Systems and methods for voltage compensation based on load conditions in power converters. For example, a system controller for regulating a power converter includes a first controller terminal; a second controller terminal; and a compensation current generator. The compensation current generator is configured to receive an input signal through the first controller terminal. The input signal indicates a first current flowing through a primary winding of a power converter. The compensation current generator is configured to receive a demagnetization signal related to a demagnetization period of the power converter and associated with an auxiliary winding of the power converter. The compensation current generator is configured to generate a compensation current based at least in part on the input signal and the demagnetization signal. The compensation current generator is connected to a resistor. The resistor is configured to generate a compensation voltage based at least in part on the compensation current.

Certain embodiments of the present invention are directed to integrated circuits. More particularly, some embodiments of the invention provide systems and methods for voltage compensation based on load conditions in power converters. Merely by way of example, some embodiments of the invention have been applied to flyback power converters. But it would be recognized that the invention has a much broader range of applicability.
In recent years, with the development of integrated circuit and information technology, a variety of battery-powered portable electronic devices, such as mobile phones, digital cameras, and notebook computers, became increasingly popular. These battery-powered portable electronic devices raise the need for high-performance power-management chips with low cost, high efficiency and good transient characteristics.
Flyback power converters have been used extensively for its simple structure and low cost in low-power power supplies. But in conventional flyback power converters, the output-voltage regulation is often performed with secondary-side feedback, using an isolated arrangement of opto-coupler and shunt regulator (e.g., TL431). Such arrangement usually increases the system cost, size, and power consumption.
To reduce the system cost and size of the flyback power converter, converters that employ primary-side regulation have become popular for certain applications. In primary-side regulation, the output voltage is sensed by detecting the voltage of the auxiliary winding that is tightly coupled to the secondary winding. Since the voltage of the auxiliary winding should image the output voltage associated with the secondary winding, the detected voltage can be utilized to regulate the secondary-side output voltage. Hence, the expensive parts of opto-coupler and shunt regulator (e.g., TL431) often are no longer needed in order to save system cost and size.
FIG. 1 is a simplified diagram of a conventional flyback power converter with primary-side regulation (PSR). The power converter 100 includes a system controller 102, a rectifying component 104 (e.g., a bridge rectifier), a primary winding 106 (e.g., Np), a secondary winding 108 (e.g., Ns), a power switch 110 (e.g., M1), a rectifying diode 112 (e.g., D1), two capacitors 114 and 116 (e.g., C0 and C1), three resistors 118, 120 and 122 (e.g., R1, R2 and R3), a current sensing resistor 124 (e.g., RCS), and an auxiliary winding 126. The system controller 102 includes a constant current (CC) control component 128, a constant voltage (CV) control component 130, a load compensation component 132, and a drive and modulation component 134. The system controller 102 further includes five terminals 136, 138, 140, 142 and 144. For example, the power switch 110 is a field-effect transistor (FET), a bipolar junction transistor (BJT), or an insulated-gate bipolar transistor (IGBT). In one example, the system controller 102, including components 128, 130, 132 and 134, is located on a chip. For example, the terminals 136, 138, 140, 142 and 144 are pins of the chip.
As shown in FIG. 1, a system controller 102 is used to control and drive the power switch 110 (e.g., M1, a power MOSFET), which turns on and off to control (e.g., regulate) the output voltage and/or output current delivered to the load 146 on the secondary side of the power converter 100. An alternating-current (AC) input voltage 148 is applied to the power converter 100. The rectifying component 104 outputs a bulk voltage 150 (e.g., a rectified voltage no smaller than 0 V) associated with the AC input voltage 148. The capacitor 116 (e.g., C1) is charged in response to the bulk voltage 150 through the resistor 118 (e.g., R1), and a voltage 152 is provided to the controller 102 at the terminal 136 (e.g., terminal VCC). If the voltage 152 is larger than a threshold voltage (e.g., an under-voltage lock-out threshold) in magnitude, the controller 102 begins to operate, and a voltage associated with the terminal 136 (e.g., terminal VCC) is clamped to a predetermined voltage.
In addition, the terminal 138 (e.g., terminal GATE) is connected to a gate terminal of the power switch 110 (e.g., M1). The controller 102 outputs a drive signal 154 (e.g., a pulse-width-modulation signal) with a certain frequency and a certain duty cycle to close (e.g., turn on) or open (e.g., turn off) the power switch 110 so that the power converter 100 operates normally.
For example, if power switch 110 is closed, the power converter 100 stores the energy associated with AC input voltage 148. In another example, if the power switch 110 is opened, the stored energy is delivered to the secondary side of the power converter 100 via the transformer including the primary winding 106 and the secondary winding 108. The output voltage 156 (e.g., Vout) is mapped to the feedback voltage 158 (e.g., VFB) through the auxiliary winding 126 and by resistors 120 and 122 (e.g., R2 and R3), and received by the controller 102 at terminal 144 (e.g., terminal FB). In this way, the controller on the primary side receives information about the output voltage and demagnetization of the power converter that can be used to regulate the output voltage, and, in turn, achieve constant voltage (CV) and/or constant current (CC) output.
Referring to FIG. 1, the feedback voltage 158 (e.g., VFB) of the power converter 100 can be determined as follows:
                              V          FB                =                                                            R                2                                                              R                  2                                +                                  R                  3                                                                                V              aux                                =                                                    R                2                                                              R                  2                                +                                  R                  3                                                                                (                                                V                  out                                +                                  V                  d                                            )                        ×                                          n                a                                            n                s                                                                        (                  Equation                                                              1                )            where Vaux represents the voltage of the auxiliary winding 126 during a demagnetization period of the power converter 100, R2 represents the resistance of resistor 120, R3 represents the resistance of resistor 122, Vout represents the output voltage 156, Vd represents the voltage drop across the diode 112 (e.g., D1), na represents the number of turns of the auxiliary winding 126, and ns represents the number of turns of the secondary winding 108.
Based on Equation 1, the relationship between VFB and Vout can be determined as follows:
                              V          out                =                                                                              R                  2                                +                                  R                  3                                                            R                2                                                                V              FB                        ×                                          n                s                                            n                a                                              -                      V            d                                              (                  Equation                                                              2                )
Hence, the output voltage 156 can be regulated through the regulation of the voltage of the auxiliary winding 126. Since VFB is an image of the output voltage Vout, the output voltage is proportional to VFB. Under certain conditions, the output voltage 156 is regulated at a constant level, if the feedback voltage VFB and voltage Vd across diode 112 (e.g., D1) are kept constant by the controller 102. However, for a given diode, the voltage Vd is current dependent, and therefore Vd changes if the load current Iload changes.
Moreover, the output cable line 160 generates a voltage drop that is proportional to the load current Iload. This voltage drop causes the load voltage Vload received by the load 146 to decrease if the load current Iload increases. Assuming the resistance of the output cable line is Rcable, the load voltage Vload at an equipment terminal 162 can be determined as follows:
                              V          load                =                                            V              out                        -                                          R                cable                            ×                              I                load                                              =                                                                                R                    2                                    +                                      R                    3                                                                    R                  2                                                                          V                FB                            ×                                                n                  s                                                  n                  a                                                      -                          V              d                        -                                          R                cable                            ×                              I                load                                                                        (                  Equation                                                              3                )
On one hand, different magnitudes of the load current result in different voltage drops across the diode 112 and the output cable line 160, and, thus, the load voltage Vload is not constant at different load current levels. Rather, based on Equation 3, the load voltage Vload decreases as the load current ILoad increases. Hence, at a default-load condition (e.g., the load current and/or load voltage being within a predetermined operating range of the power converter) or a high-load condition, the power converter 100 exhibits poor load-voltage regulation due to the voltage drop across the diode 112 and/or the output cable line 160.
On the other hand, the controller 102 is powered via the auxiliary winding 126 through the voltage 152 provided to the controller 102 at the terminal 136 (e.g., terminal VCC). Hence, the controller also represents a load of the system. If the load current is small or there is no load connected to the equipment terminal 162 of the system, the current drawn by the controller 102 is not negligible. In this case, the secondary winding 108 and the auxiliary winding 126 exhibit cross regulation that results in the controller 102 being unable to regulate the load voltage Vload. Thus, if the system is at a light-load or no load, the load voltage Vload becomes uncontrollably high due to cross regulation.
Hence it is highly desirable to improve the techniques of power converters.

On-Bright Electronics (Shanghai) Co., Ltd.


A new and improved test device and method of determining the presence or concentration of a peroxidatively active substance, such as hemoglobin, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with a peroxidatively active substance to produce a detectable or measurable response. In addition, a new and improved indicator reagent composition, comprising an indicator dye, such as a redox indicator, like a benzidine indicator; a hydroperoxide; a metal ion complex; and a phosphorous compound having the general structural formula ##STR1## wherein R.sub.1 or R.sub.2 is selected from the group consisting of hydrogen, an unsubstituted or a substituted alkyl moiety including from one to about twelve carbon atoms, an unsubstituted or a substituted aromatic moiety and a residue of an aliphatic or an aromatic polyhydric compound; and wherein X is 0, S or NH; such as glyceryl-2-phosphate or phenyl dihydrogen phosphate, is incorporated into a carrier matrix, or used in a wet phase assay, to provide a more accurate and trustworthy assay of a test sample for a peroxidatively active substance. The improved method and composition are especially useful in the assay of urine for occult blood.

