A multiple quantum well photodetector structure has superlattice which absorbs radiation polarized non-parallel to the superlattice during a first pass. Non-absorbed radiation polarized parallel to the superlattice is reflected back into the superlattice at a cross-angle to its incident angle, with its polarization shifted to a substantially non-parallel angle to the superlattice. At least part of this radiation is absorbed during its second pass through the superlattice, thereby increasing the efficiency of the device. An optical back grating is used to perform the cross-angle reflection, and a front grating may also be used to shift an incoming beam which is initially normal to the superlattice to an angle at which part of the beam is absorbed. The front grating is at a cross-angle to the back grating to enable a cross-angular shift by the back grating.

1. Field of the Invention
This invention deals with multiple quantum well photodetectors intended for unpolarized light detection.
2. Description of the Related Art
A variety of photodetectors have been developed that are useful for focal plane arrays and other applications. They may generally be classified as intrinsic semiconductor, extrinsic semiconductor and multiple quantum well devices. Each type of device, however, has certain limitations to its usefulness.
Photodetectors made from intrinsic semiconductor materials face severe material stability and produceability problems, especially if they are used to detect radiation with a wavelength greater than 10 microns. Current technology requires the use of HgCdTe to achieve an infrared detection capability, which is highly desirable. An example of this type of photodetector is discussed in Reidel, et al., "High Performance Photovoltaic Infrared Devices in Hg.sub.1-x Cd.sub.x Te on Sapphire", Applied Physics Letters, Vol. 46, No. 1, Jan. 1, 1985, pages 64-66. While mercury (Hg) is highly volatile, it is necessary to add more and more mercury to the semiconductor to obtain narrow band detection. It is quite difficult to control the mercury in many applications, resulting in non-uniform detection pixels.
Intrinsic semiconductor photodetectors generally exhibit large bandgaps, and thus can detect only high energy photons; low energy photons essentially see a transparent structure. Extrinsic semiconductor photodetectors add a dopant, such as gallium or arsenic for a silicon photodetector, to reduce the bandgap and achieve sensitivity to low energy photons. However, an optimization of detector sensitivity to specific wavelengths is restricted because of a limited availability of allowable dopant species. Furthermore, in practice it is difficult to establish and maintain the current dopant level, and to keep the dopant pure.
A different photodetector that offers more flexibility than semiconductor detectors is the one-dimensional multiple quantum well. In this type of device, the operating characteristics are controlled by the width and height of the wells, rather than by selecting from limited available materials. A multiple quantum well detector can be very thin, on the order of a micron or less, making it much more radiation hard than either intrinsic or extrinsic semiconductor detectors.
Multiple quantum well detectors are formed from superlattice stacks of ultrathin semiconductor layers, typically Group III-V semiconductors. With these materials the energy bandgap is direct, permitting light to be efficiently emitted or absorbed without the aid of lattice vibrations. Input photons transfer energy to electrons in the well, exciting the electrons from a ground state, while an electric field moves the electrons laterally. The materials are characterized by large charge carrier mobilities, and are easily doped with impurities. They can form solid solutions of various proportions with identical crystal structures and well-matched lattice parameters, but with different energy bandgaps and indices of refraction.
One type of superlattice is the "doping superlattice", which is obtained by periodically alternating n and p doping during the growth of an otherwise uniform semiconductor such as gallium arsenide. A basic discussion of this n-i-p-i structure is given in an article by Klaus Ploog and Gottfried H. Dohler, "Compositional and Doping Superlattices in III-V Semiconductors", Advances in Physics. Vol. 32, No. 3, 1983, pages 285-359. This article presents a general discussion of n-i-p-i structures, as well as the spatial control of optical absorption by a voltage pattern applied to the n-i-p-i structure. Other articles which describe specific quantum well structures are:
Choi et al., "Multiple Quantum Well 10 .mu.m GaAs/Al.sub.x Ga.sub.1-x As Infrared Detector With Improved Responsivity", Applied Physics Letters. Vol. 50, No. 25, 22 June 1987, pages 1814-16.
Levine et al., "High-Detectivity D*=1.0-.times.10.sup.10 cm/Hz/W GaAs/AlGaAs Multiquantum Well .lambda.=8.3 .mu.m Infrared Detector", Applied Physics Letters, Vol. 53, No. 4, 25 July 1988, pages 296-98.
Levine et al., "Bound-To-Extended State Absorption GaAs Superlattice Transport Infrared Detectors", Journal of Applied Physics. Vol. 64, No. 3, 1 August 1988, pages 1591-93.
While one-dimensional multiple quantum well photodetectors made of heterojunction material provide flexibility in performance optimization for long wavelength infrared detection, especially in the greater than 10 micron wavelength range, the quantum efficiency of these devices is limited for unpolarized light detection. This is because these devices are not sensitive to optical polarization parallel to the detector plane. To excite an electron in a well, the electric field associated with the photons must be perpendicular to the vertical barrier walls (in the first order).
Ideally, the light to be detected would be directed onto the detector at 90.degree. to the detector plane, to obtain the best image. However, since the plane of polarization for a light beam is normal to its direction of propagation, this would place the polarization plane parallel to the detector plane, so that it could not be detected. To compensate for this, the light is normally directed onto the detector at an angle to the detector plane which is sufficiently small so that a substantial component of the polarization is perpendicular to the detector plane and thus absorbed, but at an angle great enough to preserve adequate image clarity. In practice, an incident angle of about 45.degree. has been used for this purpose.
Since the component of the incoming beam having a polarization parallel to the detector plane will not be absorbed by the multiple quantum well detector, an inefficiency is built into the system. As the angle of the beam to the detector plane increases, a thicker detector is necessary to retain even the same partial level of absorption. However, thick detectors are undesirable because they are less radiation hard, and require a higher operating bias voltage.

High efficiency multiple quantum well structure and operating method


Construction is achieved capable of stably maintaining an inner column 43 on the inner diameter side of an outer column 42. The outer column 42, including a support section 46 is formed by using hydroforming to swell a hollow tube outward in the radial direction. A displacement bracket 34 is also integrally formed with the outer column 42 by tube swelling. Furthermore, raised sections 47a, 47b of the support section 46 are formed at three or more location in the circumferential direction on the inner circumferential surface of the outer column 42, and these raised sections 47a, 47b and the outer circumferential surface of the inner column 43 come in contact with each other at three or more locations in the circumferential direction.

