To facilitate recycling and prevent rotation of constituent parts, a lip type seal has a first lip seal member constructed from a rubber-like elastic material, a metal-made retaining ring held at the first lip seal member without bonding, and a resin-made second lip seal member and a backup ring which are held at the retaining ring by caulking. The first lip seal member has a tubular portion, a radial portion, a seal lip, and a collar portion. The retaining ring has a cylinder portion, a first flange portion, and a second flange portion, and the second lip seal member and the backup ring are held between the first and second flange portions by caulking. A convex portion is provided at a position in the circumferential direction of the first flange portion, and the convex portion engages with the second lip seal member to prevent rotation of the second lip seal member.

1. Field of the Invention
The present invention relates to a lip type seal corresponding to one kind of a sealing apparatus. The lip type seal in accordance with the present invention is used, for example, as a water pump seal for a vehicle such as a motor vehicle or the like, or is used as the other general purpose water pump seal.
2. Description of the Conventional Art
Conventionally, as shown in FIG. 4, there has been known a lip type seal 74 which is installed to an inner periphery of a shaft hole 72 of a housing 71 and slidably comes into close contact with a peripheral surface of a shaft 73 inserted to the shaft hole 72, and the lip type seal 74 has a first seal lip 75 which is arranged at a sealed fluid side A and is made of a rubber-like elastic material, and a second seal lip 76 which is arranged at an atmospheric air side B and made of a resin (refer to patent document 1).
Since the conventional lip type seal 74 mentioned above has a plurality of seal lips 75 and 76 each of which performs a seal operation, an excellent seal effect can be achieved, however, causes a disadvantage in the following point.
In particular, on the basis of necessity for recycle against an environmental problem in recent years, it is required to dispose of each of constructing parts of the lip type seal after being sorted by material, however, in the lip type seal 74 mentioned above, the first seal lip 75 made of the rubber-like elastic material is vulcanization bonded to a reinforcing ring 77 made of a metal, and both the elements 75 and 77 are formed as an integral vulcanization molded product. Accordingly, it is impossible to easily separate and sort both the elements 75 and 77 at a time of disposal, and it is therefore impossible to comply with the necessity for recycle mentioned above.
Accordingly, the applicant of the present invention has proposed a lip type seal 81 having a first lip seal member 82 provided with a first seal lip 83 arranged at a sealed fluid side A and made of a rubber-like elastic material, a second lip seal member 84 provided with a second seal lip 85 arranged at an atmospheric air side B and made of a resin, and two retaining rings 86 and 87 pinching both the lip seal members 82 and 84 from both sides in an axial direction and made of a metal, and having a structure in which these four parts are assembled without being bonded, as shown in FIG. 5 (refer to patent document 2). In accordance with this prior art, since each of the parts is not bonded, it is possible to easily separate and sort each of the parts. Accordingly, it is possible to comply with the necessity for recycle mentioned above. However, in the prior art, there is room of improvement in the following points.
(1) Assembly Retaining Characteristic Among Constructing Parts
In the lip type seal 81 mentioned above, two retaining rings 86 and 87 are respectively structured such as to have annular flat surface portions 86a and 87a for pinching both the lip seal members 82 and 84 from both sides in an axial direction and tubular portions 86b and 87b integrally formed with the flat surface portions 86a and 87a. The tubular portion 86b in the retaining ring 86 at the sealed fluid side A is fitted to an inner peripheral side of a cylinder portion 82a of the first lip seal member 82 and the tubular portion 87b in the retaining ring 87 at the atmospheric air side B is pressure inserted and fixed to an insertion hole 82b provided in the cylinder portion 82a of the first lip seal member 82. Accordingly, each of the parts is retained in an assembled state on the basis of setting of a fitting margin and a pressure inserting margin for the fitting and pressure insertion. However, in the case that each of the parts is exposed to force in the axial direction, an engagement structure for preventing separation in an axial direction of the parts is not particularly provided among the parts. Therefore, if the retaining ring 86 at the sealed fluid side A is pulled in an axial direction (a direction of an arrow C) so as to detach the lip type seal 81 in a state of being installed to an inner periphery of the shaft hole 72 of the housing 71, there is a case that only this retaining ring 86 is pulled out and the other parts remain in an installed state (alternatively, there may be a case that only the retaining ring 86 and the first lip seal member 82 are pulled out, and the second lip seal member 84 and the retaining ring 87 at the atmospheric air side B remain). This is because of nothing but the assembly retaining force among the parts depending only upon friction force.
(2) Installing Workability
Further, in the lip type seal 81 mentioned above, two retaining rings 86 and 87 do not particularly have any structure for defining an interval in an axial direction therebetween. Further, the first lip seal member 82 made of the rubber-like elastic material and pinched between both the elements can achieve a sufficient seal operation only when used in a state of being compressed in the axial direction. In other words, there is a risk that a leak of sealed fluid is caused between the first lip seal member 82 and the second lip seal member 84 made of the resin or the retaining ring 87 at the atmospheric air side B. Accordingly, at a time of installing the lip type seal 81 mentioned above, the lip type seal 81 is installed by using a snap ring 89 while the lip type seal 81 is brought into contact with a step portion 88 provided on an inner periphery of the shaft hole 72 of the housing 71 so as to apply a compression load in the axial direction, whereby the lip type seal 81 is installed in a state that the whole thereof is compressed in the axial direction between the step portion 88 and the snap ring 89. However, there is such a disadvantage that a work of installing by using the snap ring 89 while applying the compression load in the axial direction as mentioned above is extremely complicated.
Further, since the cylinder portion 82a of the first lip seal member 82 is provided with the annular insertion hole 82b which is open to the atmospheric air side B, a portion at an outer peripheral side from the insertion hole 82b in the cylinder portion 82a is formed to have such a shape that the atmospheric air side end portion 82c thereof terminates in a cylindrical shape. Accordingly, since the atmospheric air side end portion 82c rubs the inner peripheral surface of the shaft hole 72 at a time of the first lip seal member 82 being inserted into the inner periphery of the shaft hold 72 of the housing 71, there is a case that an evagination is caused in the atmospheric air side end portion 82c.

This patent is subject to a terminal disclaimer.


The invention concerns agonist anti-trkC monoclonal antoibodies which mimic certain biological activities of NT-3, the native ligand of trkC. The invention further concerns the use of such antibodies in the prevention and/or treatment of cellular degeneration, including nerve cell damage associated with acute nervous cell system injury and chronic neurodegenerative diseases, including peripheral neuropathy.

