INVESTIGATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF III – Bi SEMICONDUCTOR BINARY COMPOUNDS

USING DENSITY FUNCTIONAL THEORY

           Amusa R. A. & Oyewande E. O.

Department of Science Laboratory Technology, Federal Polytechnic, Ogun – State.

Department of Physics, University of Ibadan. Oyo – State.

Email: alade_amusa2000@yahoo.com   

ABSTRACT

Study of semiconductors physics is very important as it forms the basis for power and low current engineering. Semiconductors and their compounds are of enormous importance to information technology (IT) and Opto-electronics. To this end, band-gaps play prominent role in determining some characteristic properties of these components and devices, such properties include conductivities and optical wavelengths (Madouri D. B., 2008). In this research, structural and electronic properties of binary compounds of III-Bi semiconductors were investigated with a view to know the influence of pseudopotentials on the investigated properties of the selected compounds using first-principles (ab initio) method as embedded in Quantum espresso package. The investigated results which agreed with experiments show that the bulk moduli decrease while lattice constants increase with increasing atomic orbital’s from BBi to InBi. Interestingly, only BBi has direct energy gap while the d-orbitals have spin-orbit splitting, an attribute of spintronic devies. Though the band gaps were under estimated as predicted in some related published work, precision of the predictive power of the investigating software tool needs further improvement so that the data obtained will be better relied on and form the starting point for the manufacturing/fabrication industries in Nigeria where the alternative commercial ab-intio simulation software may prove too expensive.

SCENARIO-BASED DYNAMIC AND STATIC SEPARATION OF DUTY

Nura M. Shagari¹, Buhari Wadata², Abubakar Ibrahim³, and Salisu Modi⁴

^1,2,4,5 Department of Computer Science, Sokoto State University

 ³Department of Computer Science, Sokoto State Polytechnic

Email:abunbba@yahoo.com  

ABSTRACT Role-based access control policies allow access to the resources based on the role the user has within the system and the roles specifies what accesses are allowed to users in a given roles. This paper critically analysed role-based access control for a scenario (Medical Centre). The goal was to access how dynamic and static separations of duty are extracted in real life scenario. RBAC model standard 2004 was adopted for the definition of basic RBAC system elements from the scenario using role engineering technique. The RBAC system was found to be a promising access control model that ensures data integrity, confidentiality, and availability and lower the costs of security

DETERMINATION OF THE TEMPERATURE BALANCING IN THE ATMOSPHERE AND SURFACE OF THE EARTH BY USING PHYSICS TECHNIQUES

Hayatu Abba Ibrahim

Department of Physics

University of Maiduguri, Maiduguri,Borno State, Nigeria .

Email: hayatuabbaibrahim5@gmail.com

ABSTRACT

The need to determine the balancing temperature is very important as any increase will result into climate change. Sun behaves as a blackbody with a temperature peak of 5800k, main source of heat to the Earth is solar energy, which is transmitted from the Sun to the Earth by radiation and is converted to heat at the Earth’s surface. To balance this input of solar radiation, the Earth itself emits radiation to space .Some of this terrestrial radiation is trapped by greenhouse gases and radiated back to the Earth, resulting in the warming of the surface known as the greenhouse effect. Trapping of terrestrial radiation by naturally occurring greenhouse gases is essential for maintaining the Earth’s surface temperature above the freezing point. Once, there is an increase in the equilibrium temperature in the atmosphere and the surface of the Earth, then it results into global warming, climate change, drought, desertification, flooding e.t.c. The equilibrium temperature can be derived using physics techniques.

PRACTICAL TROUBLESHOOTING IN THE FCC WITH CFD

Yousuo Digieneni

Department of Chemical Engineering

Niger Delta University, Yenagoa, Bayelsa State of Nigeria.

E-mail: digieneniyousuo@yahoo.com.

ABSTRACT

Fluid catalytic cracking (FCC) is an extremely complex process and, as a result, unit operators can encounter numerous costly and difficult FCC problems. COMSOL Multiphysics Computational Fluid Dynamics (CFD) software is used to troubleshoot the FCC process. The Port Harcourt Refinery Company (PHRC) plant was used as a case study. The ten-lump kinetic model was used in studying the hydrodynamics and yield in the FCC process. The results showed that application of COMSOL Multiphysics CFD software by an experienced FCC and CFD specialists, combining empirical data with theoretical models provides a powerful tool for successfully troubleshooting FCC problems.

