In pursuit of environmental sustainability, polymers filled with bio-particulates are replacing
traditional plastic components. Epoxy Polymer composites of eggshell powder were prepared
at filler contents of 10 wt%, 20 wt%, 30 wt%. the particle size of the eggshell powder was 75
μm, 180 μm, and 250 μm. The composite samples were prepared using the Carver Inc.
Hydraulic Press (3851-0) by compression molding and the resulting composites were produced in sheets. Some mechanical properties of the composite were determined. the result showed that the eggshell powder improved the tensile modulus, flexural strength and impact strength of the polymer these properties increased with increase in the filler content and decrease in the
filler size. But at 30 wt% a decrease in these properties were observed which can be attributed
to agglomeration and stress concentration effects. Highlighting the fact that the dispersion and distribution of filler particles within the matrix play a crucial role in determining the mechanical properties. Inhomogeneities in mixing or particle clustering could lead to variations in the measured properties.
In this paper, the Born-Mayer potential is used to describe the core-shell polystyrene nanoparticle and the Schrodinger equation for this nanoparticle is solved rigorously using the Nikiforov-Uvarov (NU) method to obtain the exact bound state solutions and energy spectrum. This is achieved by inserting the Born-Mayer potential into the Time Independent Schrödinger Equation (TISE), obtaining the radial part and solving, exactly, for the expectation values of the energy spectrum and the corresponding eigenfunctions applying the Nikiforov Uvarov (NU) method. The eigenvalue expression obtained is similar to earlier work on Soliton solution in nonlinear lattice with the nearest neighbor Born-Mayer interaction.
The activity concentrations of natural radionuclides 238U, 232Th and 40K in soil samples from Kudan Local Government Area irrigation farming areas have been evaluated using gamma-ray
spectrometry. The results of the activity concentrations of 238U, 232Th and 40K range between
18.15 to 34.66 Bq/kg, 16.01 to 18.83 Bq/kg and 205.51 to 461.25 Bq/kg respectively. The
activity concentration of 40K was seen to be higher than the world average value of 370 Bq/kg
at Kauran Wali South (GO3K) 375.25 Bq/kg, Doka (GB1K) 389.60 Bq/kg, Kauran Wali North
(GB2K) 420.15 Bq/kg, Likoro (GB4K) 383.65 Bq/kg, Garu (GB5K) 461.25 Bq/kg, Zabi
(GB6K) 372.76 Bq/kg and Kudan (GB7K) 382.50 Bq/kg. The activity concentrations of 238U
and 232Th were observed to be high at Garu (GB5K), with values of 34.66 and 18.83 Bq/kg
respectively, however, these values were still below the world average value of 40 Bq/kg as
reported by the United Nations Scientific Committee on the Effects of Atomic Radiation
(UNSEAR) in 2000. The average values for the indoor absorbed dose rate (Din), Internal
Hazard Index (Hin), External Hazard Index (Hex) and Indoor Annual Effective Dose (ADE)
were evaluated to be 83.07 nGy/hr, 0.35, 0.28 and 0.41 mSv respectively. The estimated
radiological indices were seen to fall within the internationally acceptable limits except for the
indoor absorbed dose rate (Din) whose values were all higher than the acceptable limit of 60
nGy/hr as recommended by UNSCEAR in 2000. The high values obtained from this study
could be attributed to the excessive use of fertilizers by the farmers within the study area.
Electrical resistivity techniques of geophysical prospecting have been used to evaluate the
groundwater potential of the University of Abuja Health Services Centre at the main campus.
This research aims to identify suitable locations for productive wells and boreholes, determine
the depth of the bedrock, as well as measure resistivity and overburden thickness. The survey
employed Vertical Electrical Sounding (VES) along five profiles, comprising fifty (50) VES
stations covering the survey area. The resistivity data obtained are analysed using IPI2win
software. The analysis of the resistivity data revealed that the survey area can be divided into
four geoelectric layers: topsoil, clayey sand, weathered layer, and fresh basement. The
resistivity values of these layers range from 38.7-1427 Ωm, 16.2-310 Ωm, 32.1-1714 Ωm and
1007-9528 Ωm respectively. The fresh basement layer was found to have an infinite thickness.
