ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The ion product of H2O, dissociation constants of H2CO3 and pitzer parameters in the system Na+/H+/OH−/HCO 3 − /CO 3 2- /ClO 4 − /H2O at 25°C (1996)
    Springer
    Journal of solution chemistry 25 (1996), S. 327-343 
    Details
    ISSN: 1572-8927
    Keywords: Ion product of water ; carbonic acid ; dissociation constants ; NaClO4 solution ; iomic strength ; activity coefficients ; Pitzer model ; mixing parameters ; solution thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The ion product of water and the dissociation constants of carbonic acid have been determined in 0.1, 1.0, 3.0, and 5.0M NaClO4 at 25°C. The ion product of water K w ' has been evaluated by emf measurements with a combined glass electrode in NaClO4 solutions containing 0.001–0.1M HCLO4 or NaOH. The product K H ' K l ' K 2 ' of the Henry constant for CO2 and the dissociation constants for H2CO3 have been determined by titration of carbonate solutions equilibrated with pCO2 =10−3.52 atm, and K 2 ' has been evaluated by potentiometric titration and by measuring the H+ concentration at fixed HCO 3 − and CO 3 2- concentrations. The ion interaction (Pitzer) equations are applied to describe the constants K w ' , K 2 ' and K H ' H 1 ' K 2 ' as a function of the NaClO4 concentration. The experimental data are used to evaluate the mixing parametersΘ i/ClO 4 andΨ i/ClO 4 -/Na+ fori = OH -,HCO 3 - andCO 3 2-
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00972890
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Pitzer Parameters for the Pertechnetate Ion in the System Na+/K+/Mg2+/Ca2+/Cl−/SO 2 4 −/TcO − 4 /H2O at 25°C (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 107-120 
    Details
    ISSN: 1572-8927
    Keywords: Sodium pertechnetate ; magnesium pertechnetate ; potassium pertechnetate ; osmotic coefficients ; activity coefficients ; solubility ; seawater system ; Pitzer model ; binary parameters ; mixing parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Isopiestic vapor pressure experiments are performed at 25°C with aqueous Mg(TcO4)2 solutions and with ternary mixtures containing various combinations of NaTcO4, Mg(TcO4)2, NaCl, MgCl2, Na2SO4, and MgSO4. The osmotic coefficients of the binary solutions are used to evaluate the binary Pitzer parameters β(0), β(1), and CΦ for Mg(TcO4)2. We previously reported these parameters for NaTcO4. The binary parameters for KTcO4 and Ca(TcO4)2 are evaluated from solubilities of KTcO4 in KCl and CaCl2 solutions, respectively. The mixing parameters Θ TcO 4 − /Cl −, ΨM/TcO 4 − /Cl −, Θ TcO 4 − /SO 4 2− , ΨM/TcO 4 − /SO 4 2− , and ΨNa + /Mg 2+ /TcO4 2− are calculated from either osmotic coefficients or solubilities in the corresponding ternary mixtures. The evaluated set of Pitzer parameters predicts well the activity coefficients and solubilities of KTcO4 in multicomponent systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022625605743
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Thermodynamics of Cm(III) in Concentrated Salt Solutions: Carbonate Complexation in NaCl Solution at 25°C (1999)
    Springer
    Journal of solution chemistry 28 (1999), S. 447-462 
    Details
    ISSN: 1572-8927
    Keywords: Trivalent actinides ; curium ; americium ; solution thermodynamics ; carbonate complexation ; ionic strength ; Pitzer model ; concentrated solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The carbonate complexation reactions of Cm(III) were studied by time-resolved laser fluorescence spectroscopy in 0–6 m NaCl at 25°C. The ionic strength dependence of the stepwise formation constants for the carbonato complexes Cm(CO3) n 3−2n with n = 1, 2, 3, and 4 is described by modeling the activity coefficients of the Cm(III) species with Pitzer's ion-interaction approach. Based on the present results and literature data for Cm(III) and Am (III), the mean carbonate complexation constants at I = 0 are calculated to be: log β 101 o =8.1 ±0.3, log β 102 o =13.0 ± 0.6, log β 103 o =15.2 ± 0.4, and log β 104 o =13.0 ± 0.5. Combining these equilibrium constants at infinite dilution and the evaluated set of Pitzer parameters, a model is obtained, that reliably predicts the thermodynamics of bivalent actinide An(III) carbonate complexation in dilute to concentrated NaCl solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022664013648
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Counting of particles in aqueous solutions by laser-induced photoacoustic breakdown detection (1996)
    Springer
    Applied physics 63 (1996), S. 299-306 
    Details
    ISSN: 1432-0649
    Keywords: PACS: 42.55; 42.80; 82.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract.  Laser-induced photoacoustic breakdown detection is applied for the determination of particles in aqueous dispersion. Polystyrene (latex), alumina and thoriasol particles of different sizes are investigated for demonstration. Laser pulses at 500 nm with 28 ns pulse width (FWHM), generated by an excimer (λ=308 nm) pumped dye laser, are focused into aqueous particle dispersions to produce breakdown. The dye laser pulse energy is fixed at a value lower than the breakdown threshold of pure water to initiate a dielectric breakdown only when particles are present in a given focus volume. Focus volume parameters and particle size dependent breakdown thresholds are calculated and the results are compared with data from literature. Dependence of breakdown threshold values on the chemical composition of the particles is determined for polystyrene, alumina and thoriasol particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01833800
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Counting of particles in aqueous solutions by laser-induced photoacoustic breakdown detection (1996)
    Springer
    Applied physics 63 (1996), S. 299-306 
    Details
    ISSN: 1432-0649