1. Field of the Invention
This invention concerns agonist anti-trkC monoclonal antibodies. It further concerns the use of the agonist antibodies in the prevention and/or treatment of cellular degeneration, including nerve cell damage associated with acute nervous cell system injury and chronic neurodegenerative diseases, including peripheral neuropathy.
2. Description of the Related Art
Neurotrophins are a family of small, basic proteins, which play a crucial role in the development and maintenance of the nervous system. The first identified and probably best understood member of this family is nerve growth factor (NGF), which has prominent effects on developing sensory and sympathetic neurons of the peripheral nervous system (Levi-Montalcini, R. and Angeletti, P. U., Physiol. Rev. 48, 534-569 [1968]; Thoenen, H. et al., Rev. Physiol. Biochem. Pharmacol. 109, 145-178 [1987]). Although NGF had been known for a long time, including a homolog from the mouse submandibular gland, the mature, active form of which is often referred to as - or 2.5S NGF, it was only many years later that sequentially related but distinct polypeptides with similar functions were identified.
The first in line was a factor called brain-derived neurotrophic factor (BDNF), which was cloned and sequenced by Leibrock, J. et al. (Nature 341, 149-152 [1989]). This factor was originally purified from pig brain (Barde, Y. A. et al., EMBO J. 1, 549-553 [1982]), but it was not until its cDNA was cloned and sequenced that its homology with NGF became apparent. The overall amino acid sequence identity between NGF and BNDF is about 50%. In view of this finding, Leibrock et al. speculated that there was no reason to think that BDNF and NGF should be the only members of a family of neurotrophins having in common structural and functional characteristics.
Indeed, further neurotrophins closely related to -NGF and BDNF have since been discovered. Several groups identified a neurotrophin originally called neuronal factor (NF), and now referred to as neurotrophin-3 (NT-3) (Ernfors et al., Proc. Natl. Acad. Sci. USA 87, 5454-5458 (1990); Höhn et al., Nature 344, 339 [1990]; Maisonpierre et al., Science 247, 1446 [1990]; Rosenthal et al., Neuron 4, 767 [1990]; Jones and Reichardt, Proc. Natl. Acad. Sci. USA 87, 8060-8064 (1990); Kaisho et al., FEBS Lett. 266, 187 [1990]. NT-3 shares about 50% of its amino acids with both -NGF and BDNF (NT-2). Neurotrophins-4 and -5 (NT-4 and NT-5), have been added to the family (U.S. Pat. No. 5,364,769 issued Nov. 15, 1994; Hallbook, F. et al., Neuron 6, 845-858 [1991]; Berkmeier, L. R. et al., Neuron 7, 857-866 [1991]; lp et al., Proc. Natl. Acad. Sci USA 89, 3060-3064 [1992]). The mammalian molecule initially described by Berkmeier et al supra, which was subsequently seen to be the homolog of Xenopus NT-4, is usually referred to as NT-4/5. In addition, there is an acidic homologous protein described in mammals which is referred to as NT-6 (Berkemeir, et al., Somat. Cell Mol. Genet 18(3):233-245 [1992]). More recently, another homologus protein from the fish, Xiphophorus has also been labeled NT-6 (Gotz et al., Nature 372:266-269 [1994]). There are two proteins described in the literature as NT-7, one cloned from the carp, Cyprinus, (Lai, et al., Mol. Cell. Neurosci. 11(1-2):64-76 [1998]) and one from the zebrafish, Danio (Nilsson et al., FEBS Letters 424(3):285-90 [1998]). None of these last three described fish neurotrophins has been described outside fish, and their relationship to any mammalian neurotrophins is unclear. The amino acid sequence of zebrafish neurotrophin-7 (zNT-7) is more closely related to that of fish nerve growth factor (NGF) and neurotrophin-6 (NT-6) than to that of any other neurotrophin. zNT-7 is, however, equally related to fish NGF and NT-6 (65% and 63% amino acid sequence identity, respectively) indicating that it represents a distinct neurotrophin sequence. zNT-7 contains a 15 amino acid residue in a beta-turn region in the middle of the mature protein. Recombinant zNT-7 was able to bind to the human p75 neurotrophin receptor and to induce tyrosine phosphorylation of the rat trkA receptor tyrosine kinase, albeit less efficiently than rat NGF. zNT-7 did not interact with rat trkB or trkC, indicating a similar receptor specificity as NGF. We propose that a diversification of the NGF subfamily in the neurotrophin evolutionary tree occurred during the evolution of teleost fishes which in the appearance of several additional members, such as zNT-7 and NT-6, is structurally and functionally related to NGF.
Neurotrophins, similarly to other polypeptide growth factors, affect their target cells through interactions with cell surface receptors. According to our current knowledge, two kinds of transmembrane glycoproteins serve as receptors for neurotrophins. Equilibrium binding studies have shown that neurotrophin-responsive neurons possess a common low molecular weight (65-80 kDa), low affinity receptor (LNGFR), also termed as p75NTR or p75, which binds NGF, BDNF, and NT-3 with a KD of 2×10−9 M, and large molecular weight (130-150 kDa), high affinity (KD in the 10−11 M) receptors, which are members of the trk family of the receptor tyrosine kinases.
The first member of the trk receptor family, trkA, was initially identified as the result of an oncogenic transformation caused by the translocation of tropomyosin sequences onto its catalytic domain (Martin-Zanca et al., Mol. Cell. Biol. 9(1):24-33 [1989]). Later work identified trkA as a signal transducing receptor for NGF. Subsequently, two other related receptors, mouse and rat trkB (Klein et al., EMBO J. 8, 3701-3709 [1989]; Middlemas et al., Mol. Cell. Biol. 11, 143-153 [1991]; EP 455,460 published 6 Nov. 1991) and porcine, mouse and rat trkC (Lamballe et al., Cell 66, 967-979 [1991]; EP 522,530 published 13 Jan. 1993), were identified as members of the trk receptor family. The structures of the trk receptors are quite similar, but alternate splicing increases the complexity of the family by giving rise to two known forms of trkA, three known forms of trkB (two without functional tyrosine kinase domains) and at least four forms of trkC (several without functional tyrosine kinase domain, and two with small inserts in the tyrosine kinase domain).
The role of the p75 and trk receptors is controversial. It is generally accepted that trk receptor tyrosine kinases play an important role in conferring binding specificity to a particular neurotrophin, however, cell lines expressing trkA bind not only NGF but also NT-3 and NT-415 (but not BDNF), trkB expressing cells bind BDNF, NT-3, NT-4, and NT-415 (but not NGF), in contrast to trkC-expressing cells which have been reported to bind NT-3 alone (but not the other neurotrophins). Furthermore, it has been shown in model systems that the various forms of trk receptors, arising from alternate splicing events, can activate different intracellular signalling pathways, and therefore presumably mediate different physiological functions in vivo. It is unclear whether cells expressing a given trk receptor in the absence of p75 bind neurotrophins with low or high affinity (Meakin and Shooter, Trends Neurosci. 15, 323-331 [1992]).
Published results of studies using various cell lines are confusing and suggest that p75 is either essential or dispensable for neurotrophin responsiveness. Cell lines that express p75 alone bind NGF, BDNF, NT-3, and NT-4 with similar low affinity at equilibrium, but the binding rate constants are remarkably different. As a result, although p75-binding is a common property of all neurotrophins, it has been suggested the p75 receptor may also play a role in ligand discrimination (Rodriguez-Tebar et al., EMBO J. 11, 917-922 [1992]). While the trk receptors have been traditionally thought of as the biologically significant neurotrophin receptors, it has recently been demonstrated that in melanoma cells devoid of trkA expression, NGF can still elicit profound changes in biological behavior presumably through p75 (Herrmann et al., Mol. Biol. Cell 4, 1205-1216 [1993]). Davies et al. (Neuron 11, 565-574 [1993]) reported the results of studies investigating the role of p75 in mediating the survival response of embryonic neurons to neurotrophins in a model of transgenic mice carrying a null mutation in the p75 gene. They found that p75 enhances the sensitivity of NGF-dependent cutaneous sensory neurons to NGF. There have now been many studies showing that p75 is capable of mediating at least some of the biological effects of the neurotrophins. The field is still somewhat controversial, but p75 signaling has been implicated in controlling cell death, and neurite outgrowth. (Barker, P A, Cell Death Diff. 5:346-356 [1998]; Bredesen et al., Cell Death Diff. 5:357-364 [1998]; Casaccia-Bonnefil, et al., Cell Death Diff. 5:357-364 [1998]; Raoul et al., Curr. Op. Neurobiol. 10:111-117 [2000]; Davies, A M, Curr. Biol. 10:R198-R200 [2000]). Importantly, stimulation of p75 has been shown to modify the effects of stimulating trkC (Hapner, et al., Developm. Biol. 201:90-100 [1998]).
The extracellular domains of full-length native trkA, trkB and trkC receptors have five functional domains, that have been defined with reference to homologous or otherwise similar structures identified in various other proteins. The domains have been designated starting at the N-terminus of the amino acid sequence of the mature trk receptors as 1) a first cysteine-rich domain extending from amino acid position 1 to about amino acid position 32 of human trkA, from amino acid position 1 to about amino acid position 36 of human trkB, and from amino acid position 1 to about amino acid position 48 of human trkC; 2) a leucine-rich domain stretching from about amino acid 33 to about amino acid to about amino acid 104 in trkA; from about amino acid 37 to about amino acid 108 in trkB, and from about amino acid 49 to about amino acid 120 in trkC; 3) a second cysteine-rich domain from about amino acid 105 to about amino acid 157 in trkA; from about amino acid 109 to about amino acid 164 in trkB; and from about amino acid 121 to about amino acid 177 in trkC; 4) a first immunoglobulin-like domain stretching from about amino acid 176 to about amino acid 234 in trkA; from about amino acid 183 to about amino acid 239 in trkB; and from about amino acid 196 to about amino acid 257 in trkC; and 5) a second immunoglobulin-like domain extending from about amino acid 264 to about amino acid 330 in trkA; from about amino acid 270 to about amino acid 334 in trkB; and from about amino acid 288 to about amino acid 351 in trkC.
Neurotrophins exhibit actions on distinct, but overlapping, sets of peripheral and central neurons. These effects range from playing a crucial role in ensuring the survival of developing neurons (NGF in sensory and sympathetic neurons) to relatively subtle effects on the morphology of neurons (NT-3 on purkinje cells). These activities have led to interest in using neurotrophins as treatments of certain neurodegenerative diseases. NT-3 has also been found to promote proliferation of peripheral blood leukocytes and, as a result, it has been suggested that NT-3 can be used in the treatment of neutropenia, infectious disease and tumors (U.S. Pat. No. 6,015,552 issued on Jun. 18, 2000).
The roles of neurotrophins in regulating cardiovascular development and modulating the vascular response to injury have also been investigated (Donovan et al., Nature Genetics 14:210-213 [1996]; Donovan et al., A.J. Path. 147:309-324 [1995]; Kraemer et al., Arteriol. Thromb. and Vasc. Biol. 19:1041-1050 [1999]). Neurotrophins have been described as potential therapeutics for regulating angiogenesis and vascular integrity (PCT Publication WO 00/24415, published May 4, 2000).
Despite their promise in the treatment of cellular degeneration, such as occurs due to neurodegenerative disease and acute neuronal injuries, and potentially angiogenesis, neurotrophins have several shortcomings. One significant shortcoming is the lack of specificity. Most neurotrophins cross-react with more than one receptor. For example NT-3, the preferred ligand of the trkC receptor tyrosine kinase, also binds to and activates trkA and trkB (Barbacid, J. Neurobiol. 25:1386-1403 [1994]; Barbarcid, Ann. New York Acad. Sci. 766:442-458 [1995]; Ryden and Ibanez, J. Biol. Chem. 271:5623-5627 [1996]; Belliveau et al., J. Cell. Biol. 136:375-388 [1997]; Farinas et al., Neuron 21:325-334 [1998]). As a result, it is difficult to devise therapies that target a specific population of neurons. Another limitation of neurotrophin therapy is that neurotrophins, including NT-3 are known to elicit hyperalgesia (Chaudhry, et al., Muscle and Nerve 23:189-192 [2000]). In addition, some neurotrophins such as NT-3 have poor pharmacokinetic and bioavailability properties in rodents, which raise serious questions about their human clinical applications (Haase et al., J. Neurol. Sci. 160:S97-S105 [1998], dosages used in Helgren et al., J. Neurosci. 17(1):372-82 [1997], and data below).
Accordingly, there is a great need for the development of new therapeutic agents for the treatment of neurodegenerative disorders and acute nerve cell injuries that are devoid of the known shortcomings of neurotrophins.

