Collision-induced spectra of hydrogen in the first and second overtone regions with applications to planetary atmospheres

1971 ◽  
Vol 322 (1551) ◽  
pp. 421-434 ◽  
Keyword(s):  
Path Length ◽  
Planetary Atmospheres ◽  
Pure Hydrogen ◽  
Absorption Path Length ◽  
Helium Content ◽  
Temperature Range ◽  
The Third ◽  
Helium Mixture ◽  
Integrated Intensities ◽  
Good Agreement

The pressure-induced spectra of hydrogen in the regions of the first and second overtones have been recorded with an absorption path length of 137 m in the temperature range 85 to 116 K. For pure hydrogen the structure and integrated intensities of the bands are in good agreement with calculations based on the theory of quadrupole induction, except that the second overtone shows evidence of a small amount of overlap induction. The enhancements of the first overtone in hydrogen + argon and hydrogen + nitrogen mixtures have structures in accordance with quadrupole induction, but the calculated intensities are somewhat too high. The enhancement of the first overtone in the hydrogen + helium mixture was too weak to be recorded. Calculated profiles for the third overtone in pure hydrogen are given. The implication of these measurements for studies of the hydrogen and helium content of planetary atmospheres is discussed.

Induced Fundamental Infrared Band of Nitrogen Dissolved in Solid Argon

1971 ◽  
Vol 49 (24) ◽  
pp. 3201-3207 ◽  
Author(s):  
J. De Remigis ◽  
H. L. Welsh ◽  
R. Bruno ◽  
D. W. Taylor
Keyword(s):  
Path Length ◽  
Harmonic Approximation ◽  
Host Lattice ◽  
Mode Frequency ◽  
Local Mode ◽  
Infrared Band ◽  
Temperature Range ◽  
Solid Argon ◽  
Experimental Temperature Range ◽  
Good Agreement

The induced fundamental infrared band of nitrogen dissolved in solid argon was studied over the temperature range 55–81 K with a path length of 40 cm and molar N2 concentrations of 1−2%. The spectrum consists of combination tones of lattice transitions with the N2 1 ← 0 vibrational transition. Lattice transition frequencies of 70 and 39 cm−1 at 55 K are identified with a local mode and vibrations of the host-lattice atoms respectively. We have computed the local-mode frequency over the experimental temperature range using one-defect theory in a harmonic approximation employing temperature-corrected experimental phonon frequencies and obtain good agreement with the observed values. The 39 cm−1 peak can be identified with features of the transverse region of the Ar phonon density of states.

Antiferromagnetic exchange in triclinic crystals of tetra-u-benzoato- bits (4-methylquinoline) dicobalt II

1978 ◽  
Vol 360 (1701) ◽  
pp. 191-210 ◽  
Keyword(s):  
Cobalt Complex ◽  
Preceding Paper ◽  
Transverse Magnetic ◽  
Antiferromagnetic Coupling ◽  
Temperature Range ◽  
General Terms ◽  
Carboxylate Groups ◽  
A New Technique ◽  
Unambiguous Conclusion ◽  
Good Agreement

The magnetic susceptibilities of tetra- u -benzoato- bis (4-methylquinoline) dicobalt ii have been measured and interpreted within the theoretical model described in the preceding paper. Crystals of the title complex are triclinic, a circumstance which has lead to the development of a new technique for the measurement of triclinic crystal susceptibilities using a Faraday balance. The technique is discussed in general terms and is applicable with Faraday equipment employing either longitudinal or, as here, transverse magnetic fields. The magnetic tensor for this binuclear cobalt complex has been determined throughout the temperature range 20- 300 K. Good agreement between these results and those calculated from the quantum mechanical model have been obtained in the temperature range 90-300 K. At lower temperatures, a probable small paramagnetic impurity prevents useful theoretical treatm ent. There emerges an unambiguous conclusion that the antiferromagnetic coupling between the cobalt atoms is almost completely determined by interaction between metal xy orbitals, presumably via a superexchange process involving the delocalized n bonding framework of the bridging carboxylate groups.

Influence of Temperature on Hydraulic Conductivity in Compacted Bentonite

1997 ◽  
Vol 506 ◽  
Author(s):  
W. J. Cho ◽  
J. O. Lee ◽  
K. S. Chun
Keyword(s):  
Hydraulic Conductivity ◽  
Influence Of Temperature ◽  
Temperature Range ◽  
Compacted Bentonite ◽  
Influence Of Temperature On ◽  
Water Saturated ◽  
Increasing Temperature ◽  
Good Agreement

ABSTRACTThe hydraulic conductivities in water saturated bentonites at different densities were measured within temperature range of 20 to 80 °C. The results show that the hydraulic conductivities increase with increasing temperature. The hydraulic conductivities of bentonites at the temperature of 80 °C increase up to about 3 times as high as those at 20 °C. The measured values are in good agreement with those predicted. The change in viscosity of water with temperature contributes greatly to increase of hydraulic conductivity.

