text:
Report: Blues spoke with Flyers and Rangers about Kevin Shat
Fortune Sets On The Suns Once Again, As LaMarcus Aldridge Be
Green Bay Packers Should Move On from TE Andrew Quarless
Kvitova Loses: Affirmations And Transformations Coexist At W
Who Will Win the Copa America Final?
Andrei Kostitsyn open to playing for any NHL team
Power Ranking Every Women's World Cup Final
Astros' first base-DH surplus now helps cover George Sprin
Nissan Stadium's Facilities Leave Many USMNT Fans Furious
A-Rod gets 3,000th hit ball from Zack Hample, charity gets $
VIDEO: Timmy Chandler's Golazo (Yes, Chandler) Gives USMNT
DeAndre Jordan To Dallas: The Los Angeles Clippers Are Liter
The History and Cultural Significance of Rappers Talking Wit
Charity wins: A-Rod, Yankees settle dispute over $6 million
Are the Angels now the worst organization in baseball?
DONE DEAL: Falcao to Chelsea on Loan
Braves willing to deal starting pitching for catching
5 Reasons the Cleveland Browns Should Play Johnny Manziel
Report: Slava Voynov to begin serving 90-day jail sentence
Watch: First trailer for 'Steve Jobs' starring Michael F
Blue Jays need continued production from rookies to succeed
Petersen, Patterson, Purple, Perseverance: Can Washington Fo
'Batman v Superman: Dawn of Justice' gets Entertainment
The longest home runs for the week ending July 2nd
Which team will win the American Athletic Conference in 2015
Box office bombs? Four cult classics for your 4th of July we
Bloguin Top 50: No. 41 — Washington
The top 10 players in the AFC North
Al Pacino Sends Message to Argentine Team Before Copa Americ
DeMarre Carroll doesn't just bring skill to Toronto; he br
CC – The Podcast: Off-season Preview #7; Clippers & Nu
Miami Heat Wishes USWNT "Good Luck in the Finals tonight!�
America's hero goes to Washington: T.J. Oshie is a Capital
Hacking fallout – Cardinals fire scouting director
Nadal Loses: Storm Clouds Gather, But Will They Give Way To
'Terminator: Genisys' should kill off the Terminator fil
Warriors Show Fans They've Got It, Thanks
Monta Ellis snag puts Pacers back in title-chasin' pack
Outta here: the five best moments in home run derby history
Jose Fernandez homered in his 2015 debut
Can the Suns steal LaMarcus Aldridge from the Spurs?
Greece Football In Crisis?
NBA Free Agency: Day 1 Report
Marc Savard getting traded in 2015 is ridiculous
'Comedians in Cars' recap: Trevor Noah's Work Ethic Sh
BYU's 2015 Schedule Is Noble, Admirable, Wonderful… And
Which teams will surprise in the American Athletic Conferenc
Bloguin Top 50: No. 42 — BYU
The top 10 players in the AFC East
Much on the Line for both Argentina And Chile in Copa Americ
2012 Archives
2011 Archives
2010 Archives
Title Filter
Display #
Article Title
Jose Ceda to have Tommy John Surgery
BC Castaldo
Marlins Make Moves to Finalize Opening Day Roster
BC Castaldo
Marlins Spring Training Week 3
Brian Castaldo
2012 Fantasy Baseball Rankings
BC Castaldo
Who will be the 4th Outfielder?
BC Castaldo
Top Marlins Prospects for 2012
BC Castaldo
Recaping Miami Marlins First Week of Spring Training
BC Castaldo
Baseball Expands Playoff System
BC Castaldo
Recent Posts
Looking at the Marlins at the All-Star Break
Stanton to have Surgery
Marlins Aquire Carlos Lee
Marlins End Another Disasterous June on High Note
Giancarlo Stanton heading to the All-Star Game
Follow Us
Legal Information
Privacy Policy
MarlinsBigCatch.com is a Florida Marlins fan web site and is in no way affiliated with the Florida Marlins, Major League Baseball, or its Properties. This site is for informational and entertainment purposes only. MarlinsBigCatch.com is not an official web site for the Florida Marlins.
Copyright © 2011 www.MarlinsBigCatch.com - All Rights Reserved -
Trademarks used herein are property of their respective owners.


text:
Austal and the U.S. Navy held a keel-laying ceremony today for the future USS Manchester (LCS 14), marking the first significant milestone in its construction.
Project will enhance wharf, rail and yard infrastructure to optimize terminal operations
The Port of Los Angeles will begin construction this summer on a two-year
Seaspan Corporation accepted delivery of a 14,000 TEU containership, the YM Witness.
The new containership, which was constructed at Hyundai Heavy Industries Co.

subset: commoncrawl


text:
The Children's Courtyard Kitchen Manager Jobs
Hiring? Post a Job
Show: All Results Last 7 Days
No jobs found – change your filters above for more results
The Children's Courtyard Photos
The Children's Courtyard Reviews
Recommend to a friend
Approve of CEO
Barbara J. Beck
13 Ratings
"Great Company, Caring and Great Benefits "
- Work/Life Balance
- Culture & Values
- Career Opportunities
- Comp & Benefits
- Senior Management
I have been working at The Children's Courtyard full-time (More than 5 years)RecommendsPositive OutlookRecommendsPositive Outlook
I've worked for The Children's Courtyard for 6 years and I have enjoyed my time here. The flexibility is great and everyone really helps each other out. Benefits are great and my children even attend the program. Any issues and concerns are always addressed quickly and management is always willing to listen. Advancement opportunities have been great and I see myself working with this company for many years to come.
Staff needed however management steps in when needed and helps to cover holes.
Work at The Children's Courtyard? Share Your Experiences
The Children's Courtyard
Click to Rate


