Table of contents

ICSSD 2018 Preface

The second series of the 2018 International Conference on Science and Sustainable Development (ICSSD 2018), with the theme "The Role of Science in Novel Research and Advances in Technology" was held from 14^th to 16^th May, 2018, in Center for Research, Innovation and Discovery, Covenant University (CUCRID), Nigeria. The conference was hosted by the Department of Physics, Covenant University, Ota, Ogun State, Nigeria and supported by CUCRID, Covenant University, Petrodata Management Services Limited and some individuals. ICSSD 2018 had series of robust sessions including two (2) keynote speakers (Prof. Paulinus Ekene Ugwuoke and Dr. NANA Ama Browne Klutse), two (2) plenary speakers (Prof. Marvel L. Akinyemi and Prof. Solomon Oranusi), and nine (9) parallel sessions.

Every Innovative society of knowledge emanates from excellent and relevant scientific research results. Science and technology are fundamentally the key drivers to economic advances, improvements in health systems, education and infrastructure. Empirical research results have shown that innovation leads to new and improved products and services, higher productivity, lower prices and new advances in scientific knowledge. Innovation geared towards sustainable development has the potential to lift economic growth, create green jobs, boost social development, while at the same time contributing to environmental protection and conservation. The development of solutions to these key global challenges, and the transition towards 'green societies' will require the mobilization of a wave of creativity and intensive research focused on need.

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Solar energy is one of the primary sources of energy replacing fossil fuels due to its abundance. Its versatility and environmental friendliness has made it one of the most promising renewable sources of energy. Solar cells convert solar energy into Electrical Energy. The effort to improve the efficiency of these cells and the reduction of their costs has been a major concern for a long time. Modeling of various structures of solar cells provides an insight into the physics involved in its operation and better understanding of the ways to improve their efficiency. This work modeled Poisson Equation in 2D for an abrupt and linearly graded charge densities system with arbitrary points in space. Linear approximation and differentials, finite difference method, boundary conditions and MATLAB were used to obtain the solution. This is the first step in developing a general purpose semiconductor device simulator that is functional and modular in nature. It was observed that highest electric potential was obtained where the point charge was placed for linearly graded and doping type changed over a small distance compared to the extent of the depletion region for abrupt p-n junction. By solving Poisson equation, voltage, electric field, electric charge density and density of free carriers inside the solar cell can be known.

This study focused on planning materials supply for construction works. In achieving the objectives, various construction firms and their sites within the area studied was sampled through structured questionnaires. The paper first presented a theoretical background of the study based on the relevance of material planning. A total number of 80 sample size was used for the study; Random sampling technique. Data collected were analyzed using percentage distribution and mean supply index shown in a table to obtain a comprehensive and accurate analysis in the descriptive statistics as applicable. From the results of the analysis of data, conclusion were made and it is recommended that the planning of building materials should be effectively done to avoid delays in construction works caused by untimely ordering and delivery of materials to sites.

Aspen Hysys version 8.6 which is a modified pinch tool was used to minimize the area of two heat exchanger networks problem and the results obtained were compared with those of other methods used by researchers that have solved the same problems. Stream data adopted from previous research work comprising the inlet and outlet temperatures, heat capacity flow rate, and specific heat capacity were imputed and solved for minimum area using the principle of modified pinch technology embedded in the Aspen Hysys software.The minimum approach temperature, composite curve, grand composite curve and the grid diagram representation are all series of steps employed in the methodology to achieve minimal area targeting using the Aspen Hysys. The problems solved in this research compared well with those of other researchers and even obtained a smaller exchanger area when compared with the non-linear programming technique (NLP). For instance, an area of 22.17m² was obtained in the first example as against 29.84m² obtained by the non-linear programming techniques, resulting in a percentage difference of 25.7%. Also in the second example solved in this research, an area of 106.4m² was obtained against 188.9m²obtained with the NLP technique which gives a percentage difference of 43.67%.The overall assessment of the results on area targeting on these problems using Aspen Hysys points to the fact that the traditional pinch technique can still obtain results that are as good as those obtained using mathematical programming techniques in heat exchanger networks (HENs).

Castor and neem seed oils were first purified separately through the process of acid degumming, neutralization, bleaching, filtering, washing and drying. The refined castor and neem seed oils was mixed thoroughly at a ratio of 40:60, 50:50 and 60:40 to make up weight of 100g each. The blended ratios were synthesized separately through epoxidation and transesterification reactions to satisfactorily remove glycerol and unsaturation and form an epoxy in the triglycerides of the mixture. The epoxidation process of the triglyceride significantly increased the viscosity whereby making the blended fluids more physically, chemically and thermally balanced. The blended oil esters produced were washed properly with distilled water and dried to purify the esters. The blended epoxy castor-neem oil methyl ester in ratio of 40:60, 50:50 and 60:40 (BEME46, BEME55 and BEME64) were characterized and the following results were obtained: the viscosities of BEME46, BEME55 and BEME64 at a lower temperature of 30°C were 9.30 cSt, 9.45 cSt and 9.48 cSt respectively, while the viscosities at a higher temperature of 70°C were 3.30 cSt, 3.32 cSt and 3.48 cSt respectively, using a glass capillary kinematic viscometer and hot water bath setup. The dielectric strength of BEME46, BEME55 and BEME64 were 30.55 kV, 30.75 kV and 32.02 kV respectively using a megger test set. The acid value or neutralization number of BEME46, BEME55 and BEME64 were 0.1683 mgKOHg^-1oil, 0.1405 mgKOHg^-1oil and 0.1405 mgKOHg^-1oil respectively. The densities were 0.8260 gcm^-1, 0.8251 gcm^-1 and 0.8219 gcm^-1 respectively, while the flash points were 165°C, 168°C and 160°C respectively. BEME46, BEME55 and BEME64 were compared with Transformer Mineral oil obtained from APO Transmission station. It was revealed that the blended oil esters met the transformer standard specifications.

The elemental composition analysis and its concentration levels in percentage were done on several wood samples using Rutherford Backscattering Spectrometry (RBS) of Ion Beam Analytical (IBA) methods. A total of twenty seven (15) tropical hardwoods from south western Nigerian environment were analyzed and six (6) major elements (C, O, N, Na, S, Cl) were identified. Carbon has the highest percentage constituents, ranging from 58.30% to 73.46%, in all the samples with sample 4 (Albizia gummifera) having the highest concentration of carbon as 73.46% and sample 7 (Anadelphia afzeliana) having the least carbon quantity as 58.30%.Nitrogen N ranged from 1.21% - 7.76%, Oxygen O 17.96% - 34.83%, Sodium Na 0.36% - 1.08%, Chlorine Cl 0.11% - 0.46%, and Sulfur S 0.13% to 0.59%. C was above the overall wood estimated constituent 50%, O below estimated value of 40%. Cl and S were within estimated range as trace element percentage range. The variation in elemental composition of wood used in the experiment shows that wood species have thesame elemental compositional trend as some human tissues and could be harness for use as tissues equivalent material for application in medical radiation dosimetry.

