A continuous printhead drop deflector system includes a gas flow duct including a wall, the wall including a porous member having pores through which liquid can flow and a liquid flow channel, the flow channel being separated from the air flow duct by the porous member, the flow channel includes; a first port for extracting liquid from a first portion of the liquid flow channel; a second port for supplying liquid to a second portion of the liquid flow channel; one or more paths in the liquid channel permitting fluid to flow from the second portion to the first portion; wherein liquid, supplied through the second port to the second portion of the liquid channel and through the one or more paths to the first portion of the liquid channel, contacts and wicks into the porous member before being extracted through the first port.

Continuous stream inkjet printing uses a pressurized ink source which produces a continuous stream of ink droplets. Stimulation devices, such as heaters positioned around the nozzle, stimulate the stream to break up into drops with either relatively large volumes or relatively small volumes. These drops are then directed by one of several means, including electrostatic deflection or gas flow deflection. Printheads utilizing gas flow for deflection are known and have been described.
In one form of such printheads, the drop deflecting gas flow is produced at least in part by a gas, typically air, drawn into a negative air duct as a result of vacuum applied to the duct. Drops of a predetermined small volume are deflected more than drops of a predetermined large volume. This allows for the small drops to be deflected into an ink capturing mechanism (catcher, interceptor, gutter, etc.) where they are either recycled or discarded. The large drops are allowed to strike the print medium. Alternatively, the small drops may be allowed to strike the print medium while the larger drops are collected in the ink capturing mechanism.
It has been determined that while small drops are deflected by the lateral airflow more than large drops, not all small drops follow the same trajectory. Some of these drops can be deflected sufficiently by the air flow such that they enter the gas flow duct, causing ink puddles to form. Ink puddles in the air duct can also be formed during startup and shutdown of the printhead caused by ink dripping off the upper wall of the gas flow duct and landing on the lower wall of the gas flow duct. Additionally, ink puddles can be formed due to a crooked jet which causes ink to be directed into the gas flow duct. Ink from the puddles of ink in the gas flow duct can be dragged by the gas flow up into the vacuum source that is attached to the gas flow duct, potentially damaging the vacuum source. If the ink puddles remain close to the entrance to the duct, these puddles can affect the uniformity of the air flow across the width of the jet array. Ink puddles can induce oscillations in the gas flow that can produce a modulation in the print drop trajectories that adversely affect print quality.
Accordingly, a need exists to maintain the cleanliness of the gas flow duct and remove ink puddles formed therein.

Continuous printhead drop deflector system


A self-aligning block that includes a body that has at least one mortise therein, and at least one tenon that extends from the body. A respective tenon of one self-aligning block is received in a respective mortise in the bottom surface of the body of a next higher staggered the self-aligning block of one wall to a height that provides an automatic mortar space between the one self-aligning block and the next higher staggered self-aligning block from course to course of the one wall. That portion of the lateral alignment spacer that extends from the longitudinal alignment spacer to a respective tenon of one self-aligning block of one wall is higher than and is received by a respective longitudinal alignment recess in a respective side face of the body of a next higher staggered self-aligning block of a perpendicular wall, with a respective side face of the body of the next higher staggered self-aligning block of the one wall abutting against the longitudinal alignment spacer of the one self-aligning block of the perpendicular wall so as to assure proper longitudinal and lateral spacing between self-aligning blocks of the same course of perpendicular walls, while further assuring proper mortar spacing between courses of the perpendicular walls.

1. Field of the Invention
The present invention relates to a block. More particularly, the present invention relates to a self-aligning block.
2. Description of the Prior Art
Numerous innovations for blocks have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
FOR EXAMPLE, U.S. Pat. No. 4,436,447 to Crowe teaches interlocking concrete blocks for controlling erosion of banks of bodies of water that are provided with improved wave resistance by providing pairs of spigots on one side of the block and a slot or slots on the other side of the block so as to allow longitudinal movement of courses in a bed formed from the blocks while also allowing relative angular movement of adjacent blocks.
ANOTHER EXAMPLE, U.S. Pat. No. 4,639,345 to Olsen teaches a dry wall interlocking building block system that includes a method of manufacturing molds for casting building blocks, in which master forms corresponding in shape and size to the required blocks are cast from a cold-pouring compound in collapsible core-boxes, and in which a mould is built up around the master forms by securing the forms to a casting table, placing metal liner plates against the sides of the forms, filling the spaces around the liner plates with a similar cold-pouring compound, allowing the compound to set, and withdrawing the forms to leave a plurality of mould cavities. The mould can then be mounted in a block making machine for large scale casting of concrete blocks in the mould cavities. One feature of the preferred mould is that the liner plates are detachable, countersunk bolts having been fitted in holes in the liner plates prior to filling the spaces around the plates. The invention also includes a two-recess building block cast in the above mould.
STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,350,256 to Hammer teaches a retaining wall system constructed in several distinct layers. Each layer is formed of a side-by-side arrangement of I-shaped subassemblies with back fill chambers defined between each pair of subassemblies. Each subassembly is constructed of generally planar elongated concrete blocks which interconnect to laterally secure the blocks to one another. Interconnections are provided by dovetails joints in which a tongue is vertically slid into a groove to prevent lateral separation. The dovetail elements extend only partially across the face of each block so that the block defining the groove is not excessively weakened by the groove.
FINALLY, YET ANOTHER EXAMPLE, U.S. Pat. No. 5,421,135 to Stevens et al. teaches a modular-shaped, lightweight concrete block that can be pivotally interlocked with other blocks of the same size without having to use grout and pins or additional attachment apparatus. The building block comprises a pair of vertically aligned side faces and horizontally aligned top and bottom faces that are joined at opposite lateral ends with rounded end faces. A pair of tenons extend out the top face of the block at opposite lateral ends and are coaxially aligned with complementary mortises formed into the bottom face. The unique end face configuration in combination with the location of the tenon, allow two adjacent blocks to be interlocked together in a wide range of angles. The invention also includes a novel handle configuration that is located in the middle of the block.
It is apparent that numerous innovations for blocks have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.