text:
An aqueous liquid medium having increased low shear viscosity is provided by dispersing into the aqueous medium (1) a water-soluble polymer having pendant hydrophobic groups, e.g, an acrylamide/dodecyl acrylate/acrylic acid terpolymer. The thickened aqueous medium is suitably employed in applications requiring viscous liquids which retain their viscosity when subjected to shear, heat or high electrolyte (salt) concentrations. Such applications include uses in enhanced oil recovery processes, as fluid mobility control agents, fracturing fluids and drilling muds, as well as hydraulic fluids and lubricants.
1. A water-soluble composition for thickening aqueous liquids consisting essentially of:
A. a water-soluble thickening agent which agent consists essentially of a water-soluble terpolymer of:
(a) acrylamide,
(b) 2-acrylamido-2-methylpropane sulfonic acid salt; acrylic acid; or dimethylaminoethyl acrylate methyl chloride salt; and
(c) a C8 -C20 alkyl ester of acrylic acid, and
B. a water-soluble inorganic salt,
wherein the molecular weight of the terpolymer is such that, at the same concentration, a copolymer of only components (a) and (c) having the same molecular weight, is water-insoluble, the concentration of monomer (b) being replaced by an equal concentration of acrylamide (a).
2. The composition of claim 1 wherein (b) is acrylic acid and c) is dodecyl acrylate.
3. The composition of claim 1 wherein (b) is 2-acrylamido-2-methylpropane sulfonic acid salt and (c) is dodecyl acrylate.
4. The composition of claim 1 wherein (b) is dimethylaminoethyl acrylate methyl chloride salt and (c) is dodecyl acrylate.
5. The composition of claim 1, wherein the terpolymer has a molecular weight in the range from about 2 to about 20 million.
6. The composition of claim 1 wherein the inorganic salt is a salt of monovalent cation which salt is present in amount from about 0.1 to about 15 weight percent based on the aqueous composition.
7. The composition of claim 6 wherein the salt is sodium chloride or potassium chloride or a mixture thereof.
8. The composition of claim 6 wherein the inorganic salt is a salt of a divalent metal which salt is present in an amount from about 0.01 to about 10 weight percent based on the composition.
9. The composition of claim 8 wherein the divalent metal is calcium, magnesium or a mixture thereof.
This invention relates to thickening agents containing water-dispersible polymers which agents are used to increase the viscosity of aqueous media.
U.S. Pat. No. 4432881 discloses a thickening agent which comprises a water-soluble polymer having pendant hydrophobic groups and a water-dispersible surfactant having hydrophobic groups that are capable of associating with the hydrophobic groups of the polymer. The patentee indicates that the relative proportions of the two components of the thickening agent are such that, when the thickening agent is dispersed in water in a concentration of 0.5 weight percent based on the water, the viscosity of the water is at least doubled, the thickening agent being such that the water can be subjected to mechanical shear without significant loss of viscosity. Additionally, the thickening agents are said to be such that their viscosity is not reduced by the presence of electrolytes such as sodium chloride etc.
The copolymers disclosed as useful in the above-mentioned patent for the production of the thickening agents thereof comprise a copolymer of a water-soluble monomer such as acrylamide and a hydrophobic group-containing comonomer such as dodecyl acrylate or methacrylate. The patentee indicates that such copolymers, when used in conjunction with a hydrophobic group containing surfactant, result in thickening agents which increase the viscosity of water when added thereto.
The use of the surfactants has been found to be unnecessary by Applicants in that their necessity has been shown to be obviated by the use of a third monomer, i.e, a water-soluble monomer which when copolymerized with the other two monomers results in the formation of a water-soluble terpolymer. It was discovered that the copolymers of U.S. 4432881, when produced at certain high molecular weights, are water-insoluble as such and do not function as described therein even when a surfactant is present in amounts specified. Thus, the copolymers of said patent are actually limited to those having molecular weights such that they are water-soluble.
Applicants have discovered that useful thickening agents containing polymers having very high molecular weights, i.e, up to about 10 million can be produced in the absence of the surfactant indicated as essential by the patentees of U.S. 4432881. Thus, thickening agents containing polymers having very high molecular weights can be utilized, which polymers, when produced according to U.S. 4432881, do not function as described therein. The agents exhibit thermal stability, electrolytic tolerance and good resistance to shear.
The present invention is directed to a thickening agent which consists essentially of a water-soluble polymer having pendant hydrophobic groups and a water-soluble inorganic salt. When the thickening agent is dispersed in water, the viscosity of the water is substantially increased. Media containing the thickening agents of this invention can be subjected to substantial mechanical shear without significant loss of viscosity. The substantial viscosity increase is evidenced even when the aqueous media to which it is added contains significant concentrations of electrolyte such as in the case of hard water or brine. Consequently, the thickening agents hereof can be used for a variety of applications wherein high temperatures, substantial electrolyte concentrations and conditions of high mechanical shear, such as in high shear pumping of the aqueous medium, is required. The instant thickening agents are useful in all applications which require aqueous media having increased vicosity such as drilling mud formulations, fracturing fluids, fluid mobility control agents, aqueous solutions of inorganic salts, hydraulic fluids, lubricants, friction reducing agents, suspending agents, aqueous suspension of insoluble particulates such as paint formulations and the like.
The present invention also pertains to aqueous media containing an amount of the thickening agent hereof which is effective to increase the viscosity of the media.
In a preferred embodiment of the invention, the aqueous medium containing the thickening agent is a mobility control fluid useful in enhanced oil recovery operations. In the practice of this embodiment of the invention, the thickened aqueous medium is introduced through an injection well into a porous subterranean formation penetrated by said well and driven through the formulation through the producing well.
In further aspects of this invention, the thickening agent is employed in a drilling mud formulation or a fracturing fluid wherein the thickening agent is present in an amount sufficient to increase the viscosity of the formulation or fluid as desired.
The instant invention is directed to a water-soluble composition for thickening aqueous liquids consisting essentially of:
(A) a water-soluble thickening agent which agent consists essentially of:
a water-soluble polymer having pendant hydrophobic groups, said polymer being a terpolymer of two water-soluble ethylenically unsaturated monomers and a water-insoluble ethylenically unsaturated monomer having a hydrophobic group having at least 8 carbon atoms wherein,
(a) one water-soluble monomer is an ethylenically unsaturated amide,
(b) the other water-soluble monomer is an N-substituted derivative of an ethylenically unsaturated amide, an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated quaternary salt, a sulfoalkyl ester of an unsaturated carboxylic acid, an aminoalky ester of an unsaturated carboxylic acid, a diallylamine, a diallylammonium compound or a vinylaryl sulfonate and,
(c) the water-insoluble monomer is a higher alkyl ester of an α,β-ethylenically unsaturated carboxylic acid, an alkylaryl ester of an ethylenically unsaturated carboxylic acid, an N-alkyl ethylenically unsaturated amide, a vinyl alkyl ether or an an-alkyl styrene and,
(B) a water-soluble inorganic salt,
wherein the molecular weight of the terpolymer is such that, at the same concentration, a copolymer of only components (a) and (c) having the same molecular weight, is water-insoluble, the concentration of monomer (b) being replaced by an equal concentration of monomer (a).
For the purposes of this invention, the water-soluble polymer is one which forms the thermodynamically stable mixture when combined with water. These mixtures form spontaneously and include true solutions in which the individual polymer molecules are dispersed as well as micellular or colloidal solutions wherein the polymer molecules are aggregated to some extent, but wherein such aggregates are no larger than colloidal size.
The molecular weight of the water-soluble polymer is low enough such that an aqueous medium containing 0.1 weight percent of the polymer can be subjected to degree of shear on the order of 10,000 sec-1 without causing the polymer to degrade significantly. Moreover, the polymer has a molecular weight such that, when 0.5 weight part of the polymer is dissolved in 100 weight parts of water, the Brookfield viscosity of the water is increased to at least 2 centiposes (as measured using a Brookfield LVT viscometer equipped with UL adaptor and operated at 6 rpm and 25� C.). Preferably, the water-soluble polymers used in this invention have molecular weights (Mw), as determined by intrinisic viscosity measurements, in the range from about 2 to about 20 million, most preferably from about 5 to about 15 million.
The pendant hydrophobic groups of the water-soluble polymer are organic groups having hydrophobicities comparable to one of the following: aliphatic hydrocarbon groups having at least four carbons such as C4 to C20 alkyls and cycloalkyls; polynuclear aromatic hydrocarbon groups such as naphthyls; alkylaryls wherein alkyl has one or more carbons; haloalkyls of four or more carbons, preferably perfluoroalkyls; polyalkyleneoxy groups wherein the alkylene is propylene or higher alkylene and there is at least 1 alkyleneoxy nit per hydrophobic moiety. The concentration of hydrophobic moieties in the water-soluble polymer is that which is sufficient to increase the viscosity of an aqueous medium. Preferably, the concentration of hydrophobic groups in the polymer is such that, when one weight part of the polymer is dissolved in 100 weight parts of the aqueous medium, the Brookfield viscosity of the aqueous medium is twice that of an aqueous medium containing 1 weight percent of a hydrophillic polymer that is identical in all respects to the hydrophobic polymer except that the hydrophillic polymer contains no hydrophobic groups. For example, if an aqueous solution containing 1 weight percent of a copolymer of acrylamide and acrylic acid (hydrophillic polymer) has a Brookfield viscosity of 10 cps, the aqueous solution containing 1 weight percent of a suitable hydrophobic terpolymer, e.g., an acrylamide/acrylic acid/dodecyl acrylate terpolymer having Mw equivalent to the acrylamide copolymer, will have a Brookfield viscosity of at least 20 cps.
Exemplary water-soluble polymers include the terpolymers of water-soluble ethylenically unsaturated monomers with hydrophobic ethylenically unsaturated monomers wherein the concentration of hydrophobic monomer is sufficient to provide the requisite concentration of hydrophobic moieties. Preferably, the water-soluble polymer is a terpolymer from about 9% to about 99.995 mole percent of the combined monomers (a) and (b), described above, with from about 0.005 to 2 mole percent of one or more hydrophobic monomers. For the water-soluble terpolymers, it is found that preferred amounts of hydrophobic monomers will vary with the molecular weight of the polymer. For example, a water-soluble terpolymer having a molecular weight near 2 million, preferably contains from about 1 to about 2 mole percent of hydrophobic monomer. Alternatively, the water-soluble polymer having a molecular weight of 15 million preferably contains form about 0.05 to about 0.25 mole percent of hydrophobic monomer.
Suitable water-soluble monomers include those which are sufficiently water-soluble to form at least a 10 weight percent solution when dissolved in water and readily undergo addition polymerization to form polymers which are water-soluble. Exemplary water-soluble monomers identified as a), above, include ethylenically unsaturated amides such acrylamide, methacrylamide and fumaramide.
Suitable water-soluble monomers which are identified as (b), above, include N-substituted derivatives of an ethylenically unsaturated amide such as 2-acrylamide-2-methylpropane sulfonic acid N-(dimethylaminomethyl)acrylamide as well as N-(trimethylammoniummethyl)acrylamide chloride and N-(trimethylammoniumpropyl)methacrylamide chloride; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and fumaric acid. Ethylenically unsaturated quaternary compounds such as dimethylaminoethylacrylate methyl chloride salt, vinylbenzyl trimethyl ammonium chloride, sulfoalkyl esters of unsaturated carboxylic acids such as 2-sulfoalkyl methacrylate; aminoalkyl esters of unsaturated carboxylic acids such as 2-aminoethyl methacrylate; vinyl amines such as vinyl pyridine and vinyl morpholine, diallyl amines and diallyl ammonium compounds such as diallyl dimethyl ammonium chloride; vinyl heterocyclic amides such as vinyl pyrolidone; vinylaryl sulfonates such as vinylbenzyl sulfonate as well as the salts of the foregoing monomers. Of the foregoing (a) and (b) water-soluble monomers, combinations of acrylamide and acrylic acid are preferred. Acrylamide and combinations thereof with up to 75 mole percent of acrylic acid, based on total water-soluble monomer, are more preferred. Most preferred are polymers wherein the water-soluble monomer is a mixture of acrylamide with from about 5 to about 50 mole percent, especially from about 15 to about 30 mole percent, of acrylic acid.
