A covered self-expanding stent (114, 130, 132) with a length of 200 mm or more can be restrained against axial movement with a pusher (40) within the lumen of the stent that carries a spiral of wire (48) that provides protrusions that are accommodated within a luminal covering layer (24) radially inside the stent body. The protrusions distribute the stress over the full length of the stent. The pusher can be removed from the stent lumen by “unscrewing” the spiral relative to the covering layer (24). When the stent expands, the pusher can be withdrawn proximally, out of the stent lumen, without any need for rotatory movement. The covered stent can utilize a variety of stenting rings (110-118) along its length that manifest different mechanical properties so that the implant can exhibit mechanical properties that vary over its length, to suit the specific body and stenting site to which it is to be introduced.

This invention relates to a self-expanding stent graft for percutaneous transluminal delivery. Such a prosthesis can be regarded as a "lining" for a short length of a bodily lumen. Such lumens are often arteries but need not be. For example, stents are often used in the ureter or in the biliary tree. A prosthesis of larger diameter could be placed in the oesophagus or the trachea.
Up until now, these prostheses have had a relatively short length, and are used for treating short lengths of bodily lumen, where disease is local. The present inventor has realised that it would be useful to have a prosthesis with a length significantly longer than that available with the current stents and grafts. Specifically, the present inventor has recognised the usefulness of a stent graft having a length of at least 200 mm, and has realised how this objective can be accomplished.
In the early days of development of percutaneous, catheter-delivered stents for bodily lumens, there were proposed stainless steel cages to be mounted on a balloon and expanded at the site of stenting by inflation of the balloon in the stent lumen, to cause plastic deformation of the struts of the stainless steel cage, to achieve one way expansion of the radius of the cage, whereupon deflation of the balloon would allow the delivery system to be removed, leaving the expanded stent cage in place. Thereafter, it was proposed to cover the stainless steel cage stenting rings, to make available corresponding stent grafts.
Another form of stent, also of stainless steel, was the self-expanding form of stent, contained within a sheath until proximal withdrawal of the sheath would allow the resilient stenting ring to expand radially by elastic deformation, again allowing the delivery system thereafter to be withdrawn proximally.
The number of materials that are biologically compatible, yet with mechanical characteristics strong enough for stenting, is severely limited. Besides stainless steel, another available material is a nickel-titanium shape memory alloy which goes under the trade mark NITINOL. Stents of this material are self-expanders, again confined by a radially-overlying sheath which is withdrawn proximally to release the stent to expand radially. Another candidate is a cobalt-chromium-nickel alloy identified by the trademark PHYNOX.
It will be appreciated that proximal withdrawal of a surrounding sheath of a self-expanding stent requires a tension force in the sheath which, other things being equal, increases as the axial length of the stent increases, since the entire length of the stent within the sheath is, at the site of stenting, imposing radially outward pressure on the sheath, thereby raising the forces of friction acting between the stent and the sheath. Similarly, for the operation of loading the self-expanding stent into a suitable catheter-based delivery system, some means has to be found for advancing the sheath over the length of the stent, or pulling the stent into the sheath, until its full length is within the sheath.
The forces of friction have, until now, imposed an upper limit on the overall dimensions of length and diameter of a self-expanding stent graft that can feasibly be installed in a surrounding sheath, and then released from the sheath at the site of stenting.
The present inventor has found a way to install and deliver self-expanding stent grafts of greater dimensions than hitherto, in particular, stent grafts of greater length than hitherto.
International Patent Application No. PCT/EP2004/004486 (PCT 486), published as WO 2004/096091, is from the present inventor and declares the priority of British Patent Application No. 0309616.1 of the present inventor. The present specification includes disclosure from the description, claims and drawings of PCT/EP2004/004486.
From consideration of PCT 486, it is immediately apparent that a feature useful for loading and delivery of extra long self-expanding stent grafts, covered stents and other implants is an element that sits within the lumen of the stent graft and is characterised by a spiral formation on its radially outward-facing cylindrical surface. Edge surfaces which define the spiral form engage with the luminal face of the graft or cover material of the implant, throughout the length of the implant. In this way, axial force can be passed between the implant and the element within its lumen, along the full length of the implant, via the spiral form edges. It is this distribution of axial forces along the full length of the implant which carries, along the full length, the friction forces operating between the abluminal surface of the implant and any surrounding sheath of a delivery system for the implant.
With the use of such a means to distribute friction forces along the full length of the implant, it is envisaged that implants of significantly more than 200 mm length could be deployed. Specifically, it is envisaged to deploy, with the spiral form element mentioned above and shown in the annex to the specification, stent grafts of around 500 mm in length. Thus, for the first time, it becomes feasible to contemplate a stent graft lining for, for example, the femoral-popliteal artery of the human leg, along a substantial or even major part of its length.
DE-A-10016920 discloses electroplating a metal mesh workpiece with a length of 5 to 200 mm prior to using the workpiece to make medical implants.
FR-A-2760351 discloses making from filament a helical pattern stent which may have a length more than 20 mm, or even more than 50 mm.
FR-A-2742042 discloses making a vascular prosthesis to replace natural bodily tissue and with a length which may be as much as 120 cm.
WO 03/049641 discloses a radially expandable stent which consists of a plurality of axially spaced radially expandable cylindrical stenting rings aligned along a common axis to define a lumen and arranged around a polymer tube. The tube provides longitudinal and flexural flexibility to facilitate transluminal advance and delivery through a tortuous bodily lumen, and the rings provide the strength to maintain patency of the lumen
EP-A-788 332 discloses a self-expanding braided metallic stent tube and a delivery system that includes a soft annulus within the stent lumen that deforms and mechanically engages with the mesh of the stent for restraining the stent from axial movement relative to the inner catheter of the delivery system, during axial movement of a sleeve surrounding the stent. The disclosure of EP-A-596 145 is similar.
EP-A-836 447 discloses a system for delivering a self-expanding stent, in which a stopper ring on an inner catheter abuts the proximal end of the stent tube during proximal withdrawal of a sheath which surrounds the stent.
The tubular envelope of a stent usually has apertures through its wall thickness to permit radial expansion. Thus, an uncovered or "bare" stent has a tube wall that is normally liquid-permeable. However, there are many occasions when a stent with a liquid-impermeable wall that is not apertured would be desirable. To meet these needs, a family of "covered" stents have been developed. Applicant has particular experience with stent tubes provided with a covering of expanded polytetrafluoroethylene (ePTFE). Typically, the stent tube is covered by luminal and abluminal covering layers of ePTFE, which are bonded to each other through the apertures in the stent tube wall.
During manufacture of stents and delivery systems, attention must be paid to sterility. Specifically, one needs procedures for loading a covered stent into a catheter delivery system that will allow sterile conditions to be maintained, or at least thereafter achieved.
Typically, to introduce a covered self-expanding stent into a catheter delivery system, a tool needs to be provided that compresses the covered stent radially inwardly, down to a diameter which is smaller than the available diameter of the lumen of the delivery system that is to receive the compressed covered stent. Clearly, any structure within the lumen of the stent that resists further inward compression is better avoided, when the objective is to compress the stent radially inwardly as much as the system will tolerate, so as to keep the outside diameter of the delivery system at its distal tip as small as possible.
However, the stent has to be maintained at the stenting site during proximal withdrawal of the surrounding sheath, for progressive release of the stent at the stenting site. If there is no structure within the lumen of the stent, then the entire stress imposed on the stent, to prevent it moving proximally with the proximally withdrawing surrounding sheath, has to be carried on the proximal end annulus of the compressed stent. Often this is not really a problem, especially when the stent is short and not particularly highly compressed radially inwardly, and especially when friction between the compressed stent and the surrounding sheath can be brought to a particularly low value.
Nevertheless, it is important for management of fatigue resistance to avoid imposing on any point of the stent tube a level of stress that is higher than the designed maximum. A stent tube made of metal is susceptible to fatigue failure, if only because it is subject to cyclic stress at the frequency of the heartbeat of the body in which it is installed. For this reason, regulatory authorities require stringent fatigue performance standards which impose on manufacturers of stents and delivery systems an onerous burden to avoid any unforeseen stresses on the stent tube.
The state of the art contains numerous suggestions to use an element within the lumen of the stent to restrain the stent from proximal withdrawal when the surrounding sleeve is withdrawn proximally. However, these systems are of interest only for bare stents, because they rely upon mechanical interaction between surfaces on the stent pusher within the stent lumen, and boundary surfaces of apertures within the wall thickness of the stent tube.
The present disclosure explains how to load self-expanding covered stents into catheter delivery systems which offers better management of stress within the stent tube, facilitates quality control and maintenance of sterile conditions, and is applicable to a range of stent tube designs. In a nutshell, a pusher is provided within the lumen of the covered stent, which exhibits protrusions along the length of the lumen, that interact with the covering of the stent along the length of the stent.
