Department of Nuclear Sciences and Applications

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Using Hydrochemical And Isotopic Tracers to Assess the Impact of Anthropogenic Activities on Groundwater Quality in Bongo And Kassena Nankana West Districts in Upper East Region of Ghana
(University of Ghana, 2019-07) Zainab, D.
The population within Bongo and Kassena Nankana West Districts, in the Upper East Region of Ghana is estimated to be about 84,545 and 70,667, respectively. An estimate of about 80% of the population depends on groundwater for domestic and agricultural purposes. However, groundwater resources in the Districts is at risk due to anthropogenic activities such as rapid increase in irrigation activities and animals rearing, open defecation and uncontrolled disposal of animal droppings, improper land use, waste disposal, and illegal mining activities. “This study was carried out to use hydrochemical and isotopic tracers to assess the impact of anthropogenic activities on groundwater quality in the study areas. The study employed hydrochemistry and isotopic techniques to assess the chemical quality of groundwater in the study areas. A total of sixty-four (64) boreholes were sampled from the study areas for the study. The samples were analysed in-situ for pH, conductivity and salinity using a HACH potable meter; and bicarbonate using a titrimetry. Analytical methods employed for the determination of major and minor ions were (Na+ and K+) complexometric titration (Ca2+) and (F-, Cl-, NO3 -, PO4 3-, and SO4 2-). Atomic absorption spectrometry was used for the determination of Mg2+ and heavy metals (Fe, Mn and As). Stable isotope of 2H and 18O composition of the water samples were determined using Liquid-Water stable isotope analyser [Off-Axis Integrated Cavity Output Spectroscopy (off axis ICOS) via Laser Absorption]. In general, majority of the ions are within the permissible limit for drinking purpose except few locations in the study areas. The Gibbs Diagram, the Piper Trilinear Diagram and the Hierarchical Cluster Analysis reveal different degrees of water-rock interaction or mineralization and are consequence of silicate weathering and silicate mineral dissolution, cation exchange and to a lesser extent University of Ghana http://ugspace.ug.edu.gh vi fertilizer application. Based on the Water Quality Index (WQI) classification, the majority of the samples fall under excellent to good water category and suitable for drinking water purposes, except for groundwater in few areas which showed deteriorating water quality. The stable isotopes composition implies, there has been fractionated before recharge”. Since, the values deviate towards the positive valves.
Health and Safety Assessment of Waste-Pickers at the Kpone Landfill Site
(University of Ghana, 2019-10) Nuviadenu, A.M.
Ambient sulphur dioxide (SO2) and nitrogen dioxide (NO2) were measured mea sured from seven (7) locations at the Kpone landﬁll site in the Kpone Municipality of Greater Accra Region. Average 24-hour concentrations ranged 47 µg/m3 – 185 µg/m3 and 52µg/m3 – 164 µg/m3 were recorded for NO2 and SO2 respectively. All the measured concentrations were above the WHO guideline limits. Eight (8) heavy metals (Pb, Hg, V, Cr, Cu, Ni, Zn, and Cd) were detected and quantiﬁed in the soil and dust sampled from ten (10) locations within the study area using x-ray ﬂuorescence analysis (XRF). Cu, Zn and Pb recorded the highest concentrations that were all above their respective New Dutch List permissible limits. The concentrations, at some sampling locations, were as high as: Cu (334 mg/kg), Zn (36585 mg/kg) and Pb (4808 mg/kg) which recorded high contami nation factors as well. Contamination factors computed using elemental concentrations, as well as the degree of contamination computed for each sampling location revealed locations 4, 5, 6 and 7 as highly contaminated. Health hazard index for carcinogenic and non-carcinogenic health risk with respect to three exposure pathways (dermal, in gestion and inhalation) projected locations 4, 5, 6 and 7 as locations with high health risks for waste pickers who ply their trade around these areas. Waste pickers’awareness of health and safety risks was assessed as well. All of them seem to be aware of the physical hazard while 23% are aware of the health risks associated with their working conditions.
Assessment of Factors Affecting Indoor Radon -222 Concentration in Dome and its Environs - Greater Accra Region of Ghana
(University of Ghana, 2018-07) Kpordzro, R.
