Concentration fluctuations in water–methanol mixtures as studied by ultrasonic absorption

1976 ◽  
Vol 54 (3) ◽  
pp. 355-366 ◽  
Author(s):  
William D. T. Dale ◽  
Peter A. Flavelle ◽  
Peeter Kruus
Keyword(s):  
Experimental Data ◽  
Intermolecular Interactions ◽  
Vapour Pressure ◽  
Reasonable Agreement ◽  
Concentration Fluctuations ◽  
Ultrasonic Absorption ◽  
Diffusion Data ◽  
And Diffusion ◽  
Excess Absorption

Measurements of the ultrasonic absorption and velocity, and viscosity have been carried out in the system methanol–water at 0, 15, and 25 °C at frequencies from 10 to 50 MHz. The data show the existence of two maxima in the excess absorption as a function of composition. The existence of the two maxima are predicted by the Romanov–Solovyev theory relating the absorption to concentration fluctuations. The magnitude of the excess absorption is calculated at 25 and 0 °C from density, vapour pressure, and diffusion data. New experimental data on density and vapour pressure are presented for this system at 0 °C. The calculated excess absorption is in reasonable agreement with the measured. This indicates that any specific localized intermolecular interactions present in this system could be responsible for at best a smaller portion of the excess ultrasonic absorption, as longer range concentration fluctuations account for essentially all of the excess. Ultrasonic data on the systems methanol–octanol and n-propanol–water are also presented in the course of examining the generality of these phenomena.

Proton Transfer Kinetics in Medium-strong Inorganic Acids

1973 ◽  
Vol 51 (14) ◽  
pp. 2297-2305 ◽  
Author(s):  
David Charles Hodgkin ◽  
Peeter Kruus
Keyword(s):  
Proton Transfer ◽  
Aqueous Solutions ◽  
Rate Constants ◽  
Reasonable Agreement ◽  
Ultrasonic Absorption ◽  
Absolute Rate ◽  
Absorption Data ◽  
Inorganic Acids ◽  
Diffusion Controlled ◽  
Excess Absorption

A method of obtaining relative and absolute rate constants for proton transfer equilibria is described. It is suitable for equilibria of the type[Formula: see text]in dilute (< 0.1 M) solutions of medium strong inorganic acids. To obtain absolute values of kd, kr it is necessary to know the value of ΔV0 for the equilibrium. Ultrasonic absorption data for aqueous solutions of H3PO4, H3AsO4, and H2SO4 at 20, 10, and 0 °C are presented together with data at 20 °C for H3PO3, H2SeO3, HIO4, NaHSO4, KHSO4, and NH4HSO4. From analysis of the concentration dependence of the excess absorption, values of Ka are calculated for these acids, and values of kd, kr for those where ΔV0 is available. The Ka obtained are in reasonable agreement with literature values except for HIO4 and H2SeO4. The absolute values of kr for H3PO4, H3AsO4, and HSO4− indicate that the diffusion controlled recombination process postulated is complete when the ions are about 15 Å from each other.

Experimental investigation and thermodynamic calculation in the Ag–Bi–Ni and Cu–Bi–Ni systems

2009 ◽  
Vol 24 (8) ◽  
pp. 2644-2653 ◽  
Author(s):  
Feng Gao ◽  
Cuiping Wang ◽  
X.J. Liu ◽  
Yoshikazu Takaku ◽  
I. Ohnuma ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Equilibria ◽  
Intermetallic Compounds ◽  
Electron Probe ◽  
Reasonable Agreement ◽  
Diffusion Couples ◽  
Scanning Calorimetry ◽  
Temperatures Of Phase Transformations ◽  
Ternary Intermetallic Compound ◽  
And Diffusion

The phase equilibria at 300, 400, 500, and 600 °C in the Ag–Bi–Ni system and 300, 400, and 500 °C in the Cu–Bi–Ni system were experimentally determined by metallography and electron probe microanalysis on equilibrated alloys and diffusion couples. Differential scanning calorimetry was used to measure the temperatures of phase transformations. All the experimental results show that the solubilities of the ternary elements of the binary intermetallic compounds in the Ag–Bi–Ni system are limited. However, the binary intermetallic compounds have some solubilities of the ternary elements in the Cu–Bi–Ni system. No ternary intermetallic compound was found in the Ag–Bi–Ni and Cu–Bi–Ni systems. On the basis of the determined results, the phase equilibria in the Ag–Bi–Ni and Cu–Bi–Ni systems were thermodynamically assessed, and reasonable agreement between the calculated results and experimental data was obtained.

Virus Removal by Filtration

1982 ◽  
Vol 14 (4-5) ◽  
pp. 253-256
Author(s):  
N Sriramula ◽  
M Chaudhuri
Keyword(s):  
Experimental Data ◽  
Escherichia Coli ◽  
Cationic Polyelectrolyte ◽  
Electrokinetic Phenomena ◽  
Virus Removal ◽  
Bacterial Virus ◽  
Gravity Settling ◽  
And Diffusion ◽  
Model Virus ◽  
Good Agreement

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.