By distributing over the full length of the stent tube lumen the forces which necessarily have to be imposed on the stent in order to:    1. load it into a delivery sheath; and/or    2. restrain it from proximal movement during proximal withdrawal of the delivery sheath during placement of the stent at the stenting siteone can manage the distribution of stress within the stent tube so that it is distributed more or less homogeneously, rather than concentrated at one end of the stent tube. By using the covering of the stent as a link in the chain of stress distribution from the pusher to the sheath, one can further avoid any point at all within the metal stent tube which is subject to stress at a level higher than a prescribed design maximum. By their nature, stent coverings are more flexible than the stent tube itself, so have the capability to distribute stress from a point on a metallic stent pusher to an area, or volume, of the material of the stent tube.
Furthermore, the flexibility of the stent covering is sufficient to accommodate the protrusions of the pusher, irrespective where they lie in relation to the apertures of the stent lumen. With the present concept, there is no need to align in any way the protrusions of the stent pusher with the apertures of the stent lumen. Thus, a further technical effect is valuable simplicity and speed of operation in loading a range of different covered stent products into their corresponding delivery systems.
Yet a further advantage is that the stent pusher needs no undercut or rebated surfaces to achieve its effect, and the pusher has an outside diameter which is smaller than the inside or luminal diameter of the stent tube. These factors give greater reassurance that, when the stent has been placed, and the pusher has to be withdrawn from the stent lumen, there will be no inadvertent or unintended snagging of surfaces of the pusher on surfaces of the covered stent, or indeed of any bodily tissue that might impinge on the surfaces of the stent pusher after it has been withdrawn proximally out of the stent lumen.
Of particular interest is a stent pusher with protrusions arranged helically. Such protrusions will achieve the desired pushing effect when the pusher is subject to axial stress. However, arranging the protrusions helically would allow the pusher to be withdrawn from the stent lumen, even while the stent is within the sheath of the delivery system, simply by "unscrewing" the shaft of the pusher until the helical protrusions emerge, by continued rotation of the pusher relative to the stent, out of the lumen of the stent. In this way, one can employ the stent pusher as part of a system for loading a covered stent into a sheath, but then remove the pusher, and pass the sheath stent assembly onwards for incorporation into a delivery system which will use an entirely different stent pusher.
To assist understanding of the present invention, to be described below, and to assist in its realisation, reference will now be made to FIGS. 3 to 5 of the accompanying drawings (which come from above-mentioned PCT 486) and in which:
FIG. 3 is a side view of a tool for loading a covered self-expanding stent into a sheath;
FIG. 4 is an enlarged view of the distal end (II) of the tool of FIG. 3; and
FIG. 5 is an axial diametral section through the distal tip of a stent delivery system.
FIG. 5 shows only the distal tip of the delivery system, but the remainder of the system is not part of the contribution which the present invention makes to the art and, in any event, is familiar to those skilled in this art. The basic components of a conventional delivery system for a self-expanding stent are an inner catheter and an outer sheath, the purpose of the outer sheath being to confine the self-expanding stent radially, to the small radius delivery configuration, until its release at the site of stenting. The purpose of the inner catheter is to restrain the stent from proximal movement with the sheath, while the sheath is being withdrawn proximally.
Looking at FIG. 5 of the drawings, the outer sheath 10 of the delivery system has an integral tapered tip 12 which narrows down to an end ring 14 of a diameter appropriate to receive a guidewire (not shown). Confined within the sheath is a covered stent of which the structural foundation is a stent body 20 which is an apertured tube of nickel-titanium shape memory alloy. The stent is covered by an outer layer 22 of ePTFE on the abluminal surface of the stent body, and a covering layer 24 of ePTFE on the luminal inner surface of the stent body 20, with the inner and outer layers 24 and 22 being fused together where they can be pressed together within the apertures 26 of the stent body.
Between the luminal and abluminal surfaces of the stent body 20 is a wall thickness of the metallic stent material annulus. This annulus lies between the luminal and abluminal major surfaces of the stent body and, in the specification, we use the terminology "envelope" to indicate the generalised surfaces of the luminal and abluminal major wall surfaces of the stent body. Thus, the outer layer 22 lies outside the abluminal envelope stent body 20, except where it protrudes into the apertures 26 for fusing with the inner layer and, likewise, the inner layer 24 lies radially within the luminal envelope of the stent body 20 except where it protrudes radially outwardly into the stent body apertures 26.
The stent body carries a ring of tantalum radiopaque markers 28 at its distal end and a second ring of radiopaque tantalum markers 30 at its proximal end. It will be appreciated that the presence of these markers may further militate against pushing structures that bear against the end surface of the stent to be deployed.
The inner catheter 40 defines a guidewire lumen 42. Conveniently, the inner catheter 40 is based on a stainless steel hypo tube. This of course endows the entire delivery system with substantial pushability, but the hypo tube can also be made remarkably flexible for the desired trackability of the system through particularly tortuous bodily lumens. In any event, if stainless steel is not flexible enough for the distal zone of the delivery system, then it would be feasible to build the inner catheter 40 from other more flexible materials such as particular polymers.
The stent delivery system can be arranged as an over-the-wire system with a full length guidewire lumen, or a rapid exchange system with a guidewire lumen only in a distal zone of the system. The outer sheath 10 can be withdrawn by a full length outer catheter or a pull wire within a shaft lumen. For an example of delivery systems of the present Applicant, see WO 03/003944 and WO 2004/062458.
The inner catheter has an abluminal surface 44 which carries on it a wire 46 arranged as a helix so as to provide a plurality of protrusions (at least when seen in section as in the drawing) on the abluminal surface 44. In the illustrated embodiment, the wire is of stainless steel, fixed to the stainless steel tube 40 by deposits 50 of a bonding material which could be a weld bead or a suitable adhesive.
In any event, as can be seen on the drawing, when the stent body is radially inwardly compressed down onto the inner catheter 40, the inner ePTFE layer 24 deforms to accommodate the protrusions 48, but the protrusions 48 do not reach radially outwardly as far as the luminal envelope of the stent body 20.
In use, when the illustrated distal tip zone has been brought to the site of stenting, the outer catheter 12 is carefully and progressively withdrawn proximally so that the tip stretches and slides over the outer ePTFE layer 22 of the stent, progressively releasing the stent, starting at its distal end near the markers 28.
As the stent progressively expands, the inner ePTFE layer 24 moves radially outwardly away from the protrusions 48 until, with complete withdrawal of the tip 12 proximally beyond the proximal ring of radiopaque markers 30, the stent is fully released. It will be appreciated that there is then a substantial annular gap between the lumen of the expanded stent and the envelope containing the protrusions 48, enabling the inner catheter 40 also to be withdrawn proximally from the lumen of the stent without any snagging of the inner catheter 40 on any part of the stent.
It will be appreciated that, for loading a stent into a sheath, an analogous sequence of steps may be performed, with radially inward compression of the stent body down onto the protrusions 48 of a loading tool which has a shape in section analogous to that of the inner catheter 40. Once the stent has been so compressed, a suitable sheath can be offered up to one end of the compressed stent tube, and then the stent can be urged axially into the sheath by imposing an axial force on the line of protrusions 48 through the tube 40 on which they amounted, so that this force is transferred from the protrusions 48 to the inner layer 24 and thence to the stent body 20 and the outer layer 22, so that the entire covered stent device is urged by the protrusions 48 into the receiving sheath.
A particular advantage of the helical structure of protrusions 48 as shown in the drawing is that the pusher within the stent lumen can be removed trouble-free from the lumen of the stent even when it is in a compressed configuration within a sheath as shown in the drawing, simply by "unscrewing" the pusher from within the stent lumen.
Drawing FIGS. 3 and 4 show a suitable loading tool 60, long enough to push the covered stent along the full length of the outer catheter 10, after being compressed and introduced and advanced into the proximal end of the outer catheter. The tool 60 features at its distal end a radially-outwardly protruding wire spiral 62 with a configuration corresponding to that of the protrusions 48 and the inner catheter 40 (although non-corresponding configurations are also feasible). The covered stent is compressed around the protrusions 62 before the tool 60 is used to urge the covered stent by means of the protrusions 62, from the proximal to the distal end of the outer catheter.
The illustrated embodiment shows a system in which the tapered distal tip of the stent delivery system is carried on the distal end of the outer catheter. Those skilled in the art are well-aware that many proposed delivery systems feature a tapered tip on the inner catheter instead. The present invention is just as useful in such systems as it is in systems, as illustrated, with the tapered tip on the outer catheter.
The stent on which the present device operates can be an covered self-expanding stent. The stent which is the basis of the illustrated embodiment is the one that is the preferred embodiment of WO 2002/015820 which is cut from a nickel-titanium tube. However, the invention is equally applicable to other stent design philosophies, such as stents fabricated from wire (one example is the Gianturco "Z" stent made from zig zag wire rings) or other metals, such as stainless steel. The invention is particular useful for covered stents in which only the cover connects adjacent ones of a plurality of stenting rings, because the engagement of the pusher over the full length of the stent should avoid any tendency for the stent covering to "concertina" between the stenting rings when pushed only from its trailing (usually proximal) end.


