Free convective flow of heat generating fluid through a porous vertical channel with velocity slip and temperature jump

AbstractThis paper investigates the unsteady free convective flow of heat generating/absorbing fluid through a porous vertical channel with velocity slip and temperature jump. Exact solution of the oscillatory flow problem is obtained in the slip flow regime through a microchannel. The effects of various flow parameters on the temperature and velocity profiles together with the influence of the velocity slip and temperature jump on the rate of heat transfer and the skin friction are presented and discussed

Functions of Artifactual Code as Non-Verbal Communication in Yoruba Novels

Non-verbal communication is a wordless form of communication whereby a message is initiated from a source and channeled through a medium to a receiver who receives processes and decodes the information. Artifactual code is a form of non-verbal communication used in body adornment which has received less attention by scholars especially in Yorùbá novels. This paper filled the gap as it examined the functions of artifactual code as a form of non-verbal communication in Yorùbá novels, the contexts in which it operates with a view to establishing its communicative value. This study is grounded on the theory of semiotics. The major elements of semiotics applied are symbol and index. However, eight Yorùbá novels were purposively selected as sample and classified into three categories by this researcher for the purpose of this study. Also, the form of non-verbal code identified in the novels which is artifactual code is situated in four contexts, namely, social, religious, political and cultural contexts. This enhanced the semiotic functions performed by the novels.Key words: Artifactual code; Yorùbá novels; Symbol; Index; Semiotic

a Study of non-verbal communication in the Nigerian (Yorùbá) novels: The side code

Non-verbal communication is a very important aspect of communication which plays a very crucial role in interpersonal relationship. Its role in the accentuation of verbal communication cannot be overemphasized. Existing literature has not given enough attention to side code as a form of non-verbal communication in the Yorùbá novel. This study fills the gap as it examines side codes, the contexts in which they occur in Yoruba novels with a view to establishing its communicative value. The study adopts semiotic theories of Saussure and Charles Sanders Peirce. Four Yorùbá novels: Ìrìnkèrindò Nínú Igbó Elégbèje and Ògbójú Ọdẹ Nínú Igbó Irúnmo̩lẹ̀. By D.O. Fagunwa, Ojú rí́́́ by Kola Oni and Ṣaworoidẹ by Akinwumi Isola were purposively selected because they have elements of side code and were subjected to semiotic and textual analyses. Side code helps in cultural determinism in the codification of disaster, chaos, lopsidedness, disappointment, success, identification of prince and complementarity. Key Words: Side code; Semiotics; Purposive sample; Yorùbá novel

A One Step Method for the Solution of General Second Order Ordinary Differential Equations

In this paper, an implicit one step method for the numerical solution of second order initial value problems of ordinary differential equations has been developed by collocation and interpolation technique. The introduction of an o step point guaranteed the zero stability and consistency of the method. The implicit method developed was implemented as a block which gave simultaneous solutions, as well as their rst derivatives, at both o step and the step point. A comparison of our method to the predictor-corrector method after solving some sample problems reveals that our method performs better

Modified Block Method for the Direct Solution of Second Order Ordinary Differential Equations

The direct solution of general second order ordinary differential equations is considered in this paper. The method is based on the collocation and interpolation of the power series approximate solution to generate a continuous linear multistep method. We modified the existing block method in order to accommodate the general nth order ordinary differential equation. The method was found to be efficient when tested on second order ordinary differential equation

Numerical Computation of Electric Field and Charge Structure of a Typical Tropical Thunderstorm

Cloud charge dynamics are usually determined from ground measurements. Where in-situ cloud measurements are available they sometimes modify the cloud structure; and this can be expensive, and merely diagnostic at best. In this work, Poisson integral formula is simplified by adapting the Bessel functions to obtain the cascaded potential gradients at any point on ground as a result of charge distribution in cylindrical volumes. The model represents the cloud charges as a vertical sequence of axially aligned, uniformly-charged densities of cylindrical disk(slices), The resulting expressions for the potential gradient is solved numerically as a functions of  normalized vertical and horizontal distances to model the vertical electric field and potential profiles below a typical thunderstorm. Keywords: Electric field, Bessel functions, Charge structure, Cylindrical charge model, Lower positive charge center

Solving General Second Order Ordinary Differential Equations by a One-Step Hybrid Collocation Method

