MODELING ANNEALED GRAIN STRUCTURES OF SOME CARBON STEELS

USING VORONOI TESSELATION

^1*Oluwole, O.O, and ²Akinkunmi, A. L

¹Department of Mechanical Engineering, University of Ibadan, Ibadan, Nigeria

²Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife

e-mail:oluwoleo2@asme.org

ABSTRACT

Modeled grain structures of annealed carbon steels using voronoi tessellation is reported in this work. Three stages of programming were used in modeling the microstructures. The first stage was iteration of the voronoi cells in order to obtain equivalent grain size with experimental specimens. In the second stage, the pearlite phase was introduced using the lever rule represented by a plot of random points. The third layer was modeled to reveal the grain boundaries of the carbon steels. The values of the grain sizes of modeled microstructures showed good agreement with experimental values.The study has shown that the microstructures can be modeled fairly accurately thus enabling a fairly quick export of geometric models on to some other finite element packages for analysis of stress – strain  effect on  microstructure and generally a stress-microstructure response could be determined.

Keywords: microstructure -modeling, voronoi tessellation, and carbon steels

FOOD GRINDING STONES AS A SOURCE OF HEAVY METALS CONTAMINATION OF DIETS

Richard C. Ehiri; Ugochukwu G. Megwa and Omaka N. Omaka

Department of Industrial Chemistry

Ebonyi State University Abakaliki, Nigeria

E-mail: richcee2003@yahoo.com

ABSTRACT

The heavy metals contamination of diets by using food grinding stones in ten families in Nkalagu, Ebonyi State, Nigeria is reported in this study. Melon seeds were used in both the experimental and control samples and heavy metal analysis was carried out using atomic absorption spectrometry (AAS). Results show that the mean concentration of heavy metals added by the stones to diets were 0.184, 0.259, 0.204, 0.790, 2.390 and 0.648 ppm for arsenic, cadmium, lead, copper, iron and zinc respectively. These values were all below the recommended dietary allowance (RDA) and tolerable upper intake levels (UL) for copper, iron and zinc. Furthermore, the proportion of these metals added by the grinding stones is significant for copper (p>0.05) and not significant for both iron and zinc (p<0.05) at the 5% level of significance when compared with their RDA values. Adequate care should be taken in using food grinding stones to avoid heavy metals loading of diets and their associated toxicity.

Keywords: Heavy Metal; Contamination; Diet; Food Grinding Stone.

SAND CONTROL IN NIGER DELTA FORMATION

Oloro John.

Department of Petroleum Engineering

Delta State University, Oleh Campus

Email:joloroeng@yahoo.com

ABSTRACT

In poorly consolidated sandstone formations, grain of sand that make up the sandstone are pulled loose from the formation and are carried off by the fluid flow. The sand causes a lot of problems that can mean a considerable decrease in productivity and adverse safety conditions. Costly work over operations may become necessary as a result. This paper, generally review the meaning of sand production, its causes, effects and control. TEGA Well 002 of SPDC in Niger Delta was used as a case study .The well was drilled and completed as a dual string produce on 21^st November 1999 to a total depth of 6789ft. Sand production was influence by certain factors at the depth of 6660ft.Which include :Natural cause(un-consolidation producing) and failure of sand consolidation and the following were some of the effect of sand production:(i)The erosion of choke (ii)corrosion accelerated (iii)Deposits are laid down in the flowlines or in the process facilities equipment (iv) Loss of man-hour during the period of close-in in terms of wages, which add up to overhead cost. The method of sand control adopted in TEGA well 002 was discussed and also while sand consolidation (SCON) method failed, Internal gravel packing was chosen as the cost-effective method of sand control in the well.Finally,conclusion and recommendation were base on the benefits derived from the installation of internal gravel packing(IGP).

