A subject (10) is disposed adjacent a detector array (18) for the purposes of nuclear imaging. The subject (10) is injected with a radioactive isotope (14) and xcex3-ray emissions indicative of nuclear decay are detected at the detector array (18). P-ASIC (60) preamplifier circuits are complex low-noise integrated circuits which dissipate a considerable amount of power (300-500 mW each). These components account for most of the dissipated power on the daughter cards (62). In order to facilitate the cooling of these electrical components, they are mounted on circuit boards (62) that are arranged parallel to each other extending perpendicularly away from the detector array (18). This provides channels between the boards through which cooling air is drawn by an array of fans (84).

The present invention deals with the diagnostic imaging arts. It finds particular application in conjunction with electronics used in nuclear cameras and will be described with particular reference thereto. However, it is to be appreciated that the present invention has application in other devices that have electronics that require cooling and is not limited to the aforementioned application.
Nuclear imaging employs a source of radioactivity togs image the anatomy of a subject. Typically, a radiopharmaceutical is injected into the patient. This radiopharmaceutical contains atoms that decay at a predictable rate. Each time an atom decays, it releases a xcex3-ray. These xcex3-rays are detected, and from information such as their detected position and energy, a representation of the interior of the subject is reconstructed.
Typically, a nuclear camera has one, two, or three detector heads. Each head has a large scintillator sheet, such as doped sodium iodide, which converts incident radiation into flashes of light. An array of photomultiplier tubes is disposed in back of the scintillator to monitor for light flashes. The output of the photomultiplier tubes and associated circuitry indicates the coordinates of each scintillation on the sodium iodide crystal and its energy. Unfortunately, there are numerous non-uniformities and inaccuracies when using a large scintillator crystal and an array of photomultiplier tubes.
Rather than using a single, large scintillator and photomultiplier tubes, others have proposed using an array of small scintillators, each associated with a photodiode or other photoelectrical device which senses a scintillation in each individual scintillation crystal. Other types of individual solid-state detectors have also been suggested.
For resolution on the order of a millimeter, each scintillator/photodiode or other detector element is typically on the order of a millimeter square. Each of the detector elements needs to be powered and to have its output electrical signals processed. Typically, the powering and at least a portion of the processing circuitry is mounted in close association with the individual detectors. This leads to a high density of electrical components, many of which generate significant heat. Cooling the electronics becomes a significant problem.
The present invention provides a new and improved method and apparatus that overcomes the above referenced problems and others.
In accordance with one aspect of the present invention, a nuclear imaging apparatus is given. An array of detectors detects xcex3-rays, information about the xcex3-rays are processed by electronics, a cooling system cools the electronics, and a reconstruction processor converts the xcex3-ray information into an image representation.
According to a more limited aspect of the present invention, the detector is an array of cadmium-zinc-telluride crystals.
According to a more limited aspect of the present invention, the detectors are collimated in one dimension.
According to a more limited aspect of the present invention, the cooling system includes fans and a cooling region.
According to a more limited aspect of the present invention, L-shaped connectors allow heat producing circuit boards to be disposed such that their disposition facilitates cooling.
According to a more limited aspect of the present invention, event analyzers detect events, their strength, and their locations, and sends this information to be stored in an event archive.
According to another aspect of the present invention, a nuclear camera is given. A detector head includes a housing within which are an array of detectors, circuit boards defining air channels, and heat generating P-ASICs mounted on the circuit boards.
According to a more limited aspect of the present invention, the circuit boards are mounted back to back in pairs.
According to another aspect of the present invention, a method of nuclear imaging is given. A subject is injected with a radiopharmaceutical that emits xcex3-rays. The xcex3-rays are detected by electronics and reconstructed into an image representation. The electronics are arranged to facilitate their cooling and they are cooled.
According to another aspect of the present invention, a method of nuclear imaging is given. xcex3-rays are detected by an array of detector arrays. The array is mounted on heat generating circuitry and air is passed along the circuitry to cool it. Signals are processed from the detector array and converted into an image representation.
According to a more limited aspect of the present invention, the detector array is biased by high-voltage circuitry on the board. The signals from the detector array are pre-amplified by P-ASICs on the circuit boards.
One advantage of the present invention is that it keeps electrical components at safe temperature levels.
Another advantage of the present invention is that it allows for a large number of detectors in a small area.
Another advantage of the present invention resides in high sensitivity and detailed spatial sampling resolution.
Yet another advantage of the present invention is that it avoids the use of liquid coolant or cryogenic cooling.
Still further benefits and advantages of the present invention will become apparent to those skilled in the art upon a reading and understanding of the preferred embodiments.

Method of cooling high density electronics


A screwing tool for an impact wrench for screwing wheel nuts onto and off from a hub body for securing a vehicle wheel, having a main body, which has an open side oriented toward the wheel nuts and which includes a hollow profile. The hollow profile has a tool contour, which is arranged on the open side and can be brought into engagement with a wheel nut contour. At least one peripheral control edge is remote from the open side for releasing a retention element. The control edge has a circular arc region with a constant control edge height h1 and a cam region with a control edge height h2 that decreases continuously and then increases again continuously. Height h1 is equal to h2 in the respective transition of the circular arc region and the cam region, such that the geometrical shape of an oval is reproduced in cross section.

Particularly in motor racing, vehicle wheels are secured on the respective axle by means of a central wheel nut, which is screwed onto the vehicle hub. In order to prevent unwanted release of this single wheel nut and hence release of the entire vehicle wheel, retention devices have to be provided to additionally secure the central wheel nut. A wheel retention system of this kind, which furthermore also discloses a radial retention of the retention element used, is known from DE 102 07 815 B4, which is incorporated by reference herein. Here, the retention device consists of two retention elements offset by 180°, which are spring-loaded and which move out of the hub body after the wheel nut is screwed on and consequently secure the wheel nuts against twisting. The retention elements have a surface which rises toward the wheel nut and via which the retention elements can be pressed inward again to release the wheel nut in order to allow the necessary axial movement of the wheel nut. Just like the wheel, however, these retention elements are exposed to high loads, in particular due to operating loads, with the result that these retention elements can jam in the hub body. Such jamming sometimes makes it impossible to release the wheel nuts automatically by means of an impact wrench. The retention elements must then be released mechanically by hand with a high expenditure of force to enable the impact wrench subsequently to be used. This manual mechanical release is associated with a large expenditure of time, which is unwanted and disadvantageous especially in motorsport.
It would be desirable to avoid the abovementioned disadvantage in a simple and low-cost way.

Tool for an impact wrench for securing a vehicle wheel

Dr. Ing. h.c. F. Porsche Aktiengesellschaft


The specification describes a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then presintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing(HIP) in an inert gas atmosphere of 1500-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 -Al.sub.2 O.sub.3 -MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4 above 500.degree. C. for a while. Between the second and third steps, the temperature of the presintered body is preferably maintained above 500.degree. C. These temperature controls are effective not only to improve the strength of sintered Si.sub.3 N.sub.4 but also to save the thermal energy and to shorten the production cycle.

