Electrospinning is a simple and convenient method for fabrication of polymeric nanofibers from polymeric solution. In this paper, polyacrylonitrile (PAN) fibers are fabricated from different PAN solution concentration and applied voltages by electrospinning process. The fibers were then analyzed with Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and four-point probe to study the effect of PAN solution concentration and applied voltage on electrospun PAN fibers in terms of fiber diameters and morphologies, crystallinity and electrical properties. SEM showed that the electrospun PAN fibers with fiber diameter ranging from 0.5 to 2.7 µm. The diameter of fibers were increased with increasing PAN concentration and voltage applied. The increasing voltage also has increased the bead formation on the fibers. The amorphous structure of electrospun PAN fibers was exhibited by XRD. Electrical conductivity of electrospun PAN fibers were increased with increasing PAN concentration but somehow reduced with increasing voltage of the electrospinning.

The ability of pomelo peel (PP) as natural adsorbent to remove Cu (II) ions from aqueous solution was investigated. The influence of solution pH, contact time and temperature were evaluated. Cu (II) removal increased as the pH of the solution increased and the maximum value reached at pH 6. The adsorption was relatively fast (30 min). Adsorption kinetics followed the pseudosecondorder model. At low temperature the adsorption was not affected but at high temperature it was reduced. PP is considered as low cost material that shows potential to be applied in wastewater technology for remediation of heavy metal contamination.

Environmental contamination triggered by dyes has gained global attention. Industrial effluent of dye in high concentration into the rivers must be reduced to minimise the harmful effect on the quality of water that threatens human health. The removal of dye from wastewater is a significant step in addressing the problem of dye emission which can be achieved through adsorption separation technologies. In the most adsorption process, the adsorbent is in contact with fluid in a fixed bed. The performance of adsorptive separation of dye can be predicted through a fixed bed mathematical model which consists of coupled partial differential equations for optimizing the design and operating conditions. This paper presents a mini-review of mathematical modelling of fixed-bed adsorption of dye. The discussions are limited to the used of single component-dye separation in, convection-diffusion equations coupled with Langmuir isotherm. Besides, the numerical methods used for solving the convection-diffusion equations are also discussed in this paper.

In the present work the effect of heat treatment on the hardness behavior of AZ91 and AZ91 reinforced carbon nanotube were investigated under FESEM, Xrd and Rockwell hardness tester. Cnt was embedded homogenously into the matrix due to successfully mechanical alloying using planetary milling. Kinetic precipitation of β-phase (Mg17Al12) also reveal in the X-ray diffraction pattern. Meanwhile, the artificial aged nanocomposite found decreased in hardness, compare to monolithic has higher value form early aged until 36 hours aging.

No abstract