A semiconductor memory device includes a semiconductor substrate, a plurality of memory blocks, first and second substrate potential generating circuits and a select circuit. The semiconductor substrate includes a plurality of wells corresponding to the memory blocks. Each memory block includes a plurality of memory cells formed on corresponding wells. The select circuit supplies to the well of the activated memory block a deep substrate potential generated by the first substrate potential generating circuit, and supplies to the well of the unselected memory block a shallow substrate potential generated by the second substrate potential generating circuit. Thereby, the minimum operation in the inactive memory block is ensured in spite of the fact that a power consumption of the inactive memory block is reduced.

1. Field of the Invention
The present invention relates to a semiconductor memory device, and in particular to a dynamic random access memory (DRAM) which operates based on internal potentials such as a substrate potential, a cell plate potential, a precharge potential for bit line, a boosted ground potential and a boosted power supply potential.
2. Description of the Background Art
In general, semiconductor memory devices are broadly classified into volatile memories such as an RAM and non-volatile memories such as an ROM. Volatile memories are broadly classified into DRAMs and static random access memories (SRAMs). Non-volatile memories are broadly classified into a mask ROM, an EPROM, a flash memory, an EEPROM and a fuse ROM.
Since the DRAM stores data by accumulating electric charges in a capacitor of a memory cell, it requires a refresh operation. However, memory cells have a simple structure. Therefore, DRAMs having a large-scale memory capacity can be formed with a low cost.
The DRAM is formed on one semiconductor substrate, which is supplied with a negative potential Vbb. A cell plate of a capacitor is supplied with a predetermined cell plate potential Vcp. Cell plate potential Vcp is, for example, half a power supply potential, i.e., Vcc/2 or a ground potential Vss. Bit line pair is precharged to a predetermined precharge potential Vb1 before activation of a sense amplifier. Precharge potential Vb1 is, for example, the power supply potential Vcc or half the power supply potential, i.e., Vcc/2.
The same assignee as the present invention has proposed in U.S. patent application Ser. No. 08/312,968, filed Sep. 30, 1994, a so-called a voltage-boosted sense ground method for the purpose of reducing a power consumption and an access time. According to this voltage-boosted sense ground method, a boosted ground potential Vss' slightly higher than the normal ground potential Vss is supplied to an N-channel side of the sense amplifier.
In the write operation of DRAM, a word line is supplied with a boosted power supply potential Vpp higher than power supply potential Vcc. Boosted power supply potential Vpp must be higher than power supply potential Vcc by at least a threshold voltage of a transfer gate in the memory cell. When the potential of word line is boosted, sufficient electric charges are accumulated in a cell capacitor. The same assignee as the present invention has proposed, in U.S. patent application Ser. No. 08/357,007, filed Dec. 16, 1994, a technique for forming hierarchical lines supplied with such a boosted power supply potential. This technique is disclosed also in "Subthreshold-Current Reduction Circuits for Multi-Gigabit DRAM's", 1993 Symposium on VLSI Circuits Digest of Technical Papers, pp. 45-46.
(1) In connection with substrate potential Vbb
In the DRAM, electric charges accumulated in the cell capacitor leak as described above, so that the cell capacitor must be periodically refreshed. This leak is caused by the flow from the cell capacitor through the transfer gate and the flow from the cell capacitor to a substrate or a neighboring memory cell. The former is called "disturb refresh" and the latter is called "pause refresh".
FIG. 27 is a cross section showing a structure of the memory cell in the DRAM. Referring to FIG. 27, a memory cell 1 is formed on a semiconductor substrate 4. One memory cell 1 is formed of one transfer gate 2 and one cell capacitor 3. Transfer gate 2 is formed of two N-type source/drain regions 5 and a gate electrode forming a word line WL. Cell capacitor 3 is formed of a storage node 6 in contact with one of source/drain regions 5 and a cell plate 7. The other source/drain region 5 is connected to a bit line BL. When the potential of word line WL attains the boosted power supply potential Vpp, transfer gate 2 becomes conductive, and the potential of bit line BL is supplied to storage node 6. Thereby, data is stored in cell capacitor 3.
