Assay for detection of a form of diamine oxidase which is present only in amniotic fluid and, more especially, for detection of amniotic membrane rupture by detection of the amniotic fluid diamine oxidase. The assay includes the steps of detecting the amniotic fluid diamine oxidase and distinguishing that from another form of diamine oxidase found in serum. The assay may be carried out on a sample of vaginal fluid from a pregnant female wherein the sample is subjected to the assay to detect the leakage or presence of amniotic fluid diamine oxidase. Purified forms of amniotic fluid diamine oxidase and serum diamine oxidase which is different from amniotic fluid diamine oxidase and found in serum are also described, together with a method of purifying both forms of diamine oxidase.

Diamine Oxidase (E.C.220.127.116.11) (hereinafter called DAO) catalyses the oxidation of diamines such as histamine, putrescine and cadaverine, which yields an aminoaldehyde. During early investigations the enzyme was believed to only oxidise histamine: thus the enzyme was initially named Histaminase by Best and McHenry (1929). Further investigations proved that the enzyme was capable of oxidation of other diamines such as those listed above. The nomenclature currently in use, Diamine Oxidase, was later suggested by Zeller (1965).
Until 1965, the only intracellular mammalian diamine oxidase that had been purified was pig kidney histaminase (Kapeller-Adler, 1963; and Mondovi, 1964). Considerable purification of pig kidney histaminase (200- to 240-fold) was obtained by Tabor in 1951. Higher degrees of purification were successively obtained by applying column chromatography and electrophoresis (Mondovi, 1967a; and Uspenskaia, 1958). Diamine oxidase has also been purified from the pig kidney cortex by chromatography on hydroxylapatite and DEAE-Sephadex A-50, and gel filtration through Sephadex G-200 (Bardsley, 1971). This gave an enzyme preparation purified 230-fold with a 35% yield.
AH-Sepharose 4B was used as an affinity sorbent after partial purification of the pig kidney diamine oxidase by means of controlled heating, fractionation with ammonium sulphate and precipitation at pH 5.3. The AH-Sepharose adsorbed inactive proteins in preference to the diamine oxidase. This method provided an enzyme purified 670-fold, but with only a 14% yield (Floris, 1976). Increased yields of the enzyme from pig kidney was achieved by altering the heating conditions used by Floris (1976) on the homogenate, followed by ammonium sulphate fractionation and column chromatography on DEAE-Cellulose. Dialysis of the enzyme against 0.005M phosphate buffer resulted in an electrophoretically homogenous enzyme preparation purified 2400-fold with a 60% yield (Kluetz, 1977b).
Another method developed for purifying diamine oxidase from pig kidney cortex avoided heating the homogenate. The extract obtained after ammonium sulphate fractionation and centrifugation, was subjected consecutively to column chromatography on DEAE-Sephadex A-50 and hydroxylapatite, with subsequent gel filtration through Sephadex G-150. The enzyme was purified 1350-fold with a 20% yield, and was shown to be homogeneous by SDS-PAGE (Yamada, 1967). To simply the purification of pig kidney diamine oxidase, an affinity sorbent DAH-Sepharose was introduced by Klimova (1976). An extract of pig kidney cortex homogenate obtained after centrifugation of the ammonium sulphate treated sample was chromatographed on DAH-Sepharose and gave an enzyme preparation purified 200-fold with a 20% yield.
Human kidney diamine oxidase was purified 1800-fold by heating the homogenate, treating it with a mixture of ethanol and chloroform, chromatography on CM-Sephadex, and followed by fractionation with ammonium sulphate and gel filtration through Sephadex G-200 (Shindler, 1976).
Preparation of diamine oxidase from human placenta was achieved by fractionation with ammonium sulphate; chromatography on DEAE-Cellulose and phosphocellulose, and gel filtration through Sephadex G-200 (Smith, 1967). This preparation of diamine oxidase was purified 515-fold, although it still contained haptoglobin and methemoglobin. Paolucci (1971) obtained a 9600-fold purification of placental diamine oxidase with an 8% yield. The proteins of the human placenta were extracted using an acetone powder technique and precipitated with ethanol absorbed on DEAE-Cellulose; fractionated with ammonium sulphate, chromatographed on DEAE-Collulose and subjected to gel filtration through Biogel A-5m. A 4600-fold purification of human placental diamine oxidase was obtained by Bardsley (1974). The methods used in the purification of the enzyme were as those reported for Smith (1967), although a final chromatography step on DEAE-Sephadex or hydroxylapatite was employed which resulted in an increase in specific activity and gave an enzyme which was homogeneous by SDS-PAGE.
Hata (1976) obtained a 1200-fold purification of human placental diamine oxidase ontained by the method described by Bardsley (1974). The polyacrylamide gel electrophoresis pattern of purified human placental diamine oxidase gave a broad band, with the preparation not purified to the same extent as that described by Bardsley (1974). The purification of human placental diamine oxidase was also described by Crabbe (1976), using a modification of the procedure described by Bardsley (1974). Column chromatography incorporated DEAE-Sephadex with ionic strength and pH-gradient elution, together with affinity chromatography on Concavalin A-Sepharose. This gave a 30,800-fold purification with a 33% yield. Lin (1981) purified placental diamine oxidase in what was referred to as a one-step purification. In this procedure, placentae were homogenized and centrifuged, with the resultant supernatant applied to the affinity gel, cadaverine AH-Sepharose as was previously employed by Baylin (1975b). Elution of the enzyme was accomplished using chromotropic acid, and provided a 1800-fold purification of the enzyme which was homogeneous by SDS-gel electrophoresis.
Plasma diamine oxidase from women in the third trimester of pregnancy was purified 3000-fold with a 25% yield by means of an affinity sorbent sepharose, covalently linked with cadaverine (Baylin, 1975b). The enzyme was eluted from the adsorbent with heparin; electrophoresis by SDS-PAGE presented two protein fractions, one of which displayed the diamine oxidase activity.
Diamine oxidase was isolated from human female amniotic fluid by chromatography on DEAE-Sephadex and affinity chromatography on cadaverine-Sepharose, which was shown by SDS-PAGE to contain only 10% inactive protein (Tufvesson, 1978a). Diamine oxidase from human male serum previously given intravenous heparin (10000 I.U.) one hour before collecting the blood, was isolated by cadaverine-Sepharose affinity chromatography and then by chromatography on DEAE-Cellulose (Tufvesson, 1978b).
The enzyme can also be found in kidney and other organs in a variety of animal species. A great deal of time had been devoted to characterization studies of pig kidney (Kapeller-Adler & Macfarlane (1963)) and pig serum (Blaschko, Friedman, et al (1959)) DAO, but the human enzyme (Crabbe, (1979)) has been only poorly characterised.
According to previous studies, there seemed to be several forms of DAO and these forms exhibited some tissue specificity. Although presence of the enzyme in human placenta and human pregnancy plasma was confirmed by Swanberg (1950), this group was unable to establish any difference between the forms of human placental and pregnancy plasma DAO. Moreover, Tufvesson (1978) could find no difference between amniotic fluid DAO and pregnancy serum DAO, although he suggested that heparin stimulated male serum DAO was different.
Four active protein fractions, with molecular weights of 125,000, 250,000, 375,000 and 500,000 daltons were found in preparations of human placental diamine oxidase by Paolucci (1971). The preparation of human placental diamine oxidase obtained by Hata (1976) was purified 1200-fold, and the presence of a broad band on polyacrylamide gel electrophoresis indicated the presence of a contaminant protein which was demonstrated distinctly by immunoelectrophoresis and SDS-PAGE. The molecular weight was calculated to be approximately 300,000 by comparison with a calibration curve by gel filtration and SDS-PAGE. The molecular weight of the subunit was 170,000, which is about two times of 90,000 obtained by Bardsley (1974) and Lin (1981).
