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  • 1
    Electronic Resource
    Electronic Resource
    Indented barrier resonant tunneling rectifiers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 4174-4176 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article concerns a novel negative-conductance device consisting of a series of N laterally indented barriers which exhibits resonant tunneling under one bias polarity and simple tunneling under the opposite one, thus acting as a rectifier. Electrons undergo resonant tunneling when the bias creates a band profile with N triangular wells which can each contain a resonant state. From 1 to N the addition of each indentation can be used to increase the current density and the rectification ratio, calculated at the current-peak bias at resonance, provided that at a given bias all the states in the triangular wells align each other with the emitter Fermi energy in order to form a resonance along the structure. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363290
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  • 2
    Electronic Resource
    Electronic Resource
    Counterion specificity of the micelle surface and its implications on micellar catalysis (1996)
    Springer
    Colloid & polymer science 274 (1996), S. 662-668 
    Details
    ISSN: 1435-1536
    Keywords: Micellar catalysis ; critical micelle concentration ; micellization ; counterion distribution constants ; hydroxide surfactants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Dodecyltrimethylammonium bromide — Dodecyltrimethyl-ammonium hydroxide — water mixtures were studied with ion-selective electrodes, and the aggregation behavior, degree of ionization of the micelles and the distribution constants of bromide and hydroxide ions between water and micelles were found, showing that some suppositions about the interpretation of micellar catalysis are incorrect, and these interpretations must be revised. The results support the mass action model for the theoretical treatment of micellar catalysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00653065
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  • 3
    Electronic Resource
    Electronic Resource
    Studies on styrene phosphonic acid (1996)
    Springer
    Colloid & polymer science 274 (1996), S. 741-746 
    Details
    ISSN: 1435-1536
    Keywords: Styrene phosphonic acidcrystals ; micelle solubilization ; solubility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Some properties of styrene phosphonic acid (SPA) were studied. The crystals were triclinic, witha=0.6434 nm,b=0.5842 nm,c=2.0338 nm, α=96.17°, β=97.33°, γ=79.65° andZ=4. SPA underwent a change in crystal structure at 78.8°C, the hydrocarbon network became disordered (“liquid-like”) at 138.5°C. Crystals melted at 148.6°C giving a cubic mesophase, then changed to an isotropic liquid at 155.6°C and at 162.13°C SPA underwent decomposition. Values for pK1=2.15 and pK2=7.66 were obtained at 25°C. The water solubility of SPA at several temperatures, and its interaction with surfactant micelles were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00654669
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  • 4
    Electronic Resource
    Electronic Resource
    The aggregation ofn-dodecanephosphonic acid in water (1996)
    Springer
    Colloid & polymer science 274 (1996), S. 1089-1093 
    Details
    ISSN: 1435-1536
    Keywords: Micelles ; critical micelle concentration ; dodecanephosphonic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Several techniques were employed to study the aggregation ofn-Dodecanephosphonic Acid (DPA) in water. At 22°C, the solubillity of DPA increases, probably due to the formation of small premicellar aggregates. The CMC is (5.4±2.4) ×10−4 mol·dm−3 and the solubility reaches the CMC value at 26°C. At 30°C and at a concentration of about 9×10−3 mol·dm−3, a lamellar mesophase appears. Both micelles and liquid crystal lamellae are almost uncharged. Their polar heads have strong hydrogen bonds between them. The ionization of DPA molecules in micelles and mesophase structures is strongly reduced in comparison with monomerically dissolved molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658374
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  • 5
    Electronic Resource
    Electronic Resource
    The aggregation of aqueous dodecylphosphonic acid in dodecyltrimethylammonium hydroxide mixtures (1996)
    Springer
    Colloid & polymer science 274 (1996), S. 669-677 
    Details
    ISSN: 1435-1536
    Keywords: Dodecanephosphonic acid ; dodecyltrimethylammonium hydroxide ; mixed micelles ; critical micelle concentration ; aggregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The aggregation of aqueous dodecylphosphonic acid (DPA) and dodecyltrimethylammonium hydroxide (DTAOH) mixtures was studied by several methods. The behavior of DPA-rich mixtures is close to that of pure DPA. This is probably due to the preservation of the hydrogen-bonded structure of the micellar headgroup layer. The behavior is almost ideal. Betweeny DPA =0.5 and 0.33 (y DPA being the mole fraction of DPA in the surfactant mixture), the hydrogen-bonded structure of the micellar headgroup layer is destroyed. A sort of “micellar azeotrope” is formed, and the maximum of non-ideal interaction between the two surfactants is attained aty DPA =0.4. Fory DPA 〈0.33 the system behaves as a common mixture of a cationic surfactant and a non-ionic one (DPA.2LTA). There is a phenomenon of counterion “condensation” on aggregates at concentrations over the CMC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00653066
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  • 6
    Electronic Resource
    Electronic Resource
    The aggregation of the sodium dodecyl sulfate –n - octanol–water system at low concentration (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 735-742 
    Details