Temperature and humidity are the most significant weather parameters in human development. The monitoring of temperature and humidity manually has been characterized with inaccurate measurements due to human errors. This project describes the construction of a portable cost effective device for measuring temperature and humidity; it is based on wireless technology. The measuring device obtains temperature and humidity data by using DHT22 sensor. The hardware used for the project includes Arduino Uno, Liquid Crystal Display (LCD) and DHT22 sensor; the software employed is the Arduino IDE. C programming language was used and the libraries of each component were installed in the Arduino IDE. A program code in the Arduino IDE (sketchbook) was created to enable the DHT22 sensor, LCD and Arduino work. The DHT22 was initialized at 5 V. The readings were gathered serially and transferred to a computer which communicates with the Arduino and displays the values on the LCD for human interface. The device was tested at different locations and different times for two consecutive days. The results show that the cost effective, portable device is able to detect and record temperature and humidity effectively.

This paper presents a compilation of the design and construction of a programmable scrolling matrix display that scrolls the following characters "WELCOME TO PHYSICS DEPARTMENT". Dot Matrix Display based on the logic output signals of a digital signal processor (DSP) and microcontroller or other logic device. The Perspex board measuring 0.3x1.5 meters was acquired and holes of 4mm were drilled for the Perspex in order to allow the LED measuring 5mm in diameter fit tightly into the drilled holes. The circuit diagram was gotten after careful design and calculation had been done. The complete work was designed, simulated and routed with proteus and after the design, construction and testing, the device (programmable scrolling matrix display) was ascertained to be working satisfactorily.

The potential of kolanut pod husk as a biobase catalyst for the conversion of Thevetia peruviana (yellow oleander) seed oil to fatty acid methyl ester (FAME) in transesterification reactions was investigated. Oil was extracted from Thevetia peruviana (yellow oleander) seeds and a yield of 60 % was obtained. Kolanut pod husk was ashed in a muffle furnace at 600 °C and characterized. In producing the FAME, three concentrations (0.5, 1.0 and 1.5 wt %) of kolanut pod husk ash (KPHA) were investigated in transesterification reactions. Methanol to oil ratio was kept constant at 6:1 while temperature and time were varied at 40-60 °C and 60-120 min respectively. The design of experiments was used in the transesterification step to determine the effects of process variables on the yield of Thevetia peruviana methyl esters (TPME). The result showed the TPME was consistent with ASTM specifications for biodiesel. The best yield of 84.50 % was obtained for 1.5 wt % KHPA at a temperature of 60 °C and a time of 90 min. XRD and elemental analysis indicated that the catalytic effect of KHPA resulted from the presence of potassium and the microstructural formation from calcination at 600 °C. The study highlights the possibility of reducing the cost of production for FAME by using non edible vegetable oil and kolanut pod husk, an agricultural waste as a biobase catalyst in transesterification reactions.

Crude oil viscosity is one of the most important fluid properties that affects fluid flow behavior; either in pipeline hydraulics or in the porous media (reservoir). Viscosity is a vital physical property that plays a major role in the petroleum industry, the production processing and transportation of oil due to influence on the flow through porous rock, oil wells, multiphase flow through tubing and piping system. Therefore, the need for accurate determination of viscosity for oil and gas applications cannot be overemphasized. Numerous empirical correlations exist in literature for predicting crude oil viscosity but their accuracy is limited based on range of conditions of application, composition of the crude used in developing the correlation, specific range of data and experimental conditions. In the present work, experimental data of oil viscosity from different samples of Nigerian oil reservoirs were statistically compared with correlation predicted viscosity using the most common viscosity empirical correlations. Validity and accuracy of these empirical models has been confirmed for both saturated and under-saturated Niger Delta oil samples. It was observed that for under-saturated oil viscosities, Elshawarky & Alikhan's correlation gave a better prediction based on the Absolute average percentage error and standard deviation while for the case of saturated oil viscosities Chew and Connally proved to be the closest to the experimental results.

Exergy and Energy analysis used the principle of conservation of mass and energy, in connection with thermodynamics law in designing and analysing of thermal system This Paper focus on Energy and Exergy analysis of Solid Oxide Fuel Cell (SOFC) system by computer simulation. A comprehensive effect of Energy and Exergy analysis on SOFC using Methanol, Propane, and Butane fuel system with the aid of Thermolib simulation toolbox was investigated. From the configurations simulated for the three different fuel sources, the data produced were used for thermodynamic analysis. The result obtained showed that Butane configuration has the highest energy efficiency of 50.3% .while Methanol and Propane system has an energy efficiency of 46.5% and 47.7% respectively. The total energy produced by Methanol, Propane and Butane Fuel System are 273.66 KW, 234.67 and 263.92 kW respectively. While that required are 69.45 KW, 0.062 KW and 4.972 KW respectively. This shows that the highest energy requiring and producing system is the Methanol Fuelled system. The principle of energy conservation was met in all configurations. The Exergy analysis indicated that around equipment such as Reactor, lambda burner and SOFC stack there is a change between the inlet and outlet chemical Exergy. However the chemical Exergy for Pumps, Heat exchangers, compressor and Mixer remains the same because no chemical reaction occurs in them. In addition, equipment such as pump and compressor gives higher Exergetic efficiency than others. In terms of overall loss work, Methanol, Propane, and Butane system are 422.2 KW, 247.7KW, 195.7 KW respectively. The Overall System Exergetic efficiency of the three fuel systems are 44.2%, 49.3%, and 46.7% respectively. This shows that Propane system has the highest Exergetic efficiency and least irreversibility. While Methanol fuel system has the lowest Exergetic efficiency and most irreversibility. Exergy and energy efficiency favours the choice of propane fuel system. This is because Propane is the most Exergy efficiency system.

Over time, scientists have studied the potential of peptides as nutraceuticals by measuring their bio functionalities. The aim of this study was to ascertain the potential of isolated peptides as nutraceuticals in Nigeria using market availability. A market survey was carried out to determine the willingness of citizens who possess buying power, to purchase this product. The survey was conducted using survey monkey. 54.17% of the sample population declared unlikelihood to purchase these bioactive peptides, 20.83% of this group had no idea, of which most were men. Of the 45 and above age group, 55.5% declared high likelihood for purchase of nutraceutical peptides. On the assumption that only the aging group subscribes to nutraceutical peptides, there is little prospect of seeing these peptides being utilized to their maximum potential in Nigeria for health maintenance. Hence enlightenment of the public is necessary to increase acceptability and prospect of bioactive peptides as nutraceuticals.