A problem of the capacitor disturb refresh will be described below. It is assumed that memory cell 1 has initially stored data at H-level. Since the potential of word line WL is at the L (logical low) level of this memory cell 1, transfer gate 2 is non-conductive. In this state, when the potential of word line WL in the neighboring memory cell attains Vpp level, the potential of word line WL of this memory cell 1 slightly rises. This is due to the fact that the mutually neighboring word lines WL are coupled together via a parasitic capacitance 8. Therefore, transfer gate 2 becomes slightly conductive, whereby a subthreshold current Isth flows through a channel region under the word line WL. In accordance with miniaturization of transfer gate 2, its threshold voltage decreases. Therefore, subthreshold current Isth increases in accordance with miniaturization of transfer gate 2. In order to overcome this problem, negative substrate potential Vbb at an allowable minimum level is applied to P-type semiconductor substrate 4 in the DRAM. The reason for this is that as substrate potential Vbb is deepened, the substrate effect increases the threshold voltage, so that subthreshold current Isth decreases.
A problem of the pause refresh will be described below. The electric charges stored in storage node 6 leak as subthreshold current Isth, and also leak to semiconductor substrate 4 via a PN junction of source/drain region 5 formed under storage node 6. Electric charges accumulated-in storage node 6 further leak to a neighboring memory cell through semiconductor substrate 4 under an element isolating film 9 such as LOCOS.
FIG. 28 is a graph showing a relationship between a pause time in refresh and the number of defective memory cell(s). As can be seen from this graph, if the substrate potential Vbb is deep, the defective memory cell appears at an area where the pause time is short. If substrate potential Vbb is shallow, the defective memory cell appear at an area where the pause time is long. Therefore, shallower substrate potential Vbb can increase the pause time. The reason for this is that as the substrate potential Vbb becomes shallow, the voltage applied to a depletion layer around source/drain regions 5 decreases, so that an electric field in the depletion layer decreases. Therefore, generation of minority carriers is suppressed, which reduces the leak current flowing from source/drain regions 5 to semiconductor substrate 4.
As described above, the leak current from the memory cell increases if substrate potential Vbb is excessively shallow or excessively deep. In the conventional DRAM, semiconductor substrate 4 is entirely supplied with substrate potential Vbb which is neither shallow nor deep so as to prevent remarkable problems relating to the disturb refresh and pause refresh. Therefore, it is impossible to prevent substantially the leak current from memory cell 1.
(2) In connection with cell plate potential Vcp and bit line precharge potential Vb1.
As described before, cell plate 7 is supplied with the potential, e.g., of Vcc/2 which is half the power supply potential. During standby, bit line BL is also supplied with the potential, e.g., of Vcc/2 which is half the power supply potential. An intermediate potential generating circuit for generating the intermediate potential Vcc/2 must have such features that its output potential is hardly influenced by variation of process conditions and its output impedance is low. A large amount of current always flows in the intermediate potential generating circuit, because a transistor functioning as a diode and a transistor at the output stage must have large sizes. This results in a problem that the intermediate potential generating circuit consumes a large amount of current.
(3) In connection with boosted ground potential Vss'
Although the voltage-boosted sense ground method described before significantly reduces the power consumption of DRAM, further reduction of the power consumption is required. In the DRAM employing the voltage-boosted sense ground method, it is necessary to reduce the test time for determining whether memory cells are accepted or not.
(4) In connection with boosted power supply potential Vpp
Although hierarchization of boosted power supply lines significantly reduces the power consumption of DRAM as described before, further reduction of power consumption is necessary. It is also necessary to check the leak current from the hierarchical segment boosted power supply lines.

