Laser interferometric galvanostatic studies in the Zn/ZnSO4/Zn system with gelled electrolyte short time electrolysis

1983 ◽  
Vol 61 (10) ◽  
pp. 2316-2320 ◽  
Author(s):  
R. N. O'Brien ◽  
W. Michalik
Keyword(s):  
Parallel Plate ◽  
Liquid Electrolyte ◽  
Second Law ◽  
Transient Conditions ◽  
Short Time ◽  
Laser Interferometric ◽  
Short Times ◽  
Theory And Experiment ◽  
Good Agreement

Electrolysis in the system Zn/ZnSO4/Zn with gelled electrolyte was followed for short times to allow use of the first term only of the solution to Fick's Second Law for transient conditions. Sufficiently good agreement was found between theory and experiment to confirm that no convection occurred in the gelled electrolyte. Similarly sufficiently good agreement with liquid electrolyte runs confirmed that no convection occurred in parallel plate, horizontal electrodes when the cathode was over the anode. The conductivity of the gelled electrolyte was about 11% lower than the liquid electrolyte.

scholarly journals A Theoretical and Experimental Investigation of Creep Problems With Variable Temperature

1976 ◽  
Vol 43 (4) ◽  
pp. 639-644 ◽  
Author(s):  
A. R. S. Ponter ◽  
M. H. Walter
Keyword(s):  
Experimental Investigation ◽  
Strain Hardening ◽  
Variable Temperature ◽  
Short Time Scale ◽  
Rapid Cycling ◽  
Reference Stress ◽  
Thermoelastic Stresses ◽  
Short Time ◽  
Theory And Experiment ◽  
Good Agreement

Rapid cycling solutions are presented for a simple two-bar structure subjected to variable temperature. Three constitutive relationships are considered, nonlinear viscous, strain-hardening and Bailey-Orowan models which describe differing aspects of the creep of metals. It is shown that the solutions for the viscous and strain-hardening relations are essentially similar and possess distinct reference stress histories over ranges of the governing parameters. The presence of recovery in the Bailey-Orowan model causes a distinctly different mode of behavior. Experimental results on a simulated two-bar structure are presented, under conditions where the strain-hardening hypothesis may be expected to be most relevant. Good agreement is obtained between theory and experiment although the presence of anelastic creep, with a short time scale, tends to reduce the effective thermoelastic stresses.

Technically Classified Rubber—The Non-Rubber Content and the Measurement of Cure Rate

1953 ◽  
Vol 26 (3) ◽  
pp. 655-673 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Preliminary Investigation ◽  
National Bureau ◽  
Cure Rate ◽  
Average Value ◽  
Astm Method ◽  
Viscosity Increase ◽  
Strain Testing ◽  
Time Test ◽  
Short Time ◽  
Good Agreement

Abstract The nonrubber content of typical samples of all grades of technically classified rubber has been determined. It is found that the nonrubber content increases in the order: red, yellow, and blue. The chemical analyses performed to determine the nonrubber content were as follows: per cent ash, per cent nitrogen, per cent acetone extract, and per cent fatty acid. The pH of both a slurry of the ash and the aqueous digest indicates that blue rubber is more basic in these respects than are red and yellow rubbers. The measurement of the cure rate of these samples of technically classified rubber has been carried out by means of (1) conventional stress-strain testing, (2) the present ASTM method utilizing the Mooney viscometer, (3) the National Bureau of Standards strain test, (4) a new and more quantitative approach developed by Gee and coworkers, and (5) a utilization of the Mooney viscometer to determine two of the parameters of Gee's equation which gives the time dependence of modulus. All of these methods place the rubbers in the same relative order. The use of the viscometer to determine two of the parameters of Gee's equation was prompted by the degree of correlation between the rate parameter obtained with the present ASTM method and the rate constant k calculated by Gee's methods. As a result of a preliminary investigation as to the causes of viscosity increases at curing temperatures, it was found that, within limits of experimental error, all of the viscosity increase is due to the formation of a cross-linked network, with a linear relationship existing between viscosity increase ΔVc and modulus (at 100 per cent elongation) f. The results of a comparison of the rate constants obtained by the viscometer and by Gee's method indicate that for MBT mixes at 260° F there is good agreement between the methods. Statistical analysis shows that the samples employed for this study are significantly different in their rate of cure. The variance, range, and mean of some of the parameters obtained with the viscometer over a 10-week period are also given. It is suggested that the Mooney viscometer be employed to classify natural rubber according to its cure rate. If this is done, it will be necessary to define the degree of accuracy desired. To determine accurately the cure rate, it is necessary that the viscometer be used in conjunction with a press cure for the estimation of the parameter f∞. If it is not feasible to carry out press cures, an average value for f∞ can be assumed, and then only a short time test with the viscometer is required.