An explosive powder charge operated setting tool includes a housing (1), a handle (2) located on the housing, a piston guide (4) and a firing pin guide (8) each located within and being axially displaceable relative to the housing against the force of a damping device (17) bearing against a trailing end stop face within the housing directed in the driving direction. The housing (1) forms an axially extended receiving space (24) for guiding the piston guide (4). The receiving space has an axial length (LA) between a leading end face of the housing and a leading end face of the firing pin guide in a first position. The piston guide (4) has an axial length (LK) coinciding at the most with the axial length (LA) of the receiving space.

The present invention is directed to an explosive powder charge operated setting tool having a housing equipped with a handle, a piston guide is axially displaceable within and relative to the housing against the force of a spring. A firing pin guide is also located within the housing rearwardly of the piston guide. The firing pin guide is axially displaceable relative to the housing and cooperates with a damping device bearing against a stop face at the trailing end of the housing and directed facing in the driving direction.
An explosive counter-charge operated setting tool is disclosed in EP-O 331 168 A1 which serves for driving fastening elements, such as nails, bolts, studs and the like, into hard receiving materials. A piston guide and a firing pin guide are located within a housing with the firing pin guide located behind the piston guide and both are axially displaceable relative to the housing. The housing includes a handle. The piston guide is displaceable against the force of a spring and the firing pin guide is displaceable against the force of a damping device bearing against a trailing end stop face in the housing. The piston guide projects axially outwardly from a leading end face of the housing and includes a driving piston moveable in a guide bore within the piston guide.
A cartridge chamber is located in a trailing end region of the piston guide facing the firing pin guide. The chamber is arranged to hold an explosive powder cartridge. A firing mechanism located in the firing pin guide includes a firing pin axially displaceable against the force of a spring element. When the setting tool is pressed against a receiving material, the piston guide moves in its axial direction opposite to the driving direction until it rests against the firing pin guide. As a result, the spring element and a spring disposed between the piston guide and the housing are prestressed or preloaded.
If an operating trigger located in the handle is depressed, the firing pin is accelerated in the direction of the cartridge charge by the preloaded spring element and it ignites the cartridge. The propellant gas pressure developed in ignition of the cartridge accelerates the piston guide and the firing pin guide opposite to the driving direction and the driving piston is accelerated in the guide bore of the piston guide in the driving direction, so that the driving piston drives a fastening element located in the muzzle region of the piston guide into the receiving material. The acceleration of the piston guide and the firing pin guide relative to the housing and opposite to the driving direction is damped by the shock absorbing device.
If the pressure developed in the driving operation is great, an axial displacement of the firing pin relative to the housing takes place during the driving operation. This entails at least a partial compression of the damping device. During the subsequent driving operation, the damping device is no longer able to sufficiently damp out the rebound force acting on the housing or the handle. Accordingly, there ia a danger of injury to the tool operator.

Fastening element setting tool with shock damper


Embodiments of the present disclosure provide for Rh(I) catalysts, methods of making alkenyl substituted arenes (e.g., allyl arene, vinyl arene, and the like), methods of making alkyl substituted arenes, and the like.

Although a direct process for vinyl arene formation from arenes and olefins offers potential advantages, acid-based (i.e., Friedel-Crafts or zeolite catalysts) catalysis occurs by electrophilic aromatic substitution and does not offer a viable pathway to directly generate vinyl arenes. Transition metal complexes that catalyze olefin hydroarylation by olefin insertion into a metal-aryl bond followed by aromatic C—H activation have been reported as alternatives to acid-based catalysts. For these catalysts, β-hydride elimination from a M-CH2(CH2)nCH2Ar (n=0-10); Ar=aryl) intermediate and dissociation of vinyl arene provides a route for the direct oxidative hydroarylation of olefin. A targeted catalytic cycle exists for the direct oxidative hydroarylation of olefins to produce vinyl arenes, and, since vinyl arenes are easily hydrogenated, a route to alkyl arenes, but despite precedent for the key steps in this catalytic cycle, designing a selective catalyst represents a substantial challenge as many viable and undesirable side reactions are likely to have activation barriers that are similar or lower than the reactions along the desired catalytic cycle. In addition to these possible side reactions, designing a catalyst that achieves high turnover numbers (TON) is difficult since the conditions and the presence of potentially reactive intermediates could be anticipated to result in catalyst decomposition and/or deactivation. Consistent with these challenges, there is no example of a catalyst that achieves the desired results.

Catalysts and methods for forming alkenyl and alkyl substituted arenes

University of Virginia Patent Foundation


A bipartite compression technique is used to implement a bipartite reciprocal table that provides seed reciprocal values for multiplicative (reciprocal refinement) division. The bipartite reciprocal table (12) includes component tables P and N. The input table index is partitioned into high, middle, and low order parts x.sub.h .vertline.x.sub.m .vertline.x.sub.1 !'the high and middle order parts x.sub.h .vertline.x.sub.m ! index the P Table, and the high and low order parts x.sub.h .vertline.x.sub.1 ! index the N Table. The P and N Tables provide first and second component outputs which form a redundant output from the bipartite lookup table. The bipartite table output may be (a) optimal in that, for each entry in each table, the maximum relative error is the minimum possible, and/or (b) when fused with rounding, faithful (i.e., accurate to one unit in the last place). In an exemplary implementation, the bipartite reciprocal table is used in combination with a Booth recoded multiplier --the redundant borrow-save output from the bipartite table is input directly to the Booth recoder, such that the Booth recoder performs a fusion of the first and second component outputs.

