A memory device comprising a memory array comprising a plurality of memory cells, a plurality of bitlines and a plurality of wordlines for writing to the plurality of memory cells and a sense amplifier coupled to a first bitline of the plurality of bitlines, for reading the contents of a selected memory cell, the sense amplifier comprising a first cascode transistor pair coupled to a second cascode transistor pair, the first cascode transistor pair coupled to the first bitline and a second bitline, and a current comparator coupled to a drain side of the second cascode transistor pair for determining a value of the selected memory cell.

Modern memory devices comprise a memory array with a plurality of memory cells via corresponding column selects, bitlines and wordlines. Various operations can be performed on each individual cell by applying a pulse to the cells via the bitlines, such as a SET pulse, a RESET pulse, or a READ pulse. The READ pulse allows the current value stored in a memory cell to be read. Generally, sense amplifiers are used to perform the READ operation to determine the value of the cell.
For resistive memory, a memory cell can be in a low resistive state (LRS) or a high resistive state (HRS). A sense amplifier is an analog to digital converter that compares a current from the memory cell to a reference current to determine whether a cell is in LRS or HRS. For some memory types, resistive memories in particular, cell current is strongly dependent on the bitline voltage which must be precisely controlled. Conventionally, sense amplifiers are composed of a cascode transistor pair coupled to a reference circuit and coupled to a current mirror, with a comparator to determine whether the current across the current mirror has changed as compared to the reference current. The cascode transistor pair is used to precisely control the voltage of a bitline to sense the memory cell current.
Generally, the cascode transistors which are used in memory devices are thick oxide transistors to support a high voltage power supply (e.g., 5V). However, higher voltages at the bitlines can cause damage to the memory cells in the array and may also increase the time it takes for a bitline to charge. Additionally, thick oxide transistors have poor matching characteristics (e.g., random threshold voltage mismatches) because of their sensitivity to dopant atom fluctuation. Accordingly, it is difficult to use thick oxide transistors as cascode transistors in a sense amplifier.
Therefore, there is a need in the art for a memory device comprising double cascode sense amplifiers.

Memory device comprising double cascode sense amplifiers

Sony Semiconductor Solutions Corporation


In an embodiment, a method of masking transaction data for a secure wireless transaction includes transmitting wireless pseudo transaction data that includes false transaction data and processing received pseudo transaction data and transaction data to extract or separate the transaction data.

The subject matter disclosed herein relates to wireless transaction devices, and, more specifically, to communication traffic used to enable secure transactions between a purchaser and a point-of-sale device.
Merchants often use point-of-sale (POS) systems to complete sales transactions. POS systems may include several independent devices, each performing a different function. For example, a scanner may ring up articles of merchandise and transmit the amount to a cash register to calculate the amount due. The cash register may then transmit the amount due to a credit card reader to receive payment. The credit card reader may use a wireless protocol, such as near field communication or Bluetooth, to communicate with a transacting instrument, such as a credit card that includes a wireless enabled computer chip. The convenience of such wireless transactions enables efficient and rapid purchases, increasing profitability and sales.
However, the use of wireless transaction devices may lead to a breach of security and, in some cases, to compromising financial or personal information of the purchaser. Specifically, an eavesdropping device, utilized by an unauthorized third party, may intercept critical security information, enabling the third party to access credit and/or banking information of the purchaser. These security concerns may prevent or slow adoption and use of wireless POS devices, thereby reducing productivity and sales for retailers that may otherwise be able to use the highly efficient wireless POS systems and technology.

Method and apparatus for secure wireless point of sale transactions


Methods and apparatus are provided for reducing and/or substantially eliminating sensitivity mismatch of acoustic receivers used with acoustic sources to determine acoustic properties of geologic formations as a logging tool traverses the formations. Methods are directed to detecting waveform arrival times at receivers, determining places in a well where arrival times of waves are substantially the same at a plurality of receivers, and estimating effective receiver sensitivities and equalization factors using Stoneley wave amplitudes and windowed deconvolution of Stoneley waves. Methods are further directed to correcting wave amplitudes using estimated effective receiver sensitivities and equalization factors for receivers.

The present invention relates generally to a method and apparatus utilized in hydrocarbon exploration. More specifically, the present invention relates to the utilization of acoustic sources and receivers to determine acoustic properties of geologic formations as a logging tool traverses them, be it a wireline logging tool and/or a logging-while-drilling (LWD) tool. More particularly, the present invention is directed to methods of, and apparatus for, adaptive equalization of receivers to reduce and/or substantially eliminate sensitivity mismatch.
Geologists and geophysicists are interested in the characteristics of the formations encountered by a drill bit as the drill bit is drilling a well for the production of hydrocarbons from the earth. Such information is useful in determining the correctness of the geophysical data used to choose the drilling location and in choosing subsequent drilling locations. In horizontal drilling, such information can be useful in determining the location of the drill bit and the direction that drilling should follow.
Such information can be derived in a number of ways. For example, cuttings from the mud returned from the drill bit location can be analyzed and/or a core can be bored along the entire length of the borehole. Alternatively, the drill bit can be withdrawn from the borehole and a "wireline logging tool" can be lowered into the borehole to take measurements. In still another approach, called "measurement-while-drilling" (MWD) and/or "logging-while-drilling" (LWD), tools make measurements in the borehole while the drill bit is working. There are a wide variety of logging tools, including resistivity tools, density tools, sonic and/or acoustic tools, and imaging tools, and the like.
An acoustic logging tool collects acoustic data regarding underground formations. One of the purposes of such a tool is to measure the "interval transit time" or the amount of time required for acoustic energy to travel a unit distance in a formation. In simple terms, this is accomplished by transmitting acoustic energy into the formation at one location and measuring the time that it takes for the acoustic energy to travel to a second location and/or past several locations. The measurement is complicated by the fact that the tool is roughly in the middle of a borehole of unknown diameter and is surrounded by mud. Furthermore, the formation along the borehole may have been disturbed by the action of the drill bit and may no longer have the same acoustic characteristics as the undisturbed formation.
Acoustic well logging is a well-developed art, and details of acoustic logging tools and techniques are set forth in A. Kurkjian, et al., "Slowness Estimation from Sonic Logging Waveforms," Geoexploration, Vol. 277, pp. 215-256 (1991); C. F. Morris et al., "A New Sonic Array Tool for Full Waveform Logging," SPE-13285, Society of Petroleum Engineers (1984); A. R. Harrison et al., "Acquisition and Analysis of Sonic Waveforms From a Borehole Monopole and Dipole Source," SPE 20557, pp. 267-282 (September 1990); and C. V. Kimball and T. L. Marzetta, "Semblance Processing of Borehole Acoustic Array Data," Geophysics, Vol. 49, pp. 274-281 (March 1984), all of which are hereby incorporated by reference herein.
An acoustic logging tool typically includes an acoustic source (transmitter), and a set of receivers that are spaced several inches or feet apart. An acoustic signal is transmitted by the acoustic source and received at the receivers of the borehole tool that are spaced apart from the acoustic source. Measurements are repeated every few inches as the tool passes along the borehole.
The acoustic signal from the acoustic source travels through the formation adjacent the borehole to the receiver array, and the arrival times, and perhaps other characteristics of the receiver responses, are recorded. Typically, compressional wave (P-wave), shear wave (S-wave), and Stoneley wave arrivals and waveforms are detected by the receivers and are processed. The processing of the data is often performed on the surface, although it may also be performed real-time in the tool itself. Regardless, the information that is recorded is typically used to find formation characteristics such as formation slowness (the inverse of acoustic speed) and anisotropy, from which pore pressure, porosity, and other formation property determinations can be made. With some tools, the acoustic signals may even be used to image the formation.
Acoustic logging tools are used for both wireline logging and logging-while-drilling (LWD) applications. In wireline logging, a probe, or "sonde," housing multiple logging tools is lowered into the borehole after some or all of the well has been drilled. The sonde is attached to a conductive wireline that carries power from the surface to the tools in the sonde, and that carries telemetry information to the surface. The sonde may be transported through the borehole by the wireline, or a separate transport means may be provided. For example, in "pipe-conveyed" logging, the sonde is mounted on a tubing string. The rigidity of the tubing string allows the sonde to be transported through highly deviated and horizontal boreholes.
The problem with obtaining downhole measurements via wireline is that the drilling assembly must be removed or "tripped" from the drilled borehole before the desired borehole information can be obtained. This can be both time-consuming and extremely costly, especially in situations where a substantial portion of the well has been drilled. In this situation, thousands of feet of tubing may need to be removed and stacked on the platform (if offshore). Typically, drilling rigs are rented by the day at a substantial cost. Consequently, the cost of drilling a well is directly proportional to the time required to complete the drilling process. Removing thousands of feet of tubing to insert a wireline logging tool can be an expensive proposition.
As a result, there is a strong incentive to minimize the number of wireline logging trips. One way to do this involves collection of data during the drilling process. Designs for measuring conditions downhole including the movement and location of the drilling assembly contemporaneously with the drilling of the well have come to be known as "measurement-while-drilling" techniques, or MWD. Similar techniques, concentrating more on the measurement of formation parameters, commonly have been referred to as "logging-while-drilling" techniques, or LWD. While distinctions between MWD and LWD may exist, the terms MWD and LWD often are used interchangeably. For the purposes of this disclosure, the term logging-while-drilling (LWD) will be used with the understanding that this term encompasses both the collection of formation parameters and the collection of information relating to the movement and position of the drilling assembly.
Logging-while-drilling (LWD) tools are generally located as close to the drill bit as possible, so as to minimize the delay between reaching a formation and measuring the properties of the formation. When implemented as logging-while-drilling (LWD) tools, acoustic logging tools must overcome a number of obstacles to perform successfully. These obstacles include drilling noise, and acoustic properties of the thick tool body. Accordingly, acoustic logging tools in both wireline and logging-while-drilling (LWD) applications have challenges to overcome.
Furthermore, another well-known problem in acoustic well logging, especially for the acquisition of higher order modes, is that receiver matching is important in producing correct results. However, proper and complete receiver matching is very hard to achieve in downhole conditions.