Suitable hydrophobic monomers (c) are those which are water-insoluble, i.e, less than 0.2 weight part of the hydrophobic monomer will dissolve in 100 weight parts water. Exemplary hydrophobic monomers include the higher alkyl ester of α,β-ethylenically unsaturated carboxylic acids such as dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, the ethyl half ester of maleic anhydride, diethyl maleate, and other alkyl esters derived from the reactions of alkanols having from 8 to 20 carbon atoms with ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, itaconic acid and aconitic acid, alkylaryl esters of ethylenically unsaturated carboxylic acids such as nonyl-o-phenyl acrylate, nonyl-α-phenyl methacrylate, dodecyl-α-phenyl acrylate and dodecyl-α-phenyl methacrylate; N-alkyl, ethylenically unsaturated amides such as N-octadecyl acrylamide, N-octadecyl methacrylamide, N,N-dioctyl acrylamide and similar derivatives thereof; α-olefins such as 1-octene, 1-decene, 1-dodecene and 1-hexadecene; vinyl alkylates wherein alkyl has at least 8 carbons such as vinyl laurate and vinyl stearate; vinyl alkyl ethers such as dodecyl vinyl ether and hexadecyl vinyl ether; N-vinyl amides such as N-vinyl lauramide and N-vinyl stearamide; and ar-alkylstyrenes such as t-butyl styrene. Of the foregoing hydrophobic monomers, the alkyl esters of acrylic acid and methacrylic acid wherein the alkyl has from 8 to 20 carbon atoms are preferred. The alkyl acrylates wherein the alkyl has from 10 to 20 carbon atoms are more preferred. Dodecyl acrylate is the most preferred.
The aforementioned water-soluble terpolymers containing hydrophobic moieties are advantageously prepared by polymerizing the water-soluble monomers with the hydrophobic monomers by any conventional polymerization technique wherein the hydrophobic monomer or mixture of hydrophobic monomers is added with vigorous agitation to an aqueous solution of the mixture of water-soluble monomers. In the instances wherein the water-soluble monomers, as well as the hydrophobic monomer, are soluble in a neutral organic solvent, the water-soluble polymer can be prepared by any desired solution polymerization method wherein the neutral organic solvent is employed as the polymerization diluent. The most effective water-soluble terpolymers are prepared by copolymerizing the water-soluble monomers with the hydrophobic monomer in a molar ratio of water-soluble monomers: hydrophobic monomer in the range from about 98:2 to about 99.995:0.005, preferably from about 99:1 to about 99.9:0.1.
Polymerization of the water-soluble and hydrophobic monomers is advantageously effected in an aqueous medium containing an emulsifier for the hydrophobic monomer and a polymerization initiator capable of generating free-radicals. The emulsifier is required in most instances to suitably disperse the hydrophobic monomer and to subsequently obtain a terpolymer having a uniform composition. Optionally a chain-transfer agent may be included in the polymerization reaction mixture. Accordingly, it is desirable to employ from about 0.01 to about 0.1 weight percent of initiator, based on the monomers, and from about 0.1 to about 1 weight percent of emulsifier, based on the monomers.
Exemplary suitable polymerization initiators include the inorganic persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; azo catalysts such as azobisisobutyronitrile and dimethyl azoisobutyrate; organic peroxygen compounds such as benzyl peroxide, t-butyl peroxide, diisopropyl benzenehydroperoxide and t-butyl hydroperoxide.
Suitable emulsifiers include anionic agents such as alkali metal salts of alkyl sulfates and alkyl and aryl sulfates, e.g, dodecyl alkyl sulfosuccinates and sodium dodecylbenzene sulfate; fatty acid soaps, e.g., sodium oleate, sodium stearate and potassium oleate; alkali metal salts of sulfonated fatty alcohols, e.g, sodium dodecyl sulfate; sulfates of ethoxylated alcohols; alkyl phosphate esters, e.g., dodecyl hydrogen phosphate; fluoro emulsifiers, e.g., perfluoroalkyl sulfates; and the like. Also included are cationic emulsifiers such as alkylamine hydrochlorides, e.g., dodecylamine hydrochloride and tridecylamine hydrochloride; quaternary alkyl or aryl ammonium halides such as dodecyl trimethyl ammonium chloride; ethoxylated fatty amines and other emulsifiers as described in McCutcheon'Detergents and Emulsifiers, North American Edition, 1987 Annual. In general, when the water-soluble polymer is anionic or nonionic, an anionic emulsifier such as an alkali metal alkyl sulfate is preferably employed as the emulsifier. When the water-soluble polymer is cationic, a cationic emulsifier such as dodecylamine hydrochloride is employed. When the water-soluble polymer is nonionic, anionic or cationic, a nonionic emulsifier such as nonylphenoxy polyethylene glycol having 10 ethyleneoxy units per molecule is suitably employed.
The water-soluble terpolymers are readily recovered from the aqueous medium when such is desired by removal of water under vacuum or by azeotropic distillation. Alternatively, such terpolymers may be separated by the addition of methanol or anhydrous acetone to cause the water-soluble terpolymer to form a phase separate from the aqueous medium. As a further alternative, the aqueous medium containing the water-soluble terpolymer can be used as such.
It is also understood that water-soluble terpolymers of acrylamide, acrylic acid and hydrophobic monomer can be prepared by copolymerizing all three of these monomers or by copolymerizing acrylamide with the hydrophobic monomer and subsequently hydrolyzing a portion of the copolymerized acrylamide by contacting the copolymer with a base such as sodium hydroxide and/or sodium carbonate.
The thickening agent of the present invention is advantageously prepared by dispersing the water-soluble terpolymer in an aqueous medium under conditions such that it is uniformly distributed throughout the aqueous medium.
The amount of total thickening agent in the aqueous medium being thickened is sufficient to provide the desired increase in viscosity of the aqueous medium. Preferably, such amounts of thickening agent range from about 0.025 to about 5 weight percent, most preferably from about 0.5 to about 2.5 weight percent, based on the aqueous medium. In addition, to the thickening agent, the aqueous medium may contain a variety of other ingredients common to brines, fracturing fluids, drilling muds, paint formulations, lubricants, friction-reducing agents, suspending agents, liquid mobility control agents, hydraulic fluids and the like.
Of particular interest are the brines and other aqueous media containing salts of various metals. Such aqueous media often contain from about 0.01 to about 20 weight percent of salts of alkali metals and alkaline earth metals.
To increase the viscosity of an aqueous medium containing substantial amounts, e.g., up to about 5 weight percent, based on the aqueous medium, of monovalent inorganic salts such as sodium chloride and up to 1 weight percent, usually from 0.0015 to 0.5 weight percent, of salts of polyvalent cations such as calcium and magnesium, it is preferred to employ as the water-soluble terpolymer, a nonionic terpolymer of acrylamide, acrylic acid and a higher alkyl acrylate or methacrylate such as dodecyl methacrylate. The viscosity increase in this aqueous medium is retained at temperatures over the range from about 30� C. to about 80� C. In many instances, this viscosity increase is retained at temperatures substantially higher than 80� C.
The following examples are set forth for purposes of illustration only and are not to be construed as limitations on the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise indicated.
A solution containing 74.93 parts of 50% acrylamide, 7.5 parts of sodium dodecyl sulfate, 0.225 part (0.1 mole % on acrylamide) of lauryl acrylate, 7.5 parts of a solution containing 16.0% of acetic acid and 2.0% of pentasodium diethylenetriamine pentaacetate and 655 parts of water is deoxygenated at room temperature by sparging with nitrogen for 1 hour. The solution is then heated to 40� C. and 0.113 part of 2,2'-azobis(2-amidinopropane)hydrochloride catalyst added to initiate polymerization The resulting polymer gel is allowed to exotherm to 59� C. This temperature is maintained for 16 hours. A sample of the gel is then cut into small pieces, ca 1/8". Polymer gel disperions (0.1%) are prepared in (a) plain water and (b) in 1% surfactant solution (lauryl ether of polyoxyethylene EO=35, HLB=16.9) by adding the required amount of cut gel to a measured volume of stirred aqueous solution. It is found that the polymer does not dissolve to any extent in plain water, even after many days of stirring at room temperature, the polymer remaining as clear gel particles. However, the polymer does dissolve in the surfactant solution, giving a viscous solution (Brookfield viscosity is 3.4 mPa.s, at 25� C., 60 rpm). Addition of 1N NaCl gives a solution with a Brookfield viscosity of 4.0 mPa.s. No insoluble gel particles are observed.
A solution containing 8.98% of acrylamide, 1.01% acrylic acid, 1.0% sodium dodecylsulfate, 0.0227% (0.1 mole % on monomers) of lauryl acrylate, 1.2% acetic acid and 0.02% of pentasodium diethylenetriamine pentaacetate is sparged with nitrogen to <0.3 ppm of residual oxygen. After heating to 42� C., 2,2,'-azobis(2amidinopropane)hydrochloride catalyst (1550 ppm on monomers) is added to initiate polymerization. After the reaction mixture is allowed to exotherm to 68� C., the gel is placed in an oven at 68� C. for 16 hours. This product is then dissolved in either plain water or surfactant solution as described in Example 1, above. The pH of the final solution is adjusted to 7-8 by addition of sodium hydroxide solution (0.1N).
In Examples 3-19, the above procedure is followed except that the monomers and/or their concentrations are varied to give the results indicated.
All of the polymers described in Examples 2-19 are found to be totally soluble in both plain water and surfactant solution Brookfield viscosities are shown in Table 1.
TABLE 1__________________________________________________________________________HYDROPHOBICALLY MODIFIED ANIONIC COPOLYMERS Viscosity mPa.s1AMD2 LA3 AA4 SAPS5 Without With6Examples(mole %) (mole %) (mole %) (mole %) Surfactant Surfactant__________________________________________________________________________2 79.9 0.1 20.0 -- >50 4.63 80.0 0 20.0 -- 5.6 5.34 89.9 0.1 10.0 -- >50 5.25 90.0 0 10.0 -- 5.1 4.96 69.9 0.1 30.0 -- >50 5.17 70.0 0 30.0 -- 5.5 5.48 59.9 0.1 40.0 -- 30 4.69 60.0 0 40.0 -- 4.0 3.910 89.9 0.1 -- 10.0 22 4.711 90.0 0 -- 10.0 6.0 5.812 79.9 0.1 -- 20.0 13.0 5.213 80.0 0 -- 20.0 5.4 5.314 69.9 0.1 -- 30.0 12.5 5.615 70.0 0 -- 30.0 5.5 5.316 59 0.1 -- 40.0 10.6 6.217 60.0 0 -- 40.0 5.3 5.0__________________________________________________________________________ Polymer Concentration = 1000 ppm (c) comparative .sup. 1 Brookfield Viscosity (60 rpm) at 25� C. in 1M NaCl 2 Acrylamide 3 Lauryl Acrylate 4 Acrylic Acid 5 Sodium 2acrylalamido-2-methylpropanesulfonate 6 Polyoxyethylene ether of lauryl alcohol = 2000 ppm
TABLE 2______________________________________EFFECT OF SURFACTANT CONCENTRATION ONSOLUTION VISCOSITY Viscosity at 25� C.Polymer of Surfactant(ppm)1 (mPa.s)2______________________________________Example 2 0 11 1 5 10 3.6 50 2.7 100 2.6 200 2.6Example 3 0 2.7 200 2.6______________________________________ Polymer Concentration = 500 ppm 1 Brij 35 2 Brookfield Viscosity (60 rpm) in 1M NaCl
TABLE 3______________________________________HYDROPHOBICALLY MODIFIED CATIONICCOPOLYMER Viscosity mPa.s1 Cationic3 Without2 WithExample AMD LA Monomer Surfactant Surfactant______________________________________18 79.8 0.2 20.0 165 1919 80.0 0 20.0 13 12______________________________________ Polymer Concentration = 2500 ppm 1 Brookfield Viscosity (3 rpm) at 25� C. in M NaCl 2 2000 ppm polyoxyethylene ether of lauryl alcohol 3 Methyl chloride of dimethylaminoethylacrylate, mole %
It is well known that homopolyacrylamide (PAM) is very soluble in water giving viscous solutions. The results described in Example 1 show that hydrophobic modification causes insolubilization of PAM, most probably because intramolecular association of hydrophobic groups causes cross-linking of polymer chains. Hydrophobically modified PAMs would not therefore be useful as thickening agents when used alone. As shown in Example 1, these polymers are however, soluble in aqueous surfactant solution since surfactants tend to associate with the hydrophobic groups thereby destroying the insolubilizing crosslinks. However, the viscosity was found to be quite modest when compared to those obtained with the polymers of this invention--see Table 1, Examples 2,4,6,8,10,12,14,16.
Unexpectedly, it has been found that hydrophobically modified acrylamide terpolymers (HTERPs) containing ionizable groups such as acrylic acid are readily soluble in water containing no added surfactant, resulting in highly viscous aqueous solutions. It has thus been discovered that HTERPs do not require additional surfactant to effect solubility. Furthermore, it has been found that added surfactant has a detrimental effect on the viscosifying power of HTERPs. This is clearly shown in Table 1.
In the absence of added surfactant, the HTERPs are much more effective thickening agents than the unmodified copolymers. In the presence of added surfactant the HTERPS have the same solution viscosity as the umodified copolymers. Table 1 shows that the effect is general for both acrylate and sulfonate containing HTERPs.
By further way of illustration, Table 2 shows that extremely small levels of added surfactant have a detrimental effect on the viscosifying power of HTERPs reducing solution viscosity to the same values as are obtained with unmodified copolymers.
Table 3 shows that cationic HTERPs are also effective thickening agents.
Patent Citations
Referenced by
Legal Events
Original Image