As illustrated in FIG. 46, a steering apparatus for an automobile is constructed so that rotation of a steering wheel 1 is transmitted to an input shaft 3 of a steering unit 2, and as the input shaft 3 rotates, a pair of left and right tie rods 4 are pushed or pulled, applying a steering angle to the front wheels. The steering wheel 1 is supported by and fastened to the rear end section of a steering shaft 5, and with this steering shaft inserted in the axial direction through a cylindrical shape steering column 6, the steering shaft 5 is supported by the steering column 6 so as to be able to rotate freely. Moreover, the front end section of the steering shaft 5 is connected to the rear end section of an intermediate shaft 8 by way of a universal joint 7, and the front end section of this intermediate shaft 8 is connected to the input shaft 3 by way of a separate universal joint 9.
Conventionally, in this kind of steering apparatus, a tilt mechanism for adjusting the up/down position of the steering wheel 1 and/or or a telescopic mechanism for adjusting the forward/backward position of the steering wheel 1 according to the size and driving posture of the driver have been widely known. In order to construct the tilt mechanism, the steering column 6 is supported by the vehicle body 10 so as to be able to pivot around a pivot shaft 11 that is arranged in the width direction. In order to construct the telescopic mechanism that can displace in the forward/backward direction, the steering column 6 is constructed by combining an outer column 13 and an inner column 14 so as to be able to expand and contract freely in a telescopic manner, and the steering shaft 5 is constructed by combining an outer shaft (outer tube) 15 and an inner shaft 16 with a spline fit or the like such that torque can be freely transmitted, and so as to be able to expand and contract freely. A displacement bracket that is fastened to the portion of the steering column 6 near the rear end section is supported by a support bracket 12 that is supported by the vehicle body 10 such that the displacement bracket can displace in the up/down direction and forward/backward direction. Here, the width direction means the width direction of the vehicle, and corresponds to the left/right direction. Also, the forward/backward direction is the forward/backward direction of the vehicle. In the example illustrated in the figure, in order to reduce the force required for operating the steering wheel 1, an electric power steering apparatus, having an electric motor 17 as the source of assist power, is also assembled in the steering apparatus.
In a steering apparatus that comprises a tilt mechanism and a telescopic mechanism, construction is necessary wherein the position of the steering wheel 1 can be adjusted, and can be fastened at the adjusted position. FIG. 47 and FIG. 48 illustrate construction that is disclosed in JP2001-322552(A) wherein by rotating a rod shaped member 19 by an adjustment lever 18, the dimension in the width direction of a cam apparatus 20 is expanded or contracted, and at the same time a cam member 21 pivots and displaces. In this construction, due to the expansion or contraction of the cam apparatus 20, it is possible for a displacement bracket 22 that is fastened to the outer column 13a to engage with or disengage from a fastening bracket 12a. Moreover, it is possible to switch whether or not to allow relative movement of the inner column 14a with respect to the outer column 13 according to the pivotal displacement of the cam member 21.
The outer column 13a and inner column 14a of the steering column 6a of this kind of steering apparatus fit together such that the inner circumferential surface on the portion near the front end of the outer column 13a and the outer surface of the portion near the rear end of the inner column 14a are capable of relative displacement in the axial direction. Moreover, when the manufacturing the outer column 13a, first the main outer column is formed by aluminum die casting. After that, the inner circumferential surface of the main outer column is machined and finished. On the other hand, the displacement bracket 22 is formed separate from the outer column 13a, and integrally joined and fastened to the part of the outer column 13a by welding.
In the case of this kind of steering apparatus, it is necessary to finish the inner diameter of the outer column 13a with good precision, however, there is a problem in that the machining work is troublesome and costly. Furthermore, the inner circumferential surface of the outer column 13a and the outer circumferential surface of the inner column 14 fit all the way around, so in the case that the precision of the inner diameter of the outer column 13a is not sufficient, there is a problem in that the columns may become off centered, and the inner column 14a cannot be stably held on the inner-diameter side of the outer column 13a.
FIG. 49 illustrates construction that is disclosed in JP2008-302751(A), wherein raised sections 23 that protrude inward in the radial direction from the inner circumferential surface of the outer column 13b are formed at a plurality of locations in the circumferential direction of the inner circumferential surface of the outer column 13b that overlap the outer circumferential surface of the inner column 14a, and the tip end section (inside end sections in the radial direction) of these raised sections 23 come in contact with the outer circumferential surface of the inner column 14a. In this construction, of the inner circumferential surface of the outer column 13b, machining and finishing such as broaching only needs to be performed for the tip end section of the raised sections 23, so it is possible to reduce the processing cost.
When manufacturing the outer column 13b, first the main outer column is formed by aluminum die casting, hydroforming or the like. After that, forging and broaching is performed on a plurality of locations (eleven locations in the figure) in the circumferential direction of portions of the inner circumferential surface of the main outer column that overlap with the outer circumferential surface of the inner column 14a to form the raised sections 23 that protrude inward in the radial direction from the inner circumferential surface of the outer column 13b. However, in this case as well, the method for forming the outer column 13b and the method for form the raised sections 23 differ, so processing requires time and labor, so an increase in cost is unavoidable.
In order to stably support the inner column 14a on the inner-diameter side of the outer column 13b with the column being off center or without backlash or the like occurring, preferably all of the raised sections 23 will come in contact with the outer circumferential surface of the inner column 14a in the same contact state. However, the processing work for achieving the same contact state for a plurality of raised sections 23 is troublesome.
FIG. 50 illustrates construction of a steering column 6c that is disclosed in JP2008-302751(A). The outer column 13c of this steering column 6c is formed into a cylindrical shape by being a plate shaped material and welding together the edges on the end in the circumferential direction (top edges in FIG. 50). Moreover, support tabs 24 are formed in three locations in the circumferential direction of the inner circumferential surface of the outer column 13c such that these support tabs 24 face the outer circumferential surface of the inner column 14a in the assembled state. The support tabs 24 are formed by pressing part of the outer column 13c and bending that part toward the inside in the radial direction from the inner circumferential surface of the outer column 13.
The displacement bracket 22a is provided on part in the axial direction of the outer circumferential surface of the outer column 13c. The displacement bracket 22a is formed by bending a plate shaped raw material that is the same as the material used for forming the outer column 13c so that the edge on one end is continuous with the outer circumferential surface of the outer column 13c, and the edge on the other end is welded to this outer circumferential surface, forming a pair of left and right clamped sections 25.
In the case of the outer column 13c, support tabs 24 are formed at three uniformly spaced locations in the circumferential direction. Therefore, processing for making the contact state between the tip end edges of all of the support tabs 24 and the outer circumferential surface of the inner column 14a the same can be performed easily. However, the support tabs 24 have cantilever like construction, so there is a problem in that it is difficult to maintain rigidity for stably supporting the inner column 14a on the inner-diameter side of the outer column 13c.
Furthermore, in the telescopic steering apparatuses having these kinds of conventional construction, the longer the dimension in the axial direction of the portion of the outer column 13 and inner column 14 that overlap in the radial direction is, the higher the rigidity in the width direction of the displacement bracket 22 becomes, and it becomes difficult to bend. Therefore, it is necessary to change the operating force applied to the adjustment lever depending on the dimension in the axial direction of the portion of the outer column 13 and inner column 14 that overlap in the radial direction. As a result, there is a possibility that operability of the adjustment lever 18 will become unstable, and that it will not be possible to provide stable support rigidity (tightening force) to the inner column 14.
Moreover, in a typical telescopic steering apparatus, when adjusting the position of the steering wheel 1, the adjustment lever 18 is operated in a specified direction, which decreases the friction force acting between the fastened bracket 12a and the displacement bracket 22. On the other hand, when maintaining the steering wheel 1 at the adjusted position, the adjustment lever 8 is operated in the opposite direction of the specified direction, which increases the friction force between these brackets. In this kind of construction, the amount that the adjustment lever 18 is operated is not large, and in order to increase the force for maintaining the steering wheel 1 in the adjusted position, preferably the number of friction surfaces is increased, increasing the friction surface area. JP2008-100597(A), JP10-35511(A), JP2007-69821(A), JP2011-5896(A) and JP62-19483(Y) disclose construction in which the number of friction surfaces is increased by layering together a plurality of friction members.
FIG. 51 and FIG. 52 illustrate an example of the construction of the telescopic steering apparatus disclosed in JP2011-5896(A). In this apparatus, a long hole 29 in the forward/backward direction that extends such that it is long in the axial direction of the steering column 6d is formed in the displacement bracket 22b for inserting the rod shaped member 19, and is formed such that it passes through the displacement bracket 22 in the left/right direction (width direction). On the other hand, the fastened bracket 12a is formed by joining and fastening together an upper bracket element 26 and a lower bracket 27, which are both formed by bending metal plate. The upper bracket element 26 is supported by the vehicle using known construction so as to be able to break away in the forward direction during a secondary collision. Moreover, the lower bracket element 27 comprises a pair of left and right support plate sections 28 that are separated from each other in the width direction. The distance D between the inside surfaces of these support plate sections 28 coincides with the space W between the outside surfaces of the displacement bracket 22b (width of the displacement bracket 22b) (D≈W). Partial arc shaped long holes 30 in the up/down direction that extend such that they are long in the up/down direction centered around a pivot shaft 11 are formed in positions in the pair of support plate sections 28 that are aligned with each other, and are for inserting the rod shaped member 19 through. A plurality of first friction plates 31 and second friction plates 32 are arranged on portions on the outsides of the support plate sections 28.
First long holes 33 are formed in the first friction plates 31, and second long holes 34 are formed in the second friction plates 32. The end sections of the first friction plates 31 are connected to and supported by outside surfaces on the top end of the support plate sections 28 by first locking screws 35, and the end section of the second friction plates 32 are connected to and supported by the outside surfaces on the front end of the displacement bracket 22b by second locking screws 36, thus preventing the first friction plates 31 from displacing in the lengthwise direction of the first long holes 33, and preventing the second friction plates 32 from displacing in the lengthwise direction of the second long holes 34. These kinds of first friction plates 31 and second friction plates 32 are arranged on the outside surfaces of the support plate sections 28 so that they are alternately layered.
The rod shaped member 19 is inserted through the long hole 29 in the forward/backward direction, the long holes 30 in the up/down direction, the first long holes 33 and the second long holes 34. An outward facing flange section 38 is formed on the base end section (right end section in FIG. 52) of the rod section 37 of the rod shaped member 19. Locking convex sections 39, having an elliptical cross section, that are formed in the portion near the base end section of the rod section 37 engages with one of the long holes 30 in the up/down direction (right hole in FIG. 52) so as to be able to freely displace (move up or down) along the long hole 30 in the up/down direction.
On the other hand, a pressure plate 40 is fitted around the portion in the middle section of the rod section 37 near the tip end, that protrudes from the other support plate section 28 (left support plate section 28 in FIG. 52), the first friction plate 31 and second friction plate 32 that are provided on the outside surface of that support plate section 28, and further a cam apparatus 20 is provided on this portion. This cam apparatus 20 and the rod shaped member 19 form a pressure apparatus. The cam apparatus 20 is such that the dimension T in the axial direction thereof expands or contracts according the operation of the adjustment lever 18, and has known construction. When the adjustment lever 18 is rotated in a specified direction, the dimension T in the axial direction expands, and the space between the surface on one side of the pressure plate 40 and the inside surface of the flange section 38 contracts, and the friction force that acts between opposing surfaces that are engaged by a friction fit increases.
In other words, in this state, on both the left and right sides, the contact pressure between the side surfaces of the displacement bracket 22b and the inside surfaces of the support plate sections 28, the contact pressure between the outside surfaces of the support plate sections 28 and the inside surfaces of the second friction plates 32 that are located on the very inside, the contact pressure between the inside surfaces of the adjacent first friction plates 31 and the outside surfaces of the second friction plates 32, and the contact pressure between the outside surfaces of the first friction plates 31 located on the very outside and the surface of one side of the pressure plate 40 or the inside surface of the flange section 38 increase. In this state, the total friction force that acts between these sections of frictional engagement becomes sufficiently large. As a result, it is possible to sufficiently increase the support strength of the displacement bracket 22b with respect to the fastened bracket 12a.
On the other hand, when adjusting the position of the steering wheel 1, the adjustment lever 18 is rotated in the opposite direction from the specified direction, causing the dimension T in the axial direction of the cam apparatus 20 to contract, and the space between the surface on one side of the pressure plate 40 and the inside surface of the flange section 38 to expand. In this state, the friction force that acts between these sections of frictional engagement is decreased or lost, and it is becomes possible to adjust the displacement bracket 22b in the up/down direction and forward/backward direction with respect to the fastened bracket 12a. In this state, by rotating the adjustment lever 18 in the specified direction after the position of the steering wheel 1 has been adjusted to a desired position, it becomes possible to stably maintain the position of the steering wheel 1 at the desired position.
However, in the case of this kind of conventional construction, there is a problem in that the construction for assembling the first friction plates 31 and the second friction plates 32 is complicated, and thus the manufacturing cost increases. Moreover, when the steering wheel 1 is moved to the very front adjustable position or to the very back adjustable position, there is a possibility that the outer circumferential surface of the rod section 37 of the rod shaped member 19 and the inner surface of the long hole 29 in the forward/backward direction in the displacement bracket 22b, which are both made of metal, will collide with much energy. When these surfaces energetically collide, there is a possibility that the driver operating the steering wheel 1 will feel a strange or uncomfortable feeling. In response to this, JP10-512825(A) (WO96/15931) discloses construction where an impact absorbing sleeve is provided that surrounds the long hole in the forward/backward direction of the displacement bracket. However, construction that combines the construction of providing this impact absorbing sleeve and the construction illustrated in FIG. 51 and FIG. 52 that improves the holding force for maintaining the position of the steering wheel 1 by using a plurality of friction plates is not suggested. These kinds of construction can be independently assembled in a telescopic steering apparatus, however, the assembly work is troublesome and increased costs are unavoidable.
As technology related to the construction of a steering column is method for manufacturing a steering column as disclosed in JP2006-255785 wherein hydroforming is used to form a bulging section in the middle section in the axial direction of a hollow cylindrical shaped raw material, after which this bulging section is formed into a column bracket by forming a through hole through the side wall section of the bulging section.