1. Field of the Invention
This invention relates to a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a density equivalent to or higher than that of a conventional hot pressed body, which method facilitates the production of sintered bodies of complex configurations. More particularly, it relates to a method of further densifying and strengthening a presintered silicon nitride body, which has in advance been formed and presintered into a desired shape by the pressure-less sintering method or the like, in accordance with the hot isostatic pressing method(hereinafter referred to as "HIP method").
2. Description of the Prior Art
With a view toward improving the thermal efficiency, saving fuel, reducing pollution and lightening the weight of varied power generating equipments, active research and development work has been carried out in recent years in the field of equipment which are operated at high temperatures led by high temperature gas turbines and followed by diesel engines and MHD generators. Development of such equipment is absolutely dependent on the development of high-temperature structural materials. Thus, the development of such materials has been anxiously waited for. Under such high temperatures, conventional heat resistant metallic materials do not always exhibit sufficient mechanical strength. Also, from the view-point of saving exiguous natural resourses required for the production of such heat resistant metallic materials, intensive research is now under way to develop high-temperature structural ceramics using as raw materials Si, Al, C, N and the like elements which are relatively abundant on the earth.
The development of such high-temperature structural materials has been recognized to be also important for the purpose of their applications in super hard tools and as corrosion resistant materials, and is attracting great interests thereon.
Among such high-temperature structural ceramics, silicon nitride(Si.sub.3 N.sub.4) is attracting researchers' interests as one of most promising materials for providing sufficient strength, chemical stability and strong resistance to thermal shocks at high temperatures.
Si.sub.3 N.sub.4 has excellent physical properties as described above. These properties stem from the fact that silicon atoms (Si) and nitrogen atoms(N) are united by firm covalent bonds in silicon nitride (Si.sub.3 N.sub.4). However, this nature of Si.sub.3 N.sub.4 means, on the other hand, that it is hard to be sintered and extremely difficult to be formed into a product of complex configurations. As a matter of fact, most of the recent research in this field has been directed to how to produce formed Si.sub.3 N.sub.4 bodies having high strength. However, in view of the present state of the art, it does not appear that a fully satisfactory technique has been developed for the production of such Si.sub.3 N.sub.4 bodies.
More specifically, where high density and high strength are pursued, the shape of a formed body has to be unavoidably limited to simple ones. On the other hand, to obtain formed bodies of complex configurations, its strength has to be sacrificed to a considerable extent.
Among well-known conventional production methods of formed Si.sub.3 N.sub.4 bodies, there are the following four methods: (i) the chemical vapor deposition method(hereinafter referred to as the CVD method); (ii) a method in which Si.sub.3 N.sub.4 powder is mixed with a sintering aid and then sintered in an N.sub.2 atmosphere of atmospheric pressure or 10 atmospheres or so; (iii) the hot pressing method; and (iv) reactio bonding method. Of the above methods, the hot pressing method(ill) can provide formed bodies of a relatively high density and strength but is still accompanied by problems that formed bodies of a complex shape are difficult to obtain and it is costly to practise.
On the other hand, the reactin bonding method has a merit that complex configurations can easily be formed by a suitable conventional method owing to the use of Si powder as a raw material. However, it is accompanied by drawbacks that resultant sintered bodies do not have a high density and high strength sintered Si.sub.3 N.sub.4 cannot be obtained. The densities of sintered Si.sub.3 N.sub.4 bodies currently produced in accordance with the reaction bonding method are merely somewhat greater than 80%. This insufficient density impedes to improve the strength of sintered bodies. Moreover, an extremely long time period is required for the nitridation. For example, the reaction treatment requires at least two days in shorter cases and, in some longer cases, takes as long as 10 days or more. This is certainly a great problem in adopting the reaction bonding method.
The pressureless sintering method is a method to sinter a silicon nitride green compact which has in advance been formed into a desired shape. Thus, this method is rather easy to produce sintered products of complex configurations. However, the densities of such products are limited and are around 96% even for higher ones.
As an improved method over the above-described pressureless sintering method, there has been proposed to sinter a green compact, which has been preformed into a desired shape, in an N.sub.2 gas atmosphere of several atm to several ten atm as described in Japanese Patent Laid-open No. 47015/1977 laid-open Apr. 14, 1977 and naming as an inventor Mamoru Mitomo as well as Japanese Patent Laid-open No. 102320/1978 laid-open Sep. 6, 1978 and naming as an applicant General Electric Company. Such an improved method can provide sintered bodies having a density as high as 98% at maximum. However, it still fails to meet both of the requirements, namely, requirements for the formation of complicated shapes and the high densification. Especially, as a serious obstacle to the high densification, there is mentioned the thermal decomposition problem of Si.sub.3 N.sub.4 upon sintering. Namely, upon sintering Si.sub.3 N.sub.4, MgO, SiO.sub.2, Al.sub.2 O.sub.3 and/or the like are incorporated as a sintering aid. These compounds are however believed to volatilize during the sintering step by their reaction with Si.sub.3 N.sub.4 as described below. EQU Si.sub.3 N.sub.4 +3MgO.fwdarw.3SiO.uparw.+3Mg.uparw.+2N.fwdarw..sub.2 EQU Si.sub.3 N.sub.4 +3SiO.sub.2 .fwdarw.6SiO.uparw.+2N.uparw..sub.2 EQU Si.sub.3 N.sub.4 +Al.sub.2 O.sub.3 .fwdarw.2AlN+3SiO.uparw.+N.uparw..sub.2
On the other hand, Si.sub.3 N.sub.4 per se is known to undergo a thermal decomposition as described below. EQU Si.sub.3 N.sub.4 .fwdarw.3Si+2N.uparw..sub.2
Due to these thermal decomposition reactions, a weight loss normally takes place during a sintering step and, in some instance, such a weight loss exceeds the rate of density increase due to the shrinkage of a sintered body upon sintering. It has been reported that such a weight reduction may, in some instances, reach as high as 50%. The above-described sintering method in an N.sub.2 gas atmosphere was proposed as a measure for inhibiting the thermal decomposition but is still believed to cause a weight loss of several percents.
According to a research carried out by the present inventors, it has been recognized that the weight loss caused by the thermal decomposition has a close relationship with the density of a green compact before sintering as will be described later. The present inventors have also found that the weight loss due to thermal decomposition tends to become considerable where the initial density (i.e., the density of a green compact before sintering) is low but it becomes smaller as the initial density increases. From this finding, the decomposition reaction is considered to proceed, in the conventional sintering method in an N.sub.2 gas atmosphere, to the interior of a sintered body since the density of a green compact before sintering is merely 60% or so and its pores are completely open, and reaction products of the thermal decomposition are thus allowed to diffuse from the interior of the sintered body to the exterior of the same.
It is certainly an effective measure to increase the nitrogen gas partial pressure to suppress the aforementioned thermal decomposition in the sintering method in an N.sub.2 gas atmosphere. However, an N.sub.2 gas partial pressure of several ten atm or so, which has been employed in the conventional method, is by no means sufficient to effectively prohibit the thermal decomposition from the thermodynamical viewpoint.
As a method for highly densifying Si.sub.3 N.sub.4, it has been known to employ an HIP treatment using Ar gas. To follow this method, Si.sub.3 N.sub.4 powder is generally sealed hermetically in a capsule made of a gas-impermeable material such as glass and then subjected to an HIP treatment. This method is however impractical to produce a sintered body of a complex shape as it is extremely difficult to shape a capsule corresponding with the configurations of the intended product. It is also impractical as it still involves many problems to be solved, such as filling uniformly Si.sub.3 N.sub.4 powder in capsules, measures to avoid the reaction between Si.sub.3 N.sub.4 and capsules, and measures to decapsulate resultant Si.sub.3 N.sub.4 bodies from the capsules. In addition, it has also been proposed to close the pores of a green compact to a certain extent prior to applying an HIP treatment by subjecting the green compact to a presintering treatment. It is however difficult, generally speaking, to achieve a high density by this method as a considerable weight loss takes place due to the thermal decomposition of Si.sub.3 N.sub.4.
On the other hand, a large amount of research effort has been directed to the discovery of sintering aids suitable for producing high density sintered Si.sub.3 N.sub.4. However, under the present circumstances, it is still far away from the goal. It is considered to be promising to employ Y.sub.2 O.sub.3 or a mixture of Y.sub.2 O.sub.3 and Al.sub.2 O.sub.3 as a sintering aid for Si.sub.3 N.sub.4. As a matter of fact, it has been known that a sintered body having excellent mechanical properties can be obtained by mixing a suitable amount of such a sintering aid and Si.sub.3 N.sub.4 powder and by sintering the resultant mixture in accordance with the hot pressing method. However, such Y.sub.2 O.sub.3 system sintering aids are accompanied by the drawback that the pressureless sintering method, which is rather easy to produce bodies of complex configurations, cannot be applied to obtain sintered bodies of high density and strength. Thus, such Y.sub.2 O.sub.3 system sintering aids are employed exclusively for the production of bodies of simple configurations in accordance with the hot pressing method.
As a result of extensive research conducted by the present inventors, it has been unexpectedly found that high density sintered silicon nitride(Si.sub.3 N.sub.4) of a relative density of 98% or higher may be obtained by compacting silicon nitride powder into a green compact having a desired shape, presintering the green compact to a relative density of at least 92%, and then subjecting said presintered body to a hot isostatic pressing in an inert gas atmosphere of a temperature in the range of 1500.degree.-2100.degree. C. and of a nitrogen gas partial pressure of at least 500 atm until the former relative density is reached. In this invention, the gas used in the hot isostatic pressing is only the nitrogen or a gas mixture including the nitrogen. This method may be similar to the aforementioned prior art methods in an incorporation of the HIP method. However, the above finding of the present inventors is fundamentally different from the conventional HIP method as, in the former case, the relative density of a presintered body is raised to 92% or higher and it is then subjected to an HIP treatment in an inert atmosphere of the above specific temperature and N.sub.2 gas partial pressure.
The present inventors have also found that an incorporation of a Y.sub.2 O.sub.3 -Al.sub.2 O.sub.3 -MgO system mixture as a sintering aid in Si.sub.3 N.sub.4 powder can provide under normal pressure a presintered body of a higher density compared with the addition of a conventional Y.sub.2 O.sub.3 or Y.sub.2 O.sub.3 -Al.sub.2 O.sub.3 system sintering aid.
As a result of an experiment carried out by the present inventors to determine Whether there is any relationship between the relative density of sintered Si.sub.3 N.sub.4 and its strength, it has been found that they are not always corelated to each other. The inventors expanded the study and carried out a further experiment while paying attention to .beta.-Si.sub.3 N.sub.4 in presintered bodies. As a result of the further experiment, it has been found that the strength of a sintered Si.sub.3 N.sub.4 body corelates to the content of .beta.-Si.sub.3 N.sub.4 in the presintered Si.sub.3 N.sub.4.
Furthermore, it has been realized that the present sintering method, which makes use of an HIP treatment, involves the following problem in order to more effectively apply the same to the industry. Namely, a presintered body is discharged from a presintering furnace upon completion of the presintering step and cooled prior to charging the same into an HIP furnace. The thus-presintered body is then charged at a cooled temperature into the HIP furnace, although the HIP treatment requires 1000.degree. C. or higher, particularly, a high temperature of at least 1500.degree. C. for Si.sub.3 N.sub.4.
Such a cooling of a presintered body may be unavoidable where the sintering method is performed batch by batch. This however leads undoubtedly to a considerable loss of heat energy in view of the fact that the presintered body has been heated to a considerable extent during its presintering step. In addition, when a presintered body which has been presintered at high temperatures is rapidly cooled at the surface thereof or, after the rapid cooling, when rapidly heated, extremely fine cracks and fissures are likely to occur, whereby unavoidably deteriorating its strength and causing other problems with respect to its quality.
The present inventors have also found a measure capable of effectively overcoming the above problems of the thermal energy loss and strength deterioration caused by the rapid cooling of presintered and sintered bodies. Namely, it has been discovered that the thermal energy loss may be reduced and a high density sintered Si.sub.3 N.sub.4 body can be obtained by charging a presintered body, while maintaining its temperature above 500.degree. C., into an HIP furnace which has been in advance heated at 500.degree. C. or higher to conduct the HIP treatment, discharging the thus-sintered Si.sub.3 N.sub.4 body from the HIP furnace at a temperature of at least 500.degree. C., and then subjecting the same to a heat treatment at 500.degree. C. or higher in a heat treatment furnace.

