Reverse Differential Pulse Research Articles

New hybrid reverse differential pulse position width modulation scheme for wireless optical communication

In order to improve the power efficiency and reduce the packet error rate of reverse differential pulse position modulation (RDPPM) for wireless optical communication (WOC), a hybrid reverse differential pulse position width modulation (RDPPWM) scheme is proposed, based on RDPPM and reverse pulse width modulation. Subsequently, the symbol structure of RDPPWM is briefly analyzed, and its performance is compared with that of other modulation schemes in terms of average transmitted power, bandwidth requirement, and packet error rate over ideal additive white Gaussian noise (AWGN) channels. Based on the given model, the simulation results show that the proposed modulation scheme has the advantages of improving the power efficiency and reducing the bandwidth requirement. Moreover, in terms of error probability performance, RDPPWM can achieve a much lower packet error rate than that of RDPPM. For example, at the same received signal power of −28 dBm, the packet error rate of RDPPWM can decrease to 2.6×10−12, while that of RDPPM is 2.2×10−8. Furthermore, RDPPWM does not need symbol synchronization at the receiving end. These considerations make RDPPWM a favorable candidate to select as the modulation scheme in the WOC systems.

Study of multistep electrode processes in triple potential step techniques at spherical electrodes

In this paper, a reversible multistep electrode process is studied by the most popular triple pulse techniques as Reverse Differential Pulse Voltammetry and Double Differential Pulse Voltammetry. The equations presented here are valid for spherical electrodes of any size (including planar and ultramicrospherical electrodes as limit cases) and can be used to describe the electrochemical behaviour of molecules with multiple redox centers, whether they are interacting or not. The comparison between results in triple and double pulse techniques for reversible multistep processes allows us to draw important conclusions regarding the suitability of such techniques and the characterization of reversible processes.

Differential pulse voltammetry of toxic metal ions at the boron-doped CVD diamond electrode

Boron-doped polycrystalline diamond films were grown over a molybdenum substrate by a microwave plasma CVD process using a methane and hydrogen gas mixture at a pressure of 35 ± 1 Torr. Boron doping of diamond was achieved in situ by using a solid boron source while growing diamond in the CVD processxu. We have observed a negligible background current (Δl) for diamond by differential pulse voltammetry in 0.5 M NaCl, 0.5 M H2SO4, and 0.5 M HNO3 solutions over a wide potential range. Therefore, diamond will certainly have a use as an electrode material in electroanalytical applications to detect trace toxic/nontoxic metal ions such as cadmium, lead, copper, and silver. Differential pulse voltammetry was used to detect and evaluate the presence of lead ions in 0.5 M NaCl and cadmium ions in 0.5 M H2SO4 supporting electrolyte solution using highly conducting boron-doped diamond coated molybdenum electrode material. Furthermore, reverse differential pulse voltammetry was used to evaluate the presence of copper and silver ions in 0.5 M H2SO4 and 0.5 M HNO3 solution, respectively. Diamond electrode has been used in this study to detect metallic ions in the solution over a wide potential range that covers + 0.8 V to −0.4 V vs., SHE.

General analytical solution for a reversible i- t response to a triple potential step at an SMDE in the absence/presence of amalgamation

The theory corresponding to triple potential step chronoamperometry for a reversible charge transfer reaction in a static mercury drop electrode is presented. The equation for the current has been deduced assuming different diffusion coefficients for oxidized and reduced species and is valid when the reaction product is soluble in both the electrolytic solution and the electrode. The validity of equations proposed was verified by comparing theoretical i- t, double differential pulse and reverse differential pulse curves with those obtained experimentally for the system Cd 2+ Cd(Hg) . It can be concluded that the double differential pulse and reverse differential pulse techniques are more sensitive to the presence or absence of amalgamation than double pulse techniques.

Reverse Differential Pulse Voltammetry and Polarography

In this paper we obtain the analytical solution for the reverse differential pulse (RDP) technique for a slow electronic transfer process, starting from expressions obtained previously for the faradaic response to a triple potential pulse. The solutions are valid for the planar approximations of a static mercury drop electrode and of a dropping mercury electrode. An irreversible reduction process gives rise in the RDP technique to the appearance of two peaks, one at more negative potentials than the normal reduction potential, E°, and the other at more positive potentials than E°. From half-width peak and peak potential measurements, it is possible to evaluate approximately the kinetic and thermodynamic parameters corresponding to the electronic transfer, such as the transfer coefficient, a, the normal reduction potential, E°, and the apparent heterogeneous rate constant, k s . The solutions are checked against experimental examples of well-known processes.