School of Physical and Mathematical Sciences
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Item Design of novel hybrid 2D nanomaterials for optical, optoelectronic and micro-electro-mechanical systems applications(Hybrid Advances, 2023) Elloh, V.W.; Gebreyesus, G.; Dodoo-Arhin, D.; et al.Novel hybrid 2D class of ternary nano heterostructures have been designed by mixing aluminium nitride (AlN), and boron nitride (BN) with 2D graphene to design innovative 2D nano heterostructures for applications in electronics and other industries. The structural stability and electronic properties of these nano heterostructures have been analysed using “first-principles based calculations done in the framework of density functional theory. Different structural patterns have been analysed to identify the most stable nano heterostructures. It is more energetically favourable that the aluminium nitride and boron nitride atom chains occupy the positions of the carbon atoms in a clustered pattern in the nanoheterostructures. Carbon atom chains sandwiched between aluminium nitride and boron nitride chains of atoms are a preferred choice over isolated chains of BN, AlN and CC in the nanoheterostructures. The calculated band gaps of the novel nanoheterostructures are found to be 0.87, 0.43 and 0.65 eV respectively. These novel hybrid 2D nano-heterostructures are energetically favoured materials with both direct and indirect band gaps. They have potential applications in nanoscale semiconducting and optoelectronic devices, notably optical, optoelectronic and micro-electro-mechanical systems.Item Preparation of Vapor Grown Carbon Fiber/2-((4- dimethylamino) phenyl) amino) naphthalene-1, 4-dione Composites and their supercapacitor properties(International Journal of Electrochemical Science, 2021) Mohammed, L.; Louis, H.; Nyamful, A.; et al.In this work, a derivative of 1,4-dihydoxynaphthalene, 2-((4-dimethylamino) phenyl) amino) naphthalene-1,4-dione (HBU) was synthesized by reacting 1,4-dihydoxynaphthalene with N, N Dimethyl-p-phenylenediamine. The supercapacitive properties of the electrodes containing various weights percent of vapor grown carbon fiber (VGCF) and HBU were probed in terms of redox behavior, the effect of VGCF, and specific capacitance. The VGCF created an excellent electronic pathway in the electrode, boosting the redox transition reaction in HBU involving a total of three-electron (3e- )-three proton (3H+ ) processes corresponding to 2,3-dihydro1,4-naphthoquinone–1,4-dihydroxynaphthalene and the aliphatic amine in the backbone of the substituted derivative of aniline. This led to a higher specific capacitance of 98 F/g for the HBU-VGCF electrode with a higher weight percent of HBU. The capacity retention of about 57% was observed for the HBU-VGCF electrodes after the 1000th cycle owing to the VGCF supporting the HBU by stabilizing its redox activity.Item Environmental exposure and potential health impact of heavy metals in previous mining communities in Ghana(HSI Journal, 2024) Opoku, R.B.; Dankyi, E.; Christian, A.; Aryeetey, R.Heavy metal exposure arising from metal mining is a significant source of pollution in sub-Saharan Africa. In Ghana, concerns have been heightened due to increasing artisanal mining activities. Although efforts are being made to curb illegal mining activities, including a ban on artisanal mining by the government of Ghana, the devastating impacts of mining activities can persist in the environment for a long period. This study was carried out to assess the impact of mining activities on the exposure of toxic and potentially toxic metals in food, vegetation, soil, and water samples from communities where mining activities have been halted for several years. The samples were digested using a microwave digestion system employing a mixture of nitric acid and hydrogen peroxide and analyzed for mercury (Hg), lead (Pb), chromium (Cr), copper (Co), manganese (Mn), zinc (Zn), arsenic (As), cadmium (Cd), cobalt (Co), nickel (Ni), and iron (Fe), using an inductively coupled plasma-mass spectrometer (ICP-MS). The results showed generally elevated levels of metals in water, food, vegetation, and soils. For example, in vegetation, the average concentrations of Pb, Hg, Cd, and As were 198 μg/kg, 303 μg/kg, 75 μg/kg, and 519 μg/kg, respectively, while the average levels of As and Pb were 11,111 μg/kg, and 3,518 μg/kg, respectively, in soil samples collected from abandoned mining sites. Food crops (cassava and plantain samples) grown in abandoned mining fields had elevated levels of Pb (602 μg/kg) and Hg (15.7 μg/kg). Based on our findings of widespread exposure, high concentrations, and potential health risks posed by these metals, proactive measures for the reclamation and remediation of affected land are needed to protect the environment and human lives in these previous mining communities.Item Martingale Hardy-Amalgam Spaces(University