Agonist anti-trk-C monoclonal antibodies


This invention comprises a multiplex-capable oligonucleotide which is capable of hybridizing to at least one of the C. difficile tcdB, tcdC, or cdtB genes, wherein, wherein said primer consists of a sequence selected from the group consisting of SEQ ID NOS: 1 through 9, or a sequence that exhibits no more than one substitution of a base to a sequence selected from the group consisting of SEQ ID NOS: 1 through 9 and method for polymerase chain reaction (PCR) determining of the presence of a toxigenic strain of C. difficile in a biological sample utilizing said probes.

Clostridium difficile is a common identified cause of antibiotic associated diarrhea, accounting for 15%-25% of cases (Bartlett, 1994, Clin. Infect. Dis., 18 (Suppl 4): S265-272). A more severe form of CDI has been identified. Many cases of this severe form of CDI have been shown to be caused by an "epidemic" strain of C. difficile, which has been characterized as "BI" by restriction enzyme analysis (REA), "NAP1" (North American Pulsed Field Type 1) by pulsed field gel electrophoresis, and "027" by PCR ribotyping. In addition, it has been characterized as "toxinotype III" (by REA of toxin genes). In prior years, the great majority of "non-epidemic" hospital strains of C. difficile belonged to toxinotype 0. This BI/NAP1/027 "epidemic" strain has been shown to be a hyperproducer of toxins A and B, to which is attributed the increased virulence of the epidemic strain. The tcdC gene, within the pathogenicity locus of the "epidemic" strain, appears to be a negative regulator of toxin A and B production.
Toxigenic strains of C. difficile commonly produce two large toxins, an enterotoxin; toxin A (TcdA) and a cytotoxin; toxin B (TcdB), to which disease symptoms are attributed. Without being bound by any particular theory, it is believed that these toxins are expressed efficiently during growth of C. difficile in response to an environmental stimulus. Their activities modulate numerous physiological events in the cell and are believed to contribute directly to disease. In humans the two toxins have been associated with pseudomembranous colitis and antibiotic associated diarrhea. Reported transmission occurs primarily in health care facilities, where exposure to antimicrobial drugs and environmental contamination by C. difficile spores are common.
Without being bound by any particular theory, it is believed that toxin A and toxin B are encoded by genes tcdA and tcdB. Both have been sequenced and are reportedly found in single open reading frames. Together with three additional genes (tcdC, tcdD, tcdE), they are reported to form a 19.6 kb chromosomal pathogenicity locus (Paloc) (8). Both open reading frames are large, with tcdA spanning a reported 8,133 nucleotides and tcdB being reported as 7,098 nucleotides in length. It is further believed that C. difficile toxigenic strains produced both toxin A and toxin B whereas nontoxigenic strains lacked both toxins (Rupnik et al. supra.; Lyerly et al., Clin. Micro. Rev., 1998, Jan. 1-18). Toxigenic reference strain VP1 10463 is an example of a strain producing TcdA and TcdB.
In determining the toxicity of a C. difficile strain, rapid determination is a central concern. If multiplex PCR can be applied, the process of determining the toxicity of a C. difficile strain will be radically improved. Multiplex PCR is a variant of PCR which enabling simultaneous amplification of many targets of interest in one reaction by using more than one pair of primers. Reported uses include genotyping applications where simultaneous analysis of multiple markers is required. It is also used in detection of pathogens. However, multiplex assays can be tedious and time-consuming to establish, requiring lengthy optimization procedures. Note is made of Clostridium difficile Toxins: Mechanism of Action and Role in Disease, Voth et al., Clinical Microbiology Reviews, (18)2: 247-263 (2005), the teachings of which are incorporated herein by reference.
Optimization of a determination of C. difficile type requires particular attention to many factors including primer design/selection, annealing temperature and extension time and temperature. Noted considerations in primer selection include selecting the length of individual primers, primer melting temperature and differential melting temperatures of all primers, purine:pyrimidine content; and degree of primer-primer interactions.
A related optimization issue is the adjusting of cycling conditions and buffer concentrations required for each primer pair. Annealing temperature is also a significant concern with unduly low annealing temperatures associated with the appearance of unspecific secondary products. Establishing an extension time is a significant consideration. The given of multiplex PCR is with more loci simultaneously amplified, then the pool of enzyme and nucleotides may become a key limiting factor. Thus, determination of time necessary for the polymerase molecules to complete synthesis is useful.
Reference is made to Rupnik, M. et al., J. Med. Microbiol, 2005, 54: 113-117; Voth, D. E. et al., Clinical Microbiol. Reviews, 2005, 18: 247-263; U.S. Pub. No. 20090208948 to Paquette et al., and U.S. Pub. No. 20090203021 to Cockerill et al., the teachings of which are incorporated herein by reference in their entirety as are all publications cited herein.

Simultaneous quantitative multiple primer detection of


A method for forming alkyl silicate easily at low costs. The method comprises a reaction step of mixing and reacting an aqueous solution of sodium silicate, and a solution of alcohol or alkyl halide in a water-insoluble organic solvent, in the presence of a catalyst; and an isolating step of separating an organic layer from the reactive mixed solution and isolating a reaction product from the organic layer.

1. Field of the Invention
This invention relates to a method for forming alkyl silicate in a single step.
2. Description of the Related Art
Metallic silicon has been used as high-functional materials for solar cells, semiconductors, etc. in view of its physical and chemical properties. The metallic silicon has to have a single crystal body in order to exhibit a higher function. For this reason, researches have been conducted on growth of single silicon crystal actively and extensively since 1950's, and some methods of producing crystals have been reported. Among them, the most general and most economic method is Czochralski process which was developed in 1918. However, Today's general method of synthesizing high-purity metallic silicon is to use easily available silicon dioxide as a raw material, mix silicon dioxide with a carbon reducing agent, heat the mixture above 2000.degree. C., and continuously supply an electric power of 13 MK.sup.wh /t.
However, silicon dioxide used as a raw material is synthesized from silicon tetrachloride or alkoxy silane. Alkoxy silane is synthesized from silicon tetrachloride, and silicon tetrachloride is synthesized from crude metallic silicon.
Due to these complicated synthesizing processes, high-purity metallic silicon is very expensive. So, the present inventors have studied about a method of obtaining inexpensive alkoxy silane by using cheap water glass as a raw material.
As for organic derivatives of water glass, few researches have been made since Eblemen produced an organic silicon compound in 1844. One of the few reports is that Kird made direct esterification of polymerized silicon in 1946, and another is that in 1947, Iler et al synthesized polyester silicate in a two-step reaction in which water glass was first treated by acid and then the resultant was reacted with alcohol.


Disclosed is a method for reducing power consumption of a user terminal when synchronization between a user terminal and a base station is disrupted in a broadband wireless access communication system. The method comprises the steps of: calculating first error rate (E) based on first channel state information included in a signal transmitted from the base station; comparing the first error rate (E) with a first threshold value; determining that the synchronization is disrupted and maintaining a transmission-off mode for a predetermined period of time if the first error rate (E) is greater than the first threshold value; maintaining a reception-on mode during a period of time set for a reception mode after the transmission-off mode is performed; receiving from the base station second channel state information during the reception-on mode; calculating a second error rate (E1) based on the second channel state information; comparing the second error rate (E1) with a second threshold value; and determining that the synchronization has been reestablished and maintaining the transmission mode in a transmission-on mode if the second error rate (E1) is less than the second threshold value.

