Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The nonlinearity parameter B/A, internal pressure, and acoustic impedance are calculated for a room temperature ionic liquid, i.e. for 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide for temperatures from (288.15 to 318.15) K and pressures up to 100 MPa. The B/A calculations are made by means of a thermodynamic method. The decrease of B/A values with the increasing pressure is observed. At the same time B/A is temperature independent in the range studied. The results are compared with corresponding data for organic molecular liquids. The isotherms of internal pressure cross at pressure in the vicinity of 70 MPa, i.e. in this range the internal pressure is temperature independent.
2
Content available remote Ściśliwość cieczy jonowych jako płynów hydraulicznych
PL
Ściśliwości izotermiczne imidku bis(trifluorometylosulfonylo)1-etylo-3-metyloimidazoliowego ([Emim][NTf2]), tetratiocyjanianokobaltanu(II) 1-etylo-3-metyloimidazoliowego ([Emim]2 [Co-(NCS)s4]), tetratiocyjanianokobaltanu(II) 1-butylo-3-metyloimidazoliowego ([Bmim]2[Co(NCS)4]) oraz imidku bis(trifluorometylosulfonylo)1-butylo-1-metylopirolidyniowego ([Bmpyr][NTf2]) porównane zostały ze ściśliwością referencyjnego oleju mineralnego MIN-H01 oraz biodegradowalnego oleju BIO-H. Przedyskutowano zależność ciśnieniową i temperaturową ściśliwości izotermicznej cieczy jonowych w kontekście ich potencjalnych zastosowań jako płynów hydraulicznych. Stwierdzono, że najmniejszą ściśliwością charakteryzują się [Emim]2[Co(NCS)4] i [Bmim]2[Co(NCS)4].
EN
Isothermal compressibilities of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium tetraisothiocyanato-cobaltate(II) (I) 1-butyl-3-methylimidazolium tetraisothiocyanato-cobaltate(II) (II), and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide were compared with ref. mineral oil and a biodegradable oil. Temp. and pressure relationships of isothermal compressibility of liqs. under test were discussed for their use as hydraulic fluids. The I and II salts showed the lowest compressibility.
EN
Internal pressure as a function of pressure was estimated from the literature data for five chosen alkanols (ethanol, 1-pentanol, 3-pentanol, 3-methyl-3-pentanol, and 3-ethyl-3-pentanol). The data on isothermal compressibility and isobaric coefficient of thermal expansion obtained from acoustic method were used. The results shown that internal pressure can reaches a maximum for moderate pressures and then decreases more and more rapidly.
EN
Internal pressure as a function of pressure was estimated from literature data. Mostly, the data on isothermal compressibility and isobaric coefficient of thermal expansion obtained from acoustic method were used. The results shown that internal pressure can reaches a maximum for moderate pressures and then decreases more and more rapidly.
EN
The excess values of the molar adiabatic compressibility as well as adiabatic compressibility coefficeint were estimated for binary mixtures of 1,2-ethanediol+1-pentanol at the temperatures (293.15, 303.15, 308.15 and 313.15) K. Alsko deviations of the ultrasonic speed from the chosen additivity rules were determinated. Together with the previous result for T = 298.15K (E. Zorębski, Mol.Quant Acoust.,24 261-270 (2003)), the effect of temperature on speed of ultrasound and adiabatic compressibility is studied. It appears that both excesses decrease with increasing temprature whereas deviations of ultrasonic speed have opposite temperature dependencies.
EN
The excess values of the molar adiabatic compressibility as well as adiabatic compressibility coefficient were estimated for binariy mixtires of 1,2-ethanediol+1-pentanol at 298.15K. Also deviations of the ultrasonic speed from the chosen additivity rules were determined. Both the excess quantities as well as the speed of ultrasound are expressed by the Redlich-Kister polynomials and discussed in terms of molecular interactions
EN
The excess values of the molar volume and molar adiabatic compressibility as well as adiabatic compressibility coefficient were estimated for binariey mixtures of cyclohexanol + glycerol at 298.15K. Also deviations of the ultrasonic speed from the chosen additivity rules were determined. Both the excess quantities as well as the speed of ultrasound deviations are expressed by the Redlich-Kister polynomials and aisscused in term of molecular interactions.
EN
The absorption of ultrasound in binary mixtures of l-butanol with 1,3-butanedioI andin the pure components was measured at 298.15 K. The both components , i.e. l-butanol (GC>99.5%, H2O < 0.1%, Merck, RFN) and 1,3-butanediol (GC>99%, H2O < 0.2%, Merck-Schuchardt, RFN) were used without further purification. Only the water content was checked by the Karl Fischer dead-point method and found to be no more than 0.06% vol. and 0.01% j vol., respectively. The mixtures were prepared by weighing. The absorption of ultrasound was measured within the frequency range 10-80 MHz using a pulse transmission method. The measuring set designed and constructed at our laboratory f was used. The accuracy of the measurements was estimated to be š5%. For both pure components and all investigated mixtures the quotient alfa/f2 is independent of frequency (within the investigated frequency range); the relaxation times must be | consequently distinctly smaller than (2 . pi . 80 MHz)'1 = 2-10-9 s. The concentration dependence of the mean ultrasonic absorption alfa/f2 is monotonie, alfa/2l increased with increasing concentration of 1,3-butanediol.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.