A non-self-supporting denture care composition comprises polybutene with a molecular weight of about 300 to about 3000 and a denture care active. The denture care composition may further comprise a denture care carrier. Kits comprising polybutene, a container and instructions for use or an applicator for applying the composition directly to the denture surface are also disclosed. The polybutene composition of the kits can further comprise a denture care active.

The present invention relates to a denture care composition and denture care kit providing prolonged release of therapeutic, prophylactic and cosmetic actives to the oral cavity and inhibiting the buildup of plaque and other debris and on the dentures and other hard surfaces temporarily fixed within the oral cavity.
Denture care products by which various denture care actives can be delivered to the hard surface of the artificial teeth have been previously known. For example, effervescent denture cleansing tablets, which require the artificial teeth to soak for a period of time, work to remove plaque and debris that has built up on the denture or plate. It is well known that denture care products can provide both therapeutic and cosmetic benefits to consumers. However, such conventional denture care products typically do not maintain actives in the oral cavity long enough to optimally enhance or prolong the therapeutic, prophylactic and/or cosmetic benefits provided by the actives. In order to provide a composition with sufficient substantivity to provide sustained release of a denture care active, the use of polybutene in a denture care composition is herein disclosed.
Polybutene is recognized as a component of denture adhesives and as a gum base. U.S. Pat. No. 5,880,172, issued Mar. 3, 1999, to Rajaiah, et al., discloses a self-supporting denture adhesive that is peelable for easy removal, which incorporates polybutene as an optional ingredient. U.S. Pat. No. 5,496,541, issued Mar. 5, 1996, to Cutler, relates to a dentifrice chewing gum and teaches the use of polybutene as an optional gum base. Such known applications often employ higher molecular weight polybutene in order to achieve the desired result.
In the present invention lower molecular weight polybutene is incorporated in the denture care composition and kit to provide a protective coating on the artificial teeth. The lower molecular weight polybutene is a flowable liquid that achieves good coating of the denture and is extremely substantive. Where a denture care active is incorporated in the present invention sustained release of the denture care active is achieved.
The present invention provides denture care kits and a denture care composition that effectively coat the dentures, dental plates, and other hard surfaces temporarily fixed within the oral cavity and thereby prevents the buildup of plaque and other debris. This coating works to inhibit and prevent staining of the denture and to treat the oral cavity. This coating also provides a slick, smooth feel to the artificial hard surfaces of the oral cavity which consumers view as an indicator of clean teeth. A therapeutic, cosmetic or prophylactic denture care active can be included in the composition of the present invention.
This invention relates to a non-self-supporting denture care composition comprising polybutene with a molecular weight of about 300 to about 3000 and one or more denture care actives. The denture care actives are selected from the group consisting of anti-calculus agents; fluoride ion sources; stannous ion sources; whitening agents; anti-microbial and anti-plaque agents; anti-inflammatory agents; nutrients; antioxidants; antiviral agents; anti-fungal agents; analgesic and anesthetic agents; H-2 antagonists; fragrances and sensates; components other than polybutene which impart a clean feel to the teeth; pigments, dyes, lakes and colorants; and mixtures thereof. When desired, a viscosity modifier, flavorant, or sweetener may optionally be incorporated in the present invention. The composition is essentially free of a mucoadhesive. The denture care composition may further comprise a denture care carrier.
This invention also relates to a denture care kit comprising polybutene with a molecular weight of about 300 to about 3000, a container and instructions for use. A denture care kit comprising polybutene with a molecular weight of about 300 to about 3000 and an applicator for applying the composition directly to the denture surface is also disclosed. In one embodiment the polybutene component of the kits further comprise a denture care active.
The term xe2x80x9cdenturesxe2x80x9d, as used herein, is meant to include dentures, dental plates, bridges, artificial teeth and other hard surfaces of dental appliances which are temporarily fixed within the oral cavity and which are typically removed from the oral cavity for cleaning.
The term xe2x80x9cdenture care carrierxe2x80x9d as used herein means any safe and effective non-aqueous materials for use in the compositions of the present invention.
The term xe2x80x9ccontainerxe2x80x9d as described herein, means a jar, cup, can, tube, aerosol can, tub, pump, bottle or any other liquid holding or dispensing means.
xe2x80x9cTartarxe2x80x9d and xe2x80x9ccalculusxe2x80x9d are used interchangeably and refer to mineralized dental plaque biofilms.
By xe2x80x9csafe and effective amountxe2x80x9d, as used herein, is meant an amount of an agent (e.g., anti-calculus agent) high enough to significantly improve the condition to be treated, but low enough to avoid serious side effects (at a reasonable benefit/risk ratio), within the scope of sound medical/dental judgment. The safe and effective amount of an agent (e.g., anti-calculus agent) may vary with the particular condition being treated, the age and physical condition of the patient being treated, the severity of the condition, the duration of treatment, the nature of concurrent therapy, the specific form of the source employed, and the particular vehicle from which the agent is applied.
The term xe2x80x9cnon-self supportingxe2x80x9d is used to describe a composition that lacks integrity and strength. In the instant case, this means that the composition is unable to be detached as one solid piece from the teeth even after several hours of use in the mouth. The composition cannot be cut and formed into definite shapes, such as a sheet or cone, which maintain their initial dimensions.
The term xe2x80x9cmucoadhesivexe2x80x9d or xe2x80x9cbioadhesivexe2x80x9d as used herein refers to the phenomenon where a natural or synthetic substance applied to a wet mucosal epithelium adheres, usually creating a new interface, to the mucous layer. (CRC Critical Review in Ther. Drug Carrier, Vol.5, Issue 1, p.21 (1988)). Generally, mucoadhesion can be achieved via physical or chemical processes, or both. This mechanism is described in Journal of Controlled Release, Vol.2, p257 (1982) and Journal of Controlled Release, Vol.18 (1992) p. 249. The above references are incorporated by reference herein in their entirety.
The term xe2x80x9cunit dose formxe2x80x9d refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each containing a predetermined quantity of active material calculated to produce the desired therapeutic effect.
The term xe2x80x9cviscosityxe2x80x9d as used herein refers to kinematic viscosity, measured using the standard test method for Kinematic Viscosity of Transparent and Opaque Liquids (the Calculation of Dynamic Viscosity), ASTM D-445. As reported, viscosity is measured at 99xc2x0 C. (210xc2x0 F.) unless otherwise indicated. A sample is placed in a U-shaped xe2x80x9cCannon-Fenskexe2x80x9d type viscometer (for transparent liquids) tube and submerged into a constant temperature bath. Flow is timed between two marks on the tube and viscosity is determined by simple calculations dependent on time and a standard factor supplied by the tube manufacturer.
xe2x80x9cMolecular weightxe2x80x9d, as referred to herein, is reported as a number average, determined using gel permeation chromatography. The number average molecular weight, or arithmetic mean, is a function of the number of molecules in a given mass of polymer. It is represented by the formula:       M    n    =                    Σ                          xe2x80x83                                  N          i                                  M          i                            Σ                          xe2x80x83                                  N          i                      =          Σ                    xe2x80x83                                                n            i                                          M            i                          _
where Ni, represents the number of molecules present for a given molecular weight, Mi and ni=Ni|xcexa3Ni is the number fraction of molecular weight, Mi.
Percentages and ratios herein are by weight of total composition, unless otherwise indicated.
Polybutene
Polybutene is a viscous copolymer of isobutylene and butene monomers. xe2x80x9cPolybutenexe2x80x9d, as used herein, refers to both hydrogenated (CAS #68937-10-0) and unhydrogenated (CAS #9003-29-6) forms of the polymer. Polybutene is a viscous, colorless, non-drying, liquid polymer. Polybutenes range from a flowable liquid to a near semi-solid state. Polybutenes are clear, odorless, chemically stable, resistant to oxidation by light and heat, non-toxic and non-hazardous.
In the present invention, a composition comprising polybutene with a molecular weight of about 300 to about 3000 and a denture care active is disclosed. In one embodiment, the composition comprises, a denture care active, a denture care carrier and polybutene with a molecular weight of about 300 to about 3000. The present invention also relates to a denture care kit comprising polybutene with a molecular weight of about 300 to about 3000, a container, and instructions for use. A denture care kit comprising polybutene with a molecular weight of about 300 to about 3000 and an applicator for applying the composition directly to the denture surface is also disclosed.
The compositions and kits of the present invention comprise polybutene, generally of a lower molecular weight from about 300 to about 3000, in another embodiment from about 500 to about 2200, and in another embodiment from about 750 to about 1500. The viscosity of the polybutene disclosed herein, ranges from about 30 cSt (centi Stoke) measured at 38xc2x0 C. to about 4,500 cSt measured at 99xc2x0 C., in another embodiment from about 200 cSt measured at 38xc2x0 C. to about 3,500 cSt measured at 99xc2x0 C., and in another embodiment from about 75 cSt measured at 99xc2x0 C. to about 700 cSt measured at 99xc2x0 C. Polybutene comprises from about 0.01% to about 100%, by weight of the composition, in another embodiment from about 1% to about 100%, in yet another embodiment from about 50% to about 100%.
The lower molecular weight polybutene of the present invention does not exhibit elastomeric properties. Elastomers are amorphous polymers that have the ability to stretch out and spring back to their original shapes. Such elastomeric polymers must have a modest amount of cross-linking to prevent the polymeric chains from slipping over one another, and the chains must have an irregular shape to prevent the formation of crystalline regions within the polymeric chains. Synthetic elastomers, are described in more detail in Kirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, Volume 8, Wiley-Interscience Publishers (1996), pages 934-955, incorporated herein by reference in its entirety, including all references incorporated into Kirk-Othmer. The polybutene utilized in the present invention is not cross-linked and does not exhibit rubbery or elastic behavior. When subjected to a stretching or bending force, the polybutene herein does not return to its original shape upon the removal of the force.
Lower molecular weight polybutene (Molecular Weight=300-3000), which is a flowable liquid known for its adhesive properties, is actually non-mucoadhesive. That is, the polybutene, while displaying excellent adhesion properties on the hard surfaces of the oral cavity, will not significantly adhere to the mucosa or wet, soft tissue of the mouth. In fact, polybutene is extremely substantive when applied to the denture, making it suitable for once daily application and treatment. High retention of the polybutene is achieved, even when thorough brushing has occurred. Thus, the polybutene, once applied to the denture surface, is long lasting, and rinse resistant, which allows for sustained release of certain optional denture care actives. Importantly, the compositions of the present invention are not self-supporting neither before, during, or after application to the denture.
Once applied to the artificial teeth, the polybutene has a very smooth, slick texture, perceived by the consumer as a desirable, clean feeling. The polybutene acts as a lubricant and reduces the friction normally produced when the tongue slides over these surfaces.
Suitable polybutenes for use herein include, but are not limited to: Indopol L-14, Molecular Weight (xe2x80x9cMWxe2x80x9d)=370; Indopol L-50, MW=455; Indopol L-65, MW=435; Indopol L-100, MW=510, H-15, MW=600; H-25, MW=670; H-35, MW=725; H-40, MW=750; H-50, MW=815; H-100, MW=940; H-300, MW=1330; H-1500, MW=2145; H-1900, MW=2270; Panalane L-14E, MW=370; Panalane H-300E, MW=1330; all trade names of BP Amoco Chemicals (Chicago, Ill.). Other suitable grades of polybutene include Parapol 450, MW=420; Parapol 700, MW=700; Parapol 950, MW=950; Parapol 1300, MW=1300; and Parapol 2500, MW=2700; all trade names of ExxonMobil Corporation.
Denture Care Actives
The denture care compositions of the present invention may contain a denture care active in unit dose form where, upon directed use, the benefit sought by the wearer is promoted without detriment to the oral cavity. Examples of the dental conditions these actives address include, but are not limited to, appearance and structural changes to teeth, treatment and prevention of plaque, calculus, cavities in remaining natural teeth, inflamed and/or bleeding gums, gingivitis, fungal infections such as candida, mucosal wounds, lesions, ulcers, aphthous ulcers, cold sores, tooth abscesses, and the elimination of mouth malodor resulting from the conditions above and other causes such as microbial proliferation.
Suitable denture care active ingredients include any material that is generally considered safe for use in the oral cavity and that provides changes to the overall appearance and/or health of the oral cavity. The level of denture care active in the present invention is generally, unless otherwise noted, from about 0.001% to about 90%, in one embodiment from about 0.01% to about 50%, in another embodiment from about 0.1% to about 30%, by weight of the composition. Where the denture care actives are in particulate form, a suitable particle size for use in the present invention is from about 0.01 microns to about 1000 microns, in one embodiment from about 0.1 microns to 500 microns, in another embodiment from about 1 to about 100 microns. The denture care composition of the present invention may include many of the denture care actives previously disclosed in the art. The following is a non-limiting list of denture care actives that may be used in the present invention.