Semiconductor memory device responsive to hierarchical internal potentials


The present invention provides an entry sheet for drilling which provides higher hole position accuracy than that of a conventional entry sheet for drilling. The present invention provides an entry sheet for drilling, including a metal foil, and a layer including a resin composition and formed on at least one surface of the metal foil, wherein the resin composition includes a resin and tungsten disulfide as a solid lubricant, and the content of the tungsten disulfide included in the resin composition is 10 parts by mass to 200 parts by mass based on 100 parts by mass of the resin included in the resin composition.

In a generally adopted method of drilling processing of a laminate or a multilayer board for use as a printed wiring board material, one laminate or multilayer board or a plurality of laminates or multilayer boards stacked are provided, and on the uppermost surface thereof, a sheet as an entry board is stacked which is a metal foil of aluminum or the like alone or includes such a metal foil and a resin composition layer formed thereon (hereinafter, such a sheet is usually referred to as "entry sheet for drilling", or also simply referred to as "entry sheet"), followed by performing hole boring processing. A "copper-clad laminate" is generally used as the laminate in many cases, but a "laminate" with no copper foil on the outer layer thereof may also be used.
In recent years, progress of high density, enhancement in productivity and cost reduction, as well as enhancement in reliability has been demanded of a laminate or a multilayer board as a printed wiring board material, and there has also been demanded hole boring processing of high quality such as enhancement in hole position accuracy. In response to such demands, for example, Patent Document 1 has proposed a method of hole boring processing, in which a sheet including a water-soluble resin such as polyethylene glycol is used. In addition, Patent Document 2 has proposed a lubricant sheet for hole boring, in which a water-soluble resin layer is formed on a metal foil. Furthermore, Patent Document 3 has proposed an entry sheet for hole boring, in which a water-soluble resin layer is formed on an aluminum foil with a thermosetting resin thin film formed thereon.
Moreover, an entry sheet for hole boring in which a solid lubricant is used has also been proposed. For example, Patent Document 4 has proposed an auxiliary plate material for hole boring, in which the auxiliary plate material includes a lubricant layer, a composite material including a nanostructured powder (of tungsten disulfide or the like) and a solid, wear-resistant lubricant layer that is a highly thermal conductive compound, and a supporting agent. Patent Document 5 has proposed an entry sheet for hole boring which has a water-soluble resin layer containing zinc molybdate and molybdenum trioxide.

This patent is subject to a terminal disclaimer.


A reduced weight implantable prosthesis, including, an outer surface shell for encapsulating the prosthesis, a gel mixture comprising a mixture of a cohesive gel and micro-spheres for filling the shell, one or more inner volumes internal to the shell which do not contain the gel mixture; and wherein the gel mixture contains less than 60% by volume of micro-spheres mixed into the cohesive gel.

In the last century reconstructive and cosmetic surgery has become a common practice. Specifically cosmetic breast surgery has been developed to allow reconstruction of a woman's breast that was affected by procedures such as mastectomy. Cosmetic breast surgery has also become available to amend the appearance of a woman's breast, for example by adding an implant to increase the size of the breast, to correct asymmetries, change shape and fix deformities.
Generally the implant is required to be able to provide a specific form and maintain the form for many years, preferably for the lifetime of the woman in which the implant is installed to prevent the need for additional invasive surgery. The implant is also required to have a specific feel preferably imitating the feel of a real breast. The implant also needs to be bio-durable such that it is not ruined by interaction with the human body and it needs to be bio-compatible so that the woman's health is not detrimentally affected by the implant even under extreme circumstances, for example the implant is required to be non toxic in case of leakage from the implant.
The standard implants used today comprise an outer shell typically formed from vulcanized silicone or polyurethane, and an inner content typically formed from a silicone gel or saline. The specific weight of the commonly used filling materials is generally between 0.95 to 1.15 (grams per centimeter cube). An average implant may weigh between 50 to 1000 grams, or even more. The weight of the implant is an addition, which is not negligible for a person.
Over time breast implants are known to cause many problems, mostly related to the weight of the implant, for example: ptosis (i.e. sagging and deformity), breast tissue atrophy, prominence of the implant through breast tissue, back pain, and striae of the skin.
Traditionally, the silicone gels used had silicone oils with short polymers in them that leached out through the shell over time. Current implants involve the use of a shell with barrier layers to achieve very low permeability, and using a cohesive gel as the filling material. The cohesiveness ensures that the filling material does not leak out into the body, even in case of rupture of the shell.
An additional characteristic to be considered in selection of the filling material is the resilience, elasticity and pliability of the implant, which provides it with a specific feeling when being sensed. Generally it is desirable to provide an implant which provides a specific shape and mimics the feel of real human tissue at the position of the implant. It is important that the implant maintain its form and feel for extended periods, to prevent the need for additional surgery.
US patent application publication no. 2004/0153151 to Gonzales dated Aug. 5, 2004 of which the disclosure is incorporated herein by reference describes a breast prosthesis from silicone that is formed as a trabecular body or micro-cell body in order to obtain a prosthesis of lower density.
U.S. Pat. No. 4,380,569 to Shaw dated Apr. 19, 1983 of which the disclosure is incorporated herein by reference, describes a reduced weight breast prosthesis which is worn external to the human body or implanted into the human body. The breast prosthesis is comprised from a mixture of a silicone gel with glass micro-spheres.
U.S. Pat. No. 5,902,335 to Snyder, Jr. dated May 11, 1999 of which the disclosure is incorporated herein by reference, describes a reduced weight breast prosthesis which is worn external to the human body, based on the U.S. Pat. No. 4,380,569 to Shaw. Snyder states that the use of glass micro-spheres as described by Shaw results in a stiff product that does not mimic the human breast as well as silicone gel alone. Snyder describes a breast prosthesis having two sections. A first outer section filled with silicone gel that mimics the human breast and a second inner section of reduced weight to reduce the weight of the prosthesis.
U.S. Pat. No. 5,658,330,to Carlisle et al. dated Aug. 19, 1997 of which the disclosure is incorporated herein by reference, describes a molded silicone foam implant and method for making it.

