Browsing by Author "Job, Obalowu"

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    On a Proposed Test Statistic for Testing Equality of Two Means Under Unequal Population Variances
    (Faculty of Humanities, Umaru Musa Yar'Adua University, Katsina, Nigeria, 2017-04-30) Abidoye, Adekunle Omotayo; Sanni, Olusola O. M.; Ikoba, Nehemiah Arhoesere; Job, Obalowu
    In this paper, we propose a test statistic for testing equality of two independent sample means for unequal variances. When variances differ, the pooled sample variance is inadequate as a single value for the variances. This problem is commonly known as the Behrens-Fisher problem. Instead, the sample harmonic mean of variances is proposed, examined and found to represent the unequal variances better. The distribution of this statistic which is known to be generalized Beta is further approximated by the chi-square distribution with the degrees of freedom related to that of the degrees of freedom of the chi-square distribution of the pooled sample variance. Consequently, it is used to replace the pooled sample variance in the resulting proposed t-test. An application of the test statistic using real-life data is provided.
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    Optimization Study of A Nigerian Dolomite Ore Dissolaution By Hydrochloric Acid
    (University of Chem. Techn & Mettalurgy Bulgaria, 2014) Alafara, A. Baba; Aramide, O. Omipidan; Folahan, A. Adekola; Job, Obalowu; Abdul, A.G. Alabi; Ayonbola, Baral; Rashmirekha, Samal
    The optimum condition for leaching dolomite ore in hydrochloric acid solutions was determined in this study. The optimized parameters referred to the temperature, the acid concentration, the time and particle size. It was found that the leaching temperature was 80°C, the acid concentration was 2 mol/L, the leaching time - 60 minutes, while the particle size - 0.01 mm. The dolomite ore leaching efficiency reached 99.3 % under these conditions. The dissolution kinetic data were analysed and found to follow diffusion control mechanism