The objective of this study was to evaluate the contributions of the main factors of indoor radon concentration. This was achieved by measuring indoor and soil gas radon in three localities (Dome Afghanistan, Achimota Mile7 and Achimota ABC) in and around Ga East. 60 houses were selected in the three localities for the indoor measurements. Five sites were located in each of the localities for soil radon measurement at 75 cm depth. LR-115-type II plastic track detectors were used for the measurement in two different seasons – dry and wet. The indoor radon concentration measurement was carried out for three months in each season and the soil measurement was also carried out in a 14-day cycle for four cycles. The LR- 115-type II plastic track detectors were collected, etched at 60 0C and counted using the image j software and v-600 perfection scanner. The track densities obtained were converted into radon concentrations. The International Commission on Radiological Protection (ICRP) publication 115 model was used to estimate the annual absorb dose and effective dose to the lungs. Significant seasonal variations were observed in the radon concentrations of the dwellings studied. Indoor radon concentrations for the rainy season showed relatively high values than that of the dry season. This was expected as the sliding windows used for the dwellings are not opened during the rainy season. This might have resulted in the accumulation of radon gas in the rooms. Regular opening of windows and other means of providing air exchanges in the rooms during the dry season could have also accounted for the low levels of indoor radon concentration. The mean indoor radon concentration in the rainy season for Dome Afghanistan, Achimota Mile7 and Achimota ABC were determined to be 165 Bq/m3, 115 Bq/m3 and 119 Bq/m3 respectively. The corresponding dry seasons were 71 Bq/m3, 73 Bq/m3 and 66 Bq/m3 respectively for the three localities. The annual effective dose (AED) in the dwellings for Afghanistan ranges from 4.8 mSv/y to 20.2 mSv/y and that of Achimota Mile7 and Achimota ABC ranged from 3.23 to 13.9 mSv/y and 3.5 to 10.74 mSv/y respectively. According to ICRP Publication 115 (2010) statement on radon, the upper value for radon reference level of 300 Bq/m3 corresponds to an AED of 17 mSv/y. Thus the three localities are generally found to fall within the ICRP (2010) limit; however, dwelling AF H17 of Dome Afghanistan recorded indoor radon concentration of 334.10 Bq/m-3 with a corresponding AED of 20.2 mSv/y. These are relatively higher than the ICRP limit. The soil radon measured in both seasons was higher than the corresponding indoor radon concentrations. The concentration ranges from 0.37 to 1.19 kBq/m3 and 1.43 to 4.23 kBq/m3 in the rainy and dry seasons respectively. The concrete floors and blocks of the dwellings seemed to have provided shielding and prevented high radon diffusion from the ground and outdoor into the dwellings. Works already done on the same building materials showed that the radon exhalation rate from these materials ranged from 17.5 to 42.6 Bq/m3. This suggested that the major possible contributing factor to indoor radon concentration in dwellings is lack of ventilation which leads to the build-up or accumulation of radon. A linear correlation analysis for the influence of soil radon concentration on indoor radon concentration in rainy and dry season, gave an Rsquared value of 0.0032 and 0.0021 respectively, indicating a weak negative correlation between soil radon concentration and indoor radon concentrations. This confirms that the indoor radon concentration is weakly linked to the soil radon, possibly as a result of the concrete floor and blocks which provided good shielding.
Optimisation and Surface Morphological Analysis Of Activated Carbon from Agricultural Waste Products
(University Of Ghana, 2017-07) Nyogbe, E.K.
Many conventional or agricultural by-products and wastes go unused in Ghana. These wastes find their way into our water bodies and also sometimes become breeding grounds for mosquitoes and other insect pest causing diseases leading to severe health problems. These wastes sometimes are used as fillers in pot-holes which inadvertently blocks drainages during rainfall thereby leading to flooding in flood prone areas. The precursors used in this study to produce activated carbon were palm kernel shell and coconut shell. The produced activated carbon was activated chemically using three different activating agents, acid (H3PO4), base (NaOH) and a salt (CaCl2). The maximum yield of activated carbon, 26.3 g (PKS) and 22.9 g (CS), using H3PO4 as an activating agent were obtained at 400 oC, 1 h carbonisation time and an impregnation ratio of 1.2. Similarly, maximum yield of activated carbon, 22.4 g (PKS) and 17.3 g (CS), using NaOH as an activating agent was also obtained at 500 oC, 2.5 h and impregnation ratio of 1.2. Using CaCl2 as activating agent, the maximum yield of activated carbon were 25.5 g (PKS) and 20.8 g (CS), these maximum values corresponded to 400 oC, 1 h carbonisation time and an impregnation ratio of 1.2. The H3PO4 activated carbons were fairly better in the areas of ash content (7.17 %), moisture content (1.94 %), bulk density (0.65 g/cm3), pore volume (0.94 ml/g), iodine adsorption (743.02 mg/g) and porosity (0.49). On the other hand, the NaOH activated carbon was also advantageous in terms of carbon content (57.78 %). CaCl2 activated carbons, were also commendable in terms of volatile matter (30.46 %) and electrical conductivity (2130 μS/cm). Scanning Electron Microscopy (SEM) technique was employed to observe the surface physical morphology of the coconut shell and palm kernel shell activated carbons. Prior to chemical activation the surface morphology of the raw coconut shell compared to the palm kernel shell at a magnification of ×5000 did not show porous surface, while the external surfaces of the chemically activated carbon were rich with cavities.
Studies of Iron Removal in Drinking Water Using Limestone as Adsorbent
(University of Ghana, 2017-07) Thandiwe, P.