Peroxidase is an enzyme that catalyzes the oxidation of various compounds, such as phenols and amines, by peroxides. In addition, particular compounds have been termed pseudoperoxidases because these compounds behave in a manner similar to the peroxidase enzyme. Accordingly, pseudoperoxides liberate oxygen from hydroperoxides and transfer the oxygen to certain acceptor compounds. Therefore, in general, the pseudoperoxidases are enzyme-like in that they catalyze, or otherwise participate in, reactions between peroxides and oxidizable compounds. The pseudoperoxidases also are termed peroxidatively active substances, and include hemoglobin and its derivatives.
For example, in the assay of urine for glucose, glucose oxidase, in the presence of oxygen, first converts the glucose in the urine to gluconic acid and hydrogen peroxide. Then, the peroxidase enzyme, also present in the assay, catalyzes the interaction between the hydrogen peroxide and an oxidizable dye compound, like o-tolidine. The dye compound, usually essentially colorless in its reduced state, undergoes a color transition upon oxidation, such as to a blue color for o-tolidine, by the peroxidase-catalyzed interaction with hydrogen peroxide. The degree and intensity of the color transition are directly proportional to the amount of hydrogen peroxide generated by the glucose conversion. Then, the amount of hydrogen peroxide generated by the glucose conversion is correlated to the original concentration of glucose in the urine sample.
Similarly, a peroxidatively active substance, like hemoglobin and its derivatives, catalyzes the interaction between a hydroperoxide and an oxidizable dye. In such interactions, the peroxidatively active substance imitates the peroxidase enzyme and catalyzes or otherwise participates in an interaction between the oxidizable dye and the hydroperoxide. The oxygen liberated from a hydroperoxide by a peroxidatively active substance is transferred to an oxidizable dye. The resulting interaction provides a detectable response, such as a color transition, wherein the intensity of the response is indicative of the presence or the concentration of the peroxidatively active substance.
Assays for a peroxidatively active substance are based upon the above-described chromogenic interaction, wherein the degree and intensity of the color transition of the indicator dye are correlated to the concentration of the peroxidatively active substance in the test sample. Assays for a peroxidatively active substance are particularly useful in detecting and measuring low concentrations of blood, often termed "occult" blood, in body fluid samples such as urine, feces or gastrointestinal contents. Although occult blood in urine, feces or vomit usually is not visible to the naked eye, the detection of occult blood is important in the diagnosis of hemorrhages in the stomach, intestines and urinary tract. The hemorrhages are caused, for example, by tumors, ulcers or inflammations of the organ in question. Presently, most methods of determining the presence of occult blood in a test sample are based upon the pseudoperoxidase activity of hemoglobin or myoglobin.
Although protein in urine is the most important indicator of a renal dysfunction, the presence of blood in urine also is an indication of damage to the kidney or urinary tract. Normally, detectable amounts of occult blood are not present in urine, even with very sensitive chemical methods. Blood in the urine can appear as intact red blood cells or as free hemoglobin. Usually the presence of free hemoglobin indicates that the blood cells have ruptured either because of a traumatic passage through the kidney and urinary tract to the bladder, or because the blood cells have been exposed to dilute urine in the bladder that caused the cells to hemolyze.
More particularly, the presence of blood in urine or feces is a symptom of a variety of abnormal conditions, including cancer. The presence of blood in urine, as indicated by a positive test for occult blood, often indicates bleeding in the urinary tract. Free hemoglobin is present in the urine because of renal disorders, infectious diseases, neoplasms, or traumas affecting part of the urinary tract. Free hemoglobin in the urine also can indicate a transfusion reaction, hemolytic anemia, or paroxysmal hemoglobinuria, or can appear from various poisonings or following severe burns. In addition, a positive chemical test for hemoglobin, without the presence of red cells, can indicate myoglobinuria as a result of traumatic muscle injury.
Hemoglobinuria is defined as the presence of free hemoglobin in the urine without red blood cells. In contrast, hematuria is defined as the presence of intact red blood cells in urine. Hematuria is indicative of a specific defect in the microscopic functional unit (the nephron) of the kidney or it is indicative of bleeding in the kidney, the ureter, the bladder or the urethra. The free hemoglobin in the plasma is excreted by the kidney into the urine. In some situations, hemolysis of the red blood cells occurs after the cells have entered the urine. Most urine samples containing red blood cells also contain some hemolyzed occult blood. Presently, the differentiation of trace amounts of blood as cells versus free hemoglobin is of little significance.
Myoglobin, the red respiratory pigment of muscle tissue, is another peroxidatively active substance. Myoglobin is very similar to hemoglobin in its composition and chemical reactions. Myoglobin can be liberated from muscle cells by certain types of injury, and in such cases the myoglobin will circulate in the plasma, and then be excreted in the urine. In addition, certain genetic muscle disorders can cause the muscles to lose myoglobin that subsequently appears in the urine. Myoglobin also is found in the urine after a cardiac infarct.
Hematuria, hemoglobinuria or myoglobinuria depends upon the precise nature of the clinical and pathological disorder and upon the severity of the specific disease or injury. In addition, other peroxidatively active substances also are present in leukocytes and bacteria. Overall, the detection of a peroxidatively active substance is especially important in the diagnosis of diseases and infections of the kidneys and urinary tract.
Therefore, accurate and thorough assays of urine and other test samples for peroxidatively active substances must be available for both laboratory and home use. The assays must permit the detection and measurement of the peroxidatively active substance such that a correct diagnosis can be made and correct medical treatment implemented, monitored and maintained. In addition, it would be advantageous if the assay method could be utilized in a dip-and-read format for the easy and economical, qualitative or quantitative determination of a peroxidatively active substance in urine or other test samples.
Furthermore, any method of assaying for a peroxidatively active substance in urine or other test sample must yield accurate, trustworthy and reproducible results by utilizing an indicator reagent composition that undergoes a color transition as a result of an interaction with a peroxidatively active substance, and not as a result of a competing chemical or physical interaction, such as a preferential interaction with a test sample component other than a peroxidatively active substance or a color transition occurring due to the instability of the indicator reagent composition. Moreover, it would be advantageous if the assay method for a peroxidatively active substance is suitable for use both in wet phase assays and in dry phase reagent strips for the rapid, economical and accurate determination of a peroxidatively active substance in urine or other test sample. Additionally, the method and composition utilized in the assay for a peroxidatively datively active substance should not adversely affect or interfere with the other test reagent pads that are present on multideterminant reagent strips.
Therefore, in order to determine if an individual is excreting a peroxidatively active substance, and in order to monitor the course of medical treatment to determine the effectiveness of the treatment, simple, accurate and inexpensive detection assays for a peroxidatively active substance, like occult blood, have been developed. Furthermore, of the several different assay methods developed for the detection or measurement of occult blood in urine, the methods based on dip-and-read dry phase test strips have proven especially useful because dry phase test strip methods are readily automated and provide reproducible and accurate results.
Some test strips used in assays for peroxidatively active substances have a single test area consisting of a small square pad of a suitable carrier matrix impregnated with an indicator reagent composition comprising an indicator dye, such as a benzidine dye; a hydroperoxide; and a buffer. Other test strips are multideterminant reagent strips that include one test area for the assay of a peroxidatively active substance as described above, and further include several additional test areas on the same strip to permit the simultaneous assay of other urinary constituents. For both types of colorimetric test strips, the assay for a peroxidatively active substance in urine is performed simply by dipping the colorimetric test strip into a well mixed, uncentrifuged urine sample, then comparing the resulting color of the test area of the test strip to a standardized color chart provided on the colorimetric test strip bottle. Occult blood tests usually are included on multideterminant reagent strips to screen urine samples during routine physical examinations because it is important to detect a bleeding condition early.
The test strip method is the simplest and most direct assay for the presence of blood in urine. The test area is impregnated with an oxidizable indicator dye, like tetramethylbenzidine, and buffered hydroperoxide. The test area becomes a green to dark blue color when hemoglobin present in the urine sample catalyzes the oxidation reaction of tetramethylbenzidine by the hydroperoxide. The development of green spots on the test area indicates intact, nonhemolyzed erythrocytes. In accordance with the above-described method, an individual can readily determine, visually, the concentration of a peroxidatively active substance in a urine sample. The color of the test strip is compared with a color chart approximately 1 minute after the test strip is dipped into the urine. The color blocks on the color chart indicate negative, nonhemolyzed trace, hemolyzed trace, small (1+), moderate (2+), and large (3+) amounts of blood. The color chart ranges from orange through green to blue. The assay usually is capable of detecting from about 0.015 to about 0.06 mg/dL (milligrams per deciliter) of free hemoglobin or from about 5 to about 20 intact red blood cells per microliter.
In addition, ascorbate ion, when present, seriously interferes in the above-described assay method for a peroxidatively active compound. It has been found that including certain metal ion complexes in the indicator reagent composition essentially eliminates the ascorbate inferference problem. However, in general, the metal ion complexes also demonstrate peroxidase activity, and behave similarly to peroxidase or the pseudoperoxidases to catalyze the color-forming reaction between a hydroperoxide and an oxidizable dye. Accordingly, although the metal ion complexes eliminate ascorbate interference, the metal ion complexes also can produce false positive assays because the metal ion complexes can catalyze oxidation of the oxidizable dye by the hydroperoxide, thereby producing a color change in the device even though a peroxidatively active substance is not present in the test sample. Furthermore, if a peroxidatively active substance is present in the test sample, erroneously high assay results can occur because of additional dye oxidation mediated by the metal ion complex.
As will be discussed more fully hereinafter, investigators have found that particular ferric ion complexes substantially reduced the false positive and the erroneously high assay results attributed to most metal ion complexes used to eliminate ascorbate interference. However, although the ferric ion complexes effectively eliminated ascorbate interferences and demonstrated a substantially reduced peroxidative activity, the problem of premature oxidation of the oxidizable indicator dye was not completely eliminated. For example, dry phase test strips including a ferric ion complex, a hydroperoxide and an oxidizable indicator dye still demonstrated a color transition after extended storage, or yielded false positive assay results for test samples absent a peroxidatively active substance.
Therefore, it would be extremely advantageous to have a simple, accurate and trustworthy method of assaying urine for low levels of a peroxidatively active substance. Present day test strips for peroxidatively active substances have the disadvantage of premature oxidation of the indicator dye thereby providing false positive assays. Surprisingly and unexpectedly, the composition and method of the present invention essentially eliminate the premature oxidation of the indicator dye, and therefore solve the problem of false positive assays, while still permitting the presence of a compound, like a metal ion complex, to eliminate ascorbate interference. By providing a more accurate method of determining the concentration of a peroxidatively active substance in urine, in an easy to use form, such as a dip-and-read test strip, the urine assay can be performed by laboratory personnel to afford immediate and trustworthy test results. In addition, the test strip method can be performed by the patient at home to more precisely monitor the level of peroxidatively active compounds in urine and/or the success of the medical treatment the patient is undergoing.