1. Field of the Invention
The present invention relates to a broadband wireless access communication system, and more particularly to a method for reducing power consumption of a user terminal when synchronization between the user terminal and a base station is lost because of a poor channel environment in a broadband wireless access communication system such as IEEE 802.16e.
2. Description of the Related Art
With the 4th generation (hereinafter, referred to as "4G") communication system, a next generation communication system, providing users with services having various qualities of service (hereinafter, referred to as "QoS") and transmission speeds of approximately 10 Mbps are the focus of the developers.
At present, the 3rd generation (hereinafter, referred to as "3G") communication system supports a transmission speed of approximately 384 kbps in an outdoor channel environment, a relatively inferior channel environment, and supports a transmission speed of approximately 2 Mbps in an indoor channel environment, a relatively superior channel environment. A wireless local area network (hereinafter, referred to as "LAN") and a wireless metropolitan area network (hereinafter, referred to as "MAN") generally support transmission speeds of approximately 20 Mbps to 50 Mbps.
In the 4G communication system, new communication techniques are under development, which attempt to provide mobility and high QoS to the user terminal in the wireless LAN and MAN systems while attempting securing a relatively high transmission speed. Studies are also actively progressing to support a high-speed communication service, in the 4G communication system.
Since a wireless MAN system provides a wide service coverage area and supports high speed transmission, the wireless MAN system is suitable for supplying a high-speed communication service. However, the wireless MAN system does not provide for mobility of the user terminals and therefore does not provide a handoff procedure to control high-speed movement of a user terminal.
The IEEE 802.16e standard adds techniques to compensate for the mobility of a user terminal in a MAN which has a high-speed transmission function over a range of up to 75 km, while including a LAN capabilities. The IEEE 802.16e standard has been developed to provide data service, video service, voice service, etc., with a prescribed QoS in a point-to-multipoint network structure. According to such a standard, it is possible to provide broadband service on the assumption that the user terminal is fixed in its location. The IEEE 802.16e standard aims at enlarging a service area of the user terminal comparable to that of a cellular service environment by enabling the user terminal to receive services even while moving and by providing a handoff function to the user terminal on the basis of the IEEE 802.16a standard. The IEEE 802.16e standard includes link budget improvement, a plan to allow communication during a high speed movement of the user terminal, addition of a handoff function, addition of a low-power mode, etc.
According to the IEEE 802.16e, a modulation method is not fixed to any one method, but can be varied according to a channel environment. Modulation methods which can be used in the IEEE 802.16e include quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (16QAM), 64 quadrature amplitude modulation (64QAM) methods. Such modulation methods are applied as needed to adapt to a channel environment and a cell coverage range.
A base station and a user terminal must be synchronized with each other to provide communication between them according to the IEEE 802.16e. Although synchronization between the base station and the user terminal is established, the synchronization between them is frequently disrupted disconnected due to a poor channel state. The IEEE 802.16e standard does not define operations which are expected to be performed by the base station and the user terminal after synchronization between the base station and the user terminal is disrupted.
When the synchronization between the base station and the user terminal is disrupted the user terminal continues to maintain a state in which it was operating just prior to losing synchronization. Although the user terminal maintains such an operating state, it is impossible to perform communication until synchronization between the base station and the user terminal has been reestablished. Although synchronization between the base station and the user terminal is disconnected, the user terminal continues to perform full, high power operations which it was performing before the loss of synchronization, so that unnecessary power is continuously discharged.
Therefore, a technique for reducing power in a user terminal caused by unnecessary power discharge in a state in which synchronization between the user terminal and the base station is disconnected is needed. Furthermore, the continued discharge of power by the user terminal during times when synchronization is disconnected, unnecessary interference may occur between the relevant channel and an adjacent channel.

Method for saving power in a user terminal after synchronization loss in broadband wireless access communication system


A protective window shutter is designed to cover and uncover a door mounted “peek through” metal framed window. The shutter is made up of two shutter sections, rotatable in relation to each other. The first shutter section is secured adjacent to the window's metal frame and the second shutter section is rotatable from a first position in which the two sections are folded on each other, to a second position in which the second section is extended out from the first section, over the window. The shutter sections are maintained in the closed position by the attraction of metal strike plates on the first shutter section and corresponding magnets encased within the second shutter. The second section is maintained over the window by the attraction of the magnets to the window's metal framing. The shutter sections are made of high strength, lightweight PVC or like material.

There are many types of shutters designed to cover windows for a variety of purposes. For instance, shutters are routinely utilized for privacy, security, esthetics, control of room lighting, etc. One such purpose which has become increasingly important in today's society is the need to close of "peek through" windows mounted within doors in classrooms, offices, or other interior doors, to ensure safety, privacy, and added security to students, teachers, and others occupying a room. There is a need especially to quickly and efficiently close a shutter over a door mounted window for the safety of educators and students in schools and similar buildings. This capability has value, as well, in other buildings and environments where security and safety are important. While many different types of shutters exist, there are none which can be put in place quickly and efficiently to cover a door mounted window.


In one aspect of the invention, CHF.sub.3 gas and CF.sub.4 gas (i.e., reactant gases), and argon gas (i.e., plasma-stabilizing gas) are introduced into a vacuum chamber. RF power is then applied between the electrodes within the chamber, thereby generating plasma. The plasma is applied to a substrate placed in the chamber, thus etching the SiO.sub.2 film formed on the substrate. A spectrometer extracts a light beam of a desired wave-length, emitted from the CF.sub.2 radical which contributes to the etching. An end-point detecting section monitors the luminous intensity of the CF.sub.2 radical reacting with SiO.sub.2 during the etching. Once the SiO.sub.2 film has been etched away, the luminous intensity of the CF.sub.2 radical increases. Upon detecting this increase, the section determines that etching has just ended. The selected wavelength ranges from 310 nm to 236 nm, preferably being 219.0 nm, 230.0 nm, 211.2 nm, 232.5 nm, or any one ranging from 224 nm to 229 nm. In another aspect of the invention, the device attached to the observation window of the chamber removes products stuck to the window during the etching. The window thus cleaned, more light than otherwise passes through the window and reaches the spectrometer. This enables the section to detect even a slight change in the luminous intensity of the CF.sub.2 radical, thereby detecting the end point of etching with accuracy.

1. Field of the Invention
The present invention generally relates to a plasma-process system, and more particularly to a plasma-process system including a plasma-process method with improved end-point detecting scheme and also a plasma-process apparatus with improved end-point detecting scheme.
2. Description of the Related Art
In the manufacture of semiconductor devices, dry etching is a process indispensable to the forming of fine IC patterns on a semiconductor wafer. Various types of dry etching are known, among which is plasma process. In the plasma process, plasma is generated from reactant gases within a vacuum chamber, and ions, neutral radicals, atoms, and molecules--all present in the plasma--are applied to a semiconductor wafer, thereby removing things to be removed, such as a silicon dioxide film in non-masked potions on the wafer.
If the plasma process, or plasma etching, is continued even after the things to be removed which should be removed, have been completely removed from the semiconductor wafer, the surface of the wafer will be unnecessarily etched away, or the resist layer on the wafer will be etched to become thinner than is required. Hence, it is required that the end point of the plasma etching be detected with high accuracy.
In a typical conventional method of detecting the end point of plasma etching, the luminous intensity of the product of plasma etching is monitored, and the end point of the plasma etching is determined from the changes in the luminous intensity. In the case of plasma etching, wherein a silicon dioxide film is etched with CF-based reactant gas, the luminous intensity of carbon monoxide, i.e., the reaction product, is monitored, and the end point of plasma etching is determined from the changes in the luminous intensity of the carbon monoxide. (Refer to Published Unexamined Japanese Patent Application No. 63-81929 and Published Unexamined Japanese Patent Application No. 1-230236.)
More specifically, the plasma etching is performed in a reaction chamber containing plasma electrodes and having an observation window. The observation window is made of quartz glass and has a diameter of several centimeters. An optical system including a lens is fixed outside the reaction chamber and located near the observation window. The light emitted from the plasma during the plasma etching is applied through the window to the optical system. The optical system collects the light and outputs it to a photoelectric transducer or the like through an optical fiber. The transducer converts the input light into electric signals, which are supplied to a detecting section. The detecting section processes the signals, thereby detecting the end point of the plasma etching. In the case of plasma etching for etching a silicon dioxide film with CF-based reactant gas, the light emitted from the carbon monoxide (i.e., the reaction product) is collected by an optical system and converted into electric signals by a photoelectric transducer, and these signals are processed to monitor the changes in the luminous intensity of the carbon monoxide and ultimately to determine the end point of the plasma etching.
The end point of the plasma etching is determined for the following reason. As long as the plasma etching proceeds, the reaction product is continuously formed. When the plasma etching comes to an end, that is, when the thing to be etched is etched away completely, the forming of the reaction product stops, whereby the luminous intensity of the product decreases abruptly. Hence, the end point of the plasma etching can be detected by finding an abrupt decrease in the luminous intensity of the reaction product, at a specific wavelength.
For a successful plasma etching, it is necessary to stabilize the plasma in the reaction chamber or to increase the efficiency of etching an undercoating film or a resist layer. To this end, a gas is used in addition to the etching gas, in an amount greater than the etching gas. For example, to stabilize the plasma, argon gas is added to CF-base gas. In this case, the emission spectrum of the carbon monoxide (i.e., the reaction product) overlaps that of the argon gas, which is very broad.
This overlapping of spectra is inevitable for two reasons. First, the wavelength of the intense light the argon gas emits and that of the intense light the carbon monoxide emits fall in a range of 300 to 800 nm; in other words, the light beams emitted from the argon gas and the carbon monoxide have very similar wavelengths. Secondly the carbon monoxide is generated in a very small amount since that the etching reaction is proceeding at only a small portion of the wafer, whereas the argon gas is introduced into the reaction chamber in an amount several to ten times greater than the etching gas applied. As a result, the luminous intensity of the carbon gas is far greater than that of the carbon monoxide.
Since the emission spectrum of the carbon monoxide overlaps that of the argon gas, for the reasons mentioned above, the luminous intensity of the carbon monoxide can hardly be found correctly. Consequently, it is difficult to detect the end point of the plasma etching in the conventional method.
In the conventional method, the luminous intensity of the reaction product is monitored over a wavelength range of about 300 to 900 nm, because of the limited sensitivity of the luminous intensity detector used, such as a spectrometer. In particular, the luminous intensity is monitored with respect to a wavelength of 482.0 nm at which the peak intensity is found in the emission spectrum of carbon monoxide. Obviously, the wavelength range of 300 to 900 nm is very similar to the range of 350 to 860 nm for the intense light which argon gas emits. Consequently, the emission spectrum of carbon monoxide overlaps that of the plasma itself, making it difficult to detect the luminous intensity of carbon monoxide with sufficiently high accuracy.
In recent years it has been demanded that finer IC patterns be formed on a semiconductor wafer. To meet this demand, the IC patterns formed on wafers at present are actually finer than those formed before. Thus, the tendency is that the ratio of the etched surface portion to the entire surface area of a semiconductor wafer, i.e., the rate of hole area, is now 10% or less. In some cases, this ratio is as small as 2% or 3%. The amount of the carbon monoxide, generated generated during plasma etching, is extremely small, for example only 1% or less of the amount of the carbon gas introduced into the reaction chamber. Hence, the conventional method can no longer serve to detect the luminous intensity of carbon monoxide with high accuracy, making it difficult to determine the end point of the plasma etching.
Further, to meet the demand for the forming of finer IC patterns, or the increasing demand for the forming contact holes only, trenches only or wiring patterns only by means of plasma etching, the rate of hole area is likely to be only 1% or even less at present. As a consequence, the change in the amount of etching gas supplied immediately before or after the end of plasma etching is extremely small. Hence, the intensity of the emission spectrum of the etching gas changes very little shortly before or after the end of plasma etching, and the luminous intensity of the gas is extremely low shortly before or after the end of plasma etching. Thus, with the conventional method it would be impossible to detect the end point of plasma etching with high accuracy.
In another conventional method, not only the luminous intensity of the reaction product, but also the luminous intensity of the etching gas is monitored, and the end point of plasma etching is determined from the difference between the luminous intensity of the product and that of the gas or from the ratio of the former to the latter. This method is based on the assumption that the amount of the etching gas in the reaction chamber remains almost constant during the plasma etching, but increases at the end thereof.
This conventional method, however, is disadvantageous, too. The amount of the etching gas and that of the reaction product do not always remain constant throughout the etching. In some cases, the luminous intensity of the gas and that of the product decrease as the etching proceeds. This is perhaps because of the changes in the operating conditions of the exhaust system, the changes in the temperature in the reaction chamber, or the like. Consequently, the end point of the plasma etching cannot be correctly determined, solely from the difference between the luminous intensity of the product and that of the gas or the ratio of the luminous intensity of the product to that of the etching gas.
Particularly, in the case where the luminous intensity of an etching gas gradually decreases during the plasma etching proceeds, more than it changes at the very end of the etching, it is difficult to distinguish the change during the etching from the change at the end of the etching, or vice versa. It would be more difficult to do so in the case where the rate of hole area is low, since the luminous intensity of the etching gas changes only a little at the end of the plasma etching.
As has been described, the optical system is fixed outside the reaction chamber in a prior-art plasma-process apparatus. Here arises a problem. The position where the plasma is generated changes in accordance with the size of the semiconductor wafer being plasma-processed and also with the conditions of plasma process. Hence, in the prior-art plasma-process apparatus, it is impossible to detect the peak point of the plasma by means of the optical system, which cannot be moved at all.
In addition, the plasma is generated within the reaction chamber in various manners, depending on the conditions of the plasma process such as the size of the wafer, the way of processing the wafer, and the composition of the etching gas used. As a result of this, the peak point of the plasma, i.e., the point where the plasma has the highest luminous intensity, moves back or forth, and up or down, in the space between the plasma electrodes, every time the plasma-process conditions are changed.
With the prior-art plasma-process apparatus, wherein the optical system containing a lens used for detecting the luminous intensity of plasma is fixed in place, the peak point of the plasma can not always located. Hence, the apparatus cannot detect slight changes in the luminous intensity of the plasma, making it even more difficult to detect the end point of plasma etching. In view of this, the conventional plasma-process apparatus needs some improvement.
The recent tendency in the art is that a light beam having a short wavelength, e.g., 200 nm, which is shorter than any one within the emission spectrum of argon gas, is observed so that its luminous intensity is detected. However, as much as 50% of the light having such a short wavelength is absorbed, in some cases, by the optical fiber as it is applied from the optical system to the photoelectric transducer or the like.
Furthermore, the reaction product formed during the plasma-process sticks onto the inner surface of the observation window of the reaction chamber, inevitably rendering the window opaque. The amount of light applied from the window to the optical system is less than otherwise. This makes it still difficult to determine the end point of plasma etching with accuracy, since it is necessary at present to detect the end point from the changes in the plasma luminous intensity which are extremely small in most cases for the aforementioned reasons.

