A methodology for translating conditional expressions of a non-Verilog hardware description language (HDL) program, not readily recognized by Verilog HDL, which can then be used to prove out a logic circuit design. IF/CASE/COND (ICC) expressions occurring within the HDL program that are not recognized by Verilog HDL are categorized and accordingly translated to IF/CASE statements in Verilog HDL syntax. For ICC expressions that are part of a conditional or binary operator expression, a globally incremental variable that is representative of a corresponding variable of an ICC expression is created for each variable of the ICC expression. The ICC expression is then assigned to the globally incremental variable(s) which is placed in an always statement that is recognized by Verilog HDL. Synthesis can then be performed on the always statement by a processor to generate a logic circuit representative of the module of the non-Verilog HDL program. Translation of other conditional expressions in the non-Verilog HDL program, including simple ICC expressions, nested ICC expressions, special expressions, and edge-triggered statements, can additionally be performed.

The presented invention relates generally to the use of hardware description languages to specify circuit logic design in a format that is acceptable to logic synthesis tools, and, more particularly, to a method for translating non-Verilog HDL containing conditional expressions to Verilog HDL format and syntax.
The soundness of logic design of hardware such as complex central processor units (CPUs) must be tested prior to actually manufacturing the hardware. Logic design may be specified in the form of Boolean equations or a hardware description language (HDL) description in a language such as Verilog HDL, an IEEE standard hardware description language (IEEE Std 1364-1995). A routine can be written in an HDL such as Verilog HDL and then be converted into a logic gate circuit using a logical synthesis tool, such as Synopsys Design Compiler(trademark), operating on a general-purpose computer. In this manner, the logic design can be proven out.
Verilog HDL, as an accepted standard, is a language accepted as an input format by many design tools available on the market today. A concern arises, therefore, when a hardware description language other than Verilog HDL is used, generically referred to as a non-Verilog HDL, since third party design tools that will accept Verilog HDL may not readily accept another HDL. Since it is desirable to increase design productivity and to thus shorten the design cycle of CPUs and other relevant hardware, it is important to leverage existing and advanced tools even if they do not accept the non-Verilog HDL. This requires that the non-Verilog HDL be translated into Verilog HDL so that it can be readily used with available tools. An important aspect of the translation into Verilog HDL is that the translation be logically correct; additionally, certain inherent semantics of the code must be preserved. Logic synthesis tools such as the Synopsys Design Compiler(trademark) must be able to produce optimal results from the translated code.
A difficulty is encountered in the translation process when certain conditional expressions that are frequently used in the non-Verilog HDL are missing in Verilog HDL syntax and thus not recognized by the Verilog HDL. These conditional expressions may be broken into three types: IF expressions, CASE expressions, and COND expressions. An IF expression provides a choice between several expressions. The format of an IF expression is:
IF ifcond THEN exp1 ELSE exp2
A CASE expression returns the value of one expression out of N expressions, depending upon the value of a controlling expression. The format of a CASE expression is:
CASE caseexpr OF BEGIN
[c1] exp1;
[c2] exp2;
.
.
.
[cN] expN;
[ ] expN+1;
END;
A COND expression returns the value of one expression out of N expressions, depending on the value of the controlling expressions. The format of a COND expression is as follows:
COND BEGIN
[sel_exp1] exp1;
[sel_exp2] exp2;
.
.
.
[ ] expN+1;
END;
These types of expressions (IF/CASE/COND) will be generically referred to as xe2x80x9cICC expressionsxe2x80x9d hereafter.
The approaches to translating the various types of ICC expressions into Verilog HDL each have problems. First, a possible solution is the use of a nested conditional operator xe2x80x9c?:xe2x80x9d in the translated expression to implement the logic of the ICC expression that was translated. Consider the following examples. An IF expression of a:=IF b THEN c ELSE d; can be translated to a=b ? c: d; and a CASE expression of:
a:=CASE caseExp OF BEGIN
[xe2x80x200] b;
[xe2x80x201] c;
[xe2x80x210] d;
[xe2x80x211] e;
[ ] RETAIN;
END;
can be translated to
a=(caseExp==2xe2x80x2b00) ? b
:(caseExp==2xe2x80x2b01) ? c
:(caseExp==2xe2x80x2b10) ? d
:(caseExp==2xe2x80x2b11) ? e
a;
A COND expression is translated in a similar fashion to the CASE expression.
In the above translations of the IF and CASE expressions into Verilog, note the occurrence of the xe2x80x9c?:xe2x80x9d nested conditional operator. This approach to translating is simple and the generated Verilog HDL is clean and easy to read. Unfortunately, however, the performance of the generated Verilog code is very bad. What could be done with a single multiplexer in the pre-translated code is instead interpreted by logic synthesis tools as a multi-level chain of multiplexers in the translated code. This leads to very poor synthesis results as will be later described.
Second, ICC expressions of non-Verilog HDL code can be translated to Verilog xe2x80x9cIFxe2x80x9d, xe2x80x9cCASExe2x80x9d statements as shown below. Consider the same IF and COND expressions above. For the IF expression of a:=IF b THEN c ELSE d; the translation would be:
always @(b or c or d)
if(b)
a=c;
else
a=d;
The above CASE expression of:
a:=CASE caseExp OF BEGIN
[xe2x80x200] b;
[xe2x80x201] c;
[xe2x80x210] d;
[xe2x80x211] e;
[ ] RETAIN;
END;
can be translated to
always @(caseExp or b or c or d or e)
begin
case (caseExp)
2xe2x80x2b00: a=b;
2xe2x80x2b01: a=c;
2xe2x80x2b10: a=d;
2xe2x80x2b11: a=e;
default: a=a;
endcase
This second approach overcomes the shortcoming of the first approach since synthesis tools can recognize that a CASE statement can be interpreted as a single multiplexer rather than a multiple-level chain of multiplexers. A high quality implementation can thus be generated from the translated Verilog code using this approach.
This solution, however, has a severe limitation because it only works for non-nested ICC(IF/CASE/COND) expressions. But since ICC expressions may occur anywhere within another expression and thus be nested, this approach is limited in its usefulness. Consider, for instance, the following expression containing a nested IF expression that cannot be readily translated using this second approach:
a:=IF ( IF b THEN xe2x80x2010 ELSE xe2x80x2111)
THEN d
ELSE e;
Also, consider this additional example of an expression containing a nested ICC expression:
a:=(IF(b) THEN c ELSE d) XOR COND BEGIN
[sel_exp1] e;
[sel_exp2] f;
[sel_exp3] IF (g) THEN h ELSE i;
[ ] j;
END;
In both of these examples, there is no way to readily translate the code to Verilog IF/CASE statements and so the first approach, with its poor synthesis performance, must be used for code containing nested ICC expressions.
The properties associated with each of these two prior art approaches is best illustrated by example. Consider that the following is an example of a software module written in a non-Verilog HDL; note that the software module usually is written for the cell or block hardware level:
fub mux;
begin xe2x80x9cmuxxe2x80x9d
interface(
input node in1[3:0];
input node in2[3:0];
input node in3[3:0];
input node in4[3:0];
input node in5[3:0];
input node in6[3:0];
input node in7[3:01];
input node in8[3:0];
input node sel[2:01];
output node out[3:0];
);
structural main;
begin xe2x80x9cmuxd4v mainxe2x80x9d
out:=
case sel of
begin
[xe2x80x2000] in1;
[xe2x80x2001] in2;
[xe2x80x2010] in3;
[xe2x80x2011] in4;
[xe2x80x2100] in5;
[xe2x80x2101] in6;
[xe2x80x2110] in7;
[xe2x80x2111] in8;
end;
end xe2x80x9cmux mainxe2x80x9d;
end xe2x80x9cmuxxe2x80x9d;
If this software module is translated to Verilog HDL with the first approach using the xe2x80x9c?:xe2x80x9d Verilog conditional operator, the result would be as follows:
module mux(in1,in2,in3,in4,in5,in6,in7,in8,sel,out);
input [3:0] in1;
input [3:0] in2;
input [3:0] in3;
input [3:0] in4;
Input [3:0] in5;
input [3:0] in6;
input [3:0] in7;
input [3:0] in8;
input [3:0] sel;
output [3:0] out;
reg [3:0] out;
/* xe2x80x9cmuxd4v mainxe2x80x9d */
always @(sel or in5 or in6 or in7 or in8 or in1 or in2 or in3 or in4)
begin
out=(sel==3xe2x80x2b000) ? in1
:(sel==3xe2x80x2b001) ? in2
:(sel==3xe2x80x2b010) ? in3
:(sel==3xe2x80x2b011) ? in4
:(sel==3xe2x80x2b100) ? in5
:(sel==3xe2x80x2b101) ? in6
:(sel==3xe2x80x2b110) ? in7
:in8;
end
/* xe2x80x9cmuxd4v mainxe2x80x9d */
endmodule
As previously mentioned, the performance of the generated Verilog code using this first approach is not good because logic synthesis tools interpret the code as multi-level chain of multiplexers. The synthesis result generated from the code by a logic synthesis tool such as the Synopsys Design Compiler(trademark) after optimization is shown in FIG. 7. Since it can be seen that the critical path of FIG. 7 is still very long, a second optimization was preformed, the result of which is shown in FIG. 8. For purposes of illustration only, a timing and area analysis of FIGS. 7 and 8 revealed that the timing associated with FIG. 8 is approximately two times as fast as that associated with FIG. 7, but that the combinational area, or real estate, utilized by the optimization of FIG. 8 is almost five times greater than that of FIG. 7.
Now consider that the non-Verilog HDL module used in the above example is translated using the second approach of translating the non-Verilog HDL code to Verilog xe2x80x9cIfxe2x80x9d and xe2x80x9cCasexe2x80x9d statements; the following code is achieved:
module mux(in1,in2,in3,in4,in5,in6,in7,in8,sel,out);
input [3:0] in1;
input [3:0] in2;
input [3:0] in3;
input [3:0] in4;
input [3:0] in5;
input [3:0] in6;
input [3:0] in7;
input [3:0] in8;
input [2:0] sel;
output [3:0] out;
reg [3:0] out;
/* xe2x80x9cmuxd4v mainxe2x80x9d */
always @(sel or in5 or in6 or in7 or in8 or in1 or in2 or in3 or in4)
begin
case (sel) //synopsys Infer13 mux
3xe2x80x2b000: out=in1;
3xe2x80x2b001: out=in2;
3xe2x80x2b010: out=in3;
3xe2x80x2b011: out=in4;
3xe2x80x2b100: out=in5;
3xe2x80x2b101: out=in6;
3xe2x80x2b110: out=in7;
3xe2x80x2b111: out=in8;
endcase
end
/* xe2x80x9cmuxd4v mainxe2x80x9d */
endmodule
The synthesis result generated from this translated code by a logic synthesis tool such as the Synopsys Design Compiler(trademark) after optimization is shown in FIG. 9. A representative timing and area analysis of the optimization of FIG. 9 indicated that the timing associated with FIG. 9 is 3.6 times better than for FIG. 7. There is an improvement of 17% in area utilization over FIG. 7 and more than a 500% improvement in area utilization over the second optimization reflected in FIG. 8 for the same timing result.
From the above analysis, it is clear that there currently exists no translation approach in the art for readily translating non-Verilog HDL ICC expressions into Verilog HDL syntax in a manner that avoids the performance problems associated with the first, xe2x80x9c?:xe2x80x9d nested conditional operator translation approach and that can overcome the nested ICC expression limitation of the second translation approach. There is therefore an unmet need in the art to be able to readily and accurately translate all ICC conditional expressions occurring within non-Verilog HDL, including nested ICC expressions, to Verilog HDL in a manner that overcomes these problems and limitations while maintaining the Verilog HDL structure required for synthesis.
The present invention presents a method for translating conditional expressions of a non-Verilog hardware description language (HDL) program used to specify a logic design, that are not recognized by Verilog HDL. The methodology of the present invention may be implemented as executable computer program instructions of a computer readable medium that when executed by a processing system cause the processing system to translate non-Verilog conditional expressions to syntax recognized by Verilog HDL.
According to an embodiment of the invention, for each module of the non-Verilog containing one or more assign statements, which in turn have a plurality of IF/CASE/COND (ICC) expressions, a global link list that contains the plurality of IF/CASE/COND (ICC) expressions contained in the one or more assign statements is created; each ICC expression of the plurality of ICC expressions of the assign statement is characterized as having one or more variables. If an ICC expression of the plurality of ICC expressions contained within an assign statement of the assign statements is part of a conditional or binary operator expression, a globally incremental variable that is representative of a corresponding variable of the ICC expression is created. Next, the ICC expression is assigned to the globally incremental variable, thereby replacing the ICC expression with the globally incremental variable in the assign statement and in the global link list of the assign statement. Creating a globally incremental variable and replacing the ICC expression with the globally incremental variable is repeated for each variable within the ICC expression so as to generate one or more globally incremental variables in the assign statement and in the global link list that correspond to the one or more variables of the ICC expression. An always statement of the module, with an event expression having one or more members, that is representative of the assign statement and recognized by Verilog HDL is created by placing the one or more globally incremental variables contained within the global link list of the assign statement as the one or more members of the event expression. Synthesis can then be performed on the always statement by a processor to generate a logic circuit representative of the module of the non-Verilog HDL program. The above method can be performed for any or all modules of interest in the non-Verilog HDL program.
The above methodology can be expanded to address the concerns presented by other conditional expressions of concern in the non-Verilog HDL program, including simple ICC expressions, nested ICC expressions, special expressions and edge-triggered statements. If the ICC expression contained within the right hand side expression of an assign statement is determined to be a simple ICC expression, it is translated to an IF/CASE Verilog statement so that synthesis can be performed on it by a processor. For instance, for a simple IF expression, the left hand side expression of the assign statement is passed to the IF expression to create an IF Verilog statement. If the ICC expression is a simple CASE expression, the left hand side expression of the assign statement is passed to the CASE expression to create a CASE Verilog statement. If the ICC expression is a simple COND expression, the left hand side expression of the assign statement is passed to the COND expression and a special CASE Verilog statement is created from the COND expression. If the ICC expression is part of a conditional or binary operator expression, the methodology described above is employed. Moreover, if the ICC expression is nested within a principal ICC expression of the assign statement, the left hand side expression of the assign statement is passed to the ICC expression and then recursively passed to the principal ICC expression at a leaf level of the principal ICC expression of the assign statement. For a special ICC expression, the ICC expression is substituted with a Verilog-compatible expression that is assigned to the left hand side expression of the assign statement. Finally, if the assign statement in which the ICC expression is contained is an edge triggered assign statement, an edge triggered always statement in created into which the ICC expression is placed.