The present compositions may comprise at least one anti-calculus (i.e. anti-tartar) agent, present at a level from about 0.001% to about 50%, by weight of the composition, in another embodiment from about 0.01% to about 25%, and in yet another embodiment from about 0.1 to about 15%. The anti-calculus agent should be essentially compatible with the other components of the invention. The anti-calculus agent may be selected from the group consisting of polyphosphates (including pyrophosphates) and salts thereof; polyamino propane sulfonic acid (AMPS) and salts thereof; polyolefin sulfonates and salts thereof; polyvinyl phosphates and salts thereof; polyolefin phosphates and salts thereof; diphosphonates and salts thereof; phosphonoalkane carboxylic acid and salts thereof; polyphosphonates and salts thereof; polyvinyl phosphonates and salts thereof; polyolefin phosphonates and salts thereof; polypeptides; and mixtures thereof. In one embodiment, the salts are alkali metal salts. Polyphosphates are generally employed as their wholly or partially neutralized water-soluble alkali metal salts such as potassium, sodium, ammonium salts, and mixtures thereof. The inorganic polyphosphate salts include alkali metal (e.g. sodium) tripolyphosphate, tetrapolyphosphate, dialkyl metal (e.g. disodium) diacid, trialkyl metal (e.g. trisodium) monoacid, potassium hydrogen phosphate, sodium hydrogen phosphate, and alkali metal (e.g. sodium) hexametaphosphate, and mixtures thereof. Polyphosphates larger than tetrapolyphosphate usually occur as amorphous glassy materials. In one embodiment the polyphosphates are those manufactured by FMC Corporation, which are commercially known as Sodaphos (n≈6), Hexaphos (n≈13), and Glass H (n≈21, sodium hexametaphosphate), and mixtures thereof. The pyrophosphate salts useful in the present invention include, alkali metal pyrophosphates, di-, tri-, and mono-potassium or sodium pyrophosphates, dialkali metal pyrophosphate salts, tetraalkali metal pyrophosphate salts, and mixtures thereof. In one embodiment the pyrophosphate salt is selected from the group consisting of trisodium pyrophosphate, disodium dihydrogen pyrophosphate (Na2H2P2O7), dipotassium pyrophosphate, tetrasodium pyrophosphate (Na4P2O7), tetrapotassium pyrophosphate (K4P2O7), and mixtures thereof. Polyolefin sulfonates include those wherein the olefin group contains 2 or more carbon atoms, and salts thereof. Polyolefin phosphonates include those wherein the olefin group contains 2 or more carbon atoms. Polyvinylphosphonates include polyvinylphosphonic acid. Diphosphonates and salts thereof include azocycloalkane-2,2-diphosphonic acids and salts thereof, ions of azocycloalkane-2,2-diphosphonic acids and salts thereof, azacyclohexane-2,2-diphosphonic acid, azacyclopentane-2,2-diphosphonic acid, N-methyl-azacyclopentane-2,3-diphosphonic acid, EHDP (ethane-1-hydroxy- 1,1-diphosphonic acid), AHP (azacycloheptane-2,2-diphosphonic acid), ethane-1-amino-1,1-diphosphonate, dichloromethane-diphosphonate, etc. Phosphonoalkane carboxylic acid or their alkali metal salts include PPTA (phosphonopropane tricarboxylic acid), PBTA (phosphonobutane-1,2,4-tricarboxylic acid), each as acid or alkali metal salts. Polyolefin phosphates include those wherein the olefin group contains 2 or more carbon atoms. Polypeptides include polyaspartic and polyglutamic acids.
Fluoride ion sources are known for use in denture care compositions as anti-caries agents for remaining natural teeth and may optionally be incorporated within the present invention. Application of fluoride ions to the dental enamel of natural teeth serves to protect those teeth against decay. A wide variety of fluoride ion-yielding materials can be employed as sources of soluble fluoride in the instant compositions. Examples of suitable fluoride ion-yielding materials are found in Briner, et al., U.S. Pat. No. 3,535,421 and Widder, et al., U.S. Pat. No. 3,678,154. Preferred fluoride ion sources for use herein include sodium fluoride, potassium fluoride, stannous fluoride, mono fluoro phosphate (MFP), and ammonium fluoride. In one embodiment sodium fluoride is the fluoride ion source. The instant invention provides from about 5 ppm to 10,000 ppm, in one embodiment from about 100 to 3000 ppm, of fluoride ions in the total composition.
The compositions of the present invention may include a stannous ion source. The stannous ions may be provided from stannous fluoride and/or other stannous salts. Stannous fluoride has been found to help in the reduction of gingivitis, plaque, sensitivity, and in improved breath benefits. The stannous ions provided in an oral composition will provide efficacy to a subject using the composition. Although efficacy could include benefits other than the reduction in gingivitis, efficacy is defined as a noticeable amount of reduction in in situ plaque metabolism. Formulations providing such efficacy typically include stannous levels provided by stannous fluoride and/or other stannous salts ranging from about 3,000 ppm to about 15,000 ppm stannous ions in the total composition. Below about 3,000 ppm stannous the efficacy of the stannous is not sufficient. The stannous ion is present in an amount of from about 4,000 ppm to about 12,000 ppm, in one embodiment from about 5,000 ppm to about 10,000 ppm. Other stannous salts include organic stannous carboxylates, such as stannous acetate, stannous gluconate, stannous oxalate, stannous malonate, stannous citrate, stannous ethylene glycoxide, stannous formate, stannous sulfate, stannous lactate, stannous tartrate, and the like. Other stannous ion sources include, stannous halides such as stannous chlorides, stannous bromide, stannous iodide and stannous chloride dihydride. In one embodiment the stannous ion source is stannous fluoride in another embodiment, stannous chloride dihydrate. The combined stannous salts may be present in an amount of from about 0.01% to about 11%, by weight of the compositions. The stannous salts may typically be present in an amount of from about 0.1% to about 7%, in one embodiment from about 1% to about 5%, and in yet another embodiment from about 1.5% to about 3%, by weight of the composition.
Anti-microbial agents can also be present in the denture care composition of the present invention. Such agents may include, but are not limited to: 5-chloro-2-(2,4-dichlorophenoxy)-phenol, commonly referred to as Triclosan, and described in The Merck Index, 11th ed. (1989), pp. 1529 (entry no. 9573) in U.S. Pat. No. 3,506,720, and in European Patent Application No. 0,251,591 of Beecham Group, PLC,; 8-hydroxyquinoline and its salts; copper II compounds, including, but not limited to, copper(II) chloride, copper(II) sulfate, copper(II) acetate, copper(II) fluoride and copper(II) hydroxide; phthalic acid and its salts including, but not limited to those disclosed in U.S. Pat. No. 4,994,262, preferably magnesium monopotassium phthalate; chlorhexidine; alexidine; hexetidine; sanguinarine; benzalkonium chloride; salicylanilide; domiphen bromide; cetylpyridinium chloride (CPC); tetradecylpyridinium chloride (TPC); N-tetradecyl-4-ethylpyridinium chloride (TDEPC); octenidine; iodine; sulfonamides; bisbiguanides; phenolics; delmopinol, octapinol, and other piperidino derivatives; nicin preparations; zinc/stannous ion agents; nystatin; grapefruit extracts; apple extracts; thyme oil; thymol; antibiotics such as augmentin, amoxicillin, tetracycline, doxycycline, minocycline, metronidazole, neomycin, kanamycin, and clindamycin; analogs and salts of the above; essential oils including thymol, geraniol, carvacrol, citral, hinokitiol, eucalyptol, catechol (particularly 4-allyl catechol) and mixtures thereof; methyl salicylate; hydrogen peroxide; metal salts of chlorite; and mixtures of all of the above.
The compositions of the present invention may include an anti-plaque agent such as stannous salts, copper salts, strontium salts, magnesium salts or a dimethicone copolyol. The dimethicone copolyol is selected from C12 to C20 alkyl dimethicone copolyols and mixtures thereof. In one embodiment the dimethicone copolyol is cetyl dimethicone copolyol marketed under the Trade Name Abil EM90. The dimethicone copolyol is generally present in a level of from about 0.001% to about 25%, in one embodiment from about 0.01% to about 5% and in another embodiment from about 0.1% to about 1.5% by weight of the composition.
Anti-inflammatory agents can also be present in the compositions of the present invention. Such agents may include, but are not limited to, non-steroidal anti-inflammatory agents oxicams, salicylates, propoionic acids, acetic acids and fenamates. Such NSAIDs include but are not limited to Ketorolac, flurbiprofen, ibuprofen, naproxen, indomethacin, diclofenac, etodolac, indomethacin, sulindac, tolmetin, ketoprofen, fenoprofen, piroxicam, nabumetone, aspirin, diflunisal, meclofenamate, mefenamic acid, oxyphenbutazone, phenylbutazone and acetaminophen. Use of NSAIDs such as Ketorolac are claimed in U.S. Pat. No. 5,626,838, issued May 6, 1997. Disclosed therein are methods of preventing and, or treating primary and reoccurring squamous cell carcinoma of the oral cavity or oropharynx by topical administration to the oral cavity or oropharynx of an effective amount of an NSAID. Suitable steroidal anti-inflammatory agents include corticosteroids, such as fluccinolone, and hydrocortisone.
Nutrients may improve the condition of the oral cavity and can be included in the compositions of the present invention. Nutrients include minerals, vitamins, oral nutritional supplements, enteral nutritional supplements, and mixtures thereof. Useful minerals include calcium, phosphorus, zinc, manganese, potassium and mixtures thereof. Vitamins can be included with minerals or used independently. Suitable vitamins include Vitamins C and D, thiamine, riboflavin, calcium pantothenate, niacin, folic acid, nicotinamide, pyridoxine, cyanocobalamin, para-aminobenzoic acid, bioflavonoids, and mixtures thereof. Oral nutritional supplements include amino acids, lipotropics, fish oil, and mixtures thereof. Amino acids include, but are not limited to L-Tryptophan, L-Lysine, Methionine, Threonine, Levocarnitine or L- carnitine and mixtures thereof. Lipotropics include, but are not limited to, choline, inositol, betaine, linoleic acid, linolenic acid, and mixtures thereof. Fish oil contains large amounts of Omega-3 (N-3) polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid. Enteral nutritional supplements include, but are not limited to, protein products, glucose polymers, corn oil, safflower oil, medium chain triglycerides. Minerals, vitamins, oral nutritional supplements and enteral nutritional supplements are described in more detail in Drug Facts and Comparisons (loose leaf drug information service), Wolters Kluer Company, St. Louis, Mo., (copyright) 1997, pps. 3-17 and 54-57.
A whitening agent may be included in the present invention. The actives suitable for whitening are selected from the group consisting of peroxides, metal chlorites, perborates, percarbonates, peroxyacids, persulfates such as oxones, and combinations thereof. Suitable peroxide compounds include hydrogen peroxide, urea peroxide, calcium peroxide, carbamide peroxide, and mixtures thereof. In one embodiment the peroxide compound is carbamide peroxide. Suitable metal chlorites include calcium chlorite, barium chlorite, magnesium chlorite, lithium chlorite, sodium chlorite, and potassium chlorite. Additional whitening actives may be hypochlorite and chlorine dioxide. In one embodiment the chlorite is sodium chlorite. In another embodiment the percarbonate is sodium percarbonate. This level is generally used in compositions of the present invention at levels from about 0.01% to about,40%, in one embodiment from about 0.1% to about 20%, in another embodiment from about 0.5% to about 10%, and in yet another embodiment from about 4% to about 7% of the composition.
Antioxidants are generally recognized as useful in denture care compositions. Antioxidants are disclosed in texts such as Cadenas and Packer, The Handbook of Antioxidants, (copyright) 1996 by Marcel Dekker, Inc. Antioxidants that may be included in the present invention include, but are not limited to Vitamin E, ascorbic acid, Uric acid, carotenoids, Vitamin A, flavonoids and polyphenols, herbal antioxidants, melatonin, aminoindoles, lipoic acids and mixtures thereof.
Antiviral actives useful in the present invention include any known actives that are routinely used to treat viral infections. Such antiviral actives include, but are not limited to: phosphonoformic acid; cyosine derivatives; purine anaglogues, such as adenosine, guanosine and inosine analogues; pyrimidine bases, such as citidine and thymidine; amantadines; rimantadine HCl; ribavirin; zanamivir; oseltamivir phosphate; trifluridine; heterocyclic dyes; acyclovir; famciclovir; valacyclovir, cidofovir; ganciclovir; levimisole; idoxuridine; lipophilic xcex2-ketones; and thiosemicarbazones. These antiviral actives are described in Drug Facts and Comparisons (loose-leaf drug information service), Wolters Kluwer Company, St. Louis, Mo., (copyright)2001, pp. 1400-1423(b), and in Kirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, Volume 3, Wiley-Interscience Publishers (1992), pp. 576-607, both incorporated herein by reference in their entirety. Specific examples include antiviral actives disclosed in U.S. Pat. No. 5,747,070, to Majeti, incorporated herein by reference in its entirety. Said patent discloses the use of stannous salts to control viruses. Stannous salts are described in more detail above. While stannous fluoride may be used as an antiviral agent, it is typically used only in combination with another stannous halide or one or more stannous carboxylates or another therapeutic agent.
Anti-fungal agents can also be included in the denture care compositions of the present invention. Anti-fungals are agents that destroy or inhibit the growth of fungi. Anti-fungal agents useful in the present invention are those drugs for systemic mycoses or drugs for mucocutaneuos infections. Suitable antifungals include but are not limited to nystatin; miconazole; econazole nitrate; clotrimazole; and flucytosine. In one embodiment the antifungal agent is nystatin.
Anti-pain or desensitizing agents can also be present in the denture compositions of the present invention. Analgesics are agents that relieve pain by acting centrally to elevate pain threshold without disturbing consciousness or altering other sensory modalities. Such agents may include, but are not limited to, strontium chloride, potassium nitrate, sodium nitrate, sodium fluoride, acetanilide, phenacetin, acertophan, thiorphan, spiradoline, aspirin, codeine, thebaine, levorphenol, hydromorphone, oxymorphone, phenazocine, fentanyl, buprenorphine, butaphanol, nalbuphine, pentazocine, natural herbs such as gall nut, Asarum, Cubebin, Galanga, scutellaria, Liangmianzhen, Baizhi, etc. Anesthetic agents, or topical analgesics, such as acetaminophen, sodium salicylate, trolamine salicylate, lidocaine and benzocaine may also be present. These analgesic actives are described in detail in Kirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, Volume 2, Wiley-Interscience Publishers (1992), pp. 729-737, incorporated herein by reference in its entirety.