Lightweight implantable prosthetic device


A process for relocking a driverless, robotized vehicle (1) on a theoretical trajectory (T.sub.th2) in which during the passage of the vehicle through a joining section (S.sub.1), the curvature of the trajectory of the vehicle (1) is progressively modified as a function of the instantaneous curvature and the heading or course (.theta.). Thus, there are no orientation discontinuities along the trajectory, which imposes no impossible operating conditions on the drive members of the vehicle, but still makes it possible to converge rapidly with the theoretical trajectory.

Several processes are already known aiming at bringing a vehicle onto a reference or nominal trajectory, or in other words to bring about coincidence between a trajectory actually followed by the vehicle and a theoretical trajectory.
In general terms, the theoretical trajectory is modeled by a succession of rectilinear or curved segments with a constant or non-constant radius of curvature, which join at position finding or localization points identified by beacons. French Patent 89 08049 describes a certain number of means which can serve as beacons and in particular radiophonic wave transmitters, reflecting posts or magnets buried in the ground. No matter what the localization method adopted, absolute position fixings for the vehicle, also referred to as localizations and which make it possible to deduce the variation between the real vehicle position and the localization point, are effected by appropriate sensors of the vehicle when the latter passes close to these localization points.
Once a deviation has been determined, a known relocking process consists of calculating a joining section to the theoretical trajectory leading to one of the following localization points thereof. For this purpose the coordinates of a certain number of intermediate points between which the joining section is broken down are calculated. If it is wished to avoid excessively sudden variations of the course of the vehicle and bring about a relatively rapid convergence to the theoretical trajectory, the number of intermediate points and therefore the calculation volume must be considerably increased, which may make it necessary to temporarily stop the vehicle.
Once the localization has been made and the variation with the localization point calculated, another process consists of making a vehicle follow a connection section to said localization point and not one of the following points. In certain cases, this method involves transverse displacements of the vehicle, which are sometimes impossible or only achievable with great difficulty.

Process for relocking on a theoretical trajectory for a vehicle, whilst modifying the curvature of the real trajectory


Pallets for storage or movement of goods are provided having bamboo members. Split bamboo forms cross-members and successive layers as part of the two major surfaces of pallets. Bamboo culms are used for beams of a pallet or as components in a post-type structure. Frames of split bamboo may be fastened and removed from beams or posts of bamboo to allow more compact movement of pallets not in use. Elongated posts of bamboo culms may be used to join individual pallets for multi-deck pallets.