Method for translating conditional expressions from a non-verilog hardware description language to verilog hardware description language while preserving structure suitable for logic synthesis

Hewlett Packard Development Company, L.P.


An ejector-type gas nozzle 17 including a liquid nozzle and a gas nozzle is used. Raw material water A in ozone reaction tank 1 is pumped and pressurized by pump 19 to use it circulatingly as water jet A of the ejector gas nozzle 17. The liquid nozzle of ejector-type gas nozzle 17 introduces the water jet A into the raw material water A in the ozone reaction tank 1. Ozone gas is sucked by negative pressure to be generated along the stream of water jet A so that it is injected into the raw material water A from the gas nozzle of ejector-type gas nozzle 17 as fine gas bubbles. A high concentration ozone water solution is produced by dissolving ozone into the raw material water A due to the gas-liquid reaction between the ozone fine gas bubbles and the raw material water A.

1. Field of the Invention
The present invention relates to a method and an apparatus for producing a high concentration ozone water solution with a long half-life period based on a gas-liquid reaction between ozone and water.
2. Description of the Related Art
Ozone (O.sub.3) is chemically instable and changes into oxygen (O.sub.2) usually in several to several tens of seconds in the air or water. In particular, when it is in contact with bacteria, such as fungi, mould and algae, or organic substances emitting offensive odors, it changes into oxygen in a moment. Ozone presents strong oxydizing action when it changes into oxygen, and the oxydizing ability is second to fluorine among the naturally existing elements, which is 7 times the oxidizing effect and about 3000 times the oxidizing rate with respect to chlorine.
For the reason above, ozone has been utilized for sterilization, deodorization and bleaching, for example, in treating tap water, sewage or waste water of the water treatment works, super-precision dry cleaning or sterilization of clean rooms in the semiconductor industry, deodorization and sterilization of the air and filters in the air conditioning, coating or oxydizing treatment prior to adhesion process in the surface treatment technology, material tests utilizing oxidizing effect, such as deterioration tests on rubber or plastic materials or electric contact points, or sterilizing and deodorizing operative appliances or medical waste matter in the medical industry. Further, such an ozone treatment has been utilized not only in large-scale industries but over smaller businesses including the household scale.
There are two ways of utilizing ozone, one using gas-phase ozone and the other using liquid-phase ozone produced by dissolving an ozone gas in the water. In either case, the aim is the same in utilizing the strong bactericidal, deodorizing and bleaching action of ozone.
Both the gas-phase ozone and the liquid-phase ozone are utilized widely as mentioned above. In particular, as shown in Table 1, the liquid-phase ozone is used for purifying or sterilizing, deodorizing and bleaching tap water or sewage as well as used for similar treatments in the fish farming, stock raising and food processing industries.
TABLE 1 ______________________________________ (Examples of uses of liquid-phase ozone) Industrial Fields Subjects Objects ______________________________________ Treatment of Public water service Water purification plants tap water Public housing (sterilization and Home-service deodorization) drinking water Cleaning of water supply tanks Making drinking water pleasing to the palate Sewage Public sewer Bleaching, deodorization and disposal systems sterilization Dyeing factories Waste water disposal and hospitals Housing Cooling towers Water sterilization and Pools and public removal of algae baths Sterilization and deodorization Production of Cold saltwater Sterilization of water used in perishable sterilization packages and retention of foods of fishes freshness and shellfishes Upgrading of finishings Thawing of frozen Retention of freshness foods Cooking appliances and Cleaning and sterili- sterization of floors zation of vegetables Cleaning of food processing places Fish farming Water tanks for Increasing amount of oxygen and stock living fishes dissolved in water and raising Drinking water for decomposition of remaining Agricultural pig raising and feed industry poultry farming Sterilization and making Seeds, vegetables meat pleasing to the and fruits palate Sterilization and cleaning processing Medical Medical appliances Sterilization industry Dental treatment Treatment of stomatitis ______________________________________
To produce an ozone water solution, there is a well-known method in which a spherical glass filter having a 30 mm diameter and a pore size of about 45 to 50 .mu.m or a porous tubular ceramic air diffuser is attached to the bottom of an ozone-water contact reaction tank to produce an ozone water solution by introducing an ozone gas generated by an ozone generator (ozonizer) into the tank through the diffuser and diffusing the so-formed ozone gas bubbles in the water contained in the tank thereby causing a gas-liquid reaction. This method is used most generally in various industrial fields.
In this case, the amount of ozone to be dissolved from the gas bubbles into water per unit time can be calculated by equation (1). EQU Q.sub.z =K.sub.L .multidot.a(K.multidot.C.sub.G -C.sub.L) (1)
where:
Q.sub.z =amount of ozone to be dissolved in the water per unit time, PA1 K.sub.L =coefficient of total matter transfer, PA1 a=total surface area of all gas bubbles present in the water (m.sup.2), PA1 K=distribution coefficient of ozone gas to water, PA1 C.sub.G =concentration of ozone gas (g/m.sup.3), PA1 C.sub.L =concentration of ozone present in the water (g/m.sup.3).
As is seen from equation (1), when the ozone water solution is produced under specific condition, both coefficient K.sub.L of total matter transfer and distribution coefficient K of ozone gas to water are not changed. Therefore, the most important parameter in producing the ozone water solution under that condition is the total surface area a of all gas bubbles present in the water.
The total surface area a of all gas bubbles is determined by the diameter of bubbles, rising velocity of bubbles, depth of water in the reaction tank or the like factors. Thus, to increase the efficiently of ozone dissolution, it is necessary to reduce the diameter of bubbles by increasing the depth or pressure of water in the the closed reaction tank.
In case of the aforementioned conventional method of producing an ozone water solution, when the depth or pressure of water in the reaction tank is increased, the pressure of ozone gas to be sent to the spherical glass filter or air diffuser attached to the bottom of the reaction tank must be also increased. However, since the increase of ozone gas pressure leads to increase of the driving power for supplying the ozone gas, the practical depth of the reaction tank is limited to several meters or less. That is, the water depth of the reaction tank is limited in the light of cost to be needed for the driving force. Therefore, it is difficult to increase the efficiency of ozone dissolution by the way of increasing the water depth or water pressure.
In case of dissolving ozone into the water by the gas-liquid contact reaction, it is preferred to reduce the diameter of gas bubbles as small as possible in view of increasing the surface area of bubbles to be in contact with water. However, the mean diameter of gas bubbles to be generated from a usual spherical glass filter or air diffuser is about 3 mm. Therefore, it is very difficult to obtain the gas bubbles having a mean diameter less than that value by such a spherical glass filter or air diffuser. Though other bubble generators based on the principle different from that of the spherical glass filter or air diffuser have been used, the mean diameter of bubbles produced thereby is also 2 to 3 mm. Accordingly, almost all of the produced gas bubbles rise vertically and linearly in the water of the reaction tank so that only a small amount of ozone can be dissolved in the water, but almost all of ozone is dispersed in the air after rising through the water. Thus, it is difficult to produce a high concentration ozone water solution with high efficiency within a predetermined time period.
Accordingly, it has been very difficult to produce a high concentration ozone water solution by the conventional methods for both the economical and technological reasons as mentioned above. Therefore, the range of practical use or industrial effectiveness of the ozone water solution has been limited so far.
Another reason for degrading effectiveness of the ozone water solution Is the fact that the half-life period of ozone present in the water is far shorter than that of gas-phase ozone. Namely, the half-life period of ozone in the water is several tens of minutes in case of neutral water at ordinary temperature, and is further shortened (e.g., up to several tens of seconds in an extreme case) by pH and termperature of water or a small amount of organic or inorganic substance present in the water. This is because the large portion of ozone dissolved in the water is consumed for oxidizing such impurities. Therefore, in such a case, it is necessary to dissolve in advance a great amount of ozone in the water to obtain an ozone water solution having a desirable concentration.
If pure water or ultra-pure water containing theoretically almost no impurities was used as the raw material water, an ozone water solution having a desirably long half-life period would be obtained. In such a case, however, the production cost of the ozone water solution becomes extremely high in proportion to the cost of the raw material water. Therefore, except for the sterilization of medical appliances or the like uses in which a relatively high cost can be allowed to some extent, such a method is not suitable generally in view of the cost. That is, an ozone water solution of a much lower cost than that case should be required, for example, for cleaning of food processing places, cleaning and sterilization of vegetables or the like in the field of perishable food production, and sterilization and deodorization of water purification plants in the field of water supply.
To solve these problems, various studies have been done so far with respect to the half-life period of the ozone water solution. However, the method which can satisfy both the desirable half-life period (e.g., 4 to 5 hours or longer) of the ozone water solution and the condition of using a low cost raw material water to produce a practically allowable low cost ozone water solution has not been established yet.

