A stent graft for transluminal implantation includes a resilient tubular interbraided latticework of metal or polymeric monofilaments, a tubular interbraided sleeve of polymeric multifilament yarns, and an adhesive layer between the sleeve and latticework for bonding them together. The monofilaments and multifilament yarns are arranged in respective sets of axially spaced apart and oppositely directed helices, concentric on a common axis of the stent graft. The respective braid angles of the monofilaments and multifilament yarns are carefully matched to ensure that the latticework and sleeve behave according to substantially the same relationship governing the amount of radial reduction that accompanies a given axial elongation. According to a process for fabricating the stent graft, the latticework and sleeve are braided and thermally set independently, then bonded to one another by a silicone polymer adhesive applied evenly to the latticework in a liquid spray that also incorporates an organic solvent. Especially preferred yarns are composed of essentially untwisted filaments that define non-circular yarn cross sections. Alternative stent graft constructions feature exterior and interior sleeves on opposite sides of the latticework, two or more sleeves axially spaced from one another on the same latticework, a latticework formed of a recovery metal, and a plastically deformable latticework.

The present invention relates to body implantable devices and more particularly to prostheses incorporating the characteristics of stents and grafts and intended for long term intraluminal fixation.
A variety of patient treatment and diagnostic procedures involve devices intraluminally implanted into the body of a patient. Among these devices are stents as disclosed in U.S. Pat. No. 4,655,771 (Wallsten). The devices in Wallsten are tubular, braided structures formed of helically wound thread elements. The stents are deployed using a delivery catheter such as discussed in U.S. Pat. No. 5,026,377 (Burton et al.). With the stent positioned at the intended treatment site, an outer tube of the delivery catheter is withdrawn allowing the prosthesis to radially expand into a substantially conforming surface contact with a blood vessel wall or other tissue.
Thread elements or strands formed of metal are generally favored for applications requiring flexibility and effective resistance to radial compression after implantation. Metal strands can be thermally formed by a moderately high temperature age-hardening process while wound about a mandrel in the desired helical configuration. The strands, due to their high modulus of elasticity, cooperate to provide the needed strength. Strand flexibility also permits a radial compression and axial elongation of the stent that facilitates intraluminal delivery of the stent to the intended treatment site. Because the self-expanding device generally remains at least slightly radially compressed after fixation, its elastic restoring force can provide acute fixation.
The favorable combination of strength and flexibility is due largely to the properties of the strands after they have been age-hardened, or otherwise thermally treated in the case of polymeric strands. The braiding angle of the helical strands and the axial spacing between adjacent strands also contribute to strength and flexibility. Age hardening processes are described in U.S. Pat. Nos. 5,628,787 (Mayer) and 5,645,559 (Hachtman et al.).
A well known alterative stent construction features plastically deformable metallic strands in lieu of resilient strands. Plastically deformable strands can be arranged in the same helical configuration. A plastically deformable stent requires no gripping members or other feature on the catheter to maintain the stent in a reduced-radius state during delivery. However, radial expansion of the stent at the treatment site requires a dilatation balloon or other expansion means.
Regardless of whether stents are self-expanding or plastically deformable, they characteristically have an open mesh construction, or otherwise are formed with multiple openings to facilitate the necessary radial enlargements and reductions and to allow tissue ingrowth of the metallic structure. Also, such stents characteristically longitudinally expand as they radially contract, and conversely radially expand as they longitudinally contract.
Devices featuring more tightly woven strands are known. For example, U.S. Pat. No. 4,681,110 (Wiktor), discloses a flexible tubular liner insertable into the aorta to treat an aneurysm. The liner is a tight weave of flexible plastic strands, designed to elastically expand against the aneurysm to direct blood flow past the aneurysm. The tight weave is intended to minimize leakage, so that the liner can effectively shunt blood through to eliminate the aneurysmal sack from the blood path.
The Wiktor structure and others like it notwithstanding, those of skill in the art continue to encounter difficulty in providing a device that simultaneously accommodates the competing needs of low permeability, strength and flexibility for radial compression and expansion. One known approach to this problem is a combination stent graft, in which a compliant but substantially fixed-radius and tightly woven graft is sutured or otherwise coupled to a radially expandable stent. Upon release, the stent is intended to radially expand to the graft diameter. This requires a careful matching of the graft diameter with the lumen diameter at the treatment site. Otherwise, either an oversized graft is compressed between the stent and body tissue with undesirable folds or gathering of the graft material, or an undersized graft prevents the stent from radially expanding an amount sufficient to anchor the device.
Another difficulty arises from the fact that the stent layer and graft layer, even when both undergo combined radial contraction and axial elongation, behave according to different relationships governing the amount of radial reduction for a given axial increase. When the latticework elongates a greater amount for a given radial reduction, elongation of the composite structure tends to tear the bond joining the graft material to the stent. Conversely, if the graft layer undergoes the greater axial expansion, an unwanted increase in bending stiffness causes localized reductions in diameter when the stent graft is bent around tight radii. Consequently negotiation through tortuous vascular passageways becomes more difficult, and in some instances impossible.
The commercially available yarns used in textile vascular grafts are twisted for improved handling during weaving or knitting operations. The amount of twisting will depend upon certain factors including the process of yarn manufacture (e.g., continuous filament yarn or staple yarn) and desired denier. For continuous filament yarn processes, surface twisting angles will generally be between about 15-45 degrees. The multiple filaments typically form a substantially circular yarn cross-section. This limits the effectiveness of the stent graft, and increases the difficulty of matching the elongation behavior of the fabric graft, to that of the stent.
More particularly, the twisted multifilaments are tightly packed, yielding packing factors (or packing ratios) in the range of 0.7-0.9. Because of the tightly packed yarns, the tubular fabric graft has a tendency to kink when bent. The tightly packed filaments leave an insufficient void throughout the yarn cross-section for tissue ingrowth, reducing the effectiveness of long-term fixation. Further, the tightly packed yarn cross-section does not adjust itself in shape to accommodate axial elongation, thus limiting the radial contraction/axial elongation capability of the graft. The circular yarn cross-section further limits the elongation capability, because of its particular resistance to adjustments in shape.
Other disadvantages arise from the circular yarn cross-section. The yarn diameter determines the minimum thickness of the graft fabric. Yarn coverage typically is below 80 percent without additional compacting, and a fabric porosity usually is above 70 percent, again without additional compacting.
Several prostheses constructions had been suggested for composite braided structures that combine different types of strands, e.g. multifilament yarns, monofilaments, fusible materials and collagens. Examples are found in International Patent Publications No. WO 91/10766, No. WO 92/16166, No. WO 94106372, and No. WO 94/06373. Further, a highly favorable combination of strength, resilience, range of treatable lumen diameters and low permeability has been achieved by two-dimensionally woven and three-dimensionally woven composite devices featuring textile strands interbraided with either selectively cold-worked or independently thermally set structural strands, as disclosed in U.S. patent applications Ser. Nos. 08/640,062 and 08/640,091, both filed Apr. 30, 1996 and assigned to the assignee of this application. Although such devices are well suited for a wide range of procedures, there are costs and complexities inherent in interweaving different types of strands. Certain desirable modifications, e.g. providing selected areas of the device with only structural strands, are difficult.
All references cited herein, including the foregoing, are incorporated herein in their entireties for all purposes.
Therefore, it is an object of the present invention to provide a prosthesis structure that affords the advantages of stents and grafts, yet does not require an interbraiding of the structural strands characteristic of stents and the textile strands characteristic of grafts.
Another object is to provide a process for manufacturing a combination stent graft in which a structural layer and a low-permeability fabric layer undergo radial and axial enlargements and reductions, yet remain integrally bonded to one another.
It is a further object of the invention to provide a stent graft construction that facilitates selective alternate axial positioning of open-mesh areas and covered areas for shunting blood flow, to customize stent grafts for particular uses.
Yet another object is to provide, in a prosthesis featuring two or more layers formed of braided strands and of different materials, an effective bond to ensure that the layers remain integrally connected through radial expansions and contractions.
Another object is to provide a fabric graft that exhibits low permeability due to a high yarn coverage and low fabric porosity, in combination with a yarn cross-sectional porosity sufficient to enable tissue ingrowth.
A further object is to provide a stent graft with a fabric graft that is thinner and more closely matches the elongation behavior of the stent, yet affords acceptably low permeability.
To achieve the above and other objects, there is provided a process for making a stent graft, including:
a. forming a plurality of structural strands into a tubular open-mesh latticework adjustable between a nominal state and a radially-reduced axially-elongated delivery state according to a first relationship of radial reduction versus axial elongation;
b. forming a plurality of compliant textile strands into a tubular sleeve adjustable between a nominal state and a radially-reduced axially-elongated delivery state according to a second relationship of radial reduction versus axial elongation substantially equivalent to said first relationship, said latticework and said sleeve having substantially the same size and shape when in their respective nominal states;
c. applying an adhesive to at least one of said latticework and sleeve over at least a portion of the axial length of said at least one of the latticework and sleeve;
d. disposing a selected one of the latticework and sleeve within and axially aligned with the other of said latticework and sleeve so that said other surrounds said selected one, then bringing the latticework and sleeve into an engagement; and
e. maintaining the latticework and sleeve in said engagement for a time sufficient for the adhesive to bond the latticework and sleeve into a composite stent graft.
The step of applying an adhesive preferably involves a curable adhesive, applied uncured to the chosen one of the latticework and sleeve. Then, maintaining the latticework and sleeve in their engagement may further involve curing the adhesive to form the bond. A preferred manner of disposing one of the latticework and sleeve within the other is to adjust the selected one to reduce its radius below that in its nominal state, axially align it within the other while the other remains in its nominal state, then radially expand the selected one to achieve engagement of the latticework and sleeve.
Preferably the structural strands are interbraided in first and second sets of helices, running in opposite directions about a common longitudinal axis, and parallel to form a first braid angle with the latticework in its nominal state. The textile strands of the sleeve preferably are similarly braided in two sets of oppositely directed helices and at a second braid angle with the sleeve in its nominal state. The first and second braid angles preferably are within about 5 degrees of one another, and more preferably are within 3 degrees of each other. In a helical weave, the braid angle is an important factor in determining the degree of radial reduction for a given amount of axial elongation. Thus, the latticework and sleeve, having substantially similar braid angles and substantially the same size and shape in their nominal states, behave according to substantially the same relationship of radial reduction versus axial elongation. Accordingly, there is no tendency in the latticework to tear free of the sleeve due to its more rapid axial elongation for a given radial reduction. Conversely, there is no unwanted increase in bending stiffness due to an axial elongation of the sleeve that exceeds that of the latticework.
The latticework and sleeve are formed independently before their joinder. Structural strands forming the latticework and textile strands forming the sleeve are wound helically about respective mandrels at their respective braid angles, then thermally set, which in the case of metallic structural strands includes age-hardening. The latticework and sleeve are joined to one another with a curable adhesive, preferably a siloxane polymer. The polymer may be dissolved in a liquid organic solvent and applied to the latticework as a spray that leaves a silicone coating or residue when the solvent evaporates. The coated latticework is radially compressed and inserted axially within the sleeve, then expands to engage the sleeve. The bond is completed by heating the latticework and sleeve sufficiently to cure the adhesive. Alternative adhesives include the polycarbonate urethanes disclosed in U.S. Pat. No. 5,229,431 (Pinchuk).
There are several approaches to matching the respective braid angles. In one approach the latticework is formed on a mandrel smaller than the mandrel used for the sleeve, and the structural strands and textile strands are wound at the same braid angle. Alternatively the respective mandrels can have the same diameter. Then, the textile strands are wound at a braid angle slightly less than that of the structural strands. Then, as the sleeve undergoes the slight radial enlargement necessary for accommodating (surrounding) the latticework in the nominal state, its braid angle increases toward a closer match with the braid angle of the latticework.
Further in accordance with the present invention, there is provided a body insertable stent graft. The stent graft includes an expandable stent formed of a plurality of interconnected structural strands, adjustable between a nominal state and a radially-reduced axially-elongated delivery state. The stent graft also includes a tubular sleeve formed of a plurality of interwoven textile strands, adjustable between a nominal state and a radially-reduced and axially-elongated delivery state. Each of the textile strands is a multifilament yarn in which the multiple filaments have a surface twist angle of at most about 15 degrees. The sleeve and the latticework have substantially the same radii when in their respective nominal states. An attachment component fixes the latticework and the sleeve together, in a selected axial alignment with one another, engaged with one another and with a selected one of the latticework and sleeve surrounding the other, whereby the latticework structurally supports the sleeve.
According to another aspect of the invention, the yarns are formed to define a non-circular cross-section with major and minor axes, with an aspect ratio (major axis:minor axis) of at least about 2.
The flatter yarns with substantially untwisted filaments provide a fabric sleeve improved in the following respects: elongation behavior that more closely matches the elongation behavior of the stent; thinner walls for a reduced delivery profile; smaller interstices between yarns achieve lower permeability; and higher yarn cross-section porosity to allow tissue ingrowth.
Although the sleeve surrounds the latticework in the more preferred approach, an alternative construction features a sleeve surrounded by the latticework. In this latter case, the sleeve should be formed on a mandrel as large as the mandrel used to form the latticework, promoting a better bond with a sleeve that tends to elastically radially expand against the surrounding latticework. According to another alterative, two polymeric sleeves are employed, with the latticework sandwiched between an exterior sleeve and an interior sleeve. A variety of enhancements are provided within the scope of the present invention, e.g. incorporating one or more radiopaque strands in the latticework or sleeve, incorporating bioabsorbable materials, providing axial runners to enhance resistance to radial compression, and coating the completed stent graft or individual strands, to reduce deployment forces and lower the inflammatory response of tissue to the implanted device.
Thus in accordance with the present invention, a stent graft incorporates a structural latticework and low-permeability sleeve, independently formed and integrally connected to simultaneously provide the structural advantages of a stent and the low permeability of a graft. The latticework and sleeve are matched to undergo substantially the same degree of radial contraction for a given axial elongation. This matching, combined with an adhesive bond of the sleeve to the latticework, ensures that the stent graft radially expands and contracts as a unitary body, despite being composed of different structural and textile layers and despite the absence of an interweaving between the different layers or between the different types of strands.

