OPTIMIZATION AND PROGNOSTIC MODEL FOR SPLITTING TENSILE STRENGTH OF CONCRETE PRODUCED FROM GRANITE AND RECYCLED CONCRETE AGGREGATE

 Using recycled concrete aggregates from structural demolition wastes is presenting a potential application in the building industry as a substitute for natural aggregates. It preserves natural resources and brings about a reduction in the space needed as landfill disposal sites. This research was aimed at developing a prognostic model for splitting tensile strength of concrete produced from granite and recycled concrete aggregate. Thirteen rounds of experiments were considered utilizing the Central Composite Response Surface method. Granite was replaced with Recycled Concrete Aggregate (RCA) in varying proportions from 0% to 100% while the water-cement ratio (w/c) was varied from 0.3 to 0.7. Samples were subjected to test after 7, 14 and 28 days curing. It was observed that with a surge in the fraction of RCA, the splitting tensile strength reduced at all levels of w/c ratio. 30% RCA at 0.5 w/c gave the optimum combination that resulted in the highest splitting tensile strength of 2.11  at 28 days. This result is 7.9 % lesser than the control splitting tensile strength of 2.2

The Global Financial Meltdown and Its Effects on Manufacturing Sector: the Nigerian Perspective

The world economy is facing the most severe financial crisis since the great depression of the last century. The risk of global recession has heightened significantly and volatility of commodity prices, which is the mainstay of most developing countries like Nigeria. This study examined the influence of the global financial meltdown on the Nigerian economy. It was discovered that the financial crisis will cause fall in commodity prices, decline in export, lower portfolio etc. Also, recommendation that will minimize these effects and jump start the economy was included. Keywords: Financial crisis, Recession, Volatility and Export

JOB STRESS AND EMPLOYEES' PERSONAL FULFILLMENTS IN NIGERIAN BANKING ORGANISATIONS

In this modern world, stress has become a global phenomenon that occurs in a variety of ways in every organization, irrespective of the profession. In today’s work life, employees are generally working longer hours as the rising levels of responsibilities require them to exert themselves even more strenuously to meet targets and raise expectations about their work performance. Banking is an inherently stressful profession characterized by long working hours, serious competition, ethical dilemmas, regulatory bottlenecks, and dealing with a diverse customer base.Hence, the thrust of this paper is to examine the effects of job stress on employees' personal fulfilments in Nigerian banking organizations, with the objectives of identifying the drivers of job stress and examining the coping strategies to managing job stress to enhance employees’ personal fulfilments. While adopting Two-Factor Theory of Job Satisfaction and the Person-Environment Fit Theory, a secondary method of data collection was utilized, in which books, journals, and internet-based articles were reviewed and their content analyzed. Based on the literature reviewed, the paper showed that inadequate resources to do the job, high demands, workload, time pressures, lack of job security, understaffing, technological revolution, role ambiguity, and role conflict, among others, were the major causes of job stress affecting bank employees. The paper also showed that headaches, eating disorders, sleep disturbances, fatigue, muscle aches and pains, anxiety, irritability, low morale, depression, alcohol and drug use, feeling powerless and isolation from family, friends, and co-workers, among others, were the major effects of job stress on the employees personal fulfilments in the Nigerian banking organizations. Based on these findings, it was concluded and recommended that managers should invite employees who think that they are being given jobs that are in contradiction with their skills and clarify their roles. They should facilitate an employee skill audit that will help to place employees that feel underutilized. Management should introduce stress management techniques into banking organizations. An Employee Assistance Program should be introduced for early identification and intervention of problems capable of causing stress e.t.c

Leadership, Corporate Governance and Entrepreneurship Development in Nigeria:A Mutual Link

The study empirically examined the mutual link between Leadership, Corporate Governance and Entrepreneurship development in Nigeria using primary data by employing structure questionnaires to obtain information from the respondents in Lagos State as a population representative. In this research questionnaire were analyzed and interpreted using simple percentage table for tabular analysis and Spearman’s Rank Correlation Coefficient for the testing of the formulated hypotheses so as to know more about the topic understudy. It was proved in the research carried out that, effective leadership and good corporate governance determines the success of an organization. In the analysis, corporate governance policy has really helped Nigerian entrepreneur to grow financially. Also, effective leadership and good corporate governance was seen as a solution tools for global financial crises. We therefore recommend that, effective leadership and good corporate governance remains a solution tool for global financial crises, organizational problems and the right policy that enhances increased productivity that brings about economic growth and development globally. Key Words: Leadership, Governance and Productivity