Method of and apparatus for producing a high concentration ozone water solution


Systems and methods directed to an array of microstructures for biological cell sorting with each individual structure component including an integrated magnetic element.

The process of retrieving microstructures which have been dissociated from larger arrays, particularly when being used for biological cell sorting, tends to be difficult. Modern methods of cell sorting require chemical or physical removal of selected cells from a larger culture. These cells are then suspended in imaging solution and ran through sorting devices designed to detect physical characteristics of the sorted cells (fluorescent labels, size, etc.). These sorting conditions are especially unfavorable to adherent cell health and viability and can lead to altered cell behavior which can negatively affect research results. Adherent cells primarily make up powerful cells of interest including stem and cancer cells. Researchers working with these cell types in particular greatly benefit from the possibility of sorting and separating specific cells from diverse populations and thus need a platform that is capable of minute cell differentiation while avoiding cell function alteration due to standard sorting platform requirements.
In order to address adherent cell suspension requirement issues, efforts have been made to allow adherent cells to stay in contact with their growth substrates while sorting is being conducted. Automated systems designed to replace manual hand sorting with robot controlled pipettes and scalpels have been developed to selectively remove targeted cells and cell colonies from culture. While these systems help to solve manually intensive sorting protocols, they still rely on old methods of cell capture with the same limitations as hand sorting. These limitations arise from a sorting regime designed by removing small sections of cells from larger samples. These methods inevitably lead to the loss of purity of cells as physically retrieving specific cells from others around them is not trivial. The chemicals used to digest cell connections to their growth surfaces can also cause unwanted alterations to the cell phenotypes post sorting. Instead of trying to automate sorting processes and keeping known flaws, it becomes necessary to design systems that work around these issues. One such solution is the use of microarrays which sequester individual cells onto their own growth surfaces so that collection does not lead to loss of sample purity.
Micro arrays composed of single cell sized structures designed specifically for cell culturing have proven to be powerful tools for cell analysis and sorting by allowing for the physical manipulation of plated cells without the need for chemical digestion from their growth surfaces. These arrays typically composed of patterned, biocompatible photoresist on glass slides are designed to sequester individual cells or cell colonies onto their surfaces in order to separate heterogeneous populations into discrete groups which can be easily separated from one another. When a cell of interest is located on a structure within the array, a laser targeted at the base of the structure is used to eject the individual components from the array. Currently, the most efficient way to collect these components is to invert the entire array over a collection plate, thus utilizing gravity to transfer structures no longer adhered to the glass slide. A major weakness related to this sort of microstructure transfer method is a loss in specificity and purity among captured samples. By relying only on gravity, there is no control over where collected samples actually fall within capture plates and may lead to the unwanted mixing of cells. Methods aimed at solving this issue allow for the individual capture and transfer of released structures, but sacrifices image clarity of samples during analysis. There is a need for a micro array platform which allows for the capture of individual components while also maintaining ideal imaging conditions.
Therefore, it is desirable to provide systems and methods directed to an improved micro array platform which allows for the capture of individual components while also maintaining ideal imaging conditions.

Ferromagnet infused microstructure array

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA


Light-emitting devices having a multiple quantum well (MQW) diode structure and methods of making and using the devices are provided. The devices include aluminum nitride/aluminum oxide bilayers on their hole injection layers. The bilayers improve the energy efficiency of the devices, with respect to devices that lack the bilayers or that include only a layer of aluminum oxide on their hole injection layers.

Over the past decades, improving energy conversion efficiency of InGaN/GaN blue light-emitting diodes (LEDs) has been persistently pursued. The continuous improvement of the energy efficiency of the InGaN/GaN LEDs mainly originated from developments in wafer growth techniques, packaging technologies, and nanophotonics. The major bottleneck toward achieving high efficiency LEDs is the low hole injection rate from the p-type hole transport layer (p-GaN:Mg) due to insufficient activation of the p-type dopant. The poor hole injection leads to a significant imbalance between the number of electrons and holes, leading to poor electron-hole recombination rates and, thus, low efficiency at high current densities. A number of research efforts have been geared toward making a breakthrough in this issue, including formation of a surface polarization layer, electron blocking layer, tunnelling layer, graded barrier structure, and nanopatterning. While these approaches helped improve energy conversion efficiency, there still exist issues such as the high cost for wafer regrowth and non-uniform surface patterning over a full-wafer area, in addition to strains induced by different thermal expansion coefficients and by different lattice constants between substrates and epitaxial layers.
The InGaN/GaN LEDs grown on a c-plane sapphire substrate possess a piezoelectric polarization field induced by the lattice mismatch between the InGaN and GaN layers. Additionally, the Wurtzite crystal structure of GaN generates a spontaneous polarization field in the LEDs, which consequently forms tiled energy bands within the InGaN/GaN multi-quantum wells (MQWs), leading to a reduced spatial distribution of electron and hole wave functions and, thus, reduced radiative recombination rates (i.e., quantum-confined Stark effect (QCSE)). Several methods were attempted to suppress the QCSE in LEDs, such as adaptation of nonpolar or semipolar substrates, polar MQWs with large wave function overlap design, substrate variation, polarization-matched epi-layer, top surface modification, and 1-dimensional vertical structure array. These methods require complicated device design, special/expensive substrates, and skillful epitaxy techniques. Various processes for LED top surface modification were also attempted including surface texturing, less-strained layer growth, and thin layer deposition. Although these surface modification approaches are simpler than other epitaxial methods, the cost associated with these approaches may still be high.

Aluminum nitride-aluminum oxide layers for enhancing the efficiency of group III-nitride light-emitting devices


The present invention is directed to a portable computer having an integral case that incorporates a resilient material to protect the portable computer from wear and tear encountered when transporting and/or using the portable computer. The integral case also includes a retractable strap means that can be utilized to facilitate the transporting of the portable computer. The integral case for the portable computer also includes an identification pocket on the exterior surface of the integral case for incorporating identification documents for the portable computer.

