text
stringlengths 0
1.67M
|
|---|
A compound represented by the following general formula (I) or a salt thereof: wherein Ar1 and Ar2 independently represent a substituted or unsubstituted aryl group having at least one iodine atom as a substituent; L1 and L2 independently represent a divalent bridging group of which main chain consists of 7 or more atoms at least one of which is a heteroatom; and X represents —CH(OH)— or —CO—, which is suitable for an iodine-containing contrast medium containing liposomes. |
1. A compound represented by the following general formula (I) or a salt thereof: wherein Ar1 and Ar2 independently represent a substituted or unsubstituted aryl group having at least one iodine atom as a substituent; L1 and L2 independently represent a divalent bridging group of which main chain consists of 7 or more atoms and at least one of the atoms consisting of said main chain is a heteroatom; and X represents —CH(OH)— or —CO—. 2. The compound or a salt thereof according to claim 1, wherein X is —CH(OH)—. 3. The compound or a salt thereof according to claim 1, wherein Ar1 and Ar2 independently represent a phenyl group having at least three iodine atoms as substituents. 4. A liposome containing the compound or a salt thereof according to claim 1 as a membrane component. 5. The liposome according to claim 4, which contains a combination of a phosphatidylcholine and a phosphatidylserine as membrane components. 6. A contrast medium for X-ray radiography, which comprises the liposome according to claim 4. 7. The contrast medium for X-ray radiography according to claim 6, which is used for radiography of a vascular disease. 8. The contrast medium for X-ray radiography according to claim 6, which is used for radiography of vascular smooth muscle cells which are abnormally proliferated under an influence of foam macrophages. 9. The contrast medium for X-ray radiography according to claim 6, which is used for radiography of a tissue or a lesion where macrophages localize. 10. The contrast medium for X-ray radiography according to claim 6, wherein the tissue where macrophages localize is selected from the group consisting of tissues of liver, spleen, air vesicle, lymph node, lymph vessel, and renal epithelium. 11. The contrast medium for X-ray radiography according to claim 6, wherein the lesion where macrophages localize is selected from the group consisting of lesions of tumor, inflammation, and infection. 12. A liposome containing the compound or a salt thereof according to claim 1 as a membrane component, wherein at least one of the iodine atoms is a radioisotope. 13. A contrast medium for scintigraphy, which comprises the liposome according to claim 12. 14. The contrast medium for scintigraphy according to claim 13, which is used for scintigraphy of vascular smooth muscle cells which are abnormally proliferated under an influence of foam macrophages. 15. The contrast medium for scintigraphy according to claim 13, which is used for scintigraphy of a tissue or lesion where macrophages localize. 16. The contrast medium for scintigraphy according to claim 13, wherein an objective tissue of scintigraphy is selected from the group consisting of tissues of blood vessel, liver, spleen, air vesicle, lymph node, lymph vessel, and renal epithelium. 17. The contrast medium for scintigraphy according to claim 13, which is used for scintigraphy of a lesion selected from the group consisting of lesions of tumor, arteriosclerosis, inflammation, and infection. |
<SOH> BACKGROUND ART <EOH>In the field of X-ray angiography utilizing an iodine compound, a technique is available which comprises administration of a water-soluble iodine-containing contrast medium for visualization of vascular flows, and detection of lesions at which the flows are obstructed. However, in the aforementioned method, the iodine-containing contrast medium is present in the vascular flows to detect changes of vascular flows inside the vessels, and the method has difficulty in distinguishing the lesions from normal tissues as compared to a method wherein an iodine-containing contrast medium is localized in cells consisting a lesion. For this reason, by the above method, only a lesion where constriction progresses 50% or more can be detected, and it is difficult to detect a lesion before the onset of attack of an ischemic disease. Separately, attempts have also been reported in which a hydrophobic iodine-containing contrast medium or a hydrophilic contrast medium is formulated for selective accumulation in a target lesion (International Publications WO95/19186, WO95/21631, WO89/00812, British Patent No. 867650, WO96/00089, WO94/19025, WO96/40615, WO95/2295, WO98/41239, WO98/23297, WO99/02193, WO97/06132, U.S. Pat. Nos. 4,192,859, 4,567,034, 4,925,649, Pharm. Res., 6 (12), 1011 (1989); Pharm. Res., 16 (3), 420 (1999); J. Pharm. Sci., 72 (8), 898 (1983); Invest. Radiol., 18 (3), 275 (1983)). For example, Pharm. Res., 6 (12), 1011 (1989) discloses that injection of an oil-particle dispersion of cholesteryl iopanoate as a hydrophobic compound allows accumulation of the iodine compound in arteriosclerotic lesions of experimental animals. Further, Pharm. Res., 16 (3), 420 (1999) discloses that administration of cholesteryl iopanoate after being taken up into acetyl-LDL allows accumulation of the iodine compound in arteriosclerotic lesions of experimental animals. Further, J. Pharm. Sci. 72 (8), 898 (1983) discloses examples of X-ray hepatography and splenography by injection of an oil-particle dispersion of cholesteryl iopanoate. U.S. Pat. No. 4,567,034 describes a method of selective hepatography or splenography utilizing liposomes encapsulating an ester of diatrizoic acid. International Publications WO96/28414 and WO96/00089 disclose contrast media for imaging vascular pools or lymphatic systems. However, the methods using these formulations are not satisfactory in efficiency and selectivity for a purpose of selective contrast of vascular diseases, and no example thereof is reported in which vascular diseases are imaged by utilizing X-ray irradiation. Further, methods have been reported in which a triglyceride compound comprising an alkylcarboxylic acid having two 3-amino-2,4,6-triiodophenyl groups and a saturated/unsaturated fatty acid is formulated as an oil particle dispersion (lipid emulsion) or a Tween 20 dispersion and used for the purpose of hepatography or imaging of blood-pool (Radiology, 216 (3) 865 (2000); Invest. Radiol., 35 (3), 158 (2000); International Publication WO98/46275; J. Pharm. Sci., 85 (9), 908 (1996); Pharm. Res., 13 (6), 875 (1996); International Publication WO95/31181; J. Med. Chem., 38 (4), 636 (1995); Invest. Radiol., 29 (SUPPL. 2), S284 (1994); International Publication WO94/19025; U.S. Pat. No. 4,873,075; Appl. Radiol. Isot., 37 (8), 907 (1986); J. Med. Chem., 29 (12), 2457 (1986)). International Publication WO01/93918 discloses an example of radiological imaging of arteriosclerotic lesions in which a hydrophobic and hydrolysis-resistant radioactive iodine-containing contrast medium is formulated as a microemulsion or taken up into acetyl-LDL and then administered to experimental animals. Furthermore, it has been reported that the aforementioned cholesteryl iopanoate is not metabolized in living bodies and accumulated in living organs, especially in liver (J. Med. Chem., 25, 1500 (1982)). The above property of the compound means that the compound remains in living bodies over a prolonged period of time, which is considered as an undesired property when a diagnostic purpose such as a contrast medium for X-ray radiography is intended. From an aspect of compounds, U.S. Pat. No. 4,873,075 and J. Med. Chem., 29 (12), 2457 (1986) mentioned above contain descriptions of diacyl-1,3-glyceride compounds comprising an alkylcarboxylic acid containing two 3-amino-2,4,6-triiodophenyl groups and oxidized compounds thereof. However, no purpose thereof other than as synthetic intermediates is described. |
Rapid improvement of cognition in condition related to abeta |
The present invention is a method for effecting rapid improvement in cognition in subjects suffering from conditions or diseases related to the Aβ peptide, including Alzheimer's disease, Down's syndrome, cerebral amyloid angiopathy, mild cognitive impairment, and the like. The method comprises administering anti-Aβ antibodies to the subject, especially antibodies having a high affinity for soluble forms of Aβ. X-15240 |
1-20. (canceled) 21. A method for effecting rapid improvement of cognition in a subject having a condition or disease related to Aβ, comprising administering to the subject an effective amount of an anti-Aβ antibody. 22. The method of claim 21, wherein the subject is human. 23. The method of claim 22, wherein the condition or disease is Alzheimer's disease, Down's syndrome, cerebral amyloid angiopathy, or mild cognitive impairment. 24. The method of claim 23, wherein the disease is Alzheimer's disease. 25. The method of claim 23, wherein the disease or condition is Down's syndrome. 26. The method of claim 23, wherein the disease or condition is cerebral amyloid angiopathy. 27. The method of claim 23, wherein the disease or condition is mild cognitive impairment. 28. The method of claim 21, wherein the antibody has an affinity for soluble Aβ greater than 10−9 M. 29. The method of claim 28, wherein the affinity is measured with respect to either Aβ1-40 or Aβ1-42. 30. The method of claim 21, wherein the antibody has an affinity for soluble Aβ greater than 10−10 M. 31. The method of claim 30, wherein the affinity is measured with respect to either Aβ1-40 or Aβ1-42. 32. The method of claim 21, wherein the antibody has an affinity for soluble Aβ greater than 10−11 M. 33. The method of claim 32, wherein the affinity is measured with respect to either Aβ1-40 or Aβ1-42. 34. The method of claim 21, wherein the antibody has greater affinity for soluble Aβ than humanized antibody 266, which comprises SEQ ID NO:11 as the light chain and SEQ ID NO:12 as the heavy chain. 35. The method of claim 34, wherein the affinity is measured with respect to either Aβ1-40 or Aβ 1-42. 36. The method of claim 21, wherein the antibody is a humanized or human antibody. 37. The method of claim 36, wherein the antibody is a humanized 266 antibody, or an analog thereof. 38. The method of claim 21, wherein the anti-Aβ antibody recognizes the same epitope that antibody 266 recognizes or competes with antibody 266 for binding to soluble Aβ. 39. The method of claim 21, additionally comprising measuring cognition in the subject before administering the antibody. 40. The method of claim 39, additionally comprising measuring cognition in the subject after administering the antibody. 41. The method of claim 40, wherein the measure of cognition after administering the antibody shows a significant improvement in cognition compared with the measure of cognition before administering the antibody. |
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>We remedy this deficiency by providing herein a method for effecting rapid improvement of cognition in a subject having a condition or disease related to Aβ, comprising administering to the subject an effective amount of an anti-Aβ antibody. The invention also includes the use of an anti-Aβ antibody to prepare a medicament for effecting rapid improvement of cognition in a subject having a condition or disease related to Aβ |
Controlled release of additives in fluid systems |
A container (1) for releasing a chemical additive (7) in a fluid material selected from a lubricant or hydraulic fluid composition comprises a fluid material-impermeable casing (3) having a hollow interior and an additive composition (7) comprising at least one fluid material-soluble additive. The additive (7) is held within the container (1) by a least one fluid material-permeable element (11) provided at or near an opening (13) in the casing (1) and is effective to provide for release of additive(s) (7) into the fluid material. Methods of releasing additives (7) into fluid material are also provided. |
1. A container for releasing a chemical additive in a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition, the container comprising: a fluid material-impermeable casing defining a substantially hollow interior and at least one opening; a fluid material additive composition provided in the interior of the casing, the fluid material additive composition comprising a chemical additive effective to provide a benefit to and soluble in a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition; and at least one fluid material-permeable element provided at or near the opening of the casing and effective to provide for release of a portion of the chemical additive into the fluid material in contact with the casing. 2. The container of claim 1 wherein the casing is composed of a material selected from the group consisting of metals, polymeric materials, combinations thereof and mixtures thereof. 3. The container of claim 2 wherein the material is selected from the group consisting of metals, polyvinyl chloride, polyethylene, polypropylene, nylon, polyethylene vinyl acetate, polypropylene vinyl acetate, sulfanones, combinations thereof and mixtures thereof. 4. The container of claim 1 wherein the casing is a substantially cylindrical-shaped casing. 5. The container of claim 4 wherein the at least one opening comprises at least one open end of the cylindrical-shaped casing or at least one side opening in a sidewall of the cylindrical-shaped casing. 6. The container of claim 1 wherein the casing is a substantially bowl-shaped casing. 7. The container of claim 6 further comprising a cap member disposed across a top of the substantially bowl-shaped casing. 8. The container of claim 6 wherein the at least one opening is located in a top of the substantially bowl-shaped casing, in a side of the substantially bowl-shaped casing or in a bottom of the substantially bowl-shaped casing. 9. The container of claim 1 wherein the at least one fluid material-permeable element comprises an at least partially dissolvable seal. 10. The container of claim 9 wherein the at least partially dissolvable seal comprises a support structure coated with a fluid material soluble polymer. 11. The container of claim 10 wherein the support structure comprises a wire screen. 12. The container of claim 1 wherein the at least one fluid material-permeable element includes a filter member. 13. The container of claim 1 wherein the at least one fluid material-permeable element includes a porous membrane. 14. The container of claim 13 wherein the at least one fluid material-permeable element includes at least one retention member effective in retaining the membrane in a substantially fixed position relative to the casing. 15. The container of claim 13 wherein the porous membrane is a microporous membrane having a pore size of between about 0.2 microns to about 100 microns. 16. The container of claim 13 wherein the porous membrane comprises a material selected from the group consisting of metals, glasses, polymeric materials, combinations thereof and mixtures thereof. 17. The container of claim 12 wherein said filter member comprises a semi-permeable membrane. 18. The container of claim 17 wherein the semi-permeable membrane comprises a material selected from the group consisting of glasses, polymeric materials, combinations thereof and mixtures thereof. 19. The container of claim 1 wherein the at least one opening comprises a plurality of openings and the at least one fluid material-permeable element comprises a corresponding plurality of fluid material-permeable elements. 20. The container of claim 1 wherein the fluid material additive composition is provided in a particulate form. 21. The container of claim 1 wherein the fluid material additive composition is present in the casing in a liquid form. 22. The container of claim 1 wherein the fluid material additive composition is provided in a gel. 23. The container of claim 1 wherein the fluid material additive composition is provided in a paste. 24. The container of claim 1 wherein the fluid material additive composition is provided in a matrix. 25. The container of claim 1 wherein the chemical additive is selected from the group consisting of viscosity index improvers, antioxidants, anti-wear agents, corrosion inhibitors, demulsifiers, emulsifiers, lubricity agents, pour point depressants, antifoamants, dispersants, detergents and mixtures thereof. 26. The container of claim 1 wherein the chemical additive is selected from the group consisting of those that disperse particulate matter in oil, inhibit formation of sludge and varnish to reduce deposit formation, prevent deterioration and oxidation of oil caused by reactions with free radicals or peroxides, inhibit corrosion and rust formation, reduce wear, lower the rate of change in viscosity with temperature, lower the temperature at which the fluid flows, improve filterability by modifying wax crystallization characteristics, prevent formation of stable foam in fluids, promote oil-water separation and promote formation of stable water-in-oil emulsion. 27. The container of claim 1 wherein the at least one fluid material-permeable element is at least partially coated with a polymeric coating material. 28. The container of claim 1 wherein the at least one fluid material-permeable element comprises a fluid material-soluble seal. 29. A method for releasing a chemical additive at a sustained rate into a fluid material, the method comprising placing the container of claim 1 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 30. A method for releasing a chemical additive at a sustained rate into a fluid material, the method comprising placing the container of claim 4 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 31. A method for releasing a chemical additive at a sustained rate into a fluid material, the method comprising placing the container of claim 6 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 32. A method for releasing a chemical additive at a sustained rate into a fluid material, the method comprising placing the container of claim 9 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 33. A method for releasing a chemical additive at a sustained rate into a fluid material, the method comprising placing the container of claim 13 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 34. A method for releasing a chemical additive at a sustained rate into a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition, the method comprising placing the container of claim 17 in contact with a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition. 35. A seal assembly comprising: a fluid material-permeable membrane sized and adapted to be positioned in or near an opening in a casing defining a hollow interior containing a fluid material additive effective to provide a benefit to and soluble in a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition, the membrane is adapted to be positioned so that substantially all of the fluid material additive leaving the hollow interior through the opening passes through the membrane; and a seal member sized and adapted to be positioned relative to the opening in the casing to prevent fluid material additive leaving the hollow interior through the opening when the seal member is intact. 36. The seal member of claim 35 wherein the seal member is adapted to be compromised in the presence of a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition, thereby allowing fluid material additive to leave the hollow interior through the opening. 37. The seal assembly of claim 36 wherein the seal member is at least partially fluid material-soluble. 38. The seal assembly of claim 35 wherein the seal member comprises a support structure and a fluid material-soluble polymer. 39. The seal assembly of claim 38 wherein the support structure includes at least one of a wire screen and a woven cloth. 40. The seal assembly of claim 35 which further comprises at least one retention member sized and adapted to be positioned to be effective in retaining the membrane in a substantially fixed position relative to the casing. 41. A fluid material-permeable assembly comprising: a fluid material-permeable membrane sized and adapted to be positioned in or near an opening in a casing defining a hollow interior containing a fluid material additive soluble in a fluid material selected from the group consisting of a liquid lubricant composition and a hydraulic fluid composition, the membrane adapted to be positioned so that substantially all of the additive leaving the hollow interior through the opening passes through the membrane; and at least one retention member sized and adapted to be positioned to be effective in retaining the membrane in a substantially fixed position relative to the casing. 42. The assembly of claim 41 wherein the membrane comprises at least one of a porous membrane element and a semi-permeable element. 43. The assembly of claim 41 wherein the membrane comprises a microporous element. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Internal combustion engines are still the predominant means for propelling motorized vehicles. They are proven to offer many advantages over alternative mechanisms, among these being cost and convenience. Such engines require lubrication, usually employing a circulating lubricant. In order to achieve good performance, lubricants often include one or more additives which can become depleted and /or insufficient after a period of use. It is desirable to add lubricant additives, such as viscosity index improvers and antioxidants, and the like, to the lubricant to maintain and/or enhance the quality of the lubricant. Hydraulic fluids are of great value in systems which provide useful mechanical advantages. These hydraulic fluids are employed in such systems often for very long times, for example, in terms of years. Additives which are initially present in the fluid can become depleted and/or insufficient, for example, during long term fluid use. It would be advantageous to provide for adding additives to such hydraulic fluids, in particular while the fluids are in use. Various methods of introducing additives to vehicle fluid systems, generally, have been proposed. Rohde U.S. Pat. No. 3,749,247 describes a container for releasing an oxidation inhibitor into hydrocarbon-based fluid material in a working engine. The oxidation inhibitor is held in a polyolefin container that permits the additive to permeate through the container wall into the lubricant. A further approach is described by Lefebvre U.S. Pat. No. 5,591,330, which discloses a hydrocarbon oil filter wherein oxidation additives in a thermoplastic material are mounted in a casing between a particle filtering material and a felt pad. Reportedly, the thermoplastic material dissolves in the presence of high temperature oil thereby releasing the additives. The above-described devices suffer from a variety of limitations. It is an object of the present invention to provide an alternative, relatively low-cost device for releasing chemical additives into a fluid system at a constant rate, which requires minimal human intervention. |
<SOH> SUMMARY OF THE INVENTION <EOH>New apparatus and methods for providing release, preferably controlled and/or sustained release, of at least one additive into a fluid material selected from, a liquid lubricant composition and a hydraulic fluid composition have been discovered. The present apparatus and methods effectively provide for sustained, preferably substantially controlled, release of a chemical additive from the apparatus into such a fluid material. The chemical additive (e.g. fluid material additive) may be of any type, for example, a lubricant additive soluble in a lubricant or a hydraulic fluid additive soluble in a hydraulic fluid. The present apparatus and methods provide straightforward approaches to releasing the additive into a fluid material or fluid material system selected from a liquid lubricant composition or lubricant system or into a hydraulic fluid composition or hydraulic fluid system. Many components of the present apparatus, other than the additive or additives, are substantially insoluble in the fluid material so that these components remain intact and do not dissolve into and/or otherwise detrimentally affect the fluid material or fluid material system. In addition, several of the components of the present apparatus can be reused after the additive has been spent, that is substantially completely released into the fluid material. The present apparatus is easy and straightforward to manufacture cost effectively and can be used in such fluid material systems with little or no modification. One broad aspect, of the present invention is directed to fluid material additive containers for use in lubricant systems, for example, without limitation, associated with vehicles, airplanes, generator sets, mining equipment, and the like and hydraulic fluid systems, for example, without limitation, vehicle hydraulic systems, elevators, farm machinery and the like, which are designed to provide sustained or gradual, preferably substantially controlled, release of at least one additive(s) into a fluid material as defined herein. The present containers comprise a fluid material-impermeable casing defining a substantially hollow interior and at least one opening. A fluid material additive composition selected from a lubricant additive composition and a hydraulic fluid additive composition, comprising at least one chemical additive soluble in fluid material, for example, at least one fluid material-soluble supplemental additive, is provided in the interior of the casing. The fluid material additive may be provided in the form of a liquid, gel, paste, or in solid form. In one particularly useful embodiment of the invention, the fluid material additive composition is provided as a plurality of particles, or in particulate form, for example, in the form of beads, tablets, pellets, grains or other particulate form. The casing and other fluid material-impermeable components of the apparatus of the present invention are preferably composed of materials selected from suitable metals, fluid material-insoluble polymeric materials, combinations thereof and mixtures thereof. Useful casings can be made of materials selected from metals, such as steel, aluminum and the like, polyvinyl chloride, polyethylene, polypropylene, nylon, polyethylene vinyl acetate (EVA), polypropylene vinyl acetate (PVA), polyphenylene sulfide, polyphthalamide, sulfalone and the like, combinations thereof and mixtures thereof. The containers of the present invention may also include at least one fluid material-permeable element or component which is provided at or near the at least one opening of the casing. This fluid material-permeable element is effective to provide for release of a portion of a chemical additive composition, such as a fluid material additive, in the casing into a fluid material, for example, a liquid lubricant composition or hydraulic fluid composition, in contact with the casing. Such release occurs over a period of time so that a portion of the chemical additive is retained within the casing, at least after the initial release of additive occurs. The additive release obtained in accordance with the present invention preferably is a sustained or controlled additive release. In one embodiment of the invention, the casing is substantially cylindrical in shape. The casing includes at least one opening, for example, at an end of the casing or in a side wall of the casing, where fluid material is allowed to contact a portion of the lubricant additive composition or hydraulic fluid additive composition contained within the casing. For example, an end cap can be employed which cradles or attaches to the open end and retains the lubricant additive composition or hydraulic fluid additive composition within the casing. In one embodiment of the invention, the cylindrical shaped casing includes two open ends, each open end being covered by an end cap. The end cap preferably comprises a fluid material-impermeable material and is effective to retain the fluid material additive selected from a lubricant additive composition and a hydraulic fluid additive composition, within the casing. The end cap includes one or more inlets or openings for allowing fluid communication between fluid material located exterior to the casing and the fluid material additive within the casing to permit the release, for example, by diffusion or otherwise, of the additive into the fluid material, preferably at a substantially controlled rate. In another embodiment, the casing is substantially bowl-shaped in form. The at least one opening may be located at any point of the casing, for example, on the top of the casing, in a side (side wall) of the casing and/or in the bottom of the casing. In one useful embodiment, particularly when the bowl-shaped casing has an open end, for example, an open top end, a cap member may be included which provides means for retaining a lubricant additive composition or hydraulic fluid additive composition within the casing interior. The cap member advantageously is made of polymeric or other substantially fluid material insoluble material and includes at least one inlet or opening, and preferably a plurality of inlets or openings, for allowing contact between the lubricant additive composition or hydraulic fluid composition and the fluid material. The cap member may be secured to an interior surface of the casing, and may be somewhat recessed therein. In one embodiment of the