The study assessed the suitability of two limestone samples (EKLD01 and EKLR02) for use as adsorbent to remove excess iron in drinking water through geochemical and mineralogical characterization using an ion beam linear accelerator and petrographic thin sectioning respectively. The radiological safety (activity concentration) of the limestone was evaluated through measurement of the Naturally-Occurring Radioactive Materials (NORMs) using a High-Purity Germanium (HPGe) -ray Semi-conductor Detector. In addition, the study monitored the iron adsorption efficiency (sorption capacity and percentage adsorption) of limestone with respect to Sample Size, Adsorbent Dose, Residence Time and pH. Agreement between the adsorption isotherms obtained from this study and model adsorption isotherms proposed by Langmuir (1916) and Freundlich (1909) assessed. The iron removal technique was developed using limestone grain sizes (500-1000 μm, 1000-2000 μm and 2000-6350 μm) through Batch Adsorption experiments using Iron standard solutions, followed by Column Adsorption experiments using iron rich/contaminated ground water from the Ashongman Estates, in the Ga East Municipal of the Greater Accra Region of Ghana. The geochemical and mineral characterization indicated that Sample EKLR02 was the most suitable limestone sample for the development of technique based on its relative high calcium content (56.14%). Radiologically, both limestone samples were safe as their calculated mean annual effective dose (0.2 mSv/yr for both samples) did not exceed the UNSCEAR (2000) recommended value of 0.4 mSv/yr. In the Batch experiment, the extent of iron adsorption with respect to time, pH, and dosage of limestone (20-100 g in 200 mL of iron standard solution) were studied. Maximum adsorption was attained at pH 12, limestone dosage of 100g/200 mL, time of 60 minutes, and particle size of 500-1000 μm. Consequently, these were adopted and used for the Column experiments. University of Ghana http://ugspace.ug.edu.gh vi In the Column experiments, optimal conditions obtained during the Batch experiments were adapted and used to analyze fourteen (14) water samples from boreholes and hand-dug wells from the Ashongman Estates. The measured iron concentrations of the sampled water from Ashongman Estates ranged from 0.20 to 4.66 mg/L prior to the Column experiment. At the end of the Column experiment, the measured iron concentrations ranged from 0.19 to 0.28 mg/L [below the World Health Organization (WHO) recommended level of 0.3 mg/L]. There was linear agreement (RL =1) between the adsorption data obtained from the study with Langmuir’s Model Adsorption Isotherm (1916) at iron concentrations of 1 mg/L and above (in the ground water samples). The adsorption data obtained from the study did not correlate well (R2 = 0.0138) with the Freundlich model adsorption isotherm (1909); and the Freundlich constant, Kf , was found to be negative -5.2367 instead of a positive value.
Application of Integrated Geophysical Methods to Investigate Contaminants at a Landfill Site, Accra,Ghana.
(2018-07) Andam, E.O.
In the study electrical resistivity tomography (ERT), time-domain induced polarization (TDIP) and seismic refraction tomography (SRT) techniques were applied at an active unengineered municipal solid waste landfill site located at Pantang in the Ga East Municipality, Accra, Ghana. The environmental and public health hazards related with municipal solid waste disposal are rampant in developing countries like Ghana. The most common waste disposal system in Ghana is the open disposal of waste generated from industries, residents and commercial areas to un-engineered landfill sites. The consequences on the quality of livelihood and health risks as a result of this practice demand a comprehensive method to investigate and evaluate the impact of landfill sites on the environment. This study was aimed at mapping the conductive contaminant plume and level of contaminants migration within the subsurface, and also to determine the depth to bedrock of the landfill site. A total of five (5) survey lines were selected in conducting the electrical resistivity tomography and induced polarization methods. The dipole-dipole array was employed in investigating the extent of potential contaminant plumes beneath the subsurface. The analysis generated from the models revealed that the zones with possible leachate pollution have thicknesses ranging from 1 m to 4 m and a maximum depth of 15 m below the surface. In a complimentary effort, seismic refraction survey was conducted on two survey lines, to define shallow bedrock topography and the depth to bedrock of the landfill site. The seismic survey demonstrated that highly variable non-uniform subsurface conditions exist at the landfill site. The result proposes that, the Pantang landfill site has seismic velocities distribution ranging from; 72 ms-1 to 900 ms-1, which is interpreted as the overburden material, 1000 ms-1 to 6000 ms-1 for slightly weathered zone and velocities greater than 6000 ms-1 for competent rock material. The seismic refraction tomography helped to characterize geologic features within the waste dump and to assess the possible pathways for contaminant plumes. The outcome established by this research suggests for an evaluation of the waste management system policies in Ghana emphasizing on alleviation of the influence of municipal solid waste on the ecosystem.
Anxiety, Depression and Suicidal Ideation among Prisoners In Ghana
(2017-07) Adzam, D.A.
The present study investigated anxiety, depression and suicidal ideation among prisoners in Ghana. Specific aims and objectives for this research were to (a) find the levels of psychopathological symptoms among male and female prisoners; (b) examine the differences in psychological symptoms among prisoners based on age, educational level, duration of sentence, type of crime, and religious affiliation; (c) find the relationship between coping strategies and suicidal ideation among prisoners; (d) find the extent to which coping strategies used by prisoners would moderate the relationship between depression and suicidal ideation; (e) find the relationship between coping mechanisms and depression; (f) examine the various causes of anxiety and depression among the prison population; and (g) evaluate how the conditions in the prison affect their psychological well-being. Using 170 research participants from the Nsawam Prisons in Ghana, the depression anxiety stress scale, cope inventory, modified scale for suicidal ideation, and an interview guide were administered in a sequential transformative mixed methods design. 150 participants were used for the quantitative study and four independent focus groups of 20 participants were used to qualitatively investigate the causes of depression and anxiety among prisoners as well as how the prison environment affects the psychological wellbeing of prisoners. This qualitative aspect was achieved through open-ended questions pertaining to anxiety, depression and psychological wellbeing among prisoners. Fundamental findings from this study include the fact that, high levels of depression, anxiety, stress and suicidal ideation exists among prisoners in Ghana. Of the male and female inmates, females experience greater proportions of psychopathologies than males. Besides, the coping mechanisms used by prisoners does not help them deal effectively with their psychopathological issues. Remarkably, the causes of these psychopathological issues among prisoners are partly due to internal conditions in the prisons such as relationship with inmates and officers, inadequate resources such as water, food, and health-care facilities, and external conditions such as relationships lost or left behind such as family, friends, and property. Findings supports most literature reviewed and the transactional model of stress as well as three-step theory. It is thus recommended that immediate psychological services be provided for prisoners to make their reformative exercise complete.
Antecedents of Occupational Health, Safety Behaviour and Safety Performance: A Case Study of Selected Rice Farmers in Ghana
(2017-07) Asamani, L.