The present invention is generally directed to a portable computer and more particularly a case in which the portable computer can be housed. Portable computer that are manufactured today are positioned an openable case where the case is integral with the portable computer. However, the openable case is not designed to provide a convenient means for carrying the portable computer or for protecting the portable computer from wear and tear during the transporting of the portable computer. Accordingly, a separate protective case is utilized with the portable computer when it is necessary to transport the portable computer or to protect the portable computer from levels of wear and tear that are not normally encountered when using such a portable computer. The protective case is designed to fit around the portable computer and usually has a zipper or other securing means that allows the protective case to be secured around the portable computer. In many instances, the protective case has a layer of padding or other protective material in the interior of the protective case to provide additional protection for the protective computer. A handle or carrying strap is also usually associated with the protective case so that the portable computer can be more easily carried when the portable computer is being transported.
The protective case functions very effectively to protect the portable computer and provide a convenient means for transporting the portable computer. However, when not in use, it is necessary to store the protective case and to make sure the protective case is in a convenient location when it is desired to transport the portable computer. In addition, when the portable computer is being transported through areas where there are security concerns such as airports or into buildings with a high level of security, it is frequently necessary to remove the portable computer from the protective case so that the computer can be inspected and/or passed through an X-ray device. At airports, in particular, it has become increasingly time consuming to remove a portable computer from the protective case so that the computer can be passed through the X-ray inspection equipment. The portable computers normally do not have any identification means to identify the owner or user of the portable computer. Accordingly, it may be difficult to identify a particular portable computer after it has passed through the X-ray equipment especially if there is any confusion or additional processing that is necessary at the security checkpoint. The portable computers that are removed from the protective case for security inspection are also less protected and subject to being damages during the security checking operation. There is also a possibility that the computer can be dropped or otherwise damaged when it is being removed from or repositioned in the portable case during the security checking process.
Accordingly, it is an object of the present invention provide a portable computer that does not require a separate carrying case to protect the portable computer from wear and tear during the transporting of the portable computer.
It is a further object of the invention to provide a portable computer that has an identification means build into the exterior case of the portable computer to facilitate proper identification of the portable computer.
It is a further object of the invention to provide a case for a portable computer that has a carrying means that can be utilized to facilitate the transporting of the portable computer.


The present invention relates to the use of microorganisms (biocatalysts), or catalysts derived from these organisms (enzymes), to improve the quality of crude oil and bitumen as an attractive alternative to current upgrading methods. The invention identifies and characterizes the microorganism species, in particular, N. muscorum (UTEX 2209) and Kocuria rhizophilia (ATCC533), that have the capability to biochemically convert organic acids into chemical species that do not possess corrosive properties.

The quality of crude oil throughout the world is reduced by acidic components found in the oil. During refining, at temperatures between 220 and 400° C., these species can become corrosive. Organic acid species commonly referred to as naphthenic acids, having boiling points in this temperature range will condense on metal surfaces leading to damage in the refinery infrastructure, potential safety issues, and costly repairs. As a result, oils with high acid content, whether from conventional (crude oil) or oil sands (bitumen) sources, are more difficult to market and their value is significantly discounted.
Total acid number (TAN) is an analysis that tends to correlate with the corrosive nature of oils. Most refineries will minimize their exposure to oils with TAN values greater than 0.5 mg potassium hydroxide (KOH) per gram of oil. Some newer refineries have improved their front-end metallurgy so that they can handle TAN values up to 1.0 mg KOH/g. However, bitumens and heavy crude oils can have TAN values greater than 2.0 mg KOH/g.
Organic acids contribute significantly to the corrosion problems in refineries (Meredith et al. in Organic Geochemistry, 2000, 31, 1059-1073). In Alberta, Athabasca oil sands contain significant amounts of organic acids that are problematic not only to the refineries that receive the bitumen, but contribute to the toxicity of the waters used during bitumen extraction (Holowenko et al. in Water Research, 2002, 36, 2843-2855; and Rogers et al. in Chemosphere, 2002, 48, 519-527). The Canadian Oil Sands Network for Research and Development (CONRAD) Upgrading Research Group has identified that high total acid number (TAN) values, a number that reflects the corrosive nature of crude oil, pose a major concern to the industry that are processing Alberta bitumens and heavy crudes.
Conventional methods to remove corrosive species from crude oil involve costly and energy-intensive chemical and thermal processes. For example, the current technologies developed to remove organic acids from crude oil involve either thermal decomposition at 400° C. (Blum et al. in U.S. Pat. No. 5,820,750), adsorbing onto inert materials (Varadaraj in U.S. Pat. No. 6,454,936), treating with surfactants (Gorbaty et al. in Canadian Patent 2,226,750) or converting the organic acids into various derivatives that are easier to remove (Brons in U.S. Pat. No. 5,871,637, Sartori et al. in Canadian Patents 2,343,769 and 2,345,271, and Varadaraj et al. in U.S. Pat. No. 6,096,196).
Efforts to minimize organic acid corrosion have included a number of approaches for neutralizing and removing the acids from the oil. For example, there are numerous approaches in the literature on the reduction of the organic acid species in crude oil. They include thermal decomposition of organic acids using high temperatures in the presence (U.S. Pat. Nos. 5,914,030, 5,928,502) or absence (U.S. Pat. No. 5,820,750) of a metal catalyst and treatment of corrosive acids with group IA and IIA metal oxides, hydroxides and hydrates to form metal salts of naphthenic acids which are then thermally decomposed at elevated temperatures (U.S. Pat. Nos. 5,985,137, 5,891,325, 5,871,637, 6,022,494, 6,190,541, 6,679,987). Other methods include chemical formation of esters of the organic acids in the presence of alcohol and a base (U.S. Pat. Nos. 5,948,238, 6,251,305, 6,767,452, and Canadian Patent 2,343,769), reducing acidity by the formation of various salts of organic acids using base (U.S. Pat. Nos. 5,643,439, 5,683,626, 5,961,821, 6,030,523), removal of naphthenic acids using detergents or surfactants (U.S. Pat. Nos. 6,054,042, 6,454,936), absorbing organic acids onto polymeric amines (U.S. Pat. Nos. 6,121,411, 6,281,328) and by adding corrosion inhibitors to crude oil to prevent naphthenic acid induced metal corrosion (U.S. Pat. No. 5,552,085).
While these processes have achieved varying degrees of success, most of these methods are costly and energy-intensive and their effectiveness somewhat limited. As a result, there is a need to develop alternative approaches to treat and eliminate organic acid species in petroleum.
An alternative to utilizing energy intensive thermal, physical or chemical methods may be a biological approach using enzymes that have the capability to remove or convert the acidic carboxyl groups from organic acids into products that are not corrosive.
The art is substantially bereft of methods for upgrading the quality of crude oil comprising organic and/or naphthenic acids by the use of enzymes or biocatalysts. U.S. Pat. Nos. 7,101,410, 6,461,859 and 5,358,870 describe the use of biocatalysts, such as bacteria, fungi, yeast, and algae, hemoprotein, and a cell-free enzyme preparation from Rhodococcus sp. ATCC 53969, respectively, to improve the quality of oil specifically target organic sulphur containing molecules and so reduce the sulphur content as well as lowering their viscosity. U.S. Pat. No. 5,858,766 describes the use of microorganisms (a bacteria strain) in a bioupgrading capacity to selectively convert organic nitrogen and sulphur molecule in oil as well as remove metals.
It has been reported that Micrococcus luteus (formerly Sarcina lutea) ATCC 533 can convert fatty acids into long chain hydrocarbons via a decarboxylation-condensation mechanism (Albro et al. in Biochemistry, 1969, 8, 394-405, 953-959, 1913-1918 and 3317-3324). The organism is now known as Kocuria rhizophilia and has similar characteristics to a closely related organism M. luteus. This microorganism is one of a group of microorganisms and plants that possess enzymes that may be useful in a bioupgrading process that can biosynthesize hydrocarbons from carboxylic acids. The organisms and plants are described in a series of review articles (Hackett L. P. in Microb. Biotechnol. 2008, 1, 211-225; Ladygina, et al. in Proc, Biochem. 2006, 41, 1001-1014; Khan et al. in Biochem. Biophys. Res. Comm. 1974, 61 1379-1386; and Kolattukudy et al. in Biochem. Biophys. Res. Comm. 1972, 47, 1306-1313).
There remain the needs for bioprocesses, as attractive alternatives to current upgrading methods, which use microorganisms (biocatalysts), or catalysts derived from these organisms (enzymes), to improve the quality of crude oil and bitumen by converting organic acidic species.

Petroleum bioconversion of organic acids to prevent refinery corrosion

Her Majesty the Queen in Right of Canada as Represented by the Minister of Natural Resources


An electric light controller which serves to connect and disconnect an electric lamp element load from a power source in such rapid-fire pseudorandom seuentiality that the electric lamp appears to the eye as an illusion simulating the fluctuant brightness variations inherent in a flickering flame produced light. The result is an improved specious effect for decorative items such as electric lanterns used for outdoor lighting, simulated burning fireplace log arrangements, decorative chandeliers, holiday lighting equipment such as Christmas tree lights, and other such devices. Further enhancement of realism of the produced effect is provided for "open fire" decorative apparatus, such as electric fireplace log arrangements, through the optional inclusion of a popping acoustical sound translator, excited by a pseudorandom audio signal, which serves to simulate the crackling sound made by a burning material.

