Equilibrium model for the interpretation of the conduction properties of metal–ammonia solutions

1977 ◽  
Vol 55 (11) ◽  
pp. 2211-2216 ◽  
Author(s):  
S. Hahne ◽  
P. Krebs ◽  
U. Schindewolf
Keyword(s):  
Electrical Conductivity ◽  
Pressure Range ◽  
High Mobility ◽  
Solvation Number ◽  
Free Electrons ◽  
Solvated Electrons ◽  
Entire Concentration Range ◽  
Pressure Coefficients ◽  
Temperature And Pressure ◽  
Conduction Properties

The electrical conductivity of metal–ammonia solutions can be described by an equilibrium of solvated electrons of low mobility and of free electrons of high mobility. With proper choice of the equilibrium constant and its temperature and pressure dependence and of the solvation number of the solvated species the experimental conductivities can be matched in the temperature and pressure range from 240 to 420 K and up to 1000 bar over the entire concentration range from 0.1 mol/ℓ to saturation, also fitting the extrema of the temperature and pressure coefficients of the conductivity around 1 mol/ℓ.

Is Thermal and Light-Induced Annealing of Met Astable Defects in a-Si:H Driven by Electrons?

1995 ◽  
Vol 377 ◽  
Author(s):  
Helena Gleskova ◽  
S. Wagner
Keyword(s):  
Electrical Conductivity ◽  
Light Intensity ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Free Electrons ◽  
Free Electron Density ◽  
Independent Variables ◽  
The Third ◽  
Defect Annealing ◽  
Hydrogenated Amorphous

ABSTRACTWe report results of a search for a unifying rate law for the annealing of metastable defects in hydrogenated amorphous silicon (a-Si:H). We tested the hypothesis that defect-annealing by both heating or illumination is driven by the density of free electrons. This hypothesis is formulated via the rate equation - dN/dt = A nα N f (T), where N is the defect density, t the time, A a constant, n the free electron density, and f (T) a function of temperature derived from a distribution of annealing energies. The model fits two sets of data, with light-intensity and electrical conductivity as the independent variables, reasonably well, with a ranging from 0.39 to 0.76, but not the third set, where we varied the temperature.

scholarly journals The Electrical Conductivity of Some Hydrous and Anhydrous Molten Silicates as a Function of Temperature and Pressure

2021 ◽  
Author(s):  
◽  
John Satherley
Keyword(s):  
Electrical Conductivity ◽  
Quartz Crystal ◽  
Pressure Coefficient ◽  
General Picture ◽  
Water Composition ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Arrhenius Temperature

<p>This thesis is concerned with the measurement and interpretation of electrical conductivity in molten silicates. Physicochemical properties and structural models of silica and silicates are reviewed first, to give a general picture of their behaviour. Electrical conductivity was measured as a function of temperature, pressure and water composition. To make these measurements an internally heated pressure vessel, designed to operate at temperatures up to 1200 degrees C and pressures up to 5 kbars was constructed. Conductivity measurements were made on the following anhydrous and hydrous silicate melts: SiO2/Na2O 60/40, 65/35, 75/25, 78/22 mol%; SiO2/Na2O/CaO 72/24/4 mol%; Mt. Erebus lava; SiO2/Na2O 78/22 mol% + ~5 wt% H2O and Mt. Erebus lava + ~4 wt% H2O in the temperature range 850-1000 degrees C and the pressure range 0-1.3 kbar. Arrhenius temperature and pressure dependencies on conductivity were observed. The pressure coefficient of conductivity was zero for the anhydrous melts well above Tg but small and positive for the hydrous silicates. Water caused ~40% reduction in conductivity when added to a melt which was accounted for in terms of the mixed alkali effect. Conductivity isobars for the hydrous silicates passed through a maximum as a function of increasing temperature. The conductivity behaviour as a function of temperature and pressure is analogous to that observed in partially ionised liquids and is intrepretated in an identical way. The range of operation of a piezoelectric alpha-quartz crystal viscometer was extended to allow measurement of viscosity as a function of temperature.</p>

scholarly journals The risk of static electricity at handling diesel fuel

2021 ◽  
Vol 343 ◽  
pp. 10013
Author(s):  
Mihaela Părăian ◽  
Emilian Ghicioi ◽  
Niculina Vătavu ◽  
Dan Gabor ◽  
Sorin Iuliu Mangu
Keyword(s):  
Electrical Conductivity ◽  
Diesel Fuel ◽  
Static Electricity ◽  
Fuel Type ◽  
Point Temperature ◽  
Flammability Characteristics ◽  
Fuel Tanks ◽  
Temperature And Pressure ◽  
A Company

Diesel fuel in motion when is transporting by pipes when is mixing, pumping, filtering, agitating or by pouring them from one vessel to another can generate static charges. Also, static electricity may occur if the liquid is splashes and forms a mist inside the tank. Accumulation of static electricity can, under certain conditions, be discharge and ignite the flammable/explosive atmosphere. Ignition hazards from static discharges can be eliminated by controlling the generation or accumulation of static charges or by eliminating a flammable mixture where static electricity may be discharged. Factors that need to be considered to reduce the risk of ignition sunt flammability characteristics of explosive atmosphere (the vapor pressure, flash point, temperature, and pressure) and the factors that determine the charging of static electricity (fuel type, electrical conductivity, sulfur content, viscosity, vehicle process: flow rate, pipe diameter, filters, pumps, spark promoters). In this paper are presented some aspects regarding the technical, organizational requirements and responsibilities of the personnel designated to prevent the formation and accumulation of static electricity when loading diesel fuel tanks, starting from a case study, respectively some explosions which occurred to a company during the loading operation.

