DESIGN ADAPTATION OF BATCH CRUDE OIL BOILER FOR CONTINUOUS DISTILLATION OPERATIONS.

Purpose: Boilers are some of the most critical equipment in many production process especially in refinery operations, as it is used in generating steam for different applications. Different types of boilers are available commercially and have comparative advantages over one another. The pot or kettle boiler is the foremost of these equipment and consists of an empty vessel with a secure lid and a burner that is the source of heating. Though overtaken in industrial applications by more modern designs, these simple boilers which are often batch process equipment are still useful for small production processes at low pressures. The work here developed design adaptation of these batch boilers for continuous vaporization of crude oil for artesian refining of the oil. Methodology: Physical and assay data of Bonnylight Crude Oil (BLCO) was used for the work from the library of ASPEN Technologies. Simple mathematical models were developed from interpretation of implicit phenomena of the boiler transformation process. The models were validated using ASPEN HYSYS process simulation software Version 10. Findings: Computational results of the models and simulation results gave good convergence except for the heat transfer parameter of the model which had almost 100% of the simulation value. Nevertheless, the models have good predictive capabilities Recommendation: The design adaption models herein developed can be deployed with reasonable accuracy for the heating of crude oil especially for small artesian operations. However, the study space of the subject matter can be expanded for better accuracy and reliability.

Simulation of an Industrial Carbon Black Reactor Using Collision Kinetics

Purpose: Objective of the work was to test efficacy of the proposed flame chemistry and collision kinetics for prediction of process parametres through determination of the effect of basic process parameters on yield (which includes but not limited to grade of carbon black produced). Methodology: The research methodology in this work was simulation of an industrial Carbon Black Reactor based on reaction kinetics from flame chemistry which assumes that primary particle formation and particle growth is strictly by collision of molecular nuclei with gas molecule as proposed by the collision theory. Decant oil from the Fluid Catalytic Cracking Unit (FCCU) of the Warri Refinery and Petrochemical Company Limited of Nigeria represented by naphthalene was used as feedstock in the simulation while methane gas is the fuel for combustion needed to attain the reaction temperature. Findings: Results showed an excellent quantitative prediction of trends by models. Qualitative predictions gave far higher parameter values, something easily attributable to the excessively high values of kinetic data used for model testing. Recommendation: The simplifying assumptions of these models completely ignored microscopic phenomena such as interface mass and heat transfer and other similar processes. Consequently, the model can be improved upon by introducing some of these processes as identified.

Levels of Hydroquinone, Selected Heavy Metals (Hg, Pb, As) and Chemical requirements in Some Skin Lightening Creams Sold in Mbarara Municipality

In this study, Skin-lightening creams commonly sold in Mbarara municipality were analyzed for chemical parameters (pH, thermal stability and fatty substance content), total hydroquinone, Lead, Mercury, and Arsenic contents. Total heavy metal content was determined by atomic absorption spectrophotometry. The levels of hydroquinone were determined using High Performance liquid chromatography (HPLC). All the creams showed detectable mean levels of mercury, ranging from 0.07±0.01ppm to 0.33±0.01ppm. Only 26.31% of the creams showed detectable levels of lead and 15.79% creams recorded detectable levels of arsenic. The mean levels of hydroquinone ranged from 0.54±0.02% to 4.47±0.02%. All the creams passed the thermal stability and fatty substance content tests. However, all the creams had very low pH values below the recommended 4.5- 8.5 pH ranges by Uganda National Bureau of Standards (UNBS). The levels of mercury, arsenic and lead in the samples were less than the UNBS, European Union and US Food and Drug Administration’s acceptable limits. Only 84.2% of the cream samples analyzed contained hydroquinone levels higher than the recommended WHO limit of 2%. The use of such creams may lead to serious health hazards. While the low concentrations of heavy metals detected in the cream samples analyzed do not pose any potential risk to consumers, repeated application of these creams may cause a cumulative effect over prolonged exposure. The low pH values may cause skin irritations. Therefore, the community needs to be sensitized on the implications of using skin lightening creams and UNBS should conduct periodic analysis to ascertain the levels of hydroquinone, heavy metals, and chemical requirements of skin lightening creams sold in Uganda as well as encourage manufacturers to state the exact bleaching agents in their creams.

ELECTRODEPOSITION OF SILVER THIN FILMS ON A GOLD SUBSTRATE IN THE PRESENCE OF OCIMUM GRATISSIMUM (Og) AND VERNONIA AMYGDALINA (Va) PLANT LEAF EXTRACTS.

