Open Access Systematic Review Article

High-frequency Coronal Discharge, Infrared Thermography and Visual Acuity Measurements of Bioelectromagnetic Influence

Ignat Ignatov, Anton Antonov, Nikolai Neshev, Hugo Niggli, Chavdar Stoyanov, Christos Drossinakis

Physical Science International Journal, Page 18-28
DOI: 10.9734/psij/2021/v25i330246

Bioelectromagnetic influence on the eyes of a group of 336 subjects with various vision disorders: amblyopia, myopia and hypermetropia were investigated with high-frequency black-white and color coronal discharge, infrared thermography and visual acuity measurements. The authors have performed registration of the biggest part of electromagnetic fields – infrared and electric fields. Positive correlation with r=0.55­0.65 at a level of significance of p<0.01 was found between the temperature change (connected with vasodilation) in the influenced areas and the average change of visual acuity (visus). In the cases without correction, Student’s t-test of visus values for both eyes before and after bioelectromagnetic influence lead to t=6.0­6.7 at significance level p<0.001 and average increase of 14.5%. In the cases of refraction amblyopia, for the difference in both eyes with correction,t was equal to 6.7­7.1 at significance level p<0.001 and the average visus was increased and was 25.5%. Concerning the correlation between the temperature difference and the effective width of the high-frequency corona discharge, it was found that r=6.0­6.7 at significance level p<0.001.The dependence of the bio effect on the stage of the vision disorder (light, medium, heavy) was investigated. A distinct regularity was found with a coefficient of correlation r ranging from ­0,35 to ­0,45 at significance level p<0,001 that the influence efficiency was highest in light disorders and lowest in heavy disorders. Single-factor dispersion analysis was performed concerning age-related dependence of the healing effect in cases of visual disorders. For the three groups: 4­-10, 11-­21 and 22­-49 years of age, we found that F=4,4­-4,6 at significance level p<0.01 corresponding to higher healing results at younger ages.

Open Access Original Research Article

Implementation of Coulomb Counting Method for Estimating the State of Charge of Lithium-Ion Battery

Kevin C. Ndeche, Stella O. Ezeonu

Physical Science International Journal, Page 1-8
DOI: 10.9734/psij/2021/v25i330244

An accurate estimate of the state of charge, which describes the remaining percentage of a battery’s capacity, has been an important and ever existing problem since the invention of the electrochemical cell. State of charge estimation is one of the important function of a battery management system which ensures the safe, efficient and reliable operation of a battery. In this paper, the coulomb counting method is implemented for the estimation of the state of charge of lithium-ion battery. The hardware comprises an Arduino based platform for control and data processing, and a 16-bit analog to digital converter for current and voltage measurement. The embedded algorithm initializes with a self-calibration phase, during which the battery capacity, coulombic efficiency and initial state of charge are evaluated. The initial state of charge is determined at the fully charged state (100% state of charge) or the fully discharged state (0% state of charge). The cumulative error of this method was addressed by routine recalibration of the capacity, coulombic efficiency and state of charge at the fully-charged and fully-discharged states. The algorithm was validated by charging/discharging a lithium-ion battery through fifty complete cycles and evaluating the error in the estimated state of charge. The result shows a mean absolute error of 0.35% in the estimated state of charge during the test. Further analysis, considering prolonged battery operation without parameters recalibration, suggests that error in the coulombic efficiency term contributes the most to the increasing error in the estimated state of charge with each cycle.