Oil extracts from the African oil bean seed (Pentaclethramacrophylla Benth.) was analyzed for its phytochemical and mineral content and proximate, physicochemical and antimicrobial analyses were also performed. Phytochemical analysis showed the presence of tannins, saponins, quinones, terpenoids, phenols and coumarins in the oil sample. Mineral determination of the cotyledon showed the presence of iron (Fe) (with the highest concentration), Cu, Zn, Mn, Cr, Pb and Cd; while proximate analysis gave the following result: moisture (14.2%), ash content (1.5%), crude fibre (4.9%), crude proteins (12.8%), oil contents (4.9%), and carbohydrate (61.8%). GC-MS analysis of the partitioned petroleum ether and chloroform fractions of the oil revealed the presence of 9-Octadecenoic acid, 9,12-Octadecadienoic acid and their methyl esters,cis-9-Hexadecenal among the many components of the oil extract. Physicochemical analysis of the oil indicateda saponification value (148.67 mg KOH/g), peroxide value(8.0 meq/g), iodine value (10.41 mg iodine/g) and free fatty acid (8.98 mg KOH/g). The need for the development of new drugs for malaria led to our study of the antiplasmodial activity of the oil from the seeds of Pentaclethramacrophylla. Toxicological studies were carried out to determine the LD50with chloroquinediphosphate as positive control and normal saline as negative control. Using the Peter's 4 day suppressive test a parasite inhibition rate of 47.72% (25 mg/kg), 63.63% (50 mg/kg) and 61.36% (100 mg/kg) on day 4 after treatment was recorded. A 95.45% chemo-suppression was observed for animals treated with 10 mg/kg chloroquine. This resultis an indication that the extract had appreciable signs of chemosuppression.

All local climate zones need to develop relevant climatic models such as cloud attenuation model which can serve as correlative resources to global satellites applications and a means of determining local link margins for satellite networks services in localities. Effects of suspended water droplets (SWD) and suspended ice crystals (SIC) which constitute clouds are major concern in the design and successful operation of satellite communication system at frequencies above 3GHz because the hydrometeors reduces the services availability critically as frequency increases. This work is a review of cloud attenuation modelling, using as a case study typical research work been carried out, to develop cloud attenuation model for tropical Ota (6.7oN, 3.23oE), southwest Nigeria. Cloud attenuation modelling for a station involve obtaining clouds parametric system equation from their numerical representations, taking into consideration the climatic initial and boundary conditions. The numerical representations are collected climatological and radiometric data, derived from well-designed experiments in which cloud parameters measurements are carried out using radiances change measured by satellites and visual observations from the surface station(s) on land and ships in the ocean. The on-going research work begin with the study of performance of eight foundation cloud models at the station, through their detailed evaluation from cloud cover data and radiosonde data analysis, followed by analysis of collected over three years spectrum analyser signal attenuation data. Then modelling analysis of the station spectrum analyser data collected at computed elevation angle 56.18o to Astra 2(E-G) Satellite located at 28.2oE, which involve comparisons of the derived attenuation distribution curves, both of the spectrum analyser data and those of the existing cloud models for the station, with the derived attenuation distribution curves of output data generated by each run session of the station simulation equation program. The general representation of the station cloud attenuation model is stated and the specific model equation is been worked on.

The Aerosol Optical Depth (AOD), which is the integral part of the atmospheric extinction coefficient from the surface to the top of the atmosphere, is an important parameter for observation of visibility degradation due to atmospheric pollution, solar radiation extinction and other climate effects. The wavelength dependence of Aerosol Optical Depth (AOD) varies between different aerosol types because of their different physical and chemical characteristic. This paper presents new data points using interpolation for Aerosol Optical Depth (AOD) at four spectral wavelengths (440-870nm. The data used consist of measurements collected at Ilorin AERONET site (8°32'N, 4°34'E) for AOD and Angstrom exponent at the four wavelengths (α_440-870). Angstrom empirical formula was used to compute new data points by interpolation. A Regression analysis was then used to estimate the relationship between the interpolated AOD and the observed AOD at the different wavelengths of 440nm, 500nm, 670nm and 870nm. The coefficients of determination were found to be 0.978, 0.980, 0.999 and 0.997 respectively, indicating that the interpolated data agrees well with the measured data.

Knowledge of tropospheric scintillation is an important phenomenon in the design of satellite communication system. One year (January 2015-December 2015) scintillation data extracted from Astra 2E/2F/2G Satellite link measurement installed at Covenant University, Ota (Lat: 6.7 oN, Long: 3.23 oE) southwest Nigeria, at an elevation angle of 59.9o and a frequency of 12.245 GHz was used in this study. The analysis and the result were compared with some reputable scintillation prediction models so as to obtain best performance model for Ota region. From the result, it was discovered that the Karasawa model gives the lowest percentage error rate for both fade and enhancement of about 0.57% at 0.1 percentage of time and 6.93% at 0.01 percentage of time respectively and therefore was best found fit for the prediction of propagation impairment for the region. However, the model should be tested further using higher frequency band such as Ka and V bands to confirm the accuracy of the model. The information provided in this study will help in fade margin for antenna sizing and performance needed for satellite communication link in the region.

Light Fidelity, commonly referred to as Li-Fi is a technology that was introduced by a German physicist called Herald Hass. This technology in its own uniqueness considers the use of light (Light Emitting Diode, LED to be specific) as its medium of delivering high speed communication that complies with standard IEEE 802.15.7 bidirectional communication standard. This optical means of communications is also known as visible light communication. It is safer when compared with Wi-Fi network. This paper will focus on Li-Fi applications, comparison with existing technologies like Wi-Fi and the inclusion of an alternative source of power i.e., solar power, as a means of effectively optimizing on the availability and accessibility of the benefits in places where erratic or total power outage is a common trend.

In this study the influence of some meteorological variables on Ultra High Frequency (UHF) radio signals from Edo Broadcasting Service (EBS) in Benin City, South-South, Nigeria located within Latitude 6°20'17"N and Longitude 5°37'32"E was investigated. The measurements of the radio signal strength from EBS Television, transmitting at 743.25 MHz UHF and some meteorological variables (air temperature, atmospheric pressure and relative humidity) using the Digital Community-Access/Cable Television (CATV) analyzer and a self designed cost effective portable weather monitoring system were carried out simultaneously at a residential building within Benin City, in order to ascertain the influence of these meteorological variables on the signal strength. The measurements were done every eight hours (between 7am-8am, 3pm-4pm and 11pm-12am respectively) for a period of one year (2017). From the obtained results, it was inferentially observed that the radio signals was having inverse relationship with the air temperature, atmospheric pressure and the relative humidity; on the assumption that for any of the aforementioned meteorological variables, the others were observed constant. Statistically, the signal strength and these meteorological variables were having correlation values of -0.94, -0.92 and -0.96 for the air temperature, atmospheric pressure and the relative humidity respectively. These results obtained from this study should be taken into account by the management of radio communication systems for enhancement and planning purposes.

