ABSTRACT Acoustic effects such as absorption/amplification of acoustic phonons, Acoustoelectric Effect (AE) and Acoustomagnetoelectric Effect (AME) were studied in Carbon Allotropes. In this thesis, the Carbon Allotropes considered are Graphene Nanoribbon (GNR), 2-dimensional Graphene sheet, and Carbon Nanotubes (CNT). The Boltzmann transport equation (BTE) and the phonon kinetic equation (PKE) were used. All results were analysed numerically and graphically presented. Using BTE for Armchair ...
ABSTRACT The use of High Intensity Focused Ultrasound (HIFU) in the medical treatment of cancer has attracted scientists and engineers with interest in achieving the most financially affordable but yet curative methods of curing different types of cancers. This present work considers a 2D modeling of the prostate gland without the environmental (neighbouring) tissues such as bladder, rectum, urethra and seminal vesicle. This model uses the nonlinear Westervelt equation since the propagation i...
ABSTRACT Active polar gels are a type of viscoelastic soft material formed by polar filaments which are constantly driven out of equilibrium by the consumption of chemical fuel such as ATP. Following the approach of Voituriez et al, a generic hydrodynamic theory relying on symmetry arguments only was used to study the effects of quasi one-dimensional confinement on active polar gels. The phenomenological theory based on liquid crystal hydrodynamics is motivated by the dynamics of actin filame...
ABSTRACT River sediments are known to contain natural radionuclides, the concentrations of which if beyond certain limits can cause adverse health effects. The sediments from Ogun river provide large quantities of sand for construction purposes in Nigeria. Despite this, data are scarce on the natural radionuclides: 40K, 226Ra and 232Th distribution in the river sediments. This work was aimed at determining the spatial distribution of these natural radionuclides and their concentrations in th...
ABSTRACT The Boltzmann kinetic equation was used to investigate and derived theoretically the current density characteristics of carbon nanotubes exposed simultaneously to both constant (dc) and high-frequency (ac) electromagnetic fields. Generation and amplification of terahertz radiation at room temperature was predicted. We demonstrated that this can suppress electric current instabilities while still preserving a broadband THz gain. We have further shown that THz gain in the conditions of...
ABSTRACT Ambient air inhalable particulate matter, Black Carbon (BC) and heavy metal concentration levels in the ambient air derived from combustion at a local palm kernel production site was assessed in this study. The goal of this work was to identify the effect of biomass burning from palm kernel oil production activities on ambient air quality at Akotokyir and its environs and the possible health effects. An IVL sampler and a Sierra Anderson (GAST) pump were used to sample PM10 air partic...
ABSTRACT Luminescence sensitisation is an important stage in the application of quartz in predose retrospective dosimetry and dating. The existing techniques for sensitisation in quartz are Pre-Exposure Dose (PED) and Thermal Activation (TA). Previous works were centred on combined actions of PED and TA with less attention given to the separate contributions of these techniques in pre-dose sensitisation of quartz. This work was undertaken to determine the separate contributions of PED and TA...
ABSTRACT The prediction of Large Earthquakes (LE) constitutes a global challenge. Several methods of earthquake prediction including Pattern Recognition (PR) have been proposed but sometimes produce patterns that are not suitable. Occurrence of earthquakes is always assumed to be random when these methods produce unreliable pattern. The fact that these patterns considered to be random could be chaotic (predictable but difficult) has not been investigated. This study was designed to use chaos...
ABSTRACT Using IVL PM2.5 and PM10 particle samplers, airborne particulate matter was sampled from Ashaiman, 30 km from Accra-capital of Ghana. The airborne particles were collected on Teflon filters for a period of three months. In addition to determination of particulate mass in the two fractions by gravimetrical method, aerosol filters were analyzed to determine black carbon (BC) concentration levels using the black smoke method. BC fractions in fine and coarse, together with PM2.5 to PM10 ...
ABSTRACT Acoustic effects such as absorption/amplification of acoustic phonons, Acoustoelectric Effect (AE) and Acoustomagnetoelectric Effect (AME) were studied in Carbon Allotropes. In this thesis, the Carbon Allotropes considered are Graphene Nanoribbon (GNR), 2-dimensional Graphene sheet, and Carbon Nanotubes (CNT). The Boltzmann transport equation (BTE) and the phonon kinetic equation (PKE) were used. All results were analysed numerically and graphically presented. Using BTE for Armchair...
ABSTRACT Potable water supply in Ado-Ekiti is inadequate resulting in increased demand for groundwater in the metropolis. Geologically, Ado-Ekiti is underlain by hydrogeologically challenging crystalline basement rocks whose hydraulic properties are characterised by extreme variations over short distances. Prospective groundwater zones are poorly defined in the hard rock terrain. A thorough and definitive evaluation of the overall groundwater resource in such terrain is imperative. This study...
ABSTRACT The use of chemical fertilizers to replenish depleted soil nutrients due to over cultivation and erosion is a common practice. Natural radionuclides in these fertilizers can cause some radiological adverse health effects to animal, through indirect ingestion of fertilizer, including consumption of plants grown with fertilizers. Information on the level of contribution of chemical fertilizers to farm soil radioactivity and radiological health effects in Nigeria are scanty. This study ...
ABSTRACT Pneumatic Transfer System (PTS) is an auxiliary system of Ghana Research Reactor -1 (GHARR-1) to transfer sample capsule in and out of the reactor irradiation sites. The PTS controller unit design and construction was carried out because the transfer system was not designed to operate in cyclic Neutron Activation Analysis (NAA) and as a result could not determine radionuclides whose half-lives are equal or less than 100 seconds. In addition, most of the components used to design th...
ABSTRACT The Boltzmann kinetic equation was used to investigate and derived theoretically the current density characteristics of carbon nanotubes exposed simultaneously to both constant (dc) and high-frequency (ac) electromagnetic fields. Generation and amplification of terahertz radiation at room temperature was predicted. We demonstrated that this can suppress electric current instabilities while still preserving a broadband THz gain. We have further shown that THz gain in the conditions o...
ABSTRACT A three-dimensional (3D) laser imaging system based on digital holography has been used as a tool for testing digital holography (DH) in the infrared (IR) range in several configurations; transmission and reflection mode. The feasibility of digital holography in the infrared region was demonstrated using two beam interferometric technique for recording holograms both in reflection and transmission type geometry which employs a pyroelectric sensor array detector. The materials used ...