PREDICTION OF FLEXURAL STRENGTH OF CHIKOKO POZZOLANA BLENDED CEMENT CONCRETE USING OSADEBE’S REGRESSION FUNCTION

Chikoko mud is abundant in the mangrove swamps of the Niger Delta area of Nigeria. Its utilization in concrete production is traceable to its pozzolanic properties. In this paper, a regression model is developed to predict and optimize the flexural strength of chikoko pozzolana blended cement concrete using Osadebe’s regression function. The results obtained from the derived regression model are very close to those obtained from experiment. The model was tested for adequacy using a Fisher test at 5% level of significance and was found to be adequate. A computer program coded in basic language was used to select the mix ratios that would optimize the flexural strength of chikoko pozzolana blended cement concrete. The computer program is user-friendly and can be used to select the mix ratios corresponding to a desired strength value with reasonable accuracy and without waste of time. http://dx.doi.org/10.4314/njt.v36i3.

Investigating the Place of Population Increase and Level of Income Earning in Food Security A Study of Yam Supply in Awka Urban, Anambra State of Nigeria

This research was carried out to present yam supply and food security situation in Awka urban, Anambra State. Data used were collected through questionnaires and oral interview, using the simple random sampling to select the respondents. The Pearson Product Moment Correlation was employed in testing the hypotheses formulated. It was found out that there is a significant relationship between population increase and yam supply and that there is a significant relationship between the income of the consumers and yam consumption. The increase in the population in Awka urban has led to a decrease in food production causing the people to look outward for food supply. This can be averted if agricultural productivity is increased and more jobs are provided for the people to earn income to purchase food

Analyses Of The Effectiveness Of The Various Measures Employed By People In The Control Of Flooding In Six Communities In Awka Anambra State Of Nigeria.

This study analyzed the effectiveness of the measures already put in place to control flooding in six Communities of Awka including Agulu, Amaenyi, Ezi-Awka, Amikwo, Ifite and Nkwelle. The questionnaire survey method was adopted in which questionnaire was employed in collecting the data from the respondents which was later collated and analyzed. Three hypotheses were tested and the T-test result showed that: 1. there is significant difference in the various efforts made to check flooding in Awka, 2. there is significant difference in the effectiveness of the various efforts made to check flooding in Awka, and 3. there is no significant difference in the various measures used in flood management in Awka. The study concluded therefore that there are many measures put in place to tackle the problem of flooding in the study area in all the six Communities studied, but the problem still persists because the parties involved are fighting the menace individually. The study thus recommends an integrated approach in tackling flooding in the area, which will include the following: massive campaign against improper dumping of refuse in the drainage system as it not only create room for flooding but also encourages flooding in the area, construction of sound drainage system, creating environmental awareness to keep the drainage system from waste dumps, encouraging people to open their drainage system constantly in order to help check and control flooding, avoiding dumping of refuse in drainage system and the enforcement of all these by a strong governmental force

Assessment of Rainwater and Groundwater Quality in Izombe Town, Oguta Local Government Area of Imo State

Rainwater and groundwater quality in Izombe were assessed. Five water samples were collected from five (5) different locations, with at least one location from one of the four autonomous communities in Izombe, Oguta L.G.A of Imo State. The physicochemical and microbial parameters of rainwater and groundwater samples from Umuakpa, Ndeuloukwu, Ugbele, Ndioko, and Orsu were assessed using Varian Atomic Absorption Spectrophotometer (AAS). The study was aimed to assess the physicochemical and microbial qualities of groundwater and rainwater in Izombe and how these affect their health as individual members of the community, and their environment when compared to WHO standards. The water samples were collected from five different locations, with at least one location from each of the four autonomous communities, and were assessed. The result indicated that rainwater and groundwater pollutants in the community were turbidities, ammonia, copper and temperatures 7.59±0.02 ph, 6.42±0.28 nitrate, 59.56±0.50 ammonia, 0.29±0.07 phosphate, 0.88±0.03 iron, copper, lead, nickel, aluminum, mercury, manganese, cadmium, bacteria count, coliform count, and E-coli. Also, all the pollutant parameters were identified, only iron, copper, aluminum, and bacteria count were not identified as being associated with petroleum products and exploratory activities. This research has broadened the understanding of the suitability of Izombe water sources for both consumption and other purposes. The findings show that the rain and groundwater sources of the community are not fit for human consumption, due to the contaminants inherent in them, attributed majorly to the oil production activities in the area which corroborates other research studies

Production of Periwinkle Shell Reinforced Grindstone

The study involves the use of periwinkle shell particles as reinforcement in the production of grindstone to meliorate its physical and mechanical properties. The assessment of the properties of the periwinkle shell reinforced concrete grindstone showed that reinforcement yielded several promising results. The compressive strength was higher for samples with lower water/cement ratio (7%) than those with higher water/cement ratio (10%). The introduction of concrete that contains periwinkle shells as fine aggregates resulted in the loss of smooth like appearance and reduction in weight. The loss of its smooth like nature introduces the rough nature which improved its functionality. The reinforced sample had the lowest hardness test and in hardness test the lower the number the higher the hardness. There was an increase in the density after absorption test was carried out on specimens. There was also reduction in production cost with periwinkle shells partial replacement of cement and gravel as fine aggregate. The composite was adequate for grindstone production since its sample has a compressive of 18.15Mpa and thus satisfied MOR requirements of 11.5 MPa for general purpose boards

Comparative Analysis of the Soil Geotechnical Characteristics of the Failed and Unfailed Sections of the Onitsha-Enugu Expressway, Southeastern Nigeria.