Flow Characteristics of a Powder Lubricant in a Slider Bearing

2001 ◽  
Author(s):  
Manjunath Pappur ◽  
M. M. Khonsari
Keyword(s):  
Slip Velocity ◽  
Thrust Bearing ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Slider Bearing ◽  
Systematic Development ◽  
Powder Lubrication ◽  
Insight Into ◽  
Theory And Experiment ◽  
Good Agreement

Abstract This paper deals with a systematic development of theory of powder lubrication with the appropriate formalism based on the fundamentals of fluid mechanics. The theory is capable of predicting flow velocity, fluctuation (pseudo-temperature), powder volume fraction, and slip velocity at the boundaries. An extensive set of parametric simulations covering particle size, surface roughness, volumetric flow, load and speed are performed to gain insight into the performance of a powder lubricated thrust bearing. The results of simulations are compared to the published experimental results. Good agreement between the theory and experiment attests to the capability of the model and its potential for design of powder lubricated bearings.

A Simple Statistical Theory for Grain Growth in Materials.

1990 ◽  
Vol 209 ◽  
Author(s):  
P. Mulheran ◽  
J.H. Harding
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Statistical Theory ◽  
Stochastic Model ◽  
Grain Growth ◽  
Three Dimensional ◽  
Monte Carlo Procedure ◽  
Short Time ◽  
2D And 3D ◽  
Good Agreement

A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.

Morphology of Voltage-Triggered Ordered Wrinkles of a Dielectric Elastomer Sheet

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Guoyong Mao ◽  
Lei Wu ◽  
Xueya Liang ◽  
Shaoxing Qu
Keyword(s):  
High Voltage ◽  
Optical Sensor ◽  
Material Science ◽  
Dielectric Elastomer ◽  
Theoretical Studies ◽  
Science And Engineering ◽  
Future Design ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

Wrinkles widely existing in sheets and membranes have attracted a lot of attention in the fields of material science and engineering applications. In this paper, we present a new method to generate ordered (striplike) and steady wrinkles of a constrained dielectric elastomer (DE) sheet coated with soft electrodes on both sides subjected to high voltage. When the voltage reaches a certain value, wrinkles will nucleate and grow. We conduct both experimental and theoretical studies to investigate the wavelength and amplitude of the wrinkle. The results show a good agreement between theory and experiment. Moreover, the amplitude and wavelength of ordered wrinkles can be tuned by varying the prestretch and geometry of the DE sheet, as well as the applying voltage. This study can help future design of DE transducers such as diffraction grating and optical sensor.

Determination of Electrically Active Defect Profiles in Semiconductors Using a Photoelectrochemical Technique

1986 ◽  
Vol 82 ◽  
Author(s):  
F.D. Gealy ◽  
H.L. Tuller
Keyword(s):  
Impedance Spectroscopy ◽  
Liquid Electrolyte ◽  
Profile Measurement ◽  
Acceptor Concentration ◽  
Defect Profile ◽  
Profile Depth ◽  
Charge Capacitance ◽  
Substitutional Impurities ◽  
Good Agreement

ABSTRACTElectrically active defects are common in semiconductors. Such defects include easily ionized substitutional impurities, vacancies, and interstitials which can act as shallow donors or acceptors. If one type of defect predominates, its concentration corresponds directly to the local donor or acceptor concentration. Consequently, measurement of a carrier profile in a nonhomogeneous semiconductor is effectively the same as measurement of the defect profile.The photoelectrochemical profiling technique allows for carrier profile measurement with submicrometer spatial resolution. The sample is profiled by photoetching, then carrier measurement, and iterating this procedure until the desired profile depth is obtained.Derivation of the space charge capacitance by impedance spectroscopy is discussed. An analysis of the P-doped Si-liquid electrolyte interface is presented. Phosphorous diffusivity coefficients in good agreement with literature values are derived from photoelectrochemical derived profiles.

