A paper or board is coated with a composition comprising from 30-95 parts by weight of a synthetic, carboxylated surface size containing at least about 40 mole percent of hydrophobic groups and at least about 25 mole percent of carboxylated groups such as styrene/acrylic acid copolymer, and from 5-70 parts by weight of a substantially hydrophilic polyacrylamide such as a cationic or anionic polyacrylamide.

This invention relates to compositions and methods for improving the printability and/or strength of various types of paper and board. More specifically, this invention relates to mixtures of hydrophobic surface sizes and hydrophilic polyacrylamide which, when added to paper or board, improve print quality, sizing, as well as surface strength of the paper or board.
Sizing agents have gained wide acceptance in the paper industry for modifying paper to improve its resistance to penetration by liquids, generally water, and to improve various aspects of printability. For example, U.S. Pat. Nos. 5,122,568 and 5,139,614 teach the use of styrene acrylic copolymers for enhancing sizing, inkprint contrast, increasing ink penetration times and reducing feathering. U.S. Pat. No. 3,562,102 discloses amine reaction products of alkyl glycidyl mixed esters which are used in the preparation of sized cellulosic paper substrates, cured films and solid resinous potting compositions.
Efforts have been made to develop improved sizing agents. In U.S. Pat. No. 4,855,343 acrylonitrile acrylate monomers are copolymerized by emulsion polymerization in the presence of degraded starch and a peroxide-containing initiator to provide Improved paper sizing agents. U.S. Pat. No. 5,362,573 describes the use of, titanium, hafnium and zirconium salts such as ammonium zirconium carbonate in conjunction with surface sizing compound containing water-soluble hydroxylated polymer to improve sizing efficiency.
There are many different sizing agents used in papermaking, such as rosin soap, starch, sodium silicate, amine reaction products of alkyl glycidyl mixed esters, such as that described in U.S. Pat. No. 3,562,102, for example, and sizing can be accomplished by either internal sizing processes, which typically involve wet end addition, or surface sizing processes, which typically involve addition at the size press. Surface treatment at the size press typically with sizing agents alters the paper web primarily by imparting an increased degree of hydrophobicity. This sizing effect, in turn, generates higher ink penetration time values, reduced lateral spread of printing inks, as well as improved imaging and contrast with various printing technologies. Thus, hydrophobic surface size agents improve printability primarily by decreasing paper sheet absorbtivity and enhancing surface resistance to liquid (ink) penetration.
Paper printability and other qualities have also been improved through the use of coated paper and various ink jet recording sheets. In U.S. Pat. No. 4,442,172, an ink jet recording sheet made by coating a water-soluble polymer onto the surface of a base sheet containing synthetic silicate, wet strength additive and glass fiber is described as having superior ink absorbency and high recording density without feathering. Combinations of alkyl ketene dimer internal sizing agent, precipitated calcium carbonate and certain cationic synthetic fixing agents have also been incorporated into ink jet recording base layers, see, U.S. Pat. No. 5,126,010. Ink jet recording paper described in JP 06143799 is prepared by applying a surface size treatment of high molecular weight adhesive and styrene-maleic anhydride copolymer to both sides of base paper and disposing an ink-receiving coating containing a white pigment and adhesive on one side of the paper. Ink jet recording transfer sheets containing calcium carbonate as a filler and alkyl ketene dimer or alkenyl succinic anhydride as sizing agents are described in JP 06008617. Auxiliary agents such as starch, polyacrylamide and polyvinylalcohol may be included in the transfer sheet. J56109783-A describes paper for ink jet recording obtained by applying a hydrophilic polymer, e.g., oxidized starch or polyvinyl alcohol, to raw paper of specified water absorption degree to provide paper with balanced ink drying properties and blotting resistance for ink-jet printing. And U.S. Pat. No. 4,900,620 describes ink jet recording sheets having good ink absorption, resolution and color brightness which are made of wood pulp and precipitated calcium carbonate substrate coated with a layer of white pigment. Ink jet recording sheets composed of a support and a cation-modified acicular or fibrous colloidal silica-containing ink-receiving layer are described in U.S. Pat. No. 5,372,884; various polymers may be included in the ink receiving layer for improving ink drying properties, film-forming properties and image sharpness.
In U.S. Pat. No. 4,294,704 paper and board is coated with compositions containing aqueous latex binders of synthetic polymer such as styrene-butadiene copolymers, carboxyl styrene-butadiene copolymers, vinyl polyacetates, carboxyl vinyl polyacetates, alkyl acrylate-vinyl acetate copolymers and carboxyl alkyl acrylate-vinyl acetate copolymers in order to provide improved dry and wet tear resistance. In U.S. Pat. No. 4,439,496 a water-resistant photographic substrate containing an alkylketene dimer, a cationic polyacrylamide and an anionic polyacrylamide is coated with a water resistant polyolefin.
JP05173287 discloses base paper for use in photographic printing paper which is made by adding a cationic polyacrylamide to pulp slurry, then adding a sizing agent which has an effect in the weakly acidic to weakly alkaline pH region, e.g., high organic ketene dimers, and finally adding an anionic polyacrylamide; the base paper is described as being useful in inhibiting the permeation of developing liquids from the cut end surfaces of the photographic printing paper. Another ink jet recording sheet is described in EP 600245.
As new printing technologies continue to emerge and gain acceptance in the market place, the need for developing high performance paper surfaces having improved printability characteristics increases. Despite the benefits obtained from using coated paper or ink jet recording sheets, these materials have certain disadvantages, for example, they require two separate layers and therefore their manufacture Involves numerous paper processing steps and special converting operations. Furthermore, many of the existing coated paper sheets exhibit inadequate color image, color resolution and color bleed. Moreover, as paper products increasingly use multiple colored inks, paper exhibiting controlled ink absorption, optimal color density and reduced color bleed, and with reduced feathering and wicking has been particularly difficult to make. It is desirable, In many instances, to use single sheets of paper having superior color absorption rates, color density and resolution with reduced color bleed and feathering.
Consequently, a need, unsatisfied by existing technology, has developed for a paper additive that provides the above-described benefits in printability and sizing yet also exhibits superior dry strength.
Existing dry strength additives have not met this need. N-(chloroalkoxymethyl) acrylamides and quatemized derivatives thereof are dry strength additives described in U.S. Pat. No. 3,980,800. Canadian patent 1101158 describes improved dry strength properties obtained by admixing a fibre suspension with quaternized acrylamide polymers. The addition of acetone-triethylenetetramine-diethylenetriamine-formaldehyde copolymer and acrylamide-maleic anhydride copolymer to cellulose pulp is described in U.S. Pat. No. 4,036,682 as giving increased strength properties. Polyvinyl alcohol and starch have been applied to paper to improve sheet surface characteristics which may included surface strength, and porosity smoothness. In JP 57139599 and JP 139598 anionic polyacrylamide is added at the wet end and a sizing agent selected from alkyl ketene dimer, cationic sizing agent and substituted cyclic dicarboxylic anhydride is used along with aluminum salt to manufacture neutral paper purportedly having good wet and dry tenacity.
Various printing technologies continue to require paper surfaces with high integrity and resistance to the abrasive effects of the printing processes. Fiber picking, Tinting and filler dusting all contribute to decreased runnability of paper on impact printing processes. There therefore exists a need for surface treatment agents which overcome these surface defects.
It has now been discovered that a generally hydrophobic surface size additive and a hydrophilic dry strength agent, preferably polyacrylamide, may be combined in a single composition to provide, when added to paper or board sheet surfaces at the size press, synergistically improved sizing and strength as well as a wide range of improved paper printability properties. It was surprising to find that a hydrophilic agent such as polyacrylamide could be combined with a hydrophobic surface size as a pre-mix and that improved strength, sizing and printability properties resulted from use of that pre-mix in paper or board including paperboard. This was particularly unexpected given that hydrophobic surface size agents, in theory, increase the degree of hydrophobicity of the sheet and thus decrease paper absorptivity while hydrophilic materials such as polyacrylamide increase the degree of hydrogen boding in the paper sheet and maintain high sheet absorbitivity of liquid. Paper or board made using the compositions of the instant invention exhibit sizing properties which are superior to the use of the hydrophobic surface size agent alone. Thus, by admixing polyacrylamide with a surface sizing agent the sizing function is unexpectedly improved. A further benefit provided by the compositions of the instant invention is synergistically improved strength properties, such as internal bond strength and wax pick. In addition, paper and board comprising the surface size polyacrylamide mixtures of the instant invention exhibit synergistic improvements in print quality, e.g., controlled ink absorbency, ink drying time and color optical density; sharper half-tone dots are produced with maximized light scatter for improved print contrast. The products of the instant invention impart substantial resistance to penetration of ink and aqueous liquids to said paper, provide processing flexibility by allowing the papermaker to balance the size requirements between internal and surface sizing, increase the contact angle and surface strength, maintain the sizing level over time and impact the coefficient of friction. Other benefits relating to printability such as improved image resolution and reduced color bleed, bleed through, feathering, wicking, picking, linting and dusting are also achieved by the instant invention. The superior image resolution and bleed through properties provided by the compositions of the instant invention are particularly desirable for use in connection with modem printing technologies which use a variety of different color inks. Advantageously, the above benefits are provided by a single sheet of uncoated paper or board without having to produce a more complicated and costly multilayer paper or board, e.g. coated paper or base paper with an ink receiving layer.
The surface size materials used in the instant invention are generally synthetic, preferably, though not necessarily, water soluble, and are primarily hydrophobic, preferably containing at least about 30 mole percent hydrophobic groups, while the acrylamide polymers with which they are combined are substantially hydrophilic, preferably containing at least about 25 mole percent, more preferably at least about 50 mole percent hydrophilic monomer groups such as the amide group in polyacylamide. The surface size and polyacrylamide material must be premixed prior to application to the paper. The polyacrylamide surface size mixtures of the instant invention may be added alone as a water solution in dispersion or in combination with commonly applied paper additives such as size press starches. The compositions of the present invention may be used in the production of board such as boxboard, linerboard and bleached board, e.g. milk carton, as well as various types of paper such as, for example uncoated, woodfine papers, packaging, newsprint, and ledger. The paper and board of the instant invention is especially useful for paper or board which is designed to be or capable of being printed in its end use, i.e. printing paper or board.