A subscriber circuit, provided with a feeding circuit for feeding the current of a call to a terminal through a subscriber line and a switching circuit group for connecting the feeding circuit to the subscriber line and releasing the feeding circuit from the subscriber line, for controlling feeding to the terminal, comprising: said feeding circuit monitoring the state of a loop of the subscriber line, converting a two-wire signal sent from the terminal into a signal predetermined coefficient-fold, and supplying the same; a level converter, connected to the subscriber line through said switching circuit group, for converting a two-wire signal sent from the terminal into a signal any coefficient-fold and supplying the same, separately from said feeding circuit; and a signal monitor for monitoring a signal, using one of an output signal of said feeding circuit and an output signal of said level converter, according to upper control information and the output of monitoring the loop of said feeding circuit, and supplying signal monitor information.

1. Field of the Invention
The present invention relates to a subscriber circuit, provided with a feeding circuit and a switching circuit group, for controlling feeding to a terminal of a telephone subscriber, and more particularly, it relates to a subscriber circuit provided with a signal monitoring function for monitoring a signal transferred through a subscriber line.
2. Description of the Related Art
Generally a voice signal for telephone call has been transferred to a telephone subscriber line, as well as a signal including predetermined information such as detection of the hook with the signal superimposed on the voice signal.
In the conventional technique, a signal monitor for the exclusive purpose is provided in order to monitor this kind of signal transferred through a subscriber line. As this kind of the conventional signal monitor, there is, for example, a device disclosed in Japanese Patent Publication Laid-Open (Kokai) No. Showa 59-128855. The conventional signal monitor circuit disclosed in the same publication comprises a high impedance dc buffer connected to a subscriber line at high input impedance, a hook detecting device for detecting the state of a hook of a subscriber line through the output of the high impedance dc buffer, and a pilot sound detecting device for monitoring a pilot sound in reply to the hook detecting device.
The conventional signal monitor is designed to monitor a signal transferred from a terminal through a subscriber line, and therefore, it is able to monitor a signal only when the terminal thereof is connected to a feeding circuit and the feeding circuit is feeding the power. When the terminal side is on the hook and the subscriber line stops feeding the current of a call, or when the feeding circuit is released from the subscriber line, it cannot monitor a signal.
The above-mentioned conventional signal monitoring technique, however, must be provided with a device for the exclusive use for monitoring a signal, and therefore, the system is increased in size and it becomes complicated, which is not economical.
This is because the pilot sound monitor owes the signal monitor of a subscriber line and the high input impedance dc buffer and the hook detecting device owe the detection of the hook of a subscriber line.
In the conventional signal monitor, the high input impedance dc buffer, that is one of the components, needs to have high input impedance, which produces such ill effects that the level of a call is deviated, echoes increase, and the like.
This is because the terminal impedance in a subscriber line is deviated. Namely, since a telephone signal terminates at constant terminal impedance at the time of a telephone call, it produces little effect on the call logically if terminal impedance<<dc buffer. Actually, since even the high-input impedance has limited value, it is impossible to be completely free from ill effect, but deviation of the terminal impedance in the subscriber line will produce some effect on the call.
The conventional signal monitor cannot monitor a signal of a subscriber line when the feeding circuit stops feeding and the feeding circuit is cut off from the subscriber line. Therefore, for example, when reversing the feeding polarity of a subscriber, since the feeding circuit is stopped and the feeding circuit is once cut off from the subscriber line, the signal monitor becomes impossible.


Long-chained polymer compounds are useful to viscosify aqueous brine fluids so that they can function as drilling fluids, completion/workover fluids, fracturing fluids, agricultural products, cleaning compounds, etc. These polymers may be hydrated with a microemulsion or lactescent emulsion prior to being added to the target fluid. The rate and completeness of hydration by this method are controlled and improved. In one non-limiting embodiment the microemulsion includes a polar hydrocarbon component, a nonpolar hydrocarbon oil, a small amount of water, a surfactant and optionally a co-surfactant.

