Acid copper electroplating baths used to form ultra-fine circuitry features on semiconductor chips contain suppressor, anti-suppressor and leveler additives that must be closely controlled in order to obtain acceptable copper deposits. Cyclic voltammetric stripping (CVS) methods are available to measure the concentrations of the suppressor and anti-suppressor based on the effects of these additives on the copper electrodeposition rate. The present invention is a method that also uses measurements of the copper electrodeposition rate to determine the concentration of the leveler additive. The other two additives are included in the measurement solution at concentrations determined to provide the optimum compromise between minimal interference, high sensitivity and good reproducibility for the leveler analysis. In this case, measurement precision is greatly improved compared to that provided by inclusion of the interfering additives in the measurement solution at their concentrations in the bath sample at the time of the analysis, which would be the standard analytical procedure.

1. Field of the Invention
This invention is concerned with analysis of organic additives in plating baths as a means of providing control over the deposit properties.
2. Description of the Related Art
Electroplating baths typically contain organic additives whose concentrations must be closely controlled in the low parts per million range in order to attain the desired deposit properties and morphology. One of the key functions of such additives is to level or brighten the deposit by suppressing the electrodeposition rate at peaks in the substrate surface. Leveling/brightening of the deposit results from faster metal deposition within recessed areas where the additive, which is present at low concentration, is less effectively replenished by diffusion/bath agitation as it is consumed in the electrodeposition process. The most sensitive methods available for detecting leveling and brightening additives in plating baths involve electrochemical measurement of the metal electrodeposition rate under controlled hydrodynamic conditions for which the additive concentration in the vicinity of the electrode surface is well-defined.
Cyclic voltammetric stripping (CVS) analysis [D. Tench and C. Ogden, J. Electrochem. Soc. 125, 194 (1978)] is the most widely used bath additive control method and involves cycling the potential of an inert electrode (e.g., Pt) in the plating bath between fixed potential limits so that metal is alternately plated on and stripped from the electrode surface. Such voltage cycling is designed to establish a steady state for the electrode surface so that reproducible results are obtained. Cyclic pulse voltammetric stripping (CPVS), also called cyclic step voltammetric stripping (CSVS), is a variation of the CVS method that employs discrete changes in voltage during the analysis to condition the electrode so as to improve the measurement precision [D. Tench and J. White, J. Electrochem. Soc. 132, 831 (1985)]. A rotating disk electrode configuration is typically employed for both CVS and CPVS analysis to provide controlled hydrodynamic conditions. Accumulation of organic films or other contaminants on the electrode surface can be avoided by periodically voltage cycling the electrode in the plating solution without organic additives and, if necessary, polishing the electrode using a fine abrasive. The metal deposition rate can be determined from the current or charge passed during metal electrodeposition but it is usually advantageous to measure the charge associated with anodic stripping of the metal from the electrode. The CVS method was first applied to control copper pyrophosphate baths (U.S. Pat. No. 4,132,605 to Tench and Ogden) but has since been adapted for control of a variety of other plating systems, including the acid copper sulfate baths that are widely used by the electronics industry [e.g., R. Haak, C. Ogden and D. Tench, Plating Surf. Fin. 68(4), 52 (1981) and Plating Surf. Fin. 69(3), 62 (1982)].
Acid copper sulfate electroplating baths require a minimum of two types of organic additives to provide deposits with satisfactory properties and good leveling characteristics. The suppressor additive is typically a polymeric organic species, e.g., high molecular weight polyethylene or polypropylene glycol, which adsorbs strongly on the copper cathode surface to form a film that sharply increases the overvoltage for copper deposition. This prevents uncontrolled copper plating that would result in powdery or nodular deposits. An anti-suppressor additive is required to counter the suppressive effect of the suppressor and provide the mass-transport-limited rate differential needed for leveling. Plating bath vendors typically provide additive solutions that may contain additives of more than one type, as well as other organic and inorganic addition agents. The suppressor additive may be comprised of more than one chemical species and generally involves a range of molecular weights.
Both the suppressor and the anti-suppressor additive concentrations in acid copper sulfate baths can be determined by CVS analysis methods based on the effects that these additives exert on the copper electrodeposition rate. For the suppressor analysis, the CVS rate parameter, usually the copper stripping peak area at a given electrode rotation rate (Ar), is first measured in a supporting electrolyte having approximately the same composition as the plating bath to be analyzed but without organic addition agents. Additions of known volume ratios of the plating bath to the supporting electrolyte (or to a background electrolyte having known concentrations of other additives) produce decreases in the CVS rate parameter that reflect the concentration of the suppressor additive. This xe2x80x9cstandard additionxe2x80x9d suppressor analysis is not significantly affected by the presence of the anti-suppressor, which exerts a relatively weak effect on the copper deposition rate at the plating bath dilution levels involved. For the anti-suppressor analysis, a sufficient amount of the suppressor additive, which may be comprised of a plurality of components or species, is added to the supporting electrolyte to produce a background electrolyte exhibiting substantially the maximum suppression of the copper deposition rate (minimum CVS rate parameter). Additions of known volume ratios of the plating bath to this fully-suppressed background electrolyte produce increases in the CVS rate parameter that can be related to the concentration of the anti-suppressor additive. The exact procedures for CVS analysis of acid copper sulfate baths can vary.
Analysis for the suppressor additive (also called the xe2x80x9cpolymerxe2x80x9d, xe2x80x9ccarrierxe2x80x9d, or xe2x80x9cwetterxe2x80x9d, depending on the bath supplier) typically involves generation of a calibration curve by measuring the CVS rate parameter Ar in a supporting or background electrolyte (without organic additives or with known concentrations of interfering additives), termed Ar(0), and after each standard addition of the suppressor additive. For the calibration curve, Ar may be plotted against the suppressor concentration directly, or normalized as Ar/Ar(0) to minimize measurement errors associated with changes in the electrode surface, background bath composition, and temperature. For the suppressor analysis itself, Ar is first measured in the supporting electrolyte and then after each standard addition of a known volume ratio of the plating bath sample to be analyzed. The suppressor concentration may be determined from the Ar or Ar/Ar(0) value for the measurement solution (supporting electrolyte plus a known volume of plating bath sample) by interpolation with respect to the appropriate calibration curve (xe2x80x9cresponse curve analysisxe2x80x9d). Alternatively, the suppressor concentration may be determined by the xe2x80x9cdilution titrationxe2x80x9d method from the volume ratio of plating bath sample (added to the supporting electrolyte) required to decrease Ar or Ar/Ar(0) to a given value, which may be a specific numerical value or a minimum value (substantially maximum suppression) [W. O. Freitag, C. Ogden, D. Tench and J. White, Plating Surf. Fin. 70(10), 55 (1983)]. Note that the effect of the anti-suppressor on the suppressor analysis is typically small but can be taken into account by including in the background electrolyte the amount of anti-suppressor measured or estimated to be present in the plating bath being analyzed.
The concentration of the anti-suppressor additive (also called the xe2x80x9cbrightenerxe2x80x9d, xe2x80x9cacceleratorxe2x80x9d or simply the xe2x80x9cadditivexe2x80x9d, depending on the bath supplier) is typically determined by the linear approximation technique (LAT) or modified linear approximation technique (MLAT) described by R. Gluzman [Proc. 70th Am. Electroplaters Soc. Tech. Conf., Sur/Fin, Indianapolis, Ind. (June 1983)]. The CVS rate parameter, Ar, is first measured in background electrolyte containing no anti-suppressor but with a sufficient amount of suppressor species added to substantially saturate suppression of the copper deposition rate. A known volume ratio of the plating bath sample to be analyzed is then added to this fully-suppressed background electrolyte and Ar is again measured. The Ar measurement is then repeated in this mixed solution after each addition (typically two) of known amounts of the anti-suppressor additive only. The concentration of the anti-suppressor in the plating bath sample is calculated assuming that Ar varies linearly with anti-suppressor concentration, which is verified if the change in Ar produced by standard additions of the same amount of anti-suppressor are equivalent.
Acid copper sulfate baths have functioned well for plating the relatively large surface pads, through-holes and vias found on printed wiring boards (PWB""s) and are currently being adapted for plating fine trenches and vias in dielectric material on semiconductor chips. The electronics industry is transitioning from aluminum to copper as the basic metallization for semiconductor integrated circuits (IC""s) in order to increase device switching speed and enhance electromigration resistance. The leading technology for fabricating copper IC chips is the xe2x80x9cDamascenexe2x80x9d process (see, e.g., P. C. Andricacos, Electrochem. Soc. Interface, Spring 1999, p.32; U.S. Pat. No. 4,789,648 to Chow et al.; U.S. Pat. No. 5,209,817 to Ahmad et al.), which depends on copper electroplating to provide complete filling of the fine features involved. The organic additives in the bath must be closely controlled since they provide the copper deposition rate differential required for bottom-up filling.
As the feature size for the Damascene process has shrunk below 0.2 xcexcm, it has become necessary to utilize a third organic additive in the acid copper bath in order to avoid overplating the trenches and vias. Note that excess copper on Damascene plated wafers is typically removed by chemical mechanical polishing (CMP) but the copper layer must be uniform for the CMP process to be effective. The third additive is called the xe2x80x9clevelerxe2x80x9d (or xe2x80x9cboosterxe2x80x9d, depending on the bath supplier) and is typically an organic compound containing nitrogen or oxygen that also tends to decrease the copper plating rate. In order to attain good bottom up filling and avoid overplating of ultra-fine chip features, the concentrations of all three additives must be accurately analyzed and controlled.