This invention relates to that class of devices oftimes employed to create the illusory effect of a fluttering open flame. Such an effect is frequently desired for purpose of establishing a mood or atmosphere, as in a restaurant or lounge; creating a pseudonatural illusion, as for example a flame lit lamp for outdoor lighting or a candlelit chandelier; for simulating a burning fire as in a fireplace or the like; for creating more natural appearing traditional effects, a good example of which is candlelit appearing Christmas tree lights or the like; and a contingent of other such devices. Previous art abounds with devices attempting to satisfy this need in the form of flashers, blinkers, unstable mode gaseous lamps, mechanical shutter devices, and the like. However, in-so-far as is known, no completely binary means has been produced until this instant invention which is capable of producing an illusory effect which has all the random appearing character of nature, and is yet inexpensive to implement in quantity and requires no adjustment thereby permitting inclusion in a wide variety of products having a diversity of requirements regarding average power, or where size, color, shape, electrical power requirements, and the like are concerned. Furthermore my instant implementation is brought about through digital signal manipulation which is functionally dependent upon the state selection of a combinatorial logic circuit, thereby precluding the usual ambiguity associated with earlier known analog control circuits which require ready adjustment means, at least during manufacture, to optimize the operation: a requirement which necessitates higher manufacturing cost and less permanence of performance. In addition the taught apparatus surpasses prior art in that it is capable of operating in an extreme range of temperature, without performance variation, from near minus 40 degrees Celsius to near plus 85 degrees Celsius. No moving parts or adjustable elements are employed in the implementation of the basic teachings, the device being commercialized as an ensheathed capsule, usually impregnated with a plastic compound, or potting agent, so as to form an environmentally independent containment for the workings of the device.

Flickering flame effect electric light controller


A process for purifying 2,3-dichloro-1-propanol is disclosed, which comprises introducing a chlorination reaction mixture obtained by chlorination of allyl alcohol in a hydrochloric acid aqueous solution in a reactor, to a degassing tower, where hydrogen chloride is released, returning the hydrogen chloride to the chlorination reactor, cooling the residual liquid to separate into an aqueous layer and an oily layer, and returning the aqueous layer to the chlorination reactor while recovering 2,3-dichloro-1-propanol from the oily layer, wherein said oily layer is introduced to a first distillation tower, where hydrogen chloride, part of the produced 2,3-dichloro-1-propanol, and other low-boiling components are recovered as a distillate, cooling the distillate to separate it into an aqueous layer and an oily layer, returning the aqueous layer of the distillate to the chlorination reactor, and recovering 2,3-dichloro-1-propanol from the oily layer of the distillate and a high-boiling fraction of the first distillation tower. Where 2,3-dichloro-1-propanol is for use as a starting material of epichlorohydrin, the process involves no wasteful consumption of calcium hydroxide.

2,3-DCP is used in quantities as an intermediate for synthesizing epichlorohydrin useful as a solvent, a starting material for epoxy resins, a starting material for synthetic rubber, a stabilizer for chlorinated rubber, etc.
Conventional production and purification of 2,3-DCP is illustrated in the system diagram of FIG. 5. In FIG. 5, a hydrochloric acid aqueous solution (HClaq) and allyl alcohol (AAL) are charged in reactor 1 equipped with stirrer 1a, and chlorine gas is blown through the AAL solution in the HClaq while cooling the solution at a constant temperature to produce 2,3-DCP. The reaction mixture is forwarded to degassing tower 2, where hydrogen chloride is evolved and returned to reactor 1. The degassed mixture is then delivered to first decanter 3, where it is separated into aqueous layer 3a and oily layer 3b by cooling to 40.degree. C. or lower. Aqueous layer 3a is recycled to reactor 1, while oily layer 3b is recovered for direct use as a raw material for other compounds or purified to recover 2,3-DCP therefrom. For the conventional production of 2,3-DCP, reference can be made to U.S. Pat. No. 4,634,784.
Oily layer 3b comprises 72 to 75% by weight of 2,3-DCP, 3 to 6% by weight of by-products, e.g., glycerin monochlorohydrin and oligomers, and about 20% by weight of HClaq as an azeotropic component (20%).
For the production of epichlorohydrin, 2,3-DCP is once recovered from oily layer 3b and saponified by reaction with a calcium hydroxide aqueous solution, or oily layer 3b as separated in decanter 3 is directly subjected to saponification.
The former process in which the oily layer is purified involves an extra cost for separation into components and treatment of unnecessary and harmful components.
The latter process in which the oily layer is saponified as such is economically disadvantageous in that useful by-products such as glycerin monochlorohydrin cannot be recovered because they are incorporated into the waste liquor of the saponification mixture. Further, the hydrochloric acid contained in the oily layer is concurrently neutralized with calcium hydroxide, leading to not only wasteful consumption of calcium hydroxide but also necessity of making up for the loss of hydrochloric acid which is withdrawn from the chlorination system and is never recovered.


A computer system aligns two or more sequences with each other to identify similarities and differences between the aligned sequences. The sequences may, for example, represent proteins. The system performs alignment quickly and accurately by representing the sequences as perceptual information and conceptual information having mappings between them in a knowledgebase, and then performing the alignment based on the representations of the sequences in the knowledgebase. The alignment may be performed in polynomial time, regardless of the number of sequences that are aligned.

Sequence alignment involves arranging two or more sequences to identify similar regions within those sequences. For example, protein alignment involves arranging the sequences of two or more proteins to identify similar regions within those sequences. The outcome of a particular protein sequence alignment may indicate functional, structural, or evolutionary relationships between the aligned sequences. Although alignment may be applied to sequences representing any kind of information, some of the description below will refer to alignment of sequences representing proteins merely as one illustrative example.
The results of a particular protein alignment usually is represented by displaying each protein sequence horizontally as a sequence of letters representing the proteins in the sequence, with letter sequences arranged vertically, so that similar regions within each sequence are aligned vertically with each other. Although the description herein refers primarily to protein alignment, the same or similar techniques may be used to align other kinds of sequences, such as DNA and RNA sequences. All of these are examples of "sequence alignment."
Alignment typically involves identifying: (1) overlaps (identical or similar regions) between the aligned sequences, also referred to as intersections; (2) differences, such as a region that is contained within one of the aligned sequences but not another; (3) complements, which represent opposites within the aligned sequences, as in the case in which one aligned sequence contains a 1 and another aligned sequence contains a −1 at the same or similar position; and (4) unions, which represent all of the unique elements in some or all of two or more of the aligned sequences.
A wide variety of techniques for performing sequence alignment have been developed, such as dot-matrix methods, dynamic programming-based methods, progressive methods, methods based on hidden Markov models, and methods that use artificial neural networks. Regardless of the kind of sequence alignment technique that is used, aligning very large sequences causes the amount of computational resources (i.e., memory and/or processing) required to perform the alignment to increase exponentially. In general, the number of computations required to align sequences of length n is n2. As a result, traditional sequence alignment techniques quickly become unwieldy for aligning sequences as the size of the sequences grows.
What is needed, therefore, are improved techniques for performing sequence alignment efficiently and effectively.

Spatial arithmetic method of sequence alignment


A centrifugal separator separates a mixture of fluid and particulate matter in a cylindrical tank. The mixture enters the tank tangentially through one passage. The mixture is swirled within the tank through the use of angled blades to guide flow rotation, increasing centrifugal force on the mixture. Separated fluid flows into a discharge pipe and out of the tank. The flow of fluid into the discharge pipe may be provided by an opening along the length of the pipe, the fluid may enter and exit the tank at opposing ends, and the angled blades may be circumferentially offset from adjacent blades.

Centrifugal style separators have been used to separate particulate matter from a fluid mixture. Centrifugal style separators have useful advantages in particular applications. For example, when large amounts of particulate matter is present, mesh and screen type filters may become clogged and fail to allow the necessary or desired fluid flow rate through the separator.
Centrifugal style separators take advantage of rotational forces and gravity to assist in separating suspended particulate matter from a particulate and fluid mixture. The mixture flows into a passage in a top of the separator where it is induced into a centrifugal flow pattern. Separated particulates are retained in the separator, and cleaned fluid flows out of another passage in top, or end of, the separator. The separated particulates are periodically purged from the separator through a port supplied for that purpose. An example of a centrifugal separator is found in US Patent Application Publication 2015/0328567, incorporated herein by reference.
There is room for improvement in the known separator designs to increase their efficiency and performance, and to increase the various locations and applications in which they can be installed.


Certain squaric acid derivatives are useful for the thermochemical generation of acid. The squaric acid derivatives may be used in imaging media in conjunction with acid-sensitive materials which undergo a color change when contacted by the acid generated from the squaric acid derivatives. Preferably, the acid-sensitive materials undergo an irreversible color change, so that the image can be fixed by neutralizing all the acid generated with excess base, thereby preventing further color change in the image during long term storage.