Significantly, potential regions with low resistivity values indicating the presence of
groundwater were identified at a depth of 18.3 m. Furthermore, the average overburden
thickness in the study area was 35 m while the longitudinal conductance of the overburden
ranges from 0.04 – 1.87 mho. Results obtained indicate the main aquifer in the area consists of
a thick weathered layer of overburden and a weathered basement with relatively low resistivity,
suggesting a potentially productive groundwater yield. This information is crucial for future
planning and decision-making regarding the siting of wells and boreholes and the sustainable
utilisation of groundwater resources in the University of Abuja main campus.
A study of the occurrence of the first intense Geomagnetic storm (G4) to hit the Earth since the start of the Solar Cycle 25 is carried out. This study analyzed the Geomagnetic Storm that occurred between the 28th of October and the 7th of November 2021. The values of the Disturbance storm time (Dst) index of the storm reach -115 nT (G4) which occurred on the 4th of November at 1300UT. The storm is the first intense magnetic storm that occurred in the solar cycle 25. It is also a multiple-step storm with moderate two-step storm occurrence which occurred on the 5th and 6th of November at 1500UT and 0600UT respectively towards the recovery phase after the intense storm. The interplanetary magnetic field (IMF)Bz (nT) during these storm events decreases. Our analysis shows that the rise in solar wind speed, temperature and the enhancement of pressure plays a significant role in the occurrence of the first intense Geomagnetic storm of Solar Cycle 25.
An electrical resistivity investigation was carried out in parts of the College of Education
(Technical) Asaba to delineate the subsurface lithologic units with special emphasis on the competence and suitability for engineering foundations. A total of ten (10) vertical electrical
sounding and two (2) horizontal profiling stations were covered within the study area using the
Schlumberger and dipole-dipole configurations. The acquired data was analyzed using WinResist and RES2DINV Software; the subsurface within the study area is composed of mostly 3 geoelectric layers: topsoil, clay/sandy clay/clayey sand and sand. The second and third
layers have relatively low resistivity ranging between 29 – 94 Ωm and consist of incompetent clayey material underlying about 60 % of the investigated study area. The interpreted field results showed a significant clay overburden that is over 5 m thick. A fourth layer of sand with resistivity values ranging between 451 – 1258 Ωm was encountered at depths between 4.9 – 11.5 m; the thickness of this layer with reference from the borehole log is greater than 20 m. It is therefore recommended that the incompetent clayey material be avoided or excavated before
constructing any structure.
This study examined the levels of metals (Mg, Al, Si, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Zr, Nb, Mo, Ag, Sn, Sb, Ta, Pt, Au, Pb, and Bi) in onion bulbs and leaves in light of the latent toxicity, unsolvable character, and snowballing behaviour of heavy metals. The onion bulbs and leaves were randomly selected from the Samaru market chopped, dried, and ground
into a powder for X-Ray Fluorescence Spectrometer (XRF) measurement. Except for
concentrations of Si, Ti, Zr, and Ag, with the value of 9.996, 4.051, 2.047 and 2.082 mg/kg in
the onion bulbs and 20.23, 5.861, 1.175 and 1.538 mg/kg in the onion leaves respectively,
which were higher than the permissible level of 0.800, 0.530, 0.000005 and 0.014 respectively,
all the metals analysed were at or below the World Health Organization's (WHO) permissible
limit. The findings generally indicated that Si, Ti, Zr, and Ag poisoning could result from eating onion bulbs and leaves from the Samaru market due to the Si, Ti, Zr, and Ag health risks. To avoid metal poisoning and subsequent bioaccumulation of the metal in the systems of
consumers and the ecosystem at large, there is a need for a quarterly examination of the metal content in the onion bulb and onion leaf in the Samaru market.