Health and safety at work is not only a sound economic policy, but also a fundamental human right that must be protected and ensured at all times. A number of studies in the formal sector have established that personal, organisational and work context factors, including safety behaviour and safety culture, have immense implications for employees’ health and safety. However, the informal sector, especially production agriculture, has been neglected in terms of occupational safety research in the social sciences. This study investigated antecedent of health and safety behaviour and safety performance of Ghanaian rice farmers. The study employed the exploratory sequential mixed methods design, comprising qualitative study (study one) and quantitative study (study two). The data for the study were collected from Kpong, Ashaiman and Okyereko rice irrigation schemes.The qualitative study explored occupational health and safety hazards and the major health and safety incidents that rice farmers in Ghana experienced. The qualitative data was obtained through ten (N = 10) semi-structured interviews with key informant. The theoretical thematic analysis was the analytical procedure for the qualitative data, using Braun and Clarke’s six-step approach. Results of the qualitative study showed that rice farmers in Ghana were exposed to a myriad of health and safety hazards and also experienced several incidents that resulted in health challenges, physical injuries and disabilities. These findings were used to develop a rice farm hazards exposure scale and to adapt the rate of incident reporting scale for the study two. Study two tested the extent to which religiosity, hazards exposure and safety culture predicted safety performance in a cross-sectional survey with 469 the rice farmers comprising 122 female and 347 males.The data were analyzed using the Partial Least Square Structural Equation Modelling (PLS-SEM) with the SmartPLS 3.6.2. It was concluded that religiosity is an important antecedent of both positive safety behaviour and safety University of Ghana http://ugspace.ug.edu.gh xv culture, while safety culture is an important predictor of safety behaviour and safety performance. Safety behaviour also partially mediated the effect of safety culture, but not the effect of religiosity on safety performance. Furthermore, both safety culture and safety behaviour were found to be significant moderating variables of the effect of hazards exposure on safety performance. The findings underscore the need to distinguish safety behaviour and safety performance in safety science research. Also, the hazards exposure scale and an integrative safety performance model developed in this study could be used and tested in future studies.The implications of the findings were discussed within certain theoretical frameworks. Recommendations were also made for safety management policy directions, organisational practitioners and directions for future research.
Analysis of Watermelon from Some Selected Farms In Greater Accra Region for Nutritional and Toxicological Elements
(2017-07) Osei-Agyeman, A.S.
Watermelon is largely made of water and sugar with some antioxidants such as lycopene, lutein, and cryptoxanthin. It also contains elements such as potassium, calcium, sodium, etc. for the well-being of the body. However contamination of watermelon can occur along the production line. Contaminants include pesticide residues and heavy metals such as Zinc, Manganese, and Nickel from the soil. This study investigated the levels of essential elements (e.g., Ca, Mg, Fe, Mn, Zn, Cu, Cr, Co, Ni) and toxic elements (Cd, Pb, As) from selected farms and compared levels of elements in watermelon and soil. Watermelon samples were taken from selected farms in the Ada East District in the Greater Accra Region. Each fruit together with its seeds were homogenised, frozen, freeze dried, digested and analysed using the AAS for the determination of toxic and essential elements (Fe, Mn, Cu, Mg, Ca, Co, Cr, Ni, Zn, Pb, As and Cd). Soil was sampled from the selected farms and analysed as well. It was observed that watermelon samples analysed contained the selected essential elements with the exception of chromium and cobalt, which were below their detection limits. Nickel was detected in watermelon from all farms with the exception of farm C. The levels of nutritional elements found in watermelon samples were within WHO acceptable limits for food. Watermelon samples from farm C recorded levels of Pb and As above FAO/ WHO acceptable limits in food. All elements (toxic and essential) that were found in the watermelon samples also were present in the soil with the exception of As which was found in the soil but not the fruit. A positive correlation was observed between the concentration of elements (toxic and essential) in the soil and the watermelon samples.
Trend Evaluation Of Raw Water Quality From Kpong Dam (Volta River) Using Statiscal Analysis And Time Series Prediction Model
(University of Ghana, 2018-07) Bakomnaah, B.
This research evaluates raw water quality status from Kpong dam of the Volta River, Eastern part of Ghana, to assess its quality levels over a six-year period and predict future quality trend. The dataset identified twenty-six physicochemical constituents in each monthly sample analyzed. Hydrochemical analysis showed variation in contaminant levels for some constituents which ranged from low to considerable contamination (WHO, 2006). PO42-levels were relatively high. Results of WQI indicated general quality degradation with minimal variations across the years with respect to surface water quality rating criteria (WC,2003). The forecasted figures with the fitted ARIMA (3, 1, 1) model also suggest minimal degradation of the water quality in the light of the current prevailing conditions. It is therefore recommended that efforts be made to prevent further pollution of the Volta River.
Inorganic Profiling of Amoxicillin Drugs in Ghana Using Proton Induced X-Ray Emission (Pixe) Analysis
(University of Ghana, 2017-07) Abdul-Wahab, Z.