Density functional theory (DFT) is used to obtain the energy of an electron in the ground state which in turn enables the prediction of the inhibition efficiency of a molecule in the corrosion of metals. The electronic and molecular structure relationship of moxifloxacin acting as corrosion inhibitor on the corrosion of API 5L X-52 steel in acidic media was studied using DFT with B3LYP basis set. Quantum chemical parameters calculated from the Density functional theory model were as follows; E_HOMO, E_LUMO, electronegativity χ, global hardness η, electrophilicity index ω, the number of electrons transferred from the inhibitor molecule to the metal ΔN and energy of the back-donation (ΔE_{back-donation}). The outcome of the analysis suggests that the studied molecule functions as an effective additive that slows down the corrosion process, and the data corroborates experimental results earlier reported.

Continuous quest for safe environment has led to 'green' approach of synthesizing nanoparticles. The method is easy, eco-friendly and cost-effective. Locally sourced medicinal plant Canna indica was used as capping/stabilizing agent instead of toxic chemicals. Secondary metabolites in the plant extract acted as reducing agents. Optical measurements were carried out using Uv-vis spectrophotometer and photoluminescence (PL). Formation of core-shell was detected in the TEM micrograph, which was supported by two peaks observed in surface plasmon resonance shown in the Uv-vis spectra. FT-IR spectrophotometric analysis indicated the presence of some specific functional groups in the phytochemicals which were adsorbed on the surface of nanoparticles. This analysis depicted the presence of hydroxyl group (O-H stretching) with a broad strong peak at 3360 cm^-1, C-H stretching at 2938 cm^-1, C=C stretching at 1659 cm^-1, C=N stretching at 1557 cm^-1 and C-O deformation at 1065 cm^-1. Crystalline phase of the nanoparticles was determined using X-ray diffraction (XRD). The plant-mediated green synthesized silver/cobalt nanoparticles are potential optical materials as a result of their broad absorption band and emission.

Understanding the background concentration of heavy metals in dust samples is so much important for identifying and managing pollution. Thus, these concentrations in dust can be distributed indoors and outdoors in order of magnitudes. This study demonstrates the risk analysis of dust samples collected from selected buildings in both Covenant University and Canaanland using Atomic Absorption Spectrometer (AAS). The obtained concentrations were used to determine the Geo-accumulation, Contaminant Factor and the Pollution Loading Index (PLI). The highest geo-accumulation index and pollution loading index of 3.108 and 0.5836 due to chromium (Cr) contents in the dust samples were noted in Lecture Theatre 2 (LT2). The higher values found in LT2 may be due to the wide open of both doors and windows. Both the Geo-accumulation Index and Pollution Load Index were found to be lower than the permissible level suggested by World Health Organization (WHO) and United State Environmental Protection Agency (USEPA). Significantly, these observations from this study will provide the basis for the background concentrations and potential risks of some important heavy metals of environmental concern

The concentrations of lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), B and Fe in twenty (20) different brands of bottled water samples were investigated to ascertain the risk exposure to consumers using Atomic Absorption Spectrometry (AAS). The concentrations of the heavy metals analyzed varied from bottled water to bottled water samples. The BE bottled water sample was found to contain the least concentration of Pb with a value of 0.0232 mg/l. The risk of chronic daily intake (CDI) was determined based on the United State Environmental Protection Agency (USEPA) model for health risk. It was observed that Fe, Mg and Ca reported in all the bottled water samples. The estimated Chronic Daily Intake (CDI) of different metals from the water samples is found to be in order of magnitude of Pb> Fe>Cd>Ni. The highest CDI found in VA, SO, SO, LAT water samples are higher than the International Reference Dose Level according to WHO and USEPA respectively. This study suggest that some bottled water factories should be sited in zones that are safer from these heavy metals if Reverse Osmosis machine for proper removal of these trace elements from the raw water is not in use for water treatment.

Bio-chemical and physiological parameters of plants have been employed in the screening of suitable bio - monitors via the estimation of air pollution tolerance index (APTI) and anticipated performance index (API). In the present study, five plant species, Elaesis guineensis, Mangifera indica, Terminate catappa, Musa spp and Araucaria heterophylla within high concentrated industrial areas of Ota industrial estate were evaluated based on these two indices. APTI for all plant species ranged from 3.43 to 10.1 signifying their bio-monitoring status. Out of five species, Terminate catappa was identified as the most sensitive. Following API classification, Mangifera indica was graded as a good performer while Elaesis guineensis and Terminate catappa were grouped as moderate performers for green belt development. Further evaluation of screened trees for high grade tolerant species and carbon sequestration potential is recommended.

Most of the rural agricultural and extension officers have no access to the daily variations in meteorological data that affect the growth and yield of crops. This is as a result of little or no access to the data that could be used to predict the best agricultural practices for optimum output in the rural environments. In this work, a portable and user friendly smart Automated Weather Station (AWS) was constructed. The device that is programmed with Arduino UNO is capable of measuring the temperature, relative humidity and moisture content of the soil. The performance evaluation of the device was observed in the laboratory and on-site (Covenant University farm) both on the sunny and rainy days respectively. It was revealed that there is positive linear relationship between the volume of water added to the soil sample and the soil moisture content in the laboratory measurements. The on-site measurements showed that the temperature is inversely proportional to the relative humidity and soil moisture content. This device is efficient in taking the short-term essential parameters that could improve the yield of agricultural products in the rural environments if properly utilized.

Aeromagnetic and radiometric data of Ikole Sheet 245 were interpreted for structural mapping, rock characterization and radionuclides hazard indices assessment. The data acquired were processed, filtered and enhanced to improve signal to noise ratio of rocks magnetisation. The Total Magnetic Intensity (TMI) map revealed high and low intensity values between 65 and 180 nT and -150 to -65 nT respectively. The residual map revealed clearer the undistorted signatures of the area geology and the interpretive boundaries of the underlying geology. Reduction to Magnetic Equator (RTE) map showed NE-SW regional lineament (R-R') that diagonally divides the study area into approximately two equal halves; a central ridge between two depressions trending in NW-SE direction within Akoko complex and N–S faults of F1-F'1, F2-F'2 and F3-F'3 within Ikole axis. The upward continued maps (1 km, 2 km and 4 km) revealed the attitude of the basement rocks and structures with depth, some of the identified structures are deep-seated beyond 1.6 km downward, and as well revealed a general trend of NW-SE for the basement rocks. The radioelement maps revealed varying radioelement concentrations. Areas with high concentrations implied that the rocks are crystalline, undeformed and rich in feldspar with U-Th bearing minerals majorly within Ikole complex. Other regions with low concentrations on the other hand depicted varying geologic framework compositions. The maps also revealed uranium deposit in Ikole and mineralized structures such as veins, joints, fractures and dykes. The Ternary map showed that the two depressions (A) and deep-seated faults (F-F') contain low and high radioactive rich bearing-minerals respectively. The spectral depth analysis result showed that the shallow and deeper magnetic sources have an average depth estimate of 20 m and 3.60 km respectively. The Absorbed dose and Annual effective dose equivalent (AEDE) of the study area are below the world standard limit for radiological hazard. Hence, the study areas are mineralized and have several structures that retain important radioactive minerals with no hazardous risk.