The concentrations of the suppressor and anti-suppressor in acid copper plating baths can be analyzed with good precision in the presence of the leveler additive by the standard CVS methods. At the additive concentrations typically employed, the effect of the suppressor in reducing the copper deposition rate is usually much stronger than that of the leveler so that the concentration of the suppressor can be determined by the usual CVS response curve or dilution titration analysis. Interference from the leveler can be minimized by utilizing a background electrolyte for the suppressor analysis that contains approximately the same leveler concentration as in the plating bath being analyzed, estimated from the bath makeup composition and previous analyses. Likewise, the anti-suppressor concentration can be determined by the LAT or MLAT analysis procedure and the approximate bath concentration of leveler can be added to the fully-suppressed background electrolyte to minimize leveler interference. With some modifications, for example, to account for relatively high leveler activity or to reduce anti-suppressor interference on the suppressor analysis, these CVS procedures provide reliable measures of the suppressor and anti-suppressor additives used in currently-available acid copper electroplating baths. However, a method is needed for measuring the leveler concentration in the presence of interference from both the suppressor and anti-suppressor.
Since the suppressor and anti-suppressor concentrations can be independently determined, the obvious approach based on traditional chemical analysis practice would be to add these interfering additives, at the concentrations measured for the plating bath, to the background electrolyte used for the leveler analysis. In this matrix matching approach, the leveler concentration would be determined from the change in the CVS rate parameter produced by addition of a known volume ratio of the plating bath sample to the background electrolyte. A calibration curve would be generated by measuring the CVS rate parameter as a function of the concentration of leveler added to the same background electrolyte. However, since the suppressor and anti-suppressor concentrations in the plating bath vary with time, calibration curves would be needed for all combinations of suppressor and anti-suppressor concentrations that occur in the plating bath. An average calibration curve could be used but at a significant sacrifice in measurement accuracy. Furthermore, the sensitivity of the analysis to the leveler concentration is poor for some combinations of suppressor and anti-suppressor concentrations encountered during production operation.
There is a critical need for a method of determining the concentration of the leveler additive in acid copper baths with high precision under all bath operating conditions. It is also desirable to avoid the necessity of generating and utilizing a plurality of calibration curves, which is required for CVS analysis based on traditional analytical approaches.
This invention is a voltammetric method for measuring the concentration of a leveler additive in an acid copper sulfate electroplating bath also containing suppressor and anti-suppressor additives. The method is based on measuring the change in copper deposition rate produced by the leveler additive species. Interference from the suppressor and anti-suppressor additives, which also affect the copper deposition rate, is minimized by adjusting their concentrations in a measurement solution (comprised of sample of the plating bath and a background electrolyte), and in the background electrolyte used for calibration, to the optimum levels for analysis of the leveler. The copper deposition rate in this adjusted measurement solution provides an exceptionally sensitive and reproducible measure of the concentration of the leveler additive since the measurement is always made at the optimum concentrations of the interfering suppressor and anti-suppressor additives, which may be substantially higher or lower than their respective concentrations in the plating bath sample. Further improvement is provided by optimizing the voltammetric parameters used to measure the copper deposition rate so as to provide maximum sensitivity to the leveler and minimum interference from the suppressor and anti-suppressor. The optimum suppressor and anti-suppressor concentrations and optimum set of measurement parameters need to be determined for each additive system and, in some cases, for each additive batch. The analysis of the present invention also requires only one calibration curve for a given additive system. The concentrations of the suppressor and anti-suppressor additives in the plating bath sample are usually measured at the time of the leveler analysis but may sometimes be estimated with sufficient accuracy based on previous analyses.
The method of the present invention contrasts sharply with the obvious approach based on conventional analytical practice of utilizing a matrix matched background electrolyte containing the two interfering additives at their concentrations in the plating bath at the time of the analysis. In this conventional case, the change in copper deposition rate in the background electrolyte produced by addition of a known volume ratio of the plating bath sample also provides a measure of the leveler concentration. However, since the suppressor and anti-suppressor concentrations in the plating bath vary with time, calibration curves are needed for all combinations of suppressor and anti-suppressor concentrations that occur in the plating bath during operation. Furthermore, the sensitivity of the analysis to the leveler concentration and the extent of interference from the suppressor and anti-suppressor depend on the relative concentrations of these interfering additives. For some additive systems, additions of the leveler to copper plating solutions containing the normal levels of suppressor and anti-suppressor produces practically no change in the copper deposition rate so that the conventional matrix matching approach cannot be used.
The copper deposition rate for the method of the present invention is preferably determined by cyclic voltammetric stripping (CVS) or cyclic pulse voltammetric stripping (CPVS). The latter is also called cyclic step voltammetric stripping (CSVS). As used in this document, the term xe2x80x9ccyclic voltammetric strippingxe2x80x9d or xe2x80x9cCVSxe2x80x9d implicitly includes the CPVS method, which is a variation of the CVS method. Likewise, the term xe2x80x9cCVS rate parameterxe2x80x9d includes the analogous CPVS voltammetric rate parameters. In these methods, the potential of an inert electrode, e.g., Pt, is cycled in a plating solution, at a constant rate or in steps, so that copper is alternately plated on the electrode surface and anodically stripped back into the solution. Potential cycling improves the reproducibility of the results by establishing steady-state conditions at the electrode surface. A rotating disk electrode configuration is typically used to provide the well-defined hydrodynamic conditions that are also needed for reproducible results. The copper deposition rate is typically measured via the copper stripping peak area with electrode rotation (Ar) but might also be determined from the stripping peak height, or from the electrode impedance, current or charge corresponding to a given cathodic potential or potential range (with or without electrode rotation). Improved reproducibility and accuracy may be provided by using a normalized CVS rate parameter, for example, the ratio Ar/Ar(0) of the stripping peak area for the measurement solution to that for a supporting electrolyte without additives or to that for a background electrolyte with known concentrations of interfering additives.
Preferably, the suppressor and anti-suppressor concentrations are also determined from their effects on the copper deposition rate. In this case, synergy among the various additives is automatically taken into account and an effective or active concentration is obtained, which is more indicative of the performance of the additive in the plating bath than a strictly analytical concentration. The suppressor, which generally exerts a much stronger effect than the other additives at low concentrations, may be determined by CVS response curve or dilution titration analysis. In this case, dilution of the bath sample during standard additions to a background electrolyte renders the suppressor effect dominant. The anti-suppressor may be determined via the CVS linear approximation technique (LAT) or modified linear approximation technique (MLAT) analysis from its effect in increasing the copper deposition rate in a background electrolyte containing sufficient suppressor for maximum copper deposition suppression. Modifications in these analysis procedures may be needed for some additive systems, for example, to account for relatively high leveler activity or to reduce anti-suppressor interference on the suppressor analysis. Generally, the CVS measurement parameters are optimized for each type of analysis (leveler, suppressor and anti-suppressor) and depend on the particular additive system. Such optimization improves measurement sensitivity and reproducibility and helps minimize interference from the other additives. Within the scope of the present invention, the suppressor and anti-suppressor additives may also be analyzed by other methods, e.g., spectrophotometry, electrochemical ac impedance measurements, electrochemical impedance spectroscopy, or high performance liquid chromatography (HPLC).
Another aspect of the claimed invention provides improved precision for the leveler voltammetric analysis by taking into account variations in the inorganic content of the plating bath. Since chloride exerts a strong effect on the functioning of organic additives used in acid copper baths, its concentration should, if necessary, be adjusted to be within the appropriate range (typically, 25 to 100 ppm) in the plating bath sample being analyzed, and in the background and supporting electrolytes used for the analysis. Variations in the chloride, sulfuric acid and copper ion concentrations within the ranges recommended by the bath supplier usually have a negligible effect on the voltammetric analysis results and typically need to be adjusted in measurement solutions only for analyses requiring very high accuracy. If the particular leveler species used exerts a relatively weak effect on the copper deposition rate and/or the leveler concentration in the plating bath is relatively low, however, variations in the copper content of the plating bath can have a significant effect on the results of the leveler analysis. In this case, the accuracy and precision of the leveler analysis of the present invention may be improved by correcting the measurement solution voltammetric rate parameter for the difference in copper ion concentration resulting from addition of the plating bath to the supporting electrolyte.
Further features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings.

