HEAVY – FERMION SEMICONDUCTOR BEHAVIOUR AND PHASE TRANSITION OF CECU2SI2 IN THE SINGLE SITE IMPURITY ANDERSON MODEL

Omamoke Onorenyakpo Enaroseha¹ and Edwin Igherighe²

¹Department of Physics, University of Benin,Benin City, Nigeria

²Department of Physics, College of Education, Agbor, Nigeria

Email:enarosehaomamoke@gamil.com

ABSTRACT

We investigate the electronic properties of CeCu₂Si₂ in the low temperature regime using the Exact-Diagonalization technique. This technique allows the study of the physics of strongly correlated electron systems. We show that when the hybridization term in the Single Site Impurity Anderson Model (SIAM) is increased: (1) there is a smooth phase transition from an antiferromagnetic phase to a ferromagnetic phase and (2) there is a semiconductor gap ∆ between the singlet state and triplet states energies as the lattice sites and dimensions are increasing. The basic features of this theory are in qualitative agreement with the experimentally observed heavy-fermion semiconductor of some rare-earth compounds.

Keywords: Transition point, hybridization gap, Antiferromagnetic phase, Ferromagnetic phase

ASSESSING THE PERFORMANCE OF A DESIGNED CONSTRUCTED CHEAP ROOM LOOP ANTENNA OPERATING AT VHF/UHF BAND

Yunusa, I.Y¹, Yakub N¹ and Hussaini, L²

¹Department of Physics, University of Maiduguri, Maiduguri, Borno State.

²Department of Science Lab. Technology, Federal Polytechnic, Bida, Niger State

Email: yunbal4real@yahoo.com

ABSTRACT

The parameters that influence the performance of loop antennas were computed and analysed. This aids in designing and constructing a cheap room loop antenna operating at the frequency of 288MHz →300MHz. The designed and constructed loop antenna efficiently works within the quoted VHF/UHF Band.

SOME EXACT SOLUTIONS OF BOUNDARY LAYER FLOW IN POROUS MEDIA-II

Basant K. J .H.A, and M.L. Kaurangini

¹Department of Mathematics, Ahmadu Bello University, Zaria

²Department of Mathematical sciences,Kano University of Science and Technology, Wudil

ABSTRACT

Some exact solutions are presented for the unsteady boundary layer flows of a homogenous, viscous, incompressible fluid bounded by (i) an infinite rigid oscillating flat plate or (ii) two parallel rigid oscillating flat plates as presented in [7] was extended to porous media. An explicit representation of the velocity fields for both the configurations has been given. The structures of the associated periodic boundary layers are determined with physical interpretations as in [4]. Several results of interest have been recovered as special cases of this general theory. The Heaviside operational calculus along with the theory of residues of analytic functions is adopted in finding the solutions.

PERFORMANCE OF A LOCALLY DESIGNED SOLAR WATER HEATER

(SOLAR WATER KETTLE)

Sanusi Y. K. and Ajadi D.A     

Department of Pure and Applied Physics

Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

Email: sanusiyekinni@yahoo.com

ABSTRACT

A Built-in-Storage Solar Water Heater of 4.5 × 10^-3 m³ liter was designed, constructed and tested for its efficiency. It was observed that the highest temperature of the water obtained is 48^oC. This temperature was achieved between the hours of 16.00 and 16.30 hours local time. The efficiency of the kettle was found to be 1.65%, which is very small due to the construction size. When compared with previous work, the solar water heater that produces up to efficiency of 30% has surface area of 2.6m² while in this work surface area is 0.15m².Keywords: Temperature, Heater, Solar radiation, Efficiency, Absorber plate

AN ASSESSMENT OF SOME ANION LEVELS OF RIVER GONGOLA IN ADAMAWA STATE, NIGERIA

O.N. Maitera, D. Y. Shinggu

Department of Chemistry Adamawa State University, Mubi Nigeria.

