THE SECOND RECIPROCAL DERIVATIVE CHRONOPOTENTIOMETRY ANALYSIS

Theories of the second reciprocal derivative chronopotentiometry analysis were deduced and experimentally verificated.Results in this study show that chronopotentiometry is significantly developed in both sensitivity and resolution for signals treated by the second reciprocal derivative.

THE SECOND RECIPROCAL DERIVATIVE POTENTIOMETRIC STRIPPING ANALYSIS

A theory of the second reciprocal derivative potentiometric stripping analysis with a mercury thin-film electrode is reported.

Second law analysis of Blasius flow with nonlinear Rosseland thermal radiation in the presence of viscous dissipation

In the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional heating.The two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity transformations.The set of resultant ordinary differential equations are solved numerically.The numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan number.The velocity profile f'(ξ),temperature distributionθ(ξ),entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in detail.Further,for the sake of validation of our numerical code,the obtained results are reproduced using Matlab built-in boundary value solver bvp4c resulting in an excellent agreement.It is observed that entropy generation is increasing function of heating parameter,Prandtl number,Eckert number and radiation parameter.Further,it is observed that entropy generation can be minimized by reducing the operating temperatureΔT=T_(w)−T_(∞).

Analysis of generation of cumulative second harmonics of Lamb modes in a layered planar structure

A technique for analyzing the nonlinear generation of the cumulative second har-monics of generalized Lamb modes in a layered planar structure is developed. A theoretical model for nonlinear generalized Lamb mode propagation in a layered planar structure has been established, based on a partial plane wave approach. The nonlinearity is treated as a second-order perturbation of the linear elastic response. This model reveals some interesting features of the physics of the cumulative second harmonic generation. Although Lamb mode propagation is dispersive in a layered structure, the results of this analysis show that the amplitudes of the second harmonics do accumulate with propagation distance under certain special conditions. On the basis of the boundary and initial conditions of excitation, the formal solution of the cumulative second harmonic has been derived. Using the formal solution, we have performed some numerical simulations and obtained the cumulative second harmonic field patterns, illus-trating the distortion effect along the propagation distance, as well as the dependence of the field patterns on the position of the excitation source.

A theoretical analysis on second harmonic generation for transverse and longitudinal slice collagen fiber

Microscopic imaging based on second-harmonic generation has been proving to be a powerful tool for biomedical studies, especially in that tissues with

A theoretical analysis and its application of the second order EC' reactions at microelectrodes under steady-state conditions

With a new approach,the general current expressions of two typical second order catalytic reactions are obtained for disk,hemispherical and spherical microelectrodes under steady-state conditions.This approach is based on the concept of reaction layer.For the second order EC' reactions,we also discussed how it is possible to observe pseudo-first order or second order behavior.This consideration allows the study of the fast chemical reactions and systems where the bulk concentrations of the reactants are nearly equal.Regeneration of Fe^(3+)(EDTA) with H_2O_2 was selected as an example of a rapid catalytic reaction.

Exergy losses in premixed flames of dimethyl ether and hydrogen blends

A second-law thermodynamic analysis was conducted for stoichiometric premixed dimethyl ether(DME)/hydrogen(H2)/air flames at atmospheric pressure.The exergy losses from the irreversibility sources,i.e.,chemical reaction,heat conduction and species diffusion,and those from partial combustion products were analyzed in the flames with changed fuel blends.It is observed that,regardless of the fuel blends,chemical reaction contributes most to the exergy losses,followed by incomplete combustion,and heat conduction,while mass diffusion has the least contribution to exergy loss.The results also indicate that increased H2 substitution decreases the exergy losses from reactions,conduction,and diffusion,primarily because of the flame thickness reduction at elevated H2 substitution.The decreases in exergy losses by chemical reactions and heat conduction are higher,but the exergy loss reduction by diffusion is slight.However,the exergy losses from incomplete combustion increase with H2 substitution,because the fractions of the unbumed fuels and combustion intermediates,e.g.,H2 and OH radical,increase.The overall exergy losses in the DME/H2 flames decrease by about 5%with increased H2 substitution from 0%to 100%.