Pallets have long been used in transport and storage of goods. They are constructed from a variety of materials, but primarily from wood lumber. The lumber is often made from hardwood. A common wood pallet is made of two sizes of lumber. The thick size commonly has a cross-section of 31/2 inches.times.11/2 inches. Three pieces with this cross-section run in a first direction to form beams. Across these beams on the top and bottom are thinner pieces of wood nailed or otherwise fastened at right angles to the beams to form the top and bottom surfaces of the pallet. Thin pieces typically have a cross-section of 1/2 inch thick by 2 to 6 inches wide. It has been estimated that over 50% of the cost of pallets made of wood lumber consists of the cost of the lumber, assuming the pallet is shipped less than 200 miles from its construction site.
Other materials such as plastic and corrugated paper have also been proposed for making pallets. Recent U.S. Pat. No. 5,417,167, for example, discloses a pallet made from hollow plastic stringers and plastic deck boards. Another recent patent, U.S. Pat. No. 5,425,314, proposes a disposable pallet made of paperboard or like material. The cost of the materials is a significant disadvantage of pallets made from plastic and paperboard.
The construction of a pallet containing bamboo board has been suggested. The pallet is made of long wooden beams and multilayered bamboo fibre fabric, flame retardant and thermosetting adhesive (Abstract in World Patent Index of China Pat. No. 1079707).
Bamboo is widely grown in tropical areas of the world. It exists in a number of varieties. The structure of bamboo is strikingly different from that of trees and many other plants. The trunk of the bamboo plant is called the "culm." Nodes exist at various distances along the culm. The culm is hollow inside except where nodes exist. Some varieties of bamboo, such as Dendrocalamus Strictus, Guadua, Jimba, or Cana Bravo, produce particularly thick-walled culms. The culms of bamboo have a hard outer skin which provides a surface particularly resistive to physical damage.
The physical properties of bamboo are somewhat unique also. Bamboo is stronger than most wood which is used to make pallets. Bamboo is also more flexible and elastic. When flexed, it bends slightly and will not break as easily as wood. When flexed or deformed for a short period of time, it will return to its original configuration. Bend strength of a variety of bamboo has been reported in "Bending Strength of Guadua Bamboo," Int'l. Network for Bamboo and Rattan, Working Paper No. 3, 1994. As expected, the strength of bamboo is highly dependent on wall-thickness, for either round members or split specimens. Strength may also vary depending on position along the culm.
Bamboo is easily treated with chemicals, such as preservatives or fire retardants, if desired. Some methods, such as the Boucherie/Sap Displacement method, can be used which make it easier to treat bamboo than wood, because all the fibers in bamboo run in the same direction.
Once established, bamboo replenishes itself very fast. Therefore, bamboo culms can be cut every two to three years. Hardwoods may take twenty or more years to grow and when cut must be started again from small trees. Bamboo can be planted along permanent roads. Therefore, it can be transported easily to a factory. A very large volume of bamboo timber can be produced on small acreage, and bamboo responds economically to fertilizer and irrigation.
While a variety of materials have been suggested and utilized for constructing pallets, the inherent growth and strength properties of round and split bamboo culms have not been realized as components of pallets. Pallets and construction methods for such pallets comprising bamboo are needed.


A slat box for holding two or more slat stock rolls during the fabrication of metal window blinds. The slat box comprises a housing defining a plurality of equally sized adjacent compartments therein. Each of the stock rolls is interfaced to a respective compartment via the receipt of axle members inserted through the stock rolls into corresponding pairs of inserts attached to the side walls and partition members defining the compartments within the housing. The slat box further includes a rod member insertable through the inserts and axle members for preventing the stock rolls from being lifted out their respective compartments. Additionally, brake members are provided which are disposed between the stock rolls and inserts for preventing "free-wheeling" of the stock rolls from occurring.

As is well known, metal window blinds more commonly known as mini-blinds and/or venetian blinds generally comprise a plurality of elongate, horizontally oriented slats which are fabricated from aluminum stock. The aluminum slat stock material is typically provided in the form of relatively large diameter aluminum slat stock rolls. During the manufacturing process, one or more rolls of the slat stock material are disposed adjacent a crowning unit which is utilized to crown the slat stock as well as out the same to a desired length. Typically, the slat stock is fed directly from the stock roll into the crowning unit wherein the diameter of the roll continuously decreases as more material is payed out from the stock roll and fed into the crowning unit.
In the prior art, it is known to place one or more rolls of slat stock material on feeding fixtures which generally comprise a base member having two or more roller members attached thereto wherein the roller members are separated in a manner adapted to support the roll of slat stock material thereon. As the material is fed into the crowning unit, the entire roll rotates upon the roller members. Though these types of feeding devices are generally suitable for feeding slat stock material into a crowning unit, these devices possess certain deficiencies which detract from their overall utility.
Particularly, such devices do not include an axle or similar structure which extends through the center of the slat stock roll or rolls disposed thereon. Rather, as previously specified, the stock rolls merely rest upon the roller members and therefore are retained on the roller members only by their weight. In this respect, as the weight of the roll decreases as more material is payed out and fed into the crowning unit, often times an abrupt pulling of additional material into the crowing unit will cause the roll to lift off the support rollers. Additionally, in such prior art feeding devices no braking force is applied to the roll while material is being payed out therefrom. This lack of an applied braking force often causes "free-wheeling" to occur wherein additional slat material is fed out from the roll though no additional material is being introduced into the crowning unit. Finally, these prior art feeding devices provide no protection or barriers between multiple rolls which may be stored thereon and thus do not protect the edges of the slat material from damage. The present invention overcomes these and other deficiencies associated with prior art slat stock material feeding devices.