In yet a further embodiment of the present invention compositions comprising a hydrophobic surface size agent, a hydrophilic polyacrylamide and a cross-linking agent, such as, for example, ammonium zirconium carbonate, are provided and when applied to paper or board, at the size press, or the like, further improve printability, both non-impact and impact printability, internal dry strength, and surface strength, e.g. tensile strength, burst, and wax pick.
In a broad sense, the instant invention provides compositions comprising substantially hydrophobic surface size and a substantially hydrophilic material such as polyacrylamide which may be used in paper or board making to impart improved sizing, internal bond strength and print characteristics. The instant invention provides compositions, preferably aqueous compositions, comprising a mixture, preferably a dispersion, of synthetic preferably carboxylated surface size containing at least about 40 mole percent hydrophobic groups and water-soluble polyacrylamide, wherein the ratio of said surface size to said polyacrylamide is from about 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide. Preferred surface size agents include hydrolyzed styrene maleic anhydride copolymers, styrene maleic acid salt copolymers, styrene maleic ester copolymers, styrene (meth)acrylate copolymers, styrene (meth)acrylate ester copolymers, styrene acrylate ester acrylonitrile terpolymers, acrylonitrile (meth)acrylate salt copolymers and polyurethanes. A further embodiment of the present invention provides compositions, preferably aqueous compositions, comprising a mixture of synthetic, carboxylated polymeric surface size containing at least about 40 mole percent hydrophobic groups and hydrophilic polyacrylamide in the ratios described along with an effective amount of stabilizing agent and or crosslinking agent. Paper or board comprising the above-described compositions of the present invention are also provided. In a preferred embodiment there is provided paper or board, preferably uncoated paper or board, comprising:
(i) synthetic, carboxylated surface size containing at least 40 mole percent hydrophobic groups and
(ii) substantially hydrophilic polyacrylamide, wherein the ratio of said surface size to said polyacrylamide is from about 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide.
Also, there is provided a method for improving the printability and/or strength of printing paper or board, preferably uncoated paper or board, which comprises:
applying to the surface of paper or board, using a size press, calendar, or spray boom, a mixture comprising:
(i) synthetic surface size containing at least about 40 mole percent hydrophobic groups; and
(ii) substantially hydrophilic polyacrylamide;
wherein the ratio of said surface size to said polyacrylamide is from about 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide.
Also provided are methods for improving the printability and/or strength of uncoated paper or board which comprise:
1) adding to a liquid medium in any order
(a) a mixture comprising:
(i) synthetic, carboxylated polymeric surface size containing at least 40 mole percent hydrophobic groups; and
(ii) substantially hydrophilic polyacrylamide;
wherein the ratio of said surface size to said polyacrylamide is from bout 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide; and
(b) an effective amount of crosslinking agent to form a dilute mixture;
wherein the weight ratio of liquid medium to said mixture ranges from about 70-99 parts liquid medium to about 30-1 parts mixture; and
2) applying said dilute mixture formed in step (1) to the surface of paper or board using a size press, calendar, or spray boom.
The above and related objects of the present invention are achieved by producing a mixture, preferably an aqueous mixture, preferably a dispersion, comprising surface size containing at least about 30 mole percent, preferably at least about 40 mole percent hydrophobic groups, based on total moles in the sizing agent and a dry strength agent, generally a water-soluble or hydrophilic polyacrylamide. Surface size materials are any polymer that imparts sizing or liquid hold out. Generally surface size are non-ionic or anionic, preferably anionic. Suitable surface sizes are preferably polymeric, usually carboxylated, i.e., containing carboxyl groups, generally at least about 25 mole percent carboxyl groups, preferably at least about 50 mole percent, more preferably at least about 60 mole percent carboxyl groups, based on the sizing agent. Any synthetic surface size may be used, including non-polymeric agents, e.g. alkylketene dimers as long as they impart hydrophobic character to the paper surface. Representative examples of suitable surface size polymers useful in the instant invention include copolymers of styrene and maleic anhydride or copolymers derived from styrene maleic anhydride such as styrene maleic acid salts, hydrolyzed styrene maleic anhydride, and styrene maleic ester copolymers, as well as styrene (meth)acrylate copolymers, styrene (meth)acrylate acrylonitrile terpolymers, styrene (meth)acrylic acid copolymers, acrylonitrile (meth)acrylate salt copolymers, polyurethanes, mixtures thereof and the like. Usually the surface size materials contain at least about 40 mole percent hydrophobic groups, preferably at least about 50 mole percent hydrophobic groups, more preferably at least about 53 mole percent hydrophobic groups. Representative examples of hydrophobic groups include subunits such as styrene and xe2x88x9d-methyl styrene, mixtures thereof and the like. The surface size materials are preferably water-soluble. The weight average molecular weight of the surface size polymers used in the present invention is not critical and generally ranges from at least about 30,000 as determined by high pressure size exclusion chromatography.
The acrylamide polymers useful in the instant invention are generally water-soluble and may be water-swellable. All (alk)acrylamide polymers are encompassed in the present invention such as acrylamide, methacrylamide, ethacrylamide and the like. The term polyacrylamide for purposes of this invention includes all (alk)acrylamide homopolymers as well as copolymers and functionalized polyacrylamides. The polyacrylamides may be anionic, cationic or nonionic, although, generally, cationic and anionic are more preferred. Various monomers, preferably ethylenically unsaturated monomers may be copolymerized with (alk)acrylamide monomers to form the polyacrylamides used in the instant invention. Representative cationic monomers include diallyldialkylammonium chlorides, N,N-dialkylaminoalkyl(meth)acrylates, N,N-dialkylaminoalkyl(meth)acrylamides, salts quaternaries and mixtures thereof. Anionic monomers useful in the practice of this invention may comprise acrylic or methacrylic acid, fumaric acid, crotonic acid, maleic acid, salts thereof, 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid and their salts and the like. Water-soluble nonionic monomers suitable in the practice of this invention, generally comprise N-vinyl pyrrolidone, N,N-dialylmethacrylamides, hydroxyalkyl methacrylates; N-vinylformamide and the like.
Generally anionic and nonionic comonomers may be included in the acrylamide copolymers in amounts up to about 20 mole percent, preferably about 10 mole percent, based on the copolymer. Cationic comonomers may be included in the acrylamide copolymers in amounts up to about 15 mole percent, preferably up to about 10 mole percent, based on the copolymer. Preferable polyacrylamides include acrylamide homopolymers, copolymers of acrylamide which preferably contain from about 1 to about 20 mole percent anionic or cationic comonomers as well as hydrolyzed polyacrylamide. Representative examples of preferred polyacrylamides include copolymers of acrylamide with acrylate esters, acrylate salts, Including sodium, potassium and ammonium salts, acrylic acid, diallyldimethylammonium chloride and the like. The various types of polyacrylamides may be used alone or in combinations of two or more. Copolymers of acrylamide and sodium acrylate are generally most preferred, more preferably those containing from about 1 to about 20 acrylate salt, most preferably about 5 to about 10 acrylate salt. It is desirable that the polyacrylamides used herein be substantially hydrophilic, generally containing at least about 30 mole percent hydrophilic groups, preferably at least about 50 mole percent hydrophilic groups, based on polyacrylamide, more preferably at least about 75 mole percent hydrophilic groups, e.g., non-akylated acrylamide. The molecular weight of polyacrylamides used herein is not critical, though a molecular weight as high as possible is usually preferred, typically at least about 50,000, preferably at least about 300,000 and polyacrylamides typically can have a molecular weight up to about 500,000, more preferably up to about 100,000. Polyacrylamides may be crosslinked with crosslinking agents known in the art such as, for example those agents described hereinafter.
It is important in providing the benefits of the instant invention that the polyacrylamide and surface size is premixed before application to the paper or board. Polyacrylamides are typically available in aqueous solution form and it is preferred, in preparing the compositions of the instant invention, to adjust the pH of the aqueous polyacrylamide-containing solution to an alkaline pH, generally a pH of at least about 8 preferably at least about 9, prior to admixing it with the surface size. Preferably the pH of the aqueous solution of polyacrylamide is adjusted to a pH ranging from about 8 to about 11, more preferably about 9 to about 10. It is most desirable to adjust the pH of the aqueous solution of polyacrylamide to a pH that is substantially the same as that of the surface size, which also typically is available in solution, preferably aqueous, form. Generally this is a pH that is within about 1 pH unit. While it is not essential to combine the polyacrylamide and surface size as aqueous solutions, it is preferred. Similarly, it is not essential to adjust the pH of the aforesaid polymer solutions so that they are substantially similar, but it is preferred. When the pH of the polyacrylamide solution is substantially different from that of the aqueous solution of surface size, gel formation or agglomeration tends to occur.
While the pH of the surface size/acrylamide polymer-containing compositions of the present invention is not critical to performance, pH appears to affect physical properties of the composition; it is, therefore, generally preferred that the pH of the composition is at least about 8 or above about 8 preferably at least about 9 and up to about 11, preferably up to about 10. By adjusting the pH of the final composition within this range, the composition is less viscous, easier to handle and more stable. Thus the compositions of the present invention preferably have a pH ranging from about 8 to about 11, more preferably from about 9 to about 10; pH adjustments may be made prior to adding the composition to the paper or board but is preferably done after or during preparation of the composition. Typically any bases (or acids if the case may be) which are compatible with the particular surface size and acrylamide polymers may be used for pH adjustments, preferably hydroxide, carbonate, bicarbonate bases such as, for example, sodium hydroxide, sodium bicarbonate, sodium carbonate, lithium hydroxides, potassium hydroxide mixtures thereof and the like.
Generally the amount of polyacrylamide to be combined with surface size is not critical. Usually surface size and polyacrylamide are admixed in a ratio of from about 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide, preferably from about 40-70 parts by weight surface size to about 60-30 parts by weight polyacrylamide, more preferably from about 50-60 parts by weight surface size to about 50-40 parts by weight polyacrylamide. While mixing the materials within the above-described ratios tends to provide a homogenous mixture which tends to not exhibit phase separation, the ratios described herein are not critical and may vary depending on the paper type, the properties desired and additional materials added to the aqueous composition; the optimal ratios for each papermaking system may be ascertained using simple experimentation. In mixing the surface size agent with polyacrylamide to prepare the compositions of this invention, the order of addition is not critical, though it is preferred to add the surface size to the polyacrylamide. The compositions can contain about 100 percent polymer or surface size which comprise most, if not all of the solids, though the compositions are preferably aqueous. The solids content of the aqueous composition should be at least about 0.5 weight percent, based on total weight of the composition and broadly ranges from about 0.5 to about 30 percent, by weight, preferably about 10 to about 22 percent, by weight, based on total weight of the composition. It is more preferred to dilute the surface size acrylamide polymer-containing composition with water to obtain at least about 12 percent solids, generally from about 12 to about 17 percent solids, preferably from about 13 to about 15 percent solids, by weight, based on total weight of the composition.