On-chip cavity-enhanced absorption spectroscopy using a white light-emitting diode and polymer mirrors

Lab on a Chip ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Cathy M. Rushworth ◽  
Gareth Jones ◽  
Martin Fischlechner ◽  
Emma Walton ◽  
Hywel Morgan
Keyword(s):  
Absorption Spectroscopy ◽  
White Light ◽  
Microfluidic Chip ◽  
Path Length ◽  
Light Emitting Diode ◽  
Absorption Path Length ◽  
Light Emitting ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
On Chip

We have integrated disposable polymer mirrors within a microfluidic chip to form a multi-pass cell, which increases the absorption path length by a maximum of 28 times, providing micromolar detection limits in a probed volume of 10 nL.

New Developments for the Description of Oil Leakages by Advective Migration From Submarine Pipelines

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Renan Martins Baptista ◽  
Ricardo Antonio Francisco Machado ◽  
Marintho Bastos Quadri ◽  
Ariovaldo Bolzan ◽  
André Lourenço Nogueira ◽  
...  
Keyword(s):  
Horizontal Plane ◽  
Immiscible Displacement ◽  
Preliminary Evaluation ◽  
Leakage Detection ◽  
New Developments ◽  
Gravitational Flow ◽  
The Third ◽  
Alternative Approach ◽  
High Standards ◽  
Good Agreement

The significant growth in offshore operations increases the risk of a pipeline rupture, even considering the high standards of safety involved. Throughout a submarine leakage, four different amounts of oil may be accounted. The first one is the oil volume released until the leakage detection. The second one is the volume leaked throughout mitigation initiatives (e.g., pump shutdown and valve closure). The third parcel is the amount released by gravitational flow. Finally, the fourth and last amount of oil is released due to the water-oil entrainment, generally known as advective migration. Normally, a considerable amount of oil is released in this step. It begins just after the internal pipeline pressure becomes equal to the external one. The present work continues to introduce a mathematical alternative approach, based on the theories of perturbation and unstable immiscible displacement, to accurately estimate the leakage kinetics and the amount of oil released by the advective migration phenomenon. Situations considering different hole sizes and thicknesses were tested experimentally and through simulations. Additional experiments were accomplished using smooth and rough edge surfaces, besides different slopes (using the horizontal plane as reference). Those experiments permitted a preliminary evaluation of the importance of these factors. The results obtained with the model showed good agreement with the experimental data in many situations considered.

scholarly journals Описание колоссального магнитосопротивления La-=SUB=-1.2-=/SUB=-Sr-=SUB=-1.8-=/SUB=-Mn-=SUB=-2-=/SUB=-O-=SUB=-7-=/SUB=- на основе "спин-поляронного" и "ориентационного" механизмов проводимости в парамагнитной области температур

2020 ◽  
Vol 62 (5) ◽  
pp. 669
Author(s):  
С.А. Гудин ◽  
Н.И. Солин
Keyword(s):  
Magnetic Field ◽  
Colossal Magnetoresistance ◽  
Main Role ◽  
Spin Polaron ◽  
Temperature Range ◽  
Conduction Mechanisms ◽  
Theoretical Investigations ◽  
Temperature Dependences ◽  
The Magnetic Field ◽  
Good Agreement

Experimental and theoretical investigations of the resistance of the La1.2Sr1.8Mn2O7 single crystal in magnetic fields from 0 to 90 kOe and in the temperature range from 75 to 300 K has been studied. The magnetoresistance is determined by the “spin-polaron” and “orientation” conduction mechanisms. Using the method of separating contributions to the magnetoresistance from several conduction mechanisms, the observed magnetoresistance of La1.2Sr1.8Mn2O7 manganite in the temperature range of 75-300 K is described, good agreement between the calculated and experimental data is obtained. In a magnetic field of 0 and 90 kOe, the temperature dependences of the size of the spin polaron (in relative units) are calculated for the temperature range 75–300 K. It is shown, that the КМС value is determined by an increase in the linear size of the spin polaron (along the magnetic field), i.e. the main role in the magnitude of the colossal magnetoresistance is made by the change in the size of the magnetic inhomogeneities of the crystal.

