Heterogeneous photocatalysis is the general term that describes the technical approach. Mills, A., Le Hunte, S., “An Overview of Semiconductor Photocatalysis,” J. PhotoChem. & PhotoBio. A: Chemistry 108 (1997) 1-35; and Hoffman, M. R., Martin, S. T., Choi, W., Bahnemann, D. W., “Environmental Applications of Semiconductor Photocatalysis,” Chem Rev 1995, 95, 69-96. Of particular importance is the formation of OH., the hydroxyl radical. The hydroxyl radical is an extremely potent oxidizing agent (redox potential of +2.8 eV vs. SHE (Standard Hydrogen Electrode)) that is capable of oxidizing almost all organic compounds. By comparison, the redox potentials for the more conventional oxidants chlorine and ozone are +1.36 and +2.07 eV, respectively. Hydroxyl radicals also kill and breakdown microorganisms and endotoxins.
Contaminants in fluid streams, such as organic compounds, nitrogen and sulfur oxides, acid gasses, dissolved inorganic solids, and microorganisms are converted by the oxidizing and reducing potential of the activated semiconductor. The conversion may take the form of, but is not limited to, the oxidation of organic compounds, degradation of microorganisms, or reduction of dissolved ionic species. The products of the conversion are ideally less harmful or more easily removed from the fluid stream than the parent compounds.
Semiconductor photocatalysts that have been demonstrated for the destruction of organic contaminants in fluid media include but are not limited to: TiO2, ZrO2, ZnO, CaTiO3, SnO2, MoO3, Fe2O3, and WO3. TiO2 is the most widely investigated because it is chemically stable, has a suitable bandgap structure for UV/Visible photoactivation, and is relatively inexpensive.
TiO2 exists as three principal crystalline forms: rutile, brookite, and anatase. The rutile form of TiO2 is widely used as a pigment and can be found in almost anything white, e.g., paint, paper, textiles, inks, plastics and cosmetics. Anatase, the low temperature form, is the most photoactive form. One method for making a brookite-containing TiO2 photocatalyst is described in U.S. Pat. No. 6,337,301, the disclosure of which is incorporated by reference in its entirety.
The inclusion of co-catalysts (e.g., platinum, palladium, silver and/or their oxides and sulfides) with titanium dioxide can increase the photocatalytic activity. A variety of methods improve the quantum efficiency of TiO2 by adding various metals to increase the minority carrier diffusion length, Augustynski, J.; Hinden, J. Stalder, C.; J. Electrochem. Soc. 1977, 124, 1063, or achieve efficient charge separation to increase carrier lifetimes. Vogel, R., Hoyer, P., Weller, H., “Quantum-Sized PbS, CdS, Ag2S, Sb2S3 and Bi2S3 Particles as Sensitizers for Various Nanoporous Wide-Bandgap Semiconductors,” J. Phys. Chem. 1994, 98, 3181-3188.
The inventors have found that the performance of a photocatalytic fluid purification device is primarily a function of the activity of the semiconductor photocatalyst, the specific surface area of the irradiated semiconductor surface, the mass transfer characteristics of the device, the pressure drop across the device, and light distribution and absolute light intensity at the semiconductor surfaces. All of these factors should be considered concurrently in the design of the photoreactor. To take advantage of the activity of the semiconductor surface, conditions are preferably controlled such that the rate of transport of contaminants from the fluid bulk to the semiconductor surface is not a limiting factor. Because the rate of contaminant conversion increases with increased surface concentration of the contaminant, the concentration gradient between the fluid bulk and the fluid at the semiconductor surface should be preferably minimized. The mass transfer characteristics of the device increase with the velocity of the fluid through the device and with closer proximity of the bulk fluid to the semiconductor surfaces. Preferred mass transfer characteristics are achieved by altering pore diameter, packing diameter, or otherwise physically ensuring small characteristic lengths. Forcing the fluid to flow in a tortuous path past the semiconductor surfaces also inherently improves mass transfer.
According to the invention, the absolute conversion rate is a function of the surface concentration of the organic compound, the light intensity, and the irradiated surface area. The inventors believe that the reaction order in light intensity is <1, and that it is half order based on theoretical consideration of the accepted reaction mechanism and observed experimentally. Gerischer, H., Electrochimica Acta 38, 9 (1993) and Turchi, C. S., Ollis, D. F., Journal of Catalysis 119, 483 (1989). Based on the inventors' understanding that the reaction order for light intensity is less than unity, it is desirable to spread the light from a given source over as much surface area as possible. Therefore, according to the principles of the invention, an efficient device is one that provides intimate contact between the fluid and the semiconductor surfaces while spreading activating light over as large a surface area as is practical. Note that if the reaction order were, in fact, unity in light intensity, increasing the specific irradiated surface area, for a given light source, would not improve performance.
Since until recently known semiconductor surfaces have been opaque to UV light; the spreading of light has typically been done by using geometry or waveguides. U.S. Pat. No. 5,516,492, to Dong, uses a plurality of curved plates while U.S. Pat. No. 6,063,343, to Say, uses a series of close packed plates orientated normal to the lamp axis to provide high specific irradiated surface area. U.S. Pat. No. 6,285,816, to Anderson, uses a waveguide to distribute the light. The previously mentioned methods rely on geometry or optics to distribute light to a semiconductor film and do not rely on a semitransparent substrate/semiconductor film pairing for radiation distribution.
Much of the early research on semiconductor photocatalysis concerned methods using opaque titanium dioxide (TiO2) slurries or TiO2 wash coatings onto or inside a glass tube and the photodegradation of organic compounds and their intermediates in water. These methods of using TiO2 have limitations for commercial applications. For example, TiO2 slurry has the serious limitation of the removal of the TiO2 particles from the purified water. While wash coating TiO2 onto glass avoids the removal limitations of the slurry approach, it has its own problems in that insufficient surface area is presented for effective destruction of organics within a reasonable time period. Additionally, the wash coat is not firmly attached to the glass resulting in a loss of TiO2 to the water stream and a concomitant reduction in photocatalytic activity.
Kraeutler and Bard made a photocatalytic reactor with a water slurry of suspended TiO2 powder, in the anatase crystalline form, and studied the decomposition of saturated carboxylic acid. J. ACS 100 (1978) 5985-5992. Other researchers used UV-illuminated slurries of TiO2 to study the photocatalyzed degradation of organic pollutants in water.
Mathews created a thin film reactor by wash coating TiO2, (Degussa P25™), particles to the inside of a 7 millimeter long borosilicate glass tube wound into a 65-turn spiral. He monitored the destruction of salicylic acid, phenol, 2-chlorophenol, 4-chlorophenol, benzoic acid, 2-naphthol, naphthalene, and florescin in water. J. Physical Chemistry 91 (1987) 3328-3333. U.S. Pat. No. 5,766,455, to Berman, wash coated an opaque coating onto a glass fiber mesh. Neither of these devices uses a transparent substrate/semiconductor pairing.
U.S. Pat. No. 4,892,712, to Robertson et al., discloses the attachment by the sol-gel process of anatase TiO2 to a fiberglass mesh substrate. This mesh was wrapped around a light source contained within a quartz glass cylinder and emitting UV radiation in a wavelength range of 340 to 350 nanometers (nm). Unlike the present invention, Robertson's mesh is not rigid, lacks permanent bonding of the semiconductor to the mesh, and does not specify the transparency of the substrate semiconductor pairing.
Professor I. R. Bellobono prepared photocatalytic membranes immobilizing 23% of Titanium Dioxide (Degussa P-25). Controlled amounts of appropriate monomers and polymers, containing the semiconductor to be immobilized and photoinitiated by a proprietary photocatalytic system was photografted onto a non-woven polyester tissue. The final porosity of the photosynthesized membrane was regulated at 2.5-4.0 microns. He trade named this membrane “Photoperm”™. “Effective Membrane Processes. New Perspectives,” R. Paterson, ed., BHR, Mech. Eng. Publ., London (1993), 257-274. The process was patented in Italy in 1995, Italian Pat. No. IT1252586. Unlike the present invention, Bellobono's apparatus is not inert, not durable, and would display excess pressure drop due to low fluid permeability.
Cittenden, et al. discloses a method and apparatus for destroying organic compounds in fluids. See The 1995 American Society of Mechanical Engineers (ASME) International Solar Energy Conference, Maui, Hi., USA. An opaque coating of TiO2 was attached by wash coating to a 35×60-mesh silica gel substrate. The substrate was placed within a plastic tube that allowed the penetration of UV light. Organic pollutants in a water stream passed axially through the tube. Unlike the present invention with a semitransparent semiconductor coating, Cittenden's invention is not durable, the photocatalytic coating is not semitransparent, and has very limited fluid permeability.
Another method to make ceramic titanium membranes uses a refined sol-gel process. J. Membrane Science 30 (1988) 243-258, and U.S. Pat. No. 5,006,248, to Anderson. These membranes are porous and transparent to UV illumination. They are made from a titanium alkoxide and then fired to form the anatase crystalline structure. Unlike the present invention, Anderson's invention has very limited fluid permeability.
Thus, while attempts have been made in the prior art to enhance quantum yields by increasing semiconductor specific irradiated surface area and improving UV light penetration, serious limitations remain to the commercial development of an efficient, durable, photocatalytic purification apparatus with acceptable pressure drop characteristics and methods for its use.