This invention relates to a process for thermochemical generation of acid and for thermal imaging, and to an imaging medium for use in this thermal imaging process.
Thermal imaging processes are known which use a material capable of undergoing a color change from a colorless to a colored form, from one color to another color or from a colored to a colorless form upon application of heat. For example, U.S. Pat. No. 3,723,121 discloses several thermochromic materials for laser beam recording including inorganic compounds, such as black copper (II) oxide, which decomposes to red copper (I) oxide upon heating, and organic compounds, such as polyacetylene compounds, which subsequent to treatment with ultraviolet light undergo two changes in color, first to red then to yellow, as the temperature is increased.
U.S. Pat. No. 4,720,449 describes a thermal imaging method which comprises heating imagewise a di- or triarylmethane compound possessing within its di- or triarylmethane structure an aryl group substituted in the ortho position to the meso carbon atom with a moiety ring-closed on the meso carbon atom directly through a nitrogen atom, which nitrogen atom is also bound to a group with a masked acyl substituent that undergoes fragmentation upon heating to liberate the acyl group for effecting intramolecular acylation of the nitrogen atom to form a new group in the ortho position, whereby the di- or triarylmethane compound is rendered colored in an imagewise pattern corresponding to the imagewise heating.
U.S. Pat. No. 4,602,263 and U.S. Pat. No. 4,826,976 both describe thermal imaging systems for optical recording and particularly for forming color images. This thermal imaging method relies upon the irreversible unimolecular fragmentation of one or more thermally unstable carbamate moieties of an organic compound to effect a visually discernible color shift from colorless to colored, from colored to colorless or from one color to another. In both references, the preferred method of producing the heat required for the irreversible unimolecular fragmentation is to include in the imaging medium an infra-red absorber which generates heat upon exposure to infra-red radiation, and then to imagewise expose the imaging medium to infra-red radiation.
All thermal imaging systems which rely upon a heat-induced color change in a single material potentially suffer from the problem that, although the color change only occurs rapidly at an elevated temperature, the color change will continue at some finite, though low rate, at lower temperatures, such as ambient temperatures at which the relevant imaging medium is normally stored prior to exposure and at which the formed images are stored after exposure. Development of slight color in the imaging medium prior to exposure results in an increased minimum optical density (D.sub.min) in the image; in other words, the white portions of the image appear less white the longer the imaging medium is stored prior to exposure. Similarly, continuing color change after exposure, especially in unexposed regions of the image where the original heat-sensitive material is not decomposed during exposure, may, over a period of years, result in increased optical density in unexposed regions and a consequent loss of contrast in the image. These problems caused by unwanted color change may be exacerbated in polychrome systems by the fact that, at storage temperatures, the rates of decomposition of the various heat-sensitive materials used to produce the various colors may differ, so that when the optical density of supposedly white or grey areas of the image changes on storage, these areas may develop a colored tint rather than remaining a neutral white or grey.
The heat-sensitive materials disclosed in the aforementioned U.S. Pat. Nos. 4,602,263 and 4,826,976 comprise single compounds the molecules of which may be regarded as having a relatively small heat-sensitive center (typically a t-butoxycarbonyl group) covalently linked to a much larger chromophore (typically a polysubstituted xanthene nucleus). There are theoretical advantages to replacing such a covalently-linked compound with a two-component system comprising a small molecule which generates acid upon heating and a larger molecule which changes color upon contact with acid. Polychrome forms of such a two component system would require only a single heat-sensitive compound. By including a small amount of base with the heat-sensitive compound and the acid-sensitive compound, small amounts of acid generated during storage of the imaging medium prior to exposure could be neutralized, thereby avoiding an increase in D.sub.min in the unexposed areas of the image. Finally, such a two-component system could contain an excess of the low molecular weight heat-sensitive compound and only the amount of the high molecular weight acid-sensitive compound needed to produce the desired maximum optical density (D.sub.max) in the image. Such a system with excess heat-sensitive compound is likely to be more sensitive than a single component system, since part of the heat-sensitive material normally remains unchanged even in areas of maximum optical density; in the two-component system, use of excess low molecular weight heat-sensitive compound can compensate for its incomplete thermal breakdown without greatly increasing the mass of material to be heated, whereas a corresponding attempt to increase the amount of heat-sensitive centers in a single component system necessarily increases the amount of the high molecular weight molecule, thereby greatly increasing the mass of material to be heated.
Heat-sensitive materials which liberate acid upon heating are known. For example, Sabongi, G. J., Chemical Triggering--Reactions of Potential Utility in Industrial Processes, Plenum Press, New York, N.Y. (1987), pages 68-72 describes thermally triggered release of carboxylic acids from esters and oxime derivatives, especially benzaldoximes and oxalic acid esters, while pages 97--101 of the same work describe photochemical release of carboxylic acids from benzyl, phenacyl, sulfenyl and benzoin esters.
U.S. Pat. No. 4,603,101 describes photoresist compositions containing a compound which photochemically generates acid. The acid-generating compounds used are onium salts.
U.S. Pat. No. 4,916,046, issued Apr. 10, 1990, on application Ser. No. 243,819, filed Sept. 13, 1988, describes a positive radiation-sensitive mixture using a monomeric silylenol ether, and a recording medium produced therefrom. This patent also contains an extensive discussion of radiation-sensitive compositions which form or eliminate an acid on irradiation. According to this patent, such radiation-sensitive compositions include diazonium, phosphonium, sulfonium and iodonium salts, generally employed in the form of their organic solvent-soluble salts, usually as deposition products with complex acids such as tetrafluoroboric acid, hexafluorophosphoric acid, hexafluoroantimonic acid and hexafluoroarsenic acid; halogen compounds, in particular triazine derivatives; oxazoles, oxadiazoles, thiazoles or 2-pyrones which contain trichloromethyl or tribromomethyl groups; aromatic compounds which contain ring-bound halogen, preferably bromine; a combination of a thiazole with 2-benzoylmethylenenaphthol; a mixture of a trihalomethyl compound with N-phenylacridone; .alpha.-halocarboxamides; and tribromomethyl phenyl sulfones.
A heat-sensitive acid generating material needs to fulfil several differing requirements. It is desirable that the material generate a strong acid, since generation of a weak acid, such as the carboxylic acids generated by some of the materials discussed above, may limit the types of acid-sensitive compound which can be used. The heat-sensitive acid generating material is desirably of low molecular weight in order to reduce the amount of material required to generate a specific amount of acid, and also to reduce the amount of energy required to heat the material to its decomposition temperature. The acid generating material should decompose rapidly when heated to its acid-forming temperature, and this temperature should not be higher than about 130.degree. C., in order to reduce the amount of energy which must be supplied to decompose the acid generating material and thus reduce the energy necessary for acid formation in a medium, and increase the sensitivity of the medium Finally, the acid generating material must be compatible with all the other components of the imaging medium in which it is to be used, and should not pose environmental problems, such as offensive smell or severe toxicity.
It has now been found that certain squaric acid derivatives are effective as heat-sensitive acid generating materials, and that these derivatives are useful in thermal imaging.

Process for thermochemical generation of acid and for thermal imaging, and imaging medium for use therein


A rotary clutch assembly comprises a first hub and a second hub. The first hub has first and second ends. An inner surface in the first hub is defined by a first internal passageway extending from the first end to the second end for receiving shaft. One of the first and second ends of the first hub has a first notch. The second hub has first and second ends and an outer surface. An inner surface in the second hub is defined by a second internal passageway extending from the first end to the second end for receiving the first hub. One of the first and second ends of the second hub has a second notch. Multiple clutch assemblies may be coupled on a single shaft to form a drive assembly having increased torque capacity by engaging the first and second notches of a first clutch assembly with first and second notches of a second clutch assembly.

The invention relates to a rotary clutch assembly. More particularly, the invention relates to a rotary clutch assembly having interlocking hubs for connecting multiple rotary clutch assemblies together on a single shaft.
Rotary clutch assemblies are useful for applications in which a flexible member, such as a cable, rope, hose, conductor, electrical cord or the like (hereinafter referred to as the xe2x80x9ccablexe2x80x9d), is wound on a spool of a take-up reel assembly for storage when not in use, and which is paid out by unwinding the cable from the spool of the take-up reel assembly to the appropriate length required. The cable stored on the reel assembly may be used to carry any required type of matter, such as air, water, oil, grease, or electricity. A frame supports the clutch assembly and the reel assembly.
One example of an application for a rotary clutch assembly is temporarily supplying electrical power to an apparatus. An electrical power supply is electrically connected to the frame. The first end of the cable is electrically connected to the cable reel assembly for receiving electricity from the electrical power supply. The second end of the cable is electrically attached to a car, such as a scrap car in a steel mill, for supplying power to the car. As the car moves away from the reel, cable is paid out from the reel. When the car moves back toward the cable reel, the torsional spring acting on the cable reel rewinds the cable back onto the spool. When the temporary supply of electrical power is no longer required, the cable is detached from the apparatus and a torsional spring acting on the cable reel rewinds the cable onto the spool. The torque exerted by the torsional spring on the take-up reel assembly causes the paid-out cable to be taken-up by the spool.
In existing cable reel assembly applications, only one clutch assembly is used. Thus, the torque required by the application for which the cable reel assembly is to be used dictates the size of the clutch assembly. Accordingly, the larger the torque required, the larger the clutch assembly required to meet that demand. As the size of the clutch assembly increases radially, the size of the frame required to support the clutch assembly increases. Some cable reel assembly applications have space limitations. Thus, a large frame is not a viable option. A need exists for providing larger amounts of torque without greatly increasing the size of the frame.
Furthermore, meeting the torque demands for a variety of applications requires manufacturing of several different sized clutch assemblies, thereby increasing manufacturing costs and inventory. A need exists for a single clutch assembly that is capable of meeting the torque demands of a variety of applications while reducing manufacturing costs and keeping the amount of inventory small.
Examples of prior rotary clutch assemblies are disclosed in the following U.S. Pat. No.: 2,902,125 to House et al.; U.S. Pat. No. 3,360,927 to Cornelius; U.S. Pat. No. 4,461,375 to Brown; and U.S. Pat. No. 5,632,453 to Hioki et al.
Thus, there is a continuing need to provide improved rotary clutch assemblies.
Accordingly, it is a primary objective to provide a single clutch assembly that meets the variety of torque demands required by different cable reel assembly applications, thereby reducing the required inventory of parts and decreasing the manufacturing costs.
Another object of the invention is to provide a clutch assembly mountable on a shaft and adaptable to engage further clutch assemblies on the same shaft to provide the torque required by an application, thereby increasing the torque capacity without increasing the size of the frame.
The foregoing objects are basically attained by providing a rotary clutch assembly that comprises a first hub having first and second ends, the first hub having an inner surface defined by a first internal passageway extending from the first end to the second end for receiving a shaft, one of the first and second ends of the first hub having a first notch; and a second hub having first and second ends and an outer surface, the second hub having an inner surface defined by a second internal passageway extending from the first end to the second end for receiving the first hub, one of the first and second ends of the second hub having a second notch.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.