Adaptive equalization of downhole acoustic receivers


A semiconductor chip package structure is described. The semiconductor chip package structure comprises a first chip, which is operated through a first power connection, having a central region and a marginal region. The first chip comprises a plurality of first and second power bonding pads disposed in a marginal region on the top of the first chip. A first power ring and a second power ring are disposed on the first chip, wherein the first and second power rings are respectively electrically connected to the first and second power bonding pads. A second chip, which is operated through a second power connection, is mounted on the central region of the first chip, wherein the second chip comprises a plurality of power bonding pads thereon. A plurality of second bonding wires are electrically connected to the power bonding pads and the second power bonding pads, respectively.

1. Field of the Invention
The present invention relates to a semiconductor chip package structure, and more particularly, relates to a multi-chip package structure with multiple power connections.
2. Description of the Related Art
Due to the demand for small, lightweight and powerful electronic products, demand for multi-chip package (MCP) semiconductor chip package structures, to achieve requirements of multi-function and high performance, have increased. A conventional multi-chip package structure (MCP) integrates different types of semiconductor chips with different operating power requirements, for example, logic chips, analog chips, controller chips or memory chips, in a single chip package structure. Generally, for power requirements of the conventional multi-chip package structures (MCP), multi-power chips and corresponding input/output electrical connections of the package structures, for example, bonding pads or bonding wires, are used to provide different operating powers.
A power net of the conventional multi-chip package structure has a more complex layout because different operating powers are needed for the conventional multi-chip package structure. Therefore, a segment power net has been used, wherein the segment power net is disposed in the conventional multi-chip package structure, electrically connecting to the corresponding bonding pads. Next, the corresponding bonding pads of the conventional multi-chip package structure, is electrically connected to defined pins through a ball grid array (BGA) substrate. For the conventional multi-chip package structure, however, bonding pad positions, which respectively connect to the different operating powers, are fixed because positions of the corresponding segment power net is fixed. Thus, negatively increasing layout area of the bonding pads of the conventional multi-chip package structure. Additionally, using the BGA substrate for the conventional multi-chip package structure results in relatively higher fabrication costs.
Therefore, a novel semiconductor chip package structure with high integrated density and low fabrication costs is desirable.


An internal combustion engine control device and an internal combustion engine control system are disclosed as applied to an internal combustion engine having external EGR regulating device for regulating an external EGR amount in which a part of exhaust gases is recirculated from an exhaust gas passage to an air-intake passage, an internal EGR regulating device for regulating an internal EGR amount in which a part of combusted gases remains in a cylinder. External and internal EGR ratio control means controls operations of the external EGR regulating device and the internal EGR regulating device to variably control a ratio between the external EGR amount and the internal EGR amount depending on a surrounding atmospheric pressure.

1. Technical Field of the Invention
The present invention relates to engine control devices and engine control systems and, more particularly, to an internal combustion engine control device and an internal combustion engine control system applied to an internal combustion engine having recirculation means for recirculating a part of exhaust gases from an exhaust gas passage to an air-intake passage.
2. Description of the Related Art
In the related art, there has been known an EGR system arranged to recirculate a part of exhaust gases from an exhaust gas passage to an air-intake passage for thereby achieving a reduction in a NOx component of exhaust gases as disclosed in Japanese Patent Application Publication No. H09-53519.
With the EGR system of such a structure, under a circumstance where a vehicle, carrying an internal combustion engines is running in, for instance, high altitudes (at a height of, for instance, 1000 m above sea level), a surrounding atmospheric pressure decreases with a resultant decrease in a mass flow rate of intake air drawn into a cylinder. This results in a decrease in the amount of oxygen intake air and, hence, the EGR system is compelled to reduce a recirculation rate (hereinafter referred to as "EGR amount") for the purpose of obtaining a stabilized combusting state. This results in a difficulty of adequately exhibiting a favorable NOx eliminating effect.

Internal combustion engine control device and internal combustion engine control system


A harness protector includes a first protector formed by injection-molding and a second protector formed by extrusion-molding. The second protector is fitted with the first protector. The first protector and the second protector are connected each other.

This invention relates to a harness protector which is mounted on a required portion of a wire harness (installed, for example, along a vehicle body panel) so as to prevent the wire harness from damage due to external interference and so on and a method for producing the harness protector.
FIGS. 7 and 8 show examples of related harness protectors of this kind, respectively (for example, JP-UM-A-63-198324 (Pages 3 to 6, FIG. 1) and JP-A-3-34280 (Pages 2 to 4, FIG. 1)).
The first related example, shown in FIG. 7, is designed to prevent a wire harness from being lifted or projecting from a protector body 41. Lock portions 47 are formed respectively on partition walls 46 formed upright on a base wall 42 of the protector body 41, and openable/closable wire holder members 49 are provided at side walls 43a and 43b of the protector body 41, and are disposed in corresponding relation to their mating partition walls 46, each of the wire holder members 49 having retaining holes 50 for retaining engagement respectively with the corresponding lock portions 47.
The harness protector 40 includes the protector body 41 of a U-shaped cross-section for mounting on the wire harness, and a protector cover (not shown) which is separate from the protector body 41. The protector body 41 includes the base wall 42, and the opposite side (outer) walls 43a and 43b, and this protector body is formed into a three-dimensionally curved configuration. The partition walls 46 are formed upright on the base wall 42 of the protector body 41. The partition walls 46 are upstanding in substantially parallel relation to the two outer walls 43a and 43b, and divide the transverse cross-section of the protector body into a plurality of spaces 48.
The lock portions 47 are formed respectively at distal ends of the partition walls 46, and can be engaged respectively in the retaining holes 50 formed in the wire holder portions 49. Each wire holder portion 49 is connected at one end to the side wall 43a of the protector body 41 through a hinge 51, and the other end thereof can be retainingly engaged with the side wall 43b of the protector body 41 by retaining means. The protector cover is formed into a shape corresponding to the shape of an open side of the protector body 41, and can be locked to the side walls 43a and 43b of the protector body 41 by retaining means.
A condition in which the protector 40 is used will be described. The wire harness is divided into constituent wires, and these wires are passed respectively through the spaces separated from each other by the partition walls 46 of the protector body 41. Thanks to the provision of the partition walls 46, the wire harness is passed uniformly through the interior of the protector body 41, and therefore will not be laterally localized at one region. After the passage of the wire harness, the wire holder members 49 are engaged with the lock portions 47 formed respectively at the distal ends of the partition walls 46, so that the wire harness is fixed so as not to project from the interior of the protector body 41 to the exterior. Finally, the open side of the protector body 41 is closed by the protector cover.
The second related example, shown in FIG. 8, provides the blow-molded harness protector 60 which enhances the efficiency of a wire harness-inserting operation, and prevents a wire harness of a large diameter from damage, and besides has a small number of component parts, and therefore is excellent in economy. A wire harness-inserting slit 62 is formed through one side wall 61, and holes 63 for the insertion of a wire harness-inserting jig therethrough are formed through that side wall facing the slit 62.
The harness protector 60 is made of a synthetic resin such as polyethylene and polypropylene. The slit 62 is formed through the side wall, and extends longitudinally over the entire length thereof. The side wall 61 of the harness protector 60 is thin, and therefore has flexibility. Therefore, when the slit 62 is expanded, the wire harness can be inserted therethrough. When the wire harness is thus inserted, the slit 62 is closed because of an elastic restoring force of the side wall 61, so that the wire harness is prevented from withdrawal from the harness protector 60, thereby protecting the wire harness from external interference and so on.
The holes 63 are formed through the wall by simple technique such as punching or a heating iron. The wire harness-inserting jig is inserted through the hole 63, and a rod-like portion, formed at a distal end of the jig, is engaged in the slit 62, and expands the slit 62 wide open. After the wire harness is inserted through the widened slit, the jig is removed, so that the slit 62 is closed.
However, the above first and second related harness protectors 40 and 60 have the following problems to be solved.
The first related example is the injection-molded harness protector 40 of a curved structure, and the wire holder members 49 are formed at the side wall 43a so as to fix the wire harness. The cost for a mold was high, and the facilities increased, and therefore there was encountered a problem that the length of the harness protector 40 could not be easily changed.
In the second example, only the molded product of a simple shape with a uniform cross-section could be obtained, and there was encountered a problem that any wall for preventing the fluttering and movement of the wire harness within the harness protector 60, as well as any mounting bracket for fixing to a vehicle body could not be formed by molding. Namely, a wire fixing structure and a protector mounting structure could not be incorporated in the harness protector 60, which invited a problem that that portion of the wire harness, required to be protected, could not be properly protected.
And besides, the harness protector 60 is cut from a blow-molded product extending long in the longitudinal direction, and a sharp edge is formed at a cut portion, and also burrs are formed at the cut portion. Therefore, there was a fear that the wire rubbed against the sharp edge or the like to be damaged, so that the reliability of electrical connection could be adversely affected.
Blow molding is a molding method in which a molten resin, is extruded into a tubular shape, and is held in a mold, and the air is blown inside the extruded resin, and then the resin is cooled and solidified. Therefore, similarly with an extrusion method, the molded product could not be formed into a complicated two- or three-dimensionally curved shape, and there was encountered a problem that the molded product could not effectively protect a curved wire harness installed along a vehicle body panel or the like.

