The gross alpha and beta activity concentrations of eighteen water samples, consisting of
boreholes and Hand dug wells from Sabon Gari Local government area of Kaduna StateNigeria have been analyzed using, the potable single channel gas free MPC-2000B-DP
detector. The results show that alpha and beta activity concentrations range from 0.96 × 10^-2 Bq/L to 47.00 ×10^-2 Bq/L and from 0.309 × 10^-2 Bq/L to 310.40 × 10^-2 Bq/L, for gross alpha and gross beta respectively. It is observed that in the overall samples, the gross alpha activity concentrations were below the 0.5 Bq/L maximum allowable limits for drinking water as recommended by World Health Organization (WHO). However, for the gross beta activity concentration, eleven (11) percent of the samples, have their activity concentrations greater
than the 1.0 Bq/L maximum allowable limits for drinking water as recommended by the WHO. This high beta activity concentration in these areas might be due to the waste
generated from industries and hospitals or as a result of the nature of farming activities
occurring in the areas. Largely, results obtained are seen to be in agreement with reports from
other authors within and outside Nigeria.
The shielding effectiveness of concretes with different aggregate and cement composition was determine by shielding Co-60 gamma radiation source at center for energy research and training (CERT), Ahmadu Bello University Zaria with block concretes that contain aggregate 5.00 mm, 10.00 mm and 15.00 mm respectively. A concrete with thickness of 0.0762 m with dimension of 0.30 m x 0.30 m was formed from each of the aggregates with equal volume of sharp sand and cement. The result revealed the calculated mean free path (MFP) with values within a range of (0.033 to 0.070) m for samples DG (Dangote) and BU (BUA), mass attenuation coefficient (MAC) and half value layer (HVL) values within a range of (1.9 to 2.75) x 10-3 m2/kg and
(0.023 to 0.049) m respectively. This shows that samples DG1, DG2 and DG3 have better
shielding ability due to its lower MAC, MFP and HVL compared to samples BU1, BU2 and
Effect of sputtered silver (Ag) thin film thickness towards morphological and optical properties of black silicon (b-Si) fabricated by two-step silver-assisted wet chemical etching for solar cells applications is investigated. The method involves low temperature annealing of crystalline
silicon (c-Si) coated with Ag thin films of 10 nm, 15 nm, and 25 nm. This is followed by an
etching in a solution of HF:H2O2:DI H2O (1:5:10 volume ratio) at room temperature for 70 s. Dense and spherical Ag NPs with an average diameter of 203 ± 17.8 nm and surface coverage
of about 72.5% are achieved on a sample with Ag film thickness of 15 nm prior to the annealing
process. After the etching, the average nanopores’ height of ~420 nm with an average diameter of ~200 nm owing to denser Ag NPs on the c-Si surface before the etching are obtained. Optical absorption enhancement due to low weight average reflection (WAR) within wavelength region of 300–1100 nm is observed on the b-Si wafers. Sample with 15 nm of Ag thin film prior to annealing, demonstrates WAR of 7.7% compared 40.0% of the reference planar c-Si. The low WAR is due to the efficient light coupling effect of the b-Si nanopores. The fabricated b-Si nanopores can be used in b-Si solar cells for enhanced optical absorption and high photocurrent in the future.
This paper presents an investigation on the contamination potential of ground water using
integrated geoelectric and hydro chemical methods within Azikoro, Yenagoa, Bayelsa state,
Nigeria. The SAS 1000 ABEM Terameter was used to acquire the field data and IPI2win was
used to obtain three geoelectric layers result for the 1D VES point; with depth of 0 m, 0.91m
and 2.03m and thickness of 0.91m, 0.12m respectively with corresponding resistivity of 0.027
m and 0.00079 m, to show the subsurface lithology and water bearing level. RES2DINV was
used to interpret the data for the 2D imaging, with results indicating contamination spread in
profile 1 and 2 at depth of 6.94m and 9.94m respectively. Water samples from two boreholes,
near and after the vicinity of the cemetery were analyzed for electrical conductivity (EC), pH,
total dissolved solids (TDS), phosphorous, nitrates, chemical oxygen demand (COD),
potassium, sodium, sulfate and chloride. From the result obtained conductivity is very high due
to low resistivity. The water sample results were compared with World Health Organization
(W.H.O) permissible limit standard which indicated that the water is safe for consumption
within the period of investigation.