RESIDUE CALCULUS AND ITS SOLUTIONS

Grema Modu Bako¹, Yagana Tayib Alkali² and Falmata Alh. Mai¹

Department of Mathematics and Statistics, Ramat Polytechnic Maiduguri, Borno State, Nigeria

Department of Pre – ND Studies, Ramat Polytechnic Maiduguri, Borno State, Nigeria

Email: gremamodubako@gmail.com

ABSTRACT

In this paper Solution of definite integrals of real variable functions and its solution and solve complicated complex integrals and its solution. The solution is used to solve some problem in science and technology. Based on the findings the integral of  is good on solving of problem science and technology than . In the solution  of calculus residue theory on electrical circuit  if t > 0 it complete the contour by a large semicircle in the upper half plane therefore we conclude that there is a current flowing in the circuit.

DETERMINATION OF MIX DESIGN OF CONRETE GRADE 30N/MM2 FOR BORED PILE

Salihu Andaa Yunusa¹, Abubakar Sani    Kazaure² and Abubakar Ahmadu³

Department of Civil Engineering

Kaduna Polytechnic, Kaduna

Email: andaayunusa@yahoo.com

ABSTRACT

The increasing failure of bridges piles and other structures faced by the construction industry in Nigeria due to weak concrete strength has made it necessary to understand the causes of failure of these structures. Research was carried out to study the mix design for concrete grade 30N/mm² for bored piles. Tests on aggregates from Kaduna and cement from Dangote were carried out and concrete cubes were cast in order to determine the compressive strength and densities. Three tests were carried out before we could arrive at satisfactory results as specified by the B.S 4450. The compressive strength of the concrete cubes at seven days and twenty eight days were determined. The strengths of the first tests were 18.7 N/mm², 20.0 N/mm², 19.4 N/mm² and 28.9 N/mm², 27.6N/mm², 26.7N/mm² respectively. The second tests were 19.6N/mm², 19.1N/mm² and 30.2N/mm², 29.9N/mm², 29.3N/mm² respectively. The third test which gave us the desired results were 24.4N/mm², 23.9N/mm², 24.3N/mm² and 32.2N/mm², 32.4 N/mm², 31.9N/mm² respectively.   The standard consistency of the cement tested was 28% with initial and final setting time of 2hr. 44 minutes and 5hr. 54minutes respectively. The densities of the cubes at seven days and 28dyas were also determined. The first set were 2.36 g/cm³, 2.34 g/cm³ 2.32 g/cm³ and 2.41 g/cm³, 2.39 g/cm³, 2.43g/cm³ respectively. The second set were 2.41 g/cm³, 2.39g/cm³, 2.43g/cm³. And 2.44g/cm³, 2.46g/cm³, 2.42g/cm³ respectively. The third set were 2.39g/cm³, 2.40 g/cm³, 2.36 g/cm³ and 2.41g/cm³, 2.39g/cm³, 2.40g/cm³ respectively.      

THE MENACE OF IP-SPOOFING VULNERABILITY IN NETWORK ENVIRONMENTS AND MITIGATION RESPONSES

F. I. Onah

Department of Computer Science

Cross River University of Technology, Calabar, Nigeria

E-mail: ikonah80@yahoo.com

ABSTRACT

The menace of IP spoofing across the globe continues to pose challenges to administrators and stakeholders in today’s networked world. Online criminals repeatedly attempt to circumvent traditional authentication safeguards through sophisticated attacks that specifically targets consumers, enterprises and citizens. The detection and prevention of malicious behaviors that can compromise the security and trust of a computer system are of primary concerns. In this paper, the challenges posed by IP-spoofing in network environments are examined. Various threat cases are identified and methods of mitigation are recommended. This enables third-party software developers to design and implement defense mechanisms against organized and systematic fraudulent attacks on computer

STATISTICAL ANALYSIS OF BIOLOGICAL DATA 

¹Aboko,Simon Igboye, ²Amadi, Innocent Uchenna, ³Mazi,Yellow Dimkpa, and ⁴Anyamele Bethel Azunna

^1&2 Department of Mathematics/Statistics, Rivers State College of Arts Science, Rumuola, Port Harcourt.

³Department of Mathematics/Statistics, Rivers State Polytechnic, Bori, Port Harcourt.

⁴Department of Mathematics/Computer Science, Rivers State University of Science and Technology, Port-Harcourt.                        Email:amadiuchennainno@gmail.com.

ABSTRACT

Mann-Whitney test is a nonparametric counterpart of the t-test for the equality of two means for normal distributions. This work developed a practical approach of investigating infant Male and infant Female deaths in University of Port Harcourt teaching hospital for the period of twenty years. We discovered that there is no significance yearly difference in Mortality of infants at α=0.05 and 0.01. This Model is found to be adequate