Process for making stent graft with braided polymeric sleeve


Provided is a method of forming a compound semiconductor device. In the method, a dopant element layer is formed on an undoped compound semiconductor layer. An annealing process is performed to diffuse dopants in the dopant element layer into the undoped compound semiconductor layer, thereby forming a dopant diffusion region. A rapid cooling process is performed using liquid nitrogen with respect to the substrate having the dopant diffusion region.

The present invention disclosed herein relates to methods of forming a semiconductor device, and more particularly, to methods of forming a compound semiconductor device including a diffusion region.
Due to their miniaturization, lightweight, and other characteristics, semiconductor devices may be used as important elements in electronic industries. Generally, silicon-based semiconductor devices may be used as memory devices and/or logic devices. Modern electronic industries may require semiconductor devices with more specialized functions. For example, modern electronic industries may require light emitting diodes that generate light, semiconductor lasers used for laser oscillation, and/or RF oscillators used for RF oscillation. It may be somewhat difficult to realize silicon-based semiconductor devices with such special functions. For this reason, much research on compound semiconductors that can realize various characteristics is being performed. Compound semiconductors can easily realize various special functions that are difficult to realize with silicon-based semiconductors.
As stated above, compound semiconductor devices can realize special functions, which are difficult for silicon-based devices to realize. Also, compound semiconductor devices can realize functions superior to those that silicon-based devices can realize. Accordingly, a large amount of research on ways to realize devices with various functions using compound semiconductor is being performed.
A compound semiconductor device may include a diffusion region with dopants. The diffusion region may be one of the important elements for realizing a diode and the like. Control of the diffusion region may have a close relationship with semiconductor device characteristics. For example, when a boundary of the diffusion region is unstable, the characteristics of a compound semiconductor device may be deteriorated. Also, when the depth, etc. of the diffusion region do not meet target requirements, the characteristics of a compound semiconductor device may be deteriorated.

Methods of forming a compound semiconductor device including a diffusion region

Electronics and Telecommunications Research Institute


A single-electron controlling magnetoresistance element which comprises, a couple of first ferromagnetic bodies each magnetized in a first direction, a second ferromagnetic body magnetized in a second direction in an initial direction and sandwiched between the couple of first ferromagnetic bodies with a tunnel junction interposed therebetween respectively, and means for directing the magnetization direction of the second ferromagnetic body to a direction different from the second direction, wherein a charging energy E.sub.c of a single electron in at least one of the tunnel junctions interposed between the first ferromagnetic body and the second ferromagnetic body meets the following conditions: EQU E.sub.c >>k.sub.B T (2) EQU E.sub.c >>h/R.sub.t C (3). wherein k.sub.B T is a thermal energy at an operation temperature, h is a Planck's constant, R.sub.t is a junction tunnel resistance, and C is a junction capacity.