An improved method of synthesizing large pore zeolites is disclosed and claimed. The method comprises preparing a reaction mixture containing a source zeolite on alkali metal, nitrogen containing organic cation, a source of silica, and water, and having the following composition in terms of the mole ratios:. ______________________________________ M.sup.+ /SiO.sub.2 = 0.01-1.00 OH.sup.- /SiO.sub.2 = 0.15-0.80 H.sub.2 O/SiO.sub.2 = 20-120 Q/SiO.sub.2 = 0.10-1.00 SiO.sub.2 /Y.sub.2 O.sub.3 = Greater Than 8 ______________________________________. wherein M.sup.+ is an alkali metal not supplied by the source zeolite, Q is an organic template, and Y is a mixture of aluminum from the source zeolite, wherein said source zeolite contains soda lite substructures having tetrahedra atom densities of less than about 15 TO.sub.2 per 1000 .ANG..sup.3 ; maintaining the reaction mixture at crystallization temperature until crystals are formed; and recovering the crystals.

Zeolite materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversions. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as "molecular sieve" and are further being used as catalysts or supports for catalysts for the conversion of compounds, for example, in hydrocarbon cracking, alkylation or isomerization reactions.
These aluminosilicates can be described as a rigid three-dimensional framework of SiO.sub.4 and AlO.sub.4 in which the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen is 1:2. The electrovalence of the tetrahedra containing aluminum is balanced by the inclusion in the crystal of a cation, for example, alkali metal or an alkaline earth metal cation. This can be expressed wherein the ratio of aluminum to the number or various cations, such as Ca, Sr, Na, K or Li is equal to unity. One type of cation may be exchanged either entirely or partially by another type of cation utilizing ion exchange techniques in a conventional manner. By means of such cation exchange, it has been possible to vary the properties of a given aluminosilicate by suitable selections of the cation.
The remarkable properties of zeolites have led to the development of processes for the production of synthetic zeolites. There are many synthetic zeolites and they form the subject matter of many patents and publications. Non-limiting examples of such synthetic zeolites include A (U.S. Pat. No. 2,882,243), X (U.S. Pat. No. 2,882,244), LZ-210 (U.S. Pat. No. 4,503,023), SSZ-12 (U.S. Pat. No. 4,544,538), SSZ-16 (U.S. Pat. No. 4,508,837, Nu-3 (U.S. Pat. No. 4,372,930).
Generally, crystalline silicate zeolites are synthesized by preparing a solution containing sources of an alkali metal oxide, a nitrogen-containing cations (also known as an organic template), an oxide of aluminum, an oxide of silicon, and water. Then, under well defined operating conditions and with specific ratios between the precursors of the zeolites, crystallizing the desired zeolite.
While crystalline components are generally not good reagents in zeolite synthesis, owing to their resistance to breakdown and transformation, occasionally there are exceptional materials which turn out to be very useful reactants. This may come as a result of such features as very high surface area for the crystalline material, or there may be an unusual inherent instability in the crystal. Very small crystal size can also be a helpful feature.
It was previously shown in U.S. Pat. No. 4,689,207 that a crystalline silica, Magadiite was a useful reactant for high silica zeolite synthesis. U.S. Pat. No. 4,503,024 also discloses a method of preparing chabazite, merlinoite, edingtonite, ZSM-5, and ZSM-11 from the natural and synthetic zeolites mordenite, ferrierite, clinoptilolite, zeolite X and zeolite Y.
For a given zeolite structure it is not always possible to prepare the zeolite over a wide SiO.sub.2 /Al.sub.2 O.sub.3 compositional range. While the zeolite is largely composed of SiO.sub.2, it is the substitution of aluminum for silica which imparts acid characteristics to the zeolites.
It has been demonstrated by Barthomeuf (J. Phys Chem. 1984 pg 42) that the maximum zeolitic acidity is obtained when the SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio is from 12-18. In general, zeolites with SiO.sub.2 /Al.sub.2 O.sub.3 of 10-20 are catalytically more active than zeolites with values on either side of this ratio. In attempting to modify the SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio to a desired range, the prior art teaches several methods for replacing framework aluminum. These methods largely comprise techniques where alumina is removed from the crystalline zeolite structure thereby reducing the acidity of the zeolite. U.S. Pat. No. 5,098,687 discloses a process for removing framework aluminum from zeolites and substituting iron and/or titanium. Other methods include ion exchanging the aluminum using acid or bases or combinations of both methods.
Examples of the above methods include: U.S. Pat. No. 3,620,960 (treatment of the zeolite with molybdenum fluoride); U.S. Pat. No. 3,630,965 (treatment of the zeolite with hydrofluoric acid); U.S. Pat. No. 3,644,220 (treatment of the zeolite with volatile halides selected from the group consisting of aluminum, zirconium, titanium, tin, molybdenum, tungsten, chromium, vanadium, antimony, bismuth, iron, platinum group metals and rare earths); U.S. Pat. No. 3,575,887 and U.S. Pat. No. 3,702,312 (treatment of the zeolite with fluorides and chlorides).
Applicants have now unexpectedly discovered that it is possible to prepare a reaction mixture so that optimum SiO.sub.2 /Al.sub.2 O.sub.3 is incorporated into the zeolite without resorting to subsequent process steps.
It is an object of the invention to provide a method whereby zeolites having SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio less than about may be prepared. It is another object of the invention to prove a method for preparing zeolites whereby crystallization time is substantially reduced as compared to conventional prior art methods utilized. It is still another object of the invention to provide a reproducible method for preparing well crystallized zeolites.
We have discovered that faujasitic structures with SiO.sub.2 /Al.sub.2 O.sub.3 values in the 2 to 20 range, make excellent aluminum sources in zeolite syntheses toward attaining this maximum acidity. In addition these faujasitic materials can often lead to novel zeolites which could not be made when using the methods taught by the prior art.

Preparation of zeolites using low silica/alumina zeolites as a source of aluminum


A closure for closing a bag and a die head and method for making the closure. The closure includes two closure members having support walls and mating interlocking profiles. The support walls are resilient and have self-retaining forms in vertical section including middle sections curving outwardly away from one another when mounted on a bag. Top portions of the support walls extend outwardly away from one another to form gripping panels when the closure is closed. A die head for forming a closure member includes a body that defines a slot including a support wall segment for forming the support wall of the closure member. The support wall segment includes first and second portions oriented transverse to one another and intersecting at a vertex. To form the closure member, polymer is extruded through the slot and quenched.

Plastic bags are used for many different applications, such as shipping, food packaging, biohazard disposal, etc. Certain plastic bags are reclosable. Reclosable bags include a reclosable closing structure that can be used to selectively open and close the bag. It is desirable for the bag to have features for gripping when opening the reclosable closing structure.