The present invention relates to mastitis, an extremely important veterinary disease, and to the preparation and administration of egg antibody products which may be used to neutralize a wide variety of systemic pathogens which cause or exacerbate this disease.
The term mastitis refers to inflammation of the mammary gland, regardless of cause. It is characterized by physical, chemical, and usually bacteriological changes in the milk and by pathological changes in the glandular tissue. The most important changes in the milk include discoloration, the presence of clots and the presence of large numbers of leukocytes. Although there is swelling, heat, pain, and induration in the mammary gland in many cases, a large proportion of mastitic glands are not readily detectable by manual palpation or by visual examination of the milk using a strip cup. Because of the very large numbers of such "subclinical" cases, the diagnosis of mastitis has come to depend largely on indirect tests which depend, in turn, on the leukocyte content of the milk. Thus, it is practicable to define mastitis as a disease characterized by the presence of a significantly increased leukocyte content in milk from affected glands. This leukocyte content is commonly referred to as the "somatic cell count," or SCC.
Many infective agents, primarily bacterial but occasionally fungal or protozoal, have been implicated as causes of mastitis. The most common are Streptococus agalactiae and Staphylococcus aureus, with Escherichia coli becoming a significant cause in housed or confined cattle, principally in the northern hemisphere. Other agents include Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium (Actinomyces) pyogenes, Klebsiella spp., Mycobacterium bovis, Pseudomonas pyocyaneus, Serratia marcescens, Mycoplasma bovis, Nocardia asteroides, Proteus spp., and Chlamydia psittaci.
Infection of each mammary gland occurs via the teat canal, with the infection originating from two main sources, the infected udder and the environment. In dairy cattle and milking goats, the important infections are those which persist readily in the udder, especially Str. agalactiae and Staph. aureus. The contamination of milkers' hands, washcloths, and milking machine cups by milk from infected quarters may quickly lead to the spread of infection to the teats of other animals. These are commonly referred to as infectious or contagious mastitides.
Bacteria which are normal inhabitants of the environment, such as E. coli and Ps. pyocyaneus, cause mastitis less frequently but, when they do, the disease is much more resistant to hygienic control measures. Large, zero-grazed herds in feedlots are likely to encounter more hygiene problems than conventionally housed herds. The problems relate mainly to fouling of the udder caused by inadequate or improper bedding in the larger units. Thus, these are known as environmental mastitides.
The frequency of occurrence of mastitis is dependent upon the ability of bacterial agent to set up infection in the mammary tissue. The diferences between bacteria in their ability to set up a mastitic state is dependent on at least two important groups of factors: bacterial characteristics and transmission mechanisms. Bacterial characteristics include the ability of the organism to survive in the cow's immediate environment (i.e., its resistance to environmental influences, including cleaning and disinfection procedures), its ability to colonize the teat duct, its ability to adhere to mammary epithelium and set up a mastitis reaction, and its resistance to antibiotic therapy. Transmission mechanisms are a function of the extent of the infection in the environment (including infected quarters), the efficiency of milking personnel and machinery, milking parlor hygiene, and the susceptibility of the cow. An individual cow's susceptibility, in turn, is a function of the stage of lactation (early lactation, especially the first two months, representing highest susceptibility), the age of the cow (older cows, having had more than four lactations, being more susceptible), the level of inherited resistance (possibly related to teat shape and anatomy of the teat canal), lesions on the teat skin (especially the orifice), and the immunological status of each mammary gland (including prior infections, especially with Staph. aureus).
In most countries, surveys of the incidence of mastitis, irrespective of cause, show comparable figures of about 40% morbidity amongst dairy cows and a quarter infection rate of about 25%. The incidence is similar in goats. Surveys of the prevalence of the various infections in cattle show remarkable similarity in different countries. The predominant position of Str. agatactiae as a cause of bovine mastitis has been usurped by Staph. aureus, especially in areas where the treatment of mastitis with penicillin has been practiced intensively and where machine milking has replaced hand milking. In such areas a relative incidence of Str. agalactiae, other streptococci, and Staph. aureus of 1:1:2 is a common finding.
Although the prevalence of Staph. aureus has been significantly curbed by modem control programs based on teat dipping and dry period treatment, it remains the preeminent cause of subclinical mastitis. Mastitis is said to be subclinical when there is evidence of inflammation, e.g., a high somatic cell count in the milk, without any visible abnormality of the milk or udder. Chronic cases of mastitis, particularly those caused by Staph. aureus, are often refractory to treatment while the cow is lactating. For staphylococcal infections in general, a cure rate of 30% is about the best that can be expected. An old adage holds that "once a Staph. cow, always a Staph. cow." Thus, many dairymen choose to cut their losses and simply cull Staph.-positive cows rather than to attempt treatment.
Although mastitis occurs sporadically in all species, it assumes major economic importance only in dairy cattle. In terms of economic loss it is undoubtedly the most important disease with which the dairy industry must contend. In 1992, mastitis infections cost members of the American Dairy Association over $200,000,000. High somatic cell counts in cows result in the loss of approximately 200,000 pounds of milk per cow per year at a financial cost of approximately $288 per cow. Only 10% of the approximately 9,750,000 dairy cows in the United States attain the highest ranking on somatic cell count (below 100,000). A dairyman receives an additional 50 cents per 100-wt. of milk for the highest ranking, i.e., the lowest SCC range. Thus, the insidious presence of subclinical mastitis in a herd can have a devastating effect on milk profits, even in the absence of any external manifestations of disease.
Most estimates show that on the average an affected quarter suffers a 30% reduction in productivity and an affected cow is estimated to lose 15% of its production. Total economic losses caused by mastitis comprise the value of milk production lost, the value of cows lost by premature culling, the value of milk discarded or downgraded, and the cost of treatment and veterinary expenses.
Ordinarily, mastitis is treated either systemically by parenteral injection or locally by intramammary infusion. Parenteral treatment is usually reserved for cases of mastitis in which there is a marked systemic reaction, to control or prevent the development of a septicemia or bacteremia and to assist in the treatment of the infection in the gland. The systemic reaction can usually be brought under control by standard doses of antibiotics or sulfonamides but complete sterilization of the affected quarters is seldom achieved because of the relatively poor diffusion of the antibiotic from the bloodstream into the milk. Parenteral treatment is also used when the gland is badly swollen and intramammary antibiotic is unlikely to diffuse properly. To produce therapeutic levels of antibiotic in the mammary gland by parenteral treatment, it is necessary to use higher-than-normal dose rates, which can alter milk-withholding times, sometimes with disastrous consequences, as discussed infra.
Because of convenience and efficiency, udder infusions have been the preferred method of treatment. Disposable tubes containing suitable drugs in either an aqueous or ointment base are inserted into the teat canal, providing diffusion of drug into the glandular tissue. Strict hygiene is necessary during treatment to avoid the introduction of bacteria, yeasts and fungi into the treated quarters. Diffusion of infused drugs is often impeded by the blockage of lactiferous ducts and alveoli with inflammatory debris. Drug-withholding times are just as applicable to udder infusions as parenterally administered drugs, since these infusions rapidly undergo systemic absorption from the highly vascular udder.
Choice of a suitable drug for the treatment of mastitis is often extremely difficult. In vitro laboratory testing of bacterial sensitivity is not necessarily a justifiable basis for selecting the antibacterial agent to be used in individual cows, and the response to treatment in clinical cases is often unrelated to the results of in vitro sensitivity tests.
In the opinion of the authors of one of the leading texts on large animal veterinary medicine, very little good research and development work has been performed in the field of mastitis prophylaxis and treatment, and most of the products available have been developed with very little scientific support. Attractiveness to the consumer has been placed above efficiency, in the opinion of these authors, resulting in "intramammary preparations containing a battery of antibacterial agents, one or more of a long list of generally unhelpful adjuvants, and inappropriate recommendations about their use, especially with regard to frequency of administration and length of time after treatment for which milk must be withheld from sale." Further, "[t]he indiscriminate and improper use of antibiotics for the treatment of clinical mastitis in lactating cows which has resulted from inaccurate promotion and uninformed use by farmers has meant that the control of mastitis has really received little assistance. Drug-resistant organisms, especially Staph. aureus, have been encouraged, and the chances of human consumers of dairy products being exposed to antibiotic residues has been increased." (Blood and Radostits, Veterinary Medicine: A Textbook of the Diseases of Cattle, Sheep, Pigs, Goats and Horses, 7th ed., 1989, p. 512).
The effect of antibiotics in milk on the manufacture of dairy products and the development of sensitivity syndromes in human beings is of the utmost consequence. In most countries, the maximum intramammary dose of antibiotics is limited by legislation and the presence of detectable quantities of antibiotics in milk constitutes adulteration. Strict legislation and mandatory milk-testing in the United States have greatly decreased such risk to consumers, but the penalties for milk contamination as a result of inadequate milk-withholding times are enormous and can result in financial disaster for the dairyman and/or veterinarian found to be responsible for such a violation. Since the rate of drug excretion varies among different animals and in the same animal at different points in the lactation period, withholding times specified on drug labels are not always accurate and can lead to inadvertent violation of residue limits. As a result, some dairymen will elect to cull any but the most valuable cows rather than to run the risk of contaminated milk. Even aside from such risk, substantial loss is involved in the discarding of milk during specified withholding times, which can range anywhere from 72 hours for an udder infusion in a lactating cow to 10 days for parenteral antibiotics in long-acting bases.
For the foregoing reasons, there exists a felt need for a mastitis treatment which is not only efficacious, easily administered, and cost-effective, but which is not hampered by the uncertainty and risk of a milk-withholding period. Such a treatment would undoubtedly be enthusiastically received by the dairy industry worldwide.