invention, the cap member is removably secured or removably sealed to the casing, for example, by means of an o-ring or other suitable, e.g., conventional, sealing element or assembly. In addition, a plate member may be provided and fixed within the bowl-shaped casing. The plate member includes one or more plate inlets which substantially align with the cap member inlets. The plate member may be made of any suitable fluid material-insoluble material. In one embodiment, the container of the present invention comprises the bowl-shaped casing having both the cap member and the plate member disposed across the container open end. A fluid material-permeable element is disposed, or sandwiched, between the cap member and the plate member. The fluid material-permeable element(s) or component(s) may comprise any suitable fluid material-permeable structure, and all such structures are included within the scope of the present invention. In one useful embodiment, the fluid material-permeable element or component comprises a filter member or filter media, for example, a porous or semi-permeable membrane. In another useful embodiment, the fluid material-permeable element or component comprises a micro-orifice. The porous or semi-permeable membrane of the apparatus of the invention may be made of any suitable material that permits the desired, preferably sustained, release of chemical additive into the fluid material, particularly when the casing is in contact with fluid material. The membrane can be made of a fluid material-insoluble material, for instance, having irregularly-sized channels or discrete-sized pores therein. As used herein, a “porous” membrane refers generally to membranes having pores in a substantially discrete size range, such as a wire screen or filter paper. As used herein, a “semi permeable” membrane refers to a continuous medium, which does not have pores in a discrete size range, but instead preferably permits diffusion of molecules through narrow channels, the size of which can be difficult to measure. In one embodiment, the membrane, for example, the porous or semi-permeable membrane, comprises one or more glasses and/or one or more polymeric materials. Very useful membranes can be made of materials selected from nylon, cellulose acetate, cellulosic polymers, glasses, polyester, polyurethane, polyvinyl chloride, polyethylene vinyl acetate, polypropylene vinyl acetate, natural and synthetic rubbers, and the like, combinations thereof and mixtures thereof. Alternatively or additionally, the fluid material-permeable element(s) or component(s) can include a fluid material-soluble material, such as in the form of a dissolvable, that is, fluid material-dissolvable, seal, which dissolves, for example, dissolves gradually, in the presence of the fluid material to effect release of the additive from the casing. The dissolvable seal may comprise, for example, a fluid material-soluble polymer seal. Preferably, although not necessarily, the at least one fluid material-permeable element includes a support structure, for example, a wire screen or cloth or other fluid material-insoluble material, which may be coated with a fluid material-soluble polymer to form a suitable seal structure. Alternatively, the dissolvable seal may comprise the fluid material soluble polymer alone, without such a support structure. It is also noted that the membrane can be coated, e.g., with a polymeric material or a fluid material-insoluble polymeric material, such as a fluid material-soluble polymeric material or a fluid material-insoluble material, in order to more effectively control release of additive from the container into the fluid material. In another broad aspect, the invention is directed to methods for releasing a chemical additive, preferably at a sustained, more preferably substantially controlled, rate into a fluid material. These additives include, but are not limited to, antioxidants, anti-wear additives, viscosity index improvers, corrosion inhibitors, demulsifiers, detergents/dispersants, lubricity agents, and the like and mixtures thereof. The present methods comprise placing a container as set forth herein in contact with a fluid material selected from a liquid lubricant composition or a hydraulic fluid composition. When the container is exposed to a fluid material, the fluid material passes through, for example, diffuses through, the fluid material-permeable element or elements and contacts a portion of the lubricant additive composition or hydraulic fluid additive composition. Release, preferably sustained, substantially controlled release, of additive or additives into the fluid material is obtained, for example, by diffusion through the fluid material-permeable element. In one useful embodiment, the container in accordance with the present invention at least partially replaces and/or is integrated into the center tube of a filter assembly used to filter a fluid material, for example, while the fluid material is being used. Thus, the container is effective to provide additive release and as a structural member in a filter assembly. Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention provided that the features included in such a combination are not mutually inconsistent. Additional aspects and advantages of the present invention are set forth in the following description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals. |
Apparatus for laying a conduit on the seabed from a floating vessel |
Pipe (3) to be laid on the seabed from a floating pipe laying vessel (1) emerges from the bottom end of a vertically orientated linear pipe tensioner (8b) and is directed substantially vertically downwardly to pass through a surrounding pipe guide (12), which causes the pipe to deviate from the vertical through a small acute angle (θ). In this way, the horizontal thrust that would be exerted on the pipe tensioner (8b) due to the tension in the pipe if the tensioner were to be the last guide means for the pipe before it enters the sea is transferred to the pipe guide itself, this being mounted in the vessel at a location of greater structural strength. |
1. Apparatus for laying a conduit on the seabed from a floating vessel incorporating a moonpool, comprising: (i) linear tensioning means (8) located on the vessel (1) above the moonpool (9), with a substantially vertical axis for gripping the exterior of the conduit (3) passing downwardly through the moonpool for counteracting its downward pull, and (ii) a guide (12) on the vessel disposed in the moonpool below the linear tensioning means (8) for reorientating the conduit from a first, substantially vertically downward, orientation between the tensioning means and the guide to a second, inclined, orientation at an acute angle (θ) to said first orientation, as the conduit leaves the guide (12), the guide surrounding the conduit (3). 2. Apparatus according to claim 1, wherein the bottom edge (15) of the moonpool is rounded off. 3. Apparatus according to claim 2, wherein the guide (12) is mounted on a cover (13) on the moonpool (9) and depends downwardly therefrom. 4. Apparatus according to claim 3, wherein the guide (12) and moonpool cover (13) are axially divided and each half cover with its half guide is slideable in a lateral direction under the action of a respective hydraulic cylinder (15a:15b). 5. Apparatus according to claim 1, wherein the tensioning means (8) and guide (12) are located at the stern of the vessel, the guide being axially divided and each half guide is slideable in a lateral direction under the action of a respective hydraulic cylinder. 6. Apparatus according to any preceding claim, wherein the pipe guide comprises two flared sidewalls (14a) which form a Vee in horizontal cross-section, the apex of the Vee being located in an aft position in the vessel. 7. Apparatus according to claim 6, wherein the guide (12) comprises two further flared sidewalls, the four sidewalls being so arranged as to define a central passageway within the guide that is square in horizontal section. 8. Apparatus according to claim 7, wherein the central axis (12′) of the guide (12) is offset in the fore or aft direction relative to the substantially vertical axis of the linear tensioning means. 9. A method of laying a conduit on the seabed using an apparatus according to any preceding claim, wherein the exterior of the conduit (3) is gripped by the tensioning means (8) which lowers the conduit, the tensioning means counteracting its downward pull and the guide (12) reorientating the conduit from the first orientation to the second orientation at said acute angle to the first one. 10. Apparatus for laying a conduit on the seabed from a floating vessel, comprising: (i) linear tensioning means (8) located on the vessel (1) with a substantially vertical axis for gripping the exterior of the conduit (3) for counteracting its downward pull, and (ii) a guide (12) on the vessel disposed below the linear tensioning means (8) and having a fixed guide surface for reorientating the conduit from a first, substantially vertically downward, orientation between the tensioning means and the guide to a second, inclined, orientation at an acute angle (θ) to said first orientation, as the conduit leaves the guide (12), the guide surrounding the conduit (3). 11. Apparatus according to claim 10, wherein the vessel incorporates a moonpool (9), the tensioning means (8) being located above the moonpool for gripping the exterior of a conduit (3) passing downwardly through the moonpool and the guide (12) being disposed in the moonpool, the bottom edge (15) of the moonpool being rounded off. 12. Apparatus according to claim 11, wherein the guide (12) is mounted on a cover (13) on the moonpool (9) and depends downwardly therefrom. 13. Apparatus according to claim 12, wherein the guide (12) and moonpool cover (13) are axially divided and each half cover with its half guide is slideable in a lateral direction under the action of a respective hydraulic cylinder (15a:15b). 14. Apparatus according to claim 10, wherein the tensioning means (8) and guide (12) are located at the stern of the vessel, the guide being axially divided and each half guide is slideable in a lateral direction under the action of a respective hydraulic cylinder. 15. Apparatus according to any one of claims 10 to 14, wherein the guide comprises two flared sidewalls (14a) which form a Vee in horizontal cross-section, the apex of the Vee being located in an aft position in the vessel. 16. Apparatus according to claim 15, wherein the guide (12) comprises two further flared sidewalls, the four sidewalls being so arranged as to define a central passageway within the guide that is square in horizontal section. 17. Apparatus according to claim. 16, wherein the central axis (12′) of the guide (12) is offset in the fore or aft direction relative to the substantially vertical axis of the linear tensioning means. 18. A method of laying a conduit on the seabed using an apparatus according to any one of claims 10 to 18, wherein the exterior of the conduit (3) is gripped by the tensioning means (8) which lowers the conduit, the tensioning means counteracting its downward pull and the fixed guide surface reorientating the conduit from the first orientation to the second orientation at said acute angle to the first one. 19. A method according to claim 9 or 18, wherein the conduit is a flexible pipe. 20. Apparatus according to any one of claims 1 to 8 and 10 to 17, wherein a tower structure (7) is located on the vessel (1), the linear tensioning means (8) is mounted on the tower structure, and the guide (12) is mounted on the vessel (1) separately from the tower structure (7). |
Glycosaminoglycan-polycation complex crosslinked with polyfunctional crosslinking agent and process for producing the same |
Disclosed is a glycosaminoglycan-polycation complex as a matrix material for use in tissue regeneration, such as cartilage repair, and a preparation method thereof. The complex is synthesized by crosslinking glycosaminoglycan and polycation with a polyfunctional crosslinking agent under physiological conditions. In this method, the crosslinking agent consists of polyethyleneglycol having two or more electrophilic leaving groups (e.g. succinimidyl group or its derivatives) at the carboxyl terminal thereof, and the concentration of the crosslinking agent is in the range of 0.3 to 3 mM. According the present invention, the crosslinking reaction can be performed under physiological conditions to avoid conventional problems of adverse affect on cells (cell death) and the formation of a polyion complex (inhomogeneous precipitate) due to a crosslinking reaction in alcohol or water. Thus, the crosslinking reaction can be conducted in the presence of cells mixed to the glycosaminoglycan and polycation in advance. |
1. A biologically active glycosaminoglycan-polycation complex for use as a tissue regeneration matrix, which is formed by a homogeneous crosslinking reaction using a polyfunctional crosslinking agent in a buffer solution under physiological conditions, said crosslinking agent consisting of polyethyleneglycol having two or more electrophilic leaving groups at the carboxyl terminal thereof. 2. A method of preparing a biologically active glycosaminoglycan-polycation complex for use as a tissue regeneration matrix, comprising mixing glycosaminoglycan and polycation in a buffer solution, and homogeneously crosslinking said glycosaminoglycan and polycation with a polyfunctional crosslinking agent under physiological conditions to synthesize said glycosaminoglycan-polycation complex, wherein said crosslinking agent consists of polyethyleneglycol having two or more electrophilic leaving groups at the carboxyl terminal thereof, and the concentration of said crosslinking agent is in the range of 0.3 to 3 mM. 3. The method as defined in claim 2, wherein the crosslinking reaction between said glycosaminoglycan and polycation is homogeneously conducted in the presence of cells mixed therewith in advance. |
<SOH> BACKGROUND ART <EOH>It is known that, once damaged, articular cartilage will have serious difficulties in its tissue regeneration. According to worldwide statistics, it is reported that the number of patients of osteoarthritis caused by aging and sports injuries is no fewer than about ten million (about 1.2 million in Japan). In this context, it is strongly desired to develop a material for cartilage regeneration. Heretofore, a complex of glycosaminoglycan (hyaluronic acid: HyA or chondroitin sulfate: ChS) and polycation (collagen: Col), which are primary components of cartilage tissue, has been prepared through a method of chemically crosslinking polyion complexes. Such a crosslinked product is disclosed, for example, in Japanese Patent Laid-Open Publication Nos. 08-34747, 08-53548, 08-502082, 09-249751, 10-501706, 11-509256, 2000-501975 and 2000-502380. In methods disclosed in the above Japanese Patent Laid-Open Publication Nos. 09-249751, 08-34747 and 2000-501975, a crosslinking reaction is conducted in alcohol or water, and a resulting injectable crosslinked biomaterial composition would have an adverse affect on cells and tissues (cell death). Thus, there is the need for an improved crosslinking method capable of avoiding this problem. The above Japanese Patent Laid-Open Publication No. 10-501706 discloses that cells can be enclosed within a gel formed by crosslinking. However, any cell (membrane) will be destroyed due to the difference in osmotic pressure. Further, it is practically impossible to achieve the coexistence between collagen and glycosaminoglycan in water, and consequently the enclosing of cells is unrealizable. While the above Japanese Patent Laid-Open Publication No. 09-249751 includes a description that collagen and glycosaminoglycan can be crosslinked together by a polyfunctional crosslinking agent, any adequate crosslinked product cannot be practically obtained because a polyion complex (inhomogeneous precipitate) will be undesirably formed due to plus charges of the collagen and minus charges of the glycosaminoglycan. Thus, it is required to develop an improved crosslinking method involving no formation of the undesirable polyion complex. |
<SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>FIG. 1 is a graph showing a swelling degree of type-II collagen crosslinked at various pH values with a tetrafunctional crosslinking agent consisting of polyethyleneglycol having a succinimidyl group at the carboxyl terminal thereof. FIG. 2 is a graph showing the transmittance of each product formed under the condition that a salt is added at various concentrations into a phosphoric acid buffer solution of pH 7.4. FIG. 3 is a graph showing a swelling degree of each of collagen-glycosaminoglycan complex matrixes obtained in Inventive Examples 1 to 5 and Comparative Examples 1 and 2. FIG. 4 is a photograph showing cartilage cells enclosed in a collagen-glycosaminoglycan complex matrix obtained in Inventive Example 6. detailed-description description="Detailed Description" end="lead"? |
Coating composition for metal substrates |
The present invention relates to a composition for coating a metal substrate which is intended to be fabricated and overcoated, wherein the binder comprises an acqueous silica sol having a SiO2/M2O mole ratio, with M representing the total of alkali metal and ammonium ions, of at least 6:1, and wherein the ratio of the pigment volume concentration to the critical pigment volume concentration is smaller than 1. |
1. A composition for coating a metal substrate which is intended to be fabricated and overcoated, said composition comprising a silica binder, characterized in that the ratio of the pigment volume concentration to the critical pigment volume concentration of said composition is smaller than 1, and in that the binder comprises an aqueous silica sol and, optionally, a minor amount of alkali metal silicate, with the silica and/or silicate particles having an average size larger than 10 nm, and in that said binder has a SiO2/M2O mole ratio of at least 6:1, wherein M represents the total of alkali metal and ammonium ions. 2. A coating composition according to claim 1, characterized in that the pigment volume concentration is between 40 and 55%. 3. A coating composition according to claim 1, characterized in that the binder is a silica sol of SiO2/M2O mole ratio at least 25:1. 4. A coating composition according to claim 1, characterized in that the binder comprises colloidal silica particles with an average particle size between 10 and 22 nm. 5. A coating composition according to claim 4, characterized in that the binder comprises colloidal silica particles with an average particle size between 10 and 16 nm. 6. A coating composition according to claim 5, characterized in that the aqueous silica sol has a pH in the range 9.5 to 11. 7. A coating composition according to claim 1, characterized in that the primer coating further comprises 0 to 30% by weight of an organic resin, based on solid binder. 8. A coating composition according to claim 7, characterized in that the primer coating further comprises 10-20% by weight of an organic resin, based on solid binder. 9. A coating composition according to claim 1 characterized in that the binder comprises an alumina surface-modified aqueous silica sol. 10. A coating composition according to claim 9, characterized in that the binder comprises 0.05 to 2.5 wt. % of alumina, calculated as the percentage by weight of Al2O3, based on the silica sol particles in the composition. 11. A coating composition according to claim 1, characterized in that it is a water based shop primer. 12. A coating composition according to claim 1, characterized in that the coating further comprises zinc powder and/or a zinc alloy. 13. Water based shop primer for the coating of steel substrates which are intended to be fabricated and overcoated, said composition having a solid content of 20-40% by volume, wherein the ratio of the pigment volume concentration to the critical pigment volume concentration is smaller than 1, comprising: an aqueous silica sol binder having a SiO2/M2O mole ratio of at least 6:1 and a pH between 9.5 and 11, wherein M represents the total of alkali metal and ammonium ions and wherein the optionally alumina modified silica particles have an average size between 10 nm and 16 nm, 10-55% by volume of the coating on a dry film basis of zinc powder and/or a zinc alloy having a mean particle size in the range 2 to 12 μm, 0-35% by weight, based on solid binder, of an organic resin, 0-30% by weight, based on solid binder, of a silane coupling agent, optionally non-zinc pigment(s), and optionally a pot life extender. 14. A process for primer coating a steel substrate wherein the metal is primer coated with a coating composition according to claim 1, which is prepared using a silica sol of which the pH is adjusted to pH 9.5-11. 15. A process for primer coating a steel substrate wherein the metal is primer coated with a coating composition according to claim 1, and wherein after the primer coating has dried to the extent that it is touch dry, it is optionally treated with a film strengthening solution. 16. A process for primer coating a steel substrate wherein the metal is primer coated with a coating composition according to claim 1, and wherein after the primer coating has dried to the extent that it is touch dry, the coated substrate is immersed in water or alternatively kept in an atmosphere with a relative humidity of at least 50%. |
Mixing and kneading device for polymer compositions |
A mixing/kneading device (10) for receiving a viscous composition and for admixing at least one additional constituent therewith, said device comprising: an elongated cavity (11) formed by an enclosure (15) and having a length and a diameter, and including a first inlet (112) for introducing said viscous composition into said device, and at least one second inlet (111) for introducing said at least one 10 additional constituent; and an outlet end (119) downstream of said first and said second inlet for connecting said mixing/kneading device with a processor; a pair of elongated rotors (12,14) for co-rotation within said cavity (11); said elongated rotors each having a first and mutually inter-matching flight portion (121;141) closely fitting into said cavity (11) and being adapted to forcingly convey said viscous composition and said at least one additive distributed therein through said cavity (11) towards said outlet end (119) thereof; and at least one non-conveying portion (161;182) downstream of each of said first portions (121;141) adapted to improve said distribution of said at least one additive in said viscous composition. |
1. An apparatus for admixing a viscous composition with at least one additional constituent selected from fillers, fibers, pigments, color concentrates and gases; said apparatus comprising an upstream plasticating extruder (201, 701) for producing a stream of a viscous; polymer composition and a downstream processor for receiving said stream and for introducing said additional constituent, said downstream processor being a port device (10) for receiving said viscous composition from said upstream plasticating extruder and for admixing said at least one additional constituent therewith, said port device comprising: an elongated cavity (11) formed by an enclosure (15) and having a length and a diameter (D), and including a first inlet (112) for introducing said viscous composition into said port; and at least one second inlet (111) for introducing said at least one additional constituent; and an outlet end (119) downstream of said first and said second inlet for connecting said port device with a processor; a pair of elongated rotors (12, 14) for co-rotation within said cavity (11); said elongated rotors each having a first and mutually inter-matching flight portion (121; 141) closely fitting into said cavity (11) and being adapted to forcingly convey said viscous composition and said at least one additional constituent distributed therein through said cavity (11) towards said outlet end (119) thereof, and at least one non-conveying portion (161; 182) downstream of each of said first portions (121; 141) adapted to improve said distribution of said at least one additional constituent in said viscous composition; wherein said diameter (D) of said cavity (11) is about 1 to 5 times greater than the diameter of the upstream plasticating extruder, and wherein said cavity has a length: diameter ratio in the range of from about 2 to about 20. 2. The apparatus of claim 1, wherein said first conveying flight portion (121; 141) of each of said rotors (12; 14) is formed by a first helical scraping flight portion having a positive pitch. 3. The apparatus of claim 1, wherein said non-conveying portion (161; 182) of each of said intermeshing rotors (12; 14) is formed by a kneading element section (161a; 182a). 4. The apparatus of claim 1, wherein said non-conveying flight portion (161; 182) of each of said intermeshing rotors (12; 14) is formed by a second helical scraping flight section (161b; 182b) having a negative pitch. 5. The apparatus of claim 1, wherein said elongated cavity (11) formed by said enclosure (15) extends in an essentially vertical direction. 6. The apparatus of claim 1 for processing said stream of said viscous composition to produce an extrudate formed by said viscous composition and a filler, fiber of pigment admixed therewith, said apparatus additionally comprising: at least one processor (203; 703) arranged in operative downstream connection with said port device for producing a shaped product. 7. The apparatus of claim 6, wherein said at least one processor (203; 30; 40; 703) arranged in operative downstream connection with said port device has an output means (206; 207; 208; 37; 47; 703) for shaping said viscous composition emanating from said port device. 8. The apparatus of claim 6, wherein said plasticating extruder (201; 701) arranged in said upstream connection with said port device is a co-rotating intermeshing self-wiping extruder. 9. A method for strain-controlled mixing of a viscous composition with at least one additional constituent selected from fillers, fibers, pigments, color concentrates and gases, said method comprising the steps of producing a stream of a viscous polymer composition in a plasticating extruder (201; 701) and feeding said stream into a downstream processor for admixture with said at least one additional constituent; wherein said downstream processor is a port device (10) for receiving said viscous composition from said plasticating extruder, said port device comprising: an elongated cavity (11) formed by an enclosure (15) and having a length and a diameter (D), and including a first inlet (112) for introducing said viscous composition into said port; and at least one second inlet (111) for introducing said at least one additional constituent; and an outlet end (119) downstream of said first and said second inlet for connecting said port device with a processor; a pair of elongated rotors (12; 14) for co-rotation within said cavity (11); said elongated rotors each having a first and mutually inter-matching flight portion (121; 141) closely fitting into said cavity (11) and being adapted to forcingly convey said viscous composition and said at least one additional constituent distributed therein through said cavity (11) towards said outlet end (119) thereof, and at least one non-conveying portion (161; 182) downstream of each of said first portions (121; 141) adapted to improve said distribution of said at least one additional constituent in said viscous composition; and operating said port device for maximizing distributive effects while maintaining dispersing effects between zero and maximum. 10. The method of claim 9 for producing shaped articles made of a polymer composition containing at least one filler; comprising the step of feeding the mixture obtained into a downstream processor (203; 30; 40; 703) for producing a shaped article from said mixture. 11. The method of claim 10, wherein said filler is a particulate reinforcing filler, such as glass fibers having an average length of at least 2 mm. 12. A shaped article obtained by the method of any of claims 10, which is a load-bearing panel (50; 60) comprising polypropylene as said polymer composition and containing about 30% by weight of chopped glass fibers with an initial length of about 8-10 mm as said reinforcing filler for obtaining a flexural modulus of at least 6000 MPa. 13. The shaped article of claim 12, wherein said load-bearing panel has a wear-resistant and slip-resistant surface. 14. A shaped article obtained by the method of claim 10, which is a stretchable film comprising LLDPE and about 50% by weight of micronized calcium carbonate. 15. The apparatus of claim 2, wherein said non-conveying portion (161; 182) of each of said intermeshing rotors (12; 14) is formed by a kneading element section (161a; 182a). 16. The apparatus of claim 2, wherein said non-conveying flight portion (161; 182) of each of said intermeshing rotors (12; 14) is formed by a second helical scraping flight section (161b; 182b) having a negative pitch. 17. The apparatus of claim 2, wherein said elongated cavity (11) formed by said enclosure (15) extends in an essentially vertical direction. 18. The apparatus of claim 3, wherein said elongated cavity (11) formed by said enclosure (15) extends in an essentially vertical direction. 19. The apparatus of claim 4, wherein said elongated cavity (11) formed by said enclosure (15) extends in an essentially vertical direction. 