text:
Minnesota Set to Begin Spring Season
The Gophers will travel to NDSU on Saturday for first spring contest
Three Gophers Earn B1G Postseason Honors
Roberts, McCloskey and Larrick earn conference awards
Minnesota Drops to Wisconsin, 4-1
Taylor Wodnick scores the Gophers lone goal in 4-1 loss to Wisconsin
Wodnick Scores Golden Goal in 2OT
Senior Taylor Wodnick scored the golden goal to lift the Gophers over Illinois
Gopher Spotlight: Rachel McCloskey
Gophersports.com caught up with the freshman midfielder before the Nebraska game
2014 SEASON: 14gp, 3g, 0a, 6pts, 14sh, 4sog
Started in fourteen of the Gophers' twenty-one games as a freshman First career appearance in Gophers 10-0 victory over Stetson (8/22) Scored first career goal in first game of the season Recorded second goal of the season in Gophers 3-1 loss to Auburn (9/7) Broke Auburn's 300 minute shutout streak Six points on the season Fourteen shots on the season, four of those on target Scored equilizer in Michigan loss (9/12) Two straight games to avoid shutout (9/7 and 9/12) Named to the 2014 Big Ten All-Freshman Team.
Rounding out the recruiting class is Rachel McCloskey who joined the Gophers in January after graduating early from Southeast Polk High School in Iowa. Her club team, Iowa Rush, made several trips to the Iowa State Cup. She also played varsity basketball and was an honor student. She will practice with the team in preparation for the 2014 season.
"Rachel McCloskey is already here this semester, and she has transitioned to life as a student-athlete extremely well," said Coach Golan. "We are excited for an extra semester of work with her as she is someone who can play for us as a center back, outside back, or defensive midfielder right away. She came in fit and technically sound, and is now adjusting to the speed of play required at our level. She will do well here."
More Headlines
5/26/2015Gophers Announce 2015 Schedule
4/2/2015Gophers to Host Free Clinic
2/4/2015Gophers Sign Six for 2015
1/28/2015Golan Names Stoots to Coaching Staff
12/10/201415 Gophers Named Academic All-B1G
11/17/2014M.A.G.I.C. Visits Edgerton Elementary
11/07/2014Gophers Fall in Semifinals
11/06/2014Gophers Upset No. 25 Michigan, 1-0
11/01/2014Gophers Fall in Season Finale
10/26/2014Minnesota Upsets No. 16 Rutgers
10/24/2014Gophers Shutout Terps, 1-0


text:
Beyonce Knowles takes the "Mrs. Carter Show" world tour to the LG Arena in Birmingham, UK on Apr. 26, 2013.
Not only does Eva Longoria have a killer bod, but she wants to be exactly like George Clooney. …
She's ready for the summer!
Work it, girl.
Mariah Carey, her boobs and her new beau James Packer, aka the fourth richest man in Australia, took their love to Ibiza, Spain where they gallivanted on a yacht with her kids.