By the use of gel filtration through Sephadex G-200, polyacrylamide gel electrophoresis in the presence of SDS, or ultracentrifugation, it was demonstrated that a monomeric, catalytically active form of human placental diamine oxidase had a subunit molecular weight of 70,000 (Crabbe, 1976). This value is close to that reported by Baylin (1975b) for diamine oxidase from pregnancy plasma, which would appear to be a monomer. Sedimentation-equilibrium ultracentrifugation results indicated a single species with a molecular weight of 235,000, which could be explained on the basis of concentration-dependant-aggregation, to be dimeric and tetrameric species which were in equilibrium with each other (Crabbe 1976).
A protein component with a molecular weight of 185,000 was detected by means of gel filtration through Sepharose 6B on purified diamine oxidase from the serum of a man pretreated with heparin (Tufvesson, 1978b). However, a similar technique used on the serum diamine oxidase and amniotic fluid diamine oxidase of pregnant women revealed the presence of two active fractions in both which had native molecular weights of 245,000 and 485,000 (Tufvesson, 1978a, 1978b). Treatment of highly purified diamine oxidase from amniotic fluid with 1% SDS and 1% 2-mercaptoethanol followed by SDS-PAGE revealed the presence of a subunit with an apparent molecular weight of 100,000 dalton (Tufvesson, 1978a). Significantly, Tufvesson determined this apparent molecular weight in the presence of borate buffer which might be expected to lead to an overestimation of the subunit molecular weight. It is important to note here that Tufvesson did not determine the subunit molecular weight of his serum diamine oxidase preparation. Instead, he assumed that the pregnancy serum and amniotic fluid enzymes were identical presumably because of their identical apparent native molecular weights.
The isoelectric point of purified human amniotic fluid diamine oxidase was determined by measuring the activity of the bands which separated in two active fractions with pI values of 4.0 and 5.8. In considering the results for the isoelectric pH obtained for human placental diamine oxidase, Lin (1981) observed that the purified enzyme separated into 5 major bands and several diffuse bands, with the isoelectric pH of the major bands ranging from 5.3-6.6. In comparison, Crabbe (1976) determined the isoelectric point for human placental diamine oxidase to be 6.5. Thus, there is considerable confusion concerning the apparent isoelectric points of the various forms of diamine oxidase. It is highly likely that the observed isoelectric points are dependant on the method of purification or other factors because of the conflicting results of Lin (1981) and Crabbe (1976).
In respect to the several forms of DAO discussed above, it will be realised that pregnancy greatly modifies all metabolic patterns of histamine, putrescine and polyamines. Histamine and putrescine are produced in large amounts by the fetus. The level of DAO rises in parallel with the levels of histamine and putrescine during pregnancy (Zeller above). During a normal pregnancy the level of DAO in maternal plasma begins to rise from the second to third month reaching a maximum by the fifth to seventh month and remains at this level until parturition. The level of DAO in plasma falls quite rapidly after parturition (Lorenz, Kusche, 1970). The major function of DAO during pregnancy appears to be to ensure that the levels of the biogenic amines in the placental microcirculation do not become elevated and thus toxic to the developing fetus (Buffoni, 1966).
Premature rupture of the fetal membranes was observed in 6-16% of all pregnancies (Swartz, Napolitani, et al 1969), while another study found the rupture of fetal membranes in 3-14% of all pregnancies was not followed by labour (Larsen, 1979). On rupture of the membranes, Eastman & Hellman (1961) observed that spontaneous labour followed within 24 hours in 80% of patients, with 10% remaining undelivered after a period of 48 hours. The perinatal mortality doubles after a latent period of 24 hours and again after 48 hours (Overstreet and Romney, 1966). Delayed onset of labour carries with it an increased risk of maternal and perinatal infection and mortality (Eastman & Hellman; Kapeller-Adler & Macfarlane; Overstreet above), therefore the accurate detection of ruptured membranes is an important diagnostic aid.
In the mature fetus therefore, early diagnosis of membrane rupture allows for expediting the delivery thereby reducing infection risk to mother and baby. In the premature infant, accurate diagnosis of membrane rupture is even more important particularly if labour needs to be induced. A reliable, easy method of diagnosis of membrane rupture would be clinically useful to the obstetrician and also cost saving by reducing the need for prolonged and unnecessary hospitalisation. The benefit to those patients resident in the country areas and facing transfer to a tertiary care centre for prolonged periods of hospitalisation away from home and family environment on suspicion of having premature rupture of the membranes would be considerable.
High concentrations of DAO found in amniotic fluid are almost equal to that of maternal blood plasma (Tornqvist, 1971). After rupture of the membranes, DAO is demonstrable in the vagina; wherefore in absence of vaginal bleeding or exudation the measurement of the DAO content of vaginal fluid has been shown to be a reliable method in evaluation of membrane rupture (Ahlmark, 1944); Elmfors, Tryding, et al (1974); Gahl, Kozina, et al (1982). Besides physical examination, current techniques for establishing the diagnosis of ruptured fetal membranes are (Elmfors, Tryding (1976))
1. Determination of the vaginal pH; PA0 2. Staining for fetal fat globules; PA0 3. Identification of fetal squamous cells or hairs; PA0 4. Examination for typical crystallisation of amniotic fluid (ferming). PA0 1. urine; PA0 2. meoonium; PA0 3. antiseptics; PA0 4. pregnancy serum; PA0 5. seminal fluid; PA0 6. haemoglobin
In accordance with Friedman and McElin (1976) any three of the abovementioned methods taken together provide an accuracy of 93% although false-positive and false-negative results are frequent with all laboratory techniques which are applied in diagnosing rupture of the membranes (Larsen above). Dyes and other chemicals have been injected into the amniotic fluid transabdominally and their appearance looked for in the vagina but these techniques are not without risk (Jimsenez-Balderaz E. A. Bol. Med. Hosp. Infant Mex. 1984, 41, P341-4). Measurement of amniotic fluid volume by ultrasound before and after bed rest may be helpful but is not specific (Rudd above).
Measurements of the protein alpha-fetoprotein and the hormones prolactin and human placental lactogen have been investigated by Huber, J. F. et al (Huber, J. F. et al, Are Vaginal Fluid Concentrations of Prolactin, alpha-Fetoprotein and Human Placental Lactogen Useful for Diagnosing Ruptured Membranes, Br. J. Obstet. Gynacol. 90, 1183-1185) but he found many positive tests in patients whose membranes were intact. This was due in part to the fact that these substances are present in maternal serum and therefore the test is positive when either serum or amniotic fluid or both are present in the vagina.
Rochelson B. C. (Rochelson, B. C., A rapid colorimetric AFP monoclonal antibody test for the diagnosis of preterm rupture of the membranes. Obstet, Gynaecol, 1987, 69, P163-6) has also found blood and serum to give false positive results with his test for the presence of alphafetaprotein in vaginal fluid). Elmfors et al (above), using the information of Tornqvist & Jonassen (above) developed a method for the diagnosis of ruptured membranes by measuring the DAO activity in vaginal fluid. DAO activity is present in amniotic fluid but normally absent from vaginal secretions, presenting a method for diagnosing rupture of the membrane (Elmfors, Tryding et al above; Gahl, Kozina, et al above). The most widely used method for collection of DAO activity in vaginal secretions is the use of blotting paper to collect the secretions and phosphate buffer to elute the enzyme (Elmfors, Tryding above). Wishart, Jenkins et al (1979) also supported the use of the procedure and found an assay to offer useful clinical information. The factors which suggest that the DAO assay may be used as an adjunct to conventional tests in the diagnosis of rupture of membranes have been summarised by Gahl et al (above). However, the major drawback of the assay is that it depends on the measurement of enzyme activity and can give false results in the presence of interfering substances such as:
These substances commonly contaminate the vagina therefore invalidating current methods which are limited by interfering substances, inadequate sensitivity and subjective interpretation of results.