E-mail olivermaitera@yahoo.com, shinggudy2@yahoo.co.uk

ABSTRACT

The assessment of anion levels of River Gongola in Adamawa state was carried in ten sampling areas. Sampling was done in the months of February, March, and April 2007, representing dry season, while the months of July, August and September 2007, represent the wet season. Water samples were collected and analysed using DR/2010 spectrophotometer (LaMotte Co. 2000). The mean concentration of chloride ranged between 58.00 ± 1.22 and 90.83 ± 3.77mg/l for dry season and 53.33 ± 3.21 and 71.67 ± 5.21mg/l for wet season, sulphate was between 16.00 ± 3.02 and 37.67 ± 4.11mg/l for dry season and 48.33 ± 3.42 and 65.33 ± 8.21mg/l for wet season; while that of total nitrate is between 2.20 ± 0.51 to 5.14 ± 0.77mg/l for dry season and 18.0 ± 2.02 and 32.50 ± 4.32mg/l for wet season.  The mean seasonal variation of NH₃-N, NH₄⁺, NH₃, NO₃-N, NO₃^– were reported with highest value of 32.50±0.00 observed in nitrate and lowest value of 0.20±0.05 was observed in phosphate. The values for the wet season were higher than that of dry season which may be due to run-off from farms as a result of fertilizer and herbicide application and animal faeces around the sampling area. All the values were within the current permissible limits of the WHO and NAFDAC. The percent ion concentrations were in the following order Cl^– > CO₃^2- > SO₄^2- > NO₃^— > total nitrate > PO₄^3-. The seasonal variations of the showed that the levels of anions were higher during the wet season than the dry season.Keywords:  Season, River Gongola, Assessment, Anion levels, Pollution

COGNITIVE SCIENCE: INTEGRATIVE PERSPECTIVE IN ARTIFICIAL INTELLIGENCE AND HUMAN-COMPUTER INTERACTION

Omidiora E. O. ¹, *Ismaila W. O.¹, Ajayi A. O ¹ and Ogundele L. A. ²

¹Department of Computer Science, Ladoke Akintola University of Technology, Ogbomoso

² Department of Computer Science, Osun State College Of Education, Ilesa

ABSTRACT

Cognitive science, whose genesis was interdisciplinary, shows signs of reverting to disjoint collection fields which include psychology (especially cognitive psychology), computer technology, linguistics and psycholinguistics, philosophy (especially philosophy of mind), neuroscience, logic, anthropology and biology (including biomechanics). This paper focused on effect of cognitive science on computer science, especially artificial intelligence (AI) and Human-computer interaction (HCI). Also, various ways by which cognitive science was integrated into artificial intelligence were analysed.

Keywords Cognitive Science, Cognitive Engineering, Artificial Intelligence

EFFICIENCY IN HEALTH CARE DELIVERY

A DEA ANALYSIS OF HOSPITALS AT THE SECONDARY HEALTH CARE LEVEL IN PLATEAU STATE, NIGERIA

¹Davwar, Philemon Polycarp; ² Adelaiye, Peter O. and ³Nathan, Nachandiya

^1&2Department of Mathematics and Statistics, Federal Polytechnic Idah, Kogi State.

³Department of Statistics and Operations Research, Federal University of Technology, Yola

E-mail: ppdavwar@yahoo.com

ABSTRACT

Data Envelopment Analysis (DEA) has evolved into one of the most efficient tools for analysis of resource utilization in most systems. The operations of hospitals at the secondary health care level was analysed using DEA. Data on hospital operations were collected and analyzed using DEA EXCEL Solver add-in Zhu (2003). Benchmark and target analyses were also carried out. The results show a generally poor performance for the hospitals at this level. The target analyses show that most hospitals would have done better without a Medical Doctor. The study therefore recommends among others, a DEA analysis involving value judgment for this and similar cases.