This invention relates to a single-electron controlling magnetoresistance element, and in particular to an element which functions based on a novel single-electron controlling method taking advantages of a charging energy effect or so-called coulomb blockade and of a negative magnetoresistance effect of a ferromagnetic tunnel junction.
Attempts to further increase the integration of elements based on the conventional Si-MOSFET are now confronted with a fundamental difficulty due to an increasing complication of structure resulting from an increasing miniaturization of device as well as due to difficulty in fine working for manufacturing such a miniature device. Under the circumstances, there is a growing need for a development of an element which is simple in structure and hence suited for use in miniaturizing and integrating a device. As one example of element to meet such a need, a single-electron tunnel element which functions based on an operational principle of so-called coulomb blockade has been proposed (K. K. Likharev, IBM J. Res. Develop., 32,144(1988)).
When the tunneling of a single electron (an electric charge "e") takes place through a single tunnel junction (a junction capacity: C; a junction tunnel resistance: R.sub.t), a change in electrostatic energy before and after the tunneling, which is represented by the following formula (1), becomes a problem. EQU E.sub.c =e.sup.2 /2C (1)
The change in electrostatic energy E.sub.c may become larger than a thermal energy in an ultra-fine tunnel junction where the junction capacity "C" thereof is very small. Depending on the magnitude of quantity of electrification at this junction, even the tunneling of a single electron is forbidden because of such a high energy to be generated by the tunneling of a single electron. This phenomenon is called coulomb blockade (K. K. Likharev, IBM J. Res. Develop., 32,144(1988)), wherein the tunneling of electron is expected to be taken place one by one like a particle, in spite of the fact that this tunneling phenomenon is essentially brought about by the wave motion of electron.
In order to render this coulomb blockade to be clearly revealed, the change in electrostatic energy E.sub.c is required to be sufficiently larger than any of thermal fluctuation and quantum mechanical fluctuation. These conditions can be expressed by the following formulas (2) and (3). EQU E.sub.c >>k.sub.B T (2) EQU E.sub.c >>h/R.sub.t C (3)
The condition represented by the formula (3) may be written also by the following formula (4). EQU R.sub.q <<R.sub.t ( 4)
wherein R.sub.q is quantum resistance which can be expressed by the following formula (5). EQU R.sub.q .tbd.h/(2e.sup.2)=12.9 k.OMEGA. (5) PA1 wherein h is Planck's constant. PA1 a couple of first ferromagnetic bodies each magnetized in a first direction; PA1 a second ferromagnetic body magnetized in a second direction in an initial direction and sandwiched between the couple of first ferromagnetic bodies with a tunnel junction interposed therebetween respectively; and PA1 means for directing the magnetization direction of the second ferromagnetic body to a direction different from the second direction; PA1 wherein a charging energy E.sub.c of a single electron in at least one of the tunnel junctions interposed between the first ferromagnetic body and the second ferromagnetic body meets the following conditions: EQU E.sub.c >>k.sub.B T (2) EQU E.sub.c >>h/R.sub.t C (3) PA1 a couple of first ferromagnetic bodies each magnetized in a first direction; PA1 a second ferromagnetic body magnetized in a second direction in an initial direction and sandwiched between the couple of first ferromagnetic bodies; PA1 a tunnel junction disposed on one side of the second ferromagnetic body which faces one of the first ferromagnetic bodies; and PA1 means for directing the magnetization direction of the second ferromagnetic body to a direction different from the second direction; PA1 wherein a charging energy E.sub.c of a single electron in the tunnel junction interposed between the first ferromagnetic body and the second ferromagnetic body meets the following conditions: EQU E.sub.c >>k.sub.B T (2) EQU E.sub.c >>h/R.sub.t C (3) PA1 a couple of first ferromagnetic bodies each magnetized in a first direction; PA1 a second ferromagnetic body magnetized in a second direction opposite to the first direction and sandwiched between the couple of first ferromagnetic bodies with a tunnel junction interposed therebetween respectively; and PA1 magnetization-inversion means disposed on the second ferromagnetic body for inverting the magnetization direction of the second ferromagnetic body so as to direct the magnetization direction of the second direction in the same direction as that of the first direction; PA1 wherein a charging energy E.sub.c of a single electron in at least one of the tunnel junctions interposed between the first ferromagnetic body and the second ferromagnetic body meets the following conditions, and PA1 a tunnel resistance at each tunnel junction is in the range of 13 k.OMEGA. to 150 k.OMEGA.: EQU E.sub.c >>k.sub.B T (2) EQU E.sub.c >>h/R.sub.t C (3)
In the case of the ordinary single-electron controlling element, it is essential that the quantum fluctuation is completely suppressed, and, in view of the aforementioned formula (4), the tunnel resistance R.sub.t is required to be set sufficiently higher than the quantum resistance R.sub.q.
The single-electron controlling element may be formed, as a basic structure, of; a double tunnel junction provided with a tunnel barrier layer which is constituted by a channel electron layer pinched off electrostatically from an electrode formed of a semiconductor or a normal conductive metal, or by an insulating body; and a gate electrode which is disposed facing to the central electrode (hereinafter referred to as an island) and capacitively coupled with the central electrode (SET transistor). Alternatively, the single-electron controlling element may be formed, as a basic structure, of a gate capacitor which is serially connected to the aforementioned double tunnel junction (SET memory). FIGS. 1A and 1B, and FIGS. 2A and 2B respectively represent examples of the structure and characteristics of these conventional single-electron controlling elements (K. K. Likharev, IEEE Trans. Magn., 23,1142(1987)). Specifically, FIG. 1A represents a circuit diagram of the C-SET, FIG. 1B represents characteristics of the C-SET, FIG. 2A represents a circuit diagram of the R-SET, and FIG. 2B represents characteristics of the R-SET. The control of single-electron is performed mainly by way of a gate, i.e. by changing an excessive electron generated at the island due to the tunneling of electron.
Since the single-electron controlling element is simple in structure, it is suited for use in miniaturizing and integrating a device. Additionally, the performance of the single-electron controlling element can be further improved with an increase in miniaturization. Moreover, since the control of the single-electron controlling element can be performed based on a single electron, a clear on/off operation can be achieved, so that the single-electron controlling element is now considered as one of promising elements in future.
However, there is a problem that although the operation of this single-electron controlling element is based on a mode where the coulomb blockade can be completely taken place all over the element, it is difficult as a matter of fact to completely render the coulomb blockade to take place all over the element of high integration. In other words, there has been no idea of positively utilize a non-linear mode wherein the coulomb blockade takes place incompletely. Further, the operational principle that has been conventionally considered of is based only on the electric charge of electron, and the utilization of effects that will be generated from the degree of freedom of spin has not been considered. Namely, a diversified control of the element is not fully taken into account up to date.
On the other hand, the ferromagnetic tunnel junction, which is one of the fundamental structural element of the conventional magnetic elements, is constructed as shown in FIG. 3 (S. Maekawa and U. Gafvert, IEEE Mag. MAG-18 707(1982)). Referring to FIG. 3, the reference numeral 71 represents a first ferromagnetic electrode formed of Co, and 72 represents a second ferromagnetic electrode formed of Ni, which is connected via a tunnel barrier 73 (formed of NiO) with the first ferromagnetic electrode 71. This conventional magnetic element has characteristics as shown by a diagram shown in FIG. 4. Since the state density in the ferromagnetic substance is dependent on the orientation of spin, the generation of a negative tunnel magnetic reluctance can be generally represented by the following formula (6). ##EQU1##
It is assumed that the generation of a negative tunnel magnetic reluctance is brought about by a change in state density due to the reversal of magnetization (inverse-parallel to parallel) by a magnetic field. This structure is more advantageous in the respect that the SN ratio thereof is larger than the multi-layered structure consisting of a magnetic layer/a non-magnetic layer/a magnetic layer, which is another example of structure exhibiting the same negative magnetic reluctance as mentioned above. However, since the rate of change of magnetic reluctance is only 15% or so in the ferromagnetic tunnel junction shown in FIG. 3, a structure which is capable of exhibiting a larger change in magnetic reluctance is now desired. Furthermore, since the aforementioned conventional structure is formed of a single tunnel junction structure to be driven with a low impedance and exhibits a phenomenon called "an environmental effect of electromagnetic field" against the coulomb blockade, a large fluctuation is caused to generate in electric charge. Due to these reasons, it is very difficult to take advantage of the coulomb blockade as the operational principle of the single-electron controlling element even if the area of tunnel junction is further minimized (S. Iwabuchi, H. Higurashi, Y. Nagaoka, JJAP Series 9, 126(1992); H. Higurashi, S. Iwabuchi and Y. Nagaoka, Phys., Rev. B51, 2387(1995)).
It would be impossible in the conventional magnetic element as shown in FIG. 3 to expect the coulomb blockade to be brought about by the effect of charging energy. However, there is a need to further promote the integration of semiconductor elements in concurrent with an effort to achieve an increased miniaturization of element which can be competitive with or replaceable for the existing silicon element in future. Therefore, it is not unreasonable to find a way to effectively utilize the coulomb blockade even in a magnetic element. Accordingly, if a basic element structure/operational mode which takes full advantage of the coulomb blockade can be realized, it is expected that not only the performance of unit element can be improved, but also the freedom in design of the whole system can be expanded.

Single-electron controlling magnetoresistance element


A reference signal enhancement device for phase lock loop oscillator. In the reference signal enhancement device, a band pass filtering unit is coupled to a reference signal to filter high frequency noise, low frequency noise, and harmonic components of the reference signal or components with frequency exceeding a predetermined frequency in the reference signal. A signal amplification device including three amplifiers connected in series is coupled to the band pass filter to convert the filtered reference signal.