20. The apparatus of claim 2 for processing said stream of said viscous composition to produce an extrudate formed by said viscous composition and a filler, fiber of pigment admixed therewith, said apparatus additionally comprising: at least one processor (203; 703) arranged in operative downstream connection with said port device for producing a shaped product. 21. The apparatus of claim 3 for processing said stream of said viscous composition to produce an extrudate formed by said viscous composition and a filler, fiber of pigment admixed therewith, said apparatus additionally comprising: at least one processor (203; 703) arranged in operative downstream connection with said port device for producing a shaped product. 22. The apparatus of claim 4 for processing said stream of said viscous composition to produce an extrudate formed by said viscous composition and a filler, fiber of pigment admixed therewith, said apparatus additionally comprising: at least one processor (203; 703) arranged in operative downstream connection with said port device for producing a shaped product. 23. The apparatus of claim 5 for processing said stream of said viscous composition to produce an extrudate formed by said viscous composition and a filler, fiber of pigment admixed therewith, said apparatus additionally comprising: at least one processor (203; 703) arranged in operative downstream connection with said port device for producing a shaped product. 24. The apparatus of claim 7, wherein said plasticating extruder (201; 701) arranged in said upstream connection with said port device is a co-rotating intermeshing self-wiping extruder. 25. A shaped article obtained by the method of claim 11, which is a load-bearing panel (50; 60) comprising polypropylene as said polymer composition and containing about 30% by weight of chopped glass fibers with an initial length of about 8-10 mm as said reinforcing filler for obtaining a flexural modulus of at least 6000 MPa. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to processing of viscous compositions, preferably but not exclusively to plasticated polymer compositions, such as normally solid thermoplastic polymers at extrusion temperatures of typically in the range of from about 150-300° C. A problem connected with such processing is uniform admixing of various types of additional components or additives with such polymer compositions. Generally, such admixing is effected when the polymer composition is in a plasticated or molten state. However, because of the generally high viscosities of polymer compositions at processing temperatures this is not without problems because fillers, such as glass fillers or fibers, which—while sometimes effective to mechanically reinforce the resulting products—are relatively fragile and tend to become comminuted or excessively disaggregated or disintegrated when exposed to forces generated upon mixing so that their maximum contribution to the quality of the final product produced is not attained. 2. Prior Art Various means and methods for effective admixing additives including fillers with polymer compositions are known in the art. In fact, many processors of the screw, extruder type are used for this purpose but tend to comminute fragile fillers. Special mention deserve co-rotating twin screw extruders which are widely used for compounding thermoplastic polymers. Such devices have been developed over the past decades with increasing processing velocities, e.g. up to 1200 RPM, to satisfy highest throughput requirements. It may happen, however, that such high speed may conflict seriously with the desired quality for several applications, e.g. when a low or a very low processing speed is required to achieve a given quality. It would not be helpful, however, to use conventional plasticating mixers, such as co-rotating twin screw extruders, and to simply reduce the processing speed because at low or very low speeds melting conditions cannot be achieved. As known to those skilled in extrusion art, melting of polymers often needs a certain amount of frictional heat developed by the screws upon rotation; however, when operation speed is under a certain critical threshold, not enough frictional heat will be generated by the rotating screws, and not enough thermal energy for melting will be provided by the extrusion system. In other words, when using a conventional screw extruder where the same shaft effects both plastication and mixing, it will be difficult, at best, to simultaneously achieve an optimum speed for plastication as well as an optimum speed for mixing; this is due to the simple reason that such two optimal speeds will differ. However, a particular processor type termed “port device” for adding various constituents to viscous polymer compositions within an extruder is disclosed in EP-A-0 907 492 as well as in the references discussed therein, and EP-A-Q 907 492 is incorporated herein for the purpose of disclosure and delimitation. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>The invention will now be disclosed in more detail with reference to the enclosed drawings representing various non-limiting examples of various embodiments of the invention. In the drawings: FIG. 1 is a diagrammatic sectional view of an embodiment of a port device according to the invention; FIGS. 1A and 1B are diagrammatic sectional views of the non-conveying portion of the rotors of a port device as shown in FIG. 1 ; FIGS. 1C and 1D are sectional views to illustrate configuration of the rotors shown in FIG. 1 ; FIG. 2 is a diagrammatic side view, partially sectioned, of a multi-component apparatus or plant according to the invention; FIGS. 2A, 2B and 2 C are diagrammatic side views of various shaping tools at the outlet end of the downstream production extruder shown in FIG. 2 ; FIG. 3 is a diagrammatic side view of another shaping tool for connection with the outlet end of the downstream production extruder of FIG. 2 ; FIG. 4 is a diagrammatic side view of yet another shaping tool for connection with the outlet end of the downstream production extruder of FIG. 2 ; FIGS. 5 and 6 are perspective views of preferred products obtained according to the process of the invention; and FIG. 7 is a diagrammatic top view, partially sectioned, of a multi-component apparatus or plant according to the invention. detailed-description description="Detailed Description" end="lead"? |
Method for optimizing area shape |
Assuming a domain as an object of a body or field to be a linear elastic body, a domain as the object of the body or field and a boundary are determined, and a constraint to domain variation is provided. Further, a uniform distribution spring is set between each point of the boundary and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point. Thereby, when an objective functional is minimized, the deformation position of the domain where the reaction force of the domain generated by making a boundary force in proportion to the negative value of a calculated shape gradient function act on the domain regarded as the linear elastic body, balances the reaction force generated on the distribution spring, is considered to be a domain shape change position of the linear elastic body, and the domain shape of the domain as the object is changed. Such change processing of the domain shape is then repeated to optimize the domain shape. |
1. A domain shape optimization method for obtaining a shape of a body or field in which an objective functional is minimized (maximization is regarded as minimization of a negative value of the objective functional) under a predetermined constraint on design, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain, regarding the domain as an object of the body or field as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as an object of the body or field using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 2. A domain shape optimization method for minimizing a negative value of potential energy with a volume constraint to deformation of a linear elastic body by static load and forcible displacement, that is, maximizing a stiffness of the body, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the linear elastic body as an object, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as an object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 3. A domain shape optimization method for minimizing a volume under conditions in which a negative value of potential energy to deformation of a linear elastic body by static load and forcible displacement is restricted to a constraint value or less, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the linear elastic body as an object, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 4. A domain shape optimization method for minimizing a negative value of potential energy with a volume constraint to deformation of a continuous body having material non-linearity and geometrical non-linearity by static load and forcible displacement, that is, maximizing a stiffness of the body, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the continuous body as an object having material non-linearity and geometrical non-linearity, regarding the domain of the continuous body as the object having material non-linearity and geometrical non-linearity as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 5. A domain shape optimization method for minimizing a volume with a stiffness constraint to deformation of a continuous body having material non-linearity and geometrical non-linearity by static load and forcible displacement, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the continuous body as an object having material non-linearity and geometrical non-linearity, regarding the domain of the continuous body as the object having material non-linearity and geometrical non-linearity as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 6. A domain shape optimization method for minimizing a square error part boundary integral of a specified temperature distribution and a temperature distribution with a volume constraint to a stationary temperature of a heat conduction field, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the heat conduction field as an object, regarding the domain of the heat conduction field as the object as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 7. A domain shape optimization method for minimizing a negative value of potential energy by thermal expansion distortion with a volume constraint to a stationary temperature of a heat conduction linear elastic body, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the heat conduction linear elastic body as an object, regarding the domain of the heat conduction linear elastic body as the object as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 8. A domain shape optimization method for minimizing a pressure loss with a volume constraint to a stationary flow rate and pressure of a Stokes flow field, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of a Stokes flow field as an object, regarding the domain of the Stokes flow field as the object as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 9. A domain shape optimization method for minimizing a square error part domain integral of a specified flow rate and a flow rate with a volume constraint to a stationary flow rate and pressure of a potential flow a, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of a potential flow field as an object, regarding the domain of the potential flow field as the object as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 10. A domain shape optimization method for minimizing a sound pressure gradient square part domain integral with a volume constraint to a stationary sound pressure of a sound field, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the sound field as an object, regarding the domain of the sound field as the object as a linear elastic body, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 11. A domain shape optimization method for minimizing a KS functional in relation to a equivalent stress under conditions in which a volume to deformation of a linear elastic body by static load and forcible displacement is restricted to a constraint value or less, that is, maximizing a strength of the body in case of equivalent stress failure criterion, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the linear elastic body as an object, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. 12. A domain shape optimization method for minimizing a volume under conditions in which a KS functional in relation to an equivalent stress to deformation of a linear elastic body by static load and forcible displacement is restricted to a constraint value or less, the method comprising the steps of: calculating a shape gradient function of each point on a boundary of a domain of the linear elastic body as an object, disposing a uniform distribution spring between each point on the boundary of the domain and each point of a fixed coordinate system positioning on a normal line of the boundary from the former point, changing a domain shape of the domain as the object using deformation of each point on the boundary when a boundary force in proportion to a negative value of the calculated shape gradient function is exerted, and then repeating such change processing of the domain shape to optimize the domain shape. |
<SOH> BACKGROUND ART <EOH>A problem of analyzing the condition of an elastic body, a heat conduction field, a flow field, a sound field, or the like, can be expressed as a boundary value problem of partial differential equation. Using as a set object a domain shape in which such a partial differential equation boundary value problem is defined, for example, a problem of minimizing, under a volume constraint or the like, an objective functional that returns an evaluation value of real number when being given a condition, a problem of minimizing the volume under a condition in which a constraint functional that returns an evaluation value of real number when being given a condition is restricted into a prescribed value or less, or the like, is a shape optimization problem. In such a shape optimization problem, the rate of variation of the objective functional to the quantity of movement when the boundary of the domain as an object is moved in an outward normal direction in order to satisfy the constraint, can be theoretically defined as a shape gradient function (so-called sensitivity). This shape gradient function is represented by a vector function distributed in a definition range of the boundary of the domain and having its positive direction in an outward normal direction of the boundary. The shape gradient function is the sum of the rate of variation of the objective functional and the result of multiplying the rate of variation of the volume constraint or constraint functional by a Lagrange multiplier. The rate of variation of the objective functional and the rate of variation of the constraint functional are calculated from a solution of the boundary value problem of partial differential equation to a condition field and a solution of the boundary value problem of partial differential equation to an adjoint field derived by adjoint variable method. The Lagrange multiplier is determined in order to satisfy the constraint to the domain variation. In actual calculation of the shape gradient function, the boundary value problem of partial differential equation of the condition field or adjoint field is calculated by finite element method, boundary element method, or the like. On the basis of the definition of the shape gradient function, when the boundary is moved in the direction of the shape gradient function, the objective functional rises with satisfying the constraint. Therefore, if the boundary is moved in the negative value direction of the shape gradient function, the objective functional can be minimized with satisfying the constraint. In actual shape optimization, with again calculating the shape gradient function to updated shapes, by repeating the shape update until the value of the objective functional converges, the optimum shape can be obtained. As one of such domain shape optimization methods, for example, a method called traction method by the inventor of this case and so on has been proposed (for example, see Hideyuki Azegami “One Solution of Domain Optimization Problem” Transactions of the Japan Society of Mechanical Engineers. A, vol.60, No.574, pp.1479-1486, June, 1994). The traction method is a method in which the domain as an object is regarded as a linear elastic body and the boundary of the domain is moved using the deformation when the boundary force in proportion to the negative value of the shape gradient function is exerted. As an example of traction method, the boundary movement of the domain as illustrated in FIG. 16 will be described. A domain 1 as an object of a body or field and a boundary 2 are determined and further a constraint 3 to the domain variation is provided, on each point on this boundary 2 , it is assumed that a shape gradient function has been calculated. At this time, assuming that the domain 1 as an object of a body or field is an linear elastic body, by making a boundary force 4 in proportion to a negative value of the shape gradient function act in an outward normal direction of the boundary 2 , a boundary movement is made to occur. FIG. 2 is a block diagram of a domain shape optimization apparatus for obtaining the optimum conditions of the domain variation. This domain shape optimization apparatus first calculates field conditions in a field condition calculation unit 11 . On the basis of this, the domain shape optimization apparatus then calculates an objective functional and various constraint functionals (1), (2), . . . , (m) in an objective functional and constraint functionals (1), (2), . . . , (m) calculation unit 12 . It should be noted here that the objective functional and the constraint functionals represent negative values of potential energy to the deformation, that is, displacement by field conditions, for example, static load and forcible displacement, and are functionals using as variations displacement representing a condition. Next, in a convergence unit 13 , the calculation result is judged not to converge in case of the first time In case of the second time or later, by comparison with the last result, it is judged whether or not the calculation result converges. In case of the calculation result having converged, the current domain shape is output as the optimum shape. In case of the calculation result not having converged, in adjoint field condition calculation units 14 , 14 - 1 , 14 - 2 , . . . , 14 - m corresponding to the objective functional and constraint functionals (1), (2), . . . , (m), conditions of the adjoint field are calculated. On the basis of the calculated conditions of the adjoint field and the field condition calculated in the field condition calculation unit 11 , in shape gradient function calculation units 15 , 15 - 1 , 15 - 2 , . . . 15 - m , elements of the respective shape gradient functions corresponding to the objective functional and constraint functionals (1), (2), . . . , (m) are calculated. On the basis of the calculation results of the shape gradient functions, in domain variation calculation units 16 , 16 - 1 , 16 - 2 , . . . , 16 - m , the respective domain variation quantities corresponding to the objective functional and constraint functionals (1), (2), . . . , (m) are calculated. Each of the domain variation calculation units 16 , 16 - 1 , 16 - 2 , . . . , 16 - m calculates the domain variation quantity according to “operation program” shown in FIG. 17 . That is, a boundary force is first calculated and a stiffness matrix of the domain is then calculated, and on the basis of it, a domain variation quantity is calculated. On the basis of the domain variation quantity calculated in each of the domain variation calculation units 16 , 16 - 1 , 16 - 2 , . . . , 16 - m , in a domain variation determination unit 17 , a Lagrange multiplier is determined such that the constraint is satisfied to the domain variation. By the sum of the domain variation quantities multiplied by the Lagrange multiplier, the whole domain variation quantity is determined. On the basis of the determination result of the domain variation, after the whole domain including the boundary is varied, the field condition is again calculated in the field condition calculation unit 11 and further objective functional and constraint functionals (1), (2), . . . , (m) are calculated. Until the convergence judgment unit 13 judges the calculation result to converge, the same operation process is repeatedly performed. However, by the above traction method, for example, in a problem in which the shape constraint is loose, there is a case wherein the objective functional does not converge. For example, as illustrated in FIG. 18 ( a ), in case that the shape for minimizing the negative value of potential energy, that is, maximizing the stiffness under a volume constraint with restricting the domain variation only at both end boundaries for a notched bar-like three-dimensional linear elastic body receiving tensile load at both ends, even when a shape change by traction method was repeatedly performed, as illustrated in FIG. 18 ( b ), the three-dimensional linear elastic body could not be converged into a non-notched bar as the optimum shape. The present invention is to solve the above-described problem and aims to provide a domain shape optimization method in which a stable convergence solution can be obtained even to a problem in which no convergence solution can be obtained by the conventional traction method. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is an explanatory view for explaining a boundary movement method by the spring-loaded traction method of the present invention. FIG. 2 is a block diagram showing a general construction of a domain shape optimization apparatus used for carrying out the spring-loaded traction method of the present invention and the conventional traction method. FIG. 3 is a flowchart of “operation program” according to the present invention executed in a domain variation calculation unit of the domain shape optimization apparatus. FIG. 4 are a plan view and a front view respectively illustrating convergence shapes before shape changes and after a shape change by the spring-loaded traction method is repeated in minimizing the negative value of potential energy with a volume constraint, that is, maximizing the stiffness of a notched three-dimensional linear elastic body receiving a tensile load at both ends as a first embodiment of the present invention. FIG. 5 are perspective views showing a linear elastic deformation problem by static load and a linear elastic deformation problem by forcible displacement of a holed linear elastic body. FIG. 6 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a minimization problem of the negative value of potential energy with a volume constraint to a linear elastic deformation by static load of a holed linear elastic body as a second embodiment. FIG. 7 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a minimization problem of the negative value of potential energy with a volume constraint to a linear elastic deformation by forcible displacement of a holed linear elastic body as a third embodiment. FIG. 8 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a volume minimization problem in which the negative value of potential energy to a linear elastic deformation by static load of a holed linear elastic body as a forth embodiment is restricted. FIG. 9 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a volume minimization problem in which the negative value of potential energy to a linear elastic deformation by forcible displacement of a holed linear elastic body as a fifth embodiment is restricted. FIG. 10 are perspective views respectively showing the initial conditions and results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a minimization problem of pressure loss with a volume constraint to the stationary flow rate and pressure of a Stokes flow field in a branch pipe as a sixth embodiment. FIG. 11 is a perspective view showing the initial conditions as to the convergence shape to a sound pressure gradient square part domain integral minimization problem with a volume constraint to the stationary sound pressure of the sound field in a concert hole as a seventh embodiment. FIG. 12 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to the sound pressure gradient square part domain integral minimization problem with the volume constraint to the stationary sound pressure of the sound field in the concert hole as a seventh embodiment. FIG. 13 is a perspective view showing a linear elastic deformation problem by static load and a linear elastic deformation problem by forcible displacement of a notched linear elastic body. FIG. 14 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to an equivalent stress KS functional minimization problem with a volume constraint to a linear elastic deformation by static load of the notched linear elastic body as an eighth embodiment. FIG. 15 are perspective views respectively showing results of the conventional traction method and the spring-loaded traction method of the present invention as to the convergence shape to a volume minimization problem in which an equivalent stress KS functional to a linear elastic deformation by forcible displacement of the notched linear elastic body as a ninth embodiment is restricted. FIG. 16 is an explanatory view for explaining a boundary movement method according to a traction method as prior art. FIG. 17 is a flowchart showing “operation program” according to the prior art executed in the domain variation calculation unit of the domain shape optimization apparatus. FIG. 18 are a plan view and a front view respectively illustrating convergence shapes before shape changes and after a shape change by the traction method is repeated in minimizing the negative value of potential energy with a volume constraint, that is, maximizing the stiffness of a notched three-dimensional linear elastic body receiving tensile load at both ends as the prior art. detailed-description description="Detailed Description" end="lead"? |
Vehicle disk brake with a motion converter |
The invention relates to a vehicle disc brake comprising an actuator (42) and a piston (20) bearing a brake lining (22) and designed so that a movement of the actuator displaces the piston, the brake comprising a chamber of fluid (54) designed that pressure on the fluid so displaces the piston (20). The actuator (42) delimits the chamber (54) in such a way that the piston is remote from the chamber. |
1. A vehicle disc brake comprising a piston (20), an actuator forming part of a mechanical first means of actuation of the piston (20) and also forming part of a hydraulic second means of actuation of the piston, the brake also comprising a fluid chamber (54) designed so that pressure on the fluid displaces the piston (20), characterized in that the actuator (42) delimits the chamber (54) in such a way that the piston is remote from the chamber. 2. The brake according to claim 1, characterized in that the mechanical first means also comprise an input shaft (26) and a converter (32) for converting a rotational movement of the shaft into a sliding movement of the actuator (42). 3. The brake according to claim 2, characterized in that the actuator (42) comprises a thrust plate, the converter (32) comprising a reaction plate (36) and balls (40) inserted between the thrust plate and reaction plate, the converter having grooves (37) in which the balls are housed. 4. The brake according to claim 3, characterized in that the converter (32) comprises a sliding plate (34) secured to the shaft (26) and inserted between the thrust plate (42) and reaction plate (36), the balls lying between the reaction plate (36) and the sliding plate (34). 5. The brake according to claim 4, characterized in that the converter (32) comprises a sliding lining (46) in contact with the sliding plate (34) and thrust plate (42). 6. The brake according to claim 5, characterized in that the thrust plate (42) forms a housing accommodating the sliding plate (34). 7. The brake according to claim 6, characterized in that the reaction plate (36) is fixed rigidly to a brake caliper (4), with the shaft (26) passing through it. 8. The brake according to claim 7, characterized in that it comprises a caliper (4) and a member (110) for returning the piston (20) with respect to the caliper. 9. The brake according to claim 8, characterized in that the return member comprises an element (110) made of elastomer. 10. The brake according to claim 9, characterized in that it comprises an adjuster (70) compensating for the wear of the brake lining or linings (22, 24). 11. The brake according to claim 10, characterized in that the adjuster (70) is inserted between the actuator (42) and the piston (20). 12. The brake according to claim 11, characterized in that the adjuster (70) is able to apply a wedge effect. 13. The brake according to claim 12, characterized in that the adjuster (70) is able to immobilize the piston (20) with respect to the actuator (42) while the actuator is sliding in a first direction, and able to render the piston capable of moving with respect to the actuator while the actuator is sliding in a second direction. |
Multicast in point-to-point packet-switched oriented networks |