Histamine-2 (H-2 or H2) receptor antagonist compounds (H-2 antagonists) may be used in the compositions of the present invention. As used herein, selective H-2 antagonists are compounds that block H-2 receptors, but do not have meaningful activity in blocking histamine-1 (H-1 or H1) receptors. Selective H-2 antagonists stimulate the contraction of smooth muscle from various organs, such as the gut and bronchi; this effect can be suppressed by low concentrations of mepyramine - a typical antihistaminic drug. The H-2 antagonists useful in the present invention are those that blockade the receptors involved in mepyramine-insensitive, non-H-1 (H-2), histamine responses and do not blockade the receptors involved in mepyramine-sensitive histamine responses. Selective H-2 antagonists include compounds meeting the above criteria which are disclosed in U.S. Pat. Nos. 5,294,433 and 5,364,616 both to Singer, et al., and assigned to The Procter and Gamble Company, wherein the selective H-2 antagonist is selected from the group consisting of cimetidine, etintidine, ranitidine, ICIA-5165, tiotidine, ORF-17578, lupitidine, donetidine, famotidine, roxatidine, pifatidine, lamtidine, BL-6548, BMY-25271, zaltidine, nizatidine, mifentidine, BMY-25368 (SKF-94482), BL-6341A, ICI-162846, ramixotidine, Wy-45727, SR-58042, BMY-25405, loxtidine, DA-4634, bisfentidine, sufotidine, ebrotidine, HE-30-256, D-16637, FRG-8813, FRG-8701, impromidine, L-643728, and HB-408. Related suitable H-2 antagonists include burimamide and metiamide.
The denture compositions of the present invention may also include one or more components that provide fragrance, and/or sensate benefit (warming or cooling agents). Suitable components include menthol, menthyl lactate, wintergreen oil, peppermint oil, spearmint oil, leaf alcohol, camphor, clove bud oil, eucalyptus oil, anethole, methyl salicylate, eucalyptol, cassia, 1-8 menthyl acetate, eugenol, oxanone, alpha-irisone, propenyl guaethol, cinnamon, thymol, linalool, benzaldehyde, cinnamaldehyde glycerol acetal known as CGA, and mixtures thereof, as well as coolants. The coolant can be any of a wide variety of materials. Included among such materials are carboxamides, menthol, ketals, diols, and mixtures thereof. Preferred coolants in the present compositions are the paramenthan carboxyamide agents such as N-ethyl-p-menthan-3-carboxamide, known commercially as xe2x80x9cWS-3xe2x80x9d, N,2,3-trimethyl-2-isopropylbutanamide, known as xe2x80x9cWS-23, xe2x80x9dand mixtures thereof. Additional preferred coolants are selected from the group consisting of menthol, 3-1-menthoxypropane-1,2-diol known as TK-10, manufactured by Takasago, menthone glycerol acetal known as MGA manufactured by Haarmann and Reimer, and menthyl lactate known as Frescolat(copyright) manufactured by Haarmann and Reimer. The terms menthol and menthyl as used herein include dextro- and levorotatory isomers of these compounds and racemic mixtures thereof. TK-10 is described in U.S. Pat. No. 4,459,425, Amano et al. WS-3 and other agents are described in U.S. Pat. No. 4,136,163, Watson, et al. The disclosures of both are herein incorporated by reference.
Pigments may be added to the compositions herein to more precisely indicate the locations at which the composition has actually been in contact. Additionally, these substances may be suitable for modifying the color of the denture to satisfy the consumer. These substances comprise particles that when applied on the tooth surface modify that surface in terms of absorption and, or reflection of light. Such particles provide an appearance benefit when a film containing such particles is applied over the surfaces of the denture. Pigments, dyes, colorants and lakes may also be added to modify the appearance of the compositions herein to render the product more acceptable to the consumer. Appropriate pigment levels are selected for the particular impact that is desirable to the consumer. For example, for dentures that are particularly dark or stained one would typically use pigments in sufficient amounts to lighten the teeth. On the other hand, where individual teeth or spots on the teeth are lighter than other teeth, pigments to darken the denture may be useful. The levels of pigments and colorants may be in the range of about 0.001% to about 20%, in one embodiment from about 0.01% to about 15%, and in another embodiment from about 0.1 % to about 10% by total weight of the composition.
Pigments and colorants include inorganic white pigments, inorganic colored pigments, pearling agents, filler powders and the like; see Japanese Published Patent Application Kokai No. 9 [1997]-100215, published Apr. 15, 1997, incorporated herein by reference. Specific examples are selected from the group consisting of talc, mica, magnesium carbonate, calcium carbonate, magnesium silicate, aluminum magnesium silicate, silica, titanium dioxide, zinc oxide, red iron oxide, brown iron oxide, yellow iron oxide, black iron oxide, ferric ammonium ferrocyanide, manganese violet, ultramarine, nylon powder, polyethylene powder, methacrylate powder, polystyrene powder, silk powder, crystalline cellulose, starch, titanated mica, iron oxide titanated mica, bismuth oxychloride, and mixtures thereof. In one embodiment the pigments and colorants are those selected from the group consisting of titianium dioxide, bismuth oxychloride, zinc oxide, Opatint DandC Red 27, CI 16185:1 Acid 27 Lake E123, CI14720:1 Carmosoisine Aluminum Lake E122, Red 7 Lake, or Red 30 Lake, and mixtures thereof.
The present invention may further comprise a viscosity modifier that inhibits settling and separation of components or controls settling in a manner that facilitates re-dispersion and may control flow properties. A viscosity modifier is particularly useful to keep denture care actives that are in particulate form suspended within the polybutene components of the present invention. Suitable viscosity modifiers herein include mineral oil, organo modified clays, petrolatum, silicas, and mixtures thereof. In one embodiment the viscosity modifier is silica. Where incorporated, the viscosity modifier is present in the polybutene component of the present invention at a level of from about 0.001% to about 75%, in one embodiment from about 0.01% to about 50%, and in another embodiment from about 0.1% to about 25% of the composition.
The denture composition may optionally further comprise one or more flavorants. These flavoring agents can be chosen from synthetic flavoring liquid and/or oils derived from plants leaves, flowers, fruits and so forth, and combinations thereof. Representative flavoring liquids include: vanillin, sage, marjoram, parsley oil, spearmint oil, cinnamon oil, oil of wintergreen (methylsalicylate), peppermint oils clove oil, bay oil, anise oil, and eucalyptus oil. Also useful are artificial, natural or synthetic fruit flavors such as citrus oil including lemon, orange, banana, grape, lime, apricot and grapefruit and fruit essences including apple, strawberry, cherry, orange, pineapple and so forth; bean and nut derived flavors such as coffee, cocoa, cola, peanut, almond and so forth. Additionally, flavor adsorbed onto a hydrophilic matrix may be included, e.g. xe2x80x9cspray-driedxe2x80x9d flavors. Furthermore, encapsulated flavors may be included. The amount of flavorant employed is normally a matter of preference subject to such factors as flavor type and strength of flavor desired. Flavorants may be present in amounts up to about 4%, in one embodiment about 0.05% to about 3.0%, in another embodiment about 0.8% to about 2.5%, by weight of the total composition.
The denture composition may optionally further comprise one or more sweeteners. Suitable sweeteners include natural and artificial, water soluble, water insoluble and intense sweeteners. The sweetening agent may comprise dextrose, sucrose, maltose, dextrin, dried invert sugar, mannose, xylose, ribose, glucose, fructose, levulose, galactose, corn syrup, high fructose corn syrup, corn syrup solids, partially hydrolyzed starch, aspartame, saccharin, sugar alcohols such as sorbitol, mannitol, xylitol, maltitol, isomalt, and hydrogenated starch hydrolysate or combinations thereof. Natural artificial intense sweeteners such as dipeptide based intense sweeteners, monellin, thaumaoccous danielli, and L-aspartyl L-phenylalanine methyl ester and soluble saccharin salts may be incorporated as sweeteners. The amount of the sweetener will vary with the type of sweetener selected and the desired level of sweetness. Sweetening agents and flavoring agents are typically used in denture care compositions at levels of from about 0.005% to about 5%, by weight of the total composition.
Additional actives suitable for use in the present invention may include, but are not limited to, insulin, steroids, herbal and other plant derived remedies, and anti-neoplastics. Additionally, anti-gingivitis or gum care agents known in the art may also be included. Components, other than polybutene, which impart a clean feel to the teeth may optionally be included. These components may include, for example, baking soda or Glass-H. Also, it is recognized that in certain forms of therapy, combinations of these above-named agents may be useful in order to obtain an optimal effect. Thus, for example, an anti-microbial and an anti-inflammatory agent may be combined in a single chewing gum or confection piece to provide combined effectiveness.
Denture Care Carriers
In preparing the present composition, one or more non-aqueous denture care carriers may be optionally added. Such materials are well known in the art and are readily chosen by one skilled in the art based on the physical and aesthetic properties desired for the composition being prepared. These carriers may be included at levels that do not interfere or prohibit the surface conditioning. Typically the level of non-aqueous denture care carrier is about 0.001% to about 90%, in one another embodiment from about 0.01% to about 75% and in yet another embodiment from about 0.1% to about 50%, by total weight of the composition.
The non-aqueous denture care carrier is generally any chemical in any physical form that does not contain water. The non-aqueous vehicle is selected from the group consisting of liquid petrolatum, petrolatum, mineral oil, glycerin, natural and synthetic oils, fats, silicone and silicone derivatives, natural and synthetic waxes such as animal waxes like beeswax, lanolin and shellac, hydrocarbons, hydrocarbon derivatives, vegetable oil waxes such as camauba, candelilla and bayberry wax, vegetable oils such as caprylic/capric triglycerides; in another embodiment is selected from the group consisting of liquid petrolatum, petrolatum, mineral oil, vegetable oils such as corn, soy bean, cottonseed, castor, palm and coconut oils and animal oil such as fish oil and oleic acid, and mixtures thereof; in yet another embodiment is mineral oil.
Caprylic/capric triglycerides are triglycerides of medium chain fatty acids where the xe2x80x94Cxe2x95x90Oxe2x80x94R group is 8-10 carbons and is obtained by the addition of glycerol to a mixture of capric and caprylic acids:
Capric Acid: CH3(CH2)8CO2H
Caprylic Acid: CH3(CH2)6CO2H
Therefore, vegetable oils comprised of saturated medium chain fatty acids such as caprylic acid, capric acid and mixtures thereof, can be used in the present invention. These vegetable oils and other non-aqueous carriers for denture care compositions are further described in U.S. Pat. No. 5,561,177 to Khaledi, at el., which is incorporated herein by reference in its entirety.
Other suitable denture care carriers include preservatives such as methyl and propyl parabens, thickeners such as silicon dioxide, and polyethylene glycol.
Method of Preparation
The denture composition is suitably made as follows: Combine the polybutene and any denture care active ingredients into a mixing vessel and mix well with any means known within the art, for example, with spatula or mixer. Heat the composition, if desired, to facilitate mixing. Continue mixing the composition until homogenous. Where a denture care active is included in solid particulate form, the addition of a viscosity modifier, such as silica, may be appropriate to keep the particulate dispersed and suspended within the composition. Flavorants or sweeteners may also be added as desired.
Where a denture care carrier is desired within the composition of the present invention, the denture care carrier component and the polybutene containing component are prepared separately and then emulsified to form a single phase composition. Where a dual or multi phase composition is desired, the components are, typically, physically separated until the time of administration to the denture. The denture care carrier component is prepared using conventional methods. Generally, blending of the desired ingredients until homogenous is sufficient. A denture care active may also be incorporated within the denture care carrier component of the present invention.
The polybutene component of the denture care kits is prepared in the same manner as the denture compositions above, with the addition of the denture care active being optional. In one embodiment, a container such as a jar, cup, can, tube, aerosol can, tub, pump, bottle or any other liquid holding or dispensing means, is filled with the polybutene component. Sample accompanying instructions for the use of the kit would read: xe2x80x9cApply the denture care composition directly to the denture or dental plate when removed from the oral cavity. Apply a sufficient amount of the composition to coat the denture, directly to the denture surface by finger, brush, dental stick, or cotton swab. It is not necessary to excessively clean, by brushing, or dry the denture or dental plate either before or after application.xe2x80x9d In another denture care kit, the polybutene component is placed within any suitable applicator, such as a tube or pen applicator, for direct application to the artificial teeth. Where an applicator is included with the denture care kit of the present invention, sample instructions would read: xe2x80x9cApply the denture care composition directly to the denture or dental plate. Apply a sufficient amount to sufficiently coat the artificial teeth by use of the enclosed applicator. It is not necessary to excessively clean, by brushing, or dry the denture or dental plate either before or after application.xe2x80x9d
Method of Use
In practicing the denture care kits and composition of the present invention, the user removes the denture from the oral cavity and applies the denture care composition disclosed herein directly to the surface of the denture. Where an applicator is included in the denture care kit, the polybutene composition can be applied using the brush, pen applicator, dropper, doe""s foot applicator or other supplied application device. Where an applicator is not provided with the denture care kit or composition of the present invention, the polybutene component may also be applied by finger, cotton swab, or dental stick or the like or by dipping the denture into the polybutene composition.
It is not necessary to prepare the denture before applying the composition of the present invention. For example, the user may or may not choose to brush or cleanse the denture before applying the composition. The surfaces of the denture are neither required to be dried nor to be excessively wet with saliva or water prior to application. However, it is believed that adhesion to the denture surfaces will be improved if the surfaces are drier when the composition is applied.