This invention relates to a method and an apparatus for cutting off the beads of seam-welded pipes and especially of hot-shaped, seam-welded pipes More particularly, it relates to a method and apparatus for cutting off the beads of seam-welded pipes using a freely-rotatable circular cutting tool.
In the manufacture of seam-welded pipes and particularly hot-shaped seam-welded pipes, an endless strip, referred to as a skelp, is continuously passed through a heating furnace and heated to a temperature of at least 850.degree. C., after which it is passed through a series of forming rolls which bend the outer edges of the skelp and form it into the shape of a tube. The resulting tubular object is referred to as an open pipe. The confronting outer edges of the open pipe are as of yet unwelded. The open pipe is then passed through a tubular work coil which is somewhat larger than the outer diameter of the open pipe, and the confronting edges of the open pipe are selectively heated to a welding temperature, and the confronting edges of the open pipe are then pressure welded by squeeze rolls which are located downstream of the work coil, thereby forming a seam-welded pipe. Due to the heating and pressure welding, the inner and outer surfaces of the welded seam swells to form beads on the inside and outside of the pipe. The pipe is then sent to a finishing apparatus which cuts off the beads. It is important to cut off the beads smoothly so that there is no difference in thickness between the portion of the pipe which is cut and the adjoining portions. However, as the removal of the inner bead must be performed inside the pipe, it is generally difficult to cut the beads off smoothly. Normally, a slender mandrel is inserted from an open space upstream of where the forming rolls form the skelp into a tube to the downstream side of the squeeze rolls, and a circular cutting tool is mounted on the tip of the mandrel. Accordingly, the mandrel passes through the entire length of the open pipe and the cutting tool is secured to the mandrel downstream of the squeeze rolls.
In order to selectively heat the edge portions of the open pipe which are to be welded, a high-frequency current is passed therethrough by the work coil. Due to the skin effect, currents are induced on the circumferential surface of the open pipe, and heating is accomplished by the concentration of the current in the portions to be welded. However, if the induced current leaks to outside the portions to be welded, the welding efficiency decreases. Therefore, the leak current should be as small as possible, and in actual practice, an impeder having a ferrite core is disposed inside the open pipe so as to confront the work coil. Generally, since a mandrel for cutting off the beads on the inside of a seam-welded pipe passes through the center of the open pipe, the impeder is mounted on the mandrel opposite the work coil.
Seam welding can be formed in a hot or cold state. When cutting off the beads on the inside of a cold-shaped, seam-welded pipe, in order to prevent excess or inadequate cutting, a full-type cutting tool having the same curvature as the inside of the pipe is used. Even when the seam-welded pipe is itself in a cold state, as cutting is performed immediately after welding when the bead is still hot, the cutting tool normally has to be replaced after 1.5-2.5 hours of use. The production line must be stopped for a long time when the cutting tool is replaced. The time lost for replacement of the cutting tool has an adverse effect on productivity, since the forming and welding processes for seam-welded pipes and the bead cutting operation are all performed continuously, so that when the cutting tool is replaced, all three of these operations must be halted.
When manufacturing hot-shaped seam-welded pipes, if the same cutting method is used as for cold-shaped seam-welded pipes, decreases in productivity due to cutting tool replacement are even greater. When replacing the cutting tool, it is necessary to stop the production line just as when manufacturing cold-shaped seam-welded pipes. While the production line is stopped, it is also necessary to lower the temperature of the furnace in which the skelp is heated to the rolling temperature so that the skelp will not melt through and sever. After the cutting tool is replaced and the line is restarted, the furnace temperature is again raised, but skelp must be passed through the furnace for some length of time before the skelp temperature stabilizes, and the length of skelp which passes through the furnace until the skelp temperature stabilizes must be discarded. Furthermore, as the cutting tool operates in a high-temperature environment, the life span of the cutting tool and the length of time between replacements of the cutting tool are much shorter than in the manufacture of cold-shaped seam-welded pipes. Accordingly, if the cutting tool must be frequently replaced, not only are there large time losses, but the energy consumption rate rises and there is a large amount of material loss in the form of scrap.
Moreover, when the inside beads of hot-shaped seam-welded pipes are cut off on a production line, just as with cold-shaped seam-welded pipes, a mandrel is inserted into a pipe from a position upstream of where the skelp is formed into an open pipe and the inside bead is cut off by a cutting tool mounted on the end of the mandrel. In hot shaping, the temperature of the skelp is at least 850.degree. C., so even without the heat generated by welding, the mandrel would be heated to around 700.degree. C. by the heat from the open pipe. Therefore, it is generally necessary to provide some form of heat protection for a mandrel used to cut off the inside beads of hot-shaped seam-welded pipes.
For these reasons, in a production line for seam-welded pipes and particularly hot-shaped seam-welded pipes, there is a great need to increase the life span of the cutting tool used for cutting off inside beads and to cool the mandrel on which the cutting tool is mounted.
There have been various proposals for using a circular cutting tool for removing the inside beads of seam-welded pipes. Japanese Published Unexamined patent application No. 48-56547 (1973) discloses the use of a circular cutting tool for removing the inner beads of cold-shaped seam-welded pipes. The cutting tool has a skew angle of 22.5.degree., although the diameter and the tilt angle of the cutting tool are not specified. No mention is made of the life span of the cutting tool.
Japanese Published Unexamined patent applications Nos. 58-143908 (1983) and 59-144586 (1984) also disclose the use of circular cutting tools for removing inside beads of hot-shaped seam-welded pipes. By using a cutting tool with a diameter of 0.6-0.8 times the diameter of the pipe, a skew angle of 10.degree.-45.degree., and a tilt angle of 5.degree.-15.degree., a long life span of 2.5 hours (application No. 58-143908) or 5 hours (application No. 59-144586) can be achieved. For cutting in a high-temperature environment, these life spans are extremely long.
In above-mentioned Japanese Published Unexamined patent applications Nos. 58-143908 and 59-144586, in order to protect the mandrel from heat, the mandrel is formed with a hollow center, and cooling water is passed through the entire length of the mandrel from the base end and then continuing through the holder, the impeder, and the outer end, i.e., head portion on which the cutting tool is mounted. The cooling water is discharged into the seam-welded pipe through gaps between the outer end, i.e., head portion of the mandrel and a plurality of rollers which guide the mandrel along the inside beads of a pipe.
As for the cutting tool itself, in above-mentioned Japanese Published Unexamined patent application No. 48-56547, if the tilt angle is 5.degree.-15.degree., at a relatively slow line speed of at most 40 m/min, for example, satisfactory cutting can be carried out. However, when the line speed exceeds 100 m/min, the rotation of the cutting tool becomes unstable, and the cutting tool tends to remove too much or too little of the inside surface of a pipe being processed.
In Japanese Published Unexamined patent applications Nos. 58-143908 and 59-144586, the same tendency can be seen when the skew angle is small, but when the skew angle is large, the shape of the cutting tool as seen from the direction of advance of the pipe becomes elliptical, the difference between the curvature of the inside of the pipe and the cutting tool increases, and the cut surface takes on a U-shaped cross section, so that it becomes difficult to perform smooth cutting.
As the life span of cutting tools increases, the length of time which the mandrel must be inserted into an open pipe necessarily increases, and problems occur which were not experienced when cutting tools had a shorter life span.
The holder of the mandrel must support the mandrel so that the opposite end of the mandrel is located downstream of the squeeze rolls, and it must support an impeder so that the impeder confronts a work coil. Therefore, the holder is generally long, and the length of time for which cooling water passes therethrough is also long. As it passes through the holder, the cooling water undergoes a great increase in temperature, and even if the cooling water does not boil, gases which are dissolved in the cooling water come out of solution and remain inside the holder. The longer the mandrel is inserted into an open pipe, the larger the amount of gas which will accumulate inside the holder, and as the gas does not conduct heat as well as the cooling water, a difference in the rate of cooling will develop between the top side of the holder, where the gas accumulates, and the bottom side of the holder, which is in contact only with cooling water. This difference in cooling rates causes the holder to bend. Even if the amount of curvature is minute, as the holder itself is long, the misalignment between both of its ends and the center of the holder is large. Not only does this curvature affect the depth of cutting of the cutting tool, in the worst case, it becomes impossible to detach the rest of the mandrel from the pipe.
The impeder of the mandrel contains a ferrite core which is self-heated by magnetic induction caused by the action of the work coil. Accordingly, the greater the ability to cool the impeder the better. However, the gas which is generated in the holder is carried downstream to the impeder, and due to the gas, the impeder may be inadequately cooled. If the thermal load on the impeder is too large, not only will the ferrite core lose its magnetism, but the FRP cover which surrounds the ferrite core can be damaged, possibly resulting in the breakage of the impeder.


Known hydroelectric generating equipment systems have mechanical drawbacks which substantially limit their economic utilization - particularly at low head sites. Particularly, all known types require a direct mechanical connection between the turbine and the generator. Known low-head axial turbine equipment are of three types; (1) The rim-generator type--in which the generator rotor is located on the periphery of the turbine runner; (2) the tube-type--in which the generator is located outside the water passage and connected to the turbine through an extended drive shaft; and (3) the bulb turbine type--in which both the runner and the generator are directly connected and enclosed within the water passage.
All three types require expensive complicated concrete Civil Works to encase and structurally support the turbine and generator in a common housing. There are also problems in matching up turbine speeds with generator speed requirements, accessibility for maintenance purposes to the important components and the inability to install most known equipment into most already existing dams or structures.
The following described invention proposes to solve all of the above problems and more, by allowing a physical separation of the turbine and the generator and accomplishing several other required features (such as synchronous generator speed control) through the unique application of certain fluid drive components.