Polymer compounds are frequently used to increase the viscosity of drilling fluids, fertilizers, completion fluids, etc. to improve the fluids' ability to carry solids, prevent fluid loss, etc. Further, situations arise when it is desired to increase the viscosity of an aqueous cleaning fluid so that it releases more slowly from a hard surface that is to be cleaned of grease, oil or other debris.
Often, problems arise when attempting to viscosify fluids such as brines that have high concentrations of dissolved salts, such as CaBr2, CaCl2, NaBr, ZnBr2 and the like. When polymer is added directly to these brines, some of the difficulties encountered include, but are not necessarily limited to: (1) failure of the polymer to yield or viscosify in the aqueous environment; (2) formation of "fish-eyes"; (3) formation of a distinct gel phase; (4) slow rate of viscosification or hydration of the polymer; and (5) incomplete polymer hydration.
Failure of the polymer to hydrate is a more extreme problem when the polymer used to viscosify the aqueous fluid does not interact with the target fluid. The desired effect would be for the polymer to absorb water or "hydrate" such that it eventually becomes soluble in the aqueous medium and imparts a higher viscosity to the brine as compared with the brine without the polymer. This situation arises when there are high concentrations of salts dissolved within the aqueous fluid such as is the case with completion and workover brines. In these aqueous brines there is but a limited amount of free water available to hydrate the polymer. In addition, the small amount of water that is present in the brine can be chemically interacting with the dissolved salts and further limiting its activity. The net result is that the chemical potential differential is very low if not non-existent and hydration of the polymer does not occur.
When polymer is added to brine as a dry powder, lumps may be created that are referred to in the industry as "fish-eyes". A fish-eye is a term that is used to describe the small polymer particles having a hydrated outer shell with a dry core. They may be prevalent in systems where there is inadequate mixing and therefore, low shear forces. Note that in this discussion particles are used to describe discrete groupings of polymer. Thus, a particle, in actuality, is a mass of tangled polymer chains that are wrapped around each other and held in close contact due to hydrogen bonding. Many polymers, on a molecular level, will form hydrogen bonds to each other creating a tight mass that does not become dispersed until the shearing forces exceed these bonding forces. Nevertheless, rapid hydration will take place at the interface between the polymer droplet and the aqueous medium. This surface hydration leads to the formation of a tight gel-like surface that limits the further diffusion of water into the core of the polymer mass, leaving interior polymer chains unhydrated. The fluid will then have different sized gel particles that do not dissolve. Dissolving is a second step in the viscosification process where the polymers that have hydrated, begin to untangle and become discrete entities unto themselves in a brine fluid. The size and number of polymer particles relates inversely to the level of agitation in the mixing vessel.
Fish-eye formation is not a good thing. Because the hydration is incomplete, the use of expensive polymer is very inefficient, as more polymer must be used to achieve the desired viscosity. In addition, these partially reacted polymer gel particles can be damaging to the producing formation of an oil or gas well. These unhydrated particles can flow into a producing formation and cause plugging. Often their successful removal is difficult if not impossible. This plugging, which can result in formation damage, may likely reduce the hydrocarbon production from the reservoir.
The polymer gels may also plug filters, limiting their on-stream time and making them difficult to clean and bring back on line. The filter blinding difficulty leads to increased downtime on a rig or production platform. Downtime on a rig relates directly to increased costs. In certain brine environments, the hydration proceeds beyond the fish-eye stage, but the brine and the gelled polymer remain as separate phases. Some of the brine hydrates the polymer, but the hydrated polymer remains as a separate phase from the brine because the individual polymer chains are still entangled. This problem is known to occur in heavy brines when the mixing capabilities are less than adequate. In both situations, inadequate mixing limits the homogeneity of the final viscosified brine. By not hydrating the polymer completely, more polymer is required to attain the desired viscosity leading to higher polymer costs.
To a certain degree, the problems with polymers like hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), hydroxyethylcarboxymethylcellulose (CMHEC), and the like may be reduced with intense mixing during addition and further improved by increasing the temperature. However, excellent mixing of polymer and brine is not always possible and seasonal variations in temperature can also lead to poor hydration of the polymer. Even with good mixing, hydration can be slow and the fish-eyes still form, albeit smaller in size. The very small fish-eyes may be much more damaging to a producing formation because they have the potential to migrate further into the formation before becoming lodged in reservoir pore throats. At this point their removal is difficult and the very effort made to remove them may lead to even more reservoir formation damage.
The aforementioned difficulties have been recognized and steps have been taken to minimize the problems by pre-hydrating brines in a controlled environment where near-impermeable gels are avoided. Thus, products like HEC powders are pre-mixed as a liquid dispersion in a non-polar environment so that the clumping and fish-eye problems caused by hydrogen bonding are reduced. U.S. Pat. Nos. 4,330,414; 4,392,964; 4,427,556; 4,435,217 and 4,496,468 describe methods of premixing of HEC polymer prior to its addition to an aqueous brine fluid.
U.S. Pat. No. 4,330,414 relates to a hydrophilic polymer composition for use in thickening aqueous mediums comprising HEC and a water miscible polar organic liquid which acts as solvating agent for the hydroxyethyl cellulose, where the solvating agent is a type which forms a semi-solid to viscous mixture with the hydroxyethyl cellulose under certain conditions. The polymeric composition alone, or in admixture with a diluting agent which is a non-solvating agent for the hydroxyethyl cellulose, can be added to aqueous mediums, particularly heavy brines, to produce well servicing fluids.
A polymeric composition useful in the thickening of aqueous brines comprising HEC, a water miscible organic liquid and an aqueous liquid is described in U.S. Pat. No. 4,392,964.
U.S. Pat. No. 4,435,217 concerns improving the thermal aging stability of liquid suspensions of hydrophilic, water-soluble polymers in an organic liquid by adding to the suspension a liquid fatty acid. Superior liquid polymer compositions having improved resistance to settling (syneresis), thermal aging characteristics, viscosity, and dispersibility in aqueous liquids comprise from about 40% to about 55% of an organic liquid, from about 35% to about 55% of a hydrophilic, watersoluble polymer, from about 2.0% to about 4.5% of an organophilic clay suspending agent, from about 0% to about 2.0% of a dispersant for the organophilic clay, from about 0.5% to about 2.5% of a non-ionic surfactant, and from about 1.25% to about 5.0% of a liquid fatty acid.
Processes are disclosed for activating HEC in U.S. Pat. No. 4,435,564 such that the HEC will disperse and hydrate in compatible heavy brines having a density greater than about 13.5 pounds per gallon (1.62 kg/liter) containing one or more salts including one or more of calcium chloride, calcium bromide, zinc chloride, and zinc bromide, at ambient temperatures such that the HEC will be at least 80% hydrated within one hour. The activation process comprises admixing the HEC with an organic liquid which has no appreciable swelling effect on the HEC and an amine activator. The invention in the '564 patent also provides activated HEC compositions and a process of increasing the viscosity of a heavy brine utilizing these compositions.
U.S. Pat. No. 4,439,333 involves polymeric compositions for, and methods of, increasing the viscosity of aqueous brine well servicing fluids by adding to the brine a composition containing HEC, a solid organic activating agent for the HEC, and a solvent for the activating agent which also functions as a suspending medium or carrier for the HEC.
A method of producing a well servicing fluid containing zinc bromide in which an activated HEC is either admixed with a zinc bromide solution containing above about 30% by weight zinc bromide, or, in the alternative, is admixed with a non-zinc bromide containing solution to produce a viscosified solution which is then admixed with a zinc bromide containing solution is described in U.S. Pat. No. 4,476,032.
U.S. Pat. No. 4,496,468 concerns a method of activating HEC such that the HEC will hydrate in heavy brines having a density greater than about 13.5 pounds per gallon (1.62 kg/l) at ambient temperature. The activated HEC compositions so produced, and viscous well servicing compositions wherein an oleaginous liquid and a compatibilizing agent are admixed to form a viscous slurry, admixing therewith an aqueous solution of an inorganic salt which has an exothermic heat of solution, and thereafter admixing HEC therewith to form a viscous pourable composition are described.
Alkali and alkaline earth metal and zinc halide brines are also known to be viscosified with compositions incorporating a viscosity inducing hydrophilic polymer, mineral oil, oil soluble non-ionic surfactants, polar solvents, and diluent.
In spite of these improvements, concerns still exist. Pre-hydration of polymer, once started, is not easily stopped. Thus, a dilemma arises: in order to have rapid hydration or viscosification on an oil exploration rig e.g., either a powerful pre-hydrator must be added or a large amount of polymer must be added. This addition is not only expensive, but also it initiates the hydration of the polymer in the container or vessel that cannot be easily stopped. If the container used to inventory the polymer is not used promptly, then hydration may go to completion or to a point where the material cannot be removed from the container at all. This is not desirable because the polymer in the container must be in a liquid state where pourability is maintained. Otherwise, the labor costs associated with getting the polymer into the brine system will be excessive. Further, when the polymer hydration is near completion, it often has a rigid gel structure that prevents the homogeneous viscosification of the brine. Another problem that parallels that of the fish-eyes is now encountered. Solutions to these problems may involve: (1) putting less HEC or other polymer into the container, or (2) adding more of a non-reactive diluent to limit the rate of polymer hydration. These supposed remedies have their downside as well. By inhibiting the rate of pre-hydration, the rate of hydration in the brine is reduced, increasing the amount of costly rig time. Also these measures limit the amount of polymer that can be put into the container causing more containers being required at the rig location to achieve the desired effect. This means that more of the associated chemicals in the admixture per unit weight of polymer must be increased to achieve the desired viscosity effect. In addition, the labor, container and freight costs associated with this remedy will increase. Also, when the polymer concentration added from the container is low, unacceptable lowering of the brine fluid density occurs. Now additional amounts of the expensive high density brine must be added to bring the brine back to the desired density. The higher the density difference between the polymer admixture and the brine, the more serious this problem becomes. For example for high density zinc brines at the upper limit of their density, compensation with additional brine cannot be achieved without adding special formulations.
With all of these recognized issues, still another less apparent problem exists. Until the some of the approaches discussed above, fish-eyes were quite visible to the rig personnel because they were relatively large and blinded filters and shaker screens. They surmised that these larger "gel-balls" would also cause damage to the producing formations. The improvements did not necessarily cause them to disappear. Instead, they became smaller and less noticeable. While the problems associated with screens and filters were reduced, the potential for formation damage increased. These very small fish-eyes now could proceed further into the formation before causing the plugging of pore throats. This interior damage is much more difficult to reverse and much more expensive, as it reduces the well production and revenues.

Polymer hydration method using microemulsions


A ball grid array ceramic filter including a substrate having a ground layer of conductive material disposed over one of the surfaces thereof and a plurality of strips of conductive material on the other of the substrate surfaces defining resonators adapted to receive and pass RF signals. A plurality of vias extend through the substrate and define opposed ends terminating in the respective substrate surfaces. In one embodiment, a plurality of conductive spheres defining respective ground and RF signal input/output pads are disposed on the substrate surface with the ground layer thereon. Certain of the vias couple the resonators to the ground layer while others of the vias couple the resonators to respective spheres adapted for coupling to the respective RF signal input/output contacts on the top surface of a printed circuit board to which the filter is adapted to be direct surface mounted.

Ceramic block filters offer several advantages over lumped component filters because they are relatively easy to manufacture, rugged, and relatively compact. In the basic ceramic block filter design as shown in, for example, U.S. Pat. No. 4,431,977 to Sokola et al. and U.S. Pat. No. 6,559,735 to Hoang and Vangala, resonators are formed by cylindrical passages, called through-holes, which extend through the block. The block is substantially plated with a conductive material (i.e., metallized) on all but one of its six (outer) sides and on the inside walls formed by the resonator holes.
One of the two opposing sides containing holes is not fully metallized, but instead bears a metallization pattern designed to couple input and output signals through the series of resonators. The reactive coupling between adjacent resonators is dictated, at least to some extent, by the physical dimensions of each resonator, by the orientation of each resonator with respect to the other resonators, and by aspects of the top surface metallization pattern.
Although these types of RF filters have received widespread commercial acceptance for RF frequencies of 5.8 GHz or lower, efforts at improving this basic design for RF frequencies above that level has continued. Specifically, and in the interest of allowing wireless communication providers to provide additional service, governments worldwide have allocated new higher RF frequencies for commercial use in, for example, wireless base stations, WiMax base stations, WLAN, and UWB (ultra wideband) consumer and infrastructure products. To better exploit these newly allocated frequencies, standard-setting organizations have adopted bandwidth specifications with compressed transmit and receive bands as well as individual channels. These trends are pushing the limits of currently available filter technology to provide sufficient frequency selectivity and band isolation.
The need thus continues for improved ceramic RF filters which can offer selectivity and other performance improvements at 5.8 GHz and higher, all in a lower cost, smaller, higher performance, and lower height package than the ceramic filters available today. This invention provides such an improved ceramic filter.


A belt includes one or more tension members extending along a length of the belt, a jacket at least partially enclosing the plurality of tension members, and one or more layers of one or more of a fluorescent, absorbing, or reflecting material located in the belt such that when subjected to a light source, an indication of fluorescence or absorbance or reflection of the one or more layers of fluorescent or absorbent or reflective materials is indicative of a wear condition of the belt.