The invention relates to a signal enhancement device, and more particularly, to a reference signal enhancement device and satellite signal transmitter using the same.
Typically, a phase lock loop oscillator (PLO), using an internal accurate reference signal with low frequency variation and a feedback of closed loop control system, drives operating frequency of an external inaccurate operating element with high frequency variation, such that the external operating element can be operated in the same phase and frequency as the reference signal, with the resulting phase locked state allowing can be application in communication modulation/demodulation circuits.
In one phase lock loop oscillator (PLO), one reference signal is required for circuit operation in which phase noise in loop bandwidth depends on reference signal. The reference signal, however, may interfere causing transmission loss, air noise and circuit noise and degrading operating performance of the phase lock loop oscillator during transmission.

Signal enhancement device for phase lock loop oscillator


A server, and a number of client stations interconnected by a token ring network, specifically an FDDI-II network. The FDDI-II ring is connected in a star-ring topology, with the server and the clients preferably connected to the network through a wiring closet, as is the usual practice for such a topology. The server has separate physical connections to the single FDDI-II ring with each physical connection to the ring providing access to a separate physical domain. This partitions the same ring into different physical domains, so that an increase in the total effective bandwidth of the network is achieved by the server reallocating the same isochronous bandwidth in each of the domains for reuse by the server. An allocation of bandwidth in an isochronous channel in one domain can be reused by the server in another physical domain.

1. Field of the Invention
This invention relates to a method and apparatus for increasing the effective bandwidth of isochronous, ring networks, and more particularly to a method and apparatus for increasing the effective bandwidth of networks conforming to FDDI-II standards.
2. Description of the Prior Art
The Fiber Distributed Data Interface (FDDI-II) standard prescribes a high-performance, fiber optic, isochronous, ring Local Area Network (LAN) running at 100 megabits per second (Mbps). Such networks provide a high bandwidth, general purpose interconnection among, for example, processors. However, even 100 Mbps is not sufficient bandwidth for many high data rate applications that exist today. In some client/server applications, such as those which manage large video disk arrays, the isochronous bandwidth requirement of the server for all the clients on the network is in excess of 100 Mbps. At the same time, it is highly desirable that such client/server networks conform to existing FDDI-II standards, using commercially available FDDI-II hardware, cabling, cycle structure, and protocols.
FDDI-II is a high-performance, fiber optic, token ring LAN running at 100 MBS. FDDI-II is a successor to FDDI with a modification to handle synchronous circuit-switched pulse code modulated (PCM) data for voice or ISDN traffic, in addition to ordinary data. In addition to regular (asynchronous) frames for ordinary data, special frames are permitted for isochronous circuit switched data. These frames are generated every 125 microseconds by a master station. The FDDI-II cycle structure is defined in Section 5 of the ANSI FDDI Hybrid Ring Control standard (X3T9/89-43 Rev 6.3) and incorporated herein by reference. Each new cycle or frame consists of control and data bytes or octets. The master station adjusts the latency of the FDDI-II ring so that there are always an integral number of these frames or cycles on the ring. Each frame is partitioned into four parts: a preamble, a cycle header, a dedicated packet group, and sixteen, wideband channels (WBCs). Each wideband channel can be dynamically allocated to either isochronous or packet data use. For isochronous use, each wideband channel provides 6.144 Mbps of bandwidth, and consists of 96 octets interleaved across the cycle. Once a station has acquired one or more time slots in a frame, those slots are reserved for it until they are explicitly released. The allocation of bandwidth to isochronous users is defined in Section 9.3 of the ANSI FDDI Station Management-2 Isochronous Services (SMT-2-IS) standard (X3T9/93-122 Rev 3.0).
The FDDI-II ring is a collection of ring interfaces connected by point-to-point lines. Each bit arriving at an interface is copied into a buffer and then copied out onto the ring again. This copying step introduces a 1-bit delay at each interface. A token (i.e. a special bit pattern) circulates around the ring whenever all stations are idle. When a station wants to transmit a frame of packet data, it is required to first seize the token and remove it from the ring before transmitting. Bits that have been propagated around the ring come back to the transmitting interface and are removed from the ring by the sender. In FDDI-II, a transmitting-interface may put a new token on the ring as soon as it has finished transmitting its frames.
Isochronous WBCs can be subdivided into individual transmission channels. A transmission channel consists of a contiguous sequence of octets within a WBC. Each data octet of a transmission channel provides 64 kbps of isochronous bandwidth. A logical channel is a unit of allocation that may consist of one or more transmission channels. WBCs are subdivided into separate logical channels to permit simultaneous, independent isochronous dialogues.
An FDDI-II management agent, such as a call control, must receive an allocation of isochronous bandwidth before completing a connection between two or more isochronous users. It is the responsibility of a Channel Allocator (CA) to create logical channels and assign isochronous bandwidth to those channels for use by call control.
Existing data base management routines are useful to a channel allocator in optimizing the way logical channels are created from a pool of bandwidth. One way that a channel allocator can manage bandwidth allocation for the different physical ring domains is defined in U.S. Pat. No. 5,422,883 which is incorporated herein by reference. The use of such routines is outside the scope of this patent. The operation of a channel allocator as defined in the FDDI-II standards will require modifications to account for the different physical ring domains that are described below.
U.S. Pat. No. 5,517,498 discloses a method of extending the effective bandwidth of a ring network connecting a plurality of stations connected one to the next. Here, some or all of the stations on the network comprise a group of contiguous stations that only communicate with one another. Outside the group, the bandwidth assigned to the group can be assigned to another such group.


The present invention relates to pharmaceutical compositions, formulated for injectable administration, which comprises a testosterone ester, in particularly testosterone undecanoate, in a vehicle comprising castor oil and a co-solvent. Upon injecting the compositions according to a particular administration scheme, reliable levels of testosterone in serum in the normal physiological range is achieved for a long period. This allows for the use of the compositions in hormone replacement therapy and male contraception without concomitant monitoring of testosterone levels in serum by a physician.

For several decades, testosterone preparations have been used clinically to treat primary and secondary male hypogonadism in order to achieve normal physiologic levels of testosterone and to relieve symptoms of androgen deficiency. Furthermore, testosterone preparations have been used in male contraception as the sole active therapeutic agent for suppressing spermatogenesis or as an active agent in combination with progestins or further gonadotropin suppressive agents.
Male hypogonadism is characterised by a deficiency of endogenous testosterone production resulting in abnormally low levels of circulating testosterone, i.e. serum testosterone levels below 10 nmol/l.
Male hypogonadism may be classified in primary and secondary causes: primary or hypergonadotropic hypogonadism, congenital or acquired, may be derived from testicular failure due to cryptorchidism, bilateral testicular torsion, orchitis, orchidectomy, Klinefelter syndrome, chemotherapy or toxic damage from alcohol or heavy metals. Secondary or hypogonadotropic hypogonadism, congenital or acquired, is caused by idiopathic gonadotropin releasing hormone (GnRH) deficiency or pituitary-hypothalamic injury from tumours, trauma, or radiation. In the vast majority of cases, hypogonadism is related to a primary defect of the testes.
The clinical picture of hypogonadal adult men varies a lot. For example, testosterone deficiency is accompanied by symptoms of different severity, including sexual dysfunction, reduced muscle mass and muscle strength, depressed mood and osteoporosis.
Current standard therapies aims at restoring physiologically relevant levels of testosterone in serum, which applies to concentrations of about 12 nmol to about 36 nmol. Intramuscular injection of testosterone esters, such as testosterone enanthate or testosterone cypionate, administered every two to three weeks, still represents the standard of testosterone replacement therapy in most countries of the world. Apart from the inconvenience of frequent visits to the doctor's office, the patients complain about variations in well-being due to short-term fluctuations of serum testosterone levels resulting from the pharmacokinetic profile after intramuscular injection of for example testosterone enanthate.
Recently, the use of testosterone esters with longer aliphatic chain length and/or higher hydrophobicity, such as testosterone undecanoate, has become interesting in terms of prolonging the interval between injections. Longer intervals between injections are advantageous from a patient's point of view.
For example Zhang G et al, 1998, report the injection of compositions comprising testosterone undecanoate in a concentration of 250 mg in 2 ml tea seed oil so as to administer a dose of 500 mg or 1000 mg of testosterone undecanoate (Zhang G et al., A pharmacokinetic study of injectable testosterone undecanoate in hypogonadal men. J. Andrology, vol 19, No 6, 1998). Zhang et al, 1999, relates to injectable testosterone undecanoate as a potential male contraceptive (Zhang et al, J clin Endocrin & metabolism, 1999, vol 84, no 10, p 3642-3646).
Furthermore, Behre et al, 1999, relates to testosterone undecanoate preparations for testosterone replacement therapy such as testosterone undecanoate 125 mg/ml in teaseed oil and testosterone undecanoate 250 mg/ml in castor oil (Behre et al, Intramuscular injection of testosterone undecanoate for the treatment of male hypogonadism: phase I studies. European J endocrin, 1999, 140, p 414-419).
Intramuscular injections of 250 mg testosterone undecanoate and 200 mg MPA every month have been suggested for male contraception (Chen Zhao-dian et al, clinical study of testosterone undecanoate compound on male contraception. J Clin androl, 1986, vol 1, issue 1, abstract)
Wang Lie-zhen et al. report testosterone replacement therapy using monthly intramuscular injections of 250 mg testosterone undecanoate (Wang Lie-zhen et al. The therapeutic effect of domestically produced testosterone undecanoate in Klinefelt syndrome. New Drugs Market 8: 28-32, 1991.
WO 95/12383 (Chinese application) relates to injectable compositions of testosterone undecanoate in vegetable oils, optionally in admixture with benzyl benzoate. The compositions are injected monthly when applied for male contraception and substitution therapy.
U.S. Pat. No. 4,212,863 is a patent which relates to a lipid formulation of steroids for oral or parenteral administration various oil carriers, optionally including benzyl benzoate, which is said to lower the viscosity of the lipid carrier and/or enhance the solubility.
Eckardstein and Niesclag, 2002, report the treatment of hypogonadal men with testosterone undecanoate, wherein physiological relevant levels of testosterone may be achieved for an extended period of time upon initially injecting testosterone undecanoate four times in intervals of 6-weeks followed by subsequent injections of longer intervals (Eckardstein and Niesclag, treatment of male hypogonadism with testosterone undecanoate injected at extended intervals of 12 weeks, J Andrology, vol 23, no 3, 2002)
However, it is well known that therapies with testosterone esters, such as testosterone undecanoate, still need to be improved in terms of achieving reliable serum testosterone levels in the physiologically acceptable range for a prolonged period of time. There is a need of providing reliable standard regimens acceptable for a broad population of men in need thereof, preferably regimens without the need of occasional control of serum testosterone levels, and regimens wherein steady state conditions are achieved within a shorter time period.