The physical properties of crystalline compounds are highly essential for predicting their
applications in various nanodevices. Density functional theory is very useful in that regard.
Herein, some physical properties such as structural stability, and electronic, optical and
mechanical properties of two-phase bulk WSe2 have been comparatively investigated by first
principle calculations. Band structure calculations elucidate that the materials are indirect band
gap semiconductors having band gap energy in the range 1-1.5 eV. It was observed that the
hexagonal crystal has higher absorption coefficients compared to the trigonal phase. Analysis
of elastic constants of the materials carried out using the Born criteria method indicates that all
systems are mechanically stable at room temperature. Our findings are in close agreement with
the previous experimental and theoretical results, this further suggests that the materials are
promising in optoelectronics applications.
A geophysical study has been carried out using the electrical resistivity method, Very LowFrequency Electromagnetic (VLF-EM) and physiochemical analysis to investigate the effects
of groundwater contamination in the vicinity of an open dumpsite at Idugosa. A Vertical
Electrical sounding was carried out at 100 m away from the dumpsite and the results revealed
an H-type curve with 3- layers, with a low resistivity value of 90.0 Ωm, thickness of 9.8 m and
depth of 11.3 m at the weathered basement. The control VES revealed 5 –layers of HK-type
curve. The resistivity of the weathered and fractured basement ranged from 241.8 Ωm to 2908.4
Ωm with a thickness range of 3.5 m to 13.6 m and a depth range of 5.6 m to 19.1 m. Results
of the horizontal profiling using Wenner profiling revealed a low resistivity value of 1.6 Ωm to
3.8 Ωm at a depth of 15 m to 30 m, concentrated at stations 20 to 100. The bottom of the western
part showed that the leachate plume had infiltrated and contaminated the groundwater in the
zone. The VLF-EM with the three profiles revealed high current density values on the KarousHjelt filter plot at distances of 20 m to 38 m for profile 1, 25 m to 50 m and 75 m to 95 m for
profile 2, revealing the presence of contaminants which is mainly from decayed organic matter
from waste bodies and heavy metals from the dumpsite. Profile 3 which is further away from
profile 1 revealed that the contamination is reduced as we move further away from the dumpsite
at about 10 m to 20 m, 50 m to 60 m and 90 m respectively. The physio-chemical analysis
results showed a pH range of 6.73 – 7.17 which is within the World Health Organization
(WHO) standard (6.5 - 8.5). The Electrical Conductivity (EC) value of the Idugosa dumpsite
was found to be 804.9 μS/cm, which is above the WHO standard for EC values, which should
not exceed 400 μS/cm. This high value can be attributed to the infiltration of the leachate plume
from the dumpsite. The EC for Idugosa control which is 188.0 μS/cm is within the WHO limit
for groundwater, thus its safe for consumption.
Kidney failure has become a growing problem at Hadejia Emirates over the last decade. This can be attributed to water pollution, possibly due to heavy metal contamination of River Hadejia that affects organisms living in it, such as fish. This study is aimed to determine the
concentration of heavy metals (As, Cd, Cr, Pb) in two fish muscles. The research was conducted on tilapia and catfish where two samples of both fishes were used. The fish tissues were cut and oven-dried at 110 °C, and then a motor and pestle were used to powder the dried fish
sample. A wet digestion method was used based on the analytical methods for Atomic
Absorption Spectrometry (AAS). The result obtained shows that the concentrations of heavy
metals (Cr, Cd, As and Pb) in both fishes were found to be 0.3220 ± 0.0028; 0.1656 ± 0.002
(𝑚𝑔/𝑘𝑔), 0.0319 ± 0.0018; 0.0333 ± 0.0018 (𝑀𝑔/𝑘𝑔), 0.0697 ± 0.0011; 0.1035 ± 0.0015
(𝑚𝑔/𝑘𝑔) and 1.008 ± 0.0035; 0.600 ± 0.002 (𝑚𝑔/𝑘𝑔) respectively. The mean concentration value of the two samples of both tilapia and catfish were found to be above WHO standard limit except for cadmium in tilapia which is below WHO standard limit.