Non-Equilibrium Critical Relaxation of Heisenberg Ferromagnets with Long-Range Correlated Defects

2012 ◽  
Vol 190 ◽  
pp. 39-42
Author(s):  
M. Medvedeva ◽  
Pavel V. Prudnikov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Critical Behavior ◽  
Critical Exponents ◽  
Heisenberg Model ◽  
Three Dimensional ◽  
Initial State ◽  
Short Time ◽  
Theoretic Description ◽  
Good Agreement

The dynamic critical behavior of the three-dimensional Heisenberg model with longrangecorrelated disorder was studied by using short-time Monte Carlo simulations at criticality.The static and dynamic critical exponents are determined. The simulation was performed fromordered initial state. The obtained values of the exponents are in a good agreement with resultsof the field-theoretic description of the critical behavior of this model in the two-loopapproximation.

On an Approximate Method of Calculating Pressures on Non-lifting Head Shapes at Supersonic Speeds

1955 ◽  
Vol 6 (1) ◽  
pp. 31-45
Author(s):  
H. K. Zienkiewicz
Keyword(s):  
Method Of Characteristics ◽  
Order Theory ◽  
Stagnation Pressure ◽  
Slender Body Theory ◽  
Pressure Losses ◽  
The Method Of Characteristics ◽  
Curvature Approximation ◽  
Body Theory ◽  
Theory And Experiment ◽  
Good Agreement

SummarySlender-body theory is used to derive the ogive of curvature approximation for very slender, pointed, convex head shapes at supersonic speeds. Results of application of this approximation, together with the λ-method for circular arc ogives, to a variety of non-slender head shapes show very good agreement with the method of characteristics, van Dyke's second-order theory and experiment. Good agreement with the method of characteristics and with experiment is obtained even in cases when the stagnation pressure losses across the nose shock wave are not negligible.

Sound Propagation in Dilute Polyatomic Gases

1972 ◽  
Vol 27 (4) ◽  
pp. 583-592
Author(s):  
H. Moraal ◽  
F. Mccourt
Keyword(s):  
Pressure Range ◽  
Sound Propagation ◽  
Plane Waves ◽  
Point Of View ◽  
Perturbation Function ◽  
Sound Waves ◽  
Polyatomic Gas ◽  
Measured Pressure ◽  
Theory And Experiment ◽  
Good Agreement

Abstract Sound propagation in dilute pure gases, both monatomic and polyatomic, has been considered from the point of view of the Waldmann-Snider equation. It is shown that the commonly employed assumption that sound propagation in gases is equivalent to the propagation of plane waves is valid only in the region where collisions restore equilibrium faster than it is perturbed by the sound waves. A systematic truncation procedure for an expansion of the perturbation function in irreducible Cartesian tensors is introduced and then illustrated in solutions for three specific kinds of molecules, helium, nitrogen and rough spheres. The agreement between theory and experiment is rather good for sound absorption in the region where the ratio of the collision and sound frequencies is greater than 1.5. The agreement in the case of dispersion is good over the whole measured pressure range. One useful result obtained is to show the polyatomic gas calculations in second approximation have as good agreement with experiment as the calculations for noble gases in third approximation. This can be related to the possession by the polyatomic gas of a bulk viscosity which dominates in sound propagation.

Theoretical and Experimental Investigation on Forming Limit for TNW700 Titanium Alloy

2014 ◽  
Vol 622-623 ◽  
pp. 340-346 ◽  
Author(s):  
Bao Sheng Liu ◽  
Wei Wu ◽  
Xiu Quan Han
Keyword(s):  
Experimental Investigation ◽  
Titanium Alloy ◽  
High Temperature ◽  
Forming Limit ◽  
Minor Strain ◽  
Resistant Material ◽  
Dimple Rupture ◽  
Short Time ◽  
Fractographic Observation ◽  
Good Agreement

Forming limit is identified to evaluate the formability of sheet metal. The in-plane limit strains of sheets are plotted in a diagram with coordinates of major strain vs. minor strain. TNW700 titanium alloy is a high temperature resistant material. The products made of TNW700 can be used in a long serving period at 500°C, short time at 700°C. In this work, the forming limit of TNW700 will be investigated in theoretical and experimental ways. The experiment to test limit strains was carried out at 750°C under different loading paths. Marciniak – Kuczynski (M-K) model was calculated with Swift constitutive equations to predict the curves of limit strains. The effect of the groove angle on forming limit is that, the same angle on both sides of centerline determines the same FLC, and the limit points shift from left side to right side. The experiment shows that, the formability of TNW700 is not excellent, and it is lower than that of TC4 and TA15 at the same condition. The comparison shows that the curve predicted by M-K model is in a good agreement with that at plane strain, however higher than that in both sides. The fractographic observation shows that the fracture mode of TNW700 is dimple rupture.

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