Method for producing high density sintered silicon nitride (SI.sub.3 N.sub. 4


Provided are methods for making metal gates suitable for FinFET structures. The methods described herein generally involve forming a high-k dielectric material on a semiconductor substrate; depositing a high-k dielectric cap layer over the high-k dielectric material; depositing a PMOS work function layer having a positive work function value; depositing an NMOS work function layer; depositing an NMOS work function cap layer over the NMOS work function layer; removing at least a portion of the PMOS work function layer or at least a portion of the NMOS work function layer; and depositing a fill layer. Depositing a high-k dielectric cap layer, depositing a PMOS work function layer or depositing a NMOS work function cap layer may comprise atomic layer deposition of TiN, TiSiN, or TiAlN. Either PMOS or NMOS may be deposited first.

Microelectronic devices are fabricated on a semiconductor substrate as integrated circuits in which various conductive layers are interconnected with one another to permit electronic signals to propagate within the device. An example of such a device is a complementary metal-oxide-semiconductor (CMOS) field effect transistor (FET) or MOSFET.
Over the past decades, the MOSFET has continually been scaled down in size and modern integrated circuits are incorporating MOSFETs with channel lengths of less than 0.1 micron. Devices with a 65 nm feature size (with the channel being even shorter) are currently in production. The decrease in feature size has resulted in certain challenges because small MOSFETs exhibit higher leakage currents, and lower output resistance than larger devices. Still, smaller MOSFETs are desirable for several reasons. The main reason to make transistors smaller is to pack more and more devices in a given chip area, reducing the price per chip. Additionally, the reduction in transistor dimension can help increase the speed.
Because of small MOSFET geometries, the voltage that can be applied to the gate must be reduced to maintain reliability. To maintain performance, the threshold voltage of the MOSFET has to be reduced as well. As threshold voltage is reduced, the transistor cannot be switched from complete turn-off to complete turn-on with the limited voltage swing available. Subthreshold leakage, which was ignored in the past, now can have a significant impact on device performance.
A gate electrode is part of an integrated circuit. For example, a CMOS transistor comprises a gate structure disposed between source and drain regions that are formed in the semiconductor substrate. The gate structure generally comprises a gate electrode and a gate dielectric. The gate electrode is disposed over the gate dielectric to control a flow of charge carriers in a channel region that is formed between drain and source regions beneath the gate dielectric. The gate dielectric typically comprises a thin material layer having a dielectric constant of about 4.0 or greater (for example, gate oxides such as silicon dioxide (SiO2), silicon oxynitride (SiON), and the like).
The gate oxide, which serves as insulator between the gate and channel, should be made as thin as possible to increase the channel conductivity and performance when the transistor is on and to reduce subthreshold leakage when the transistor is off. However, with current gate oxides with a thickness of around 1.2 nm (which in silicon is ˜5 atoms thick) the quantum mechanical phenomenon of electron tunneling occurs between the gate and channel, leading to increased power consumption.
It is often traditional transistors, which are often planar, which may experience the aforementioned current leaks. Thus, as transistors become smaller, current leaks through them, which increases as the transistor size decreases. A possible solution to this problem is a three-dimensional gate structure. In these gates, the channel, source and drain are raised out of the substrate and the gate is then draped over the channel on three sides. The goal is to constrain the current to only the raised channel, and abolish any path through which electrons may leak. One such type of transistor is known as FinFET, in which the channel connecting the source and drain is a thin, "fin" jutting out of the substrate. This results in the current being constrained to only the now raised channel, thereby preventing electrons from leaking. These gates are often termed multi-gate. An example of such a multi-gate trasnsitor design is the FinFET, in which the channel connecting the source and drain is a thin "fin" extending from the silicon substrate.
However, while current leaks are prevented, there is a different challenge where a 3-D structure is used, because it is necessary to deposit work function material extremely conformally. Despite the promise that these multi-gates structures show, there are difficulties because the three-dimensional nature of the gates requires that the work function metal be highly conformally deposited. Current methods utilize physical vapor deposition (PVD) techniques for work function metal, which makes it exceedingly difficult to deposit the thin, conformal films that are needed. Thus, there is a need for improved methods for forming metal gates, particularly in the field of mutli-gate structures.


An Internet telephony system is capable of not only restraining a delay of transfer of a voice packet but also transferring a data packet at a high efficiency by fragmenting the data packet and thus routing the data packet only when the voice packet flows. The Internet telephone system has an Internet network for transferring voice information as the voice packet which is transmitted from a voice communications terminal incorporating a voice communications function, and transferring data as the data packet which are transmitted from a data communications terminal incorporating a data communications function. This system includes a first detecting unit for detecting a transition of a call-out state of the voice communications terminal, a packet assembling unit for assembling, when the first detecting unit detects the transition of the call-out state of the voice communications terminal, a control packet containing indication information for changing, to a predetermined limit value, a maximum length of each of the data packets transferred via the Internet network, and a first routing unit for routing, when receiving the control packet containing the indication information, each of the data packets and the voice packet to the Internet network while restricting the maximum length of the data packet to the predetermined limit value.

The present invention relates generally to a composite switched network system capable of reducing costs for equipment and operations by integrating a circuit switched network such as a telephone network with a connectionless packet switched network such as an Internet network or an Intranet network, and more particularly to an Internet telephone system capable of communications of voice information in the form of packets via the Internet network or the Intranet network.
With a progress of networking technology such as acquiring a much broader band of Local Area Network (LAN) and a progress of PC technology such as attaining multi-functions of a personal computer (PC) and a speed-up of a CPU applied to the PC over the recent years, it is feasible in terms of utilization to perform communications of voice information at a high speed between the PCs on a plurality of LANs. With those technological progresses, application software executed between the PCs on the Internet network (which includes the Intranet network if not particularly specified in this Specification), constructed of private lines for voice communications on conventional telephones, the LAN and Wide Area Network (WAN) and a hardware system incorporating this software, have been rapidly put into markets. This system is called [Internet telephony].
In this Internet telephony system, a VoIP (Voice over Internet Protocol) technology is used for integrating the voice communications with data communications. The VoIP technology is that the voice is converted into a frame at an interval of a short time (on the order of 20 ms) according to a network layer protocol used in the Internet, i.e., on the network having the IP (IP network), and a packet assembled by adding an IP header to the frame is transmitted and received. Note that the communications of the voice information in a computer network have a long history in which the first packet switching was experimented in 1974 in ARPANET (Advanced Research Projects Agency Network) as the predecessor to the Internet (refer to "RFC741: Specifications for the Network Voice Protocol (NVP)", IETF, Danny Cohen, 1976).
Further, there has been developed an Internet telephony gateway which incorporates a gateway functions for making a communications protocol conversion between the telephone network and the Internet network and actualizes the communications between the telephone network and the Internet network. There was proposed and has already been utilized a system (Internet-telephony-based cored system) in which the information is relayed via the Internet network between respective switches in the conventional telephone network by use of the Internet telephony gateways.
Generally, an operation for a telephone talk in the cored system of the Internet telephony has a lower cost than a telephone talk (voice communication) through the conventional telephone network, and therefore this cored system and services are now in the process of a rapidly spread. The transmission (transfer) standard in the cored system using the Internet telephony gateways is not, however, established, and what exists at the present is only ITU-T Recommendation H.450.2 (H.323) which defines the services within the Internet network, and the services in the conventional telephone network. Namely, there is no transmission standard on which to communicate the information to between the Internet telephony gateway having a function of converting the voice information given from the telephone network into a packet on the basis of the Internet Protocol (IP) and a router incorporating a function of routing the IP packet.
In the Internet telephony system, it is indispensable for routing the voice packet based on the Internet Protocol while restraining a delay to fragment short each of data packets (such as file-transfer packets) flowing simultaneously in the Internet network and thus transfer those packets. To describe it in depth, when starting the forwarding of the data packet as in the file transfer even if the voice packet is controlled with a high priority, the voice packet exhibiting a higher urgency which has arrived at afterward can not be forwarded if not waiting till a transmission of the data packet now undergoing the processing is finished. In a low-speed link, this waiting time is long, and a voice quality declines due to a transfer delay of the voice packet. In the case of transferring, for example, a 1500-byte packet onto a private line having a transmission speed on the order of 64 Kbps, a time of 180 ms is needed. A time for which the voice delay is allowable in the telephone talk is, generally speaking, 200 ms between the terminals (End-to-End), and the waiting time of 180 ms described above is extremely long.
A scheme for obviating this problem is to reduce a packet processing time by fragmenting the data packet having a packet length into pieces of small fragments and transfer the packet in such a manner that the voice packet is inserted into a gap between the fragmented data packets, thereby restraining the transfer delay. A prior art for thus fragmenting the data packet may involve multilink PPP (Point-to-Point Protocol) interleaving (IETF (Internet Engineering Task Force) draft: MCML) and setting an MTU length. According to this prior art, however, the data packet is always fragmented even when the voice packet does not flow, and hence a decrease in efficiency is inevitable in terms of transferring the data packet. That is, in the case of the data packet having a short packet length, the router as a relay device in the network has a high load. As a result, for instance, a file transfer is finished sooner by forwarding the data packet on a 1500-byte basis than forwarding the data packet with a fragmentation by every 300 bytes.