We have used artificial neural network (ANN) for the prediction of transmissivity (T) from geoelectric parameter in an aquifer of a typical basement complex, Southwestern, Nigeria. The study area is composed of migmatite-gneiss, charnockite and granite gneiss. A geophysical investigation involving Vertical Electrical Sounding (VES) was carried out in the study area. Twenty VES were acquired using Campus Ohmegaresistivity meter. VES curves were interpreted quantitatively by using the technique of partial curve matching and with 1D forward modeling by means of computer using WinResistsoftware. The interpreted data were used to determine transverse resistance, TR. Transmissivity were measured in the boreholes drilled at the 20 VES locations. T_R and measured T were subjected to ANN analysis using MATLAB 2017a software in order to predict T of the aquifer. Root mean square error (RMSE) was used to test the performances of our model. The results show that T_R range from 133.00 -381.20 Ωm², T also vary from 0.4 to 4.1 m²/day. However, ANN model was able to predict T values with coefficient of correlation (R) values of 0.97, 1.00, 0.99 and 0.94 for training, test, validation and all network models respectively. RMSE value for the ANN model was found to be 0.085 which implies high performance of our model. A linear relationship was suggested for the ANN analysis to predict T. It can therefore be concluded that with ANN model, it is possible to predict T of aquifer in the study area where geoelectric data such as TR is known and T values unknown.

The slow escape of a liquid or gas through a porous material or small openings is called seepage. It is a process of seeping in soil engineering whereby water in soils move. Seepages often pose a grave problem in building foundations and also a common problem in earth dams (Dams are structures built to retain water/fluild) due to abnormal or excessive leakage. Seepage through or around dams have been responsible for most dam failures. Dam failures are usually catastrophic with many fatalities and causing the destruction of infrastructure and properties. Therefore, monitoring of seepage through and around dams becomes a necessity in other to maintain dam's stability. The main field of application of this investigation is subjected to site characterization and foundation quality assurance. This paper reviews the geophysical techniques which have been considered for the monitoring and control of seepages around dams.

Timely and reliable soil information with respect to their nature extent and spatial distribution is very essential for the optimal utilization of available natural resources in sustained bases. The technology advances in the field of remote sensing; Geographical Information System (GIS) have augmented the efficiency of soil survey. The use of advanced computer technologies with database can be used in decision making, risk assessment and environmental modelling. Precisely this project aims at the application of high spatial resolution satellite data (LANDAT 7) for assessing soil properties which include soil pH, soil texture and soil drainage. This study was carried out in South Western Nigeria in order to map out some soil characteristics with the use of remotely sensed data to assess their variability within the area in order to improve precision agriculture within the area.

Geoelectrical resistivity surveys have been carried out using Schlumberger configuration within the Iyana Iyesi area of Ota, Ogun state. The aim of this research was to experimentally estimate the hydrogeophysical parameters of an aquifer (porosity, transmissivity, hydraulic conductivity and permeability) which have been completed successfully. Since drilling of boreholes specifically to compute the hydraulic parameters is relatively expensive, estimation of the parameters from vertical electrical soundings is considered a reliable alternative. The results showed that the study area has majorly low value of overburden materials serving as the protective capacity to the aquifers that are characteristically high in porosities and transmissivities. This low protective capacity denote the high vulnerability of the aquifer system to the influx of surface-based contaminants. The aquifer systems within the study area possess significantly high storativity property based on their high porosity and transmissivity.

This research involves the subsurface geological characterization for groundwater potential assessment within the campus of the Polytechnic of Ibadan, southwestern Nigeria. The study is directed towards groundwater resources exploration, development and management in the campus. Five 2D resistivity imaging traverses were conducted using Wenner array in addition to five VES surveys using Schlumberger array that provide layering information and geoelectrical parameters. Three geologic layers delineated from the 2D resistivity inversion models include predominantly clayey sand/sandy clay top soil (overburden), partly weathered or fractured basement and fresh basement. Their inverse model resistivity values ranges 6.68 − 98.6 Ωm, 68.0 − 929 Ωm and ≥ 2252 Ωm with bottom depths ranges 3.8 − 6.4 m and 6.4 − 10 m respectively. 1D model inversion from VES results also delineate three lithologies classifying both topsoil and some part of the partly weathered basement as overburden with resistivity and thickness range 483 − 1746.9 Ωm, 1.1 − 1.8 m; partly weathered or fractured basement 60.3 − 93.5 Ωm, 8.4 -12.9 m and fresh basement 984.6 − 2078.9 Ωm . The saturated portion of the partly weathered or fractured basement at depth will favour groundwater exploration and development in this area, while the relatively shallow overburden thickness would serve as the protective layer and recharge for the fractures.

Mapping of the configuration of bedrock is paramount in civil engineering and hydrogeological settings. In civil engineering, areas that are extensively fractured (either shallow or deep) are adjudged as weak zones whereby these provinces are regarded as copious zones for groundwater exploration. Very Low Frequency Electromagnetic (VLF-EM) and ground magnetic survey were carried out in Olupona Housing Estate along seven traverses with interstation spacing of 20 m. For the two methods, traverses 1 to 3 were taken in North-South azimuth which covered distance 300 m while traverses 4 to 7 were acquired along East-West azimuth which covered distance 400 m. VLF-EM results revealed Type-1 fracture along traverse 1, traverses 2 to 4 showed no fracture but a fairly competent bedrock. Type-2 fractures were revealed on traverses 5 to 7 while Type-3 fracture was shown on traverse 5 alone. Ground magnetic results depicted that the depths to biotite or biotite muscovite granite are relatively deep. The mineral rocks with very thin, intermediate, and very thick bodies have their depths range as 14.7 m, 11.0 m and 8.8 m respectively. On the average, the depths to these mineral rocks from the surface varied from 6.5 to 19.6 m. The trends of the identified fractured zones are NE-SW and NW-SE directions. It is concluded that in order to avoid building collapse in future, construction of high-rise buildings is unadvisable in the study area. If the identified fractured zones are properly maximized for groundwater exploration, the fractured zones can be optimized such that reservoir(s) can be constructed so as to supply water to the houses for domestic usage.

