Theory and Applications of Physical Science Vol. 2

Quantum Oscillations of the Landau-Pekar Polaron in the Dielectric Layers and Bipolaron Formations

2021-08-07T07:53:25+00:00

The conditions are identified under which the electrostatic image forces at an interface dielectrics result in spatial confinement of the large polarons. This paper presents the theoretical study of large polarons state near the interface of two and three insulators. Action of a combination of external magnetic and electric fields and forces of the electrostatic image on polaron quasi two-dimensional nanostructures is analyzed. It is established that at certain ratios of dielectric constants of two dielectrics there is a fixing of polarons at some equilibrium distance from an interface of dielectrics. Polarons are fixed in the plane of the parallel to plane of the interface, forming a quasi two-dimensional nanolayer. The Bogolyubov method of collective coordinate is used to derive equations describing quantum oscillations of the center of inertia of a polaron near its equilibrium position. A long-range resonant interaction of two oscillators resulting in the appearance of effective attraction between polarons is discussed. The dielectric properties of adjacent insulators required for complete compensation of the Coulomb interpolaron repulsion are determined. Derivation is given on the temperature and magnetic field in which the polaron oscillations are not suppressed. The reasons are discussed why in some experiments high-temperature superconductivity of metal-ammonia systems was found, while in other experiments it was not possible to detect superconductivity.

Sums of Powers of Integers and Bernoulli Numbers Clarified

2021-08-07T09:47:24+00:00

We exposes a very simple method for calculating at the same time the sums of powers of the first integers and the Bernoulli numbers . This is possible thank to integrations of the equation which lead to a formula saying that the vector is the transform of the vector by a matrix built from the Pascal triangle and obtainable by a simple algorithm. Very useful relations between the sums , the Bernoulli numbers are deduced, leading straightforwardly to known and new properties of them. The proof of the Faulhaber formulae on powers sums are outlined briefly at the end.

Prediction of Concrete Compressive Strength in Buildings that would be Reinforced by Fuzzy Logic

2021-08-07T09:55:09+00:00

In this study, core samples were taken from column or reinforced wall in order to make reinforcement or restoration. The effect of the element height and volume of voids of these samples to the compressive strength were investigated. C25 type ready to use concrete was used and a column without steel was produced. During the production process, 15 cm reference cube samples were taken from the fresh concrete. After 28 days, 8 cores from reference cubes and 128 samples from column were taken and their compressive strengths were determined. As a result, the average compressive strength of the reference core samples was 36.95 Mpa and according to the height compressive strengths of other samples was ranging between 37.3 and 43.0 Mpa. The ratio of the increasing of the compressive strength changes between 0.95 and 16.37% according to the reference sample. Based on the experimental results, fuzzy Logic method was used for modelling of the experimental results. The paper demonstrates that fuzzy logic can be successfully used in modelling the compressive strength of concrete for different height and volume of voids. This model enables us to easily and reliably estimate the compressive strength of concrete.

Role of Rose Bengal-Mannitol System for Generation of Electrical Energy in Photo Galvanic Cell

2021-08-07T09:57:54+00:00

Rose Bengal is used as a photo sensitizer in photo galvanic cell for solar energy conversion and Mannitol is used as an electron donor in this study. The effects of various parameters like pH, light intensity, diffusion length, reductant concentration and dye concentration on the electrical output of the cell is studied. The photo potential and photocurrent generated by this cell are 850 mV and 135 μA, respectively. The current voltage (i–V) characteristic of the cell is also studied and a mechanism for the generation of photocurrent is proposed.

Investigating the Neutronics Parameters of NIRR-1 Core Using Venture-PC and Scale 6.1 Codes in the 19.75% Enriched UO2-Zircaloy-4 Material

2021-08-07T10:02:20+00:00

This study is an investigation on neutronics parameters for Nigeria Research Reactor-1 (NIRR-1) core, a low power Miniature Neutron Source Reactors (MNSRs) using VENTURE-PC and SCALE 6.1 codes in the 19.75% enriched uranium dioxide (UO₂)-Zircaloy-4 material. The number of active fuel pins used for this analysis is approximate 200 pins, which shows that the fuel pins have been reduced to about 58% when compared with the present Highly Enriched Uranium (HEU) fuel (UAl₄-Al alloy clad in aluminum) of 347 pins. These reductions in the number of fuel pins have given room for more moderators in the core and hence increase the number of hydrogen available to thermalize the neutron in the potential 19.75% UO₂ fuelled core for NIRR-1. The value of the total control rod worth, reactivity worth, and shutdown margin were 7.23 mk, 4.04 mk, and 3.19 mk, respectively. Moreover, the thermal neutrons flux level, peak power density, and maximum neutron density were 1.24 x 10¹² ncm^-2s^-1, 4.31033 W/cc and 6.94535 x 10^-6 neutron/cc, respectively. These results are in good agreement when compared to the experimental result of the HEU core. The diffusion theory based calculated values of thermal flux profiles for the vertical as well as for the horizontal radial directions have been found to agree well with similar calculations using various nuclear analysis tools. These studies indicate that LEU (19.75%) results are conservative and can be applied to ascertain the reliability of VENTURE-PC code, SCALE 6.1 code, and UO₂-zircaloy-4 as the potential material for future calculation of NIRR-1 core neutronics parameters.