1. Technical Field
The invention relates generally to arithmetic processing systems, and more particularly relates to look-up tables used to obtain function values, such as seed values for iterative refinement division or square root.
In an exemplary embodiment, the invention is used to provide table look-up of reciprocal seed values for a conventional multiplicative division implementation.
2. Related Art.
Floating point units (and other arithmetic processors) commonly use multiplier based algorithms for division. These division algorithms initially employ a seed reciprocal of the divisor.
The seed reciprocals have a selected number of bits of accuracy. Iterative multiplies are performed to iteratively increase the accuracy of the reciprocal approximation until a final quotient value of predetermined accuracy can be obtained.
The seed reciprocals are typically obtained from a ROM reciprocal look-up table, or equivalent PLA (programmed logic array). The number of table input index bits and table output bits of the seed reciprocals determines the size of the look-up table --more input bits allowing more bits of accuracy in the seed reciprocals reduces the necessary number of iterative multiply cycles, reducing division time albeit at the cost of exponential growth in the reciprocal table size.
Without limiting the scope of the invention, this background information is provided in the context of a specific problem to which the invention has application: for a floating point unit design, achieving reciprocal table compression to improve the design trade-off between division time (i.e., the number of necessary interative multiply cycles) and reciprocal table size. A collateral design problem is establishing, for a desired accuracy in reciprocal table output, what is the minimum table size required.
Current day designs of IEEE standard floating point units for PC's and workstations generally have substantial design effort and chip area devoted to providing a multiplier with at most a couple of cycles latency. In addition to special function computations, this multiplier resource is typically exploited to obtain faster division. Moreover, if multiplicative division is used, it is common to also use a multiplicative square root algorithm.
Newton-Raphson, convergence, prescaled, and short reciprocal division are multiplier based iterative division algorithms that have been employed in recent floating point unit implementations. These multiplicative division algorithms each provide speedups by factors of 2 to 4 over the traditional shift-and-subtract iterative division algorithms such as non-restoring and SRT. However, for these multiplicative division algorithms, note that division time relates to multiplier latency, not throughput, because pipelining through the multiplier cannot be employed for the iterative dependent multiplications required for reciprocal refinement.
Each of the multiplicative division algorithms initially employs a seed (approximate) reciprocal of the divisor obtained (such as by table look-up) with a certain precision measured by the number of bits of accuracy. In general, the precision of an approximate reciprocal of an input argument measured in bits of accuracy is given by the negative base 2 logarithm of the relative error between the approximate reciprocal and the infinitely precise reciprocal of the input argument.
To illustrate the affect of the accuracy of the seed reciprocal on the division time of the multiplicative division algorithm, consider Newton-Raphson division, which uses a reciprocal refinement algorithm that converges quadratically. Initially a seed (approximate) reciprocal of the divisor is obtained with a certain precision measured by the number of bits of accuracy. Iterative multiplier operations are used to compute successive refined reciprocal approximations of the divisor to a desired precision. Specifically, each Newton-Raphson iteration effectively doubles the precision of the reciprocal approximation, i.e. doubles the number of accurate bits. Thus, the precision of the seed reciprocal directly determines the number of such iterations to obtain a final reciprocal approximation with a desired precision.
The final reciprocal approximation is then multiplied by the dividend to produce an approximate quotient. The quotient is multiplied by the divisor and subtracted from the dividend to obtain a corresponding remainder. Note that no part of the quotient is generated until the multiplication of the dividend by the refined reciprocal in the last step.
The Newton-Raphson division algorithm for Q=N/D is:
1.Initialize: x.sub.0 .apprxeq.1/D PA1 2.Iterate: x.sub.i+1 =x.sub.i .times.(2-D.times.X.sub.i) PA1 3.Final: Q=X.sub.last .times.N R=N-(Q.times.D) PA1 D.times.X.sub.i =1+.epsilon.such that
X.sub.i .apprxeq.1/D can be written as x.sub.i .apprxeq.(1/D)(1+.epsilon.)
where .epsilon. is the relative error in the approximation (assumed to be small). Thus, in the iterative step:
2-D.times.X.sub.i =1-.epsilon.So that, for the next iteration ##EQU1## That is, for each iteration, the relative error as measured by the number of accurate bits doubles.
Consider the application of this algorithm to obtain the double precision (53 bits) quotient Q where N and D are double precision dividend (numerator) and divisor respectively. N and D are normalized (1.ltoreq.N, D<2), such that the reciprocal of D must fall in the interval (1/2, 1!, where "()" indicate exclusive bounds and "!" indicate inclusive bounds.
If a single value of the seed reciprocal X.sub.0 .apprxeq.1/D is used for any 1.ltoreq.D<2 then X.sub.0 .apprxeq.2/3 is the most accurate seed reciprocal, accurate to about 1.585 bits. With X.sub.0 =2/3, the Newton-Raphson division requires 6 iterations (12 multiplications) to attain the desired number of bits of accuracy for a double precision quotient (1.53612244853+).
Notice that it takes three iterations (6 multiplications) to increase the accuracy to over 7 bits. These initial iterations can be conveniently replaced by a look-up table to provide a seed reciprocal accurate to 7 bits, specifically requiring 7 leading bits of D for table look-up to provide a seed reciprocal X.sub.0 accurate to 7.484 bits. With this small reciprocal table having 128 entries, the algorithm requires only 3 iterations (6 multiplications) for a double precision quotient (7142853+). Thus, using a seed reciprocal table of 2.sup.7 .times.7 bits=896 bits, the number of multiplications is cut in half.
More bits of accuracy in the seed reciprocal further reduces the number of necessary multiply cycles. Consider the seed reciprocal X.sub.0 to be accurate to 14 bits. Then the above algorithm requires only 2 iterations (4 multiply cycles) for a double precision quotient (142853+). However at least 14 leading bits of D are needed for input to a conventional reciprocal table to provide a seed reciprocal accurate to 14 bits. Such a table requires 2.sup.14 .times.14 bits=230 Kbits a size that is prohibitive for current technology.
The limitation of conventional reciprocal tables is that increasing the accuracy of the seed reciprocal by one bit results in more than doubling the reciprocal table size. Because there are no obvious efficient techniques for improving the rate of convergence beyond the current quadratically converging multiplicative division algorithms, such as Newton-Raphson, the critical design trade-off is between table size (and therefore area) and division cycle time.
