Accurate Four-Step Hybrid Block Method for Solving Higher-Order Initial Value Problems

يركز هذا البحث على التعامل مع طريقة عددية ذاتية البدء والتي يمكن استخدامها لايجاد التكامل بشكل مباشر لمسائل القيم الابتدائية للمعادلات التفاضلية الاعتيادية ذات الرتب العالية. هذه الطريقة مشتقة من تقريب متسلسلة القوى مع المعادلات الناتجة التي تم تقديرها في الشبكة المحددة ونقاط خارج الشبكة.تم تطبيق الطريقة باستخدام طريقة االبلوك  كمكامل عددي لمسألة القيمة الأبتدائية ذات الرتب الأعلى. تم التحقق من الخصائص الأساسية لطريقة البلوك والتحقق من أدائها ثم تنفيذها ببعض االتجارب الاختبارية للتحقق من دقة الطريقة وتقاربها.This paper focuses on developing a self-starting numerical approach that can be used for direct integration of higher-order initial value problems of Ordinary Differential Equations. The method is derived from power series approximation with the resulting equations discretized at the selected grid and off-grid points. The method is applied in a block-by-block approach as a numerical integrator of higher-order initial value problems. The basic properties of the block method are investigated to authenticate its performance and then implemented with some tested experiments to validate the accuracy and convergence of the method

The Impact of Modern Technologies on Peace, Security and Development in Africa

Since the independence processes in the African continent, armed conflicts, peace, security and development has remain contesting issues that have raised concern and attention both at the national and international level. In recent years, most of these issues have heightened the tempo which has given rise to their strong deliberation in the region of Africa. Although, efforts are been made in different quarters in the continent particularly, the African Union to deal with these teething issues still, the growing pace and role of technologies currently in the world has not been appropriately and adequately explored to respond to these concerns in Africa. However, this paper does not aim to give a comprehensive impression of the landscape of new technologies, but focuses on the opportunities and challenges these technologies present to the African continent and how best these technologies could be anchored in the African Union agenda to address the challenges before it. The paper further offers concrete recommendations on the best practices of these new technologies in key areas that would propel Africa in the attainment of sustainable peace, security and development in the region

Thermodynamic parameters of elasticity and electrical conductivity of reinforced natural rubber (nr) vulca nizates

The thermodynamic parameters (change in free energy of elasticity, DGe; change in enthalpy of elasticity, DHe; and change in entropy of elasticity, DSe) and the electrical conductivity of natural rubber composites reinforced separately with some agricultural wastes have been determined. Results show that the reinforced composites are relatively more ordered and more spontaneous to elasticity than the unreinforced composite. These more ordered composites were observed to conduct electricity better than the unreinforced. The inclusion of the agricultural wastes examined in the formulation of natural rubber composite enhances the elasticity and the electrical conductivity of natural rubber.  KEY WORDS: Thermodynamic parameters of elasticity, Natural rubber, Electrical conductivity of natural rubber composites, Reinforced composites, Unreinforced composites Bull. Chem. Soc. Ethiop. 2004, 18(2), 229-234