of Ghana, 2022-07) Bansah, J.S.In this work, we introduce the new spaces, Hs p;q; HS p;q; H_ p;q; Qp;q; Pp;q; called the martingale Hardy-amalgam spaces. We study some of the properties of these newly introduced spaces; two de_nitions of atoms are given and hence two atomic decompositions are given, dualities of these spaces are characterized and the martingale inequalities and embeddings of these spaces are also discussed. It is proved that the dual of Hs p;q; (0 < p _ q _ 1); is a Campanato-type space and the dual of Hs p;q; (1 < p _ q < 1); is Hs p0;q0 where (p; p0); (q; q0) are conjugate pairs. The variation integrable space Gp;q is also introduced and it is established that the jump bounded space BDp;q is the dual of Gp;q: To be able to characterize this duality, a larger space, which we denote by K(Lp;q; `r); is introduced, such that Gp;q can be embedded into. The classical Doob's martingale inequality is also extended from the classical martingale Hardy spaces to the newly introduced martingale Hardy-amalgam spaces. The Burkholder-Davis-Gundy inequality is also extended from the classical martingale Hardy spaces to the martingale Hardy-amalgam spaces as well as the convexity inequality and the concavity inequalities involving measurable functions. The classical martingale Hardy space embeddings are also extended to the martingale Hardy-amalgam spaces. The Davis decompositions of martingales in the classical martingale Hardy spaces are also extended to the martingale Hardy-amalgam spaces. As an application of the Davis decomposition and the Garsia space, a duality theorem for H_ p;q (1 _ p; q _ 2) is provided. Finally, the boundedness of martingale transforms between the martingale Hardy-amalgam spaces are also discussed. No data was collected for this study as the methodology used is purely theoretical in nature.Item Site-Specific Soil Classification Of Seismic Site Effects For The Greater Accra Metropolitan Area Of Ghana Using Multichannel Analysis Of Surface Waves(University Of Ghana, 2021-12) Nortey, G.The study presents site classification for Greater Accra Metropolitan Area (GAMA) of Ghana. Multichannel analysis of surface waves (MASW) is used to calculate shear wave velocity to various depths within the study area. Calculated shear wave velocity up to a depth of 30 m has been used to assess seismic site effects and soil conditions for a major part of the GAMA. Seismic risk has become overwhelmingly apparent from many studies carried out over this area. The area is overpopulated, poorly planned, with the largest convergence of major and minor faults, as well as several historical and recent events. Despite the exposed seismic risk, a regional soils conditions map is yet to be completed for the GAMA. Dispersion data from 42 test sites was inverted and classified according to suggested seismic site classification scheme by National Earthquake Hazard Risk Program (NEHRP). From results of calculated shear wave velocity up to 30 m of soil, two main site classes have become apparent (D and C). Considering the geology of the underlying subsoils, two subdivisions for site class D is suggested (D1 and D2). The residual soils to the southwest and northwest of the study area are derived predominantly from granitoids, and their response is characteristically low. These values are generally within a range of 180 -360 m/s and thus fall into suggested site class D1, the most vulnerable within the test site. Similar to site class D1, D2 is also characterized by low shear wave velocity values (180 -360 m/s), however the underlying subsoils derived from phyllites within the study area. D2 occupies area to the southeast, lower and upper middle of the study area. Several vulnerabilities were identified for soils of site class D within the study area.Item Theorising Mobile Technology Addiction: Evidence From A Developing Country Context(University Of Ghana, 2023-02) Nyamadi, M.Several unprecedented benefits of mobile technology have been realised globally. In developing countries, this seemingly ubiquitous technology has created socio-economic impacts, including post-economic recovery after the COVID-19 pandemic. Despite this promise, there are unintended consequences which tend to threaten the social behaviour of its mobile adopters or users and thereby have the potential of marring the sustainability of its benefits. Mobile technology addiction (MTA) is one of the unintended consequences of adopting and using this mobile technology that requires attention. Operationally, MTA is defined as a non-chemical (behavioural) addiction which involves human-technology interaction. The urgency of the attention is echoed in the 5th edition of the American Psychiatric Association (APA) Diagnostic and Statistical Manual of Mental Disorders. However, attempts to address this urgency in literature face four main research gaps. The first gap is the lack of a