A data alignment circuit of a semiconductor memory apparatus includes: a data strobe clock phase control block configured to control a phase of a data strobe clock signal in response to a strobe delay code and generate a delayed strobe clock signal; a plurality of data phase control blocks configured to control phases of input data in response to data delay codes and generate delayed data; a plurality of data alignment blocks configured to latch the delayed data in response to the delayed strobe clock signal and generate latched data and aligned data; and a delay code generation block configured to perform an operation of determining phases of the latched data and generate the strobe delay code and the data delay codes.

The present invention relates generally to a semiconductor memory apparatus, and more particularly, to data alignment circuit and method of a semiconductor memory apparatus.
Generally, a semiconductor memory apparatus transmits and receives multi-bit data in series using an external memory controller. On the other hand, a plurality of global data buses (GIO) are provided inside of the semiconductor memory apparatus in order to transmit multi-bit data to a core area or output multi-bit data from a core area, and the multi-bit data transmitted through the global data buses are arranged in parallel. In this manner, multi-data data is transmitted in parallel inside of the semiconductor memory apparatus but is transmitted in series outside of the semiconductor memory apparatus. Thus, a circuit for aligning serial data in parallel is required in a data input area, and a circuit for aligning parallel data in series is required in a data output area. To this end, the semiconductor memory apparatus is configured to include data alignment circuits in the data input area and the data output area.
Generally, the data alignment circuit of the semiconductor memory apparatus provided in the data input area is configured to perform synchronization of data inputted through a plurality of data pads by using a data strobe clock signal (DQS), synchronizing the data with an internal clock signal, and transferring the data to the global data buses. In a semiconductor memory device such as a double data rate synchronous dynamic random access memory (DDR SDRAM), a faster data input operation may be performed by latching data bits at rising and falling edges of the data strobe clock signal (DQS). The internal clock signal is generated from a delay locked loop (DLL) circuit or a phase locked loop (PLL) circuit and has recently been implemented in the form of a multi-phase clock signal in order to support a faster operation speed.
However, it is difficult to exactly synchronize the timing of a plurality of data transferred to data pads from outside of the semiconductor memory device, and often a slight timing difference occurs among the plurality of data. As development of the semiconductor memory apparatus is advanced to perform higher-speed operation, even a slight difference of data input timing may cause malfunction in a data alignment operation. Accordingly, a conventional data alignment circuit of a semiconductor memory apparatus should be configured in a structure for preventing such a malfunction.
FIG. 1 is a schematic configuration diagram of a conventional data alignment circuit of a semiconductor memory apparatus, illustrating a block which extracts phase information of input data.
Referring to FIG. 1, the conventional data alignment circuit of the semiconductor memory apparatus includes: a counter 1 configured to generate a counting signal CNT; a multiplexer (MUX) 2 configured to sequentially output first through eighth data DQ<1:8>; first through eighth flip-flops FF1 through FF8 configured to latch first through eighth clock signals CLK<1:8> in response to the data transferred from the multiplexer 2; an encoder 3 configured to encode output signals of the first through eighth flip-flops FF1 through FF8 and generate a 3-bit encoding signal ENC; and a register 4 configured to store the encoding signal ENC.
The first through eighth clock signals CLK<1:8> are multi-phase clock signals generated from a DLL circuit or a PLL circuit, and the clock signals are generated by dividing a phase of a single clock signal by 8. When the multiplexer 2 transfers any one of the first through eighth data DQ<1:8> to the first through eighth flip-flops FF1 to FF8, the flip-flop to which a clock signal whose phase leads the phase of the data is inputted outputs a high-level signal, and the flip-flop to which a clock signal whose phase lags behind the phase of the data is inputted outputs a low-level signal. During such a phase information extraction operation, all of the first through eighth data DQ<1:8> are controlled to have a high-level potential.
The encoder 3 is configured to encode the output signals of the first through eighth flip-flops FF1 through FF8, and transfer the encoded signals to the register 4. The register 4 is configured to store phase information of the 1-bit data. Subsequently, if the multiplexer 2, the first through eighth flip-flops FF1 through FF8, and the encoder 3 are repetitively operated, the register 4 can store phase information of the respective bits of the first through eighth data DQ<1:8>.
Subsequently, the phase information of the respective bits of the first through eighth data DQ<1:8>, which are stored in the register 4, are used to control the phases of the first through eighth data DQ<1:8> in a circuit area (not shown). In such a manner, the data alignment circuit of the semiconductor memory apparatus can support a stable data input operation by performing the operation of controlling the respective phases of the first through eighth data DQ<1:8> and aligning the first through eighth data DQ<1:8>.
However, since the above-described data alignment circuit must receive the multi-phase clock signals from the DLL circuit or the PLL circuit upon its operation, a large number of signal lines are necessarily provided in the data alignment circuit. Therefore, a disadvantage arises in that the area efficiency is degraded. Furthermore, as a complicated circuit configuration is provided for extracting the phase information of the data, the design facilitation is degraded. As such, the conventional data alignment circuit of the semiconductor memory apparatus has a technical limitation in that the occupied area is large and the design facilitation is degraded, which serves as a factor to obstruct the implementation of a high-performance semiconductor memory apparatus.