The present invention relates to wellbore tools and more particularly to an apparatus for retrieval of metal objects, such as cuttings and other foreign objects that accumulate in the process of perforating or milling over bridge plugs and other down hole obstructions from a wellbore.
Various types of bridge plugs are conventionally used in the oil and gas industry. These bridge plugs are installed in the annulus and are often covered in cement. Removal of such plugs can sometimes pose a problem for the industry. A rotary bit drills the cement and plugs out, while some of the cuttings of the plugs are carried out to the surface by a liquid circulated down hole.
Sometimes, a production packer needs to be removed together with the metal pipe that it surrounds. In those cases, milling tools with gravity fed boot baskets are used for retrieving pieces of metal from the wellbore. After retrieval of the production packer, it may become necessary to run a conventional fishing magnet to retrieve additional junk and cuttings.
A conventional fishing magnet is mounted inside a housing that is lowered into a wellbore. It is limited in the ability to retrieve cuttings in that its magnetization is restricted to the extreme bottom surface of the magnet. The fact that circulating fluids lift the cuttings away from the bottom surface of the magnet renders that conventional fishing magnet useless in this situation.
Often times, a boot basket is used for collecting cuttings that did not attach themselves to the conventional magnet. A boot basket has small openings for catching these particles. Consequently, many large size pieces or very small pieces suspended in the fluid flow are not trapped in the basket and remain in the wellbore.
The present invention contemplates elimination of drawbacks associated with the prior art and provision of a wellbore apparatus for removal of metal objects, such as cuttings, and other foreign particles that provides for the use of sets of magnets spaced longitudinally along the tool body.
It is, therefore, an object of the present invention to provide an apparatus for retrieval of metal cuttings and other foreign objects from a wellbore.
It is another object of the present invention to provide a packer-milling tool with magnets set in a spaced relationship longitudinally along the tool body to increase xe2x80x9ccatchingxe2x80x9d capacity of the tool.
These and other objects of the invention are achieved through a provision of an apparatus for removal of metal cuttings and other foreign objects from a wellbore that uses at least two magnet assemblies vertically spaced from each other and mounted on the body of the tool. Each magnet assembly is comprised of a plurality of magnets encircling the body of the tool and covering a surface area greater than one half of the tool body.
One of the embodiments of the invention provides for arcuate in cross section magnet members that are detachably secured on the tool body. The second embodiment provides for trapezoidal in cross section magnet members that extend longitudinally in parallel relationship to a central axis of the tool body. The tool of the second embodiment further provides for magnet protectors mounted adjacent to each magnet member. Each magnet protector has a triangular cross section and has a slanted surface that is angled in the direction of rotation.
The space between each magnet and the next adjacent magnet protector forms a xe2x80x9ctrapxe2x80x9d that receives and retains metal particles pushed away by the leading surface of the adjacent magnet member. Consequently, the capability of the tool to retain cuttings for subsequent retrieval to the surface is significantly increased in comparison with conventional magnet tools.


Field
This invention relates generally to transceivers, and more specifically, to a reconfigurable multi-mode transceiver.
Background
A transceiver in a communication system may transmit data using a transmitter and receive data using a receiver for two-way communication. The transceiver may also support carrier aggregation (CA), which is simultaneous operation on multiple carriers. Multi-mode transceivers including Long Term Evolution (LTE)/Frequency Division Duplex (FDD). LTE/Time Division Duplex (TDD). Circuit-Switched FallBack (CSFB), Simultaneous Voice and LTE (SVLTE), Simultaneous GSM and LTE (SGLTE), Dual SIM Dual Standby (DSDS), and other similarly-configured devices co-exist in several different combinations in different regions of the world. Further, LTE carrier aggregation with 2, 3, and 4 downlinks is already out or will soon be available. Thus, a device that can handle multiple modes and bands while providing seamless FDD and TDD interoperability is needed in order to meet the growing demands for wireless data. However, the support of both FDD and TDD operations complicates the local oscillator LO and synthesizer connections to the receive (RX) and transmit (TX) links in the multi-mode transceiver.
To address the issues connected with a need for multi-band, multi-mode devices, a two-chip configuration in which one transceiver (e.g., an FDD transceiver) resides on a first chip and another transceiver (e.g., a TDD transceiver supporting LTE-CA and other technologies) resides on a second chip can be used. Although this configuration may provide the needed features, it will occupy more chip area, consume more current, and support less number of combinations of CA than a single-chip solution. Accordingly, a need exists for reconfiguring and reusing the transceiver flexibly with minimum hardware to provide a single-chip solution for improving the FDD and TDD interoperability and better spectrum utilization.


The present invention relates generally to methods for treatment of pulmonary diseases and diseases associated with upper respiratory tract infection. Such diseases, including cystic fibrosis, emphysema, chronic bronchitis, sinusitis, and the common cold, have in common bronchial or sinus congestion, production of large amounts of sputum, and the possibility of secondary bacterial infection requiring antibiotic therapy.
Acute otitis media is a bacterial or viral infection in the middle ear which is usually secondary to upper respiratory tract infections and is most common in children. Microorganisms may migrate from the nasopharynx to the middle ear over the surface of the eustachian tube's mucous membrane or by propagating in the lamina propria of the mucous membrane as a spreading cellulitis or thrombophlebitis. Pain and hearing loss are the most common presenting complaints although fever, nausea, vomiting and diarrhea may occur in young children. Therapy for acute otitis media includes analgesics, decongestants and antibiotics. In addition, topical vasoconstrictors may be administered into the nasal cavity to improve eustachian tube function. Further, systemic sympathomimetic amines such as ephedrine sulfate may also be administered.
Serous otitis media (secretory otitis media) is an effusion in the middle ear resulting from incomplete resolution of acute otitis media or obstruction of the eustachian tube. Traditional therapy includes a trial of antibiotic therapy in case of bacterial infection. Such antibiotic therapy is effective in relieving eustachian tube obstruction due to bacterial infection and in sterilizing the middle ear. Systemic sympathomimetic amines may also improve eustachian tube function by their vasoconstrictive effects and antihistamines may relieve eustachian tube obstruction in allergic patients. Surgical therapies include myringotomy for aspiration of the fluid and for insertion of a tympanostomy tube which allows ventilation of the middle ear and ameliorates the eustachian tube obstruction. Alternatively, the middle ear may be temporarily ventilated with the Valsalva maneuver or politzeration.
Despite the efficacy of these approaches there remains a desire to avoid surgical intervention in cases of otitis media. Moreover, there exists a growing concern that the widespread use of antibiotics for treatment of otitis media in children promotes the development of antibiotic resistant bacteria. Accordingly, there remains a desire in the art for improved treatment of conditions associated with upper respiratory infections and pulmonary disorders including otitis media.


This invention relates to a range detecting device which detects or measures a distance between an object and the device. Various types of range detecting devices for enabling automatic or semi-automatic focus adjustment of camera lenses are conventionally known, and they are generally classified as passive or active types. The passive type has merit in that the mechanism is simple, but it has a disadvantage in that range detection is difficult when the scene is dark.
However, the active type of detecting devices projects the light from the device toward the object, and the reflected light is sensed, so that the disadvantage of the passive type devices is not present in this type. A camera having this active type of a range detecting devices is disclosed in U.S. Pat. No. 3,443,502.
In cameras using active devices such as the type shown in U.S. Pat. No. 3,443,502, a light source emits a beam which is moved angularly to sweep the field of the camera lens. The angular motion of the beam is linked to and calibrated with concomitant motion of the lens-focus-adjustment. A sensor is positioned to receive light reflected from the object, and, upon receiving this reflected light, the displacement of the focus-adjustment is arrested, thus positioning and holding the camera lens at the correct range adjustment.
In range detecting devices of the active type mentioned above when the light sensor fully receives the reflected light from the object and produces a signal of high intensity, the camera lens is at the correct range adjustment, and when the light sensor does not receive the reflected light and produces a signal of low intensity, the camera lens is not at the correct range adjustment. Therefore, for increasing the accuracy of the range detection, it is desirable that the sensor have a small displacement from the position of the beam which produces a low output signal to the position of the beam which produces a high output signal, namely, that the intensity of the sensor output signal vary definitively from a low state to a high state while the beam emitted from the light source is angularly moving to sweep the field of the camera lens.
It has been also desired to increase the maximum detectable distance that the active type range detecting device may detect between the object and the device.


1. Technical Field
The present invention relates to lighting devices.
2. Description of Related Art
When the lighting device is applied to the car lamp, the illuminative range and intensity of the lighting device should conform to the traffic standard and is provides safety while driving at night or in dark places such as tunnels.
In general, the lighting device includes a lens, a light source and a gobo. The gobo is located between the lens and the light source and controls the shape of the emitted light. But, the light from the light source is focused at the focal point by the lens. It's difficult to adjust the illuminative pattern of the lighting device.


The present invention relates to a hydraulic brake system with anti-lock control. Such brake systems include a pedal-operated pressure generator, normally a tandem master cylinder actuated by a booster-aided brake pedal. The master cylinder is connected to wheel brakes via at least one brake line which includes an electro-magnetically operated, normally open two-way, two-position valve. For pressure relief during anti-lock control operation, each of the wheel brakes is also connected to a low-pressure accumulator or reservoir via a pressure relief line. In the pressure relief line, an outlet valve is inserted which is a normally closed, electro-magnetically operated two-way, two-position valve. To return the fluid released from the wheel brakes into the brake circuit, a pump is connected with its suction side to the low-pressure accumulator or the fluid reservoir respectively, and with its pressure side through a pressure line to the brake line.
After assembling such a brake system, the entire circuitry has to be evacuated and filled with brake fluid. In order to enable a non-powered evacuation and filling of such a brake system, a check valve with a low opening pressure was placed to connect the pressure relief line to the pressure line of the pump. The check valve would open in the direction enabling a pressure flow from the relief line to the pressure line, thereby permitting the evacuation of the pressure relief line during evacuation of the pressure line. Vacuum will be kept in the pressure relief line after filling the system with brake fluid. This area will be filled with brake fluid at the end of testing the brake system during activation of the anti-lock control, thus forcing brake fluid into the pressure relief line while the normally closed valves are energized and the pump is running. While this constellation worked well for the purpose of evacuation and fill, however, it caused vacuum trapping in the return circuitry, which is the pressure relief line, after installation of the hydraulic circuitry including a valve block into a vehicle. The biggest restrictions in the brake line are the normally open electro-magnetically operated valves. When a driver releases the brake pedal, in brake systems according to the prior art, vacuum can be created between the normally open valves of the valve block and the tandem master cylinder since pressure energy between the wheel brakes and the normally open valves changes to kinetic energy at the location of the normally open valves. When this vacuum creates a sufficient pressure difference between the brake line and the pressure relief line, the bleed valve opens and traps vacuum in the pressure relief line. After a while, the vacuum will be replaced by air due to small leakage in the pressure relief line of the hydraulic circuitry, and air accumulates after a certain number of brake operations. The result is a long brake pedal stroke or a reduced braking force during electronic control of the brake operation such as anti-lock control, traction control, or driving stability control during cornering. By raising the opening pressure of the bleed valve, not as much vacuum can be trapped, however, this would result in an unsatisfactory evacuation operation.
The object of the current invention therefore is to create a brake system which enables a non-powered evacuation and filling of the circuitry on the one hand and which prevents the trapping of vacuum on the other hand.
Another object of the invention is to create a low-cost solution to the above-mentioned problem without adding excessive additional equipment.
These objectives are achieved by a brake system of the above-mentioned kind where a bypass line connects the pressure relief line with the wheel brake. This bypass line includes a bleed valve opening from the pressure relief line to the wheel brake. A possible point for connecting the bypass line including the bleed valve to the brake line is any point in direct connection with the brake line. That means if the bypass line is connected to the pressure line of the pump without any other hydraulic element in-between, that would be equivalent to connecting the bypass line directly to the brake line. This solution provides a reliable vacuum compensation during pedal releases while having a low opening pressure for the bleed valve in order to evacuate the pressure relief line properly.