In this study, the development of briquettes from agricultural waste mainly rice and maize husk
is presented. A 0.12 kg of each sample with a combination ratio of 1:1 was used in the buildup. The results obtained shows that, rice husk, maize husk and the combination of rice and maize husk have calorific value of 15.27 kJ/kg, 17.13 kJ/kg and 16.20 kJ/kg, moisture contents of 78.8 %, 86.8 % and 79.1 %, ash contents of 39.74 %, 18.07 % and 13.39 % and densities of 1084.3 kg/m3, 1011.5 kg/m3 and 1012.4 kg/m3 respectively. The research shows that briquette made from maize husk has the highest calorific value that can meet domestic use as an alternative fuel compared to briquttes from rice husk and the combination of rice and maize husk.
The objective of this paper is to evaluate briquettes produced through quaternary level
combination of four types of common sawdusts from major wood sources. This was achieved
by producing seven briquettes made up of four primary sawdusts and three from
combinations of all primary saw dusts in rations of 25% each, 60/40 rations of A and B and C
and D and vice versa (i.e. 40/60 %). The sawdust samples are from four different wood species; Terminalia superba (Afara), Khaya ivorensis (Mohagany), Anogeissus leiocarpus (Marke) and Isoberlina doka (Ububa/Doka). The samples of the sawdust were collected from selected sawmills in Kaduna, Nigeria. Proximate analysis was applied when evaluating the
produced briquettes. The results of proximate analysis for the seven sawdust briquette
samples tested shows the range of values as; moisture content is 4.3 – 5.0%, ash content (0.7 – 4.2) %, volatile matter (81.5 – 90.8) % and fixed carbon (7.7 – 18.0) %. Calorific Values (CV) are within the range of (17.202 – 18.933) MJ/Kg. The results of proximate analysis of all seven sawdust briquette produced shows that heterogeneous sawdust samples at quaternary levels (or perhaps even at higher levels) of combination do not necessarily
produce briquette with much higher CV, as show in difference between the highest and
lowest CVs obtained with a difference of 1.072 MJ/kg.
In this paper, radio-frequency radiation levels from some selected Base Transceiver Stations of different network providers (MTN, 9mobile, Airtel and Globacom) within Kaduna metropolis, Kaduna State, Nigeria were measured using a portable hand-held spectrum analyzer model 2658A, within radial distance intervals of 20 m to 100 m from the foot of each Base Transceiver Station. The measured values range between 0.24 μWm-2 to 30.42 μWm-2 with an average value of between 0.298 μWm-2 to 14.578 μWm-2 respectively. The measured radiation levels were found to be less than the acceptable standard value of 4.5 Wm-2 recommended by International
Commission on Non-ionizing Radiation Protection for Global System for Mobile communication with frequency 900 MHz. Results obtained show exposure to RF emissions
from the sampled Base Transceiver Stations will not impose health risk to humans living within that area.
In this paper the economics of a small-scale humidification dehumidification desalination
(HDD) unit driven by a concentrating v-trough solar thermal collector is explained. A
comparative analysis using the net present value method was carried out for when the system
is operated using solar energy and electricity from fossil fuels. The system could provide
different amount of fresh water depending on mode of operation. It was shown that by end of
year six the investment for the solar system reaches breakeven when compared to the electric
system. The analysis also considers the amount of carbon savings that could be achieved and
final cost of water produced per cubic meter. The factors that influence the systems economic
viability are the outputs and costs of the desalination unit and solar collector systems, the cost
of alternative energy source, cost of operation and maintenance, and the geographic location
of the system, i.e. solar intensity, environmental temperature and humidity.