Electrodeposition an advanced thin film deposition method originally used for decorative purposes and now widely used in industrial applications such as electronics, phonics, magnetic recording and protective coatings, has also been used for the production of size and structure-controlled nanoparticles. In this research, the electrodeposition of silver (Ag) films on gold (Au) substrates with two plant (Ocimum gratissimum (Og) and Vernonia amygdalina (Va) leaf extracts as additives was explored . The effect of these leaf extracts immediately after addition and after a prolonged exposure in the electrolyte on the silver deposits was studied using cyclic voltammetry (CV), chronoamperometry (CA) and linear sweep voltammetry (LSV). Silver thin films were electrodeposited on gold film from an electrolyte of 5 mM AgNO3 and later 5 mM AgNO3 +0.1 M KNO3 for 10 minutes, using a double potential step protocol and potentials -0.15 V and -0.3 V with and without the plant leaf extracts. As silver was grown on the gold substrate, silver nanoparticles were also discovered to have been formed in the electrolyte. Though the deposition potential in the presence of the plant leaf extracts affected the kinetics of the silver deposition on the gold substrate, it only slightly affected the silver film thickness on the gold. CV graphs with the plant leaf extracts show lower current densities indicating a slowing down of the deposition/dissolution rates of silver probably due to the adsorption of the leaf extracts on the surface of the growing silver films which may have affected the transport of silver ions (Ag+) towards the electrode and impacted on the silver deposition/dissolution kinetics. The deposited silver film thickness was 7 nm to 8 nm with the Og leaf extract and 1.5 nm to 2 nm with the Va leaf extract. Atomic Force microscope (AFM) was used for viewing the silver films and the mean grain sizes of the Og silver films was calculated to be . This was larger than those of the Va silver films calculated to be While the Va silver films surface roughness was higher at 10.6 , that of the Og silver film was 9.3.

MATHEMATICAL MODELING OF WATER QUALITY WITH A DIFFERENT CHEMICAL STATE; NUTRIENTS AND ARID ENVIRONMENTAL CONDITIONS, SIWA OASIS, EGYPT

Purpose: A comprehensive monitoring and evaluation study was conducted on wells, water table and drainage water for water quality index. The study aimed to achieve a sustainable integrated management for water and soil at the study area. Methodology: Assessment and evaluation of water samples were: Evaluate the physic- chemical properties; Discuss the Hydro chemical coefficient; Assessment of the appropriate use of water quality such as permeability index (PI) and Kelly's indicator (KI); Water quality identification and assessment through calculate of WQI; It was conducted various assessments of the elements within the water, such as the contamination factor (CFi); geo-accumulation index (Igeo) and the potential ecological risk index (RI). Findings: The results shown that the dominance of Na+ cation and Cl- anions due to the influence of marine sediments on water elements which resulted in increased the mention ions in drainage water> water table> wells. TDS values of wells, water tables and drainage water were no detected, 2374 to 9088 and 3641.6 to 13952mg L-1, respectively and RSC values of water samples were not significant. KI indicated that the well water is safe for drinking and the water table and drainage water are not acceptable for drinking. PI indicated that the suitability of water to be used in agriculture. WQI confirmed that the water is highly appropriated for Olive's tree and Palms cultivation. CFi indicated that the wells gave low to moderate contamination of Mn, Cu and B while, the Fe, Zn and Si concentrations were low. A very high degree of contamination by Fe, Mn, Zn, Cu and B were observed in water tables; however Si concentration was low to considerable degree. Generally, drainage water gave a very high degree of contamination with Mn, Cu, and B, whereas the concentration of Fe, Zn and Si were low, moderate and considerable degree. Analytical modeling proved that the Igeo values for Mn, Zn, Cu and Si were assigned to Class 0 for water sources at study area. RI indicated the wells and water table samples (exception of Cu was moderate to high) were slightly risk as well as the RI of drainage water samples was low risk. Contribution to theory, practice and policy: The results provided the relationships between the water resources assessment and water quality management, and to ensure their environmental reflections such as (contamination factor (CFi); geo-accumulation index (Igeo); the potential ecological risk (RI)), with the safe use of water based on its properties. Keywords: Hydro chemical coefficient; permeability index (PI); Kelly's indicator (KI); water quality index (WQI); contamination factor (CFi); geo-accumulation index (Igeo); the potential ecological risk (RI).

ANALYSIS OF THE DAILY HOURLY DEPARTURES OF THE GEOMAGNETIC H FIELD OVER LOW-LATITUDE STATIONS

The telecommunication technologies deployed in the last decades have shown that there are better days ahead. From electric telegraphs systems in the 19th century to today’s wireless communication using satellites and land links (Lanzerotti, 2001). The horizontal component (H-field) of the geomagnetic field has great impacts in the present-day communication technologies. The aim of this paper was to analyse the daily hourly departures of geomagnetic H-field along the low-latitude stations on the equatorial chain in relation to their correlation coefficients with their longitudes. The magnitude of H-component is a very significant factor in the determination of the total magnetic field of any location on the earth. The baseline values (H0) which is the average of H components at 23LT, 24LT, 1LT and 2LT were subtracted from the hourly values of H (Ht) to obtain the hourly departures of H (dH). The hourly departures of H (dH) from the baseline is non-cyclic since H1 ≠ H24 as observed over the three MAGDAS stations in Nigeria. The correlation coefficients between dHs of Lagos/Ilorin, Ilorin/Abuja and Abuja/Ilorin are 0.97, 0.75 and 0.66 respectively. This suggests that substorms are deflected eastwards along different longitudes due to the rotation of the earth such that locations in the same longitudes have the same hourly departures. There is no solar radiation during the nighttime, thus dH should be zero but for the energy stored in the magnetotail, the reduction of hourly departures towards nighttime in Nigeria is evident. This is further revealed as the midnight dH amplitudes decrease regularly. The eastward motion of the electrons during substorms was suggested to be responsible for the reduction of the H-field at the nightside magnetotail region for all the stations. These findings will assist the telecommunication companies to know which location is best for their transmitters to be sited in order to reduce loss of signals along the optical cables to the receivers. Furthermore, global telecomms companies should have business continuity plan which should include risk assessment and prompt response to geomagnetic disturbances being one of the causes for telecommunication outages.