With an increased interest in cell-specific drug testing, diagnosis, and other assays, systems that allow for individual cell isolation, identification, and retrieval are becoming more desirable within the field of cellular analysis. Furthermore, with the onset of personalized medicine, low-cost, high fidelity cellular sorting systems are becoming highly desirable. However, preexisting cell capture systems suffer from various shortcomings that prevent widespread adoption for cell-specific testing. For example, flow cytometry requires that the cell be simultaneously identified and sorted, and limits cell observation to a single instance. Flow cytometry fails to allow for multiple analyses of the same cell, and does not permit arbitrary cell subpopulation sorting. Conventional microfluidic devices rely on cell-specific antibodies for cell selection, wherein the antibodies that are bound to the microfluidic device substrate selectively bind to cells expressing the desired antigen. Conventional microfluidic devices fail to allow for subsequent cell removal without cell damage, and only capture the cells expressing the specific antigen; non-expressing cells, which could also be desired, are not captured by these systems. Cellular filters can separate sample components based on size without significant cell damage, but suffer from clogging and do not allow for specific cell identification, isolation, and retrieval.
Thus, there is a need in the cell sorting field to create a new and useful cell capture and analysis system.


The subject invention relates to smoking articles, cigarettes for example, and smoking material therefor.
The patents literature contains many proposals for smoking materials for use in place of conventional cut tobacco cigarette filler.
It is an object of the subject invention to provide new smoking materials which provide for mainstream smoke which although containing low levels of tobacco derived components, is fully acceptable to the consumer.
The subject invention provides a smoking material comprising a non-polyol aerosol generator, up to 20% by weight tobacco, binder at not more than 20% by weight and not less than 30% by weight inorganic filler.
Triethylene glycol diacetate (‘TEGDA’), glycerol triacetate (‘triacetin’) or glycerol diacetate (‘diacetin’), for example, can be used as the non-polyol aerosol generator either individually or in combination. As is well known to those skilled in smoking article science and technology, TEGDA and triacetin are substances with an established use as plasticisers (bonding agents) for cellulose acetate cigarette-filter tow. It was thus surprising to find that these substances and similar substances, when used as aerosol generating substances in smoking materials according to the subject invention, provide aerosols in mainstream smoke which smokers register as very acceptable.
Non-polyol aerosol generator is usefully present in smoking materials of the subject invention at levels in a range of about 2% to about 30% by weight. More usually the range will be about 5% to about 20% by weight, and more usually 5-15%.
Total aerosol generator can include a polyol aerosol generator, such as for example one or more of glycerol, propylene glycol and triethylene glycol.
Smoking materials according to the subject invention can, as will be readily appreciated by those skilled in the art, be fabricated by slurrying the components, in fine particulate form, with water and casting the slurry to sheet form on a band or wire sheet-forming machine or on a heated drum. An alternative is to feed a mixture of the components, together with water, to an extruder. The product of casting or extrusion is suitably cut and shredded to provide smoking material of particulate form.
If the components used to provide the smoking material do not include tobacco, then advantageously the smoking material, in particulate form, is blended with particulate tobacco. In such case, the smoking material expediently accounts for at least about 30% by weight of the blend. Suitably, the smoking material will account for the majority, by weight, of the blend, that is more than 50% by weight of the blend. The tobacco in the blend may be expanded tobacco.
A class of substance suitable for the selection therefrom of binder in smoking materials according to the subject invention is the alginates. Sodium alginate has been found to be advantageous. Other suitable binder substances are celluloses or modified celluloses, hydroxypropyl cellulose or carboxymethyl cellulose, for example, starches or modified starches and natural gums.
Suitable substances for use as inorganic filler are calcium carbonate, perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulphate, magnesium carbonate or other low density inorganic filler materials known to those skilled in the art.
In smoking materials according to the subject invention inorganic filler is preferably present at a level of at least about 35%, preferably at least about 40% and more preferably at least about 45% by weight.
In smoking materials according to the subject invention tobacco may be present at less than 15%, preferably less than 10% and more preferably less than 5%. The binder of smoking materials according to the invention may be present at less than 15%, and more preferably less than 10% by weight.
Smoking materials according to the subject invention may comprise one or more mechanical stabiliser or strengthening materials, examples being cocoa, sugar and fibre, paper fibre for instance. Expansion medium, such as starch, pullulan or other polysaccharides or foaming agents, for example, and high fat or high oil materials, such as cocoa butter or olive oil, corn oil, for example, may also be advantageously included.
Smoking material according to the invention may be used in a conventional smoking article, either blended with another smoking material, which may be tobacco material, or not or in a coaxial arrangement, for example.
According to a second aspect of the subject invention a smoking article comprising a smokable rod and a filter, said rod comprising a core and an outer part, said core comprising a first particulate smoking material and a first cigarette paper wrapper enwrapping said first smoking material and said outer part comprising a second particulate smoking material disposed annularly about said core and a second cigarette paper wrapper enwrapping said second smoking material, wherein either of said first or said second smoking material comprises a non-polyol aerosol generator, up to 20% by weight tobacco, binder at not more than 20% by weight and not less than 30% by weight inorganic filler.
As will be observed, one of the said smoking materials of the smoking article of the second aspect of the subject invention is as per the smoking material of the first above recited aspect of the subject invention. The smoking material of the first above recited aspect of the subject invention may be present in both the first smoking material and the second smoking material of the smoking article above.
Preferably the said second smoking material of the smoking article is as per the smoking material of the first above recited aspect of the subject invention.
Expediently, the first smoking material is cut tobacco filler, suitably cut lamina filler.
Much by preference, in smoking articles in accordance with the subject invention both the core and the outer part of the smokable rod extend over the full length of the rod. It is much by preference too for the core to be disposed coaxially of the rod.
In a third aspect of the invention, there is provided a smoking article comprising a smokable rod and a filter, the smokable rod comprising smoking material and the filter comprising filtration material provided with an elutable aerosol generator which is a polyol and/or a non-polyol aerosol generator, the aerosol generator being elutable from the filter upon smoking of the smoking article to enhance the aerosol provided from the smoking material.
The smoking article may be of a coaxial arrangement or non-coaxial arrangement.
Advantageously the smoking material comprises an aerosol generator, a binder and an inorganic filler, and is more advantageously comprised of a non-polyol aerosol generator, up to 20% by weight tobacco, binder at not more than 20% by weight and not less than 30% by weight inorganic filler. Alternatively the smoking material may comprise one or more of the aerosol generating means or aerosol generating fuel sources of our co-pending application filed on 6 Sep. 1995 under International Patent Application No. PCT/GB 95/02110. As a further alternative, the smoking material may comprise conventional cut tobacco leaf material.
The aerosol generator may be a polyhydric alcohol, an ester, a high boiling point hydrocarbon, glycerol, propylene glycol, triethylene glycol, methylene glycol, methyl citrate, triacetin or diacetin, either alone or in combination.
In a smoking article of an exterior circumference conventional for a cigarette, i.e. c.25 mm, the exterior circumference of the said core is suitably about 17 mm.


1. Field of the Invention
The present invention relates to a misting apparatus for a boat and more particularly pertains to creating a fine mist to be sprayed into a boat with a misting apparatus for a boat.
2. Description of the Prior Art
The use of misting devices is known in the prior art. More specifically, misting devices heretofore devised and utilized for the purpose of delivering a water mist in numerous applications are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
By way of example, U.S. Pat. No. 5,340,345 to Brodbeck et al. discloses a water pickup cooling apparatus for boat drive systems.
U.S. Pat. No. 5,121,882 to Skidmore discloses a mist apparatus for sunbathing.
U.S. Pat. No. 4,765,542 to Carlson discloses a liquid misting attachment for sunbather's chair.
U.S. Pat. No. 3,759,449 to Ruthman et al. discloses a device for producing coolant mist.
While these devices fulfill their respective, particular objective and requirements, the aforementioned patents do not describe a misting apparatus for a boat for creating a fine mist to be sprayed into a boat.
In this respect, the misting apparatus for a boat according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of creating a fine mist to be sprayed into a boat.
Therefore, it can be appreciated that there exists a continuing need for new and improved misting apparatus for a boat which can be used for creating a fine mist to be sprayed into a boat. In this regard, the present invention substantially fulfills this need.