Borate glass systems have been extensively studied for practical applications in optical display
devices by virtue of their peculiar luminescence efficiency. However, the attainment of high
emission from borate glass materials via apposite control of rare earth ions (REIs) contents
remains a topical issue in Material Physics. In this paper, we report the influence
of REIs (Dy3+, Eu3+, and Sm3+) on multiple-colour emission of magnesium sodium borate
(MSB) glasses fabricated by using the conventional melt-quenching method. These glasses were optically characterized via X-ray Diffraction (XRD), UV-VIS-NIR and
Photoluminescence techniques. The XRD pattern confirms the amorphous nature of the as-prepared glasses. The absorption spectra disclosed several absorption bands at 347 nm (6H15/2 → 6P7/2) for Dy3+, 393 nm (7F0 → 5L6) for Eu3+ and 403 nm (6H5/2 →6P5/2) assigned for Sm3+ respectively. Also, the emission spectra radiate at 463 nm (4F9/2 → 6F11/2 + 6H9/2), 612 nm (5D0 → 7FJ) and 599 nm (4G5/2 → 6H7/2) for Dy3+, Eu3+, and Sm3+ correspondingly, wherein Dy3+ emits blue, yellow, and red light, Eu3+ emits red light and Sm3+ emits reddish-orange light. Finally, 1.0 mol% content of Dy3+, Eu3+, and Sm3+ in MSB glasses was found to be optimal and hence considered the best optical host for colour display devices.
Stanene is a quantum spin hall insulator and a favourable material for electronic and
optoelectronic devices. Density functional theory (DFT) calculations are performed to study the band gap opening in stanene by investigating the effect of beryllium and magnesium doped stanene single layer to study the electronic and structural properties in stanene. The electronic band energy of pure stanene without spin orbit coupling (SOC) appear to show no energy gap
at the Fermi level showing that stanene is a gapless material with Dirac cones at the K point and the band gap opens by a gap of 0.08 eV is opened at the K point. The electronic structure
of Be and Mg doped stanene shows that the Fermi level is shifted towards the valance band
edge when compared to pure stanene. We have considered 6.25, 12.5, 18.75 and 25% of both
Be and mg doping. The electronic structure of Be doped stanene show that the Fermi level is
shifted towards the valance band edge when compared to pure stanene. The Dirac point of
stanene locates at Γ shifted by 0.38 and 0.51eV for 6.25 and 12.5 %, an energy band gap of 0.27 and 0.50 eV were obtained above the Fermi level for 6.25 and 12.5% respectively. In the case of Mg, the bandgap remains slightly above the Fermi-level and amounts to 0.34 eV for 6.25 % and 0.43eV for 12.5 %, in the case of 18.75 and 25 % the Dirac cone disappear
completely, an energy gap of 0.28 eV and 0.60 eV were obtained above the Fermi level for
6.25 and 12.5% respectively, our findings show that the band gap of stanene open at 12.5%
doping concentration of both Be and Mg impurities. These obtained band-gap value seem to
be sufficient for use of alkaline earth metal doped stanene in optoelectronic and such
applications where stanene is incapacitate for its use to switch on/off devices.