EFFECTS OF CO-DIGESTION OF POULTRY DROPPINGS AND MAIZE COBS ON BIOGAS YIELDS AND SOME PROXIMATE PROPERTIES OF THEIR BY-PRODUCTS

Purpose: The study focused on Co-digestion trials of poultry droppings and maize cobs in order to assess its effects on biogas yield and some proximate properties of their by-products.Methodology: Five different treatment ratios A(25:75), B(50:50), C(75:25), D(100:0) and E(0:100) of these wastes in triplicates were made into slurries (1:3w/v ratio) and separately fed to 13.6L locally fabricated digesters for 56 days retention time. There was a progressive increase in biogas yield across the treatments within the first six weeks of digestion, followed by a sharp decline at the 7th and 8th weeks.Findings: All co-substrates treatments had higher gas yields in the order of B(2481.30ml) > D(2197.90ml) > A(2163.00ml) > C(2116.30) > E(1713.20ml). The proximate contents gave E(763.60%), A(153.73%), B132.44%), C(79.37%), D(48.06%) as % increases in ash, while %decreases in crude lipid and moisture contents were E (77.04, 21.02), B(72.70, 56.90), D(65.99, 40.94), A(65.70, 53.21) and C (56.83, 49.89), respectively. All but treatment D(5.74%) had % increases in crude protein. There was a general decrease in total solids(TS), volatile solids (VS), chemical oxygen demands (COD), metabolizable energy(ME). All co-substrates had higher % bioconversion efficiencies(%BE) over the singles with B(24.50%), C(57.90%) and A(21.39%) highest values for TS, VS and ME reduction, respectively. The % C/N reduction was in the order of treatment E(81.80%)> A(68.02%)> B(54.42%),>C(54.23%) >D (12.94%).Unique contribution to theory, practice and policy: The process had revealed the alternative energy potentials and consequential implication on the biochemical composition of the effluents

ASSESSMENT OF GROSS ALPHA, GROSS BETA RADIOACTIVITY AND HEAVY METALS CONCENTRATION IN SOIL SAMPLES IN WUKARI, TARABA STATE

This study is aimed at assessment of gross alpha, gross beta radioactivity and heavy metals concentration in soil samples. It involves ten (10) different locations in Wukari, Taraba state. The analyses included gross alpha and beta radioactivity using MPC-2000-DP and the measurement of heavy metals concentration using Atomic Absorption Spectroscopy (AAS). The results obtained showed that the gross alpha activities ranged from (0.0027±0.0003- 0.0177±0.0001) Bq/g while the gross beta ranged from (0.0125±0.0020-0.2379±0.0012) Bq/g .The present study indicates that the nature of soil in the study area has a very low level radiation. Measured values of gross alpha contamination in soil samples collected from different locations in the study area were found below the permissible range of WHO. The total heavy metals Cu, Pb, Zn, Co,Fe were evaluated in the soil samples. Based on the findings concentrations of these soils were analyzed showed significantly higher concentrations which follow the order Pb˃Fe˃Cu˃Co˃Zn, comparing with WHO standards guidelines, the results revealed that food samples planted on this soil could be disastrous to human health

EFFECT OF CHEMICAL REACTION ON MIXED CONVECTION FLOW OF AN EXOTHERMIC FLUID IN A VERTICAL POROUS CHANNEL

In this paper, effect of chemical reaction on mixed convection flow of an exothermic fluid in a vertical porous channel is considered. The dimensionless ordinary differential equations were solved using differential transformation method (DTM) to obtain the expression of velocity, temperature and concentration from momentum, energy and mass equations. The effect of Skin friction, Nusselt number and Sherwood number with various parameters on velocity, temperature and concentration are presented and discussed. The result indicated that the velocity, temperature and concentration increases with the increase in suction/injection and mixed convection parameters.

HYDROMAGNETIC MIXED CONVECTION FLOW OF AN EXOTHERMIC FLUID IN A VERTICAL CHANNEL

In this paper, Hydromagnetic mixed convection flow of an exothermic fluid in a vertical channel is considered. The dimensionless ordinary differential equations were solved using differential transformation method (DTM) to obtain the expression of velocity, temperature and concentration. From momentum, energy and mass equations. The effect of Skin friction, Nusselt number and Sherwood number with various parameters on velocity, temperature and concentration are presented and discussed. The result indicated that the effect of t, is to increase the Skin friction while K increases it at upper plate and suppresses it at lower plate.