In order to stably maintain a combustion capability in a combustion furnace for coal gassification, it is necessary to exhaust molten slag produced within the furnace without the slag stagnating. The present invention provides, in a combustion furnace for coal gassification, a slag exhausting device which is configured in such a manner that the cooling of molten slag being exhausted from the furnace is minimized to prevent the slag from solidifying and causing other slag to stagnate. The slag exhausting device is disposed at the center of a bottom wall of the combustor, and has a lower cylindrical portion and an upper bank opening upwardly and flared at an angle of 300.degree.-45.degree.. The height H from the bottom wall to the top of the upper bank, a height L and an inner diameter ds of the cylindrical lower portion and a diameter D of the combustor are set to satisfy the relations of ds/D=0.2-0.4, L/ds=0.2-0.6 and H/D=0.05-0.15.

1. Field of the Invention
The present invention relates to a coal combustor applicable to a coal gassification apparatus, a boiler or the like for business use and industrial use and a slag exhausting device therein.
2. Description of the Prior Art
At first, as one example of the prior art, a coal combustor in an entrained bed coal gassification furnace and a slag exhausting device provided at the bottom portion of the coal combustor will be described with reference to FIG. 5.
A slag exhausting device 11 is disposed at the center of the bottom portion of a coal combustor 12. Coal and char, combusted by burners 13 oriented in the circumferential direction of the combustor 12, first produce combustion gas as a result of the combustion, then produce combustible gas as a result of gassification. At the same time an ash content of the coal and char is converted to molten slag, which is centrifugally separated from the gas by a swirling stream 15 flowing from the burners, then adheres to a cylindrical wall surface 4 of the combustor 12 , flows down due to the gravity and accumulates at the bottom portion 16 of the combustor, and finally is exhausted via the slag exhausting device 11 into a slag chamber 17 and towards a slag hopper 18 disposed thereunder.
During this process, in order to facilitate the exhausting of the molten slag 14 through the slag exhausting device 11, it is necessary to maintain the molten slag 14 at a temperature as high as possible.
Although the molten slag 14 is held at a sufficiently high temperature and has a good fluidity (a low viscosity) at the bottom portion 16 of the combustor where the slag is subjected to strong radiation within the combustor 12, on the vertical surface of the slag exhausting device 11 the radiation is weak. Hence the temperature of the molten slag 14 decreases with a consequent loss in fluidity (its viscosity becomes high).
Therefore, as a contrivance for preventing the temperature of the molten slag in the slag exhausting device from decreasing, a bank 19 and a gate 20 around a slag hole as shown in FIG. 5 were adopted.
However, in the case in which a circular hole (slag hole) is open at the center (the central axis CA of the cylindrical combustor) of the bottom portion 16 of the combustor 12 in which a stream is flowing and in which the combustor is connected with a slag chamber 17 thereunder, due to a pressure distribution along the radial direction R within the combustor shown in FIG. 3, a descending flow flowing from the combustor 12 towards the slag chamber 17 is generated at the circumferential wall defining the hole (region A) while an ascending flow flowing from the slag chamber 17 towards the combustor 12 is generated at the central portion of the hole (region B) as shown in FIG. 4. The solid arrow in FIG. 4(b) shows the swirling direction of flow within the combustor whereas the dashed arrows show the direction of gas flow within a boundary layer at the bottom of the combustor.
Consequently, high-temperature gas within the combustor 12 descends along the lower surface of slag flowing to the slag hole, and the molten slag is heated by the high-temperature gas.
However, the prior art described above gives rise to the following problems.
(1) At the bottom portion of the combustor 12, molten slag flows out through the gate 20 only, and the bank 19 around the slag hole must be high. The vertical surface defining the slag hole is accordingly high. Hence, little heat radiates to the vertical surface from the combustion region and because the temperature of the slag decreases at the vertical surface, the fluidity of the slag decreases as well. PA0 (2) Furthermore, since increasing the height of the vertical surface defining the slag hole would further block the gas flow at the slag hole portion described above, a flow rate of high-temperature gas flowing from the combustor towards the slag chamber 17 along the circumferential wall portion would correspondingly decrease. Hence, such a measure would also result in the fluidity of the slag decreasing at the slag hole portion. PA0 (3) In the event that the decrease in fluidity of the slag is remarkable, slag would solidify (coagulate) in the slag hole portion, thereby blocking the slag hole and rendering the furnace inoperative. PA0 (i) The flare angle .theta. of the upper bank 2 of the slag exhausting device is 30.degree.-45.degree.; PA0 (ii) The radio ds/D of the inner diameter ds of the cylindrical lower portion 3 of the slag exhausting device to the inner diameter D of the combustor is 0.2-0.4; PA0 (iii) The ratio L/ds of the height L of the inner cylindrical vertical surface of the cylindrical lower portion 3 to the inner diameter ds of the cylindrical lower portion is 0.2-0.6; and PA0 (iv) The ratio H/D of a height H, taken between the upper surface of the bottom wall 5 and the top of the upper bank 2, to the inner diameter D of the combustor is 0.05-0.15. PA0 (1) Molten slag accumulated at the bottom of a combustor is forcibly collected in the slag exhausting device provided at the central axis of the cylindrical peripheral wall of the combustor under the influence of flows at a boundary layer at the bottom of the combustor and smoothly flows into a gate of the upper bank. PA0 (2) The flare angle of the upper bank is properly chosen so that a large an amount of heat radiates to the slag hole from the combustion chamber. Therefore, the amount of heat allowed to dissipate from the molten slag (the slag flowing through the gate and the slag flowing along the inner wall defining the slag hole) is suppressed, and accordingly, a lowering of the temperature of the slag is suppressed. PA0 (3) The height H, and the height L and diameter ds of the cylindrical lower portion are properly chosen so that a part of the high-temperature gas within the combustor flows into the slag hole jointly with the molten slag and flows out of the combustor. Therefore, the molten slag is heated and a lowering of the temperature of the slag can be suppressed.

Coal combustor and slag exhausting device therein


Microelectronic cleaning compositions for cleaning microelectronic substrates, and particularly cleaning compositions useful with and having improved compatibility with microelectronic substrates characterized by silicon dioxide, sensitive low-κ or high-κ dielectrics and copper, tungsten, tantalum, nickel, gold, cobalt, palladium, platinum, chromium, ruthenium, rhodium, iridium, hafnium, titanium, molybdenum, tin and other metallization, as well as substrates of Al or Al(Cu) metallizations and advanced interconnect technologies, are provided by microelectronic cleaning compositions comprising halogen acids, salts and derivatives thereof.

Many photoresist strippers and residue removers have been proposed for use in the microelectronics field as downstream or back end of the manufacturing line cleaners. In the manufacturing process a thin film of photoresist is deposited on a wafer substrate, and then circuit design is imaged on the thin film. Following baking, the unpolymerized resist is removed with a photoresist developer. The resulting image is then transferred to the underlying material, which is generally a dielectric or metal, by way of reactive plasma etch gases or chemical etchant solutions. The etchant gases or chemical etchant solutions selectively attack the photoresist-unprotected area of the substrate. As a result of the plasma etching process, photoresist, etching gas and etched material by-products are deposited as residues around or on the sidewall of the etched openings on the substrate.
Additionally, following the termination of the etching step, the resist mask must be removed from the protected area of the wafer so that the final finishing operation can take place. This can be accomplished in a plasma ashing step by the use of suitable plasma ashing gases or wet chemical strippers. Finding a suitable cleaning composition for removal of this resist mask material without adversely affecting, e.g., corroding, dissolving or dulling, the metal circuitry has also proven problematic.
As microelectronic fabrication integration levels have increased and patterned microelectronic device dimensions have decreased, it has become increasingly common in the art to employ copper metallizations, low-κ and high-κ dielectrics. These materials have presented additional challenges to find acceptable cleaner compositions. Many process technology compositions that have been previously developed for "traditional" or "conventional" semiconductor devices containing Al/SiO2 or Al(Cu)/SiO2 structures cannot be employed with copper, tungsten, tantalum, nickel, gold, cobalt, palladium, platinum, chromium, ruthenium, rhodium, iridium, hafnium, titanium, molybdenum, tin and other metallized, and low-κ or high-κ dielectric structures. For example, hydroxylamine based stripper or residue remover compositions are successfully used for cleaning devices with Al metallizations, but are practically unsuitable for those with copper and other metallizations. Similarly, many copper metallized/low-κ strippers are not suitable for Al metallized devices unless significant adjustments in the compositions are made.
Removal of these etch and/or ash residues following the plasma etch and/or ashing process has proved problematic. Failure to completely remove or neutralize these residues can result in the absorption of moisture and the formation of undesirable materials that can cause corrosion to the metal structures. The circuitry materials are corroded by the undesirable materials and produce discontinuances in the circuitry wiring and undesirable increases in electrical resistance.
The current back end cleaners show a wide range of compatibility with certain, sensitive dielectrics and metallizations, ranging from totally unacceptable to marginally satisfactory. Many of the current strippers or residue cleaners are not acceptable for advanced interconnect materials such as porous and IOW-κ dielectrics and copper metallizations. Additionally, the typical alkaline cleaning solutions employed are overly aggressive towards porous and low-κ and high-κ dielectrics and/or copper metallizations. Moreover, many of these alkaline cleaning compositions contain organic solvents that show poor product stability, especially at higher pH ranges and at higher process temperatures.
Heretofore, oxidizers have been used in cleaning compositions in primarily aqueous form. Oxidizers, such as the commonly used hydrogen peroxide and peracids, are known to react readily or decompose easily, especially in organic solvent matrices that have been generally employed in stripping compositions. In such instances the oxidizing agent is consumed and becomes unavailable for its intended use. Additionally, microelectronic cleaning compositions containing oxidizers often show poor product stability, especially in the presence of significant amounts of 10 wt % or more of organic solvents, and at higher pH ranges and high process temperatures. Furthermore, in many compositions the use of stabilizers and solvents often tie up the oxidizing agent resulting in diminished capabilities of performing effective oxidation/reduction reactions employed in the cleaning process. In U.S. Pat. No. 6,116,254 the inventors teach introducing chlorine gas into pure water in a tank to thereby generate chloride ions, hypochlorite ions, chlorite ions and chlorate ions in the pure water and, then immersing a substrate in the pure water solution for cleaning. Such a cleaning scheme is not well controlled or stable over a period of days and is certainly not environmentally friendly and has toxic properties. Additionally, the amount of dissolved chlorine is limited to no more than 0.3% due to the limitation of the amount of chlorine gas dissolvable in the water. Furthermore, the pure water solutions with dissolved chlorine gas is always an acidic mixture and, thus, not usable in situations where an alkaline cleaning solution is desired or required. Moreover, such a cleaning solution is not a preformed product capable of being packaged and transported for use at a site remote from its production. Also, the patentees state that it is sometimes necessary to screen the irradiation of visible and/or UV light to the pure water solution containing the dissolved chlorine gas in order to prevent decomposition from occurring. The pure water solution containing the dissolved chlorine gas is also temperature sensitive and is generally kept at a temperature of 10° C. while being generated and until ready for use. All of the drawbacks make this cleaning system not very desirable and severely limits its use.