In this paper, a proposal for the development of a neighbourhood network (n-network) automatic power sharing system that will bring about regulatory paradigm and mobilization of the private sector to lead in deployment of clean energy solutions while letting local residents to buy (consumer) and sell (producer) electricity among the neighbours is presented. Here the neighbourhoods become prosumers. Until now, electricity production and supply has
traditionally been implemented via a centralized grid where the power generation companies
otherwise known as Gencos generate electricity that is fed through the grid to individual homes. The proposed solution aims to create a peer-to-peer trading system where consumers will identify each other’s needs and willingness to buy and sell electricity. This offers the chance to bypass the traditional electricity grid and create a viable generation and storage micro grid that functions independently.
A psychrometric energy process desalination unit has been experimentally tested. The system is based on humidification and dehumidification process where seawater is heated and then sprayed to humidify the incoming air in the humidification chamber. The humidified air
enters the dehumidification chamber and is cooled by the incoming cold seawater. The
moisture is condensed out and the pure water is accumulated at the base of the chamber, and
the dehumidified air is discharged to the outside. The seawater was heated to temperature between 60 - 90°C using a 2.4kW electric heater. Performance data on temperature, seawater mass flow rate, air flow rate and the amount of fresh water produced were obtained, and the maximum coefficient of performance (COP) of the system was calculated based on the data obtained. The result achieved indicates the system had a maximum fresh water production of 13kg/h with a maximum COP of 3.6. The initial test shows that the system has great potential with room for improvements and further optimisation.
A geophysical and geotechnical pre-foundation study on the proposed ICT center of the
Olusegun Agagu University of Science and Technology (OAUSTECH), Okitipupa, was carried
out to determine the suitability and competency of the subsurface soil and evaluate its
engineering implications for infrastructural development. The Dipole-Dipole array, with a
spacing of 5 meters, was used to investigate the subsurface lithology and its suitability for
construction application in relation to the depth, thickness, and resistivity of subsurface
materials. Three (3) traverses, 110 meters each, were employed. Four (4) soil samples randomly
taken at depths of 0.5 meters were used to carry out geotechnical laboratory tests. The first
layer resistivity ranges from 153 ohm-m – 1005 ohm-m with maximum thickness of
approximately 2 meters, the second layers resistivity value ranges between 1162 ohm-m to
84965 ohm-m with corresponding thickness of 10 meters – 15 meters, and the third layer has
resistivity values above 221486 ohm-m. Geotechnical analysis carried out on the soil samples
obtained are Natural Moisture Content (NMC) with values between 14.1% to 14.3%, Grain
Size Analysis with > 50% finer passing, Atterberg Limit Test with plastic limit ranging from
19.4% to 19.9%, Consolidation test ranging from 0.0131 – 0.0136m²/yr, Unconfined
Compression (UC) Test revealing approximately 182.5Kla, Permeability test ranging from
1.33×10-5 cm/s to1.85×10-5 cm/s, and Specific Gravity (SG) of 2.648 - 2.654. Three geological
layers were inferred namely; clayey sand, sandy clay and sand. From the geophysics and
geotechnical it can be inferred that the study area is competent. But Excavation of soil to a
depth of about 2 meter at which the soil is adequately competent (consolidated) is
Iron copper sulphide (FeCuS) thin films have attracted much importance due to their
exceptional properties for device applications. The chemical deposition techniques of
chemical bath deposition (CBD) and Successive ionic layer absorption and reaction (SILAR)
have been employed to synthesize FeCuS thin films with good substrates adhesion. The
various advantages and shortcomings of these methods were discussed with their capability to
control the morphology and opto-electrical properties of the films. The experimental
measurements indicated that the films exhibit great potential for optoelectronic applications
such as window materials in solar cell fabrications and coatings of different types. Due to the
current interest in FeCuS thin films, this review is intended to provide current information on
the synthesis, characterization, and applications of iron copper sulphide thin films.