The increase of drug counterfeits and its unconscious use has become a major cause for concern to healthcare practitioners and relevant stakeholders. The occurrence of counterfeit or fake drugs is perceived to be a problem encountered in both developing and underdeveloped nations where Ghana is not an exemption. The lethal implications of counterfeit/fake medications are well understood to be a major challenge to the soundness of public health systems around the world, as well as a direct threat to our individual health and well-being. Sub-standard and counterfeit/fake drugs are a widespread problem in Ghana and the need to address it is eminent. The volume of drugs that require control, from the statutory organisations like Food and Drugs Authority of Ghana (FDA) and Ghana Standard Authority (GSA) is enormous, and hence the need to explore other faster analytical techniques to help control cannot be over emphasised. According to the World Health Organization (WHO), Antibiotics are the most counterfeited drugs and Amoxicillin (C16H19N3O5S) happened to be ranked first on the list. The most used and prescribed method for drug quality control analysis is the High-Performance Liquid Chromatography (HPLC) technique which accesses the quality of drugs from its Active Principal Ingredient (API) perspective. The main focus of this study is to harness additional analytical procedure to enhance the routine monitoring of the quality of some Amoxicillin drugs in Ghana from the inorganic constituent point of view. HPLC and the physical parameter tests were carried out on the samples analysed to help validate the interpretation of the inorganic element results from the PIXE technique. Two different local brands of amoxicillin and two imported amoxicillin brands were chosen for this study. A total 30 samples were analysed for this study including one (1) standard reference material (amoxicillin) acquired from a licenced pharmaceutical company in Ghana. Particle Induced X-ray Emission (PIXE) analysis of the amoxicillin standard reference material revealed ten (10 ) elements which include Al, S, K, Ca, V, Cr, Mn, Fe, Ni, and Zn. Sulphur was identified as the major element in the standard reference material and recorded concentration value of 396,805 ppm. Samples from "Kwame Nkrumah Circle", a locally manufactured brand recorded the lowest sulphur concentrations of 251,745 ppm, compared to all drugs analysed using PIXE; imported amoxicillin (395,753 ppm) and "Okaishi" locally manufactured (384,710 ppm). Additionally, the elements Cr, Mn and Fe were found to be relatively higher in the "Kwame Nkrumah Circle" sample hence raising concerns over the quality of the "Kwame Nkrumah Circle" brand. When a physical parameter test was performed on all samples, all brands with the exception of "Kwame Nkrumah Circle" passed the disintegration and dissolution test deeming the "Kwame Nkrumah Circe" brand substandard. After an HPLC test was performed for all samples, it was discovered that all the drugs analysed passed the acceptance criteria (90-120%) for drugs set by the British Pharmacopeia; with the "Kwame Nkrumah Circle" brand recording a value of 97% relatively lower than all the other samples which range from 113 to 117%. Sulphur as an active principle ingredient was correlated with the other identified elements. Strong correlations with correlation coefficients within the range 0.9936 – 0.9978 were found with the elements Cr, Mn, and Fe. Hence the elements S, Cr, Mn, and Fe lend themselves as element signature for amoxicillin medical drug. This was done to discover element signatures that will facilitate differentiating between genuine and counterfeit amoxicillin drugs. Considering the simplicity in sample preparation, the non-distractive nature of PIXE analysis, and also fast turn out in producing results. PIXE offers a considerable advantage when analysing antibiotic drugs on a large scale.
Seismological And Geological Investigation For Earthquake Hazard In The Greater Accra Metropolitan Area
(University of Ghana, 2013-07) Doku, M.S.
A seismological and geological investigation for earthquake hazard in the Greater Accra Metropolitan Area was undertaken. The research was aimed at employing a mathematical model to estimate the seismic stress for the study area by generating a complete, unified and harmonized earthquake catalogue spanning 1615 to 2012. Seismic events were sourced from Leydecker, G. and P. Amponsah, (1986), Ambraseys and Adams, (1986), Amponsah (2008), Geological Survey Department, Accra, Ghana, Amponsah (2002), National Earthquake Information Service, United States Geological Survey, Denver, Colorado 80225, USA, the International Seismological Centre and the National Data Centre of the Ghana Atomic Energy Commission. Events occurring in the study area were used to create an Epicentral Intensity Map and a seismicity map of the study area after interpolation of missing seismic magnitudes. The least square method and the maximum likelihood estimation method were employed to evaluate b-values of 0.6 and 0.9 respectively for the study area. A thematic map of epicentral intensity superimposed on the geology of the study area was also developed to help understand the relationship between the virtually fractured, jointed and sheared geology and the seismic events. The results obtained are indicative of the fact that the stress level of GAMA has a telling effect on its seismicity and also the events are prevalent at fractured, jointed and sheared zones.
Study Of The Origin Of Salinity In The Unsaturated Soil Zone Using Chloride Profiles And Stable Isotope At Ekumfi Akwakrom And Ekumfi Asokwa Mankessim Municipality Of The Central Region Of Ghana
(University of Ghana, 2013-07) Otoo, I.A.
This research was carried out to investigate the origin of salinity in the unsaturated soil zone with emphasis on chloride profile and stale isotopes in the Ekumfi Akwakrom and Ekumfi Asokwa in Mankessim Municipality of the Central Region of Ghana, which has been reported to have high saline groundwaters. A total of 159 samples were analysed, which comprises: fifty – six (56) rainwater samples, fifty – three (53) soil from the unsaturated zone, two (2) groundwaters, forty – two (42) water extracted from soil and six (6) water from unsaturated zone. Samples of soil, rainwater, groundwater and water from unsaturated zone were analysed for physical parameters, major ions, trace elements, nutrients and stable isotopes composition. Chloride concentrations varied as the depth increases along the profile, showing accumulation of Cl in the unsaturated zone at depth of 80 cm and 120 cm. Stable isotope of the rainwater, water extracted from soil, water from unsaturated zone and groundwater in the study area indicates that, rainfall is the only source of recharge to the groundwater in the area. The chloride mass balance (CMB) approach was used to estimate recharge rate in the flushed portion of profiles in the study area and is 65.56 mm/yr., (mean for 9 profiles), any heavy/intense rainfall can result in downward movement of salts that had accumulated near the surface of the soil. The high chloride concentration found in groundwaters in the coastal aquifers is as a result of dissolution of soluble salts ( ) accumulated in the unsaturated zone at a depth of 80 .0 cm and 120.0 cm and not direct sea water intrusion. Movement of water through the unsaturated zone dissolves these salts without any isotopic fractionation and discharges them into the groundwater system leading to groundwater salinization in the study area.