Microelectronic cleaning composition containing halogen oxygen acids, salts and derivatives thereof


A portable plastic film wrapping system comprises a push-cart having a vertical mast member mounted thereon. A film roll carriage is vertically movable along the mast member, and the film roll carriage is operatively connected to a counterweight which is movably disposed within the mast member. The mast member is provided with a plurality of apertures, and a redundant dual stop pin assembly is engageable within particular ones of the mast member apertures so as to incrementally lockingly retain the film roll carriage at a particular elevations along the mast member such that safe controlled movement of the film roll carriage along the mast member is achieved.

The present invention relates generally to plastic film wrapping apparatus for wrapping palletized loads or products, and more particularly to a new and improved plastic film wrapping apparatus or system which is portable, relatively simple in structure, and readily enables the manually controlled wrapping of palletized loads or products with plastic wrapping film while ensuring a high degree of safety for operator personnel.
As has been noted within previously filed U.S. patent application Ser. No. 09/432,284, which was filed on Nov. 2, 1999 and in the name of Hugh J. Zentmyer et al. for an APPARATUS AND METHOD FOR MANUALLY APPLYING STRETCH FILM TO PALLETIZED PRODUCTS, it is a known fact that approximately fifty percent (50%) of all stretch film that is manufactured is applied to, for example, palletized loads or products by manual means. It is also known that when applying such stretch film to, for example, palletized loads or products, the manner in which such stretch film is manually applied to such loads or products usually comprises either one of two methods. In accordance with a first one of such manual methods, as illustrated, for example, within U.S. Pat. No. 5,398,884 which issued to Stanford on Mar. 21, 1995, the operator respectively inserts four fingers of each hand into each one of two oppositely disposed recessed portions defined within the film core end caps so as to effectively hold or grasp the film roll, and while placing his thumbs upon outside surface portions of the film roll, so as to effectively cause a predetermined amount of back tension to be applied to the film whereby the film is effectively stretched as the film is being unrolled or dispensed from the film roll, the operator walks around the palletized load or product. In accordance with a second one of such manual methods of applying a stretch film to such palletized loads or products, as illustrated, for example, within U.S. Pat. No. 5,458,841 which issued to Shirrell on Oct. 17, 1995, and in lieu of directly holding or grasping the film roll, the operator holds or grasps a film roll dispensing or holding device which has a built-in tensioning mechanism. In accordance with either one of the aforenoted modes, methods, or manners in which stretch film is applied manually to the palletized products or loads, several operational drawbacks or disadvantages common to both methods or modes were apparent. Firstly, for example, the film roll, or the film roll and film roll dispensing or holding device, must be supported by the operator personnel, and yet the film roll and the film roll dispensing or holding device are quite heavy and cumbersome. In addition, in order to fully wrap a palletized load, the operator must bend down while holding the film roll, or the film roll and film roll dispensing or holding device, in order to wrap the film around the lower extremity portions of the palletized loads or products. Such requirements upon the operator personnel have been noted to cause acute discomfort, fatigue, and stress-related injuries. In addition, the operators experience fatigue and discomfort even when the operators are wrapping the upper regions of the palletized loads or products due to the continuous need for supporting the entire weight of the film roll, or the film roll and film roll dispensing or holding device.
A need therefore existed in the art for an apparatus, and for a method of operating the same, for overcoming the various operational disadvantages or drawbacks characteristic of the known PRIOR ART systems as briefly discussed hereinbefore and as disclosed within the aforenoted patents, and this need was substantially met by means of the apparatus or system, and the method of operating the same, which has been disclosed within the aforenoted U.S. patent application Ser. No. 09/432,284 and which has been quite commercially successful. However, while it has been noted in such aforenoted patent application that the apparatus or system disclosed within the aforenoted U.S. patent application Ser. No. 09/432,284 is portable in that the same is mounted upon a platform which has wheels, rollers, or the like so as to render the same movable or mobile, the apparatus is nevertheless relatively large and not readily transportable so as to, in turn, not be readily or easily movable within a particular wrapping plant or facility, or even yet further, readily or easily transportable between different wrapping plants or facilities located at different production sites.
Accordingly, the film wrapping apparatus or system disclosed within the aforenoted U.S. patent application Ser. No. 09/814,861 filed on Mar. 23, 2001 in the name of Gale W. Huson et al. for a PORTABLE FILM WRAPPING SYSTEM sought to overcome the various operational disadvantages of the known PRIOR ART and in fact successfully did so. Further improvements to such system were deemed necessary, however, in order to render such system simpler in structure, and accordingly, such improvements were in fact developed and accordingly disclosed within the aforenoted U.S. patent application Ser. No. 09/947,364 which was filed on Sep. 7, 2001 in the name of Gale W. Huson et al. and entitled PORTABLE PLASTIC FILM WRAPPING SYSTEM. While the apparatus or system as disclosed within the patent application Ser. No. 09/947,364 has operated quite satisfactorily, it has been determined still further, however, that additional improvements might optimally be incorporated within such a system in order to render the same essentially failsafe with respect to operational safety aspects for operator personnel. Occupational Safety and Health Administration (OSHA) regulations are continuously seeking to improve and ensure the occupational safety of manufacturing workplace environments in order to in fact protect operator personnel, and in accordance with the broad objectives of such regulations, it has been determined that a further need exists in the art for a new and improved film wrapping apparatus wherein the film wrapping apparatus is truly portable, transportable, simple in structure, and in effect comprises redundant safety mechanisms so as to readily enable the manual wrapping of palletized loads or products with wrapping film at a particular location within a production facility, so as to readily enable the manual wrapping of palletized loads or products with wrapping film at different locations within a particular production facility, so as to readily enable the manual wrapping of palletized loads or products with wrapping film at different production facilities, and wherein the film wrapping apparatus is relatively simple in structure and yet capable of ensuring a safe operational mode for operator personnel.
Accordingly, it is an object of the present invention to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products.
Another object of the present invention is to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products wherein the various operational drawbacks and disadvantages, characteristic of PRIOR ART apparatus, systems, or methods of operating the same, are overcome.
An additional object of the present invention is to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products wherein the wrapping or packaging film can be applied to or wrapped around the palletized loads or products by means of operator personnel who can simply walk around the pallet upon which the loads or products are disposed and simultaneously push or guide the roll of wrapping film around the palletized loads or products whereby the palletized loads or products are accordingly packaged or wrapped within such wrapping film.
A further object of the present invention is to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products wherein the wrapping or packaging film can be applied to or wrapped around the entire vertical extent of the palletized loads or products by means of operator personnel who need not support the weight of the film roll, or the film roll and the film roll dispensing mechanism, and in addition need not bend down in order to wrap or apply the stretch film upon or to the lower extremity portions of the palletized loads or products.
A still yet further object of the present invention is to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products wherein the film wrapping apparatus or system is truly portable and transportable so as to readily enable the manual wrapping of palletized loads or products with packaging or wrapping film at a particular location within a production facility, so as to readily enable the manual wrapping of palletized loads or products with packaging or wrapping film at different locations within a particular production facility, or so as to readily enable the manual wrapping of palletized loads or products with packaging or wrapping film at different production facilities.
A last object of the present invention is to provide a new and improved apparatus or system for applying wrapping or packaging film to palletized loads or products wherein the film wrapping apparatus or system is relatively simple in structure, economical to manufacture, and exhibits redundant safety mechanisms for operator personnel.
The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved apparatus or system, for applying packaging film to palletized loads or products disposed at a wrapping station or location, which comprises in effect, a manually movable cart which is formed by means of a chassis wherein a pair of relatively large non-pivotal or non-caster type wheels are mounted upon a rear end portion of the chassis, while a pair of relatively small pivotal or caster-type wheels are mounted upon a front end portion of the chassis so as to permit the cart to be steered. The chassis is also provided with a vertically upstanding mast member, and a film roll carriage, upon which a roll of plastic wrapping film is rotatably disposed so as to be capable of dispensing the plastic wrapping film therefrom, is movably mounted upon the mast member. A counterweight is operatively connected to the film roll carriage, through means of a suitable cable, so as to normally tend to elevate the film roll carriage and the roll of plastic wrapping film mounted thereon. The mast member is provided with a plurality of vertically spaced apertures, and the disposition of a spring-biased, dual-pin bracket system, pivotally mounted with respect to the individual apertures, is able to be controlled by means of a manually-operated cable and lever mechanism.
More particularly, when the lever is squeezed, in a manner similar to that of a hand-operated brake lever upon a bicycle, the cable causes a first end of the pivotally mounted bracket to be moved so as to effectively withdraw a first one of the two pins comprising the dual-pin system to be released from a particular one of the apertures of the mast member while the second end of the pivotally mounted bracket is moved so as to effectively cause the second one of the two pins comprising the dual-pin system to be moved toward the mast member in preparation for insertion within another one of the mast apertures. The film roll carriage, along with the roll of plastic wrapping or packaging film mounted thereon, will be elevated along the mast member under the influence of the downwardly moving counterweight so as to wrap the palletized load or product as the operator pushes the cart along a circular path around the palletized load or product, however, it can be appreciated that the elevation of the film roll carriage is incrementally limited by means of the dual-pin control system.
Accordingly, if continuous spiral wrapping of the palletized load or product is desired to be achieved, the operator simply needs to alternatively squeeze and release the lever so as to permit the film roll carriage to elevationally move upwardly along the mast member as determined by means of the dual-pin control system. Alternatively, if continuous concentric wrap-ping of the palletized load or product with the packaging or wrapping film at a particular elevational level is desired, which is known as reinforcing wrapping, the lever is simply released so as to permit the cable-controlled pin to enter a particular aperture located along the mast member. When such cable-controlled pin enters such aperture upon the mast member, further elevation of the film roll carriage, and the roll of wrapping film mounted thereon, is prevented. At the completion of a wrapping cycle or operation, the operator can manually release the cable-controlled pin independently of the cable-control mechanism such that both pins are effectively simultaneously retracted from their mast apertures thereby permitting the carriage assembly to be lowered to its lowermost position in preparation for a new palletized load or product packaging or wrapping cycle or operation. It can therefore be appreciated that as a result of the alter-natively actuated dual-pin control system, redundant safety is inherently incorporated within the system.