Methods and pharmaceutical compositions for reliable achievement of acceptable serum testosterone levels


A non-pressurized liquid supply system is provided for supplying a liquid, such as water, to a plurality of liquid treatment units. Pipes in an outflow stage split liquid flow from an inflow stage, possibly via at least one intermediate stage. The inflow stage and outflow stage have substantially equivalent cross-sectional areas, and the outflow stage has at least two pipes in order to split the flow to the plurality of liquid treatment units in order to achieve more effective treatment of the liquid. The inflow stage and outflow stage co-operate to maintain substantially constant liquid flow throughout the non-pressurized liquid supply system. The system preferably includes a flow-splitting horizontal manifold. The non-pressurized liquid supply system can be, for example, a drainwater system, a waste water system, or a chemical process system.

Drainwater typically flows out of a commercial building by way of a drain pipe. Such a drain pipe typically has a diameter of 3 or more inches. It is sometimes advantageous to treat or to remove heat from the outgoing drainwater on-site, such as in-house. Many water treatment systems (such as acid neutralization, disinfection, solids removal, and heat recovery) are not able to treat the full flow of drainwater with one unit but instead work much better by treating lower flow in several units.
Drainwater systems in which flow is split for the purposes of water treatment are taught in U.S. Pat. No. 6,092,549 to Eriksson entitled "Device in a Waste Disposal System in a Building" which issued on Jul. 25, 2000, as well as in U.S. Pat. No. 6,261,443 to Eriksson entitled "System for Handling Drain Waters of Different Degrees of Contamination" which issued on Jul. 17, 2001. These two patents are primarily concerned with the separation of drainwater having differing degrees of contamination into separate containers for separate treatment, and employ pumps to regulate the flow of drainwater.
Flow-splitting occurs most commonly when a flow of liquid, such as water or waste water, is split from one or more pipes to a plurality of pipes. Flow-splitting from one 4 inch line to multiple 4 inch lines (e.g. 16 lines) is not specifically prevented in the typical published plumbing codes. However, such flow splitting does not meet the intent of the plumbing codes because it results in a slowing down of the drainwater velocity. The reason for this slowing down is that the total drainpipe cross-sectional area increases substantially as the number of drainpipes used in the system is increased due to desired flow-splitting. Such a situation is exemplified in U.S. Pat. No. 3,853,142 to Gorman entitled "Drainage System" which issued on Dec. 10, 1974, and which relates to a drainage system for multi-floor buildings. Fittings for interconnecting drainpipes which are provided in this system have an inner diameter corresponding to that of the pipes in the stack.
U.S. Pat. No. 5,099,874 to Della Cave entitled "Residential Waste Disposal System" and issued on Mar. 31, 1992 relates to a residential waste water disposal system for a building which saves and recycles the grey waste water for lawn and plant irrigation. The system includes three different types of T-fittings used with two passageway waste water pipes, each T-fitting designed to interconnect to axially aligned waste water pipes and having an offset opening to one of the waste water passageways in the fitting. The figures of the '874 patent show a waste water fitting having two parallel but separate passageways within the pipe, each for different types of drainwater. The different types of fittings disclosed communicate with each other by means of interconnecting passageways or where one passageway meets a wall so as to prevent cross contamination of drainwater in that particular path.
Although different cross-sectional areas are used in certain cases in the '874 patent, they are used in order to selectively limit the flow of certain types of drainwater based on their known contents or degree of contamination. The use of different cross-sectional areas does not improve drainwater flow, or the rate of such drainwater flow. Moreover, such a system does not rely solely on gravity to feed the water through the system, but uses applied pressure, such as pumps to regulate the water flow.
It is, therefore, desirable to provide a system for water supply that allows flow splitting with minimal change in drain water velocity. It is further desirable to provide a system for liquid supply, not limited for use with aqueous solutions, that allows flow splitting with minimal change in liquid flow velocity.

Non-pressurized flow-splitting water supply system


An electrical connector includes a window assembly including an electrically insulating transparent base and a plurality of electrically insulating transparent windows extending outwardly therefrom. The connector may include an electrically conducting body having spaced apart cable-receiving passageways for receiving respective insulation-free electrical cable ends therein, and with each cable-receiving passageway having a cable inlet opening and a cable end viewing opening opposite the cable inlet opening. The body may also have at least one respective fastener-receiving passageway intersecting each cable-receiving passageway. The individual windows of the window assembly are aligned with respective cable end viewing openings to provide a cover and to permit visual confirmation of proper placement of the insulation-free electrical cable end within a corresponding one of the cable-receiving passageways. The connector may further include an insulating cover on the body and defining a seal with the window assembly.

Underground and submersible junction bus connectors are widely used in electrical power distribution systems. One type of such connector is offered under the designation SWEETHEART® by Homac Mfg. Company of Ormond Beach, Fla., the assignee of the present invention. The SWEETHEART® connector is a cast or welded aluminum connector including a bus, or bar, portion and a series of tubular posts extending outwardly from the bus portion. The posts have an open upper end to receive one or more electrical conductors. A threaded bore is provided in the sidewall of the post, and which receives a fastener to secure the electrical conductor within the upper end of the post. An insulating coating is provided on the lower portion of the posts and bus of the connector. In addition, EPDM insulating sleeves may be used to provide waterproof seals for the posts. U.S. Pat. Nos. 6,347,966; 6,345,438 and 6,262,567 disclose various embodiments of such bus and post connectors.
Homac also manufacturers a RAB series of "Flood Seal"® Rubberized Aluminum Bar connectors suitable for direct burial, handhole or pedestal applications. The RAB connector includes a generally rectangular aluminum body having a plurality of spaced apart cable-receiving passageways therein. These cable-receiving passageways are blind holes, that is, they extend inward, but do not extend fully through the connector body. The blind hole is useful to provide sealing at the lower end of the connector body for the later molding of the rubber insulating cover.
The connector body also has a fastener-receiving passageway intersecting each cable-receiving opening. A fastener is provided in each fastener receiving passageway. Each fastener comprises a blunt end for bluntly contacting a corresponding insulation-free cable end. In particular, the blunt end may be a ball bottom screw end that helps break up aluminum oxides of the insulation-free cable end to ensure better electrical contact.
As the name states, the RAB connector includes a rubber insulating cover over the connector body. The insulating cover includes integrally molded inlets for both the cable-receiving openings and fastener-receiving openings. An insulating boot, such as a cable size adaptor or Rocket may be provided for the cable-receiving inlet, and a sealing cap may be received over the screw in the fastener-receiving inlet. Unfortunately, with less experienced labor crews, it is possible that a cable end may not be fully seated in its blind hole. Thus, even if the fastener initially presses partially against the cable end, this connection may work lose as the RAB connector is subsequently repositioned.
U.S. Pat. No. 6,688,921 to Borgstrom et al. discloses a connector similar to the Homac RAB series connector. In place of EPDM, the patent uses a thermoplastic elastomer (TPE) that combines the properties of thermoplastic with the performance characteristics of a thermoset rubber. The use of TPE enables the molding to further form sealing plugs and cable size adaptors attached to the cover with respective tethers. The connector also includes blind cable-receiving passageways, and is thus also susceptible to less reliable connections if the cable ends are not fully seated.
Michaud Electrical Equipment of France offered an insulation displacing connector (IDC) including a generally rectangular connector body, and transverse cable-receiving and fastener-receiving passageways. More particularly, the connector body included a backwall having a pattern of sharp ridges thereon to pierce the insulation on the cable end as the end of the fastener engages and presses against the cable end from the opposite side. To be sure the cable end is fully pressed onto the sharp ridges, a plastic viewing window is provided opposite the inlet of the cable-receiving passageway. Accordingly, an installer can view the cable end to be sure the insulation has been pierced. The window is adjacent the rubber cover. Unfortunately, the Michaud IDC device is likely to leak at the window since the seal is only a mechanical seal. In addition, insulation displacement technology may not be suitable for larger cable sizes with thicker insulation coverings.