The invention provides a solution for performing multicast within a telecommunication network. The basic idea is to introduce multicast transmission for parts of a network that is basically point-to-point oriented. This is done by creating transport multicast groups TLMG to transport data between network entities. The idea is to have a TLMG going to a node being close to the user. In one embodiment of the invention one TLMG is established between the SGSNs and RNCs and a second one between the GGSN and SGSNs. From the RNC the data is sent via a radio bearer to a user. |
1-20. (canceled) 21. A method for performing multicast transmission for a multicast group within a telecommunication network, wherein said network includes a core network comprising a router and at least one host in an access network part for handling users, wherein at least one intermediate node is located between the router and the host, and wherein the telecommunication network has a point-to-point layer above a transport layer, said method comprising the steps of: a user registers to a multicast group for the multicast transmission; the router receives the registration; the host is informed about the user being served by the host and registering to the multicast group; the multicast transmission between the router and the host is introduced on the transport layer and said transmission is performed by means of at least one transport level multicast group tunnel on the transport layer, wherein said tunnel is assigned to the multicast group and wherein said tunnel is established by means of a transport layer protocol for tunnelling; and, the host uses radio bearer signaling towards the user registered to the multicast group to route the multicast data to the user. 22. The method according to claim 21, wherein the transport level multicast group tunnel has a structure of a multicast delivery tree. 23. The method according to claim 21, wherein the multicast transmission is performed by means of one transport level multicast group tunnel between the router and the host. 24. The method according to claim 21, wherein the multicast transmission is performed by means of one transport level multicast group tunnel between the intermediate node and the host. 25. The method according to claim 21, wherein at least two transport level multicast group tunnels are established between the router and the host involving at least one intermediate node. 26. The method according to claim 24, wherein the intermediate node relays information exchanged between the router and the host. 27. The method according to claim 24, wherein the intermediate node is the root of the transport level multicast group tunnel going from the intermediate node to the host. 28. The method according to claim 22, wherein the multicast delivery tree is a source based multicast delivery tree to involve the intermediate nodes into the multicast transmission. 29. The method according to claim 21, wherein in order to perform registration or de-registration of a user to or from a multicast group, the user informs the router directly or via the intermediate node, the router informs the intermediate nodes and/or the hosts to register or de-register to the transport level multicast group tunnel and an updating of the corresponding entries in the data structure is performed. 30. The method according to claim 21, wherein the multicast data packets are identified by means of a multicast-flow-identifier, which corresponds to an identifier of the transport level multicast group tunnel, or to an address of the multicast group to which the user is registering or to a GTP Tunnelling ID TEID. 31. The method according to claim 21, wherein the router administrates a relation between multicast group and the multicast-flow-identifiers in the core network, the host administrates a relation between the multicast-flow-identifier and an identifier of the user or group of users. 32. The method according to claim 31, wherein the identifier of the user is the International Mobile Subscriber Identifier IMSI or the identifier of the radio bearer. 33. The method according to claim 22, wherein the intermediate nodes administrates the relation of the multicast-flow-identifier identifying the incoming multicast data from the router and the multicast data outgoing towards the hosts involved in the multicast transmission 34. The method according to claim 21, wherein the transport level multicast group tunnel is a dynamic transport level multicast group tunnel in case for a user being the first one registering to a multicast group the transport level multicast group tunnel is to be established. 35. The method according to claim 21, wherein the transport level multicast group tunnel is pre-established and pre-configured and a pre-configured multicast delivery tree is created. 36. The method according to claim 35, wherein multiple multicast groups are multiplexed on the one pre-configured transport level multicast group tunnel in case the pre-configuration corresponds to the requirements of the multiple multicast groups. 37. A router for performing multicast transmission for a multicast group within a telecommunication network, wherein said network includes a core network comprising a router and at least one host in an access network part for handling users, wherein at least one intermediate node is located between the router and the host, and wherein the telecommunication network has a point-to-point layer above a transport layer, said router comprising: means for handling a user request for registration to a multicast group; means for providing a transport multicast group tunnel established by means of a transport layer protocol for tunnelling on the transport layer; and, means for administrating a relation between the multicast group and the transport multicast group tunnel. 38. An intermediate node for performing multicast transmission for a multicast group within a telecommunication network, wherein said network includes a core network comprising a router and at least one host in an access network part for handling users, wherein said intermediate node is located between the router and the host, and wherein the telecommunication network has a point-to-point layer above a transport layer, said intermediate node comprising: means for handling a user request for registration to a multicast group; means for providing a transport multicast group tunnel established by means of a transport layer protocol for tunnelling on the transport layer towards the host; and, means for administrating a relation between incoming and outgoing multicast data of the multicast transmission. 39. A host for performing multicast transmission for a multicast group within a telecommunication network, wherein said network includes a core network comprising a router and said host in an access network part for handling users, wherein at least one intermediate node is located between the router and said host, and wherein the telecommunication network has a point-to-point layer above a transport layer, said host comprising: means for receiving multicast transmission arriving on the transport multicast group tunnel established by means of a transport layer protocol for tunnelling on the transport layer; and, means for administration a relation between the received multicast transmission and the user in order to forward the multicast transmission by means of radio bearer to the user. |
<SOH> TECHNICAL FIELD OF THE INVENTION <EOH>The present invention relates to a method, router, intermediate node, host and system for performing multicast in a telecommunication network. Multicasting is a service that permits sources to send a single copy of the same data to an address that causes the data to be delivered to multiple recipients. Under multicasting only one copy of a message passes over any link in a network and copies of the message are made only where paths diverge. From the network perspective, multicast dramatically reduces overall bandwidth consumption, since the data is replicated in the network at appropriate points rather than in the end-systems. Further a server, which is sending multicast message needs to manage only one session. Local area networks have supported multicasting for many years. For networks, where nodes share a common communication medium multicasting is easy to support. A specially addressed packet can be read off the communication medium by multiple hosts. Extending multicasting capabilities to internetworks however led to the introduction of a router at the edge of a network in order to figure out dynamically how to forward the arriving data packets. The way of forwarding is for example delivered from the address included in the header of the data packet and from the routing table, which is administrated in the router. There are few possibilities of performing the multicast addressing, for example to use the address indicating the multicast group. In case the multicast is used in Internet Protocol IP network then it is called IP multicast. Within the IP multicast the membership of a multicast session group is dynamic it means that the hosts may join and leave groups at any time. In order to allow hosts on networks to indicate whether they wish to join or leave a particular multicast group there is a protocol called the Internet Group Message Protocol IGMP. Thus this protocol lets the system know which hosts currently belong to which multicast group. This information is required by the multicast routers to know which multicast data packet is to be forwarded into which interface. The IGMP is a part of the IP layer and the IGMP messages are transmitted in IP data packets. The version 1 of IGMP is described in RFC 1112 “Host extensions for IP multicasting” S. E. Deering, Aug. 1, 1989, RFC 2236 “Internet Group Management Protocol, Version 2” W. Fenner, November 1997 describes the version 2. The IGMP has been developed for IP version 4. In Internet Protocol IP version 6 there is a similar protocol called Multicast Listener Discovery MLD, which is used for the same purpose as the IGMP. The description of the first version of MLD is described in RFC 2710 “Multicast Listener Discovery (MLD) for IPv6” S. Deering, W. Fenner, B. Haberman, October 1999. However the messages used in MLD correspond to the IGMP messages. In the following the IGMP will be used as an example. This should not be restricted to the IGMP, the functionality of the invention is also given by usage of MLD. The IGMP uses messages to fulfil its tasks, for example the membership report and the membership query message and the following rules are applied. The different versions of IGMP contain also additional messages. A multicast router sends a membership query at regular intervals to see if any host still belongs to any group. The router must send one query out each interface. The group address in the query is 0 since the router expects one response from a host for every group that contains one or more members on each host. It is also possible to send a membership query for one particular group rather than for all groups. A host responds to an IGMP query by sending one IGMP report for each group that still contains at least one user. A host joins a group also by sending the membership report. Using the information received by applying the report and the query messages a table with its interfaces having at least one host in a multicast group is established. After receiving of the multicast data, the router forwards the data out the interface, which has at least one member. With IP multicast receivers do not need to know who or where the senders are to receive traffic from them and the senders do not need to know who the receivers are. Neither senders nor receivers need to care about the network topology as the network optimises delivery. The distribution of the information via the IP multicast is performed on the base of a hierarchical connection of the hosts, like for example a multicast delivery tree. Several algorithms have been proposed for building multicast distribution trees, like for example spanning trees, shared-trees, source-based trees, core-based trees. The descriptions of the corresponding algorithms can be found in “SIP telephony: Packet-based multimedia communications systems” O. Hersent, D. Gurle, D. Petit, Addison-Wesley, Harlow, 2000. After the establishment of the multicast delivery tree, the distribution of the information is done by the IP multicast routing protocols. The detailed description of the corresponding IP multicast routing protocols can also be found in the above-mentioned document. Multicasting in the internetworking between a fixed network and a mobile network like, General Packet Radio System GPRS or Universal Mobile Communication System UMTS causes problems. The impacts on the problems have for example the mobility of the end users and the low transmission bandwidth of the mobile network on the air interface. Further the communication in a mobile communication networks like for example in UMTS is a unicast communication. The unicast communication is also called point-to-point communication, because a message is sent from a single sender to a single receiver. In such kind of network, in particular in the core network it is not foreseen to perform a multicast communication. The group communication is implemented by means of a point-to-point communication having a sender transmitting separately packets to each of the members of the group. For a group with n members, n packets are required on the whole way between the sender and the receivers, instead of one packet when multicasting is used. In order to explain the problem occurring in a point-to-point oriented telecommunication system in the following an overview of the architecture of the General Packet Radio System GPRS network is given. The GPRS is the packet-switched enhancement of the Global System for Mobile Communication GSM, which is a circuit switched network. It means that the user can be permanent online connected but it has to pay only for the real data transfer. In order to fulfil the new requirements some changes are to be introduced into the GSM. Among other new logical nodes are to be introduced, the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). The main functions of the GGSN involve interaction with external IP packet networks providing connections to Internet Service Providers ISPs. From the external IP network's point of view, the GGSN acts as a router for the IP addresses of all subscribers served by the GPRS networks. The GGSN also exchanges routing information with the external network. The SGSN serves all GPRS subscribers that are physically located within the geographical SGSN service area. It forwards incoming and outgoing IP packets addressed to or from a mobile station. Additional to the new logical nodes also new interfaces between the nodes are to be defined. For the invention in particular the Gn, Gi, Gp and IU-PS interfaces are relevant. The Gp interface is defined between GGSN nodes belonging to different operators. The Gn interface defines the IP based backbone between the SGSN and GGSN. The Gi is the interface between GGSN and a further network, like Internet. The restriction of GPRS is that GGSN and SGSN are to be connected in a way that IP is run on top of the technology chosen, meaning that SGSN and GGSN communicate via IP addresses. The IU-PS interface defines the communication between the SGSN and a Radio Network Controller RNC. The RNC manages Radio Access Bearers for user data, the radio network and mobility. The Radio Base Station, often called also Base Station BS or in 3GPP Node B, provides the radio resources and communicates with the user equipment over the Uu interface. A detailed description of the architecture is to be found in 3GPP TS 03.60 V7.5.0 (2001-01) 3 rd Generation Partnership Project; Technical Specification Group Services and System Aspects, Digital cellular Telecommunications System (Phase 2+), General Packet Radio Service (GPRS), Service Description, Stage 2 (Release 1998) and 3GPP TR 25.925 3 rd Generation Partnership Project; Technical Specification Group Radio Access Network; Radio Interface for Broadcast/Multicast Services (Release 1999), 3GPP TS 29.060 V4.1.9 (2001-06) 3 rd Generation Partnership Project; Technical Specification Group Services and System Aspects, General Packet Radio Service (GPRS), GPRS Tunnelling Protocol (GTP) (Release 4) and 3GPP TS 25.413 V4.0.0 (2001-03) 3 rd Generation Partnership Project; Technical Specification Group Radio Access Network; UTRAN Iu interface RANAP signalling (Release 4) and Internet Protocol RFC 791. The similar nodes and interfaces are also used in the next generation of the wireless networks, in UMTS as described in 3GPP TS 23.060 V3.6.0 (2001-01) 3 rd Generation Partnership Project; Technical Specification Group Services and System Aspects, General Packet Radio Service (GPRS), Service Description, Stage 2 (Release 1999). In order to distinguish between the functionality of these nodes in UMTS extended names are often used, 3G-SGSN and 3G-GGSN. In the following description it will not be distinguished between the GPRS and UMTS nodes. In the following an overview of an UMTS network, as specified in the 3GPP specifications, UMTS Standard 23.060 mentioned above, in respect to FIG. 1 is given. The FIG. 1 includes the core network with a packet switching domain, depticted as Packet. The core network is connected to a radio network, depicted as Radio NW. On top of the packet switching domain of the core network, there is the IP Multimedia Subsystem (IMS), IP Multimedia for conversational multimedia services. Each of the subsystem includes the corresponding nodes. Relevant for the present invention are the nodes of the core network, the RNC, the SGSN and the GGSN node with the involved interface Gn, Gi and Iu-PS which will be further described in more detail. IMS as an example uses the packet switching domain to provide bearers for the conversational multimedia services. Streaming multimedia services are also possible without IMS by using for example a streaming server in the Internet on top of a corresponding packet switched bearer. With the introduction of streaming and conversational multimedia services, many new point-to-multipoint services will evolve. These will have high demands on the network infrastructure and consume considerable amounts of bandwidth. Some examples of such services are video-conferencing, whiteboarding, real-time multi-user games, multimedia messaging, virtual worlds. According to FIG. 1 an external IP network, like the Internet is depicted as Multimedia/IP Network, the mobile station as TE and the core network as Packet. Currently the IP multicast messages in the UMTS are sent from a router settled in an external IP network to the mobile station transparently through the core network via a unicast connection. Then as already mentioned the multicast is performed on the IP layer and from the view of the mobile station TE the router in the Internet is the first node in which the IP connection terminates and therefore the first node applicable for multicast. It means the IP layer in the GGSN, which allows the communication to the external networks, is currently not seen as capable for performing multicast. The router forwards multicast messages to the SGSN without distinguishing between a multicast message and a unicast messages. The separation of the multicast flows is already done in the router in the Internet and the same data packets are sent over the wireless network multiple times depending on the number of recipients. It means the existing UMTS technology does not foresee the utilisation of efficient multicasting on the part of the network denoted by the Gn and the Iu-PS interface in the FIG. 1 . Any service that is simultaneously provided to multiple clients is replicated at the edge of the wireless network and multiple unicast connections are used towards the clients. Especially with the evolution of high-demanding streaming or conversational multimedia services regarding for example to the bandwidth this implies that resources in the network are used very inefficiently. Further the existing nodes are not prepared for performing a multicasting. Further the existing solutions are restricted to parts of the network transmission, for example only for the part between GGSN and SGSNs. It is required to find a solution, which could be applied to the whole path in the core network this means between the edge nodes. For example in case of UMTS the edge nodes of core network are the GGSN and the base station like RNC. In general introducing and performing of multicast in a network, that is basically point-to-point oriented causes problems, than in such kind of networks a unicast channel is established for performing a communication between two nodes. It means the problem does not only occur in a wireless network like UMTS. Further examples of protocols being multicast capable, are SIP (Session Initiation Protocol) or RTSP (Real-time Streaming Protocol). The SIP protocol is described in Multiparty Multimedia Session Control (MMUSIC) WG in IETF, and the RTSP is covered by RFC 2326 Real Time Streaming Protocol (RTSP) H. Schulzrinne, A. Rao, R. Lanphier, April 1998. These protocols belong also to point-to-point oriented protocol stacks and the following invention applies also for them. |
<SOH> SUMMARY AND DESCRIPTION OF THE INVENTION <EOH>It is an object of the present invention to provide a solution for an efficient performing of the multicast transmission for multicast groups within a wireless telecommunication network. In particular it is an object of the invention to perform a replication of the multicast data packets close to end users of said network. The invention is embodied in a method, router, serving node and system as disclosed in claims 1 , 17 , 18 , 19 and 20 . Advantageous embodiments are described in the dependent claims. The basic idea is to provide at least one transport level multicast group tunnel between a router and a host, which are the edge nodes of a wireless telecommunication network and wherein the host is located as close to the user as possible. For example in case of UMTS the router is the GGSN and the host is the RNC. However this invention does not restrict the multicast to be extended even further to the Uu interface in case of UMTS. The transport level multicast group tunnel can be either established directly between the router and the host or in case further intermediate nodes like for example the SGSNs are involved in the transmission then a further transport level multicast group tunnel or tunnels are established towards the host. One transport level multicast group tunnel can be established between the GGSN and the SGSN and a further one between the SGSN and the RNC. In this case the relation between the transport level multicast group tunnels are to be guaranteed in the intermediate node connecting said tunnels. The transport level multicast group tunnel is established by means of a signalling transport layer protocol for tunnelling. There are different possibilities depending on the interface. For example on the Gn interface the GTP-C protocol is to be used and on the Iu-PS interface the RANAP protocol. These protocols are used on one hand as means for the establishment of the transport level multicast group tunnel and on the other hand as means for providing the multicast data packets for the transmission. According to claim 1 a user requests a multicast transmission of a multicast group. The registration is received by the router, which informs the host about the user being served by the host and registering to the multicast group. The multicast transmission between the router and the host is performed by means of at least one transport level multicast group tunnel, which is assigned to the multicast group and which is established by means of a transport layer protocol for tunnelling. The routing to the user is performed either by means of a point-to-point connection or by means of a multicast transmission with point-to-point multi radio bearer. In case of the point-to-point connection if there is more than one user being connected to a host, the host performs the replication to the multicast data packets. Anyhow the multicast data to the at least one user is routed by means of a radio bearer. The transport level multicast group tunnel has a structure of a multicast delivery tree. By means of this structure the nodes are hierarchical connected with the router, the GGSN, as a root of the tree. The nodes are connected by means of transport level multicast group tunnels established between the nodes. In one embodiment of the present invention the multicast transmission is performed by means of one transport level multicast group tunnel between the router and the host. It means the router is the root of the multicast delivery tree established by means of the transport level multicast group tunnel and the hosts are leafs of the tree. In other embodiment the multicast transmission is performed by means of one transport level multicast group tunnel established between the intermediate node and the host. In this case the multicast delivery between the router and the intermediate node can be performed by means of a multicast transmission performed on a higher layer then on the transport layer as this is the case by the transport level multicast group tunnel. As an example of the multicast transmission on a higher layer serves the GTP-U protocol, in case of UMTS, with the TEID as the multicast identifier, as it is described further. In other embodiment of the present invention at least two transport level multicast group tunnels are established between the router and the host involving at least one intermediate node. The function of the intermediate node is either to relay the information exchanged between the router and the host or the intermediate node is the root of the transport level multicast group tunnel going from the intermediate node to the host. In order to ensure that the intermediate node is involved into the multicast transmission the multicast delivery tree is a source based multicast delivery tree. In one possible embodiment in order to perform registration or de-registration of a user to or from a multicast group, the user informs the router. This can be done either by a direct contacting the router or by informing the intermediate node, which consequently takes care on informing the router. The router informs the intermediate nodes and/or the hosts to register or de-register to the transport level multicast group tunnel and an updating of the corresponding entries in the network is performed. This method is an embodiment of the invention and it should not be seen as a restriction for performing the registration procedure. The invention requires a form of an identification of the multicast data packets to forward said data to the corresponding receivers. The multicast data packets are identified by means of a multicast-flow-identifier, which can be an identifier of the transport level multicast group tunnel, or an address of the multicast group to which the user is registering or a GTP Tunnelling ID TEID. The choice of the multicast-flow-identifier depends on the used method for multicast delivery, like the transport level multicast group tunnel or the multicast transmission on the higher layer. It is preferably for the invention to provide an administration of the entries in the corresponding nodes of the network. The router administrates a relation between the identifier of the multicast group to which the user is registering and the identifier of the chosen multicast-flow-identifiers in the core network. The host administrates a relation between the multicast-flow-identifier and an identifier of the user, which can be for example the International Mobile Subscriber Identifier IMSI or the identifier of the radio bearer. In case the intermediate node is involved in the multicast delivery then said node administrates the relation of the multicast-flow-identifier identifying the incoming multicast data from the router and the multicast data outgoing towards the hosts. In one embodiment of the invention the transport level multicast group tunnel is a dynamic transport level multicast group tunnel. It means in case a user is the first one registering to a multicast group the transport level multicast group tunnel is established. In case the transport level multicast group tunnel is already established the registering user are attached to said tunnel. In other embodiment of the present invention the transport level multicast group tunnel is pre-established and pre-configured and a pre-configured multicast delivery tree is created. It means the network operator takes care on the establishment of the transport level multicast group tunnel and the registering users are attached to the appropriate tunnel. The operator can consider for example different Quality of service or different geographical requirements as the parameters for the pre-configuration of the tunnel. It is also advantageous in case of the pre-established and pre-configured transport level multicast group tunnel to provide multiplexing of the multiple multicast groups on the same pre-configured transport level multicast group tunnel. In this case an additional administration is required in order to perform the multiplexing and the de-multiplexing in the considered nodes. The invention discloses also a router, a host, an intermediate node and a system. The router is adapted to perform a multicast transmission for a multicast group within a telecommunication network with said router and at least one host handling users, wherein between said router