Ultrasonic dispersion studies in 3-methylcyclohexanone

1981 ◽  
Vol 59 (21) ◽  
pp. 3084-3086 ◽  
Author(s):  
Budideti Ananda Reddy ◽  
Nagineni Prabhakara Rao
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Ultrasonic Velocity ◽  
Velocity Dispersion ◽  
Frequency Range ◽  
Ultrasonic Dispersion ◽  
Temperature Range ◽  
Energy Parameters ◽  
Relaxation Parameters

Using a variable path interferometer, ultrasonic velocity dispersion in 3-methylcyclohexanone was studied in the temperature range 323.15 K to 363.15 K and in the frequency range 0.5 MHz to 5.0 MHz. The relaxation parameters were evaluated from the experimental data. These values were utilised to evaluate the energy parameters; the differences in the enthalpy (ΔH0), the free energy (ΔG0), and the entropy (ΔS0) are 2.79 kcal/mol, 0.88 kcal/mol, and 5.9 cal/mol K, respectively. The enthalpy (ΔHr) for the backward reaction was 7.63 kcal/mol.

Study of potential curves by UHF type methods. CH4 molecule and its dissociation products

1986 ◽  
Vol 51 (4) ◽  
pp. 731-737
Author(s):  
Viliam Klimo ◽  
Jozef Tiňo
Keyword(s):  
Experimental Data ◽  
Quantum Chemistry ◽  
High Energy ◽  
Basis Set ◽  
Electronic Correlation ◽  
Exact Methods ◽  
Energy Parameters ◽  
Bond Functions ◽  
The Individual ◽  
Potential Curves

Geometry and energy parameters of the individual dissociation intermediate steps of CH4 molecule, parameters of the barrier to linearity and singlet-triplet separation of the CH2 molecule have been calculated by means of the UMP method in the minimum basis set augmented with the bond functions. The results agree well with experimental data except for the geometry of CH2(1A1) and relatively high energy values of CH(2II) and CH2(1A1) where the existence of two UHF solutions indicates a necessity of description of the electronic correlation by more exact methods of quantum chemistry.

scholarly journals Kinetics and thermodynamic properties related to the drying of 'Cabacinha' pepper fruits

2016 ◽  
Vol 20 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Hellismar W. da Silva ◽  
Renato S. Rodovalho ◽  
Marya F. Velasco ◽  
Camila F. Silva ◽  
Luís S. R. Vale
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Removal Rate ◽  
Effective Diffusion ◽  
Drying Time ◽  
Three Samples ◽  
Different Temperatures

ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathematical models often used in the representation of fruit drying. Effective diffusion coefficients, calculated from the mathematical model of liquid diffusion, were used to obtain activation energy, enthalpy, entropy and Gibbs free energy. The Midilli model showed the best fit to the experimental data of drying of 'Cabacinha' pepper fruits. The increase in drying temperature promoted an increase in water removal rate, effective diffusion coefficient and Gibbs free energy, besides a reduction in fruit drying time and in the values of entropy and enthalpy. The activation energy for the drying of pepper fruits was 36.09 kJ mol-1.

Ultrasonic velocity dispersion in bovine cortical bone: An experimental study

2008 ◽  
Vol 124 (3) ◽  
pp. 1811-1821 ◽  
Author(s):  
Guillaume Haïat ◽  
Magali Sasso ◽  
Salah Naili ◽  
Mami Matsukawa
Keyword(s):  
Experimental Study ◽  
Cortical Bone ◽  
Ultrasonic Velocity ◽  
Velocity Dispersion

scholarly journals Thermal Degradation Behaviour of Ni(II) Complex of 3,4-Methylenedioxaphenylaminoglyoxime

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emin Karapınar ◽  
Ilkay Hilal Gubbuk ◽  
Bilge Taner ◽  
Pervin Deveci ◽  
Emine Ozcan
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Free Energy ◽  
Thermal Degradation ◽  
Metal Complex ◽  
Kinetic Parameters ◽  
Preexponential Factor ◽  
Degradation Behaviour ◽  
Mechanism Of Decomposition ◽  
Pyrolytic Decomposition

Thermal degradation behaviour of the Ni(II) complex of 3,4-methylenedioxaphenylaminoglyoxime was investigated by TG, DTA, and DTG at a heating rate of 10°C min−1under dinitrogen. The acquired experimental data shows that the complex is thermally stable up to 541 K. The pyrolytic decomposition process occurs by melting metal complex and metal oxide remains as final product. The energies of the reactions involved and the mechanism of decomposition at each stage have been examined. The values of kinetic parameters such as activation energy (E), preexponential factor (A) and thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) are also evaluated.

scholarly journals High Frequency Magnetoimpedance of FeNi/Cu/FeNi Sensitive Elements with Different Geometries

