Pat. No. 5,432,652 (incorporated herein by reference) relates to a magnetic tape that has three evenly spaced-apart longitudinally-extending servo track areas. Four equal-sized longitudinally-extending data track areas are disposed between the servo track areas and between longitudinal edges of the tape and one of said longitudinally-extending data track areas. For track following, all servo track areas are simultaneously sensed for producing one head positioning signal.
U.S. Pat. No. 5,008,765 (incorporated herein by reference) relates to a method for reading or writing data on a tape which has a plurality of data tracks and at least a first dedicated servo track. A multiple channel head is used to access the tracks on the tape. The head is moved proximate one of a plurality of predetermined positions. The channels are located so that, in any one predetermined position of the head, one channel accesses the center of a dedicated servo track on the tape and at least two other channels will access the center of distinct data tracks.
U.S. Pat. No. 5,262,908 (incorporated herein by reference) relates to a tracking control device for a magnetic recording/reproducing apparatus arranged in such a manner that a head unit having a plurality of magnetic heads is successively moved in the widthwise direction of a magnetic tape for switching racking positions so that data recording/reproducing is, by each of the plurality of magnetic heads, performed along a plurality of data tracks formed on the magnetic tape in parallel to a direction in which the magnetic tape moves.
U.S. Pat. No. 5,574,602 (incorporated herein by reference) relates to a magnetic tape drive. A magnetic head simultaneously senses plural track lateral position indicators to generate a like plurality of independently generated sensed position error signals. The sensed position error signals are combined to provide an output position error signal that drives a positioning system to position the magnetic head laterally of the length of the magnetic tape. The output position error signal represents an average of the position errors indicated by the sensed position error signals. The quality of the sensed position error signal is monitored, eliminating poor quality signals from the output position error signal for maintaining a quality servo control.
U.S. Pat. No. 5,450,257 (incorporated herein by reference) relates to a head-track orienting system for use in magnetic recording tape drives which automatically corrects for misalignment between the head assembly and a recorded servo track on the tape. Using a servo control loop, the system calculates head-track alignment error during operation of the tape drive and either pivots the head assembly or adjusts the tape cartridge to compensate for the error. Transverse head-track positioning mechanisms are also included in the system to locate and maintain a centered position of the heads on the servo track.
It is desirable for a servo system to be able to tolerate defects in the magnetic layer of the media. For example, some tape drive systems can tolerate long scratches in a data track. So called "infinite" scratches do not cause stream failures in a data channel generated by the data track. The data tracks are recovered using error control code techniques known in the art. It is desirable to have servo systems that can tolerates defects in the servo track as capably as the defects in the data track are tolerated. It is therefore desirable to have servo systems that can tolerate long scratches in a servo track and scratches or other defects extending in the direction of the width of the tape.

Device for reading data from or writing data to magnetic storage media and a method of positioning a tape head relative to the magnetic storage media


A master hologram is generated in a first optical medium by use of a plurality m of different reference beams, each beam bearing information suitably recorded in one or more of a plurality n layers of the second optical medium that are distinct from layers in which information in all other beams is suitably recorded. The generated master hologram is then used to optically holographically stamp, or record, multi-layer bit-oriented optical media by writing all n layers of the volume of the blank optical medium with m recording beams produced by simultaneously illuminating the master hologram with all m different reference beams, each illuminating reference beam being at a different reference angle and from a coherent light source which is incoherent with respect to every other illuminating reference beam. By this generating and this using a high degree of incoherency is obtained, making that during subsequent readout of a selected, focused, layer of the recorded optical medium signals from all other layers will become as background noise having nearly uniform intensity. The method requires a highly non-linear optical medium: a new dye-doped photopolymer is preferred.

1. Field of the Invention
The present invention generally concerns optical data storage, coherence and statistical optics, volume holographic gratings, and holographic optical elements.
The present invention particularly concerns a volume holographic element, and the use of same for the simultaneous optical stamping of data into multiple layers of a three- dimensional bit-oriented optical medium that exhibits a suitable sensitivity threshold.
2. Description of the Prior Art
2.1 Stamping of Optical Disks
Owing to the relative economy of the medium, and the ease of reproduction, optical discs are currently (circa 2000) the preferred method for distribution of large quantities of information. Computer software, music, and video are among the most popular forms of data encoded on digital optical discs.