Power Amplifier- Memory-less Non Linear Modeling

2021-08-07T10:05:04+00:00

The power amplifier’s nonlinearity broadens the input signal’s bandwidth. This is known as spectral re-growth which is undesirable since it causes interference with adjacent channels. It also causes distortions within the signal bandwidth, which affects the bit error rate at the receiver. Most recent transmission schemes, such as wideband code division multiple access (WCDMA) or orthogonal frequency division multiplexing (OFDM), are especially vulnerable to the nonlinear distortions due to high fluctuations in their power levels. To ensure that linearity is maintained to a high degree, it is necessary to examine the nature of amplifier distortion. Audio amplifier distortion is of concern for many years. The conventional feedback techniques used at audio frequencies are not applicable to many RF amplifiers due to following problems: 1. Stability at high bandwidth. 2. Cost for high gains in RF stages. Memory less or Instantaneous Nonlinear Model assumes that the PA has no memory effects, that is, it has no knowledge of past events and hence the present o/p signal is only a function of present i/p signal. The model is further simplified by restricting the analysis to signal and distortion contained within the first harmonic zone, such models are referred to as band pass memory-less nonlinear models and are further simplified since they do not need to model even order nonlinearities. A memory less nonlinear model can be modeled in polar (amplitude and phase) or Cartesian (I and Q) form.

Solar Wind, Earth’s Rotation and Changes in Terrestrial Climate

2021-08-07T10:07:56+00:00

Solar variability affects Earth climate. It is proposed that this forcing primarily goes via the interaction of the Solar Wind with the Earth’s magnetosphere, rather than via changes in irradiance, which is generally assumed. The cyclic variations in Solar Wind emission generate corresponding changes in the Earth’s rate of rotation (LOD), as recorded by correlations between sunspot numbers and LOD-variations. Variations in Earth’s rotation affect not only the atmospheric circulation but also the ocean circulation. Because the ocean water has a very high heat storing capacity, changes in the ocean circulation will affect regional climate. The redistribution of oceanic water masses also gives rise of irregular changes in sea level over the globe. During the last 6000 years this redistribution of ocean water masses seems to have been the dominate sea level variable. The El Niño/ENSO events contain a part, which represent an interchange of angular momentum between the solid earth (LOD) and the equatorial ocean circulation in the Pacific. The 60-year solar-terrestrial cycle controlled the climatic conditions and main fish stocks in the Barents Sea via an oceanic beat in the inflow of warm Atlantic water. The major Solar Maxima and Minima of the last 600 years correspond to decreases and increases in the Earth’s rotation, which altered the ocean circulation in the North Atlantic by that generating major climatic changes and sea level changes. Speeding-ups of the Earth’s rotation during the Spörer, Maunder and Dalton Solar Minima forced the Gulf Stream to be concentrated on its southern branch and cold Arctic water to penetrate far down along the European coasts, which lead to Little Ice Age conditions in the Arctic and in northern to middle Europe but extra warm periods in the Gibraltar to northwest African region. During the Solar Maxima, the situation was the reverse. By around 2040, we will be in a new major Solar Minimum and may, therefore, expect a period of cold climatic conditions.

Estimation of the Geophysical Parameters Effect on the Altimetric Measurements for Sea Surface Height Determination

2021-08-07T10:12:35+00:00

The emergence of satellite altimetry has allowed us to determine the ocean surface with a great precision; it also allows a large contribution for most applications and oceanographic activities. The geometric principle of space altimetry is to measure the range between the satellite and the sea surface.

The objective of this paper is to estimate the geophysical parameters (sea state bias and ocean tide) affecting the altimetric measurements for Jason-1 satellite, using the analytical and empirical models.

The comparison of the estimated and provided values permit to minimize the default values for and improve its estimation, and also improve the ocean tide estimation.

The comparison of obtained results of six (6) years Jason-1 data processing on the western Mediterranean of every parameter with data transmitted in the satellite message permitted us to validate our developed methodological approach. The quality of these results permits the determination of the Western Mediterranean mean sea level.