Generally, the compositions of the Instant invention consist essentially of the above-described surface size and polyacrylamide, preferably the compositions consist of the previously discussed surface size and polyacrylamide in the ratios described above. Optionally, the surface size polyacrylamide containing compositions preferably further contain an effective amount of stabilizing agent sufficient to reduce phase separation. Any agent that reduces phase separation is suitable as a stabilizing agent. Generally, cationic polyacrylamides, cationic homopolymers, such as polydiallyidimethyl ammonium chloride, polyhydroxyalkylamines and starch are preferred. Anionic polymers such as, for example, carboxymethylcellulose and phophoralated starches are also suitable stabilizing agents. Stabilizing agents may generally be added in amounts sufficient to prevent phase seperation, generally at least about 0.3 percent, preferably at least about 0.5 percent by weight, based on the weight of surface size and acrylamide polymer and up to about 5.0 percent, preferably up to about 3.0 percent by weight, based on the weight of surface size and acrylamide polymer. Accordingly, preferred amounts of stabilizing agent range from about 0.3 percent to about 5.0 percent, based on the total weight of surface size and polyacrylamide.
The paper and board that is produced acording to the instant invention may contain auxiliary materials known in the art as useful for incorporation into paper or board by adding them to the pulp at the wet end, directly to the paper or board or to a liquid medium, e.g. starch solution which is then used to impregnate paper sheets or board. Representative examples of auxiliary agents include defoamers, bacteriocides, pigments, fillers and the like. The addition of a crosslinking agent, generally a water soluble crosslinking agent is particularly preferred. It has been found that a crosslinking agent tends to enhance the improved sizing, strength and printability benefits provided by the surface size/polyacrylamide compositions. Generally any known crosslinking agent is useful in the instant invention, including those zirconium hafnium or titanium salts described in U.S. Pat. No. 5,362,573 which is incorporated herein by reference, glyoxiated polymers such as glyoxylated vinylamide polymers, formaldehyde, melamine-formaldehyde condensation polymers and glyoxyl extended materials such as dihydroxyethylene urea. Ammonium zirconium carbonate (AZC) is particularly preferred. The crosslinking agent may be added directly to the composition or mixture containing surface size and acrylamide polymer or, applied to paper or board during the paper/board making process, e.g., added directly to the paper or through use of a liquid medium such as water or aqueous starch solution at the size press. Crosslinking agent may be added to the liquid medium before, after or simultaneously with the polyacrylamide/surface size mixture. An effective amount of crosslinking agent sufficient to provide improved strength, sizing or printability properties should be used,. generally an amount of at least about 0.3 percent, preferably about 2.0 percent, by weight, based on total weight of surface size and acrylamide polymer; and generally no more than about 10.0 percent, preferably no more than about 5.0 percent, by weight, based on total surface size and acrylamide polymer; thus the range of crosslinking agent is generally from about 0.3 to about 10.0 percent, by weight, based on total surface size and acrylamide polymer, preferably from about 2.0 to about 5.0 percent by weight, based on total surface size and acrylamide polymer. When crosslinker is added to a liquid medium such as an aqueous starch solution or water, the amount of crosslinking agent used may be based on starch pickup or water pick-up; typically amounts of crosslinker applied to paper or board are those known in the art and preferably the amount ranges from about 0.02 to about 10 pounds of crosslinking agent per ton of paper or paperboard, though this range may vary.
Generally, surface treatment may be applied to paper as either a post production operation or as a portion of the paper-making process itself. Surface size is applied typically in the papermaking process after the paper sheet has been formed and dried but not passed through a calendar stack. The formed and dried sheet (web) is conducted through a size press (actually a blade, rod or roll coater of various configurations) which re-wets the sheet to some degree (depending on the type of size press) with a liquid medium such as starch solution or a starch/surface size solution, or a water/surface size solution. Upon the wetting of the web, it is again dried and subsequently passed through a series of nips at the calendar to control caliper and smoothness in the finished sheet prior to wind-up, slitting or sheeting.
In yet another embodiment of the instant invention, methods for improving the printability and/or strength of paper or board, generally printing paper or board, are provided by applying to the surface of paper or board, the mixtures of the above described surface size compounds and substantially hydrophilic polyacrylamide in the ratios described above. The polyacrylamide/surface size containing compositions are generally applied to base sheets or pre-formed paper or board (or webs) at the dry end of the papermaking process using a size press, calendar spray boom, or the like. The size press is most common; however, the calendar, or calendar stack has been used with paperboard. Any size press designs may be used, including but not limited to horizontal press, vertical press, gate roll size press and metering blade size press, rod, puddle type, or combinations thereof. The compositions may also be sprayed onto the paper or board surface, optionally with a crosslinking or other auxiliary material. It is important that the compositions of the instant invention are added after the paper or board is formed in the papermaking process, for example at the size press. When applied to paper or board using a liquid medium, such as starch solution or water, the polyacrylamide surface size mixture amount to be used generally depends on starch pick-up or water pick-up, and may vary though preferably amounts sufficient to provide from about 0.5 to about 15 pounds of polyacrylamide surface size per ton of paper or board, preferably from about 1 to about 10 pounds polyacrylamide surface size per ton of paper or board. Depending on the means used for applying the surface size polyacrylamide mixtures to paper or board (e.g., size press or calendar) and design of such, the compositions or mixtures added to the paper or board may be diluted to about 0.5 to about 6 percent solids. Optionally, the polyacrylamide surface size containing compositions of the present invention may, prior to addition to the paper or board, be admixed with a liquid medium, such as water. The surface size/polyacrylamide compositions are added to liquid medium, typically contained in a size press or the like, to form a dilute mixture and paper sheets or pre-formed board is contacted with the dilute mixture or liquid medium containing surface size/polyacrylamide and optionally crosslinking agent. Preferably the liquid medium is water, more preferably an aqueous starch solution. Any type of starch may be used including cationic nonionic or anionic starch. Typical starch solutions range in concentration from about 3 to about 13 weight percent, preferably from about 6 to about 8 weight percent starch solids; however, these concentrations may vary depending on the type of size press. The ratio of liquid medium to polyacrylamide surface size mixture may also vary depending on the paper grade and type of size press and type of liquid and the. sheet properties that are desired. Generally, however, the weight ratio of liquid medium to mixture comprising polyacrylamide surface size ranges from about 70-99 parts liquid medium to about 30-1 part mixture comprising polyacrylamide/surface size, preferably from about 90-99 parts by weight liquid medium to about 10-1 part by weight mixture. Preferably, the weight ratio of aqueous starch solution (liquid medium) to surface size/polyacrylamide containing composition is from about 95-99 parts starch solution to about 5-1 parts mixture comprising surface sizelpolyacrylamide. If water is used as the liquid medium, preferred ratios are about 90-95 parts water to about 10-5 parts surface size/polyacrylamide containing composition. After or before adding the polyacrylamide surface size mixture to a liquid medium such as water or aqueous starch solution to form a dilute mixture, it may be preferable to adjust the pH of the dilute mixture to from about 6 to about 11, preferably from about 7 to about 10, prior to contacting the dilute mixture with the pre-formed paper or board. The pH of the dilute mixture may also be above about 8 to about 11.
After application of the polyacrylamide surface size mixtures or dilute mixtures (further containing water or starch solution) to the paper or board, the paper or board is typically dried using drying means known in the art such as, for example, steam heated dryer cans, and infrared heaters. Any suitable drying temperature may be implemented and generally temperatures ranging from about 220xc2x0 F. to about 260xc2x0 F., preferably from about 235xc2x0 F. to about 255xc2x0 F. are used.
Also provided by the instant invention are paper and board made according to the methods described above as well as paper and board which comprises the polyacrylamide surface size compositions or mixtures described above including those which further contain an effective amount of crosslinking agent and or stabilizing agent as described above. The paper and board comprises substantially near the surface, surface size comprising at least about 30, preferably at least about 40 mole percent hydrophobic groups and substantially hydrophilic polyacrylamide generally in a ratio of from about 30-95 parts by weight surface size to about 70-5 parts by weight polyacrylamide. As a result of addition at the dry end, the surface size and polyacrylamide are generally localized substantially on the paper or board surface as opposed to being uniformly distributed throughout the paper or board . The paper and board of the instant invention are especially designed for printing and are preferably uncoated. Paper and board of the instant invention may be acid, alkaline or neutral paper, through preferably alkaline. Preferably amounts of polyacrylamide surface size range from about 0.5 to about 15 pounds of polyacrylamide surface size per ton of paper or board, preferably from about 1 to about 10 pounds polyacrylamide surface size per ton of paper or board. The invention is further illustrated by the following examples.
Preparation of Liquid Media (Aqueous Starch Solution)
To a stainless steel beaker, 233 grams (herein xe2x80x9cpartsxe2x80x9d) of a typical size press starch (containing about 0.17 mole percent cationic groups) was slurried in 767 parts of water with good agitation to from an aqueous starch slurry containing about 20 percent by weight starch. The temperature of the resulting slurry was then adjusted with steam to about 90xc2x0-95xc2x0 C. Once steady state was achieved, the temperature was maintained for about 30 minutes. After that time, the heat was removed from the starch cooker and the resulting starch was placed in an ice-water bath. The temperature of the resulting solution was reduced to less than about 40xc2x0 C. The starch solids were then adjusted to a final concentration of about 3 percent, by weight, with water. All applications or tubsizing herein (unless noted otherwise) were performed using 3 weight percent cooked starch solution.