text:
On June 22, 2015, Keswick's CEO Carmel Roques was featured in the Maryland Daily Record's article "Health Care Nonprofits Launch Program for Seniors to Stay Healthy and at Home". This program allows Keswick to expand its efforts and help seniors stay in their homes as long as possible. A team of community health workers stay in close touch with patients to make sure they have what they need once they leave a facility. This program is further bolstered by its partnership with Action in Maturity (AIM) and Goven's Ecumenical Development Corporation (GEDCO).
Keswick Welcomes James Warner Executive Director and Nursing Home Administrator of Record
Keswick, a Baltimore healthcare provider for older adults, announced the appointment of James Warner. Warner will serve as the organization's Executive Director and Nursing Home Administrator of Record.
"Jim brings extensive experience in executive and staff leadership at every level within a medical facility and has the unique ability to connect with all audiences," said Carmel Roques, President and CEO of Keswick. "He will be highly effective in leading the day-to-day operations at Keswick and working together with staff and leadership in providing our on-campus services."
In his new role, Warner will be responsible for operations for the facility's long-term care, rehabilitation and assisted living services. Keswick serves more than 1,000 persons annually on its 40th Street campus (and 755 more within its Community Health Resources branch). – Read More
Keeping memories sharp while aging…WMAR TV features Keswick's art program
You're In Charge…Brain Health!
Keswick's Brain Health program offerings inspire, educate and create opportunities for YOU to enhance your brain power! Explore new interests and engage in brain fitness practices that contribute to overall well-being. The Mind-Body Connection focuses on key component for improved Brian Health. Recharge Your Brian! Grow New Brian Pathways! Have Fun!
Hospice 101 For Families and Caregivers
Learn how proper planning now can protect you and your family in the years to come.
Surprisingly, many people still don't know what hospice is, and others have misconceptions about what hospice does. This workshop will inform you about how hospice can help patients live with grace and dignity and support the family as they find the courage to move forward after loss.
PRESENTER: Regina Bodnar, RN, MS, MSN, CHPCA, Gilchrist Hospice Care
Join us for this FREE community event and learn about the plans all adults should have in place to make sure their wishes are followed and their assets are protected. Bring your family, and learn how to achieve peace of mind about what the future holds.
Light hors d'oeuvres & beverages will be provided.
RSVPs are encouraged: email@example.com or call 410.662.4346
Keswick has teamed up with Gilchrist Hospice Care to bring this series of informative discussions to the members of our community.


text:
Wakalat Street
From Wikipedia, the free encyclopedia
Wakalat Street (Arabic: شارع الوكالات) sometimes spelled as Al-Wakalat Street, is a street in Amman, Jordan, in the district of Sweifieh. The street was rehabilitated in 2007. The project included paving the street, planting trees, and regulating commercial signs. The idea of the rehabilitation of the street was to create a place in Amman where pedestrians would walk safely and freely away from traffic. With its completion Amman had finally gained its very first first-rate pedestrian public space. Before the completion of the project, the street used to allow parking, and cars driving through. [1]
|This Jordanian road or road transport-related article is a stub. You can help Wikipedia by expanding it.


text:
This plugin allows you to use Jambopay Online Payment Gateways on your Woocommerce store via Mpesa, VISA Cards, Mastercards, Airtel Money, Kenswitch a
No reviews yet! Be the first to review this plugin!
You must log in to submit a review. You can also log in or register using the form near the top of this page.


text:
1994 Chevrolet S10 Blazer Q&A
1994 Chevrolet S10 Blazer Question: Heater Core Replacement
How hard is it to replace the heater core for my 94 Blazer and what do i need to remove to get to it? - Visitor
2 Answers
Answer 1
this is a very difficult and time consuming project, you will have to remove most of the dashboard and the right front fender to get to the heater core, unless you have the time and handyness to do this i would suggest taking it to a mechanic. - hollander62292
Answer 2
It is a big pain in the behind. I don't know who designed the 94 Blazer but it seems that they deliberately made it to where you will have to take it to a mechanic to fix it. I replaced mine and you have to take off so much stuff, pull the dash out, prop it up with something to hold the dash up and you will bust your knuckles trying to get all the screws and bolts out. I put the core cover back on and just put one screw in to hold it on because there are a bunch of screws you have to take off. Cheapest estimate I could find was about $250 dollars to do it. - stonecoldsteele
Related Items:
The heater core under the right side of the dashboard may leak engine coolant which can puddle on the passenger front floor. The loss of coolant may cause an engine overheating condition. Our tech...
Related Content
1. pushrod
2. stevieray1
3. globalhelper
4. Shivers
5. csubak30
6. ziptie12
7. Hal...
8. IsraelS
9. goodguy
10. BrianLankford