Harness protector and method for producing the same


Unitary beverage containers and methods of filling thereof are disclosed where the beverage container includes a main body and a filling conduit extending from the top thereof which is closed off after filling. In embodiments with a separate straw, an attaching mechanism removably attaches the distal end of the flexible straw to the top of main body and closes the aperture in the distal end. The attaching mechanism includes a short hollow bridge extending from the aperture which is broken during removal of the flexible straw to uncover the aperture prior to use. The hollow bridge is connected to a hollow chamber member which is otherwise isolated fluidly from the container volume. A concavity is provided at the top in which a mouthpiece at the distal end of the straw is received. In some preferred embodiments, the filling conduit extends from the top of the main body, and from adjacent the mouthpiece or from the mouthpiece itself. In another embodiment, the filling conduit acts as a beverage conduit and mouthpiece for both filling and ultimate drinking by the consumer. With this latter embodiment, the beverage conduit is inverted into the main body after filling and returned outside of the main body for drinking.

Many different beverages are provided in various containers. Of particular use by small children are small beverage containers which are accessed by a straw. Typically, the straw is removably attached to the outside of the container and is separately wrapped. Thus, the straw can be lost making the beverage hard to consume. In addition, the loose straw and wrapper for the straw are potential problems with small children who might accidentally try to swallow them. These loose items are also a trash nuisance as they tend to be dropped. Further, many of these small beverage containers are made from multi-ply laminates which include paper, foil and plastic and are therefore not easily recyclable.
A beverage container made of a synthetic resin and having a sipping tube or straw connected to the container bottom is disclosed in U.S. Pat. No. 4,982,854 (Ichimiya). A middle portion of the sipping tube is provided with a flexional bellows and the sipping tube is fitted into a longitudinal groove formed on the container body. Filling is accomplished by an inlet provided in a concave portion of the bottom which inlet is subsequently covered by an adhesive film. Another plastic beverage container including an attached straw is disclosed in U.S. Pat. No. 5,078,286 (Hashimoto). With this beverage container, excess filling tube material is removed after filling.
Other patents have also disclosed various integral sipping tubes or straws. Among these are the following U.S. Pat. No 4,607,755 (Andreozzi), U.S. Pat. No. 4,573,631 (Reeves), U.S. Pat. No. 4,830,204 (Lin), and U.S. Pat. No. 5,054,631 (Robbins). Other containers of general interest including various straw mounting means are shown in the following U.S. Patents: U.S. Pat. No. 5,005,717 (Oilar), U.S. Pat. No. 3,332,567 (Pugh, Sr.), U.S. Pat. No. 4,669,608 (Thompson), and U.S. Pat. No. 4,712,702 (Ayabe et al.).


There are provided on a substrate a block layer having an electron affinity smaller than that of the substrate, a p-type strained superlattice structure having no lattice relaxation and operating as a generation region of spin polarized electrons and a surface layer for accommodating a bending portion of the energy band. The superlattice structure is formed of a multilayer in which a strained well layer and a barrier layer are alternately laminated plural times. The strained well layer has a lattice constant greater than that of the substrate and a thickness equal to or less than a wavelength of electron wave, and the barrier layer has a conduction band lower in energy than that of the strained well layer and a thickness such that an electron in the conduction band can transmit based on tunnel effect. A difference in energy between the band for heavy holes and the band for light holes is further widened in the valence band of the superlattice structure due to compressive stress in the strained well layer.

1. Field of the Invention
The present invention relates to a spin polarized electron semiconductor source and an apparatus utilizing the same, and more particularly, to improvement of spin polarization and quantum efficiency in the spin polarized electron semiconductor source.
2. Description of the Related Art
The charged weak bosons couple only chirality-left quarks and leptons. In high energy interactions of massless limit, the chirality equals the helicity. A polarized electron beam, therefore, can control weak interactions in high energy experiments, and is expected to play important roles in experiments of e.sup.+ e.sup.- linear colliders. In the experiments using polarized electron beams, in most cases, the sensitivities of the experiments increase proportionally to the square of the spin polarization degree. Therefore, a spin polarized electron source as a photocathode by which electrons having as high spin polarization as possible can be extracted is urgently required. Besides the degree of spin polarization, the amount of charge which can be extracted from the spin polarized electron source is important in the collider. Therefore, it is desirable for a spin polarized electron semiconductor source to satisfy a spin polarization close to 100% for electrons having an aligned spin and a high quantum efficiency for a large current.
As such a spin polarized electron source for extracting spin polarized electrons, an example in which the band structure of a bulk semiconductor is utilized is described in a paper (Solid State Communication, Vol. 16, p. 877, 1975) by G. Lanpel et al. In this spin polarized electron semiconductor source, a multilayer in which Cesium (Cs) layers and oxygen (O) layers are alternately laminated is deposited on the surface of a p-type GaAs semiconductor to produce a negative electron affinity. Electrons having a maximum spin polarization of 50% can be extracted from the semiconductor surface by irradiating it with a circularly polarized laser beam having an energy substantially equal to the forbidden band of GaAs. In the band structure of the GaAs semiconductor, a band for heavy holes and a band for light holes are degenerated in the valence band and therefore the ratio of electrons having a downward spin to electrons having an upward spin is 3:1 because of the difference in transition probability when electrons are excited from these bands to the conduction band. For this reason, the maximum polarization of 50% can be obtained.
In order to obtain a further higher polarization close to 100%, it is necessary to remove the degeneracy of the heavy hole band and the light hole band in the valence band. For this purpose, spin polarized electron sources utilizing strained crystal or a short period of a semiconductor superlattice structure are proposed.
As an example of a spin polarized electron semiconductor source utilizing strained crystal there is the paper (Physics Letters A., Vol. 158, p. 345, 1991) by T. Nakanishi et al. FIG. 1A shows the structure of such a spin polarized electron semiconductor source utilizing strained crystal. In the example, a lattice relaxation layer 102 of p-type GaPAs which has a lattice constant greater than that of a p-type GaAs substrate 101 and no lattice relaxation is provided on the substrate 101, and a thin strained layer 103 of p-type GaAs in which lattice relaxation is not generated is provided on the lattice relaxation layer 102. A compressive stress acts due to the strain in a direction along the plane in the uppermost GaAs strained layer 103 to align the lattice of the strained layer 103 with the lattice of the relaxation layer 102. As a result, the degeneracy of the heavy hole band and the light hole band is removed in the valence band so that the heavy hole band is positioned higher in energy than the light hole band. Therefore, if the energy of exciting light is chosen to be equal to the energy from the heavy hole band to the conduction band, i.e., a forbidden band energy, electrons are excited only from the heavy hole band so that electrons having completely aligned spin can be obtained. In this manner, spin polarization of 100% ought to be achieved in theory. However, the spin polarization of extracted electrons is lower than 100% in reality because of extension of bands by thermal energy and spin scattering in the strained crystal. As a result of an experiment in which the spin polarization of electrons extracted from the surface of an alternate lamination multilayer of Cs and O formed on the strained layer 103 is measured, a high polarization of 80% or above was obtained.
On the other hand, an example of a spin polarized electron semiconductor source device using a superlattice structure of a short period is described in, for example, a paper (Physical Review Letters, Vol. 67, p. 3294, 1991) by Omori el at. The structure of the electron semiconductor source device using the superlattice structure is shown in FIG. 1B. On a substrate 101 of p-type GaAs, there are sequentially formed a buffer layer 104 of p-type GaAs and a block layer 105 of p-type AlGaAs having a wide forbidden band. The buffer layer 104 is formed to provide a flat surface and the block layer 105 is formed to prevent electrons excited in the substrate 101 from going into a superlattice structure 110. The superlattice structure 110 having a short period is formed on the block layer 105. In the superlattice structure, a well layer 112 of p-type GaAs having a thickness equal to or shorter than a wavelength of electron wave and a barrier layer 114 of p-type AlGaAs having a thickness through which an electron can transmit due to the tunnel effect are alternately laminated. A protection layer 120 of As is formed on the superlattice structure 110. In this case, the degeneracy for heavy holes and light holes is removed in the superlattice structure 110 and a mini band for the heavy holes and a mini band for the light holes are formed in the valence band due to quantum effect. These mini bands occupy different energy levels because of a great difference in effective mass. As a result, similar to the case of the strained crystal, the mini band for the heavy holes takes a position higher in energy than that of the mini band for the light holes. Accordingly, if exciting light is chosen to have the energy from the mini band for the heavy holes to a conduction band and is irradiated to the semiconductor source with a circular polarization, electrons can be excited only from the mini band for the heavy holes and can have completely aligned spins. Therefore, electrons having spin polarization of 100% ought be obtained in theory. As a result of are experiment in which spin polarization of electrons extracted from the surface of a device in which a CsO multilayer was laminated on the surface was measured, a high spin polarization over 70% was obtained.
As described above, when that the GaAs non-strained crystal or the superlattice structure is used as in the conventional spin polarized semiconductor electron source, although the quantum efficiency is relatively high, the spin polarization is insufficient. On the other hand, when the strained crystal is used for the spin polarized electron semiconductor source, although a great polarization is obtained, the quantum efficiency is as low as 0.5% or below because there are defects in the crystal due to the doped impurity and the strained crystal layer cannot be made thicker. In this manner, a high spin polarization and a high quantum efficiency could not be both satisfied simultaneously.