Embodiments disclosed herein relate to elevator systems, and more particularly to load bearing members to suspend and/or drive elevator cars of an elevator system.
Elevator systems are useful for carrying passengers, cargo, or both, between various levels in a building. Some elevators are traction based and utilize load bearing members such as belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.
Referring to FIG. 14, where a belt is used as a load bearing member, a plurality of tension members 104 are embedded in a common jacket 102. The jacket 102 retains the tension members 104 in desired positions and provides a frictional load path. In an exemplary traction elevator system, a machine drives a traction sheave 108 with which the belts interact to drive the elevator car along a hoistway. Belts typically utilize tension members formed from steel elements, but alternatively may utilize tension members formed from synthetic or natural fibers or other materials, such as carbon fiber reinforced composites.
Due to numerous factors, such as long-term service, curvature of sheave 108, multiple belts with tension non-uniformity, variability in fabrication and installation, wear 106 is observed, such as shown for example of non-uniform pattern in FIG. 14. Wear increases with duration of service, and eventually can result in the tension member being exposed to or contacting the environment, or the remaining jacket layer too thin to meet requirements for durability, traction, tracking, noise, or the like. Reliable solutions to monitor actual wear of the belt can help mitigate premature belt replacement or avoid risky belt service life extension, while reducing the cost of belt maintenance and inspection.


The disclosure discloses an information processing method for an electronic device with a touch screen. The method includes: touch with a touch screen is detected; an information pickup area is set on the touch screen according to the touch; and information in the information pickup area is picked up according to an information pickup command and the picked-up information is stored. In the disclosure, existing information, such as an image or a signature, is picked up via an information processing device, such as a stylus, on a touch screen of an electronic device; and a user can autonomously control its image, signature and other information to display on the touch screen of the electronic device when needed. Therefore, great convenience is brought to users using a portable electronic device such as a tablet PC and a smart phone, and their personalized application can also be met to a great extent.

At present, there are two common schemes in the handwriting input field of mobile terminals: input via a resistive touch screen and input via a capacitive touch screen.
An input principle of the resistive touch screen is: when a corresponding stylus is adopted for writing on such touch screen, a part where the stylus touches the touch screen may deform due to the change of a touch pressure between the stylus and the touch screen, so that the resistance of this point is changed to implement touch input of the resistive touch screen. The resistive touch screen is characterized in that it has no particular requirement on the stylus and a relatively low cost but it cannot support identification of multi-point touch. At present, the resistive touch screen is applied to a large number of middle-end and low-end mobile phones with touch screens.
An input principle of the capacitive touch screen is: a capacitive sensing device is built in the screen to form an inductance with a charged object which gets close enough to the capacitive sensing device, and the capacitive sensing device absorbs partial inductive charge through the inductance, and determines a specific touch operation location by detecting the row and column where the absorbed inductive charge is located. The capacitive touch screen can support the multi-point touch but has a certain requirement on an input medium. Generally, only a charged object can implement input. For example, the input medium is generally a finger of a person. But now, some techniques for handwriting input on the capacitive touch screen using a special stylus also appear.
Along with the emergence of high-end mobile terminal products such as tablet Personal Computers (PCs) and smart phones, the mobile terminal is increasingly becoming an important tool for daily record and writing of people. Therefore, people propose an increasingly strict requirement on each function of the mobile terminal. For example, for such product as a tablet PC or a smart phone with a large screen, people hope to utilize its accessary stylus to implement more functions besides existing text control and writing functions of the stylus, for example utilizing the stylus to implement a function like paper writing on the screens of these mobile terminals, such as drawing, signature and stamping. However, there is still no such technology in the related art.

Information processing method and device for electronic device with touch screen


A method of etching or removing an amorphous carbon organic hardmask overlying a low dielectric constant film in a lithographic process. The method includes providing a dielectric film having thereover an amorphous carbon organic hardmask to be removed, the dielectric film having a dielectric constant no greater than about 4.0, introducing over the amorphous carbon organic hardmask an ionizable gas comprising a mixture of hydrogen and an oxidizing gas, and applying energy to the mixture to create a plasma of the mixture. The method further includes contacting the amorphous carbon organic hardmask with the plasma, with the amorphous carbon organic hardmask being at a temperature in excess of 200° C., to remove the amorphous carbon organic hardmask without substantially harming the underlying substrate.

1. Field of the Invention
The present invention relates to a cleaning process used in a semiconductor lithographic manufacturing system and, in particular, to a method for etching or removing an organic hardmask such as amorphous carbon from a low dielectric constant film.
2. Description of Related Art
Integrated circuits (ICs) are fabricated on semiconductor wafer substrates by a lithographic process. The lithographic process allows for a mask pattern of the desired circuit or portion thereof to be transferred via radiant energy of selected wavelengths to a photoresist film on a substrate. Those segments of the absorbed aerial image, whose energy exceeds a threshold energy of chemical bonds in the photoactive component of the photoresist material, create a latent image in the resist. The latent image marks the volume of resist material that either is removed during the development process (in the case of positive photoresist) or remains after development (in the case of negative photoresist) to create a three-dimensional pattern in the resist film. In subsequent processing, the resulting resist film pattern is used as an etch mask to remove underlying substrates from the areas of the patterned openings in the resist layer.
Damascene processing techniques are often used in integrated circuit manufacturing, and involve forming inlaid metal conductors in trenches and vias in a dielectric layer. Openings in a hardmask layer are used to etch the desired portions of the dielectric layer to form the trenches and vias. The hardmask layer openings are themselves formed by etching through openings formed in an overlying resist layer. Hardmasks in damascene process are often made from amorphous carbon, also known as a-carbon or alpha-carbon.
The move from 248 nm to 193 nm wavelength lithography has increased the complexity of the masking integration, often requiring a multi layer stack to be deposited on top of the layer to be etched. An example of this is a three layer stack of an amorphous carbon hardmask layer covered by a SiON anti-reflective coating (ARC) layer on which conventional resist can be spun and processed. After the resist is developed, a fluorine dry etch transfers the pattern to the SiON layer. The resist is stripped in conjunction with an oxygen based etch process to remove a-carbon in the hardmask layer from the openings in the SiON layer. A dielectric etch process then transfers the pattern from the a-carbon hardmask into an underlying dielectric layer used in a dual damascene approach. Following the etching of the dielectric layer, the a-carbon hardmask layer must be removed prior to forming Cu or other metal interconnects in the backend of the wafer process flow.
Sudijono et al. U.S. Pat. No. 6,787,452 discloses a method of controlling a critical dimension during a photoresist patterning process which can be applied to forming vias and trenches in a dual damascene structure. An amorphous carbon ARC is deposited on a substrate by a plasma enhanced chemical vapor deposition (PECVD) method. The alpha-carbon layer provides a high etch selectivity relative to oxide and is disclosed as being readily removed by a plasma ashing step using oxygen. Ye et al., U.S. Pat. No. 6,458,516 teaches a method of removing a polymeric, organic masking layer using a hydrogen/nitrogen-based plasma.
Low dielectric constant (low-k) materials, i.e., those having a dielectric constant generally below about 2.7 to 3.0, have been used in damascene processes as inter-metal and/or inter-layer dielectrics between conductive interconnects employed to reduce the delay in signal propagation due to capacitive effects. The lower the dielectric constant of the dielectric material, the lower the capacitance of the dielectric and the lower the RC delay of the integrated circuit. Typically, low-k dielectrics are silicon-oxide based materials with some amount of incorporated carbon, commonly referred to as carbon doped oxide (CDO). An example of a CDO is CORAL brand carbon-doped oxides, from Novellus Systems, Inc. of San Jose, Calif. It has been found that highly oxidizing conditions are generally unsuitable for use on low-k materials. When exposed to an O2 plasma, the oxygen scavenges or removes carbon from the low-k materials. In many of these materials such as CDOs, the presence of carbon is instrumental in providing a low dielectric constant. Hence, to the extent that the oxygen removes carbon from these materials, it effectively increases the dielectric constant. As processes used to fabricate integrated circuits move toward smaller and smaller dimensions and requires the use of dielectric materials having lower and lower dielectric constants, it has been found that the conventional strip plasma conditions are not suitable.
Consequently, a need exists in the art for the development of an alternative process that effectively removes organic hardmask layers such as amorphous carbon, and that does not remove excessive amounts of the low-k dielectric materials or otherwise materially alter the properties of low-k dielectric materials.


A vegetable oil based paint stripping composition used in a process where it is applied to a substrate coated with fully or partially cured paint, having particular utility for use in stripping paint or stripping organic polymer coatings, and a method of employing same is described.