A roof drilling and bolting device comprising a mobile chassis and two cabs mounted to the front of the chassis for independent transverse (outward to the side) movement. The cabs have floors and protective canopies. Extensible hydraulic devices position the cabs outwardly of the chassis. Other extensible hydraulic devices raise and lower the cabs relative to the chassis. Mounted to the front of each cab is a drilling assembly including a rectilinear positioning device for drill pods which provides up-down and side-to-side movement of the drill pod in front of the cab. An extensible standard is positioned by a boom which extends forward of the chassis to provide a temporary roof support.

Roof drilling and bolting is a well known process for maintaining the integrity of mine roofs; in other words for preventing the collapse of the roof. Special machines have been developed for assisting in the roof drilling and bolting process (hereafter the "roof bolting" process). See, for example, U.S. Pat. Nos. 3,252,525; 3,375,880; 3,768,574; 3,842,610; 3,951,215; 4,050,259; and 4,079,792. In a typical roof bolting process, a bore is drilled upwardly into the roof a distance depending upon the nature of the overburden. Thereafter, a self-anchoring bolt is turned up into the bore to compress the roof (ceiling) adjacent the bore and the bolt. In some practices, the bolt is secured in the bore with epoxy cement. The applicants' roof bolting device differs from those disclosed in the prior art in having a unique configuration which enables two driller operators to always remain under protective canopies while tramming into position and drilling or bolting. Further, the unique configuration will encourage the operators to use the machine exactly as intended. Prior machines, while in theory designed for safety, often fail to make it more convenient and comfortable for the operators to remain under a protective canopy at all times.
In a mine passageway of typical width, say 15 to 20 feet, it is desirable to place roof bolts transversely spaced across the passage to within about 2 to 4 feet of the side walls. Most efficient roof bolting will take place with a minimum of chassis positioning and repositioning. Applicants provide a roof bolting device that enables two operators to work opposite sides of a mined passageway from cabs transversely positionable independently of one another. Hence, the chassis which is, say 9 feet wide, may be moved down the center of the passageway and, without further repositioning roof bolts can be placed out to 6.5 feet from the center line of the chassis (also the center line of the passageway) on both sides.
It is an advantage of the device set forth herein that two canopy covered cabs are independently movable transversely of the center line of the chassis. Each cab has its own controls for cab positioning relative to the chassis and each cab has its own controls for positioning the associated drill pod relative to the cab. Each cab can be simultaneously extended to its outer transverse position. When the cabs are retracted to their innermost position no transverse beams or the like extend transversely outwardly of the chassis. There is no need for a plurality of stabilizing jacks to support the cabs relative to the floor during operation as the cabs may be rested upon the floor in any position and the tower for raising the drill pod is designed to automatically drop to engage the floor before the drill steel engages the mine roof.
It is a requirement of the mine safety laws that in most instances temporary roof supports must be positioned in front of a roof drilling and bolting device before the actual drilling and bolting process commences. Until recently, it has been necessary for miners to enter under the unbolted roof to place temporary roof support jacks. Some recent roof bolting devices propose extending the canopy generally positioned over the operator to engage the roof. This, of course, necessitates the repositioning of the roof support each time the operator's position is changed.
It is an advantage of the device set forth herein that a temporary roof support is carried by the chassis on a boom extending forwardly of the chassis and once the temporary roof support is positioned, it does not require repositioning during the repositioning of operator cabs transversely of the chassis.