Data alignment circuit and method of semiconductor memory apparatus

Industry-University Cooperation Foundation, Hanyang University


A system or a board that interacts with a processor and multi I/O devices such as high-speed facsimile modems. The processor inputs/outputs data to I/O devices. Each I/O device includes an indicator, such as an Interrupt Request output, to signify a request that the I/O device will output or input data. If the indicator signifies a request, the processor will input data from or output data to the I/O device within a predetermined period Ti, in order to prevent the data from being lost. To this end, the new system or board includes a timer that periodically interrupts the processor and causes it to execute an interrupt service at a period T, where T<=Ti, whereupon the processor detects the indicators of I/O devices, and reads data from or writes data to any I/O device that signals a request.

1. Field of the Invention
The present invention is directed toward data transfer methods between a processor and input/output (I/O) devices such as facsimile modems. The invention particularly relates to computer interrupt technology, and more specifically to a new interrupt hardware and software architecture for multiple I/O devices including multi-line facsimile boards.
2. Description of the Prior Art
Computers are increasingly used to service multiple I/O devices, such as facsimile modems, keyboards, sensors and other computers or processors. However, a major problem that limits the expanding use of multiple computer-based I/O devices is that the computer has limited interrupt inputs and limited communication ports. A computer readily supports two serial ports, with the hardware generally providing for up to four serial ports (COM 1 through COM 4). However, exceeding four serial ports currently presents problems. For example, in order to run 24 or 30 facsimile channels (lines) in a computer, it is not possible to simply architect a COM 1 through COM 30 solution.
The foregoing problem is particularly accentuated in the design of facsimile servers, multi-line fax-on-demand systems, facsimile store-and-forward node systems, facsimile packet-switched node systems, and facsimile broadcast systems, which need multiple high-speed facsimile channels to simultaneously service multiple subscribers in a computer system. For instance, in a facsimile packet-switched node, data from a plurality of facsimile machines are sent together over a common channel, and therefore multiple modems are needed in the node to service multiple subscribers.
High-speed facsimile modem such as Class 1 modem communicates to the host computer by way of an interrupt driven, with each interrupt occurring on a character-by-character basis. Since most faxes go out at high-speed such as 9,600 BPS or faster, the serial port would have to run at 19,200 BPS in order to feed the facsimile modem fast enough. At this speed, there is an interrupt required every 400-500 used. As a result, if for instance the computer supports ten facsimile modems, the computer will be interrupted every 40 to 50 used in order to read in the next character to the serial port, thus causing interrupt overload. Interrupt overload is highly undesirable since it degrades the computer general performance by forcing it away from other tasks to service an interrupt and then returning to continue the previous task.
The intelligent facsimile boards, such as GammaFax (a registered trademark of Dialogic), TR114 series (a registered trademark of Brooktrout), and SatisFAXtion series (a registered trademark of Pure Data), are developed to resolve above problems. For each facsimile channel of the intelligent facsimile board, a processor is dedicated to service a high-speed facsimile modem. So, when the board supports multi facsimile channels, it has to include multi processors, which renders that board expensive and relatively large in size, with complicated hardware designs. For example, a GammaFax CP-6/SC board includes six facsimile modems, six 20 MHz microprocessors, six 64 KB memory and six system bus control circuits.
Even if the computers were dedicated for the facsimile system only, most multi-line higt-speed facsimile systems still have to be established by using the intelligent facsimile board because of the limited interrupt inputs and the interrupt overload of the computer. The facsimile system based on such facsimile boards is expensive and requires more technologic maintenance, because such facsimile boards are complicated. Though the speed of the computer is becoming faster and faster, such as from the 8086 PC to the present Pentium 5 PC, the computer still tends to support one high-speed facsimile modem only such as Class 1 modem because of conventional interrupt method.
In general, an I/O device has an Interrupt Request output and status bits. When the I/O device has a request to input or output data, it sets the status bits and/or interrupts the computer by means of the Interrupt Request output. The computer responds to the I/O device within a period Ti after the I/O device signals the request, in order to prevent data from overrunning. For example, when a facsimile modem is receiving data, if the computer does not timely read the received data byte from the data buffer of the modem within the period Ti, the modem will continue to write the subsequently new received data byte to the data buffer and data might be lost. On the other hand, when a facsimile modem is transmitting, if the computer does not write the next transmitted data byte to the modem within the period Ti, the modem will not have the subsequent data byte on time, and it will erroneously transmit the data.
It should be noted that the I/O device such as higt-speed facsimile modem may very frequently and very randomly or at any time signify the interrupt request, however, when the I/O device such as facsimile modem signifies a request, it will allow a short period for the computer to respond, and if the computer can respond the request within the period, the computer will service the I/O device correctly.
FIG. 3 shows a conventional computer (CPU) 1 that services multi facsimile modems 2, 3 and 5. An interrupt requests IQR 2A, IQR 3A and IRQ 5A of the facsimile modems 2, 3 and 5, respectively, are connected to a programmable interrupt controller (PIC) 4. It should be noted that this conventional design uses multiple interrupt request inputs of the computer 1. After the facsimile modems begin communication, when any facsimile modem 2, 3 or 5 requests a data byte, it sends an interrupt request signal to PIC 4 by its IRQ output 2A, 3A or 5A. It should also be noted that this conventional design enables the interrupt request to the computer 1 from the multi facsimile modems 2, 3 or 5, as opposed to disabling the interrupt requests to the computer 1 from the multi facsimile modems 2, 3 or 5 (as performed by the present invention). Then, the PIC 4 responds to the request (IRQ) of the facsimile modems 2, 3 or 5, and interrupts the CPU 1 by the IRQ output of the PIC 4. In response to the interrupt request IRQ of the PIC 4, CPU 1 goes to interrupt service and transfers a data byte for the facsimile modems 2, 3 or 5. In the method, if any facsimile modem has a request, it will independently interrupt the CPU 1, and the CPU 1 will execute an interrupt routine for the facsimile modem only, rather than the CPU executing an interrupt service to check and service the modems 2, 3 or 5 as performed by the present invention.