As will be described more fully hereinafter, the method of the present invention allows the fast, accurate and trustworthy assay for a peroxidatively active substance by utilizing a test strip that includes a test pad comprising a suitable carrier matrix impregnated with an indicator reagent composition of the present invention. The indicator reagent composition comprises an indicator dye, a hydroperoxide, a metal ion complex and a phosphorus compound including at least two free acid functionalities. The indicator reagent composition is sensitive to low concentrations of a peroxidatively active substance, eliminates ascorbic acid interference with the assay and, surprisingly and unexpectedly, essentially eliminates the premature oxidation of the indicator dye by the metal ion complex and the hydroperoxide that leads to false positive assays. Accordingly, the improved stability of the indicator reagent composition enhances the sensitivity of the assay, thereby providing a more accurate and trustworthy assay for a peroxidatively active substance.
Prior to the present invention, no known method of assaying urine or other test samples for peroxidatively active substances included an indicator reagent composition comprising an indicator dye; a hydroperoxide; a metal ion complex to eliminate ascorbate interference; and a phosphorus compound including at least two free acid functionalities that stabilizes the indicator reagent composition and essentially eliminates the premature oxidation of the indicator dye by the metal ion complex and the hydroperoxide. Consequently, the improved stability of the indicator reagent composition increases the sensitivity of the assay such that accurate and trustworthy assays for peroxidatively active compound are achieved. Although a dry phase test strip including an oxidizable indicator dye, such as o-tolidine or 3,3',5,5'-tetramethylbenzidine; a ferric ion complex; and a hydroperoxide has been used previously, dry phase test strips incorporating these three compounds demonstrated a tendency to prematurely undergo a color transition due to oxidation of the indicator dye. Accordingly, the false positive assay decreased the utility and the sensitivity of the test strip to the peroxidatively active substance in the test sample.
The prior art contains numerous references on the wet phase chemistry and the dry phase chemistry utilized in assaying urine for a peroxidatively active substance. For example, investigators developed wet chemistry assay procedures and dry phase test strip devices for peroxidatively active substances that rely on the enzyme-like catalysis of the peroxidative oxidation of indicator dyes. An example of a wet chemistry assay for a peroxidatively active substance is presented in R. M. Henry, et al., Clinical Chemistry Principles and Techniques, 2nd ed., Harper and Row, pp. 1124-1125 (1974). This wet phase assay procedure employs glacial acetic acid as a buffer, diphenylamine as an indicator dye and hydrogen peroxide. Although such wet phase assays are analytically useful, they nevertheless possess severe disadvantages, including poor reagent stability and inadequate analyte sensitivity. For instance, the reagent solutions used in the wet phase assays rapidly decline in stability, and consequently in sensitivity. Therefore, fresh reagent solutions must be prepared after a few days of storage. The continuous preparation of fresh reagent solutions is time-consuming and uneconomical because costly reagents are wasted.
The preferred method of assaying for a peroxidatively active substance utilizes a dry phase test strip device. A typical dry phase test strip is commercially available from the Diagnostics Division of Miles, Inc. under the trademark HEMASTIX.RTM.. The test strip comprises a test pad, including a porous carrier matrix, such as a paper matrix, impregnated with a buffered mixture of an organic hydroperoxide and an indicator dye, affixed to a plastic strip or handle. The test pad is immersed in a test sample containing hemoglobin, myoglobin, erythrocytes or another peroxidatively active substance, and the test pad develops a blue color. The intensity of the blue color is proportional to the concentration of the peroxidatively active substance in the test sample. By comparing the color developed in the test pad to a standardized color chart, the analyst can determine, quantitatively, the amount of peroxidatively active substance present in the test sample.
In general, dry phase test strips are more advantageous than the wet phase assays because the test strip format is easier to use, requiring neither the continual preparation of reagents nor the attendant apparatus. In addition, reagent stability is greater in the test strip, thereby resulting in improved assay accuracy, sensitivity and economy. Notwithstanding that present day test strips for determining peroxidatively active substances are substantially more stable and more sensitive than wet phase assays, present day test strips need improvement in the areas of stability and sensitivity. Therefore, it would be a significant advance in the art of diagnostic assays if test strips were even more stable during storage and even more sensitive to peroxidatively active substances. It was towards achieving these improvements that the investigations resulting in the composition, device and method of the present invention were directed.
Several attempts at achieving the above-mentioned goals of increased stability and sensitivity are found in the prior art. For example, in Chemical Abstracts, Vol. 85, p. 186 (1976), a two-dip method of preparing a dry phase test strip containing o-tolidine and phenylisopropyl hydroperoxide is described. In this method, filter paper strips impregnated with ethyl cellulose were dipped into an ethanolic solution comprising an indicator, o-tolidine hydrochloride; polyvinylpyrrolidone; a surfactant; and sufficient citrate buffer to provide a pH of 3.7. The impregnated filter paper then was dried, and subsequently was dipped into a second solution containing 1,4-diazobicyclo[2.2.2]octane, phenylisopropyl hydroperoxide and polyvinylpyrrolidone dissolved in an ethanol-toluene mixture. The investigators desired to stabilize the hydroperoxide and indicator with the bicyclooctane compound and the polyvinylpyrrolidone.
Another test strip and method are disclosed in U.S. Pat. No. 3,853,471 to Rittersdorf et al. Rittersdorf described the use of phosphoric acid amides or phosphonic acid amides to stabilize test strips used to assay for peroxidatively active substances. The phosphoric or phosphonic acid amides disclosed by Rittersdorf are triamides and diamides, wherein the substituent amido groups are primarily N-morpholine moieties, and wherein no free acid functionalities remain on the phosphoric or phosphonic acid amide.
Adams et al, in U.S. Pat. No. 3,252,762, disclosed physically encapsulating an organic hydroperoxide within a colloidal material, such as gelatin, to stabilize the test strip. Accordingly, when an aqueous test sample contacts the test strip, the gelatin capsules dissolve, thereby freeing the hydroperoxide for a peroxidatively active substance mediated interaction with an indicator dye. However, the encapsulation process of Adams is time-consuming and requires relatively expensive apparatus and excessive manipulative steps. Each of these prior art disclosures was directed at stabilizing the reagents incorporated into the test pad of the test strip such that the potentially incompatible reagent ingredients, i.e., the hydroperoxide and the indicator dye, would not prematurely interact, and thereby provide a false positive test or render the test strip less sensitive to a peroxidatively active substance.
U.S. Pat. No. 3,975,161 disclosed a test strip comprising a bibulous carrier impregnated with a composition containing an organic hydroperoxide, an acid buffer, a chromogen, a wetting agent, a solid film-forming natural or synthetic polymeric substance and an accelerator. The accelerator is isoquinoline or an isoquinoline derivative. The acid salts or adducts of quinoline and quinoline derivatives also have been described in U.S. Pat. No. 3,986,833 as potentiating agents in reagent compositions for the detection of peroxidatively active substances.
Ku, in U.S. Pat. No. 3,411,887, described the elimination of ascorbate interference with reagent compositions that rely on enzymatic oxidizing substances, such as glucose oxidase, by using an ascorbate "trapping system". The "trapping system" utilizes a heavy metal ion that has an oxidation-reduction potential falling between a redox indicator dye and ascorbate. Suitable heavy metal compounds cited as examples include cobalt, iron, mercury and nickel.
In addition to the disclosure of Ku, the prior art also discloses that metal ions, such as Co(III), are actually pseudoperoxidases. For example, The Merck Index, 9th ed., p. 311 (1976) discloses that Co(III) acetate is used commercially to catalytically decompose cumene hydroperoxide. In addition, a series of Co(III) complexes to catalytically decompose peroxides are reported by K. Lohs, Monatsber. Deut. Akad. Wiss. Berlin, 8, pp. 657-659 (1966). Accordingly, one skilled in the art is taught that using such a metal ion complex in a typical indicator reagent composition for the determination of a peroxidatively active substance would cause a deleterious interaction between the hydroperoxide and the indicator either to produce false positive results or to otherwise render the composition unreactive to the peroxidatively active substance of interest, such as occult blood. In fact, efforts to use mercuric complexes, such as mercuric sarcosinate, in occult blood tests failed.
U.S. Pat. No. 4,587,220, to Mayambala-Mwanika et al., disclosed the use of a chelated ferric ion to eliminate ascorbic acid and ascorbate ion interference in an assay for a perioxidatively active substance. Mayambala-Mwanika disclosed that a ferric chelate, like the ferric chelate of N-(2-hydroxyethyl)ethylenediaminetriacetic acid (Fe-HEDTA), eliminated ascorbate interference and did not produce a false positive test for the peroxidatively active compound. In accordance with the method of Mayambala-Mwanika, a test device for a peroxidatively active substance is prepared by first incorporating the ferric chelate and hydroperoxide into the carrier matrix of the test pad. Then, after drying, the indicator dye is incorporated into the carrier matrix. This two-step method of preparing the test device provided an ascorbate resistant test pad that also demonstrated a sufficient stability to resist a false positive assay result during storage.
Ismail et al., in U.S. Pat. No. 4,755,472, disclosed a stable test pad to assay for a peroxidatively active substance that includes a carrier matrix impregnated with 1,4-diisopropylbenzene dihydroperoxide and a benzidine indicator in a molar ratio of hydroperoxide to indicator of from about 0.9 to 3.0. A ferric chelate also can be included to provide ascorbate resistance. The test pad was stable during storage and does not lead to false positive tests on other test pads present on a multideterminant test strip, such as a glucose test pad based on a peroxidase/potassium iodide indicator.
Lam, in U.S. Pat. No. 4,071,318, disclosed a composition for determining a peroxidatively active substance comprising a hydroperoxide, an indicator dye, and a bicyclic borate ester. Lam theorized that the bicyclic borate ester complexed with the hydroperoxide, thereby precluding the hydroperoxide from interacting with the indicator dye during storage. The improved stability of the composition accordingly provided more accurate assays for a peroxidatively active substance by reducing the premature oxidation of the indicator dye.
In contrast to the prior art, and in contrast to the presently available commercial test strips, the composition of the present invention imparts increased stability to the test strip, and therefore increased sensitivity of the test strip, in the detection and measurement of a peroxidatively active substance in a test sample. The method of the present invention utilizes an indicator reagent composition that effectively resists oxidation of the indicator dye until the indicator dye contacts a test sample containing a peroxidatively active substance. Surprisingly and unexpectedly, the method and composition of the present invention essentially eliminate color formation, or other detectable responses, attributable to a premature indicator dye oxidation by the metal ion complex and the hydroperoxides. Hence, in accordance with the method of the present invention, new and unexpected results are achieved in the dry phase test strip assay, and the wet phase assay, of urine and other test samples for a peroxidatively active substance by utilizing an oxidation resistant indicator reagent composition.

