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Classification of rocks radionuclide data using machine learning techniques

Khan A. R., Mir A. A., Saeed S., Rafique M., Asim K. M., Iqbal T., Jabbar A., Rahman S. U.

Acta Geophysica

2018

Vol. 66, no. 5

1073--1079

The aim of this study is to assess the performance of linear discriminate analysis, support vector machines (SVMs) with linear and radial basis, classification and regression trees and random forest (RF) in the classification of radionuclide data obtained from three different types of rocks. Radionuclide data were obtained for metamorphic, sedimentary and igneous rocks using gamma spectroscopic method. A P-type high-purity germanium detector was used for the radiometric study. For analysis purpose, we have determined activity concentrations of 232Th, 226Ra and 40K radionuclides, published elsewhere (Rafique et al. in Russ Geol Geophys 55:1073–1082, 2014), in different rock samples and built the classification model after pre-processing the data using three times tenfold cross-validation. Using this model, we have classified the new samples into known categories of sedimentary, igneous and metamorphic. The statistics depicts that RF and SVM with radial kernel outperform as compared to other classification methods in terms of error rate, area under the curve and with respect to other performance measures.

Investigation Of Sound Absorption Properties Of Bark Cloth Nonwoven Fabric And Composites

Rwawiire S., Tomkova B., Gliscinska E., Krucinska I., Michalak M., Militky J., Jabbar A.

Autex Research Journal

2015

Vol. 15, no. 3

173--180

The quest for sound-absorbing materials that are not only environmentally friendly, but also sustainable is the foremost reason for natural fibre-acoustic materials. Bark cloth is a natural non-woven fabric that is largely produced from Ficus trees. An exploratory investigation of bark cloth a non-woven material and its reinforcement in epoxy polymer composites has been fabricated and investigated for the sound absorption properties so as to find the most suitable applications and also to see whether bark cloth can be used in some applications in place of man-made fibres. Three types of material species were investigated with their respective composites. The fibre morphology showed bark cloth to be a porous fabric that showed promising sound absorption properties at higher frequencies. The sound absorption results of four-layer material selections of Ficus natalensis, Ficus brachypoda and Antiaris toxicaria bark cloth showed sound absorption coefficient of 0.7; 0.71 and 0.91 at f > 6400 Hz, respectively. The bark cloth reinforced laminar epoxy composites had reduced sound absorption coefficients, which ranged from 0.1 to 0.35, which was attributed to decreased porosity and vibration in the bark cloth fibre network.

Recursterols A and B, Chymotrypsin Inhibiting Sterols from Haloxylon recurvum

Hussain S., Ahmed E., Malik A., Ferheen S., Jabbar A., Ashraf M., Lodhi M., Choudhary M.

Polish Journal of Chemistry

2006

Vol. 80, nr 3

409-415

Recursterols A(1) and B (2), the new C-24 alkylated sterols, have been isolated from the chloroform-soluble fraction of Haloxylon recurvum. Their structures have been deduced through spectroscopic techniques including 2D NMR. Both 1 and 2 showed promising inhibitory potential against the enzyme chymotrypsin.