Tax Incentives and Household Portfolios: A Panel Data Analysis

This paper investigates the responsiveness of household portfolios to tax incentives by exploiting a substantial tax reform that altered after-tax returns and cost of debt for a large number of households. An extraordinary panel data set that covers two years before and after the reform is used for the analysis. Our empirical findings suggest that households reshuffle their balance sheets in the case of a partial deductibility phase-out. In particular, heavily taxed, interest-bearing assets are used to pay off mortgage debt. Furthermore, we find that taxes have a significant impact on the structure of household portfolios even after controlling for unobserved heterogeneity.Household portfolios, taxation, panel data, natural experiment

Probabilistic Approach to Structural Appraisal of a Building During Construction

Probabilistic assessment methods are very attractive as they allow a systematic treatment of uncertainties.  In this paper, probabilistic models are formulated to predict the reliability of concrete in a structure under construction, a case study of Laboratory Block for College of Continuing Education, University of Port Harcourt, Rivers State.  The safety of the structure is predicted based on the safety index obtained from the probabilistic model.  The design strength of concrete in the structure (grade of concrete) is obtained from schmidt hammer test.  The concrete in the structure gave a safety index value of 2.83 which is less than the target reliability index value of 3.7 for  concrete for safety class 1 BKR[1] and less than the target reliability index of 4.5 for slabs, 4.9 for beams in flexure, 3.6 for beams in shear and 3.9 for columns under dead and live-load combination[2] proving that the structure is not safe and is prone to risk of serious injury to persons and damage to properties

OPTIMISATION OF COMPRESSIVE STRENGTH OF PERIWINKLE SHELL AGGREGATE CONCRETE

In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe’s regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for adequacy using a student t-test at 95% confidence level and was found to be adequate. A computer programme coded in basic language was used to select the mix ratios that optimized the compressive strength of periwinkle shell aggregate concrete. The optimum compressive strength was found to be 19.50N/mm2corresponding to a mix ratio of 1:3:6 (cement, sand and periwinkle shell) at a water-cement ratio of 0.65. With the formulated model, the mix ratios corresponding to a desired strength value can be predicted with reasonable accuracy and without waste of time. http://dx.doi.org/10.4314/njt.v36i1.

Effect of oral administration of aqueous extract of cassia occidentalis l. seeds on serum electrolytes concentration in rats

The effect of aqueous extract of C. occidentalis seeds on serum electrolytes concentration, in rats, was investigated in order to assess the acclaimed hypotensive effect of the seeds and also the seeds extract’s relation with acid – base balance of the body. Serum concentrations of sodium, potassium, chloride and bicarbonate ions were determined in 64 rats grouped into 4. Groups I, II and III rats were orally administrated with the seeds extract at a daily dose of 30 mg/kg, 60 mg/kg and 90 mg/kg respectively for 1,2,3 and 4 weeks each. Group IV served as control. Concentration of sodium, potassium, chloride and bicarbonate in the serum of control rats were found to range from 130 – 155 mEq/L, 3.4 - 8.7 mEq/L, 80 – 107 mmol/L and 20 -35 mmol/L respectively. The results of this study showed no significant difference (

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.

Evaluation of the layering of rock strata and basement rock depth of a university teaching hospital premises in northern Nigeria

The layering of rock strata and depth to the basement rocks of a Federal University Teaching Hospital premises in Northern Nigeria was investigated in this study with the aim of providing 2D geo-electrical resistivity images of the subsurface for geotechnical development using a modern and state-of-the-art field instrument, the ABEM Automatic LUND Imaging System (Terrameter SAS 4000 and ES 464). Three profiles were covered and the data processed to display the variations of electrical resistivity using the RES2DINV software. The results of the survey in correlation with borehole data in the area revealed three distinct layers: the overburden which is about 16 m - 26 m thick having a resistivity range of about 194 Ωm – 1759 Ωm. The weathered basement which is appreciably thick (about 5 m – 14 m),which is highly fractured and weathered, so constitutes a good aquifer having a resistivity range of about 0.687 Ωm – 678 Ωm and the fresh crystalline basement having a resistivity of about 1223 Ωm. The fresh crystalline rock is at variable depths of about 21 m - 40 m below the surface.Keywords: Rock strata, Geotechnical, Electrical resistivity, Basement, Overburde

2D geo-electrical imaging for groundwater exploration in Shika, along Zaria-Funtua Road north of Ahmadu Bello University main campus, Samaru, Zaria

A two dimensional (2D) geoelectrical tomography of Ahmadu Bello University Teaching Hospital Premises was carried out with the aim of identifying a suitable location for siting a borehole. This was sequel to the fact that a borehole drilled without proper geophysical investigation in the quarters for resident doctors did not produce water. State-of-the-art equipment was employed and 2D surveying proved a powerful geological mapping tool, for use in hydrogeological mapping including engineering and environmental applications. The 2D inversion results of the survey were correlated with the lithology information obtained from the boreholes in Jama’a village, and the hostels and the residential quarters of ABUTH. The stratigraphic structure of the study area is very complex and is a product of volcanic and magmatic activities of various ages. Based on the geo-electrical images obtained in the study area, three distinct layers were revealed, the overburden with an average thickness of about 16 m – 26 m. The overburden is immediately underlain by the weathered basement, 5 m – 14 m thick which consists of disintegrated schistose rock materials, sand and gravel. This layer has a relatively low resistivity due to the presence of water and clay, which reduces the permeability, so this layer is thus regarded as the aquifer. The fresh basement rock was encountered at a variable depth of between 21 m and >30 m with resistivity 1223 Ωm up to 11918 Ωm. These results agree with the borehole logs. The complete set of borehole logs used in this research were obtained from the original hydro-geologic assessment report of the groundwater research department of the National Water Resources Institute (NWRI), Mando, Kaduna; Kaduna State, Nigeria.Keywords: Tomography, Inversion, Lithology, Geo-electrical, Aquifer, Borehol