GEOLOGICAL OBSERVATIONS OF BASEMENT ROCKS, AROUND GANAJA, KOGI STATE, NIGERIA

Imasuen, O.I^1*, Olatunji J.A² and Ibitoye V.T²

¹ Department ofGeology, University of Benin, Benin City

² Department of Earth Sciences, Kogi State University, Anyigba

ABSTRACT

A detailed geologic mapping coupled with petrographic mineral separation and geochemical studies were carried out on various rock types around Ganaja in Kogi state. The area is located between latitudes 7^o 42^/ and 7^o 44^/N and longitude 6^o 42^/ and 6^o 45^/ E and is about 29 square kilometre (29km²). Mapping was done by transverse mapping method together with systematic sampling of the outcrops on a scale of 1:25,000. Field relations observed on the rock samples collected from this area coupled with available information and literature showed that the rocks belong to the migmatite gneiss complex of the south-western basement complex of Nigeria. The rock types within the area of study include migmatite, augen, gneiss (porphyroblastic granite gneiss) biotite gneiss and pegmatite. There were also minor occurrences of quartz and quartzo – feldspathic veins. Petrographic and chemical analysis of the rock samples from this area show the migmatites to generally consist of quartz, feldspar (plagioclase microcline and orthoclase) biotite and a few accessory minerals like epidote and zircon. The chemical analysis data and the petrographic studies of the migmatites mapped in the study area suggest its igneous parentage. However, with their uncomplicated mineralogical composition these migmatites differ from those of the north-eastern part of Lokoja which are of pelitic rocks parentage. It is being suggested that the deformational episode occurred along with the metamorphism of the various rocks of the mapped area and its environs causing varied metamorphic derivatives from the amphibolite facies to a higher metamorphic facies condition. These migmatites may have been formed from the metamorphism and metasomatism of fractionated igneous bodies during tectonism .The segregation and migration of the melting minerals such as quartz and feldspar in the rocks during regional metamorphism resulted in the banding of the leucosome (light) and melanosome (dark) minerals. The outcrops and their associated foliation generally trend in NNE-SSW and NNW-SSW directions.KEYWORD: Ganaja migmatites, geochemical , metamorphism leucosome , melanosome

WATER SUPPLY AND POPULATION PROJECTIONS: CASE OF BENIN CITY

Idiata, David J., Omoruyi, Friday O., and Iguisi, Akugbe

Department of Civil Engineering and Department of Chemical Engineering

Edo State Institute of Technology and Management, Usen, Benin City.

E-mail: djgrandmaster4christ@yahoo.com

ABSTRACT

The UN general assembly, in December 2003 proclaimed the years 2005 to 2015, as the international decade for action “water for life”. A decade of action; the primary goal of the “water for life” decade is to promote efforts to fulfill international commitments made on water and water related issues by 2015 and this ‘water for life’ is part of its millennium development goals. The provision of adequate water supply and sanitation to the rapidly growing urban population is increasingly becoming a problem for governments throughout the world. The absence of virtually any reliable current demographic data has not prevented national and international bodies from generating estimates and projections of population and population growth in Nigeria, the population of Benin city 1.225 million is growing by 3.3% for Nigeria and average of 1.14% or the world per annum and this has place tremendous pressure on the main source of water the government own Ikpoba River dam facilities. The population projection is to range from 1.45 million in 2010 to over 2.35 million in 2025 and the water demand of the city per day is to range from 172 million litres in 2010 to over 280 million litres in 2025.

Keywords:  Population, Projection, Population Growth rate, water demand

ANALYSIS OF INTERNAL SUPPORT MOMENTS OF CONTINUOUS BEAMS OF EQUAL SPANS USING SIMPLIFIED MATHEMATICAL MODEL APPROACH

Okonkwo, V.O., Aginam, C.H., and Chidolue, C. A.

Department of Civil Engineering

Nnamdi Azikiwe University, Awka

ABSTRACT

This paper developed the mathematical Model for the evaluation of the internal support moments of a uniformly loaded continuous beam of equal span and the number of spans, taking the uniformly distributed load on the beam to be equal for all spans. The internal support moments of a continuous beam with unit uniformly distributed load (UDL) and unit span length were evaluated at different number of spans (n). The result showed that the values of the internal support moments oscillate (alternately increase and decrease) with rapidly diminishing magnitude at every unit increase in the number of spans (n) of the continuous beam. This showed that it is possible to express the values of the internal support moments with a model. The Euler method for linear interpolation was applied repeatedly between subsequent values of the moments at each internal support for different values of number of spans (n) and each internal moment expressed as a series comprising the sum of their initial values and the subsequent increases and decreases to their values as a result of an increase in the number of spans of the continuous beam. The results obtained showed perfect and close comparison with that obtained using Clapeyron’s Method as depicted on the graphs shown in the appendix.

Keywords: Continuous beams, equal Spans, Internal Support moment, Mathematical Model.