A vascular occlusion assembly for therapeutically occluding a vascular site in a patient. The assembly comprises a foldable material occlusion bag having an expanded diamond shape and an elongated flexible filler member which is inserted in the internal cavity of the occlusion bag. When positioned in the internal cavity of the bag, the filler member assumes a convoluted configuration expanding the bag to the expanded shape. The occlusion bag is positioned on the flared distal end of a positioning catheter. A collar is wrapped around the neck of the bag to securely position the bag and prevent premature detachment from the positioning catheter. A pusher catheter is coaxially positioned around the positioning catheter to release the expanded occlusion bag from the flared distal end of the positioning catheter. A handle is releasably attached to the proximal end of the flexible filler member and inserted into the positioning catheter for expanding the occlusion bag to the diamond shape. The distal portion of the filler member is hook-shaped for readily inserting the filler member in the bag without tearing the bag. The distal end segment of the filler member is also enlarged to minimize perforation of the bag and prevent withdrawal through the positioning catheter.

Catheters for performing a therapeutic embolization procedure typically have detachable, inflatable balloons formed of latex or a C-FLEX.TM. material. During an embolization procedure, the detachable balloon is attached to the distal end of a delivery catheter and positioned at the treatment site using a visualization aid such as fluoroscopy. Once positioned, the balloon is filled with a solidifying gelatinous fluid until a predetermined pressure is reached within the balloon for forcing the balloon valve closed and away from the delivery catheter. In this manner, the balloon is detached from the delivery catheter. The gelatinous fluid quickly solidifies for achieving long-term occlusion of the blood vessel at the treatment site.
A problem with these detachable balloons is that there is no positive means of detachment. Detachment of a balloon depends on fluid forces in the balloon and in the bloodstream at the treatment site. Blood flow surrounding the balloon on the delivery catheter potentially causes premature balloon detachment. As a result, the balloon is not filled with gelatinous fluid, and the balloon valve is not sealed. The partially collapsed balloon moves through the vascular system of a patient to an undesirable site such as the heart, brain, or lungs to cause a heart attack, stroke, or pulmonary embolism and possibly death.


A vacuum holddown has a holddown member with an outer surface for temporarily capturing a flexible sheet material via a vacuum force distributed across the outer surface through discrete vacuum channels. A vacuum force valve mechanism abuts an inner surface of the holddown member in a selectable sliding engagement. The valve mechanism has a pattern of apertures therethrough in predetermined pattern such that discrete valve mechanism positions produce discrete vacuum force patterns at the outer surface of the holddown member.

1. Field of the Invention
The present invention relates generally to vacuum holddown apparatus and methods of operation and, more specifically, to a cut-sheet print media vacuum holddown particularly useful for a hard copy apparatus, such as an ink-jet printer.
2. Description of Related Art
It is known to use a vacuum induced force to adhere a sheet of flexible material to a surface, for example, for holding a sheet of print media temporarily to a platen. [Hereinafter, "vacuum induced force" is also referred to as "vacuum induced flow," "vacuum flow," or more simply as just "vacuum" or "suction".] Such vacuum holddown systems are a relatively common, economical technology to implement commercially and can improve machine throughput specifications. For example, it is known to provide a rotating drum with holes through the surface so that a vacuum through the drum cylinder provides a suction force at the holes in the drum surface. [The term "drum" as used hereinafter is intended to be synonymous with any curvilinear implementation incorporating the present invention; while the term "platen" can be defined as a flat holding surface, in hard copy technology it is also used for curvilinear surfaces, such as a common typewriter rubber roller; thus, for the purposes of the present application, "platen" is used generically for any shape holddown surface used in a flexible material holddown apparatus.]
Generally in a hard copy apparatus implementation, the platen is used either to transport cut-sheet print media to a printing station of a hard copy apparatus, such as a copier or a computer printer, or to hold the cut sheet print media at the printing station while images are formed (also known as the "print zone"), or both. [In order to simplify discussion, the term "paper" is used hereinafter to refer to all types of print media. No limitation on the scope of the invention is intended nor should any be implied.]
One universal problem, particularly pertinent in the adaptation of a vacuum holddown to use in a hard copy apparatus, is the management of different sizes, shapes, and thicknesses of available paper. Open holes around the edges of a sheet smaller than the dimensions of the vacuum field across the platen surface results in vacuum losses and a lower or ineffective holding force. In other words, too many exposed vacuum ports result in a loss of suction at the platen surface and the paper is not firmly adhered to the surface.
One technique for controlling a vacuum holddown is proposed by Rasmussen et al. in U.S. Patent Application Ser. No. 09/292,767 for a PRINT MEDIA VACUUM HOLDDOWN (assigned to the common assignee of the present invention and incorporated herein by reference). A vacuum holddown for sheet materials has a surface having a field of vacuum ports in which each individual port is gated. When a vacuum is applied to the underside of the holddown, the gates close. When a sheet of material is introduced onto a region of the field, the gates only within vacuum manifold passageway covered by the material are configured to spring open, applying a suction force to the sheet via the now opened ports. The holddown thus automatically adjusts to material size. An implementation for use in an ink-jet printer with cut-sheet print media is demonstrated.
Another technique is demonstrated by Rhodes et al. in U.S. patent application Ser. No. 09/292,125 for a VACUUM CONTROL FOR VACUUM HOLDDOWN (assigned to the common assignee of the present invention and incorporated herein by reference). A mechanism for manifolding a vacuum force to separate surface sectors of a vacuum holddown uses subsurface ducting to apply the vacuum to separate subsurface vacuum plenums wherein each is fluidically coupled to a separate surface sectors. The plenum is segregated by a diaphragm into surface side and vacuum side cavities. Trigger ports and appropriate ducting through the holddown subjacent the surface associated with each sector determine how the vacuum is routed. Only when a trigger port is covered is the vacuum routed to the surface sector associated therewith. The system can be implemented in planar or curvilinear constructs and be provided with features to accommodate a near-continuous range of flexible material sizes. A specific implementation in an ink-jet hard copy apparatus is also described.
Related to the Rasmussen et al. and Rhodes et al. Applications, U.S. patent application Ser. No. 09/292,838 for a VACUUM SURFACE FOR WET DYE HARD COPY APPARATUS by Wotton et al. (assigned to the common assignee of the present invention and incorporated herein by reference) shows a platen surface structure construct, particularly useful in a hard copy apparatus for a vacuum holddown, configured by dimensioning print media platen surface structure channels and ports in order to ensure print media leading edge and trailing edge holddown. The vacuum is distributed across the platen surface in accordance with predetermined dye flow characteristics based upon known dye composition and known print medium composition and such that print artifacts are not created by vacuum pulling wet dye through the capillaries Df the medium.
There is a continuing need to direct vacuum forces to specific locations of a holddown to increase vacuum efficiency and improve holddown force. Moreover, there is a need for a vacuum holddown for sheet material transport that can adjust to hold a variety of sizes of materials.