Diamine oxidase and assay for rupture of amniotic membrane in pregnant mammals


A method and diagnostic tool diagnoses a charge cycle behavior of an internal combustion engine with a plurality of cylinders. The method determines a diagnosis time window within a torque dropout of one of the cycles of the internal combustion engine, and associates a deviation type with the diagnosis time window determined.

The invention relates to a method and a diagnostic tool for the diagnosis of charge exchange behavior of an internal combustion engine, and to an internal combustion engine with multiple cylinders with a diagnostic tool of said type.
Rough engine running and misfiring are a fundamental problem in internal combustion engines, which can lead at least to an erroneous build-up of the propulsion torque. The fact that an erroneous build-up of torque is occurring can generally be observed from the output variable of the engine rotational speed—that is to say from the rotational speed development of the crankshaft.
However, the mere knowledge that a fault of some kind is present is normally not sufficient to provide a remedy. To eliminate the fault, positive diagnosis of the malfunction is necessary, wherein the causes of misfiring and/or rough engine running may differ widely.
With present diagnostic systems, an accurate diagnosis is highly complex and requires various items of information from different subsystems of the internal combustion engine. Even a distinction between mechanical problems in the cylinder (for example in the tribological pairing), on the one hand, and problems in terms of the gas charging (charge exchange) or in the air path, on the other hand, is difficult to establish during a workshop visit by the customer with the functionally impaired engine.
A workshop visit with a rough-running engine can therefore be disappointing for the customer with regard to the likelihood of success in attaining an accurate first diagnosis.
Against this background, it is an object of the invention to make possible improved identification of a fault causing rough engine running and/or misfiring, and in particular to provide improved diagnosis of charge exchange behavior of an internal combustion engine with multiple cylinders.
This object is achieved by means of a method for the diagnosis of charge exchange behavior of an internal combustion engine, a diagnostic tool for diagnosing charge exchange behavior of an internal combustion engine, and an internal combustion engine, in accordance with the claimed invention.
According to one aspect of the invention, a method for diagnosing charge exchange behavior of an internal combustion engine with multiple cylinders is provided, which method is suitable in particular for identifying a fault causing rough engine running and/or misfiring. The method has at least the following steps:
a) Determining a diagnosis time window within a torque dropout of one of the strokes of the internal combustion engine. A diagnosis time window is to be understood in particular to mean a coherent time period as a fraction of a stroke (for example of one of the strokes of a four-stroke combustion) of the combustion in the internal combustion engine. In the present case, a torque dropout is to be understood in particular to mean a crank angle range in which the cylinder under consideration, and/or all cylinders of the engine, do not make any contextually relevant contribution to a propulsion torque.b) Identifying at least one of the cylinders, which is in a compression stroke at the start of the diagnosis time window. The identification of this/these cylinder(s) may be performed in particular by reading out available information from an operation model, in particular of the engine controller. In particular, in the case of a four-stroke engine with four cylinders, the one cylinder which is in a compression stroke at the start of the diagnosis time window is identified.c) Assigning a deviation type to the identified cylinder in a manner dependent on an ascertained rotational speed development of the internal combustion engine during the diagnosis time window. A rotational speed development is to be understood in the present case as the manner in which a rotational speed present at the crankshaft of the internal combustion engine develops during the diagnosis time window. A deviation type is to be understood in the present case to mean a particular peculiarity of the rotational speed development, which is assigned to a particular fault type which leads to rough engine running and/or misfiring. In particular, here, different predetermined rotational speed developments are assigned to different deviation types.
According to one embodiment, for the assignment of the deviation type, the following steps are performed:
c1) Ascertaining a peculiarity of a charge exchange characteristic variable on the basis of the ascertained rotational speed development. In particular, a cylinder pressure variable which is dependent on the rotational speed development and/or a rotational speed profile and/or a curve parameter of a development of the cylinder pressure variable may be used as charge exchange characteristic variable.c2) Comparing the ascertained peculiarity with predetermined peculiarities of the charge exchange characteristic variable which are assigned to different deviation types. In particular, a setpoint-actual value comparison is performed between the ascertained peculiarity and previously ascertained peculiarities which are regarded as representative for different particular fault types—which result in rough engine running and/or misfiring.c3) Assigning a deviation type to the determined diagnosis time window in accordance with the result of the comparison. In particular, a deviation type is assigned if the comparison has yielded a sufficient correlation—which is to be specified in accordance with routine considerations—between the ascertained peculiarity and a predetermined peculiarity of the charge exchange characteristic variable.
The result is then in particular a rough statement regarding the area in which the fault causing the rough engine running and/or the misfiring lies; for example, as a result of the method, it is possible to distinguish whether the deviation or the fault can be assigned to piston friction, to a preparation of a combustion mixture or to a feed of fresh air and/or recirculated exhaust gas. Furthermore, by means of a process of elimination, it is also possible to specify areas of the causal fault where the fault is suspected not to lie.
According to one embodiment, in order to perform diagnosis for all cylinders in the internal combustion engine, a torque dropout is respectively identified for each cylinder, at the start of which torque dropout said cylinder is in the compression phase, and a corresponding diagnosis time window is determined in said torque dropout.
According to a further aspect of the invention, a diagnostic tool for the, in particular on-board, diagnosis of charge exchange behavior of an internal combustion engine, in particular of a four-stroke internal combustion engine, with multiple, in particular four, cylinders, is provided, which diagnostic tool serves in particular for identifying a fault causing rough engine running and/or misfiring. The diagnostic tool has at least one acquisition unit which is configured to acquire a rotational speed of a crankshaft of the internal combustion engine, in particular a corresponding sensor unit and/or access to a stored suitable operation model.
Furthermore, the diagnostic tool has a processing unit which is at least configured i) to control the acquisition unit. The processing unit is additionally configured ii) to determine a diagnosis time window within a torque dropout of one of the strokes of the internal combustion engine, iii) to identify at least one cylinder which is in a compression stroke at the start of the diagnosis time window, and iv) to assign a deviation type to the identified cylinder in a manner dependent on an ascertained rotational speed development of the internal combustion engine during the diagnosis time window.
According to a further aspect of the invention, an internal combustion engine with multiple, in particular three, four or six cylinders is provided, which has at least one diagnostic tool according to an embodiment of the invention.
The invention is particularly easy to implement in an internal combustion engine with four cylinders, which is in particular in the form of a four-stroke internal combustion engine, owing to the isochronal alternation between the individual strokes of the various cylinders. Other numbers of cylinders are of course also possible in other embodiments.
The invention is based inter alia on the consideration that the cycles of a four-stroke internal combustion engine (intake, compression, working cycle, exhaust) overlap in terms of time between the individual cylinders—they occur in parallel with one another in different cylinders.
The invention is now based inter alia on the concept of identifying a time window directly prior to the ignition in the cycles, which time window contains no significant build-up of propulsion torque, that is to say in which the crankshaft continues to rotate substantially exclusively owing to inertia. In this time window, the drop in rotational speed (for example start of time window vs. end of time window) is then for example identified. This is made up of friction losses in the mechanism and the piston braking owing to the gas compression.
If, in this time window, diagnosis is performed on specifically that cylinder which is presently in its compression stroke, the influence thereof on the rotational speed profile can be examined most effectively: this is because, in the compression phase, a cylinder has the greatest influence on the profile of the rotational speed, because it brakes the mechanism with the greatest intensity owing to the compression of the gas spring; with much greater intensity than the braking imparted by the other strokes.
The approach according to the invention of ascertaining the torque development during the—substantially—torque-free diagnosis time window makes it possible, with different, possibly combinable, charge exchange characteristic variables, to perform, on the basis of this torque development, a comparison with previously ascertained, fault-specific peculiarities—possibly stored in an operation model—of the respective charge exchange characteristic variables.
This makes it possible to roughly localize the fault causing rough engine running and/or misfiring to these predetermined deviation types (in the present case also referred to as fault types if the deviation is associated with a relevant erroneous build-up of torque). Deviation types or fault types may for example be: 1) insufficient or excessive charging of the cylinder with fresh air and/or recirculated exhaust gas; 2) insufficient compression of the cylinder; 3) excessive mechanical friction in the cylinder; 4) premature ignition and/or other irregular combustion.
With the rotational speed acquisition, for this purpose, use is made in particular of existing sensor means (rotational speed acquisition) with enhanced functions. The capabilities of the existing rotational speed acquisition at the engine, in particular at the crankshaft, have hitherto not been utilized to perform such a rough classification of the causal faults.
The invention makes it considerably easier to establish causes for rough running problems including misfiring, in particular by identification of the problem in the gas charging (charge exchange) or a blockage of the air path.
Online data acquisition of the diagnosis results during driving operation, which is to be performed according to one embodiment, makes it possible for the workshop to access real driving situations and thus in particular permits a more directed execution of servicing operations and/or a faster execution of maintenance work. As a consequence of the latter, this gives rise to lower warranty costs, greater customer satisfaction and/or fewer repeat repairs.
According to various embodiments of the invention, diagnostic methods are possible on the basis of different charge exchange characteristic variables. Advantageous embodiments described below present possible method steps for different charge exchange characteristic variables.
According to one embodiment, in order to support an implementation of the method with the lowest possible processing intensity, for the ascertainment of the rotational speed development, a rotational speed difference is calculated from a rotational speed value at the start of the diagnosis time window and a rotational speed value at the end of the diagnosis time window.
In particular, then, a pressure characteristic number calculated on the basis of the ascertained rotational speed difference, said rotational speed difference being ascertained in particular in the compression stroke, is used as charge exchange characteristic variable.
For this purpose, according to one embodiment, it is sufficient to perform a balancing of the rotational speed drop with the aid of mechanical equations. This balancing makes it possible to infer the compression pressure prior to the ignition. The compression pressure is directly related to the cylinder charge and thus to the enclosed air mass in the individual cylinder. A deviation detection can thus relate running roughness faults to the charge exchange or rule out the charge exchange as a cause.
This implementation of an analytical method by means of a formula system in the time domain can be used effectively in particular above mean engine load and up to mean rotational speeds, in particular in the case of smooth and continuous rotational speed profiles, and is based in particular on a calculation of a pressure characteristic number in the cylinder during the compression from the rotational speed profile. An exemplary use is illustrated in the first exemplary embodiment of the description of the figures.
In order to permit a diagnosis even if no rotational speed signal can be read out in the diagnosis time window, in one embodiment, for the ascertainment of the rotational speed development, a pressure profile in the cylinder during the diagnosis time window is ascertained, in particular is estimated and/or read out from an operation model, wherein the rotational speed development is in particular derived from the ascertained pressure profile. In particular, then, at least one curve parameter of the ascertained pressure profile is used as charge exchange characteristic variable. Such an approach is however very processing-intensive, and should therefore be used in particular if the rotational speed signal is not available with sufficient quality.
This recursive method in the time domain can be used effectively in particular above mean engine load and up to mean rotational speeds, and is based in particular on a definition of suitable parameters of a pressure profile for the forward simulation of an erroneous rotational speed signal. An exemplary use is illustrated in the second exemplary embodiment of the description of the figures.
In one embodiment, the diagnostic tool is, for the assignment of the deviation type, configured to ascertain a peculiarity of a charge exchange characteristic variable on the basis of the ascertained rotational speed development, to compare the ascertained peculiarity with predetermined peculiarities of the charge exchange characteristic variable which are assigned to different deviation types, and to assign a deviation type to the determined diagnosis time window in accordance with the result of the comparison.
According to one embodiment, in order to be able to implement the various proposed embodiments of a method according to the invention with suitable hardware, the diagnostic tool is configured to carry out methods according to any embodiments of the invention.
Further features, advantages and possible uses of the invention will emerge from the following description in conjunction with the figures.

Diagnosis of a charge cycle behavior of an internal combustion engine

Bayerische Motoren Werke Aktiengesellschaft


The present invention relates to a plasticizer composition, a resin composition, and a method of preparing the plasticizer composition. The plasticizer composition comprising an isophthalate-based material; and an epoxy-based alkyl ester compound represented by Chemical Formula 1.

Conventionally, a plasticizer forms an ester through a reaction between an alcohol and a polycarboxylic acid such as phthalic acid or adipic acid. In addition, in consideration of domestic and international regulations for phthalate-based plasticizers harmful to humans, there is ongoing research on plasticizer compositions that can replace phthalate-based plasticizers such as terephthalate-, adipate-, and other polymer-based plasticizers.
Meanwhile, to manufacture products such as flooring materials, wallpaper, sheets, interior and exterior materials for automobiles, films, electric wires and the like, the use of a suitable plasticizer is required in consideration of migration, volatile loss, extension, elongation, plasticizing efficiency and the like. According to properties required according to the type of industry in such various applications, i.e., tensile strength, elongation, light resistance, migration, gelation properties and the like, a PVC resin is mixed with a plasticizer, a filler, a stabilizer, a viscosity reducing agent, a dispersant, an antifoaming agent, a foaming agent or the like.
For example, among plasticizer compositions applicable to PVC, when inexpensive diethylhexylterephthalate is used, plasticizing efficiency is low, an absorption rate of the plasticizer is relatively low, and light resistance and migration are also poor.
Therefore, there is a need to develop products of a novel composition such as products with superior properties to diethylhexylterephthalate, and continuously conduct research on the most suitable technology for the use thereof as a plasticizer for vinyl chloride-based resins.