Paper or board with surface of carboxylated surface size and polyacrylamide


A method for injection foaming molding of a thermoplastic resin includes the steps of (1) injecting the foaming-agent-containing plasticized resin from an injection apparatus 30 to fill a mold cavity 10a, (2) releasing a clamping force of a mold 10 immediately after the foaming-agent-containing plasticized resin is injected and filled into the mold cavity 10a, so as to release the pressure of the foaming-agent-containing plasticized resin in the mold cavity 10a, (3) maintaining the pressure-released state of the foaming-agent-containing plasticized resin in the mold cavity 10a for a predetermined period of time, (4) expanding the mold cavity 10a to foam the foaming-agent-containing plasticized resin, and (5) cooling and maintaining the foaming-agent-containing plasticized resin while the mold cavity 10a is in the expanded state.

Molded foam products, in which many bubbles are present in the inside of resins, are used in various fields because excellent physical properties such as lightweight properties, heat insulating properties, sound absorbing properties, and rigidity on a unit mass basis, are exhibited. Particularly in recent years, weight reduction has been highly valued because the weight reduction leads directly to reduction of the raw material cost, the transportation cost, and the like. Therefore, application fields of molded foam products have been further expanded. Methods for foam-molding resins are classified into a physical foaming method and a chemical foaming method depending on the type of foaming agent to be blended into the resin. In the physical foaming method, inert gases such as nitrogen and carbon dioxide and volatile substances such as hydrocarbons and fluorocarbons, which are physical foaming agents, are used. On the other hand, in the chemical foaming method, organic foaming agents such as azo compounds and nitroso compounds and inorganic foaming agents such as sodium bicarbonate, which are chemical foaming agents, are used. In a injection foaming molding method, in which the above-described foaming method is applied to an injection molding method serving as a method for molding a resin, a foaming-agent-containing molten resin, in which a foaming agent and the resin have been mixed, is injected and filled into a mold cavity and the resin is foamed, so that an injection-molded foam product having a bubble diameter of about 80 to 300 μm in the inside of the molded product can be produced.
For the method for foam-molding a resin, for example, a molding method in which a chemical foaming agent or a physical foaming agent is blended into an olefin resin, the resulting mixture is melted, and a molded foam product including bubbles in the inside of the molded product is produced by using a short-shot method (low-pressure method), is disclosed (refer to Patent Document 1). In the method disclosed in Patent Document 1, a molding apparatus is composed of an extruder, an accumulator, and a mold. A foaming-agent-containing molten resin prepared by mixing a physical foaming agent, which is an inert gas such as a nitrogen gas; a volatile substance such as a hydrocarbon or a fluorocarbon; or the like, or a chemical foaming agent and a resin is fed into the accumulator with the extruder, the foaming-agent-containing molten resin fed into the accumulator is injected into the mold, and the resin is foamed so as to produce an injection-molded foam product including bubbles in the inside of the molded product.
On the other hand, for the method for producing a molded foam product by using a physical foaming agent, for example, a method, in which a gas such as air; a volatile substance; or the like is supplied from an extruder hopper under a pressure concurrently with supply of a resin, and melting of the resin and inclusion and dispersion of bubbles are performed with a screw extruder, is disclosed (refer to Patent Document 2). In the method disclosed in Patent Document 2, a polyethylene is used, and air is supplied at a pressure of about 0.69 to 0.78 MPa (7 to 8 kgf/cm2) so as to produce an extrusion-molded product of spongy substance including isolated bubbles.
For example, a method, in which a bubble density (the number of bubbles per unit area) is significantly increased as compared with the density of bubbles formed in the inside of a molded foam product by using a known chemical foaming agent or a physical foaming agent, is disclosed (refer to Patent Document 3) as a method in which carbon dioxide that is an inert gas serving as a blister gas is used in a supercritical state so as to produce a molded foam product. In the method disclosed in Patent Document 3, a system composed of a pressurizer for a supercritical fluid, an apparatus for supplying the supercritical fluid, and a gas bomb is attached to a molding apparatus, carbon dioxide in a supercritical state is infused from a plasticizing cylinder of the molding apparatus so as to dissolve into a molten resin, the molten resin, in which infused carbon dioxide is dissolved, is injected and filled into a mold, and the resin is foamed so as to produce a molded resin product having ultrafine microporosity of below 1 μm, which is referred to as microcell, in the inside of the molded product.    Patent Document 1: JP-A-S44-006080    Patent Document 2: JP-A-S43-009913    Patent Document 3: JP-K-H06-506724

Method for foam injection molding of thermoplastic resin


After an element isolation region is formed using a field-forming silicon nitride film, the silicon nitride film and a semiconductor substrate are patterned. Thereafter, the silicon nitride film and the semiconductor substrate are patterned, thereby forming a gate trench reaching the semiconductor substrate in an active region. Next, after a gate electrode is formed within a gate trench, the silicon nitride film is removed, thereby forming a contact hole. A contact plug is buried into this contact hole. Accordingly, a diffusion layer contact pattern becomes unnecessary, and the active region can be reduced. Because a gate electrode is buried in the gate trench, a gate length is increased, and a sub-threshold current can be reduced.

Conventionally, the following method of manufacturing a MOS transistor on a semiconductor substrate is generally used. First, an isolation region is formed on the semiconductor substrate using a field-forming insulation film as a mask. The field-forming insulation film is then detached to expose the active region, and a conductive film is deposited on the exposed region. The conductive film is patterned to form a gate electrode. A sidewall is formed on a side surface of the gate electrode, and a contact plug to be connected to a source/drain diffusion region is formed, thereby completing the MOS transistor.
However, according to the conventional method, three mask patterns are necessary including a mask pattern to form a field-forming insulation film (an active field pattern), a mask pattern'to form a gate electrode (a gate electrode pattern), and a mask pattern to form a contact plug (a diffusion contact pattern). A part of these three mask patterns cannot be omitted. Therefore, manufacturing cost cannot be reduced by reducing steps of manufacturing process. Furthermore, a positional mismatch between the contact plug and the active region needs to be considered at the time of forming the contact plug using the mask pattern (the diffusion layer contact pattern). Consequently, a wide active region needs to be secured by taking into account a margin for forming the contact plug, and it is difficult to reduce the area of the active region.
Furthermore, in order to form a lightly doped drain (LDD) region and a self-aligned contact, a cap insulation film is necessary on the gate electrode. In this case, a total film thickness of films including the gate electrode becomes about two times the thickness of the gate electrode, which results in a very high aspect ratio. Consequently, a processing margin becomes short in patterning the gate electrode. A margin of burying various kinds of materials in a space between gate electrodes such as a sidewall and a contact plug, and a processing margin of an interlayer insulation film that is once buried into a space between the gate electrodes and then removed become short. This problem is particularly evident in a transistor having a large film thickness of a gate electrode and a very small distance between the gate electrodes due to the employment of a polymetal structure such as a memory cell transistor of a dynamic random access memory (DRAM).
The problem of the very high aspect ratio can be solved somewhat by using a damascene process in the manufacturing of a memory cell of the DRAM, as described in Japanese patent application laid open No. 2002-43544 and Japanese patent application laid open No. 2002-110930. According to the damascene process, an inter-gate insulation film is formed before the gate electrode. Therefore, a defect due to a shortage in a covering rate of the inter-gate insulation film (a short-circuiting between contacts) can be prevented. However, in this case, it is difficult to substantially reduce steps of the photolithography process or substantially reduce the active region.
When a transistor size becomes small due to miniaturization of the transistor, a sub-threshold current increases based on what is called the "short-channel effect". Accordingly, a refresh characteristic reduces in the DRAM, for example. In order to solve this problem, it is effective to secure a sufficient gate length while suppressing the area per one transistor by burying a gate electrode within a trench formed on a semiconductor substrate (see Japanese patent No. 3,150,496).
However, in order to embed a gate electrode into the trench, a mask pattern to form the trench on the semiconductor substrate is separately necessary. Therefore, it is also difficult to reduce steps of a photolithography process and to substantially reduce an active region.