VLF-EM geophysical technique was employed to delineate potential cassiterite mineralization
at Rafin Bareda, Dutsen-Wai, Kubau Local Government area of Kaduna state, North Western,
Nigeria. A total area of 3.025 km2 was covered along eleven (11) traverses separated by 25m
with a measurement interval of 10m taken in the East-West direction. The response of the inphase component revealed various anomalous zones while Fraser-filtered plots of the in-phase
peaked over the anomalous zones and the Karous-Hjelt filtered response of the in-phase
correlates quite well with the results of the Fraser filtered data. In order to achieve the aim of
the investigation, and since the VLF data was collected in the magnetic mode, enhancement
procedures such as reduced to equator and analytical signal techniques were applied to the
Fraser Filtered response of the In-phase component and correspondingly, Center for
Exploration Targeting (CET), Source Parameter Imaging and Euler Deconvolution algorithms
of the Oasis Montaj were successively employed to delineate potential mineralization zones
and best locations for drilling productive cassiterite in the study area. Enhanced maps show
linear features trending in the NE-SW and NW-SE directions with minor traces in the N-S
direction. Most of the delineated zones of high analytical signal signature were either
intercepted or flanked by the extracted lineament which is indicative of positive correlation
between the extracted lineament and the high amplitude response of the analytical signal and
also, validated the occurrence and positioning of the cassiterite mineral deposits is greatly
controlled by the lineament system across the study area and the development of conductive
zones of high apparent current with positive values reflects inferred subsurface structural
fractures and/or mineralized zones. Depths evaluation analysis from the Euler Deconvolution
(ED) technique using structural index of 1, ranged from 5 m to 15 m while depths varying from
4.9 m to 13.7 m were obtained from the Source parameter imaging technique.
In this paper, the effect of substituting europium (Eu3+) ion on physical and photoluminescence
properties of zinc phosphor-sulfo-tellurite glasses is reported for the first time. The glass
matrices with novel compositional range of 10ZnO–40TeO2–10SO3–(40-x)P2O5– xEu2O3 were
synthesized by convectional melt-quenching route and characterized via density and
photoluminescence (PL) measurements. The non-linearity properties of these glasses was
ascertained and dependence of red emission performance under λex= 394 nm excitation
wavelengths disclosed bright red emission at λem. = 612nm. The concentration quenching
phenomenon was observed after a particular value of europium ions (beyond 2 mol %). Thus,
2 mol% of Eu3+ in the glass composition was identified as the optimized concentration for the
design and development of solid state red laser and color display devices.
Rain attenuation is a major source of impairment to signal degradation at millimetre wave bands above 10 GHz. This research work determines the extent of signal degradation due to rainfall on terrestrial radio links within Minna and Lapai. The meteorological rainfall data collected from the Automatic Weather Stations installed at the Federal University of Technology, Minna, and at Ibrahim Badamasi Babangida University, Lapai, for a period of 3 years (2011-2013) were used to computate the rainfall attenuation on Microsoft Excel spreadsheets. The Lavergnat-Gole (LG) model was used for the conversion of cumulative distributions of rainfall of 5-min to 1-min integration time in Minna and Lapai respectively. The LG model was used to estimate the rain attenuation in the two stations at a frequency range of 10-18 GHz. The relationship between rain rate and specific attenuation was studied using three years rainfall data. It was observed that a power-law relationship exists between rainfall rates of different integration times. The results for the rain rate exceeded for 0.01% of time, show that the horizontal polarisation experiences more degradation than the vertical polarisation. The results also show that specific and total attenuations increase with increasing operational frequency, and are polarisation-dependent. These results would be useful for planning terrestrial radio networks within the study area.
In this research the effect of imbalance and nonlinear load on power quality was investigated via the electronic method with the aid of a Fluke 435 power quality analyser and the results obtained compared with IEEE standards. The study was carried out on 11 kV Pama feeder Kaduna state, Nigeria, which is comprised of Nassarawa, Boro1, Pama 1, Pama 2, and Pama 4 substation. The analyzed result shows an average value of 230 and 1327 times voltage dips and swells, 11.74 % harmonics current, 2.33 % harmonic voltage, 5.96% imbalance voltage and 25% imbalance current respectively. When compared with the IEEE standard limits of 5 % and 2 % harmonic current and voltage, 10 % and 5 % imbalance current and voltage, it could be seen that these results imply the presence of harmonics within the system which are fundamentally due to imbalance and non-linear load, triggering operating complications on the distribution system. These complications include load disruptions, over current, over voltage, heating, leading to forceful outage, increased power losses, faster ageing of insulations, unstable power supply, burnt cables, sockets and connectors, thus reducing capacity and ultimately resulting in premature failure of transformer.