System architecture for multiple input/output devices

No. 14-36, Blk 513, Jurong West Street 52


A neurostimulation system is shown and described. The neurostimulation system may include a stimulation device implantable into a patient, a lead operatively coupled with the stimulation device, a first power cell providing power to the stimulation device where the first power cell is charged by an externally applied AC (High HF) magnetic field.

Neurostimulation, i.e., neuromuscular stimulation (the electrical excitation of nerves and/or muscle that may directly elicit the contraction of muscles) and neuromodulation stimulation (the electrical excitation of nerves, often afferent nerves, to indirectly affect the stability or performance of a physiological system) and brain stimulation (the stimulation of cerebral or other central nervous system tissue) can provide functional and/or therapeutic outcomes. While existing systems and methods can provide remarkable benefits to individuals requiring neurostimulation, many quality of life issues still remain. For example, existing systems are, by today's standards, relatively large and awkward to manipulate and transport. There exist both external and implantable devices for providing neurostimulation in diverse therapeutic and functional restoration indications. The operation of these devices typically includes the use of an electrode placed either on the external surface of the skin and/or a surgically implanted electrode.
Deep Brain Stimulation (DBS) has been found to be successful in treating a variety of brain-controlled disorders, including movement disorders. Generally, such treatment involves placement of a DBS type lead into a targeted region of the brain through a burr hole drilled in the patient's skull, and the application of appropriate stimulation through the lead to the targeted region.
Although effective, conventional high frequency stimulation generates stronger side-effects than low frequency stimulation, and the therapeutic window between the voltage that generates the desired clinical effect(s) and the voltage that generates undesired side effects decreases with increasing frequency. Precise lead placement therefore becomes important. Further, high stimulation frequencies increase power consumption. The need for higher frequencies and increased power consumption shortens the useful lifetime and/or increases the physical size of battery-powered implantable pulse generators. The need for higher frequencies and increased power consumption requires a larger battery size, and frequent charging of the battery, if the battery is rechargeable.
The art of electrical stimulation would benefit from improved systems and methods of applying electrical neurostimulation.


In a pipelined processor, when a conditional branch is effected in accordance with a state of calculation generated by immediately previous instruction, it is necessary for a conventional technique to insert a NOP (no operation) instruction before a conditional branch instruction. This lowers the processing efficiency. In order to solve this problem, a delay circuit generates a clock signal .phi.' which is supplied to a program counter and an instruction memory. The clock signal .phi.' is delayed behind a system clock .phi.. This obviates the need to insert such a NOP instruction and the processing efficiency is improved.

The present invention relates to a signal handling processor and, in particular, a processor for enabling the decoding and execution of instructions through a pipeline system.
FIG. 6 is a block diagram of a conventional microprocessor. Like reference numerals are employed to designate like parts or elements throughout the specification and any further explanation is omitted for similar parts or elements above.
The microprocessor shown in FIG. 6 comprises a program counter (PC) 1, an instruction memory 2, an instruction decoder 3, a data memory 4, a register file 5, a calculation circuit 6, [such as an arithmetic logic unit (ALU)], an accumulator 7, and a flag register 8.
The program counter 1 outputs an address signal P, which is applied to an address signal input terminal of the instruction memory 2. The instruction memory 2 allows the reading of an instruction Q stored in an address corresponding to the address signal P and writing of the instruction Q to an instruction register IR (not shown).
The instruction Q stored in the instruction register IR is applied to an instruction input terminal of the instruction decoder 3. The instruction decoder 3 decodes the content of the instruction and applies control signals g, h, i, j and k corresponding to the instruction Q to control terminals of the data memory 4, the register file 5, the calculation circuit 6, the program counter 1 and the instruction memory 2, respectively.
The data input and output terminals of the data memory 4, the register file 5 and the calculation circuit 6 are connected to a data bus. Data D is transferred between the data memory 4, the register file 5 and the calculation circuit 6 via the data bus. A system clock signal .phi. is applied to the clock input terminals of the program counter 1, the instruction memory 2, the data memory 4, the register file 5, the accumulator 7 and the flag register 8. The program counter 1, the instruction memory 2, the data memory 4, the register file 5, the accumulator 7 and the flag register 8 are operated in synchronism with a rise of a system clock signal .phi..
The calculation circuit 6 performs a calculation on data A' stored in the accumulator 7 and the data D supplied via the data bus. The result of the calculation is data A, which is stored in the accumulator 7. Any specific state, occurring upon the calculation, such as overflowing, sign of a result, zero as a result, and a carry output, is represented as a state signal of one bit called a "flag". The calculation circuit 6 collects such flags, and produces a flag signal F.
The flag register 8 stores the flag signal F. An output signal F' of the flag register 8 is applied as a calculated flag signal to a flag input terminal of the instruction decoder 3. The instruction decoder 3 utilizes the calculated flag signal F' as a branching condition of a conditional branch instruction. The conditional branch instruction is used when an instruction execution procedure is controlled.
The above-mentioned state signal is allocated to the calculated flag signal F' in the following way:
A third bit F3': an overflow flag V is "1" at an overflowing time and otherwise "0".
A second bit F2',: a signal flag S is "1" for a negative result and otherwise "0".
A first bit F1': a zero flag Z1 for a result of all 0s and otherwise "0".
A zero-th bit F0': a carry flag C is "1" at a carry from the most significant digit and otherwise "0".
For the instruction set of the processor, the following conditional branch instructions are prepared for controlling an instruction execution procedure in accordance with the respective flags.
JUMPV LABEL1; at F3'="1", branch to an address LABEL1
JUMPS LABEL1; at F2'="1", branch to an address LABEL1.
JUMPZ LABEL1; at F1'="1", branch to an address LABEL1.
JUMPC LABEL1; at F0'="1", branch to an address LABEL1.
In order to enhance the processing efficiency of the processor, a conventional technique is used for performing the instruction decode processing and instruction execute processing through a pipeline system. According to this technique, except for a first instruction reading step, a subsequent instruction reading and instruction executing step can be simultaneously effected. For this reason, a processor can achieve processing throughput about two times higher than a processor not using any pipeline system.
In such a processor using the pipeline system, the period in which an instruction described immediately before the conditional branch instruction is superimposed on the period in which the conditional branch instruction is decoded. It is, therefore, impossible, based on the instruction described immediately before the conditional branch instruction, to effect branching with the use of a content-varied flag.
The following is an example of a program with a combined calculation instruction and conditional branch instruction.
ADD A, R0; add the content of the register R0 to the accumulator's content A. PA1 NOP; not operated. PA1 JUMPV LABEL1; at an overflow flag F3'="1" branch to LABEL1.
For this exemplary program, at a first line the content of the register R0 at a zero-th of the register file 5 is applied to the input terminal of the calculation circuit (ALU) 6 via the data bus. The calculation circuit 6 adds the content in the register R0 and the content in the accumulator ACC 7 together and again stores the result of the addition into the accumulator 7.
At a second line, nothing is executed. This is a NOP (no operation) instruction, which is used for timing matching. Such an NOP instruction is included in an instruction set of most processors.
At a third line, detection is made to determine whether any overflowing occurs, and, if YES, a branch is made to LABEL1 address.
FIG. 7 shows a timing chart for executing the above-mentioned program with a calculation instruction and conditional branch instruction combined in a conventional processor using a pipeline system. This timing chart shows a time variation of an address signal P output from the program counter 1, an instruction Q held in the instruction requester IR, data D at the data bus, and a flag calculation signal F' held at the flag register 8. T represents a machine cycle.
As shown in FIG. 7, at a time T, an ADD instruction is read from an n address in the instruction memory 2 and written to the instruction register IR.
Then an ADD instruction is decoded and, at a time 2T, the content (R0) of the register R0 is read onto the data bus. Further, an NOP instruction is read from an n+1 address in the instruction memory 2 and written to the instruction register IR.
Subsequently, the content A' held in the accumulator 7 and data (R0) on the data bus are added together in the calculation circuit 6. At a time 3T, the result of the addition is written to the accumulator 7 and a flag F is written to the flag register 8. The flag register 8 outputs the flag signal F as a calculated flag signal F'. And at the time 3T a JUMPV instruction is read out from n+2 address in the instruction memory 2 and written to the instruction register IR.
Then the JUMPV instruction is decoded. At a time 4T, the instruction decoder 3 decides, with the use of an overflow flag F3' output from the flag register, whether or not any overflowing occurs. If YES, using the control signal j, the instruction decoder 3 causes an address signal, which is output from the program counter 1, to vary.
As evident from the above, the time 3T at which an overflow flag F3' is varied by the addition instruction is 2 machine cycles after the time T at which the ADD instruction is read out as the instruction Q. Therefore, if the conditional branch instruction is described immediately after the addition instruction, the output flag signal F' of the flag register 8 varies after the conditional branch instruction has been decoded by the instruction decoder 3. As a result, it becomes impossible to use, as a branching condition, the variation of a flag resulting from the addition instruction. In order to prevent this, the NOP instruction is inserted so that a result of the ADD instruction can be used as a condition of the JUMPV instruction.
In the conventional processor, in order to use the result of the addition instruction as the condition of the branch instruction, it is necessary to insert the NOP instruction as described above, thereby lowering the processing efficiency. In the case where, the conditional branch is executed in the repeating loop, its adverse effect appears prominent. As a result, the actual execution speed of the program becomes slower and an unexpected error actually occurs.