Unfortunately, theoretical limits in terms of the capacity of the planar, single-recorded-layer, optical disc are quickly being reached. Despite the small gains that may be made from alternative laser sources and improved coding techniques, it is becoming more and more apparent that a new storage technology will be necessary as the successor to the reflective optical disc.
There are several new optical technologies currently being investigated including multi-layer reflective media, volume holography, two-photon storage, near-field recording, and others. Although many of these technologies have shown promise as being re-writable and having very high data densities, none of these technologies have retained the one main advantage of the standard optical disc which is its ease of production.
For example, some 4.7 GB of information on a Digital Versatile Disc, or DVD, is presently (circa 2000) mechanically stamped onto each disc, permitting a fabrication line to produce discs at a rate of 1 every 12 seconds. No other advanced optical storage system currently under investigation today has exhibited a mass replication process as simple and practical as that for optical discs.
2.2 Recent Developments in Volume Optical Materials
Meanwhile, recent advances in non-linear optical materials have stimulated interest in the development of three-dimensional memory technologies. In particular, demonstrations have been made using polymeric materials that exhibit a non-linear optical response for multi-layer (volumetric) data storage. See J. H. Strickler and W. W. Webb,xe2x80x9cThree-dimensional optical data storage in refractive media by two-photon point excitation,xe2x80x9d Opt. Lett. 16, 1780-1782 (1991); S. Kawata and A. Toriumi,xe2x80x9cThree-dimensional Optical Memory Using Photopolymer, Photorefractive Crystals, and Photochromic Materials,xe2x80x9d Proc. SPIE 3109, 174-180 (1997); and M. M. Wang and S. C. Esener,xe2x80x9cThree-dimensional optical memory in fluorescent dye-doped photopolymer,xe2x80x9d submitted to Applied Optics (Dec. 12, 1998).
Demonstrations have been also been made of the use of polymeric materials for three-dimensional micro-component fabrication. See S. Maruo, O. Nakamura, and S. Kawata,xe2x80x9cThree-5 dimensional microfabrication with two-photon-absorbed photopolymerization,xe2x80x9d Opt. Lett. 22, 132-134 (1997).
A key factor which will determine whether these new technologies will become practical for the mass production of memory devices that are already recorded at the time of sale will be the speed and economy at which these devices may be fabricated.
Two possible approaches to increasing the fabrication rate are, first, to increase the sensitivity of the materials to allow high speed serial raster recording of the desired data, and, second, to attempt to record data in some degree of parallelism. The present invention is concerned with second possibility, specifically with three-dimensional data stamping, meaning the recording of data in parallel into each of multiple regions, normally planes, of a three-dimensional bit-oriented volume optical medium.
Any ability to emplace voluminous digital data in parallel, and all at the same time, within the three-dimensional volume of a optical memory, normally an optical disk, as a type ofxe2x80x9cdata stampingxe2x80x9d would be very useful in many areas. Data stamping is projected to be useful for data recording in fields including (i) entertainment, such as audio, video, and multimedia information distribution, video games; (ii) computer data storage, such as software distribution, large database, data archiving, 3D video; (iii) information processing, such as image recognition, voice recognition, relational databases; and (iv) optoelectronics, such as fiber optics, free-space optics, optical processing and communication.
Additionally, if the data stamping transpires at sufficiently fine spatial resolution, and if the process is not adversely affected when extensive spatial volumes are written entirely to one binary state or the other, then data stamping can be envisioned as a means of creating three-dimensional objects, complete with cavities and voids if any be present. The object created by three-dimensional data stamping might appear, proper materials being chosen, as if encased in glass or might actually, proper materials being chosen, become separable from a surroundingxe2x80x9cunwrittenxe2x80x9d matrix, and usable as axe2x80x9cformedxe2x80x9d object.