GEOPHYSICAL INVESTIGATION OF OLI RIVER LODGE DAM AXIS, KAINJI LAKE NATIONAL PARK, NIGERIA

¹J. B. Arubayi; ²B. D. Ako; and ²T. R. Ajayi

¹Department of Physics, Federal University of Petroleum Resources, Effurun

²Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria

E-mail: jarubayi@yahoo.com

ABSTRACT

The Kainji Lake National Park is composed of the Borgu and Zurguma sectors. The main objectives of the parks are the conservation of gene resources of indigenous wild life plants and animals and management for educational and tourist purposes.  The need to complement the above objectives with a lake for recreation (boating, fishing etc) at the Oli river lodge resulted in proposing a weir across the Oli River at the camp site. Investigations using geophysical (Vertical electrical sounding, resistivity profiling and electromagnetic) methods were carried out, along geophysical traverses TS1, TS2 and Ts3 at the proposed weir across the river. The geoelectrical section along the major Weir axis varies from two to four layers.  The western bank depth to basement varies from 3 to 6m. Granite exposures occur along the river channel with highly jointed features (width 80m). The eastern bank shows a more variable and compact topsoil than that of the western bank.  The underlying layer is a zone of varying resistivity values, which suggest fracturing/faulting, or jointing. The geophysical result of the marked complexity at the eastern bank, show that it is underlain by conductive materials which probably are due to the presence of water saturated fracture/fault zones within the area. Depth to the fresh bedrock will however be ascertained by the drilling of two additional boreholes that will allow a seepage-free foundation to be laid.

Key words: Weir axis, resistivity, fracture/faulting and geoelectric section

STOCHASTIC MODELING OF DYNAMIC PILE CAPACITY USING HILEY, JANBU AND GATES FORMULAE

J.O. Afolayan and D. A. Opeyemi

Department of Civil Engineering, Federal University of Technology, Akure, Nigeria

Department of Civil Engineering Technology, Rufus Giwa Polytechnic, Owo, Ondo State, Nigeria

E- mail: da_opeyemi@yahoo.com or davidopeyemi@gmail.com, and joafol@yahoo.com

ABSTRACT

The reliability assessment of the load carrying capacities of piles based on dynamic approach using Hiley, Janbu and Gates formulae is reported in this paper, this has become necessary because pile capacities determined from dynamic formulae have shown poor correlations and wide scatter when statistically compared with static load test results. In practice, uncertainties are common phenomena in engineering, therefore all the interrelated variables in the load carrying capacities of piles should be treated as random variables. Assuming practical probability density functions, the concept of the First-Order Reliability Method (FORM) as a powerful tool for estimating nominal probability level of failure associated with uncertainties is therefore invoked for estimating the implied reliability levels associated with the formulae of Hiley, Janbu and Gates. The results show that there is a good correlation between the implied safety levels in Hiley and Janbu formulae, while those associated with Gates are exceptionally different and grossly conservative.   

Key words: Stochastic model, dynamic pile capacity, dynamic pile formulae.

QUALITY CHARACTERISTICS OF COOKIES PRODUCED FROM COMPOSITE FLOURS OF WHEAT AND MUSHROOM

Adebayo-Oyetoro A.O^*; Olatidoye O.P; Ogundipe O.O; Balogun I.O and Aro F.O

Department of Food Technology, Yaba College of Technology, Nigeria

E-mail:wonunext@yahoo.com

ABSTRACT

The use of mushroom flour (MF) substitution in wheat flour (WF) from 10 to 30% each, for the production of cookies was investigated. The proximate analysis, sensory evaluation and microbiological examination of the cookies samples were determined.Fresh mushroom samples were sorted and dried at 55⁰C for 2hrs to produce four blends with wheat flour baked produce cookies The crude protein, crude fibre, and ash content of the mushroom supplemented cookies (MSCs) increased with progressive increase in the proportion of mushroom floor, with the 30% MSCs having higher values of 14.05%; 4.22% and 5.5% respectively, while lowest values we recorded for the whole wheat cookies (WWC). The carbohydrate content was observed to decrease with corresponding increase in the percentage of mushroom flour in MSCs. The sensory evaluation shows that no significant differences were observed between the WWC and the 10% MSCs, in the sensory attributes of aroma, texture, taste and overall acceptability (p<0.05). The crude protein of mushroom supplemented cookies and WWC ranges between 12.5 to 14.05% with the mushroom supplemented cookies (MSCs) having the highest value. The ash content increased with progressive increase in the proportion of mushroom flour, the highest value (5.50) was recorded for the 30% MSCs.There were significant differences (p<0.05) between WWCs and MSCs up to 10% supplementation in all the sensory attributes tested; aroma, texture and overall acceptability. The data obtained from the study clearly show the nutritional potentials of the nut as alternative food ingredient for protein supplementation and its reliability as a good source of amino acids for school children and adults.

Keywords: Mushroom flour, proximate analysis, sensory evaluation, total plate count, quality, wheat.