multidisciplinary and stakeholders’ understanding of MTA from a developing country context. The second gap is the lack of theorisation in research that recourse is drawn from a socio-technical perspective per the multifaceted nature of mobile technologies. Currently, no socio-technical theorisation exists in the literature. The third gap is the lack of theorising the moderating effects of Fear of Missing Out (FoMO) and self-regulation in one study since they are the two main moderators with opposing effects. The relationship between MTA and its outcome is either strengthened or weakened by these two moderators. The fourth gap is that developing countries are less represented in literature. The Global Mobile Economy data reports that 5.3 billion people subscribed to mobile services globally as of 2021. The future growth is estimated to be driven by younger people from developing countries in Asia and Sub-Saharan Africa (SSA). MTA is a threat to this potential growth and needs urgent attention. A study among young people in universities with a higher potential for meaningful use of mobile technology from a developing country context is needed. This study consolidates the Technology Acceptance Model 3 (TAM3) and Unified Theory of Acceptance and Use of Technology 3 (UTAUT3), Flow Theory, and Stimulus Organism Response (S-O-R) Framework to address the gaps in the literature. The combination of these theories addresses the weaknesses in the existing literature that sought to theorise MTA (particularly smartphones and tablets) from either a social or technical perspective. Adoption theories (i.e., TAM3 and UTAUT3) present MTA's technological dimension. The flow theory describes how the interaction between users and mobile technologies leads to flow and triggers MTA. The S-O-R framework explains how a stimulus (user attributes and technology attributes) leads to the organism (social presence, flow and telepresence) and triggers a response (MTA and negative consequences). This study is conducted from a critical realism perspective using a mixed methodology. It uses a survey of 528 respondents for the quantitative and a multi-case study approach for the qualitative. Structure Equation Modelling (Smart Partial Least Square) is used for the quantitative and thematic content analyses for the qualitative. The above approaches and methods present a comprehensive view of MTA, enabling qualitative data and results to provide rich explanations for the quantitative findings. The first objective is to understand from multidisciplinary and stakeholders’ perspectives the nature and causes of technology addiction in a developing country context. The findings from Ghana suggest a multiplicity of perspectives by professional practice or experiential knowledge from health-related disciplines (i.e., psychiatry, psychology, nursing and medicine). They describe MTA as a mental health disease which involves users' over-dependence on mobile technology despite harmful consequences. Even among healthcare professionals, differences exist per their practice. Neuroscientists describe MTA as an altered brain condition where the brain can get into a state of uncontrollability toward external stimuli like mobile phones and their contents. Religious leaders in Ghana Pentecostal and Charismatic Council (GPCC) describe MTA as a sickness caused by strange spirits. Technology developers described MTA as a technological disorder caused by ubiquitous, communicative, responsive, flexible, and attractive multimedia interfaces of mobiles, which enable users to engage in online social behaviours that lead to addiction. Finally, the definition deduced and agreed upon by all stakeholders for MTA is a chronic brain condition where one feels preoccupied with an uncoerced compulsion to repeat or continue using mobile technology with severe negative consequences or outcomes. The process of addiction is divided into four stages, experimental use, regular use, abusive use and addictive/dependence use (see Fig 8.6). The second objective is to explain how the socio-technical interaction between users (university students) and mobile technology leads to mobile technology addiction. This study posits that users must be motivated by their self-traits, hedonic and utilitarian values to be socially connected to mobile technology, thus social presence. Mobile technologies must have usability and interactivity attributes to aid telepresence. The interaction between social presence and telepresence results in flow, which predicts MTA. This study explained the concept of flow as the result of users’ interest, abilities, and skills to effectively use mobile technologies that have immersive capabilities to result in total immersion and absorption to the extent that the user may eventually lose control of time and immediate environment which result in addiction, for the detailed structures and mechanisms that trigger MTA (see Fig 9.1). The third objective is to explore the moderating effects of Fear of Missing Out (FoMO) and Self-Regulation. This research found that FoMO intensifies the relationship between MTA and their outcomes, while self-regulation weakens the relationship between MTA and their outcomes. Therefore, if FoMO is intensified, the relationship between MTA and its impact on academic performance and/or well-being is increased negatively. However, if self-regulation is enhanced, the relationship between MTA and its impact on academic performance and well- being is weakened. This study conceptualised FoMO and self-regulation as IS Use Regulation moderating construct in the final MTA Model (see Fig.9.2). The fourth objective is to investigate and explain the effect of mobile technology addictions on university students’ academic performance and well-being in a developing country context. This study found that MTA significantly predicted negative academic performance. The qualitative findings explain the negative effects of academic performance as school abandonment, playing truancy, phubbing, and learning table disruptions and on well-being as mental health disorders, relationship complications, emotional and psychological instability and impaired social behaviour. This study contributes to research, theory, policy and practice. First, this research describes MTA and presents its nature and causes from a multidisciplinary and stakeholder perspective. It discovers the stages in the process of addiction and reveals the socio-technical structures and mechanisms that trigger MTA and its impact on outcomes. This research contributes to theory by extending flow theory from the original four (4) dimensions to five (5) dimensions. It hypothesised and empirically tested presence as the fifth dimension and found it to be significant (see Table 6.7). For contribution to the S-O-R framework, this study proposed new constructs for stimulus (user attributes and technology attributes), organism (flow) and response (MTA and negative consequences), which is a unique way of applying it in literature (see Fig 9.2). Finally, this study develops an MTA framework and model from a socio-technical perspective which could be equally used to study other forms of addictions. Per the findings, researchers, practitioners and policy-makers must start thinking about developing design principles and artefacts to regulate, block and mitigate MTA. This study proposes that MTA interventions should be regulatory, market-based and voluntary. The contributions have been published in two (2) book chapters and three (3) conference articles. The three journal articles are currently being worked on for publication in three leading information systems journals.Item Large Deviations of the Throughput in Multi-Channel Medium-Access Protocols(University Of Ghana, 2022-04) Kwofie, C.This thesis considers Aloha and slotted Aloha protocols as medium access rules for a multichannel message delivery system. Users decide randomly and independently with a minimal amount of knowledge about the system at random times to make a sending attempt. The system has a fixed number of available channels; equivalently, interference constraints make the delivery of too many messages at a time impossible. We derive probabilistic formulas for the most important quantities like the number of successfully delivered messages and the number of sending attempts, and we derive large-deviation principles for these quantities in the limit of many participants and many sending attempts. We analyse the rate functions and their minimizers and derive laws of large numbers. In particular, we are interested in questions like “if the number of successfully delivered messages is significantly lower than the expectation, was the reason that too many or too few sending attempts were made?”. The main tools are from the theory of large deviations.Item Hydrochemical And Isotopic Characterization Of Aquifers In The Lower Tano River Basin, Ghana, West Africa.(University Of Ghana, 2020-07) Edjah, A.The Lower Tano River basin is one of the basins endowed with minerals, oil, and gas resources in West –Africa. It covers 104,000 km2, and the major riparian countries are Ghana and Ivory Coast. The basin, underlain by the Birimian supergroup rocks and the rocks of the Apollonian has enough surface water resources to meet current water demands, but there are many challenges including high population growth rate (due to influx of oil and gas industrial workers), land degradation, mining activities, climate change etc. These challenges have put immense pressure on the groundwater resources in the basin. Also, the surface water is unreliable to meet the basin’s water demand for socio-economic development. This therefore makes groundwater the most cost effective and preferred means of supplying water to the dispersed population and rural settlements across