Composition, device and method of assaying for peroxidatively active substances


An acoustic gas analyzer for gas mixture has an acoustic velocity meter that provides a first output dependent on a detected transmission of acoustic energy through a gas to be analyzed, a temperature probe having a probe time constant that provides a second output indicative of a measured temperature of the gas, and a calculation unit that receives the first and the second outputs and determines compositional information of the gas therefrom. A signal processor is connected between the acoustic velocity meter and the calculation unit and temporally adapts the amplitude of the first output from the meter in a manner dependent on the probe time constant and provides a temporally adapted first output for use as the first output within the calculation unit.

1. Field of the Invention
The present invention relates to an acoustic gas analyzer.
2. Description of the Prior Art
In medical and clinical settings it is useful to be able to measure accurately the composition of respiratory (inspiration and/or expiration) gases or changes therein since such measurements can provide, for example, valuable information on patient metabolic conditions. This is particularly the case during the provision of mechanical respiratory aid to a patient where knowledge of the relative and absolute amounts of oxygen and carbon dioxide within the expiration gas may be used to provide information on the metabolization of oxygen as well as respiratory function. Moreover, knowledge of the oxygen/nitrogen ratio in an inspiration gas is useful for controlling or monitoring the provision of respiratory aid using a mechanical breathing aid such as a ventilator, respirator or anesthetic machine.
Gas analyzers are known, for example from WO 92/03724 and from U.S. Pat. No. 5,247,826, for acoustically analyzing the ratios of a mixture of gases comprising two known gases, such as the oxygen/nitrogen ratio in a breathing gas to be supplied to a patient by a mechanical breathing aid. The oxygen concentration or changes therein can then be determined. The known analyzers utilize the physical phenomenon that acoustic waves travel with different velocities through different gases. It is well known that the acoustic velocity, Vg, within a gas mixture can be described by an equation of the form:Vg=√{square root over (CP*R*Tg/M*Cv)}  (1)
CP and Cv are the specific heat capacities of the gas mixture at constant pressure and volume respectively; M is the molecular weight of the gas mixture; R is the universal gas constant; and Tg is its absolute temperature. Thus for a gas mixture at a known temperature, Tg, the acoustic velocity, Vg, in the mixture can be used to provide a measure of the relative concentrations of the constituents of the gas.
In general, the known acoustic gas analyzer has an ultrasonic velocity meter with a transducer arrangement that to transmits ultrasound energy along an acoustic path through a gas mixture to be analyzed within a measurement cell or a section of a flow conduit containing the flowing gas mixture and to receive the transmitted energy, a temperature probe disposed to monitor the gas temperature at a point within the cell or section and a calculator for calculating the acoustic velocity Vg of the ultrasound from signals received from the velocity meter and for employing this velocity together with the temperature reading from the probe, in a determination of compositional information for the analyzed gas mixture based on equation (1) above.
In order to determine the instantaneous composition of the gas mixture it is therefore necessary to know simultaneously the temperature of the gas and the acoustic velocity in the gas. It is often the case, however, that the time constant of the temperature probe is long compared with that of the ultrasonic transducer arrangement. The temperature probe may then provide a time-delayed picture of the actual temperature within the gas. This is particularly true where the gas undergoes temperature changes that are more rapid than the time constant of the temperature probe. A simultaneous measurement of the acoustic velocity and the temperature therefore can produce a small temperature error which will result in incorrect compositional information being determined. This can be a problem when the analyzer is employed in the determination of respiratory gas compositional information, since rapid gas pressure changes that normally occur within a ventilator system will result in temperature changes that may be faster than the time constant of the temperature probe.


A programming tool for providing a graphical representation of the relationships among a plurality of nested blocks integrated into a processed "C" source code listing is disclosed. For each line of code including a "{" character, an outbound arrow is appended. Similarly, for each line of code including a "}" character, an inbound arrow is appended, and the inbound and outbound arrows are tabbed into vertical alignment. A "depth number" is developed for each line now having arrows by performing an increment when a line having an outbound arrow is encountered and a decrement for the starting depth number value of the next line when a given line having an inbound arrow is encountered. The depth numbers, and also one or more (as indicated by the depth number for a given line) right justified vertical line segments, are appended to the lines having outbound or inbound arrows. Intermediate lines have appended the same number of vertical line segments as the last arrowed line if it was outbound or one less than the last arrowed line if it was inbound. Then, horizontal line segment characters are entered in the spaces between the depth number and the leftmost vertical line segment in a given line having an outbound or inbound arrow.

As notoriously well known to those skilled in the art of computer programming, it is difficult to follow the structure and flow of a program from a study of the source code listing. Even in a review of one's own work, difficulties may be encountered if the program was written in the past such that its "philosophy" is not fresh in mind. But, it is particularly difficult to undertake the study of a source code listing of a program written partly or wholly by another person or persons since each programmer has his or her own style and thought process in writing programs. Further, it is a perhaps unfortunate fact that (because of productivity demands or even because of poor discipline) programs are no longer routinely subject to higher level documentation, such as by the preparation of detailed flow charts; consequently, the difficulty of following one's own program, let alone the work of others, is additionally aggravated.
One highly regarded programming language in wide use among both professional and amateur programmers is "C". Well written "C" programs often frequently employ code blocks which may be "nested" to several levels, or nested blocks of the source code listing, and it is troublesome, when examining a source code listing which may have been prepared in the past or by others, to determine the beginnings and ends of the code blocks and the levels of nesting. Those skilled in the art will appreciate that it would be highly desirable to provide, in a "C" source code listing, annotations which will assist the peruser of such in following the code blocking and nesting structure of the listed program, and it is to these ends that my invention is directed.


The invention relates to a device for processing objects, said device being provided with a number of stations comprising supporting means for supporting objects in said stations, and with conveying means, by which the objects can be moved from one station to another station. A transport means, which is capable of rotating movement about a vertical axis of rotation and translating movement parallel to said axis of rotation, is fitted with gripping means for gripping and moving the objects between the various stations. The transport means is supported by at least three spaced-apart carriers, which are in turn supported by sliding pieces, which are journalled in such manner as to be capable of sliding movement in vertical direction. Two hinged-together links are provided between a sliding piece and the frame, one being hinged to the sliding piece, the other being hinged to the frame and both being hinged to a connecting rod which is movable in a plane extending transversely to the axis of rotation. The links are capable of pivoting movement between a position in which the two links include an angle with each other and a position in which the two links are at least substantially in line with said sliding piece.