Method for analysis of three organic additives in an acid copper plating bath


A light-emitting device includes: a substrate; a light reflection layer that is formed on the substrate and reflects light; a first electrode that is formed on the light reflection layer and transmits light; a light-emitting layer that is formed on the first electrode and emits light; a second electrode that is formed on the light-emitting layer and transmits a part of light from the light-emitting layer and reflects the rest of the light from the light-emitting layer; and a conductive transflective layer that is formed on the second electrode and that transmits a part of light from the second electrode and reflects the rest of the light from the second electrode. A work function of the second electrode is 4 eV (electron volts) or less. The conductive transflective layer is formed of a metal material having a higher optical reflectance than the second electrode.

1. Technical Field
The present invention relates to a light-emitting device, an image forming apparatus, a display device, and an electronic apparatus.
2. Related Art
In a light-emitting device having EL (electroluminescent) elements, such as organic EL elements or inorganic EL elements, it is necessary to make a band of an emission spectrum narrow and to increase an amount of emitted light for the purpose of facilitating many applications thereof. As a light-emitting device that meets the above requirements, there is a light-emitting device having microcavities formed by arranging a dielectric mirror between EL elements and a substrate (refer to Japanese Patent No. 3274527). The light-emitting device is of a bottom emission type, and light from EL elements is transmitted through the substrate and is then emitted.
In a light-emitting device having EL elements, a substrate on which the EL elements are arranged is very thick. Therefore, from the point of view of increasing an amount of emitted light, a top-emission-type light-emitting device that causes light from EL elements to be emitted toward a side opposite to a substrate is preferred rather than a bottom-emission-type light-emitting device. In addition, even in the top-emission-type light-emitting device, it is necessary to further increase the amount of emitted light. In addition, in the case of using a light-emitting device having organic EL elements as an exposure unit of an electrophotographic image forming apparatus or as a display device that displays an image, it is necessary to further narrow a band of an emission spectrum. Here, a case is considered in which a technique disclosed in Japanese Patent No. 3274527 is applied to a top-emission-type light-emitting device.
However, in the case of the top-emission-type light-emitting device to which the technique disclosed in Japanese Patent No. 3274527 is applied, it is necessary to form a dielectric mirror on EL elements formed on a substrate in manufacturing the top-emission-type light-emitting device, which may cause the EL elements (for example, light-emitting layer) to be greatly damaged. Since the light emission characteristics of the EL elements that are greatly damaged noticeably deteriorate, it is difficult to apply the technique disclosed in Japanese Patent No. 3274527 to the top-emission-type light-emitting device.

Light-emitting device, image forming apparatus, display device, and electronic apparatus


The invention relates to a low-lactose and a lactose-free milk product and to a process for the production thereof. The lactose in the milk raw material is hydrolyzed, proteins, minerals and sugars are separated into different fractions by the membrane technique, and a low-lactose or a lactose-free milk product is composed from the fractions. The invention provides a milk product, the water therein originating from the original milk raw material. In addition, useful by-products are produced in the process.

Several processes for producing low-lactose and lactose-free milk by using membrane techniques are known. A conventional enzymatic process for splitting lactose is also generally known in the field, the process comprising the step of adding lactase from fungus or yeast to milk in such a manner that lactose is split into monosaccharides, i.e. glucose and galactose, in over 80%.
Several membrane filtration process solutions have been presented for removing lactose from milk raw material. Four basic membrane filtration processes are generally used: reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF). Of these, UF is mainly suitable for separating lactose from milk. Reverse osmosis is generally applied to concentration, ultra- and microfiltration to fractionation, and nanofiltration to both concentration and fractionation. A lactose removal process based on a membrane technique is described in WO publication 00/45643, for instance, wherein lactose is removed by ultrafiltration and diafiltration. When filtration processes are used, the problem often created is the generation of side fractions, such as a permeate or lactose fractions. Published US application 2007/0166447 discloses the use of a lactose-containing NF retentate fraction generated as a side fraction as the raw material of fermentation in the production of yoghurt, for example.
Recent studies have indeed been concentrated on the membrane filtration of milk and to the use of such filtrated, low-carbohydrate milk in the production of dairy products, such as cheese, ice cream and yoghurt. It is common to the known, multi-step membrane filtration processes comprising several different processes that the processes include the separate addition of water, which does not originate from the milk raw material, for diluting milk components and for obtaining a suitable sweetness in milk products containing little carbohydrate (i.a. lactose). It is particularly problematic in the field that a product containing liquid that does not completely originate from the original milk raw material cannot be called milk. It is also common to known processes that the residual lactose is not removed until from the membrane-filtrated milk raw material.
It is known in the field that a problem with membrane techniques in general is that during ultrafiltration not only lactose is removed from the milk, but also some of the minerals that are significant to the taste of milk and milk products prepared thereof. Controlling the mineral content is particularly problematic in the field, and extensive loss results from the known processes, which is why these minerals must often be returned or added separately.
Often membrane processes also produce, for instance, sugar-containing and mineral-containing secondary flows, which cannot be exploited efficiently and which also increase waste water load, require further processing and add to the costs.
WO publication 2005/074693 discloses the use of the membrane technology in the production of lactose-free milk. It is typical of the process that the ultrafiltration retentate is diluted with water, resulting in a lactose content of about 3.0%. The residual lactose is hydrolyzed enzymatically.
WO publication 03/094623 A1 discloses a process in which a milk product is ultrafiltered, nanofiltered, and concentrated by reverse osmosis, after which the minerals removed during ultrafiltration are returned to the UF retentate. The residual lactose of the thus obtained low-lactose milk product is hydrolyzed with a lactase enzyme into monosaccharides, whereby an essentially lactose-free milk product is obtained. With this process, lactose is removed from milk without affecting the organoleptic properties of the milk product being prepared. In the process for producing a milk product, water not originating from any steps of said process is added. Also, the process produces minerals containing secondary flows, which cannot be utilized in the process and which require post-processing.
Patent publication KR20040103818 describes a process for the production of low-lactose milk, comprising nanofiltering milk hydrolyzed with lactase to partially remove galactose and glucose, and adding water to the nanofiltration retentate to achieve a suitable sweetness. Choi et al. (Asian-Aust. J. Anim. Sci 20 (6) (2007) 989-993) describe a process for the production of lactose-hydrolyzed milk, wherein raw milk is hydrolyzed with β-galactosidase (5 000 lactase activity unit/g, Validase, Valley Research) partially (0.03%; 4° C., 24 hours) or 'completely' (0.1%; 40 h), heat-treated to inactivate the enzyme (72° C., 5 min), cooled to 45 to 50° C., and nanofiltered at a pressure of approximately 9 to 10 bars (130 to 140 psi; concentration factor 1.6). Water was added to the NF retentate and the heat treatment was performed at 65° C. for 30 min. The processes disclosed in said publications and comprising a hydrolysis step, heat treatment of the enzyme, nanofiltration, and addition of water, are not suitable as such for the production of a milk product without separate addition of water. The process also comprises separate heat treatment for inactivating the enzyme and for eliminating microbiological problems in the filtration step (i.e. in NF filtration in a warm environment). The high hygiene requirements of milk processing also set limitations on industrial processes. In the industrial processing of milk raw material and membrane processes, a temperature of e.g. 10° C. is generally desirable for eliminating microbiological problems.
It is therefore desirable to provide processes for controlling also the secondary flows in the process and for recovering them more efficiently than at present, which also enables new kinds of applications. Thus, the processes are made still more effective. However, it is extremely challenging to achieve products having a completely flawless taste and structure and meeting consumers' expectations of an organoleptically acceptable milk product and being produced economically and simply without separate addition of water.
A process for the production of low-lactose and lactose-free milk products that are completely flawless in their organoleptic properties without any extra costs has now been unexpectedly invented. The process of the invention enables a more efficient and simpler control of milk components as compared with conventional processes without special additional costs and with minimized losses. No separate addition of water is required in the production of a milk product. In addition, the process of the invention does not generate secondary flows requiring post-processing, making the process more efficient.

This patent is subject to a terminal disclaimer.

Low-lactose and lactose-free milk product and process for production thereof


A system for use with a motor vehicle, the system including a gas sampler device including a wireless communication subsystem and an input element configured to receive a gas sample. The system further includes an interlock device including a second wireless communication subsystem and a computing device configured to: determine a location of the gas sampler device within the motor vehicle based on proximity of the wireless communication subsystem, and activate an alarm event in dependence of the location of the gas sampler device within the motor vehicle.

1. Field of the Invention
The invention relates to the field of automotive interlocks.
2. Prior Art
It is known to secure a motor vehicle against operation by a person who has consumed alcohol. A typical arrangement, known as an breath alcohol ignition interlock device (BAIID), involves a relay between the breath tester and the starter motor, pursuant to which the starter motor cannot be engaged until a satisfactory breath sample has been given. In this regard, a 'satisfactory' gas sample is conventionally understood to be one that (i) is of sufficient volume and pressure to permit alcohol analysis; (ii) has alcohol concentration below a predetermined limit; and (iii) appears to have originated from the exhaled breath of a human being. Criterion (iii) is often assessed through measurements of pressure, humidity and temperature, but various other techniques such as hum recognition sensors are occasionally used. In some jurisdictions, a person convicted of driving under the influence of alcohol may be required by law to have a device of this type installed as a condition associated with the extension of driving privileges. While the engine is running, the BAIID may randomly require the driver to provide another breath sample. The time between required breath samples is dependent on the setting of the unit but, for example, it is typical for random breath samples to be required every 10 to 20 minutes while the vehicle is in operation. All events are logged, for the purpose of, inter alia, compliance purposes. It is known for persons to attempt to circumvent a BAIID device by having a "sober" friend blow into the device to start or maintain operation of the vehicle.
Other difficulties with existing systems may be appreciated in view of the description below.

Vehicle interlock with location detection

Alcohol Countermeasure Systems (International) Inc.


Systems and methods for discovery and mapping of industrial control and SCADA networks are described herein. The disclosed systems and methods help operators ensure the cyber security of their SCADA network through accurate discovery, fingerprinting and mapping the industrial control network map, including PLCs (Programmable Logic Controller) and RTUs (Remote Terminal Unit), using passive techniques.