Table compression can be obtained by applying conventional interpolation techniques to the table output. However, interpolation has the disadvantage of requiring the added cost of a multiplication and/or addition to effect the interpolation Fa 81, Fe 67,Na 87!.
A collateral issue to table size is to specifically define the accuracy that can be obtained from a table of a given size --stated another way, for a desired accuracy of the seed reciprocal, the design problem is to determine what is the minimum table size. For current reciprocal table designs, rather than pursue the exhaustive investigation of minimum table size at the bit level, the design approach has often been to employ oversized tables.
The proper accuracy measure of a reciprocal table to be optimized depends on the division algorithm being implemented and the size and architecture of the multiplier employed. In general, two principal accuracy measures have been used for reciprocal tables: precision and units in the last place (ulps). In particular, if table output is guaranteed accurate to one ulp for all inputs, then the table is termed faithful. A third approach to measuring the accuracy of a reciprocal table is the percentage of inputs that yield round-to-nearest output.
Reciprocal tables are typically constructed by assuming that the argument is normalized 1.ltoreq.X <2 and truncated to k bits to the right of the radix point --1.b.sub.1 b.sub.2. . . b.sub.k. These k bits are used to index a reciprocal table providing m output bits which are taken as the m bits after the leading bit in the m+1 bit fraction reciprocal approximation --0.1b.sub.2' b.sub.3'. . . b.sub.m+1 '. Such a table will be termed a k-bits-in m-bits-out reciprocal table of size 2.sup.k' .times.m bits.
Regarding the precision measure of table accuracy, the maximum relative error for any k-bits-in m-bits-out reciprocal table denotes the supremum of the relative errors obtained between 1/x and the table value for the reciprocal of x for 1.ltoreq..times.<2. The precision in bits of the table is the negative base two logarithm of this supremum. A table precision of .alpha.bits (with a not necessarily an integer) then simply denotes that the approximation of 1/x by the table value will always yield a relative error of at most 1/2.sup..alpha.. For Newton-Raphson (and other convergence division algorithms), the precision of the table determines the number of dependent (i.e., non-pipelined) multiplications to obtain the quotient of desired accuracy.
The following Table gives the precision in bits of the k-bits-in m-bits-out reciprocal table for the most useful cases 3.ltoreq.k, m.ltoreq.12, facilitating evaluating tradeoffs between table size and the number of reciprocal refinement iterations to achieve a desired final precision. This Table appears in DM 94!.
__________________________________________________________________________ bits in/ 3 4 5 6 7 8 9 10 11 12 __________________________________________________________________________ bits out 3 3.540 4.000 4.000 4.000 4.081 4.081 4.081 4.081 4.087 5.087 4 4.000 4.678 4.752 5.000 5.000 5.000 5.042 5.042 5.042 5.042 5 4.000 4.752 5.573 5.850 5.891 6.000 6.000 6.000 6.022 6.022 6 4.000 5.000 5.850 6.476 6.790 6.907 6.950 7.000 7.000 7.000 7 4.081 5.000 5.891 6.790 7.484 7.775 7.888 7.948 7.976 8.000 8 4.081 5.000 6.000 6.907 7.775 8.453 8.719 8.886 8.944 8.974 9 4.081 5.042 6.000 6.950 7.888 8.719 9.430 9.725 9.852 9.942 10 4.081 5.042 6.000 7.000 7.948 8.886 9.725 10.443 10.693 10.858 11 4.087 5.042 6.022 7.000 7.976 8.944 9.582 10.693 11.429 11.701 12 4.087 5.042 6.022 7.000 8.000 8.974 9.942 10.858 11.701 12.428 __________________________________________________________________________
Regarding the faithfulness measure of table accuracy, reciprocal table output is faithful if it is accurate to one ulp (unit in the last place), i.e. the table output always has less than one ulp deviation from the infinitely precise reciprocal of the infinitely precise input argument. The general measure of accuracy is the determination of the worst case error in ulps --although a sufficiently large number of input guard bits allows a worst case error bound approaching one half ulp, the useful and computationally tractable threshold of one ulp accuracy is a conventional standard for transcendental functions where infinitely precise evaluation is not tractable.
Regarding the faithfulness measure of accuracy, for both the prescale and short reciprocal division algorithms, the size (length in bits) of the reciprocal affects the size of the circuitry employing the reciprocal BM 93, EL 94, Na 87, WF 91!. Many compelling arguments can be made in favor of providing that the final results of function approximation should both (a) satisfy a one ulp bound (faithfulness), and (b) uniformly attempt to maximize the percentage of input arguments that are rounded to nearest AC 86, BM 93, FB 91, Ta 89, Ta 90, Ta 91!. One approach is to have the table result itself be the round-to-nearest value of the infinitely precise reciprocal, providing a useful metric for those platforms where a reciprocal instruction is provided in hardware. This requires that the table input be the full argument precision, which is currently prohibitive in table size even for single precision arguments (23 bits).
A robust reciprocal table construction algorithm that is appropriately optimal for each of the two principal accuracy measures, precision and faithfulness (ulp), is the midpoint reciprocal algorithm described in DM 94!. The midpoint reciprocal methodology generates tables such that the relative error for each table entry is minimized, thereby uniformly maximizing table output precision. This table design methodology further generates minimum sized tables to guarantee faithful reciprocals for each table entry, and for faithful tables maximizes the percentage of input values obtaining round-to-nearest output.
The midpoint reciprocal design methodology generates tables that have maximum table precision. For such k-bits-in m-bits-out tables, the design methodology generates a k-bits-in, k-bits-out table with precision at least k+0.415 bits for any k, and more generally with g guard bits that for the m=(k+g)-bits-out table the precision is at least k+1 -log.sub.2 (1+1/2.sup.g+1) for any k. To determine extreme-case test data, and to compute the precision of a reciprocal table without prior construction of the full reciprocal table, the midpoint reciprocal design methodology only requires generation and inspection of a small portion of such a table to identify input values guaranteed to include the worst case relative errors in the table.
The precision and faithfulness (ulp) measures of lookup table quality, and the midpoint reciprocal algorithm for generating optimal conventional lookup tables regarding these metrics, establish a benchmark for the size and accuracy of conventional tables. This benchmark can be used in assessing the quality of any table compression methodology in terms of accuracy versus table size.