Superluminal Speeds in Mezodynamics

2021-08-07T10:16:02+00:00

In the framework of Fermi theory, nonstationary -decay is considered. In order to simplify the calculations, the theory omits the accounting of antineutrino and neglects the presence of spin in the particles. The electron is called the mezon. Specifically, the non-stationary process of meson exchange between the neutron and the proton at the final distance from it, which turns proton into a neutron as a result of such exchange, is considered. The calculations are performed both in Schrödinger representation and Heisenberg representation. Schrödinger presentation shows that the meson resulting from the neutron emission can be absorbed by the proton at the final distance from the emitter before the light needs to cover this distance. This quantum effect with the superluminal transmission of information is in dissonance with the classical theory, which does not allow particles of finite mass to possess speeds even close enough to the speed of light in vacuum. Calculations in Heisenberg representation of the existence of superluminal signals do not allow. The non-equivalence of Heisenberg and Schrödinger representations in non-stationary quantum mesodynamics, known in electrodynamics, is stated. The preference is given to Schrödinger representation with reference to an experiment that numerically confirms the presence of superluminalsignals in electrodynamics.

General Relativity Theory Violates the Energy Conservation Law, which is the Fundamental Law of Physics Including the Curved Space-Time Metric

2021-08-07T10:18:43+00:00

The violation of energy conservation law is a death sentence for the General Relativity Theory (GRT). This paper investigates the correctness of the General Relativity Theory by studying the energy conservation during the relativistic free fall of a small test body in a uniform gravitational field. The paper compares predictions of energy conservation obtained from the GRT and from the Metric Theory of Gravity (MTG). It is found that the gravitational mass dependence on velocity in the GRT is not correct, because this dependency leads to a prediction of violation of energy conservation while the MTG having a different gravitational mass dependency on velocity predicts correctly the energy conservation.

Use of Banana Tree Residues as Pulp for Paper and Combustible

2021-08-07T10:24:35+00:00

The aim of this work is to characterize banana tree residues and use it in pulping and combustion processes. The soda-anthraquinone pulping of the banana tree residues can be simulated by polynomial models, and then predict the pulp properties (yield, Kappa number, viscosity and brightness) as a function of operating variables (temperature 160 to 180°C, time 40 to 60 min and soda concentration 7.5 to 12.5%) with errors less than 20%. Operating under optimal conditions (160°C, 40 min and 7.5% soda), a pulp with 39.23% yield, 28.59 Kappa number, 48.25% brightness, 1149 ml/g viscosity, 48.0 Nm/g tensile index, 3.80 kN/g burst index and 4.83 mNm²/g tear index was obtained. On the other hand, heating values (17751 kJ/kg), the flame temperature (1300 to 2400°C) and dew point temperature (48 to 54°C), of the different values of excess air used (10 to 50%) in combustion of the banana tree residues were determined and compared with other non-wood lignocellulosic materials. As a consequence, the price of energy obtained by combustion of these residues (3.38 10^-6 €/kJ) was less than the price of coal (25.94 10^-6 €/kJ) and much lower than those of fluid fossil fuels (>37.67 10^-6 €/kJ).

Patient Organ Dose Estimation Due to Some Selected Fluoroscopy Procedures Using Kerma Area Product Meter: The Ghananian Experience

2021-08-07T10:29:26+00:00

Aim: With the acquisition of the Kerma-Area-Product (KAP) meter, patient organ doses were estimated in order to analyze patient dose trends due to fluoroscopy exposure in two fluoroscopy centers. This gave the opportunity to report patient doses due to fluoroscopy exposure using the appropriate dosimetry procedure.

Study Design: Cross-sectional study.

Place and Duration of Study: Two fluoroscopy machines located in Greater Accra Region of Ghana in Korle-Bu Teaching Hospital and Cocoa Clinic. The duration of the study was within six and a half months.

Methodology: 182 adult patients undergoing barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examinations collectively were investigated (98 men, 84 women, age group 20-81 years). Radiation dose was measured using KAP meter. The KAP readings, patient’s data and other relevant information from the control console were used to estimate organ doses using Monte Carlo base program (PCXMC version 2.0). Quality control tests were performed on the two fluoroscopy machines before the start of the study to ensure that they were performing self-consistent with national and international requirement.

Results: The ovaries, breast, thyroid and testes recorded high doses for barium enema, barium meal, barium swallow and retrograde urethrogram examination respectively. Mean KAP values measured were 23.57±1.78 Gy.cm2, 18.08±2.08 Gy.cm2, 5.99±0.62 Gy.cm2, 8.53±0.67 Gy.cm2, 2.13±0.15 Gy.cm2 and 1.47±0.07 Gy.cm2 for barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examinations respectively.

Conclusion: The recorded KAP values for all the examinations were compatible with ICRP values but in some cases where a little bit lower. The KAP values were also higher than NRPBs’ values except for barium swallow examination which was comparable. Due to the varying patient doses in the institutions, standard protocol for fluoroscopy procedure is recommended.