Semiconductor device and method of manufacturing the same


An electronic animal collar designed to reduce the load applied to the animal's neck by one or more stimulating electrodes or sensors that extend from or through an inside surface of the collar housing into the skin of the animal during use, and to permit the collar to be securely fastened to the neck of the animal without risk of causing discomfort or damage to the skin of the animal due to pressure from the stimulating electrodes. The inside surface of the collar housing has one or more high point surfaces that are raised to extend the inside surface above the base of the stimulating electrodes or sensors toward the animal during use so as to increase contact between the inside surface and the animal's skin and to thereby relieve and distribute the load caused by collar tension around the animal's neck over a larger contact friction area. A connecting strap for connecting the electronic collar to the animal includes a stretchable insert to ensure good electrode/skin contact and provide comfort for the animal.

Various electronic animal collar-type training aids are known for enabling an animal trainer to encourage or discourage certain behaviour in animals, such as dogs. The devices may be used to discourage barking or digging, or contain the animal within a defined area.
Generally, the trainer uses a transmitter capable of sending electronic signals, such as radio frequency (RF) signals, to a receiver unit contained within a boxlike enclosure strapped around the animal's neck (see FIG. 1—Prior Art). The transmitter unit may be a stationary boundary unit, a stationary centrally located unit, or a portable transmitter carried by the trainer as part of a remote control unit. Also contained within the boxlike enclosure strapped to the animal are a power supply and a signal generator for generating a stimulus (normally an electric stimulus) that is transmitted to the animal through one or more electrodes, which protrude from the inside surface of the boxlike enclosure and press into the neck of the animal. In response to signals received by the receiver from the transmitter, a voltage is applied to the one or more electrodes to provide an electric stimulation to the animal when it exhibits undesirable behaviour. A device of this type is shown in FIG. 1 of the present application and is also shown and described in U.S. Pat. No. 6,327,999, issued to Duane A. Gerig on Dec. 11, 2002.
As shown in FIGS. 1 and 2, currently available animal collars 1 generally comprise a boxlike collar housing 2 attachable to the animal's neck using strap 3. One or more electrodes 4 typically protrude from an inside surface 5 of boxlike collar housing 2 between ⅜ inch (0.95 cm) and ¾ inch (1.9 cm). Electrodes 4 generally have contact points approximately ⅛ inch (0.32 cm) in diameter. One problem with such collars, is that their effectiveness is limited by the amount of contact that can be obtained between electrodes 4 and the animal's skin 6. Getting the proper tension on the collar requires considerable experience and many inexperienced trainers over tighten or under tighten the devices around the animal's neck. The problem with the electronic collars of the prior art is that 90% of the collar tensioning load is concentrated on the tiny electrodes 4, which jab into the animal's neck. This causes animal discomfort, and over time, the electrodes can harm the animal by causing sores. If the collars are worn loosely, sufficient electrode-skin contact can be lost when the animal runs or shakes itself, especially when the animal becomes wet.
So called 'no-bark collars' of the prior art are similar to the electronic collars described above, and shown in FIGS. 1 and 2, except, in place of the receiver/transmitter combination, no-bark collars have a bark sensor generally located on inside surface 5. The bark sensor is similar to the one or more electrodes 4 and is designed to contact the animal's neck and detect vibrations associated with barking. When such vibrations are detected, an electric stimulus is transmitted to the animal through the one or more electrodes 4 to deter the barking behaviour.
No-bark collars and other similar collars used in various animal containment systems or animal training systems, suffer from the same disadvantages described above.
It would therefore be advantageous if an electronic collar device was developed that could permit sufficient electrode-skin contact to allow the device be effective, and yet provide comfort to the animal and prevent damage and sores.


A navigation system for a vehicle includes a man-machine interface to enter at least one key word for characterization of a point of interest and to enter a geometric figure and a search module to search for at least one of the points of interest assigned to the key word within a geographic area defined by the geometric figure.

A navigation system for a vehicle is known from U.S. Pat. No. 6,401,029 B1. In navigation systems for vehicles a search option according to the so-called points of interest (POIs) can be implemented. Details concerning points of interest or implementation of a search option according to so-called points of interest in a navigation system for a vehicle can be deduced for example, from U.S. Pat. No. 6,278,940 B1, U.S. Pat. No. 6,542,814 B1, EP 1 365 213 A1 or DE 101 32 887 A1.
Thus, DE 101 32 887 A1 discloses the system for navigation of a vehicle from a location to a destination, having an input device to enter a command and/or a location and/or a destination, in which the input device has a voice input module that recognizes a voice input and converts it to a corresponding input to the system, in which the voice input module has a memory unit for elements of a navigation database especially for command names and/or location names and/or street names and/or points of interest, in which an element of the navigation database, especially a command name or location name or a street name or point of interest is assigned to a voice input by comparison by means of a comparator device and this allocated element is sent as a system, location and/or destination to the system, in which the comparator device is laid out for comparison of the voice input with subsets, especially with sequential sections or with consecutive subsets of elements of the navigation database entered in the memory unit.


Methods, systems, and computer program products for automatically issuing travel documents. Tasks relating to issuance of travel documents are generated by an originating application in response to booking a travel service. The tasks are received and stored in a first queue until a triggering event, such as the arrival of a time for issuance of a document. In response to the triggering event, a task in the first queue may be placed in a second queue for transmission to an issuing application. The documents to be issued may be determined based on records in a passenger name record (PNR) stored in a database. The PNR may be determined based on the task. The PNR may be updated with information indicating whether task processing was successful. In the event of an error, information indicating the cause of the error may be added to the PNR.

The invention generally relates to computers and computer systems and, in particular, to methods, systems, and computer program products for automated issuance of travel-related documents.
Travelers who purchase travel services are typically issued travel documents prior to receiving travel services. Travel documents, such as electronic or paper tickets, are then redeemed by the traveler to obtain the purchased services. Travel documents thereby provide a way for the travel service provider to determine that the traveler is entitled to receive the service. Travel documents may be generated based on the content of a Passenger Name Record (PNR). PNRs are typically stored in a computerized reservation system, and define an itinerary for a traveler or a group of travelers travelling together. PNRs are typically generated or modified each time a travel service is booked for or added to a trip. A PNR may be accessed by computer systems, such as ticketing and reservation computer systems, to obtain information regarding the travelers or services that are to be provided for the trip, or to update the PNR. Travel service providers and travelers are linked by documents issued from the PNR to finalize the sale. In addition to providing proof of payment, issuing the documents may trigger a financial settlement between the service provider and the traveler.
To issue the documents to the traveler, a travel agent may access the ticketing system and request the documents be issued one at a time. The travel agent may also simultaneously issue multiple documents for a single PNR using burst ticketing. Burst ticketing causes travel documents to be issued for multiple services defined in the PNR. When multiple documents are simultaneously issued, the ability of the travel agent to select different dates or times for issuing each travel document, or having documents issue at different ticketing offices may be limited. Thus, if the travel agent wants travel documents to be issued on different days or at different ticketing offices, the travel agent will typically have to remember to manually trigger issuance at the selected time and place for each travel document. If the travel itinerary is spread across multiple PNRs, burst ticketing may require that each PNR be handled separately. Burst ticketing may also leave PNRs in the queue, until cleared by the travel agent, in cases where one or more travel documents cannot be issued for a service defined by the PNR.
Thus, improved systems, methods, and computer program products are needed for generating and issuing travel documents in the travel industry.


The present disclosure provides a method and a system for transmitting an uplink signal between a plurality of carriers, user equipment, and a base station, so that channel reciprocity can be effectively utilized. In some implementations, the method includes receiving indication signaling sent by a base station; and transmitting an uplink signal in a target subframe of a corresponding target carrier based on the indication signaling.

In a Long Term Evolution (English full name: Long Term Evolution, LTE for short) system, channel estimation is required. Channel estimation is a process of estimating a model parameter of an assumed channel model when receiving data.
Currently, for a carrier that supports both uplink transmission and downlink transmission, it is beneficial to perform channel estimation by using sounding reference information (English full name: Sounding Reference Signal, SRS for short) and channel reciprocity.
However, user equipment (English full name: User Equipment, UE for short) generally can aggregate a larger quantity of downlink carriers than a quantity of uplink carriers. As a result, when uplink transmission resources are in shortage, some downlink carriers with downlink transmission cannot be used for uplink transmission, for example, transmission of an uplink SRS signal. Obviously, for these downlink carriers, channel reciprocity cannot be effectively utilized.

Method, user equipment, and base station for transmitting uplink signal based on carrier and subframe indication information


A convex polyhedron is formed from planar polygonal members, wherein aligned sides of adjacent abutting polygonal members meet to form edges of the polyhedron. A flexible polycarbonate plastic joining tab fits into slots in the centers of sides of adjacent polygonal members to enable adjustment of the dihedral angle between the adjacent polygonal members. A supplemental source of support such as hook and loop strips are used to fasten joined polygonal members securely in place at a desired alignment and dihedral angle. The polygonal members have mirrored interior faces which impart infinite internal reflections within an interior of the polyhedron, wherein one of the polygonal members is a two-way transparent mirror serving as a viewport, allowing a user to see into the infinitely-reflective interior of the polyhedron.