the basin. One probable requirement for a sustainable and efficient management of groundwater is the characterization of aquifers in terms of its quantity, quality, and quantification of the recharge sources. Hence in this study, the aquifer hydraulic parameters were estimated, the overall quality of groundwater including the level of trace elements contamination, and its suitability for domestic and agricultural purposes was assessed, the hydrogeochemical processes that produces the chemical characteristics or compositions of the aquifer system was determined, the sources of recharge to the aquifer was investigated and the ages of groundwater was determined. The methodology used involved pumping tests carried out on 55 boreholes drilled across the basin, yearly sampling of surface water and groundwater resources, measurement of cations, anions, trace elements, stable isotopes of deuterium (δ2 H), oxygen-18 (δ18 O), tritium (3H) and measurement of silica. Pumping test together with Theis (1934) graphical method was used to estimate the aquifer hydraulic parameters (transmissivity, hydraulic conductivity, and specific capacity). From the estimation of the aquifer hydraulic parameters, it was observed that the mean transmissivity, hydraulic conductivity, and specific capacity values were 5.96 m2/day, 5.70 m/day and 18.80 L/min/m, respectively. The cations (calcium, sodium, potassium, magnesium) and anions (chloride, bicarbonate, nitrate, and sulphate) show that the aquifer of the Apollonian formation and the Birimian super group produces fresh groundwater with most being soft and few being moderately hard and hard. Na+ and SO42- were the dominant cation and anion in the surface water and ground water sampled in 2016. Likewise, Na+ and HCO3- were the dominant cation and anion in the surface water sampled in 2017, the groundwater sampled from 2013 to 2015, and the hand dug wells sampled in 2017. The boreholes sampled in 2017 had Na+ and SO42- as the dominant cation and anion, respectively. All the measured ions (bicarbonates, sulphate, chloride, nitrate, calcium, magnesium, sodium, potassium) in most of the surface water and groundwater sampled from the rocks of the Apollonian and the Birimian supergroup were within the WHO (2011) allowable limits for drinking water. The results of the measured trace elements that is Fe, Pb, Cd, Ni, As, and Al were high in most of the surface water samples. Also, the results of Cu, Cd, Zn, Cr, Fe, Ni, Mn, Co, Pb, As and Al in most groundwater especially those sampled from the aquifer of the Apollonian formation were higher than the WHO (2011) permissible limits for drinking water. The elevated concentrations of trace elements in the surface water and the groundwater were mostly related to geogenic sources. Based on water quality index (WQI) results, it was observed that majority of the groundwater sampled from the aquifer of the Apollonian formation were unsuitable for drinking whiles most groundwater samples taken from the aquifer of the Birimian supergroup were suitable for drinking. As per sodium adsorption ratio (SAR), 99% of the groundwater sampled from both aquifer of the Apollonian formation and the Birimian supergroup were suitable for irrigation. The sodium percent classification indicates that, minority of the groundwater sampled from the aquifer of the Apollonian formation and the Birimian supergroup falls under excellent category for irrigation. Wilcox diagram and magnesium hazard classification indicate that majority of the groundwater especially those sampled from the aquifer of the Apollonian formation gave out excellent to good water for irrigation. The residual sodium carbonate and Permeability index classification specify that all the sampled groundwater from the aquifer of the Apollonian formation and the Birimian supergroup were suitable for irrigation. The chlorinity index classification indicates that the aquifer of the Apollonian formation and the Birimian super group produce groundwater that were suitable for irrigation. Graphical including hydrogeochemical modelling and statistical approaches applied in the delineation of the major factors influencing the evolution of groundwater and the general hydrochemical characteristics revealed that the chemistry of groundwater in the Apollonian formation aquifer and the aquifer of the Birimian supergroup was mainly rock weathering and rainfall. In addition, ion exchange processes, rock-water interaction and incongruent dissolution were the major natural factors governing the formation of the groundwater chemistry in the Lower Tano River Basin. However, the occurrence of sulphate implies that sulphide mineral (pyrites, arsenopyrites and chalcopyrite) oxidation or mobilization and mining activities including illegal and legal small-scale mining possibly have an impact on the groundwater chemistry in the Lower Tano River Basin. The hydrochemistry of