Table compression using bipartite tables


There is provided apparatus for the measurement of particle mass concentration of an aerosol and which comprises at least one aerosol inlet and at least one electrostatic precipitator which directs an aerosol flow towards a mass sensor on which the particles are collected, the sensor being housed in a magazine including a plurality of other sensors, each of which may be substituted for the sensor, and a control. The control selectively connects one of the at least one aerosol inlet with one of the sensors.

This invention relates to apparatus used for the analysis of the particles in an aerosol, and in particular measurement of particle mass concentration and size distribution of an aerosol.
Apparatus having piezoelectric crystal sensors have been used for a number of years to measure particle concentrations of aerosols. Such sensors are described in "The Performance of Piezo-Electric Crystal Sensors Used to Determine Aerosol Mass Concentration" by Daly S P and Lundgrun D A, American Industrial Hygiene Assoc. Journal, July, 1975, p518-532, Piezo-Electrostatic Aerosol Mass Concentration Monitor by Olin J G, Sem G J & Christenson D L, Amer. Ind. Hyg. Assoc. J. 32:209 (1970) and U.S. Pat. No. 3,653,253. Such apparatus include a piezoelectric crystal sensor which is exposed to a gas stream containing particles that deposit on the surface of the crystal. By measuring the frequency shift of the crystal and by knowing the mass sensitivity for the crystal, it is possible to determine the mass accumulated on the crystal surface. If the volume of the gas flow is known, the mass concentration can be determined.
A problem with the apparatus is that the crystal sensor can only function properly up to a maximum mass loading and, when used for environmental monitoring of particles, the sensor often becomes overloaded before the expiration of a standard test period; for example, a crystal sensor may overload in 1 or 2 days within a 14-day monitoring period for monitoring environmental particulates. Furthermore, the problems associated with the overloading of crystal sensors reduces the usefulness of such sensors for testing vehicle emissions.
The present invention provides improved apparatus which is useful for continuous monitoring of particulate concentrations, and which is also useful for the analysis of collected particles.


An imaging method and imaging system for inspecting features located at a known inter-feature pitch on portions of a target surface. The system includes a lens array having a plurality of lenses wherein the lenses of the lens array have an inter-lens pitch and an inter-field of view pitch corresponding to the inter-feature pitch, and an array of imaging elements having an inter-element pitch corresponding to the inter-feature pitch, whereby the imaging system images only field of view areas of the target surface containing features.

The manufacture of high density microelectronic packages and devices, such as integrated chip packages (ICPs) or printed circuit boards for cell phones, requires the fabrication of single or multilayer printed circuit boards (PCBs) having high density arrays of small holes referred to as microvias. Microvias are formed using sophisticated mechanical and laser drilling systems and, once formed are plated to provide electrical connections and leads to and between the layers, circuits and circuit elements of single and multi-layer PCBs.
Over the last several years the number of microvias that can be and are formed into a single layer or a single or multi-layer PCB has increased dramatically and it is now conceivable to have several hundreds of thousands of microvias in a single layer of a PCB used to manufacture ICPs. Since microvias provide the electrical or communication link or links to each layer or level of a PCB or multi-layer PCB it is critical that these small holes are processed and fabricated correctly to fulfil their intended purposes and functions. The fabrication of vias, however, is subject to numerous potential defects, such as missed holes, blocked or partially drilled holes, over or under sized or mis-shapen holes, liftoff, fracture or failure of the printed circuit pads surrounding the vias, often due to the ablation of pads by the microvia hole drilling process, and the presence of organic and other residues or smears on the pads due to inadequate de-smearing and cleaning processes, including residues or smears of transparent substances that are very difficult to detect.
The inspection of single or multi-layer PCBs, and in particular the inspection of microvia holes and microvias at various points in the fabrication process is therefore critical to the fabrication of PCBs and ICPs. The inspection of vias is typically automated and several illumination and inspection techniques using flood illumination and automated camera frame grabbers and analysis software have been employed to inspect these partially drilled microvias, typically <100 μm (˜0.004″) in diameter and with aspect ratios of 1:1 to 1:3, hole diameter to depth, by imaging and analyzing successive fields of view across the PCB.
The methods of the prior art, however, inherently provide only low magnification of the fields of view, however, resulting in a relatively low number of image pixels in each image and a lack of resolution as regards any features, such as microvias or portions of microvias, appearing in an image. To illustrate, and as shown in FIGS. 1A and 1B, the methods of the prior art could only image one field of view over the entire array of pixels for the camera. The magnification and image resolution of the system is limited by the separation between the features being inspected, since the single field of view magnifies both the features of interest and increases the separation between the features shown in the image. The choice is thereby between an imaging system such as illustrated in FIG. 1A that images a larger field of view, that is, a larger area of a PCB, but at a lower resolution, or an imaging system such as illustrated in FIG. 1B that has higher magnification to resolve smaller features but at the cost of a correspondingly smaller field of view that often will not include all of the features of interest. The ability of the methods of the prior art to detect flaws and problems of various types is thereby limited, because pitch separation increases with magnification. The limits on image resolution in turn result in a significant possibility that defects, sometimes a majority of the actual defects, are not detected, which in turn results in unacceptable or undesirably low yields from the fabrication process.
Another problem with the methods of the prior art, and in particular scanning systems having wide fields of view and using retro-reflected laser illumination together with fluorescence emission or flood illumination, is that a large part of the illumination energy and the subsequent image scanning process is expended on relatively large areas that do not include microvias. The illumination and scanning of areas that are, in fact, not of interest thereby undesirably wastes a significant part of the system energy emission and processing throughput.
It must also be noted with regard to these problems of the prior art that these methods of the prior art are not readily scalable, so that these problems of the prior art become rapidly more severe as the microvias are reduced in size and as higher and higher microvia and circuit densities are achieved in PCBs.
To illustrate, current AOI systems cannot be increased in resolution, that is, cannot use higher image magnification, because the resulting increase in image processing load would unacceptably reduce the inspection throughput of the systems. The effective decrease in image feature resolution per pixel, however, is significantly decreased as the microvias become smaller and smaller, that is, each pixel represents a proportionally larger portion of the microvia image as the sizes of the microvias is reduced. The decrease in image resolution with decreasing microvia size, however, proportionally decreases the probability that a given feature of a microvia, such as a fault or a contaminating object or objects, can or will be adequately represented and detected in the image. For example, since the field of view of the imaging mechanism is fixed, a reduction in microvia size from 0.65 μm to 0.25 μm results in a reduction of more than half in the pixel resolution of the image. Since defects on the order of 2 μm can be problematic, the current systems of the prior art will thereby fail to achieve the required level of quality control necessary to ensure high yields on such products as chip packages which utilize <+25 micron diameter microvias.
This problem will continue to become more and more severe as PCBs Boards become denser and denser with potential microvias densities of >300 k per panel layer and forseeable densities approaching 500 k microvias per panel.
The present invention provides solutions to these and other problems of the prior art.

Apparatus and methods for the inspection of microvias in printed circuit boards


A bale discharge for an outlet of a baling chamber of an agricultural baler has a first segment and a second segment that are moveable between an extended operating position and a retracted transporting position, wherein a support structure is provided for supporting, in the retracted position, a component of the second segment, wherein the support structure includes a first protrusion and a second protrusion.