Dolomite-calcite equilibrium at 220 to 240 °C at saturation vapour pressure: Experimental data

1994 ◽  
Vol 58 (1) ◽  
pp. 169-177 ◽  
Author(s):  
David W Morrow ◽  
Brad L Gorham ◽  
Jenny N.Y Wong
Keyword(s):  
Experimental Data ◽  
Vapour Pressure ◽  
Saturation Vapour Pressure

Impurity-Induced Layer Disordering in AlxGa1−xAs-GaAs Quantum well Heterostructures -

1988 ◽  
Vol 126 ◽  
Author(s):  
D. G. Deppe ◽  
L. J. Guido ◽  
N. Holonyak
Keyword(s):  
Experimental Data ◽  
Quantum Well ◽  
Laser Diodes ◽  
Growth Direction ◽  
High Power Laser ◽  
Power Laser ◽  
Frenkel Defects ◽  
Buried Heterostructure ◽  
And Diffusion ◽  
Disordered Regions

ABSTRACTSelective interdiffusion of Al and Ga at AlxGa1−x As-GaAs heterointerfaces can be carried out by conventional masking procedures and diffusion of acceptor impurities (e.g., Zn), or donor impurities (e.g., Si), or also by ion implantation. This process, impurity-induced layer disordering (IILD), makes it possible to convert quantum well heterostructures (QWHs) such as AlxGa1−xAs-GaAs superlattices (SLs) into bulk homogeneous AlyGa1−yAs where y is the average Al composition of the QWH or SL. Since th IILY process is maskable and thus selective, heterojunctions can be formed in directions perpendicular to the crystal growth direction, i.e., between as-grown “ordered” and IILD “disordered” regions. To date this process has been used most effectively in the fabrication of buriedheterostructure QW lasers, single and multiple stripe, where the disordered regions provide both optical and electrical confinement. The IILD process has also been used to advantage in the fabrication of high power laser diodes with non-absorbing “windows” at the laser facets and thus with better immunity from facet damage. In this paper we present data on the application of the IILD process to the fabrication of buried-heterostructure QW laser diodes. We also describe possible mechanisms by which the impurity-induced layer disordering proceeds based on Column III “Frenkel” defects and the influence of the crystal Fermi level on the defect solubility. These mechanisms are supported by experimental data.

Numerical Simulations as a Reliable Alternative for Landmine Explosion Studies: The AUTODYN Approach

2010 ◽  
Author(s):  
Stephanie Follett ◽  
Amer Hameed ◽  
S. Darina ◽  
John G. Hetherington
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Reasonable Agreement ◽  
Specific Impulse ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Time Of Arrival ◽  
Linear Dynamics ◽  
Non Linear

In order to validate the numerical procedure, the explosion of a mine was recreated within the non-linear dynamics software, AUTODYN. Two models were created and analysed for the purposes of this study — buried and flush HE charge in sand. The explosion parameters — time of arrival, maximum overpressure and specific impulse were recorded at two stand-off distances above the ground surface. These parameters are then compared with LS-DYNA models and published experimental data. The results, presented in table format, are in reasonable agreement.

The thermodynamic properties of mixed phospholipid bilayers: a theoretical analysis

1984 ◽  
Vol 62 (8) ◽  
pp. 796-802 ◽  
Author(s):  
Maryse Mondat ◽  
A. Georgallas ◽  
D. A. Pink ◽  
M. J. Zuckermann
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Reasonable Agreement ◽  
Phospholipid Bilayers ◽  
Scanning Calorimetry ◽  
Phase Separations ◽  
Lipid Mixtures ◽  
Wide Range ◽  
Acyl Chains ◽  
Gel Phase

A theoretical model is presented with the intention of describing lateral phase separations in binary lipid mixtures in which the acyl chains of the components differ in their length. The model includes explicitly interactions between the acyl chains and between polar heads of the lipid molecules. Phase diagrams and thermodynamic properties of binary lipid mixtures were calculated using a wide range of interaction parameters. It is shown that the occurrence of immiscibility in the gel phase is related to the interactions between the polar heads of the lipid molecules. The calculated results for binary lipid mixtures are compared with the available experimental data. In particular, the calculated specific heat for dilauroyl phosphatidylcholine – distearoyl phosphatidylcholine is in reasonable agreement with experimental results obtained from differential scanning calorimetry measurements.

scholarly journals Spectral Fourier-microscopy of the periodic structures based on Ge2Sb2Te5

2021 ◽  
Vol 2103 (1) ◽  
pp. 012173
Author(s):  
A I Solomonov ◽  
S I Pavlov ◽  
P I Lazarenko ◽  
V V Kovalyuk ◽  
A D Golikov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reasonable Agreement ◽  
Angular Resolution ◽  
Periodic Structures ◽  
Diffraction Gratings ◽  
Dispersion Curves ◽  
Reflection Spectra ◽  
Waveguide Modes ◽  
Periodic Gratings

Abstract The method of spectral Fourier microscopy was used to study the reflection spectra with an angular resolution of submicron periodic gratings based on amorphous and crystalline Ge2Sb2Te5. The form of the dispersion curves of quasi-waveguide modes in the structures under study was established. The experimental data were compared with the calculations of dispersion curves in synthesized diffraction gratings. Reasonable agreement between theoretical and experimental data was obtained.

Dynamical Theory for Simultaneous X-Ray Diffraction

1966 ◽  
Vol 10 ◽  
pp. 67-79
Author(s):  
P. Penning
Keyword(s):  
Experimental Data ◽  
Plane Wave ◽  
Quantitative Data ◽  
Reasonable Agreement ◽  
Dynamical Theory ◽  
Inversion Symmetry ◽  
Surprising Result ◽  
X Ray Diffraction ◽  
Wave Fields ◽  
X Ray

AbstractComplete dynamical solutions for three coupled plane-wave components in crystal structures with inversion symmetry have been found. After reviewing briefly the dynamical solutions for wave fields with two coupled plane-wave components, the results for the three-beam case are discussed in qualitative terms. Attention is paid to singular points and lines on the ω-surface, and to the attenuation of the mode-intensity because of absorption. The most surprising result is that in the case one of the reflections is forbidden (Umweganregung) the absorption is reduced in comparison with the adjoining two-beam cases. Experimental data are in reasonable agreement with the theory. Quantitative data are presented for a few three-beam cases of simultaneous diffraction of Cu Kα. radiation in germanium.

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