Spin polarized electron semiconductor source and apparatus utilizing the same


A removable side rack system for typical moving dollies includes two inverted U-shaped frames each having an lockable, articulating stabilizer-support arm anchored to its top crossing bar, an E-track anchor bar spanning between its respective legs and an extending mounting foot at the distal end of each fame leg. Socket brackets secured to lower side members on opposite sides of a moving dolly are adapted to receive and secure the extending mounting feet of the respective U-shaped frames.

1. Field of the Invention
The invention relates to removable side racks for a typical moving dolly presenting opposed, lockable, articulating stabilizer-support arms.
2. Description of the Prior Art
Typical moving dollies comprise a rectangular platform with swivel casters located proximate each corner sized for allowing easy navigation through doors and hallways in homes and offices. Usually, the dolly platform is provided a pair of longitudinal side members and a pair of crossing perpendicular end members typically secured either above or below the side members. The upper or top member of the dolly platform is typically carpeted presenting an engaging surface that does not damage (furniture) articles placed on the dolly for transport.
Removable side racks for moving dollies are not uncommon. For example, a multipurpose material cart with a 1″×2″ 14 gauge rectangular tubing base offered for sale by American Moving Supplies, Inc. has removable side bars that are made of 1¼″ 14 gauge round tubing that seat in 4″ deep pipe pockets firmly welded to the frame rolling on 6″×2″ deluxe gray non-marking casters. U.S. Pat. No. 6,967,140, Neuman describes a modular dolly bed with sockets adapted for mounting removable interlocking cart bars to provide dolly side frames. Then U.S. Pat. No. 6,824,152, Scott describes a dolly with a central base with a pair side rails that translate to sandwich, vertically holding and supporting an article on the base, rolling on casters structurally mounted in the side rails. U.S. Pat. No. Des. 333,200, Berrian, depicts a moving dolly with outwardly inclined side racks one of which appears hinged for pivoting inwardly.
Removable attachments for moving dollies adapting them for carrying planar furniture pieces are also not uncommon. For example, U.S. Pat. No. 5,163,695, Pakowsky, U.S. Pat. No. 4,793,624, Mace, U.S. Pat. No. 5,037,177, Hershberger, and U.S. Pat. No. 1,836,362, Crowley, each describe removable attachments for dollies that structurally support large planar items inclined relative to the dolly platform. U.S. Pat. No. 4,488,733, Hellsten, describes a dolly specifically designed for moving large plates supported inclined on a stand above the rolling plane of the casters where top edges of the plates extending above the stand may be secured by a hook member coupled to the top of the stand.
The problem with supporting and moving planar items inclined relative to the rolling plane of the casters is that the center of gravity/mass of the loaded dolly must in all cases be within a rectangular perimeter defined by the rolling casters, otherwise it will simply topple over. Accordingly, inclinations of either the dolly support platform or the rolling plane as a loaded dolly is handled can cause it to topple.
A third kind of dollies are those that are integrated into the structure of the item or object being moved. For example U.S. Pat. No. 4,921,264, Duffy, describes a dolly adapted for carrying library ranges, and U.S. Pat. No. 5,330,064, Hall, shows a dolly fame integrated with a rack structure.


This invention is a robot control system based on a high level language implementing a spatial operator algebra. There are two high level languages included within the system. At the highest level, applications programs can be written in a robot-oriented applications language including broad operators such as MOVE and GRASP. The robot-oriented applications language statements are translated into statements in the spatial operator algebra language. Programming can also take place using the spatial operator algebra language. The statements in the spatial operator algebra language from either source are then translated into machine language statements for execution by a digital control computer. The system also includes the capability of executing the control code sequences in a simulation mode before actual execution to assure proper action at execution time. The robot's environment is checked as part of the process and dynamic reconfiguration is also possible. The languages and system allow the programming and control of multiple arms and the use of inward/outward spatial recursions in which every computational step can be related to a transformation from one point in the mechanical robot to another point to name two major advantages.

Robotic control systems and robots are a fairly new technology. The first digital computer-controlled apparatus operating in real time began to appear about the early 1960s. Before that, "control" took the form of analog controllers which could read analog inputs from sensors (e.g. pressure, temperature, etc.) and output electrical, pneumatic, or other forms of control signals to mechanical operators connected thereto for opening valves, etc. whereby the controlled function could be maintained at pre-established operating levels.
With the advent of digital computers, a number of sensors and operators could be connected to the computer and be controlled by the programs thereof. The programs, of course, could implement far more elaborate control logic for the system as a whole than the proportional band, rate, and reset functions typically implemented by the prior art controllers operating on an individual (and non-interconnected) basis.
What could probably be considered as the first industrial "robots" were the numerically controlled (NC) machines and assembly apparatus. Where previously such apparatus was operated under the control of human operators (with attendant possibility of error), the NC-controlled machines could repetitively perform manufacturing and assembly operations without error. Early versions of NC machines employed pre-punched paper tape inputs to provide the positional movement sequences for the machine. Later, the numerical sequences were stored in the memory of a digital computer.
While the mechanical aspects of such industrial (where the term "industrial" includes robots employed in space operations) robots have become more exotic in the period since their first introduction, the control (and programming) considerations thereof have not moved much beyond the starting point. Take for example the robot 10 of FIG. 1. The robot 10 comprises an arm 12 attached to a base 14 on one end and having a gripping hand 16 on the opposite end. The arm 12 comprises an upper portion 18 and a lower portion 20. There is a powered "shoulder" joint 22 connecting the upper portion 18 to the base 14, a powered "elbow" joint 24 connecting the upper portion 18 to the lower portion 20, and a "wrist" joint 26 connecting the lower portion 20 to the gripping hand 16. The robot 10 is connected to have the powered joints 22, 24, 26 operated by a computer 28 so as to effect desired movement of the gripping hand 16 as, for example, to pick up and move an object. While early NC machines were simply moved known amounts from a known starting point to effect their functions, robots such as robot 10 typically have force and motion sensors (not shown) incorporated within their joints so that there is feedback information available to the computer 28. Also, with an articulated arm such as arm 12, the dynamics of movement are much more exotic and important to the accuracy of the robot than simply moving a clamped part in X and Y axes along a bed under a rotating machine tool which is moved up and down in the Z axis to cause the machining of the part. Accordingly, the instructional sequences to the joints 22, 24, and 26 from the computer 28 are highly complex; and, like the NC apparatus where the sequence of movements to effect the desired machining of a part was pre-programmed into the controlling apparatus, the sequence of movements for the joints 22, 24, and 26 is pre-programmed into the computer 28. If any changes occur in the robot 10 or in the actions to be performed thereby, the instruction sequence must be re-programmed.
To fully comprehend the problem at hand, one must consider the typical environment for digital computer programming and the prior art aids provided therefore. The computer 28 only performs slavishly a sequence of machine language instructions which have been pre-loaded for execution at run time. In the execution of its instructions, a real-time computer can perform arithmetic calculations, make decisions, input dynamic information from sensors, and input information from tables. The tables can contain pre-established information and/or dynamically altered information. Typically, as depicted in FIG. 5, there are pre-defined instruction run-time support programs 40 (such as subroutines) that can be used by the main instruction sequence to accomplish routine tasks of a repetitive nature (such as trigonometric function calculation) necessary to the accomplishment of overall system performance. While the first programmers were forced to do their programming in machine language (an extremely tedious and error-prone process), support programs in the form of assemblers and then compilers (such as the compiler 30 of FIG. 5) made later (and present) efforts much easier to program and to debug. Through processes of experimentation and trial and error, formulas for expressing movement of the various arms and joints of a robot have been established to some degree of accuracy. While these formulas are complex and include many terms, the programming process has been greatly simplified by high level language compilers such as FORTRAN. The system's analyst/programmer must still establish and set down the sequence of formulas which is assumed will accomplish the desired sequence of movements to effect a required end result. As depicted in FIG. 2, the sequence of formulas comprising the movement instruction sequence is then input to a compiler 30 (a program running in a computer) which outputs a sequence of machine language instructions which are then loaded into the robot controlling computer 28 for later execution.
The instruction sequence to move the hand 16 of the robot 10 so as to pick up the object 32 in FIG. 1 can run several pages. Note that this is with the base 14 fixed and the object 32 fixed at a pre-established location. The instruction sequence is of such length simply to account for all the forces and inertial factors of the various joints 22, 24, 26 and the arm portions 18, 20 as the gripping hand 16 is moved from an initial point, to the object 32, and from thence to a final point. The object, of course, is to move the hand 16 smoothly along a trajectory from point to point and not in a jerky fashion constantly correcting from deviation errors. The robot must also apply a pre-described amount of force or stress to the objects that it is handling. As in all real-time movement control systems, a principle design factor in the system design and programming process is the elimination of any instability in the feedback control loop. Instability can lead to the robot 10 going into increased oscillations (leading finally to an error shutdown before damage can occur) or the inability to finally position the hand 16 at a desired point because of excessive overshoot as the result of each movement in a corrective direction.
Because of the foregoing approach to basic robotic programming and control, a computer-controlled two armed robot as shown in FIG. 3 is virtually impossible employing prior art techniques. This is particularly true in situations where the robot task is not numerically pre-programmed and must be changed or designed by the human operator at run time. The object of the robot 10' shown in FIG. 3 is for the two arms 12, 12' to pick up the two object halves 34, 34', bring them into alignment with one another, and push them together to form the object 32 while simultaneously lifting the object 32 up to and placing it on the shelf 33. A human performing the task would first pick up the two object halves 34, 34', bring them into alignment, and then push them together to form the object 32. Having formed the object 32, the object 32 would then be lifted up and be placed on the shelf 33. Obviously, the robot 10' has the potential to perform the assembly and placement process simultaneously. Using the prior art programming technique described above, however, it would be virtually impossible for a human programmer to program the sequence of operations necessary to cause the robot 10' to do so. As can be appreciated from pondering the various aspects which must be taken into consideration as compared with the simple one-arm robot of FIG. 1, the complexity with two arms and two components to perform a combined assembly and placement operation is vastly greater.
Another aspect which is not even considered in prior art robotic control schemes is changing dynamics of the environment. Take the situation depicted in FIG. 4, for example. This is the single armed robot 10 of FIG. 1 into which an obstacle 36 has been placed. If the robot 10 has been pre-programmed to move the hand 16 along the trajectory indicated by the dashed arrow 38, it will do so and strike the obstacle 36 rather than moving to the alternate trajectory indicated by the dashed arrow 40 as necessary to reach over the obstacle 36.
Yet another aspect of robotic control which is not even considered by prior art robotic control systems is the checking of anticipated movement in a fast simulation mode prior to actual implementation on a real-time basis to assure that what is desired has a high probability of occurring and adjusting the projected movement until the desired object is achieved in simulation prior to actual implementation.