Conventionally, agricultural balers comprise a frame which is travelled on a pair of wheels over a field for picking up therefrom hay, straw or silage grass and feeding such crop material to a baling chamber in which it is compressed to parallelepiped packages under action of a plunger which reciprocates inside the baling chamber. When the packages have reached a predetermined length a tying mechanism is operated to encircle the completed package with a plurality of strands to form a finished bale which will be ejected out of the baler.
As the outlet of the baling chamber is at a substantial height above the field, there is a risk that bales get damaged by their fall from the baling chamber, e.g. because the impact breaks some or all of the strands. Commonly this problem has been solved by providing a guide or slide means at the exit of the baling chamber for reducing the height from which the bale is released onto the field and/or giving a wanted orientation to the bale. In the art such apparatus usually is referred to as "bale chute" or "bale discharge means".
It has been observed that while manoeuvring on a field, the tail portion constituted by the bale chute is particularly vulnerable to damages caused by collisions with objects on or around the field. In particular the previously deposited bales may form serious obstacles while the baler is driven backwards, e.g. to realign the pick-up to the windrow. When the baler is driven backwards the bale chute may hit the bale on the ground and the impact may seriously deform this chute to the extent that it becomes impossible to use.
Furthermore when an agricultural baler is transported from one place to another, more often than not via public roads, the tail portion of the baler significantly increases the length of the baler. In an attempt to solve this drawback, prior art balers are provided with bale discharge means that are mounted in an extendable manner. This allows the discharge means to be moved between an extended operating position and a retracted transporting position. In a further attempt to facilitate use of such extendable discharge means, the latter can be provided with automatic extending means (for example in the form of an actuator). Via this automatic extending means, the discharge means can be automatically moved between the extended operating position and the retracted transporting position. Such a baler is known from EP 0 974258. The capability of automatically moving the discharge means from one to another position will tend the baler operator to make frequent use of this feature. As a result, the operator will retract the discharge means any time these means are not required for the operation of the baler, thereby driving with retracted discharge means more often. As a result, the frequency of driving the baler with the discharge means in the retracted position significantly increases. For example where a baler with manual discharge means is only driven with retracted discharge means on public roads, an operator might choose to retract the discharge means (automatically) when driving on the field or on a lane.
A drawback of the existing systems is that, where the bale discharge means have been dimensioned to be used in the retracted position when driving on public roads, the discharge means prove to be not strong enough for frequent driving in this retracted position. Particularly when the baler is driven on a field or on a lane (which is typically more uneven than a public road), the discharge means can swing open.
Tests have shown that, when an agricultural baler is driven over an uneven ground surface and when the bale discharge means are in the retracted position, the bale discharge means tend to move out of this retracted position into the extended operating position. In practice, the segments of the bale discharge means will swing open due to the vibrations of the agricultural baler, whereby the swing is further powered by the gravity forces. The swinging forces appear to be larger than the forces that can be born by typically used automatic extending means. In such situation, the automatic extending means fail to keep discharge means in the retracted position, and the discharge means will swing open to the operating position. It will be clear that such a situation is highly dangerous.


Methods are provided for determining and controlling polymer product properties on-line in a slurry reactor system, such as a stirred slurry or slurry loop reactor. The methods include obtaining a regression model for determining a polymer product property, the regression model including principal component loadings and principal component scores, acquiring a Raman spectrum of polymer product in the slurry reactor system, calculating a new principal component score from at least a portion of the Raman spectrum and the principal component loadings, and calculating the polymer product property by applying the new principal component score to the regression model. The property can be controlled by adjusting at least one polymerization parameter based on the calculated polymer product property.

Slurry processes for the homopolymerization and copolymerization of monomers, especially olefin monomers, are well known in the art. Such processes can be conducted, for example, by introducing the monomer or monomers into a stirred and/or circulated stream of resin particles, catalyst and diluent. As used herein, the term "slurry reactor" includes any reactor suitable for polymerizing monomers in a heterogeneous medium including diluent (solution phase) and polymer product (solid phase), such as a stirred slurry reactor or a slurry loop reactor. As used herein, the term "slurry reactor system" includes the slurry reactor and associated recycle systems and product drying and recovery systems.
The properties of the polymer produced in a slurry reactor system are affected by a variety of operating parameters, such as temperatures, monomer feed rates, slurry density, and catalyst feed rates. In order to produce polymer having a desired set of properties, such as melt index and density, polymer product exiting the reactor is conventionally sampled and laboratory measurements carried out to characterize the polymer product. If it is discovered that one or more polymer product properties are outside a desired range, polymerization conditions can be adjusted, and the polymer product resampled. This periodic sampling, testing and adjusting, however, is undesirably slow, since sampling and laboratory testing of polymer product properties such as melt index, molecular weight distribution, and density is time-consuming. As a result, conventional processes can produce large quantities of "off-spec" polymer product before manual testing and control can effectively adjust the polymerization conditions. This occurs during production of a particular grade of resin as well as during the transition process between grades.
Methods have been developed to attempt to provide rapid assessment of certain polymer properties and rapid adjustment of polymerization conditions. PCT publications WO 01/09201 and WO 01/09203 disclose Raman-based methods using principal components analysis (PCA) and partial least squares (PLS) to determine concentrations of components in a slurry reactor. The concentration of a particular component, such as ethylene or hexene, is determined based on measurements of a known Raman peak corresponding to the component. U.S. Pat. No. 5,999,255 discloses a method for measuring a physical property of a polymer sample, preferably nylon, by measuring a portion of a Raman spectrum of the polymer sample, determining a value of a preselected spectral feature from the Raman spectrum, and comparing the determined value to reference values. This method relies on identification and monitoring of preselected spectral features corresponding to identified functional groups, such as NH or methyl, of the polymer.
Additional background information can be found in U.S. Pat. Nos. 6,479,597, 6,144,897 and 5,151,474; European Patent application EP 0 561 078; PCT publication WO 98/08066; and Ardell, G. G. et al., "Model Prediction for Reactor Control," Chemical Engineering Progress, American Institute of Chemical Engineers, U.S., vol. 79, no. 6, Jun. 1, 1983, pages 77–83 (ISSN 0360-7275).
It would be desirable to have methods of determining polymer product properties such as melt index, density, molecular weight distribution, and tab swell, on-line in a slurry reactor system, without the need to preselect or identify spectral features of a polymer to monitor. It would also be desirable to have methods of controlling a slurry reactor system to maintain desired polymer product properties, based on a rapid, on-line determination of the polymer product properties.