his research presents an investigation on the shale volume effect on hydrocarbon prospectivity of Green Field within Niger Delta, Nigeria. Delineation of potential reservoirs was done with Petrel Version 2010® and OpendTect 4. 6.0® exploration and production softwares, and data obtained were quality checked to eliminate null values. Three different empirical models were used to estimate the shale volume for fifteen delineated reservoirs from the three identified “Green” wells. The shale volume ranges from 0.111 to 0.162 for Green 1, 0.056 to 0.092 for Green 2 and 0.007 to 0.140 for Green 3 reservoirs. An average shale volume obtained from a merger of the three models was compared to the permeability in each of the fifteen reservoirs to determine the hydrocarbon prospectivity of the wells. It was noticed that shale volume increases with a decrease in the permeability. The ratio of shale to sand ranges from 0.125 to 0.192 for Green 1, 0.059 to 0.101 for Green 2 and 0.007 to 0.111 for Green 3 reservoirs. The presence of sand in higher volume which ranges from 0.838 to 0.889 for Green 1, 0.908 to 0.944 for Green 2 and 0.900 to 0.993 for Green 3 reservoirs than shale which ranges from 0.111 to 0.162 for Green 1, 0.056 to 0.092 for Green 2 and 0.007 to 0.140 for Green 3 reservoirs and higher resistivity which ranges from 5.61 to 96.93 for Green 1, 16.01 to 103.42 for Green 2 and 14.75 to 22.17 for Green 3 reservoirs than the conductivity which ranges from 0.0100 to 0.1800 for Green 1, 0.0096 to 0.0625 for Green 2 and 0.0450 to 0.0680 for Green 3 reservoirs are some major signals confirming a substantial hydrocarbon in the reservoirs. Results from this study indicates prospective presence of fractured shale deposits in the study area. Petrophysically, subsurface reservoirs in the “Green” field have reasonable hydrocarbons in their pore-spaces and estimated producibility indicators are good enough to support secondary migration of the oil into the borehole, if developed.
Seismic activities leading to tremors have been a subject of interest in geophysical survey. Here in, we reported the (seismic) tectonic activities of Langbodo field, an area where tremors have occurred in the Niger Delta, Nigeria. The seismic data used in this research work were analyzed using the CPillar® and the Plaxis 2D® seismic softwares. These softwares are based on sensitivity, probabilistic and finite element analyses. The variation in the depth of the exploration boreholes for the five identified locations, LCT A, LCT B, LCT C, LCT D and LCT E with respective values 7525 km, 7000 km, 8000 km, 7600 km and 9000 km showed the extent to which the underlying crust can be pressurized. The seismic information from the drilled wells revealed that the tensional force created through stress ranges from 5.517 × 10^13 N to 6.130 × 10^14 N and that of compression ranges from 3.065 × 10^14 N to 5 517 × 10^14 N. The tectonic activities of each of the locations were recorded using the seismic reflection method. This study revealed that more than 50 % of the earth tremors experienced in the area were humanly triggered. Seismic records of the areas showed that human activities that result to rapid injection of fluid into the plates, if not controlled, can trigger tremors. The magnitudes of tremors that have occurred in the five identified locations LCT A, LCT B, LCT C, LCT D and LCT E are respectively 3.50 ML, 3.20 ML, 4.20 ML, 4.00 ML and 4.32 ML. This research work however concluded that the study area is likely to witness earthquakes of about 7.0 ML magnitude should explorations continue indiscriminately. Probable occurrence of earthquakes in this location can be nipped in the bud by setting up agencies that monitor and assess subsurface pressures, quantities of injected fluid, volume of extracted fluid, and the seismicity of vulnerable regions with time.