The density, electrical conductivity, freezing point, and viscosity of mixtures of trifluoromethanesulfonic acid and water

1978 ◽  
Vol 56 (13) ◽  
pp. 1832-1835 ◽  
Author(s):  
Ronald Corkum ◽  
John Milne
Keyword(s):  
Electrical Conductivity ◽  
Composition Range ◽  
Freezing Point ◽  
Specific Conductivity ◽  
Trifluoromethanesulfonic Acid ◽  
Maximum Deviation ◽  
Incongruent Melting ◽  
Point Curve ◽  
The Ideal

Density, viscosity, specific conductivity, and freezing point measurements over the whole composition range of water–trifluoromethanesulfonic acid mixtures are reported. A maximum in viscosity and minimum in specific conductivity are observed at the composition corresponding to the monohydrate, H3O+SO3CF3−, and a maximum deviation from the ideal density is found at the composition corresponding to H5O2+SO3CF3−. The freezing point curve gives evidence for four hydrates with 1:1, 2:1, 4:1, and 6:1 water/trifluoromethanesulfonic acid mole ratios. An incongruent melting hydrate, probably 2:1 acid to water mole ratio is also indicated.

THE SYSTEM NAPHTHALENE–p-NITROPHENOL: AN EXPERIMENTAL INVESTIGATION OF ALL THE VARIABLES IN AN EQUATION OF THE FREEZING POINT CURVE

1941 ◽  
Vol 19b (3) ◽  
pp. 73-85 ◽  
Author(s):  
A. N. Campbell ◽  
A. J. R. Campbell
Keyword(s):  
Surface Tension ◽  
Freezing Point ◽  
Heat Of Fusion ◽  
Heat Of Mixing ◽  
Raoult’S Law ◽  
Compound Formation ◽  
Point Curve ◽  
Freezing Curve ◽  
The Ideal ◽  
Raoult's Law

With the object of determining the factors responsible for the inapplicability of the ideal equation of the freezing curve,[Formula: see text]a number of experimental determinations have been carried out on the system naphthalene–p-nitrophenol. These were: (i) specific heat, (ii) heat of fusion, (iii) heat of mixing, (iv) vapour pressure, (v) vapour composition, (vi) density, (vii) surface tension, (viii) viscosity.The conclusion is arrived at that the discrepancy is due principally to the invalidity of Raoult's law in this case. Since the deviation is positive with respect to both components, it cannot be ascribed to compound formation in solution. Apart from the deviation from Raoult's law, the solution does not exhibit marked abnormality.The data obtained also permit of the complete, or almost complete, construction of the p–t–x model for this system.

Electrical Conductivity of Magnesium Oxide/Molten Carbonate Eutectic Coexisting System

2019 ◽  
Vol 74 (9) ◽  
pp. 739-742
Author(s):  
Elena V. Nikolaeva ◽  
Andrey L. Bovet ◽  
Irina D. Zakiryanova
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Magnesium Oxide ◽  
Solid Phase ◽  
Specific Conductivity ◽  
Maxwell Model ◽  
Impedance Method ◽  
Molten Carbonate ◽  
Carbonate Ions ◽  
Alkali Carbonate

AbstractThe electrical conductivity of molten ternary alkali carbonate eutectic, coexisting with MgO particles, has been investigated. The conductivity was measured by the AC impedance method. The apparent activation energy ΔEa increased with the MgO content. This fact can be attributed to the effect of the solid phase. The specific conductivity of those systems could not be described using the Maxwell model over the solvation process of the carbonate ions on the particles of the magnesium oxide.