Accordingly, besides the objects and advantages of the polycarbonate plastic strip joining mechanism described above, several objects and advantages of the present invention are:                a) to provide a joining mechanism that facilitates the assembly of Platonic or Archimedean solids from component regular polygons;        b) to provide a joining mechanism that has hinge-like qualities and serves to keep the sides of two joined polygons aligned on the same line;        c) to provide a joining mechanism that has a great deal of spring action and allows ready adjustment of the dihedral angle formed by the faces of said two joined polygons;        d) to provide a joining mechanism that resists deformation and can be bent through a wide range of dihedral angles without permanently kinking;        e) to provide a joining mechanism that allows an assembled polyhedron to easily be disassembled into its component polygons;        f) to provide a joining mechanism that allows an assembled polyhedron to be disassembled without damage to its component polygons;        g) to provide a joining mechanism that allows an assembled polyhedron to assembled without the need for permanent adhesives;        h) to imbue convex polyhedra with the potential for infinite internal reflections by providing one-way mirrored faces on the component polygons;        i) to realize said potential for infinite internal reflections by orienting said one-way mirrored faces of the component polygons such that said mirrors face the interior of the convex polyhedron;        j) to provide a way to readily view said infinite internal reflections by fashioning one or more of the said component polygons wholly or partially from two-way mirror;        k) to create a viewport by including at least one polygon that has been wholly or partially fashioned from two-way mirror in the construction of a polyhedron;        l) to provide a joining mechanism that consists of two parts: an aligning means that serves to help position the joined pieces relative to one another, and a supporting means that holds the joined pieces in said relative position.

Joining mechanism for lightweight applications


A novel control system for altering a fixed pattern of gas flames in a fireplace having artificial logs comprises a log set having a burner system and the burner system having a gas valve control which is coupled to source of gas or air to be regulated. The control system has a valve which controls the air or gas being supplied to the burner and a control sensor is coupled to the control system for activating the time sequence of the cycle of the control system so as to raise or lower the gas flames being regulated and to disturb the pattern of gas flames to produce the effect of dancing flames.

1. Field of the Invention
The present invention relates to gas burners for gas fireplaces. More particularly, the present invention relates to a system for controlling a gas used in combustion to affect the disturbance of the gas flame pattern of gas burner system.
2. Description of the Prior Art
It is well known that candles will flicker when the air around the burning flame is disturbed. It is also well known that a closed fireplace having closed doors across the front of the gas fireplace displays little or no flicker until the doors are opened and a draft or excess combustion air is drawn into the combustion system. A natural fire of wood logs in a closed door fireplace displays a noticeable disturbance of the pattern of flames even when the doors of the fireplace remain closed.
It would be desirable to emulate the changes of the flame pattern of a natural wood burning fireplace by changing a fixed flame pattern of an artificial gas log fireplace.

Dancing flame control system for gas fireplaces


A training apparatus for improving a golfer's golf swing is disclosed. The training apparatus can restrict movement of the golfer's hands, as well as the shaft of the golfer's golf club, during the swing. A set of rails supported by a support structure are oriented so as to restrict the golfer's hand movement, and golf club shaft movement. The set of rails include at least two rails for inducing the golfer to move the golfer's hands within the hand space, throughout at least a portion of the swing, and at least two rails for inducing the golfer to move the golfer's golf club shaft within the golf club shaft space. The rails can include various adjustability features, allowing for adjusting the height and angular orientation of the set of rails, as well as the spacing and orientation of individual rails relative to each other.

Golfing is a popular recreational sport, and many golfing enthusiasts are highly motivated to improve their golfing skills. The golf swing is the most essential part of the game of golf. A swing that is executed with even a small error can translate into great error in the game, since the golf swing precisely dictates the trajectory of the golf ball hit by the golf club during the swing.
Apparatuses for guiding a golfer's golf swing are known in the art. Some of these apparatuses employ a system of rails or cables so as to restrict some or all of the movement of a golfer's swing. However, these apparatuses do not appropriately restrict the golfer's swing, instead leaving too much of the swing's movement to the freedom of the golfer.


A storage system comprises a cache device and a storage device group. A technique involves: the cache device of the storage system receiving from a host an input/output (I/O) request for the storage system; and upon determining that the storage system is just recovered from a hardware failure and the storage device group in the storage system is in a ready but degraded state, safely performing data write/read by sending a new Recover State I/O request to the storage device group. Such a technique may be used to reduce a Data Lost window, reduce or avoid data loss. In addition, such a technique may be implemented in a current RAID technology, namely, can be used in combination with the current RAID technology.

A cache is a buffer between a bottom storage device (e.g., hard disk, or Redundant Arrays of Independent Disks RAID) and an external interface. The cache may store, for example, hot data to reduce data exchange between the external interface and a bottom drive, improve a data transmission rate and reduce delay of data access. In current RAID technology, there is a cache layer above a RAID group. When a write request is sent to the storage system from a host, the cache device stores the data in its memory and notifies the host that the input/output (I/O) is completed. The cache device may send the data to a RAID group later and may invalidate the memory after the RAID group finishes the I/O. This technology is called "WriteBack", which may improve I/O performance significantly and is used widely in storage systems. However, data loss might occur when RAID group comes back online after a hardware failure and attempts to recover data using the WriteBack technology.

Processing a recover state input/output request


The invention concerns a device in fuel tanks, preferably for vehicles, said tanks being provided with a mouth socket to which a filler tube is connected so as to have its one end portion projecting into the tank. Between the mouth socket and the filler tube a seal is provided, the latter being formed with a portion grippingly enclosing the mouth edge of the socket and defining, together with the filler tube, an intermediate space allowing oscillation of the filler tube relatively to the socket. A washer is pressed against the filler tube and is formed with a bent-over portion grippingly engaging said portion of the seal. A reinforcement sleeve is positioned inside the filler tube and presses against the inner face of the filler tube. A clamp-joint sleeve is fitted around the mouth socket, enclosing portion of the seal and the washer.

The invention concerns a device in fuel tanks, preferably for vehicles, the tank being provided with a mouth socket to which a filler tube is connected.
Previously, fuel tanks for vehicles within the car industry were made from deep-drawn, lead-covered sheet metal. In accordance with prior-art technology, an upper and a lower section are welded together and the tank thus formed is provided with a socket to which a filler tube is in turn connected. In order to prevent leakages from arising at the socket mouth, as may be caused by vibrations when the vehicle is running, a rubber hose is inserted between the socket and the filler tube and attached to said components with the aid of hose clamps. In particularly exposed positions reinforced rubber hoses are usually used.
In later years, synthetic resin tanks have come into use as they are now capable of satisfying the strength and security requirements on fuel tanks. However, the technology used in the manufacture of sheet metal tanks as concerns the interconnection between the socket and the filler tube has been adopted also for synthetic resin tanks. Thus, the socket, now manufactured from blow-moulded synthetic resin, is connected to the filler tube by means of a rubber hose and hose clamps. The joint between the tank and the filler tube is, however, a weak link. The rubber hose ages more rapidly than the rest of the components, particularly when used in positions where, during vehicle running it is exposed to sprays of water mixed with sand and salt from the roadway. This increases largely the risks for leakages caused by cracks in the tube, and also increases the risks for rupture of the tube, which could easily occur in the event of a collision. Obviously, fuel leakages constitute serious fire hazards.


Methods and systems for delivering a pharmaceutical gas to a patient. The methods and systems provide a known desired quantity of the pharmaceutical gas to the patient independent of the respiratory pattern of the patient over a plurality of breaths every nth breath, where n is greater than or equal to 1. The pharmaceutical gases include CO and NO, both of which are provided as a concentration in a carrier gas. The gas control system determines the delivery of the pharmaceutical gas to the patient to result in the known desired quantity (e.g. in molecules, milligrams or other quantified units) of the pharmaceutical gas being delivered. Upon completion of that known desired quantity of pharmaceutical gas over a plurality of breaths, the system can either terminate, continue, activate and alarm, etc.