and the host at least one intermediate node is located. Said router has means for handling a user request for registration to a multicast group. This can for example includes the receiving of an IGMP message, checking the multicast address. In case there is no multicast group in the core network the router establishes a transport multicast group tunnel. This is done by means for providing a transport multicast group tunnel established by means of a transport layer protocol for tunnelling. Further the router has means for administrating a relation between the multicast group and the transport multicast group tunnel in order to sort and forward the multicast data in an appropriate way. The intermediate node is adapted to perform a multicast transmission for a multicast group within a telecommunication network with a router and at least one host handling users, wherein between the router and the host at least one of said intermediate node is located. Said node has means for handling a user request for registration to a multicast group. The user can either registers to the intermediate node or to the router. The function of said means can be also a forwarding of this message to the router. In one embodiment of the invention a multicast delivery tree established by means of transport multicast group tunnel is built between the intermediate node and the hosts. In this case the intermediate nodes has to provide a similar functionality as the router. This is achieved by means for providing a transport multicast group tunnel established by means of a transport layer protocol for tunnelling towards the host. Further the intermediate node has means for administrating a relation between incoming and outgoing multicast data of the multicast transmission. The incoming data arrives from the router and the outgoing data is sent to the host. The host is adapted to perform a multicast transmission for a multicast group within a telecommunication network with a router and at least one of said host handling users, wherein between the router and the host at least one intermediate node is located. The host has means for receiving multicast transmission sent either from the router or from the intermediate node. Further the host has means for administration a relation between the received multicast transmission and the user in order to forward the multicast transmission by means of radio bearer to the user. In case there is more than one user being registered to the multicast group, for which the multicast transmission is foreseen, a replication of the data is performed. The application guarantees that the replication is performed as close as possible to the user and the host is a node handling the users. Further the invention discloses a system adapted to perform a multicast transmission for a multicast group within a telecommunication network having a router and at least one of said host handling users, wherein between the router and the host at least one intermediate node is located. The system includes at least one of the router according to claim 17 , at least one of the intermediate node according to claim 18 and at least on of the host according to claim 19 wherein in the system the method according to claim 1 is performed. In the following the transport level multicast group, which is assigned to a transport level multicast group tunnel will be called TLMG. In the following a detailed description of the invention is given. FIG. 1 : UMTS architecture, FIG. 2 : Protocol-oriented architecture of UMTS nodes, FIG. 3 : An example of a multicast delivery tree, FIG. 4 : Syntax of the source routing based packet, FIG. 5 : Data administration in RNC, FIG. 6 : Data administration in SGSN, FIG. 7 : Registration procedure and a procedure for TLMG establishment as an embodiment of the invention. detailed-description description="Detailed Description" end="lead"? According to the invention the basic approach is disclosed in the following FIG. 2 , by applying the TLMG method on the GN and on the IU-PS interface. A protocol related view is reflected in the FIG. 2 . The FIG. 2 shows architecture of a network as standardised in 3GPP. However this should not be seen as a restriction for the invention. The FIG. 2 shows a mobile station MS, which communicates with an access network UTRAN. The Iu-PS interface connects UTRAN with 3G-SGSN, which communicates over the Gn interface with the 3G-GGSN. The FIG. 2 provides an overview of the different protocol stacks in the different nodes. It shows a mobile station MS with an Application layer, Appl., on the top of the protocol stack, with Internet Protocol IP or with Point to Point Protocol PPP on the network layer. The lower layers are depicted as L 1 and L 2 layers, because they can differ in the corresponding nodes in dependence on the underlying physical network. The logical IP or PPP connection from the mobile station is terminated in the 3G-GGSN. Between the UTRAN, the 3G-SGSN and 3G-GGSN the GTP-U protocol for building a tunnel between these nodes is used. Below the GTP-U is an IP layer with UDP as a protocol for transport of the payload information. The following description concentrates merely on the two IP layers in the packet switched domain, depicted as IP PPP and UDP IP. As the result of the function of the GGSN as a router and as an interface to the external networks the IP layer below the application layer, Appl., was introduced. Further due to the restriction of having an IP network between the GGSN and the SGSN and the RNC an IP logical connection is introduced as a transport mean, below the GTP-U layer. Therefore in respect to the FIG. 2 there are two IP layers, in the following described as application IP and transport IP layer. The application IP layer is located directly below the application protocols in the protocol stack and connecting the mobile station and the 3G-GGSN. The second IP layer is the transport IP layer used for transmission between the SGSN, GGSN and UTRAN. The payload traffic is transported across the Gn and Iu-PS encapsulated in an application-specific tunnelling protocol, the GPRS Tunnelling protocol GTP. It is to differentiate between the GTP-C, which is an example of a transport layer protocol for tunnelling and between the GTP-U, which is a protocol for transport of user data on a higher layer then the transport layer. In GSM or GPRS the GTP protocol is only used between the SGSN and GGSN. GTP packets use UDP as transport protocol. However there are different tunnelling protocols, which are responsible for building a tunnel. The GTP is merely an example and it does not restrict the invention. The introduction of the multicast in on the transport layer in a point-to-point oriented network is presented in respect to FIG. 2 . The idea is to introduce the multicast functionality from the application IP layer to the transport IP layer. In FIG. 2 the cloud on the Gi interface shows the multicast capability in a further network. This functionality in the core network to the transport IP layer on the Gn interface and also to the transport layer on the IU-PS interface. The arrow going from the Multicast cloud on the Gi interface to the Multicast cloud on the Gn and Iu-PS interfaces shows the redirection of the multicast performed on the application IP layer to the transport IP layer. The connection to the mobile station can remain unicast or a multicast on the radio connection can be performed. Also the logical point-to-point connection on the application IP layer is left. On the Iu-PS and on the Gn interface different signalling protocols are used for group management. On the Iu-PS the extended RANAP protocol as described in 3GPP TS 25.413 V4.0.0 (2001-03) 3 rd Generation Partnership Project; Technical Specification Group Radio Access Network; UTRAN Iu interface RANAP signalling (Release 4), and on the Gn interface a new or an extended GTP-C is used. These protocols use different messages however the functionality remains the same. It is also possible to specify a new protocol for both interfaces. An example of multicast delivery tree is depicted in the FIG. 3 . The FIG. 3 shows spanning tree between the GGSN and the corresponding RNCs. The multicast delivery tree between the edge nodes consists of two spanning tree, one between the GGSN and the SGSNs and a second one between the SGSNs and the RNCs. It means on the whole way between the edge nodes multicast is provided. Only on the last part, it means between a host and the user on the radio interface, unicast can be applied. In the following the enhanced functionality of the GGSN are described. This new functionality of the GGSN is required in order to perform the invention. In order to fulfil the new tasks the GGSN has to act as a local multicast router, which is able to handle IGMP message arriving from the subscribers. The subscribers register for specific multicast groups in the GGSN and the GGSN keeps track of the active multicast groups in the packet switched network. The GGSN terminates the IGMP or MLD messages and propagates the relevant information via IGMP or MLD towards the neighbouring routers. The GGSN also handles the multicast routing protocols. So far, the GGSN acts very much like a standard local multicast router. In general a Public Land Mobile Network PLMN external local multicast router may be used instead of the GGSN itself. Additionally, the GGSN is responsible for the creation of a multicast group in the scope of the core network, it means between the GGSN and SGSN and a major part of the radio access network, it means between the SGSN and RNCs. The GGSN then informs the corresponding SGSNs and/or RNCs that these have mobile stations registered for multicast groups. Also the SGSN and RNC are to be enhanced by a new functionality to relay the multicast data flow from GGSN to the Iu-PS interface. It means the nodes administrate the relation between the addresses of the incoming and the outgoing multicast data. For these purpose the nodes are to have association means for mapping and forwarding the incoming multicast data to the outgoing interface. The association means can be realised by means of a table as it is described further. Further the functionality of the SGSN can be enhanced with functions needed for performing the registration of the user, in case the user registers to the SGSN and not to the GGSN by means of an IGMP message. In the following a registration procedure of a user to a multicast group is described. A mobile station, which wants to receive multicast messages, has to inform the corresponding GGSN about its wish. At the reception of a multicast group registration message from a mobile station, the GGSN informs the corresponding SGSNs and/or RNCs that these have mobile stations registered to multicast groups. The GGSN determines the correspondence between the multicast groups identified by a Multicast Group ID and a TLMG address. The TLMG address is included in the message sent to the SGSNs and/or to the RNCs. In a first alternative, alternative A, the SGSN relays the TLMG registration request from the GGSN to the corresponding RNC. In the second alternative, alternative B, the SGSN registers itself to the TLMG, only for the first mobile station that registers to the multicast group, and requests the RNC to register to the TLMG. In this case the SGSN is the root of the multicast delivery tree being built between the SGSN and the RNCs by means of the established TLMGs. In the third alternative, alternative C, the SGSN is bypassed on operator request. It means the intermediate node, the SGSN, is not involved in the multicast transmission. In fact a multicast data delivery tree is created between the edge nodes in all three alternatives. This can be either a multicast delivery tree between the GGSN and the RNC or two multicast delivery trees between the GGSN and the SGSNs and the SGSN and the RNCs. Of course one RNC can have one or more subscribers for the multicast group. Preferably IP multicast is used to deliver the data to the RNC upon which the RNC replicates the packets and forwards these to the mobile stations concerned in case there are more than one user. In the further description the three alternatives are described in more details. In the following the source based multicast routing will be described in more details. The source-routing multicast is a mechanism to force the multicast tree establishment procedures to consider specific nodes/routers. It is a general mechanism that can be applied to other scenarios as well. With source-routing multicast network operators can force the multicast delivery tree to include certain routers and nodes for example for charging or network management purposes that may be excluded without the use of source-routing multicast. For the Iu-PS multicast, source-routing multicast is used to force, that the SGSN is included in the multicast delivery path between the RNC and the GGSN. This forces the multicast traffic for mobile subscribers to pass the corresponding SGSN. Source-routing is one of the IP options in both IPv4 and IPv6. Two source-routing options are defined, the Strict source routing and the Loose source routing. The strict source routing gives the complete path from source to destination as a sequence of IP addresses. A data packet follows that exact route. The loose source routing requires the packet to traverse the list of routers specified, and in the order specified, but it is allowed to pass through other routers on the way. The syntax of the source-routing options is disclosed in respect to FIG. 4 . Both source-routing options have the same syntax. The Route Data contains a list of IP destination addresses through which the packet must be relayed. In the list an IP header destination field is included, which always indicates the next address to which the packet must be routed. When that destination is reached, the option is examined. The loose source and record route option provides a means for a source of a data packet to supply routing information to be used by the routers in forwarding the data packet to the destination, and to record the route information. The pointer field, Ptr, contains an index, or an octet count starting from the beginning of the option. If it is greater than the option's length, Length, the packet has reached its final destination. Otherwise, if the address in the IP destination address field has been reached and the pointer is not greater than the Length, the next destination address in the source route replaces the address in the IP destination address field, and the recorded route address replaces the source address just used, and the pointer is increased. This option is a loose source route because the router or host is allowed to use any route of any number of other intermediate routers to reach the next address in the route. In case of strict source routing, this must be the address of an adjacent router; there is no constraint in case of loose source routing. The local router's must then replace the address in the list and the pointer, Ptr, is incremented. The field Type has the information, whether it is the strict or the loose source based routing. Strict source routing is very similar to loose source routing. Instead of allowing routers or hosts to use any route of any number of intermediate routers to reach the next address in the route, these must send the data packet directly to the next address in the source route through only the directly connected network indicated in the next address to reach the next router or host specified in the route. The loose source routing and the strict source routing can be applied in order to guarantee that a node, like a SGSN is part of a multicast delivery tree. The GGSN uses the address of the SGSN as the destination IP address and puts the address of the RNC in the source-routing options field. The SGSN then replaces the IP destination address by the RNC IP address that is contained in the source-routing options field. Optionally, the SGSN removes the source-routing options field from the IP packet header and updates other fields in the packet header accordingly. In order to perform the alternative A the RNC reports its TLMG membership to the GGSN. This is performed only for the first registering user. In order to ensure that the SGSN is part of the tree, the membership report message must pass the SGSN on its way from the RNC to the GGSN. This can be achieved by means of configuration of the network or by having the multicast routing protocols consider loose source routing extension header when relaying the membership report messages between the multicast routers as described above. The SGSN routes the information, either the signaling information exchanged between the GGSN and the RNC or the multicast data arriving from the GGSN. The SGSN acts as a neighborhood router for the RNC with the additional processing required for the invention. Both SGSN and RNC can be requested to join the Multicast group by the GGSN. By source routing it is ensured that all packets first traverse the SGSNs. In the alternative B the SGSN reports its TLMG membership to the GGSN and requests the RNC to report its membership to the SGSN. Logically, the SGSN can be seen as both a leaf of a TLMG and as the root of another TLMG, in case there are two TLMGs established between the GGSN and the RNCs. Therefore it is automatically ensured that the multicast traffic towards the RNC passes the SGSN. In the alternative C the SGSN as a function in the network may be by-passed on operator's choice. In this case the GGSN is the root of the multicast tree and the RNCs are the leaves. In dependence on the implementation it may be that the multicast traffic still traverse through the SGSN, but is not further processed there. This requires a management interface through which the operator can control whether this alternative is chosen or not. This interface might be a central multicast database wherein all multicast groups are classified. In dependence on the alternative the SGSN stores information on how to process the multicast stream coming from the GGSN. The IP multicast is used to deliver the data to the RNCs, eventually via the SGSNs upon which the RNC replicates the packets and forwards these to the users concerned or the RNC uses the multicast radio bearer to forward the data to a group of users. In the following a preferred embodiment for a multicast delivery procedure is described. For the multicast data delivery, the application multicast packets are addressed with a multicast identifier, which is valid within the core networks domain, the so-called multicast-flow-identifier or MC-ID. There are some alternatives for the assignment of the MC-ID. The MC-ID can be for example the TLMG address. This can be applied, when an one-to-one relation of the multicast group to which the user is registering to the TLMG in the considered point-to-point oriented telecommunication network is defined and if no additional encapsulation protocol is used, which can lead to the difficulties of packet identification. Further the MC-ID can be the actual multicast address of the multicast group, which can be the same as used in the further network and received from the IGMP message sent from the subscriber during the registration. In case the GTP-U is used to encapsulate and forward the multicast packets via the Iu-PS interface the identifier of this protocol the Tunneling Identifier TID or TEID can be used as the multicast-flow-identifier. The receiving side of the GTP-U tunnel assigns the TEID. In case of the IU-PS interface it is the RNC. The multicast delivery is performed on a higher layer as in case of TLMGs. The protocol layers are described in respect to FIG. 2 . With the GTP-U tunnels as an example of a transport level multicast group tunnel, delivery tunnels are established between the nodes and on each tunnel one multicast message is transferred. In one embodiment of the invention it is foreseen to have the GTP-U tunnel for multicast transmission on the Gn interface and a TLMG multicast delivery tree on the IU-PS interface, wherein according to the standard protocol stack of course a GTP-U protocol is also available above the TLMG, it is not used for multicast transmission. On the connection between GGSN and SGSN and also between SGSN and RNC different types of TLMGs can be used. For example a TLMG can be established on demand, the so-called dynamic TLMG. It means, when a user register to a multicast group then a dynamic TLMG is established in case the user is the first one registering to the certain multicast group. In case a TLMG for a certain multicast group to which a user wants to register, already exist then the user is only added to the corresponding TLMG. In another solution the TLMGs are pre-established. In order to save the establishment time, the TLMGs are pre-established according to the known multicast groups and the known configuration parameters. The configuration parameter can be for example geographical regions or Quality of service requirements. A multicast flow is checked for the fulfilling of the configuration parameter. According to the result the multicast flow is assigned to the corresponding TLMG. Because of the different alternatives to address and identify multicast flows the tables in the SGSN and RNC are to be structured in dependence on the used multicast-flow-identifier. This is disclosed in regard to FIGS. 5 and 6 . The different alternatives in dependence on the multicast flow identifier and the method for the multicast transmission on the Iu interface is described in the following in respect to FIG. 5 . It is to mention that FIG. 5 discloses an embodiment of the present invention, so that the existence of the multicast flow identifier in the table is optional and implementation dependent. Further not all-possible mappings are covered by the FIG. 5 . Within each RNC, an association with the mapping for incoming multicast traffic from the Iu-PS interface having the multicast-flow-identifier to the actually used Radio Bearer or the Radio Access Bearer Context RAB-context is to be maintained. For this purpose a new multicast-group identifier, which is unique to all members of the same multicast group, or just a multicast flag is added to the RAB context. The number of the RAB context is saved in the RNC context and a RNC context is maintained per mobile terminal. The FIG. 5 includes four alternatives depicted as option 1 to option 4 . Option 1 administrates multicast flows sent by means of TLMG. In option 1 this is disclosed in the first column, depicted as TLMG, and including two TLMGs, tlmg 1 and tlmg 2 . The tlmg 1 administrates two mobile stations, which are identified by means of the International Mobile Subscriber Identifier IMSI, imsi- 1 and imsi- 2 . This is included in the third column depicted as MS ID. However this column is optional, because every user equipment can be identified by means of the assigned radio bearer. The radio bearer identifier rab-ids are listed in the second column RAB ID. For example the second TLMG, tlmg 2 relates to three radio bearers, rab-id 1 , rab-id 4 and rab-id 5 . In option 2 the possibility of multiplexing of multiple multicast session on one TLMG is shown. Two multicast groups, mc 1 and mc 2 are multiplexed on one TLMG. The MC-Addr is used to identify the multicast flows transmitted over one TLMG. The used TLMG can be either dynamic or pre-configured, as it is described further. The difference between option 2 and 3 is the identifier of the multicast flow in the core network. In option 2 this is the identifier of the multicast group to which a user is registering MC-Addr. In the option 3 this is the identifier of the GTP tunnel GTP-ID, which is received during the PDP context activation. The PDP context activation is like dialling to the external IP network. For this aim a mobile subscriber identity is associated with an IP address. During the PDP Context Activation a tunnel with an identity, in the following identified with TEID is created between the SGSN and GGSN for the PDP context. In case the GTP is used during the PDP Context Activation a GTP tunnel is established. During this procedure also a Quality of Service QoS negotiation takes place between the MS and the SGSN/GGSN. The option 4 discloses an association, which put into relation the GTP-ID and a succeeding multicast radio bearer MC RAB ID. A multicast radio access bearer is a succeeding point-to-multipoint radio bearer. A list of mobile stations, which are covered by the Multicast Radio Bearer, may be kept separately. Under consideration of the chosen options the RNC either replicates the received multicast packets from the Iu-PS interface in the options 1 to 3 or the data is multicast by means of the multicast radio bearer in option 4 . In the following the data administration done in the SGSN is described in respect with FIG. 6 . Within the SGSN a table similar to a routing table is maintained. The multicast flow identifier from the Gn interfaces needs to be mapped to the identifier on the Iu-PS interface. Since a SGSN can serve several RNCs the table may contain several multicast flow identifiers for the Iu-PS interface. In general the task of the SGSN is to administrate the identifier used on the Gn and on the Iu-PS interface and the relation between the identifiers. Moreover the SGSN can administrate further parameters, which depend on the chosen identifier, the alternative of the multicast delivery and the sort of the TLMG. The FIG. 6 discloses four examples for the entries in the SGSN. In the first table, SGSN Table 1 , a tlmg-gn 1 , which is the TLMG used on the Gn interface is mapped to two TLMGs on the Iu-PS interface, tlmg-iu 1 and tlmg-iu 2 . The tlmg-IU entry refers to the transport bearer to be used. Since in some alternatives the SGSN is the root of the multicast tree for the Iu-PS interface, packet replication from the TLMG on the Gn towards several TLMG-Iu can occur. Another option is that different tlmg-IU groups exist for different multicast groups, wherein said groups have different QoS requirements. This is especially to consider in case of pre-established and pre-configured TLMGs. In the second and in the third table, SGSN table 2 and 3 , additionally the multicast flow identifier for the Iu-PS interface is administrated in the MC-ID-IU column in order to distinguish between the different multicast groups. This can be for example the multicast address, mc-addr or the tunnel identifier teid as described above. The additional multicast flow identifier can be used in order to distinguish between the different QoS classes, in case such classes are defined and the pre-configuration is provided in respect to the defined classes. In the fourth table, the SGSN table 4 the case is shown, in which no TLMGs are available on the Gn interface. The multicast transmission on the Gn interface is performed on the GTP-U protocol layer. Therefore the multicast flow identifier is the teid-gn on the Gn interface. In this case there are two tunnels, teid-gn 1 and teid-gn 2 . The teid-gn 1 forwards the traffic of one multicast group. In the SGSN the traffic is replicated and forwarded on three ongoing GTP-U tunnels depicted in the second column as teid 1 to teid 3 . On the Iu interface the multicast transmission is performed by means of the TLMGs, shown in the third column, TLMG-iu. In this embodiment, five different TLMGs are used, each configured with different QoS properties. In case of the alternative, in which the same TLMGs are used on Gn interface and on Iu-PS interface, the TLMG-iu entry can become optional. In the following an embodiment of a signaling sequence of the present invention for multicast group registration and TLMG establishment for the alternative A, B and C is described. It means one TLMG multicast delivery tree is established between the GGSN and the SGSNs and a second one between the SGSN and the RNCs. The description is based on FIG. 7 . The FIG. 7 shows a time sequence of the sent messages between mobile Station MS, a SGSN and a GGSN. An arrow indicates the sent message. Above an arrow the name of the message is given and below the arrow the main parameters of the corresponding message are listed. The boxes on the right side show the action, which are performed in a node after receiving a message. In the first step the PDP context is established as described above. In order to register to a multicast group it is the task of the mobile station MS to initiate it. Different from local multicast routers as specified in IGMP the GGSN does not send out membership queries to all mobile stations with an active PDP context. This would merely waste scarce radio resources. Instead, the mobile stations MSs initiate the joining of a multicast group by themselves. Without being requested by a membership query message, for example IGMP query message the MSs report their membership by means of a IGMP membership report message with the multicast group address, MC Addr as parameter. In this case the GGSN terminates the IGMP protocol and stores information about the multicast group membership of the MS. In the next step MC Group Membership Verification in GGSN is done in order to determine whether the mobile station is allowed to register for the multicast group. It may be for example that security checks do not allow the mobile station to join the multicast group or that the operator does not allow the multicast group registration because of the characteristics of the group or that the maximum number of allowed multicast group members has been reached. Several other checks may be performed in the GGSN. In case the multicast group as