Rotary clutch assembly having interlocking hubs


A system and method for determining the detachment of an embolic material using a single power supply are disclosed, wherein the determination is made by applying a DC power to an assembly with an embolic material, a sacrificial link and a guiding wire which are serially connected and repeatedly measuring a voltage and current between the assembly and the ground for a plurality of cycles and a plurality of times in each cycle; computing an average of the measured voltages and an average of measured currents; and determining the detachment of the embolic material from the guiding wire based on a change in impedance between the guiding wire and the ground, wherein the change is detected using the present average of the measured voltages, the present average of the measured currents and a previous average voltage which is previously measured for a plurality of times.

The present invention relates to an apparatus and method for filling a target site in a living being with an embolic material to occlude the site; and, more particularly, to an apparatus and method for automatically notifying an operator of the instant the embolic material is detached from a guiding member by electrolytic action.
There is an operative treatment of treating vascular malformations such as a cerebral aneurysm, which includes the processes of putting a patient under general anesthesia to craniotomy, exposing the cerebral aneurysm in the patient using an operating microscope and a microsurgical unit, and clipping a cervical portion of the cerebral aneurysm with a particular metallic clip. However, such a treatment suffers from drawbacks that it still involves a considerable hazard and a prolonged operating time, which, in turn, may cause serious sequelae.
In an alternative treatment, a Minimal Invasive Treatment (MIT), which employs a technique disclosed in U.S. Pat. No.5,122,136 issued to Guglielmi et al, and U.S. Pat. Nos.4,884,579 and U.S. Pat. No. 4,739,768 issued to Engelson, is utilizing. The MIT Treatment inserts an embolic material within vascular malformations such as a cerebral aneurysm through the use of a micro catheter and a guiding wire under fluoroscopy to occlude the vascular malformations. In contrast with the craniotomy treatment previously explained, the MIT treatment has merits that it is possible to operate under a slight anesthesia with a short operation time, to thereby minimize sequelae and also lower an operation cost.
An embolic material mainly utilized in the MIT treatment includes a metallic coil. The metallic coil is disclosed in, for example, U.S. Pat. Nos. 5,354,295, 5,669,905 and 6,066,133 and Japanese Patent Nos. 10-057385, 11-047138 and 11-076249. In the following, the metallic coil cited in U.S. Pat. No. 5,669,905 will be described.
FIG. 1 is a pictorial view of a metallic embolic coil used in the conventional MIT treatment.
As shown in FIG. 1, a guiding wire assembly 100 typically includes a stainless steel-based guiding wire 1 and a coil-shaped embolic material 8, the guiding wire 1 being tapered its distal end and the embolic material 8 being connected with the distal end of the guiding wire 1 by a micro welding. The embolic material 8 is made of a radiopaque material including Platinum, Tungsten, Iridium or these alloys, and has welded portions 6 and 7 at its both ends. The welded portions 6 and 7 are made of platinum that acts as a marker under fluoroscopy.
A surface of the guiding wire 1 is coated with an insulating material such as Teflon, with the exception of a proximal end 5 acting as a sacrificial link to be connected with the welded portion 6 of the embolic material 8. The sacrificial link 5 is made of an electrically conducting material such as stainless steel, which is a portion to be detached from the guiding wire 1 by electrolytic disintegration. The guiding wire 1 is coupled with the welded portion 6 of the embolic material 8 via the sacrificial 5, which is interposed in a sleeve 2 and a plug 3 with inserted within an internal coil 4. The internal coil 4 is designed to provide column strength to the guiding wire 1, without a bad influence for a flexibility of the tapered portion in the guiding wire 1. As shown in FIG. 1, the embolic material 8 has been designed its shape changed into a coil form when it is gradually withdrawn from a micro catheter 7, to thereby allow the embolic material to adapt to the shape of the vascular malformation.
FIG. 2 is a pictorial view illustrating insertion and detachment processes of the embolic material 8 in the prior art.
Typically, the insertion of the embolic material 8 in a vascular malformation 11 is performed using fluoroscope under local anesthesia. Specifically, as shown in FIG. 2A, an operator guides a micro catheter 10 to near neck 12 of the vascular malformation 11 in a living being or a patient. After that, the operator inserts the guiding wire 1 attached the embolic material 8 on its distal end into the micro catheter 10, and gently push the guiding wire 1 using the fluoroscope at least until the sacrificial link 5 is exposed beyond the distal end of the micro catheter 10.
In an ensuing step, an electrical loop is formed wherein a positive electrode of a power supply 13 is attached to the proximal end of the guiding wire 1 and a negative electrode is placed in electrical contact with the skin of the patient. Thereafter, the power supply 13 is turned on to allow a DC power with AC superposition to be applied to the embolic material 8 through the sacrificial link 5 of the guiding wire 1. As a result of the above process, the embolic material 8 is detached from the guiding wire 1 by electrolysis as shown in FIG. 2B. Next, the guiding wire 1 and the micro catheter 10 are withdrawn from the vascular malformation 11.
FIG. 3 shows a schematic block diagram of the prior art apparatus of detecting the detachment of the embolic material from the guiding wire.
The prior art apparatus 200 includes a constant current source 16, a circuit 18 for detecting the detachment of the embolic material and a microprocessor 19. The constant current source 16 provides a constant current to the patient 17, which includes an operational amplifier (OP Amp) 16a and a DC feedback loop 16b. The OP Amp 16a will oscillate in approximately 30 kHz at amplitude of several hundred milli-volts due to a lagging error correction signal (out-of-phase feedback). That is, the OP Amp 16a provides a DC current with AC superposition. The amplitude of such AC signal is dependent on bandwidth characteristics of the OP Amp 16a, AC impedance of the stainless steel and the embolic material 8, and the patient""s body. The DC constant current flowing out of the OP Amp 16a flows through the sacrificial link 5 of the guiding wire 1 to the embolic material 8.
Although the sacrificial link 5 and the embolic material 8 are physically connected in series, immersion of them in an electrolytic solution forms two parallel DC current paths each of that is grounded through the body of the patient 17. Specifically, by ion flow away from the stainless steel-based link 5 during electrolysis, the DC current with AC superposition flowing between the sacrificial link 5 and the embolic material 8 in the vascular malformations 11 is branched as follows. That is, the majority of the DC current (above 99%) flows through the sacrificial link 5 with the remaining (less 1%) flowing through the embolic material 8. Thus, if the embolic material 8 is separated from the link 5 and a portion of the sacrificial link 5 remains attached to the guiding wire 1, the main DC current is fed back to the DC feedback loop 16b of the constant current source 16. The AC current is grounded through the embolic material 8.
As shown in FIG. 3, the DC current with AC superposition is blocked out by a pick-off capacitor (not shown), only the AC signal is fed to the detection circuit 18 for measurement of AC impedance. The detection circuit 18 receives the AC current from the embolic material 8 in the patient 17 to detect whether or not the embolic material 8 is detached. Specifically, the AC current fed to the detection circuit 18 is amplified in an AC signal amplifier 18a and is rectified in an AC-DC rectifier 18b. Then, the rectified DC signal is amplified in a DC level amplifier 18c and sent to the microprocessor 19, wherein the amplified DC level is representative of the amplitude of the AC voltage of the OP Amp 16a.
The microprocessor 19 monitors the level of the amplified DC signal every 50 to 200 milliseconds and constantly averages the signal every specific sample. In this manner, if a sudden DC voltage drop is incurred, the microprocessor 19 determines that the embolic material 8 is detached from the guiding wire 1.
In the prior art, the OP Amp 16a oscillated on its own, which allowed the monitoring of the AC impedance fluctuation by the detection circuit 18. Since, however, there were fluctuations in the self-oscillation signal flowing- from unit to unit, it fails to exactly determine the instant the embolic material is detached. That is to say, a fluctuation in the AC impedance depends on a length of the embolic material and other physical factors, thereby invoking poor detachment detection.
To support this, as shown in FIG. 4, an external AC source 20b is utilized to ensure all units will show the identical response to the fluctuation in the AC impedance. In FIG. 4, the AC source 20b is coupled with a reference input Vref of an OP Amp 20a so as to modulate the output current of the OP Amp 20a (i.e., provide AC superposition on the DC current). A DC current with AC superposition is outputted from the OP Amp 20a and sent to the embolic material 8 through the sacrificial link 5 of the guiding wire 1. As a result, two AC and DC current paths branch as described above with reference to FIG. 3. The DC current with AC superposition from the patient 17 is fed back to an AC and DC feedback loop 20c of a constant current source 20 and fed to the OP Amp 20a.
As stated above, the DC current with AC superposition is blocked out by a pick-off capacitor (not shown), only the AC signal is fed to the detection circuit 21 for measurement of AC impedance fluctuation. In the detection circuit 21, since the amplitude of the AC signal is substantially greater than that of FIG. 3, the DC level amplifier 18c in FIG. 3 is not necessary. As noted, the AC signal is amplified in an AC signal amplifier 21a in the detection circuit 21 and is rectified in an AC-DC rectifier 21b. Then, the rectified DC signal is sent to the microprocessor 19.
In short, the prior art apparatuses previously disclosed detect the detachment of the embolic material using the AC signal. Accordingly, the prior art apparatuses suffer from a drawback that if a fluctuation in the AC impedance depends on a length of the embolic material and other physical factors, it is difficult to exactly detect the detachment instant. In addition, the prior art guiding wire assembly for embolization demands to an additional coil for maintaining the shape of the guiding wire and an additional signal source, thereby rendering the apparatus rather complex and costly. Likewise, although the embolic material in the prior art has been fabricated in platinum, tungsten, gold, iridium or alloy for thrombus in vascular malformations, it would be desirable to effectively enhance the rate of thrombus without any application of high power to the material.
It is, therefore, an object of the present invention to provide a system and method for exactly determining the instant an embolic material is detached through the use of a single power supply, without any additional circuits.
It is another object of the present invention to provide an assembly for embolization, which includes a simplified guiding member and an embolic material inducing an improved thrombus in vascular malformations.
In accordance with a preferred embodiment of the present invention, there is provided to a system for detecting the detachment of an implant from a guiding member coupled thereto, wherein the implant is guided by the guiding member into a target site in a living being, comprising: means for generating a current; means for supplying the generated current via the guiding member to the implant; means for measuring a voltage and current between the guiding member and the ground for a plurality of cycles, during each of which the voltage and current are measured for a plurality of times; means for computing the average of the measured voltages and the average of measured currents in each cycle; and means for determining the detachment of an implant from the guiding member based on a change in impedance between the guiding member and the ground, wherein the change is detected using the average voltage and average current of the latest cycle of voltage and current measurements, and the average voltage of the previous cycle of voltage and current measurements.

