13 research outputs found
Analysis of magnetohydrodynamics effects on convective flow of dusty viscous fluid
This paper presents a finite difference analysis of Magnetohydrodynamics (MHD) effects on convective flow of dusty viscous fluid incorporating viscous dissipation with respect to fluid and dusty particle. The criterion for the existence and unique solution is established and the properties of solution are examined. The dimensionless governing coupled non-linear partial differential equations governing the phenomenon were solved numerically using finite difference scheme. The effects of various parameters on the velocities are shown graphically and discussed. It is observed that both the velocity of the fluid φ and dust particles χ increases with an increase in Grashof number. Velocity of the fluid decreases with an increase in Magnetic parameter. Increase in Porosity parameter has little effects on the velocity of the fluid and that of the particle. Slight increase in volume faction of dust particles increases the velocity of the particles rapidly and increases moderately the velocity of the fluid. Increase in Mass concentration of dust particles decreases the velocity of both the fluid and particles. Also, considerable effect was noticed on the temperature ϑ by increasing the Eckert number, temperature also increased. Increase in the Prandtl number decreases the temperature of the fluid
Modelling fire spread reaction rate in atmospheric-weather condition
Fire spread in any fire environment is a thing of great concern as wind is arguably the most important weather factor that influences the spread of fire. In this paper, we present equations governing the phenomenon and assume the fire depends on the space variable x . Analytical solution is obtained via perturbation method, direct integration and eigenfunction expansion technique, which depicts the influence of parameters involved in the system. The effect of change in parameters such as Peclet mass number and Equilibrium wind velocity are presented graphically and discussed. The results obtained revealed that both Peclet mass number and Equilibrium wind velocity enhanced oxygen concentration during fire spread
Analytical simulation of two dimensional advection dispersion equation of contaminant transport
The study was designed to investigate the analytical simulation of two dimensional advection dispersion equation of contaminant transport. The steady state flow condition of the contaminant transport where inorganic contaminants in aqueous waste solutions are disposed of at the land surface where it would migrate through the verdoze zone to underground water is considered. We solved the two dimensional advection dispersion equation analytically which is solute transport model without sorption or degradation using change of variable method. We critically reviewed two dimensional equations depicting the transport of contaminant in groundwater and investigate with the help of graphical representation the effect of Peclet number on the concentration of contaminant and established real life interpretation of contaminant transport. Two cases were considered, when Peclet number is less than one and when Peclet number is greater than one. The result obtained revealed that the contaminant concentration increases along x direction and decreases along y direction for both values of peclet number greater than one and less than one. The study has contributed to knowledge through the method utilized to achieve the model analytical solution and the Physical interpretation of Peclet number. From the analysis, we recommend for further studies on the contaminant transport which also depends on the available data, that the extension of advection –dispersion model to three dimensions and comparison of travel time of contaminant transport solution to Kinetic or multi-component mode.Keywords: Contaminant, Seepage Velocity, Aquifer, Advection-dispersion Equation, change of variable method
Modeling and analytical simulation of a smouldering carbonaceous rod
Modeling of pyrolysis and combustion in a smouldering fuel bed requires the solution of flow, heat and mass transfer through porous media. This paper presents an analytical method for describing the smouldering of a porous carbonaceous rod. We assume that no local thermal equilibrium exist between the phases. Also, the initial temperatures are assumed to depend on space variable. We prove the existence and uniqueness of solution of the model by actual solution method. The coupled non-linear partial differential equations describing the phenomenon have been decoupled using parameter-expanding method and solved analytically using eigenfunction expansion technique. The results obtained were discussed. The study shows that the Frank-Kamenetskii number, Scaled thermal conductivity of gas and solid phases and Species diffusion coefficient have a significant effects on the slow burning process associated with porous carbonaceous rod.Keywords: Pyrolysis, smouldering, combustion, carbonaceous rod, pyrolysis reactions, analytical solutio
Modeling and analytical simulation of high-temperature gas filtration combustion
High temperature filtration in combustion and gasification processes is a highly interdisciplinary field. Thus, particle technology in general has to be supported by elements of physics, chemistry, thermodynamics and heat and mass transfer processes. Presented in this paper is the analytical method for describing hightemperature gas filtration combustion in an inert porous medium. We assume the porous media is highly permeable and both the contact time between the phases and the rate of oxidizer diffusion through the gas stream to the surface of the solid particles where the reaction occurs are not large. Also, we assume that the initial temperatures increase lengthwise. The coupled nonlinear partial differential equations describing the phenomenon have been decoupled using the parameter-expanding method and solved analytically using eigenfunctions expansion technique. The results obtained revealed that the combustion wave is propagated and oxidizer is consumed. A self-oscillating mode of gas filtration combustion was found with variation in the values of interfacial heat transfer.Keywords: Analytical method, filtration combustion, fuel, oxidizer, porous medium, temperatur