On-line measurement and control of polymer product properties by Raman spectroscopy


Techniques for providing a multimode ion source are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for ion implantation, the apparatus including an ion source having a hot cathode and a high frequency plasma generator, wherein the ion source has multiple modes of operation.

Ion implantation is a process of depositing chemical species into a substrate by direct bombardment of the substrate with energized ions. In semiconductor manufacturing, ion implanters are used primarily for doping processes that alter the type and level of conductivity of target materials. A precise doping profile in an integrated circuit (IC) substrate and its thin-film structure is often crucial for proper IC performance. To achieve a desired doping profile, one or more ion species may be implanted in different doses and at different energy levels.
FIG. 1 depicts a conventional ion implanter system 100. The ion implanter 100 includes a source power 101, an ion source 102, extraction electrodes 104, a 90° magnet analyzer 106, a first deceleration (D1) stage 108, a 70° magnet analyzer 110, and a second deceleration (D2) stage 112. The D1 and D2 deceleration stages (also known as "deceleration lenses") are each comprised of multiple electrodes with a defined aperture to allow an ion beam to pass therethrough. By applying different combinations of voltage potentials to the multiple electrodes, the D1 and D2 deceleration lenses can manipulate ion energies and cause the ion beam to hit a target workpiece 114 at a desired energy. A number of measurement devices 116 (e.g., a dose control Faraday cup, a traveling Faraday cup, or a setup Faraday cup 122) may be used to monitor and control the ion beam conditions.
The ion source 102 is a critical component of the ion implanter system 100. The ion source 102 is required to generate a stable and reliable ion beam 10 for a variety of different ion species and extraction voltages.
FIG. 2 depicts a typical embodiment of an ion source 200 that may be used in the ion implanter system 100. The ion source 200 may be an indirectly heated cathode (IHC) ion source, which is typically used in high current ion implantation systems. The ion source 200 comprises an arc chamber 202 with conductive chamber walls 214. At one end of the arc chamber 202 there is an indirectly heated cathode (IHC) 203 having a cathode 206 with a tungsten filament 204 located therein. The tungsten filament 204 is coupled to a first power supply 208 capable of supplying a high current. The high current may heat the tungsten filament 204 to cause thermionic emission of electrons. A second power supply 210 may bias the cathode 206 at a much higher potential than the tungsten filament 204 to cause the emitted electrons to accelerate towards and heat the cathode 206. Heating the cathode 206 causes the cathode 206 to emit electrons into the arc chamber 202. A third power supply 212 may bias the chamber walls 214 with respect to the cathode 206 so that the electrons are accelerated at a high energy into the arc chamber. A source magnet 224a may create a magnetic field B inside the arc chamber 202 to confine electrons, and a repeller 216 at the other end of the arc chamber 202 may be biased at a same or similar potential as the cathode 206 to repel the electrons. A gas source 218 may supply a dopant species (e.g., BF3 AsH3, GeF4) into the arc chamber 202. The electrons may interact with the dopant species to produce a plasma 20. An extraction electrode (not shown) may then extract ions 22 from the plasma 20 through an extraction aperture 220 for use in the ion implanter 100.
A problem that currently exists in conventional ion implantation is that conventional ion implanters cannot effectively implant dopant species at both low energies (e.g., sub-kev) and high energies (e.g., keV). For example, conventional ion implanters utilizing an IHC ion source are relatively inefficient at transporting low-energy ion beams due to space charge within the ion beams. In general, the lower the energy, the greater the space charge problems.
One approach that has been proposed to solve the problem of low-energy boron implantation is molecular beam ion implantation. That is, instead of implanting an ion current I of atomic B+ ions at an energy E, a decaborane molecular ion (B10Hx+), for example, is implanted at an energy 10×E and at an ion current of 0.10×I. Although the resulting implantation depth and dopant concentration (dose) of both approaches have been shown to be generally equivalent, the decaborane implantation technique may have significant potential advantages. For example, since the transport energy of the decaborane ion is ten times that of a dose-equivalent boron ion and the decaborane current is one-tenth that of the boron current, space charge forces may be substantially reduced when compared to monatomic boron implantation.
While BF3 gas is used by conventional ion sources to generate B+ ions, decaborane (B10H14) must be used to generate the decaborane ion B10Hx+. Decaborane is a solid material which has a significant vapor pressure, on the order of 1 Torr at 20° C., melts at 100° C., and decomposes at 350° C. To be vaporized via sublimination, decaborane must be vaporized below 100° C. and must operate in an ion source whose local environment (e.g., chamber wall and chamber components) is below 350° C. to avoid decomposition. In addition, since the decaborane molecule is relatively large, the molecule easily disassociates into smaller components, such as elemental boron or diborane (B2H6), when subject to charge-exchange interactions within plasma. Therefore, it may be understood why conventional ion sources are not reliable in commercial production. Furthermore, ion source vaporizers typically cannot operate reliably at the low temperatures required for decaborane, due to radiative heating from the ion source to the vaporizer that causes thermal instability of the molecules. For example, vaporizer feed lines easily become clogged with boron deposits from decomposed vapor as the decaborane vapor interacts with their hot surfaces.
Additionally, a conventional ion source is generally incompatible with decaborane ion implantation and/or ion implantation using any other molecular species. Thus, a conventional ion source may only be satisfactory for atomic and small molecular ions.
While conventional ion sources, such as duoplasmatrons, may consist of two plasma regions: a cathode plasma (e.g., between a cathode and an intermediate electrode (IE)) and a high-density plasma (e.g., between the IE and an anode), the plasma is compressed by a double layer into an IE channel and by an axial magnetic field. Although a high axial magnetic field improves the yield of multiply charged ions, this two-region ion source cannot produce sufficiently high intensity electron beams because of high-frequency instabilities and leads to poor ionization of atomic species. As a result, a conventional ion source cannot reliably be used in high current ion implantation situations. Furthermore, in this example, filament lifetime is relatively short because of sputtering of heavy ions.
In addition, operating temperatures of an IHC ion source are typically 800° C. to 2300° C. from the chamber body to the heated cathode. Such extremely high temperatures shorten the performance and lifetime of IHC ion sources. As a result, the performance degradation and short lifetime of IHC ion sources greatly reduce the productivity of ion implanters. While these temperatures are generally required for thermal dissociation and atomic creation during implantation, they are not conducive for producing large molecular ions.
In view of the foregoing, it may be understood that there are significant problems and shortcomings associated with current ion source technologies.