    ISSN: 1435-1536
    Keywords: Key words Mixed micelles ; Octanol ; Sodium dodecyl sulfate ; Surfactants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Micelle formation in sodium dodecyl sulfate (SDS)–n-octanol mixtures was studied by several techniques and the results were interpreted using regular solution theory for mixed-micelle formation. Octanol was considered as a nonionic surfactant. The composition of micelles at the critical micelle concentration (cmc) was computed together with the interaction parameter and the activity coefficient of the components of the micelles. The fluorescence quenching technique with pyrene was employed to obtain the SDS and octanol aggregation numbers at the cmc. The results were in agreement with similar studies on other alcohol–SDS systems. At the cmc spherical, almost fully ionized micelles formed, while at a higher concentration there was a transition to anisometric (probably rodlike) micelles which pushed sodium counterions into their Stern double layer. Mixed anisometric micelles were more ionized than pure SDS micelles. When the octanol:SDS total ratio exceeded 0.85:1, an emulsion of octanol appeared in equilibrium with the micelles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050447
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  • 7
    Electronic Resource
    Electronic Resource
    Low-concentration aqueous solutions of undecenoic acid and sodium undecenoate (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 1072-1078 
    Details
    ISSN: 1435-1536
    Keywords: Key words Polymerizable surfactant ; Micelles ; Undecenoic acid ; Sodium undecenoate ; Critical micelle concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The behaviors of low-concentration aqueous solutions of 10-undecenoic acid and its sodium salt were studied by several techniques. The acid does not have a critical micelle concentration, but gives an emulsion of very small droplets at (0.8–1) ×  10−4 mol dm−3. The emulsion was clearly visible by eye at 0.002 mol dm−3. The sodium salt has a stepwise aggregation process, giving premicellar aggregates at 0.023 ± 0.008 mol dm−3, which grow to form micelles at 0.117 ± 0.007 mol dm−3. The compositions of the solution and the micelles were also studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050492
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  • 8
    Electronic Resource
    Electronic Resource
    Influence of the deacetylation degree on chitosan emulsification properties (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 1087-1092 
    Details
    ISSN: 1435-1536
    Keywords: Key words Chitosan ; Emulsion ; Deacetylation degree ; Emulsion stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The emulsification of sunflower oil by chitosan solutions with deacetylation degrees (DD) between 73 and 95% was studied using different techniques. The droplet size distributions, conductivity, ageing behavior and viscosity of emulsions were studied as functions of the chitosan DD. All DD gave stable polydisperse water-in-oil-in-water emulsions with different viscosities. Two optimum DD values were found, 81 and 88%, giving complete emulsification without residual oil or sedimentation. Chitosans with intermediate DD were less effective emulsifiers. Chitosans with higher DD gave poor emulsification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050495
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  • 9
    Electronic Resource
    Electronic Resource
    Polymerization of aqueous liquid-crystalline allyldimethyldodecylammonium bromide (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 1215-1219 
    Details
    ISSN: 1435-1536
    Keywords: Key words Allyldimethyldodecylammonium bromide ; Liquid crystals ; Polymerization ; Polymerizable surfactant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Allyldimethyldodecylammonium bromide was polymerized by γ-ray irradiation in both hexagonal and cubic mesophases, and the conversion–time curves were obtained. The maximum conversion was about 35%, and the polymer remained in the liquid-crystalline structure formed by the nonpolymerized monomers. The influence of polymerization on the distribution of water in the different types related to the hydrophilic surfaces of microstructures was studied using Fourier transform infrared spectroscopy. The incomplete polymerization was explained by steric constraints in the liquid-crystalline structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050513
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  • 10
    Electronic Resource
    Electronic Resource
    Anti-labyrinthine antibodies in a patient with relapsing polychondritis (1999)
    Springer
    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. 163-166 
    Details
    ISSN: 1434-4726
    Keywords: Key words Relapsing polychondritis ; Audiovestibular symptoms ; Antilabyrinthine antibodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Relapsing polychondritis is a rare inflammatory disease that causes destruction of cartilaginous tissue in various anatomical regions. We report here about a 55-year-old female patient with relapsing polychondritis that involved the right auricle, both audiovestibular organs and both eyes. The patient presented with persisting inflammation of the right auricle, sudden lower-frequency hearing loss, acute moderate vertigo with nausea and mild ocular symptoms. Immunofluorescence assays were used for the detection of antibodies against the cochlea and the vestibular organ and demonstated the presence of circulating antibodies against the audiovestibular organ. No staining for anti-corneal IgG was detected. Improvement of clinical disease was achieved by treatment with systemic steroids and vasodilator drugs, and long-term medication with low-dose corticosteroids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004050050133
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