Trace Elements And Naturally Occurring Radioactive Materials In “Non-Traditional Fertilizers” Used In Ghana
(University of Ghana, 2013-07) Assibey, E.O.
Fertilizers have been implicated for being contaminated with toxic trace elements and naturally occurring radioactive materials (NORMs) even though they are an indispensible component of our agriculture. This phenomenon of contamination has been investigated and established world-wide in various forms of fertilizers (i.e., granular or “traditional” type and liquid/powder or “non-traditional type”). In Ghana, the crop sub-sector has seen a gradual rise in the importation and use of „non-traditional fertilizers‟ which are applied to both the foliar parts and roots of plants. This notwithstanding, research on fertilizers has been largely skewed towards the “traditional” types, focusing principally on the subjects of yield, effects of application and their quality. This study was, therefore, undertaken to bridge the knowledge gap by investigating the levels of trace elements and NORMs found in the „non-traditional‟ fertilizers used in Ghana. The principal objective of the study was to investigate the suitability of the “non-traditional fertilizers” for agricultural purposes with respect to trace elements and NORMs contamination. Atomic Absorption Spectrometry and Instrumental Neutron Activation Analysis were employed to determine the trace elements (Cu, Zn, Fe, Na, Al, Br, Ni, Cd, As, Hg, Co, Pb, La, Mn, Si, Ca, Cl, S, K, Ba and V) and NORMs (238U, 232Th and 40K) concentrations in thirty-nine (39) fertilizer samples taken from two major agro-input hubs in the country (Kumasi-Kejetia and Accra). Multivariate statistical analyses (cluster analysis, principal component analysis and Pearson‟s correlation) were applied to the data obtained in order to identify possible sources of contamination, investigate sample/parameter affinities and groupings and for fingerprinting. The toxic trace element concentrations determined in all samples were found to be in the order Fe > Cu > Co > Cd > Cr > Ni > Pb > As > Hg. The study found most of the trace elements determined to be within limits set by international standards (Canada and Hungary and Washington State) except for Cu and Cd. However, all toxic trace elements were within allowable limits projected by the SUIT#25 model. Minimum guaranteed nutrients other than Nitrogen, Phosphorus and Potassium determined were largely found to be below levels set by the Part III of Act 803-Fertilizer Control and its Regulations even for the companies who declared the results on their labels. Generally, the activity concentrations in both the liquid and solid fertilizers were found to be in the order K-40 > Th-232 > U-238. The activity concentrations and hazard indices (Radium equivalent, Dose rate and Representative level) for the natural radionuclides U-238 and Th-232 were also found to be within safety limits and world average figures. However, the activity concentrations and computed hazard indices for K-40 in some products such as SKMKi were higher than the world average and standards set by United Nations Scientific Committee for Effect of Atomic Radiations (UNSCEAR). It was found from the Multivariate analysis that the toxic element Cd clustered with nutrients Zn and Fe, indicating that Cd might have been introduced during the process of nutrient addition to the fertilizers in the form of chelates. The natural radionuclides, 232Th and 238U also largely grouped together indicating that they are from a common source rock. The naturally occurring radioactive material K-40 also groups with Na, Br and partially with K indicating their common origin. The results from the cluster analysis, principal component analysis and Pearson‟s correlation show good agreement and suggest that all the liquid fertilizers can be grouped into five major groups with respect to their elemental contents. The CA, PCA and Pearson‟s correlation analysis for the solid samples also indicate similarities of 3 major clusters with sub-groupings and 5 components respectively. In conclusion, the dangers associated with the use of “non-traditional” fertilizers in Ghana are low with respect to toxic trace elements since their concentrations in the fertilizers are low. The potential for trace element accumulation in soil has also been found to be low. Furthermore, the liquid fertilizers are not radiologically significant whereas some solid fertilizers are significant due to their high activity concentrations and hazard indices. It is recommended that regulators continue to monitor imported fertilizers for toxic trace element content in order to ensure their safety for agriculture and environment at large. Further research and monitoring of trace elements and naturally occurring radioactive materials in other forms of fertilizers is required trace element and radiological data generation. The study has indicated the usefulness of multivariate analysis in contamination source determination and finger printing that may play a significant role in fertilizer quality monitoring.
Optimisation of Sugar and Blood Feeding Regimen in Anopheles gambiae Mass Production System
(University of Ghana, 2013-07) Kwashie, S.B.