Plasticizer composition, resin composition and method of preparing the same


The invention discloses a hand warmer step-less regulating circuit, and relates to the field of hand warmer regulating circuits; the hand warmer step-less regulating circuit comprises a comparing chip, pin 2 of the chip is connected with an NTC temperature sensor, the NTC temperature sensor is connected with a power supply VCC through resistor R16, pin 8 of the chip is connected with the power supply VCC, the power supply VCC is connected with light-emitting diode D3, and light-emitting diode D3 and the power supply VCC are connected with resistor R13 in series; pin 5 is connected with an output end of the NTC temperature sensor; by arranging the slide rheostat or an encoder, any temperature in a required area can be reached through heating, and any temperature required by a user can be maintained to realize a better temperature experience.

A hand warmer is a kind of automatic warming health care product that is developed by using physical and chemical principles. With the gradual popularization and use of lithium batteries, hand warmers with lithium batteries have been used more and more widely. The function of lithium batteries is mainly used, internal heating pieces can be used for heating, and USB interfaces are used for charging and discharging. However, single-button switches with fixed gears are generally adopted by existing hand warmers with lithium batteries, thus only fixed gears can be used to regulate the temperature. Generally, only temperature set by three gears can be reached, and temperature in other ranges cannot be achieved. Especially when the hand warmers are used outdoors, as the outdoor temperature is low, a low gear of a hand warmer with a fixed gear switch cannot meet the heating requirements, and the temperature set by a high gear would be too high, thus it is quite inconvenient to select gears.

Hand warmer step-less regulating circuit


A computer that can easily identify which setting items are enabled and which setting items are not enabled when conducting setup setting operations, and can efficiently conduct correct setup. Setup history information is stored when the use environment settings are executed in the computer, the user and/or others can identify and display in an easily recognizable state the setting items from among many setting items in which the setting values set during the setup setting operation are not reflected in the use environment of the computer.

1. Field of the Invention
The present invention is related to a computer having a setup function setting device for setting the use environment of the computer (referred to hereinafter as "setup"), and, more particularly, the present invention is related to a computer wherein an operator of the computer (referred to hereinafter as "user") can set the use environment by him/herself.
2. Description of the Related Art
Computers are conventionally provided with a setup function by which the user can set up the hardware environment. Recently, many functions that did not previously exist in conventional personal computers have been added to the setup functions of personal computers.
An example of setup functions of a notebook personal computer will be described below. A notebook personal computer is a small-size, lightweight portable personal computer. The notebook-type portable personal computer was developed mainly for uses such as connecting to a network from an external destination. When the notebook-type personal computer (PC) is used at an external destination, the environment differs from an office where ordinary computers are used, and often there is no convenient power supply source. As a result, batteries often power the notebook-type of personal computer, and a variety of techniques have been used to extend the length of usable battery time. An example of a technique used to extend the length of usable battery time is to have an energy-saving function that reduces the amount of power consumption and extends the usable battery time.
Furthermore, in addition to the energy-saving function, security functions are also used to prevent information leaks when the notebook-type PC is connected to the network via external destination points.
Accordingly, many functions have recently been added to computers that did not exist in conventional computers. As a result, when performing setup, it is necessary to setup many items that include the power saving functions and security functions.
Furthermore, in the past, the display screens generally used during setup were display screens controlled by a Basic Input Output System (BIOS) program (hereinafter referred to as a "BIOS setup screen"). BIOS, which is normally stored in read-only memory (ROM), is a computer activation program that initiates operations when the power is turned on, and that conducts the most basic processing in relation to the hardware.
However, the general user does not ordinarily use the BIOS setup screen. Therefore, unless a highly trained personal computer user is operating the personal computer, it is very difficult to conduct the setup operations by oneself from the BIOS setup screen.
To simplify setup, commercial products have recently appeared that have functions to set the setup settings from display screens controlled by an operating system (referred to hereinafter as "OS") or by an application program (referred to hereinafter as "application") for some of the setup setting items, such as the energy saving function.
FIG. 4 is a block diagram of a conventional computer hardware configuration, and FIG. 5 is an example of a conventional BIOS setup screen.
As shown in FIG. 4, the computer hardware is mutually connected via a bus 60, and is provided with a central processing unit (CPU) 51 that controls all systems, a keyboard 52, a mouse (not shown in FIG. 4), a display device 53 for display, a system random access memory (SRAM) 54 used when operating the applications, a BIOS ROM 55 in which the BIOS program is stored, a ROM (not shown in the figure) to store a real time clock 56 operating as a timer, a CMOS memory 57 to store setting values relating to the BIOS setup, a backup battery 58 to supply power to the real time clock 56 and CMOS memory 57, a hard disk drive (HDD) 59 in which programs, such as the OS and applications, and data are stored, a floppy disk drive (FDD) (not shown in the figure), a compact disk-ROM (CD-ROM) drive (not shown in the figure), a communications control device (not shown in the figure), and various interface circuits (not shown in the figure).
The interface relationships between the computer hardware shown in FIG. 4 and software, such as the applications, OS and BIOS, are shown in FIG. 6. As shown in FIG. 6, a BIOS 73 has an interface (arrows a, b) to control the computer hardware 72, and directly controls the hardware 72. Moreover, the BIOS 73 also has an interface (arrows c, d, e, f) with the software that operates on the BIOS, such as the OS 77 and application 78. As shown in FIG. 6, the OS 77 that operates on the BIOS controls the hardware 72 through the BIOS 73. Furthermore, the BIOS 73 includes an interface control unit 74 that interfaces with the input devices, etc., a setup screen control unit 75 that controls the setup screen, and an initialization control unit 76 that conducts power on self test (POST) processing.
The application 78 can indirectly access the BIOS 73 (arrows e, f, g, h) through the OS 77, and has direct access to the BIOS 73 (arrows c, d) without going through the OS 77.
As described above, the hardware 72 can be set from the display screen controlled by the OS 77 or set from the display screen controlled by the application 78. In either case, the contents of these settings are always transmitted to the hardware 72 after having passed through the BIOS 73.
The type of computer does not specifically determine the type of setup method. This is because, of the various setting items, in addition to being able to make the settings from the BIOS setup screen, some setting items may be set from display screens controlled by the OS 77 or the application 78. Further, some setting items, which may be set only from the BIOS setup screen, cannot be set from the display screens controlled by the OS 77 or application 78, and depend on the BIOS specification or the OS and application specification that are operated on the BIOS 73.
For example, if there is no access to the hard disk for a fixed time, a hard disk timeout function that sets the time up to when the hard disk motor is stopped may be configured as described below.
The hard disk timeout function settings for personal computers that operate with Microsoft MS-DOS can be set only from the BIOS setup screen, and those set values are enabled. In contrast, for personal computers that operate with Microsoft Windows 95 or Microsoft Windows 98, in addition to settings from the BIOS setup screen, it is possible to make settings from the display screen controlled by Windows 95 or Windows 98 ("Windows" is a registered trademark of the Microsoft Corporation). Of the various setting values, the one having the shortest time is enabled. Moreover, if there is no keyboard input or data input for a fixed time, the display is automatically canceled, and the hard disk enters the standby state.
An auto-suspend timeout function to stop the CPU 51 is configured as described below. In personal computers that operate with Microsoft MS-DOS or Windows 95, the auto-suspend timeout function settings are possible only from the BIOS setup screen, and those setting values are enabled. In contrast, in personal computers that operate with Windows 98, in addition to making settings from the BIOS setup screen, it is possible to make settings from the display screen that is controlled by Windows 98. In this case, the settings from the BIOS setup screen are disabled, and only the setting values from the display screen controlled by the OS (Windows 98) are enabled.
Nonetheless, the setup method described above is only listed in the BIOS operating manual and, as shown in FIG. 5, the BIOS setup screen does not identify and display whether or not the setup settings are actually enabled. Because the BIOS setup screen does not identify whether the settings are actually enabled, for example, if a new version of the OS or the application is installed, there may be setting items (referred to hereinafter as "substitutable setting items") which have been modified from the setting contents that were set from the setup screen controlled by the BIOS, and the settings set from the display screens controlled by the OS or the application have priority. A user who is only experienced performing setup with the BIOS setup screen may not know this fact. In this case, the user performs setup by the same operational method as before, but the desired setting values are not achieved.
The specific process by which the setup is executed in relation to the hardware when turning on the power supply will be described below. In the discussion below, it will be assumed that Windows 98 is the operating system.
Because the BIOS is used when the power is turned on, the BIOS executes the environmental settings in relation to the hardware in accordance with the setting values for setup that are pre-stored in memory (referred to hereinafter as the "BIOS setting values"). After the setup based on the BIOS setting values is complete, the OS is activated. In the process of the OS being activated to set the "hard disk timeout function" or the "auto-suspend timeout function," the OS directs the BIOS to overwrite the BIOS setting values that were once set in relation to the hardware with setting values from the display screen controlled by the OS, and the hardware settings are overwritten. As a result, the environmental settings that were actually executed produce a state that is completely different from the setting values desired by the user.
If the user notices this state and attempts to reset the setting values from the BIOS setup screen, the user has to restart the power source and open the BIOS setup screen once again. Nonetheless, the BIOS setting values that were previously set by the user him/herself from the BIOS setup screen will be displayed on the BIOS setup screen. The set values of the use environment in the period immediately prior to turning on the power source (referred to hereinafter as the "prior power source cycle") will not be displayed on the BIOS setup screen. For this reason, the user mistakenly thinks that some kind of trouble has occurred in relation to the difference between the set values and the actual environmental settings, and performs the wrong countermeasures. As a result of these inappropriate countermeasures, a problem arises in that the correct setup may not be executed.
Even assuming the user knows that there are substitutable setting items among the setting items displayed on the BIOS setup screen, if the setup is conducted correctly, it is necessary to look at a manual or to seek out a trained person to confirm which setting items are substitutable by the OS or by an application, and an effective process does not occur.
Conducting the setting operations for the computer setup as described above takes a long time, and places a large burden on a user who wants to set the setup settings effectively in a short period of time.