The term, organic electronic device, refers to a device which requires electronic charge exchange between an electrode and an organic material by using holes and/or electrons. The organic electronic device can be largely classified into two types according to its operational principle as follows. One type is an electronic device having a configuration in which an exciton is formed in an organic material layer by photons flown from an external light source into the device and the exciton is separated into an electron and a hole, the electron and the hole formed are transported to a different electrode, respectively and used as a current source (voltage source), and the other type is an electric device having a configuration in which holes and/or electrons are injected into an organic material semiconductor forming an interface with an electrode by applying a voltage or current to two or more electrodes to allow the device to operate by means of the injected electron and hole.
Examples of the organic electronic device comprise an organic light emitting device, an organic solar cell, an organic photoconductor (OPC) and an organic transistor, which all require a hole injecting or transporting material, an electron injecting or transporting material, or a light emitting material for driving the device.
Hereinafter, the organic light emitting device will be mainly and specifically described, but in the above-mentioned organic electronic devices, the hole injecting or transporting material, the electron injecting or transporting material, or the light emitting material functions according to a similar principle.
In general, the term “organic light emitting phenomenon” refers to a phenomenon in which electric energy is converted to light energy by means of an organic material. The organic light emitting device using the organic light emitting phenomenon has a structure usually comprising an anode, a cathode and an organic material layer interposed therebetween. Herein, the organic material layer may be mostly formed in a multilayer structure comprising layers of different materials, for example, the hole injecting layer, the hole transporting layer, the light emitting layer, the electron transporting layer, the electron injecting layer and the like, in order to improve efficiency and stability of the organic light emitting device. In the organic light emitting device having such a structure, when a voltage is applied between two electrodes, holes from the anode and electrons from a cathode are injected into the organic material layer, the holes and the electrons injected are combined together to form excitons. Further, when the excitons drop to a ground state, lights are emitted. Such the organic light emitting device is known to have characteristics such as self-luminescence, high brightness, high efficiency, low drive voltage, wide viewing angle, high contrast and high-speed response.
The materials used for the organic material layer of the organic light emitting device can be classified into a light emitting material and a charge-transporting material, for example, a hole injecting material, a hole transporting material, an electron transporting material and an electron injecting material, according to their functions. The light emitting materials can be divided into a high molecule light emitting material and a low molecule light emitting material according to the molecular weight thereof, and can be divided into a fluorescent material that is derived from a singlet excite state of electrons and a phosphorescence material that is derived from a triplet excite state of electrons according to the light emitting mechanism. In addition, the light emitting materials can be divided into a blue, green or red light emitting material and a yellow or orange light emitting material required for giving more natural color, according to a light emitting color.
Meanwhile, in the case of when only one material is used as the light emitting material, the maximum light emitting wavelength is moved into the long wavelength by the interaction between molecules, the color purity is reduced, or efficiency of the device is lowered by the light emitting reducing effect. Accordingly, a host/dopant system can be used as the light emitting material for the purpose of enhancing the color purity and the light emitting efficiency through energy transfer. It is based on the principle that if a small amount of a dopant having a smaller energy gap than a host which forms a light emitting layer is mixed with the light emitting layer, excitons which are generated in the light emitting layer are transported to the dopant, thus emitting a light having a high efficiency. Here, since the wavelength of the host is moved according to the wavelength of the dopant, a light having a desired wavelength can be obtained according the kind of the dopant.
In order to allow the organic light emitting device to fully exhibit the above-mentioned excellent characteristics, a material constituting the organic material layer in the device, for example, a hole injecting material, a hole transporting material, a light emitting material, an electron transporting material and an electron injecting material should be essentially composed of a stable and efficient material. However, the development of a stable and efficient organic material layer material for the organic light emitting device has not yet been fully realized. Accordingly, the development of new materials is continuously desired. The need to develop the above material is the same as the case of the above-mentioned other organic electronic devices.


Spun yarns of synthetic staple fibers have been produced by cutting continuous filaments into staple fibers, which are then assembled into yarn in the same manner as fibers of cotton or wool. A simpler direct spinning process is also used wherein parallel continuous filaments are stretch-broken and drafted between input rolls and delivery rolls in a drafting zone to form a sliver of discontinuous fibers which is thereafter twisted to form a spun yarn as disclosed, for example, in New U.S. Pat. No. 2,721,440 or Preston U.S. Pat. No. 2,784,458. A true twisting operation is inherently slow. Higher speeds can be obtained by using a false-twisting device, as disclosed in Tissot et al. U.S. Pat. No. 2,946,181 or Field, Jr. U.S. Pat. No. 3,079,746. Tissot et al. teaches that the use of gelatin size will provide adequate strength for weaving or knitting. However, the yarn lacks strength after the size is removed during fabric finishing. Field, Jr., teaches the use of a twisting jet to produce a yarn having surface fibers wrapped about a core bundle which is substantially free of true twist. However, improvements in this product are desirable to make it even more like a conventional spun yarn.
Bunting, Jr., et al. U.S. Pat. No. 3,110,151 discloses at column 23, lines 33-52, a process in which staple fibers averaging 7.6 centimeters long and 2 denier per filament were fed as a roving to drafting rolls and then through an entangling jet device, referred to therein as an interlacing jet, for entangling into yarn. Such products are not comparable to conventional spun yarns in strength, cleanness (freedom from neps and slubs), and uniformity.


1. Field of the Invention
The present invention relates to lawn ornaments and more particularly pertains to a new decorative lawn ornament for providing inspirational three-dimensional ornamentation.
2. Description of the Prior Art
The use of lawn ornaments is known in the prior art. More specifically, lawn ornaments heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art includes U.S. Pat. No. 2,646,497; U.S. Pat. No. Des. 373,097; U.S. Pat. No. Des. 371,987; U.S. Pat. No. Des. 304,347; U.S. Pat. No. 4,601,924; and U.S. Pat. No. 5,584,571.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new decorative lawn ornament. The inventive device includes a main body frame formed in the shape of an angel and having a plurality of elongate frame members, a plurality of main body lights, a secondary frame formed in the shape of a bird, a plurality of secondary lights coupled to the secondary frame, a wing motor interior to the secondary frame, a rod motor interior to the main body frame, a rod, and a linkage assembly.
In these respects, the decorative lawn ornament according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing inspirational three-dimensional ornamentation


Semiconductor device manufacturing processes include various processes such as a lithographic process, an etching process, and an ion implantation process. After the end of each process and before shifting to the next process, a cleaning process and a drying process are performed so as to remove impurities and residues remaining on the surface of a semiconductor substrate to clean the surface of the semiconductor substrate.
In recent years, following the downscaling of elements, the aspect ratio of patterns on a semiconductor substrate has become higher. At a higher aspect ratio, there occurs a problem that capillary causes collapsing of the patterns on the semiconductor substrate in the drying process.
To deal with such a problem, there has been proposed a technique for making surfaces of the patterns on the semiconductor substrate water repellent and lowering the capillary that acts between the patterns and a chemical liquid or the DIW (Deionized Water). However, a water-repellent agent used for making the surface of the semiconductor substrate water repellent is often deactivated after reacting to the water. For example, it often occurs in a cleaning device that the water-repellent agent is deactivated after reacting to the water in a chamber. If such deactivation of the water-repellent agent occurs, the water-repellent agent is unable to make the surface of the semiconductor substrate water repellent and to suppress collapsing of the patterns on the semiconductor substrate resulting from the capillary. Furthermore, if the water-repellent agent is deactivated while spreading throughout the surface of the semiconductor substrate, water repellency varies on the surface of the semiconductor substrate.


PTFE (polytetrafluoroethylene) is used as a material for packings for sealing an annular gap between a shaft and a housing that move relative to each other. PTFE can be used under high temperatures and high pressures, and has excellent characteristics such as high chemical resistance and excellent sliding properties. On the other hand, PTFE has a shortcoming that it is prone to plastic deformation (settling) particularly when used in high temperature environments. If settling occurs in a sealing lip of the packing, it leads to deterioration of sealing properties.
A technique for maintaining the sealing lip in tight contact with an outer circumferential surface of a shaft or an inner circumferential surface of a shaft hole of a housing is known (see Patent Literatures 1 and 2), wherein a metal spring member is mounted in an annular mounting groove formed in the packing.
However, PTFE has a higher linear expansion coefficient than that of metal materials commonly used as the housing material. In high temperature environments, therefore, the sealing lip on an outer circumferential side of the packing (outer circumferential lip) tends to deform so as to expand radially outward, so that it is firmly pressed against the inner circumferential surface of the shaft hole of the housing. As a result, a large settling occurs in the outer circumferential lip, hence, as a countermeasure for settling, it is not sufficient to simply mount a spring member.
Conventionally, in order to prevent the metal spring member from coming off, an annular protrusion that protrudes radially inward is provided at the distal end of the outer circumferential lip. The outer circumferential lip thus has a relatively high rigidity.