Open Access Original Research Article

Magnetoresistance Recovery in the Amorphous Dielectric Material SiCOH

Philip A. Williams, James R. Lloyd

Physical Science International Journal, Page 9-17
DOI: 10.9734/psij/2021/v25i330245

The use of a magnetoresistance in the characterization of transport properties in the amorphous low-k dielectric material SiCOH is demonstrated. The double occupancy of charge carriers in trap states within the dielectric material can only exist in spin singlet formation due to Pauli Exclusion. The trap-assisted negative magnetoresistance (MR) in amorphous SiCOH, driven by an applied electric field that results in an observed increase in magnitude of the current in the conduction band is due to singly occupied trap spin-mixing suppression of carriers with the application of an external magnetic field. The material MR decays with time under electrical bias and temperature stress as traps are filled by charge carriers and from space charge accumulation. The MR can be reinstated by the ionization of these traps via the conduction mechanisms of nonthermally activated tunneling and thermal ionization with the assistance of an applied coulombic potential barrier lowering electric field. In this work a direct correlation is shown between a material MR and the trapping, de-trapping, and trap avoidance of singly occupied traps in the transport of charge carriers in the amorphous low-k dielectric material SiCOH (a-SiCOH).

Open Access Original Research Article

Errors Related to General Relativity, Repulsive Gravitation and the Question of Black Holes

C. Y. Lo

Physical Science International Journal, Page 29-47
DOI: 10.9734/psij/2021/v25i330247

Galileo and Newton considered gravity to be independent of temperature, while Einstein claimed that the weight of metal will increase as temperature increases. Further, Maxwell maintained that charge is unrelated to gravity. Experiments show, however, that the weight of a metal piece is reduced as its temperature increases. Thus, charge-initiated repulsive gravitation exists. In fact, repulsive gravity has been demonstrated by the use of a charged capacitor hovering over Earth. Further, it is expected that a piece of heated metal would fall more slowly than a feather in a vacuum. Einstein developed an invalid notion of gravitational mass, and failed to establish the unification of gravitation and electromagnetism since he overlooked repulsive gravitation. Moreover, photons are a combination of the gravitational wave and the electromagnetic wave. For electromagnetic energy    is invalid, and is in conflict with the Einstein equation. The non-linear Einstein equation has no bounded dynamic solution, Space-time singularity theorems are based on an invalid implicit assumption that all the couplings have a unique sign. Since gravity is no longer always attractive, the existence of black holes is questionable. The fact that Penrose was awarded the 2020 Nobel Prize in Physics for the derivation of black holes is due to that the Nobel Prize Committee for Physics did not sufficiently understand the physics of general relativity. A distinct characteristic of Penrose's work, as usual, is that it is not verifiable.

Open Access Original Research Article

Shielding Effectiveness, Mechanical and Dielectric Properties of NiO/PCL Nano Composites at Microwave Frequency for Electronic Devices

Abubakar Yakubu, Zulkifly Abbas, Sirajo Abdullahi, Suleiman Sahabi, Garba D. Sani

Physical Science International Journal, Page 48-58
DOI: 10.9734/psij/2021/v25i330248

There is a continuous generation of electromagnetic fields through operations of electronic devices for this reason it is paramount that these fields be shielded so as to prevent interferences. The, conventional method for shielding these fields are by the use of thin metal foils or sheets. The metals foils are heavy, difficult to fabricate, costly and in many cases not suitable for use in many applications. For these reasons, this work is focused on using materials that is flexible, cost effective and durable, with considerable shielding effectiveness (SE). Hence, polycaprolactone (PCL) and nickel oxide (NiO) nanocomposite were synthesized using the conventional melt blending (CMB) technique. The synthesis method used is fast, easy and produces large mass of controlled composites within a short period. Rectangular waveguide, vector network analyzer, coaxial cable and open ended coaxial probe were used in the measurement of microwave properties. Measured scattering parameter was used to calculate the shielding effectiveness of the NiO/PCL composites. Findings indicates that the dielectric constant increased with increasing filler content, where the highest dielectric property was 5.09 for the 62.5 % filler and it was able to shield electromagnetic fields by up to -9.35 dB at the frequency range measured. The average particle size of the NiO nano particles was 40.5 nm using TEM analysis. The best hardness and tensile strength was recorded for the highest loading percentage. It is then concluded that the substrate produced can be tailored for electronic, telecommunication, medical applications and military shield applications.