High level language-based robotic control system

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A method and apparatus for transferring a reaction gas between a high pressure environment and a low pressure environment. A baffle channel is disposed in a fluid communication path between the high pressure environment and the low pressure environment. Also disposed in the path is an element for limiting gas flow conductance. A shield gas is introduced into the baffle channel and a longitudinal laminar counterflow of the shield gas established toward the high pressure environment, opposing the flow of the reaction gas toward the low pressure environment. The shield gas hinders access of the reaction gas to the element for limiting gas flow conductance, so that a desired ratio of partial pressures of the gas to be transferred in the high pressure environment exceeds the partial pressure of that gas at the end of the baffle channel nearest the low pressure environment, protecting the element for limiting gas flow conductance, and regulating the amount of reaction gas transferred into the low pressure environment.

1. Field of the Invention
This invention relates to a method and apparatus for introducing samples of a gas into a vacuum chamber. More particularly, this invention relates to a method and apparatus for introducing samples of a chemically reactive atmosphere at relatively high pressure into the low pressure chamber of a mass spectrometer.
2. Description of the Prior Art
Mass spectrometers are extensively utilized to provide information concerning the components of a gas mixture. A typical application is chemical vapor deposition, where gas samples from the process reactor are analyzed by a mass spectrometer, the information obtained thereby being used to control the partial pressures of active components in the process reactor. The technique is also used to monitor the progress of chemical reactions wherein the reactants are in a gaseous state.
The analyzer chamber of a mass spectrometer is maintained at sufficiently low pressure, usually below 10.sup.-4 Torr, to assure that ion separation is not hindered by collisons with gas molecules. It is often the case that the pressure in the process reactor exceeds the maximum permissible pressure in the mass spectrometer. For example sputtering, in which a source material is subjected to ion bombardment, usually takes place at pressures from 10.sup.-3 to the low 10.sup.-2 Torr range. Other examples of processes that are conducted at pressures beyond the operational range of mass spectrometers are chemical vapor deposition and etching processes. In such cases the mass spectrometer is provided with its own pumping system in order to maintain desired pressure conditions in its vacuum chamber.
As the gas samples being introduced from outside the vacuum chamber are at relatively high pressure, in order to achieve pressure reduction a component having a low gas flow conductance is interposed between the vacuum chamber and the process reactor. This is usually one or more very small orifices.
Many of the above mentioned processes employ highly reactive or corrosive gases that can attack the mass spectrometer. A longstanding problem in the analysis of such gases has been degraded performance of the mass spectrometer due to reaction of its components with these gases. Another problem in the art is the deposition or sorption of non-volatile reaction products on the surfaces of the spectrometer, leading to undesirable memory effects or signal drift. Such reaction products can even obstruct the orifice and thus completely invalidate the analysis. Orifice blocking is particularly severe in chemical vapor deposition processes that are performed at pressures exceeding 1 Torr, and rising as high as atmospheric pressure. The sampling orifice must be extremely small to accommodate such high pressures and is consequently highly vulnerable to physical obstruction by reaction products.
It has been attempted to retard the interaction of reactants with the components of the mass spectrometer by reducing gas flow into the vacuum chamber. When this is done by reducing the orifice size, blocking becomes more severe. Furthermore the small orifice can limit the signal developed from the sample and hence the sensitivity of the mass spectrometer. A more satisfactory approach uses staged pressure reduction, in which the vacuum chamber of the mass spectrometer is separated from the process reactor by a plurality of intervening chambers, each having a progressively lower pressure, and having larger orifices for fluid flow therebetween. This method, however, requires complex and expensive apparatus, and due to practical limitations on vacuum pump capacity, the gain in orifice size is limited.
Another approach is shown in French et al, U.S. Pat. No. 4,023,398, in which a gas curtain flows through a chamber disposed between an ionization region and a vacuum chamber. The curtain blocks gas flow through an orifice leading to a mass spectrometer. The chamber containing the curtain gas constitutes a dead space that limits the switching rate of the protective effect of the curtain. Furthermore the degree of blocking of the orifice by the curtain cannot easily be controlled. In practice this approach requires high curtain gas flows to provide effective protection, and the gas has to be separately pumped. As the curtain gas flow is high, only condensable cryopumped curtain gases are feasible in many mass spectrometric applications, as other commonly used pumping methods cannot easily provide high pumping rates in the small volume of a mass spectrometer housing. Furthermore in order not to affect the chemical process being carried out, it is desirable to minimize the volume of protective gas that is introduced to the reaction. The high curtain gas flows needed in the French approach directly conflicts with this requirement.

Method and apparatus for sampling a reactive atmosphere into a vacuum chamber of an analyzer


The present invention relates to compounds of the general formula (I), their tautomeric forms, their stereoisomers, their pharmaceutically acceptable salts, pharmaceutical compositions containing them, methods for their preparation, use of these compounds in medicine and the intermediates involved in their preparation. The present invention is directed to compounds suitable for the treatment of Disease conditions such as hyperlipidemia.

Higher LDL cholesterol levels in the plasma increase cardiovascular risk and reduction in the levels of LDL would decrease CVD risk by a comparable percentage (PNAS, 2009, 106, 9546-9547). Clearance of LDL cholesterol from plasma is through the action of LDL receptors in the liver and LDL receptors are cell surface glycoproteins that bind to apoliporpotein B100 (apoB100) on LDL particles with high affinity and mediate their endocytic uptake (Journal of Biological Chemistry, 2009, 284, 10561-10570). Defect in hepatic cholesterol clearance and elevated levels of plasma LDL cholesterol that result from the mutations cause familial hypercholesterolemia. Such mutations are identified in the human LDL receptor and later in apolipoprotein-B (Nature Structural and Molecular Biology, 2007, 14, 413-419). Recently, mutations within the pro-protein convertase subtilisin/kexin of the subtype 9 (PCSK 9) gene were found to represent a third class of mutations associated with autosomal dominant hypercholesterolemia (ADH). Abifadel et al in 2003 discovered pro-protein convertase subtilisin/kexin of the subtype 9 as the third gene involved in autosomal dominant hypercholesterolaemia (ADH) (Nature Genetics, 2003, 34, 154-156, Trends in Biochemical Sciences, 2008, 33, 426-434). Several mis sense mutations (S127R, D129G, F216L, D374H, D374Y) are associated with hyperdiolesterolemia and premature atherosclerosis (J Lipid Res. 2008, 49, 1333-1343). Loss-of-function mutations (R46L, L253F, A433T) lead to elevated receptor abundance, enhancing clearance of LDL cholesterol from the circulation and reducing cardiovascular risk (Nature Structural and Molecular Biology, 2007, 14, 413-419).
Pro-protein convertase subtilisin/kexin of the subtype 9 belongs to the subtilisin family of serine proteases and its protein structure consists of a pro-domain, catalytic domain, and cysteine/histidine rich C-terminal domain (Structure, 2007, 15, 545-552). Unlike other pro-protein convertases, wherein the pro-domain is further proteolytically processed to activate the serine protease, the pro-domain of secreted subtype remains intact and tightly bound. Within endoplasmic reticulum this enzyme undergoes autocatalytic process which results in release of ˜14 kDa prodomain that remains associated with the catalytic/C-terminal domains, wherein the pro-domain serves as both a folding chaperon and as an inhibitor of enzymatic activity (Journal of Biological Chemistry, 2009, 284, 10561-10570).
It is well documented that epidermal growth factor-like repeat A (EGF-A) of LDLR interacts with this pro-protein subtype mainly with residues 367-381. This EGF-A interaction site is located >20 Å from the catalytic site of this pro-protein subtype. Once EGF-A and this pro-protein subtype interacts they form a complex with the LDLR that enters endosomal pathway and hence LDLR recycling is prevented leading to LDLR degradation. Detailed molecular mechanisms explaining the association of LDLR and this pro-protein subtype and LDLR degradation is not very clear (Drug News Perspectives, 2008, 21, 323-330). Because of inhibition of LDLR recycling, number of LDL receptors on the cell surface are decreased and this increases plasma LDL levels (PNAS, 2009, 106, 9546-9547).
Various approaches for inhibiting this pro-protein subtype are reported, including gene silencing by siRNA or antisense oligonucleotides, mAb disrupting protein-protein interactions or by peptides; all the above-mentioned strategies have shown lowering of LDL cholesterol which may be effective therapy for treating hypercholesterolemia (Biochemical Journal, 2009, 419, 577-584; PNAS, 2008, 105, 11915-11920; Journal of Lipid Research, 2007, 48, 763-767; PNAS, 2009, 106, 9820-9825). However, very little success has been reported in trying to inhibit this pro-protein subtype by using small molecules. Small molecule inhibitors of this pro-protein subtype has its obvious clinical and therapeutic benefit over the other approaches as discussed above for the inhibition of pro-protein convertase subtilisin/kexin of the subtype 9. Small molecule inhibitors of this subtype have been disclosed by us in our application nos. 3556/MUM/2010 & 2292/MUM/2009. We herein disclose novel small molecules which have shown to inhibit the pro-protein convertase subtilisin/kexin of the subtype 9 in in-vitro studies and therefore provides an alternate beneficial approach for treating patients in need of such therapy.