Industrial Control Systems (ICS) refer to the networked equipment and software used to control and monitor industrial systems. Such systems are key elements in a range of critical infrastructure sectors and other industries including electrical, water, wastewater, oil and natural gas, chemical, manufacturing and transport. These systems may be localized, as in the case of a manufacturing facility, or highly distributed, as in the case of an oil or gas pipeline or electrical grid.
Industrial control systems are composed of specialized components and applications such as Programmable Logic Controllers (PLCs), Distributed Control Systems (DCSs), and Supervisory Control and Data Acquisition (SCADA) systems. PLCs are solid state electronic devices that form the core of industrial control networks. DCSs are fully automated systems that control the operation of processes within an industrial facility, and are sometimes called Process Control Systems (PCS) (Stouffer et. al.). Industrial Control and SCADA networks control critical infrastructure such as power plants, nuclear facilities, water supply/treatment systems and transportation systems. These systems are increasingly becoming the target of sophisticated and unsophisticated cyber attacks by cyber threat actors of different kinds, with successful attacks having the potential to cause widespread damage, cost and injury/loss of life.
It should be noted that the term SCADA is often used to describe Industrial Control System (ICS) networks. This is somewhat of a misnomer, as SCADA systems themselves make up one component of the larger ICS networks, but the term is broadly used to denote such networks—a convention we shall follow in the presenting description.
Situational awareness tools are widely used in diverse sectors such as, for example, military command and control, ship navigation and power plant operations. In general, such tools combine disparate data and analytics with visual maps (either geographic or otherwise) to allow decision-makers to quickly process complex and dynamic data and make critical decisions. More recently, situational awareness tools have been developed and utilized in the Information Technology (IT) industry to distill large amounts of data from different security and network sensors, allowing security and network operators to make decisions to defend the IT network against security threats. As industrial control networks continue to witness greater connectivity to the outside world, the need for SCADA Cyber Situational Awareness tools (SCADA CSAT) becomes greater. The larger and more connected the SCADA network, the more critical it becomes to have a SCADA CSAT tool.
FIG. 1 illustrates an example of a SCADA network. SCADA networks differ from traditional corporate networks in a number of ways. These differences present a number of challenges in the quest to defend the network against cyber threats—malicious, criminal or otherwise. First of all, a number of specialized protocols have been developed, often for historical reasons, which are used exclusively within SCADA networks. Some of the more popular protocols include Modbus, DNP3, Profinet, EtherNet/IP (not to be confused with either the Ethernet or IP protocols). These protocols, some of which are quite old, have not necessarily been designed with security in mind. Secondly, as they are niche protocols, popular network security tools such as signature-based IDS (Intrusion Detection Systems) like Snort or Suricata, have limited support for many of these protocols.
Traffic characteristics of SCADA networks also differ drastically from traditional corporate IT networks. The majority of traffic in SCADA networks is generated by devices controlling or monitoring the physical environment and master control and monitoring systems. Such communications are often based on timers and occur at regular intervals, and between the same hosts within the network. Thus the pattern of communications is relatively deterministic and periodic in nature. This is quite different compared to traffic on an IT network which is generated by human beings and which can be quite noisy and non-deterministic in nature.
Historically, proprietary technologies were utilized for SCADA and ICS networks. This proprietary nature greatly assisted in their security—a factor sometimes referred to as "security by obscurity". The standardization of various elements of ICS networks over the last few years coupled with the trend of connecting these systems to WAN (Wide Area Networks), Enterprise Networks and the Internet, has opened up access to such networks. This opening up of ICS networks has led to a number of security issues. This is partly because the specialized protocols at the heart of ICS devices such as PLCs (Programmable Logic Controllers) were not designed with security in mind, leaving them susceptible to cyber security threats. In addition, the network architectures and security tools of SCADA networks have not received the same attention from a security perspective as IT networks which were earlier subjects of malicious cyber threats (Galloway et. al.). Finally, SCADA software such as HMI (Human Machine Interface) are used to control physical industrial processes via PLCs. HMI software is often run on Windows platforms which are susceptible to many security threats.
While SCADA networks are in many ways like IT networks, they also present a number of distinctive characteristics which means that traditional IT security products and solutions cannot be used as-is on a SCADA network. As such, specialized cyber security tools are required for such networks. Systems and methods are required to successfully discover the network topology for SCADA systems and provide security operators with situational awareness capabilities to defend against cyber threats.
Traditional approaches to device discovery scan an entire network to find live IP addresses. This is done by sending a packet or set of packets to each possible IP address in a network range and waiting to receive a response (e.g. sending ping messages). This approach takes a long time to complete discovery of devices. For example, some networks utilize a large address space but live devices may only be found on a small section of the network. (e.g. a large company may use the 188.8.131.52/8 address space which could hold 16 million IP addresses, but at a maximum only use 2% of the address space. Sending pings too frequently would cause overload of traffic on the network (e.g. sending a ping every millisecond would generate 1000 packets per second which is far too heavy weight to be acceptable for IT networks). As such network management solutions may send a ping packet every 10 ms which translates to 100 packets per second. Scanning the full address range would take 160,000 seconds (44 hours). Approaches such as this are the norm in deployed network discovery and network topology mapping solutions.
Typically, existing approaches to discover the network mapping and network topology for a SCADA network use the following general method:                1. Identify the IP address range for the network to be discovered;        2. Send ping packets to every IP address in the range to discover live devices which respond;        3. Identify devices that respond as eligible devices;        4. Determine which devices respond to SNMP queries;        5. Interrogate the devices using SNMP to determine whether they are routers, switches or end-systems; and        6. Based on SNMP Management Information Base (MIB) information, begin determining the connectivity map (ie topology of the network).
These approaches have several drawbacks. The discovery time is slow for large networks due to having to search through too many IP addresses, most of which may not correspond to actual devices. Further, there may be a number of silent or inactive devices in the network that won't be discovered by these methods, making a full discovery impossible. Therefore, there is a need for improvement. It would be beneficial to cyber security and other network application to achieve a fast network topology discovery and an accurate discovery of devices in the network.

Method and system for discovery and mapping of a network topology


A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or ester thereof, (Formula (I)) wherein: R1 is (CH2)mNR11R12; R2 is selected from H, halo, OR13, NHR13, alkyl, alkenyl and alkynyl; R3 is selected from alkyl, alkenyl, alkynyl, aryl, halo, aryloxy, NHCO2R4, NHCONR5R6, NHCOR7, NH-alkyl, NH-alkenyl, NH(CH2);n-aryl, (CH2)p-heteroaryl, (CH2)qCO2R8, (CH2)rCOR9 and NHSO2R10, wherein each alkyl, alkenyl, aryl or heteroaryl moiety in the aforementioned list is optionally further substituted by one or more groups selected from alkyl, halo OH, NH2, alkoxy, aryloxy, alkylamino, arylamino, carboxyl and carboxamide; R4 to R10 and R13 are each independently selected from alkyl, alkenyl and aryl; R11 and R12 are each independently selected from alkyl and alkenyl; or R11 and R:12 are linked together with the nitrogen to which they are attached to form a heterocycloalkyl or heterocycloalkenyl group; n, m, p, q and r are each independently selected from 0, 1, 2, 3, 4, 5 and 6. Further aspects relate to pharmaceutical compositions, therapeutic uses and process for preparing according to the invention.

Most drug discovery programs begin with a screening campaign (e.g. biochemical, virtual or biophysical) for agonists, antagonists or inhibitors of a nominated target associated to a particular disease [1-4]. After hit identification, subsequent chemical optimization is fundamentally based upon "on-target" potency [1]. Generation of so-called lead compounds (=high-affinity ligands) is followed by medicinal chemistry refinement into derivatives of superior potency and/or selectivity, and desirable pharmacokinetic properties (=druglikeness) [1, 5]. Selected drug candidates are then validated in vivo and, upon verified safety and efficacy, progressed to human trials [5]. This well-defined process, which typically consumes over a decade of research work and tens of millions of pounds on its path to the clinic, is finding a particularly low success rate in the development of anticancer drugs [6]. This is because, on top of the enormous difficulties of translating a drug discovery program from target identification—through preclinical and clinical development—into regulatory approval and marketing, it has become apparent that conventional approaches are not appropriately tailored to pathologies generated by the concurrent or sequential action of multiple etiologic factors such as cancer [6-8]. High attrition during late-stage drug development has underlined that elucidating cancer heterogeneity across patients and adaptive drug resistance mechanisms are the major obstacles to the development of effective targeted anticancer therapies [9-11]. These challenges are stimulating out-of-the-box thinking in pharmacotherapy research (e.g. targeted polypharmacology [10], antibody-drug conjugates [12], innovative prodrug approaches [13-17], etc.) and the reexamination of the core principles of drug discovery in oncology [18-20]. The rise of modern phenotypic drug discovery [18, 19] together with the use of clinically-relevant cancer models to guide early drug development [20], are representative examples of the paradigm shift initiated in the field to trigger a positive inflection point.
Protein kinases are integral components of intracellular signal transduction cascades. They govern a wide range of basic cellular functions and coordinate cell-to-cell and extracellular matrix (ECM)-to-cell communications to influence cell and tissue physiology. Thereby, kinases are directly involved in progressive diseases including cancer and inflammation [21]. Advances in the understanding of cancer cell biology along with the approval of several kinase inhibitors for cancer treatment have demonstrated the validity of a number of kinases as anticancer targets [22], while, on the contrary, other protein kinases have been shown to play an essential role in tumor suppressor pathways (anti-targets) [23-26].
The vast majority of kinase inhibitors target the kinase ATP pocket and because all kinases (>500) necessarily possess this relatively well-conserved catalytic site, there is a great potential for cross-reactivity [10]. In fact, even if most clinically-approved kinase inhibitors have been developed from a single target hypothesis, they typically display a broad selectivity profile which, in some cases, have resulted in unanticipated clinical applications (e.g. sorafenib) [26]. An inhibitor's promiscuity may also be advantageous for anticancer therapy when off-target activities assist to address bioactivity issues related to pathway redundancies, molecular heterogeneity or resistance mechanisms [9, 10, 26]. On the contrary, if these activities result in the inhibition of anti-oncogenic pathways or lead to severe side effects, drug promiscuity becomes a major drawback. Paradoxically, there is strong evidence indicating that some kinases may behave as a target or an antitarget depending of the cancer context. By way of illustration, the expression of the activated fusion oncoprotein Bcr-Abl is a genetic abnormality associated with chronic myeloid leukemia (CML) and Abl inhibitors (imatinib, dasatinib) are clinically used in chronic phase CML treatment [27]. In addition, Abl family kinases are abnormally activated in various solid tumors, supporting their involvement in oncogenesis [27]. However, Abl (Abl1) and Arg (Abl2) have been found to negatively modulate breast cancer progression in vivo [28-30], indicating that Abl inhibition could be counterproductive for its treatment (=breast cancer anti-target). This example serves to delineate the complexity of cancer etiology and highlights the necessity of developing kinase inhibitors with tailor-made pharmacodynamic profiles for the effective targeting of each cancer subtype. Unfortunately, despite the vast amount of small molecule inhibitors and biomedical knowledge built over the years, the limited understanding of cancer biology prevents the appropriate targeting of orchestrated actions that generate, maintain and progress most neoplastic processes.
Acknowledging these limitations, many research groups are frontloading the search of robust empirical data to progress anticancer drug development programs away from classical black-and-white anticancer hypotheses.
The present invention seeks to provide tyrosine kinase inhibitors having potent antiproliferative properties. The invention is founded on three hypotheses: (i) the use of phenotypic screening in designated models of cancer can be used to generate target-agnostic structure-bioactivity relationships and guide ligand optimization tailored to particular cancer types/subtypes; (ii) targeting the kinase ATP pocket with compounds derived from promiscuous kinase inhibitors can enable "rationally-biased" serendipitous discoveries; and (iii) early improvement of druglikeness on promiscuous ligands can be concurrently used to explore pharmacodynamic diversity. By means of this pragmatic approach to kinase inhibitor discovery, target deconvolution of identified hits and leads was largely facilitated, thereby enabling the rapid identification of the molecular targets and antitargets involved in the observed phenotype.