System for improving processing efficiency in a pipeline by delaying a clock signal to a program counter and an instruction memory behind a system clock


A method for erecting absorber towers using trestle means (26) with jack means (32) to assemble a course and then lift it while constructing the next course below it. The first course is lowered on the just assembled course and welded thereto. These steps are repeated to form the outer wall (34) of the absorber tower (10). A clearance (48) is provided between the elevated course and the course to be assembled for installing the internal components of the tower. Advantageously, the method of the present invention allows for the construction of an absorber tower on site in retrofit applications where space may be restricted and access limited.

1. Field of the Invention
The present invention relates in general to a method for constructing absorber towers, and in particular, to a method for erecting an absorber tower for flue gas desulfurization (FGD) using a jacking system.
2. Description of the Related Art
Absorber towers are devices known in the art, and are employed in conjunction with furnaces or boilers, as part of their flue gas desulfurization (FGD) system. The purpose of the flue gas desulfurization system is to treat the flue gas emissions produced by the combustion process taking place in the boiler.
When planning the installation of a new boiler or furnace such as for a modern utility power plant, absorber towers are often included in the overall scope of work for the project. However, many of the existing boilers in use today were not originally equipped with absorber towers, and in fact are operating with no means provided for flue gas desulfurization.
The recent enactment of the Clean Air Act requires utilities and industry to limit their operations' flue gas emissions, so as to be at or below specified compliance limits. As such, viable options for minimizing said emissions are being sought and implemented. The installation of flue gas desulfurization systems, with their respective absorber towers, is one means of ensuring compliance with the Act.
In the case of an existing plate site, the installation of absorber towers must be performed on a retrofit basis. Space available for (1) material receipt, storage, laydown, and staging; (2) ground assembly of FGD system components; and (3) construction accessibility, is typically limited on these types of installations. This space limitation presents a problem to the FGD system owner and erecting contractor(s) with regard to work scheduling, logistics, and overall productivity.
To date, several scenarios of absorber tower shipping configuration/erection method have been realized. One scenario has been to maximize absorber tower shop fabrication and assembly, and ship a minimal number of "modules" per absorber tower to the jobsite. A typical "module" has consisted of a circumferential shell complete between established horizontal field weld lines, with external stiffeners, internal supports, and respective absorber internals installed. Upon receipt on the jobsite, modules have been "stacked" on top of each other, horizontal field welds completed at the splice lines, and upon completion of field testing, the absorber tower was ready for operation. This scenario is an effective approach contingent on the existence of the following conditions:
1. A jobsite accessible via a navigable waterway; PA1 2. An absorber tower fabricator with facilities, material handling, and barge loading capabilities on a navigable waterway; PA1 3. Barge landing and off loading facilities available on the jobsite; PA1 4. Jobsite accessibility for transport of the modules from the barge landing and off loading area to the point of final absorber tower installation; PA1 5. Available space on the jobsite for the placement and utilization of heavy lift cranes for the erection of absorber tower modules in their final position.
Although this approach has proven to be effective on certain projects in the past, the jobsite enhanced by each of the above conditions in rare.
In the absence of a navigable waterway, or when the jobsite is not conducive to the receipt of shop assembled modules, absorber tower material has been shipped to the jobsite in a "knocked down" configuration. Shell plates have been provided in sizes commercially available from the mills, typically 8'.times.20', shop rolled to the curvature of the respective absorber tower shell, and delivered to the jobsite in specially designed cradles, either via trunk or rail load. External stiffeners, internal support members, and absorber internals have been shipped as loose pieces for field installation. Upon receipt of the loose material on the jobsite, two basic methods have been used for the erection of the absorber tower. Given the availability of space for ground assembly "tables" in close proximity to the final location of the absorber tower, loose shell plates have been fit and welded as required to form continuous shell course "rings". Depending on available crane capacity and the accessibility from the ground assembly table to the final location of the absorber tower, shell course "rings" may have been further ground assembled and welded two or three high on the table. Loose stiffeners, internal supports, and absorber internals may have been installed on the ground assembly table as well. Upon completion of the ground assembly activity, the effort for final erection of the absorber tower in place became similar to that required for the erection of shop assembled modules. Heavy lift cranes have been used to "stack" the ground assembled shell courses on top of each other, so as to allow for completion of the horizontal weld between them.
If space has not been available on the jobsite for a ground assembly area, absorber tower components received "knocked down" have been erected, fit, and welded piece by piece in place. The absorber tower was scaffolded as required to access the work, and crawler cranes or derricks were provided for handling the loose material from the ground to final position in the absorber tower. Further, until such time as the tower is inherently structurally stable, temporary bracing, supports, and shoring have been provided as required to withstand the effects of wind and construction dead loads encountered during the erection process.
Associated with each of these absorber tower shipping configuration/erection method scenarios has been a unique set of costs, benefits, advantages, disadvantages, and required conditions for their implementation. In the case of shop assembled modules, benefit has been derived in minimizing the amount of field labor and time required for the erection of an absorber tower. This savings in field labor and time has been offset by the increased costs of transporting and handling heavy modules from the shop to the towers' final location on the jobsite. On the other hand, shop, transportation, and lifting equipment costs have been minimized with the provision of "knocked down" material; but costs associated with increased field labor, schedule time, scaffolding, and the achievement of a quality product have tended to make this option unattractive to the absorber tower erecting contractor. Nevertheless, the option finally selected for a particular project is governed by a unique set of site specific conditions.
Retrofit installations typically present the worst possible conditions to be faced by the absorber tower erecting contractor. In most cases, they are not accessible via navigable waterway; jobsite access and space availability is minimal; and the project construction time span is accelerated to beat a scheduled FGD compliance date. Hence, there is a need for a method of erecting absorber towers in retrofit applications with minimal access and available space. The method should preclude the need for heavy construction equipment, and should minimize the amount of scaffolding required to access the work. The method should be adaptable to any jobsite, regardless of its location and specific site conditions.

Method for erection of absorber towers using jacking system


A photovoltaic energy conversion device and methods for forming the same with relatively high efficiency, high stability, low cost, low weight, and low toxicity. The device comprises a thin film n/p or n/i/p type, gradient-doped heterojunction which uses compatible, lattice-matched, non-hazardous semiconducting compounds from the I-III-VI.sub.2 (14), I-III-VI-VII (15) and I-VI.sub.3 -VII (16) series, an ohmic contact (13) to the n-layer comprising a group III metal, a transparent ohmic contact (17) to the p-layer, a grid (18), and an antireflection coating (20).