A reading apparatus for reading information recorded on a first longitudinal recording medium in the form of helical scanned information tracks, according to a first format in which the tracks have been recorded on the medium at a first track pitch and have a first track width, the information being read by the apparatus at a given tape velocity, the information being read from the first medium at a first bit rate, immediately adjacent tracks exhibiting alternately a first and a second azimuth angle, pilot tones being recorded in information tracks, the frequency of the recorded tones cycling through at least two different frequencies (f1, f2); and a second longitudinal recording medium recorded in the form of helical scanned information tracks, in accordance with a second, new, format in which the information track pitch is substantially twice the first track pitch, the information track width is greater than the first track width, the information being read from the second medium at substantially half the first bit rate, all of the information tracks on the second medium exhibiting the same azimuth angle, this angle being one of the first and second azimuth angles, immediately adjacent tracks containing pilot tones having mutually different ones of at the least two frequencies (f1, f2).

1. Field of the Invention
The invention relates to a reading apparatus for reading a first type of digital information recorded on a first longitudinal recording medium in the form of information tracks recorded at an angle to the direction of travel of said recording medium, according to a first format in which said tracks have been recorded on said medium at a given angle to said direction of travel, at a first track pitch and have a first track width, said first type of information being readable by said apparatus at a given tape velocity during a normal mode of operation of said reading apparatus, whereby said first type of information can be read from said medium at a first bit rate, immediately adjacent tracks exhibiting mutually different azimuth angles, each track exhibiting either a first or a second azimuth angle, a pilot tone having one of at least two different frequencies being recorded in every second information track, the pilot tone frequency cycling through said at least two different frequencies, said reading apparatus comprising at least one read head adapted to read tracks having said first azimuth angle and at least one read head adapted to read tracks having said second azimuth angle.
2. Description of the Related Art
An apparatus of this type is disclosed in, for example, U.S. patent specification U.S. Pat. No. 4,597,023, which is incorporated herein by reference.
Such an apparatus may accurately track the recorded information tracks, by detecting a crosstalk component in the playback signal originating from a track that is read, this crosstalk signal being caused by the tracking signals recorded in the neighboring tracks. The crosstalk component is used to accurately position the reading head with respect to the track from which information is to be read.
The tapes which are used as the longitudinal recording medium in such an apparatus may be blank tapes on which a user (re)records material, or may be prerecorded software tapes.
Two exemplary types of tape which may be used are Particulate and Metal Evaporated (ME) tapes. Examples of particulate tapes are metal particle (MP) tape and barium ferrite tape.
The particulate type of tape has the advantage that it is cheaper than the metal evaporated type, but has the disadvantage that it performs more poorly in terms of parameters such as S/N ratio, etc. In attempting to use a cheaper tape to carry prerecorded software, this poorer performance leads to problems, as explained below.
In order to produce prerecorded software tapes, the following processes are possible :
"Fast Copy". In this process, a master tape and the tape to be recorded are placed in contact, and a copy of the information on the master tape is transferred to the copy tape by a thermomagnetic or by an anhysteretic process, for example. The copying is carried out at a tape speed higher than the nominal tape speed. PA1 Alternatively, the master tape is placed in a master playing apparatus, and a number of slave recording apparatuses are used to record the information on copy tapes. This process is carried out at the nominal tape speed.
A characteristic of both these processes is that the signal-to-noise ratio on the copy tapes is reduced by several dB.
The solution to this problem, which is adopted in the VHS system, is that a master tape which has a higher signal level than the normally used tapes is chosen for use as a master tape. In the absence of such a master tape, the recording format must be changed. In the RDAT system, for example, the track width is greater than the head width, which results in an increased signal-to-noise ratio, thus compensating for the signal loss resulting from the high speed duplication process.
The disadvantage associated with the RDAT solution is that the linear tape speed is increased to make the track pitch greater, in order to accommodate the wider tracks. This causes an increase in the quantity of tape required, making the prerecorded software more expensive.
The use of the higher performance ME type of tape to carry prerecorded software (e.g. in the case of video tape: films, either for sale or for hire from a video library) results in increased duplication costs, as this type of tape cannot be used in the "Fast Copy" process.

Information track format and reading and recording apparatuses therefor


Disclosed herein are aggregators that can be cellulosic particles having high oil sorption capacity, high hydrophobicity, high buoyancy in water, and an aggregation quality that can support environmental remediation of hydrocarbon spills (e.g., crude oil spills) by various cleanup strategies including burning, skimming, or bioremediation. Also disclosed are methods of making the materials and methods of using the materials for environmental remediation.

Hydrocarbons like crude oil are some of the most important energy sources worldwide. However, when these vital resources are spilled or are out of control, it causes significant environmental and ecological problems. For example, when crude oil is spilled in an aqueous environment, effective decontamination and cleanup are necessary for the protection of environment and human health. One important technology for mitigating crude oil spills is to apply a chemical herding agent that corrals the oil by reacting with water to reduce the air-water surface tension, which causes oil to retract or "push inward" from the periphery of the spill due to a negative spreading coefficient. This may be used to prevent a spill from spreading into a sensitive area, or to corral the oil into a thicker slick covering a smaller surface area. One such herding agent is the US Navy's (USN) cold water herder formulation (65% sorbitan monolaurate [Span-20] and 35% 2-ethyl butanol). Herding agents typically work most effectively when they are applied to undisturbed thin layers of oil slicks (<3 mm) for several hours. The objective is to create an oil slick thickness greater than approximately 3 mm, a thickness that allows the oil to be ignited and burned off. However, chemical herding agents suffer from several limitations. For example, they work best under calm sea conditions with low wind velocity and an absence of ice. Each application of a herding agent has a limited effectiveness of about an hour upon deployment. Furthermore, the herding agents themselves may be toxic.
Alternatives to herding agents can include sorbents. A sorbent acts by attracting and holding oil onto its surface; sorbents typically have highly interconnected pore spaces to increase the available surface area to increase the amount of oil that can be captured. An ideal sorbent rejects water (is hydrophobic) and is buoyant. After collecting oil, sorbents must then be retrieved and treated to recover, treat, or dispose of the oil. To facilitate retrieval, sorbents are formatted into sheets (for small spills typically in a confined area) or booms (for small to large spills, including open water spills). Mineral and synthetic sorbents can have high oil sorption capacity. However, they can be slow to degrade and/or can leave undesirable combustion products and are therefore not used with in situ burning. Vegetable-based sorbents are relatively friendlier to the environment, but do not perform as well, especially in the presence of waves and wind. They tend to have relatively low oil sorption capacity, low hydrophobicity and poor buoyancy compared to synthetic and mineral sorbents.
Accordingly, a need exists for oil adsorption materials that are environmentally friendly, have high oil sorption capacity, are highly buoyant, and can create oil slicks of sufficient thickness and stability (i.e., limited spreading, fragmenting, or sinking) to be burned in situ, even under windy, wavy, or icy conditions. A need also exists for methods of making the materials, and methods of using the material for environmental remediation.

Solid, hydrophobic aggregators and methods of making and using the same


A method and apparatus for leveling of metal sheets conveyed through leveling gaps formed by several adjustable upper and lower leveling rollers and adjusted as a function of the sheet cross-section and the nominal sheet strength is disclosed. After initial maximum deformation, the sheets are subsequently repeatedly bent in alternate directions with a greatly diminishing degree of deformation resulting in an improved operational mode if the leveling range of a leveling machine is expanded toward the thicker metal sheets by a smaller quantity of leveling rollers in engagement, and thus a larger roller pitch, in case of sheet thicknesses exceeding the nominal sheet thickness of the leveling range.

German Offenlegunschrift 3,308,616 discloses a method in which uniformly planar metal sheets are produced with a small number of deformations steps. In this method, the leveling roller adjustments in a leveling machine, comprising several top and bottom, individually adjustable leveling rollers, are continuously corrected in the course of the leveling process, depending upon the sheet metal strength determined from the sheet cross-section and the leveling force. In this method, the changes in strength and cross-section, as well as the resulting difference in stretch or strain of the leveling machine occurring across the length of the sheet, are taken into account when adjusting the leveling gaps or grooves. The thickness of the sheet, the material yield strength and the width of the sheet govern the layout of levelers for sheet metal and strip. The diameter of the leveling roller and the pitch are determined, either from the maximum leveling force or from the maximum torque to be transmitted. Once the leveling roller pitch is determined, taking into account the required maximum deformation (over-stretch) of the metal sheet, the minimum sheet thickness to be leveled is already preset and the thickness range to be leveled is established. For leveling very wide, thick sheets, large drive spindles must be selected because of the large roller diameters for achieving the required torsional stiffness and a larger pitch than with narrower, thinner metal sheets. This, however, greatly limits the capability for leveling thin metal sheets. A thick metal sheet must be bent, to a lesser extent than a thin sheet, in order to achieve equal plastic deformations, because the thin sheet acts like a spring when slightly bent.
German Offenlegunschrift 3,731,234 discloses the reduction of the quantity of rollers in a metal sheet leveler by deforming the sheet metal spasmodically to a lesser extent after maximum bending by intensive deformation rollers and subsequent leveling rollers. In the known leveller, the top and bottom leveling rollers are therefore individually adjustable in the vertical direction.
In view of these drawbacks, it is an object of the invention to create a method and an apparatus enabling an improved operational functioning of a roller leveler.