Compounds for the treatment of dyslipidemia and related diseases


A highly safe non-aqueous electrolyte secondary cell with excellent self-extinguishing property or flame retardancy is provided which comprises an anode, a cathode, a non-aqueous electrolyte in which an Li-salt as a supporting salt is dissolved in an organic solvent, and a separator. When a high crystalline carbon material such as graphite is used as cathode active substances, it is possible to provide a non-aqueous electrolyte secondary cell whose charging/discharging life is lengthened, whose interface resistance at the non-aqueous electrolyte can be reduced, and which has excellent discharging characteristics at low temperature.

Conventionally, nickel-cadmium cells have been the main cells used, particularly as secondary cells for memory-backups or sources for driving the memory-backups of AV (Audio Visual) and information devices such as personal computers, and VTRs (video tape recorders). Lately, non-aqueous electrolyte secondary cells have been drawing a lot of attention as a replacement for the nickel-cadmium cells because non-aqueous electrolyte secondary cells have advantages of high voltage, high energy density, and displaying excellent self-dischargeability. Various developments of the non-aqueous electrolyte secondary cells have been attempted and a portion of these developments have been commercialized. For example, more than half of notebook type personal computers, cellular phones and the like are driven by the non-aqueous electrolyte secondary cells.
Lithium ion secondary cells using carbon materials that are capable of injecting or removing lithium as active substances for a cathode are the most commercially available materials for the non-aqueous electrolyte secondary cells. Various organic solvents are used for electrolytes of lithium ion secondary cells in order to mitigate the risk when lithium is produced on the surface of cathode, and to increase outputs of driven voltages. For example, electrolytes in which lithium salts are dissolved in mixed solvents of cyclic carbonates and non-cyclic carbonates are widely known (Japanese Patent Application Laid-Open (JP-A) Nos. 2-172162, and 4-171674).
Further, in non-aqueous electrolyte secondary cells for use in cameras, alkali metals (especially, lithium metals or lithium alloys) are used as cathode materials, and electrolytes thereof ordinarily use aprotic organic solvents such as ester organic solvents.
However, although these non-aqueous electrolyte secondary cells are high performance cells, they have a problem with safety as described below.
First, when alkali metals (especially, lithium metals or lithium alloys) are used as cathode materials for non-aqueous electrolyte secondary cells, the alkali metals are extremely highly-active with respect to water. Accordingly, when a non-aqueous electrolyte secondary cell is imperfectly sealed and water enters therein, a problem is caused in that hydrogen is generated due to a reaction of the cathode materials and water, leading to a high risk of ignition or the like.
Moreover, since lithium metals have a low melting point (about 170° C.), they have a problem in that, when a large current suddenly flows into a cell during a short circuit or the like, the cell generates an extreme amount of heat, leading to a high risk of melting the lithium metal of the cell, or the like.
Further, a problem occurs in that the electrolyte comprising the aforementioned organic solvent vaporizes or decomposes due to the heat-generation of the cell, generates gas, and causes an explosion or ignition.
In order to solve the aforementioned problems, for example, a method has been proposed of providing a cylindrical cell with a mechanism for suppressing flow of excessive current, which exceeds a predetermined amount, into the cell by operating a safety valve as well as by breaking an electrode terminal when internal pressure of the cell increases in accordance with the increase of the temperature of the cell during a short circuit or overcharge of the cell (Nikkan Kogyo Shinbun, Electronic Technology, Vol. 39, No. 9, 1997).
However, the mechanism cannot be relied upon to operate normally all the time. In cases in which the mechanism does not operate normally, a problem still remains because it is feared that an amount of heat due to the excessive current will increase, resulting in a risk of ignition or the like.
Accordingly, in order to solve the aforementioned problems, development of a highly safe non-aqueous electrolyte secondary cell, which reduces the aforementioned risks and is not a safety measure providing an attachment part such as a safety valve, is desired.
Performance has been developed to improve performance of the non-aqueous electrolyte secondary cells, and active substances themselves have been studied to improve capacity characteristics thereof. Of the active substances, evolution of carbon materials is noticeable, and of the carbon materials, it has been disclosed that high crystalline carbon materials such as graphite and graphitized carbons are excellent from the viewpoints of having large charging/discharging capacity per unit weight, low average potential during charging/discharging, and large energy density (JP-A Nos. 57-208079 and 5-13088). Low crystalline carbon materials have also been noticed for comprising highly conductive solvents such as ethylene carbonate (EC), γ-butyrolactone (γ-BL) or propylene carbonate (PC) or mixtures thereof with highly dielectric solvents without being limited to the same.
However, it is known that the carbon materials used as active substances for a cathode might have poor compatibility depending upon the type of the electrolytes.
For example, it has been disclosed that propylene carbonate or butylene carbonate i.e., cyclic carbonate decompose at cathodes, and are thereby unsuitable as electrolytes (JP-A Nos. 2-10666 and 4-184872).
It is also known that, when γ-butyrolactone, dimethyl ether (DME) and tetrahydrofuran (THF) are used as electrolytes, a problem is caused in that cathodes and electrolytes react with each other to form coatings on cathode surfaces, increasing interface resistance and deteriorating charging/discharging characteristics at low temperature.
In order to improve the charging/discharging characteristics at low temperature, it has been disclosed that use of electrolytes containing 2-methyltetrahydrofuran (2-MeTHF) as solvent components is effective. It has also been disclosed that electrolytes in which ethylene carbonate (EC) is added to 2-MeTHF tend to show longer charging/discharging duration (U.S. Pat. No. 4,737,424 (1998)).
However, it is known that 2-MeTHF is a combustible solvent which has a low flash point (−11° C.), is volatile and combustible, and is easily oxidized to thereby easily generate explosive peroxides. Accordingly, a problem with safety has been pointed out. With respect to this combustible electrolyte, it is desired to decrease an amount of the electrolyte used and to increase flame retardancy.
In order to prevent decomposition of electrolytes at cathodes, since ethylene carbonate (EC) shows appropriate stability even when used with high crystalline carbon materials, EC is used as an electrolyte having excellent cyclic characteristics. However, since EC has a high freezing point (37° C.) and deteriorates discharging characteristics at low temperature, the EC cannot be used alone. In order to obtain non-aqueous electrolyte secondary cells having excellent discharging characteristics at low temperature, ethylene carbonate (EC) must be mixed with tetrahydrofuran (THF), diethyl carbonate (DEC), dimethyl carbonate (DMC), methylethyl carbonate (MEC) or the like. For example, a three-component mixture of ethylene carbonate (EC), dimethyl carbonate (DMC) or diethyl carbonate (DEC), and ethylmethyl carbonate (EMC) has been proposed (JP-A No. 5-13088).
However, in accordance with a mixing ratio in the three-component mixture described above, ethylene carbonate (EC) is crystallized at low temperature of −20° C., and conductivity decreases, whereby discharging capacity is greatly decreased.
Further, since all of these mixture-type electrolytes are combustible solutions, in the same manner as described above, the problem remains in that the mixture-type electrolytes have an extremely high risk of ignition or the like.

Non-aqueous electrolyte secondary battery


A first communication request including a digital certificate of a first node sent from the first node in a blockchain is received at a second node in the blockchain, where the digital certificate of the first node is stored in the blockchain. Certificate validity information stored in the blockchain and associated with the nodes in the blockchain is accessed by the second node based on the first communication request, where the certificate validity information reflects the validity status information of digital certificates of the nodes in the blockchain. A verification of whether the digital certificate of the first node is valid is performed by the second node based on the first communication request and the accessed certificate validity information. A communication connection to the first node is established by the second node in response to verifying that the digital certificate of the first node is valid.

With the development of computer technologies, a blockchain technology (also referred to as a distributed ledger technology) is favored for advantages such as decentralization, openness and transparency, tamper-resistance, and dependability, and therefore, is widely applied to many fields, for example, intelligent contracting, securities transaction, e-commerce, the Internet of Things, social communications, file storage, existence proving, identity authentication, and equity crowdfunding.
Currently, blockchain systems mainly fall into three types: a public blockchain, a private blockchain, and a consortium blockchain. These three types of blockchains mainly differ in open objects. The public blockchain is open to everyone. The private blockchain is open to a single individual, entity, or organization. The consortium blockchain is open to a particular individual, entity, or organization, and is not open to other individuals, entities, or organizations.
In the blockchain, especially in the consortium blockchain for the particular organization, to improve communication security, a certificate authority center (CA center) is usually designed to issue a node certificate to each node that joins in blockchain communication, so that only nodes that hold valid certificates can communicate with each other. In some implementations, a node certificate that is issued and information related to certificate validity, for example, a certificate revocation list, are stored in a server in the CA center. When nodes in the blockchain need to communicate with each other, the information that is stored in the CA center and that is related to certificate validity is invoked and queried, so as to confirm the validity of the certificate and complete verification of a communication process. Main disadvantages of the method are as follows:
Secure communication among blockchain nodes depends on verification of the validity of the node certificate when a communication connection is established. Once the CA center is hacked, the hacker can arbitrarily modify the information related to the certificate validity. For example, the hacker can tamper with the certificate revocation list and restore a revoked certificate back to normal. The hacker can further use these previously revoked certificates to join in the blockchain without being authorized, and the node in the blockchain confirms the certificate validity based on the information that is tampered with, which threatens the security of the blockchain.