1. Field of the Invention
The invention relates to a device for processing objects, said device being provided with a number of stations comprising supporting means for supporting objects in said stations, and with conveying means, by which the objects can be moved from one station to another station, whereby said conveying means are provided with a transport means being capable of rotating movement about a vertical axis of rotation and translating movement parallel to said axis of rotation, which transport means is fitted with gripping means for gripping and moving the objects between the various stations, and with driving means, by which said transport means can be reciprocated about its axis of rotation and be translated parallel to said axis of rotation so as to move said gripping means between said stations.
2. Description of the Prior Art
In such a device known from DE-A-37.09.354 the transport means is moved parallel to the axis of rotation by means of a piston which is movable in a cylinder. Since the axis of the cylinder coincides with the axis of rotation of the conveyor, the transport means can be tilted about a line extending transversely to the axis of rotation in a relatively simple manner. The consequence of such tilting is that the positioning accuracy of the transport means in the direction parallel to the axis of rotation is relatively small.
A device of this type is also known from U.S. Pat. No. 5,411,588. The contents of said U.S. Pat. No. 5,411,588 are considered to be incorporated herein by this reference and consequently it is not considered necessary to give a full description of the construction and operation of such a device herein.
As is set forth in said U.S. Pat. No. 5,411,588, the mechanism for reciprocating the transport means fitted with gripping means in horizontal and vertical direction comprises a cam mechanism, as well as three annular means, fitted with a wave-shaped guideway and followers cooperating therewith. In practice it has become apparent that this known construction is satisfactory per se, but that in some cases the fact that this known construction is comparatively heavy and that the various parts may take up a comparatively great amount of space in the device may constitute a drawback.
The object of the invention is to obtain a device of the above kind, which makes it possible to meet the above-described drawbacks when being used.
According to a first aspect of the invention this may be achieved in that said transport means is supported by at least three spaced-apart carriers in such manner as to be rotatable about its vertical axis of rotation, said carriers in turn being supported by sliding pieces, which are journalled in such manner as to be capable of sliding movement in vertical direction, whereby two hinged-together links are provided between a sliding piece and the frame, the first link being hinged to said sliding piece, the second link being hinged to said frame and both links being hinged to a connecting rod which is movable in a plane extending transversely to the axis of rotation, whilst said links are capable of pivoting movement between a position in which the two links include an angle with each other and a position in which the two links are at least substantially in line with said sliding piece.
This leads to a simple and compact mechanism for effecting the up-and-down movement of the transport means and the gripping means for the objects connected thereto, whereby the spaced-apart carriers provide a relatively rigid construction, which cannot be tilted.
It is noted that from GB-A-2.168.447 a device is known wherein a plate is movable in vertical direction by means of two pairs of hinged-together links. Since said links are connected to connecting rods which are movable in a plane extending parallel to the vertical direction, the number of pairs of links equals two at most. For supporting a plate or transport means firmly in one plane at least three spaced-apart supporting points are required, however. In the device according to the invention the carriers form said supporting points.
According to another aspect of the invention a crank connecting rod mechanism is connected to the transport means for reciprocating said transport means about its axis of rotation. Also this measure leads to a light and compact driving mechanism. It is preferred to connect the connecting rod to the transport means at a point located as far as possible from the axis of rotation, in order to obtain a relatively high positioning accuracy.
By using this construction a very light and simple mechanism for reciprocating the transport means can be obtained, in particular when a motor rotating in one direction, preferably an electromotor, is used for driving said crank connecting rod mechanism.


A minimally-invasive bone graft harvesting device, kit, and method are provided. The device includes a hollow cutting element and an extraction element. The hollow cutting element may define a longitudinal axis and includes a distal end, a proximal end adapted to be coupled to a powered or manual-operated rotary tool, and an inner lumen extending longitudinally between the distal and proximal ends. The hollow cutting element may also include one or more blades protruding from an outer surface of the cutting element. Each blade may be arranged adjacent to an opening extending between the outer surface and the inner lumen to allow cancellous bone material cut by each blade during use to pass through the opening into the inner lumen. The extraction element may be removably received within the inner lumen of the hollow cutting element to allow withdrawal of the bone material in the inner lumen.

1. Field of Invention
The field of the currently claimed embodiments of this invention generally relates to devices and methods for harvesting bone grafts.
2. Discussion of Related Art
In the current U.S. healthcare market, cost constraints are becoming a central and ever-growing issue. In this landscape, hospitals and surgeons are being pressured to cut the costs of various procedures while still maintaining good clinical outcomes. One area which has potential to concurrently reduce costs and increase care is in the area of bone graft harvesting for use in complex surgical procedures such as, for example, spinal fusions. Hundreds of thousands of people in the U.S., and millions worldwide, undergo spinal fusion procedures every year. Generally speaking, the long term success of a spinal fusion is dependent on a successful bone graft for inducing the fusion of two spinal vertebrae. A failed fusion can mean an additional surgical procedure, with potentially life threatening risks to the patient, as well as huge additional costs to the healthcare system.
According to at least one common procedure, a bone graft may be harvested from the patient's own body (autologous bone) such as, for example, from the iliac crest, the superior border of the wing of ilium and the superolateral margin of the pelvis. Autologous bone is often preferred because there is less risk of graft rejection since the graft originated from the patient's own body. Nevertheless, there are still risks and substantial costs associated with harvesting bone grafts using currently available techniques and methods.
There is a need for new bone harvesting methods and devices which are complementary to spinal fusion surgeries (as well as other uses of autografts such as, for example, maxiofacial reconstruction, dental procedures, bone trauma, bone cancer, fracture repairs and joint replacement, etc.) and which allow hospitals to maintain high standards of care at a fraction of the cost of current options without compromising patient safety. In particular, there is a need for a minimally-invasive device and method to harvest iliac crest bone graft (ICBG) to help reduce the morbidity associated with bone harvesting procedures and allow physicians to achieve high fusion rates without burdening the hospitals with the high costs of utilizing bone graft substitutes such as bone morphogenetic proteins (BMP) products, allografts, or demineralized bone matrices (DBM).

Minimally-invasive device, kit, and method for harvesting bone graft


Rule-based content filter is described, including receiving from a user an indication of an attempted posting of content to a target, wherein the attempted posting of the content by the user comprises at least one item provided by the user for display on a website to the target; selecting a rule associated with the user, wherein the rule is selected based on at least one of the content of the attempted posting and an identity of the target; applying the rule to the attempted posting to determine whether a condition applies, the condition relating to whether the attempted posting complies with the rule; when the condition applies, posting to the target; and when the condition does not apply, providing an indication to the user that the attempted post does not comply with the rule.

Technical Field
The subject matter discussed herein relates generally to data processing and, more particularly, to a rule-based content filter.
Related Background
Users may assume more than one role in the physical world as well as in online virtual communities. For example, a user, Jon, may assume the roles of son, grandson, husband, father, teacher, former college student, current graduate student, hiker, beer collector, traveler, member of an aviation club, politician, etc.
Jon may communicate and share content with other users online, such as on a social network or an email communication system. Jon may group users with whom he communicates in social graphs, such as circles or groups based on one or more criteria. For example, Jon may group users who are his family members in a "Family" circle. Jon may group users who are his students in a "Students" circle or a "Teaching" circle. Jon may create an "Aviation" circle for users with like interests. For example, the users in the "Aviation" circle that Jon creates may predominantly include his former university colleagues (e.g., alumni) who may be friends. Additionally, the "Aviation" circle that Jon creates may also include his students and members of his family (e.g., relatives).
Due to the number of circles and users that Jon has created, it may be difficult for Jon to continually remember the members of his circles or groups. Accordingly, unintentional posting or sharing of content that is inappropriate for a particular group may occur when Jon cannot remember all of the members of that group. For example, Jon may freely express himself to the users in the "Aviation" circle that are mature users using language that may be considered inappropriate to family members and students who are part of the "Aviation" circle.
A solution without the above limitations is needed.


A fully independent suspension system (20) for a vehicle includes a plurality of components mounted above the bottom side (502) of the frame (500) of the vehicle so that the rear end (508) of the frame (500) may be selectively lowered to the roadway. In a preferred embodiment, the components are mounted on the longitudinal edges (510) and (512) of the frame (500). The suspension system (20) includes raising and lowering components for selectively lowering the rear end (508) of the frame (500) to the roadway, and raising the rear end (508) so that the frame (500) is substantially horizontal. The suspension system (20) retains the frame (500) in a position below the is rolling axis (65) of the wheel (514).