The invention relates to a process for the preparation of an olefin polymerization catalyst component containing magnesium, titanium, halogen and an electron donor. The invention also relates to such a catalyst component and its use for the polymerization of xcex1-olefins such as propene.
Generally, so called Ziegler-Natta catalyst components of the above kind have been prepared by reacting a magnesium halide-alcohol complex with a titanium tetra-halide and an electron donor which usually is a phthalic acid diester. The preparation involves the use of large amounts of reagents and washing liquids, which are difficult to handle. Additionally, byproducts are formed, which cannot easily be regenerated or destroyed, but form an environmental problem.
For example, the preparation of a conventional polypropene catalyst component involves the reaction of a magnesium dichloride-alcohol complex with titanium tetrachloride to give reactive xcex2-magnesium dichloride as intermediate and hydrogen chloride and titanium alkoxy trichloride as byproducts. Then, the reactive xcex2-magnesium dichloride intermediate is activated with further titanium tetrachloride to give said catalyst component (the treatment with a titanium halide such as titanium tetrachloride is henceforth called titanation).
The titanium alkoxy trichloride byproduct formed in the titanation is a catalyst poison and must be carefully removed by extensive washing using large amounts of titanium tetrachloride. Further, the titanium alkoxy trichloride must be carefully separated from the titanium tetrachloride washing liquid, if the latter is to be reused e.g. for activating the reactive xcex2-magnesium dichloride. Finally, the titanium alkoxy trichloride is a problem waste, which is difficult to dispose of.
Thus, in a typical propene polymerization catalyst component preparation involving two titanations and three heptane washes, one mol of produced catalyst component (mol Mg) requires about 40 mol of titanium tetrachloride e.g. as washing liquid to be circulated (see Table 15 below), and produces as problem waste about three mol of titanium alkoxy trichloride as well as about three mol of hydrogen chloride.
Sumitomo, EP 0 748 820 A1 (hereinafter referred to as xe2x80x9cSumitomoxe2x80x9d), has prepared dialkoxy magnesium, reacted it with titanium tetrachloride to form an intermediate and then reacted the intermediate with phthalic acid dichloride to form a catalytically active propene polymerization catalyst component. The activity was raised by repeated titanations, as well as repeated washes with toluene and hexane. See page 10, lines 14 to 37, of said publication.
Said process of Sumitomo has avoided the reaction between the magnesium dichloride-alcohol complex and titanium tetrachloride, and thereby eliminated the formation of catalytically poisonous titanium alkoxy trichloride byproduct. However, as much as four titanations and hydrocarbon treatments are still needed to give satisfactory catalytic activity.
The purpose of the present invention is to provide a process which results in a catalyst component having satisfactory activity without producing harmful byproducts such as said titanium alkoxy trichloride or requiring the use of a large amounts of titanation reagent and/or washing liquid.
The problem described above has now been solved with a novel process for the preparation of a catalyst component of the above type, which is mainly characterized by the steps of:
(i) reacting a titaniumless magnesium compound (a) containing an alkoxy moiety, which titaniumless magnesium compound is selected from the group consisting of a compound or conplex containing halogen and alkoxide linked to magnesium, a complex containing a magnesium dihalide and an alcohol, and a non-complex magnesium dialkoxide, with a halogen compound (b) being capable of forming the electron donor by replacement of its halogen by said alkoxy moiety, to give an intermediate (ab); and
(ii) reacting said intermediate (ab) with a titanium halide (c), or
(i)xe2x80x2 reacting a titaniumless magnesium compound (a) containing an alkoxy moiety, which titaniumless magnesium compound is selected from the group consisting of a compound or complex containing halogen and alkoxide linked to magnesium, and a complex containing a magnesium dihalide and an alcohol, with a titanium halide (c), to give an intermediate (ac), and
(ii)xe2x80x2 reacting said intermediate (ac) with a halogen compound (b) being capable of forming the electron donor by replacement of its halogen by said alkoxy moiety.
It was found by the applicant, that the activity of a stoichiometric catalyst component, comprising a magnesium dihalide, a titanium tetrahalide and an electron donor, is the higher, the more magnesium dihalide it contains. Thus it is believed, that the purpose of the repeated toluene washes of e.g. Sumitomo has partly been to remove titanium tetrachloride and electron donor from the catalyst component precursor in order to raise the magnesium dichloride content and thus the catalytic activity, of the final catalyst component. The present invention solves the problem in another way. In the claimed process, magnesium dihalide is included or synthesized as part of the reacting material before any titanation takes place, and thus, the need for repeated cycles of titanation and washing is significantly reduced.
Preferably one, most preferably all of steps (i), (ii), (i)xe2x80x2 and (ii)xe2x80x2 are performed in solution. Then, the reaction product of step (ii) or (ii)xe2x80x2 is preferably recovered by precipitation.
According to one embodiment of the present invention, said compounds (a), (b) and (c) are in the claimed process contacted in essentially stoichiometric amounts. According to another embodiment, a stoichiometric excess, preferably a 5-20 fold excess, of said titanium halide (c) with respect to said magnesium compound (a), gives even better results.
Said halogen compound (b) used in the claimed process is an electron donor precursor, i.e. itself capable of forming the electron donor of the catalyst component by replacement of its halogen by an alkoxy group. By electron donor is in this connection meant an electron donor which forms a part of the titanous catalyst component produced by the claimed process and is in the art also called an internal electron donor. Such halogen compounds (b) are, e.g., C1-C20 alkyl halides, C7-C27 aralkyl halides and C2-C22 acyl halides, which react with alkoxy compounds to replace their halogen with the alkoxy group of the alkoxy compound and form e.g. the corresponding ethers and esters acting as internal electron donors.
Preferably, said halogen compound (b) is an organic acid halide having the formula Rxe2x80x3(COXxe2x80x2)n, wherein Rxe2x80x3 is an n-valent organic group having 1-20 carbon atoms, preferably an n-valent benzene ring, Xxe2x80x2 is a halogen, preferably chlorine; and n is the valence of Rxe2x80x3 and is an integer 1 to 6, preferably 1, 2, 3 or 4, more preferably 2. Most preferably, said halogen compound is phthalic acid dichloride Ph(COCl)2, wherein Ph is o-phenylene. Correspondingly, the electron donor formed therefrom is preferably an organic acid ester having the formula Rxe2x80x3(COOR)n, wherein R is an n-valent C1-C20 aliphatic group or an n-valent C7-C27 araliphatic group and Rxe2x80x3 and n are the same as above, and more preferably a phthalic acid diester Ph(COOR)2, wherein R is a C1-C20 alkyl or a C7-C27 aralkyl, more preferably a C1-C16 alkyl. Most preferably said electron donor is dioctyl phthalate.
The titanium halide (c) used in the claimed process is preferably a titanium halide of the formula (ORxe2x80x2)kTiX4-k, wherein Rxe2x80x2 is an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 16 carbon atoms, X is a halogen and k is 0 to 3. More preferably, said titanium halide (c) is a titanium tetrahalide TiX4, wherein X is the same as above, most preferably titanium tetrachloride TiCl4.
It is preferable, if said titaniumless magnesium compound (a) is not a part of a solid magnesium halide, e.g. in the form of complex molecules on the surface of a solid magnesium halide carrier, but form a separate compound with an essentially stoichiometric composition. Often, said titaniumless magnesium compound is a complex. A complex is, according to Rxc3x6mpps Chernie-Lexicon, 7. Edition, Franckh""sche Verlagshandlung, W. Keller and Co., Stuttgart, 1973, page 1831, xe2x80x9ca derived name of compounds of higher order, which originate from the combination of molecules,xe2x80x94unlike compounds of first order, in the creation of which atoms participatexe2x80x9d.
According to one embodiment of the invention, the titaniumless magnesium compound (a) used in the claimed process is a titaniumless complex of the formula [MgX2]x.[K(OR)m]y, wherein X is a halogen, K is hydrogen, a metal of group 1, 2 or 13 of the Periodic Table, R is an alkyl having 1 to 20 carbon atoms, an aralkyl having 7 to 27 carbon atoms or an acyl having 2 to 22 carbon atoms, x is 0 to 20, m is the valence of K and is an integer from 1 to 6, and y is 1 to 20.
The magnesium dihalide MgX2 of said titaniumless complex (a) can be selected from magnesium chloride, magnesium bromide and magnesium iodide. Preferably, it is magnesium dichloride.
The alkoxy compound K(OR)m is in its most general form defined as a component of said titaniumless complex (a), which complex (a) is reacted further with said halogen compound (b) and said titanium halide (c) or said titanium halide (c) and said halogen compound (b). The alkoxy compound is, however, more closely defined in the following description of three main embodiments of the claimed process.
The gist of the invention is to choose the reactants and their order of reaction so that the magnesium dihalide is present when the titanium halide (c) is reacted.


1. Technical Field
The present invention relates to a charging unit. In particular, although not exclusively, the present invention relates to a charging unit comprising a switched mode power supply.
2. Description of Related Art
Portable devices are often powered by a rechargeable battery. Most commonly, the rechargeable battery is charged by a charger including an AC to DC converter and being connected to an AC mains power supply. In addition, DC chargers such as vehicle chargers can be used to recharge batteries. Such chargers typically can provide charging currents of around 1 A.
Some portable devices have a USB port for connection to a host device. The USB connection can be used for data transfer. For example, a mobile phone may be connected to a computer for synchronising their respective address books.
The USB specification also provides that a USB connection is able to supply power to a device. However, the power that can be supplied is limited. The USB specification recites a DC voltage of 4.75 to 5.25V, and the current that can be provided through a USB connection is limited to around 0.5 A. Thus, the time taken to charge a portable device using only USB charging can be significantly longer than is found when using AC mains charging.
Portable devices that allow both USB charging and AC mains charging have been proposed. One example is described in US 2005/0141208. This document describes a USB device that can be connected simultaneously to an AC adapter and to a USB port on a host device by a USB connection. When the AC adapter is connected, the USB device operates as a self-powered USB device, i.e. it is not supplied with power from the host device.


Digital Subscriber Line (DSL) has become popular in recent years because it can provide high-bandwidth connections between a telephone switching station and a home or office over existing telephone lines. DSL technologies use sophisticated modulation schemes to pack data onto copper wires of plain old telephone system (POTS). Among the exiting DSL technologies, Asymmetric Digital Subscriber Line (ADSL) is the most practical since it fits average users' need for greater downstream bandwidth than upstream bandwidth.
Discrete Multi-tone (DMT) is a method of modulating a DSL signal for transmission on a usable frequency spectrum divided into a plurality of sub-carriers or frequency channels. For example, a spectrum may be divided into 256 channels (“bins”) of 4.3125 kHz each. The center frequency of a bin is 4.3125 kHz multiplied by the bin number. Thus, a specific bin may be referred to by its bin number instead of its actual frequency range. Dividing the frequency spectrum into multiple channels reduces cross-talk in signal transmissions. In a DMT system, a usable frequency spectrum is typically allocated to the upstream and downstream transmissions based on a standard scheme. For example, according to International Telecommunication Union (ITU) standard G.992.1 (Annex A), the downstream transmission may occupy bins 6 through 255 and the upstream transmission may occupy bins 6 through 31. In a common operation mode, to reduce near-end cross-talk (NEXT), the downstream transmission may start from bin 33. Other standards or schemes also exist that allow an overlap in bin allocations to the upstream and downstream traffic.
However, none of the fixed bin allocation schemes can consistently achieve optimal data rates. Due to the ever-changing operation environment (e.g., noise level, loop attenuation and echo rejection rate), quality of a connection based on a particular scheme usually drifts over time. Especially when the cross-talk noises become highly asymmetric, it may be difficult to rely on a fixed bin allocation scheme to maintain link performance. As a result, the available bandwidth is not fully utilized and customers may become dissatisfied with inconsistent link performance.
In view of the foregoing, it would be desirable to provide an efficient and cost effective solution for bin allocation that overcomes the above-described inadequacies and shortcomings.