Method, apparatus, and electronic device for communication between blockchain nodes, and method, apparatus, and electronic device for blockchain-based certificate management


According to one embodiment, an MRI apparatus includes an amplifier and a control circuit. The amplifier amplifies an RF pulse and supplies it to an RF coil. The control circuit is configured to determine whether an output RF pulse outputted from the amplifier is fed back to an input side of the amplifier to correct an input RF pulse to be inputted into the amplifier, based on a determination value being set according to a slew rate of the input RF pulse.

Since an MRI apparatus has no problem with exposure to X-rays and can perform internal examination in a minimally invasive manner, an MRI apparatus is an essential modality in the current medical treatment.
An MRI apparatus is an imaging apparatus that magnetically excites nuclear spin of an object placed in a static magnetic field by applying an RF pulse having the Larmor frequency and reconstructs an image on the basis of MR (Magnetic Resonance) signals emitted from the object due to the excitation. In order to acquire the MR signals, high frequency pulses, i.e., RF pulses are applied to the object. Each RF pulse is amplified by an amplifier so as to have a predetermined power and radiated to the object. From the viewpoint of the safety of the object and accuracy of each image to be acquired, each RF pulse outputted from the amplifier is required to have stability and linearity.
As a method for improving stability and correcting nonlinearity of each RF pulse outputted from the amplifier, feedback processing is included. The feedback processing is processing of monitoring at least a part of an RF pulse actually outputted from the amplifier and then correcting the RF pulse to be inputted to the amplifier on the basis of the outputted RF pulse.
In addition to sinc pulses, ultrashort square waves and trapezoidal waves have come to be used as RF pulses applied to the object. However, square waves and trapezoidal waves have a sharp rise (a high slew rate). For this reason, when the feedback processing is applied to RF pulses that are square waves or trapezoidal waves, the rise of each RF pulse outputted from the amplifier is deteriorated to degrade the image quality in some cases.

MRI apparatus and RF amplification circuit


Disclosed is a method of manufacturing magnetic disks, comprising a magnetic layer, a protective layer, and a lubricating layer on a substrate. In the process, a lubricant alpha comprising a compound denoted by chemical formulaHO—CH2—CH(OH)—CH2—O—CH2—CF2(—O—C2F4)p-(O—CF2)q-O—CF2—CH2—O—CH2—CH(OH)—CH2—OH

In magnetic disk devices such as hard disk drives (HDDs), a contact start and stop (CSS) system is employed in which a magnetic head is brought into contact with a contact slide area (CSS area) located in the inner-circumferential area of the magnetic disk surface when stopped, and the magnetic head flies upward while sliding in contact with the disk surface in the CSS area and then recording or reproduction is conducted in a disk area surface for recording and reproduction that is located to the outside of the CSS area when activated. When an operation has been completed, the magnetic head is withdrawn from the recording and reproduction area into the CSS area, after which the magnetic head descends while sliding in contact with the disk surface in the CSS area and comes to a stop. In the CSS system, the operations of starting and terminating in which sliding contact occurs are called CSS operations.
In a magnetic disk employing the CSS system, it is necessary to provide both a CSS area and a recording and reproduction area on the disk surface. It is also necessary to provide an uneven topography having a certain surface roughness on the magnetic disk surface so that the magnetic head and magnetic disk do not adhere to each other when in contact.
To reduce the damage caused by the magnetic head sliding in contact with the magnetic disk during CSS operations, a magnetic recording medium in which a coating of a perfluoroalkylpolyether lubricant of the structure HOCH2—CF2O—(C2F4O)p—(CF2O)q—CH2OH is applied is known, for example, through Japanese Unexamined Patent Publication (KOKAI) Showa No. 62-66417 (Patent Reference 1).
Similarly, magnetic recording media of high CSS durability are known through Japanese Unexamined Patent Publications (KOKAI) Heisei No. 9-282642 (Patent Reference 2) and Heisei No. 10-143838 (Patent Reference 3).
Recently, magnetic disk devices based on the load-unload (LUL) system have been introduced as substitutes for the CSS system. In the LUL system, the magnetic head is withdrawn to an inclined base, called a "ramp", positioned beyond the disk when stopped. When activated, the magnetic disk is caused to rotate, after which the magnetic head slides over the magnetic disk from the ramp to conduct recording and reproduction. This series of operations is referred to as LUL operations. Since a broader recording and reproduction area can be ensured on the magnetic disk surface than in the CSS system, the LUL system is desirable for achieving high information capacity. Further, since the uneven topography employed in the CSS system is not required on the magnetic disk surface, the magnetic disk surface can be made extremely smooth. This permits a significant decrease in the flying height level of the magnetic head, making it possible to achieve high S/N ratios for recording signals.
With the introduction of the LUL system, as the magnetic head flying height level has decreased sharply in discontinuous fashion, the requirement that a magnetic disk stably operate even at an extremely low flying height level of 10 nm or less has emerged. However, when the magnetic head is moved rapidly while flying over the surface of the magnetic disk at an extremely low level, there are problems in that "fly-sticking" impairment and head corrosion impairment frequently occur.
"Fly-sticking" impairment refers to impairment in the form of modulation in the position and flying level of the magnetic head during flying. It is accompanied by irregular reproduction output. In some cases, the magnetic disk contacts the magnetic head during flying, causing the head to crash and damaging the magnetic disk.
"Corrosion" impairment refers to impairment in the form of the corrosion of elements of the magnetic head that creates problems during recording and reproduction, and in some causes, renders recording and reproduction impossible. The corroded elements sometimes expand, damaging the surface of the magnetic disk during flying.
Recently, the rotational speed of the magnetic disk has been increased to enhance the response time of the magnetic disk device. The rotational speed of 2.5-inch magnetic disk devices of small diameter suited to mobile applications was formerly 4,200 rpm, but has recently been increased to 5,400 rpm and above to enhance response characteristics.
When the magnetic disk is rotated at such high speeds, a phenomenon occurs in which the centrifugal force accompanying movement causes the lubricating layer to migrate, resulting in nonuniformity of the thickness of the lubricating layer within the magnetic disk surface.
When the thickness of the lubricating layer is increased on the outer circumference portion of the disk, fly-sticking impairment and head crashing impairment tend to occur when the magnetic head enters from the outer circumferential portion of the disk during an LUL operation. When the thickness of the lubricating layer is reduced on the inner circumferential portion, the reduction in lubricating performance tends to cause head crashing.
The lubricating techniques described in above-cited Patent References 1, 2, and 3 that have been employed thus far were primarily developed with emphasis on improving CSS operations. When they are employed in LUL-system magnetic disks, the frequency of the above-described impairments is high, and it is already difficult to satisfy the reliability that has recently come to be required of magnetic disks. Thus, they have become factors impeding the development of high-capacity, high S/N ratio, rapid-response LUL-system magnetic disks.
Based on such problems, the present invention has for its object to provide a magnetic disk, particularly a load-unload magnetic disk, equipped with a highly adhesive lubricating layer that is capable of preventing migration even at high rotational speeds of 5,400 rpms and above and that is capable of preventing fly-sticking and corrosion impairment even at extremely low flying levels of 10 nm or less, for example.

Magnetic disk and method of manufacturing same

Abstract: wherein p and q are natural number,

Abstract: and a compound denoted by chemical formulaHO—CH2—CF2(—O—C2F4)m-(O—CF2)n-O—CF2—CH2—OH

Abstract: wherein m and n are natural number,

Abstract: is fractionated by molecular weight to prepare a lubricant a having a weight average molecular weight (Mw) of from 3,000 to 7,000 and a molecular weight dispersion of less than or equal to 1.2;

Abstract: a lubricant beta comprising a compound denoted by the chemical formulaHO—CH2—CF2(—O—C2F4)m-(O—CF2)n-O—CF2—CH2—OH

Abstract: wherein m and n are natural number,

Abstract: is fractionated by molecular weight to prepare a lubricant b having a weight average molecular weight (Mw) of from 2,000 to 5,000 and a molecular weight dispersion of less than or equal to 1.2;

Abstract: a lubricant c comprising a mixture of lubricants a and b is prepared; and

Abstract: a film of lubricant c is formed on a protective layer provided on a substrate to form a lubricating layer. A magnetic disk comprising a magnetic layer, a protective layer, and a lubricating layer on a substrate, in which the lubricating layer has been formed on the protective layer is also enclosed.


In a method for detecting a variation, such as a variation in the concentration of a substance, in a flowing medium, a sample of the medium is made to flow past a sensor for detecting the variation, with the direction of flow of the sample being reversed and the velocity of the sample in relation to the sensor being reduced during passage of the sample through the sensor. A device for detecting such a variation contains a sensor and a pump controlled to reverse the direction of flow and to reduce the velocity of the sample of the medium for making a measurement of the sample.