The present invention contemplates a new 3D optical storage technology which has the potential to replace standard optical discs as the next generation of distributable optical media. The invention is manifest in a new technique by which digital data may be optically stamped, in a process calledxe2x80x9cdata stampingxe2x80x9d, simultaneously into (i) bit-oriented (ii) multiple layers within (iii) the 3D volume of a volume optical memory, typically a (thick) disc. The virgin optical memory medium, prior to being data stamped, is typically as a continuum, and without any content or indexing (optical or otherwise) whatsoever. The data stamping xe2x80x9cwritesxe2x80x9d the entire volume of the media simultaneously in one operation, leaving (most typically) multiple layers of data each of which layers is fully organized into addressable voxels.
Multi-layer volume optical memories, particularly in the form of optical discs, have the advantage of being able to significantly increase the data capacity of a single disc without incurring a large increase in access time. The technique of the present invention is directed to recording digital data just as quickly, cheaply and reliably as single-layer planar optical discs are recorded today (circa 2000). Components similar to those used in the technique of the present invention have been in use for many years, and have already been demonstrated to possess all the necessary performance requirements for use in the present invention.
1. A (i) Particular Holographic Element for (ii) Data Stamping (iii) A Volume Optical Memory Made From a Non-linear Optical Medium
The present invention has several parts. In aggregate, the present invention teaches a multi-step process. First, an appropriate special holographicxe2x80x9cdata stampingxe2x80x9d element is generated. Then, second, this generated holographic data stamping element is used and re-used for the simultaneous optical data stamping of multi-layer data into the volume of a three-dimensional optical medium. Importantly, this optical medium must, and does, exhibit a suitable non-linear responsexe2x80x94manifested as a sharp radiation sensitivity thresholdxe2x80x94so as to permit the recording of large numbers of data bits in parallel.
Each of the processes of (i) generating the special holographic data stamping element (and the holographic element so generated), (ii) performing the optical data stamping by use of the generated holographic element, and (iii) using an appropriately non-linear three-dimensional optical medium, constitute separate parts of the present invention.
1.1 Generating a Holographic Data Stamping Element
The (i) generating of the holographic data stamping element, and the holographic data stamping element so generated, are special both for (a) how the element is generated, and (b) what the element contains. If the holographic element is to xe2x80x9cstamp dataxe2x80x9d in each of multiple planes, then a practitioner of the holographic arts might recognize that, by way of example, a recordable holographic material, such as the photopolymers of the DuPont Corporation specifically preferred for this task, could be and should be placed in the optical path of a 4-f imaging system, in location either before or after the image plane. The data mask of a single layer would then be recorded in the hologram. The position of the image plane would then be shifted axially and the next data mask recorded.
This rudimentary prior process is insufficient, and possessed of a serious flaw. Since the light that is imaging all of the planes (in turn) is coherent, coherent interference between the data planes will cause a large amount of noise in the reconstruction. To solve this problem the present invention employs several angularly-multiplexed reference beams instead of just one.
Moreover, these reference beams should be, and, in accordance with the present invention, preferably are, mutually incoherent so as to avoid coherent artifact noise.
The holographic data stamping element ultimately generated contains multiple images of planes of data, each image plane having been generated by (i) multiple (ii) incoherent (iii) angularly-separated reference beams. (Note that one reference beam does not generate one image plane; multiple reference beams generate each image plane.)
1.2 Using the Holographic Data Stamping Element
In accordance with the present invention the generated holographic data stamping element is used to record the same data with which it has been impressed into a volume optical medium, forming thereby a volume optical memory. The recording is done redundantly, with a number of different reference beams. It is done all at the same time in axe2x80x9cdata stampingxe2x80x9d operation. The optical data content of each layer to be recorded in the medium of the optical memory will necessarily be imaged in focus at only one plane (in depth) within the memory. However, the optical power intended for each layer will by necessity propagate through all layers in the media. The light from all other layers propagating through any given layer will be manifest as noise at that layer.
Now, by reference to the preceding section 1.1, it will be understood that a higher degree of incoherency in the readout of the holographic data stamping element is achieved by reconstructing the hologram with all of a number of illuminating reference beams simultaneously, each reference beam being (i) at a different reference angle, and being derived from (ii) a separate coherent light source which is incoherent with respect to the light source of every other reference beam. As the number of mutually incoherent reference beams is increased the magnitude of the coherent noise will go down until the only evidence of neighboring data layers at any given layer will be a background optical noise of nearly uniform intensity.