LOW TEMPERATURE RESISTIVITY OF TRANSITION ELEMENTS: VANADIUM, NIOBIUM, AND HAFNIUM

1957 ◽  
Vol 35 (8) ◽  
pp. 892-900 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Electrical Resistance ◽  
Thermal Resistivity ◽  
Superconducting Transition ◽  
Transition Elements ◽  
Pure Niobium ◽  
Temperature Resistivity ◽  
The Ideal

Measurements of the thermal conductivity from 2° to 90 ° K. and electrical conductivity from 2° to 300 ° K. are reported for vanadium, niobium, and hafnium. Although the vanadium and hafnium are not as pure as we might wish, measurements on these metals and on niobium allow a tabulation of the "ideal" electrical resistivity clue to thermal scattering for these elements from 300 ° K. down to about 20 ° K. Ice-point values of the "ideal" electrical resistivity are 18.3 μΩ-cm. for vanadium, 13.5 μΩ-cm. for niobium, and 29.4 μΩ-cm. for hafnium. Values for the "ideal" thermal resistivity of vanadium and niobium are deduced from the experimental results although for vanadium and more particularly for hafnium, higher purity specimens are required before a very reliable study of "ideal" thermal resistivity can be made. For the highly ductile pure niobium, the superconducting transition temperature, as determined from electrical resistance, appears to be close to 9.2 ° K.

scholarly journals Influence of Dental Composite Viscosity in Attachment Reproduction: An Experimental in Vitro Study

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4001
Author(s):  
Vincenzo D’Antò ◽  
Simone Muraglie ◽  
Beatrice Castellano ◽  
Ettore Candida ◽  
Maria Francesca Sfondrini ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Dental Composite ◽  
Maximum Deviation ◽  
Force System ◽  
Maximum Value ◽  
Significant Difference ◽  
The Difference ◽  
Level Of Significance ◽  
The Ideal

Background: Attachments are composite auxiliaries that are used during a clear aligner orthodontic therapy to achieve difficult tooth movements. Two important factors are the planned configuration and the actual position of these auxiliary elements to obtain the desired force system. The aim of the present study was to evaluate the role of different composite materials in the correct reproduction of attachment shape and position. Methods: The materials that were considered in the study were a flowable resin, a dental restorative material, and an orthodontic composite. The attachments were created on three models of extracted teeth. Once the impressions were performed, 25 attachments of different shapes were added onto each virtual model to obtain the necessary templates to make the attachments. Each tested material was used to create a set of 25 attachments that were then scanned with an accuracy of 10μm. The resultant STL (stereolithography) files were superimposed onto the ones from the initial virtual plan, through Geomagic software, and the aligned scans were then compared while using a color map. The parameters that were calculated to make a comparison between the created attachments and the ideal ones were the maximum deviation in defect and in excess, the overflow, and the volume’s difference. In addition to these measurements comparing the three above-mentioned groups, the difference in volume between all the ideal and realized samples were analyzed. To test for differences among the three groups, a one-way Analysis of variance (ANOVA) was used with a Bonferroni post-hoc test. The level of significance was set at p < 0.05. Results: No statistically significant results were found between the three groups regarding the maximum value in defect, the maximum value in excess, and the minimum value as control, while a statistically significant difference was found between the overflow of orthodontic resin when compared to the flowable composite. Conclusions: The three materials that were used in this study were appropriate for attachment fabrication. The fidelity of attachment reproduction was similar when using the three different composites. The orthodontic composite showed more overflow when compared with the flowable one.

Effect of Electrical Pulse Ageing on Microstructure and Properties of Cu-2.5Fe-0.03P-0.1Zn Copper Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 2635-2638
Author(s):  
Jin Liang Huang ◽  
Qiang Li ◽  
Ping Liu ◽  
Qi Ming Dong
Keyword(s):  
Electrical Conductivity ◽  
Theoretical Analysis ◽  
Copper Alloy ◽  
High Density ◽  
Experimental Results ◽  
Electrical Pulse ◽  
Lead Frame ◽  
Microstructure And Properties ◽  
Nano Size ◽  
The Ideal