Plasma-process system with improved end-point detecting scheme


The present invention provides novel non-immunogenic, hydrophilic/cationic block copolymers comprising a neutral-hydrophilic polymer and a cationic polymer, wherein both polymers have well-defined chain-end functionality. A representative example of such a block copolymer comprises poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA) and poly(N-[3-(dimethylamino)propyl]methacrylamide) (PDMAPMA). Also provided is a synthesis method thereof in aqueous media via reversible addition fragmentation chain transfer (RAFT) polymerization. Further provided are uses of these block copolymers as drug delivery vehicles and protection agents.

Poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA) as a delivery vehicle has been well studied over the past few decades (Jensen et al., 2003; incorporated herein by reference). Originally, much of the work with this neutral, hydrophilic, biocompatible polymer focused on its use as a plasma expander; however, it has more recently been employed in the delivery of anticancer drugs (Kopecek et al., 2000; Putnam and Kopecek, 1995; Vasey et al., 1999; Duncan et al., 1992), site specific delivery in the GI tract (Yeh et al., 1995; Kopeckova et al., 1994), tumor-specific delivery of antisense oligonucleotides to their target mRNAs (Wang et al., 1999; Jensen et al., 2001), and hydrogels (Yeh et al., 1995; Wang et al., 1999; Subr et al., 1990; Rihova et al., 1997). As with other successful delivery vehicles, drug conjugates of PHPMA are well suited to pharmaceutical applications because they exhibit the enhanced permeability and retention (EPR) effect, therefore increasing the concentration of an active drug in tumor cells (i.e. 10-100 times higher concentration than that of the free drug) and decreasing the dose limiting toxicity (Matsumura and Maeda, 1986; Duncan, 1997).
Controlling the free-radical polymerization of N-(2-hydroxypropyl)methacrylamide (HPMA) and, therefore, controlling the molecular weight and molecular weight distribution of PHPMA is a crucial factor in the synthesis of well defined polymer-drug conjugates. The first attempts to control the polymerization of HPMA were reported by Teodorescu and Matyjaszewski (1999 and 2000) and employed atom transfer radical polymerization (ATRP) in organic media (1-butanol or ethanol) with two different ligand-initiating systems. However, these systems suffered from elevated polydispersities (Mw/Mn) and, in some cases, low conversions. An indirect method for the preparation of well-defined polymers of HPMA and PHPMA-drug conjugates was demonstrated by Godwin et al. (2001) in which N-methacryloxysuccinimide was first polymerized via ATRP followed by reaction of the succinimidyl-ester side-chains with stoichiometric amounts of 1-amino-2-propanol and an amino-terminal, peptide-linked "model drug," glycine-glycine-β-naphthylamide.
In recent years, efforts have been focused on the controlled polymerization of water-soluble, acrylamido monomers via reversible addition-fragmentation chain transfer (RAFT) polymerization (McCormick et al., 2004; incorporated herein by reference). To date, the controlled RAFT polymerization of anionic, zwitterionic, and neutral acrylamido monomers has been reported in both organic and aqueous media employing a variety of chain transfer agents (CTA) including xanthates, dithiocarbamates, trithiocarbonates and dithioesters. All of these CTAs can afford control over the molecular weight and yield (co)polymers with low Mw/Mn values under appropriate conditions.
Most recently, attention has turned to methacrylamido monomers and the first "truly" controlled polymerization of HPMA via aqueous RAFT polymerization mediated by 4-cyanopentanoic acid dithiobenzoate (CTP) (Scales et al., 2005; incorporated herein by reference). HPMA was polymerized with good control over the molecular weight and polydispersity (Mw/Mn) in an acetic acid/sodium acetate buffer solution. The first RAFT polymerization of a cationic methacrylamido species, namely N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA), mediated by CTP in aqueous media under the same conditions used for the polymerization of HPMA has also been reported (Vasilieva et al., 2004; incorporated herein by reference). DMAPMA was also polymerized in an acetic buffer with good control over the molecular weight (Mn=47,000 g/mol, Mw/Mn=1.08), while the corresponding polymerization in water alone exhibited a loss of control due to thiocarbonylthio hydrolysis (Mn=44,500 g/mol, Mw/Mn=1.62).
The control of gene expression using specific nucleic acid sequences represents a significant step toward preventing or eliminating several genetic diseases, viruses, and cancers. Discovery of RNA interference (RNAi) has made it possible to turn off (silence) specific genes by small interfering RNA (siRNA)—19-24 base-paired RNA fragments with 2-nucleotide overhangs at the 3′ ends (Elbashir et al., 2001; McCaffrey et al., 2002; both of which are herein incorporated by reference). An increasing number of experiments using siRNA in various biological systems have overwhelmingly demonstrated siRNA's effectiveness and great potential as the next generation of RNA-based therapeutic agents. Although preliminary results suggest that siRNA is a more potent inhibitor of gene expression and is less toxic to cells than other gene silencing agents (e.g., antisense oligodeoxyribonucleic acids (ODNs) (Xu et al., 2003; Miyagishi et al., 2003; Kretschmer-Kazemi and Sczakiel, 2003; Grunweller et al., 2003; Toth et al., 2002) DNAzymes (Yokota et al., 2004; Lee et al., 2002) or ribozymes (Lee et al., 2002)), its delivery to the appropriate tissues and susceptibility to hydrolytic and enzymatic degradation in the bloodstream still pose a significant challenge (Braasch et al., 2003; Dorsett and Tuschl, 2004; Heidenreich, 2004).
One possibility for effective delivery and protection of siRNA in vivo involves stabilization with synthetic polycations or polycation containing block copolymers to form specialized interpolyelectrolyte complexes (IPECs) or block ionomer complexes (BICs), respectively. Such systems employed with other polynucleic acids are well documented and variations of this concept continue to be employed in gene delivery today (Kabanov and Kabanov, 1995; Kabanov et al., 1989; Perales et al., 1994; Wu and Wu, 1987; Izumrudov et al., 1999; Van de Wetering et al., 1999; Kabanov and Kabanov, 1998; Dautzenberg, 2001; Michaels and Miekka, 1961; Alvarez-Lorenzo et al., 2005; Andersson et al., 2004). IPEC systems used in gene therapy are composed of complexed polycations (e.g. poly(vinyl pyridine) or poly(L-lysine)) and polynucleic acids (e.g., DNA or RNA). Strong electrostatic interactions between oppositely charged polyelectrolytes (e.g., polycations and polynucleic acids) allow for "self-assembly," which can substantially hinder or prevent enzymatic degradation of the incorporated polynucleotide in the bloodstream (Kabanov and Kabanov, 1995; Van de Wetering et al., 1999; Kabanov and Kabanov, 1998). The spontaneous formation of these complexes is largely driven by electrostatic interactions between the synthetic polycations and the "backbone" phosphate units of the polynucleotides. Furthermore, an overall gain in entropy due to the liberation of low molecular weight counterions and water during complexation increases the thermodynamic spontaneity of the process (Kabanov and Kabanov, 1998; Dautzenberg, 2001; Michaels and Miekka, 1961; Alvarez-Lorenzo et al., 2005; Andersson et al., 2004). The structural characteristics and solubility of IPECs in aqueous conditions are governed by the polymeric cation/polynucleotide phosphate (N/P) ratio and are maintained by the formation of non-stoichiometric IPECs, where the N/P ratio ≠1. These imbalanced IPECs can form two types of structures: 1) positive IPECs that contain an excess of polycations; and 2) negative IPECS that contain an excess of unoccupied or unpaired phosphates. While the preparation of these two electrosterically-stabilized IPEC systems does eliminate solubility issues observed with stoichiometric IPECs, the negative IPECS are typically not effective transfection agents and positive IPECs, due to their residual cationic nature, are often too interactive with a host of anionically charged small molecules and organelles (Kabanov and Kabanov, 1998). Unfortunately, stoichiometric IPEC systems are not very soluble in water due to their hydrophobic nature and lack of water-soluble stabilizing moieties.
More recently, the synthesis of block ionomer complexes (BICs) has provided a solution to the many solubility issues observed with conventional IPEC-based systems. Typically, BICs are formed by the complexation of a polyanion, such as DNA or RNA, with a block copolymer composed of cationic and neutral-hydrophilic block-segments. Although there are many examples of copolymers used in the formation of BICs, most incorporate poly(ethylene oxide) (PEO) as the neutral-hydrophilic block along with various cationic block types. For example, poly(ethylene oxide)-block-poly(spermine) (Kbanov and Kabanov, 1995), poly(ethylene oxide)-block-poly(L-lysine) (Katayose and Kataoka, 1996; Wolfert et al., 1996; Katayose and Kataoka, 1997), and poly(ethylene oxide)-block-poly(L-lysine-co-L-glycine) (Kabanov et al., 1996) block copolymer systems have each been used in the formation of stable BICs for gene delivery applications. The use of such neutral, hydrophilic blocks with a cationic block in lieu of a linear cationic homopolymer allows for the preparation of well-defined, electro-neutral (i.e. N/P ratio=1) complexes that are water-soluble and have a greater potential for use as effective transfection agents in gene delivery.
Because of its non-immunogenic properties and its well-documented behavior in the body, PHPMA as a neutral block in conjunction with a suitable cationic block offers great potential for improved transfection and retention behavior of the resulting BIC structures over more traditional PEO-based BIC systems. Such application of these polymers therefore renders a new generation of DNA/RNA delivery agents based on vinyl monomers prepared by a facile, controlled radical polymerization technique. Recently, it has been reported that the chemical coating of polyelectrolyte-based DNA-containing nanoparticles with multifunctional and telechelic PHPMA increased their in vivo residence times (Subr et al., 2006; incorporated herein by reference).
There is always a need for effective drug delivery agents that can be prepared through a controlled process.