This invention relates to a photovoltaic (PV) energy conversion device, specifically a thin film n/p or n/i/p heterojunction with graded carrier concentration, using semiconducting compounds from the I-III-VI.sub.2, I-III-VI-VII and I-VI.sub.3 -VII series. It relates further to methods of manufacturing the cells, directed to producing a cell, especially an indium-tin-oxide (ITO)/n-CulnSe.sub.2 /i-Culn.sub.x Se.sub.y I.sub.z /p-CulSe.sub.3 cell, with relatively high efficiency, high stability, low cost, and low toxicity.
Photovoltaic cells offer the prospect of a more benign and renewable source of power than either fossil or nuclear systems. The criteria for a successful photovoltaic device are high energy conversion efficiencies, long-term stability and low cost. The high efficiency solar cells are based on monocrystal absorbers, for example, Si, GaAs, InP, and CdTe, which require high energy, labor, and highly purified materials. The less expensive amorphous Si cell is unstable and less efficient. CulnSe.sub.2 meets the criteria of low cost, high efficiency, stability, and environmental safety. It has thus emerged as the most promising material for terrestrial and space applications. It is a direct band gap semiconductor with a low minority carrier diffusion length, a high absorption coefficient, and a steep absorption edge. These attributes permit fabrication of lightweight, low material-usage thin film cells; its radiation hardness ranks CulnSe.sub.2 ahead of Si and GaAs for space use.
In the prior art, p-CulnSe.sub.2 has been used in thin film Mo/p-CulnSe.sub.2 /n-CdS/ZnO cells (p-CIS) by various workers. U.S. patents to Mickelson et al (1980) U.S. Pat. Nos. 4,335,266, 4,465,575; Kapur et al (1986) U.S. Pat. No. 4,581,108, Ermer et al (1989) U.S. Pat. No. 4,798,660 provide background information on the development of the p-CIS cell. Numerous deposition techniques have been employed, including: (a) selenization of Cu/In layers; (b) evaporation (thermal, electron-beam, sputtering or ion plating); (c) electrodeposition; (d) chemical spraying; (e) screen printing; (f) sintering; and (g) laser annealing. The description of these methods and the resulting films along with references are summarized by Zweibel et al (1989), Chopra and Das (1983). The key processes that have yielded high quality p-CIS films are co-evaporation of Cu, In, and Se, and selenization of electron beam deposited Cu and In layers. Although single junction efficiencies in the range of 14% have been recently reported, the sensitivity of cell performance to several processing steps and safety issues associated with some cell components continue to be of serious concern and have hindered its commercialization. For example:
(i) the toxicity of the CdS window component has been the primary deterrent in its terrestrial use (Cd and its compounds present health, safety and environmental hazards, e.g. Moskowitz et al (1990)); PA1 (ii) the Mo contacts to p-CuInSe.sub.2 affect the mechanical stability (poor adhesion) and the performance of the cell, possibly due to the formation of a layered compound, MoSe.sub.2, at the interface. Mo is also toxic to some degree; PA1 (iii) interdiffusion of Cu and Cd at the heterojunction interface can induce conductivity type inversion in thin films of p-CuInSe.sub.2 which could undermine the cell stability, especially in radiative environments; PA1 (iv) lattice mis-match of 1.2% between CuInSe.sub.2 and CdS increases interface state density, leading to efficiency losses due to the associated recombination.
The n-CuInSe.sub.2 material has not been employed in a thin film photovoltaic cell for two reasons: (a) first, the difficulties encountered in preparing non-resistive n-CuInSe.sub.2 films, e.g. Thornton (1987) indicated that the deposition of In-rich films by reactive sputtering in H.sub.2 Se medium led to In rejection; other workers have noted similar In rejection for the co-evaporation and in the e-beam deposition/selenization methods. Noufi et al (1987) reported the formation of highly compensated and resistive n-type films by co-evaporation. Similarly synthesized films were unsatisfactory even after vacuum annealing at high temperatures in the presence of Cd or In, according to Haneman (1990); and (b) the second reason was the lack of a highly conducting and transparent p-type window, as most wide bandgap materials, e.g. oxides, are n-type.
Nevertheless, high efficiency photoelectrochemical cells with n-CuInSe.sub.2 single crystal were reported by Menezes et al (1983, 1984, 1986) and by Cahen (1984). Our U.S. Pat. No. 4,601,960 (1986) describes the first n-CuInSe.sub.2 photoelectrochemical cell that was stabilized from corroding in the electrolyte by inducing the growth of a new semiconducting interphase from the corrosion products. The n-CuInSe.sub.2 single crystal based solar cell with a CuISe.sub.3 interfacial film was 12.2% efficient and stable. An energy difference between the work functions of CuInSe.sub.2 and CuISe.sub.3 suggested the possibility of a buried p/n heterojunction between the two materials. Although our approach at surface stabilization was reproduced by various other workers, no further evidence of a solid state junction was reported. Thus, no solid state cell has been constructed primarily because (c) large single crystal CuInSe.sub.2 substrates are difficult to fabricate and impractical for scale-up and (d) since CuInSe.sub.2 thin films tend to corrode and peel off the substrate during surface conversion in the electrolyte.
The uncertainties regarding the existence of a solid state junction persisted because of the above mentioned difficulties in verifying the concept of a buried p/n junction. These difficulties also prevented the construction of a practical photoelectrochemical cell. In general, the utility of photoelectrochemical cells is limited by several engineering constraints:
(e) Inflexible cell design;
(f) Susceptibility to leaks and corrosion at the various inherent solid/liquid interfaces;
(g) Uncertain long-term stability of the electrolyte/semiconductor interface in hostile environments; and
(h) Need for expensive bulk (thick) single crystal or polycrystalline CuInSe.sub.2 substrates which are not economical in terms of material and energy usage, and unsuitable for large area applications (Single crystal grain size rarely exceeds 2 cm.sup.2).

Thin film photovoltaic cells from I-III-VI-VII compounds


Provided herein is a photocurable dianhydrohexanehexol derivative, a method preparing the same, and a composition including the same, for example, to a photocurable compound derived from environmentally friendly biomass, the compound having a structure where a 2-hydroxypropyl methacrylate (HPM) functional group prepared by reacting a biomass derived dianhydrohexanehexol (1,4:3,6-dianhydro-d-hexane-1,2,3,4,5,6-hexol, DHH) compound under an optimal reaction condition is combined, a preparing method thereof, and a photocurable composition comprising the photocurable compound.

1. Field
The following description relates to a photocurable dianhydrohexanehexol derivative, a method preparing the same, and a composition including the same, for example, to a photocurable compound derived from environmentally friendly biomass, the compound having a structure where a 2-hydroxypropyl methacrylate (HPM) functional group prepared by reacting a biomass derived dianhydrohexanehexol (1,4:3,6-dianhydro-d-hexane-1,2,3,4,5,6-hexol, DHH) compound under an optimal reaction condition is combined, a preparing method thereof, and a photocurable composition comprising the photocurable compound.
2. Description of Related Art
Curable materials such as adhesive, glue, sealant, coating, encapsulant, and paint etc. are used in various industrial areas including civil engineering, architecture, paving, bookbinding, electronics, precision, optical products, carpentry, plywood, textile, leather, and medical treatment. These are used in increasingly wide range of areas.
These curable materials are prepared in the form of a mixture having chemical materials with synthetic resin as the main material. And they generate harmful chemical materials such as volatile organic chemicals (VOC), dioxin, and endocrine disruptors due to various volatile additives that are added to enhance the organic solvents used in the preparing processes and properties.
Recently, environmental regulations of international treaties are placing strict limitations on production and use of such harmful materials, and furthermore, EU is utilizing these regulations as a new means for trade sanctions. In step with this trend, conventional solvent-based adhesives are being replaced by water soluble, solvent free type, and hot melt type adhesives.
Meanwhile, most of the fine chemical materials that we currently use including the aforementioned curable materials are petrochemicals derived from oil refinery processes. However international oil prices are steadily increasing due to reduced oil reserves and sudden increase of demand mainly from BRICs, and as international treaties that strictly regulate emission of greenhouse gases take effect, use of irreversible fossil resources such as petroleum is expected to cause significant amount of environmental costs.
Therefore, much effort is being made to obtain conventional-oil resources-derived fine chemical products from new resources, and a case in point is using carbohydrate biomass as a source of supply. (Ghheda, J. N. et a; Angew. Chem. Int. Ed. 2007, 46, 7164-7183, Corma, A. et al., Chem. Rev. 2007, 107, 2411-2502)
The natural world produces a significant amount of carbohydrate of about 170 billion tons each year, and humans use only about 3% of it for food, paper, furniture, and building materials. Therefore, fine chemical products prepared from carbohydrate biomass that is renewable and can be sustainably used are expected to replace petrochemical products.
Meanwhile, of the compounds derived from oil resources, bisphenol A is a material used as the starting material of various chemical materials. It is applied to polycarbonate and various curable materials.
However, bisphenol A is a toxic material that causes the problem of endocrine disruptor. And recently, bisphenol A polycarbonate used in baby feeding bottles is being thrown out from the markets.
Accordingly, many attempts are being made to replace bisphenol A, and the most representative one is dianhydrohexanehexol derived from carbohydrate biomass (1,4:3,6-dianhydro-hexane-1,2,3,4,5,6-hexol, DHH).
Polycarbonate prepared by using isosorbide which is an isomer of DHH, instead of bisphenol A, is already being applied to lens in eyeglasses.
Accordingly, the present inventors conducted research considering the aforementioned, and as a result, by reacting a biomass-derived dianhydrohexanehexol compound under optimal reacting conditions, succeeded in preparing a compound where a 2-hydroxypropyl methacrylate (HPM) functional group is combined. They completed the present invention by ascertaining the capability of providing a photocurable compound having a biomass-derived DHH frame which may replace a bisphenol A compound derived from conventional oil resources with a photocurable compound derived from environmentally friendly biomass, and which has not only high yield rates and economic feasibility, but also fast curing speeds.

Photocurable dianhydro-hexane-hexol derivative, manufacturing method thereof, and photocurable composition including same

KOREA INSTITUTE OF INDUSTRIAL TECHNOLOGY


An assembly includes a magnetostrictive transducer that provides a transducer output. Amplifier circuitry receives the transducer output and generates a transducer output burst and a bias output burst. The transducer output burst and bias output burst overlap in time and differ by a phase difference. A burst processor receives the transducer output burst and the bias output burst. The burst processor provides a displacement output that is a function of a time when the transducer output burst and the bias output burst are at the same voltage level.

The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
Magnetostrictive displacement transducer assemblies are typically mounted to industrial equipment for use in sensing displacement of a machine part or displacement of a level sensing float. Magnetostrictive displacement electronics are typically enclosed in a housing mounted to a machine or a tank. As the range of applications of magnetostrictive displacement transducers expands, there is a desire to sample displacement at lower displacement jitter levels. The jitter is a small rapid variation in a measured displacement. Displacement is measured as a function of a sonic time delay interval along a magnetostrictive element. The end of the time delay interval is determined by a transducer output burst voltage crossing a nominally fixed bias voltage level. Both the bias voltage level and the transducer output burst voltage include noise. The noise causes a measurement of the end of the time delay interval to jitter excessively. Jitter can be masked by circuit damping, however, damping undesirably limits a response speed of the displacement measurement. There is a desire for a stable, low jitter displacement measurement that is not excessively slowed by damping in a magnetostrictive displacement transducer assembly.

Magnetostrictive displacement transducer with phase shifted bias burst