However, this uniform intensity background noisexe2x80x94which is an achievement of the present inventionxe2x80x94is also a drawback. This is because this noisexe2x80x94which is consequence not only of the data stamping method of the present invention but any method optically writing more than one layer at one timexe2x80x94significantly reduces the contrast ratio observed at any given layer.
Certain optical media that exhibit highly non-linear recording characteristics are, however, able to remove this background from the signal during the recording process. In particular, the dye- doped photopolymer media that is the subject of the related patent application, and that is preferred for use in the method of the present invention, exhibits a sharp step-like threshold in its recording intensity curve. See that related application, incorporated herein by reference. See also M. M. Wang and S. C. Esener,xe2x80x9cThree-dimensional optical memory in fluorescent dye-doped photopolymer,xe2x80x9d submitted to Applied Optics (Dec. 2, 1998), op cit.
Intensities below the threshold of the dye-doped photopolymer do not stimulate recording. However, intensities just beyond this threshold exhibit a high recording rate. By setting the signal intensity of the data layer above the recording threshold of the media and the background intensity below the threshold, the desired data may be recorded with a high contrast ratio.
2. Generating a Master Hologram Suitable for Data Stamping
Accordingly, in one of its aspects the present invention is embodied in a method of generating in a first optical medium a master hologram containing information suitably imaged simultaneously into multiple bit-oriented layers within a volume of a second optical medium. The master hologram is thus suitable for holographic stamping of multi-layer bit-oriented optical medium.
The preferred method consists of redundantly generating the master hologram in the first optical medium by use of a plurality m of separate reference beams, each beam bearing information suitably recorded in one or more of a plurality n layers of the second optical medium that are distinct from layers in which information in all other beams is suitably recorded.
The redundantly generating is preferably by use of a plurality m of different reference beams. The m different reference beams may differ in angular separation and/or by being incoherent.
The present invention is also embodied in an optical hologram produced by this method.
3. Holographically Stamping a Multi-layer Bit-oriented Optical Medium
In another of its aspects the present invention is embodied in a method of holographically stamping a multi-layer bit-oriented optical medium.
The method consists of recording information within a plurality n layers of the volume of the blank optical medium with m separate recording beams. The recording beams are produced by simultaneously illuminating a master hologram with m reference beams simultaneously. The recorded optical medium exhibits highly non-linear recording characteristics sufficient so that a recording beam holographically focused to a target layer possesses intensity sufficient to write the layer while the cumulative intensities at all layers arising from the collective beams not focused to the target layer remain insufficient to write the target layer.
By this procedure, performed on this optical medium, the entire optical medium may be optically written, or stamped, in its multi-layer three dimensional volume entirely at one time.
The recording is preferably by use of a plurality m of separate reference beams that are different by being (i) mutually incoherent and/or (ii) angularly separated, and preferably both.
The first optical medium exhibiting highly non-linear recording characteristics is preferably unresponsive to beam intensities below a threshold, these beam intensities being insufficient to write the medium, while beam intensities just beyond this threshold are sufficient to write the medium. This makes that when a recording beam holographically focused to a layer will possess intensity sufficient to write the layer while the cumulative intensities at all layers arising from the collective beams not holographically focused to that layer will remain insufficient to write the layer.
The recording is more preferably within a dye-doped photopolymer medium exhibiting the highly non-linear recording characteristics.
4. Holographic Data Stamping
The (i) generating of a master hologram suitable for data stamping and (ii) the holographically stamping of a multi-layer bit-oriented optical medium may usefully be combined as an integrated system, and method.
The method may be considered an improvement upon more rudimentary prior methods where a master hologram within a first optical medium containing information to be placed within the volume of a second optical medium is first generated, and then this generated master hologram is used to record the information within multiple layers of the three dimensional volume of a (blank) second optical medium.
In accordance with the present invention, the generating is improved by redundantly generating the master hologram in the first optical medium. The redundant generation transpires by use of a plurality of m separate reference beams, each beam bearing information suitably recorded in one or more of a plurality n layers of the second optical medium.
The using is also improved: generation of the master hologram recording the information within the n layers of the volume of the blank optical medium by is improved by use of m recording beams that are produced by simultaneously illuminating the master hologram with m separate reference beams.