Detail knowledge about the subsurface properties and its engineering implications is crucial in pre-foundational studies. Geophysical investigation has been found relevant in probing the subsurface for the purpose of deducing its characteristics before any engineering construction activities would commence because of its non-invasiveness. The deduced soil characteristics are used as preliminary information to determine the suitability of the site under investigation. When the results from such study are properly utilized, it prevents prospective structural failure and loss of valuable asset. Ground magnetic technique and Vertical Electrical Sounding (VES) was used to characterize the subsurface layers of Ayetoro Housing Scheme, Ojongbodu, Oyo West Local Government Area, with a view to determining the competency of the subsurface and hydrogeological prospect of the study area. A total of six traverses were established in the E-W direction and N-S direction in order to map the magnetic signatures in the study area. Thirty VES stations were occupied across the study area using the Schlumberger electrode array configuration with current electrode spacing varying from 130 to 200 m. The data acquired was interpreted qualitatively and quantitatively. The magnetic highs and lows were observed in all traverses. The magnetic highs represent regions of magnetic minerals such as metamorphic or igneous rocks while magnetic lows represent regions with linear geologic features. Power spectrum and analytical signal filtering techniques were used for the ground magnetic interpretation. Depth to magnetic sources from power spectrum analysis (local field) ranged from 5 to 62 m. However, depth to magnetic sources from analytical signal varied from 20 to 160 m with an average variation from 38.3 to 77.6 m. The western part, some part of the northwestern zone, base of the northeastern zone and some part (probably base) of the southern region of the study area were interpreted as regions of magnetic highs while others belong to average and low magnetic distribution. Twelve of the thirty modeled curves were H-type, eight were QH-type, three were HA-type, one was Q-type, two were A-type, two were HK-type and two were KH-type. The overburden thickness ranges from 1.8 m to 44.8 m, the geoelectrical sections obtained from the Sounding curves showed both 3-layer and 4-layer earth model. Nine of the VES stations show fresh bedrock while the remaining twenty one showed fractured basement. The models showed that the subsurface layers categorized into topsoil, weathered/clay layer, and fractured/fresh basement. It was concluded that the subsurface is incompetent for high-rise buildings since the lithology of the area showed that clayey zones, thick overburden and fractured bedrocks constitute two-third of the study area. However, groundwater exploration (hand dug wells and boreholes) for domestic uses would not be problematic in the study area.

Radioactivity in soil occurs naturally due to the presence of ²³⁸U, ²³²Th and ⁴⁰K. Undue exposure of humans to these radiations can result in some serious health problems. There is need to have adequate information on the level of radiation that is available around us in order to take adequate measures for protection. Electrical resistivity and radiometric methods were used in this study. The results by the radiometric method revealed the activity concentrations of U, Th and K to vary from 12.658 Bq kg^-1 - 42.299 Bq kg^-1, 44.9645 Bq kg^-1 -128.702 Bq kg^-1 and 31.3Bq kg^-1 - 453.85 Bq kg^-1, respectively. The result of the electrical resistivity method varied between 75 and 2025 Ωm. Finally, it was observed that region of high resistivity was prone to higher level of radiation, which could be as a result of some radioactive geological features in the subsurface.

High resolution aeromagnetic data that covers Igbeti-Moro area, within southwestern Nigeria, has been subjected to data enhancement processes and interpreted to establish significant geologic features associated with occurrence of marble, gabbro and muscovite mineralization in the area. These were established by applying 2D Fast Fourier transform filters for reduction to equator (RTE), lineament enhancement of vertical and total horizontal gradient, edge detection of analytic signal amplitude (ASA), and magnetic source depth parameter imaging (SPI) and average power spectrum (APS); using Oasis Montaj software. The RTE residual magnetic intensity of the area ranged between - 338.3 nT to - 2.4 nT, 9.9 to 27.7 nT and 32.1 to 208.0 nT for low, intermediate and high magnetic susceptibility respectively which indicate contrasting basement rocks (namely; granite-gneiss) and intrusion of quartz and amphibolite schists. The lineament development and its disjoint revealed fractures and faults associated with emplacement of the quartz-schist and muscovite-schist, which would have formed synchronously with isoclinal fold and hosts marble, gabbro, amphibolites and muscovite mineralogy at shallow depth that ranges from 0 to 200 m in the northeastern, western, north central sections of the area. The geologic features observed in the study area have been established to be associated with the solid minerals that can be of social-economic benefit.

Depth to magnetic basement and mapping of source geometries were estimated from High Resolution Aeromagnetic (HRAM) data of Benisheikh using wavelet transformation technique. This technique was chosen because it has been proven to be a powerful and efficient tool in interpreting potential field data. In this work, a non-orthogonal wavelet function with a good symmetry and higher vanishing moment, Morlet was chosen as the analyzing wavelet. Wavelet power spectrums of the aeromagnetic anomalies were obtained using the scaled normalized analyzing wavelet in order to estimate the depth to the magnetic basement. Also, the square of the absolute value of the wavelet coefficient were plotted against the period in other to identify and map variations of pronounced and least energy values which can be regarded as magnetic source geometric features found from the HRAM data profiles. The results obtained from the analysis have shown the ability of wavelet transform as a tool in depth estimation and mapping of geological features of HRAM data of this part of Nigeria.

There is a growing awareness of medicinal benefits of renewable forest resources that can be used as natural cosmetics for the benefits of human skin health. Today, more rural dwellers in forest reservation have resorted into utilizing more Non-Timber Forest Products (NTFPs) and agro-processing wastes products (APWPs) into African Black Soap (ABS) otherwise called Herbal Soap (HS). Some of the NTFPs that fall under natural cosmetics are herbal soap (black soap) produced from Cocoa Pod Husks (CPH); Shea-butter; Coconut Oil; Aloe-Vera Gel, and Natural Fragrance Oil. This is an excellent natural body-care soap in the original fashion and suitable for all skin types. The major raw materials that are used to produce herbal soap are from NTFPs and APWPs such as CPH; Palm Kernel Oil (PKO); cassava peels (CP) and, Plantain Peels (PP). 5g weight of each sample was dissolved in 50ml of solution (10% Concentration) to get the results. The results of the physico-chemical analysis (PCA) on Herbal soap and photographic impressions of ten (10) samples collected during field survey from different locations in South western, Nigeria revealed the following: The pH range of the herbal soaps (10% solution) is between 9.89 to 10.18 which is a good indication that the herbal soaps fall in the mid alkaline pH range - (that is, ideal soap pH range that have little or no irritation on mildest skin texture. Some synthetic soap that bleaches gives a pH range above 10.50 and other acidic soap below 6.98. pH range of the soap (10%) lies between (981-3110) x 10 mg/L which is a good indication. The Total Dissolved Solid (TDS) mg/L of the herbal soaps falls between 981-3110 mg/L which is a good indication of inertness of the soap to atmosphere when expose to moisture. Industrial PKO (981-1775) melted but traditional processed PKO (1800 -3110) stayed dried. The Conductivity (US/cm) of the herbal soaps ranges from 18,200-47,150 (US/cm)^x10. This measured parameter indicates the extents of dissolved ions present in the herbal soap materials that when releases nourishes the skin on use. The higher the dissolved ions, the better for skin absorption of the desirable ions which result into healthy skin in human being

Water samples from Hadejia River in the north eastern part of Nigeria were studied in order to ascertain the suitability and radiological safety of water from the river for human consumption. Radioactive measurements, using a lead shielded sodium iodide detector coupled to a multichannel analyzer were used to estimate eight radiological parameters of water samples from Hadejia River. The results show that the values of all the parameters fall within the minimum universal standard, indicating that consuming the water pose no serious radiological hazard, especially for adults. The values of the Absorbed Dose Rate (50.10511 nGyh-¹) and AEDE (12.458 mSvy^-1) for the infant however portend that infant consumer could be susceptible to radiation hazard on consuming water from the River. It is however recommended that activities that are capable of enhancing the radiological content of the River be avoided within the area.

