International Journal of Engineering Research in Africa Vol. 7

Abstract: Barrier Systems Built with Fine Grained Soils Frequently Loose their Hydraulic Integrity due to Desiccation Cracking either during Construction or Shortly Thereafter. Moreover, Typical Specifications for the Construction of Compacted Soil Liners and Covers Require that the Soil Be Compacted Wet of Optimum Water Contents to Achieve the Lowest Possible Hydraulic Conductivity, a Condition that Results in High Desiccation Shrinkage Values. however, such Soils Can Be Treated with Fly Ash to Maintain Low and Tolerable Desiccation Shrinkage Strains. in this Study, Volumetric Shrinkage Strains of Representative Fine Grained Soil Containing 0 – 20% Fly Ash by Dry Weight of Soil Compacted with the British Standard Light (BSL), West African Standard (WAS) and British Standard Heavy, (BSH) Compaction Efforts at Moisture Contents Ranging from 10 – 20% Were Evaluated. Measurements Indicate that Volumetric Shrinkage Strain Decreased with Higher Fly Ash Content and that Fly Ash Effectively Reduced the Shrinkage of Untreated Soil Prepared Wet of Optimum from 4.4 – 7.7% to Values Well below the 4% Threshold. the Measured Shrinkage Strains Were Related to Water Content and Dry Unit Weight on the Dry Unit Weight – Moulding Water Content Curve in what Is Referred to as Acceptable Zone. Data Points within the Acceptable Zone Represent Test Results with Shrinkage Strain ≤ 4% which Ensures Compaction Efficiency. this Study Therefore Established that Fly Ash Application and Appropriate Regulation of the Moulding Water Content Are Feasible Means of Reducing the Risk of Barrier Soil Damage by Shrinkage Cracks while still Realizing Very Low Hydraulic Conductivity and Adequate Strength.

Abstract: The Development of Sustainable Processing Technologies for the Vast Mineral Resources Available in Nigeria and their Varied Applications Is a Major Pursuit by the Federal Ministry of Science and Technology. in this Work, Alum Was Produced from Three Different Kaolin Deposits in Nigeria Namely Kankara Brown, Bauchi and Kankara White by Acid Dealumination of the Metakaolin Obtained by Calcination of the Beneficiated Kaolinites and the Yields Were Measured to Ascertain the Process Repeatability. the Reproducibility Studies Carried Out on Samples from each Deposit Showed a Mean Yield of 80 %, 92 % and 87 % and Standard Deviation of 2.50 %, 1.063 % and 1.296 %, for Kankara Brown, Bauchi and Kankara White Respectively. the Values from the Three Deposits Fall within 3 Standard Deviations of the Mean in Accordance with the 68-95-99.7/three-Sigma Rule. the Alum Quality Also Compares Well with Available Commercial Alums in the Market. BET Analysis, of the Alumina Obtained by Calcination of the Alum (Kankara White), Gave a Surface Area of 192.2441m2/g Comparable to Commercial Alumina. these Results Suggest/establishes the Huge Possibility of Commercial Alum Production, Including Alumina, Using Kaolinite Clay from these Deposits as Starting Materials.

Abstract: In Recent Times, Environmental Concerns Arising from Pollution, Global Warming and Waste Management Have Led to the Generation of Interest in the Use of Environmentally Friendly Materials, Especially, Biological Materials such as Natural Fibres and Particulates in Composite Materials Manufacture. in this Work, Natural Fillers (Afara-Mahogany Particulates of 150µm) and Fibre (Caesar Weed Fibre of 5mm Length) Were Mixed with Epoxy Resin at the Various Fibre/filler Weight Percentages as Follows: 2%, 4%, 6%, 8% and 10% with Random Fibre Orientations. some Physical and Mechanical Properties of the Composite Were Determined Using Standard Procedures. Ninety (90) Wt% of Epoxy Resin Mixed with 10 Wt% for each of the Following: Caeser Weed Fibre, Afara and Mahogany, Improved the Tensile Modulus by 2652.6%, 321.37%, and 129.73% and the Impact Strength by 162.7%, 133.9% and 15.25%, Respectively. Also, Composites Density Reduced by 26.26%, 3.03%, and 3.03%, and its Hardness too Reduced by 5.41%, 1.35%, and 4.05%, Respectively. Meanwhile, the Water Absorption Were 4.9%, 2.79%, and 4.12% for 10wt% of Caeser Weed Fibre, Afara and Mahogany, Respectively and 90wt% Epoxy Resin. Therefore, Caeser Weed Fibre Had the Greatest Positive Effect on the Tensile Strength, Impact Energy Absorbed and Density. however, Afara-Epoxy Composite Had the Least Water Absorption and Higher Shore Hardness Value than Mahogany-Epoxy and Caeser Weed Fibre-Epoxy Composites.