The sterile insect technique (SIT) is being developed for the control of malaria transmitting mosquitoes. Critical to the success of applying the SIT is the establishment of standardized mass production systems for the target species. As part of efforts to develop standardised mass production systems for malaria vectors, this project sought to optimize adult blood and sugar feeding in a mass production system. Different sugar types (glucose, sucrose and honey) were evaluated at 6 % and 10 % concentrations in water to determine the best sugar diet and concentration for feeding adult An. gambiae. Different blood feeding methods, restrained Guinea pig, anaesthetised Guinea pig and human arm feeding were evaluated. Adult survival, female insemination and egg production were used as criteria to determine optimum sugar and blood feeding. The effect of anaesthetics on blood feeding response and egg production of female An. gambiae was determined by comparing feeding response and egg production of females fed with anaesthetised Guinea pigs as against physically restrained Guinea pigs (Control). The specific effect of different anaesthetic agents on blood feeding response and egg production of female mosquitoes was also determined by comparing the feeding response and egg production of females fed with either Ketamine/Xylazine anaesthetised Guinea pigs or Ketamine/Diazepam anaesthetised Guinea pigs. Effects due to sugar types and concentrations on percentage survival of male and female mosquitoes were observed to be significant at (p < 0.05). Honey at 10 % concentration recorded the highest survival of 84.3 % after 1 week and 12.7 % after 6 weeks whilst glucose and sucrose recorded 81.0 % and 78.0 % respectively after 1 week and 1.3 % for both after 6 weeks. Survival up to 35 and 49 days for males and females respectively occurred only in adults fed with honey. The combined effects of blood feeding methods, anaesthetic types and feeding times on the propensity of female An. gambiae to feed and produce eggs were not significantly different (P > 0.05). However, human arm feeding (HAF) method and Ketamine/Xylazine (KX) anaesthetics fed for 25 minutes recorded higher percentage feeding (76.0 % and 68.0 % respectively) and egg production of 19.0 % and 20.8 % respectively. Anaesthetised Guinea pig feeding (AGF) of adults for 15 minutes followed closely with 60.0 % and 15.1 % blood feeding and egg production respectively whilst restrained Guinea pig feeding (RGF) method and Ketamine/Xylazine (KD) anaesthetic agents recorded the least values. It can be concluded that 10 % honey solution resulted in optimum feeding, survival and female insemination in adult An. gambiae compared to other treatments. Although both human arm feeding and Ketamine/Xylaxine anaesthetised Guinea pig feeding resulted in optimum productivity, anaesthetised Guinea pig feeding of adults for 15 minutes is the ideal feeding method for mass production systems. We recommend that 10 % honey solution, anaesthetised Guinea pig feeding method using 0.05 ml Ketamine/Xylazine anaesthetics and 15 minutes feeding time be employed for adult feeding in mass production of this species.
Investigation Of The X - Ray Shielding Properties Of Concrete Containing Lime Kiln Dust
(University of Ghana, 2013-06) Ampadu, E.K.
An x-ray dose above the maximum permissible limit is harmful to human beings. A study of x-ray attenuation by materials is an important subject in protecting humans from harmful effects of radiation. Thus it is desirable to have knowledge about materials for effective x-ray shielding. Concrete is the most widely used construction material for this purpose and its composition plays an essential role in modifying the mechanical properties which affects significantly the shielding properties. This study summarizes the results of investigation carried out on concrete containing lime kiln dust, LKD in varying proportions. The objective of this research was to investigate the effects LKD has on the mechanical and shielding properties of concrete using it as part replacement material for cement. Compressive strength, flexural tensile strength, modulus of elasticity, unit mass and density were the mechanical properties investigated whilst linear and mass attenuation coefficients, half and tenth value layers and mean free path investigated for the shielding properties. The ability of concrete to attenuate x-ray intensity is assessed using its mass attenuation coefficient. The average mass attenuation coefficient for 100% concrete at 80 kVp was (0.1529 ± 0.0226) cm2g-1. At the same energy, 90% cement, 10% LKD concrete which had the highest density of (2.4622 ± 0.0218E-3) gcm-3 recorded an average mass attenuation coefficient of (0.1454 ± 0.2157) cm2g-1. The average density for all the concrete types was (2.4093 ± 0.4089E-3) gcm-3. It was observed that increasing LKD ratio affected mechanical and shielding properties of concrete hence for x-ray facilities such as in hospitals and laboratories, LKD can be included in the cement mix used for plastering to form a multilayer aiding in attenuation.
Energy and Exergy Based Performance Analysis of Westinghouse AP1000 Nuclear Power Plant
(University of Ghana, 2014-02) Eshun, R.B.
Energy and exergy analyses of the performance of the Westinghouse Advanced Passive 1000-MWe Nuclear Plant (AP1000) was conducted with the primary objectives to identify and quantify the operational locations having the largest energy and exergy losses under normal operating conditions. The energy and exergy losses in the reactor units were determined from formulations of the energy and exergy rate balances based on the Gouy-Stodola theorem. The performance of the overall AP1000 plant was estimated by component wise modeling and detailed break-up of energy and exergy losses in the various plant sections. Operating at maximum core power of 3400 MW, the AP1000 reactor core experienced moderately small thermal loss of 125.1 MW and very substantial exergy consumption of 1814.8 MW, achieving energy and exergy efficiencies of 96.3 % and 46.6 % respectively. For the entire AP1000 plant, energy losses occurred mainly in the condenser where 1849.8 MW was lost to the environment. Exergy analysis, however, revealed lost energy in the condenser was thermodynamically insignificant due to the low quality and that irreversible losses in the reactor and steam generator assembly (1868.4 MW) were the major source of irreversibilities in the plant. The study confirmed that the major heat transfer inefficiencies occurring in nuclear reactor plants resided in the reactor cores, and efforts to increase the efficiency of the station should concentrate on the design of the core components.
Assessment Of Atmospheric Aerosol Content In Abuesi: A Suburban Coastal Community In Ghana
(University of Ghana, 2013-07) Bempong-Manful, E.