A wireless power transmitting device includes: a rectifier configured to rectify alternating current (AC) power; a capacitor configured to store the rectified AC power as direct current (DC) power; a voltage divider configured to divide a voltage of the DC power; and a wireless power transmitter configured to wirelessly transmit power using the voltage divided by the voltage divider.

1. Field
The following description relates to a wireless power transmitting device.
2. Description of Related Art
Currently, wireless power transfer technology has been widely used in the chargers of various electronic devices such as communications devices as well as in smartphones and wearable devices in accordance with current trends.
As the wireless power transfer technology, a magnetic induction method and a magnetic resonance method have both been developed. A magnetic induction method according to the wireless power consortium (WPC) standard, for example, generally operates with certain characteristics, such as voltage or frequency (e.g. within a frequency of about 110 kHz to about 205 kHz), and a magnetic resonance method according to the alliance for wireless power (A4WP) standard, for example, operates with certain other characteristics, such as voltage or frequency (e.g. within a frequency of about 6.78 MHz).
When the magnetic induction method is used, it may be disadvantageous, in that long range wireless charging may be difficult, and when the magnetic resonance method is used, a problem may arise in that there may be limitations on receiving wireless power due to a complex circuit or one fixed resonance frequency.


This invention relates to a heating/cooling system operating on the basis of a novel SPLIT BUFFER TANK; representing an efficiency improvement alternative to HVAC systems functioning with existing commercial buffer tanks. Currently, commercial buffers have the heat source provider (HSP)-return and system-return discharging to a common buffer/vessel. Novel SPLIT BUFFER is provided with a SEPARATION DISK placed inside the tank as mechanical way of separating the hot water inflow from the HSP from the warmer water inflow from system return. The disk moves up and down along the tank driven by demanded water supply and return. Pump-1 circulates hot water from the hot section of the buffer to the secondary system claiming for heat. Pump-2 circulates warmer water from the warmer section of the buffer through the HSP where it is reheated, and subsequently stored in the hot section of the buffer to reinitiate this cycle again.