Properties of Gainasp Alloys Investigated by Optically Detected Macnetic Resonance Techniques

1990 ◽  
Vol 216 ◽  
Author(s):  
C. Wetzel ◽  
B.K. Meyer ◽  
D. Grützmacher ◽  
P. Omling
Keyword(s):  
High Mobility ◽  
Chemical Vapor ◽  
Alloy System ◽  
Organic Chemical ◽  
Free Electrons ◽  
Quaternary Compound ◽  
Semiconductor Alloy ◽  
Device Applications ◽  
Metal Organic ◽  
Optically Detected

The quaternary GaxIn1−xAsyP1−y semiconductor alloy system has considerable importance for present day optoelectronic and microwave device applications. For state of the art high mobility samples grown by metal organic chemical vapor deposition (MOVPE) there are few experimental techniques which both can asess band structure related properties (effective mass m*, g-values of free electrons) and impurity related properties (luminescence, mobility and lifetimes). In this paper we compare optical and transport properties of the quaternary compound GaxIn1−xAsyP1−y, (x=0.47,y-l; x=0.42,y=0.92; x=0.28,y=0.61; x=0.12,y=0.34) lattice matched to*{nP by optically detected magnetic resonance techniques.

Competing Channels in the Propene + OH Reaction: Experiment and Validated Modeling over a Broad Temperature and Pressure Range

2011 ◽  
Vol 225 (11-12) ◽  
pp. 1271-1291 ◽  
Author(s):  
Claudia Kappler ◽  
Judit Zádor ◽  
Oliver Welz ◽  
Ravi X. Fernandez ◽  
Matthias Olzmann ◽  
...  
Keyword(s):  
Pressure Range ◽  
Temperature And Pressure

scholarly journals Thermodynamic modeling of solid solubility in supercritical carbon dioxide: Comparison between mixing rules

2013 ◽  
Vol 19 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Hadi Baseri ◽  
Ali Haghighi-Asl ◽  
Nader Lotfollahi
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Thermodynamic Modeling ◽  
Pressure Range ◽  
The Other ◽  
Mixing Rules ◽  
Calculation Results ◽  
Temperature And Pressure ◽  
Robinson Equation ◽  
Supercritical Carbon

In this paper, Peng Robinson equation of state is used for thermodynamic modeling of the solubility of various solid components in the supercritical carbon dioxide. Moreover, the effects of three mixing rules of Van der Waals mixing rules, Panagiotopoulos and Reid mixing rules and modified Kwak and Mansoori mixing rules on the accuracy of calculation results were studied. Good correlations between calculated and experimental data were obtained in the wide temperature and pressure range. A comparison between used models shows that modified Kwak and Mansoori mixing rules give better correlations in comparison with the other mixing rules.

scholarly journals On some electron properties of tellurium and Wilson's mechanism of semi-conductivity

1935 ◽  
Vol 148 (865) ◽  
pp. 648-664 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Free Electron ◽  
Previous Investigation ◽  
Room Temperature ◽  
Specific Resistance ◽  
Mean Free Path ◽  
Free Electrons ◽  
Conduction Electrons ◽  
Classical Statistics ◽  
Limiting Case

In a previous investigation it was found that the unusually high value for the Wiedemann-Franz ratio of tellurium could be explained as being only a formal anomally. The amount of heat transferred by the bound atoms is the same in tellurium as in conducting metals; but, in tellurium, in contrast to good conductors, it is responsible for almost the entire heat conductivity because the heat transferred by the free electrons is especially small. This indicates that tellurium differs from true metals in that the density of free electrons is very small. Classical statistics is therefore applicable and the electrical conductivity is given by x = 4/3 e 2 ln (2 πmk T) -5/9 , (1) where n is the density of free (conduction) electrons and l is their mean free path. Taking the specific resistance of tellurium at room temperature as 0.3 ohm-cm and l as 5.2 X 10 -6 cm (Sommerfeld's value for silver, found by applying Fermi-Dirac statistics), n is 2.9 X 10 16 , or about one free electron per million tellurium atoms in contrast to good conductors in which there is approximately one free electron per atom. Even in the limiting case with l = 3.2 X 10 -3 cm (the distance between the tellurium atoms), n is 4.7 X 10 18 which is about one free electron for every 6000 tellurium atoms.

HYDROGEN CHEMISORPTION ON NICKEL–MAGNESIA CATALYSTS

1963 ◽  
Vol 41 (1) ◽  
pp. 68-73 ◽  
Author(s):  
N. Ramasubramanian ◽  
L. M. Yeddanapalli
Keyword(s):  
Kinetic Data ◽  
Pressure Range ◽  
Hydrogen Adsorption ◽  
Catalyst Surface ◽  
Hydrogen Chemisorption ◽  
Oxygen Contamination ◽  
Different Types ◽  
Elovich Equation ◽  
Temperature And Pressure ◽  
Oxygen Addition

The hydrogen adsorption activities, per gram of nickel, of two nickel–magnesia catalysts are compared and explained on the basis of different types of nickel being present. The application of the Elovich equation to interpret the kinetic data shows the possibility of the presence of three kinetic stages in the temperature and pressure range studied. A study of the effect, on the hydrogen adsorption, of deliberate oxygen addition to and re-reduction of the catalyst surface shows that the nature of the oxygen contamination in the catalyst is different from that of the added oxygen.

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