text:
Department of Bust Out Profit Models and Vampiric Capitalism
Return of the Coin?
The last few weeks have seen at least two posts calling attention to the potential use of the platinum coin in America's political economy. The first to appear was Rob Urie's piece in Counterpunch provocatively titled: "The Trillion Dollar Catshit Coin" And the second was Mike Sandler's post in The Huffington Post called "Greece and the U.S. Senate: Economics for the 99%.
Let's begin looking at these with Sandler's effort. He reports on two challenges to austerity. The first is from Syriza's victory in Greece and its promise to Greek voters that it will end austerity. The second:
The austerity mindset faces a new foe in the U.S. Senate as well. The re-shuffle of the last U.S. election that put austerity-minded Republicans in power has ironically resulted in a new anti-austerity economist being hired by Senator Bernie Sanders (I-VT) in the Senate Budget Committee -- Professor Stephanie Kelton of the University of Missouri-Kansas City. Professor Kelton is a proponent of Modern Monetary Theory (MMT), a very pro-stimulus economic approach. Her hiring represents the biggest step forward for MMT, since the PR coup of the Trillion Dollar Platinum Coin in 2013. At that time, Kelton reportedly created the #mintthecoin hashtag that was featured in columns by Paul Krugman and others.
Sanders' hiring of Kelton is a break from the more conciliatory "balanced budgeting" approach of some Democrats, such as former treasury secretaries with ties to Wall Street and fiscally-conservative "deficit hawks." Kelton and her MMT colleagues go beyond the traditional Keynesian stimulus of short-term deficit spending. They seek to unleash the power of monetary policy to circumvent the scarcity mindset imposed on government action, perhaps even bringing the Trillion Dollar Coin back into the discussion.
Of course, Sandler means to say fiscal policy in the above, since MMT economics greatly favors reliance on fiscal, rather than monetary policy, in spite of the "monetary" in its name. But apart from that, he projects that we may see the platinum coin come back into prominence soon. Read more about Return of the Coin?
- letsgetitdone's blog
- 6 comments
- Log in or register to post comments
Obama Budget 'Partisan-Gridlock' Fake-Out!
Andre Damon in "Obama's 'pro-middle class' budget: Cut corporate taxes, raise military spending, slash Medicare" calls out Obama's supposed populist, legacy-saving, proposed fiscal budget for 2016 and the NYT's propagandizing of it as an "unfettered case for spreading the wealth."
More Obama and corporate media bullshit. What else is new?
Damon: Read more about Obama Budget 'Partisan-Gridlock' Fake-Out!
- libbyliberal's blog
- 5 comments
- Log in or register to post comments
Major 'Mayor-de-Blasio-FAIL' re NYC Homelessness & Housing
Philip Guelpa in "New York City's housing and homelessness crisis intensifies under de Blasio" offers some very troubling statistics and analyses. Bill de Blasio, NYC Democratic mayor, has been in office a year now and the enormous problems of homelessness and unaffordable housing are worsening even from the "12-year-mayoral-tenure" of billionaire Mike Bloomberg.
Here are 15 serious considerations from Guelpa's report and analysis: Read more about Major 'Mayor-de-Blasio-FAIL' re NYC Homelessness & Housing
- libbyliberal's blog
- 3 comments
- Log in or register to post comments
A Technological Fix for Failing Democracies
Dysfunctional democracies are provoking anger, confrontations, crises and conflicts for the following reasons:
- In many cases, the citizens of dysfunctional democracies are unable to decide who runs for office, who gets elected and what laws are passed because of obstacles erected to prevent them from doing so.
- Several of these obstacles, for example election laws in the U.S., result in the election of lawmakers, such as those who control the U.S. Congress, who represent only a minority of eligible voters and pass legislation that rarely represents the will of a majority of voters.
- According to extensive research, special interests, wealthy individuals, corporations and financial institutions tend to exert greater influence than voters over lawmakers' legislative actions because they finance lawmakers' electoral campaigns.
- Rogue lawmakers whose actions are not controlled by their constituents but by influential groups and wealthy campaign funders are contributing to the creation of increasing inequalities of wealth that enable a small percent of the population to acquire most of their nation's wealth, while the rest of the population has little or no wealth and few if any opportunities to create wealth.
- Undemocratic political parties that control electoral machinery and do not allow competitive parties to take root prevent voters from setting party agendas and nominating and electing candidates of their choice, increasing the legislative disconnect between voters' and lawmakers' priorities.
- letsgetitdone's blog
- 2 comments
- Log in or register to post comments
The Technology Solution to the Democracy Crisis
The spectacular intrusion of special interests into the passage of the $1.1 trillion government spending bill on December 13, 2014 was breathtaking as bankers and lobbyists whipped the vote by calling Congressional representatives directly to demand a host of special interest provisions, including the following:
- Repealing the Dodd-Frank prohibition on locating derivatives trading activities in the same bank subsidiary company as their depositories containing checking, savings, and other accounts insured by the FDIC.
- Raising individual campaign contribution limits by roughly 10 times the present limit.
- Allowing businesses to default by as much as 1/3 of their private pension obligations.
- Preventing the EPA from introducing new climate protections.
So it is now abundantly clear that what we have is government by minority rule in which special interests reign supreme. Clearly, this cannot continue. It is for this reason that we are sharing the post below describing the only solution to the democracy crisis of which we are aware that can be implemented in the near future. It is long and we do not expect many readers to get through it in one sitting, or even at all. But if it piques your interest, you can re-locate it here at a more opportune time.
Technical Features of the Interactive Voter Choice System (U.S. Patent No. 7,953,628)
Accelerating the Technological Evolution of Democracies
Group Forming Network
World's First Large Scale Consensus Building and Conflict Resolution Platform
A Closer Look at Complex Adaptive Systems (CASs)
Integrating IVCS-Enabled CASs into Electoral and Legislative Processes
Summary and Conclusion Read more about The Technology Solution to the Democracy Crisis
- letsgetitdone's blog
- 16 comments
- Log in or register to post comments
A Credibility Problem?
President Obama's remarks to the Business Roundtable on Trade raise alarm bells for us all, and suggest that he is still pushing his pro- 1% agenda for all it is worth. Perhaps it would be better if Congress just treated him as a lame duck from here on in. Here are a number of statements from his talk and answers to questions, and my comments on them. Read more about A Credibility Problem?
- letsgetitdone's blog
- 2 comments
- Log in or register to post comments
The Way Out of Shutdown Shenanigans
Today I received an e-mail from the Friends of (the very popular with progressives) Senator Bernie Sanders. In it the Senator says:
I'm joining with the members of Progressives United to send a clear message to President Obama that we will stand with him when he vetoes Republican legislation that attacks the well-being of the struggling middle class.
Join me and members of Progressives United to urge the president to VETO any Republican legislation that attacks working families.
- letsgetitdone's blog
- 13 comments
- Log in or register to post comments
Why Democrats Lost: It's Not All About Millennials
Carl Gibson, a writer blogging at Reader Supported News, provides an "Open Letter to the Democrats" giving his view of why they lost the Congressional Elections of 2014. He endorses the President's view that people didn't show up to vote because their choice of politicians didn't motivate them. And to this view he adds that the Democrats did not get his generation's support because they didn't ". . . get populist." And he goes on to say:
2014's low voter turnout was historic. Voter turnout actually hasn't been this low since the 1940s. As Mother Jones pointed out, voter turnout for people under 30 was dismal. In this election, people like me only made up 12 percent of those who voted, while people aged 60 and older made up almost 40 percent of total voters. In 2012, when President Obama was re-elected and Congressional Democrats made gains in the House and Senate, millennials made up almost one-fifth of all voters, and voters 60 and older made up just 25 percent of the electorate, bringing us a little closer to a tie. It isn't hard to see the difference – this year, Republicans steamrolled you, Democrats, because most of us stayed home and let our Fox-watching uncles and grandparents decide on who was going to represent everyone else.
So how do older people pick who runs Congress? Like every other voting bloc, they pick the ones who run on issues most important to them. And as Vox reported, data consistently shows that younger people want their tax dollars spent on education and job creation. Older voters want their money spent on Social Security and war. The Republicans who swept the U.S. Senate ran largely on fear campaigns over ISIS, promising to be more hawkish than their opponents in an eagerness to pour money and troops into Iraq and Syria to snuff out America's newest boogeyman.
Contrast the unified Republican message with the profound silence from you Democrats on addressing the trillion-dollar student debt crisis, rampant inequality and underemployment, and your collective fear of openly embracing economic populism, and you cook up what we saw on Tuesday night. Older people showed up, highly motivated to elect war hawks. Younger people mostly stayed home, disillusioned with the only alternative on the ballot who didn't even talk about the issues affecting our lives every day.
- letsgetitdone's blog
- 10 comments
- Log in or register to post comments
Elizabeth Warren: Better, But Not there Yet
In her recent post-election piece "It's Time to Work on America's Agenda" Elizabeth Warren points out that the changes in Washington and in various States aren't changing the fact that
The stock market and gross domestic product keep going up, while families are getting squeezed hard by an economy that isn't working for them.
- letsgetitdone's blog
- 2 comments
- Log in or register to post comments
Libya Today, If Any Americans Remotely Care
It always resonates the pace of "Lucy and the chocolate factory" manic-ness, US-government, often with NATO, produced chaos and misery around the world, not to mention the chaos and misery from our own government on us domestically.
We collectively are easily numbed out by the "velocitization" of global and domestic tragedies our government is responsible for, though that responsibility rarely is dwelled upon if admitted to by a colluding and propagandizing mainstream media. Read more about Libya Today, If Any Americans Remotely Care
- libbyliberal's blog
- 2 comments
- Log in or register to post comments
Piketty's Neoliberal Capital
Let's get this out of the way. I agree with Piketty's overall conclusion in Capital about inequality, that: the distribution of wealth in many industrial nations is highly unequal, wealth concentration has been increasing; and there is a high likelihood that the extent of wealth inequality will continue to grow unless appropriate fiscal policy is used to reverse current trends. However, I don't agree with:
-- the framework he uses to define and specify "capital";
-- the way he looks at Government finance and net worth; and
-- the fiscal policy proposals he offers to reduce Inequality and put a stop to current trends of growth in the capital to income ratio. Read more about Piketty's Neoliberal Capital
- letsgetitdone's blog
- Log in or register to post comments
Cantor Repeats the Same Old Nonsense: Shows He Hasn't Learned A Thing From Defeat
Eric Cantor weighed in today at Quora on the balanced budget Amendment. This is what he said:
Once created, government programs build constituencies of special interests determined to keep the money flowing, whether or not the particular program is effective. There have been many times when the House has placed wasteful and duplicative programs on the chopping block, only to see pressure from the spending lobby win the day in the Senate.
Near-term spending cuts are necessary to alter the course, but they will not be enough without long-term changes. Likewise, promises of cuts 10 years from now mean little without a way to enforce them. The only way to truly guarantee delivery from future elected officials is for the Constitution to demand it.
To that end, the House has scheduled a vote on a balanced budget amendment that would require supermajorities in both chambers to run a deficit, raise the debt ceiling, raise taxes and spend more than 18% of the GDP. With the balanced budget movement gaining momentum, members of the spending lobby want to argue that Congress and the President already have the ability to control spending. Ability and discipline are not the same. If Washington actually had the discipline to live within its means over the long-term, every American citizen would not owe $46,000 toward the national debt.
In my view, the importance of these upcoming votes cannot be overstated. The adoption of a Balanced Budget Amendment would make reckless borrowing a thing of the past, and will ensure that our children enjoy futures full of opportunity.
Democrats and Republicans should join together to do the right thing, pass this amendment, and make a real difference for the future of our country.
- letsgetitdone's blog
- Log in or register to post comments
Beware of Policies and Legislation Based on the Generational Accounting Scam
The Peter G. Peterson Foundation (PGPF) and its allied army of associated deficit hawks want the Congressional Budget Office (CBO), the General Accountability Office (GAO), and the Office of Management and Budget (OMB) to do fiscal gap accounting and generational accounting on an annual basis and, upon request by Congress, to use these accounting methods to evaluate major proposed changes in fiscal legislation. Generational Accounting is an invalid long-range projection method that doesn't take into account inflation, the projected value of the Government's capability to issue fiat currency and reserves in the amounts needed to fulfill Congressional appropriations, and re-pay its debts, the projected non-Government assets corresponding to government liabilities, the likely economic impacts of Government spending, surpluses, and deficits, the impact of accumulating errors on projections, and the biases inherent in pessimistic AND contradictory assumptions. It is a green eye shade method that ignores both economic and political reality.
If you want America to end deficit terrorism and austerity, and to have the fiscal policy space it needs to begin to restore the American Dream, then you need to defeat proposed policies or legislation which puts building blocks in place to bias fiscal policy towards austerity and the economic decline it will surely produce for ourselves, our children, and for their children. Proposed policies and legislation of this kind must be defeated for the following seven reasons. Read more about Beware of Policies and Legislation Based on the Generational Accounting Scam
- letsgetitdone's blog
- 4 comments
- Log in or register to post comments
Yes We Can Pay for Increasing Social Security Benefits
Some time ago, in the pages of USA Today, Duncan Black, better known to some as Atrios voiced the immediate need for increased Social Security benefits of 20% or more even if it means raising taxes on high incomes, or removing the payroll tax cap on salaries.
Black is right about the need for increased benefits; but legislating that increase doesn't require increasing taxes. In fact, Congress should both increase benefits and remove the payroll tax entirely.
But how is that possible without greatly increasing "the national debt"? The answer to that one is easy. Don't tax or borrow to pay for it. Just mint a single one oz. platinum coin at the beginning of each fiscal year with a face value large enough to cover expected the cost of SS payments. Doing it that way will both take care of retirement needs and also provide a huge shot in the arm for employment, since the increase in Social Security benefit payments and the ending of the payroll tax won't be offset by tax increases elsewhere that will depress aggregate demand. Read more about Yes We Can Pay for Increasing Social Security Benefits
- letsgetitdone's blog
- Log in or register to post comments
Inequality, MMT, Real Fiscal Responsibility, and Re-inventing Democracy
- letsgetitdone's blog
- 3 comments
- Log in or register to post comments


text:
Tuesday 7th July 2015.
Full price tickets : £7.80, concessions available.
Wednesday 8th July 2015.
Full price tickets : £12, concessions available.
Thursday 9th July 2015.
Full price tickets £10.
Running from Friday 10th July 2015.
Full price tickets : £8.50.
It's a pleasure to work on this brilliant play. Written by Michael Snelgrove "Bums" is, as the title suggests, a hilarious take on everyday life working in the theatre. The "Usherettes" (resting actors) are our guides throughout the evening. ...
Owing to upgrades to Bracknell's water supply, Ringmead (from SHP to just past Herondale) will be closed from August to November. Leave extra time and approach SHP from Crowthorne Road / Mill Lane end. Diversions will be in place.
Please note that our kitchen will be closing for essential routine maintenance on Wednesday July 1 at 3pm. There will be no food served beyond that time, but the bar will still be open for drinks.
Join @sbutlerbooks author of The Diary of Dennis the Menace this Sat for fun and games! #Beano southhillpark.org.uk/events/d… pic.twitter.com/MLnMlT9y8L
|Monday to Saturday
|9:00am to 11:00pm
|Sunday & Bank Holidays
|11:00am to 10.30pm
|Monday to Saturday
|10:00am to 8:00pm
|Sunday & Bank Holidays
|12:00pm to 8:00pm
+44 (0)1344 484 123