INSTALLATION AND TESTING OF A 5kW HYDROPOWER TURBINE

This work focused on installation and testing of a hydro power turbine to generate 5 kW of energy for domestic applications.  Water flows into the penstock  from the dam at a height of 6m; the pipe diameter was reduced to   with a reducer socket. Water pressure decreases as it flows through the elbow joint. But such decrease or loss is recovered by a reduction of the pipe diameter to 80 mm and the pipe is long enough, (length = 2000mm) for the water to be fully developed before it enters the turbine at optimum speed. As the water flows through the runner of the turbine, its pressure reduces. The reduction imparts reaction on the runner and power is transferred to the turbine shaft. To prevent back flow or sucking back of water pressure into the turbine, a draft tube and a non-return valve are incorporated into the outlet of the turbine. The turbine shaft speed recorded with the aid of a tachometer is 298.33rpm and the dynamic pressure recorded at the turbine inlet, with the aid of a water pressure gauge is 170 kN/m2. This gave an output power of 4.98 kW  at a design flow rate of 0.106 m3/s. The installation and testing of Francis turbine, pipe network and fittings were successfully carried out. It is obvious from the test results that the output power can power the street lights along Imo-street in the University of Ibadan, Ibadan, Nigeria.     &nbsp

Effect of Epoxy-based Adhesives and Embedded Length in the Bond Strength of Post-installed Reinforcement in Concrete

In Nigerian building industry, there has been events in practice that required improving the structural integrity of existing structures: such as strengthening the interconnection between members. In cases where new structural members are to be added to the existing ones, instead of condemning the whole structure for demolition and rebuilding, post-installation process offers a remedial approach. However, the bond strength (BS) between the reinforcements and the concrete in the post-installed structural element goes a long way to determine the anchorage and effectiveness of the whole structural system. In this study, the BS characteristics of post-installed reinforcement in concrete using four different locally available epoxy-based adhesives in Nigeria were examined. Compressive strength test on concrete cubes and pull-out test on post-installed concrete were carried out for embedment lengths of multiples of 10 and 15 of bar diameters used. Average compressive strength at 28 days was 23.91N/mm2 while the highest BS for 10d and 15d are respectively 5.52 and 6.80 N/mm2 for 12mm bar diameter while corresponding values are respectively 5.38 and 6.35 N/mm2 for 16mm bar diameter. From the results, it was observed that the pull-out force which is a measure of bond Stress is more influenced by the embedded length while increasing the embedment depth from 10d to 15d for the same bar size has less influence compared to increasing bar diameter. The epoxy-based adhesives possess appreciable BS characteristics for post-installed reinforcement in concrete. However, of the three types of adhesives used, Hilti gave the highest BS capacity

Relationship Between Compressive Strength and Splitting Tensile Strength of Palm Kernel Shell Concrete

The use of palm kernel shell (PKS) has gained acceptance in the production of concrete. Compressive strength is the mostly used strength characteristics of concrete. The compressive strength CS of concrete should provide a good basis for predicting the splitting tensile strength STS. The aim of this study is to establish a mathematical relationship between the CS and STS of concrete produced with PKS. In this study, coarse aggregates was fully replaced with PKS at varying water-cement ratios (w/c) for concrete mix ratios 1:1½:3 and 1:2:4. Unit weigth of the PKS, slump, compressive and splitting tesnsile strength were determined. A relationship between CS and STS was developed for the different w/c ratios using exponential function aproximation. Physical property tests carried out on the PKS characterized it as lightweight aggregate with saturated surface dry unit weight of 1.27. The slump revealed that PKS concrete at 0.3 and 0.4 w/c is stiff and not workable. CS and STS at 28day for mix ratio of 1:1½:3 at w/c of 0.3, 0.4, 0.5 and 0.6 were respectively 3.2 and 1.2; 9.4 and 2.1; 10.8 and 2.6; 9.0 and 2.4 N/mm2. The corresponding values obtained for mix ratio 1:2:4 were 3.0 and 1.0, 1.7 and 1.3, 4.5 and 1.6, 7.7 and 1.9N/mm2, respectively. Equations relating CS and STS at 0.3, 0.4, 0.5 and 0.6 w/c were established. It was concluded that PKS concrete produced with mix ratios 1:1½:3 and 1:2:4 performed better in compression and splitting tensile strength at w/c of 0.5 and 0.6

Morphological characterisation of selected African accessions of bambara groundnut (Vigna subterranea (L.) verdc.)

Open Access ArticleThree hundred (300) accessions of Bambara groundnut (Vigna subterranea (L.) Verdc) among the 1973 maintained in the global repository at the International Institute of Tropical Agriculture (IITA), Ibadan, genebank were selected for this study. Two to three seeds of each accession were planted during the 2014 / 2015 planting season at IITA, Ibadan, Nigeria. Seedlings were thinned to a single plant prior to flowering. Thirty - seven (37) agro-morphological parameters, representing 28 quantitative and 9 qualitative traits were recorded on each plant (IPGRI, 2000). The data were subjected to analysis using the statistics application system (SAS) software, version 9.3, both to depict correlation among parameters and eigen values with principal component on scree plot and dendrogram construction. The results revealed lines (e.g TVSu – 293, TVSu – 395, TVSu – 1243) that had high yield potentials. Also, TVSu -397 and TVSu – 1168 had the highest number of leaves while TVSu – 520 and TVSu – 1022 had the least. The least number of seeds per plant was given by TVSu – 1, TVSu – 353 and TVSu – 454, while TVSu – 395, TVSu – 618 and TVSu – 1897 gave the highest number of seeds at harvest. The result provides information necessary for future nutrition and breeding studies on Bambara groundnut and its improvement