the sampled groundwater transited from Ca-HCO-3 to Na-Cl water type along a flow direction for the groundwater samples taken from 2014 to 2015 and 2017. For the groundwater sampled in 2016, the hydrochemistry evolved from Ca-HCO3- to Ca-SO42- water type and then to NaCl water type along the flow direction. The evolution was influenced by ion exchange processes and rock-water interaction. Based on mineral stability diagram, most groundwater in the aquifer of the Apollonian formation and the aquifer of the Birimian super group appears to be stable within the Kaolinite field suggesting ion exchange processes. Stable isotope composition (δ18O and δ2H) of rainwater indicates that the rainwater was not highly evaporated. Also, the slope and intercept of the rainfall regression lines obtained for this study were slightly similar to the local meteoric water line for Ghana and the global meteoric water line. Stable isotope composition (δ18O and δ2H) of surface water (rivers, streams, lagoon, and seawater) and groundwater (hand dug wells and boreholes) reveal that the mechanism of recharge to the aquifer of the Apollonian formation and the Birimian supergroup was rapid with the source being meteoric. Also, the surface water (rivers and streams) contributed to the groundwater recharge of the Lower Tano River Basin. Tritium in rainfall ranges from 1.27 to 10.11 TU. That of the rivers ranges from 2.04 to 3.08 TU and that of the groundwater ranges from 0.99 to 6.78 TU. The tritium results revealed that groundwater from the aquifer of the Apollonian formation and the Birimian supergroup were young, of modern recharge with short residence time. Also, the groundwater was recharged between 1960- 1965 and 1965 – 1970. The outcome of this study has added to the current hydrogeological knowledge about Lower Tano River Basin. It has also added to the characteristics of semi-confined and unconfined aquifers.Item Geophysical And Hydrogeological Characterisation Of The Nasia Basin, Northern Ghana(University of Ghana, 2020-11) Abdul-Samed, AABSTRACT The development of groundwater resources across the Voltaian Sedimentary Basin (VSB) is constrained by lack of knowledge on the location and suitability of aquifers for borehole construction. The main objective of this study is to evaluate the hydrogeological characteristics of the Nasia Basin to help in delineating suitable locations for groundwater exploration. An integrated geophysical investigation involving resistivity survey using 2D Electrical Resistivity Tomography (ERT), Electromagnetic Survey with EM34-3 and wireline logging of boreholes were employed to determine the resistivity of the different type of lithology occurring in the area and for providing information about the lateral and vertical extent of weathering and fracturing in the subsurface. A total of 58 ERT profiles were run at selected locations and at existing boreholes to obtain information about resistivity in different depth intervals. Majority of the profiles were run across the general strike of rocks of the VSB in the study area with length being either 400 m or 800 m. Five EM-34 ground conductivity profiles of 500-1000 m were conducted on each of two approximately parallel South-North traverses (EM campaign 1) to record the conductivity in the various geological formations and to assess its possible variation related to major geological structures. In addition to the two-parallel profile (EM campaign 1), 12 other EM-34 profiles each 500 m long were carried out at six selected communities in the central part of the study area (EM campaign 2) with the objective of locating areas within the weathered zone capable of storing groundwater for small scale pilot irrigation from dug-wells. The conclusion of the integrated geophysical investigation is that combining interpretations from various geophysical methods provides an improved characterisation of the hydrogeology. Secondly, hydrogeological investigations were conducted which involved analysis of pumping test results, evaluation of various methods of estimating aquifer transmissivity and assessment of the major factors controlling groundwater occurrence. Using remote sensing and geographical information system (GIS), thematic maps of slope, drainage density and lineament, geological formation were prepared. Other thematic maps such as static water level, regolith thickness, depth, recharge and transmissivity developed from kriging were incorporated into GIS. Finally, multi-criteria analysis and GIS techniques were used to integrate these thematic maps to delineate suitable zones to obtain a comprehensive groundwater potential map of the study area. The results also show that in certain locations such as portions of the Bimbilla formation, probability of obtaining aquifers is very low and therefore the target should be to locate thick regolith for groundwater storage. The results from the hydrogeological