1. Technical Field
The present invention relates to a paint stripping composition used in a process where it is applied to a substrate coated with fully or partially cured paint. The composition of the present invention has particular utility for use in stripping paint and will be described in connection with such utility, although other utilities, for example, stripping organic polymer coatings, are contemplated. The present invention is also directed to a method of employing the stripping composition.
2. Brief Description of the Background Art
A paint or varnish remover should ideally remove all traces of the coating quickly and with a minimum of labor, and it should leave the substrate unharmed and suitable for reprocessing or refinishing. A number of design criteria have been identified for a modern stripper: stripping ability, lack of corrosiveness to substrates, freedom from galvanic attack at the juncture of dissimilar materials, freedom from noxious and toxic chemicals, good shelf life, high viscosity, where needed, sealable internally or with a water cap to prevent rapid evaporation, and ability to leave a readily recoatable surface. See The Encyclopedia of Chemical Technology, Third Edition, Volume 16, 762-768 (1981).
Methylene chloride paint strippers have long been the industry standard for paint stripper performance. It has been established that methylene chloride is effective for quickly softening most types of paints. It has been suggested that the effectiveness of methylene chloride results from its smaller molecular size. Its low molecular weight enables it to penetrate rapidly into a coating, and its intermediate solvency enables the coating not to be dissolved so that redisposition on the substrate is avoided. Methylene chloride removers have also been modified to increase stripping power for special purposes. These modifying chemicals include amines, alkalies and organic acids. See U.S. Pat. No. 3,538,007 to Cooper et. al. Other reported uses of methylene chloride include solvent degreasing, plastics processing, blowing agent in foams, solvent extraction, a solvent for cellulose acetate, and as an aerosol propellant.
The safe use of methylene chloride has been questioned by Federal agencies including the Food and Drug Administration (FDA). As a chlorinated solvent, methylene chloride has now been closely regulated for environmental protection. Recently, it was discovered that methylene chloride can cause tumors in rats and mice. The LD.sub.50 orally in rats (young adults) has been found to be 1.6 ml/kg. Furthermore, the threshold limiting value (TLV) has been set at 100 ppm in air. See Kimura, et. al., Toxicol. Appl. Pharmacol. 19, 699 (1971). Since these discoveries, the wide use of the solvent by industry and consumers has come under close scrutiny by federal regulatory agencies. See, U.S. Pat. No. 4,749,510 to Nelson. Accordingly, it is now highly desirable to avoid the use of methylene chloride in paint stripping formulations.
The search for an alternative product to methylene chloride has focused attention on pyrrolidone type compounds, more specifically, N-methyl-2-pyrrolidone (NMP). NMP is less toxic than many competitive aprotic solvents and does not appear to be a sensitizing agent. NMP, a dipolar aprotic solvent, has a high dielectric constant and cannot donate protons for hydrogen bonding. Consequently, many of its applications involve its strong and frequently selective solvating power. NMP is commercially available (e.g., from BASF Wyandotte or GAF) and used industrially as a processing aid for polymeric resins, in petroleum processing (e.g., the extraction of aromatics from lube oil), for the production of electronic circuitry, and as a general industrial cleaning ingredient. NMP is a colorless liquid with a mild amine odor, is miscible with water as well as various organic solvents. See the Encyclopedia of Chemical Technology, Third Edition, Vol. 19, 514-520 (1981).
Although NMP was recognized as an early candidate for replacing chlorinated solvent type paint strippers, it was soon discovered that a formulation based entirely on NMP had a number of disadvantages.
For example, NMP has low viscosity and low adhesive properties which work against its efficiency to remove dried coats of paint on a vertical surface. In U.S. Pat. No. 4,764,222 to Colegrove, a NMP composition is reported where a viscosifying agent (rhamsan gum) is added to the NMP to improve the ability of the composition to cling to a painted surface when inclined in a vertical position. An effort to optimize or target the paint removing efficiency and water solubility of NMP, while at the same time controlling and minimizing any potential toxicity and volatility, has led to a variety of specific formulations combining NMP with other organic and inorganic compounds. In U.S. Pat. No. 4,276,186 to Bakos et. al., cleaning compositions containing at least 50% by weight of NMP and at least about 5% by weight of a water miscible alkanolamine and about 0-35% by weight of a hydrocarbon solvent were described as especially suitable for removing solder flux from a ceramic substrate. In U.S. Pat. No. 4,664,721 to Valasek, non-aqueous compositions of NMP, butyl cellosolve and cyclohexanone and a surfactant are disclosed which degraded or solubilized broad classes of printing ink residues on printing screens. In U.S. Pat. No. 4,812,255 to Suwala, an aliphatic organic acid, and alkylene glycol ether and NMP are combined and reported effective as an overall composition for paint removal. In U.S. Pat. No. 4,732,695 to Francisco, a paint stripper and coatings remover composition consisted of three essential components: NMP, a mixture of aromatic hydrocarbons and benzyl alcohol. In U.S. Pat. No. 4,749,510 to Nelson, there is described a paint stripping composition comprising about 20-90% by weight NMP, 30-70% by weight aromatic hydrocarbon solvent, and about 1-15% by weight of either formic, oxalic, acetic, citric, gluconic or glutamic acid. According to another aspect of Nelson, organic amines such as diethanol amine could replace the various organic acids. In U.S. Pat. No. 4,780,235 to Jackson, there is described a composition comprising at least 20% of at least one C.sub.1 to C.sub.4 dialkyl ester of at least one C.sub.4 to C.sub.6 aliphatic dibasic ester, in combination with 1-50% of such a nonhalogenated solvent such as NMP, and a second type of non-halogen containing solvent such as aromatic naptha.
Finally, for purposes of further illustrating the background art, reference is also made to the prior filed and commonly owned U.S patent application Ser. No. 398,052 which describes the use of 5-membered lactams in combination with compounds such as ethyl-3-ethoxypropionate. This particular composition provided enhanced solvating capability as compared to some of the earlier-mentioned lactam based strippers, along with partial water solubility for ease of removal, with non-toxic and biodegradable environmental characteristics.
Finally, an ARCO Chemical Company Technical Update recently suggested that NMP was the key active ingredient when combined at high dilution ratios (35-40%) with either soybean or coconut oil. However, it is to be emphasized that there was no appreciation, as disclosed herein, that natural oils themselves become active in the paint removing process since: (1) lowering the overall individual oil concentration develops a synergism between the oils and NMP that cannot be attributed to an increase in NMP levels alone; and (2) mixtures of oils act synergistically in combination with NMP at a much broader range of NMP concentrations than previously reported.
It can therefore be seen that the combination of NMP with a variety of organic compounds represents what has been a long-standing effort to maximize the stripping ability of this alternative paint and coatings remover. While some of the presently disclosed paint strippers have relied upon formulations and proportions of organic compounds in combination with NMP, none have recognized the novel and enhanced solvating power of the present invention which utilizes a natural oil component that is commercially widely available, less expensive than NMP, removes certain paints, coatings, inks or crayon at the same or better rate than NMP alone, can replace the majority of NMP in a given formulation, and are biodegradable, non-flammable and no-toxic.
It is accordingly an object of the present invention to provide an effective non-methylene chloride paint stripper composition that can be readily mixed and formulated to produce a stripper with the aforementioned solvating capability.
Another object is the provision of a stripper of the above type which can be applied by any conventional method, including wetting, wiping, spraying, brushing, dipping, troweling or otherwise.
Yet another object is to provide an effective composition with the aforementioned properties for cleaning urethane, polyester and epoxy compounds off of tools, molds, etc., particularly before the cure is complete.
A still further object is to provide a stripper composition of the above type which can be completely removed by water.

Vegetable oil based paint removing compositions


A method and apparatus for agent-less auditing of a server, wherein the apparatus processes data for auditing a server. One or more portions of audit information (e.g., transaction log, trace log, or both) are coupled from a target server to an information server. The one or more portions of the audit information are processed at the information server to create audit data. The audit data is stored in an audit data repository.

1. Field of the Invention
Embodiments of the present invention generally relate to auditing events occurring upon a server. More particularly, the present invention relates to a method and apparatus for creating and processing audit data from events within a target server, without using an agent that resides on the target server.
2. Description of the Related Art
A software agent is a piece of computer code (e.g., C++, Java, etc.) that acts on behalf of a user and/or another computer program in an agency relationship. The software agent may comprise functions, methods, and objects. For the most part, the software agent is defined by its behavior.
A software agent is generally capable of operating autonomously. Usually, software agents run in the background of a system (e.g., operating system, control system, etc.) to analyze their computer environment and react accordingly. Software agents communicate with other system components in order to coordinate activities or collaborate on a given task. In one particular use of an agent, the agent is placed upon a server to audit server activity by gathering server events and transaction information. The agent communicates this information to a monitoring server that analyzes the information to understand the operation of the server as well as other servers in a network.
Since agents are executable programs, they create a processing burden for the server on which they are executed. Furthermore, software agents require constant monitoring and maintenance by well-trained, qualified professionals (e.g., database administrators, software engineers, and system specialists). Thus, the use of agents creates an administrative burden as well as a processing burden.
Therefore, there is a need for a method and apparatus for performing agent-less auditing of a server.