The present disclosure is directed to a composite component defining a component aperture extending between a first surface and a second surface. The composite component includes an insert having an insert annular wall positioned in the component aperture. The insert annular wall defines an insert aperture therethrough. An insert flange extends radially outwardly from the insert annular wall and contacts the first surface of the composite component. The insert flange includes a diameter about 1.5 times to about 5 times greater than a smallest diameter of the component aperture defined by the composite component.

Gas turbine engines typically include a compressor section, a combustor section, a turbine section, and an exhaust section. A rotor shaft rotatably couples the compressor section and the turbine section. In this respect, the compressor section compresses air entering the gas turbine engine. This compressed air mixes with fuel in the combustor section to form an air and fuel mixture, which produces hot exhaust gases when ignited. These hot exhaust gases then flow through the turbine section, which extracts kinetic energy therefrom. This, in turn, rotates the rotor shaft, which provides the necessary mechanical energy to the compressor section to compress the incoming air. After flowing through the turbine section, the hot exhaust gases exit the gas turbine engine via the exhaust section.
In particular configurations, the exhaust section may include a center body that couples to a rear frame of the turbine section. The components defining the hot gas path, such as the center body, may be constructed of a ceramic matrix composite ("CMC") material or another composite material capable of withstanding prolonged exposure to the hot combustion gases. The components positioned radially inward or radially outward from the hot gas path, such as the rear frame of the turbine section, typically experience lower temperatures than the components along the hot gas path. In this respect, these components may be constructed from suitable metallic materials.
Conventional attachment systems typically used in gas turbine engines to couple a composite component (e.g., the CMC center body) to another component (e.g., the metallic rear frame of the turbine section) require machining of the composite component. This is a time-consuming and expensive process that results in increased manufacturing time and cost when constructing the gas turbine. Accordingly, an attachment assembly for coupling a composite gas turbine engine component to another gas turbine component that eliminates the need for machining of the composite component would be welcomed technology.

Metallic attachment system integrated into a composite structure


In an arrangement for suppressing spurious signals occurring in a reception signal in a receiver of a high-frequency message transmission system, these spurious signals resulting from at least one neighboring channel that neighbors the useful signal channel, the reception signal is distributed onto at least two branches. One of the branches has a summing element as well as a circuit for generating a signal with a frequency, phase and amplitude corresponding to the useful signal. The other branch also has a summing element as well as a circuit for generating a signal having a frequency, phase and amplitude corresponding to the spurious signal. The signals of these branches are respectively supplied anti-phase to the summing element of the respective other branch. In addition, an evaluation and control circuit is allocated to the branches, the momentary frequency, phase and amplitude of the useful or spurious signal allocated to the respective branch being measured and evaluated therewith and with which the frequency, phase and amplitude of the signal generated in the respective branch is correspondingly set dependent on these measured and evaluation values.

The present invention is directed to an arrangement for suppressing spurious signals in a reception signal of a receiver in a high-frequency transmission system. The spurious signals come from a neighboring channel to a useful signal channel.
An arrangement of this type for suppressing spurious signals in a reception channel is known (Recommendations and Reports CCIR, Vol. I "Spectrum Utilization and Monitoring", Dubrovnik, 1986, pages 63-79, particularly FIG. 3). The local generation of compensation signals having the frequency and phase of the useful signal or of the spurious signal is achieved with a phase control loop having a voltage-controlled oscillator. The setting of the amplitude of these signals occurs by means of level-setting elements that are arranged between an output of the voltage-controlled oscillator and a summing element of another branch. Both the setting of the frequency of the oscillators of the phase control loops to the frequency of the useful signal or spurious signal, as well as, the setting of the level-setting elements to the respective amplitude of the signals occurs manually in the known arrangement and remains unaltered during operation. The known arrangement is, thus, only suitable for receivers wherein the reception frequency of the useful signal and the frequency of the spurious signals is precisely known in advance and does not change during operation.

Arrangement for suppressing spurious signals occurring in the reception signal of a receiver of a high-frequency message transmission system


A conditioning shampoo containing an anionic cleansing surfactant, in an amount of about 5% to about 65% by weight, preferably about 5% to about 25% by weight, e.g., (C.sub.12 -C.sub.22) alkyl sulfate, and/or a long chain (C.sub.12 -C.sub.22) partially or fully ethoxylated alkyl sulfate, and/or a long chain (C.sub.12 -C.sub.22) alkyl sulfonate, and a combination of cationic polymers comprising (1) a cationic (protonated) polyethyleneimine in an amount of about 0.1% to about 4% by weight, preferably about 0.1% to about 1% by weight, and (2) a cationic oil-soluble, water-dispersible, cross-linked quaternary acrylate/acrylamide copolymer (Polyquaternium 32), in an amount of about 0.1% to about 20% by weight of the composition, provides excellent foaming, conditioning and stability, without settling of water-insoluble materials due to anionic-cationic complexing. The composition preferably also includes one or more silicone conditioning agents, and has extended product stability, excellent overall conditioning to human hair, particularly superior wet and dry combing properties, and unexpectedly maintains very high levels of foam.

Soiled human hair is shampooed to remove sebum that is naturally secreted by the head as well as soil and other atmospheric contaminants that accumulate on the hair. Sebum, in particular, accumulates on the hair in a relatively short period of time leaving the hair with a greasy, dirty feel and poor manageability. The most effective shampoos for cleansing the hair for removal of the atmospheric contaminants and sebum, are those that contain high lather synthetic anionic detergents, such as the long chain alkyl sulfates, the partially ethoxylated long chain alkyl sulfates and the long chain sulfonates. These synthetic anionic detergents are very effective for cleansing the hair but, after rinsing with water, leave the hair with a dried touch, usually called "creak" and result in hair, when wet, that is in an extremely tangled and unmanageable after-shampoo condition.
Thoroughly cleansed hair is extremely difficult to comb, in either the wet or dry state because the individual hair fibers tend to snarl, kink, and interlock with each other. Particularly, prior to complete drying of thoroughly cleansed hair, in this after-shampoo stage, the hair is very difficult to comb or brush. Even after complete drying, the thoroughly cleansed hair remains difficult to comb or brush and does not set well. Thoroughly clean, dried hair also has undesirable electrostatic properties in a low humidity atmosphere that causes the hair to "fly away", thereby further reducing the combing or brushing property of the hair. Generally, these above-outlined problems that result from synthetic detergent cleansing of the hair, particularly in the high-lather synthetic anionic detergents, have been alleviated either by the after-shampoo treatment of the hair with hair conditioners, for example, in the form of a hair rinse, or by including hair conditioners directly within the shampoo composition.
After-shampoo hair conditioning compositions are easily formulated but are inconvenient to use because of the necessity of applying the conditioner to the hair in a separate stage, after shampooing. The preparation of a conditioning shampoo has been more difficult because of inherent incompatibility problems between anionic surfactants and the cationic compounds that are good conditioning agents. Contact between an anionic surfactant and a cationic surfactant or cationic polymer produces a precipitate that forms immediately or causes an interaction between the anionic and cationic compounds that significantly reduces their respective cleaning and conditioning properties, and especially a very noticeable severe loss of foam attributed by the anionic cleansing surfactant. The reduction in cleansing and conditioning effectiveness is observed even in compositions wherein the anionic and cationic compounds do not precipitate from the composition but remain in solution or suspension. This incompatibility between an anionic surfactant and a cationic conditioning compound is well recognized by those skilled in the art. For example, Sagarin in Cosmetics, Interscience Publishers, Inc., New York, p. 538 (1957), states that anionic and cationic compounds cannot be used in combination because they react to form insoluble salts.
A partial solution to this incompatibility problem in the formulation of conditioning shampoos is exemplified by the following patents that disclose compositions that contain surfactants that are not anionic, e.g., non-ionics, amphoterics and zwitterionics together with cationic conditioning compounds: U.S. Pat. No. 3,849,348 to Hewitt; U.S. Pat. No. 3,990,991 to Gerstein; and U.S. Pat. No. 3,822,312 to Sato.
Another problem inherent in formulating a conditioning shampoo is an instability problem that results when water-insoluble conditioning agents are also included in the conditioning shampoo composition, such as the non-volatile silicones that are well recognized in the art as providing a degree of softness to the hair.
Silicones in shampoo compositions have been disclosed in a number of different patents: U.S. Pat. No. 2,826,551, Mar. 11, 1958 to Green; U.S. Pat. No. 3,964,500, Jun. 22, 1976 to Drakoff; U.S. Pat. No. 4,364,837, Dec. 21, 1982 to Pader; British Patent No. 849,433, Sep. 28, 1960 to Woolston; U.S. Pat. No. 4,741,855 to Grote, et al.; U.S. Pat. Nos. 4,788,006 and 4,902,499 to Bolich, Jr., et al. and U.S. Pat. No. 4,704,272 to Oh, et al. The silicones are well known to substantially reduce the foaming of anionic cleansing surfactants.
A particularly difficult problem to solve in silicone-containing conditioning shampoos is that of providing a conditioning shampoo that provides excellent cleansing of the hair while providing high foaming and, at the same time, also has excellent conditioning performance. The capability of providing excellent conditioning, cleansing and foam levels is achieved with the compositions of the present invention. In accordance with one embodiment of the present invention, it has been found that a combination of (1) a cationic (protonated) polyethyleneimine (PEI) in an amount of about 0.01% to about 4% by weight of the composition, preferably about 0.01% to about 1% by weight, together with (2) a cationic oil-soluble, water-dispersible cross-linked quaternary acrylate/acrylamide copolymer (Polyquaternium 32), in an amount of about 0.1% to about 20% based on the total weight of the composition, is stable over long periods of time while providing excellent simultaneous conditioning, cleansing and foaming. Optionally, a number of materials can be included in the conditioning shampoos of the present invention for purposes of thickening and stabilization such as xanthan gum, long chain acyl derivatives, long chain amide oxides or amine oxides, and long chain alkanolamides, as disclosed in U.S. Pat. Nos. 4,788,406; 4,704,272; and 4,741,855, hereby incorporated by reference.