UNIVERSITY COURT OF THE UNIVERSITY OF EDINBURGH


An image processing apparatus includes a calculation unit configured to calculate information indicating similarity among a plurality of tomographic images, and a generation unit configured to generate a tomographic image from the plurality of tomographic images based on the calculated information indicating similarity.

A tomographic imaging apparatus for the eye portion such as an optical coherence tomography (hereinafter referred to as OCT) is usable to three-dimensionally observe a state inside a retinal layer. In recent years, the tomographic imaging apparatus has attracted attention because it is useful in accurately diagnosing disease.
In an ophthalmologic diagnosis, there can be used a volume image for grasping the state of the entire retinal layer and a high image-quality two-dimensional tomographic image for grasping a layer which is not imaged on a low image-quality tomographic image. The volume image refers to aggregation of the two-dimensional tomographic images.
The image quality of the tomographic image acquired by the OCT depends on the strength of near infrared light incident on a retina. For this reason, the strength of the light with which the retina is irradiated needs to be increased to improve the image quality of the tomographic image. However, from the viewpoint of safety, the strength of the light with which the retina can be irradiated is limited. This requires the high image-quality tomographic image to be generated while the retina is being irradiated with near infrared light within the unquestionable strength of the light from the viewpoint of safety. To meet such a requirement, Japanese Patent Application Laid-Open No. 2008-237238 discusses a technique in which two-dimensional captured tomographic images are superposed on each other to generate a noiseless sectional image.
In Japanese Patent Application Laid-Open No. 2008-237238, however, a plurality of tomographic images are merely subjected to arithmetic mean. For this reason, in a case where correlation is low between the added tomographic images, a reduction in diagnosis information can be increased. In particular, since involuntary eye movement occurs in eyes, the entire areas of adjacent images are not always similar.

Image processing apparatus, image processing method, and program


The splitting of storage applications and functions into a control path (CP) component and a data path (DP) component is disclosed. Reads and writes may be handled primarily in the DP. The CP may be responsible for discovery, configuration, and exception handling. The CP can also be enabled for orchestrating complex data management operations such as snapshots and migration. Storage virtualization maps a virtual I/O to one or more physical I/O. A virtual target (vTarget) in the virtual domain is associated with one physical port in the physical domain. Each vTarget may be associated with one or more virtual LUNs (vLUNs). Each vLUN includes one or more vExtents. Each vExtent may point to a region table, and each entry in the region table may contain a pointer to a region representing a portion of a pExtent, and attributes (e.g. read/write, read only, no access) for that region.

Traditional storage applications have been monolithic systems, running all aspects of storage applications and analysis on a single processor. This leads to huge amounts of functionality resident on one piece of hardware and/or software.
Conventional systems are monolithic in that they did not distinguish between control and data paths. Processors and software in these monolithic systems were used to handle both control and data functions. This results in slower performance of data functions.
Therefore, there is a need for a split-path architecture that enables control functions to be handled in the CP, while data functions are handled in the DP, producing a more efficient flow of data across a storage area network (SAN) fabric.

Apparatus for performing storage virtualization


A power take off (PTO) clutch control system for an agricultural tractor is disclosed herein. The PTO clutch is a hydraulic clutch which is operated by a proportional valve capable of pressurizing the clutch with hydraulic fluid at a pressure related to the pulse width of a pulse width modulated (PWM) signal applied to the valve. The PWM signal is produced by a controller which monitors the output shaft speed and movement to determine the time at which the shaft begins movement. Prior to shaft movement, the PWM signals control the proportional valve to prevent clutch engagement when the hydraulic fluid in the system is cold, clutch engagement has not occurred in a timely fashion and the operator has left the seat of the tractor.

PTOs are used on agricultural vehicles such as tractors to provide power for equipment or implements such as combines, mowers and spreaders. Many modern PTOs are controlled by engaging and disengaging a clutch coupled to the engine of the tractor through an drive train. In at least the higher power tractors, the clutches are hydraulic clutches which are engaged and disengaged using a hydraulic system including appropriate valves and hydraulic fluid.
During cold weather operation of such clutches, there exists a condition whereby the clutch will not engage in a timely fashion when the PTO is turned 0N (i.e. the associated hydraulic valve is opened). This condition is caused by a delay in hydraulic fluid pressurization which is the result of high oil viscosity at cold temperatures. In particular, high oil viscosity substantially reduces the response time for fluid flow when an associated valve is opened. Subsequent to the delay, pressurization will occur and the PTO clutch will engage the PTO with the tractor engine. However, this delay can allow an operator to leave the seat and tractor cab (i.e. operator area) not realizing that the PTO is turned ON, but not engaged.
Accordingly, it would be useful to provide a hydraulic PTO clutch control system which, when the operator leaves the operator area and the PTO is turned ON, warns the operator if the PTO switch is turned 0N within a first predetermined period of time, and operates to disengage the clutch if the operator does not return to the operator area during the warning and within a second predetermined time.

Power take off clutch engagement control system for cold weather starting


An assembly includes a case structure, a seal interfacing with the case structure, a first pin, and a main pin hole on one of the seal and the case structure. The first pin extends through the main pin hole and is fixed relative to the other of the seal and the case structure. The assembly also includes a second pin and a secondary pin hole on one of the seal and the case structure. The second pin extends through the secondary pin hole. A cross-sectional gap area between the second pin and the secondary pin hole is greater than a cross-sectional gap area between the first pin and the main pin hole. Also included is a bolt hole on one of the seal and the case structure. The bolt hole is circumferentially located between the main pin hole and the secondary pin hole.

The present embodiments relate generally to seals, and more particularly to seals for use within gas turbine engines.
The use of seals within gas turbine engines improves efficiency. Seals serve to prevent unintended leaks of various fluids, such as hot combustion gasses, cooling air, and lubricant, used in the operation of the gas turbine engine. By preventing such fluids from entering unintended cavities and other locations, the gas turbine engine is able to make more work out of the fluid. However, in order for seals to prevent unintended leakage and improve efficiency, the seals must be configured in appropriate locations within the gas turbine engine.
Often, seals are required to be positioned within the gas turbine engine at locations which can be difficult to access, necessitating at times a blind assembly. Consequently, assembly of the seal in its appropriate location can be complicated and time consuming. For example, some current seals are designed to be snap-fit to an interfacing structure to both center the seal and create a substantially air-tight interface. However, assembling the snap-fit seal in position can be a blind assembly further complicated by a tightly toleranced snap-fit between the seal and the interfacing structure required to create the air-tight interface. One solution to simplify this blind assembly is to apply heat to the interfacing structure to cause the interfacing structure to expand and thus ease the snap-fit. Nevertheless, this increases the time needed to assemble the seal in position, and especially when compounded with numerous other seal assemblies within the same engine, further acts to increase the complexity and costs associated with assembling the seals.


An inner-rotor-type heat dissipating fan includes a fan housing, a seal casing, an inner-rotor-type motor, an impeller and a circuit board. The fan housing includes an outer frame portion and a motor casing. The seal casing is a hollow housing made of magnetically conductive material. One end of the seal casing forms a connecting portion coupling to the motor casing. The inner-rotor-type motor is mounted inside the seal casing. The impeller is coupled to the inner-rotor-type motor and outside the seal casing. The circuit board is electrically connected to the stator. By this configuration, rotation stability of the impeller is enhanced by the inner-rotor-type motor, airflow generated by rotation of the impeller is effectively concentrated and guided by the fan housing, and a sealing effect for avoiding magnetic flux leakage is provided by the seal casing. Consequently, heat dissipating efficiency is enhanced.