Non-immunogenic, hydrophilic/cationic block copolymers and uses thereof


An air seeder distribution apparatus has seed and fertilizer tanks, and a like plurality of metering devices mounted on each product tank. A manifold set comprises a like plurality of product manifolds and each manifold is separately fed from one metering device on each of the seed and fertilizer tanks. A control selectively starts and stops rotation of the feed roller of each metering device to feed product from either tank, or both tanks to the connected manifold. The weight of each tank can be displayed on a weight indicator. Balancing of the pressure in each supply conduit can be provided. A remote opener exerts downward force on the tank lid to maintain interior pressure.

Air seeders typically include an implement frame mounted on wheels, with a plurality of furrow openers mounted on the frame. The furrow openers can be moved from a raised non-operative position to a lowered operating position where the furrow openers engage the ground and create furrows. Agricultural products such as seed and various types of fertilizer are carried in separate tanks which can be mounted on the implement frame or on a cart towed along with the implement frame.
The application rate of the various products varies significantly from as low as about three pounds per acre to 300 pounds per acre or more. In order to keep track of the amount of product remaining in each tank it is known to provide sight glasses or low level alarms to measure product remaining in the tank, or at least warn when a tank is approaching empty. Cameras are also sometimes used in the tank so the operator can visually monitor the product quantity, and it is further known to mount load cells under a tank and provide a readout of the weight of product in the tank. Present product containers for air seeders however, are typically are built with a number of compartments in a single tank assembly. The assembly thus contains a number of tanks separated by walls, and it is thus not possible to weigh the product in each tank, but only the entire tank assembly.
Metering devices dispense products from the tanks into one or more air streams that carry the products through a network of hoses and manifolds to the furrow openers where same are deposited in the furrows. Most modern air seeders have furrow openers that deliver seed to seed furrows and fertilizer to separate fertilizer furrows. These may be totally separate furrow openers mounted on separate shanks, such as mid row fertilizer banding furrow openers which are remote from the seed furrow openers, or combination furrow opener where a single shank supports a furrow opening tool that makes one furrow for seed and a separate furrow for fertilizer. There are also then two separate distribution networks, one delivering product from selected ones of the tanks to the seed furrows, and one delivering product from selected ones of the tanks to the fertilizer furrows.
The terms "seed" and "fertilizer" are not meant restrictively, since in many cases some fertilizer is metered into the air stream carry the seed, and also in some instances it may be that fertilizer may be directed into the "seed" furrows, and vice versa if conditions warrant it. The terms "seed" and "fertilizer" are simply convenient to differentiate the two separate "runs" or air streams. Basically in an air seeder it is desirable to be able to direct agricultural product from any of the tanks into any of the available air streams.
The wide range of application rates applies not just to total product but also to the product mix. When seeding canola for example the application rate of canola seed may be three pounds per acre while fertilizer is applied at 300 pounds per acre. It is desirable then to use a smaller product tank for canola seed, and direct the seed from that tank to the seed air stream for carriage to the seed furrows. On the other hand when seeding peas for example the application rate of pea seed may be 200 pounds per acre while fertilizer is applied at 50 pounds per acre, and it is then desirable to use one or more larger product tanks for pea seed, and direct the seed from those tanks to the seed air stream for carriage to the seed furrows. Thus the frequency of the need to stop and fill when one tank is empty can be reduced.
In a typical air seeder a metering roller, auger, or the like dispenses product from each tank into an air stream. A conduit or the like generally connects the air stream to the top of the interior of the tank to pressurize the tank so that there is no pressure differential between the tank and the air stream which would put back pressure on the product as it is being metered into the air stream. This requires that the lid on the tank fill opening is sealed and clamped when closed.
The air stream carries the product through a primary hose to a manifold where the air stream and product is divided and directed into multiple secondary hoses connected to the manifold outlet ports. In some arrangements each secondary hose connects into a further manifold and the air stream is divided again into further final hoses leading to each furrow opener. It is desired to have an equal product quantity in each of the secondary hoses to provide equal product quantity in each of the final hoses, however the secondary and final hoses are typically of varied lengths. A longer hose will exert more back pressure and resistance to flow from the manifold compared to a shorter hose, and so air and product flows from the manifold are unequal as the longer hoses have a reduced flow and the shorter hoses have increased flow. In addition, manifolds of various sizes are also often used on one air seeder, for example some of the manifolds may have six outlets, and some eight outlets, to conveniently match the number of openers on the air seeder. As a result different pressures in the different sized manifolds again contribute to uneven distribution to the furrow openers.
Wider air seeders require more furrow openers and therefore more manifolds. Thus it is also known to divide product by delivering product from different sections along the length of a continuous meter roller into different air streams in different primary hoses, and then into manifolds. With this system, it is desirable to have the air pressure at the metering area to be the same for all primary hoses, so that reverse air flow through the meter won't affect the metered rate in one primary hose compared to another. To help achieve this balanced pressure all primary hoses are typically the same length.
Dividing at the meter roller reduces the number of manifolds required, but with a continuous meter roller divided into sections, sealing between sections is problematic and air and product can cross over from one meter section to another section, reducing the desired uniformity of metered product distribution to each opener.
In order to reduce overlap in very wide air seeders it is further desirable to be able shut off the supply of product to sections of the air seeder. It is known to use gate mechanisms for shutting off flow of product from the tank to a section of a continuous meter roller however these gate type shut off mechanisms result in product flow on/off lead times that are difficult to deal with. The product between the gate and the meter roller continues to be metered until it is used up, even after the gate is closed. For products that are metered at a low rate, it takes a significant time for the product to stop flowing to the furrow openers. Again for these products, when the gate is re-opened it takes some time for the meter to turn enough to start dropping product into the air stream. Such a gated meter is disclosed for example in U.S. Pat. No. 7,690,440 to Dean.
In some air distribution systems gate mechanics are also used to direct the product from one metering device to either the seed air stream or the fertilizer air stream. Again sealing such gates is difficult and air can pass between the seed and fertilizer air streams, especially when the speed and pressure of one air stream is significantly greater than the other. When seeding low rates of light seed like canola, it is desirable to have a low air speed and pressure, while often at the same time it is desired to apply a high rate of fertilizer which requires a high air speed and pressure to carry the high product volume through the system. When two different pressures and air speeds enter such a gated meter system, the air crosses over from the fertilizer to the seed side resulting in increased air speed on the seed air stream and reduced air speed in the fertilizer air stream.