Milisecond high density electrical pulse was used to age one of the typical IC lead frame materials Cu-2.5Fe-0.03P-0.1Zn copper alloy. The effects of electrical pulse aging on the microstructures, electrical conductivity and microhardness of this alloy were systematically investigated. The experimental results shown that the alloy phase precipitated in Cu-2.5Fe-0.03P-0.1Zn copper alloy during electrical pulse aging could be controlled to the order of nano-size and the ideal match of electrical conductivity and microhardness could be achieved in the condition of optimized parameters of electrical pulse. The electrical conductivity of the alloy was kept at above 60%IACS while the microhardness reached to HV115. A preliminary theoretical analysis was made to explain the unique action of electrical pulse.

scholarly journals The Freezing-Point Curve of the System: Ortho-cresol–Naphthalene

1921 ◽  
Vol 25 (6) ◽  
pp. 491-494 ◽  
Author(s):  
F. H. Rhodes ◽  
F. E. Hance
Keyword(s):  
Freezing Point ◽  
Point Curve ◽  
Ortho Cresol

scholarly journals Thermodynamic properties of 1-ethyl-3-methylimidazolium ethyl sulphate with nitrogen and sulphur compounds at T = (298.15 - 318.15) K and P = 1 bar

2016 ◽  
Author(s):  
◽  
Siyanda Brian Chule
Keyword(s):  
Refractive Index ◽  
Thermodynamic Properties ◽  
Binary Mixture ◽  
Binary Mixtures ◽  
Mole Fraction ◽  
Ethyl Acetoacetate ◽  
Binary Systems ◽  
Composition Range ◽  
Molar Refraction ◽  
The Ideal

In this work, the thermodynamic properties for the binary mixtures containing the ionic liquid (IL): 1-ethyl-3-methylimidazolium ethyl sulphate ([EMIM] [EtSO4]) were calculated. The binary systems studied were {pyridine (Py) or ethyl acetoacetate (EAA) or thiophene (TS) + [EMIM] [EtSO4]}. The results were interpreted in terms of the intermolecular interactions between the (pyridine + IL), (ethyl acetoacetate + IL), and (thiophene + IL) molecules. The physical properties: density, speed of sound, and refractive index were measured for the binary mixtures over the complete mole fraction range using an Anton Paar DSA 5000 M vibrating U- tube densimeter and an Anton Paar RXA 156 refractometer, respectively. The measurements were done at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K and at p = 0.1 MPa. The experimental data was used to calculate the derived properties for the binary mixtures namely:- excess molar volume (V E ), isentropic compressibility (ks), molar refractions (R) and deviation in refractive index (Δn). For the binary mixtures, (Py or EAA or TS + IL), V E was negative throughout the whole composition range which indicates the existence of attractive intermolecular interaction between (pyridine + IL) and (ethyl acetoacetate + IL) for (thiophene + IL), V E was negative at low mole fraction of thiophene and became positive at high mole fraction of thiophene. For the binary mixtures (pyridine + IL), (ethyl acetoacetate + IL), ks was positive indicating that the binary mixtures were more compressible than the ideal mixture. For the binary mixture (thiophene + IL) ks was negative at low thiophene composition and positive at high composition indicating that the binary mixture was less compressible than the ideal mixture at low thiophene composition and more compressible at high composition of thiophene. The molar refraction, R, is positive for the (Py or EAA or TS + IL) binary systems at T = (298.15 – 318.15) K, molar refraction decreases as the organic solvent composition increases. For the binary mixture (pyridine + [EMIM] [EtSO4]), Δn is negative at mole fractions < 0.75 of pyridine and positive at mole fractions >0.75 at all temperatures and decreases with an increase in temperature. For the binary system (ethyl acetoacetate + [EMIM] [EtSO4]), Δn values are positive over the entire composition range and at all temperatures and increases with an increase in temperature. Δn values for the (thiophene + IL) system are negative for mole fractions of thiophene < 0.62 and becomes positive for mole fractions of thiophene > 0.62 and Δn increases with an increase in temperature. The Redlich-Kister smoothing equation was used successfully for the correlation of V E and Δn data. The Lorentz- Lorenz equation gave a poor prediction of V E , but a good prediction of density or refractive index.

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