1. Field of the Invention
The present invention relates to a heat dissipating fan and, more particularly, to a heat dissipating fan including a motor having an inner rotor.
2. Description of the Related Art
Referring to FIG. 1, a conventional heat dissipating fan 70 including an outer-rotor-type motor is shown. Specifically, the heat dissipating fan 70 includes a frame 71 with a shaft tube 711 disposed inside the frame 71 and receiving a bearing 712, a stator 72 mounted around the shaft tube 711, a circuit board 73 mounted around the shaft tube 711 and electrically connecting with the stator 72, and a rotor 74 having a shaft 741 and an impeller 742. One end of the shaft 741 rotatably extends through the bearing 712, and the impeller 742 is mounted to the other end of the shaft 741. The impeller 742 includes a permanent magnet 743 facing the stator 72. The circuit board 73 controls the stator 72 to generate an alternating magnetic field for reacting with the permanent magnet 743, so that the impeller 742 is driven to rotate for heat dissipation purposes.
Said conventional heat dissipating fan 70 is driven by an outer-rotor-type motor. However, in comparison with inner-rotor-type motors, outer-rotor-type motors are generally less stable in rotation and can only provide a lower rotation rate at full speed. However, owing to the current trend of research and development in electronic products, which includes high operation speed, function integrity, and miniaturization, heat dissipation with high efficiency has become an urgent demand. Unfortunately, the conventional heat dissipating fans with outer-rotor-type motors can not fulfill the heat dissipation need of these electronic products.
Taiwan Patent Publication No. 200744290 entitled "FAN AND ITS INNER-ROTOR-TYPE MOTOR" is an example that meets the demand for efficient heat dissipation. As illustrated in FIG. 2, a conventional inner-rotor-type heat dissipating fan 80 includes a housing 81 consisting of a first shell 811 and a second shell 812, a stator 82 having a magnetically conductive member 821, a rotor 83 having a shaft 831 and a magnetic element 832, a driving device 84 electrically connected to the magnetically conductive member 821, and an impeller 85. The shaft 831 is mounted into the housing 81, and the magnetic element 832 inside the housing 81 is mounted around the shaft 831 and faces the magnetically conductive member 821. The impeller 85 is outside the housing 81 and coupled to the shaft 831. The driving device 84 controls the current direction of the magnetically conductive member 821 to cooperate with the magnetic element 832 for generating an alternating magnetic field to drive the rotor 83 and the impeller 85 to rotate.
However, when it is desired to dissipate heat in various electronic products with the heat dissipating fan 80, airflow generated by rotation of the impeller 85 can not be effectively guided to a heat-generating portion in an electronic product since a fan frame is absent from the heat dissipating fan 80. Thus, heat dissipating efficiency of the heat dissipating fan 80 is low.
To overcome the problems of the heat dissipating fan 80 without a fan frame, FIG. 3 shows a conventional heat dissipating fan 90 driven by an inner-rotor-type motor. The heat dissipating fan 90 includes a frame 91 made of plastic material by injection molding, an inner-rotor-type motor 92, an impeller 93 and a circuit board 94. The frame 91 has a fan housing 911 and a motor housing 912 inside the fan housing 911. The inner-rotor-type motor 92 is mounted inside the motor housing 912 and has a shaft 921 with one end thereof extending out of the motor housing 912, a magnetic element 922 mounted around the shaft 921 and a stator 923 surrounding the magnetic element 922 and electrically connected to the circuit board 94. The impeller 93 is outside the motor housing 912 and coupled to the end of the shaft 921 extending out of the motor housing 912. Thus, the inner-rotor-type motor 92 drives the impeller 93 to rotate to dissipate heat.
The frame 91 of the heat dissipating fan 90 is formed by injection molding to guide airflow generated by rotation of the impeller 93. However, since the motor housing 912 of the frame 91 is made of plastic material, the motor housing 912 does not provide sealing effect and allows magnetic flux leakage when the circuit board 94 controls the stator 923 to generate an alternating magnetic field for reacting with the magnetic element 922. Said magnetic flux leakage leads to electromagnetic interference to affect rotating performance of the impeller 93. Hence, heat dissipating efficiency of the heat dissipating fan 90 is decreased.

Sunonwealth Electric Machine Industry Co., Ltd.


A rigid tubular housing provides separate enclosures for a drive shaft and a dental tool that are rotatable on axes that are angularly related. A wall separating the two enclosures provides bearing support for tool-driving gears in one of the enclosures and connection to a driving shaft in the other. A latching mechanism envelops the housing and covers it smoothly. The latching mechanism is movable on the longitudinal axis of the tubular housing for controlling access to the enclosure for a dental tool.

Contra-angle heads for use in dentistry, as presently known in the art, have become highly developed for both general and specific purposes. Examples, taken at random, are described in U.S. Pat. Nos. 3,369,298; 3,578,745; and 4,053,983; which are directed respectively to a clutch mechanism, an oscillating broach for endodontic work, and a prophylactic head for a dental handpiece. These examples illustrate, in a limited way, the variety of applications existing for contra-angle heads, and the variety of structures which have evolved in response to them.
Those contra-angle heads intended for use by a dentist to drive interchangeably one or more of drills, burs, broaches, files and other tools used in dentistry incorporate rugged and usually precise mechanisms for accepting and locking the tools in place, driving them at desired speeds, and releasing them for removal, quickly and reliably, but for the most part such contra-angle heads are bulky and large, have awkward shapes, and are heavy. The positions into which a dentist can put a tool in the mouth of a patient are restricted, and often a tool can be used to treat a patient only at the expense of great discomfort to the patient, and risk of harming surrounding tissue that is not directly involved in the procedure being undertaken.
Projecting parts, such as extending gear boxes and external latching levers, which are commonly found on contra-angle heads currently in use tend to aggravate such discomfort and risks. For example, in U.S. Pat. No. 3,369,298 a clutch is permanently rotatably fixed in a stub-housing oriented transverse to the principal housing, and gears to rotate the clutch on an axis transverse to the main drive shaft axis are housed in the stub housing, which is enlarged for that purpose. A tool can be removably inserted into the clutch from one end of the stub housing, and a lock lever is provided, externally, at the other end.
Attempts to provide smaller and smoother contra-angle heads with interchangeable tools have lead, in one instance, to a construction in which the tool is inserted through the stub housing from the locking end, and a threaded cap is provided at the same end to perform the locking function. As it is attempted to make a contra-angle head smaller, these parts, especially removable caps, become so small that they are easily lost, wasting the time of the dentist, and so expensive that their prices are difficult to justify in times of rising prices of other more important medical procedures.


One embodiment includes a power supply system. The system includes a pulse-width modulation (PWM) system configured to generate a PWM signal. The system also includes a power stage comprising a gate driver, a high-side switch, and a low-side switch. The gate driver can be configured to alternately activate the high-side and low-side switches to provide an output signal to a load in response to the PWM signal, and to provide an activation dead-time between the alternate activation of the high-side and low-side switches. The system further includes a digital delay system configured to measure the activation dead-time and to add the measured activation dead-time to the activation of the high-side switch.

Power supply circuits, such as implemented in amplifiers, can implement a high-side switch and a low-side switch that are alternately activated to provide an output signal. The driver that provides the alternate activation of the high-side and low-side switches can be designed to ensure that the high-side and low-side switches are never activated concurrently to avoid a shoot-through current from a high-voltage rail to a low-voltage rail (e.g., ground). Thus, the driver can implement a "break before make" activation of the high-side switch with respect to the low-side switch by providing a predefined activation dead-time between activation of each of the high-side and low-side switches. However, the output signal can be substantially unstable during the activation dead-times. Furthermore, when the duty-cycle of the PWM signal is very short, the activation dead-time can undesirably shorten the activation of the high-side switch, and can possibly prevent activation of the high-side switch entirely, thus introducing distortion in the output signal.

Dead-time compensation in a power supply system


A disk drive backplane is described which includes a connector for interfacing with a corresponding connector on each of a plurality of carrier types. A plurality of status indicator arrays is provided, each of which corresponds to at least one of the carrier types and is operable to transmit status information. Each of the arrays is positioned to interface with a corresponding status interface on the corresponding carrier type(s). Circuitry is provided which enables one of the status indicator arrays thereby configuring the backplane to interface with a particular one of the carrier types.

The present invention relates to enclosures for housing computer disk drive carriers. More specifically, the present invention provides a backplane for use with such enclosures which can accommodate multiple disk drive carrier designs.
Computer disk drive carriers, particularly those capable of live insertion and removal (i.e., "hot-pluggable" disk drives), are typically installed in carrier frames which provide mechanical support and guidance for the specific carrier type. Within such carrier frames, each carrier is latched into place and secured to a backplane which provides the interface to the rest of the computer system. Indicators, e.g., light emitting diodes or light pipe terminations, representing disk drive status and activity are typically provided on the front bezel of such carriers. These indicators are typically controlled by electronics or light sources on the backplane to which the carrier is secured.
As is well known to those familiar with the industry, the variability in the form factors and interface configurations of computer disk drive carriers corresponds roughly to the number of manufacturers providing such devices. This is particularly the case with regard to the manner in which status information is transmitted to the front bezel of the carriers. That is, the nature and position of each carrier's status information interface relative to the backplane vary considerably. As a result, carrier frames are typically constructed with mechanical guides and backplanes which are suitable for only a single carrier type. Not only does this create barriers to using disk drives from different manufacturers, it also represents manufacturing inefficiencies in that a different type of backplane is typically designed and manufactured for each carrier type.