The present invention relates to a suspension system for cargo-hauling vehicles of all sizes and types. Almost all present vehicles require that the cargo-receiving deck, which is mounted to the vehicle's frame, be situated above the vehicle's axle, drive-train, and/or suspension related hardware. This raises the deck to an undesirable height, thereby creating a high center of gravity, creating instability, and reducing the vertical distance available for cargo storage. The deck height of these vehicles also creates difficulties in cargo loading and unloading, requiring elevators attached to the vehicle, loading ramps, fork lifts, or loading docks. For example, U.S. Pat. No. 2,507,980 shows an independent wheel suspension for a trailer. The entire frame of the trailer is constructed of channel irons, and the wheels are rotatably arranged in wheel hangers pivotally secured to the trailer frame. U.S. Pat. No. 2,644,696 defines a convertible spring and hydraulic loading means for vehicles. The bed of the vehicle can be lowered to rest on the supporting surface such as a roadway, platform, or on the ground, thereby permitting convenient cargo loading and unloading. U.S. Pat. No. 2,852,266 depicts a retractable boat carrier or trailer. The boat carrier is adjustable to various sizes of boats wherein the wheels and struts are easily and quickly retracted into the boat when not in use. U.S. Pat. No. 3,001,796 discloses a retractable trailer uppercarriage for semi-type trailers and commercial carriers. The uppercarriage is removable from service without disassembly, and is constructed so that the running gears are two separate assemblies connected by one common hydraulic system. U.S. Pat. No. 3,356,386 comprises an underslung wheel suspension system for a trailer in which one end of a lever arm is pivotally engaged to the frame at its lower point and extends rearwardly into the wheel well and the free end of the lever bears against a coil spring in a spring receiver mounted on the frame at the rear of the wheel well. The wheel axle is mounted on a plate extending upward from the lever arm. U.S. Pat. No. 3,779,594 consists of a retractable wheel assembly wherein the frame is external and mates with the bottom of the body by engaging elongated channels formed therein. The frame serves to support the retractable wheel assembly and the detachable pontoon whereby stress and strain is isolated from the body. U.S. Pat. No. 3,784,218 describes a vehicle trailer having a frame pivotally mounted on wheels with a mechanical lock to lock the frame in a predetermined position in relation to the wheels and with fluid pressure means to release a mechanical lock and cushion lowering and to effect raising of the frame. The frame is adjustable in height relation to the wheels. U.S. Pat. No. 4,856,812 includes an axle suspension system that is soft in ride and stiff in roll. Two air bags are coupled between a beam and the frame. The two air bags carry substantially all the weight of the vehicle over the front axle. U.S. Pat. No. 4,878,691 evidences a trailer suspension apparatus for increasing the cargo capacity of the trailer. The apparatus includes a U-shaped frame having a transverse structure and upright structures at the ends of the traverse structure. The transverse structure is positioned beneath the rolling axes of the wheels to permit the trailer body to provide cargo space between the wheels and over the transverse structure. U.S. Pat. No. Re. 32,736 shows an alignment and elevating system for a vehicle load bed. The system includes a suspension system having a suspension support assembly pivotally mounted at one end of the load bed and releasably mounted at the second end of the load bed. Selective release of the second end allows pivotal separation of the load bed and suspension system. U.K. Pat. Document 2,042,433 defines an improved vehicle suspension system of the trailing arm type in which the arms are supported by the cooperative effort of primary and secondary springs. The suspension system comprises a frame including first and second spaced elongated side rail members and traversely extending interconnecting members secured to the side members, wheel mounting means adapted for the securement of ground engaging wheels, and a suspension means for movably mounting the wheel mounting means to the vehicle frame.
Since there are legal limits which regulate the height, length, and width of cargo-hauling vehicles, the only way to increase cargo capacity for a particular vehicle is to lower the frame and therefore the deck. This has the added advantage of lowering the vehicle's center of gravity, thereby increasing stability. This cannot usually be done with present technology due to drive-shafts, differentials, live axles, dead axles, and suspension components which are located beneath the frame and deck. Similarly, because of the presence of these under-frame components, present vehicles cannot lower one end of the frame to the roadway for easy and quick cargo loading and unloading. The present invention overcomes both of these problems by providing an independent suspension system with a lowered frame and attached deck which is situated below the rolling axes of the wheels, and by allowing the rear end of the frame to be lowered completely to the roadway using the front wheels as a pivot point.


A Web browser is augmented with collaborative features to support community aware browsing sessions. The augmentation provided includes a data mining plug-in for the browser to establish collaborative context based on Uniform Resource Locator (URL) meta data keywords, or mined topics, and a collaboration co-browser (explorer bar) which displays a collaboration space, called CollabSpace, corresponding to the document that is displayed in the main browser. With this augmented browser, a user can perform various collaboration functions from the collaboration explorer bar, including viewing the online status of members of the CollabSpace, communicate with members of the CollabSpace via electronic mail (e-mail), instant messaging or discussion threads, and register as a member of the CollabSpace. CollabSpaces can be established and associated with one or more Web documents, meta data keywords or topics.

1. Field of the Invention
The present invention generally relates to collaborative data processing systems and, more particularly, to a method and system for collaborative Web browsing which allows the collective knowledge and experience of an appropriate community to be leveraged during browser sessions.
2. Background Description
Web browsing is usually a solitary activity. Routinely, people browse various sites to research topics, technologies, markets, competition and to obtain reference information in their daily work and lives. Given the vast quantity of distributed information hosted on the Web, people are often confused or lost. There is a need to provide support and help to individuals' browsing activity.
Some Web sites centrally serve as a navigation assistant. These Web sites accompany a user from pate to page, recommending documents or hyperlinks that may be important to the user. This is done on a per Web site basis, and is not part of every Web site an individual may visit. Recommendations can be made based on a combination of factors, including the user's browsing experience, other users' browsing patterns, other users' explicit recommendations, and analysis of document content. Although such systems are useful for helping users find related documents, they do not facilitate direct people-to-people collaboration.
Web browsing should be more community aware or team based. Many have had the experience of browsing a Web page that they could not quite understand but thought it might somehow be relevant to their search or the company's business. Community or team based Web browsing has the potential of benefitting both the individual user and the corporate user during browsing sessions. As users browse various pages with various content, analysis of the browsed page can help identify related pages, or other individuals, in the public or corporate community who have knowledge about the page or page content. As members of the community adapt to community aware browsing, knowledge bases and topical support groups can be established pro-actively. Confidential corporate communities or teams can be formed in order to leverage each other's knowledge and experience during browser sessions.

Method and system for collaborative web browsing

International Business Machines Corporation


A friction-reducing lubricating oil composition and a method for reducing the fuel consumption of an internal combustion engine are disclosed. The lubricating oil composition comprises (a) a major amount of an oil having lubrication viscosity; (b) a minor amount of a friction-modifying, polar and surface-active compound; (c) a minor amount of a Group IA alkoli metal containing compound and (d) a minor amount of a transition element metal in a hydrocarbon-soluble or dispersible compound. The method for reducing fuel consumption of a spark-ignited internal combustion engine comprises utilizing an embodiment of the lubricating oil composition in the crankcase of the engine.

1. Field of the Invention
This invention relates to friction-reducing lubricating oil compositions which provide improved fuel economy and oxidation inhibition in internal combustion engines. More particularly, this invention relates to finished lubricating oil compositions that contain both a fuel economy additive system and an antioxidant component. The fuel economy system comprises: (1) a member selected from the group consisting of mono and higher esters of polyols, primary amines, primary ether amines, ether diamines, polyethoxylated amines and polyethoxylated diamines, ethoxylated ether amines, the said amines and diamines containing alkyl and alkylene groups of from 2 to about 30 carbon atoms, aliphatic amides and polyethoxylated amides containing alkyl and alkylene groups of up to about 30 carbon atoms; and (2) a compound containing a Group IA metal of the Periodic Table wherein the Group IA metal is present in the finished lubricating oil in an amount of from about 10 ppm (wt) to less than about 1000 ppm (wt). The antioxidant component comprises a transition element metal compound that is soluble or at least dispersible in hydrocarbons, wherein the metal is a transition metal of an atomic number of from 21 to 47 of the Periodic Table of Elements.
2. Description of the Prior Art
Since the automobile fuel shortage of the 1970's, emphasis has been placed on the conversion of energy and fuels. The government of the United States of America has enacted Federal Regulations which define gasoline-mileage requirements which must be met by the automobile manufactures in that the new automobiles must provide a specified minimum gasoline mileage. The newer automobiles are smaller in size and lighter in weight, as a result of these regulations.
Another way to conserve fuel is to use friction-reducing additive materials in the lubricating oils employed in crankcases of internal combustion engines. A reduction in friction in the engine results in a decrease in the amount of fuel consumed by that engine.
It is known that various lubricating oil additives are capable of reducing the amount of fuel that is consumed by an internal combustion engine. For example, in United Kingdom Patent Application GB 2,097,813A, it was disclosed that certain esters provide reduced fuel consumption. In U.S. Pat. No. 4,208,293, Zaweski disclosed that a fatty acid amide of diethanolamine, or a fatty acid ester of diethanolamine, or a mixture thereof, or esteramides formed therefrom can be used as additives in a lubricating oil composition to reduce friction in an internal combustion engine. In U.S. Pat. No. 4,201,684, Malec taught that a sulfurized fatty acid ester, a sulfurized fatty acid amide, or a sulfurized fatty acid esteramide of an alkoxylated amine, such as ethanolamine, can be used also as a friction modifier in a lubricating oil composition. In U.S. Pat. No. 4,383,931, Ryu et al. disclosed that an oil-soluble molybdenyl bis-b-diketonate is capable of providing antifriction properties to a lubricating oil composition when used in combination with an oil-soluble active sulfur donor, such as zinc dialkyldithiophosphate,
In U.S. Pat. No. 4,326,972 and its British equivalent, United Kingdom Patent Application GB 2,023,169A, Chamberlin III disclosed certain lubricating oil compositions and a method for reducing fuel consumption in an internal combustion engine. He stated that fuel economy is attained by employing a lubrication oil composition comprising: (1) an oil of lubrication viscosity; (2) a sulfurized mixture comprising at least one ester of a substantially aliphatic carboxylic acid containing from about 8 to about 30 carbon atoms and a substantially aliphatic alcohol, at least one substantially aliphatic carboxylic acid containing from about 8 to about 30 carbon atoms, and at least one substantially aliphatic monoolefin containing from about 8 to about 36 carbon atoms; and (3) at least one oil-dispersible basic alkali metal sulfonate. He disclosed that such a lubricating oil composition, when used as a crankcase oil in an internal combustion engine, improves the operation of that engine by decreasing fuel consumption.
European Patent Application No. 83302155.3 (European Publication No. 092946) taught that a partial ester of a fatty carboxylic acid containing from 16 to 18 carbon atoms and glycerol and an oil-soluble organic copper compound, when present in a lubricating oil composition, act together to reduce friction in the crankcase of an internal combustion engine utilizing said composition.
In U.S. Pat. No. 4,280,916, Richards et al., disclose a motor oil composition which contains an oil of lubricating viscosity, an ashless dispersant, such as a polyisobutenyl succinate, an oil-soluble detergent sulfonate, salicylate, and/or phenate, and at least one C.sub.8 -C.sub.24 aliphatic monocarboxylic acid amide, the latter being present in an amount that is sufficient to reduce fuel consumption of an internal combustion engine that is employing the motor oil composition as the crankcase lubricating oil of that engine.
Now there has been found unexpectedly a lubricating oil composition that not only reduces fuel consumption, but also provides outstanding stability to oxidative degradation.