Air seeder tank and distribution apparatus


An image forming apparatus includes an image forming portion, a high-voltage generation circuit, a current detection portion and a control portion. The image forming portion includes an image carrying member, a charging device, an exposure device and a developing device which includes a developer carrying member for carrying a developer including a carrier and a toner. The control portion can perform a development ghost prediction mode that includes a step of measuring the amount of charge of the toner within the developing device at the time of non-image formation, a step of measuring, as a carrier current, the direct-current component of a development current when the amount of development of the toner is 0 [mg/cm2] and a step of estimating the level of occurrence of development ghost and the cause of occurrence based on the amount of charge of the toner and the carrier current which are measured.

The present disclosure relates to image forming apparatuses, such as a copying machine, a printer, a facsimile machine and a multifunctional peripheral thereof, which include an image carrying member, and particularly relates to a method of reducing development ghost in which after a developer carrying member is rotated one revolution, an immediately previous image appears on an image.
In an image forming apparatus using an electrophotographic process, the following process is generally performed, a photosensitive layer on the surface of a photosensitive drum (image carrying member) is charged with a charging device so as to have a predetermined surface potential (the same polarity as the charging polarity of a toner), and thereafter an electrostatic latent image is formed on the photosensitive drum with an exposure device. Then, the formed electrostatic latent image is visualized with a toner within a developing device. Furthermore, the following process is generally performed, and specifically, the toner image thereof is transferred on a recording medium which is passed through a nip portion (transfer nip portion) between the photosensitive drum and a transfer member that makes contact with the photosensitive drum, and thereafter fixing processing is performed.
Disadvantageously, in an image forming apparatus of a two-component development type which uses a two-component developer including a carrier and a toner, when an electrostatic latent image is developed on a photosensitive drum, after a developing roller is rotated one revolution, an immediately previous image pattern appears on an output image. This is called development ghost (development history).
This development ghost occurs due to a reason as described below. In a development region in which a developing roller and the photosensitive drum are opposite each other, the toner is moved from the developing roller to the photosensitive drum in the image (solid) portion of an image pattern. By contrast, in a white background portion, the toner is moved from the photosensitive drum to the developing roller. Hence, on the developing roller, a toner layer in a place corresponding to the white background portion of the image pattern has a larger thickness than the image portion. Although in general, in the two-component development type, the developer carried on the developing roller is separated from the developing roller after the completion of development, it is difficult to completely separate the developer.
When a portion where a previous image pattern was developed enters the development region again by the rotation of the developing roller, in a part where the toner layer is thick (the previous white background portion), the toner layer serves as a resistance layer, and thus a change in which a development voltage is shifted or the like is made, with the result that a phenomenon occurs in which as compared with a part where the toner layer is thin (the previous image portion), an image density is increased at the time of the subsequent round of development. This difference in the image density is the development ghost. Since the development ghost easily occurs when the amount of charge of the toner is lowered and the development ghost is worsened when Vpp of the alternating-current component of the development voltage is increased, when it is predicted that the amount of charge of the toner is lowered in a high temperature and high humidity environment or the like, it is possible to reduce the development ghost by lowering Vpp of the development voltage.
For example, an image forming apparatus configured as described below is known; in a development type in which a two-component developer is carried on the surface of a developer carrying member, in which only a toner is moved from the two-component developer on the surface of the developer carrying member to the surface of a toner carrying member so as to form a toner layer on the surface of the toner carrying member and in which the toner is flown from the toner layer to the surface of an electrostatic latent image carrying member where an electrostatic latent image is formed so as to develop the electrostatic latent image, a control mechanism is provided that decreases a difference between the density of an image (first patch) formed in the first revolution of the toner carrying member and the density of an image (second patch) formed in the second revolution thereof.


The disclosure relates to a charging device that supplies electrical charging energy for electrical energy stores of mobile electrical consumer units. The mobile electrical consumer units have at least one electrical energy storage unit and at least one charging interface via which electrical charging energy can be transferred from the energy storage unit to an energy store of a mobile electrical consumer unit. In order to improve the availability of electrical charging energy for energy stores of mobile electrical consumer units, the charging device takes the form of a self-driving motor vehicle.

As the demand for environmentally sustainable motor vehicles grows, more and more motor vehicles are being equipped with electric drive units that have electrical energy stores. The electrical energy stores need to be charged regularly with electricity, which usually takes place at fixed charging stations to which users need to drive.
The number of mobile appliances such as, for example, smartphones, laptops and the like, is also rapidly increasing and these also have electrical energy stores. These electrical energy stores also need to be charged regularly with electricity, which can take place at public and private charging stations or power outlets.
In the context of the present application, motor vehicles that can be powered electrically and mobile appliances are generally referred to as mobile electrical consumer units. A mobile electrical consumer unit can, however, also take other forms as long as it has at least one electrical energy store which can be charged with electricity.
Because of the limited number of charging stations, they are, however, not always available everywhere, which can be a problem in particular during a drive with a motor vehicle that can be powered electrically when the electrical energy store of the motor vehicle needs to be charged immediately.

Charging device for supplying electrical charging energy


An exhaust fan for use in bathrooms or similar areas has a generally rectangular fan housing formed from two independent structural members to reduce manufacturing waste and decrease production cost. The fan housing includes a receptacle panel that can be installed and removed from within the housing without additional tools. The fan housing includes two series of spaced view holes formed in its back wall such that during installation of the exhaust fan, the installer can view the ceiling joist to correctly position the fan housing relative to the bottom surface of the joist. The back wall of the fan housing also includes a pair of bend down tabs that can be placed in contact with the bottom surface of the joist to correctly position the bottom edge of the fan housing the required distance from the joist to accommodate the most common drywall thickness. The fan wheel contained within the fan housing includes a mounting hub having an expanded diameter insertion portion formed on its central bore to receive drive shaft of driving motor of the exhaust fan.