To better illustrate the nature of the invention, take for instance the case of a condensing boiler as a heat source provider (HSP). It is common to find all variety of brands and models operating at steady-state-efficiency levels from 70-80% for non-condensing to 82-98% for condensing. Steady-state Efficiency—refers to a measuring parameter for boiler maximum efficiency capability assessed under a controlled steady test and carried out by recognizable standard certification bureau. In the test, parameters such as air-intake temperature and volume, air/gas mixture, water/brine temperature/flow entering/leavening the boiler, system heat demand, and some others, are all fixed during boiler firing to obtain a better judgment of its efficiency at artificial steady state conditions. Test Standards for Gas-Fired Boilers. CGA P.2-1991 (R1999)/ENERGY START Canada, and the U.S. Department of Energy's/Title 10/Code of Federal Regulations for the Energy Conservation Program for Consumer Products, make indications that during the steady state testing of a condensing boiler water outlet temperature shall be at 180° F./82° C. and inlet temperature shall be at 80° F./26.7° C. at all times.
Drifting away from the stationary conditions dictated by the test, it arrives at the real world, a different place. A world loaded with always changing conditions where lab subsets are not so frequently encountered during the operating life span of the boiler. To complicate matters, there appears the need for adding buffer capacity in order to eliminate problems associated with excessive cycling, poor temperature control, and erratic system operation. The HVAC industry learned a long time ago that it was by adding a buffer tank to the boiler-system that they resolved all these problems. However, one issue remains unsolved. That is, the loss of the boiler high efficiency during continuous operation due to the water mixing inside the tank. But with no solution on hand, they were forced to look the other way.
In today's commercial buffers (See FIG. 2), boiler water-return at temperature tb and secondary system water-return at temperature ts easily get mixed in the buffer because of the lack of mechanical medium capable of isolating the encountering of the two flows inside the tank (See also FIG. 4). This mixed water at temperature equal tmix when going to the boiler produces the same effect on efficiency behavior as the one depicted in FIG. 3. There, and independent study (by Jim Cooke) shows how condensing and non-condensing boilers thermal efficiency gets influenced by water return temperature during steady-state conditions. Cooke's study also shows thermal efficiency behavior for a condensing boiler at three different firing rates (33/67/100%).
FIG. 4 shows some water/brine supply/return hydraulic connections for some brand name buffer tanks and their prevailing flow pattern when all intakes/outlets are in used. Water/brine motion inside the buffer not only gets affected by physical characteristics of the system such as pumps flow, buffer diameter and height, inlet/outlet configuration, among other variables, but also by changing set of dynamic conditions regulated by DCS (Distributed Control System). Flow patterns in the buffer are chaotic and unpredictable with limited opportunities for creating stratification conditions. For this to occur pumped flow coming from HSP/boiler and/or secondary system need to be slowed down to such extent that entering speed must be close to laminar flow. Only such minimal disturbance in the body of water inside the tank will have no major mixing effect in the natural convection phenomenon associated with stratification. From a design stand point this may lead to uneconomical alternatives such as having a much bigger diameter for piping inlet/outlet connections, otherwise designed with acceptable velocity of 2.1±0.9 m/s (7±3 ft/s) for normal liquid service applications, with maximum velocity of 2.1 m/s (7 ft/s) at piping discharge points. Perhaps even requiring a buffer tank with oversize uneconomical dimensions in diameter and/or height. This, without mentioning the time factor to allow the stratification process to evolve and settled in a constant demand HVAC system.
The more realistic assumption is that any flow leaving the buffer will do so at a temperature tmix.
From FIG. 2 and FIG. 4 it may be concluded that:tmix=(tb+ts)/2                tb Water/brine temperature at boiler outlet. Considered equal to t1 (See FIG. 1) when no heat losses occur in pipe connection between boiler and buffer        ts Water/brine temperature at system return. Considered equal to t2 (See FIG. 1) when no heat losses occur in pipe connection between system and buffer        tmix Water/brine temperature from the mixture of warm and hot water if there is no separation disk (as it happens in existing commercial buffers). Water temperature going to the boiler        t1 Water temperature from hot section of the buffer to the secondary system        t2 Water temperature from Secondary System to warm section of the buffer        t1-t2 Delta temperature. Q=W×Cp×(t2−t1)        Q Secondary system heat demand. Q=W×Cp×(t2−t1)
Using data results from chart on FIG. 3 and applying the same analogy to evaluate water return/supply configuration on boiler efficiency for the typical commercial buffer connections on FIG. 4; It may be proven that when water gets mixed in the buffer and returned to the boiler at mixed temperature tmix, it will produce the same effect on the thermal efficiency of the boiler. As flow pattern and temperature of the mix evolve over time, the rising temperature of the water/brine will increasingly hamper its ability to quickly regain thermal energy when recirculating through the boiler, resulting in longer less efficient runs with increasingly unnecessary consumption of energy resources (See FIG. 6). This in turn will force chimney gases to escape the boiler without fully rendering their caloric load.
When dealing with condensing boilers it is crucial to realize that continuous 80° F./26.7° C. water-return and below is the determinant factor in achieving continuous outstanding higher efficiencies (See chart on FIG. 3); and that, boilers serving a buffer/system in which mixed water return temperature does not fall below 80° F./26.7° C. will never meet the necessary temperature requirements for achieving such continuous performance. Ignoring this fact, when justifying a boiler selection, will result in having a boiler that cost 50% more than necessary (comparing to condensing boiler) and achieves, from time to time, just above condensing boiler performance.
Currently buffer technology has not corrected the problems created with usual configurations such as the one on FIG. 4 (and the like); and as a result, its usage just exacerbate the sub-utilization of condensing boilers in boiler/buffer/systems that ONLY occasionally allow condensation to occur.

Heating or cooling system featuring a split buffer tank


A media drive includes drive side circuitry that, in response to a request to validate compressed data read from media, validates packets of the compressed data while compressed and, in response to detecting end of data on the media without having detected an unrecoverable corrupt one of the packets and without decompressing the compressed data, generates a message indicating that the compressed data read from the media has been validated.

Media, such as magnetic tape, are frequently used for long-term storage of large quantities of data, such as in data backup or archiving operations. As more and more data are stored on media, users of such media may grow increasingly concerned that the data being stored is "good" (i.e., that the data has been successfully recorded on the media) so that it will be available for recovery and use at a later time. Users may thus periodically perform a verify step after data is stored or written to media.