Modeling and analytical simulation of anterior polymerization in the presence of an inert material
The ability to fabricate advanced materials with specific properties efficiently requires a complete understanding of the polymerization kinetics and the effect of several preparative variables such as temperature, monomer and initiator. This paper presents an analytical method for describing anterior polymerization in two adjacent thin layers. Both the initial temperatures and initial monomer and initiator concentrations are assumed to depend on the space variable. We prove the existence and uniqueness of solution of the model by actual solution method. The equations are solved using parameter-expanding method and eigenfunctions expansion technique. The results obtained were discussed. The study shows that the Frank-Kamenetskii number and frequency factors of the two reactions have significant effects on the propagation of the polymerization wave.Keywords: Polymerization, anterior polymerization, polymers, Arrhenius kinetics, parameter-expanding method, eigenfunctions expansion techniqu
Characterization and Taxonomic Classification of Soils in Onigambari Forest Reserve South Western Nigeria
A soil survey of Onigambari forest reserve in Oyo State, Nigeria was carried out. Three soil mapping units Established-Teak-Plantation (ETP), Natural-Forest (NF) and Farm-Land (FL) were identified with observation base on vegetative pattern. Morphological properties of the study area show that the soil unit ETP is deep and texture ranges from loamy-sand at the surface to sandy clay loam in the subsurface. The soil unit NFand FL is not deep due to presence of hard pan but the texture ranges from sandy-loam to sandy-clay and loamysand to sandy-clay respectively. Physical properties of the soils showed the bulk density of the soils to be moderately good for growing plant with high porosity. The soils chemical properties indicate that the pH value of the soils in ETP, NF and FL are slightly acidic and organic-matter was very low in the soils of ETP compared to NF and FL soils. The total-nitrogen values of the soils in the area changed irregularly with depth and values ranged from 0.028 to 0.1g kg1 in ETP, 0.05 to 0.25g kg-1 in NF, the value ranged from 0.03 to 0.26 g kg-1 in FL. 0.03 to 0.26 g kg-1. According to USDA soil Taxonomy system, all the profiles pits in the study area showed distinguishing characteristics of the order Alfisols, therefore the soils are classified as Alfisols. Profile in the Established-Teak-Plantation is classified as Typic isohyperthermic paleustalfs, Profiles Natural-Forest and Farm-Land with petro-plinthic material within 100cm of the soil surface qualified as plinthic isohyperthermic paleustalfs
Passenger Expectations about the Quality of Service on the Inter-City Rail System in South-West Nigeria
Rail transport is essential for economic and industrial development. Passenger Perceptions of Service Quality on the Inter-City Rail System in South-West Nigeria are investigated in this study. To achieve this goal, a descriptive research design was utilised to analyse data obtained by a questionnaire survey from 300 passengers on a single route. The passengers were chosen using a convenient/purposive selection approach, and the respondents were chosen using simple random sampling procedures. With the use of SPSS, the data acquired through the questionnaire was examined utilising statistical tools such as descriptive and inferential analysis. Security and safety measures have a considerable impact on passenger happiness (R2 = 0.762, p value=0.000), while rail accessibility has a large impact on passenger satisfaction (R2 = 0.762, p value=0.000). The study’s main finding is that passengers’ evaluations of the service quality provided by the intercity rail system were mediocre. As a result, basic requirements and monitoring of passengers’ assets must be carefully verified to ensure the safety of their possessions, and the government should strive to establish a strong road network so that passengers who use rail service regularly may access rail stations more easily. Keywords: Accessibility, Rail service quality, passenger satisfaction DOI: 10.7176/EJBM/14-10-11 Publication date:May 31st 202
Mathematical Modeling of Effect of Pumping Rate on Contaminant Transport in Riverbank Filtration System
Riverbank filtration (RBF) is a natural technology that is used for river water treatment. This research seeks to investigate the effect of pumping rate on the transport of colloids in RBF. However, this work considered Dissolved Organic Matter (DOM) as a nutrient for bacteria. The mathematical model consists of groundwater flow equation and colloids concentration equations. The equations were solved analytically using parameter expanding method and Eigen function expansion techniques. The results obtained are presented graphically and discussed. It was observed that increase in pumping rate value enhance both the hydraulic head and concentration of colloids which slightly reduces the quality of pumped water from RBF.
Keywords: Riverbank filtration, analytical model, colloids, hydraulic head and pumping ra
Co-infection Model Formulation to Evaluate the Transmission Dynamics of Malaria and Dengue Fever Virus
A mathematical model of the co-infection dynamics of malaria and dengue fever condition is formulated. In this work, the Basic reduction number is computed using the next generation method. The diseasefree equilibrium (DFE) point of the model is obtained. The local and global stability of the disease-free equilibrium point of the model is established. The result show that the DFE is locally asymptotically stable if the basic reproduction number is less than one but may not be globally asymptotically stable.
Keywords: Malaria; Dengue Fever; Co-infection; Basic reproduction number; Disease-Free equilibriu