Fuel economy and oxidation inhibition in lubricant compositions for internal combustion engines


Systems and methods for BIOS failover. A processor reset is detected and a timer is set to expire after a predetermined time corresponding to a time to complete loading a first BIOS image from a first BIOS chip. Loading of the first BIOS image is initiated and it is determined whether the first BIOS image loaded successfully before the timer expired. If the timer expires before the first BIOS image is loaded successfully, loading is switched to a second BIOS image from a second BIOS chip. According to another aspect, loading of a first BIOS image from a first BIOS chip is initiated and a reset of a processor is detected. A reset counter is incremented in response to detecting a reset of the processor and loading is switched to a second BIOS image from a second BIOS chip when the reset counter reaches a reset threshold.

A PC system architecture normally uses a basic input/output (I/O) system (BIOS) as a boot loader. The BIOS image is typically stored on a BIOS flash chip, which may be a flash memory or electrically erasable programmable read only memory (EEPROM). The BIOS image may include a BIOS firmware as well as machine specific data values stored in a non-volatile random access memory (NVRAM). Conventionally, the PC system stores only one copy of the BIOS image. The BIOS is generally the first code loaded and executed by the PC system and can be used to load an operating system (OS) of the PC system.
The BIOS image may become corrupted if an update process, which may include an erase step, is interrupted. The PC system may then not be able to boot, thereby disabling the PC system and preventing access to files to restore the BIOS image. The BIOS flash chip may then be physically replaced to restore the BIOS image, but physically replacing the BIOS flash chip may not be a feasible option, because of the added cost and greater chance of mechanical failures.

Motherboards and methods for BIOS failover using a first BIOS chip and a second BIOS chip


An electrical power supply and controller for supplying electrical power from a common platform in a plurality of distinct electrical waveforms, including voltages, and frequency, and to a plurality of distinct loads including distinct motor loads, and controlling alternatively the speed and torque of these motor loads. The power supply and controller of this invention automatically accepts and adjusts to an electrical input across a wide range of electrical waveforms, including voltage and frequency, and includes an interface for accepting a plurality of distinct computer programs for controlling each load type. The electrical power supply and controller supplies electrical power to the plurality of distinct load modules, accepts the plurality of distinct electrical inputs, and accepts the plurality of distinct computer programs without any modification to the electrical power supply and controller itself.

This invention relates in general to an electric power controller for providing electrical power to an electrical load, and more particularly to a universal controller that accepts any one of a variety of different input voltage waveforms, magnitudes, and frequencies, and, under computer program control, provides a controllable output voltage to any one of a variety of different electrical loads that include, among others, AC and DC motors.
Electrically powered devices have a wide variety of voltage, current and control requirements. Some types of electrically powered devices require an AC operating voltage having a fixed frequency and a fixed magnitude. Others require an AC operating voltage having a fixed magnitude and a variable frequency or an AC voltage having a variable magnitude and a fixed frequency. Similarly, some types of electrically powered devices require a DC voltage having a fixed or variable magnitude and/or a polarity that can be reversed. In many cases, these devices can be operated by a DC voltage which can be chopped or pulse width modulated. Still other types of electrically powered devices, such as AC/DC motors, can operate from AC or DC sources.
Electrical power sources also have a wide variety of types. Some types of power sources provide single or multiple phase AC voltages and currents at fixed frequencies and magnitudes. Fixed frequency AC sources typically provide a selectable one of a plurality of frequencies, 50 Hz single and multiple phase AC voltages being widely used in Europe, while 60 Hz single and multiple phase AC voltages are widely used in North America. Depending only on the application, AC sources typically provide a selectable one of a plurality of magnitudes, such as 220 or 440 volts, among others. Similarly DC power sources come in a variety of different types having different magnitudes and reversible or non-reversible polarities. Some DC sources, such as batteries, provide a virtually ripple free DC voltage having a fixed magnitude. Others, such as DC to DC converters are able to operate from variable magnitude DC input voltages or to provide variable magnitude DC output voltages.
Prior to the present invention, it was common to deal with these differing load requirements and source types by stocking a variety of different types of power conversion and control devices, including transformers, controlled rectifier devices, inverters, voltage regulators, DC to DC converters and various combinations thereof. With this approach, it was necessary to stock devices having various combinations of input and output voltage ranges. In applications involving the control of motors, this approach is made even more difficult by the fact that motors come in a variety of types having different input voltage and load current requirements and different control requirements. As a result, the task of designing and stocking power conversion and control devices that are dedicated to operating with each of a variety of different types of motors and each of a variety of different types of power sources is a daunting and expensive one.
It will therefore be seen that there exists a need for a power conversion and control device that is able to operate from any one of a variety of different types and magnitudes of power sources and to meet the power and control requirements of any one of a variety of different types of loads.


A method, system, and program product for creating network isolation between virtual machines is provided, including receiving, by a security virtual machine (SVM), an outgoing network packet from a virtual machine (VM). The source internet protocol (IP) address and a source media access control (MAC) address is extracted from the outgoing network packet. A zone identifier table is searched for a zone id, whereby the zone identifier table includes the source IP address and the source MAC address. The outgoing network packet is sent to a physical Ethernet adapter connected to an external network switch whereby the external network switch is connected to an external network, based on the zone id not being found in the zone identifier table. The outgoing network packet is sent to a physical Ethernet adapter that is connected to an internal switch, based on the zone id being found in the zone identifier table.

This disclosure relates generally to computer system networking, and more particularly to creating network isolation between virtual machines.
In networking technology, virtual local area networks (VLANs) are used to isolate network traffic. However, in a cloud environment, it may not be possible to create enough VLANs to isolate traffic due to limitations on the physical Ethernet adapters and switches, for example. A physical computer may include several virtual machines (VMs), which are logical emulations of a physical computer. The physical computer may host multiple VMs, each sharing the hardware resources of the physical computer, and each emulating a physical computer. In a cloud environment, a physical computer may include VMs that may belong to different organizations within the same enterprise, or to several unrelated enterprises, each sharing the physical computing environment. In general, several VMs may share the same physical Ethernet adapter. Although one physical network adapter may be trunked, i.e., carry multiple VLANs, it may not be physically possible to create enough VLANs to keep traffic segregated, for example to ensure security and to maintain adequate performance.
To maintain network security, VLANs, internet protocol (IP) subnets and addresses, and media access control (MAC) addresses may be used to keep network traffic segregated among the different organizations. However, in a cloud environment an organization or enterprise may only lease a VM for a brief period of time, such as for example, to process a monthly payroll. Consequently, VMs may be continually deployed and destroyed, resulting in repeated reuse of IP addresses and MAC on the physical computer. This, along with the probability that VMs on a physical computer may belong to multiple enterprises, increases the challenge of isolating network traffic and keeping out external undesired network traffic.

This patent is subject to a terminal disclaimer.

Creating network isolation between virtual machines


A method of forming a device is disclosed. A substrate defined with a device region is provided. A gate having a gate electrode, first and second gate dielectric layers is formed in a trench. The trench has an upper trench portion and a lower trench portion. A field plate is formed in the trench. First and second diffusion regions are formed. The gate is displaced from the second diffusion region.

High voltage field-effect transistors having high breakdown voltage and low on-state resistance are used in, for example, power management products. Such high voltage field-effect transistors include lateral double-diffused (LD) transistors. The performance of the LD transistors depends on the drain-to-source on-resistance (Rdson) as well as breakdown voltage. For example, low Rdson results in high switching speed while high breakdown voltage (BVdss) increases reliability.
High breakdown voltage may be achieved by increasing the device pitch. For example, an expanded drain region may be provided along the surface of the substrate, increasing the drain-to-gate surface area on the substrate. The higher the desired breakdown voltage, the larger the expanded drain region or larger the drain-to-gate surface area on the substrate. This however increases gate-to-drain capacitance, resulting in a larger Rdson which negatively impacts the switching speed of the transistor. As such, conventional LD transistors achieve a high breakdown voltage by sacrificing switching speed.
The disclosure is directed to transistors with fast switching speed and high breakdown voltage.