Embolic material detachment detection system and method and assembly for embolic treatments

Hyundai Villa 7-201, 172 Sangil-dong, Gangdong-gu


The invention relates to a rollover protection system for automobiles, comprising an extensible rollover body (1) held in an initial position by means of a holding device and secured against retraction, in a functional position by means of a locking device, and comprising an extension drive and an actuator (2) for releasing the holding device. Separate holding and locking devices are usually provided in such rollover protection systems, which is expensive both from a technological and an economic point of view. For simplification it is suggested according to the present invention that the holding device and the locking device be combined in one assembly (3). The assembly is arranged on the side adjacent to the rollover body (1) in a housing (16). The rollover protection system can be attached to the vehicle body by means of mounting elements (14 and 15), and the assembly (3) can be mounted in a position fixed on the vehicle. Upon extension of the rollover body (1), an engagement element of the assembly (3) engages the locking recess (6) of the rollover body (1).

1. Field of the Invention
The present invention relates to a rollover protection system for automobiles, comprising an extensible rollover body held in an initial position by means of a holding device and secured against retraction, in a functional position by means of a locking device, and comprising an extension drive and an actuator for releasing the holding device.
Such rollover protection systems are used for the equipment of automobiles that do not offer sufficient protection for the passengers in case of a rollover, such as convertibles, where no roof is provided, or where the roof can be removed or folded away and where rigid, non-extensible rollover bodies are not desirable for aesthetic reasons.
The rollover bodies must be secured against inadvertent extension in a retracted initial position, and the extended rollover body must be secured against retraction in the functional position.
2. Description of Related Art
Mechanically biased springs or other stored-energy means which are blocked in the initial position by means of a releasable holding device, are used in many instances as an extension drive. In a similar way to airbags, a signal is generated by acceleration sensors, which triggers the activation of the rollover protection system, wherein the holding device is released by means of an actuator and the extension of the rollover body is enabled. Such a holding device is described in German Patent Specification 100 27 753 C1.
In the functional position, the extended rollover body is intended to support the overturned vehicle on the ground and to provide a protective space for the passengers. In this position, the rollover body must be locked against retraction, which is often realized by means of detent protrusions or the like biased in the engagement direction and automatically engaging a recess in the rollover body. Locking devices of this type are known from DE 100 27 753 C1 and DE 198 38 989 C1.
Hitherto the holding and locking functions have been treated as separate technical tasks, and thus separate devices have been designed for fixing the rollover body in the initial position and the functional position (cf. DE 100 27 753 C1). The technological and economic overhead is relatively high and a considerable drawback in the economic viability of such products.

Rollover protection system for automobiles


A support stand for an electronic device having a base having a first end and a second end, the first end including a bifurcation forming a first leg and a second leg; a first clamp pivotably attached to the first leg; a second clamp pivotably attached to the second leg; a first post having a first end pivotably connected to the second end of the base; a second post having a first end telescopically connected to a second end of the first post; a platform pivotably connected to a second end of the second post; a horizontally adjustable first arm pivotably attached to the first pole, the horizontally adjustable first arm having a first telescopic section extending away from the first pole; a horizontally adjustable second arm pivotably attached to the first pole, the horizontally adjustable second arm having a second telescopic section extending away from the first pole; a first adjustable fastening device located at a distal end of the first telescopic section; and a second adjustable fastening device located at a distal end of the second telescopic section.

Over the years, the use of exercise machines has become a regular part of many people's lives. In addition, people rely on a TV or social media to be up to date in the latest news or friend's status. This causes an increasing trend for people that exercise to have an increasing desire to be connected to a TV and/or an electronic device while exercising.
The prior art shows exercise machines provided with small shelves that can accommodate a phone, a book, or a magazine. Unfortunately, the person usually cannot read or watch clearly the information on the electronic device, since the person is often in a variety of orientations and height with respect to the shelves while using the exercise machine. It is desirable for the person to be able to comfortably watch his/her cell phone or TV or Tablet or Display monitor regardless of his/her orientation.
Usually, the gym includes several TV screens that show different shows. Unfortunately, the TV screens are located far away from the user and set to show general audience shows. In view of this, the user cannot clearly see the show or watch his/her favorite shows or the application they prefer or any other kind of streaming service like YouTube or smart-TV content.
The prior art also shows book-holding and computer-holding devices that are supported on the frame of the exercise machine. Unfortunately, in most of these devices the height cannot be adjusted to fit the user's height; thus, the user has trouble reading the book or looking at the computer.
In addition, the prior art shows some books or computer holders in which the height can be vertically adjusted. Unfortunately, on these devices the articles or electronic devices cannot be horizontally orientated so that the person can adequately view the articles or electronic devices.
Adjustability is an important factor in order for the person to be able to comfortably watch his/her tv, read cell phone, electronic devices, a book, or magazine regardless of his/her orientation. Adjustability should be provided for vertical adjustment, horizontal adjustment, and angular adjustment, depending on the user who is in a wide variety of personal orientations.

Support stand for hands free use of electronic devices while using an exercise machine


Natural language solution generating devices and methods are provided herein. Exemplary devices may execute logic via one or more processors, which are programmed to receive a complex query in natural language format, the complex query including a real-world problem that requires interrogation of a plurality of information sources in order to ascertain a response to the problem, evaluate the complex query to determine query segments, which are each included with at least one domain, wherein a domain corresponds to an information source, query the information sources to obtain responses for the query segments, and generate a natural language solution using the responses.

Search engines and natural language processors are often used to fulfill a query. Unfortunately, these systems only provide one dimensional answers (e.g., interrogation of a single information source or a plurality of similar information sources) to queries. Thus, these systems are ill suited to providing answers to queries that require a more intricate interrogation of disparate types of information sources and/or multifaceted/multistep computations of data, as is often required when formulating responses to human interest driven (e.g., real-world) queries. For example, a business person may desire an answer to a complex query, such as, when is the best time to initiate marketing campaigns for a particular product in a variety of countries. This question inherently requires interrogation of a wide variety of information sources to formulate a coherent response or set of responses.


Process and apparatus for measuring variations in a stream of material, such as thickness in a strip from a mill. A radiation source and detector are positioned at a gauging station. The stream of material moves past the station providing an electrical signal varying as a function of material at the station which signal includes a lower frequency component, a higher frequency cyclical component, and a higher frequency noise component. A circuit for providing a thickness output varying as a function of the lower frequency component of the signal, and a circuit providing an output indicating chatter varying as a function of the higher frequency cyclical component. Digital and analog versions are disclosed.

This invention relates to the detection of low frequency variations and high frequency cyclical variations in a signal, particularly those from on-line thickness measurement instruments.
Continuous processing of strip products such as steel, aluminum, rubber, paper, etc., has grown enormously over the past three decades. The quality of on-line instrumentation has improved correspondingly, and manufacturers are able to measure and control their processes within tighter and tighter tolerance bands. In many processes there are prolonged regions of high frequency variations in the product. An example is the thickness variation that occurs in the cold rolling of steel--in particular the phenomenon known as "chatter". A common cause of chatter is a mechanical resonance in the rolling mill which makes the rolls bounce. This gives rise to a thick (or thin) spot in the steel for each bounce. The thickness variations are a quality defect which may render the steel unsuitable for an end use such as can making.
Chatter may be characterized by the amplitude of the thickness variation and the spatial separation of the thick spots. For the roll bounce chatter described above, separations of 5-20 cm and amplitudes of 5-20 microns are found in 0.25 mm can stock. Such can stock is rolled at speeds from 600 to 2100 meters/minute, and finished on inspection, tinplating, and slitting lines at speeds from 300 to 600 meters/minute. The chatter shows up as high frequency variations in the range of 5 to 300 Hz. Regions of chatter may be as short as ten meters or as long as hundreds of meters. FIG. 1 shows an example of chatter, detected on a tinplating line with the strip of material moving at 500 meters/minute. The chatter is superposed on a much lower frequency variation in thickness, typically less than 2 Hertz.
Increasing concern on the part of the manufacturers has created the need to identify chatter on-line as part of the thickness measuring procedure. By identifying the chatter on a rolling mill it is possible to correct the cause of the chatter, and to identify the location of chatter within a coil of steel. On finishing lines the chatter can be cut out, or identified within the coil.
In conventional thickness gauges the thickness signals are integrated or filtered to improve the precision of the measurement. This smooths out the signal and destroys the chatter information. The present invention analyzes the signal prior to this integration and provides an output signal which identifies the presence of cyclical thickness variations such as chatter. The invention also provides means for identifying the amplitude and frequency of the chatter, and for calculating the spatial "wavelength" of the chatter. Such devices are not presently available, and the present invention represents a new type of instrumentation for on-line analysis of chatter.
While the example given above and the specific embodiments disclosed herein are for measurement of steel strip using a non-contacting nuclear thickness gauge, many other applications are possible using other non-contacting or contacting gauges, materials other than steel and properties other than thickness. The chatter detector is applicable to any continuous process in which there are high frequency signal variations. A very different example is measurement of optical density of liquids flowing through a pipeline.

Chatter detection in thickness measuring gauges and the like