The redundantly generating is more preferably by use of the plurality m separate reference beams that are different by being (i) angularly separated and/or (ii) mutually incoherent. The reference beams are more preferably both (i) angularly separated and/or (ii) mutually incoherent.
Likewise, the using of the generated hologram is more preferably by simultaneously illuminating the master hologram with the m different reference beams that are themselves different by being (i) angularly separated and/or (ii) mutually incoherent, and preferably both (i) angularly separated and (ii) mutually incoherent.
The using is preferably so as to record information within a second optical media exhibiting highly non-linear recording characteristics. Namely, recording beam intensities below a threshold are insufficient to stimulate recording while recording beam intensities just beyond this threshold exhibit a high recording rate. The intensity of the recording beams are set above a recording threshold of the second optical medium where the recording beams are focused on layers while background intensity within the second optical medium remains below this threshold, making that the second optical medium is recorded with a high contrast ratio.
The using of the master hologram is still more preferably to record information within a dye-doped photopolymer medium that exhibits the highly non-linear recording characteristics.
A least two combinations of reference beams are suitable. The m separate reference beams as do redundantly generate the master hologram may be used to record each of the n layers of the volume of the blank second optical medium. Alternatively, each of the n layers of the second optical medium is recorded with the m separate reference beams, resulting in a total of m x n separate reference beams.
5. Optical Holograms for Data Stamping, and Data-Stamped Optical Memories
In still yet another of its aspects the present invention is embodied in a an optical hologram suitable to holographically stamp a multi-layer bit-oriented first optical medium. The optical hologram is characterized in that (i) information within the optical hologram is organized for bit-oriented recording of another multiple layers within the three-dimensional volume of another, second, optical medium, while (ii) the optical hologram has itself been generated by use of a plurality m of separate reference beams, each beam bearing information suitably recorded in one or more of a plurality n layers of the second optical medium that are distinct from layers in which information in all other beams is suitably recorded.
The optical hologram is preferably so generated by use of m separate reference beams that differ in (i) angular separation and/or (ii) by being mutually incoherent. The reference beams preferably differ in both (i) angular separation and (ii) by being mutually incoherent.
The optical hologram may be generated (i) so as to be suitably redundantly illuminated by the same m separate reference beams in order to record each of the n layers of the volume of the blank second optical medium, or, alternatively, (ii) so as to be suitably redundantly illuminated by a different m reference beams in order to record each of the n layers of the volume of the blank second optical medium.
In a similar manner, the present invention is also embodied in a multi-layer bit-oriented information-containing volume optical memory characterized for having been made by a process of data stamping, meaning that all the information that is within the memory was placed into all the multiple layers thereof all at the same time. As a consequence of this data stamping, the volume optical memory is optically readable in layers, each layer by a plurality of reference beams that are typically so many in number as there are layers.
In particular, the multi-layer bit-oriented information-containing volume optical memory is preferably made by use of a plurality m of separate reference beams, each beam bearing information that was recorded in one or more of a plurality n layers of an optical medium of the memory. The m separate reference beams may differ in angular separation and/or by being mutually incoherent.
The memory may be suitably redundantly illuminated by a same m separate reference beams in order to read each of n layers within the volume of the memory or, alternatively, by a different m reference beams in order to record each of the n layers within the volume of the memory.
These and other aspects and attributes of the present invention will become increasingly clear upon reference to the following drawings and accompanying specification.

Three-dimensional holographic stamping of multi-layer bit-oriented non-linear optical media

The Regents of the University of California


The invention is a method of automatically feeding and transporting food products from an in-feed device to a combination weigher, which automatically selects from a number of portions of known weight the optimum combination of portions to create a batch of fixed weight with minimum give-away The method consists mainly of ensuring that the raw material being processed, which typically consists of fresh and unfrozen food products of various kinds that are fragile and have the tendency to stick to the equipment underlay, especially fresh fish, poultry and meat products, fruit and vegetable products and other unfrozen food products of this type, is fed onto at least one or an unlimited number (n) of independent, endless movable conveyors (14a , 14b, . 14n) or (53) and (54-58) which are movable as a whole in both directions along their longitudinal plane independently and transport the product evenly, accurately and securely by means of these conveyors to a combination weigher (16) or (52).