Over the years, there has been significant increase in population and urbanization in Kogi State as a result of rural - urban migration. This has become a major threat to soil sustainability which is a natural non-renewable resource. The aim of this research is to carry out magnetic susceptibility mapping on the surface and subsurface soil of Kogi State using environmental magnetism techniques and geochemical analysis. The susceptibility test on rock samples and background soil samples within the study area shows an average of about 112.0 × 10^-5 SI. The magnetic susceptibility measurement on soil from Kogi State shows magnetic susceptibility enhancement of about (450.0 - 700.0) × 10^-5 SI. These values were dominant along the major towns, road pavements and commercial areas at the surface to a depth of about 50.0 cm in soil profiles. The 2D spatial distribution of magnetic susceptibility with depth reveals that theses magnetic grains are distributed in the subsurface as a result of anthropogenic loading. The frequency-dependence of magnetic susceptibility (χfd%) values are very low (2 - 10.0 %) in most of the areas on the surface soil. This values indicate that the magnetic properties are predominantly contributed by the coarse multi - domain (MD) and stable single domain (SSD) grains of anthropogenic origin. Atomic Absorbtion Spectrometer (AAS) analysis of these soil samples indicates the presence of Lead (300.0 - 900.0) mg/l and Cadmium (20.0 - 60.0) mg/l in large concentration at the surface soil in most part of the Kogi State. While Chromium show relatively low concentration on the surface soil. From the statistical correlation analysis, Lead and Cadmium show high positive correlation with magnetic susceptibility. These results suggests that the high enhancement of magnetic susceptibility on the surface and sub-surface soil in most part of Kogi State arise from anthropogenic activities rather than lithological and pedogenic processes and most likely cause by high concentration of Lead and Cadmium.
Enumabia being the only surviving river in Orokam community gave us the concern to assess the concentration of heavy metals in water and sediment in the river. 20 samples of water and Sediment were taken from four (4) different points 20 meters apart and analysed for heavy metals by the use of AA-700 Dual Atomizer Atomic Absorption Spectrophotometer in Energy
Research Centre, University of Nigeria, Nsukka. In water, the concentration of Fe ranges from
0.7669 to 0.9214 mg/l, Pb ranges from 1.3300 to 1.7210 mg/l, As ranges from 0.9032 to 2.0120
mg/l, and there was no concentration of Hg, Cr and Al. The concentration of metals in the water samples are at the range of permissible limit set by World Health Organization (WHO) except Pb, and As that are fairly higher than the permissible limit. In sediment, the concentration of
Fe ranges from 128.8812 to 113.9563 mg/l, Pb ranges from 0.2500 to 0.9520 mg/l, Cr ranges
from 0.1240 to 0.6676 mg/l, Al ranges from 10.0000 to 16.0000 mg/l, As ranges from 0.0000
to 1.1240 mg/l, Cu ranges from 0.2420 to 0.8490 mg/l and there was no concentration of Hg.
The concentration of Fe, Pb, Cr and As in the sediment exceeded the standards set by WHO.
This presence could be detrimental to plant, human being and aquatic life. Since there is fast accumulation of toxic and carcinogenic metals present in the water and sediment samples collected from Enumabia River in Orokam there is need for a follow up study to determine how the human and aquatic lives have been affected.
To fully harness the increasing number of observations and variant data sets available and put them to efficient use in geological studies aimed at solving earth science-related problems, GIS technique is a veritable tool. The dynamic techniques and the complex nature of earth sciences
is a serious cause for worry for geologists. In this work vertical electrical sounding (VES) was
integrated with geographic information system (GIS) to delineate subsurface characteristics and evaluate groundwater potential zones in Idi Ayunre, Oluyole Local Government Area, Oyo State. The results of the VES curves obtained from the partial curve matching were used to constrain the interpretation by the computer using iteration software known as WINRESIST®
and extended analysis on the data set was done using geostatistical analysis tool on archGIS 10.0®. The Root Mean Square (RMS) errors for the analysis were found to be very low with an average of 2.96% . This underscores the reliability of the analysis tool for this type of work. The area is dominated predominantly by Type-H curves which amassed twenty (20) out of the twenty-one (21) VES and one (1) VES producing a type-K curve. The VES results revealed a
maximum of three geo-electric layers, viz: topsoil, weathered layer, bedrock respectively. The
yields of wells dug in most of these locations may be insufficient, even for domestic use because of its relatively small thicknesses. However, at a depth of 7.8 m, a fractured zone occurs in VES 10 with resistivity value of 21.2 Ωm suggesting the presence of groundwater, which may be
considered the main aquifer units suitable for groundwater exploration.