Stable conditioning shampoo having a high foam level containing a silicone conditioner, a cationic quaternary acrylate copolymer, an anionic surfactant and polyethyleneimine


A metal oxidation treatment apparatus to form the passivation film on the surface of the metal to be oxidized such as stainless steel or the like, comprising an oxidation furnace, a gas inlet to introduce gas into said oxidation furnace, a discharge outlet to discharge the gas from said oxidation furnace, and a heater to heat said oxidation furnace to the predetermined temperature, so that the metal to be oxidized is heated and oxidized in dry oxidation atmosphere while gas is passed in said oxidation furnace.

In recent years, the technique to attain ultra-high vacuum or the technique to produce ultra-high clean reduced pressure atmosphere by introducing the gas at low flow rate into vacuum chamber is becoming increasingly important. These techniques are applied for the research of material characteristics, for the formation of various types of thin film, for the manufacture of semiconductor devices, etc. As the result, higher degree of vacuum is attained, while there is a strong demand on the reduced atmosphere, where the intermingling of impure elements and impure molecules could be reduced to utmost extent.
For example, in the manufacture of semiconductor devices, the dimensions of unit elements are being reduced year by year to attain higher integration of integrated circuit. Fervent research and development activities are carried out for the practical application of semiconductor devices having the dimension of 1 .mu.m to submicron, or 0.5 .mu.m or less.
Such semiconductor devices are manufactured by repeating the process to form thin film and the etching process of the film thus formed into the specified circuit pattern. Usually, such processes are performed in ultra-high vacuum conditions or in reduced pressure atmosphere with the specified gas by placing the silicon wafers into vacuum chamber. If the impurities are intermingled during these processes, the quality of thin film may be reduced or the precision fabrication may not be achieved. This is the reason why ultra-high vacuum and ultra-high clean reduced pressure atmosphere is wanted.
One of major reasons to hinder the actualization of ultra-high vacuum and ultra-high clean reduced pressure atmosphere has been the gas released from the surface of stainless steel widely used for the chamber of gas pipe. Above all, the source of the worst contamination has been the moisture adsorbed on the surface, which comes apart under vacuum or reduced pressure atmosphere.
FIG. 9 is a graphic representation showing the relation between total leakage of the system, including the gas piping system and reaction chamber in each apparatus (the sum of gas quantity released from inner surface of piping system and reaction chamber with the external leakage), and gas contamination. It is assumed that original gas does not contain the impurities. The lines in the diagram indicate the results when the values are changed with gas flow rate as parameter. Naturally, the lower the gas flow rate is, the more the concentration of the impurities increases as the influence of the released gas from inner surface becomes conspicuous.
In the semiconductor manufacturing process, there is a trend to increasingly reduce the gas flow rate in order to attain the process of higher accuracy by opening and filling the holes with high aspect ratio. For example, it is now normal to use the flow rate of several tens of cc/min. or less for the process to manufacture ULSI of submicron order. Suppose that the flow rate is 10 cc/min. and that the total leakage of the system is 10.sup.-3 to 10.sup.-6 Torr l/sec. as the apparatus currently in use, the purity of the gas is 1% to 10 ppm, and this is far from the high clean process.
The present inventors have invented the ultra-high clean gas supply system and have succeeded in reducing the leakage from outside the system to less than 1.times.10.sup.-11 Torr l/sec. which is the detection limit of the detectors presently in use. However, the concentration of the impurities in the reduced pressure atmosphere could not be reduced due to the leakage from inside the system or due to the components of the released gas from the surface of said stainless steel. The minimum value of the surface released gas quantity as obtained by the surface treatment in the ultra-high vacuum technique at present is 1.times.10.sup.-11 Torr l/sec. cm.sup.2 in case of stainless steel. Suppose that the surface area exposed to the interior of the chamber is estimated to the minimum, e.g. to 1 m.sup.2, the total leakage is 1.times.10.sup.-7 Torr l/sec. This means that only the gas with purity of about 1 ppm can be obtained to the gas flow rate of 10 cc/min. The purity is doubtlessly decreased when gas flow rate is lowered further.
In order to decrease the released gas from inner surface of the chamber to 1.times.10.sup.-11 Torr l/sec., i.e. to the same level as the external leakage of total system, it is necessary to set the released gas from the surface of stainless steel to less than 1.times.10.sup.-15 Torr l/sec. cm.sup.2. As the result, there is strong demand on the better processing technique for the surface of stainless steel to have lower gas release.
In the semiconductor manufacturing process, a wide variety of gas is used from the relatively stable common gas (such as O.sub.2, N.sub.2, Ar, H.sub.2, He) to special gas having higher reactivity, corrosive property and toxicity. As the material for the piping and chamber for these gases, stainless steel is normally used because of its higher reactivity, corrosion resistance, high strength, easy secondary fabrication, weldability and easy polishing of inner surface.
Stainless steel shows excellent corrosion-resistant property in a dried gas atmosphere. Among the special gases, however, there are boron trichloride (BCl.sub.3) or boron trifluoride (BF.sub.3), which generates high corrosive property by generating hydrochloric acid or hydrofluoric acid through hydrolysis when moisture exists in the atmosphere. Thus, stainless steel is easily corroded when moisture exists in the gas atmosphere containing BCl.sub.3 or BF.sub.3. Therefore, anti-corrosion processing is indispensable after surface polishing of stainless steel.
As the anti-corrosion processing, there are the methods, one of which is Ni-W-P coating (clean escorting method) to coat the highly corrosion-resistant metal on stainless steel. There are some problems with this method because cracking and pinholes often occur and the adsorbed moisture on inner surface or the residual solution components increase because the wet type metalplating is employed. There is also another anti-corrosion processing method by passivation treatment to produce the oxide film on metal surface. Stainless steel is passivated when it is immersed in the solution containing sufficient quantity of oxidizer. In this method, stainless steel is usually immersed in the nitric acid solution at normal temperature or a little higher and the passivation treatment is performed. However, this method is also of wet type, and the residues of moisture and the processing solution remain on inner surface of the piping and the chamber. In the methods as described above, the existence of moisture adsorbed on inner surface gives severe damage to stainless steel when the gas of chlorine type or fluorine type is introduced.
Therefore, it is very important for the ultra-high vacuum technique or in the semiconductor manufacturing process to fabricate the chamber or the gas piping system with stainless steel having the passivated film, which is not easily damaged by corrosive gas and which occludes or adsorbs less moisture.
For example, in the passivation treatment of stainless steel pipe, the passivated film having excellent degassing property is obtained when heating and oxidation are performed in a highly clean atmosphere with moisture content of less than 10 ppb.
FIG. 10 summarizes the changes of moisture contained in the purge gas when the stainless steel pipes with different internal process conditions are purged at normal temperature. In the experiment, argon gas was passed at the flow rate of 1.2 l/min. through a stainless steel pipe of 3/8" with total length of 2 m, and the moisture content in argon gas at the outlet was determined by APIMS (atmospheric pressure ionization mass spectrometer).
The stainless steel pipes under test are divided into three types: (A) Stainless steel pipe with inner surface processed by electrolytic polishing; (B) Stainless steel pipe with inner surface processed by passivation treatment with nitric acid after electrolytic polishing; (C) Stainless steel pipe, on which the passivated film is formed by heating oxidation in highly clean and FIG. 10, these are represented by the curves A, B and C. The experiment was performed after leaving each of these stainless steel pipes in a clean room maintained at relative humidity of 50% and at temperature of 20.degree. C. for about one week.
As it is evident from the curves A and B, a large quantity of moisture was detected from the electropolished pipe (A) and the electropolished pipe with passivation treatment with nitric acid (B). After gas was passed for about one hour, moisture of 68 ppb was detected in A and 36 ppb in B. Moisture content did not decrease after 2 hours, showing 41 ppb and 27 ppb in A and B respectively. In contrast, moisture content decreased to 7 ppb within 5 minutes after the gas was passed through the pipe (C) with the passivation film formed in high clean and dry atmosphere. After 15 minutes, it decreased to less than the background level of 3 ppb. Thus, it was demonstrated that (C) has excellent degassing property to adsorption gas.
However, in order to attain ultra-high clean oxidation atmosphere with moisture content of less than 10 ppb to produce the stainless steel pipe similar to (C) in FIG. 10, it is essential to have high-grade condition control. This involves higher cost and lower production efficiency and is not suitable for mass production. In other words, it is impossible to attain ultra-high clean oxidation atmosphere by the metal oxidation apparatus and metal oxidation method as conventionally employed.
Particularly, in the stainless steel pipes with smaller inner diameter such as 1/4", 3/8", and 1/2", gas is very likely to stagnate, and oxidation treatment is performed with the inside of the stainless steel pipe exposed to atmospheric air, resulting in contamination. This makes it impossible to form the passivation film of good quality having superb corrosion-resistant property and with lesser moisture occlusion and adsorption. Because outer surface of stainless steel pipe is not directly related with the supply of ultra-high purity gas, the surface becomes contaminated after oxidation treatment due to roughness and dirtiness of the surface. The oxidation of outer surface of stainless steel pipe results in the problems such as poor external appearance or the generation of particles when pipes are installed in a clean room.
Therefore, there have been strong demands on the establishment of the mass production technique for the passivation treatment for stainless steel pipe in order that the passivation film is formed to provide inner surface with excellent corrosion-resistant property and to occlude or adsorb the moisture in lesser content and that outer surface is not oxidized.
The object of the present invention is to solve these problems by offering metal oxidation treatment apparatus and metal oxidation treatment method, by which the contamination caused by the released gas or the impurities such as moisture from the oxidized surface of stainless steel pipe is reduced and the stainless steel pipe for ultra-high vacuum and ultra-high clean reduced pressure apparatus and for gas supply system having excellent corrosion-resistant property can be produced in large quantity.
Another object of this invention is to offer metal oxidation treatment apparatus capable of self-cleaning and self-maintenance in addition to the above object.