System for identifying, based on setup use history, and displaying a setup of a system to indicate enabled and disabled setting items to a user


A low-temperature process for selectively etching oxide with high selectivity over silicon in a high-density plasma reactor. The principal etching gas is a hydrogen-free fluorocarbon, such as C.sub.2 F.sub.6 or C.sub.4 F.sub.8, to which is added a silane or similar silicon-bearing gas, e.g., the monosilane SiH.sub.4. The fluorocarbon and silane are added in a ratio within the range of 2 to 5, preferably 2.5 to 3. The process provides high polysilicon selectivity, high photoresist facet selectivity, and steep profile angles. Selectivity is enhanced by operating at high flow rates. Silicon tetrafluoride may be added to enhance the oxide etching rate. The process may operate at temperatures of chamber parts below 180.degree. C. and even down to 120.degree. C. The process enables the fabrication of a bi-level contact structure with a wide process window.

The level of integration in semiconductor integrated circuits continues to increase. The next generation of dynamic memories will have a capacity of 64 megabits and that of microprocessors will have upwards of ten million transistors. Further generations are being planned. These densities are obtainable only by the continuing shrinkage of feature sizes, now pushing towards 0.15 .mu.m. However, layer thicknesses cannot similarly shrink because of physical effects such as dielectric breakdown and resistive losses. Hence, current designs call for features with high aspect ratios, that is, the ratio of the depth of a feature to its width. For example, a via electrically connects two levels of metallization through an intervening dielectric layer. Since the dielectric layer is constrained to a moderately large thickness because of dielectric breakdown thresholds, a dense circuit requires very narrow vias, and the resulting aspect ratios are three and higher. Etching high aspect ratio holes requires a highly anisotropic etch.
A further problem is that for economic reasons, the size of wafers being processed is increasing. Most current high-production equipment is designed for 200 mm wafers, and equipment is being designed for 300 mm wafers. Such large wafers impose stringent uniformity requirements on the etching process.
Some of the increased density is being achieved by using more complex integrated circuit structures, which however impose additional requirements upon the processing, particularly in etching. An example is the structure for a bi-level contact shown cross section in FIG. 1. A silicon substrate 10 includes unillustrated structure already formed therein that requires contacting from an upper level. A first oxide layer 12, for example, of plasma-deposited silicon dioxide, is formed over the silicon substrate 10. A relatively thin polysilicon interconnect 14 is deposited and defined over the first oxide layer 12, and a second oxide layer 16 is deposited over both the interconnect 14 and the first oxide layer 10. Thereafter, a single photolithographic etching step using a single photomask etches both a relatively shallow via hole 20 to the polysilicon interconnect 14 and a deeper substrate contact hole 22 to the silicon substrate 10. It is to be appreciated that a very similar process may be used where both of the holes are used to contact respective polysilicon interconnects on different levels.
The bi-level contact structure requires an etch process that is highly selective to silicon. That is, a process that selectively etches silicon oxide but etches silicon to a much less extent. If the selectivity is insufficiently high, the polysilicon interconnect 14 would be etched through while, under the same etching conditions, the thicker first oxide layer 12 is being etched through. Even in a less demanding structure, selectivity to silicon is greatly desired so that the oxide etch dependably stops on the underlying silicon to thus provide a wide process window for the etching. With poor selectivity, if the etch were performed for too short a time, the silicon would not be exposed, and if it were performed for too long a time relatively thin underlying silicon layers would be etched through. Process variables make a precisely timed etch difficult to implement commercially.
Oxide etch selectivity has been achieved in a plasma reactor with a fluorocarbon etching gas and a fluorine scavenger. A fluorocarbon as used in this application is a compound consisting only of carbon, fluorine, and possibly hydrogen. A hydrogen-free fluorocarbon consists only of carbon and fluorine. Examples of hydrogen-free fluorocarbon etching gases are CF.sub.4, C.sub.2 F.sub.6, C.sub.4 F.sub.8. On the other hand, a hydrofluorocarbon compound also contains at least one carbon atom, for example, CHF.sub.3. It is believed that under common conditions most fluorocarbon gases deposit a polymer on all surfaces. However, if the polymer has a sufficiently low fluorine content, oxygen in an underlying silica (SiO.sub.2) layer reacts with the polymer to form volatile CO and CO.sub.2. That is, the underlying silica prevents the polymer from being formed, and the silica is etched. On the other hand, an underlying layer of silicon (or silicon nitride, Si.sub.3 N.sub.4) does not contain oxygen, and the polymer deposits faster than it is etched to thereby protect the underlying silicon layer from being etched. As a result, etching of the via and contact holes 20, 22 proceeds until silicon layers 14, 10 are reached, at which point etching stops or is substantially reduced.
The selectivity provided by the polymer depends, however, on the polymer having a relatively low fluorine content. Silicon is the most preferable of a number of materials known to scavenge fluorine from a fluorocarbon plasma. The silicon reacts with the fluorine radicals F* in the plasma, and any polymer resulting from the plasma then has a low fluorine content. Generally, however, the silicon requires some activation. Rice discloses thermal activation of the silicon in U.S. Pat. No. 5,477,975. It has been recognized that alternatively the silicon can be activated with RF biasing of the silicon electrode. See for example U.S. Pat. No. 5,556,501 to Collins et al. and European Patent Application 552,491-A1.
Schneider et al. in U.S. patent application Ser. No. 08/734,015, filed Oct. 18, 1996, incorporated herein by reference, address these many problems involved in oxide etching. Among several embodiments, they disclose the conically shaped plasma reactor 30 illustrated in cross section in FIG. 2. A wafer 32 is supported on a pedestal 34 that is preferably vertically movable with respect to a lower chamber body 36. A ring 37 surrounds the upper portion of the pedestal 34. In the examples described here, the ring 37 is composed of quartz and is left thermally floating. However, it is possible to form the ring 37 of silicon or silicon carbide and use it as a thermally activated fluorine scavenger. The heating can either rely upon the balance between plasma heating and active cooling or can rely upon, for example, controlled radiant heating of the silicon ring 37 if higher activation of the ring is desired.
An upper chamber assembly includes a conical dome 38 supported on the lower chamber body 36 through an electrical insulating joint including a plasma guard 40, a seal ring 42, and intervening support pads 44. Preferably, the conical dome is composed of an electrically insulating bulk body of sintered silicon carbide and an electrically conductive inner film of chemical vapor deposited (CVD) silicon carbide. Alternatively, the conical dome can be composed of high resistivity (.rho.>20 .OMEGA.-cm) polysilicon material. An RF inductive coil 46 supported in a coil carrier 48 is wrapped around the conical dome 38. The resistivities of the sintered and CVD silicon carbide portions of the conical dome 38 are chosen such that the RF magnetic field induced through the inductive coil 46 can pass through the dome 38 with minimal loss but the inner CVD film can be set to a predetermined electrical potential to provide a grounding plane.
An electrically insulating plasma guard 50 rests on the top inner rim of the conical dome 38 and in turn supports a roof 52. A vacuum O-ring or Vespel ring provides the electrical isolation. A center gas feed 54 is integrated with the roof 52 and supplies processing gas into the reactor 30 through unillustrated holes in the roof 52. Most of the remaining illustrated structure is involved with the temperature control of the conical dome 38 and the roof 52 and is fully described in the referenced patent application to Schneider et al. The roof thermal control includes a resistively heated plate 56 and a water-cooled chiller plate 57. The dome thermal control includes a resistively heated conical sheath 58 and a water-cooled collar 59.
The diameter of the exposed portions of the roof 52 is approximately equal to the diameter of the pedestal. That is, the two electrodes sandwiching the plasma have the same size.
For an oxide etcher, the roof 52 is preferably formed of an electrically conductive fluorine scavenger, examples of which are polysilicon, silicon carbide, and glassy carbon. Preferably, the conical dome 38 is formed of one of these same materials and has a conductivity sufficient to present an electrical grounding surface to the plasma. Typically, the etching gas is a fluorocarbon, and hexafluoro-ethane (C.sub.2 F.sub.6) has been extensively tested in the illustrated reactor for oxide etching. When RF power, typically in the frequency range of 1 to 2 MHz, is applied both to the coil 46 and across the two electrodes formed by the pedestal 34 and the roof 52, a fluorocarbon plasma is excited in the reactor 30, including a processing space 56 above the wafer 32. The fluorine scavenger is made to contact the plasma and to remove a certain amount of fluorine from the plasma. Thereby, any polymer formed on the wafer 32 from the fluorocarbon plasma is deficient in fluorine. As is now well known, a low-fluorine polymer can produce a highly selective etch to silicon, for example, in the bi-level contact structure of FIG. 1. In this approach, the activation is accomplished with substantially no heating of the roof and dome.
It is now known that one way to activate the solid fluorine scavenger is to apply RF energy to it. That is, the roof 52 is not merely grounded, but a significant RF signal is applied to it. As is shown in U.S. patent application Ser. No. 08/804,430, filed Feb. 21, 1997 by Wu et al., the electrical circuit in this use is illustrated schematically in FIG. 4. The conical dome 38 is electrically grounded, and its surrounding coil 46 is powered by a first RF power supply 60. A power-splitting RF power supply 62 is coupled through two coupling capacitors 64, 66 to both the roof 52 and the pedestal 34. An example of a power-splitting RF power supply 62 is schematically illustrated in FIG. 4. A second RF power supply 66 supplies single-phase RF power to a power splitting circuit 68. For example, the RF power is applied to the primary of a wide-band transformer 70. The secondary of the transformer 72 has a number of taps, and a switch 72 selectively connects any one of these taps to a predetermined potential such as ground. Respective ends of the transformer secondary are connected through the coupling capacitors 64, 66 to the roof 52 and the pedestal 34. Dependent upon the setting of the transformer tap switch 72, varying amounts of RF power are split between the roof 52 and the pedestal 34. In the illustrated position at the midpoint of the transformer secondary (which is not a recommended position, a lower fraction of RF power delivered to the roof 52 being desired) and assuming equal sizes for the roof 52 and the pedestal 34, equal amounts of RF power are delivered to the roof 52 and the pedestal. On the other hand, if a tap at the roof end of the transformer secondary is switched to ground, then the roof 52 is AC grounded and no RF power is delivered to the roof 52. This is the mode of operation that has been used by Rice et al. when the silicon-based fluorine scavenger is thermally activated. Tap positions between these two extremes split different ratios of power with a majority of power going to the pedestal 34.
Silicon-based scavenging for fluorine in the presence of a fluorocarbon etchant has also been applied to achieve high selectivity of oxide etching to an underlying layer of silicon nitride. Marks et al. disclose in U.S. Pat. No. 5,423,945 high selectivity to nitride can be achieved by use of either a silicon counter electrode or using a silicon-containing gas such as silane, but they offer the solid and gaseous silicon sources as alternatives.
Collins et al. have described an alternative approach to fluorine scavenging in U.S. Pat. No. 5,556,501. In one of several embodiments, they combine a fluorocarbon etching gas, such as C.sub.2 F.sub.6 or CF.sub.4, with a fluorine-consuming silicon-containing additive gas, such as silane (SiH.sub.4), tetraethylorthosilicate (TEOS), diethylsilane, or silicon tetrafluoride (SiF.sub.4). They also recommend using a polymer-forming additive gas such as CH.sub.3 F or CHF.sub.3. The same patent and its second-generation continuation application Ser. No. 07/941,507, filed Sep. 9, 1992, published as European Patent Application 552,491-A1, also disclose a silicon counter electrode and even RF powering of that electrode. However, Collins et al. consider the solid silicon scavenger as an alternative to a gaseous fluorine scavenger. Similarly, Tatsumi in U.S. Pat. No. 5,312,518 discloses both a silicon wall for scavenging fluorine in a sulfur halide etch and also discusses a C.sub.4 F.sub.8 etch, but he does not combine the two chemistries.
The power splitting discussed by Wu et al. provides good oxide selectivity at relatively lower temperatures, but it is desired to reduce the temperature even further, particularly to simplify the reactor design and lengthen the lifetime of temperature-sensitive parts such as O-rings. Also, RF activation of the solid silicon-based scavenger requires that an RF signal be applied to the roof, a further complication in the design and operation of the reactor.