Serologic evidence of Equine H7 Influenza Virus in polo horses in Nigeria

No Abstrac

Biogradable Starch Film from Cassava, Corn, Potato and Yam

Starch is the major carbohydrate reserve in plant tubers and seed endosperm where it is found as granules each typically containing several million amylopectin molecules accompanied by a much larger number of smaller amylose molecules. Starch films were prepared from starch extracted from cassava, corn, potato and yam with and without plasticizers to evaluate the effects of the type and quantity of plasticizer on the mechanical properties of the starch films obtained. Ubbelohde viscometer was used to determine the intrinsic viscosity and molecular weight of the prepared films in dimethylsulfoxide (DMSO)/water solution (90%/10% v/v). The molecular weights of the films were found to range from 2.70 × 1013 – 2.14 × 1017 for films prepared from corn starch, 2.86 × 1010 – 1.01× 1017 for films prepared from yam starch, 2.69 × 1013 - 3.97 × 1017 for films prepared from potato starch and 4.15 x 106 - 4.05 × 108 for films prepared from cassava starch. The molecular weights of the films were found to decrease with increase in the plasticizer content because the bonds between starch-starch molecules were replaced with the bond between starch-water molecules. This led to the reduction in the chain length of both the amylopectin and amylose, and hence reduction in the molecular weight average. Amylose and  amylopectin molecules contribute to mechanical properties and hygroscopic properties of starch. The effects of plasticizer on mechanical properties of film prepared from corn starch and yam starch were investigated at six levels of plasticizer content. The tensile strength of the films prepared from corn starch ranged from 0.10MPa - 5.20MPa, 0.05MPa - 5.10MPa for films prepared from yam starch, 0.09MPa - 5.74MPa for films prepared from potato starch and 0.51MPa – 5.33MPa for films prepared from cassava starch. The value of Young’s modulus was found to range from 0.39MPa -104.06MPa for films prepared from corn starch, 0.33MPa - 49.32MPa for films prepared from yam starch, 0.36MPa – 191.33MPa and 3.14MPa – 97.5MPa for films prepared from cassava starch. The tensile strength of films was influenced by the type and the content of plasticizer used.Generally, the Young’s modulus and the tensile strength of the films decreased with increase in plasticizers content, with concurrent increase in elongation at break and tensile strain of the films due to increase in ductility of the films. Glycerol exhibited more plasticizing effect on both starches than sucrose due to the hygroscopic or hydrophilic nature of glycerol. Keywords: biodegradable, starch films

Mathematical Model for Estimating the Standard of Living of Nigerians and Achieving the First Agenda of the Vision 20; 2020

The research is concerned with the development of a mathematical model for Nigerians’ standard of living and the achievement of the first item on the vision 20; 2020 agenda. The model was optimized to know whether it is possible for humans to have maximum or minimum standard of living. The optimization result showed that there is no specific standard of living value that can momentarily stop human existence but the snag indicated based on the work is that, those whose standard of living is critical (very close to zero percent) can take to negative ways of getting income in order to survive and thus, pose a challenge to the achievement of the overall vision 2020. Equally, the model was validated and observation about the model’s results and the questionnaire data was made, indicating that the results from our model and the questionnaire data have a higher degree of correlation of approximately 70%  or +0.7 ranking correlation coefficient and thus recommending the model as a standard measure for estimating the standard of living. Key words: MDGs, Government Parameter, Vision 20-2020, Social status, HDR, MPI, constraint, Saddle-point, extremum

Raznolikost antigena nigerijskih sojeva virusa influence konja H3.

Antigenic variation among three recent isolations of equine-2 H3N8 influenza viruses from Ibadan, Nigeria is reported. Antigenic analysis with panels of monoclonal antibodies (mAbs) and polyclonal antisera indicated that the three viruses were antigenically divergent, although they were all H3N8 subtype related to other equine 2 -viruses isolated between 1963 and 1987. Results of virus protein synthesis investigated by pulse-chase experiments showed heterogeneity among the proteins of the ribonucleoprotein complex and the haemagglutinin glycoproteins, which were not cleaved in tissue culture. The results of this study indicate that equine H3 HAs have evolved by a process of evolutionary divergence and mutational changes, as confirmed by genetic analysis in another study. The results also showed that antigenic variation occurs among equine H3 influenza viruses and that H3 viruses with antigenically different HA molecules could co-circulate in equine populations.Obra|ena je raznolikost antigena tri nova izolata nigerijskih sojeva virusa influence konja H3N8 iz Ibadana u Nigeriji. Analiza antigena s pločama monoklonskih protutijela (mAbs) i poliklonskim antiserumima pokazala je da su tri virusa antigenski različiti, iako su svi bili H3N8 podtipa i srodni s drugim virusima influence konja serotipa A2 izoliranim od 1963. do 1987. Rezultati sinteze virusnog proteina istraženi sa "pulse-chase" pokusima pokazali su heterogenost proteina ribonukleinskog kompleksa i hemaglutininskih glikoproteina, a koji nisu rasli u kulturi tkiva. Rezultati ovog istraživanja naznačuju da su konjski H3 HAs nastali procesom evolucijske divergencije i mutacijama, a to je potvr|eno i genetskim analizama u drugoj studiji. Rezultati tako|er pokazuju da se pojavljuju antigene varijacije među H3 virusima konjske influence i da H3 virusi s antigeno različitim HA molekulama mogu zajedno cirkulirati u populacijama konja

Raznolikost antigena nigerijskih sojeva virusa influence konja H3.