2009 ◽  
Vol 152-153 ◽  
pp. 373-376 ◽  
Author(s):  
Stanislav O. Volchkov ◽  
Andrey V. Svalov ◽  
G.V. Kurlyandskaya
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
External Magnetic Field ◽  
Finite Elements ◽  
Magnetic Anisotropy ◽  
Constant Magnetic Field ◽  
High Frequency ◽  
Complex Impedance ◽  
Rf Sputtering ◽  
Frequency Range

In this work magnetoimpedance (MI) behaviour was studied experimentally for Fe19Ni81(175 nm)/Cu(350 nm)/Fe19Ni81(175 nm) sensitive elements deposited by rf-sputtering. A constant magnetic field was applied in plane of the sandwiches during deposition perpendicular to the Cu-lead in order to induce a magnetic anisotropy. Sandwiches with different width (w) of FeNi parts were obtained. The complex impedance was measured as a function of the external magnetic field for a frequency range of 1 MHz to 700 MHz for MI elements with different geometries. Some of MI experimental data are comparatively analysed with finite elements numerical calculations data. The obtained results can be useful for optimization of the design of miniaturized MI detectors.

Oscillations and Long-Lasting Correlations in a Model of the Lateral Geniculate Nucleus and Visual Cortex

2000 ◽  
Vol 84 (4) ◽  
pp. 1863-1868 ◽  
Author(s):  
Kyle L. Kirkland ◽  
Adam M. Sillito ◽  
Helen E. Jones ◽  
David C. West ◽  
George L. Gerstein
Keyword(s):  
Experimental Data ◽  
Visual Cortex ◽  
Cell Membrane ◽  
Lateral Geniculate Nucleus ◽  
Feedback Inhibition ◽  
Frequency Range ◽  
Lateral Geniculate ◽  
Low Threshold ◽  
Thalamocortical System

We have previously developed a model of the corticogeniculate system to explore cortically induced synchronization of lateral geniculate nucleus (LGN) neurons. Our model was based on the experiments of Sillito et al. Recently Brody discovered that the LGN events found by Sillito et al. correlate over a much longer period of time than expected from the stimulus-driven responses and proposed a cortically induced slow covariation in LGN cell membrane potentials to account for this phenomenon. We have examined the data from our model, and we found, to our surprise, that the model shows the same long-term correlation. The model's behavior was the result of a previously unsuspected oscillatory effect, not a slow covariation. The oscillations were in the same frequency range as the well-known spindle oscillations of the thalamocortical system. In the model, the strength of feedback inhibition from the cortex and the presence of low-threshold calcium channels in LGN cells were important. We also found that by making the oscillations more pronounced, we could get a better fit to the experimental data.

scholarly journals Температурная зависимость ширины запрещенной зоны монокристаллов MnAgIn-=SUB=-7-=/SUB=-S-=SUB=-12-=/SUB=-

2019 ◽  
Vol 53 (12) ◽  
pp. 1621
Author(s):  
И.В. Боднарь ◽  
Б.Т. Чан ◽  
В.Н. Павловский ◽  
И.Е. Свитенков ◽  
Г.П. Яблонский
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Band Gap ◽  
Single Crystals ◽  
Spinel Structure ◽  
Semiconductor Materials ◽  
Transmittance Spectra ◽  
Temperature Range

AbstractMnAgIn_7S_12 single crystals 16 mm in diameter and ~40 mm in length are grown by planar crystallization of the melt. It is shown that the material grown crystallizes with the formation of the cubic spinel structure. From the transmittance spectra recorded in the region of fundamental absorption in the temperature range 10–320 K, the band gap E _ g of the single crystals and its temperature dependence are determined. The dependence has a shape typical of most semiconductor materials: as the temperature is lowered, the band gap E _ g increases. A calculation is carried out, and it is shown that the calculated values are in agreement with the experimental data.

scholarly journals STUDY OF PROCESSES OF PRESSURE AND IMPULSE FREQUENCY INFLUENCE ON PENETRATION OF LIQUIDS IN THE SAND SAMPLES

2016 ◽  
pp. 120-125
Author(s):  
M. Ya. Habibullin ◽  
R. R. Shangareyev
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
Pressure Fluctuations ◽  
Experimental Studies ◽  
Regression Equations ◽  
Linear Variation ◽  
Frequency Range ◽  
Impulse Frequency ◽  
Overburden Pressure

The article deals with the issues related to the hydrocarbon reservoirs oil recovery enhancement. It describes the bench laboratory experimental studies. The results obtained during determination of fluid leakage through the rock samples and the amount of absorption of pressure fluctuations at various regime parameters are presented. Using the experimental data the regression analysis was performed on the basis of which the qualitative correlations between factorial and resultant features were identified. Using the regression equations the graphic relations were constructed. It was found that with increasing the oscillation frequency of the fluid the amount of fluid passing through the sample of porous medium increased, with the highest value of q reached at the frequency range of 600 ... 1000 Hz. With increase in the oscillations penetration depth the absorption of the amplitude of the pressure fluctuations corresponds to the linear decrease, and with the overburden pressure increase the linear variation of absorption is distorted.

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