1. Field of the Invention
The present invention is directed to a method and device for detecting a variation, such as a variation in the concentration of a substance, in a flowing medium flowing at a flow velocity in a conduit of the type wherein a sample of the medium is with drawing from the conduit and is passed through a sensor at a velocity which is lower than the flow velocity, for detecting the variation.
2. Description of the Prior Art
The long response times of gas sensors is a major disadvantage in many applications. Sensor sluggishness can lead to distorted results in e.g. the measurement of variation, such as rapid changes in the concentration of a substance in a flowing medium. Thus, a sluggish sensor would cause change exhibiting a steep pulse slope to appear as if it had a more gradual slope. In the ventilator and anaesthesia field, such slow response time is a particular problem with oxygen sensors, but is also a problem with carbon dioxide sensors.
In an effort to avoid problems associated with sluggish sensors, special measurement methods of varying complexity must often be used. For example, European Application 0 392 503 describes a special technique for determining oxygen consumption and carbon dioxide output from breath to breath in a patient on a ventilator.
Another special measurement method is disclosed in U.S. Pat. No. 4,202,352, wherein exhaled gas from several breaths are stored in a gas storage tube. During analysis, the stored gas is passed through a gas analyzer at a reduced velocity (compared with the velocity of the exhaled gas).
One drawback with this method is the risk of diffusion of gas within the stored gas. In particular, the diffusion will be greatest within portions exhibiting rapid changes in concentration. There is also a risk that the gas analyzer tube itself will cause contamination of the gas. This happens because gas particles near the wall of the tube can have other flow characteristics than gas particles in the middle of the tube (e.g. laminar and turbulent flows have different characteristics).

Method and device for detecting a variation in a flowing medium


A magnetic composition comprising nanocomposite particles comprising from about 0.001 to about 60 weight percent of magnetic nanocrystalline particles dispersed in from about 40 to about 99.999 weight percent of a discrete phase matrix, and a continuous phase matrix, wherein the discrete phase resides in interstices within the continuous phase matrix.

The present invention relates to nanomagnetic compositions and the use thereof in magnetic compositions, articles, and processes. More particularly, the present invention relates to nanomagnetic compositions and to processes for making and using in, for example, nanocompass and navigational articles and devices, alternating current transformers, and related applications. The present invention provides magnetic compositions comprising rotationally free, single domain, nanomagnetic composites.
The compositions of the present invention are useful in a variety of magnetically responsive systems, applications, and devices including, for example, as electrical transformer compositions and devices particularly at high electric field frequencies, magnetic gyroscopy and related navigational applications, for example, two and three dimensional compasses, optical communications, switching devices and systems, electromagnetic radiation generators and sensors, transducers, electromotive force (EMF) shielding applications, and the like.
The present invention also relates to processes for preparing magnetic compositions having substantially only rotationally free, single domain magnetic particles. More particularly, the present invention relates to magnetic compositions possessing novel magnetic properties including: being free of barriers to a change in system magnetization (M); having substantially no magnetic memory or hysteresis; having high initial magnetic permeability; wherein the magnetic response of the composition becomes infinite up to about the saturation magnetization of the composition upon application of a magnetic field (H); temperature and magnetic field dependent magnetic properties; solid-liquid phase dependent reversible superparamagnetic to paramagnetic properties; low magnetic resistivity; electrically insulating; and exceptionally high resistance to quantum tunneling above about 0.degree. K.
The term "domain" is described, for example, in C. P. Bean and J. D. Livingston, J. Appl. Physics, 30, 120 (1959); and B. D. Cullity, Introduction to Magnetic Materials, Addison-Wesley Publishing Co., MA, (1972), see also The Magnetic Properties of Materials, by J. E. Thompson, Newnes International Monographs on Materials Science and Technology, CRC Press, Cleveland, Ohio, 1968, which are incorporated herein by reference in their entirety, and refers in embodiments of the present invention to single domain particles, for example, discrete magnetically isolated and non interacting superparamagnetic nanoparticles. Although not wanting to be limited by theory, it is believed that the presence of substantially or exclusively single-domain crystallites in the compositions of the present invention enable the aforementioned combination of novel magnetic properties and applications thereof.
The present invention also relates to methods for forming and manipulating the magnetic properties of isolated nanocompass particles, for example, the size or dimensions of the single domain may be controlled to a great extent by the strength and duration of an externally applied pulsed electromagnetic field that is used to "carve" or etch individual domains, interstices or cavities within a continuous solid or gel phase.
A magnetic nanocompass composition and method as used herein refers to measuring the attitude and position of the magnetic composition before and after orienting the magnetic moments of the magnetic single-domain crystallites or nanoparticles and thereafter determining the relative magnetic changes with respect to reference coordinates thereby providing a three-dimensional compass composition and compass means as illustrated herein.
Properties of magnetic fluids are disclosed, for example, in Magnetic Fluids Guidebook: Properties and Applications, V. E. Fertman, Hemisphere Publishing Corp., N.Y., 1990, the disclosure of which is incorporated herein by reference in its entirety. The magnetic properties of magnetic fluids as a function of temperature have been extensively studied. For example, for conventional ferromagnetic or ferrimagnetic single-domain particles spontaneous magnetization disappears at a certain temperature known as the Curie point(T.sub.c), also known as the magnetic transition temperature. At the Curie point, the exchange atom interaction energy is equal to the thermal interaction energy, and the substance becomes paramagnetic. The upper Curie point is the temperature above which ferroelectric materials lose their polarization and the lower Curie point is the temperature below which some ferroelectric materials lose their polarization. When ferromagnetic materials become paramagnetic at the Curie point the material exhibits the so-called Curie-Weiss effect or behavior.
The following United States patents are noted as being of interest to the background of the present invention.
U.S. Pat. No. 5,316,699, issued May 31, 1994, to Ritter, Shull, et al., discloses a chemical process for producing bulk quantities of an iron-silica gel composite in which particle size, form, and magnetic state of the iron can be selected. The process involves polymerizing an ethanolic solution of tetraethylorthosilcate, with ferric nitrate present in water at low temperature under the influence of an HF catalyst. The chemical and magnetic states of the iron in the resultant composite are modified in situ by exposure to suitable oxidizing or reducing agent at temperatures under 400.degree. C. Iron-containing particles of less than 200 Angstroms diameter, homogeneously dispersed in silica matrices may be prepared in paramagnetic, superparamagetic, ferrimagnetic and ferromagnetic states.
U.S. Pat. No. 4,238,558, discloses low density magnetic polymeric carrier materials containing a polymer material impregnated with a magnetic elemental metal or metal oxide derived from transition metal carbonyl compounds. According to the disclosure of this patent, the carrier particles are prepared by placing in a suitable vessel particles of a polymeric material, a suspending medium, and a transition metal carbonyl, heating the mixture with agitation for the purpose of thermally decomposing the transition metal carbonyl, causing the polymer to be impregnated with a magnetic elemental metal or metal oxide of a transition metal carbonyl, followed by cooling.
The disclosures of each of the aforementioned documents are totally incorporated herein by reference.
U.S. Pat. No. 5,358,659 (D/91332) assigned to the assignee of the present application, and which is incorporated herein by reference in its entirety, discloses a method of forming magnetic materials having tunable magnetic properties and the magnetic materials formed thereby. The magnetic materials contain both single-domain and multi-domain particles and have high initial permeability while maintaining coercivity and remanence in the material. A method for making a magnetic ferrofluid comprises providing a colloidal suspension of submicron ion exchange resin matrix, loading the resin matrix by ultrafiltration with a magnetic ion, precipitating single-domain particles within said resin and precipitating multidomain particles outside of the resin to form a stable colloidal dispersion of the resin and particles.
In the aforementioned commonly assigned U.S. Pat. No. 5,362,417 (D/90063) there is disclosed a method of forming a colloidal dispersion of submicron particles comprising: providing an ion exchange resin matrix; loading said resin matrix with an ion; and treating the resin to cause in-situ formation of submicron particles; and fluidizing said ion exchange resin and particles in an aqueous medium to form a stable colloid of the particles.
U.S. Pat. No. 4,474,866, assigned to the assignee of the present application, discloses a developer composition containing superparamagnetic polymers. The developer composition disclosed in this patent consists of a dispersion of fine particles of iron oxide in a polystyrene ion exchange resin. More specifically, the developer composition consists of .gamma.--Fe.sub.2 O.sub.3 (gamma) disposed in a sulfonated divinylbenzene cross-linked polystyrene resin.
In the aforementioned commonly assigned copending application U.S. Ser. No. 08/332,174 (D/94178) is disclosed a method for producing a magnetized pigment comprising the steps of: forming a magnetic material core in a vaporized state from a vaporized magnetic material; and forming a pigment coating on the magnetic material core while in the vaporized state.
The disclosures of each of the aforementioned commonly assigned documents are totally incorporated herein by reference.
There exists a need for nanomagnetic compositions, articles, devices, and systems that are suitable for use at temperatures, for example, from about 100.degree. K to about 300.degree. K and above.
There remains a need for nanomagnetic materials which can be used in microscopic magnetic processes and applications. There also remains a need for magnetic materials which are single domain and rotationally free at temperatures of about 10.degree. K and above.
Still further, there is a need for nanocrystalline nanocomposite particles that permit low cost, clean, and optionally dry micron and submicron polymeric composite particles that can be selected for use in a magnetic liquid or solid formulation, and utilized as an active component in magnetic fluids, gels and solids.
Another problem in the field of magnetic materials has been the absence of rotationally free, single domain, superparamagnetic and paramagnetic compositions and processes for making and using.
Solutions to the above problems and needs have been unexpectedly found in the compositions and processes of the present invention wherein there is provided superior magnetic materials that enable, for example, nanomagnetic articles, devices and processes, for example, wherein the individual magnetic moments contained in the nanomagnetic crystalline species are freely rotating, single domain, and therefore easily and independently oriented in low, intermediate, and high magnetic fields.
A long standing problem in the area of nanomaterials and nanotechnology has been the absence of nanoscale magnetic materials which possess the necessary combination of magnetic properties to be suitable for use in, for example, navigational, and the like devices. In embodiments of the present invention, solutions to the aforementioned problem are provided.

Magnetic nanocompass compositions and processes for making and using