indicated in the IGMP Membership Report does not exist in the GGSN yet, the GGSN can create a new entry for this in case of dynamic TLMG. In this case the GGSN creates a TLMG on the transport IP layer for the multicast data arriving on the application IP level. For this purpose the GGSN allocates a multicast address from the core network's address space. In the following it will be called the Multicast IP Address of the TLMG or alternative TLMG-MCAddress or simply TLMG address. In order to create the proper TLMG, the GGSN can take the negotiated Quality of Service QoS requirements from the PDP context into account. It is also possible to just provide the TLMG address to the SGSN, as described below and create the logical TLMG in the GGSN only upon reception of a positive result from the SGSN. The GGSN informs in this case the corresponding SGSN that it has mobile stations registered for a multicast group by means of for example enhanced GTP protocol. A new GTP message, SGSN Membership Report Request can be used. It is also possible to use existing message, for example an enhanced Packet Data Unit PDU notification message on the UDP connection for this purpose. It can also be, that the SGSN is passed on the way from the mobile station to the GGSN or that the IGMP message terminates in SGSN and therefore it is not required to send this message. For the multicast group traffic the GGSN ignores the tunnel that is already established for that MS by the SGSN during the PDP context activation and rather uses TLMGs, which form a multicast delivery tree. This kind of multicast delivery tree will be called in the further description a TLMG delivery tree. After receiving the SGSN Membership Report Request message the SGSN makes Multicast Group MC Membership Verification. In particular it means that the SGSN can do subscription check or charging accounts check to determine whether the mobile station is allowed to register for any or for this specific multicast group. In dependence on the chosen alternative the SGSN either relays the messages transparently between the GGSN and RNC or it terminates messages from one node and sends similar new messages to the other node. It means at reception of a IGMP Membership report message from a mobile client, the GGSN either sends an SGSN Membership Report to the SGSN as shown in FIG. 7 upon which the SGSN relays the message by for example sending a dedicated RNC Membership Report, first arrow in step 1 message with different mobile client identification parameters to the RNC or the GGSN directly sends an RNC Membership report to the corresponding RNC. The RNC Membership report is merely a fictive name for a message, which is introduced in order to guarantee a clearness of the description. This message is to be translated in an appropriate signalling protocol. For example on the Iu-PS interface this is the RANAP protocol, of which signalling message are described further. Optionally, the GGSN includes the address of the SGSN for example the IP-address in order to be used for source routed multicast routing when establishing the multicast delivery tree. The SGSN only requests the membership reporting from the RNC when all the analyses in the SGSN have been passed successfully. Optionally, the RNC may perform some checks at reception of the membership report request from the SGSN or the GGSN, such as the availability of a multicast radio bearer, replication resources, etc. This may result in an RNC membership report result message sent back to the SGSN or GGSN. The result of the verification done in RNC can be sent back to the SGSN or to the GGSN in a RNC Membership Report Result message, second arrow in step 2 . The result of the verification done in SGSN is included in SGSN Membership Report Result message. Furthermore, the SGSN and RNC then store the relation between the TLMG on the different interfaces, Gn, Iu-PS and radio. Upon receipt of the SGSN Membership Report Result, the GGSN returns IGMP Membership Report Accept or Membership Report Reject, possibly containing a cause indication, depending on the outcome of the verification. This is a new message, which is not specified in IGMP. It is also feasible to send an existing error message only in case of a negative result. Otherwise, when the result of the membership report is positive, none information message is sent back. Whenever a first MS registers to a multicast group then in dependence on the chosen alternative the SGSN itself is to register to the TLMG and is to be added to the TLMG multicast delivery tree. In this case the SGSN sends an IGMP Membership Report message to the GGSN. In case the RNC has to be added to a multicast delivery tree spanning between the SGSN and the RNC then the RNC sends an IGMP Membership Report message to the SGSN, step 2 . It means the RNC can register to the TLMG with the SGSN or with the GGSN as root. The TLMG either consists of a single multicast delivery tree between the GGSN and RNC or a TLMG is created consisting of a subtree between the RNC and SGSN it means the SGSN as root and RNC as a leaf, and a subtree between the SGSN and GGSN with the GGSN as root and RNC as leaf. Optionally, in case of two subtrees, different types of TLMGs may be used, for example the TLMG between the SGSN and GGSN is pre-configured, whereas the TLMG between the RNC and SGSN is established upon request. It is also possible to have a multicast delivery tree delivering by means of TLMGs either between the GGSN and the SGSNs or between the SGSNs and the RNCs. In this case the other part of the transmission path uses the GTP-U with the TEID for performing the multicast on the higher layer without the multicast on the transport layer. The disadvantage of this solution is that the replication of the multicast data packets is performed in the root node and not in a router located as close as possible to the receiver of the multicast data packet. For the signaling between the SGSN and RNC the RANAP protocol as an example for performing the transmission of the RNC membership report and RNC membership report result. These messages are translated into the so-called RAB messages, which are messages for establishing the Radio Access Bearers, the so-called “RAB assignment procedures”. It means the RNC membership report and the RNC membership report result are carried out by means of the messages RAB assignment request, RAB assignment response. In order to support multicast the RANAP protocol is to be enhanced. For example the messages RAB assignment request, RAB assignment response and a release messages are to be enhanced with new parameters, like for example a flag for indicating a multicast traffic, the TLMG address or the TEID. To setup a new Radio Access Bearer, the SGSN sends the RAB assignment request message to the RNC. The response of this message is the RAB assignment response message. Either this message is enhanced by the needed multicast parameters or a new message needs to be specified. However, the message needs to contain a traffic type indicator for multicast. This can be done either with a flag or by enhancing an existing enumerator with the multicast, for example the Traffic Class enumerator, which already includes conversational, interactive, streaming, background enumerator. Depending on the multicast-flow identifier, which is used on the Iu-PS interface, the following mechanisms are applied by using the RANAP protocol. In case dynamic TLMG on the Iu-PS interface are used either the SGSN or the RNC can allocate the TLMG address. If the SGSN allocates a TLMG address from the core network address space, the TLMG address as parameter is mandatory in the enhanced RAB Assignment Request message. In case the RNC allocates a TLMG address, it is part of an enhanced RAB Assignment Response message. In both cases the RNC and the SGSN update their tables accordingly. In case pre-configured TLMGs on the Iu-PS interface are used all RNCs join the pre-configured TLMGs. If pre-configured TLMGs are used, either the SGSN selects the TLMG with respect to the required QoS level or the RNC selects the TLMG with respect to the requested QoS level and the radio conditions. If the TLMG is selected by the SGSN, the TLMG-Address is part of the RAB Assignment Request message. If the TLMG is selected by the RNC, the selected TLMG is part of the RAB Assignment Response Message. The mapping table in the SGSN is updated accordingly. In a preferred embodiment multicast flows are multiplexed on the TLMGs. The TLMGs can be based on different service classes, like for example on different Quality of Service QoS parameter and optionally multiplexing of multiple multicast streams in the GGSN can be applied in the concept of pre-configured TLMGs. On each TLMG several multicast groups may be multiplexed. This means multiple multicast groups are transported on the same TLMG, as long as they have the same QoS requirements that are fulfilled by the TLMG. With this solution it is required that the multicast flows are uniquely identified. This can be achieved using additional to the TLMG address the multicast addresses, MC-Address, of the multicast groups existing in the further network. On the Gn interface the GTP protocol is to be used in order to inform the involved entities about the relation between the entities. In case of Iu-Ps interface the RANAP can be used. For this purpose the RAB Assignment message is to be enhanced. For example in case the multicast addresses of the multicast groups MC-Address is used as multiplexing identifier then the MC-Address is passed to the RNC in the RAB Assignment Request message. It is also possible to additional encapsulate the data packets in order to introduce a multicast address. A special protocol the Generic Routing Encapsulation GRE protocol, as described in RFC 1701 can be used to encapsulate the Multicast IP packets in order to add an additional field carrying the multicast address. In case the GTP is used on the Iu-PS interface another multiplexing flow identifier can be used, the TEID. According to the UMTS specification, the receiving side of the GTP-U tunnel assigns the TEID. If GTP is used to encapsulate the multicast flow on the Iu-PS interface, the TEID is assigned to a multicast flow and therefore it can be used as a multiplexing flow identifier Above a procedure of TLMG establishment and registration is described. Appropriate procedure, using appropriate messages are used for de-registration procedure. For example in order to leave a multicast group the RNC sends an IGMP Leave message. It is possible to have a scenario, in which TLMGs are used on the Gn interface and no TLMGs are established on the Iu-PS interface. In this case the TEID is used to identify the multicast flow on the Iu-PS interface. The TEID is assigned by the RNC and passed back to the SGSN in the RAB Assignment Response message. However, the RAB Assignment Request message still contains a Traffic Class Multicast parameter. Either the RNC or the SGSN can create a RAB-ID for the multicast flow. If the SGSN create the RAB-ID, it is passed over to the RNC with the enhanced RAB Assignment Request message. On reception of the enhanced RAB assignment Request message, the RNC either sends an IGMP Report message via the Iu-PS interface to the SGSN to join the multicast group. This is done only for the very first RAB assignment Request message for this multicast group. In this scenario the replication of the data packets between the registered RNCs is performed in the SGSN it means one data packet is transmitted to one registered RNC. detailed-description description="Detailed Description" end="tail"? |
Method of producing a cryptographic unit for an asymmetric cryptography system using a discrete logarithm function |
The invention relates to a group of public-key cryptography schemas that use the discrete logarithm problem with the purpose of reducing the cost of developing, producing and maintaining a cryptographic unit. One of the entities (10) performs a calculation comprising at most a small number of additions, subtractions and multiplications of integers, said calculation being common to all of the schemas of the group. The aforementioned calculation is preferably the main calculation to be performed by the entity in question while most of the other calculations can be performed in advance. In particular, said calculation is of the y=ar+bs type, wherein r is a random number and s is a secret key that is specific to the entity (10). The calculation is common to a group of schemas for entity authentication, message authentication, digital signatures and key exchange. |
1. A method of producing a cryptographic unit associated with an integer secret key s in an asymmetric cryptography system, comprising the steps of: providing the cryptographic unit with a component produced independently of the cryptography system and suitable for delivering an integer y through a combination between several integer operands including a random number r, the secret key s and at least one further operand (a, b); selecting the cryptography system by associating with the secret key s a public key comprising a first element g of a set G provided with a multiplication operation[[,]]; and providing the cryptographic unit with a generator of cryptographic data suites each including a random number r submitted as operand to said component and a value x dependent on the element gr of the set G, and delivered by the unit in association with the integer y. 2. The method as claimed in claim 1. wherein the public key comprises a second element v of the set G such that v=gs or v=g−s. 3. The method as claimed in claim 1 wherein the generator of cryptographic data suites comprises a programmable memory for receiving pairs {r, x} or {r, gr} calculated in advance. 4. The method as claimed in claim 1, wherein the combination performed by said component is of the form y=ar+bs, where a and b are two further operands. 5. The method as claimed in claim 4, wherein the further operands a and b are received from a verification unit to which the value x and the integer y are sent. 6. The method as claimed in claim 4, wherein one of the further operands equal to 1. 7. The method as claimed in claim 6, wherein the set G provided with the multiplication operation possesses a group structure. 8. The method as claimed in claim 7, wherein said component is so arranged that the other further operand is received from a verification unit to which the value x and the integer y are sent, and wherein the obtaining of the value x as a function of the element gr comprises applying a hash function. 9. The method as claimed in claim 7 for the production of a cryptographic unit implementing a message authentication protocol, wherein said component is so arranged that the other further operand is received from a verification unit to which the value x and the integer y are sent, and wherein the value x is a function of the element gr and of the content of a message to be certified by a device incorporating the cryptographic unit. 10. The method as claimed in claim 7 for the production of a cryptographic unit implementing a digital message signature protocol, wherein the further operand b is calculated as a function of the value x, and wherein the value x is a function of the element gr and of the content of a message to be certified by a device incorporating, the cryptographic unit. 11. The method as claimed in claim 1 for the production of a cryptographic unit implementing a key exchange protocol, wherein the cryptographic unit is equipped with means of communication with another cryptographic unit to which the value x and the integer y are sent, said other cryptographic unit being associated with another integer secret key s′, and wherein the step of selecting the cryptography system comprises associating with the secret key s′ a public key composed of the element g aid of another element v′ of the set G such that v′=gs′, wherein each cryptographic data suite produced by said generator includes, in addition to the random number r and said value x, a common key K dependent on the element v′r of the set G, which is not transmitted to said other cryptographic unit. 12. The method as claimed in claim 11, wherein the generator of cryptographic data suites comprises a programmable memory for receiving triplets {r, x, K} or {r, gr, v′r} calculated in advance. |
Process for the preparation of activated polyethylene glycols |
The present invention relates to a process for the preparation of activated polyethylene glycols, or PEG(NPC)2s, comprising reacting polyethylene glycol with an activator while in the presence of an aromatic nitrogen containing heterocyclic base. The process is carried out at temperatures ranging from about 20 to about 30° C., more preferably at room temperature, and under stoichiometric conditions. |
1. A process for preparing a bis-activated polyethylene glycol having the formula: Y-Q-O-(CH2—CH2—O)n-Q-Y wherein n is an integer greater than 4: Y is a leaving group; Q has the formula: Q=(U0)n0-[(Q0)n1(CHR1)n2-(Q1)n3]p-[(R2C═CR3)n4-(Q2)n5]m-[(CHR4)n6-(Q3)n7]q-(U1)n8 wherein Q0, Q1, Q2, and Q3 independently are O or S; R1,R2, R3 and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; n0, n1, n3, n4, n5, n7, and n8 independently are 0 or 1; n2 and n6 independently are 0, 1, 2, or 3; U0 and U1 are independently selected from the group consisting of C(O), SO2, and P(O); p and q independently are 0, 1, 2, 3, 4, 5, or 6; and m is 0, 1, or 2, wherein 0≦p+m≦8; the method comprising the steps of: (i) providing a polyethylene glycol having the formula: H—(O—CH2—CH2—)n—OH wherein n is an integer greater than; and (ii) reacting the polyethylene glycol with an activator having the formula of Y-Q-X; wherein X and Y independently are a leaving group; and Q has the formula Q=(U0)n0-[(Q0)n1(CHR1)n2-(Q1)n3]p-[(R2C═CR3)n4-(Q2)n5]m-[(CHR4)n6-(Q3)n7]q-(U1)n8 wherein Q0, Q1, Q2, and Q3 independently are O or S R1, R2, R3, and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; n0, n1, n3, n4, n5, n7, and n8 independently are are integers selected from the group 0 or 1; n2 and n6 independently are 0, 1, 2, or 3 U0 and U1 are independently selected from the group consisting of C(O); SO2, and P(O); p and q independently are 0, 1, 2, 3, 4, 5, or 6: and m is 0, 1, or2, wherein 0≦p+m≦8; in the presence of an aromatic nitrogen-containing heterocyclic base having the formula: wherein (NR5R6)c is located either in the ortho or para position; R5 and R6 are independently selected from the group consisting of a lower straight alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; and c is 1 or 2; to produce said bis-activated polyethylene glycol. 2. The process of claim 1, wherein n is an integer between 65 and 800. 3. (canceled) 4. (canceled) 5. The process of claim 1, wherein Q is selected from the group consisting of SO2, CO(CHR1)tSO2, C(O), SO2(CHR1)tSO2, SO2—O—(CHR1)t—O—SO2, P(O), CO—O—(CHR1)t—CR2═CR3—(CHR4)t—O—CO, and SO2—O—(CHR1)t—CR2═CR3—(CHR4)t—O—SO2, wherein t is 1, 2, or 3; and R1, R2, R3 and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group. 6. The process of claim 5, wherein R1, R2, R3 and R4 are independently selected from the group consisting of H, a methyl group, an ethyl group, an isopropyl group, and a propyl group. 7. The process of claim 5, wherein Q is selected from the group consisting of SO2, CO—O—CH2—CH═CH—CH2—O—CO, COCH2SO2, C(O), and SO2CH2CH2SO2. 8. The process of claim 1, wherein the activator is selected from the group consisting of Cl—CO—O-Ph-NO2, Cl—SO2—O—CH2—CH2—O—SO2—Cl, Cl—SO2—O—CH2—CH2—O—CO—Cl, and Cl—CO—O—CH2—CH═CH—CH2—O—CO—Cl. 9-18. (canceled) 19. The process of claim 1, wherein the process is carried out in an organic solvent. 20. The process of claim 19, wherein said organic solvent comprises an aprotic solvent. 21. The process of claim 20, wherein the aprotic solvent has a boiling point ranging from about 35° C. to about 230° C. 22. The process of claim 21, wherein said aprotic solvent is selected from the group consisting of DMSO, DMF, acetonitrile, nitromethane, HMPA, acetone, acetic anhydride, pyridine, o-dichlorobenzene, chlorobenzene, benzene, toluene, xylene, methylene chloride, carbon tetrachloride, THF, dioxane, ethyl acetate, DME, and carbon disulfide. 23. The process of claim 22, wherein the aprotic solvent comprises emethylene chloride. 24. The process of claim 1, wherein said process is carried out at temperatures ranging from about 20° C. to about 30° C. under stoichiometric conditions. 25. The process of claim 24, wherein said process is carried out at room temperature. 26. A bis-activated polyethylene glycol having the formula: Y-Q-O—(CH2—CH2—O)n-Q-Y wherein n is an integer greater than 4: Y is a leaving group; Q has the formula: Q=(U0)n0-[(Q0)n1(CHR1)n2-(Q1)n3]p-[(R2C═CR3)n4-(Q2)n5]m-[(CHR4)n6-(Q3)n7]q-(U1)n8 wherein Q0, Q1, Q2, and Q3 independently are O or S R1, R2, R3, and R4 are independently are selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; n0, n1, n3, n4, n5, n7, and n8 independently are 0 or 1; n2 and n6 independently are 0, 1, 2, or 3; U0 and U1 are independently selected from the group consisting of C(O); SO2, and P(O); p and q independently are 0, 1, 2, 3, 4, 5, or 6; m is 0, 1, or 2, wherein 0≦p+m≦8. 27. The bis-activated polyethylene glycol of claim 26, wherein Q is selected from the group consisting of SO2, CO(CHR1)tSO2, C(O), SO2(CHR1)tSO2, SO2—O—(CHR1)t—O—SO2, P(O), CO—O—(CHR1)t—CR2═CR3—(CHR4)t—O—CO, and SO2—O—(CHR1)t—CR2═CR3—(CHR4)t—O—SO2, wherein t is 1, 2, or 3; and R1, R2, R3 and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group. 28-36. (canceled) 37. The process of claim 1, wherein X and Y are independently selected from the group consisting of a halide group, a mesyl group, a tosyl group, a phenoxyl group, and a substituted phenoxyl group. 38. The process of claim 37, wherein the substituted phenoxyl group is a nitro-phenoxyl group. 39. A process for preparing a bis-activated polyethylene glycol having the formula: Y-Q-O—(CH2—CH2—O)n-Q-Y wherein n is an integer greater than 4; Y is a leaving group; Q has the formula: Q=(U0)n0-[(Q0)n1(CHR1)n2-(Q1)n3]p-[(R2C═CR3)n4-(Q2)n5]m-[(CHR4)n6-(Q3)n7]q-(U1)n8 wherein Q0, Q1, Q2, and Q3 independently are O or S; R1, R2, R3, and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; n0, n1, n3, n4, n5, n7, and n8 independently are 0 or 1; n2 and n6 independently are 0, 1, 2, or 3; U0 and U1 are independently selected from the group consisting of C(O), SO2, and P(O); p and q independently are 0, 1, 2, 3, 4, 5, or 6; and m is 0, 1, or 2; wherein 0≦p+m≦8; the method comprising the steps of: (i) providing a polyethylene glycol derivative having the formula: M-(OCH2—CH2)n—O-M wherein n is an integer greater than 4; and M is selected from the group consisting of Li, Na, K, Rb, and Cs; and (ii) reacting the polyethylene glycol derivative with an activator having the formula of Y-Q-X; wherein X and Y independently are a leaving group; and Q has the formula: Q=(U0)n0-[(Q0)n1(CHR1)n2-(Q1)n3]p-[(R2C═CR3)n4-(Q2)n5]m-[(CHR4)n6-(Q3)n7]q-(U1)n8 wherein Q0, Q1, Q2, and Q3 independently are O or S; R1, R2, R3, and R4 are independently selected from the group consisting of H, a lower alkyl group, a lower branched alkyl group, an aryl group, and an aralkyl group; n0, n1, n3, n4, n5, n7, and n8 independently are 0 or 1; n2 and n6 independently are 0, 1, 2, or 3; U0 and U1 are independently selected from the group consisting of C(O); SO2, and P(O); p and q independently are 0, 1, 2, 3, 4, 5, or 6; and m is 0, 1, or 2, wherein 0≦p+m≦8; to produce said bis-activated polyethylene glycol. 40. The process of claim 37, wherein X and Y are independently selected from the group consisting of a halide group, a mesyl group, a tosyl group, a phenoxyl group, and a substituted phenoxyl group. 41. The process of claim 37, wherein the substituted phenoxyl group is a nitro-phenoxyl group. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Polyethylene glycol (PEG) is a polymer having the structure H(O—CH 2 CH 2 —) n OH. It is generally synthesized by the ring opening polymerization of ethylene oxide. While the polymer usually has a linear structure at molecular weights ≦10 kD, the higher molecular weight PEGs may have some degree of branching. 1 Polyethylene glycols of different molecular weights have previously been used in a number of applications, including to increase the solubility of drugs. During the last three decades, polyethylene glycol has been extensively investigated for delivery of various proteins via parenteral routes. Generally, PEGs have been most widely used for the delivery of both traditional drugs (small molecules) and proteins/enzymes in the treatment of cancer. Several chemical procedures have been developed for the preparation of activated PEGs, which can then be used to react specifically with free amino groups on an enzyme's surface, under mild aqueous conditions. PEGs have been successfully activated by reaction with 1,1-carbonyl-di-imidazole, cyanuric chloride, tresyl chloride, 2,4,5-trichlorophenyl chloroformate or 4-nitrophenyl chloroformate, various N-hydroxy-succinimide derivatives as well as by the Moffatt-Swern reaction. 2-10 In most cases, the activating agent acts as a linker between the PEG and the enzyme or protein. One of the major disadvantages encountered with the processes currently available involves the reaction temperatures at which the activation reactions are carried out. The most commonly used solvents are acetonitrile (CH 3 CN) and dichloromethane (CH 2 Cl 2 ), containing small volumes of a co-solvent, usually triethylamine (TEA). Usually, the activation reactions are carried out under refluxing conditions at a temperature of about 84° C. when acetonitrile is used, or at a temperature of about 40° C. when dichloromethane is chosen as the solvent. Several crystallization steps are commonly required for the isolation and purification of the activated PEG product. Such steps can make currently available processes for the activation of PEGs inconvenient. The activation of PEGs with 4-nitrophenyl chloroformate, to generate PEG-di-nitrophenyl carbonates, has been described by Fortier and Laliberte. 10 The reactions were carried out in acetonitrile containing triethylamine (TEA) over a period of 5 hours at 60° C. The long reaction times and the reaction temperatures required to perform the activation reactions are major disadvantages of this process. Additionally, in order to keep the system as anhydrous as possible, the use of a cumbersome soxhlet is required. This imparts a severe limitation on the activation process, especially when transposed on a larger scale. There is thus a need for a low-cost process for the activation of PEGs that is time efficient and that can be performed at room temperature. There is also a need for a process allowing for the rapid isolation and purification of the activated PEGs. Moreover, there is a need for a process for PEG activation that is amenable to large-scale production. The present invention seeks to meet these and other needs. |
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to a novel process for the activation of PEGs that is characterized by improved reaction efficiency and improved reaction conditions. The present invention relates to a novel process for the activation of PEGs that is characterized by the use of stoichiometric amounts of reagents and that provides a very high degree of activation. The present invention also relates to a novel process for the activation of PEGs that is further characterized by low manufacturing costs and that is easily amenable to large scale production. In addition, the present invention relates to a novel process for the isolation and purification of the produced activated PEGs, characterized by an efficient extraction and precipitation procedure. According to one aspect of the present invention, there is provided a process for preparing activated polyethylene glycols (PEGs), comprising reacting polyethylene glycol (PEG) with an activator in the presence of an aromatic nitrogen-containing heterocyclic base, wherein the activator has the general structure Y-Q-X and may be selected from, but is not limited to, the group consisting of ClSO 2 Cl, ClCOCH 2 SO 2 Cl, 4-O 2 NPhOCOCl, 2-O 2 NPhOCOCl, PhOCOCl, ClSO 2 CH 2 CH 2 SO 2 Cl, POCl 3 , PhOPOCl 2 , PhPOCl 2 , CCl 3 COCl, CBr 3 COCl, and X b PhOCOCl wherein X and Y may be identical or different and represent an electron withdrawing group, and wherein “b” is an integer ranging from 1 to 3. Unless defined otherwise, the scientific arid technological terms and nomenclature used herein have the same meaning as commonly understood by a person of ordinary skill. Generally, procedures such as extraction, precipitation and recrystallization are common methods used in the art. Such standard techniques can be found in reference manuals such as for example Gordon and Ford (The Chemist's Companion: A handbook of Practical Data, Techniques and References, John Wiley & Sons, New York, N.Y., 1972). The present description refers to a number or routinely used chemical terms. Nevertheless, definitions of selected terms are provided for clarity and consistency. As used herein, the expression “aprotic solvent”, refers to a solvent that does not possess an acidic proton. As used herein, the expression “electron withdrawing group”, refers to a substituent on an aromatic ring that withdraws electrons from the aromatic ring by inductive effects and/or by resonance effects. As used herein, the term “about” refers to a ±5% variation from the nominal value. As used herein, the formula PEG(NPC) 2 , refers to a polyethyleneglycol, bis activated with a 4-Nitro-Phenyl Carbonate group. Further scope of applicability will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications will become apparent to those skilled in the art. |
