Production of Bricks for Building Construction and Predictability of Its Post-Fired Volume Shrinkage Based on Apparent Porosity and Water Absorption Capacity

ABSTRACT The high demand for durable building materials has led to the growing rate of production and application of bricks. Successful predictability of PostFired Volume Shrinkage (PFVS) was carried out based on its apparent porosity and water absorption capacity (WAC). The bricks were produced from clay which was prepared and processed, following a well detailed step-wise route. Prediction of the PFVS was carried out using a two-factorial empirical model expressed as; ϑ = -0.3988 ₰ -0.3789 ξ + 39.256 The validity of the derived model was rooted in the core expression ϑ -39.256 = -0.3988 ₰ -0.3789 ξ where both side of the expression correspondingly approximately equal. Results from both experiment and model prediction shows that decrease in PFVS resulted to increase in apparent porosity and WAC. This implied that the inter-particle spacing increased (with decreasing PFVS) to allow increased water absorption as result of increased apparent porosity. Results from evaluations indicated that the standard error incurred in predicting PFVS for each value of the WAC & apparent porosity considered, as obtained from experiment, derived model and regression model were 0.0842, 0.0010 and 0.0033 & 0.0834, 0.0011 and 4.2286 x 10 -5 % respectively. Furthermore the correlation between PFVS and WAC & apparent porosity as obtained from experiment, derived model and regression model were all > 0.97. The maximum deviation of the model-predicted water absorption (from experimental results) was less than 5.57%. This translated into over 94% operational confidence for the derived model as well as over 0.94 effective response coefficients of WAC and apparent porosity to PFVS of the bricks

A reconstruction of Africa’s political culture in the purview of Fulani herdsmen current mode of operations in Nigeria

It is an established fact that Nigeria is the most populous nation in Africa. It is equally a common understanding that the internal political dynamics in Nigeria invariably, little or more, have their effects on the general well-being of Africa as a continent. In mind of this strategic position of Nigeria in relation to the majority of African nations, and in the light of the current mode of operation by the Fulani herdsmen in Nigeria; this study argues that a reconstruction of Nigeria’s Political Culture, and by extension, that of Africa as a whole is imperative. This is because, just like Nigeria, almost all African nations have the challenges associated with immigration. With the concept of communistic Culture as a proposed solution, it is believed in this study that a cue from it will to a greater extent solve the problems of immigration, that is, majority culture versus minority culture challenges in African nations’ corporate existence.Keywords: Reconstruction, Political Culture, Fulani, Herdsmen, Communistic Cultur

Efficacy of Reflective Questioning Instructional Strategy on Students’ Achievement in Gas Laws Contents of Secondary Schools Chemistry

This study investigated the efficacy of reflective questioning instructional strategy on students’ achievement in gas laws contents of secondary schools Chemistry. A pre-test-post-test, control group quasi-experimental research design was adopted in the study. The participants were 129 students (72 females and 57 males) of four intact classes sampled from two government owned secondary schools in Nigeria using multi-stage sampling procedure. Two intact classes each were assigned to experimental and control groups respectively. Data collection was done using a 25-item gas laws achievement test (GLAT). Data collected were analyzed using mean, standard deviation and analysis of covariance (ANCOVA). The result showed that there was a significant difference between the experimental and control groups indicating that reflective questioning instructional strategy enhances students’ achievement in gas laws. Also, there was no significant influence of gender on the mean achievement scores of students in gas laws and there was no significant interaction effect of questioning instructional strategies and gender on students’ achievement in gas laws. Chemistry teachers and pre-service teachers should be trained on how to adopt reflective questioning instructional strategy in the classroom instructions.

MODEL FOR PREDICTING THE INITIAL SOLUTION pH AT PRE-ASSUMED FINAL pH AND CONCENTRATION OF DISSOLVED LEAD DURING LEACHING OF GALENA IN BUTANOIC ACID SOLUTION

Model for predicting the initial solution pH at pre-assumed final pH and concentration of dissolved lead, during leaching of galena in butanoic acid solution has been derived. The model shows that the initial pH of the leaching is dependent on the values of the pre-assumed final solution pH and concentration of dissolved lead. The validity of the model was rooted in the expression e^(Nγ/α)=∛Pb where both sides of the expression were approximately equal to 5. The maximum deviation of the model-predicted initial solution pH value from that of the corresponding experimental value was less than 3% which is quite within the acceptable deviation limit of experimental results

Model for predicting the quantity of water evaporated during oven drying of Otamiri clay

Model for calculating the quantity of water that evaporated during oven drying of Otamiri clay has been derived. The model; j = exp ((In1/2.9206)18) showed that the quantity of water that evaporated during the drying process was dependent on the drying time, the evaporation surface being constant. It was found that the validity of the model is rooted in equation (1), where both sides of the equation were correspondingly almost equal. The respective deviation of the model-predicted quantity of evaporated water from the corresponding experimental value was less than 26%, which is quite within the acceptable deviation range of experimental results, hence depicting the usefulness of the model.Keywords: Model, water, evaporation, drying, cla

MODEL FOR CALCULATING THE CONCENTRATION OF DISSOLVED IRON RELATIVE TO THE WEIGHT-INPUT OF IRON OXIDE ORE AND FINAL SOLUTION PH DURING NITRIC ACID LEACHING

Model for calculating the concentration of dissolved iron during leaching of iron oxide ore in nitric acid solution has been derived. The model was found to be dependent on the value of the weight-input of iron oxide ore and final solution pH measured during the leaching process. It was observed that the validity of the model is rooted on the expression where both sides of the relationship are correspondingly approximately almost equal. The maximum deviation of the model-predicted dissolved %Fe values from the corresponding experimental values was found to be 28% which is quite within the acceptable range of deviation limit of experimental results. Dissolved iron concentration per unit mass of iron oxide ore input evaluated from experimental and model-predicted results are 0.0010%/g and 0.0011%/g respectively, indicating proximate agreement

INVESTIGATION OF THE OPTIMUM DISSOLUTION TEMPERATURES OF PHOSPHORUS IN SULPHURIC, NITRIC AND OXALIC ACID SOLUTIONS DURING LEACHING OF IRON OXIDE ORE

Studies were carried out to determine the optimum dissolution temperatures of phosphorus in oxalic, nitric and sulphuric acid solutions during leaching of iron oxide ore. Phosphorus dissolution rates and dissolution per unit rise in temperature were determined and compared to ascertain the preferred acid in terms of effective dephosphorization of iron oxide ore using leaching process. The results of the investigation show that the optimum dissolution temperatures of phosphorus in these acids were found to be 45, 55 and 70ºC respectively. Phosphorus dissolutions per unit rise in temperature in these acid solutions during the increasing and decreasing stage of dissolution were 9.4 and -3.07 mg/kg/ºC 2.88 and -4.7 mg/kg/ºC and also 2.16 and -7.95 mg/kg/ºC respectively. Phosphorus dissolution rates in these acid solutions during the increasing and decreasing stage of dissolution were also determined as 0.67 and -0.13 mg/kg/s, 0.14 and -0.19 mg/kg/s and also 0.1 and 0.44 mg/kg/s for oxalic, nitric and sulphuric acid solutions respectively. This confers to oxalic acid a better dissolution power on phosphorus over nitric and sulphuric acid, followed by nitric acid