A one-step hybrid method is developed for the numerical approximation of second order initial value problems of ordinary differential equations by interpolation and collocation at nonstop and step points respectively. The method is zero stable and consistent with very small error term. Numerical experiment of the method on sample problem shows that the method is more efficient and accurate than the results obtained from our earlier methods

Designing a new molecular probe : the potential role for Tilmanocept (Lymphoseek) in the assessment of patients with painful hip and knee joint prostheses

There is a long history of nuclear medicine developments in orthopaedics beginning in the early 20th century. Technetium-99m (99mTc) has a short half-life of six hours, emits 140 keV gamma rays and is the most widely used isotope, imaged with the Anger (gamma) camera. Gamma image quality and test sensitivity in painful prosthetic joints can be improved with single photon emission computed tomography (SPECT) and SPECT/CT. Positron Emission Tomography-Computed Tomography (PET-CT) with Sodium Fluoride (18F-NaF) and 18Fluorine-fluorodeoxyglucose (18F-FDG) PET have promising and limited roles respectively in the investigation of painful prosthetic joints. New SPECT/CT and PET-CT isotopes targeting activated macrophages with 99mTc Tilmanocept (Lymphoseek®) and 68Gallium labelled Tilmanocept respectively show potential as agents to demonstrate wear particles ingested by macrophages and multinucleated giant cells. An imaging algorithm using SPECT and/or PET agents is proffered as a cost effective way of speedily and accurately arriving a diagnosis. Methods: Review of the historical role of nuclear medicine in orthopaedics and research into the potential role of new radiopharmaceutical agents was undertaken. Guidelines and algorithms for the imaging of complicated joint prosthesis are provided. Results: There is an established role for nuclear medicine in orthopaedics and particularly in the investigation of complicated joint prostheses. Imaging with Tilmanocept provides new opportunities to shorten the time to diagnose loosened and infected joint prostheses. Conclusion: There is a potential new role for Tilmanocept, which can be utilised with both PET-CT and SPECT-CT technologies. Tilmanocept is a relatively new radiopharmaceutical which has a potential role in the imaging assessment of painful joint prosthesis

Numerical Simulation of Electric Field and Charge Structure within an Isolated Thunderstorm

The study of electrical structure of thunderstorm is a deterministic factor in characterizing the behavior of lightning. It is impossible to measure the value of electric field at every point within the thunderstorm, even when the in situ measurements are made, they are done along the path of balloon-borne instruments or other methods employed in the measurement. The average data obtained from past measurements were employed in determining the electric field generated by the thunderstorm as observed along the horizontal distance using the cylindrical charge model. The data consisted of a screening charge layer firstly located “between” 1.8-2.0 km and later between 10.0-10.2 km respectively above the ground level (agl) to see the effect of positioning on the resultant computation. The lower positive charge center with radius ranging from 0.5 km to 2.0 km was placed at various heights between 2.0 and 6.0 km. This is to determine the effect of cloud base height on the resulting field profile. The main negative charge is accommodated between 4.0 and 7.5 km and the upper positive charge layer existed between 7.5- 10.0 km agl for a cloud base height of 2.0 km and 6.0- 9.5 km agl for a negative charge layer, 7.5- 11.0 km agl for upper positive charge with a cloud base of 4.0 km high. The resulting potential gradient (PG) profiles were obtained for spatial distribution with screening charge layer playing no active role in the thunderstorm electrification. The effects of wind shear due to increasing wind speed with height were also investigated to have a clear picture of the cloud charge dynamics; hence the vertical PG patterns produced by a moving thunderstorm for various cloud cell life-times were modeled. The results showed that a typical tropical thunderstorm can exhibit charge layer more than the normal tripolar structure, and the pocket of lower positive charge can be more than one or larger than the usual size. Wind shear was found to enhance lightning discharges at the surface of charge discontinuities. Keywords: Potential gradient, Wind shear, Cloud charge, Lower positive charge center, Noninductive charging.

One Step Continuous Hybrid Block Method for the Solution of y'''=f(x,y,y',y'')

In this paper, we present a block method for the direct solution of third order initial value problems of ordinary differential equations. Collocation and interpolation approach was adopted to generate a continuous linear multistep method which was then solved for the independent solution to give a continuous block method. We evaluated the result at selected grid points to give a discrete block which eventually gave simultaneous solutions at both grid and off grid points.  The one-step block method is consistent and A -stable, with good region of absolute stability. Experimental results confirmed the superiority of the new scheme over an existing method. Keywords: consistent, convergent, collocation, hybrid points, independent solution, interpolation, zero stabl