Airborne particulate matter (APM) composition has been studied at the Abuesi area. Aerosol samples in two size fractions were collected over a period of 3 months using the Gent stacked filter unit (SFU). Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) was used to measure concentrations of up to 28 elements at the INFN-Accelerator Laboratory, University of Florence, Italy for the coarse fraction which accounted for 53.84 % of PM10 aerosols in the Abuesi area. Mean values of 41.890 μg/m³, 22.469 μg/m³ and 19.422 μg/m³ were measured for Inhalable Particulate Matter (IPM/PM10), Coarse mode Particulate Matter (CPM) and Fine mode Particulate Matter (FPM) respectively and these were within the World Health Organisation (WHO) guidelines. Chlorine is established as an important component of the aerosol in Abuesi, originating mainly from sea spray. It accounted for 32.13 % of the total coarse mode aerosol elemental concentration. Characterisation of aerosols in the study area was performed using Principal Component Analysis (PCA) with VARIMAX rotation. Six factors score accounted for the three main identified APM sources (i.e. crustal material/soil dust, marine/sea spray and mechanical operations) in the area with crustal material/dust representing the dominant source. Enrichment Factor (EF) values also showed no enrichment for about 86 % of the measured elements with only Na which resulted predominantly from sea spray recording a moderate enrichment score of EF=3.386. The results obtained suggest that ambient air quality in the Abuesi area is safe. There is, however, the need to conduct further studies to estimate the black carbon concentrations of both fine and coarse aerosol fractions and, as well, investigate the elemental source profile of the various APM sources in the study area.
A Theoretical Study Of The Production Of Technetium-99m (99MTC) Using A Cyclotron
(University of Ghana, 2013-07) Nyaaba, R.A.
A theoretical study of the production of Technetium-99m (99mTc) using a cyclotron has been conducted. A nuclear reaction model code (Talys code) was used to generate reaction cross sections as functions of particle energies for 100Mo (p, 2n)99mTc reaction channel which would lead to the direct production of 99mTc. Excitation function for the desired reaction channel for the production of 99mTc and excitation functions for the reaction channels of competing products (contaminants) were plotted and analyzed. From the analysis, the optimum energy range for the production of 99mTc was obtained to be 10-20 MeV. This result compared favorably with experimental as well as theoretical works in literature. Using the radionuclide production yield equation (Celler et al, 2011), the saturated thick target radionuclide production yield in this work was estimated to be 565MBq/μAh. To investigate the effects of certain operational parameters on the saturated thick target yield of 99mTc, a numerical solution was obtained in this work for the saturated thick target radionuclide production yield equation by employing Newton‘s Forward Difference (NFD) formula and, concluding deductions made. The findings drawn from these theoretical considerations confirmed that a cyclotron production of 99mTc may be a feasible alternative to the reactor-based production.
Assesment of Heavy Metals Introduced Into Food through Milling Process: Health Implications
(University Of Ghana, 2015-07) Adeti, P.J.
The present study was conducted to characterised and assess heavy metal contamination in food through milling process and their health implications. Grinding plate made from Ghana, India and Nigeria purchased from the Ghanaian open market were used for this work. Maize from the same farm was milled into flour using the three grinding plates inserted into three different corn milling machines operating on commercial bases. The first grinding was done immediately after the insertion of the newly sharpened plates into the machines. The plates were left for continuous daily usage. Subsequent milling of the maize was done after intervals of one month. The grinding plates and maize flour was analysed using Atomic absorption spectrophotometer (AAS). The results recorded indicated that the heavy metals content of the Ghanaian, Indian and Nigerian made plates had the similar metal contents but varied in terms of the individual metal concentrations. Flour from the Ghanaian made plates had the highest level of contaminants with the least from that of the Indian made plates. Generally the highest levels of contamination were observed in the first milling for the three plates as compared to the three subsequent milling at monthly intervals. The contamination levels showed a decreasing trend from the first month (first milling) to the fourth month (fourth milling). Cu, Cr and Ni showed concentrations above the permissible limit set by FAO/WHO in milled maize using Ghanaian made plate. Copper (Cu) recorded a concentration value between 15.04 mg/kg to 10.21mg/kg, 11.25 mg/kg to 9.13mg/kg and 10.36mg/kg to 9.68mg/kg using the Ghanaian-, Indian and Nigerian made plate respectively. Chromium (Cr) recorded a concentration between 1.51 mg/kg to 0.96 mg/kg, 1.03 mg/kg to 0.91 mg/kg and 0.98mg/kg to 0.80 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. Nickel (Ni) recorded a concentration value between 23.23 mg/kg to 10.43 mg/kg, 11.46 mg/kg to 10.43 mg/kg and 12.55 mg/kg to 10.09 mg/kg Using Ghanaian-, Indian and Nigerian made plates respectively. Which shows that the Cu, Cr and Ni concentration decreases from the first month (first milling) to the fourth month (fourth milling).The Ghanaian made plate was found to wear faster relative to Nigerian- and Indian made plate with that of showing the least rate of wear. The Ghanaian made plates was found to cause more contamination than the other two but generally, the Indian made plates caused least contamination. The Indian made plates had the least Cd and Pb concentration levels. The elemental concentration and the risk assessment calculations have shown that contamination of milled products are highest within the first month of the use of the grinding plates but can decreases considerably with time. The HRI value for first milled maize with locally made grinding plate showed human health problem for Cr and Ni metals contaminations in the maize flour.

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