Varian Semiconductor Equipment Associates, Inc.


A system and method for providing IP services. A packet is received at a line interface/network module and forwarded to a virtual routing engine The virtual routing engine determines if the packet requires processing by a virtual services engine. If the packet requires processing by the virtual services engine, the packet is routed to the virtual services engine for processing.

Internet or WAN service providers (SPs) operate in a crowded marketplace where cost effectiveness is critical. Cost control is, however, difficult. At present internetwork bandwidth is a commodity item with extremely tight margins. If the SP wishes to provide additional value-added services such as firewalls, the SP must install and configure expensive Customer Premises Equipment (CPE) at subscriber locations. Problems that arise often require a trip by a service technician to the subscriber's location. It can be difficult to add new services.
This model of value-added service delivery creates an expensive up-front capital investment, as well as significant operational expenses that are associated with onsite installation and management of thousands of distributed devices. The results are service delivery delays, increased customer start-up costs and/or thinner service provider margins.
Service providers need a way of escape from commoditized bandwidth offerings and from traditional equipment-intensive service delivery architectures that drain profits.


A system, apparatus and method are provided for preparing water for human consumption. Water from a public or other source is input to the system or apparatus and is filtered internal or external to the system/apparatus. A temperature adjustment may be applied, such as cooling or heating the water to a specific or approximate temperature. One or more water enhancements may be added to the water, in specified amounts or proportions. Enhancements potentially include flavoring agents, sweeteners, vitamins, nutrients, minerals, carbonation, and so on. A given combination of enhancements and corresponding amounts, and possibly other characteristics (e.g., the temperature, a quantity of water to prepare), may be saved as a recipe. The system, apparatus and method operate in association with an application or online service for creating, sharing, and preparing recipes.

This disclosure relates to the field of water preparation. More particularly, a system, apparatus and methods are provided for preparing water for human consumption.
In many locales around the world, tap water delivered by public and/or private authorities does not suit consumers' tastes. Also, some consumers may question the composition, quality or safety of their tap water. Other consumers may be averse to water that is fluoridated and/or chlorinated.
As one result, a large and growing market in bottled water has developed. Bottled water purchased by consumers to replace or augment water delivered to their homes and/or places of business may come from different sources and/or have different characteristics or components than their delivered water. For example, some consumers prefer bottled water that is captured at a natural source (e.g., a spring) without being processed by a municipal water authority. Others prefer the taste of a particular brand of bottled water, perhaps due to its composition of minerals.
Unfortunately, bottled water is relatively expensive (especially in comparison to tap water) and most plastic water bottles are not recycled, thereby wasting resources. Unrecycled plastic waste (including empty water bottles) significantly contributes to pollution and constitutes an increasing threat to earth's oceans and marine life. Consumers who find their tap water as delivered to be unsatisfying or unpalatable may wish to avoid contributing to this problem by not purchasing bottled water, but their options are presently very limited.


A hybrid laser source including a solid state laser driven by an array of fiber laser amplifiers, the inputs of which are controllable in phase and polarization, to compensate for distortions that arise in the solid state laser, or to achieve desired output beam properties relating to direction or focus. The output beam is sampled and compared with a reference beam to obtain phase and polarization difference signals across the output beam cross section, at spatial positions corresponding with the positions of the fiber laser amplifiers providing input to the solid state laser. Therefore, phase and polarization properties of the output beam may be independently controlled by predistortion of these properties in the fiber laser amplifier inputs.

This invention relates generally to high power laser sources and, more particularly, to solid state lasers or fiber phased array lasers that are scalable to high powers. There is a significant need for high power laser sources for both military and industrial applications, such as directed energy weapons (DEW) systems, ladar and illuminators, as well as industrial cutting, welding and material processing. Scalable laser technologies under development fall into two principal categories: bulk crystal solid state lasers (SSL) and fiber phased array sources. In the bulk crystal group, slab lasers, rod lasers, disk lasers and heat capacity lasers are all under active consideration. In the fiber laser area, there are approaches that feature active near field beam control, far field beam control, passive beam combining using pulse code modulation (PCM) technology and nonlinear beam combining. The bulk crystal approaches suffer from thermo-optical distortions of the laser medium that render the output beams unacceptable, though fabrication of high power SSL devices has been demonstrated. Fiber array approaches, on the other hand, promise exquisite control of the output wavefront, but require control systems that are complex and to a large degree yet unproven.
Therefore, there is still a significant need to provide a high power laser source that avoids the drawbacks of the two principal approaches. Ideally, what is needed is a laser source scalable to high powers in the manner of solid state lasers, but retaining the desirable beam control features of fiber phased arrays. The present invention is directed to this end.

Laser source comprising amplifier and adaptive wavefront/polarization driver


According to an embodiment, a method for fabricating a pattern includes forming a mask covering a first layer, and a second layer selectively provided on the first layer, and forming a groove dividing the first layer and the second layer using the mask. The mask includes a first portion formed on a region of the first layer on a first side of the second layer, a second portion formed on a region of the first layer on a second side of the second layer opposite to the first side, first extending parts extending over the second layer from the first portion toward the second portion, and second extending parts extending over the second layer from the second portion toward the first portion. Each of the second extending parts is located between the first extending parts adjacent to each other.

The development of non-volatile memory devices with a 3-dimensional memory array is progressing. For example, there are memory devices having word lines stacked on an underlying layer, and semiconductor pillars that pierce therethrough. Memory cells and selection gates are disposed on the side face of the semiconductor pillars. Also, the gap between the semiconductor pillars is tending to become narrower due to size reduction in the memory array associated with the increasing of storage capacity. Therefore, manufacturing processes such as photolithography are becoming more difficult, and then, production yield may be reduced.

Non-volatile memory device, method for fabricating pattern on wafer and method for manufacturing non-volatile memory device using same