The invention controls the opening of an oil control valve (OCV), which controls the operation of a variable valve timing mechanism in an internal combustion engine, according to a duty ratio of a driving pulse signal. An electronic control unit (ECU) performs feedback control on a duty ratio DR of the driving pulse signal during ordinary operation based on a target value and an actual value of the valve timing. When the oil temperature is low (i.e., when the operating oil viscosity is high), the ECU controls the valve timing of the engine by repeating an inching operation that maintains the duty ratio DR of the signal at a large value (i.e., 0% or 100%) for a predetermined hold time so as to operate the variable valve timing mechanism, and then maintaining the duty ratio DR of the signal at a value (50%) that does not operate the variable valve timing mechanism.

The disclosure of Japanese Patent Application No. 2002-051439 filed on Feb. 27, 2002, including its specification, drawings and abstract, is incorporated herein by reference in its entirety.
1. Field of the Invention
The invention relates to a valve control apparatus and method for an internal combustion engine. More particularly, the invention relates to a valve control apparatus and method provided with means for changing a valve operating characteristic such as valve opening timing (i.e., valve timing), valve lift amount, and open valve period of one or both of an intake valve and an exhaust valve in each cylinder of an internal combustion engine.
2. Description of the Related Art
A valve control apparatus for an internal combustion engine is known that changes an operating characteristic of one or both of an intake valve and an exhaust valve of the internal combustion engine while it is running, so as to enable constant optimal engine performance regardless of the running state of the engine. One known example of this type of valve control apparatus controls one or more of a valve opening and closing timing (i.e., valve timing), a valve lift amount, and an open valve period, and the like of an intake valve and an exhaust valve according to the operating state of the internal combustion engine.
When changing the valve timing, for example, a method is used that changes a relative rotation phase of a camshaft with respect to a crankshaft using a hydraulic actuator or the like. Further, to change the valve lift amount, the open valve period and the like, various methods are used. One method aligns a plurality of cams having profiles with different cam lift amounts and cam operation angles in the axial direction on a camshaft, and switches the cam that drives the valve by moving the camshaft in the axial direction using a hydraulic actuator. Another method changes the valve lift amount and open valve period by providing a cam having a cam profile with a continuous change in the actuation angle and the like, instead of providing a plurality of cams, and moving the camshaft in the axial direction using a hydraulic actuator.
An example of this type of valve control apparatus is disclosed in Japanese Patent Laid-Open Publication No. 6-159021, for example.
The valve control apparatus in the foregoing publication controls the valve timing of an intake valve to an optimal value according to the operating state of the engine. This valve control apparatus is provided with a hydraulic actuator that rotates the camshaft relative to the crankshaft, and an oil control valve able to supply an oil pressure that actuates the hydraulic actuator in a direction to advance the valve timing and an oil pressure that actuates the hydraulic actuator in a direction to retard the valve timing.
Also, the valve control apparatus in the foregoing publication is provided with a cam position sensor that detects a rotation phase difference between the camshaft and the crankshaft. The valve control apparatus calculates the actual valve timing using the cam position detected by the sensor, obtains the difference between a target valve timing set from the operating state of the engine and the actual valve timing that was calculated, and performs feedback control on the oil control valve based on this difference.
For example, this feedback control is made PID control based on the difference, and the opening of the oil control valve is set as the sum of the difference and the components proportional to an integral value and a derivative value of the difference.
According to the apparatus in the publication, the proportional coefficient (i.e., gain) of each of the components of the PID control is set according to the engine speed. Ordinarily, because the oil pressure supplied to the actuator is supplied by an oil pump that is driven by the engine, the discharge pressure of the pump changes according to the engine speed. Therefore, if the gain of each of the components of the PID control are fixed, the response rate of the control may change according to a change in the pump discharge pressure (i.e., the engine speed). Therefore, because the output of the apparatus and the gain of each of the components of the PID control in the foregoing publication are not fixed, but set according to the engine speed, the pressure and amount of oil supplied to the hydraulic actuator can be controlled based on the ability (i.e., discharge pressure, discharge amount) of the engine driven oil pump. Accordingly, consistently stable valve timing control is able to be performed regardless of the engine speed.
By setting the gain of the PID control according to the engine speed, the apparatus disclosed in the aforementioned publication prevents the operation speed of the hydraulic actuator from decreasing by setting the gain large in the low speed region, in which the discharge pressure and discharge amount of the engine driven oil pump decrease, and prevents overshooting and hunting in the control by setting the gain low when the engine is running at high speeds, for example.
With the apparatus disclosed in Japanese Patent Laid-Open Publication No. 6-159021, however, even though control is performed according to the engine speed, there are times, such as when the oil temperature is low when the engine is cold, when the valve operating characteristic is unable to be controlled appropriately.
At times such as when the engine is running but is cold after starting, the temperature of the operating oil supplied to the hydraulic actuator has not risen sufficiently so the viscosity of that operating oil is high. Accordingly, an increase in flow resistance within the oil passages and an increase in friction resistance of the sliding portions, and the like, reduce the operating speed of the hydraulic actuator, thereby lowering the responsiveness in the control over the valve operating characteristic and narrowing the operating range of the hydraulic actuator.
The apparatus in the aforementioned publication compensates for the decrease in oil pressure and oil amount when the engine is running at low speeds by increasing the control gain. However, hydraulic systems and engine driven oil pumps and the like are ordinarily designed so that the discharge pressure and the discharge amount will not change much when the engine speed changes, so changes in the oil pressure and oil amount due to changes in the engine speed are kept comparatively small. In contrast, there are times when the increase in flow resistance and the increase in friction resistance due to increased oil viscosity at low temperatures may become far greater than the increase in flow resistance and the increase in friction resistance due to a change in the engine speed.
Therefore, when attempting to prevent a decrease in control responsiveness by only increasing the control gain when the oil temperature is low, there is a tendency for the increase in the gain to become quite large, which may result in overshooting or hunting or the like, making control unstable. Also, the deterioration in the control accuracy of the actuator due to the increased oil viscosity cannot be corrected by just increasing the gain. Just increasing the gain when the oil temperature is low results in the control becoming unstable, which in turn results in a delay in reaching the target valve operating characteristic, and the like, which ultimately leads to a deterioration in engine performance at low temperatures and a deterioration in the exhaust gas emissions, and the like.
In view of the foregoing problems, it is an object of the invention to provide a valve control apparatus and method that enables the responsiveness in valve control to be improved without losing stability in the control, even when the engine is cold.
According to a first aspect of the invention, a valve control apparatus is provided which changes a valve operating characteristic of an internal combustion engine, the valve operating characteristic including at least one of a valve timing, a valve lift amount, and an open valve period. The valve control apparatus includes a actuator that changes the valve operating characteristic. This actuator is actuated according to a value of a driving signal that is input thereto. The valve control apparatus also includes a controller that detects an operating characteristic parameter indicative of the valve operating characteristic and outputs a driving signal value according to a difference between an operating characteristic target value according to an operating condition of the engine and the detected parameter value to the actuating means. The controller performs a forced driving operation that repeats an operation for maintaining the driving signal at a predetermined forced driving signal value for a predetermined hold time when the difference is greater than a predetermined value.
That is, according to the first aspect, when the feedback control is performed on the actuator based on a difference between a control target value and an actual value for a valve operating characteristic parameter and that difference is large, the value of the driving signal is not determined based on the size of that difference, as it is with the conventional feedback control. Instead, the driving signal is set to an appropriate value and an operation which maintains that driving signal value at this value (i.e., a forced driving signal value) for a certain period of time is repeatedly performed. That is, the amount of change in the valve operating characteristic is controlled by increasing or decreasing the number of times the operation is repeated.
As described earlier, at times when the viscosity of the operating fluid is high, such as when the engine is cold, in order to obtain good response to the valve operating characteristic, it is necessary to greatly increase the gain of the feedback control. If the control gain is greatly increased and the difference between the control target value and the actual value is large, however, the value of the driving signal also increases accordingly, which may result in overshooting or hunting, which may cause a delay in reaching the target value. According to this invention, because the forced driving operation that intermittently maintains, or holds, the driving signal value at a large value only when the difference is large is performed without the gain of the feedback control being increased, the value of the driving signal returns to a comparatively small value each time the hold time elapses. As a result, it is possible to increase the overall operation speed of the actuating means while minimizing overshooting and hunting.
The forced drive signal value does not need to be a fixed value throughout the forced driving operation. It may be any value as long as it is able to reliably change the valve operating characteristic. Further, the forced driving signal value does not need to be maintained at a fixed value throughout one hold time. It may be a value that changes during one hold time as long as it is within a range of a size able to reliably change the valve operating characteristic.
It is preferable that the forced driving signal value be set to a comparatively large value (e.g., a value which will result in the greatest operating speed of the actuator) able to operate the actuator even when the operating range of the actuator is narrow, such as when the temperature is low.
According to a second aspect of the invention, a valve control method for an internal combustion engine having an actuator that changes a valve operating characteristic is provided. The actuator is actuated according to a value of a driving signal that is input thereto. The valve operating characteristic includes at least one of a valve timing, a valve lift amount, and an open valve period. This control method comprises the steps of: detecting an operating characteristic parameter indicative of the valve operating characteristic; outputting the driving signal value according to a difference between an operating characteristic target value according to an operating condition of the engine and the detected parameter value to the actuator. In this control method, a forced driving operation that repeats an operation to maintain the driving signal at a predetermined forced driving signal value for a predetermined hold time is performed when the difference is greater than a predetermined value.