text:
A single mode optical fiber comprises a core, a first cladding surrounding the core, and a second cladding surrounding the first cladding. It also comprises a third cladding region (or index "ring"). The core, has radius a and refractive index nc, the first, second, and third cladding regions have inner radii, R1i, R2i, and R3i, outer radii R1o, R2o, and R3o, and indices n1, n2, n3, respectively. The fiber has n1 <n3, R1o ≦R3i, R3o ≦R2i. In preferred embodiments, a=R1i, R1o =R3i, R3o =R2i. Appropriate choice of ring parameters can result in a lowering of the cut-off wavelength of the fiber, or in fiber that is less sensitive to macrobending than similar prior art fiber lacking an index ring, without substantial change in fiber parameters that depend primarily on the waveform in the core. An optical fiber communications system comprising the inventive fiber is also disclosed.
1. Optical fiber adapted for guiding electromagnetic radiation, guided radiation comprising a LP01 mode and, possibly, a LP11 mode, the fiber being a single mode fiber for electromagnetic radiation of an operating wavelength, the optical fiber to be referred to as the first fiber, the first fiber comprising
(a) a core region having an equivalent radius a and an equivalent maximum refractive index nc ;
(b) a first cladding region surrounding the core and having an equivalent outer radius R1o, an equivalent inner radius R1i, and an equivalent refractive index n1, with n1 <nc ; and
(c) a second cladding region surrounding the first cladding region and having an equivalent inner radius R2i and an equivalent refractive index n2, with n2 ≧n1 ;
characterized in that
the first fiber further comprises a third cladding region having an equivalent inner radius R3i, an equivalent outer radius R3o, and an equivalent refractive index n3, with R3o ≦R2i, R1o ≦R3i, and n3 >n1 ; wherein n3, R3i and R3o are chosen such that
(d) at R3i the square of the amplitude of the LP01 mode is at most 10-5 of the square of the amplitude of the LP01 mode at the center of the core, for radiation of the operating wavelength of the optical fiber;
(e) at R2i in the first fiber, the square of the amplitude of the LP11 mode is at least 50% larger than the square of the amplitude of the LP11 mode in a second fiber at a radius equal to R2i, the second fiber being identical to the first fiber except that in the second fiber R3i =R3o, the third cladding region thus being absent in the second fiber, the second fiber having a cut-off wavelength, the squares of the amplitudes being compared at the cut-off wavelength of the second fiber; and
(f) at R2i and at the operating wavelength, the square of the amplitude of the LP01 mode in the first fiber is at most 50% larger than the square of the amplitude of the LP01 mode in the second fiber, at the same wavelength and the same radius.
2. Fiber of claim 1, wherein R3o =R2i.
3. Fiber of claim 2, wherein R1i =a, and R1o =R3i.
4. Fiber of claim 3, wherein n1 <n2.
5. Fiber of claim 4, wherein R3i ≧4a.
6. Fiber of claim 5, wherein n1 <n3 <n2.
7. Fiber of claim 6, wherein 0.1Δ- ≦h≦0.75Δ-, with h=(n3 2 -n1 2)/(n2 2 -n1 2), and Δ- =(n2 2 -n1 2)/2n2 2.
8. Fiber of claim 7, wherein R3o -R3i ≧a.
9. Fiber of claim 7, wherein R2i /a≧6.5.
10. Fiber of claim 4, wherein the first fiber is a silica-based fiber, and at least the first and the third cladding regions comprise fluorine.
11. Fiber of claim 10, wherein the core comprises an element selected from the group consisting of Ge, Al, and P.
12. An optical fiber communication system comprising optical fiber according to claim 1, and further comprising a source of electromagnetic radiation of wavelength substantially equal to the operating wavelength, means for coupling the radiation into the optical fiber at a first fiber region, and means for detecting radiation emitted from the fiber at a second fiber region spaced from the first fiber region.
13. System according to claim 12, wherein R3o =R2i, R1i =a, R1o =R3i, nc ≧n2, n1 ≦n2, and n1 <n3.
14. System according to claim 13, wherein 0.1Δ- ≦h≦0.75Δ-, with h=(n3 2 -n1 2)/(n2 2 -n1 2), and Δ- =(n2 2 -n1 2)/2n2 2, and R3o -R3i ≧a.
15. System according to claim 14, wherein R2i /a≧6.5.
16. System according to claim 15, wherein n1 <n2.
17. System according to claim 12, wherein at least the first and the third cladding regions comprise fluorine.
18. System according to claim 12, wherein the core comprises an element selected from the group consisting of Ge, Al, and P.
19. System according to claim 12, wherein at R2i and at the cut-off wavelength of the second fiber, the square of the amplitude of the LP11 mode in the first fiber is at least 100% larger than the square of the amplitude of the LP11 mode in the second fiber, at the same wavelength and the same radius.
20. System according to claim 19, wherein at R2i and at the operating wavelength, the square of the amplitude of the LP01 mode in the first fiber is at most 10% larger than the square of the amplitude of the LP01 mode in the second fiber, at the same wavelength and the same radius.
This invention pertains to optical fiber, and to a communications system comprising such fiber.
Although optical fiber communications is a relatively young field, it has reached by now a high level of sophistication. For instance, single mode optical fiber that permits repeater spacings of the order of 30 km and transmission rates of the order of hundreds of megabits/seconds is now available.
Almost all currently used high performance optical fiber is silica-based fiber (comprising more than 50% by weight, typically more than 80%, of SiO2) typically with a core region having a relatively high refractive index, surrounded by one or more cladding regions of lower refractive index than the core. The indices are raised or lowered, relative to the refractive index of silica, by means of dopants. As is well known, Ge, Al, and P, for instance, raise the refractive index of silica, whereas F and B lower it. Methods for producing optical fiber are well known to those skilled in the art and need no review here. See, for instance, U.S. Pat. No. 4,217,027.
Single mode optical fiber, i.e., optical fiber in which only the fundamental mode (to be designated herein LP01) of electromagnetic radiation of wavelength equal to the operating wavelength of the fiber propagates with low loss, can have a variety of known index profiles. Typically, the core region and the surrounding cladding region consist of high purity deposited glass material, which is frequently surrounded by a further cladding region consisting of glass derived from a frequently much less pure silica substrate or sleeve tube. The core region typically has a refractive index that is greater than, or at least not less than, that of pure silica, and the deposited cladding region immediately surrounding the core typically has a refractive index that is equal to or less than that of pure silica. The normalized difference between the core refractive index and the refractive index of the cladding region immediately surrounding the core, often designated Δ, is typically of the order of 1% or less. For instance, in a commercially available single mode optical fiber, the core has an effective diameter of about 8 μm, and Δ of about 0.40%. In that fiber, the deposited cladding region surrounding the core has an outer radius that is about 6.5 times the radius of the core, and has a normalized refractive index that is about 0.15% less than that of silica. The deposited cladding is surrounded by a second cladding region consisting of material derived from a silica substrate tube, resulting in a fiber outside diameter of about 125 μm. The above described fiber is an example of "depressed" cladding fiber. See, for instance, U.S. Pat. No. 4,447,127, and H. Etzkorn et al, Electronics Letters, Vol. 20 (10), pp. 423-424 (1984). In a "matched" cladding fiber the refractive index of the deposited cladding is substantially equal to that of silica, and therefore, to that of the outer cladding.
Fibers with more complicated index profiles comprising a multiplicity of deposited cladding regions are also known. See, for instance, U.S. Pat. No. 4,435,040, and U.S. patent application Ser. No. 357,053, filed Mar. 11, 1982 by L. G. Cohen et al. The multiple cladding regions known to the prior art typically are designed to affect the transmission characteristics of the optical fiber. In particular, such profiles may be designed to lead to increased bandwidth of the fiber, since the additional cladding layers make it possible to produce fiber having two or more wavelengths of zero dispersion, with low dispersion between the zero-dispersion wavelengths.
A characteristic parameter of optical fiber is the cut-off wavelength λc, namely, that wavelength above which only the fundamental mode can propagate over significant distances in the fiber. For step index fiber, the theoretical cut-off wavelength is defined by V=2.405, where V=ka(nc 2 -n1 2)1/2, with nc being the core refractive index, and n1 the refractive index of the deposited cladding surrounding the core. k=2π/λ, where λ is the wavelength, and a is the radius of the core.
It is to be noted that the index profiles of real fibers typically only approximate the ideal profiles used in theoretical work. However, it is essentially always possible to define an equivalent profile in which all fiber regions have well-defined indices and radii, with the "equivalent" fiber having essentially the same transmission properties as the fiber which it represents. See, for instance, R. J. Black et al, Journal of Lightwave Technology, Vol. LT-2, No. 3, June 1984, pp. 268-276. It is to be understood that the terms "refractive index" and "radius" of a fiber region herein are intended to refer to the equivalent index and equivalent radius of the fiber region, unless otherwise noted.
Although the theoretical cut-off wavelength of a single mode fiber is well defined, in actual fibers the attenuation of higher order modes (most importantly, the first higher order mode designated LP11) does not become infinite discontinuously, but rather increases over a range of wavelengths. Thus, it is usual practice to define an experimental cut-off wavelength, which typically differs somewhat from the theoretical cut-off wavelength. For instance, the experimental cut-off wavelength can be defined as that wavelength at which the attenuation of LP11 is 4 dB/m. The term "cut-off wavelength" herein is intended to refer to the experimental cut-off wavelength, unless otherwise noted.
In single mode optical fibers, the fundamental mode should have the lowest possible loss even when the fiber is bent, and the higher order modes should either be absent or have sufficiently high attenuation at the operating wavelength, to avoid significant intermodal dispersion and modal noise. Changes in the index profile of a fiber that strengthen the guiding of the fundamental mode, to thereby reduce the susceptibility of the fiber to macrobending loss (e.g., increasing the V-number by increasing Δ) often strengthen the guiding of higher order modes as well, and thus may not be able to simultaneously further both of the above objectives.
We are disclosing herein a new fiber profile that promotes differential mode attenuation, allowing the fundamental mode guiding to be strengthened relative to that of the secondary modes.
Disclosed is an optical fiber communications system that comprises at least one source of electromagnetic radiation, at least one optical fiber that is part of an optical fiber transmission path, means for coupling radiation into the fiber transmission path, the radiation being guided axially through the fiber transmission path to an output location, where the radiation is typically detected by a radiation detector. The fiber transmission path can be a single length of fiber, or it can consist of a multiplicity of optically coupled segments. At least part of the fiber transmission path consists of fiber according to the invention. Fiber according to the invention is single mode optical fiber at the operating wavelength of the system, the fiber having a core region, at least a first cladding region concentrically surrounding the core, and a second cladding region concentrically surrounding the first cladding region. The inventive fiber further comprises a third cladding region which will frequently be referred to as a "ring". The core and the first, second, and third cladding regions have equivalent refractive indices nc, n1, n2, and n3, respectively. Furthermore, the core has an effective radius a, the first, second, and third cladding regions have effective inner radii R1i, R2i, and R3i, and effective outer radii R1o, R2o, and R3o, respectively. Furthermore, n3 <n1, R3o ≦R2i, and R3i ≧R1o. The fiber parameters, e.g., R3i, R3o, and n3, are chosen such that, for radiation of wavelength equal to the operating wavelength of the system, at R3i the square of the amplitude of LP01 is at most 10-5 of the square of the amplitude of that mode at the center of the core. The parameters are also chosen such that at R2i the square of the amplitude of the LP11 mode is at least 50% larger than that of the LP11 mode of a second (reference) fiber that is identical in all respects to the inventive fiber, except that in the reference fiber R3i =R3o (i.e., no ring is present), with the comparison being made at a wavelength equal to the cut-off wavelength of the reference fiber. Also, in the fiber according to the invention, at the operating wavelength, the square of the amplitude of the LP01 mode at R2i is at most 50% larger than that of the LP01 mode of the reference fiber at the same radius and wavelength. These conditions assure that the presence of the ring does not substantially affect such fiber properties as spot size, bandwidth and macrobending sensitivity, but does have a substantial effect on the guiding of higher order modes.
In preferred embodiments, the first and third cladding regions are deposited cladding, whereas the second cladding region consists of less pure tube-derived silica, with R3o =R2i. In preferred embodiments of the depressed cladding type, typically n1 <n3 <n2. In at least some preferred embodiments, we have found it to be advantageous if R3i ≧4a, where a is the core radius. In preferred depressed cladding fiber the "height" h of the ring is between 10% and 75% of Δ-, the (to be defined) normalized cladding index depression.
Fiber according to the invention can have a lower cut-off wavelength than comparable prior art fiber, or can be less sensitive to macrobending, without substantial change in such important fiber parameters as spot size and dispersion, which primarily depend on the wave form in the core. In conjunction with appropriate core parameter changes, microbending and/or macrobending sensitivity can be reduced without change in cut-off wavelength.
As will be appreciated by those skilled in the art, the ability to lower the cut-off wavelength of a fiber, without substantially altering fiber characteristics that depend primarily on the waveform in the core, gives added design freedom. For instance, this ability is considered to be useful for designing dual (or multiple) "window" fibers (e.g., fiber having two operating wavelengths, such as 1.31 μm and 1.55 μm), since it may permit reducing λc below the shortest operating wavelength, while retaining otherwise advantageous values of nc, n1, and a. Fiber according to the invention also can, for instance, be advantageously used when short lengths of fiber (e.g., fractions of a meter to a few meters) are to be inserted into a fiber communications system. As is well known, the actual cut-off wavelength of optical fiber is somewhat length dependent, with a short length of fiber having a cut-off wavelength greater than that of an otherwise identical longer length of fiber. Short lengths of fibers must frequently be present in fiber communications systems, for instance, as "pigtails" for coupling radiation sources or detectors into the system, or as "patch cord", either temporarily or permanently. Use of short lengths and long lengths of the same fiber in the same transmission path, however, may result in the introduction of modal noise, and thus result in degradation of system performance. See, N. K. Cheung et al, Electronics Letters, Vol. 21(1), pp. 5-7 (1985). Use of short lengths of fiber according to the invention may prevent such degradation.
FIGS. 1, 2, and 3 depict exemplary refractive index profiles of fibers according to the invention;
FIG. 4 shows cut-off contours for depressed index fibers according to the invention, for a range of ring parameters;
FIG. 5 shows macrobending contours for exemplary depressed index fibers according to the invention, for a range of ring parameters; and
FIG. 6 schematically shows an exemplary fiber communications system according to the invention.
A central aspect of the invention is the addition of an index ring, i.e., of a relatively narrow cladding region having an index that is greater than that of a first cladding region enclosed by the ring, at an appropriate radial distance from the core of the fiber.
FIGS. 1-3 show exemplary index profiles of fibers according to the invention. In all three figures, numerals 10 refer to the fiber core, 11 to the first cladding region (typically deposited cladding), 12 to the second cladding region (typically consisting of material derived from a silica substrate or sleeve tube), and 13 to the third cladding region, the index ring. In all three figures only the right half of the relevant profile is shown, and the profiles are understood to schematically represent equivalent step index profiles. The refractive indices are referred to an arbitrary origin, and absolute and relative radial distances and refractive indices are not intended to be to scale. Although the (equivalent) profiles of FIGS. 1-3 show only step changes in refractive index, this is not a necessary requirement. For instance, the core can have a graded index, e.g., a triangular or parabolic profile. Such profiles are well known to the practitioner. In case of a graded index core, nc is intended to refer to the maximum equivalent index value in the core. In principle the transitions between cladding layers could also be graded.
FIG. 1 shows the profile of an exemplary multiple depressed cladding fiber having a "trench" 14 between the core and the first cladding region, and a "gap" 15 between ring 13 and second cladding 12. The core radius is a, the inner and outer radii of the first cladding region are R1i and R1o, respectively, the inner and outer radii of the ring are R3i and R3o, respectively, and the inner radius of the second cladding region is R2i, with the outer boundary of the fiber not being shown. The same symbols are used in FIGS. 2 and 3. FIG. 1 is intended to be exemplary only. For instance, it is not necessary that R3i =R1o.
FIG. 2 shows the profile of an exemplary fiber having substantially matched indices, with a gap 15 between the ring and the second cladding region. Of course, it will be appreciated that such a gap need not be present, and indeed frequently will not be present in matched cladding fibers according to the invention. FIG. 3 depicts the profile of an exemplary fiber having depressed index cladding. The Figure also illustrates the meaning of the refractive indices nc, n1, n2, and n3, and of the normalized indices Δ, Δ+, and Δ-, as well as those of the ring parameters W and h.
Although the invention can be practiced with multiple cladding fibers, it is currently believed that the invention can be most advantageously used in fibers that have only two cladding regions, in addition to the ring. An exemplary profile of such fiber is depicted in FIG. 3. The profile of FIG. 2 is also of this type if R3o =R2i. The discussion below is primarily in terms of a depressed cladding fiber of the type shown in FIG. 3. This is for purposes of concreteness only, and is not intended to imply that the invention is so limited. Those skilled in the art will appreciate that the principles of the invention can be applied to other fiber types as well, and will easily be able to do so.
The normalized index differences Δ, Δ+, and Δ-, and the "height" h and "width" W of the ring are defined as follows:
Δ+ =(nc 2 -n2 2)/2n2 2
Δ- =(n2 2 -n1 2)/2n2 2
h=ΔR /Δ-,
ΔR =(n3 2 -n1 2)/2n2 2.
We have discovered that by appropriate choice of fiber parameters, especially of ring parameters such as h, W and R3i, it is possible to strengthen the guiding properties of the fiber for the LP01 mode relative to LP11 and other higher order modes. This in turn can result in lower macrobending loss of the fiber, in a reduced cut-off wavelength, in reduced microbending loss, in improved manufacturability of the fiber, or in combinations of the above, without significantly affecting such important fiber parameters as bandwidth and spot size.
In general, the ring parameters are to be chosen such that, at the operating wavelength (or wavelengths) of the system, the amplitude of the LP01 mode at R3i is very small, typically such that the square of the amplitude at R3i is less than 10-5 of the square of its amplitude at the center of the core. Furthermore, the parameters are also to be chosen such that at R2i the square of the amplitude of the LP11 mode is at least 50%, preferably more than 100%, larger than the square of the amplitude of the LP11 mode in a second fiber that does not have a ring but is identical to the inventive fiber in all other respects, the comparison being made at the cut-off wavelength of the second fiber. And lastly, the parameters are to be chosen such that, in the fiber according to the invention, at the operating wavelength(s), the square of the amplitude of the LP01 mode at R2i is at most 50%, preferably no more than 10%, larger than that of the LP01 mode of the second fiber, at the same radius and wavelength(s). The first condition assures that the influence of the ring on fiber parameters such as spot size and bandwidth is substantially negligible, whereas the latter two assure substantial differential attenuation of LP11 relative to LP01.
As will be appreciated by practitioners of the art, the above referred to mode amplitudes can, for essentially any given fiber, be reliably determined by means of calculation. A particularly advantageous calculation method is described in T. A. Lenahan, The Bell System Technical Journal, Vol. 62(9), November 1983, pp. 2663-2694. After determination of the refractive index profile of a fiber or of a fiber preform (see, for instance, page 2688 of the above Lenahan reference for an example of an actual preform profile) by known methods, the mode amplitude can be calculated for any mode, wavelength, or radial position in the fiber. For some other computational methods, it may be required that the equivalent profile be determined first. It will also be understood that, in order to facilitate comparison of the inventive fiber with the reference fiber, normalized mode amplitudes are to be computed, and all comparisons herein refer to normalized amplitudes.
We will next present some simple theoretical considerations. It can be shown that, for fiber with a single inner cladding region, the leakage loss for a higher order mode is directly proportional to the square of the amplitude of the mode at R2i. Likewise, bending loss for LP01 is approximately proportional to the square of the amplitude of LP01 at R2i. Since both LP01 and higher order modes have radially exponentially decaying waveforms in the inner cladding region, the radial decay constants are approximately
ηj =(2π/λ)(ne,j2 -n1 2)1/2
where j=1 for LP01, j=2 for LP11, etc., and ne,j is the effective refractive index for the jth mode. For a definition of the effective index of a mode, see, for instance, page 2673, equations 44 and 45, of the above cited paper by Lenahan. Typically, at a wavelength above the cut-off wavelength λc, ne,1 >ne,2, and therefore, η1 >η2.
Addition of a ring to the profile causes the decay constants in the ring region to change to
ηj '=(2π/λ)(ne,j2 -n3 2)1/2,
with the decay constants satisfying
1≧(η1 '/η1)>(η2 '/η2)≧0.
This shows that the ring has proportionately greater effect on higher order modes than on the fundamental mode. By placing the ring sufficiently far from the core, e.g., such that R3i is greater than about 4a, it can be assured that, at least in some fiber designs, the ring affects only the tails of the waveforms.
Results of exemplary calculations for a depressed cladding silica-based fiber (2a=8.3 μm, Δ+ =0.25%, Δ- =0.15%) are given in Table I, in which α1.20 is the (longitudinal) attenuation constant for LP11 at a wavelength of 1.20 μm (i.e., below the cut-off wavelength of the fiber), for a straight fiber, and α1.60 is the macrobending attenuation constant for LP01 at a wavelength of 1.60 μm (i.e., above the cut-off wavelength of the fiber) for fiber having a constant 1.5 inch radius of curvature.
TABLE I______________________________________Calculated Leakage Loss LP11 LP01Ring R2i /a α1.20 (dB/m) α1.60 (dB/km)______________________________________None 6.5 2.85 1.62None 7.5 0.41 0.12Yes (W = 2a, 7.5 2.70 0.205h = 0.20______________________________________
The above results show that increasing the thickness of the inner cladding results in decreased attenuation for LP11 and decreased bending loss for LP01, whereas addition of the ring to the fiber with increased cladding thickness substantially increases the attenuation of LP11, without substantially affecting the bending loss of LP01.
The details of the effects produced by addition of a ring depend, inter alia, on the parameters of the ring, as is exemplified by the data in Table II. The fiber was again assumed to be a depressed index cladding fiber of the type shown in FIG. 3, with 2a=8.3 μm, R2i /a=6.5, Δ+ =0.25%, Δ- =0.15%.
TABLE II______________________________________Calculated Leakage LossRing LP11 LP01W/2a h (% Δ-) α1.20 (dB/m) α1.60 (dB/km)______________________________________1.25 30 173 4.3 20 26.7 3.1 10 7.6 2.20.75 30 37.6 3.0 20 12.3 2.4 10 5.4 2.0None 2.85 1.62______________________________________
The results show that, for the fiber and the rings considered, suppression of LP11 is greatest for the "widest" and "highest" ring. Addition of a ring with W/2a=1.25, and h=30% was found to reduce λc from about 1.21 μm to about 1.14 μm.
FIG. 4 shows exemplary computed contours of those ring parameters (W, h) that result in cut-off wavelengths of 1.20, 1.15, 1.10, and 1.05 μm, in a depressed cladding silica fiber of the type depicted in FIG. 3, with 2a=8.3 μm, R2i =R3o, R2i /a=6.5, Δ+ =0.25%, and Δ- =0.15%. In the absence of the ring (i.e., h=W=0), the cut-off wavelength of the fiber is 1.21 μm. The contours show that beyond a certain ring height that depends on the ring width, the cut-off wavelength depends substantially only on the width. For instance, when W=1.2a and h≧0.5 Δ-, λc is 1.15 μm; increasing W to 1.8a gives λc =1.10 μm, for h≧0.6 Δ-.
The exemplary computed contours in FIG. 5 indicate the ring parameters that result in macrobending loss of LP01 (for 1.5 inch radius of curvature) of 0.75 dB/km, 1.0 dB/km, and 2 dB/km at a wavelength of 1.55 μm, for the fiber that was used in FIG. 4. With no ring the loss is calculated to be 0.56 dB/km. The contours indicate that macrobending loss grows slowly with the ring size. As mentioned before, this growth can be prevented by an increase of the deposited cladding thickness.
FIG. 6 schematically shows a telecommunication system comprising a radiation source 60 which emits radiation 61, coupled by coupling means 62 into fiber 63. The radiation is guided axially through the fiber and is emitted from the output end of the fiber. Emitted radiation 64 is detected by detector 65. The detector output can be processed by known means. Optical communications systems are well known to those skilled in the art and need no detailed discussion here. It will be appreciated that all the optical fiber in a system according to the invention can be fiber according to the invention. On the other hand, such a system may contain prior art fiber, as well as fiber according to the invention. Typically, a length of inventive fiber may be optically coupled to prior art fiber, thereby forming an optically continuous transmission path for radiation of the system operating wavelength.
A preform was manufactured by the standard MCVD process. The preform refractive index profile was measured and the fiber core diameter corresponding to a standard 125 μm diameter fiber was determined to be 8.3 μm. From the same measurement, the normalized refractive index difference Δ was found to be 0.36%, Δ- =0.12%, h/Δ- =0.28, W/a=2.1. Several fibers were drawn from the collapsed preform by a standard method, the outside diameter of the fibers being 125 μm. These fibers were found to have an average cut-off wavelength of 1.20 μm and an average loss (including the macrobending loss induced by a three inch radius of curvature) of 0.25 dB/km at 1.55 μm. A similarly prepared fiber, with essentially the same parameters (2a=8.3 μm, Δ=0.37%, Δ- =0.12%) as the above described inventive fiber, except having no index ring, was found to have a cut-off wavelength of 1.28 μm and a loss at 1.55 μm of 0.24 dB/km for the same radius of curvature. Other fiber characteristics such as spot size and bandwidth were substantially the same in the two fibers.
Patent Citations
Non-Patent Citations
Referenced by
Legal Events
Original Image