Disk drive backplane capable of supporting multiple disk drive carrier designs


A vehicle control device is provided that performs control to suppress a dangerous situation for a vehicle without causing a driver to experience discomfort when an accelerator is erroneously operated, by setting an abnormality judgment threshold for the accelerator operation to a value based on a degree of risk to the vehicle. An accelerator position judgment threshold is set to be lower when risk in the periphery of the vehicle is higher, intermediate when the risk is intermediate, and higher when the risk is lower. When the risk is higher, an abnormality judgment is made upon the accelerator being lightly stepped on, and control is performed to suppress a dangerous situation. As the risk changes to intermediate and lower, the abnormality judgment is made at a greater accelerator position.

1. Field of the Invention
The present invention relates to a vehicle control device that controls a vehicle. In particular, the present invention relates to a vehicle control device capable of suppressing collision of a vehicle with an obstacle caused by an erroneous driving operation, such as a brake pedal or an accelerator pedal being mistakenly stepped on instead of the other.
2. Description of the Related Art
As this type of vehicle control device, a device is proposed that performs control to reduce the speed of a vehicle, when an inter-vehicle distance is shorter than a safe inter-vehicle distance set in association with the speed of the vehicle and an accelerator pedal stepping force is a predetermined value C or more (refer to, for example, JP-A-H04-215527). In this device, even when the inter-vehicle distance is short and the accelerator is mistakenly operated instead of the brake which should have been operated, the speed can be reduced without the vehicle being accelerated in adherence to the accelerator operation.
However, in the technology disclosed in JP-A-H04-215527, although the safe inter-vehicle distance changes depending on the speed of the vehicle, the predetermined value C does not change. Therefore, even in a situation where the slightest acceleration is not permissible, if the accelerator pedal is lightly stepped on, the vehicle may accelerate in adherence to the accelerator operation. On the other hand, even in a situation allowing some leeway, the speed is reduced if the accelerator pedal stepping force exceeds the predetermined value C. In this way, an abnormality judgment threshold for the amount of accelerator operation is conventionally set to a fixed value regardless of the risk to the vehicle. Therefore, the driver may experience discomfort.
Thus, there is a demand for a vehicle control device that is capable of performing control to suppress dangerous situations for the vehicle without causing the driver to experience discomfort, when the accelerator is erroneously operated.


A system for the conversion of the potential energy of hydrocarbon fuels to heat, the system being particularly adapted to the use of the available heat in the heating of a fluid, especially water. The system includes special forms of heat transfer devices by which the available heat, particularly of natural gas may be transferred to a water supply in a heat exchange device of special construction.

All of my prior applications and patents above identified disclose certain features of energy conversion systems adapted to increase the efficiency of energy conversion, particularly the efficiency of conversion of energy of gaseous fuels such as natural gas; and all of said prior applications and patents disclose certain heat exchanger devices adapted to increase the efficiency of heat transfer from the products of combustion of petroleum fuels, especially natural gas, to fluids, particularly liquids such as water. In all of said prior applications and patents heat exchanger devices are disclosed and such devices are arranged to provide for indirect heat transfer from the products of combustion to the liquid or other fluid to be heated by means of tube-in-tube type heat exchangers in which conditions are established providing for cooling of the combustion products to a temperature below the dew point, in order to utilize the large amount of BTU's released upon condensation of the water vapor present in the products of combustion.
The present application also contemplates highly effective recovery of the BTU's by establishing conditions which will reduce the temperature of the products of combustion to a temperature below the dew point, before discharge of the gaseous products of combustion. The present invention, however, is concerned with a combination of a number of improvements and features which further enhance the efficiency and which also provide numerous additional advantages, most of which are described hereinafter in relation to individual embodiments of the equipment herein disclosed.
Before proceeding with more detailed description of the structural embodiments and features and advantages of the operation of systems according to the present invention, it is here first pointed out that while certain aspects of the invention are adaptable to use with a variety of fuels, the invention is especially adapted to the use of flammable gases, particularly natural gas, but others may be used including methane, synthetic gases or even hydrogen. Moreover, while the equipment and heat exchangers provided according to the invention are adapted to the heating of a variety of fluids, either liquid or gaseous, the invention is particularly well suited to the transfer of the available BTUs of the products of combustion to liquids and especially to the heating of water. For these reasons, the description given hereinafter refers to the utilization of the available BTUs in natural gas in the heating of water, but it is to be understood that these references are not to be construed in a limited sense.
One of the important objects of the present invention is the provision of a water heater employing a special combination of features including a combustion chamber and heat transfer tubes through which the combustion gases or products of combustion flow in a downward direction, while at the same time the conditions of heat transfer are established so as to reduce the temperature of the products of combustion to or below the dew point, provision further being made for downward delivery under the action of gravity of the condensate formed, thereby avoiding the necessity for the condensate and the flue gases to flow in the flue gas passages in opposite directions to each other. In accomplishing the foregoing, the present invention utilizes a blower effecting forced downward flow of the products of combustion from the combustion chamber through flue gas passages.
It is also contemplated according to the present invention to employ flue tubes for the flue gas and products of combustion, the flue tubes having their external surfaces in heat exchange relation to the water to be heated in a surrounding water flow space. In some instances the water flow space takes the form of annular passages surrounding the flue tubes, the passages being established by employment of water tubes surrounding the flue tubes, with appropriate tube sheets and water headers providing for circulation of the water in counterflow to the direction of flow of the gases through the inside flue tubes. This configuration is of particular importance in a heat exchanger as herein contemplated in which the temperature of the products of combustion is brought down below the dew point. The consequent development of the condensate results in development of certain acids having corrosive influence with respect to common types of metals employed in heat exchangers. In view of this, the invention contemplates employing highly acid resistant metals or surface treatment or coating of the metals to impart high acid resistance; and by confining the products of combustion to the interior of the inner tubes of the "tube-in-tube" heat exchangers disclosed, it is necessary to employ such special alloys or special surface treatments for the flue tubes only, instead of for both the inner and outer tubes, as would be needed in certain prior arrangements where the flue gases are passed through the tubular flow space between inner and outer tubes.
The invention also provides a novel form of gas and air admission means associated with the combustion chamber and providing increased efficiency in the intermixture of the gas and air being admitted into the combustion chamber.
It is another object of the invention to further enhance the efficiency of the heat transfer by employing a special form of helical fin within the flue tubes. Preferably these fins comprise individual twisted strips fitting into the interior of the flue tubes and providing for turbulence of the gas flow through the flue tubes. Preferably, such helical fins are metallurgically bonded to the interior surface of the flue tubes, and the fins not only provide the desired turbulence in the gas flow but also extensively increase the surface area within the flue tube providing for heat exchange from the products of combustion to the tube and thence through the tube wall to the surrounding water.
The invention also contemplates a system of automatic controls of novel form, as will be pointed out more fully hereinafter.
Still further the invention contemplates the employment of a novel form of gas discharge damper which is particularly adapted for use in combination with the downward flow of the flue gases as above described.
How the foregoing objects and advantages are attained, together with others which will be more fully developed hereinafter will be more fully apparent from the following description referring to the accompanying drawings illustrating four different embodiments of combustion and heat exchange devices according to the present invention.


Techniques for protecting a superconducting (SC) article are disclosed. The techniques may be realized as an apparatus for protecting a superconducting (SC) article. The apparatus may comprise a porous sleeve configured to fit around the superconducting (SC) article. The porous sleeve may be made of non-conductive, dielectric material.

In electric power transmission and distribution networks, fault current conditions may occur. A fault current condition is an abrupt surge in the current flowing through the network caused by a fault or a short circuit in the network. Causes of a fault may include lightning striking the network, and downing and grounding of transmission power lines due to severe weather or falling trees. When a fault occurs, a large load appears instantaneously. In response, the network delivers a large amount of current (i.e., overcurrent) to this load or, in the case, the fault. This surge or fault current condition is undesirable and may damage the network or equipment connected to the network. In particular, the network and the equipment connected thereto may burn or, in some cases, explode.
One system used to protect power equipment from damage caused by a fault current is a circuit breaker. When a fault current is detected, the circuit breaker mechanically opens the circuit and disrupts overcurrent from flowing. Because a circuit breaker typically takes 3 to 6 power cycles (up to 0.1 seconds) to be triggered, various network components, such as transmission lines, transformers, and switchgear, may still be damaged.
Another system to limit a fault current and to protect power equipment from damage caused by a fault current is a superconducting fault current limiter (SCFCL) system. Generally, an SCFCL system comprises a superconducting circuit that exhibits almost zero resistivity below a critical temperature level TC, a critical magnetic field level HC, and a critical current level IC. If at least one of these critical level conditions is exceeded, the circuit quenches and exhibits resistivity.
During normal operation, the superconducting circuit of the SCFCL system is maintained below the critical level conditions of TC, HC, and IC. During a fault, one or more of the aforementioned critical level conditions is exceeded. Instantaneously, the superconducting circuit in the SCFCL system is quenched and resistance surges, which in turn limits transmission of the fault current and protects the network and associated equipment from the overload. Following some time delay and after the fault current is cleared, the superconducting circuit returns to normal operation wherein none of the critical level conditions are exceeded and current is again transmitted through the network and the SCFCL system.
The SCFCL system may operate in a direct electrical current (DC) or an alternating electrical current (AC) environment. There may be steady power dissipation from AC losses (i.e., superconducting thermal or hysteresis losses), which may be removed by a cooling system. Conductors, typically in the form of a flat wire or conductive tape, are typically used to transmit electrical energy or signals in the SCFCL system. However, traditional conductive tapes used in SCFCL systems typically result in substantial heat loss. In other words, temperature of these conductive tapes may increase significantly, causing them to expand, which may in turn increase the likelihood of the conductive tapes touching each other. In addition, conductive tapes typically vibrate due to magnetic fields generated by current flowing through the conductive tapes. Therefore, together with the increase in temperature, the vibration of the conductive tapes may increase contact between the conductive tapes, during normal or fault conditions. Such contact, even if minimal, may result in electrical and/or mechanical interference, which may lead to decreased longevity and reliability of the conductive tapes. As a result, protecting conductive tapes from such interference may be an important factor to consider by manufacturers.
Accordingly, in view of the foregoing, it may be understood that there may be significant problems and shortcomings associated with current technologies for conductive tapes used superconducting (SC) systems.