The prior art is replete with light duty liquid detergent compositions containing nonionic surfactants in combination with anionic and/or betaine surfactants wherein the nonionic detergent is not the major active surfactant. In U.S. Pat. No. 3,658,985 an anionic based shampoo contains a minor amount of a fatty acid alkanolamide. U.S. Pat. No. 3,769,398 discloses a betaine-based shampoo containing minor amounts of nonionic surfactants. This patent states that the low foaming properties of nonionic detergents renders its use in shampoo compositions non-preferred. U.S. Pat. No. 4,329,335 also discloses a shampoo containing a betaine surfactant as the major ingredient and minor amounts of a nonionic surfactant and of a fatty acid mono- or di-ethanolamide. U.S. Pat. No. 4,259,204 discloses a shampoo comprising 0.8 to 20% by weight of an anionic phosphoric acid ester and one additional surfactant which may be either anionic, amphoteric, or nonionic. U.S. Pat. No. 4,329,334 discloses an anionic-amphoteric based shampoo containing a major amount of anionic surfactant and lesser amounts of a betaine and nonionic surfactants.
U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition containing an alkali metal silicate, urea, glycerin, triethanolamine, an anionic detergent and a nonionic detergent. The silicate content determines the amount of anionic and/or nonionic detergent in the liquid cleaning composition. However, the foaming properties of these detergent compositions are not discussed therein.
U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent for laundering fabrics comprising a mixture of substantially equal amounts of anionic and nonionic surfactants, alkanolamines and magnesium salts, and, optionally, zwitterionic surfactants as suds modifiers.
U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition for laundering socks or stockings comprising a specific group of nonionic detergents, namely, an ethylene oxide of a secondary alcohol, a specific group of anionic detergents, namely, a sulfuric ester salt of an ethylene oxide adduct of a secondary alcohol, and an amphoteric surfactant which may be a betaine, wherein either the anionic or nonionic surfactant may be the major ingredient.
The prior art also discloses detergent compositions containing all nonionic surfactants as shown in U.S. Pat. Nos. 4,154,706 and 4,329,336 wherein the shampoo compositions contain a plurality of particular nonionic surfactants in order to affect desirable foaming and detersive properties despite the fact that nonionic surfactants are usually deficient in such properties.
U.S. Pat. No. 4,013,787 discloses a piperazine based polymer in conditioning and shampoo compositions which may contain all nonionic surfactant or all anionic surfactant.
U.S. Pat. No. 4,450,091 discloses high viscosity shampoo compositions containing a blend of an amphoteric betaine surfactant, a polyoxybutylenepolyoxyethylene nonionic detergent, an anionic surfactant, a fatty acid alkanolamide and a polyoxyalkylene glycol fatty ester. But, none of the exemplified compositions contain an active ingredient mixture wherein the nonionic detergent is present in major proportion which is probably due to the low foaming properties of the polyoxybutylene polyoxyethylene nonionic detergent.
U.S. Pat. No. 4,595,526 describes a composition comprising a nonionic surfactant, a betaine surfactant, an anionic surfactant and a C.sub.12 -C.sub.14 fatty acid monoethanolamide foam stabilizer.


Conventionally, a signal processing system has a TI-ADC (time-interleaved analogue digital converter), an ADC (analogue-to-digital converter), and a correction processor. The correction processor estimates an error to be corrected by using the steepest descent method of the covariance norm and corrects an error caused by mismatch between interleaves by using the estimation result and an adaptive filter.
However, since the adaptive filter is large-scale, the size of the correction processor is extremely large, and a process amount necessary to correct an error caused by mismatch between interleaves is extremely large. As a result, it is difficult to realize small size and high speed of the TI-ADC.


1. Field of the Invention
The present invention relates to integrated circuit fabrication, and more particularly to methods for fabricating high-density integrated circuit devices.
2. Description of Related Art
Photolithographic processes can be used to form a variety of integrated circuit structures on a semiconductor wafer. In photolithography, features of these structures are typically created by exposing a mask pattern (or reticle) to project an image onto a wafer that is coated with light sensitive material such as photo resist. After exposure, the pattern formed in the photo resist may then be transferred to an underlying layer (e.g. metal, polysilicon, etc.) through etching, thereby creating the desired features.
One problem associated with manufacturing devices having very small features arises because of variations introduced by the photolithographic processes. Specifically, resist material properties, process conditions, optical distortions and other factors can cause systematic and random deviations in the etched shapes of the features from their desired shapes. Examples of deviations include corner-rounding, line-shortening and line edge roughness.
In a typical lithographic patterning process, a line of resist is used as an etch mask to create a corresponding line of material in the underlying layer. In such a case, the deviations in the patterned line of resist will be transferred to the critical dimensions of the etched line in the underlying layer. As process technologies continue to shrink, these deviations become a greater percentage of the critical dimension of the etched lines, which can reduce yield and result in significant performance variability in devices such as transistors implemented utilizing these etched lines.
Accordingly, it is desirable to provide high-density structures such as integrated circuit devices which overcome or alleviate issues caused by deviations introduced by photolithographic processes, thereby improving performance and manufacturing yield of such devices.


The present invention relates generally to broadband transmission of information and, more particularly, to time synchronization of a received OFDM signal.
Orthogonal Frequency Division Multiplexing (OFDM) is a spread spectrum technology wherein the available bandwidth is subdivided into a number of discrete channels or subcarriers that are overlapping and orthogonal to each other. Each channel has a well defined frequency. Data are transmitted in the form of symbols that encompass some number of subcarrier frequencies. The amplitude and/or phase of the subcarriers represents the encoded information. Before a received OFDM symbol can be decoded, frequency and time synchronization of the signal have to be determined. This process is referred to as synchronization.
Time synchronization may be achieved through the use of time-based correlation in the time domain or phase correlation in the frequency domain. Phase correlation has several advantages over time-based correlation. Phase correlation is more robust as it is significantly less affected by amplitude variations than time-based correlation. Also, symbols can be synchronized in the presence of a much stronger jammer by correlation in the frequency domain.
OFDM symbols can be synchronized in the frequency domain by correlating the phases of the carriers with the phases of a reference symbol. Alternatively, or in addition, autocorrelation can be performed by correlating the phases of a received symbol with those of an earlier received symbol.
Time synchronization of the received OFDM signals is more difficult to achieve, in particular, in the presence of narrow band interference in the OFDM channel. Apodizing window functions, such as Hanning windows, are typically used to deal with the effects of a narrowband interferer, such as a jammer signal, in samples that are passed to a phase correlator. While the apodizing window confines interference from the narrowband interferer to only several of the OFDM subcarriers, it introduces intercarrier interference into the subcarrier frequencies. The intercarrier interference can result in destructive canceling (i.e., frequency nulls") in transmitting subcarriers of equal amplitude and phase. In the presence of a frequency null, a phase correlator may miss a peak correlation pulse and thus provide unreliable synchronization. The intercarrier interference can also cause phase and amplitude distortion in each of the transmitted subcarriers processed by the apodizing window. Phase distortion in sample phases, as well as in the autocorrelation or reference phases with which they are compared, can result in poor phase correlation. Even using a best possible set of reference phases (typically, nonwindowed referenced phases), in conjunction with Hanning windowed phases reduces correlation by some factor. That is, it takes a much stronger signal to perform correlation than would be needed if a Hanning window was not used.


This invention relates to a method of and apparatus for determining the no-flow temperature of a liquid, such as domestic heating oil, plastic, paint, ice cream, margarine, oil, distillate fuel and aviation fuel. The determination of the no-flow temperature of such materials is important, because their production and handling is limited by their low temperature properties. It is evident that significant problems may arise, for example, if fuels such as aviation fuel or domestic fuel fail to flow through the handling system to a burner because of their limiting low temperature properties.
One of the critical specifications of liquids such as jet fuel, is the freeze point which is defined as the temperature at which wax crystals formed on cooling disappear when the temperature of an agitated fuel sample is allowed to rise. A major shortcoming of the freeze point specification is that it bears little relation to the fuel property that limits low temperature performance, viz., the ability of the fuel to flow from a fuel tank at low temperature. A prior art cold flow test consists of characterizing fuel by its hold-up factor, which is defined as the amount of fuel that is unable to flow from a first section of a tester to a second section and varies with the temperature of the fuel. The most important test parameter is the "zero percent hold-up temperature", which represents the lowest temperature to which the fuel can be subjected before total hold-up will occur, that is, the point at which none of the fuel can flow. It is this temperature that is likely to define the limit of a specification based on the low temperature flow properties of the fuel. The zero percent hold-up temperature cannot be determined directly by the prior art techniques. Rather, the usual procedure consists of constructing a graph of the temperature dependence of the hold-up factor over a range of readily determined values, which are typically between 10-90% hold-up, and extrapolating the plot to zero percent hold-up to obtain the zero percent hold-up temperature by this method, several points are necessary to construct the hold-up temperature profile, particularly in the region of low hold-up factors. Obviously, this is a time-consuming exercise.
Therefore, it is an object of the present invention to provide a method of and an apparatus for determining the no-flow temperature of liquids.