This patent is subject to a terminal disclaimer.

Electrical connector including viewing window assembly and associated methods


A liquid treatment apparatus includes: a substrate holder for holding a substrate; a discharge nozzle for discharging a treatment liquid onto the substrate; a liquid supply pipe for supplying the treatment liquid from a treatment liquid storage source to the discharge nozzle; a gas pipe that encompasses the liquid supply pipe and through which an inert gas for adjusting the temperature of the treatment liquid flows in a space between the gas pipe and the liquid supply pipe; a processing container in which the substrate holder, the discharge nozzle, the liquid supply pipe, and the gas pipe are provided; and an atmosphere gas supply part for supplying an atmosphere gas into the processing container. The gas pipe is provided so that an extension portion between an upstream end inside the processing container and an encompassing portion is folded back inside the processing container in a plan view.

Patent Document 1 discloses a film coating apparatus which includes a coating container into which a substrate is loaded and a film coating is performed on the substrate, a coating liquid container for holding a coating liquid, and a liquid transport system for transporting the coating liquid from the coating liquid container to the coating container. The film coating apparatus is provided with a means for suppressing the content of water in the coated film. Further, in Patent Document 1, the suppressing means includes a double resin pipe, and a gas including an inert gas exists in a space between an inner pipe and an outer pipe of the double resin pipe so that the double resin pipe is used in the transport system. Further, a resist coating apparatus used as the film coating apparatus of Patent Document 1 includes a resist discharge device, resist lines as the liquid transport system, a resist supply container as the coating liquid container, and a pipe connecting them. The resist discharging device includes a resist temperature adjusting pipe having a triple structure, and a nozzle. In addition, the triple-structured resist temperature adjusting pipe includes a cooling-water for temperature-adjustment inflow pipe composed of a polyvinyl chloride (PVC)-based tube into which a cooling water for temperature adjustment flows, and a cooling-water for temperature-adjustment outflow pipe composed of a tetrafluoroethylene perfluoroalkylvinylether copolymer (PFA) tube from which the cooling water for temperature adjustment is discharged.

Liquid treatment apparatus and method of adjusting temperature of treatment liquid


A paraffin isomerization process is described and claimed. The process involves contacting the paraffins with an isomerization catalyst at isomerization conditions. Additionally, the process requires the injection of a nitrogen containing compound such as an amine, e.g., t-butylamine, and raising the operating temperature by about 20.degree. C. to about 150.degree. C. The effect of these modifications is to provide improved selectivity and sulfur resistance to the catalyst.

Paraffinic oils containing C.sub.10+ (ten carbons or higher) compounds find various uses as lubricating oils, heating oils, jet fuels, etc. One requirement of these oils is that they have a low viscosity or pour point at low temperatures. However, these paraffin mixtures usually contain straight chain or slightly branched paraffins which are waxes at lower temperatures which result in the paraffin mixture having a high pour point or viscosity at the lower temperatures. In order to remove these waxes, various processes are used to dewax the paraffin feed. Dewaxing processes include catalytic cracking where the long chain paraffins are cracked to smaller chain paraffins and isomerization where the straight chained paraffins are isomerized to branched paraffins.
Dewaxing by isomerization is disclosed in U.S. Pat. No. 4,419,220. The isomerization catalyst which is used is a zeolite beta having a silica: alumina ratio of at least 30:1 and having a hydrogenation component such as platinum. It is further disclosed that lower temperatures favor isomerization over cracking and therefore, lower temperatures are preferred. The '220 patent also discloses a preliminary hydrotreating step to remove nitrogen and sulfur compounds in order to improve catalyst performance and permit operation at lower temperatures.
As the '220 patent discloses, a bifunctional catalyst is used in order to achieve high isomerization selectivity. The two functions are hydrogenation and isomerization. Hydrogenation (and dehydrogenation) is carried out by the metal function, e.g., platinum, palladium, nickel, etc., while isomerization is carried out by the acid function, e.g., zeolites, Si--Al, etc.
The specific steps in paraffin isomerization are as follows. First, the paraffin is dehydrogenated on the metal function to give an olefin. The olefin reacts with the acid function to give a n-carbenium ion which is isomerized to an iso-carbenium ion. Next the iso-carbenium ion will be converted to an iso-olefin followed by hydrogenation to an iso-paraffin. Additionally, the iso-paraffins can be cracked on the acid sites to give low molecular weight paraffins and low molecular weight carbenium ions which will in turn be hydrogenated to light paraffins. Competition between hydrogenation and cracking explains product distribution. To maintain the high isomerization activity the hydrogenation function of the catalyst should be high enough to convert the intermediate carbenium ions to iso-paraffins and prevent their cracking. In the presence of sulfur hydrogenation activity will be suppressed owing to formation of metal sulfides with low hydrogenation activity and thus cracking will dominate resulting in low isomerization selectivity and the formation of light paraffins. Accordingly, there is a need for an isomerization catalyst/process which can function well in the presence of sulfur.
Applicant has found a solution to this problem which involves injection of a nitrogen containing compound, e.g., ammonia, into the isomerization reactor and simultaneously increasing the temperature by about 20.degree. C. to about 150.degree. C.
There are several references which disclose the use of nitrogen compounds in refining processes. For example, U.S. Pat. No. 5,419,830 discloses the use of ammonia to control the temperature in the reactor and prevent temperature runaway. U.S. Pat. No. 4,158,676 discloses the isomerization of monocyclic methyl-substituted aromatic hydrocarbon compounds in which nitrogen containing compounds are injected. U.S. Pat. No. 5,275,720 describes a two stage hydrocracking process in which ammonia is injected in the first stage to increase catalyst cracking activity.
In contrast to these references, applicant's process combines the injection of a nitrogen containing compound with an increase in the operating temperature. Increasing the temperature is contrary to the teachings in the art which state that lower temperatures favor isomerization. This results in improved selectivity and sulfur tolerance.

Process for the isomerization of paraffins


A shift register unit including a first output circuit configured to transfer a clock signal at a clock signal terminal to a signal output terminal as an output signal in response to a first node being at an active potential, a second output circuit configured to transfer the clock signal at the clock signal terminal to a carry output terminal as a carry output signal in response to the first node being at the active potential, and a delay circuit configured to generate a delayed version of a carry input signal in response to the carry input signal at a carry input terminal being active, and to transfer an inactive voltage at a first voltage terminal to the signal output terminal in response to the delayed version of the carry input signal being active.

Parasitic capacitance is inevitably present in a thin film transistor liquid crystal display (TFT-LCD). The parasitic capacitance may, for example, be due to storage capacitance (which is formed by overlapping of a pixel electrode and a common electrode line), liquid crystal capacitance (which is formed by overlapping of a pixel electrode and a common electrode), and/or an overlap capacitance (which is formed by overlapping of a gate and a source of a pixel transistor). Owing to the presence of the parasitic capacitance, a sudden change in a gate scan signal on a gate line affects the magnitude of a pixel voltage on a pixel electrode. For example, a high to low transition of the gate scan signal may pull the pixel voltage on the pixel electrode to change accordingly. This causes a change in the display brightness and hence a defect such as flicker of the display screen.

Shift register unit, gate driving circuit, display device and driving method

Hefei Xinsheng Optoelectronics Technology Co., Ltd.


A gimbal mount for mounting a seeker for a large look angle comprises a base support frame for attachment to an airframe, a roll axis frame having a base and a pair of spaced apart forwardly positioned gimbal supports mounted for rotation about the roll axis of the frame, a pitch gimbal ring pivotally mounted on the roll axis frame for pivoting about a pitch axis, a yaw gimbal frame pivotally mounted for pivoting about a yaw axis on the pitch gimbal, a pitch drive motor and a yaw drive motor coaxially mounted directly on and coaxial of the roll axis frame, and a drive cable connecting the respective motors to the respective gimbals.

The present invention relates to gimbal mounts for seekers and pertains particularly to an improved gimbal mount providing a large look angle.
Aircraft, both manned and unmanned, utilize information serving or seeker devices, such as antennas, IR/UV sensors, optical devices and the like for transmitting and receiving information. These are typically mounted for orientation within a hemispherical zone for either specific directional orientation or sweeping movement.
Many different gimbal mountings of sensing devices are known in the art, and various approaches to gimbal mounting of such sensing devices on airframes and aircraft have been attempted in the past. Because weight and space are a premium on such aircraft, it is essential that the mechanisms and instrumentation of such devices be as compact and lightweight as possible. It is also desirable that the mass of moving parts be kept to a minimum in order to reduce control complications and other problems.
High performance tactical missiles require seeker heads which can achieve look angles greater than 60 degrees for effective tracking of high speed, high altitude crossing targets. These missiles also need gimballed multiple sensors and/or additional processing electronics which reduce the achievable look angle on traditional gimbals. Historically, gimbal look angles have been restricted to about 60 degrees due to structural stiffness limitations, sensor beam blockage problems and sensor/servo control component packaging volume constraints.
It is also desirable that the seeker gimbal assemblies have means to provide stabilization by decoupling the seeker from body motion.
We have developed a three degree of freedom gimbal with roll, pitch, and yaw combined with a unique pitch and yaw drive concept that overcomes many of the aforesaid problems of the prior art. This arrangement provides for 70 degree look angles, 70 percent gimballed mass for sensor packaging, and 90 percent decoupling of body motion.