Method and a device for evaluating the integrity of a control substance in a nuclear plant |
The invention refers to a method and a device for evaluating the integrity of a control rod material in a nuclear plant. The plant includes a reactor vessel (1), a reactor core (2) that is enclosed in the reactor vessel and formed by a number of nuclear fuel elements (3) and a number of cladding members (4), in which said control material is enclosed, and a circuit (6) that permits a flowing of a fluid through the reactor core and through an external conduit arrangement In order to estimate the integrity of the control material, the value of at least one primary parameter that includes the concentration of a substance, which is released from the control rod material during the operation of the nuclear plant, is determined (21, 23, 28) in said fluid. Furthermore, the value of at least one operational parameter related to said fluid is determined (30, 33, 34, 36). The value of said primary parameter is standardised with respect to the value of said operational parameter, and the standardised value of said primary parameter is analysed of said estimation of the integrity of the control rod material. |
1. A method for evaluating the integrity of a control rod material in a nuclear plant, the nuclear plant including a reactor vessel, a reactor core enclosed in the reactor vessel and having a number of nuclear fuel elements and a number of cladding members, in which said control rod material is enclosed and which are movable into and retractable from the reactor core, and a circuit adapted to permit fluid flow through the reactor core and through an external conduit arrangement, the method including the steps of: determining the value of at least one primary parameter that includes the concentration of a substance, which is released from the control rod material during the operation of the nuclear plant, in said fluid, wherein said primary parameter includes a first primary parameter, which includes the concentration of tritium in said fluid, a second primary parameter, which includes the concentration of helium in a gas flow discharged from said fluid, determining the value of at least one operational parameter related to said fluid, standardizing the value of said primary parameter with respect to the value of said operational parameter, analyzing the standardized value of said primary parameter, and estimating the integrity of the control rod material on the basis of said analysis. 2. A method according to claim 1, wherein said fluid includes feed water supplied to the reactor vessel and wherein said step of determining the value of at least one primary parameter includes measuring on the feed water. 3. A method according to claim 1, wherein said fluid includes reactor water present in the reactor vessel and wherein said determining the value of at least one primary parameter takes place by measuring on the reactor water. 4. A method according to claim 2, wherein said measuring takes place after the fluid has passed an ion exchanger. 5. A method according to claim 2, wherein said measuring takes place after the fluid has passed a particle filter. 6. A method according to any one of claims 2 to 5, wherein 15 said measuring takes place after the fluid has passed a delay circuit. 7. A method according to claim 1, including the step of determining a reference value for said primary parameter. 8. A method according to claim 1, further including the step of determining guide lines for the continuing operation of the plant with respect to said estimation. 9. A method according to claim 1, further including the step of determining guide lines for inspection and removing of defect control rods from the reactor core during a future shutdown of the plant. 10. A method according to claim 8, further including the step of controlling the plant with respect to said guide lines. 11. A method according to claim 1, wherein the step of determining of the value of said primary parameter is performed substantially continuously during the operation of the plant. 12. A method according to claim 1, wherein said operational parameter includes a first operational parameter related to an addition of said fluid to the circuit. 13. A method according to claim 12, wherein the plant is supplied with diluting feed water and wherein the method includes the further step of determining the supply of tritium via the diluting feed 4 water by measuring on the diluting feed water. 14. A method according to claim 13, wherein said determining of the tritium supply includes measuring the volume and the flow of diluting feed water. 15. A method according to claim 1, wherein said operational parameter includes a second operational parameter related to the effect generated by the plant. 16. A method according to claim 1, wherein said operational parameter includes a third operational parameter related to said gas flow. 17. A method according to claim 1, wherein said analysis is performed with respect to historical data regarding said parameters. 18. A method according to claim 17, wherein if the said analysis indicates a defect control rod the extension of the defect is calculated by means of a comparison of the leakage of tritium and helium from the defect control rod with the inventory of tritium and helium. 19. A method according to claim 17, wherein said historical data are loaded from a memory unit in which they are stored. 20. A device for evaluating the integrity of a control rod material in a nuclear plant, the plant including a reactor vessel, a reactor core enclosed in the reactor vessel and having a number of nuclear fuel elements and a number of cladding members, in which said control rod material is enclosed and which are movable into and retractable from the reactor core, and a circuit disposed to permit fluid flow through the reactor core and through an external conduit arrangement, comprising: first means for determining the value of at least one primary parameter that includes the concentration of a substance, which is released from the control rod material during the operation of the nuclear plant, in said fluid, wherein said first means includes a measuring device, which is arranged to measure the concentration of tritium in said fluid, and a measuring device, which is arranged to measure the concentration of helium in a gas flow discharged from said fluid, second means for determining the value at least one operational parameter related to said fluid, third means for standardizing the value of said primary parameter with respect to the value of said operational parameter, fourth means for analyzing the standardized value of said primary parameter, and fifth means for estimating the integrity of the control rod material on the basis of said analysis. 21. A device according to claim 20, wherein said second means includes a measuring device which is arranged to measure said gas flow. 22. A method according to claim 20, wherein said second means includes a measuring device, which is arranged toe measure an addition of said fluid to the circuit, and a measuring device, which is arranged to measure the concentration of tritium in said added fluid. 23. A device according to claim 20, wherein said second means includes a measuring device, which is arranged to measure the effect generated by the plant. 24. A device according to claim 20, further comprising a processing unit arranged to determine guide lines for the continuing operation of the plant with respect to said estimation. 25. A device according to claim 24, further comprising a control unit for controlling the plant with respect to said guide lines. 26. A device according to claim 20, further comprising a memory unit for storing historical data regarding said parameters. |
<SOH> THE BACKGROUND OF THE INVENTION AND PRIOR ART <EOH>The present invention refers to a method for evaluating the integrity of a control rod material in a nuclear plant, which includes a reactor vessel, a reactor core that is enclosed in the reactor vessel and is formed by a number of nuclear fuel elements and a number of cladding members, in which said control material is enclosed and which are introduceable into and retractable from the reactor core, and a circuit that is arranged to permit a flowing of a fluid through the reactor core and through an external conduit arrangement. The invention also refers to a device for evaluating the integrity of a control rod material in a nuclear plant, which the plant includes a reactor vessel, a reactor core that is enclosed in the reactor vessel and is formed by a number of nuclear fuel elements and a number of cladding members, in which said control material is enclosed and which are introduceable into and retractable from the reactor core, and a circuit that is arranged to permit a flowing of a fluid through the reactor core and through an external conduit arrangement. It is well known in such nuclear plants to use boron carbide as control material in so called control rods. Each control rod forms one or several pressure vessels housing a determined quantity of boron carbide. A known control rod is designed with four longitudinal wings, which form a cross seen in a cross-section through the control rod. Each wing includes a cavity and thus forms such a separate pressure vessel. The control rods are introducable into and retractable out of the reactor core in order to control the nuclear reaction in the nuclear fuel, and in such a manner control the effect of the plant. The boron carbide has an ability to absorb neutrons, wherein the nuclear reaction will be reduced when a control rod is introduced into the reactor core since the number of free neutrons decreases. One may differentiate between control rods for controlling the nuclear reaction during operation and shutdown rods. The latter are, during operation of the nuclear plant, completely retracted from the reactor core and merely intended to be introduced into the core when the operation of the plant is to be interrupted. It is to be noted, that it is also possible to use shutdown rods as control rods and vice versa. During operation of the plant neutrons, which are captured by the boron carbide as mentioned above, are released. A nuclear reaction will then take place in the boron carbide, wherein tritium and helium are formed. The active boron (B—10-isotopes) are consumed during the formation of the reaction products. A substantially larger amount of helium, approximately by a factor 10 5 , then tritium is formed. The tritium formed and a part of the helium will be dissolved in the boron carbide. However, the helium is also released from the boron carbide and forms a gas in the cavity mentioned above in the control rod. This gas formation leads to an increase of the pressure in the control rod. The cladding members of the control rods may be manufactured of a steel alloy. Defects may rise on the cladding members for various reasons, for instance due to mechanical wear, material defects etc. Such a defect may lead to the formation of a hole in the cladding member, through which the gaseous helium in the control rod may be pressed out into the reactor core, and through which the water present in the reactor vessel may penetrate into the control rod. If the reaction products of the spent boron comes into contact with water, the helium and the tritium dissolved in the boron carbide structure will be released and after a time period tritium may thus reach the water in the reactor vessel together with the released helium. If the defect is serious also boron will be released and one may have a so-called washing out, i.e. boron carbide is washed out of the control rod. It is of course desirable to avoid defects on the control rods and to replace control rods having a defect. A control rod defect may lead to reduced possibilities to control the plant since the neutron absorbing capability is deteriorated. Furthermore, a control rod defect may lead to a deformation of the cladding member, which may make the manoeuvring of the control rod into and out of the reactor core impossible. WO99/27541 discloses a device for evaluating the integrity of the fuel rods in a nuclear plant. The evaluation is made by means of continuous measurements of the activity in the off-gases and in the reactor water. |
<SOH> SUMMARY OF THE INVENTION <EOH>The object of the present invention is to reduce the need of inspection of the control rods in a nuclear plant. More specifically, it is aimed at improved the possibilities to supervise the integrity of the control rods. This object is obtained by the method initially defined, which is characterised by the steps of: determining the value of at least one primary parameter that includes the concentration of a substance, which is released from the control rod material during the operation of the nuclear plant, in said fluid, determining the value of at least one operational parameter related to said fluid, standardising the value of said primary parameter with respect to the value of said operational parameter, analysing the standardised value of said primary parameter, and estimating the integrity of the control rod material on the basis of said analysis. By means of such a method it is possible to supervise substantially continuously the control rods in a reactor vessel and to determine if there is any defects on any of the control rods. Thanks to the standardisation of the concentration of the released substance it is also possible to make an estimation of the size of the defect since this size depends on the quantity of the released substance. By observing when the concentration of the substance increases one may also determine when a defect occurs. In such a way the method also enables an estimation of how many defect control rods and control rod blades are present in the reactor core. The analysis is possible to make by measuring the concentration of many different substances, for instance tritium, helium, lithium, boron etc. The analysis may thus be performed by a supervision of any of the substances released when the control rod material comes into contact with the fluid flowing through the reactor core. However, it is important to take into consideration and to correct for the tritium recirculated to the reaction via the deluting feed water. Therefore, it is advantageous also to measure the tritium content in the deluting feed water, and the volume and flow of the deluting feed water. According to an embodiment of the invention, said primary parameter includes a first parameter, which includes the concentration of tritium in said fluid. Tritium is formed in the boron carbide, which may be used as control material, when the boron carbide is subjected to neutron radiation. As long as the cladding member is complete, the tritium formed will be enclosed in the cladding member. However, if a defect arises on the cladding member, the tritium will reach the reactor water and by a measurement of the tritium concentration in the reactor water, a defect on the cladding member for the control material will thus be established. According to a further embodiment of the invention, said primary parameter includes a first primary parameter, which includes the concentration of tritium in said fluid. It is to be noted that the fuel rods produce substantially smaller quantities of tritium when they are subjected to neutron radiation than the control material enclosed in the cladding member. According to a further embodiment of the invention, said fluid includes the feed water supplied to the reactor vessel, wherein said determining takes place by measuring on the feed water. By such a measuring of the tritium concentration in the feed water a proper result is achieved since the water then has been distilled one time. According to an alternative or supplementary embodiment of the invention, said fluid includes the reactor water present in the reactor vessel, wherein said determining takes place by measuring on the reactor water. Advantageously, said measuring may take place after the fluid has passed an ion exchanger. Furthermore, said measuring may take place after the fluid has passed a particle filter. It is also advantageously to make said measuring after the fluid has passed a delay circuit. According to a further embodiment of the invention, said primary parameter includes a second primary parameter, which includes the concentration of helium in the gas flow discharge from said fluid. When the control material, in the form of boron carbide, is subjected to neutron radiation, also helium is produced. Helium will then be bound in the boron carbide but may also be present in the cladding member as a free gas. When a defect arises this free gas will very quick be pressed out of the cladding member, and thus there arises a substantially instantaneous peak level for the helium concentration in said gas flow. The helium, which is bound in the control material, will thereafter at a more slow speed be released and result in an increased helium level in the off-gases. Also a defect fuel rod may give rise to the release of helium. In the nuclear fuel, there is however not as large quantities of helium bound and therefore no slow release of helium arises after the initial peak level. In such a way it is possible to differentiate a defect cladding member for the control material from a fuel defect. When a fuel defect occurs also radioactive inert gases are released. By simultaneously measuring these, for instance by the device described in WO99/27541, defects on the fuel rods may be separated from the defects on the control rods. By determining both the concentration of tritium in said fluid and the concentration of helium in the gas flow, a very reliable instrument for detecting a defect on a cladding member for a control material is achieved. According to a further embodiment of the invention, the method includes the step of determining a reference value for said primary parameter. As mentioned above, tritium is also produced by the fuel when it is subjected to neutron radiation. Further tritium production in a reactor is obtained due to reactions in the reactor water and from the lithium which may be present in a reactor vessel in the form of contaminations. Furthermore, tritium may during a relatively long time period be present in the fluid or reactor water since previous defects that are already detected and determined on the cladding members for the control material. Thus there is during normal operational conditions always a certain content of tritium in the fluid. It is therefore advantageous to determine, by measurements, this content and to let it form a reference value from which the determinations mentioned above may be performed. Such a reference value may advantageously also be determined for other substances, for instance helium. According to a further embodiment of the invention, the method includes the following step of determining guide lines for the continuing operation of the plant with respect to said estimation. By the determinations made one may thus determine the size of a detected defect, on which cladding member the defect has occurred etc. Such a knowledge is important for determining if the plant is to be further operated or if the operation is to be interrupted. The knowledge may also lead to continuing operation of the plant in a modified manner, for instance at a lower effect in the part of the reactor core where the defect has occurred. According to the invention, such guide lines may be produced in an automatic manner from the estimation made. According to a further embodiment of the invention, the method includes the following step of controlling the plant with respect to said guide lines. It is thus possible to transfer the produced guide lines to a control unit for in such a way automatically controlling the plant in accordance with these guide lines. According to a further embodiment of the invention, the determining of the value of said primary parameter is performed substantially continuously during the operation of the plant. The concentration of helium in said gas flow may by methods known per se be measured continuously. By such a substantially continuous measurement it is also possible to study the helium concentrations over the time and in such a way the peak levels mentioned above may be detected in an efficient manner. Also the tritium concentration may be subjected to a substantially continuous on-line measurement, which advantageously is measured on the feed water, wherein a part of the fluid flow is discharged to a measuring device for the establishment of the tritium concentration. From this measuring device, this part flow may be recirculated to a main flow for the fluid. According to a further embodiment of the invention, said operational parameter includes a first operational parameter related to an addition of said fluid to the circuit. The exchange of the fluid of course plays an important role for the size of the concentration of the substance in question. If the exchange is high, one obtains a value of the concentration which is smaller than if the exchange would have been small. The plant normally is supplied with deluting feed water and thus, the method may include the further step of determining the supply of tritium via the deluting feed water by measuring on the deluting feed water. Advantageously, said determining of the tritium supply includes a measuring of the volume and the flow of deluting feed water. According to a further embodiment of the invention, said operational parameter includes a second operational parameter related to the effect generated by the plant. The effect generation is also substantial for the concentration of for instance tritium and helium, both instantaneously and historically. According to a further embodiment of the invention, said operational parameter includes a third operational parameter related to said gas flow. For the determining of for instance the concentration of helium in the gas flow, it is advantageous to consider the size of the total gas flow. According to a further embodiment of the invention, said analysis is performed with respect to historical data regarding said parameter. As mentioned above, for instance the effect by which the plant has been operated during a longer period of time will influence the concentration of the measured substances. Such historical data may be loaded, from a memory unit in which these are stored. The memory unit includes operational statistics and defect risks according to the operational experiences that has been accumulated, and calculated inventory of helium and tritium in the control rods. If a defect has been indicated, an order of priority is established for inspection during the future, normally yearly operation shutdown. The order of priority is based on the follow up of operational parameters, and the operation history and operation experiences of the control rods. In the memory unit, there may also be information about each individual cladding member for control material. Such information may refer to the age of the cladding member, type, manufacturer, estimated burn out of B-10 for each control rod, and accumulated operation history of each control rod etc. In the memory unit a knowledge about the cladding members which are present in the rector vessel may thus be built up and in such a way the analysis may be developed with the time and become even more sophisticated. The object is also obtained by the device initially defined, which is characterised in that the device includes first means for determining the value of at least one primary parameter that includes the concentration of a substance, which is released from the control rod material during the operation of the nuclear plant, in said fluid, second means for determining the value of at least one operational parameter related to said fluid, third means for standardising the value of said primary parameter with respect to the value of said operational parameter, fourth means for analysing the standardised value of said primary parameter, and fifth means for estimating the integrity of the control rod material on the basis of said analysis. Advantageous embodiments of the device are defined in the dependent claims 23 - 30 . |
Method of gas carburizing |
A method of gas carburizing is carried out at a carburizing temperature which is not higher than a peritectic point temperature at which δ iron and liquid phase are transformed into γ iron and not less than a eutectic point temperature at which liquid phase is transformed into γ iron and cementite. The method comprises the step of predetermining the limiting carburizing conditions at which the surface layer of a sample of a steel treatment object present in a carburizing atmosphere is austenitized without melting and the step of gas carburizing the treatment object under carburizing conditions which are set so as not to contradict the limiting carburizing conditions, at a carburizing temperature which is not higher than the peritectic point temperature and not less than the eutectic point temperature. The limiting carburizing conditions comprise an upper limit value of a partial pressure of carburizing gas at which the surface layer of the sample is austenitized without melting. |
1. A method of gas carburizing comprising the steps of: predetermining limiting carburizing conditions at which the surface layer of a sample of a steel treatment object present in a carburizing atmosphere is austenitized without melting at a carburizing temperature which is not higher than a peritectic point temperature at which δ iron and liquid phase are transformed into γ iron and not less than a eutectic point temperature at which liquid phase is transformed into γ iron and cementite; and gas carburizing the treatment object under carburizing conditions which are set so as not to contradict the limiting carburizing conditions, at a carburizing temperature which is not higher than the peritectic point temperature and not less than the eutectic point temperature, wherein the limiting carburizing conditions comprise an upper limit value of a partial pressure of carburizing gas in the carburizing atmosphere at which the surface layer of the sample is austenitized without melting. 2. The method of gas carburizing according to claim 1, wherein the limiting carburizing conditions comprise an upper limit value of carburizing temperature and an upper limit value of carburizing time at which the surface layer of the sample is austenitized without melting, the relationship between the upper limit value of the partial pressure of carburizing gas, the upper limit value of carburizing temperature, and the upper limit value of carburizing time is predetermined, and the partial pressure of carburizing gas, carburizing temperature, and carburizing time are set as the carburizing conditions of the treatment object so as not to contradict the limiting carburizing conditions which satisfy the predetermined relationship. 3. A method of gas carburizing comprising gas carburizing a steel treatment object, wherein a carburizing temperature is set at a temperature which is not higher than a peritectic point temperature at which δ iron and liquid phase are transformed into γ iron and not less than a eutectic point temperature at which liquid phase is transformed into γ iron and cementite; a target value of carbon concentration in the surface of the treatment object is set at a value which is not higher than a value at which the surface of the treatment object is not melted at the set carburizing temperature; and a partial pressure of carburizing gas in a carburizing atmosphere is set at a value at which the carbon concentration in the surface of the treatment object can reach the set target value as a result of gas carburization carried out during a preset time. 4. The method of gas carburizing according to claim 3, wherein the treatment object is cooled without carrying out a diffusion treatment after the gas carburization has been carried out. 5. The method of gas carburizing according to claim 4, wherein the treatment object is reheated after the cooling. 6. The method of gas carburizing according to claim 5, wherein hardening of the reheated treatment object is carried out. 7. The method of gas carburizing according to any of claims 3 to 6, wherein the is set at 1200° C. or higher. 8. The method of gas carburizing according to any of claims 1 to 6, wherein said gas carburizing is carried out, while causing the carburizing atmosphere comprising the carburizing gas at a constant partial pressure to flow. |