Elevated background ionizing radiation has its health effects on people who reside in such areas, this necessitate the need for constant monitoring. The activity concentrations of K-40, Th-232 and U-238 were measured in three different selected study areas in Ota using RS-230 gamma spectrometer. The highest activity concentrations for the three radionuclides were recorded in the Industrial Estate. The mean dose rate recorded was 45.37 nGyh^-1, 37.12 nGyh^-1 and 33.33 nGyh^-1 for Industrial Estate, Obasanjo Estate and Atan respectively. The mean outdoor annual equivalent dose estimated was 0.056 mSvy^-1, 0.045 mSvy^-1 and 0.041 mSvy^-1 respectively for the three locations. The estimated excess lifetime cancer risk ranged from 0.14 x 10^-3 − 0.277 x 10^-3 for the study areas. The radiological variables estimated in this study were all within world average recommended limit. The study concluded that the locations considered in this work are safe for dwellers and that industrial activity has influence on the background radiation.

The goal of this study is to evaluate the risk of cancer induction in head radiography procedures with a view to promote dose optimization and enhance patient safety. Thermoluminescent dosimeter (TLD 100) was used to determine the entrance surface dose (ESD) of 20 patients presented for head radiography in two tertiary healthcare institutions in Southwest Nigeria. The corresponding effective dose and doses to the brain, oral mucosa and salivary gland were evaluated using PCXMC software. Incidence cancer risks were evaluated using BEIR VII model. The total entrance surface dose (ESDT) for mandible, paranasal sinuses and skull radiography ranged between 3.01-19.12 mGy with a mean of 7.52 mGy. The resulting effective dose, brain dose, oral mucosa dose and salivary gland dose has a mean of 0.25 mGy, 2.84 mGy, 3.06 mGy, and 4.97 mGy respectively. The least incidence of cancer risk obtained in this study is 1: 7000. Failure in the adoption of complete optimization technique was responsible for the increased risk. Periodic dose audit and enforcement of radiation protection policy will help to checkmate the lapses and alleviate patient risk.

The radiation from different types of Visual Display Units (VDU) (that is, Liquid Crystal Display (LCD) and Cathode Ray Tube (CRT)), projector and interactive screen were examined using a Cell Sensor Extremely Low Frequency (ELF) detection meter. The study revealed that ELF radiation in CRT VDUs is eight (8) times greater than in LCD VDUs. The mean ELF obtained from interactive screen at 30 cm was 1.6 mG and 1.9 mG at start-up and after 3 hours of use respectively with a mean value of 1.03 mG for a distance of 100 cm at start up. The mean ELF radiation from the projector screen at a distance of 10 cm is 0 mG, while that of interactive screen is 2.4 mG at the same distance. Thus, the study suggested that, projector and screen is better than interactive screen when making presentation considering the closeness of user to the interactive screen throughout the course of presentation.

As a result of twin problems of environmental pollution and continuous depletion of fossil fuels, a search for renewable and clean energy sources is necessary. This paper discusses the simple extraction techniques without any further purification of natural dyes from some fruit peels and their performance in DSSCs. Natural dyes extracted from fruit peels of Carica papaya, Citrus lanatus, Persea americana and Solanum melongena were used as sensitizers to fabricate ZnO-based dye-sensitized solar cells (DSSCs). The extracts of the natural dyes were characterized and studied using UV-Vis absorption spectroscopy, Fourier transforms infra-red (FTIR) and Photoluminescence (PL) spectroscopy. The photo-anode semiconductor material was prepared and characterized. The photo-voltaic characteristics of the fabricated DSSCs were measured under simulated solar light (power of incident light 100 mWcm^-2 from Air Mass 1.5G). These studies indicated the presence of pheophytin 'a' in most of the extracts studied as the main pigments with other accessory pigments. The solar to electric conversion efficiencies for the pheophytin 'a' dye based solar cells are estimated as 0.017%, 0.013%, 0.010% and 0.011% for Carica papaya, Citrus lanatus, Persea americana and Solanum melongena, respectively. The dye extracts from Carica papaya exhibits higher photo-sensitized performance compared to the other extracts and this is due to the better charge transfer between the dyes of Carica papaya and ZnO photo-anode surface. Conversion of visible light into electricity was accomplished with natural dyes and ZnO-based DSSCs, resulting in excellent photo-electric properties compared to those in literature.

This research presents the synthesis of alumina-supported chicken eggshell for the transesterification of waste cooking oil. The major materials used in the research are from renewable sources because the research focuses on addressing issues associated with renewable energy and the environment. Biodiesel was produced from waste cooking oil using alumina-supported calcium oxide from chicken eggshell. The alumina was leached from kaolinite clay using hydrochloric acid while the eggshell was from chicken. The prepared catalyst was characterized using XRF, FT-IR, BET, and TGA. Using a 2⁴ factorial design, the catalyst synthesis was optimized and the effect of the parameters used in catalyst synthesis such as the impregnation ratio and time, calcination temperature and time, on the yield of biodiesel from waste cooking oil were investigated. The optimization study showed that; impregnation ratio of 1.17:1, 1.32 hours of impregnation, calcination at 740.31°C for 2.62 hours gave the best results of 75.4% with 95% confidence level. The conditions for transesterification were methanol to oil molar ratio of 12:1, 6wt% catalyst, 60°C reaction time, and mixing speed of 250rpm for ninety minutes. The result of the characterization of the biodiesel produced using the CaO/Al₂O₃ produced proves that the biodiesel compares favourably with ASTM standards.