Methods and apparatus are provided for deriving precision position and rate information for motors using relatively low precision analog sensors, and for implementing compensation techniques that overcome inherent sensor errors and rotor magnet flux tolerances.

Electric motors, such as brushless motors, may be used for many different applications. In many instances, analog Hall-effect sensors are used for sensing rotor position in brushless motors where, for example, trapezoidal commutation is employed. This can be a cost effective solution when precision motor control is not needed. However, for precision motor (e.g., fine resolution) control applications, which employ sinusoidal or field oriented control commutation, relatively higher resolution position and rate sensing may be needed. Historically, this higher resolution sensing has been accomplished with relatively more expensive and complex resolver type AC sensors and resolver to digital conversion circuitry.
Recently, other techniques have been implemented that use relatively low-cost analog Hall-effect sensors. In accordance with these techniques, analog Hall-effect sensors generate three sinusoidal signals representative of the position of the motor rotor. Using a rigorous mathematical approach, the rotor position and rate may then be derived. One example of a mathematical approach, which is disclosed in U.S. Pat. No. 6,744,230, combines the three sinusoidal signals into two orthogonal vectors using known trigonometric identities. Standard arctangent algorithms and other trigonometric identities may then be used to derive the rotational position and rate from the orthogonal vectors.
While the above described mathematical technique works quite well, it can exhibit certain drawbacks. For example, the derived position and rate can be subject to a number of errors. These errors may be associated with individual Hall-effect sensors or specific magnet poles. In particular, the Hall-effect sensor errors may arise from positioning errors (phase and amplitude) and/or from electrical offset of the sensors. The magnet pole errors may appear as overall magnetic flux intensity variations or distortions in the sinusoidal waveform.
Hence, there is a need for a relatively low-cost motor control scheme that may implement fine resolution motor control and that overcomes inherent sensor errors and rotor magnetic flux intensity variation errors. The present invention addresses at least this need.


An electrical generator inspection system comprises an electro-magnetic core imperfection detector that provides an analog signal representative of fault currents detected between adjacent laminations of a stator core; an analog-to-digital converter coupled to the detector for converting the analog signal to a digital signal; a digital filter coupled to the output of the converter for digitally filtering the digital signal to remove noise therefrom; and means for storing predetermined signal criteria and for comparing the filtered digital signal to the predetermined criteria to determine the location of the insulation defects along the stator core. In one embodiment, the system further comprises means for storing the filtered digital signal in a memory.

The stator cores of electrical generators and other electrical machines are made up of a "stack" of thousands of individual steel sheets or laminations. The thickness of an individual sheet is measured in thousandths of an inch. Each of the laminations is coated with a thin layer of electrical insulation to insulate it electrically from its neighbors. This insulation prevents the 60 HZ alternating magnetic flux in the stator core from inducing eddy currents between laminations. If the insulation between adjacent laminations becomes damaged during assembly, operation or maintenance, a conducting path may be formed through which currents are induced by the alternating flux. These conducting currents create "hot spots" which, if undetected, can result in catastrophic failure of the machine.
One type of apparatus suitable for detecting such stator core hot spots is an Electro-magnetic Core Imperfection Detector ("EL-CID"). An EL-CID detects potential hot spots electromagnetically by exciting the stator core and then measuring any resulting fault currents flowing through a damaged region. Typically, the EL-CID's sensors are held against the stator core laminations and transported the length of the stator core. As the sensors move along the length of the core, they produce an analog signal having a magnitude proportional to detected fault currents. By examining a plot of the magnitude of the analog signal versus the sensor distance along the length of the core, operators are able to detect which stator laminations have damaged insulation.
U.S. Pat. No. 4,970,890, assigned to Westinghouse Electric Corp. and incorporated herein by reference, discloses a stator core inspection system that employs such an EL-CID detector. In the past, the analog output signal from the EL-CID detector was fed directly to an X-Y plotter for visual inspection by the operator. From the plot, the operator was able to determine the location of any hot spots. In the '890 patent, however, the analog EL-CID signal is sampled by an analog-to-digital converter and the digital representation is stored in a computer. The operator is then able to use the panning and zooming capabilities of the computer to examine the EL-CID signal more closely.
One problem with all EL-CID inspection systems, and the system of the '890 patent in particular, is that the power plant surroundings and machinery introduce a significant amount of noise in the analog EL-CID signal. Noise in the EL-CID signal makes it more difficult for the operator to discover faults. Because analog-to-digital converters naturally perform some low-pass filtering at certain sampling rates, analog-to-digital conversion of the EL-CID signal eliminates some of the noise. However, this natural filtering is not enough to remove the bulk of the background noise from the EL-CID signal. Consequently, there is a need for a system and method for removing noise from an EL-CID signal while keeping the integrity of the EL-CID signal intact. The present invention satisfies this need.


A timing-driven simultaneous placement and floorplanning method based on a multi-layer density system for heterogeneous field programmable gate arrays are disclosed. The field programmable gate arrays are designed with heterogeneous resources including look-up tables, memory blocks and dedicated logic blocks. Each layer in the multi-layer density system is modeled with a different architectural resource. The placement of look-up tables and the floorplan of computational blocks are concurrently determined in the multi-layer density system. A dynamic timing optimization scheme is also seamlessly integrated in the placement process.

1. Field of the Invention
The present invention relates generally to programmable chips, and more particularly to floorplanning and placement of field programmable integrated circuits (ICs).
2. Description of Related Art
Field programmable gate arrays (FPGAs) are often selected by designers to provide a flexible approach in programming and re-programming integrated circuits in order to accommodate a system specification, correct errors in the system, or make improvements to the system by reprogramming the field programmable gate array. One conventional field programmable gate array architecture is implemented using groups of look-up tables and programmable interconnect circuits. While the look-up tables and sequential elements are connected to each other, the connections to the groups of look-up tables typically originate from a switchbox located in each group of the look-up table. A hierarchical interconnect structure connects to elements in a look-up table through a switchbox, thereby serving as the primary source of connecting look-up tables from one logic block to another logic block. The inputs to the look-up tables are therefore generated primarily from the switch box. The look-up table outputs are directly fed to other look-up tables as well as the elements within the look-up tables, but the connections to other look-up tables' inputs are made through the switch box.
Although field programmable gate arrays enable user programming of integrated circuits, these integrated circuits typically produce slower performance (clock speed) because of the delays through the transistors, switches or multiplexers used to program the interconnects between configurable logic elements. Each logic element can be connected to a multitude of other logic elements through switches in which the path from one programmable logic element to the next may be strewn with many switches, slowing down circuit operation. Some paths in a programmable IC are not as critical as others. Therefore, a customized programmable IC can be designed such that speed in the critical paths are optimized over other non-critical paths.
Routing elements have increasingly been added to programmable logic devices/ICs so that routing elements now typically occupy a much larger area than the configurable logic elements themselves. Adding to the problem is the fact that routing delays are typically much greater than logic delays, resulting in a slow operating clock frequency. In a conventional implementation, a large fraction of the routing elements may be redundant.
As semiconductor process advances into deep sub-micron regime, the cost of manufacturing a complex Application-Specific Integrated-Circuit (ASIC) chip using the state-of-art technology is sky-rocketing. As a viable solution to reduce cost, shorten product development cycle while minimizing production risk, field programmable gate array has been gaining acceptance in various applications than ever before. Traditional homogeneous field programmable gate array is mainly based on programmable Look-Up Tables (LUTs). Its logic density and performance are usually inferior to ASIC implementation. However, as the leading-edge technology is more rapidly adopted in field programmable gate array industry, and more ASIC-like dedicated functional blocks are integrated nowadays, the overall density and performance disadvantages are mitigated in modern high-end field programmable gate arrays. The integration of such dedicated blocks marks the transition from homogeneous architecture to heterogeneous. Consequently due to the shift to the heterogeneous architecture, it is desirable to optimize the economy of space on an integrated circuit chip with a more efficient method and system for the placement of heterogeneous blocks.

Simultaneous timing-driven floorplanning and placement for heterogeneous field programmable gate array


Disclosed herein is a degradable diverter material having a urea compound. In particular, the degradable diverter material may be a particulate with each individual particle being a nanocompo site of a urea compound and clay. The degradable diverter material may be introduced into a wellbore penetrating a subterranean formation. The degradable diverter material may then be allowed to divert at least a portion of fluid present downhole, the fluid being introduced from the surface or already present dowhole. The degradable diverter material can then be allowed to at least partially degrade.

During various stages in the development, stimulation and production of hydrocarbons it is often necessary to control the flow of various subterranean fluids. Accordingly, diversion materials are often introduced downhole to reach various subterranean locations to affect the flow of fluids. The diversion materials can prevent the flow of fluids to unwanted locations, divert flow to desirable locations, or prevent the loss of fluids from desired subterranean zones, among other functions. Additionally, after diverting fluid flow, it may be desirable to remove the diverting material from the well, either to permit flow again, or to prevent harm to the environment or wellbore, and accordingly degradable diverting material has been used.
One of the more common oil and gas processes includes hydraulic fracturing. In a typical hydraulic fracturing treatment, a treatment fluid often referred to as a "fracturing fluid" is pumped through a wellbore and into a subterranean formation producing zone at a rate and pressure such that one or more fractures are formed or extended into the zone. The fracturing fluid can include proppants which are introduced into the fractures.

Degradable diversion material having a urea compound