Antigenic variation among three recent isolations of equine-2 H3N8 influenza viruses from Ibadan, Nigeria is reported. Antigenic analysis with panels of monoclonal antibodies (mAbs) and polyclonal antisera indicated that the three viruses were antigenically divergent, although they were all H3N8 subtype related to other equine 2 -viruses isolated between 1963 and 1987. Results of virus protein synthesis investigated by pulse-chase experiments showed heterogeneity among the proteins of the ribonucleoprotein complex and the haemagglutinin glycoproteins, which were not cleaved in tissue culture. The results of this study indicate that equine H3 HAs have evolved by a process of evolutionary divergence and mutational changes, as confirmed by genetic analysis in another study. The results also showed that antigenic variation occurs among equine H3 influenza viruses and that H3 viruses with antigenically different HA molecules could co-circulate in equine populations.Obra|ena je raznolikost antigena tri nova izolata nigerijskih sojeva virusa influence konja H3N8 iz Ibadana u Nigeriji. Analiza antigena s pločama monoklonskih protutijela (mAbs) i poliklonskim antiserumima pokazala je da su tri virusa antigenski različiti, iako su svi bili H3N8 podtipa i srodni s drugim virusima influence konja serotipa A2 izoliranim od 1963. do 1987. Rezultati sinteze virusnog proteina istraženi sa "pulse-chase" pokusima pokazali su heterogenost proteina ribonukleinskog kompleksa i hemaglutininskih glikoproteina, a koji nisu rasli u kulturi tkiva. Rezultati ovog istraživanja naznačuju da su konjski H3 HAs nastali procesom evolucijske divergencije i mutacijama, a to je potvr|eno i genetskim analizama u drugoj studiji. Rezultati tako|er pokazuju da se pojavljuju antigene varijacije među H3 virusima konjske influence i da H3 virusi s antigeno različitim HA molekulama mogu zajedno cirkulirati u populacijama konja

LE STYLE EN TRADUCTION: UN APERÇU CONCEPTUEL

De nombreuses théorisations et de théoristes qui ont contribué aux approches du style, se présentent complémentaires sur leurs conceptions de style ou leurs approches d’étude de style ; néanmoins peu d’attention a été accordée à cette étude (du style) dans le contexte traductionnel. Certes, ce travail de recherche trace donc la conception de style et les approches conventionnelles qui guident l’étude de style en traduction littéraire en vue de mettre en évidence la valeur du style en traduction. En reconsidérant l’antiquité de style, de monisme jusqu’au pluralisme et de la cohérence à la déviation, cette théorisation a mis l’emphase sur l’avancement d’étude de style vers l’identité et l’identification, tout en soulignant que le style en traduction est « l’esprit et le feu du texte » (Boase-Beier, 2011) 1

Satisficing solutions for multiobjective stochastic linear programming problems

Multiobjective Stochastic Linear Programming is a relevant topic. As a matter of fact, many real life problems ranging from portfolio selection to water resource management may be cast into this framework. There are severe limitations in objectivity in this field due to the simultaneous presence of randomness and conflicting goals. In such a turbulent environment, the mainstay of rational choice does not hold and it is virtually impossible to provide a truly scientific foundation for an optimal decision. In this thesis, we resort to the bounded rationality and chance-constrained principles to define satisficing solutions for Multiobjective Stochastic Linear Programming problems. These solutions are then characterized for the cases of normal, exponential, chi-squared and gamma distributions. Ways for singling out such solutions are discussed and numerical examples provided for the sake of illustration. Extension to the case of fuzzy random coefficients is also carried out.Decision Science