Open Access Original Research Article

Evaluating the Effect of Optical Coupler in a 1.5KVA PWM Inverter

Ikenga Onyeka Anthony, Ejeka Joshua C., Anyanor Oliver O.

Physical Science International Journal, Page 1-7
DOI: 10.9734/psij/2021/v25i630261

This paper presents the design and implementation of a 1.5KVA inverter system. The aim of the paper is to evaluate the effect of optocoupling technology on inverter system. The developed circuit compares the output load with the input voltage when 4N35 opto coupler is used and in the absence of it. Two different inverter systems were designed and the voltages at the output pins of Sg3524 were measured. It was observed that there seems to be fluctuation in the output voltage of the system without optocoupling and the voltage of the inverter keeps dropping till the system shuts down. The basic principle of the operation of the inverter is a simple conversion of 12V DC at a frequency of 50Hz to 230V AC. The result shows that optocoupling technique is essential part of an inverter system to achieve a good efficiency.

Open Access Original Research Article

Laser-induced Fluorescence with Multivariate Analysis in Characterizing Crude Oils from Some Selected Oil Fields in Ghana

Calvin Kwesi Gafrey, Robert Wilson, George Amoako, Benjamin Anderson

Physical Science International Journal, Page 8-20
DOI: 10.9734/psij/2021/v25i630262

Developing scientific practices and procedures for finding the characteristics of various crude oils from different geological sources based on fluorescence spectra fingerprints would be beneficial to the petroleum industry. Laser-Induced Fluorescence (LIF) has gained relevance worldwide because of its advantages in crude oil analysis. Presently, the use of this technique in the characterization of crude oils from the oil fields in Ghana has not been studied. The study employed the LIF technique to determine some physical qualities of crude oils from Jubilee Oil Field, Tweneboa Enyenra Ntomme (TEN) Oil Field and Saltpond Oil Field. Specifically, this study used multivariate analysis methods to link the spectral signatures of the crude oils to their properties for identification and classification. The LIF technique was applied on four crude oil samples. Fluorescence spectra were obtained using a continuous wave 405.0 nm laser. The excitation source revealed five (5) peak wavelengths after deconvolution. Using Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA) and Hierarchical Cluster Analysis (HCA), the crude oil samples were classified accurately.

Open Access Original Research Article

The Transition to Equilibrium in a System with Gravitationally Interacting Particles. I. Temperature Relaxation

A. M. Boichenko, M. S. Klenovskii

Physical Science International Journal, Page 21-47
DOI: 10.9734/psij/2021/v25i630263

The distribution function of systems in equilibrium must have the canonical form of the Gibbs distribution. To substantiate this behavior of systems, attempts have been made for more than 100 years to involve their mechanical behavior. In other words, it seems that a huge number of particles of the medium as a result of interaction with each other according to dynamic laws, is able to explain the statistical behavior of systems during their transition to equilibrium. Modeling of gravitationally interacting particles is carried out and it is shown that in this case, the distribution function does not evolve to the canonical form. Earlier, the same results were obtained for classical Coulomb plasma. On the other hand, such a statistical effect as relaxation is well described by the dynamic behavior of the system, and the simulation data are in agreement with the known theoretical results obtained in various statistical approaches.