A fastening element guide device for a power drive-in tool includes a coupling section (14) having a chamber (17) for receiving a matching coupling section (41) of power drive-in tool (40) at least one locking member (21, 22) displaceable between a locking position (28) in which its locking section (23) projects into the receiving chamber (17) for engaging a recess (43) provided on the matching coupling section (41) of the power drive-in tool (40) for lockingly secure the guide device (10) on the power drive-in tool (40), and a release position (29) in which the locking section (43) is withdrawn from the receiving chamber (17) a spring (25) for biasing the at least one locking member (21, 22) to its locking position (28), and an actuation section (24) accessible from outside for manually displacing the at least one locking member (21, 22) from the locking position (28) to the release position (29).

1. Field of the Invention
The present invention relates to a fastening element guide device for a power drive-in tool and which includes a coupling section having a chamber for receiving a matching coupling section of the power drive-in tool, and at least one locking member arranged on the coupling section, having a locking section and displaceable between a locking position in which the locking section projects into the receiving chamber for engaging a recess provided on the matching coupling section of the power drive-in tool for lockingly secure the guide device on the power drive-in tool, and a release position in which the locking section is withdrawn from the receiving chamber.
2. Description of the Prior Art
Fastening element guide devices of the type described above are used with power drive-in tools such as e.g., screwdriving tools, and are formed, e.g., as pure fastening element magazines or also as extension devices.
U.S. Patent Publication US 2004/0099105 A1 discloses a screw guide device for a drive-in or screwdriving tool the main body of which can be secured on a flange of a screwdriving tool with a clamping ring. A barrel of the fastening element guide device is displaceably arranged with a tubular member on a first constructural component. A lever with an eccentric is arranged on the clamping ring. With the lever, a screw that extends through the two ends of the clamping ring, can be tightened to reduce the clamping ring diameter.
The drawback of the disclosed guide device consists in that for releasing the lever, dependent on screw prestress, a rather big force has to be applied. In addition, the clamping ring is susceptible to wear and damage.
German Publication DE 103 57 485 A1 discloses a screwdriving tool with a fastening element guide device mounted thereon. The screwdriving tool has a holding projection on the outer circumference of which a groove is formed.
On the holding projection of the screwdriving tool, the attachment sleeve of the fastening element guide device, which is fixedly secured in the guide device housing, can be secured. The attachment sleeve has two opposite openings in which clamping members are radially displaceable. A rotatably supported locking collar surrounds the attachment sleeve. The locking collar is provided on its inner surface with circumferential grooves for clamping elements. By pivoting the locking collar, the clamping element can be reversibly displaced in a locking position in which the clamping surfaces of the clamping elements engage in the recess or recesses on the holding projection and in the circumferential grooves of the locking collar. A detent collar with spring fingers provides for retaining of the locking collar on the attachment sleeve.
The drawback of the device according to DE 103 57 485 A1 consists in large number of parts necessary for mounting of the fastening element guide device on the screwdriving tool.
An object of the present invention is a fastening element guide device in which the drawbacks of the prior art devices are eliminated and which can be easily handled.

Fastening element guide device for a power drive-in tool


A quantitative analysis of the constituents in a specimen and being classified by the conditions of the constituents in the specimen, using a spectroscopic analysis is made by exciting the specimen a number of times for emission, detecting the light intensity data of the line of the constituent element and the non-constituent element of the specimen per emission, storing the light intensity data of the lines specifying emission which contains the constituent element and the non-constituent element over a predetermined level based on the stored data, and determining that there is present a composition of the constituent element and the non-constituent element at a portion of the specimen corresponding to the specified emission.

The present invention relates to a spectroscopic analyzing method and system in which the constituents of the sample are quantitatively analyzed with being classified by the conditions in the sample.
In the controlling the quality of the metal during smelting, it is necessary to analyze the constituents of the metal with classifying the conditions in the sample. The conditions of the constituents in the sample can be classified into two. One is the composite conditions such as nitrogen, oxide, and sulfide etc.
The other is the conditions of an alloy in which the elements are dispersed in a metal.
To analyze the constituents elements depending on the classification of the composite conditions and the alloy conditions, there are conventional chemical methods for separately analyzing using various solutions methods.
However, they are not rapid enough so that they cannot be effectively applied to controlling the method during smelting.
Thus quality control during smelting the metal is then difficult.

Emission spectrochemical quantitative analysis method and apparatus


Disclosed adjustable seat systems that provide a self-contained height-adjustable seat system for sit-on-top kayaking that allows the seat to be adjusted into various height and angle positions, while maintaining independent adjustment to the fore/aft position of the seat in the kayak. Some of the adjustable seat systems include a seat upper that includes a seat bottom and a seat back; a seat base adapted to slidably engage a flat surface in the watercraft; and at least two pivot mechanisms coupling the seat upper to the seat base, wherein the at least two pivot mechanisms allow the seat upper to be raised and lowered relative to the seat base. Some of the adjustable seat systems further include a front seat axis, a rear seat axis, a front base axis, and a rear base axis, a front pivot mechanism that pivotally engages both the front seat axis and the front base axis, and a rear pivot mechanism that pivotally engages both the rear seat axis and the rear base axis.

Seats for kayaks typically are provided with a substantially horizontal seat bottom and a substantially vertical seat back. The seats may be adjustable to allow for incline adjustments for the seat back to accommodate paddlers of various heights. Height adjustability of the seat itself, however, typically is not provided.
The limited options that do exist for kayak seat height adjustments generally involve placing blocks or other rigid support structures beneath the entire seat structure. On-the-fly height adjustments, while afloat, for example, may be complicated and may require the paddler to carry the blocks or other rigid support structures at all times.


The present invention discloses a thin film transistor and a method of fabricating the same. The thin film transistor includes an insulating substrate; and a semiconductor layer, a gate insulating layer, a gate electrode, an interlayer insulator, and a source/drain electrode which are formed on the substrate, wherein the gate insulating layer is formed of a filtering oxide layer having a thickness of 1 to 20 Å.

1. Field of the Invention
The present invention relates to a thin film transistor and a method of fabricating the same and, more particularly, to a thin film transistor having excellent characteristics and a method of fabricating the same in which a dual capping layer is formed of an oxide layer that a metal catalyst is difficult to diffuse and a nitride layer that a metal catalyst is easy to diffuse, a metal catalyst layer is formed on the dual capping layer, and then a crystallization process is performed to form a polysilicon layer having a large-size grain because the metal catalyst does not easily pass through the oxide layer and so a small amount of metal catalyst contributes a crystallization, and a semiconductor layer is formed of the polysilicon layer.
2. Description of the Related Art
In thin film transistor ("TFT") used in a display device, a semiconductor layer is formed such that an amorphous silicon layer is deposited on a transparent substrate made of a glass or a quartz and the amorphous silicon layer is subjected to a dehydrogenation treatment and then is crystallized.
At this time, the semiconductor layer which constitutes a source, a drain and a channel area is formed by depositing an amorphous silicon layer on a transparent substrate made of a material such as a glass using a chemical vapor deposition ("CVD") technique. The silicon layer deposited directly on the substrate using a CVD technique is an amorphous silicon layer which contains a 12% of hydrogen and thus has a low electron mobility, and when the amorphous silicon layer having such a low electron mobility is heat-treated and crystallized into a silicon layer of crystalloid structure having a high electron mobility, the silicon layer may be damaged since hydrogen contained therein may burst. In order to prevent a burst of hydrogen which may occur during crystallization, a dehydrogenation process is carried out. The dehydrogenation process is performed such that a heat-treatment is performed in the furnace at a temperature of more than about 400° C. for tens of minutes to tens of hours. Then, the dehydrogenated amorphous silicon layer is subject to a crystallization process.
The crystallization technique which crystallizes an amorphous silicon layer to form a poly silicon layer includes a solid phase crystallization technique, an excimer laser crystallization technique, a metal induced crystallization (MIC) technique, and a metal induced lateral crystallization (MILC) technique. The solid phase crystallization technique is one which heat-treats and crystallizes an amorphous silicon layer for several hours to tens of hours at a temperature of less than about 700° C. which is a temperature that may transform a glass which forms a substrate of a display device on which a TFT is formed. The excimer laser crystallization process is one which scans an excimer laser to an amorphous silicon layer to be heated and crystallized at a high temperature for a very short time.
However, the solid phase crystallization technique has disadvantages in that a relatively lengthy processing time is required and a substrate is exposed to a high temperature for a long time and thus may be easy to transform. The excimer laser crystallization technique has also disadvantages in that a high price laser device is needed and also an extrusion may occur on a crystallized surface so that an interface characteristic between a semiconductor layer and a gate insulating layer is bad. The MIC or MILC technique has disadvantages in that a large amount of metal catalyst remains on the polysilicon layer to thereby increase a leakage current of the semiconductor layer of the TFT.