<SOH> BACKGROUND ART <EOH>When gas carburizing of steel treatment objects is carried out, the carburizing treatment time can be shortened by raising the carburizing temperature. However, if the carburizing temperature becomes too high, the treatment object melts down. For this reason, the carburizing temperature that has been conventionally used in practice was less than the eutectic point temperature (in the case of an iron-carbon equilibrium diagram shown in FIG. 1 , it is the C point temperature which is 1147° C.) at which the liquid phase is transformed into γ iron and cementite, and usually was not higher than 1050° C. In order to shorten the carburizing treatment time at the conventional carburizing temperature, the carburizing treatment was carried out till the concentration of carbon in the surface layer of the treatment object became higher than the final target value, and then diffusion treatment which caused the carbon in the surface layer of the treatment object to diffuse was carried out in a high-temperature atmosphere with a carbon concentration less than that of the carburizing atmosphere, thereby decreasing the carbon concentration in the surface layer to the final target value (Japanese Examined Patent Publication No. 1994-45868). However, when the carburizing temperature is limited to a temperature less than the eutectic point temperature, the diffusion rate of carbon atoms in the treatment object is restricted. Therefore, the carburizing time cannot be shortened significantly. Thus, the problem is that the diffusion treatment requires a long time, thereby reducing productivity. It is an object of the present invention to provide a method of gas carburizing capable of resolving the aforesaid conventional problems. |
<SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>FIG. 1 is an iron-carbon equilibrium diagram. FIG. 2 illustrates the state of heating a sample of the treatment object by the gas carburizing apparatus in an embodiment of the present invention. FIG. 3 illustrates an example of relationship between the upper limit value of partial pressure of carburizing gas, different carburizing temperatures and carburizing times. FIG. 4 illustrates the state of heating a treatment object with the gas carburizing apparatus in an embodiment of the present invention. FIG. 5 illustrates the relationship between the carburizing treatment time till the surface of the treatment object starts melting at a carburizing temperature of 1573 K, partial pressure of carburizing gas, and concentration of carbon in the surface. FIG. 6 illustrates the relationship between the carburizing treatment time till the surface of the treatment object starts melting at a carburizing temperature of 1623 K, partial pressure of carburizing gas, and concentration of carbon in the surface. FIG. 7 shows the relationship between the hardness and the distance (depth) from the surface of the treatment object carburized with a carburizing time of 1 min at a carburizing temperature of 1250° C. in an example of the present invention. FIG. 8 shows the relationship between the hardness and the distance (depth) from the surface of the treatment object carburized with a carburizing time of 1 min at a carburizing temperature of 1300° C. in an example of the present invention. FIG. 9 shows the relationship between the hardness and the distance (depth) from the surface of the treatment object carburized with a carburizing time of 10 min at a carburizing temperature of 1250° C. in an example of the present invention. FIG. 10 shows the relationship between the hardness and the distance (depth) from the surface of the treatment object carburized with a carburizing time of 10 min at a carburizing temperature of 1300° C. in an example of the present invention. FIG. 11 is a microphotograph as a substitution for a drawing illustrating the metallurgical structure prior to quenching in the surface layer of the gas-carburized treatment object. FIG. 12 is a microphotograph as a substitution for a drawing illustrating the metallurgical structure after quenching in the surface layer of the gas-carburized treatment object. FIG. 13 illustrates the relationship between the concentration of carbon and the distance (depth) from the surface of the treatment object obtained in an example of the present invention. FIG. 14 illustrates an example of the relationship between the carburizing time, diffusion time, and concentration of carbon in the treatment object that was treated by the conventional carburizing method. detailed-description description="Detailed Description" end="lead"? |
Mounting for disk drive unit and method of handling |
A mounting for a disk drive unit includes a carrier for carrying a disk drive unit during required movement of the disk drive unit. The carrier defines a space into which the disk drive unit can be inserted, and the carrier is adapted to be inserted with the disk drive unit into a receiving frame for operational use. At least two resilient devices are mounted on the carrier for securing the disk drive unit in the receiving frame when the carrier is inserted into the frame, at least one resilient device being mounted on each side of the carrier. Each resilient device is movably mounted on the carrier to allow movement of the device as a whole relative to the carrier and the resilient device is arranged to secure the disk drive unit in the receiving frame by acting between the disk drive unit and the receiving frame. A method of handling the disk drive unit includes placing the disk drive unit into the carrier engaging a robotic device with a coupling structure projecting from the front of the carrier. The method then includes lifting the carrier by the robotic device and inserting the carrier into a receiving frame by a substantially horizontal movement. |
1. A method of handling a disk drive unit comprising the steps of: placing a disk drive unit into a carrier for carrying the disk drive unit during required movement of the disk drive unit; engaging the carrier by engaging a robotic device with a coupling structure projecting from the front of the carrier; lifting the carrier by the robotic device and inserting the carrier into a receiving frame by a substantially horizontal movement; and releasing the robotic device from the coupling structure on the carrier. 2. A method of handling a disk drive unit according to claim 1, in which the step of placing the disk drive unit into the carrier comprises: picking up the disk drive unit by a further robotic device by gripping the unit at the sides thereof; and depositing the disk drive unit into the carrier by lowering the unit into the carrier whilst gripped at the sides and releasing the further robotic device from the sides of the unit after the unit is housed in the carrier. 3. A method according to claim 1, including retaining the disk drive unit in the frame by a retaining assembly adapted to act between a main body of the disk drive unit and the receiving frame, and actuating the retaining assembly to retain the disk drive unit in the frame by the effect of the movement of the carrier into the receiving frame. 4. A method according to claim 1, including retaining the disk drive unit in the frame by means of resilient members bearing against the sides of the disk drive unit and being resiliently biased inwardly against the disk drive unit, each resilient member being movable between a first retracted position in which the resilient member is retracted wholly or partially outside the space in the carrier for receiving the disk drive unit and a second operating position in which the resilient member is biased towards the said space in the carrier to a greater extent than in the first position; the method comprising: depositing the disk drive unit into the carrier, including moving each resilient member to the said retracted position by the effect of the movement of the disk drive unit into the carrier; and moving the carrier into the receiving frame, including moving the resilient member into the second operating position by the effect of the movement of the carrier into the receiving frame. 5. A mounting for a disk drive unit having a data storage disk, a movable disk head, and a main body supporting the disk and disk head, the mounting comprising a carrier for carrying the disk drive unit during required movement of the disk drive unit, the carrier defining a space into which the disk drive unit can be inserted, and the carrier being adapted to be inserted with the disk drive unit into a receiving frame for operational use; in which the carrier has a coupling structure projecting outwardly from a front of the carrier adapted to be engaged by a robotic device for moving the carrier into and out of the frame. 6. A mounting according to claim 5, including a latch for securing the carrier in the said frame, and a latch actuator mounted on the coupling structure and adapted to co-operate with the robotic device to release the latch automatically upon engagement of the coupling structure by the robotic device. 7. A mounting for a disk drive unit having a data storage disk, a movable disk head, and a main body supporting the disk and disk head, the mounting comprising a carrier for carrying the disk drive unit during required movement of the disk drive unit, the carrier defining a space into which the disk drive unit can be inserted, and the carrier being adapted to be inserted with the disk drive unit into a receiving frame for operational use; in which each side of the carrier has an opening exposing the side of the disk drive unit when the disk drive unit is in the carrier, the opening being shaped to allow the disk drive unit to be deposited into or lifted from the carrier by gripping the exposed sides of the disk drive unit. 8. A mounting according to claim 5 including a retaining assembly for securing the disk drive unit in a required position, the retaining assembly being mounted on the carrier and being operable to retain the disk drive unit in the receiving frame when the carrier is inserted into the frame. 9. A mounting according to claim 8, in which the retaining assembly is actuated by the effect of the movement of the carrier into the receiving frame. 10. A mounting according to claim 8, in which the retaining assembly is adapted to secure the disk drive unit in the receiving frame by acting between the disk drive unit and the receiving frame. 11. A mounting according to claim 8, in which the retaining assembly comprises resilient members arranged to retain the disk drive unit by bearing against the sides of the disk drive unit and by being resiliently biased inwardly against the disk drive unit. 12. A mounting according to claim 11, in which each resilient member is movable between a first retracted position in which the resilient member is retracted wholly or partially outside the said space in the carrier, allowing the disk drive unit to be inserted into the carrier, and a second operating position in which the resilient member extends into the said space in the carrier and bears against the disk drive unit. 13. A mounting according to claim 8, in which the retaining device includes an outwardly extending actuating surface adapted to co-operate with portions of the receiving frame, in such a way that when the carrier is located in the frame, the portions of the frame bear against the said actuating surface and push the resilient members inwardly to bear against the disk drive unit which is located in the carrier. 14. A mounting according to claim 8, in which the retaining assembly comprises four resilient members positioned with two resilient members towards the front of the carrier and two resilient members towards the rear of the carrier, relative to the direction of insertion of the carrier into the frame, each side of the carrier having an opening exposing the side of the disk drive unit when the disk drive unit is in the carrier, the opening being shaped to allow the disk drive unit to be deposited into or lifted from the carrier by gripping the exposed sides of the disk drive unit. 15. A handling assembly comprising a mounting according to claim 5, in combination with a receiving frame into which the carrier can be inserted with the disk drive unit for operational use of the disk drive unit, and a robotic device for moving the carrier into and out of the frame by engaging the robotic device with the coupling structure projecting outwardly from the front of the carrier. 16. A handling assembly according to claim 15 including a further robotic device for depositing the disk drive unit into the carrier by lowering the unit into the carrier whilst gripped at the sides and releasing the robotic device from the sides of the unit after the unit is housed in the carrier. 17. A handling assembly according to claim 15, in which the receiving frame comprises a tester rack adapted to receive a plurality of carriers with respective disk drive units for testing the disk drive units. 18. A handling assembly according to claim 15, in which the receiving frame comprises a data storage assembly adapted to receive a plurality of carriers with respective disk drive units for operational use of the disk drive units for data storage. 19. A handling assembly according to claim 15, in which the receiving frame comprises a frame of a computer adapted to receive a single carrier with its associated disk drive unit for data processing. |
Safety steering column for a motor vehicle |
The invention relates to a safety steering column for a motor vehicle, with a column tube which is arranged concentrically to a steering spindle and is fastened to the vehicle body and which, during an axial impact action, can be shortened, while absorbing energy, and at the same time cooperates with at least one energy absorption element. According to the invention, the at least one energy absorption element is a chip removal element which, in the event of a relative movement of the column tube with respect to the vehicle body, caused by the axial impact action, breaks down energy by chip removal. |
1-10. (Cancelled) 11. A safety steering column for a motor vehicle, comprising a column tube arranged concentrically to a steering spindle and operatively connected to the vehicle body to be shortenable during an axial impact while absorbing energy, and at least one energy absorption element operatively cooperating with the column tube, the at least one energy absorption element being at least one of chip removal element which, in the event of relative movement between the column tube and the vehicle body caused by the axial impact is configured to break down energy by chip removal, wherein a chip removal cross section to be worked by the at least one chip removal element is settable, with adaptation of the energy absorption during travel, as a function of at least one of current driving and driver parameters. 12. The safety steering column as claimed in claim 11, wherein setting of the chip removal cross section is effective via a change in chip removal width. 13. The steering column arrangement as claimed in claim 11, wherein the at least one chip removal element comprises two chip removal elements arranged mirror symmetrically outwardly of the column tube. 14. The steering column arrangement as claimed in claim 13, wherein setting of the chip removal cross section is effected via a change in chip removal width. 15. The steering column arrangement as claimed in claim 11, wherein the at least one chip removal element is at least one cutting plates fastenable at least one guide block. 16. The steering column arrangement as claimed in claim 15, wherein setting of the chip removal cross section is effected via a change in chip removal width. 17. The steering column arrangement as claimed in claim 16, wherein the at least one chip removal element comprises two chip removal elements arranged mirro-symmetrically outwardly of the column tube. 18. The steering column arrangement as claimed in claim 15, wherein the guide block is guided in a groove running transversely to a center axis of the column tube. 19. The steering column arrangement as claimed in claim 16, wherein the at least one guide block is moveable in the groove of the column tube such that the chip removal width is settable for the at least one cutting plate. 20. The steering column arrangement as claimed in claim 19, wherein the at least one guide block comprises plural guide blocks and movement of the guide blocks takes place via an electric motor arranged centrally between the guide blocks (. 21. The steering column arrangement as claimed in claim 20, wherein the at least one cutting plate bears against a respective chip removal rail produced as cutting material. 22. The steering column arrangement as claimed in claim 21, wherein the chip removal rail is fastened to guide rails which are fixed in relation to the motor vehicle and via which the fastening of the column tube to the vehicle body takes place. 23. The steering column arrangement as claimed in claim 21, wherein the chip removal rail has an indentation. 24. The steering column arrangement as claimed in claim 23, wherein the chip removal rail is fastened to guide rails which are fixed in relation to the motor vehicle and via which the fastening of the column tube to the vehicle body takes place. |
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a safety steering column for a motor vehicle comprising a column tube arranged concentrically to a steering spindle and operatively connected to the vehicle body to be shortenable during an axial impact while absorbing energy, and at least one energy absorption element operatively cooperating with the column tube, the at least one energy absorption element being a least one chip removal element which, in the event of relative movement between the column tube and the vehicle body caused by the axial impact is configured to break down energy by chip removal. DE 196 24 218 A1 shows a safety steering column with a column tube which is arranged concentrically to a steering spindle and is fastened to the vehicle body and which, during an axial impact action, can be shortened, while absorbing energy. At the same time, the column tube cooperates with at least one energy absorption element which in this case is designed as a corrugated tube. WO 98/58831 describes a safety steering column with an associated energy absorption device, the energy absorption device being designed in the form of a chip removal element. In this case, a retainer of the column tube is mounted displaceably on a holder fixed to the body. Furthermore, a tubular body with grooves of different depths and also a cutting device are provided on this holder. In the event of a displacement of the retainer in relation to the holder, the cutting device is drawn into a groove of the tubular body via a pull element, while at the same time performing cutting work, and thus absorbs the impact energy of an occupant. The absorption capacity of the device is adapted by way of a controlled selection of a groove having an appropriate depth. WO 01/03991 shows a safety steering column, in which chip removal elements are activated according to the load situation and which likewise absorb energy by the performance of cutting work. |
<SOH> SUMMARY OF THE INVENTION <EOH>Against this background, an object of the invention is to provide a safety steering column which indicates an optimized possibility for energy absorption when the safety steering column is pushed together during an axial impaction action. According to the invention, one or more chip removal elements are used as energy absorption elements between the column tube mounting fixed with respect to the vehicle and the column tube itself. In contrast to the prior art, the chip removal elements do not bring about energy absorption by overcoming pressing-in forces, but, instead, by forming work during chip removal. When, in the event of a frontal impact, an axial force acts on the safety steering column, the latter is pushed together in the axial direction as a result of the relative movement of the column tube with respect to its mounting which is fixed in relation to the vehicle. Owing to this relative movement, the chip removal elements work according to material arranged for them, so that energy is thus broken down when the safety steering column is pushed together. As also occurs in the prior art, the chip removal elements may be adapted individually to the conditions of the respective safety steering column during assembly, for example by a selection of the size of the chip removal elements or the arrangement of these with respect to the chip removal cross section to be worked, so that the safety steering column can be designed optimally. It is particularly advantageous to fasten the chip removal elements to the column tube or to the mounting fixed in relation to the vehicle, in such a way that it is possible to adapt the energy absorption, during travel, as a function of the current driving and/or driver parameters. Thus, for example, the weight of the driver can be determined by a suitable sensor technology and the chip removal elements can be set in such a way that, in the case of heavy drivers, a larger chip removal cross section is worked, that is to say more energy is also absorbed. Moreover, the vehicle speed, which is known in any case, can be utilized for regulating the energy absorption. It is also contemplated to design the control as a function of other parameters which characterize the situation of the driver and of the vehicle, such as, for example, which sitting position the driver assumes, whether he is strapped in, what distance he is at from the steering wheel or which relative speed the vehicle has with respect to an obstacle, etc. In one embodiment, the setting of the chip removal cross section worked by the chip removal elements can take place via regulation of the chip removal width. Of course, the chip removal cross section may also be varied via regulation of the chip removal depth, in that, for example, the inclination of the chip removal elements with respect to the material to be cut is made adjustable. In order to set the chip removal width, two chip removal elements may be arranged mirror-symmetrically in each case on the outsides of the column tube and are mounted so as to be displaceable transversely to the axial extent of the column tube via a suitable drive means. In order to make displacement possible, cutting plates, which are fastened in each case to a guide block, may be provided as chip removal elements. The cutting plates should be fastened to the guide block in such a way that, during the action of the axial impact force, they are not tilted out of place on the material to be worked. The guide blocks may be guided in a groove running transversely to the axial extent of the column tube, thereby affording a simple and cost-effective possibility for setting the chip removal width. Insofar as the chip removal cross section is to be regulated via the chip removal depth, the guide blocks must be oriented differently. In order to adapt the energy absorption capacity of the safety steering column to the respective driving or driver parameters during travel, the guide blocks are moveable in the groove of the column tube. Adaptation to the respective driving or driver situation may take place at intervals, that is to say not every brief change in the detected measurement values results in a regulation of the chip removal cross section. An electric motor arranged between the guide blocks can receive a control pulse according to the measured driving or driver parameters and reduce or increase the distance between the guide blocks, for example via threaded rods, the chip removal width thereby being varied simultaneously, and can thus vary the energy absorption capacity of the safety steering column. The material to be worked by the cutting plates may be made available as a chip removal rail to the cutting plates. The advantage of this is that the material, for example aluminum, of the chip removal rail is freely selectable and independent of the materials of the safety steering column. Of course, all other materials suitable for chip removal may also be used. Depending on structural conditions, the chip removal rail may be fastened, fixedly in relation to the vehicle, to guide rails on which the column tube is mounted fixedly in relation to the vehicle. The necessary relative movement between the column tube and the mounting fixed in relation to the vehicle can thus be achieved in a simple way. In order, during the action of the axial impact, to prevent an impact on the mutual cutting means, that is to say a blockage of or damage to the mutual cutting means, the chip removal rail may be provided with an indentation. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. |
Nucleic acids having expression differentails between hepatoblastoma and normal liver |
A nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing and a protein encoded by the nucleic acid, particularly a nucleic acid displaying differential expression levels in hepatoblastoma and normal liver based on comparison therebetween and a protein encoded by the nucleic acid as well as tumor detection utilizing the foregoing. |
1. A nucleic acid having differential expression levels in hepatoblastoma and normal liver based on comparison therebetween, the nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:79 in the Sequence Listing. 2. A nucleic acid comprising a portion of any one of base sequences set forth in SEQ ID NO:1 to NO:79 in the Sequence Listing. 3. An isolated nucleic acid capable of hybridizing to the nucleic acid according to claim 1 or 2, or a complementary nucleic acid thereof under stringent conditions. 4. A probe for tumor detection comprising a nucleic acid, the nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing. 5. A probe for tumor detection comprising a nucleic acid, the nucleic acid comprising a portion of any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing. 6. A probe for tumor detection comprising an nucleic acid capable of hybridizing to the nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing a fragment thereof, or a complementary nucleic acid thereof under stringent conditions. 7. The probe for tumor detection according to any one of claims 4-6, wherein the tumor is selected from the group of consisting of liver cancer, colorectal cancer, breast cancer, kidney cancer, gastric cancer, ovarian cancer and thyroid cancer. 8. The probe for tumor detection according to claim 7, wherein the tumor is hepatoblastoma. 9. A PCR primer for tumor detection capable of amplifying a nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing. 10. The PCR primer for tumor detection according to claim 9, wherein the tumor is selected from the group of consisting of liver cancer, colorectal cancer, breast cancer, kidney cancer, gastric cancer, ovarian cancer and thyroid cancer. 11. The PCR primer for tumor detection according to claim 10 wherein the tumor is hepatoblastoma. 12. A marker protein for tumor detection, the protein capable of being encoded by a nucleic acid comprising any one of base sequences set forth in SEQ ID NO:1 to NO:104 in the Sequence Listing. 13. The marker protein for tumor detection according to claim 12, wherein the tumor is selected from the group of consisting of liver cancer, colorectal cancer, breast cancer, kidney cancer, gastric cancer, ovarian cancer and thyroid cancer. 14. The marker protein for tumor detection according to claim 13, wherein the tumor is hepatoblastoma. 15. A diagnostic agent for tumor detection containing at least one nucleic acid comprising a portion or the whole of any one of bases sequence set forth in SEQ ID NO:1 to SEQ ID NO:104 in the Sequence Listing. |
<SOH> BACKGROUND ART <EOH>Individual tumors exhibit distinct characteristic natures, and their biological properties are not necessarily identical even though the basic principle of oncogenesis is the same. Rapid advances in the understanding of cancer from a molecular biological and molecular genetic perspective in recent years have opened the way to an explanation of oncogenesis and tumor cell biology on the genetic level. Hepatoblastoma is a malignant hepatoma occurring in infants with the highest frequency and 70% of the infants develop it before they reach two years of age. The infants who have been afflicted with hepatoblastoma generally experience a systemic decline in health and exhibit a large mass in the right upper abdomen. In hepatoblastoma if its detection is at an early stage, there will be some hope of long-term survival through chemotherapy and surgical operation. When the detection is late, complete cure will be difficult; therefore, early detection is desired. AFP (alpha-fetoprotein) in blood is the only hepatoblastoma marker in the diagnosis of hepatoblastoma that has been known to date. Hepatoblastoma has thus been diagnosed by detection or quantification of AFP. However, it is known that the blood concentration of AFP rises not only in hepatoblastoma but also in hepatoma. There is also a drawback that its specificity is low and its values have sometimes been elevated in diseases other than hepatoblastoma or hepatoma (such as liver cirrhosis). Accordingly, AFP is insufficient for the use as a tumor marker specific for hepatoblastoma. A problem has existed that there is no other way but the ultimate collection of part of the carcinoma tissue followed by its pathological and histological diagnosis. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a figure corresponding to an electrophoregram showing an example of the results from differential screening by RT-PCR. FIG. 2 is a figure corresponding to an electrophoregram showing another example of the results from differential screening by RT-PCR. FIG. 3 is a figure corresponding to an electrophoregram showing a still further example of the results from differential screening by RT-PCR. FIG. 4 is a figure corresponding to an electrophoregram showing an example of Plk-1 gene resulting from differential screening by RT-PCR. FIG. 5 is a figure of Northern blotting in which the expression of Plk-1 was examined in a hepatoblastoma tissue and a normal liver tissue. FIG. 6 is a Kaplan-Meier curve plot showing the survival rates of hepatoblastoma patients. detailed-description description="Detailed Description" end="lead"? |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.