Apparatus and method for oxidation treatment of metal

1-17-301, Komegabukuro 2-chome, Aoba-ku, Sendai-shi, Miyagi-ken 980


The apparatus for providing milk for a coffee maker comprises a milk container having a base container for receiving the milk and a lid disposed on the base container, and at least one tube element, wherein the respective tube element protrudes into the base container and has an inlet opening for the milk, said inlet opening being in fluid connection with an outlet opening for the milk disposed on an upper side of the lid. An elastic sealing collar surrounding the outlet opening is disposed at the outlet opening. A docking system for docking to the milk container comprises a docking piece, which can be brought into a top position and a bottom position, wherein the docking piece has at least one opening for receiving the milk on an underside. If the docking piece is in the top position, the docking piece has no contact with the sealing collar and the sealing collar is shaped such that at least one section of the sealing collar protrudes upward above the respective outlet opening. If the docking position is in the bottom position, the underside of the docking piece is pressed against the sealing collar such that the sealing collar is compressed in the vertical direction and rests in a fluid-tight manner against the docking piece along a closed curve enclosing the particular opening.

Coffee makers which are able to deliver various milk products such as, for example, macchiato, cappuccino, white coffee etc, require a safe, sealed and interruption-free connection to the milk stored in a storage container for the supply of milk.
As a result of the need to store the milk chilled, there are two possibilities for the delivery of milk.
If milk products are only delivered occasionally, it may be appropriate to store the milk container in a chilled environment, preferably in a refrigerator. This container is only fetched as required and placed next to the coffee maker. The connection to the machine can be made by dipping a suction hose into the container. The milk container is then removed again and the parts coming in contact with the milk must be cleaned.
However, if milk products are to be delivered permanently, i.e. at relatively short time intervals, it is better if the milk container stays permanently connected to the machine in a chiller unit provided. Since milk products are enjoying increasing popularity, this arrangement will be increasingly used in future.
The last-mentioned arrangement has the consequence, however that the connection of the milk container is more inconvenient since the line(s) must be passed through the insulating jacket of the chiller unit.
Added to this, for various reasons the interior of the chiller is kept as small as possible for a predefined amount of milk. The associated disadvantages lie in more difficult handling when setting up for milk delivery and also for cleaning, longer hose lines and therefore hygiene problems, and increased liability to breakdown.
Known from U.S. Pat. No. 5,473,972 is a coffee maker having a device for providing milk froth accommodated in a housing of the coffee maker. The device for providing milk froth (hereinafter "frothing device") can be supplied with milk by placing a transportable, milk-filled milk container in a spatial area under the frothing device and thereby connecting a lid of the milk container to a wall section of the coffee maker housing, which wall section is disposed underneath the frothing device and is aligned parallel to the lid of the milk container. During this process a fluid connection must be made at the same time between a supply line accommodated in the coffee maker housing for supplying the frothing device with milk and a tube element by which means milk can be removed from the milk container. The tube element is fastened to the lid of the milk container and has a section having an inlet opening for the milk, which protrudes into the milk container starting from the lid and is guided through the lid in such a manner that a section of the tube element extends vertically upwards above the lid, with the tube element having an outlet opening for the milk at its upper end. In order to make the said fluid connection between the tube element and the supply line to supply the frothing device with milk, a section of the tube element accessible on the upper side of the milk container must be placed over its entire length in its longitudinal direction into a section of the supply line protruding vertically downwards in the coffee maker housing. In order to ensure that the connection between the supply line and the tube element is fluid-tight, the tube element is surrounded by a sealing ring, which is disposed at a distance from the upper end of the tube element and is connected to the lid of the milk container. The distance of the sealing ring from the upper end of the tube element is determined so that the lower end of the supply line is brought in contact with the sealing ring when the milk container is connected to the coffee maker housing and the upper section of the tube element is thereby inserted into the lower end of the supply line. This type of provision of milk has the disadvantage that the milk container must be moved and positioned with great accuracy both horizontally and vertically relative to the housing of the coffee maker or to the supply line in order to be able to make a fluid connection between the tube element and the supply line. Making the fluid connection is therefore inconvenient, time-consuming and difficult to carry out or not practicable in confined spaces. In addition, the dimensions of different parts of the coffee maker and the milk container, which parts must be interconnected when making the fluid connection, must be matched relatively precisely to one another. The construction and manufacture of these parts is therefore relatively complex and costly.
It is the object of the present invention to avoid the said disadvantages and provide an apparatus which ensures a rapid provision of fresh milk for a coffee beverage optionally over a long period of time in a simple and cost-effective manner.

Apparatus for providing milk for a coffee maker


Disclosed herein is a method and an apparatus for controlling or determining and estimating an object system which controls or determines parameters for specifying the object system and estimates an internal condition of the object system based on a measured value obtained for the object system. The method and apparatus compute a function characteristic distribution of the object system as a function of variable parameters using a boundary element method or finite element method. An equation is set by making equivalance between the computed distribution and a predetermined distribution. Values of parameters can be obtained by solving the equation.