investigation indicate that cokriging gives better estimates of spatial aquifer transmissivity and therefore is a better approach considering the paucity of long duration pumping test data. Regression models and variographic analysis conducted confirmed the findings of previous researchers that groundwater within the study area is mainly structurally controlled and not by lithology. The groundwater potential map was classified into five zones that describe the potentiality of each cell in the study area for groundwater exploration. These classes are; very poor, poor, moderate, good and very good groundwater potential areas. It was found that 2% and 18% of the study area was classified as very good and good potential areas respectively. These are areas found to be concentrated in the Kodjari formation southwest of the Panabako sandstone formation of the study area. About 38% of the study area was classified as moderate potential which is sparsely distributed across the study area and 41% represent poor potential for groundwater exploration occurring mainly in the Bimbilla formation. Less than 1% of the study area was classified as very low potential areas and also concentrated in southeast of the study area. The reliability of the groundwater potential map was tested against successful and dry boreholes and the results showed that generally, the majority of high- and low-yielding boreholes fall in areas predicted by the map. Furthermore, a sensitivity analysis was performed to study the effect of each parameter on the overall groundwater map using the effective weight. It was found that the transmissivity was the most effective among the parameters that have the greatest influence on groundwater occurrence in the study area which is consistent with literature. The integrated geophysical method coupled with the comprehensive groundwater map has provided better information about subsurface geology of the Nasia Basin which is critical for understanding the lithological character in terms of hydrogeological conditions. The general concept of interpreting low resistivity zones as the presence of a sub-vertical fracture zone and therefore regarded as a favorable site has been refuted. A more scientific approach of interpreting geophysical results has been proposed for exploration hydrogeologist in the area and in similar geology. The groundwater potential map further shows that the potential for high yielding boreholes is limited to about 20% of the study area. Therefore, other strategies to augment for increasing irrigation such as exploring the weathered zone for groundwater storage should be considered.Item Monitoring and High-Resolution Studies of Some Hydroxyl and Methanol Masers in the High Mass Star Forming Region G9.62 + 0.20 E(University of Ghana, 2020-07) Woode, B.This thesis presents the observational data reduction and results of an investigation into the 1:6 GHz OH and 6:7 GHz methanol masers in the G9:62+0:20E massive star forming region. Monitoring observations from the Hartebeesthoek Radio Astronomy Observatory (HartRAO) radio telescope were employed to establish correlated variabilities between the 6:7 GHz methanol masers and the left and right circular polarizations (LCP and RCP) of the mainline 1:6 GHz OH masers. This is the first reported incidence of periodic variations of the LCP and RCP components of the 1:6 GHz OH mainline masers associated with the 6:7 GHz methanol masers in this high mass star forming region. Correlated variability between the varying features in the LCP components of both hydroxyl masers and methanol masers was observed but the variability profiles were different for both species. Time lags were recorded between the methanol and the OH maser variabilties. Within the OH masers the variability profiles were preceded by a dip in flux density. The first high resolution observation of the L-band and Cband continuum of G9:62+0:20E were conducted with the e-MERLIN interferometric array. A flux density of 2:25 0:20 mJy and an angular size of 130 mas were measured for the C-band continuum. At L-band, an upper limit of 162 mJy on the integrated flux density was calculated at the position of the continuum. These results unlike previous observations reveal that the spectrum turns over steeply at low frequencies which could be explained with a truncated inverse square law density distribution model. The peak brightness temperature indicates that the continuum is optically thin at C-band and optically thick at L-band. In the context of the colliding wind binary model for periodic maser sources it is the variation of the seed photons from the background HII region that explains the variability. The continuum results in this thesis place firm constraints on models of the HII region that can be used to test the predictions of the colliding wind binary model in terms of the variability profiles of the OH and methanol masers.