A compensation membrane and a pen or the equivalent including a compensation membrane. The compensation membrane being configured for compensating a pressure difference between the outside and the inside of a free ink reservoir of a pen or the equivalent. The membrane including a first portion having a first rigidity and a second portion having a second rigidity, the first rigidity being less than the second rigidity.

Free ink pens are known that have an ink reservoir connected to a writing tip. Controlling the pressure and the leaktightness of such reservoirs under all circumstances (as the ink is used up or in extreme conditions such as onboard an airplane, at high altitude, at high temperatures, etc.), in particular under conditions that might lead to ink leaking via the writing tip, is a recurrent problem, and no known system is fully satisfactory.
For example, a baffle device is known (also known as a deflector or a labyrinth device) for controlling pressure in the reservoir. Depending on the pressure in the reservoir, the baffle device can become saturated with ink or can become emptied of ink so as to match the pressure inside the reservoir with the outside pressure, with this happening both while ink is being consumed and as a result of accidental pressure variations, while still feeding the writing tip with ink.
However, the baffle device on its own, as is to be found in most conventional pens, is not satisfactory: it operates essentially as a buffer having a vent connected to the outside and capable of storing a limited quantity of ink. Thus, if the ink reservoir is subjected to excessive overpressure, the buffer capacity offered by the baffle device can be insufficient and the pen can leak, e.g. via the vent of the baffle device. Conversely, if the pressure inside the reservoir is lower than outside, situations can arise in which the baffle device no longer manages to prevent the feed of ink to the writing tip being interrupted. There exists a need for a novel type of device for controlling pressure for free ink pens.

Pressure difference compensation membrane


A layer pad (10) comprises a substantially flat sheet (12) having first and second opposite substantially planar faces (14, 16). The layer pad (10) further includes at least one raised formation (18) on at least one of the faces (14, 16).

This invention relates to pads. More particularly, but not exclusively, this invention relates to layer pads for use on layers of a load. Embodiments of this invention relate to slip sheets for use between layers of a load.
Layer pads are used between layers of loads on pallets to hold the lower layer in place and provide a base for the upper layer. One example of a layer pad is disclosed in EP1833728A. It has been discovered, however, that some prior art layer pads have a tendency to warp after having been manufactured.


The invention relates to an ultrasonic flow meter arranged to measure a flow rate of a liquid, the flow meter comprises a flow tube 2, optionally a measurement insert, and two or more ultrasonic transducers 8 which are arranged in transducer inserts 20 to be inserted into the flow tube through openings in the flow tube. The transducer inserts are formed monolithically with the housing as a part of the bottom of the housing. The transducer inserts are in a mount position inserted through the openings in the flow tube to extend into the flow passage so that the surface 15 of the transducer inserts protrude into the flow passage. In this manner, gas bubbles, such as air bubbles, released from the flowing liquid will not rest in front of the transducer insert irrespectively of the orientation of the flow meter in the pipe installation.

In an ultrasonic flow meter, ultrasonic transducers emit ultrasonic signals into a flowing medium in order to measure the flow rate, or other parameters, of the flowing medium. Flowing liquids may contain gas bubbles, in particular air bubbles, which are continuously released from the liquid and into the pipe system. The released air bubbles reside in the pipe system as air pockets in cavities of the pipe system for a period of time until they are flushed away by the flowing liquid.
Ultrasonic flow meters installed in a pipe system may provide cavities in which released air can rest for a period of time. Air pockets in the pipe system need not be a problem, however for ultrasonic flow meters there is a risk that the air pockets interfere with the ultrasonic signal path and thereby interfere with the measurement and affect the accuracy. This is particularly a problem if the transducers reside at the highest point in the flow passage, since the space in front of the transducers may provide a cavity in which air can rest and adhere to the transducers.
In most compact flow meters, that is flow meters where the control electronics are mounted directly on the flow part, the control electronics as well as the display are positioned on the top side of the transducers. To avoid problems with gas bubbles that are caught in front of the transducers, the flow meter is rotated so that the transducers are moved away from the area of the highest point. However this results in that the display is also rotated away from a vertical view. Flow meters are installed in a variety of tube installation. In many situations, optimal visibility of the display would be achieved with a display pointing vertically upwards.
EP 1 967 828 A1 discloses a flow meter with a holding mechanism for a display which can be attached to a flow tube to ensure that the transducers are tilted away from the area of the highest point to avoid problems with air bubbles, while the display can be mounted in a horizontal plane to ensure a vertical viewpoint. While the problem with air bubbles is solved, the solution requires an elaborate holding mechanism.
DE 10 2007 011 547 A1 discloses, in FIG. 5, a flow meter where two transducers are inserted into the central area of the flowing fluid with opposing surfaces, since air bubbles by virtue of gravitation seek the top most part of the flowing fluid, such a flow meter construction would not have problems with air bubbles attaching to the transducers, irrespective of orientation of the flow tube. However, fabrication and mount of the transducer inserts is a difficult task.
WO 2007/020375 A1 discloses a flow meter where the transducers are mounted outside a bending flow tube, so that two transducer surfaces oppose each other in the central area of the flowing fluid. Such a flow meter construction would not have problems with air bubbles attaching to the transducers, irrespective of orientation of the flow tube. However, the meter construction requires a bend flow tube, opposing transducers and electrical connection of the transducers in the form of wires attached to the transducers and lead to the control electronics.


The present invention provides a group of water-soluble sulfur dye having carboxyl groups. For the kind of dye, a sulfur dye is first reduced to a leuco compound by sodium sulfide, and the leuco compound reacts with an active compound containing carboxyl groups to obtain a water-soluble sulfur dye containing the carboxyl group. The water-soluble sulfur dye provided by the present invention is applicable to dying of cotton, wool, silk, and leather. Being both water-soluble and carboxyl group reactive, the product has a simple application process and desirable color fastness, thereby having broad application prospects.

Sulfur dye is a group of dye containing sulfur. It contains sulfur bonds consisting of two or more sulfur atoms in its molecule. When in application, it can be reduced to leuco dye to dissolve in water and dye the fiber. The features of sulfur dye are short production process, low prices, good stability, convenient application and it is a popular dye which can be applied to the dyeing of fiber, such as cotton, linen, rayon, etc. However, sulfur dye is insoluble in water and when it is use do dye something it needs sodium sulfide or other reducing agents to reduce the dye into soluble leuco dye. Lecuo dye can be dyed on fibers because of its affinity to fibers, and then can be restored into its insoluble state after oxidation coloration so that it can fix on fiber. For ease of use, the common sulfur dyes are reacted with sodium sulfite or sodium hydrogen sulfite to produce thiosulfate of dye whose solubility is 150 g/l at 20° C. and can be used in continuous dyeing. However, it does not have affinity with the fibers and the dyeing liquor should be pad dyeing to the fiber and then treated with reducing solution to make the dye generate leuco dye with high affinity and can be attached to fibers. Then it should be watered and oxidation fixing the color. The feature of this dye is good levelness. However, it is not common to applied in the dyeing cellulose fibers, but often applied in paper dyeing. Introducing carboxyl group to sulfur dye structure to synthesize carboxylic acid type sulfur dye which can not only give good water solubility to the dye but also make the dye can be combined with fiber (cotton, wool, silk and leather) with the covalent bonds by making use of the reaction of carboxyl group and therefore gives sulfur dye good application features. As a result, the development of carboxylic acid type sulfur dye in recent years has caught people's attention.
U.S. Pat. No. 5,383,961 use common sulfur leuco dyes to react with chloroacetic acid in aqueous medium to prepare carboxylic acid type water-soluble sulfur dyes with good water solubility and the contents of carboxyl groups are between 5 to 20%. The salt-free dyes synthesized can be obtained with precipitating in acid, filtering, washing with water, and the salt can also be removed with membrane separation. Professor ZHANG Shufen from Dalian University of Technology uses Sulphur Black to react with chloroacetic acid to obtain carboxylic acid type water-soluble sulfur dyes and the carboxyl group content of dye reaches 11.9% (Chinese Chemical Letters, 2005, 16 (4): 554-556; Coloration Technology, 2007, 123 (3):191-196).
Water-soluble sulfur dye containing carboxyl group is a research direction of the improvement and gentrification of sulfur dye. Currently, the only reported carboxylic acid type sulfur dyes are generated by the reaction of sulfur dyes with α-chlorinated carboxylic acid. There is no research on carboxylic acid water-soluble sulfur dyes generated by the reaction of sulfur dyes with other active compounds containing carboxylic acid to introduce the carboxyl group into the dye.