1. Field of the Invention
The present invention relates to a method and an apparatus for controlling or determining and estimating an object system which controls or determines, in order to obtain, for example, predetermined distribution concerning a function characteristic distribution of an object such as magnetic flux distribution and temperature distribution, a parameter for specifying an object such as shape and a physical value of the material and also estimates an internal condition of the object such as a physical value of the material on the basis of a measured value obtained for the object.
2. Description of the Prior Art
FIG. 27 is a flowchart explaining a method for obtaining the predetermined uniform magnetic flux distribution by optimizing the shape of an electromagnet explained on page 393 of the Proceedings of Electric Society in Japan, A No. 9, Vol. 109 (1989). FIG. 28 shows a model under the bidimensional analysis of an electromagnet as an object.
In FIG. 28, the reference numeral 90 denotes a coil to which a current is applied to generate a magnetic field in the gap 93 of a magnetic body 91 and poles 92 of the electromagnet. In this case, the magnetic field distribution in the gap 93 is determined by the shape of the poles 92. Therefore, it is desired to obtain a shape of the poles 92 which unifies as much as possible the magnetic flux density in the y direction of evaluation region 94 enclosed by a dotted line in the gap 93. Now, the electromagnet is assumed to be placed within the air region.
Operations will then be explained. In this case, the shape of poles 92 is a parameter which specifies an object and the predetermined function characteristic distribution is a uniform magnetic field distribution. Moreover, a boundary element method is used as an analysis method in the above reference. The boundary element method is used for analyzing the characteristics of a complicated analysis object through a division of elements on the boundary using the boundary element equation.
First, the initial condition is set (step ST51). This includes setting of the initial condition means, setting of coordinates of each node and setting of physical values of a material in each boundary element when the analysis object is divided into a finite number of boundary elements. In this case, the initial shape of poles 92 is set to a flat shape as shown in FIG. 20(a).
Next, a target value in the finite number of evaluating points i (i=1, . . . , M) within the evaluating region 94, namely a value of the predetermined uniform magnetic field in this case, is set (step ST52). Next, a y element of the magnetic field in the M evaluating points is calculated by the boundary element method (step ST53). Moreover, a sum of the squares of the errors between the calculated values and the target values in the M evaluating points is calculated and error evaluation is conducted for this sum of the squares (step ST 54).
When an error is the predetermined value or less, processing is completed and if not, calculation of the evaluating function described in the above reference is conducted (step ST56). In addition, the amount of correction of the shape of poles 92 is determined by using the calculation result of the evaluating function (step ST55). The boundary element analysis is executed again for the corrected shape to calculate the y element in the evaluating point (step ST53).
The shape of poles 92 is converted to that suitable for predetermined uniform magnetic field distribution by repeating the processings of the steps ST 53 to ST 55 several times, namely repeating the boundary element analysis as explained above. FIG. 29 shows a converging process of the shape of poles 92. In this figure, (a).about.(f) show the shape of poles 92 corresponding to the number of times of repetition of the boundary element analysis. Namely, these illustrations show a profile where a relative error of the generated magnetic field for the target magnetic field is reduced with the increase in the number of times of repetition.
FIG. 30 illustrates a sectional view of a cross-sectional model of the chest portion of a human body for obtaining the distribution of conductivity within a human body described in the IEEE Transaction on Biomedial Engineering, Vol. BME-32, No. 3, 1985). A method of obtaining the distribution of conductivity within a human body is an example of a method for estimating an internal condition of an object from the measured values of the object. In this case, distribution of conductivity shows an internal condition of an object.
The chest portion of a human body includes lungs (dotted regions in FIG. 30) and conductivity is largely different in the spaces. Therefore, as shown in FIG. 30, when a current is applied externally, distribution of the conductivity within a human body can be estimated by measuring voltages generated at the surface of a human body at many points. It is called a impedance CT problem.
For the processings, the interior of a human body is divided into triangular elements as shown in FIG. 30 and the conductivity of each element is supposed as .sigma.i (i=1, . . . , M). The processing procedures are similar to that shown in the flowchart of FIG. 27. First, the initial condition is set. Namely, the coordinates of each node 101.about.120 is set and a node to which a current is applied is determined. For example, it is assumed that a current is applied across the nodes 101 and 111. Moreover, the initial value of the conductivity .sigma.i of each element is set.
Next, potential values at the surface of a human body, namely potential values at the nodes 102.about.110, 111.about.120 are computed. The finite element method is an approximate solution method in which an interior analysis of an object having a complicated shape and distribution of physical value is divided into finite number of elements and a physical condition assigned to each element is calculated based on the principle of energy minimization. As a result of the analysis by the finite element method, the potential at each node can be computed in this case.
Here, an error between the computed node potential and the actually measured node potential is evaluated. If an error exceeds the predetermined value, the conductivity .sigma.i (i=1, . . . , M) of each element is corrected using the evaluation result and analysis by the finite element method is executed again using the corrected conductivity .sigma.i of each element. Moreover, such processings are repeated until an error between the computed node potential and the measured node potential becomes the predetermined value or less, for example, until a sum of the squares of the error becomes the predetermined value or less.
FIG. 31 shows a profile where a mean value of estimated errors, namely a mean value of the error between the computed node potential and the measured node potential is reduced as the number of times of repetition of analysis by the finite element method increases.
Since a conventional method and apparatus for controlling or determining and estimating an object system is configured as explained above, if the initial condition (the initial shape or distribution of initial physical value) is largely deviated from the final condition (final shape or distribution of true physical value), such method and apparatus shows a problem that the number of times of repetitive computation of the boundary element method and finite element method increases and the time rquired until the final condition is obtained becomes longer. It is because the time required for single execution of the boundary element method and finite element method is considerably longer.
Moreover, there lies a problem that it is probable that the processing will be completed, in the error evaluation, before the true error is minimized when many local minimum values exist. For example, as shown in FIG. 32, when a parameter value at the point C is employed as the initial value of the parameter which specifies an object, an error can be set to the minimum true value. However, when a parameter value at the point A or B is employed as the initial value, an erroneous parameter is determined as the parameter in the final condition.

Method of manufacturing, determining and designing an object


A convolutional encoding/decoding system encodes a data bit stream into n bit parity sets from k bit data bit sets, using code words of length L. The system is dependent upon the finding that unique data to parity tables can be generated where both data and parity bit blocks are w bits in length. The value of w=n(L-k)/(n-k). An encoded parity bit stream is subjected to Exclusive OR operation through a connection mask or masks that are dependent upon the encoding code words. The Exclusive OR operation generates syndrome symbols indicative of the presence of errors in the parity bit stream and which are employed to address a correction table. Parity correction values are derived from the correction table and are used to revise the parity bit stream, which is then decoded, using a parity to data table. A number of parity correction procedures are disclosed.

To convolutionally encode a digital data stream in the manner taught by the prior art, n code words of length L (called the constraint length) are employed as a mask. For each mask, the bits of the data stream that appear through the mask are Exclusive OR'd to obtain one parity bit for each mask from the L length of data bits, a total of n parity bits. The bit stream is then moved by k bit position with respect to the mask, and the process is repeated. This results in the generation of another set of n parity bits which includes information from the new L data bits.
If two different code words are used as masks, then two bits of parity information result for every data bit. The ratio of the number of original data bits to the number of replacement parity bits is called the coding rate. Thus, where one data bit is replaced by two parity bits, the coding rate is one half.
As will be understood, Exclusive-OR or modulo 2 sum logical operations are vital to the functioning of convolutional encoders and decoders. Furthermore, it is vital in parity encoding a data stream, that the encoded sequence of parity bits uniquely represents a sequence of data bits. In U.S. Pat. No. 5,077,743 to Bitzer et al., a system is described for decoding a convolutionally encoded data stream that has been encoded at a one half rate. The disclosure of the Bitzer patent is incorporated herein by reference. Bitzer et al. determined that for a constraint length L, code words could be chosen such that a data word of length D would have a unique relationship to a series of parity bits where the following equation was satisfied: EQU D=2(L-1)
Thus, where the length L of a code word is three bits, a convolutional encoding technique can generate two pair of parity bits uniquely related to a four bit data word. As shown by Bitzer et al., for each of sixteen values of 4 bits of data (i.e., 0000-1111), a unique 4 bit parity relationship exists. It can thus be understood that identical mathematical operations may be carried out with respect to corresponding parity and data bit groups, while still maintaining the unique one to one relationship.
It was also shown that the 2.sup.2(L-1) unique relationships between parity and data could be reduced to 2(L`1) relationships, from which the remaining ones could be derived through Exclusive OR functions. Given these unique relationships and an uncorrupted run of parity bits, a decoder could readily reconstruct the data bits from which the parity bits had been originally derived. In FIG. 1, an example is shown of how a sequence of uncorrupted parity bits can be decoded, independent of the data that gave rise to the parity bits. A run of data bits, shown on the top line of FIG. 1 is converted to a run of parity bits P1P2, utilizing a half rate convolutional encoding circuit. It will be noted, that all parity bits are uncorrupted and for half rate encoding two parity bits are generated for each data bit, so that as each data bit moves out of an encoding shift register, two parity bits are transmitted. At the receiving end of a communication link, each time two parity bits are received, a single data bit has been cycled through the encoding shift register. At time TO, two parity pairs, 10 00 are in the decoding register. At time T1, an additional parity pair is received and shifted into the decoding register, etc. On the right side of FIG. 1, each parity pair has been converted to its corresponding data bit sequence, using a conversion table that includes the unique data/parity relations.
By examining the aligned vertical columns of data bits, an important relationship was discerned. In specific, when uncorrupted parity bit pairs were received, the columns of overlapping, derived data expressions were identical. Thus, as each column of data bits was examined, completely identical bits were resident therein. This relationship existed no matter what the data was and thus was totally independent of the data. Thus, if two successive overlapping columns of data bits were Exclusive OR'd together, the result was always zero. Only when there was a parity error, was the zero Exclusive OR relationship not true.
When parity errors occurred in the received parity stream, Bitzer et al. found that the Exclusive OR relationship between overlapping bits in each column of succeeding data bit groups was either zero or a fixed number (N), which number N was dependent only on the code words used to encode the data stream. Thus, as the parity bit stream slid by, two bits at a time, the Exclusive OR differences between successive columnar sets of overlapping data bits produced unique patterns of zeros or ones for any single corrupted parity bit. Also, for any combination of corrupted parity bits, the Exclusive OR operation yielded a unique pattern of zeros and ones, which pattern was the reverse of the code word used to generate the accompanying parity bit position. That unique pattern was thus used to address a correction table that produced bits used to correct the corrupted parity.
Those skilled in the art will realize that the relationships set out in the Bitzer et al. patent established the basis for decoding half rate convolutionally encoded parity streams. That encoding technique was directly dependent upon unique 2(L-1) bit parity to data (and vice versa) relationships. However, for other coding rates, it was then not known how to establish the required unique parity to data relationship to match an encoding rate of other than one half and a chosen constraint length.
Accordingly, it is an object of the present invention to provide a convolutional encoding/decoding method and apparatus for encoding rates other than one half.
It is a further object of this invention to provide a convolutional decoding method and apparatus which exhibits improved decoding capability.
It is another object of this invention to provide a convolutional decoding method and apparatus which is capable of decoding actions in the presence of parity errors that give rise to ambiguous correction results.
It is still another object of this invention to provide a convolutional decoding method and apparatus wherein error correction is enabled by tables that store correction values, the tables enabling reconstruction of lost groups of data.

System for encoding and decoding of convolutionally encoded data