Valve control apparatus and method for internal combustion engine


A light irradiating device includes a processing chamber in which a substrate is accommodated; a beam source chamber in which a beam source of an energy beam is accommodated; a partition wall configured to partition the processing chamber and the beam source chamber; multiple window members provided at the partition wall to transmit the energy beam outputted from the beam source toward the substrate within the processing chamber; and multiple gas discharge units respectively disposed around the multiple window members within the processing chamber, and configured to discharge an inert gas along surfaces of the multiple window members.

Patent Document 1 describes a manufacturing process for a semiconductor device. In this manufacturing process, a process of forming a resist film on a surface of a substrate, a process of performing exposure, a process of patterning the resist, a process of irradiating light having a wavelength equal to or less than 200 nm to the entire surface of the resist and a process of etching an underlying film of the resist film are performed in sequence.
Patent Document 1: Japanese Patent Laid-open Publication No. 2001-127037

Light irradiating device, light irradiating method and recording medium


A method of producing soot, including: combusting a first fuel stream and a first oxidizer at a burner face; combusting a second fuel stream and a second oxidizer at the burner face, wherein the second fuel stream and the second oxidizer are premixed in advance of the burner face and a second equivalence ratio of the second fuel stream and the second oxidizer is less than about 1; and combusting a silicon-containing fuel into a plurality of soot particles, wherein the second fuel stream and the second oxidizer are combusted between the first fuel stream and the silicon-containing fuel. Applying this method of producing soot to deposit a preform suitable for the manufacture of optical fibers.

Outside vapor deposition is utilized in the formation of optical fiber preforms. Outside vapor deposition involves the process of combusting one or more silicon-containing fuels to form silica soot. The silica soot is then deposited on a bait rod or core cane to form the optical fiber preform. In conventional outside vapor deposition systems, a jet of the silica soot may be produced under conditions which lead the silica soot to be dispersed. The dispersed silica soot may lead to a lower than ideal efficiency of soot capture. The dispersion of the silica soot jet may be affected by a variety of properties related to the combustion of the silicon-containing fuels. Dispersed soot not captured on the bait rod or core cane to form the optical fiber preform is generally either exhausted out of the deposition chamber and captured downstream as a waste material or deposited undesirably on surfaces and components within the deposition chamber, typically requiring time and effort to remove and clean before initiating deposition of the next optical fiber preform. It is therefore generally desirable to minimize both the amount and relative fraction of soot not deposited or captured on the optical fiber preform. Additionally, the process of combusting silicon fuels in the outside vapor deposition process creates audible noise. In a large-scale soot generation operation, it may be desirable to reduce such noise. The magnitude of the audible noise may be affected by a variety of properties related to the combustion of the silicon-containing fuels.


A load distributor for a sternum closure device comprises a wire receiving section configured to be attached to a wire of the sternum closure device, and a load distributing section. A tool for cutting the load distributor comprises a pair of jaws movable between a load distributor receiving position and a cutting position, wherein at least one of the jaws has substantially V-shaped cutting edges tapered towards the other jaw in an angle to the longitudinal extension of the tool.

The present disclosure generally relates to surgical devices. In particular, a load distributor for a sternum closure device, a sternum closure device comprising the load distributor, a tool for cutting the load distributor, and a sternum closure system comprising the load distributor and the tool are described.
To promote the healing process of fragmented or cut bone, it has been known to exert an external force on bone parts by tightly clamping them together. To this end, flexible elongated members such as wires can be used which are tensioned around the bone parts.
For example, prior to heart surgery, the sternum bone is often cut into two halves by means of a longitudinal section to obtain access to the heart. The sternum halves later need to be fixedly joined again. This can be done by arranging a wire around the sternum halves in a circumferential manner so as to surround a cross-sectional area thereof. Said cross-sectional area extends typically transverse to the longitudinal section through the sternum. Afterwards, the wire is tensioned and fixed by connecting and twisting the free ends thereof.
Furthermore, it has been known to arrange protector pads between the wire and an adjacent surface of the respective bone fragments. The protector pads avoid that the wire cuts into the bone surface when tensioning it, thus causing damage to the bone.
U.S. Pat. No. 6,287,307 B1 discloses an apparatus and a method for clamping the split bone sections of a sternum. For doing so, protector pads in form of sternal plates are arranged in opposite configuration at the split sternum halves. The sternum plates are provided with spikes which are driven into outer side surfaces of the sternum halves by means of a forceps. The sternum plates are hence directly fixed at the bone fragments in a first step. Afterwards, a surgeon can guide and tension a circumferential wire around the sternum plates and the bone fragments arranged therebetween.
U.S. Pat. No. 8,597,327 B2 teaches a method and apparatus for securing a fractured or sectioned sternum by means of a flexible member construct forming circumferential loops around the sternum halves. In addition, protector members are provided for guiding and fixing said flexible member construct around the sternum halves.
WO 2012/027025 A2 discloses a method for closing a sternum with help of adhesives. The adhesives may also be applied in contact regions between the sternum halves and an additionally provided circumferential wire to form a protective layer similar to the known protector pads.
WO 2014/149244 A1 relates to protective sleeve. A guide wire is movable within the protective sleeve and comprises a stop, such that it can abut on the protective sleeve in order to advance the protective sleeve to a desired resting position. Once this resting position is reached, the guide wire is pulled from the protective sleeve.

Load distributor for a sternum closure device and tool for cutting the load distributor


A wireless charging shelf is described where a charging surface with a wireless power transmission structure is coupled with an electrical connector, providing a truly wireless charging solution. The wireless charging shelf may have a plug for installation in an electrical receptacle, or may be part of a cover plate for replacing an existing cover plate with a wireless charging shelf cover plate.

1. Field of the Invention
This invention relates generally to wireless charging, and more particularly to a wireless charging shelf.
2. Description of the Related Art
With the proliferation of electronic devices such as cell phones, MP3 players, handheld email and text messaging devices, handheld or pocket PCs, and the like, there exists an ongoing need to recharge the batteries in these devices on a regular and ongoing basis. The proliferation of these rechargeable electronic devices create a great deal of clutter in one's living space or office space that, when combined with charging cords, cradles, interface cords, and the like, can become unmanageable or at the least create disorganization. When one charges these devices, an electrical outlet that is at a convenient height with a counter or other surface, is usually used. This outlet is most often located in the kitchen or bathroom, as most remaining electrical outlets in a home are located close to the floor. Unfortunately, this means that cell phones are commonly charged in the kitchen or bathroom, and take up valuable counter space. The clutter of electronic devices, chargers, and cables also creates a less than desirable visual landscape in one's home. In the past, there have been attempts to manage this situation through the use of charging cradles or charging stands. Unfortunately, while creating a neater visual appearance, these cradles and stands still take up valuable counter space.
Recently wireless charging mats have been manufactured that claim to eliminate the clutter associated with chargers and cords; this clutter fondly known by some as "black spaghetti". Unfortunately, while these wireless charging mats claim to eliminate cord clutter, in reality there is a cord from the charging mat to a wall outlet, thereby only replacing one cord with another. In addition, these wireless charging mats are placed on a counter, desk or other flat surface, taking up space and merely adding one more gadget to the clutter. Heretofore, a truly wireless charging solution has not existed. While the transmission of electric energy has been known and experimented with for more than 100 years, it has never seen commercial success. Nikola Tesla, for example, worked extensively with the transmission of electric energy without wires. He published numerous papers on his findings. For example, "The True Wireless" as published in the Electrical Experimenter, May 1919, and "The Transmission of Electric Energy Without Wires" as published in Electrical World and Engineer on Mar. 5, 1904.
The present invention and the various embodiments described and envisioned herein solve the need for a truly wireless charging solution for electronic devices.
It is therefore an object of the present invention to provide a wireless charging shelf for electronic devices that eliminates the electronic clutter found on many counter, desk and other surfaces. It is another object of the present invention to provide a wireless charging shelf where loose wires are not required between the charging surface and the electrical connector. It is yet another object of the present invention to provide a wireless charging shelf having operational logic. It is yet another object of the present invention to provide a cover plate with a wireless charging shelf. It is further an object of the present invention to provide a system for charging an electronic device having a wireless charging shelf. It is yet another object of the present invention to provide a wireless charging shelf and an electronic device having a wireless power receiver. These and other objects of the present invention are not to be considered comprehensive or exhaustive, but rather, exemplary of objects that may be ascertained alter reading this specification with the accompanying drawings and claims.