Carboxylic acid type water-soluble sulfur dye


A laser straight ruler having a main body and a beam scanner installed on the main body. A laser beam is scanned to form a beam spot on an object. A position sensing device receives a laser beam reflected by the object and senses a position of the beam spot. A signal processing unit drives the beam scanner and processes a signal of the position sensing device. A display displays a change in a distance between the main body and the object and data including a measured distance value from the signal processing unit. An input portion inputs data including adjustment of a scanning width of the beam spot and sets start and end positions of the measured distance. A straight distance of the object is measured or the beam spot having a scanning width corresponding to a measured distance or a predetermined distance is projected to the object.

1. Field of the Invention
The present invention relates to an optical non-contact laser straight ruler and a method for measuring a distance and projecting a line using the laser straight ruler, and more particularly, to an optical non-contact laser straight ruler which can measure the distance of an object in three dimensions and reproduce the distance of the object, and a method for measuring a distance and projecting a line using the laser straight ruler.
2. Description of the Related Art
In general, a measuring tape or bar ruler which is used to measure a distance or draw a line in a contact manner is inconvenient to carry and difficult to measure the distance such as height or width of an object placed at a position that one cannot easily access. To address the problem, a straight ruler which can measure a distance optically in a non-contact manner is needed.
FIG. 1 shows a conventional non-contact type measuring device which is disclosed in U.S. Pat. No. 4,494,874. Referring to FIG. 1, the conventional non-contact type measuring device measures an object in a triangulation method and includes a projector 3, a camera 5, and a control portion 7. The projector 3 projects a laser spot SL that is movable onto an object 1 to be measured. The camera 5 photographs the laser spot SL illuminated onto the object 1 to measure the light intensity and position of the laser spot SL. The control portion 7 receives a signal proportional to the intensity of light received by the camera 5 and adjusts the amount of light projected by the projector 3.
Thus, the object 1 is scanned by flying the laser spot SL illuminated onto the object 1 so that three dimensional information of the object 1 can be obtained in a triangulation method from a signal measured in synchronization with the scanning. In the meantime, since the use of the conventional non-contact measuring device is restricted to the obtainment of the three dimensional information of the object 1, the application field of the device is limited.

Laser straight ruler and method for measuring distance and projecting line using the straight ruler


A filtration system for filtering particulates from air. A plurality of point ionization sources are positioned in the proximity of the periphery of an air flow channel and being oriented to generate ions in the proximity of the air flow channel in a direction generally upstream from each respective one of the plurality of point ionization sources. A particulate collection surface is positioned within the air flow channel in a downstream direction from the plurality of point ionization sources. The particulate collection surface is electrostatically charged in an opposite direction with respect to ground than the electrical charge of the ions. An ion trap is positioned within the air flow channel between the plurality of ionization sources and the particulate collection surface. The ion trap is relatively electrically neutral as compared with the particulate collection surface and the ions.

One type of prior art clean air filtration system employs an ionizer to create ions which attach themselves to dust and dirt particles. The charged particles are then collected such as in a filter or an electrostatic precipitator. The efficiency of such a system depends heavily on the effectiveness of the ionizer to create charged particles which can then be collected.
Traditionally, two types of ionizers have been used in clean air filtration systems (room purifiers) to enhance the performance of the filter used to collect dust and dirt particles.
One type of ionizer consists of a plurality of wires and ground plates. When a high voltage is applied to the plurality of wires, the electric field created between the wires and plates breaks down air molecules, creating large numbers of ions. The ions move to the ground plates at very high speed and collide with dust and dirt particles in the air, transferring electrostatic charges to the dust and dirt particles. These wire-plate type of ionizers are usually disposed upstream of a filter system to pre-charge dust and dirt particles for collection in the filter system. While an effective mechanism for charging particles, this type of ionizer is expensive to construct, requires a high operating current, making it expensive to operate, and is a potential safety hazard due to the very high voltages and high currents employed. This type of ionizer is commonly used in controlled air spaces such as furnace and air conditioning ducts.
Another type of ionizer, which is widely used in room air cleaners or purifiers, is a point ionizer. In a point ionizer, a high voltage, but a much lower current than is typically used in a wire-plate type ionizer, is applied to a point electrode or electrodes to create ions. Again, these ions charge particles of dust and dirt and thereby enhance the performance of a filter.
It is typical of these cleaners or purifiers for the point ionizers to be positioned at or near the exit of the air passing through the cleaners or purifiers. Typically, this is done to disperse ionized particles throughout the room. At least some of these ionized particles would then find their way back to the inlet of the cleaners or purifiers and aid in the operation of the cleaners or purifiers.
An example of an exit point ionizer is U.S. Pat. No. 4,376,642, Verity, Portable Air Cleaner Unit, which describes a portable air cleaner unit. An air mover such as a fan is disposed downstream of the main filter, and an exposed negative ion source is disposed downstream of the fan on the external surface of the air outlet. The main filter consists of fibers shredded from a non-carcinogenic plastic membrane which has been permanently electrostatically charged. The negative ion source ionizes the cleaned air as it leaves the cabinet.
Another example of an exit point ionizer is U.S. Pat. No. 5,268,009, Thompson et al, Portable Air Filter System, a portable air filter system for use in the home, offices, or other areas where it is desired to remove airborne particulate matter from the air. The air filter system includes an ionizer for supplying negative ions to the air exiting through the outlet. The ions charge foreign particles in the air. As a result, when the charged foreign particles are drawn into the inlet of the system, the particles are retained on the filter medium.
Still another example of an exit point ionizer U.S. Pat. No. 5,332,425, Huang, Air Purifier, which describes an air purifier having an extended and tapered discharging copper needle is electrically coupled to a high voltage generator contained within the purifier housing and produces negative ions. The discharging needle is pointed in contour and has an apex end located adjacent the air exit opening. The discharging needle extends in the direction of the passage of high pressure air from the purifier housing which allows the discharging needle to vibrate responsive to the high pressure air flow and increases the amount of negative ions mixed with the air passing from the purifier housing.
These exit ionizers are very effective at charging particles, and has much lower cost and little safety hazard. However, point ionizer systems typically are positioned at the air exit of the purifier, i.e., downstream of the filter. With exit air ionizers, charged particles are discharged into room air, and stay in the air for a significant amount of time before being re-circulated through the filter. As a result, a significant number of these charged particles are removed by other external surfaces such as walls, carpets, human bodies and furniture surfaces, instead of the filter.
Other ionizing filtration systems use point source ionizers at or near the air inlet to the filtration system. Typically, these filtration systems are designed to either disperse ions throughout the room, as do exit ionizers, or are designed to inject ions directly into the air stream within the air inlet of the filtration system.
An example of the type of air cleaning apparatus which diffuses ions throughout the room is shown in U.S. Pat. No. 5,980,614, Loreth et al, Air Cleaning Apparatus, which describes an air cleaning apparatus, especially for cleaning of room air. The device includes an ionizing device having a unipolar ion source formed by a corona discharge electrode, an electrostatic precipitator connected to a high-voltage source and having a flow-through passageway for air to be cleaned and two groups of electrode elements of one group being interleaved with and spaced from the electrode elements of the other group and arranged to be a potential different from that of the other group. While the corona discharge electrode is positioned near the air inlet to the apparatus, the corona discharge electrode is arranged such that the ions generated at the electrode can diffuse essentially freely away from the electrode and thereby diffuse substantially freely throughout the room in which the ionizing device is positioned. As such, the apparatus described in Loreth et al suffers from many of the same disadvantages as the exit ionizers discussed above.
Air filtration systems which are designed to inject ions directly into the air stream at or near the air inlet of the air filtration system or with the internal air stream of the filtration system typically do not achieve optimum efficiency in air cleaning. Typically, in these systems the number of ions generated and the ability of the ions generated to attach to particles of dust and dirt are limited both by the proximity of the ion generation source to the ion collector and by the limited length of time in which the ions have to attach to particles of dust and dirt in the air flow stream within the filtration system.
Thus, while many prior art systems exist which utilize ion generators, and which utilize point source ionizers, such prior art systems suffer numerous disadvantages as discussed above.
Some prior art air filtration systems utilize a centrifugal fan to move air through the filtration system. While such fans are efficient and are operational over a wide range of pressure drops, centrifugal fans are relatively noisy. As such, centrifugal fans suffer significant disadvantages for use in portable, room air filtration systems. Axial fans are considerably less noisy, deliver a uniform straight airflow and can be made very small but are very sensitive to pressure drops as such their use in filtration systems is limited.

This patent is subject to a terminal disclaimer.