This work compared the soil geotechnical characteristics of the failed sections of the road and that of the un-failed sections of the road to establish whether they are significantly different or related. To achieve this, soil samples from both failed and un-failed sections of the road were analyzed. The data so generated, were tested using Correlation Coefficient for relationship and Students T-test for difference. It was found that there exist insignificant relationship between the failed and the un-failed sections of the road, there is significant difference between the two variables and there is wide discrepancies between the geotechnical characteristics of the failed sections and the standard of soil geotechnical characteristics set by the Federal Ministry of Works for highway sub-grades.  It was therefore concluded that the road failure was due to poor geotechnical characteristics of the soil. The work recommended that the variation in the geotechnical characteristics of the soils along the roadway should be accommodated during reconstruction. Sequel to this, knowledge of soil geotechnical characteristics and underlying geology of an area becomes indispensable before any construction, reconstruction or rehabilitation project commences.

Evaluating the Causes of the Road Failure of Onitsha-Enugu Expressway, Southeastern Nigeria.

Considering the persistence of road failure along the Onitsha -Enugu expressway and many other roads in the southeastern Nigeria, this work was conceived with the aim of evaluating the causes of the road failure in other to help marshal out effective and efficient measures of tackling this problem of road failure. The study adopted a survey design which employed the use of a well structured questionnaire to gather information on the causes and effects of the road failure. To determine the sample size, volumetric analysis was used and the data so generated was analyzed using One-way Analysis of Variance and Post HOC test. The ANOVA shows the variation among the causes is not significantly different while the Post HOC test ranked the causative factors treated. The work thus concluded that all the factors listed contribute to the failure of the road with inadequate maintenance, mismanagement by the government and old age of the road pavement being the major factors. The work therefore recommends that there should be Quality Determination for materials during construction, Effective Maintenance Programme (routine or preventive maintenance, periodic maintenance, and disaster maintenance or major repairs of our roads) and Establishment of an Active Maintenance Crew

Impact of Capital Market on Domestic Resource Mobilization for Economic Development in Nigeria (2000-2015)

The study investigated the impact of Nigerian capital market on domestic resource mobilization for economic development, using time series data from 2000 to 2015. The study employed secondary data obtained from the Central Bank of Nigeria Statistical Bulletin, the Nigerian Stock Exchange Fact Book and Securities and Exchange Commission database. To evaluate the impact of the independent variables on the dependent, the Ordinary Least Square (OLS) method of estimation was employed. Augmented Dickey Fuller (ADF) test was used to identify the order of integration. Economic growth was proxied by Gross Domestic Product (GDP) while the capital market variables considered include: Market Capitalization (MCAP), Total New Issues (TNI) and Value of Transactions (VLT). Applying Johansen and Juselius co-integration test, the result showed that there was at most one co-integrating equation in the model, implying that there is a long run relationship between the variables in the model. The causality test results suggest bidirectional causation between the GDP and the Value of Transactions (VLT) and to the GDP but not vice-versa. Using two-tailed test, the F-statistics is significant at 5 percent level of significance. Furthermore, there was no evidence of reverse causation from GDP to market capitalization and there was no evidence of independence causation between the GDP and Total New Issues (TNI). The study showed that the major problem with domestic resource mobilization in Nigeria have been that not enough savings are being generated to facilitate the required investment. Also, the type of savings available does not easily make financial intermediation possible. The Nigerian stock market has been constrained by policies that tend to make the exchange look like a mechanism by which government raise loan finance rather than an instrument for mobilizing industrial finance. It is recommended therefore that the regulatory authority should appraise and modify the restrictive policies that constrained resource mobilization capacity of the Nigerian capital market

Business Mentoring and Domestic Entrepreneurship in Nigeria’s Manufacturing Sub-sector: The place of Foreign Direct investment Inflows

Although there is a fairly extensive literature on the theory of foreign direct investment, not much of it is useful in providing insights into its effect on domestic entrepreneurship in Nigeria. This paper looks at the theoretical basis for business mentoring, examines the influence of foreign direct investment (FDI) inflow on domestic entrepreneurship in Nigeria’s manufacturing sub-sector from 1973 to 2010 while employing OLS technique. Results identified a positive and highly significant effects of each of human capital and infrastructural development on activities on Nigeria’s manufacturing sub-sector while each of manufacturing FDI, market size and anti-FDI policies has a negative and highly significant effect on activities in Nigeria’s manufacturing sub-sector. This paper therefore recommends that policies on investment should be geared towards wooing foreign investors into the manufacturing sub-sector while giving the diversification of the country’s productive base a top priority. Keywords: Domestic entrepreneurship, Foreign Direct Investment, Spill-ove

Cooperative-hybrid detection of primary user emulators in cognitive radio networks

Primary user emulator (PUE) attack occurs in Cognitive Radio Networks (CRNs) when a malicious secondary user (SU) poses as a primary user (PU) in order to deprive other legitimate SUs the right to free spectral access for opportunistic communication. In most cases, these legitimate SUs are unable to effectively detect PUEs because the quality of the signals received from a PUE may be severely attenuated by channel fading and/or shadowing. Consequently, in this paper, we have investigated the use of cooperative spectrum sensing (CSS) to improve PUE detection based on a hybrid localization scheme. We considered different pairs of secondary users (SUs) over different received signal strength (RSS) values to evaluate the energy efficiency, accuracy, and speed of the new cooperative scheme. Based on computer simulations, our findings suggest that a PUE can be effectively detected by a pair of SUs with a low Root Mean Square Error rate of 0.0047 even though these SUs may have close RSS values within the same cluster. Furthermore, our scheme performs better in terms of speed, accuracy and low energy consumption rates when compared with other PUE detection schemes. Thus, it is a viable proposition to better detect PUEs in CRNs