Thin film transistor and method of fabricating the same


A catalyst 3 which has oxygen storage performance is installed in an engine exhaust passage 2, an oxygen storage amount is estimated based on the output of an upstream air-fuel ratio sensor 4 installed in the upstream of the catalyst 3, and an air-fuel ratio is controlled so that this oxygen storage amount coincides with a target value. When the output of a downstream air-fuel ratio sensor 5 has become lean or rich for longer than a fixed time, the output of the upstream air-fuel ratio sensor 4 is corrected based on the output of the downstream air-fuel ratio sensor 5 placed in the downstream of the catalyst 3. In this way, the output fluctuation due to deterioration of the air-fuel ratio sensor 4 upstream of the catalyst is corrected, and the catalyst oxygen storage amount is always precisely controlled to the target value.

This invention relates to an air-fuel ratio controller of an engine.
A catalyst which purifies engine exhaust known in the art which has oxygen storage capacity, absorbs oxygen when the air-fuel ratio of the exhaust is lean, and releases the absorbed oxygen when the air-fuel ratio of the exhaust is rich. This is disclosed in JP 5-195842A and JP 7-259602A which are Japanese Patent Publications.
Therefore, in this catalyst, when the air-fuel ratio of the exhaust varies slightly from stoichiometric to rich or lean, the catalyst atmosphere can be maintained at stoichiometric so that oxidation of HC, CO and reduction of NOx are both performed well.
However, there is a limit to the oxygen storage amount of the catalyst. If this is exceeded, the catalyst atmosphere becomes lean, and moreover, when the air-fuel ratio is rich and the oxygen storage amount becomes zero, the catalyst atmosphere becomes rich.
As a result, if the air-fuel ratio is controlled so that the oxygen storage amount of the catalyst is always about xc2xd of the maximum oxygen storage amount, the oxygen absorption and release capacities of the catalyst are equalized so that it is possible to cope when the air-fuel ratio fluctuates to either rich or lean from stoichiometric.
For this purpose, it determines whether the oxygen in the exhaust flowing into the catalyst is insufficient or excessive based on the detection value of this air-fuel ratio sensor placed upstream of the catalyst, estimates the oxygen amount stored in the catalyst, and controls an air-fuel ratio so that this storage amount is a target value.
However, as the air-fuel ratio sensor installed upstream of the catalyst comes in direct contact with high temperature exhaust, its performance deteriorates due to the effect of the hot exhaust, and errors may appear in the detection of the air-fuel ratio. In this case, the output of the air-fuel ratio sensor shifts relatively to either rich or lean. This may also occur due to scatter in the quality of the air-fuel ratio sensor when it is manufactured.
If there are errors in the detected air-fuel ratio, the computation of the oxygen storage amount in the catalyst which is based on the output of the air-fuel ratio sensor may be incorrect, and it may be difficult to precisely control the oxygen storage amount of the catalyst to the target value. In this case, the exhaust purification efficiency of the catalyst decreases.
It is therefore an object of this invention to correctly determine whether or not there are errors in the output of an air-fuel ratio sensor.
It is a further object of this invention to correct output errors when such errors occur in the output of the air-fuel ratio sensor, and precisely control the oxygen storage amount to the target value.
In order to achieve the above object, the invention provides an engine air-fuel ratio controller which comprises a catalyst installed in an exhaust passage which absorbs oxygen when an exhaust air-fuel ratio is lean, and releases the absorbed oxygen when the exhaust air-fuel ratio is rich, an air-fuel ratio sensor installed upstream of the catalyst, which detects an air-fuel ratio upstream of the catalyst, an air-fuel ratio sensor installed downstream of the catalyst, which detects an air-fuel ratio downstream of the catalyst, and a microprocessor.
The microprocessor is programmed to control a fuel supply amount of the engine to obtain the stoichiometric air-fuel ratio, which is a target air-fuel ratio, based on the detection value of the upstream air-fuel ratio sensor, to estimate the oxygen storage amount absorbed by the catalyst based on the detection value of the upstream air-fuel ratio sensor, to modify the target air-fuel ratio so that the estimated oxygen storage amount coincides with the target value, and to determine whether or not there is an error in the output of the upstream air-fuel ratio sensor based on the detection value of the downstream air-fuel ratio sensor, and correct the detection value of the upstream air-fuel sensor according to this determination result, and determine that there is a fault in the upstream air-fuel ratio sensor when the absolute value of the integral of the detection values of the upstream air-fuel ratio sensor exceeds a predetermined value.
The details as well as other features and advantages of the invention are set forth in the remainder of the specification and are shown in the accompanying drawings.


A server selectively filters and caches internet downloading requests from attached terminals, subsequently resubmitting cached requests appropriately. With the terminals connected to the internet via the server, the server is a focal point for all internet requests. Initially, the server receives a request from an attached terminal to download desired information from the internet. The received request contains a download code, such as a universal resource locator, identifying the desired information. The server determines whether the requested download should proceed based upon information obtained from one or more of sources such as (1) server-related limitations and status, (2) limitations set forth in a user profile, and (3) characteristics of the download itself, obtained from the download code and by tentatively forwarding the request to the internet and inspecting an initial response. The server applies certain criteria to these current conditions. If the criteria are satisfied, the server proceeds to receive the complete response from the internet and then forward the response to the requesting terminal. If the criteria are not satisfied, the current conditions are not appropriate for the user's particular request. In this case, the server caches the download code (if not already cached), sends a message to the internet to abort the request, determines when to resubmit the request in compliance with the criteria, and schedules resubmission of the download code to the internet at the determined time. If conditions warrant, the server may forego resubmission of the request.

1. Field of the Invention
The present invention relates to the exchange of data over a network such as a public or private internet. More particularly, the invention concerns the operation of a server to selectively filter and cache internet access requests from the computers attached to the server, and subsequently resubmit the cached requests appropriately.
2. Description of the Related Art
Access to an "internet" is imperative for most computer users today. Public and private internets provide an especially convenient means for exchanging information. Internet users can quickly transmit data to others internet-connected sites, as well as research various subjects by downloading a variety of materials, such as text, graphics, and executable programs. Although the term "internet" is usually associated with the global and public Internet, there are both public and private internets. Private internets, often called "intranets" or "enterprise internets," often have access limited to employees of a particular company. One of the earliest and largest intranets, for example, is the network of the International Business Machines Corp.
An internet is an open interconnection of networks, supporting the exchange of information among various attached computers. An internet includes a network of routing computers, which receive access requests and cooperatively route the requests to appropriate host computers capable of executing the request. Advantageously, routing computers and hosts may use almost any different type of architecture and operating system. Within an internet, communications are typically conducted under a standard protocol, such as Transmission Control Protocol/Internet Protocol ("TCP/IP"). Internets may employ a variety of electronic transport media, such as telephone lines, optical fiber, satellite systems, local area networks, etc. Users can access internets by a number of different means. In one example, a user's computer connects to a host computer directly via telephone line, cable television line, ISDN line, or another line, the host computer itself being coupled to internet routers by a T3 connection or other suitably fast link. In another example, a user's computer may be coupled to a network, such as a local area network, which connects to an internet by an appropriate means, such as a T3 connection.
Although the depth of information available through internets is nearly unlimited, there are definitely limits to internet access speed. Even the fastest internet access links can only carry so much data in a given period of time. Due to the limited communications bandwidth of internet access links, internet users may confront a number of different penalties. For example, users with local network connection to an internet may experience slow download times because or the local network's internet workload from other users. In this case, since the network server operates as a conduit to the internet, it may be burdened by many different simultaneous user requests to download information from the internet. In a corporate intranet environment, users can suffer from slow network performance despite whether their particular download request is urgent or not. For example, one user with a particularly urgent request to download critical accounting information may be delayed because of many other users busy obtaining weather information, checking stock prices, idly "surfing the net," and doing other less urgent tasks.
Especially frustrating is the fact that burdensome internet access tasks can prevent the network server from efficiently completing other processing tasks, completely unrelated to internet access. For instance, a large number of concurrent internet communication requests may slow the network server's completion of spreadsheet programs, personal calendars, mathematical computations and modeling, and other programs running on the network on behalf of individual users.
On the other hand, users that individually connect to the internet can avoid many of the problems experienced with internet access through local networks. Nonetheless, users with individual internet connect on still encounter different problems of their own. If the user's internet link is a telephone line, for example, long downloads may result in higher charges from the telephone company, and longer periods during which a shared telephone line is unavailable for other purposes, such as voice calls and fax use. Consequently, known approaches to internet access are not completely adequate for some applications due to certain unsolved problems.

Selective internet request caching and execution system

International Business Machines Corporation