Method and apparatus for agent-less auditing of server


A new and distinct cultivar of Alstroemeria plant named Florence, characterized by its predominanly dark pink flowers with outer petals having green tips and substantially dark pink color with some brown spotting occurring in highest concentration around the green tips; the two top inner petals are light pink at the base and dark pink at the apex and have a cream with yellow band and patterns of elongated brownish stripes; and, with the bottom inner petal being dark pink with elongated brownish stripes.

The present invention comprises a new and distinct cultivar of Alstroemeria plant referred to by the cultivar name Florence. Florence was originated from a hybridization program in Roelofarendsveen, The Netherlands in 1985. The female parent was an unnamed hybrid. The male parent was also an unnamed hybrid. Each of the parent plants were proprietary, and have not been released or marketed, and are maintained strictly for use in the breeding program. Florence was discovered and selected as one flowering plant within the progeny of the stated parentage by me on Jul. 21, 1985 in a controlled environment in Roelofarendsveen, The Netherlands. The first asexual reproduction of Florence was accomplished when vegative cuttings were taken from initial selection on Nov. 6, 1985 in a controlled environement in Roelofarendsveen in The Netherlands. Horticultural examination of selected units initiated in November 1985 has demonstrated that the combination of characteristics as herein disclosed in Florence are firmly fixed and retained through generations of asexual reproduction. The following observations, measurements and comparisons describe plants grown in Roelofarendsveen, The Netherlands under greenhouse conditions which approximate those generally used in commercial practice. The following traits have been repeatedly observed and are determined to be basic characteristics of Florence, which in combination distinguish this Alstroemeria from its parents and all other varieties of which I am aware:
1. The outer petals are distinctive dark pink with green tips and some mostly small brownish spots occurring in highest concentration around the green tips and around the vein pattern of the outer petals.
2. The inner portion of the body of the two top inner petals is light pink at the base, cream and yellow in the center, and the upper most portion of the body being dark pink similar to the color of the outer petals; the lowerr inner petal is dark pink and does not have a cream with yellow band.
3. Small brownish streaks appear on the inside portion of the inner petal body, increasing in length and width from the attachment point to the apex of each of these petals.


A channel layer is formed in a surface of a semiconductor substrate, and a plurality of trenches are formed in the surface of the semiconductor substrate, the trenches being deeper than the channel layer. Then, gate electrodes are formed in the trenches, respectively, after which body layers are formed between the trenches and source layers are formed adjacent to the trenches.

1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a vertical MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) having a trench structure.
2. Description of the Prior Art
Recent vertical MOSFETs that have attracted much attention have a trench structure which includes a gate electrode embedded in a trench. Known structures of a vertical MOSFET having a trench structure and methods of fabricating such a vertical MOSFET are disclosed in Japanese laid-open patent publication Nos. 4-146674 and 5-335582, for example.
The structure of a known vertical MOSFET having a trench structure will be described below with reference to FIG. 1 of the accompanying drawings. As shown in FIG. 1, the vertical MOSFET includes a semiconductor substrate having a p.sup.- channel layer 12 in its surface, an n.sup.- drain layer 11a underneath the p.sup.- channel layer 12, and an n.sup.+ drain layer 11b underneath the n.sup.- drain layer 11a. The semiconductor substrate has a number of trenches 13 defined in the p.sup.- channel layer 12 and extending vertically into the n.sup.- drain layer 11a. A gate oxide layer 14 is formed on the surface of each of the trenches 13, and a gate electrode 15 made of polycrystalline silicon or the like is embedded in each of the trenches 13. The vertical MOSFET also has a number of p.sup.+ body layers 17 disposed on the surface of the p.sup.- channel layer 12 at respective positions intermediate between adjacent ones of the trenches 13. N.sup.++ source layers 16 are disposed adjacent to the p.sup.+ body layers 17 and the trenches 13. Insulating layers 18 are disposed on the respective gate electrodes 15. A metal electrode 19 made of aluminum or the like is disposed over the entire surface of a cell region of the vertical MOSFET. The insulating layers 18 isolate the gate electrodes 15 and the metal electrode 19 from each other. The metal electrode 19 is held in ohmic contact with the n.sup.++ source layers 16 and the p.sup.+ body layers 17.
When a voltage equal to or higher than a predetermined threshold is applied to the gate electrodes 15 between the drain layers 11a, 11b and the n.sup.++ source layers 16, an n-type inverted layer is developed along the trenches in the p.sup.- channel layer 12, forming a current path thereby to turn on the region between the drain layers 11a, 11b and the n.sup.++ source layers 16. When the voltage applied to the gate electrodes 15 is reduced below the predetermined threshold, the n-type inverted layer developed in the p.sup.- channel layer 12 is eliminated, turning off the region between the drain layers 11a, 11b and the n.sup.++ source layers 16. Since the vertical current path is formed along the trenches 13 upon application of a voltage equal to or higher than the predetermined threshold, the current path has an area much greater than with a planar MOSFET, and hence the vertical MOSFET has a reduced resistance when it is turned on.
A process of manufacturing the conventional vertical MOSFET will be described below. First, a semiconductor substrate comprising an n.sup.+ drain layer 11b with an n.sup.- drain layer 11a disposed thereon is prepared. A p.sup.- channel layer 12 is formed in the surface of a cell region of the semiconductor substrate by ion implantation or the like. Then, p.sup.+ body layers 17 and n.sup.++ source layers 16 are formed by ion implantation or the like. Thereafter, trenches 13 extending from the channel layer 12 into the drain layer 11a are formed substantially centrally in the respective n.sup.++ source layers 16.
Gate oxide layers 14 are formed respectively in the trenches 13. A polycrystalline silicon film is deposited on the entire surface formed so far, and etched back to produce gate electrodes 15 embedded in the respective trenches 13. The entire surface is then covered with an insulating film, and apertures are formed in the insulating film above the source layers 16 and the body layers 17 by photolithography, leaving insulating films 18 respectively on the gate electrodes 15. A metal film such as a film of aluminum or the like is deposited on the entire surface, and processed by photolithography to form a metal electrode 19 on the entire surface of the cell region. The reverse surface of the n.sup.+ drain layer 11b is formed with a metal back electrode. In this manner, a principal structure of the vertical MOSFET is completed.
The above process of manufacturing the conventional vertical MOSFET suffers the following problems: First, various heat treatment steps are required. For example, a heat treatment step for sacrifice oxidization is needed to form and remove an oxide layer for processing crystal defects, etc. caused due to the formation of the trenches 13 subsequent to the formation of the n.sup.++ source layers 16. Other heat treatment steps include a heat treatment step for forming the gate oxide layers 14 and a heat treatment step for forming the gate electrodes 15 by CVD or the like. These heat treatment steps are responsible for causing the n.sup.++ source layers 16 to be diffused again, developing a short channel between them and the drain layer 11a with a resulting increase in current leakage between the source and drain.
Secondly, since the trenches 13 are formed after the n.sup.++ source layers 16 are formed and the gate electrodes 15 are embedded in the trenches 13 by etchback, when the gate electrodes 15 of polycrystalline silicon are etched back to a large depth with respect to the diffused depth of the source layers 16, the upper ends of the gate electrodes 15 tend to be separated from the lower ends of the source layers 16, with no overlapping region left between gate electrodes 16 and the source layers 15. As a consequence, the vertical MOSFET has a higher threshold, and suffers a reduced yield.

Method of manufacturing semiconductor device having gate electrodes formed in trench structure before formation of source layers


A connector assembly includes a connector housing defining a cavity, a cylindrical terminal disposed within the cavity, a primary terminal locking feature configured to retain the cylindrical terminal within the cavity, and a secondary terminal locking feature configured to retain the cylindrical terminal within the cavity. The secondary terminal locking feature has a pair of arms defining concave features that engage the cylindrical terminal as the concave features of the pair of arms are wedged between the cylindrical terminal and inner walls of the cavity.

Achieving the desired terminal retention forces for miniaturized coaxial connectors is very difficult due to low profile geometries required of the primary and secondary terminal locking features and the terminal position assurance devices. Due to the circular geometry of the coaxial cavity, it is difficult for the secondary locking feature to overlap with the terminal. Therefore, a coaxial connector that addresses these shortcomings is desired.
The subject matter discussed in the background section should not be assumed to be prior art merely because of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.


An internally-cooled turbomachine element has an airfoil extending between inboard and outboard ends. A cooling passageway is at least partially within the airfoil and has at least a first turn. Means are in the passageway for limiting a turning a loss of the first turn. The turbomachine element may result from a reengineering of an existing element configuration lacking such means.