The present invention generally relates to a centrifugal ventilating exhaust fan, such as those typically utilized in bathrooms and other enclosed living spaces. More specifically, the present invention is a ventilating exhaust fan that includes an improved receptacle mounting panel, improved mounting alignment aids and an improved two-piece construction.
Ventilating exhaust fans, such as those typically included in bathrooms, draw air from within the enclosed area and pass the exhausted air out a vent in the gable or roof of the home. Ventilation is thus provided for the enclosed living space. Centrifugal exhaust fans include a rotating fan wheel having a plurality of vanes that create an outward airflow which, in turn, is directed out of an outlet opening by a curved fan scroll surrounding the fan wheel
Typical exhaust fans currently in use include a box-like housing positioned above a hole cut in the ceiling and are fastened to one of the ceiling joists. The fan wheel is typically directly coupled to a driving motor that is supported within the fan housing. A number of problems exist in such ventilating exhaust fans. Some of these problems arise during the installation of the fan to the ceiling joist. Since the ventilating exhaust fan is installed in new home constructions before the finishing drywall is put in place, the fan housing must be properly positioned along the ceiling joist to create the required spacing between the lower edge of the fan housing and the ceiling joist such that the drywall sheets properly abut against the edge of the ventilating exhaust fan.
In addition, the ventilating exhaust fan is typically connected to a supply of electricity to power the electric driving motor and possibly a lighting assembly associated with the exhaust fan. During installation, the supply of electricity must be fed into the enclosed fan housing and coupled to the wiring of the exhaust fan. Since the electric wiring of the exhaust fan is typically fixed within the fan housing, wiring of the ventilating exhaust fan during installation often proves to be cumbersome.
Therefore, it is an object of the present invention to provide a ventilating exhaust fan for bathrooms and other similar locations that includes a removable receptacle panel that can be removed from the fan housing to allow the exhaust fan to be connected to the electrical wiring of the home outside of the fan housing. Once the exhaust fan has been properly wired, the receptacle panel can be repositioned within the fan housing. It is a further object of the present invention to provide a fan housing that includes a series of vertically spaced view holes along the back wall of the fan housing to aid in the vertical alignment of the fan housing along the ceiling joist. Further, it is an object of the present invention to provide a pair of bend down tabs on the back wall of the fan housing to aid in vertically aligning the fan housing when the home in which the fan is being installed includes a common thickness of drywall. Further, it is an object of the present invention to provide a fan wheel that includes a mounting hub having an expanded inner diameter insertion portion that aids in the initial positioning of the fan wheel on the drive shaft of the electric driving motor. Finally, it is an object of the present invention to provide a fan housing formed from two pieces of bent, sheet-like material such that the fan housing can be constructed in a cost efficient manner.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.
The exhaust fan of the present invention includes a generally rectangular fan housing with a base wall. When the exhaust fan is installed on a joist above the ceiling of a bathroom or similar enclosed area, the base wall forms the top of the housing. Two sidewalls, a front wall and a back wall depend from the base wall to define the generally rectangular fan housing. A fan scroll is positioned within the fan housing and is in contact with the base wall to form a centrifugal path leading to an exhaust opening formed in one of the sidewalls. The exhaust opening includes an outlet fitting to direct the flow of exhausted air from the bathroom or similar enclosed area.
The fan housing of the present invention is formed from a first structural member and a second structural member joined to each other. The first structural member is formed from a sheet of stamped material that is bent to form the front wall and a pair of sidewalls. The second structural member is also a sheet of stamped material that is bent to form the base wall and the back wall. The first structural member includes a pair of mounting flanges that align with a corresponding pair of mounting flanges formed on the second structural member when the first and second structural members are joined to form the fan housing. The double thickness of the material created by the overlapping mounting flaps increases the material thickness of the fan housing in the area where the fan housing is attached to the ceiling joist.
To enhance the ease of the electrical connection between the exhaust fan of the present invention and the electrical power supply within the home, the exhaust fan includes a removable receptacle panel that can be removed from the fan housing, connected to the electrical wiring and reinstalled within the fan housing after the wiring connections have been made. The receptacle panel includes a first locking tab that engages a slot formed in the front wall of the fan housing. A second locking tab formed on the base plate of the receptacle panel is received behind a retaining clip formed on one sidewall of the fan housing to secure the receptacle panel in its installed position.
The receptacle panel further includes a removal tab that can be grasped by the user to pull the receptacle panel from its frictional interaction with the retaining clip. In this manner, the receptacle panel can be easily installed and removed from within the fan housing without any tools.
In accordance with another aspect of the invention, the fan wheel includes a central mounting hub having a central bore whose internal diameter corresponds to the outer diameter of the motor shaft. The mounting hub further includes an insertion portion formed along the central bore near the outer end of the mounting hub. The insertion portion has an increased inner diameter such that the inner diameter of the insertion portion is slightly larger than the outer diameter of the drive shaft to facilitate the initial application of the fan wheel to the drive shaft.
The fan scroll mounted to the base wall of the fan housing includes a pre-load notch having a reduced height relative to the remaining portions of the fan scroll. The reduced height pre-load notch allows the installed motor support plate to pivot slightly within the fan housing and permit removal of the motor support plate from within the four walls defining the fan housing.
In yet another aspect of the invention, the back wall of the fan housing includes two series of view holes. Each series of view holes is positioned adjacent to a side edge of the back wall of the fan housing. The view holes of each series are vertically spaced from each other such that the view holes can be aligned with the bottom edge of a ceiling joist to provide the required spacing between the bottom edge of the ceiling joist and the bottom edge surface of the fan housing to accommodate the most common thicknesses of drywall.
In an additional feature of the invention, the back wall of the fan housing includes a pair of bend down tabs that can be bent to a horizontal position. When the bend down tabs are in their horizontal position, the bend down tabs can be placed in contact with the bottom edge of the ceiling joist to provide the required spacing between the ceiling joist and the bottom-most edge of the fan housing to accommodate the most popular thickness of drywall.


A wind powered electrical generation assembly having a portable wind powered generator tower for supporting a wind powered generator allowing the wind powered generator to be raised, lowered, and removed from the tower. The wind powered electrical generation assembly also includes a vertical elevator on the tower configured to vertically lift the wind powered generator with a carriage to position the wind powered generator at a top of the tower. The wind powered electrical generation assembly further includes a wind powered generator is having at least spars and at least six airfoils with mating cams to rotate the airfoils relative to the spars as the airfoils move along the spars towards an end of the spars as wind passes the airfoils.

This invention relates generally to wind turbines, and more particularly to wind powered electrical generation assembly.
Shortages and increased cost of fossil fuels have stimulated renewed interest in the use of wind power to generate electricity. Wind powered generators are used to harness the power of the wind and to translate the mechanical energy of the wind into electrical energy with a generator. The energy from the generator can be used to power any number of electrical devices, potentially including all of the power requirements of a home.
Heretofore, wind powered generators have included airfoils designed specifically for wind turbines. Wind blowing past a turbine does not push the blades, but rather the air passing over the blades' upper surface travels farther than air crossing the underside, thus resulting in a pressure difference that creates lift. As lift drives the blades forward, they turn a drive shaft connected to a generator. However, wind powered generators typically have been too large, too expensive or too loud to allow a typical homeowner to use the wind powered generator to power their homes. Furthermore, the wind powered generators have been too hard for a typical home owner to transport and install easily at their homes.
Accordingly, a wind powered electrical generation system solving the aforementioned disadvantages and having the aforementioned advantages is desired.


There is provided a ceramic matrix composite whose strength is less degraded even in a high-temperature range at, especially, 1,400.degree. C. or higher, and a method of manufacturing the ceramic matrix composite. The ceramic matrix composite in which reinforcements are arranged in a ceramic matrix to be combined to the ceramic matrix is characterized in that the main component of the ceramic matrix consists of silicon carbide and molybdenum silicide based compound, the density ratio of the matrix is 90% or higher.

1. Field of the Invention
The present invention relates to a ceramic matrix composite obtained by combining ceramic fibers with a silicon carbide (SiC) matrix and to a method of manufacturing the same and, more particularly, to a ceramic matrix composite having high strength even in a high-temperature range at, especially, 1,400.degree. C. or higher and a method of manufacturing the same.
2. Description of the Related Art
In general, a ceramic sintered body has strength which is less degraded up to a high temperature, and is more excellent than a conventional metal material in hardness, electric insulating properties, abrasion resistance, heat resistance, corrosion resistance, light-weight properties, and the like. For this reason, the ceramic sintered body is popularly used in a large field as an electronic material or a structure material such as a heavy electric equipment part, an aircraft part, an automobile part, an electronic equipment, a precision instrument, or a semiconductor device material.
However, the ceramic sintered body is easily affected by tensile stress rather than compression stress, and, especially, the ceramic sintered body is broken by the tensile stress at once. That is, the ceramic sintered body disadvantageously has so-called high brittleness. For this reason, in order to make it possible to apply a ceramic part to a portion whose reliability should be high, high toughness of the ceramic sintered body or an increase in fracture energy are strongly demanded.
More specifically, a ceramic structure part used as a gas turbine part, an aircraft part, an automobile part, or the like requires high heat resistance, high refractory, and high reliability. In order to reply to this demand, studies for realizing the following ceramic composite material have advanced in domestic and foreign laboratories. That is, ceramic matrix composites (CMC) are improved on a toughness value or a fracture energy value in such a manner that reinforcements (strengthening materials) such as reinforcement fibers, whiskers, blades, and particles which consist of an inorganic material or a metal are dispersed in a matrix sintered body to be combined with each other.
Among the above ceramic matrix composites (CMC), a ceramic matrix composite using fibers as reinforcements is is excellent in fracture toughness or an increase in fracture energy, and has a great effect for improvement on reliability. As the reinforcement for the CMC, continuous fibers or short fibers such as glass fibers, carbon fibers, or ceramic fibers are mainly used.
Among the ceramic matrix composites which are reinforced or strengthened by fibers, a composite having silicon carbide (SiC) as a matrix is hopeful as a material constituting a structure member for high temperature because the composite has high heat resistance and high oxidation resistance.
Conventionally, as a method of combining reinforcements in the above ceramic matrix composite, the following method is employed. That is, a ceramic material powder is filled in a preform such as a fabric consisting of ceramic fibers by a wet method such as a slip cast method to manufacture a preliminary green body containing reinforcements. As in a conventional method of manufacturing a sintered body, the green body is sintered by atmospheric-pressure sintering, atmosphere pressing sintering, hot press, HIP, or the like.
On the other hand, when a matrix is formed by a reaction-sintering method, a material slurry containing carbon and SiC is impregnated in a preform such as a fabric consisting of ceramic fibers to form a preliminary green body, and reaction-sintering is performed while melted silicon (Si) is impregnated in the preliminary green body to cause the carbon component and melted Si to react with each other. A matrix consisting of a reaction-sintering SiC sintered body is integrally formed to manufacture a composite.
The reaction-sintering SiC sintered body manufactured as described above is rarely contracted during sintering, exhibits high dimensional precision, and has an advantage that a sintered body having a high density can be obtained under the heat condition at a relatively low sintering temperature of about 1,450.degree. C. Furthermore, the reaction-sintering SiC can cope with a complex shape, and has the manufacturing cost which is considerably lower than that of another manufacturing process. For this reason, practical use of the reaction-sintering SiC as a matrix constituent material of a ceramic matrix composite is expected.
However, in a ceramic matrix composite using a reaction-sintering SiC as a matrix, a manufacturing process for impregnating melted Si is employed. For this reason, the reaction-sintering SiC contains 15 to 30% by volume of free Si, and the free Si disadvantageously degrades the high-temperature strength of the composite. More specifically, since the melting point of free Si is relatively low, i.e., 1,410.degree. C., the structural strength of the composite is sharply degraded because of softening and melting of free Si under the high-temperature use condition at 1,400.degree. C. or higher. Therefore, there is a severe problem that the reaction-sintering SiC cannot be used as a structure part material.

Ceramic matrix composite and method of manufacturing the same