A world with constant and unhindered supply of power from thermal sources is a feasible possibility. It is left to us researcher to find out the most optimal way to collect and store energy in this form. This review work seeks for thermal storage materials and methods to promote harnessing the thermal component of renewable and abundant solar energy at Covenant University, Ogun state, in Nigeria. The efficient implementation of thermal renewable energy sources is still being faced by a few challenges such as storage and efficiency. The review seeks methods of incorporating cost effective and efficient thermal energy storage techniques into the University campus energy system. Such techniques can be in form of thermal energy storage materials such as LiNO₃-NaCL containing 87 wt% of LiNO₃ and 13 wt% of NaCL with latent heat capacity of 300 kJ/kg and melting temperature of 220 °C. This paper reviews the evolution as well as trends of thermal energy storage systems considering the sensible and latent heat storage materials. Results of previous researches are discussed and these include the thermal properties of various proposed heat storage and heat transfer materials such as the heat capacity, latent heat capacity, melting point, thermal conductivity and maximum temperature of stability. These results were reviewed for the two categories of storage materials considered namely: latent and sensible heat materials.

Wood waste (saw dust) from sawmills if well harnessed is a potential alternative source of energy for electricity production. This is due to its prospects in the production of fuel such as biogas (methane, carbon dioxide and other trace gases) having high calorific value that can be used to drive a gas turbine in the production of electricity. However, since the electrical energy generated mainly through the hydro power generating stations along with the other power plants including the conventional coal and gas currently in existence in the country is not meeting the energy demand of Nigerians, it is therefore necessary to introduce additional sources of alternative energy in order to be able to augment these existing energy sources, and wood waste is the proposed alternative source of fuel energy used in this study. The fuel properties and characterization of six different wood waste samples (Iroko (Milicia excelsa), Masonia (Masonia altissima), Afara (Terminalia superba), Arere (Annona senegalensis), Ayin (Anogeissus leiocarpus) and Obeche (Triplochiton scleroxylon)) obtained from sawmills located within Bodija, Sango and Idi Ayunre areas of Ibadan were determined by following the procedure of the American Society Standard Test Method (ASTM E870-82(2013)) for the analysis of wood fuels. The result of characterization of the wood samples showed a range of values for the gross calorific values (20.14MJ/Kg to 22.30MJ/Kg), volatile matter (74.22% to 82.62%) and ash content (0.605% to 5.03%). The overall ratings of the fuel properties of the six wood samples in terms of their average ranking were obtained as 3.25 (Iroko), 3.13 (Masonia), 3.25 (Afara), 2.0 (Arere), 2.6 (Ayin) and 1.75 (Obeche) which suggests that wood waste from Obeche has the best fuel property because of its least rating while that of Afara and Iroko were the worst.

Solar panels produce higher output power when the solarradiation reaching it is perpendicular to its surface. Trackers are used to orient the solar panels perpendicular to the incident irradiation for maximum power output.In the temperate region, there is low irradiation compared to the Tropical region, thereby necessitating the use of solar trackers in order to harness as much energy as possible. This research seeks to investigate the effect of using trackers in the Tropical region by making a comparative analysis of the power and voltage output between a static solar panel and a panel mounted on a solar tracker. A cost-benefit analysis is also carried out. The results showed that there was an increase in output power with the use of a solar tracker, relative to a static photovoltaic module by 23.87%. It was concluded that use of trackers in the tropical region could be beneficial if it is used for a large generating solar plant or during the raining season, when there is more cloud cover.

Metal halide perovskites have been the subject of intense theoretical and experimental research in recent years due to their huge potential over their silicon based counterparts for tunable optoelectronic applications in high-tech device innovation. The current best perovskite for solar cell applications, with a power conversion efficiency of 22%, methyl ammonium lead iodide (CH₃NH₃PbI₃), is toxic due to the presence of lead and is therefore harmful in solar cell applications despite its low concentration in solar cells. Hence, research exploits are geared towards perovskites without lead. Unfortunately, this has taken back the gains in PCEs by about 15%, and a lot is being done for improvement. In this paper, we performed molecular dynamics and Monte Carlo simulations of ion-beam sputtering of lead and tin perovskites to determine differences between the sputtering characteristics of lead perovskite and a lead-substituted perovskite (tin perovskite). Our results show that they both exhibit similar sputtering characteristics of linear projected ion range, and maximum yield around 78° ion incidence.

The study focus on CO₂ adsorption using activated carbon and zeolite for the purification of the produced biogas and developed kinetic study for the AC and zeolite CBV 8014 adsorption. Furthermore, model equations were developed for the upgraded biogas purity as a function of adsorption time and adsorbent dosage to predict biogas purity. The adsorbents and kinetic study was evaluated using a cylindrical glass column. The biogas produced from chicken droppings and cow dung were characterized and found to contains CH₄ gas (53.26%), CO₂ (33.44%) and other gases in small quantity. The highest purity of 84.34% and 91.01% was obtained for AC and zeolite CBV 8014 respectively at 20 min adsorption time and the model equations developed well represent the experimental data. The adsorption capacity of the adsorbents was evaluated using a cylindrical glass column and was found to be in the order of zeolite CBV 8014 (91.01%) ˃ AC (84.34%) at 0 − 20 min adsorption time with adsorption increasing over time. The kinetic study of the biogas purification shows that the CO₂ adsorption onto AC and zeolite CBV 8014 obeys the pseudo-second-order model, due to its regression coefficient (R²) value closer to unity. The equilibrium and kinetic study of CO₂ adsorption onto AC and zeolite CBV 8014 shows that the magnitude of activation energy for both adsorbent are lesser than 40 kJ/mol, indicating the occurrence of physisorption mechanism. The intra-particle diffusion model also indicates that intra-particle diffusion is not the sole rate-limiting step in the adsorption process for both adsorbent (AC and zeolite CBV 804). The zeolite CBV 8014 has higher CO₂ adsorption capacity than AC.

Dye-sensitized solar cells still offer an encouraging option in the photovoltaic family. It is endowed with several attributes such as ability to generating green energy at low cost, ease of fabrication and yearlong availability of raw materials. Betalain an important constituent of B.vulgaris shows diverse changes to temperature and solvents as they alter the fluidity of its membrane. This experiment seeks to explore the latter with a keen interest on the IPCE and efficiency of beetroot dye-sensitized solar cells (DSCs). The Doctor blade method of application of TiO₂ photoanode using ethanol as precursor and high temperature sintering reveals diverse spectral responses in the efficiency of the DSCs with the most efficient B.vulgaris dye recording 0.27% and the highest IPCE of the dye revealed as 28.34%.

The study explored the production of biogas from a composite of Lemon grass and Poultry droppings by studying the total gas pressure exerted on a sealed near-cylindrical plastic container used as a digester. The composite pre-fermented substrates were mixed with water and the formed slurry was digested for a month. The temperature was kept relatively constant by lagging the digester with fiberglass wool. The exerted stress on the digester by the produced biogas was determined using a tri-axial quarter-bridge strain gage rectangular rosette, carefully fixed to the external surface of the plastic digester. Subsequently, the total pressure exerted on the wall of the digester container was determined. The daily gas production potential in form of computed pressure is presented. Results showed a maximum gas pressure of 31,200 pascal above atmosphere produced from the composite over the period of four weeks. The research demonstrated that pressure changes at relatively constant volume can be used to monitor gas production.