This invention relates to a method for fully automatically feeding and transporting raw material of food products from bulk to a combination weigher, which then automatically selects from a number of portions of known weight the optimum combination required to make batches of fixed weight with minimum give-away.
The main purpose of the invention is to ensure that product is fed equally and accurately from bulk to the combination weigher, where the main feature of the invented method is, more precisely, the transporting of a measured and controlled amount of the food products from an infeed device to a combination weigher. The most important issue when feeding an combination weigher is to be able to control the average weight fed to the weighing hoppers which then weigh the product precisely. It is however not undesirable that there is some variation in the weight in each hopper as long as the average is kept at the desired level. The meaning of feeding the combination weigher precisely and accurately is therefore to be able to control accurately the average amount of product fed to the weighing hoppers.
Various types of infeed and dispersion equipment are known. These have been designed to feed a variety of products to automatic weighing equipment, including combination weighers. Most of this equipment is based on using vibration of some sort, and is designed for firm, non-sticky products, such as frozen food products, which do not tend either to stick together or to the surfaces of the equipment.
There are two main types of combination weighers; those in which the weighing hoppers are arranged circularly around a common axis, and others in which they are placed in a linear arrangement. In the former, the dispersion device is located at the centre of the circular array of weighing units, and the raw material is fed to its central portion dispersed in a radial direction and supplied to the pool hoppers. In the latter type, the dispersion device is located behind the weighing hoppers. Product is fed to the inlet end of the dispersion device and the outlet is next to the weighing hoppers. In both cases, however, the principle is basically the same, with an independent plate in front of each weighing hopper being vibrated when product is required in any given hopper. The main disadvantage of this method is that it is difficult to precisely control how much product goes into the hopper when the plates are vibrated.
Combination weighers do not always have one pool hopper above each weighing hopper. In some versions raw material in the pool hoppers can be weighed in such a way that better control is achieved of the weight of each product portion accumulated in the pool hopper before it is released to the weighing hopper. Other versions can include multiple pool hoppers placed above each of the weighing hoppers in order to ensure more rapid filling of the weighing hoppers. This is especially useful if the dispersion device does not feed product reliably when activated. Yet another variation is to place a pool hopper below the weighing hopper so that the product in the weighing hopper can either be released to the outlet trough or into the pool hopper. This gives the operator a greater variety of possible combinations as the weight of the product in the pool hoppers below the weighing hoppers is known. An increased number of possible combinations generally leads to better performance of the combination weigher in terms of reduced over-weight or increased capacity.
Several patents exist for dispersion devices. One of the first patents for an automatic weighing device with a dispersion device as a critical component is U.S. Pat. No. 4,398,612. Another, newer patent which also describes a dispersion device for dispersing product to a circular array of weighing hoppers is U.S. Pat. No. 4,561,510, and a similar device has also been patented in U.S. Pat. No. 4,600,096. These patents share in common the inclusion of multiple dispersion devices operating on the same pile of products. Each device can be individually controlled, and thus used to selectively feed multiple weighing hoppers or pool hoppers located above weighing hoppers.
Examples of combination weighers of the latter type mentioned above, that is those involving a linear arrangement of pool and weighing hoppers, are described in U.S. Pat. Nos. 4,442,910 and 4,821,820. However, these combination weighers do not provide automatic feeding into each hopper, and are therefore fed manually.
When processing sticky products—e.g. fresh fish, meat, fruit, vegetables or other similar fresh food products, dispersion devices which are based on the use of vibration as a means of transfer are no longer usable.
Several attempts have been made to design dispersion devices for sticky products that cannot be conveyed by vibration. One example is U.S. Pat. No. 4,662,508, where rotating discs in a horizontal plane are used to disperse the product. Another example is U.S. Pat. No. 6,493,605, where flexible tabs and vertical movement of the inlet chute are used to obtain more uniform feeding to the dispersion tables.
Neither of these two methods is sufficiently effective to convey sticky product reliably or accurately enough to the weighing hoppers. Furthermore, the quality of the handling of sensitive product such as fresh fish fillets or pieces is not acceptable.