The present invention relates to methods and systems for administering a pharmaceutical gas to a patient and, more particularly, to methods and systems for introducing carbon monoxide CO or nitric oxide NO to a patient in a predetermined quantity.
The normal or conventional way of giving a pharmaceutical drug to a patient is to prescribe the dose based on the quantity of drug (usually in weight) per unit weight of the patient (e.g. mg/Kg) with the dose being specified to be delivered over a period of time or being repeated at specified intervals of time. This allows the user to control the quantity of drug and ensures the quantity of drug being delivered is in proportion to the patient's size. This is to reduce the patient to patient variability in response to the drug due to the size of the patient i.e. a 7 Kg baby will not get the same quantity of drug as a 80 Kg adult.
In recent times there have been a number of gases which have been shown to have pharmaceutical action in humans and animals. Examples include Nitric Oxide (NO) Zapol et al U.S. Pat. No. 5,485,827 and more recently Carbon Monoxide (CO) Otterbein et al (U.S. Published Patent Application No. 2003/0219496). In the Otterbein patent application, CO is described as having a pharmacological action in a number of medical conditions including ileus and vascular disease.
In these cases, the carbon monoxide gas needs to be delivered to the patients' alveoli where it can move across the alveolar membrane and into the blood stream where its action can take effect. The current dosing used in these cases is for the patient to breath at a specified concentration of CO in ppm for a specified period of time. Accurate dosing of CO for these treatments is important as CO reacts with the hemoglobin in the blood to form carboxyhemoglobin which means the hemoglobin is no longer able to carry oxygen to the tissues of the body. If too much CO is given, the patient may exhibit the toxic effects of CO for which it is usually known.
There is a tight window for CO delivery between the therapeutic level and the level that causes carboxyhemoglobin above safe levels. Up until now CO has been delivered as a constant concentration in the gas breathed by the patient/animal for a specified period of time. For example in reference 3 of the Otterbein publication, (Example 2 pg 13) the therapeutic dose delivered to mice for the treatment of ileus was 250 ppm of CO for 1 hour.
However, this method of dosing CO can be associated with large variability in the actual dose being delivered to the animal/humans alveoli. This variability is because the quantity of CO being delivered to the animal/patient is dependent on a number of variables including, but not limited to, the patients tidal volume, respiratory rate, diffusion rate across the alveolar and ventilation/perfusion (V/Q) matching.
The amount of CO delivered into a patient's alveoli can be determined by the ideal gas law as shown in the following equation:N=PV/(RuT)   (1)Where: N is the number of moles of the gas (mole) P is the absolute pressure of the gas (joule/m3) V is the volume of the particular gas (m3), Ru is the universal gas constant, 8.315 joule/mole-K and T is the absolute temperature (K).
If we assume atmospheric pressure (101,315 joule/m3) and 20° C. (293 K) as the temperature and we express the volume in mL (10−6 m3), then equation (1) reduces to:N=4.16×10−5V (moles)   (2)
Equation (2) can be used to calculate the number of moles of gas delivered to a patient's alveolar volume over a period of time when given a specified concentration by using the following equation:NCO=RR·t·CCO·10−6·4.16×10−5Va   (3)Where; CCO is the concentration of CO (ppm), Va is the alveolar volume (mL), RR is the respiratory rate (BPM) and t is the time in minutes.
For example, if the CO dose for ileus in humans was 250 ppm of CO for one hour (60 minutes), the alveolar volume is 300 mL and the patients respiratory rate is 12 breaths per minute (bpm) then the amount of CO gas in moles delivered to the patients alveoli over that period would be:NCO=12—60·250·10−6·4.16×10−5·300=2.25×10−3 moles
This can be converted into the mass of drug delivered (MCO) using the gram molecular weight of CO which is 28 as shown in the following equation:MCO=NCO·28=63×10−3 g=63 mg   (4)
However, although this works for a given set of assumptions, a spontaneous patient's respiratory rate can vary widely from perhaps 8 to 20 breaths per minute depending on circumstances and the patient's alveolar volume per breath can also vary significantly from say 200 to 400 mL depending on the metabolic need. These variables can have a dramatic effect on the amount of gaseous drug being delivered to the patient over the same period of time. For instance, if the patients respiratory rate was 8 bpm and the alveolar volume was 200 mL, the CO dose delivered to the patients alveoli would have been 27.8 (mg). Likewise if the patients respiratory rate was 20 bpm and the alveolar volume was 400 mL, then the dose delivered to the patients alveoli would have been 139.2 (mg) thus representing a five-fold difference in the amount of drug being delivered.
This means, in the example of CO, the quantity of gaseous drug a patient gets as measured in grams could vary substantially depending on the patient's ventilation pattern. For a dose based on constant concentration and time, the effect of these variables could mean that an individual patient could get significantly higher or lower doses of CO in grams and this could result in either high unsafe levels of carboxyhemoglobin or doses too low to be effective. Although not all the gaseous drug delivered to the alveoli will be taken up by the body's bloodstream (due to variables such as cardiac output and the diffusion coefficient of the gas) controlling the amount delivered to the alveoli takes away a major source of variability.
In addition, there is a need to administer NO to a patient in a predetermined quantity as described in "Cell-free hemoglobin limits nitric oxide bioavailabllity in sickle-cell disease", Nature Medicine, Volume 8, Number 12, December 2002, pages 1383 et seq. This paper describes the use of inhaled NO to react with cell free hemoglobin to form plasma methemoglobin and so reduce the ability of the cell free hemoglobin in the plasma to consume endogenously produced NO (FIG. 5, page 1386). The quantity of NO delivered to the patient blood needs to be equivalent to the amount of cell free hemoglobin that is in the patients plasma. The amount of NO delivered to a sample of sickle cell patients was 80 ppm of NO for 1.5 hours. However, there was variability in the amount of methemoglobin produced in individual patients as shown by the error bars on FIG. 4b. So, in a similar way to the CO example, a known quantity of NO needs to be delivered to a patient to provide the desired therapeutic effect and again it is important to remove any variability of delivery because of differences in the individual patient's respiratory pattern.
Accordingly, it would be advantageous to have a system and method of introducing pharmaceutical gases (such as carbon monoxide and nitric oxide) that allows for the precise control of a known quantity of the pharmaceutical gas to be delivered to the patients alveoli and which is not subject to change based on the patients respiratory patterns.

This patent is subject to a terminal disclaimer.

System and method of administering a pharmaceutical gas to a patient

Mallinckrodt Hospital Products IP Limited


A method for forming microlenses of different curvatures is described, wherein a substrate having at least a first and a second areas different in height is provided. A transparent photosensitive layer having a planar surface is formed on the substrate and then patterned into at least two islands of different thicknesses respectively over the first area and the second area. The at least two islands are heated and softened to form at least two microlenses of different curvatures respectively over the first area and the second area, wherein the higher an area is, the smaller the curvature of the corresponding microlens is.

1. Field of the Invention
The present invention relates to a method for fabricating optical components. More particularly, the present invention relates to a method for forming microlenses of different curvatures, and to a fabricating process of a solid-state image sensor which utilizes the method so that the sensitivities to different color lights can be optimized respectively.
2. Description of the Related Art
A solid-state image sensor, such as a CCD image sensor or CMOS image sensor (CIS), is essentially composed of red, green and blue pixel sensors that are respectively equipped with red, green and blue filters. To increase the quantum yield of incident light for improving the sensitivity, a microlens can be formed over each color filter to focus the incident light, as described in U.S. Pat. No. 6,379,992, for example.
Referring to FIG. 1A, in a typical microlens process of a CIS device, a substrate 100 is provided, on which a passivation layer 110 for protecting the circuit of the sensor, blue, green and red filters 120, 130 and 140, and a planarization layer 150 have been formed. A transparent photosensitive layer 160 is formed on the planarization layer 150 and then patterned into islands 160a of the same thickness, wherein each island 160a is form over one color filter.
Referring to FIG. 1B, the islands 160a are heated and softened such that the surface tension makes their surfaces spherical, thus forming multiple microlenses 160b, which have the same curvatures because all of the islands 160a have the same thickness. Hence, the focal lengths of the three microlenses 160b over the blue, green and red filters 120-140 are the same.
However, as shown in FIG. 1B, because respective maximal absorption regions 122, 132 and 142 of blue, green and red lights 124, 134 and 144 are different in depth in the substrate 100, the absorptions of the blue, green and red lights cannot be optimized respectively with the microlenses 160b of the same curvature that have a single focal length only. Hence, the sensitivities of the image sensor to different color lights are different to cause chromatic deviation of the recorded images.
To solve the above problem, for example, the method disclosed in U.S. Pat. No. 5,592,223 can be used, in which the sensitivities to different color lights are equalized by varying respective areas and/or curvatures of the microlenses formed over different color filters. Besides, the method provided in U.S. Pat. No. 6,643,386 equalizes the sensitivities to different color lights by altering respective colors or shapes of the microlenses over different color filters, wherein the shapes include areas and curvatures.
However, when the sensitivities are equalized by forming microlenses of different areas or colors, a color light of higher sensitivity is made to have a lowered intensity incident to the corresponding sensor diode. Therefore, the overall sensitivity of the CIS device cannot be improved. In addition, forming microlenses of different colors needs more than one lithography processes, so that the fabrication is tedious.
On the other hand, when the sensitivities are equalized by forming microlenses of different curvatures, the sensitivities to different color lights can be respectively optimized by adjusting respective curvatures to obtain different focal lengths. However, this microlens process is very tedious because three lithography processes are conducted to form photoresist islands of three thicknesses for making the three curvatures.

Method for forming microlenses of different curvatures and fabricating process of solid-state image sensor


A laundry treating apparatus includes a housing, which includes first and second wash units within the housing. The first and second wash unit include first and second tubs, first and second drums mounted inside the first and second tubs, and first and second drive units configured to drive rotations of the first and second drums, respectively. The laundry treating apparatus also includes a valve assembly that is configured to receive tap water and that is configured to control a supply of the tap water to each of the first wash unit and the second wash unit within the housing. The laundry treating apparatus further includes at least two supply lines configured to supply the tap water from the valve assembly to at least two supply points of the second tub in the second wash unit.

In general, laundry treatment apparatuses are appliances for washing laundry using detergent and mechanical friction.
Generally, a laundry treating device is a device capable of washing, drying, or washing and drying laundry and the like. Herein, the laundry treating device may perform a wash or dry function only, or may perform both of the wash and dry functions. Recently, a steam supplier equipped washer having a refresh function (e.g., wrinkle press-out, deodorization, static electricity removal, etc.) for laundry have come into wide use.
Laundry treating devices are typically categorized into a front load type or a top load type according to a withdrawal direction of laundry. Moreover, there is a vertical axis type having a pulsator or wash tub rotated therein or a horizontal type having a drum rotated according to a wash performed scheme.
A representative example of the horizontal type is a drum washer or a drum dryer. Hereinafter, a laundry treating device of a front type is defined as a laundry treating device including an opening provided to a front side and a drum of which rotation axis is in parallel with a ground surface or has a predetermined inclination. A laundry treating device of a top load type is defined as a laundry treating device including an opening provided to a top and a drum of which rotation axis is vertical to a ground surface.
Generally, each home uses a single laundry treating device of large capacity. In some situations, the laundry treating device is used several times to wash laundries according to their categories. For instance, in case of intending to separately wash the laundry such as adult clothes and the laundry such as underwear, baby clothes and the like, after the wash of the former has been completed, the laundry treating device used again to wash the latter.