Abstract: The Quality of Silk Yarn Is Affected by the Reeling Process. the Silk Reeling Process Is Affected by Several Factors which Include the Reeling Temperature and Silk Cocoon Boiling Time. the Aim of this Paper Was to Investigate the Effect of Reeling Temperature and Cocoon Boiling on the Silk Filament Strength and Frequency of End Breaks during Reeling by Using Regression Models. the Results of this Research Work Indicated that Boiling Time and Reeling Temperature Were Positively Correlated with Filament Strength. on the other Hand the Number of End Breaks Increased with Boiling Time. as Reeling Temperature Increased the Number of End Breaks Showed a Decreasing Trend.

Abstract: This Paper Presents a Classification System for Managing and Indexing Hardcopy Engineering Drawings, Referred to, in this Paper, as Drawings Library Management System (DLMS), Developed for an Appropriate Technology Research Centre in Botswana. the System Is Akin to Common Library Cataloguing and Classification Systems such as the Dewey Decimal Classification (DDC), Universal Decimal Classification and Others, which, though Are Well-Known and Have Been around for many Years, Are yet to Be Exploited for the Classification and Management of Paper Drawings. in Fact, Hardcopy Drawings Appear to Be Neglected Compared to the Softcopy Type, for which Various Scholarly Articles Have Been Done on their Classification, Retrieval and Management. this Is Unfortunate as, Invariably, it Is Hardcopy/paper Drawings that Are Mostly Used in Production, Especially in Developing Countries where the Power of CAD/CAM Is yet to Be Fully Harnessed. Accordingly, the DLMS, a Model Successfully Used in a Research Centre in Botswana for over Ten Years Is Proposed.The System Was Further Analysed against and Compared to Three Main Library Classification Systems, Namely, the Dewey Decimal, the Universal Decimal and the Library of Congress Systems. Results Show that the DLMS Is a Better Classification System for Managing Hardcopy Drawings.

Abstract: Fundamental Information on Drying and Re-Wetting Characteristics of Agricultural Seeds Is Required in the Design and Aeration Systems as Well as in the Prediction of Drying Rate Using Various Mathematical Models. Thin-Layer Drying Experiments Were Conducted Using Air-Ventilated Oven to Simulate the Artificial Drying at Various Moisture Contents of Sesame Seed (6.9 to 18.2 % W.b) at Three Drying Temperatures of 40, 50 and 60 ^OC. Five Drying Models Were Evaluated for the Thin-Layer Data. the Page Equation Fitted the Data Best, where Selection of the Best Model Was Obtained by Comparing the Coefficient of Determination (R2), the Standard Error of Moisture Content (SEM) and Mean Relative Percent Error (e) between the Experimental and Estimated Values. the Drying Rate of Sesame Seed under Drying Conditions Increased with Increased Temperature of Drying( 40 to 60 ^OC) and Initial Moisture Content of Seed( 6.9, 11.5 and 18.2 % W.b). the Parameters “K” of the Page Model Increased with Increase in Temperature, while, Parameter ”n” Decreased with Temperature Increase and Increased with Increase in Moisture Content of Seed. the Effective Diffusivity Was Found to Be 2.32 X 10-11 M²s-¹.

Abstract: Many Production and Business Time Series Are Non-Stationary Time Series that Contain Trend and Seasonal Variations. Seasonality Is a Periodic and Recurrent Pattern Caused by Factors such as Weather, Holidays, or Repeating Promotions. this Paper Presents a Trend and Seasonal Time Series Analysis of Soft Drink Production over the Period 2003–2010, it Is Necessary to Know the Trend in Soft Drink Production to Elicit the Reasons why Demand of Soft Drink Is Increased or Decreased at Specific Periods. the Objectives of this Paper Are (i) to Study the Trends in the Production and Productivity of a Soft Drink Bottling Company, and (ii) Analyze the Demand of the Firm with a View to Identifying Trend that Exists in the Company Using Time Series Analysis. A Software Program Was Developed Based on Applicable Methodology to Facilitate Accurate and Faster Analysis of Data. Characterization of Demand Data Using Decomposition Was Done, which Reveal the Nature of Seasonality, Cyclical Activity, Trend and Noise. on the Whole, the Results of the Decomposition Analysis Clearly Show that there Is a Remarkable Linear Trend in Demand Pattern. the Study of Seasonality Shows that the Highest Peak in Demand of the Product Occurred at 12th, 24th, 36th, 48th 60th, 72nd, 84th and 96th Months which Turn Out to Coincide with Yuletide. the Study Further Indicated a Positively Increasing Trend in the Demand Rate of Company’s Product.