The invention relates to the cooling of turbomachine components. More particularly, the invention relates to internal cooling of gas turbine engine blade and vane airfoils.
A well developed art exists regarding the cooling of gas turbine engine blades and vanes. During operation, especially those elements of the turbine section of the engine are subject to extreme heating. Accordingly, the airfoils of such elements typically include serpentine internal passageways. Exemplary passageways are shown in U.S. Pat. Nos. 5,511,309, 5,741,117, 5,931,638, 6,471,479, and 6,634,858 and U.S. patent application publication 2001/0018024A1.
Nevertheless, there remains room for improvement in the configuration of cooling passageways.


In a semiconductor integrated circuit device, a sheet-like temperature monitor member of vanadium oxide is provided, whose one end is connected to one via while the other end is connected to another via. A sheet-like thermal conducting layer of aluminum is provided below the temperature monitor member. A region equal to or greater than a half of the entire temperature monitor member overlies the thermal conducting layer in a plan view.

1. Field of the Invention
The present invention relates to an integrated circuit device with a built-in monolithic temperature sensor.
2. Description of the Related Art
Recently, there are growing needs for monitoring the operation temperature of an integrated circuit device for the purpose of preventing thermal breakdown of devices in the integrated circuit device and stabilizing the operation of a device whose characteristic has temperature dependence.
In this respect, Japanese Patent Laid-Open Publication No. H1-302849, for example, discloses a technique of providing a temperature sensor on the same substrate as that of an LSI (Large Scale Integrated circuit). In the technique, the temperature sensor decides that the LSI is abnormally overheated when the temperature detected by the temperature sensor exceeds a predetermined value and then shutting down the LSI. Therefore, it can protect the LSI from thermally broken by a temperature rise. Japanese Patent Laid-Open Publication No. H9-229778 proposes the technique of using a parasitic pn junction diode as such a temperature sensor.
The technique that uses a parasitic pn diode as a temperature sensor has a problem such that as the temperature coefficient of the parasitic pn junction diode is as low as 0.2 (%/K), therefore a sufficient SNR (Signal-to-Noise Ratio) cannot be acquired.
The present inventors have developed a technique of forming a vanadium oxide film as a resistor having an electric resistivity whose temperature coefficient has a large absolute value, and has disclosed it in Japanese Patent Laid-Open Publication No. H11-330051.
The prior art technique suffers the following problems. When a resistor consisting of a vanadium oxide, for example, is formed and the temperature of an integrated circuit device is measured by measuring the resistance of the resistor, the ambient temperature of the resistor may not become uniform due to the influence of the internal and external environments of the integrated circuit device. For example, the flow of the current to wires or the like provided around the resistor locally raises the temperature, thus making the ambient temperature non-uniform. In this case, the internal temperature of the resistor becomes non-uniform, thus making the internal resistivity of the resistor non-uniform, so that the temperature cannot be measured accurately or stably.

Integrated circuit including a temperature monitor element and thermal conducting layer


The present invention is an apparatus and method that identifies and localizes fiber breaks or faults automatically, utilizing a fiber optic data transceiver that has μOTDR functionality. The transceiver of the present invention is a single wavelength bi-directional transceiver that during normal operation sends and receives optical data streams in the same wavelength window using any protocol and reports the distance to the fault or multiple faults nearly instantaneously when the transfer of data is disrupted, without the need to have fiber lines dedicated for this purpose or physically connect and reconnect each fiber line to check for faults and eliminates the need to map out the distance to the remote transceiver.

1. Field of the Invention
The present invention relates to the detection of faults within a fiber optic network and the determination of the location of the detected fault and more specifically to the method and apparatus to determine the presence of, and location of, a fiber network fault, within a single optical fiber strand, utilizing, in particular, a transceiver that operates as both a digital bi-directional data transport on the same fiber, and a micro optical time-domain reflectometer (μOTDR).
2. Description of the Prior Art
In general terms, the detection of communication line faults has been a concern in the art for a long time. The advent of the communication age was accompanied by the proliferation of the necessary wires and cables to support that communication. As the communication networks grew larger, so too did the lengths of wires, cables, and now fiber optic lines, which now comprise networks thousands of kilometers in length. These wires, cables and optical fibers may be damaged for a number of reasons and need repair. Pinpointing the location of a fault is valuable information, regardless of whether the network is just a few meters or a few thousand meters in length.
The following are some examples of prior art fault detection devices:
U.S. Pat. No. 4,449,247 issued to Waschka (hereafter the "Waschka Patent") depicts a system that transports additional data regarding the local status of each terminal, between the different terminals of a communication system. Unlike the present invention, the Waschka Patent does not check the status of the optical fiber or the location of a fault in the fiber, but merely has each station send out its own status to its neighboring terminal, receive status from a neighboring terminal and create separate alarms based on the various status notices. Additionally, the Waschka Patent recognizes only that it lost data and cannot determine if there is an electronic failure, a fiber failure, or a failure with the detector. Further, the Waschka Patent does not measure the distance to any fiber that is broken or determine if a fault is a fiber failure or an electronic failure. The Waschka Patent is merely a generic structure that sends and reads status reports to and from the various terminals without doing any type of analysis.
U.S. Pat. No. 5,586,251 issued to James A. Coleman et al. and assigned to the United States of America as represented by the Secretary of the Army on Dec. 17, 1996 for "Continuous On-Local Area Network Monitor" (hereafter the "Coleman Patent"), discloses a high level monitoring system of interconnected instruments having a plurality of connections to transmit and receive data regarding the status of the various segments of the system, including a preamble to notify the system that the following is not data. The Coleman Patent transmits information, doesn't look at the reflection of light and requires a plurality of transceivers and is incapable of detection by the transmission and receiving of light and using same to determine the location of a fault within the optic fiber itself.
U.S. Pat. No. 6,385,561 issued to John James Soraghan (hereafter the Soraghan Patent") discloses detecting faults in electrical cables by coupling signals and comparing them and having separate input and output leads. The Soraghan Patent applies this same detection technique of coupling and comparing signals to fiber optic cables and storing sample signals. Soraghan is incapable of detecting a fault utilizing only one fiber and without any sampling, storage or comparisons.
U.S. Pat. No. 6,714,021 issued to Emrys J. Williams (hereafter the "Williams Patent") discloses detecting faults within an electrical system by using electrical impedance and further requires a center plane, a back plane and a second back plane. The Williams Patent cannot be used for an optical circuit.
U.S. Pat. No. 7,139,668 issued to Eric Robert Bechhoefer (hereafter the "Bechhoefer Patent") discloses the utilization of storing digitized electrical reflections and scoring them to determine the presence of an event. The Bechhoefer Patent is designed for a cable system, not a fiber optic system, and utilizes different components to transmit and receive than it does to determine an event in the system.
U.S. Pat. No. 7,218,388 issued to Gordon A. Keeler et al. and assigned to Sandia Corporation on May 15, 2007 for "VSCEL Fault Location Apparatus And Method" (hereafter the "Keeler Patent") discloses the use of the same light source that transmits the light to also detect a reflection. Additionally, the Keeler Patent discloses the addition of an electronic circuit that changes the bias, and hence performance and characteristics, of the device, in order to perform a fault detection. Additionally, the transmitter in the Keeler Patent cannot, in normal operation, transmit and receive data, it can only transmit. The Keeler transmitter can receive data after a first and a second bias has been applied, after which it cannot transmit until the biases have been removed. The Keeler Patent does not have a data receiver in its system.
U.S. Pat. No. 7,239,680 issued to Sang T. Bui (hereafter the "Bui Patent") discloses a method to diagnose an electrical system utilizing adaptive coefficients as filters which is used to determine the status of the cables as either open or short. An optic fiber doesn't have shorts, thus the Bui Patent cannot be used for fiber optic systems.
U.S. Pat. No. 7,558,212 issued to Jerome Edwin Olinski (hereafter the "Olinski Patent"), discloses a method for performing diagnostics by comparing the signal to stored data. Additionally, the Olinski Patent has mapped out and stored the physical locations of points along its pathway and it is to one of these points that the Olinski Patent directs a user as the location of the fault. In other words, the Olinski Patent requires prior knowledge of everything on its line, to which it then matches the response signal with the cable information and thus gives, as the location of the fault, the location of the nearest physical object on its line.
An Article dated February 1995 from the Hewlett-Packard Journal by Frank A. Maier and Harald Seeger entitled "Automation of Optical Time-Domain Reflectometry Measurements" (hereafter the "Hewlett Packard Article") discloses the use of an OTDR which must be physically attached to each cable one at a time for testing for faults, whether by switching the lines internally or physically reconnecting the OTDR to the fiber. The Hewlett Packard Article does not teach that the same unit that is used to detect the fault is also used to transmit data.

Fiber fault detection within data transceiver having micro OTDR (μOTDR) for fiber optic network