A method of performing XSLT processing is disclosed. The method involves defining a binary tree, each node representing either an XML document or XSLT stylesheet, each leaf representing a an existing file, and each non-leaf node having two child nodes, one representing an XML document, and one representing an XSLT stylesheet, performing a post-order traversal of the binary tree, each non-leaf node being constructed by transforming the non-leaf node's respective XML document child node using the non-leaf node's respective XSLT stylesheet to create the non-leaf node, and creating a final text document as the root node.

The extensible markup language (XML) is a general purpose markup language. Extensible stylesheet language (XSL) transformation (XSLT) is a language that translates one XML document into another XML document, allowing for chained translations. XSLT is itself an XML document and may be generated from another XSLT transformation. Current extensible stylesheet language (XSL) transformation (XSLT) processing is limited to one extensible markup language (XML) document processed by one XSLT document. In general, custom applications are required in order to perform multiple transformations of XML when multiple translations need to be performed. These custom applications tend to be relatively complex, relative expensive, and have long development cycles.
Thus, there is a need for a method and system of XSLT processing that is not limited to a single XML document processed by a single XSLT document.

Method and system for XML multi-transform


This invention relates to compounds which are generally alpha-1A/B adrenoceptor antagonists and which are represented by Formula I:

Alpha-1-adrenergic receptors are G-protein coupled transmembrane receptors that mediate various actions of the sympathetic nervous system through the binding of the catecholamines, epinephrine and norepinephrine (NE). Currently, several subtypes of the alpha-1 adrenergic receptors are known to exist for which the genes have been cloned: alpha-1A (previously known as alpha-1C), alpha-1B and alpha-1D. Recently the existence of a low affinity alpha-1 adrenoceptor for prazosin named alpha-1L, in human prostate has been determined. However, the gene for the alpha-1L-adrenergic receptor subtype has yet to be cloned.
Alpha-1 adrenoceptor antagonists have been shown in numerous clinical studies to be effective in relieving the symptoms associated with benign prostatic hypertrophy, also known as benign prostatic hyperplasia (BPH), an illness typically affecting men over fifty. The symptoms of the condition include, but are not limited to increased difficulty in urination and sexual dysfunction. Drugs such as prazosin, indoramin, doxazosin and tamsulosin are in common clinical use for BPH, and are effective in reducing both "obstructive" symptoms (eg. weak stream) and "irritative" symptoms (eg. urinary urge and frequency, nocturia). However, these compounds are all non-subtype-selective, and have the potential to cause significant side-effects, particularly cardiovascular effects such as postural hypotension, dizziness and syncope, and CNS effects including aesthenia (tiredness). These effects can limit dosing and thus clinical efficacy in reducing symptoms associated with BPH.
Pharmacological studies resulting in the subdivision of alpha-1 adrenoceptors into alpha-1A, alpha-1B and alpha-1D adrenoceptors have led to the suggestion that development of subtype-selective antagonists may allow improved symptomatic treatment of BPH/unstable bladder with a lower incidence of dose-limiting side-effects. Recently, much interest has been focused on the role of the alpha-1A adrenoceptor subtype in BPH, as a result of studies demonstrating that this subtype predominates in the urethra and prostate of man (Price et al., J. Urol., 1993, 150, 546–551; Faure et al., Life Sci., 1994, 54, 1595–1605; Taniguchi et al., Naunyn Schmiedeberg's Arch. Pharmacol., 1997, 355, 412–416), and appears to be the receptor mediating NE-induced smooth muscle contraction in these tissues (Forray et al., Mol. Pharmacol., 1994, 45, 703–708; Hatano et al., Br. J. Pharmacol., 1994; 113, 723–728; Marshall et al., Br J. Pharmacol., 1995, 115, 781–786). The resulting smooth muscle tone is believed to contribute substantially to the total urinary outflow obstruction observed in patients with BPH (Furuya et al., J. Urol., 1982, 128, 836–839), with the remaining being attributable to increased prostate mass. These observations have fuelled the hypothesis that an alpha-1A subtype-selective antagonist may, via a selective and significant decrease in outlet resistance, lead to improved pharmacotherapy for BPH.
However, it must be noted that in BPH, it is often the irritative symptoms which prompt the patient to seek treatment, and that these irritative symptoms may be present even in patients with no demonstrable obstruction (i.e. normal urine flow rates). Recently in U.S. patent application Ser. No. 09/521,185 Ford et al. have described the use of selective alpha-1B adrenoceptor antagonists for the treatment of disorders resulting in irritative bladder symptoms. The current proposal is that by combining both alpha-1A and alpha-1B subtype selectivity in a drug molecule, it would be possible to reduce both obstructive and irritative symptoms in patients with BPH. The lack of alpha-1D adrenoceptor antagonism is expected to lead to reduced or fewer side effects than those associated with the use of non-subtype-selective agents.
All publications, patents, and patent applications cited herein, whether supra or infra, are each hereby incorporated by reference in its entirety.

Quinazolone derivatives as alpha 1A/B adrenergic receptor antagonists

Abstract: wherein Z is —C(O)— or —S(O)2—, X is carbon or nitrogen, Y is carbon, and X-Y considered together are two adjoining atoms of the ring A, said ring being a fused aromatic ring of five to six atoms per ring optionally incorporating one to two heteroatoms per ring, chosen from N, O, or S; and the other substituents are as defined in the specification; or individual isomers, racemic or non-racemic mixtures of isomers, or pharmaceutically acceptable salts or solvates thereof. The invention further relates to pharmaceutical compositions containing such compounds, methods for their use as therapeutic agents, and methods of preparation thereof.


An electronic device according to an aspect of the invention include: a substrate; an underlayer having an opening and being formed on the substrate; a functional element provided on the underlayer; and a surrounding wall forming a cavity that accommodates the functional element, at least a part of the surrounding wall being disposed in the opening.

1. Technical Field
The present invention relates to an electronic device, a method for producing the same, and an oscillator.
2. Related Art
Electronic devices in which a functional element such as a MEMS (Micro Electro Mechanical Systems) is disposed in a cavity formed on a substrate are known. For example, JP-A-2008-221435 describes an electronic device in which a functional element is formed on a substrate. The electronic device described in JP-A-2008-221435 is produced by forming a functional element on a substrate, forming an interlayer insulating layer so as to cover the functional element, and removing (release etching) the interlayer insulating layer located around the functional element to form a cavity.
With the recent progress in the micronization of electronic devices, the sizes of vias, contacts, guard rings and so forth are becoming very small. When a cavity as that of the electronic device described in JP-A-2008-221935 above is formed using a thin guard ring or the like, the side wall tends to collapse during release etching, so that the interlayer insulating layer may be removed in a region that is not supposed to be removed. This leads to a small margin in the time management for release etching. Also, there is a concern that the mechanical strength is insufficient because of the thin side wall.
When a transistor is additionally formed on the same substrate, it is necessary to interpose a titanium layer between the transistor and a contact in order to improve the junction therebetween. When a side wall that covers the cavity and the contact are formed in the same process, a titanium layer is formed on the side wall. Accordingly, the titanium layer is etched during release etching, so that the interlayer insulating layer may be removed in a region that is not supposed to be removed.

Electronic device, method for producing the same, and oscillator


A method for controlling the spread of HIV/AIDS and other infectious diseases. Individuals desirous of reducing the risks of infection and preventing the spread of such diseases voluntarily participate in a testing program whereby regular periodic screening tests are performed to indicate the infection status of each such individual for any of several infectious diseases. The infection status information is coded for each individual and is stored in a confidential database. An individual can access his infection status information upon making an inquiry using a unique personal identification number, or PIN. The individual's identification information is matched with his infection status information in the database and provides that information immediately either orally or in written form. Two participating members of the program can obtain their infection status data jointly, thereby providing reliable, current infection status information to each other contemporaneously while avoiding the risks of nondisclosure or misrepresentation of such information by one or both parties.

The existence of sexually transmissible diseases is a reality of the human condition. Infectious diseases such as hepatitis, and venereal diseases such as gonorrhea, syphilis, chlamydia and herpes, have not yet been eradicated, although they are currently treatable if properly diagnosed. Other sexually transmissible diseases, such as HIV/AIDS and certain strains of hepatitis, are virulent and continue to spread worldwide. Although much work is currently being done in the area of HIV/AIDS research, there is so far no cure, no vaccine, and no effective long-term treatment for the disease.
Current knowledge does not even extend to an understanding of all the mechanisms by which HIV/AIDS is transmitted. It is known, however, that certain high-risk behaviors render one more susceptible to infection with HIV. These high-risk behaviors include, but are not limited to, promiscuity, unprotected sex, homosexual sex, drug use, sex with drug users, and the sharing of hypodermic syringes and needles. Identification of high-risk behaviors and individuals tending to engage in such behaviors, and education of those individuals about the risks inherent in their activities, is an important step in reducing the incidence of HIV infection in the general population. Behavior modification is thus a critical goal in the war against the spread of HIV/AIDS and other sexually transmissible diseases for which no cure or suitable treatment is known.
It is an object of the present invention to provide a method for preventing the spread of sexually transmissible diseases, principally through behavior modification, particularly among individuals engaging in potentially high-risk behaviors.
It is another object of the present invention to provide a method for preventing the spread of infectious diseases by providing an easily-accessible information database which contains updated infection status information about individuals who participate in a regular screening program to test for infection and who wish to minimize the risks of becoming infected.

System for controlling the spread of HIV/AIDS and other infectious diseases