Air filtration system using point ionization sources


A capture system may capture client events for an application session. Some client events may contain display information associated with screen gestures. The screen gestures may be associated with any user input that changes how images are displayed during the application session. For example, the screen gestures may comprise one or more of a scroll gesture, a touch start gesture, a touch move gesture, a touch end gesture, and/or a pinch gesture. In another example the screen gesture may comprise a reorientation of a device operating in the application session. A replay system may replay the application session based on the captured client events to recreate images displayed during the application session in response to the screen gestures.

Monitoring systems may monitor and capture user interface (UI) events during application sessions. For example, the application session may comprise a web session where the user accesses a website for purchasing a product on-line. The captured UI events may comprise user inputs, selections, and/or navigation through the webpages of the website. A replay system may replay the UI events to reproduce the images and states that the user viewed and created during the original application session. The replayed application session may identify problems or other conditions that the user experienced during the original application session.
More application sessions are being conducted on relatively small portable devices with touch screens, such as laptops, smart phones and notebook computers. The user may manipulate content displayed within the touch screen using screen gestures. For example, the user may zoom-in on an image by placing two fingers on the touch screen and performing a pinch-in gesture. In another example, the user may scroll to a different location of an image by sliding one of the fingers across the touch screen.
Screen gestures may be more common on smaller computing devices where touch screens provide the primary user interface. Screen gestures also may be more prevalent in smaller computing device with smaller display screens that require more screen manipulations to view the correct information on displayed webpages.
Current monitoring systems may not adequately capture screen gestures and thus may not be able to accurately recreate some user experiences from the original application session. For example, current monitoring systems may only capture Hyper Text Markup Language (HTML) for webpages and use the HTML during replay to render the webpages.

System for capturing and replaying screen gestures

INTERNATIONAL BUSINESS MACHINES CORPORATION


An exothermic well tool and method of use for the repair of failure spots along a section of a first tubular conduit, such as casing, wherein the housing of the tool is heated to at least a temperature approximately in excess of that required to activate and melt an exothermic metal alloy composition and may include an ignitable starter fuel charge with a series of solid activation fuel charges spaced throughout the chamber. The tool may also include a length of a second tubular conduit for positioning around the exterior of the housing to define an annular area relative to the first tubular conduit for deposit of a low temperature metal alloy therein.

(1.) Field of the Invention
The invention relates to an apparatus and method for the repair of failure spots along a first tubular conduit, such as casing, in a subterranean well.
(2.) Brief Description of the Prior Art
Subterranean wells, such as oil, gas or water wells, oftentimes are completed with the introduction and cementing in place a long string of tubular sections of metallic casing. Since the expected production life of such a well has been known to last decades, and in view of the fact that the abrasive well fluids and treatment chemicals flowing interiorally of the casing often result in defects, such as small holes, pock marks leading to small holes and cracks, ("failure spots") it is not at all surprising that a failure in circulation of the fluids oftentimes results, with the holes eventually getting larger and larger and even penetrating through the cement securing the casing within the well. It is therefore necessary from time to time to inspect the casing for such defects and attempt to repair them, as opposed to retrieving the entire casing string and running and setting another string of casing.
The present invention addresses the problems as set forth above.

Exothermic tool and method for heating a low temperature metal alloy for repairing failure spots along a section of a tubular conduit


A vacuum coating apparatus for forming a thin film evenly coated over a material to be treated as well as providing excellent productivity. The vacuum coating apparatus includes a chamber, an evacuating device, a fluid supplier, a hood, and a gas reservoir. During operation, the chamber is subjected to a partial vacuum by the evacuating device and filled with treatment fluid. At this time, air at predetermined temperature supplied from the gas reservoir is admitted into the chamber. As a result, the temperature and viscosity of the treatment fluid in the chamber become constant. The material to be treated is then fed into the chamber via an inlet port and an outlet port. An air flow caused by evacuation removes excess fluid on the material at the outlet port, resulting in evenly forming a thin coating film.

1. Field of the Invention
The present invention relates to a vacuum coating apparatus for forming a thin layer coating film of treatment fluids such as paints over the surface of a material with a long body, i.e., wood, to be treated.
2. Description of the Prior Art
As a coating apparatus for forming the thin layer coating film over the material to be coated, a brush, spray, roll coater, curtain coater, dip coater, blade coater, and the like are well known. When applying treatment fluids over the material surface, however, such known apparatus often causes the mist or gas of the treatment fluid to scatter around. Moreover depending on the type of such coating apparatus in use, special skill for the fluid application is required.
In order to solve the above problem, a vacuum coating apparatus for wood treatment has been invented (GB2145442B). As FIG. 4 shows, the apparatus has a chamber 91 through which a material 8 is passed via an inlet port 911 and an outlet port 912, an evacuating device 92 by which the chamber 91 is subjected to a partial vacuum, and a fluid supplier 93 from which treatment fluid 7 is supplied to the chamber 91.
The material 8 is continuously fed into the chamber 91 through the inlet port 911 to be drawn out thereof through the outlet port 912. At this time, the chamber 91 is kept subjected to a partial vacuum by the evacuating device 92 so that the treatment fluid 7 is supplied into the chamber 91 from the fluid supplier 93. This causes air to flow into the chamber 91 via the clearances at the inlet port 911 and outlet port 912, resulting in an air flow 910 over the surface of the material 8. The air flow 910 removes excess fluid from the material 8 to have a thin layer coating film evenly formed over the surface thereof.
The apparatus of the above type is so constructed as to form the thin layer coating film over the material surface at high speed. The apparatus also prevents the fluid mist from scattering and requires no special skill for the fluid application. In FIG. 4, reference numerals 921, 922 designate exhaust passages, 931 and 94 designate a fluid passage, and roller guides, respectively.
With the apparatus of the known type, however, it is difficult to ensure to have the coating film thin and evenly applied over the material surface without lowering productivity and independent of the type of the treatment fluid in use, and change in the environmental temperature.
When treating the material, particularly wood, the thickness of the film to be coated thereon is often required to be 30 .mu.m or less in order to accentuate its natural grain. For such a treatment, a substantially thin film is formed over the wood surface only without filling the naturally formed vessels in the wood with the fluid. In case of coating the film so as to have relatively a large thickness, cracks occur in the film surface. Or in such a case, processing, i.e., cutting and nailing, the wood that has been treated with the fluid might also cause the film to be cracked.
A thin film can be formed over the material surface by decreasing the speed for feeding the material in the chamber. This method, however, considerably decreases the level of productivity.
When using a paint either of water-based nature or ultraviolet curing type as the treatment fluid in an apparatus of the known type, a film with desired thickness cannot be obtained in spite of decreasing the feeding speed. In case of using the ultraviolet curing paint, the viscosity of oligomer, a component thereof, cannot be lowered easily, thus preventing a sufficient reduction of the viscosity of the paint. Generally as TABLE 2 set forth hereafter shows, the viscosity of the treatment fluid is likely to vary with the temperature. The treatment fluid thus should be kept a predetermined temperature during coating. In the known apparatus, since outside air is admitted into the chamber through the inlet port and outlet port, the temperature in the chamber is likely to vary with the outside air temperature. The temperatures in the chamber in summer and winter, or early in the morning and daytime, thus, become different. This change influences the viscosity of the fluid, preventing the thin layer coating film to be evenly formed over the material surface.


Methods of fabricating a multi-layer semiconductor device such as a multi-layer damascene or inverted multi-layer damascene structure using only a single or reduced number of exposure steps. The method may include etching a precursor structure formed of materials with differential removal rates for a given removal condition. The method may include removing material from a multi-layer structure under different removal conditions. Further disclosed are multi-layer damascene structures having multiple cavities of different sizes. The cavities may have smooth inner wall surfaces. The layers of the structure may be in direct contact. The cavities may be filled with a conducting metal or an insulator. Multi-layer semiconductor devices using the methods and structures are further disclosed.

1. Field of the Invention
This invention relates, in general, to semiconductor manufacturing, and more particularly the invention typically relates to multi-damascene structures and methods for their fabrication.
2. Description of the Related Art
One of the primary challenges in the production of semiconductor devices involves the ability to create circuits of increasing density with smaller and smaller critical dimensions. As devices become smaller and have higher resolution, production costs become a greater concern, especially at the sub-micron level and smaller.
One type of conventional semiconductor manufacturing method is the damascene process. The damascene semiconductor processing method differs from conventional semiconductor processing methods in that the metal lines are not etched. Rather, the metal conductor is deposited in grooves formed within a dielectric layer. Excess metal is then removed by chemical mechanical polish (CMP) techniques and other techniques. In general, a single damascene process involves lithographic patterning, trench or hole imaging, gap filling with conductor, and then CMP. A dual damascene process typically involves repeating the damascene structure for one layer having a hole and another layer having a trench, and then simultaneously filling both the trench and the hole with metal.
The damascene process and the dual damascene process are popular for laying metal lines and interconnects on chips. An advantage of the damascene process is that the many of the processing problems associated with metal etch steps, including corrosion, resist burn, and time critical with resist are reduced. This is due in part to the use of lithographic patterning. Lithography processes, however, typically drive up the overall cost of the production process significantly.
Semiconductor manufacturing techniques typically involve several costly lithography steps. Conventional industry approaches utilize more than one ILD layer or etch stop to pattern the insulative layer. These approaches employ two separate lithographic and RIE steps to create a dual damascene cavity profile. Additional lithographic and material removal processes are required for each additional layer. The production complexity also increases exponentially with additional layers.
The lithographic imaging step is one of the most expensive steps in the device fabrication process. Also, the two RIE material removal steps add additional cost and complexity to dual damascene process.
Accordingly, there is a need for a method to create a multi-layer damascene pattern on a substrate with reduced complexity and costs. What is needed is a device and methods which overcome the above and other disadvantages.

Single exposure in multi-damascene process