Characterisation and Soil Pollution in Agrarian Floodplain of Ibadan Peri-Urban in South Western Nigeria

Ibadan metropolis in Nigeria has population of about 6millons people. There is increasing concern about lowland soils around Ibadan periurban where most of the industrial wastes transported  majorly by River Ona were deposited. These soils are used for dry season farming and  contribute to food security. This research was carried out to characterise and  determine the vulnerability of periurban lowland  soils to industrial pollution . The area was studied using 50mx50m  grid. Surface samples were taken at 50m interval. Representative profile pits were dug and described using USDA method. Particle size analysis and chemical analyses including Phosphorus, Nitrogen , exchangeable Cations (Ca, Mg, Na, K,),  Mn and heavy metals such as Pb. Cu, Zn, Cr, Fe, Cd determinations were carried out. The results shows that the surface soil of the flood plain was fertile with high N (0.35cmol/kg), P (51.25 cmol/kg), K (0.61 cmol/kg) with very high to toxic levels of phosphorous in the soil which range between 28.99 to 87.70 ppm. Average lead concentration was (34.30 mg/kg), Zn (171.20 mg/kg), Fe (83.97 mg/kg), Cu (19.11 mg/kg), Mn (31.10 mg/kg), Cr (0.69 mg/kg), Cd (0.3 mg/kg). The predictions from soil-plant heavy metal transfer coefficient (Pb:35-343; Cr:0.46-4.6; Zn:171-1712; Cu:19-191; Fe:83-840; Mn:31-281; Cd:0.1-10)  shows that there might be toxic level in crops in the area but the high yield and health of plant from field evidence and farmers interaction indicate that the  high level of P (28.99-87ppm) must have inhibited uptake of some metals such as Pb, Zn and Cu. Keywords: Fadama, Urban waste, Heavy metals, Soil pollution, Peri-urban farmin

An ion-beam surface sputtering approach to the quest for lead-free metal halide perovskite for solar cells

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 hightech device innovation. The current best perovskite for solar cell applications, with a power conversion efficiency of 22%, methylammonium 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 70%, and a lot is being done for improvement. In this paper, a new approach to these studies is introduced by performing Monte Carlo simulations of ion-beam sputtering of lead and tin perovskites, as well as other promising candidate materials, in order to throw some light on their potentials for higher efficiencies in photovoltaic applications. The sputtering characteristics of six promising perovskites, including lead perovskite and lead-substituted perovskites, were compared. The results showed a remarkable exhibition of similar sputtering characteristics of linear projected ion range for Pb and Sn, with a maximum sputter yield around 78° ion incidence. The results also indicated a correspondence between the sputtering characteristics and PCE

Projected Range and Sputter Yield of Ne+ and Ar+ in the Sputtering of Lead and Tin Perovskites

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

A Numerical Simulation and Modeling of Poisson Equation for Solar Cell in 2 Dimensions

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

REZIDUALNO DJELOVANJE MUCUNE NA RAST SEZAMA (SESAMUM RADIATUM) U RAZLIČITIM RAZMACIMA BILJKE

A field experiment was conducted at the National Horticultural Research Institute (NIHORT) Ibadan. The experiment was aimed at determining the growth and development of sesame grown at different spacing in a land previously cultivated with and without mucuna. It was a split plot experiment arranged in a randomized complete block design and was replicated three times. The main plot treatment was the residual effect of mucuna at two levels and the sub-plot treatment was spacing at three levels (50 × 30 cm, 50 × 40 cm and 50 × 50 cm). The result showed that sesame planted on mucuna fallowed land at wider spacing between plants significantly enhanced the growth of sesame. All the growth parameters examined had over 10 % increase with the leaf length and breadth having the highest value of 17.91 and 17.65 % respectively under the mucuna fallowed land compared with the non fallowed land. Increasing the spacing between sesame plants and consequently decreasing the plant population will be beneficial if the plant is grown for its vegetative part.Obavljen je terenski pokus pri Nacionalnom institutu za poljoprivredna istraživanja u Ibadanu. Cilj je pokusa bio odrediti rast i razvoj sezama uzgajanog u različitim razmacima na zemlji koja je ranije obrađivana sa i bez mucune. Bio je to pokus metodom podijeljenih parcela (split plot) u slučajnom potpunom bloku s tri ponavljanja. Tretman glavne parcele bilo je rezidualno djelovanje mucune na dvije razine, a tretman podparcele bio je razmak na tri razine (50 x 30 cm, 50 x 40 cm i 50 x 50 cm). Rezultat je pokazao da je sezam zasijan na ugaru s mucunom uz veći razmak između biljaka značajno povećao rast. Svi ispitani parametri imali su porast iznad 10% s duljinom i širinom lista najveće vrijednosti od 17,91 odnosno 17,65% na zemlji tretiranoj mucunom u usporedbi s netretiranom zemljom. Povećanje razmaka između biljaka sezama i prema tome smanjenje populacije biljaka bit će korisno ako se biljka uzgaja radi vegetativnog dijela

Rutherford Backscattering Spectrometry (RBS) method for the Determination of Elemental Constituent of Tropical Wood Matrices from Western Nigeria

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

Measurements of Physiochemical Parameters and Trace Element Concentration of Rock Samples in Ogun State

Trace elements occur in tiny quantities but detectatble, in minerals and rocks. They are always less than 1% of the all the minerals. When trace elements’ concentration is low, they become beneficial and aids growth an metabolism but when present at high concentrations begin to pose health risks. This paper aimed at investigating and analyzing the pH, electrical conductivity,and trace element concentrations in the rocks samples collected from twenty local government headquarters of Ogun state, using a pH meter, an atomic absorption spectrometer and an electrical conductivity meter,respectively.The measured pH ranged between 6.63 to7.34, which suggests that the rocks in these areas are neutral. The electrical conductivity estimated varied between 46.3 and 598μScm-1, with Ewekoro having the highest conductivity, which may be due to the accumulation of limestone in this area. It was noticed that all the elements were present in minute quantities except iron (Fe), which was present in high concentration that exceeded the recommended value. It was thenconcluded that the rocks in the study area are neutral and contain a high concentration of iron

Design and Construction of LED Matrix Display

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

Evolvement of Thermal Energy Storage Systems

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 oC. 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

Potential Health Risks of Heavy Metal Contents in Bottled Water from Lagos State and Its Environs, Nigeria

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