text:
Registration takes less than 1 minute.
U.S. Army Corps of Engineers signed off on the port dredging project, paving the way for the engineering and design phase.
An official from the U.S. Agency for International Development said discussions about the Maritime Security Program are ongoing.
The new Senate bill would allow state governors to invoke Taft-Hartley in an attempt to mitigate port congestion stemming from labor disputes.
International Longshoremen's Association and employers represented by the United States Maritime Alliance will begin full wage scale meetings in mid‐September.
Total shipments and total revenues for third party logistics providers both fell in first quarter 2015 compared to fourth quarter 2014, according to a recent benchmarking report from the Transportation Intermediaries Association.
Daseke, Inc., an open-deck and specialty transportation company, announced it would merge with Charleston, S.C.-based Bulldog Hiway Express.


text:
#121 of 785
Radford, VA
Comment, Like, Favorite
Expert Printing and Assembly
Shipping Within 2 - 3 Business Days
Millions of Satisfied Customers
Buy the Original Painting
18.000 x 24.000 x 1.000 inches
This original painting is currently for sale. At the present time, originals are not offered for sale through the Fine Art America secure checkout system. Please contact the artist directly to inquire about purchasing this original.
Click here to contact the artist.
Blue Ridge Morning
Kendall Kessler
Painting - Oil/canvas
Blue Ridge Morning is a peaceful, sensuous look at a Blue Ridge Vista. This is a calm, serene view of the beginning of the day in the gorgeous Blue Ridge.
I have lived in Southwest Virginia my adult life with Clyde Kessler, a great guy from Ferrum, VA.
He has introduced me to all these beautiful vistas he loves and tries to protect in a number of different ways. He has lead countless hikes and hawk watches since the seventies and continually researches the area for bird and butterfly populations. His discovery of the endangered Mitchel Satyr in 1996 is considered to be the most important wildlife find in the second half of the twentieth century in Virginia. He works with the US Forest Service to monitor wildlife in the Spring and Summer. I never tire of looking at this beautiful region of Virginia and I try to add my emotional response to the paintings with my unique use of color and texture. One of my teachers in college said my colors sing. I would like to think that is true.
My paintings have been seen throughout the United States in national, international, and group shows. I have won numerous awards, including awards from Dorothy Gillespie, May Stevens, Frank Webb, and Daniel Greene. My best-selling print, "Reaching Out", was selected from over three million works of art on Fine Art America to be on the set of The Mindy Project and I will be appearing with my artwork on The Hour of Joy on FoxTV out of Roanoke on March 10th 2013. I live to paint and it is important to me to find homes for all of my creations. I have originals and prints in twenty-one states, Canada, Germany, and Australia. I want to cover the world with my art.
Towhee Hill Studio is open to the public by appointment. 540-257-3437
Prints on clothing, paper products, and kitchen wares can be purchased at www.zazzle.com/newriverartisst
November 15th, 2010
Viewed 1,525 Times - Last Visitor from Beverly Hills, CA on 06/30/2015 at 10:26 PM
Sales Sheet
More from Kendall Kessler
Vali Irina Ciobanu 16 Days Ago
Bucharest, Bu - Romania
Congratulations Kendall!
Kendall Kessler replied:
Thanks Vali!
Kendall Kessler 17 Days Ago
Radford, VA - United States
Thanks MingTa!
MingTa Li 17 Days Ago
Lyndhurst, NJ - United States
Congrats on your sale!
Radford, VA - United States
Thanks Colette!
Viborg - Denmark
Fav/ Features
Radford, VA - United States
Thanks David!
Tampa, Fl - United States
Congratulations, your work is featured on the homepage of "Created by my Hands".
Radford, VA - United States
Thanks Marija!
Belgrade - Yugoslavia
What a beautiful morning Kendall :) Liked
Radford, VA - United States
Thanks Lianne!
Strykersville, NY - United States
The Blue Ridge is beautiful any time of day but mornings are special. Lovely lovely work. F/V
Radford, VA - United States
Thanks Suzanne and Ernie!
Colorado Springs, CO - United States
Congrats on your sale!!!
Little River, SC - United States
Congratulations, Kendall!! Like the composition and colors! Blessings, Suzanne
Radford, VA - United States
Thanks Robin! There is nothing like the Blue Ridge Mountains!
New London, WI - United States
Very nice. Congratulations on your sale!
Please Wait...
Beverly Hills, CA (United States)
Sign up for our newsletter for exclusive deals, discount codes, and more:
Unsubscribe at any time.
Server Status OK
Copyright © 2015 FineArtAmerica.com - All Rights Reserved


text:
Unprofessional Fridays: Thursday Edition 07/02/2015
Become Premium to Watch
Her Story is a bold and largely successful experiment in interactive crime fiction.
Rocksteady's gorgeous-looking third Arkham game refines its open-world format a bit and lets you drive a whole hell of a lot of Batmobile.
It's squid kids and ink blasting abound in Nintendo's exceptionally fun new online shooter.
Character »
A mobile action-RPG based in the Marvel Universe.
Marvel Avengers Alliance Tactics is a tactics RPG spin-off of the popular Facebook/mobile social RPG.
Disney Interactive is set to include Marvel characters in the next version of its Disney Infinity series.
Not content to wait for another movie, Gameloft weaves a tale of multiple Spider-Men fighting against the machinations of the likes of Green Goblin and Vulture. The game also ties into Marvel's 2014 multimedia crossover event, "Spider-Verse".
Marvel Run Jump Smash! is an endless running game by Marvel Games.
The denizens of the Marvel Universe battle it out LEGO style.
This edit will also create new pages on Giant Bomb for:
Until you earn 1000 points all your submissions need to be vetted by other
Giant Bomb users. This process takes no more than a few hours and we'll
send you an email once approved.
Because you're new to wiki editing, we sent your
submission off to our moderators to check it over. Most
changes are approved within a few hours. We'll send an
email when it is.
Once you've earned over points you'll be able
to bypass this step and make live edits to our system.
Until then, gain points by continuing to edit pages.
No changes were submitted, nothing was done! Please make changes to the wiki!
Thanks for continuing to improve the site. Some of your changes are
now live. However, some of your changes were sent to moderation because you do not
have enough points to make those live edits. You need points to
live edit the changes you commited.
For the changes that went through, our robot math gave you points for this
Thanks for continuing to improve the site. Your changes are
now live. Our robot math gave you points for this
Use your keyboard!
Log in to comment


text:
: Olympics:
2014 - Canada Roster Discussion (Part III)
View Single Post
Registered User
Join Date: Apr 2012
Posts: 6,925
vCash: 500
Originally Posted by
It's not the Cup or Conn Smythe making me pick Ward. It's his current level of play - Cam Ward has really stepped it up in the last 2 seasons ... quietly playing well behind a bad defence in Carolina. He hasn't been elite, but he definitely isn't an average goalie like Niemi.
One game in this year's WC is making you doubt Ward? Remember, the only active Canadian goalies who have won a World Championship are ... Roberto Luongo and Cam Ward.
Really don't want to beat a dead horse any more. Luongo's stinkers didn't cost Vancouver a Cup - horrible special teams and the offence drying up did. Even if Luongo had played like an elite goalie, the Bruins would still have won - they just wouldn't have posted blowout scores. If anything, Luongo was a major reason we were even in position to win the Cup in the first place.
Oh, and if one bad playoff series disqualifies you from Olympic competition, then Ward and Fleury are out too.
Except Luongo's been terrible for the last three years.
No, he's the only thing that kept them from winning it: When the chips were down and he needed to make a save, he couldn't. The dude didn't even play every game in the SCF because of how bad he was, and yet he played "like an elite goaltender"? Give me a break.
Last edited by DyerMaker66: 08-26-2012 at
View Public Profile
DyerMaker66's albums
Find More Posts by DyerMaker66


text:
Release Date:
June 25, 2013
A taciturn ex-con known as The Rambler (Dermot Mulroney) embarks on a surreal cross-country journey to his long-lost brother's Oregon horse ranch, encountering a variety of enigmatic figures -- including a scientist (James Cady) who can record dreams onto VHS tapes -- along the way. Natasha Lyonne and Lindsay Pulsipher co-star. ~ Jason Buchanan, Rovi
- Genre: Drama
- Category Road Movie
- Theme: Journey of Self-Discovery
- Run Time: 01 hr 39 min
- Language: English
- Subtitle Language: Spanish , English
- Picture Format: widescreen
- Lead Actor: Dermot Mulroney
- Director: Calvin Reeder
other Info.
- Online Item #: 14627381
- Store Item Number (DPCI): 058-16-1078
- Made in the USA or Imported