It should, however, be mentioned that a combination weigher has been produced by Pols ehf, a company based in Iceland, which can be used to create batches of sticky food products, mainly fish, of fixed weight with minimum give-away. But as no automatic dispersion devices are connected to this weigher, it must be fed manually, which reduces its capacity. The need for manual labour to feed this combination weigher also makes it more expensive to operate.
For many years, very little progress has been made in the development of equipment for the packaging of fresh fish products. As a result, packaging remains a highly labour-intensive—and therefore expensive—activity in which give-away is higher than it need be if performed automatically using an accurate combination weigher. Further encouragement for the invention described comes from the fact that fish products are now being increasingly sold fresh from Iceland to markets in Europe, where the call is for smaller batch sizes. Whereas a few years ago these were often 10-15kg, a batch size of 2 kg is now common. As a result, the need for labour is even greater than before, with significant cash being lost due to unnecessarily high give-away.
It is therefore clear that none of the known methods or equipment is suitable for solving the problem of packaging sticky food product. The invention relates to a means of feeding sticky product, such as fresh fish products, quickly, precisely and accurately from bulk to a combination weigher, in such a way that the quantity fed will be well controlled.

Method for automatically feeding a combination weigher


A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

This invention relates to an electrochemical cell used in reducing a metal oxide or a combination of metal oxides to the corresponding metal in which an electric potential is established between an anode and cathode, usually in a molten salt electrolyte. In general, the molten salt electrolyte is selected from one or a combination of the alkali metal halides or the alkaline metal earth halides and the oxide to be reduced is positioned in a container which acts when filled with the metal oxide as a cathode, and the anode is generally some material which is impervious to attack by the products in an anode reaction or by the electrolyte or dissolved materials within the electrolyte.
In general, the reaction is according to the following wherein the base metal is (M) and the oxide to be reduced is (MOx), both contained in a molten salt electrolyte, the electrochemical cell operating according to the overall reaction (1):
                              MO          x                ->                  M          +                                    x              2                                                  O              2                                                          [        1        ]
Although this invention will be explained using an example of spent oxide-based nuclear fuels, which are mostly uranium oxide, the invention is not so limited and pertains to variety of metals such as the actinide and rare earths, except for those metal oxides having sufficiently negative Gibbs free energy of formation such that reduction is not commercially advantageous. Classically this process is accomplished with a two-electrode electrochemical cell having a cathode where the metal oxide is reduced to the metal and a second electrode where oxygen is evolved through the oxidation of oxygen anions, called the anode. The individual electrode reactions are given by [2] for the cathode and [3] for the anode.MOx+2xe−→M+xO−2  [2]20−2→O2+4e−  [3]
Although a number of molten salts, such as CaCl2 can be used for the electrolyte in this process, work has concentrated on lithium chloride. An oxide traditionally has to be present in the electrolyte melt to sustain a significant current density at the oxygen-evolving anode.
Several difficulties with the two-electrode cell have been identified. These include: (1) Cell control for optimum efficiency. It is necessary to maintain the anode potential at the highest possible value to increase cell throughput, but this value must be kept below the potential where excessive chlorine evolution occurs. Likewise, the cathode must be maintained at the lowest practical potential for best throughput, but not so low that metallic lithium is deposited on and in the metal oxide. Maintaining these voltages requires a very stable reference and a good means for constantly adjusting the power supply output. The voltage must be limited to accommodate whichever electrode is slowest at various stages of the reduction process; the current, and hence the rate, is limited correspondingly. (2) Elimination of oxygen-containing compounds from the cell. Any oxygen compounds in the cathode product or the electrolyte that is inevitably carried with the cathode product are deleterious to following operations. These compounds include lithium oxide in the electrolyte and unreduced oxides, such as rare earth oxides, that will be mixed with the cathode product and can not be eliminated without generating excessive chlorine. (3) The demanding performance requirements that this cell places on the anode. The current in a two-electrode cell is highest at the beginning of operation, and decays to a low value at the end. The anode must support the full current of the cell early in the reduction process, and must continue to function without excessive chlorine generation at the end of the process, when it is desirable to reduce the lithium oxide concentration in the electrolyte, preferably to one ppm or less.

This patent is subject to a terminal disclaimer.

Three-electrode metal oxide reduction cell