A Two-Dimensional Potential Flow Model of the Wave Field Generated by a Semisubmerged Body in Heaving Motion

1988 ◽  
Vol 32 (02) ◽  
pp. 83-91
Author(s):  
X. M. Wang ◽  
M. L. Spaulding
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Potential Flow ◽  
Flow Model ◽  
Second Order ◽  
Two Dimensional ◽  
Third Order ◽  
The Third ◽  
Potential Flow Model ◽  
Good Agreement

A two-dimensional potential flow model is formulated to predict the wave field and forces generated by a sere!submerged body in forced heaving motion. The potential flow problem is solved on a boundary fitted coordinate system that deforms in response to the motion of the free surface and the heaving body. The full nonlinear kinematic and dynamic boundary conditions are used at the free surface. The governing equations and associated boundary conditions are solved by a second-order finite-difference technique based on the modified Euler method for the time domain and a successive overrelaxation (SOR) procedure for the spatial domain. A series of sensitivity studies of grid size and resolution, time step, free surface and body grid redistribution schemes, convergence criteria, and free surface body boundary condition specification was performed to investigate the computational characteristics of the model. The model was applied to predict the forces generated by the forced oscillation of a U-shaped cylinder. Numerical model predictions are generally in good agreement with the available second-order theories for the first-order pressure and force coefficients, but clearly show that the third-order terms are larger than the second-order terms when nonlinearity becomes important in the dimensionless frequency range 1≤ Fr≤ 2. The model results are in good agreement with the available experimental data and confirm the importance of the third order terms.

Modelling of an alternating oxidation ditch system

1999 ◽  
Vol 39 (4) ◽  
pp. 169-176 ◽  
Author(s):  
A. Stamou ◽  
A. Katsiri ◽  
I. Mantziaras ◽  
K. Boshnakov ◽  
B. Koumanova ◽  
...  
Keyword(s):  
Pilot Plant ◽  
High Speed ◽  
Dispersion Coefficient ◽  
Carbon Oxidation ◽  
Correction Factors ◽  
Oxidation Ditch ◽  
The Third ◽  
Basic Equations ◽  
Short Presentation ◽  
Good Agreement

This paper presents a mathematical model for an alternating oxidation ditch system, performing carbon oxidation-nitrification, denitrification and settling. The model consists of 1-dimensional mass balance (convection-dispersion) equations, based on the IAWPRC activated sludge model No 1. The data used for the calibration and the application of the model, are collected from a pilot plant. The present work consists of 3 parts. In the first part a brief description of the pilot plant is made. The second part deals with a short presentation of the basic equations and the boundary conditions of the model. The calibration and application of the model with the corresponding conclusions are contained in the third part. In the calibration, the values of the dispersion coefficient, E, and the correction factors α and β of the equation of the aeration equipment (rotors) have been determined equal to E=170000 m2 day−1, β=0.85 and α=0.3 and 0.825, for the operation of the rotors in the low and high speed, respectively. The application of the model shows that predicted effluent concentration values are in a very good agreement with experiments.

Basic Experiment on Lithium Removal Technique

2012 ◽  
Author(s):  
Tomohiro Furukawa ◽  
Yasushi Hirakawa
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dissolution Rate ◽  
Chemical Reaction ◽  
Pure Water ◽  
Preliminary Investigation ◽  
Testing Temperature ◽  
Temperature Range ◽  
Removal Technique ◽  
Good Agreement

As a preliminary investigation into the establishment of a lithium removal technique for the components used at the International Fusion Materials Irradiation Facility (IFMIF), experiments were performed on the dissolution of lithium in three solvents: ethanol, pure water, and ethanol–water. In these experiments, hemispherical lithium was immersed in the solvents at constant temperatures, and the degree of dissolution was measured continuously from the height of the sample. From the obtained data, the average dissolution rate in the solvents at each testing temperature (10–90 °C) and the amount of hydrogen generated by the chemical reaction were calculated. The average dissolution rates in ethanol, pure water, and ethanol–water at 30 °C were 0.01, 1.6, and 0.43 mm/min, respectively. Although the average dissolution rate increased with the testing temperature in the low-temperature range (10–50 °C) for all solvents, this increase was saturated in the high-temperature range (50–90 °C) in experiments with pure water and ethanol–water as solvents. The volume of gas collected during each experiment was in good agreement with the volume of hydrogen assumed to be generated from the chemical reaction of lithium with the solvents.

THE KINETICS OF THE THERMAL DECOMPOSITIONS OF THE LOWER PARAFFINS: V. THE NITRIC OXIDE INHIBITED DECOMPOSITION OF n-BUTANE

1940 ◽  
Vol 18b (1) ◽  
pp. 1-11 ◽  
Author(s):  
E. W. R. Steacie ◽  
H. O. Folkins
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Free Radical ◽  
High Pressures ◽  
Free Radical Processes ◽  
Temperature Range ◽  
Radical Recombination ◽  
Radical Processes ◽  
Kinetics Of ◽  
Good Agreement

A detailed investigation of the inhibition by nitric oxide of the thermal decomposition of n-butane has been carried out over the temperature range 500° to 550 °C.In all cases it was found that inhibition decreased with increasing butane concentration. This suggests that radical recombination occurs in the normal decomposition by ternary collisions with butane molecules acting as third bodies.The activation energies of the normal and inhibited reactions have been determined. For high pressures the two values are in good agreement, viz., 58,200 and 57,200 cal. per mole respectively. The products of the inhibited reaction were also found to be the same as those of the normal reaction.It is concluded that free radical processes predominate, involving comparatively short chains.

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