    Keywords: 42.55 ; 42.80 ; 82.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Laser-induced photoacoustic breakdown detection is applied for the determination of particles in aqueous dispersion. Polystyrene (latex), alumina and thoriasol particles of different sizes are investigated for demonstration. Laser pulses at 500 nm with 28 ns pulse width (FWHM), generated by an excimer (λ = 308 nm) pumped dye laser, are focused into aqueous particle dispersions to produce breakdown. The dye laser pulse energy is fixed at a value lower than the breakdown threshold of pure water to initiate a dielectric breakdown only when particles are present in a given focus volume. Focus volume parameters and particle size dependent breakdown thresholds are calculated and the results are compared with data from literature. Dependence of breakdown threshold values on the chemical composition of the particles is determined for polystyrene, alumina and thoriasol particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01833800
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    EXAFS investigation of the interaction of hafnium and thorium with humic acid and Bio-Rex 70 (1999)
    Chester : International Union of Crystallography (IUCr)
    Journal of synchrotron radiation 6 (1999), S. 394-396 
    Details
    ISSN: 1600-5775
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0909049598013478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Temperature compensation of hot-wire anemometer with photoconductive cell (1995)
    Springer
    Experiments in fluids 19 (1995), S. 362-365 
    Details
    ISSN: 1432-1114
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A new temperature compensation technique for hot-wire anemometer is proposed in this article. In contrast to the available compensation techniques, a photoconductive cell is introduced here as a variable resistor in the bridge. The major advantage of adopting an active component such as photoconductive cell is that temperature compensation can be achieved by using any kind of temperature sensors, once the output of temperature sensor is given as a voltage. Validation experiments using a photoconductive cell with a thermocouple-thermometer are conducted in the temperature range from 30 to 50 °C and the velocity ranges from 8 to 18 m/s.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Characterization of groundwater humic and fulvic acids of different origin by GPC with UV/Vis and fluorescence detection (1999)
    Springer
    Fresenius' journal of analytical chemistry 364 (1999), S. 737-745 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Gel permeation chromatography (GPC) was applied for recognizing the origin of groundwater humic and fulvic acids. GPC was performed with Fraktogel TSK HW-50 in 0.1 M NaCl, pH 8.5 (0.05 M phosphate buffer), 1 mM EDTA, with 10% by volume methanol added. Humic substances from groundwaters and sediments of four different aquifer systems in Germany were isolated, purified and characterized. Both UV/Vis and fluorescence detection were applied. UV/Vis detection was found to be more powerful in identifying differences between the various humic and fulvic acids. The four aquifer systems investigated (“Gorleben”, “Fuhrberg”, “Franconian Albvorland” and “Munich”) differed from one another with respect to hydrological and geochemical conditions. The results showed that the GPC-elution behavior reflects the geochemical environment and origin (source material and generation process) of aquatic humic and fulvic acids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160051424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effects of pressure on the pore formation of carbon/carbon composites during carbonization (1999)
    Springer
    Journal of materials science 34 (1999), S. 4585-4595 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract In this study, porosity and graphitizability of coal tar pitch with the treatment pressure were investigated. 4-directional carbon/carbon composites (4D C/C) were made from the matrix precursor of coal tar pitch through the process of impregnation and carbonization. Then the effects of applied pressure during the densification on the composites were observed. The matrix pitch which had 600 bar applied during the carbonization process had one and a half times less pore area ratio than that treated at 1 bar. When the pitch was heat treated up to 2300°C after the high pressure carbonization, the degree of graphitization was improved on a small scale and the crystal size tended to reduce. As the applied pressures to 4D C/C composites increased from 1 to 600 bar, the densification ratio was greatly improved. In the pore size distribution of the 4D C/C composites, the macropore portion was decreased while the mesopore portion increased, when high pressures were applied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004674213884
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Multielement determinations in ground water ultrafiltrates using inductively coupled plasma mass spectrometry and monostandard neutron activation analysis (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 351 (1995), S. 745-751 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Twelve ultrafiltrates of two ground waters rich in humic substances (up to 97.8 mg CL−1) and in salinity (up to: cations 44.3 meq L−1, anions 44.9 meq L−1) were investigated with ICP-MS and with NAA in parallel. With both techniques 22 elements were analysed in a wide concentration range (mg/L to ng/L). Ultrafiltration at pore sizes from 1000 nm down to 1 nm lowers the humic colloid content as well as the concentration of the colloidborne polyvalent cations. Carbon interferences were studied in detail using artificially prepared model waters. The detection limits of ICP-MS in the ultrafiltrates (0.01 μg/L–10 μg/L) and in pure analyte solutions (5 ng/L–600 ng/L) are compared with those of NAA for pure water analysis (0.004 ng/L–50 ng/L).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...