Techniques for protecting a superconducting (SC) tape

Varian Semiconductor Equipment Associates, Inc.


Novel farnesylacetic acid ester derivatives containing an amine nitrogen in the alcohol residue thereof and represented by the following general formula exhibit high levels of antiulcerogenic activity and very low levels of toxicity: ##STR1## wherein A is an alkylene radical containing at least 2 carbon atoms; R.sup.1 is H, alkyl, cycloalkyl, aryl, aralkyl or alkenyl; R.sup.2 and R.sup.3 are independently H, alkyl, aryl, aralkyl or alkenyl or one of R.sup.2 and R.sup.3 forms, together with A, a piperidine, pyrrolidine, tetrahydropyrimidine or piperazine ring which contains the nitrogen atom lying therebetween or R.sup.2 and R.sup.3 combine to form, together with the adjacent nitrogen atom, a piperazine ring; provided that the total number of carbon atoms contained in A, R.sup.1, R.sup.2 and R.sup.3 is at least 5.

1. Field of the Invention
This invention relates to novel farnesylacetic acid ester derivatives containing an amine nitrogen in the alcohol residue thereof and to the use thereof as antiulcer agents.
Farnesylacetic acid esters have heretofore been the object of a number of investigations because of their utility principally as medicinals, especially as antiulcer agents, and a number of methods for their preparation have been proposed (for example, U.S. Pat. Nos. 3,154,570; 3,928,403 and 4,025,539 and British Pat. No. 1,420,802). Typical of the farnesylacetic acid esters is the geraniol ester (3,7-dimethyl-2,6-octadienyl 5,9,13-trimethyl-4,8,12-tetradecatrienoate) which exhibits high antiulcerogenic activity and has found wide use in clinical medicine.
2. Description of the Prior Art
In most of the known farnesylacetic acid esters, the alcohol residue is, for example an alkanol residue or a terpene alcohol residue. The known farnesylacetic acid esters containing a nitrogen atom in their alcohol residue only include the following 5 compounds described in Il Farmaco, Ed. Sc., vol. XIX, fasc. 9, pp. 757-764 (1964): ##STR2## In the above formulas, F represents a farnesyl group. However, these compounds reportedly are inactive or only moderately active as far as antiulcer activity is concerned.


A suspension system including an integrally formed axle seat provides reduced suspension system maintenance, increased reliability, reduced number of parts, reduced stress on axles, reduced manufacturing cost, and more convenient assembly as compared to conventional suspension systems. In a preferred embodiment, a suspension system has a hanger attachable to a vehicle frame, a bushing received in the hanger and fastened thereto, a spring beam pivotably attached to the bushing, an integrally formed axle seat coupling the spring beam to an axle, and an air spring mounted between the axle seat and the vehicle frame.

The present invention relates generally to suspension systems for trucks and trailers and, in a preferred embodiment thereof, more particularly provides a suspension system which includes an integrally formed axle seat.
Suspension systems for large trucks and trailers perform many functions related to the comfort, convenience, and safety of transporting such vehicles on a highway surface. Simply stated, a suspension system acts as an interface between a frame or body of a vehicle and a portion of the vehicle which engages a road surface. The suspension system typically supports or "suspends" the frame and/or body above the road-engaging portion, provides compliance which permits relative motion between them, absorbs shock, adjusts for varied loads and road conditions, structurally interconnects various components of the frame and road-engaging portion, etc.
Many types of suspension systems are well known in the art. One of these is known as a fabricated "trailing arm" suspension system. Generally, a trailing arm suspension system incorporates an approximately horizontally disposed arm that is aligned with a direction of travel of a vehicle. A forward end of the arm is usually pivotably attached to a hanger or bracket extending downwardly from the vehicle's frame.
An end of an axle is typically attached to the arm, such that the axle is perpendicular to the arm, and the axle is in most cases rearwardly disposed relative to the hanger. The other end of the axle is likewise attached to another arm. In this manner, the axle is secured to the vehicle and aligned perpendicular to the direction of travel of the vehicle.
A biasing member, such as a spring, is usually connected between the frame and the axle or arm. The spring, thus, biases the frame away from the axle. As a load is added to the vehicle, the spring may compress, or, conversely, as the load is removed from the vehicle, the spring may expand. Where the vehicle is equipped with conventional air springs and leveling valves, the leveling valves automatically adjust air pressure in the air springs so that the springs are maintained at substantially the same heights regardless of the load added to the vehicle. In that case, spring rates of the air springs are varied as the air pressure in the air springs are adjusted by the leveling valves, such that the spring rates increase with increased load added to the vehicle. While the vehicle is being transported across the road surface, the spring may be temporarily compressed as the road-engaging portion strikes an irregularity in the road surface, the spring later expanding when the irregularity has been traversed.
An example of a typical trailing arm suspension system may be found in U.S. Pat. No. 5,116,075 to Pierce, the disclosure of which is hereby incorporated by reference. In the trailing arm suspension system described therein, an air spring is utilized as the biasing member and a complex clamp is used to attach the axle to the arm. However, in addition to the exceedingly complicated axle clamping structure, the Pierce suspension system suffers from a disadvantage in that the axle clamping structure imparts substantial transverse loads to the axle. Most vehicle axles are highly stressed in the first instance and additional loads imparted by an axle clamp may either cause premature failure of the axle or require a stronger, and, thus, heavier, axle to compensate for the additional loads.
Furthermore, axle clamps, such as those utilized in the Pierce trailing arm suspension system, must be periodically checked for tightness. Loose axle clamps are known to cause premature suspension system failure. This periodic maintenance adds to the overall cost of the suspension system to its user.
One type of trailing arm suspension system is known as a "spring beam" suspension system. In a spring beam suspension system, the arm is a relatively flexible elongated member known as a "spring beam". Advantages of a spring beam suspension system include additional vertical compliance afforded by the spring beam and an ability of the spring beam to absorb torsional loads imparted thereto by the axle.
A typical spring beam suspension system is found in U.S. Pat. No. 4,506,910 to Bierens, the disclosure of which is hereby incorporated by reference. An axle is rigidly clamped to two transversely spaced apart spring beams. The axle is longitudinally intermediate hangers suspending forward ends of the spring beams from a vehicle frame, and air springs disposed between rear ends of the spring beams and the frame.
If one opposite end of the axle is vertically displaced relative to the other opposite end of the axle, such as when a wheel attached to one end of the axle traverses an irregularity on the road surface, the axle is effectively rotated about a longitudinal axis of the vehicle. Since the axle is rigidly clamped to the spring beam, such rotation is transferred from the axle to the spring beam, causing the spring beam to torsionally flex. Some of this torsional loading is absorbed by a pivot bushing attached to the forward end of the spring beam.
In trailing arm suspension systems having rigid arms, instead of spring beams as hereinabove described, such torsional flexing is typically absorbed by elastomeric bushings mounted at the pivotable attachments of the arms to the hangers. An example of such bushings may be found in U.S. Pat. No. 4,991,868 to VanDenberg, the disclosure of which is hereby incorporated by reference. The VanDenberg bushings have vertically spaced apart voids formed therein which enable the bushings to have greater compliance in response to the torsional flexing. Some trailing arm suspension systems are bushed both at the front pivot and at the attachment of the axle to the trailing arm, thereby absorbing the torsional flexing in multiple bushings.
Transverse links, which extend generally parallel to the axle and couple the axle directly to the vehicle frame via pivoting bushed connections at each end of the transverse links, are sometimes required to control transverse displacement of the axle relative to the vehicle frame. Such transverse displacement is commonly referred to as "track out" and may occur when, for example, the vehicle negotiates a corner. Transverse links are typically required where the spring beam is not sufficiently rigidly attached to the axle of the suspension system and, thus, add to the installation time, maintenance requirements, and overall cost of such suspension systems.
A disadvantage of each of the above-described suspension systems is that the axle is clamped to the arms or spring beams with complex, maintenance intensive, potentially stress-inducing, and/or unreliable clamping devices. Most of these suspension systems, and others, rely solely on U-clamps to clamp the axle to the arms. Unfortunately, U-clamps are notorious for their tendency to loosen over time. Other clamping devices, such as that described in the patent to Pierce, impart undesirable stresses to the axle.
From the foregoing, it can be seen that it would be quite desirable to provide a suspension system which does not include an axle clamping device that is complex, maintenance intensive, stress-inducing, or unreliable, but which includes an axle seat that effectively and rigidly attaches an axle to the suspension system, is simple and straightforward in design, is economical to manufacture, and that is reliable in operation. It is accordingly an object of the present invention to provide such a suspension system.

Suspension system including an integrally formed axle seat