Key words: Envelopment, Benchmark, Efficiency, Performance

APPLICATION OF INDUCED POLARIZATION METHOD TO DELINEATE SULPHIDE ORE DEPOSIT IN OSINA AREA OF BENUE STATE, NIGERIA

                Olowofela J.A*, Ajani O.O** and Oladunjoye, M.A***

*Department of Physics, University of Agriculture, Abeokuta, Nigeria

**Department of Physics and Solar Energy, Bowen University, Iwo, Nigeria

***Department of Geology, University of Ibadan, Nigeria

E-mail: aj_ani2000@yahoo.com

ABSTRACT

The occurrence of sulphide ore bodies in Osina area of Benue state has been reported earlier in the geology of Nigeria map, but the extent and abundance of the mineral was not known. In this work, we investigated the thickness and depth of the mineral deposit.Induced Polarization (IP) survey employing the dipole-dipole array was conducted. The survey consisted of three lines, each of length 600m with a dipole separation of 30m in the E-W direction covering an area of approximately 1km². A total of 150 data points each were taken for three lines in the survey area. Measurements were taken for chargeability in the time domain and Percentage Frequency Effect (PFE) in the frequency domain. Using an iterative process, an inversion scheme was carried out on the measured data to find a model M that minimizes the objective function φ_m subject to fitting the data to a specified degree. This model was formed and used to solve the optimization problem defining a global objective function Φ. Measured and calculated apparent chargeability’s are plotted as pseudo-sections to get the estimated depth of the ore deposit from the surface. Model generated is the section of the true estimated resistivity and chargeability.

The results showed eight anomalous zones revealing certain mineralization having attributes of galena, sphalerite and pyrite with a resistivity ranging from 100-300 ohm-m at an estimated depth of 50m. The plots of chargeability along the three traverse lines also showed a consistent range of values between 20 – 90mV/V over the distance of 90 – 100m along the lines. Different regions of high anomaly are evident in the inverse model resistivity section for the first two lines but due to bulk resistivity of the disseminated body investigated, no distinct zone could be localized. The quantitative interpretation showed that the range of overburden thickness to the top of base-metal sulphide is about 30m.

Based on the result of this investigation, it was concluded that the sulphide ore in this area is not economically viable and can be best mined through shafts or tunnels due to the depth and dipping shape of the deposit.

Key words:   Sulphide ore bodies, Osina area, Induced Polarization, Chargeability,

Percentage Frequency Effect (PFE), Overburden thickness and recoverable deposit.

ECONOMIC MODELS FOR SOFTWARE SECURITY

Akwuwuma Veronica and Egwali Annie

Department of Computer Science

 University of Benin, Benin City, Nigeria

E-mail: vakwukwuma@yahoo.com; egwali.annie@yahoo.com

ABSTRACT

The economics of software security is an evaluation of the cost and benefits of adding security to software. Most firms are mainly concerned with making software functional without paying much consideration to security because of the rigors of adding security to software and because buyers have no low cost method of ascertaining quality. These nonchalant practices will only give attackers an upper hand in the race for compromising system software.  It is crucial therefore that software developer protect their customers by embedding security and confidentiality into their software. Security should be a factor in software development undermining the cost.  In this paper, we therefore focus on the economics of building security properties into software application. To cover the entire dimension of the economics of software security, we incorporate cost-benefit analysis models^[1] to incur the cost of adding security properties into software development. We also expanded our security framework to integrate the security properties^[2] and incorporated encryption, TCP/IP hardening and Buffer overflow checks.

 Keyword:  Cost, Security, Software, Economics, Attacks

FACIES CHARACTERISATION OF WELL A, FIELD Y, NORTH-EASTERN NIGER DELTA

M, E Okiotor and O.I Imasuen

Department of Physics and Energy Studies

Western Delta University, Oghara

ABSTRACT

The facies characteristics of well A in the field Y were studied using wireline log signatures and data derived from them and cores. The lithostratigraphy, facies types which helped in the interpretation of the depositional environments and their characteristics were read from the wireline logs. The logs were environmentally corrected and normalized. The core data analysis helped in confirming the properties of the various facies types and the effective establishment of the facies boundaries.

Keywords: Facies, wireline logs, characteristics, depositional environment.