Romisuhani Ahmad

Bio: Romisuhani Ahmad is an academic researcher from Universiti Malaysia Perlis. The author has contributed to research in topics: Geopolymer & Ceramic. The author has an hindex of 10, co-authored 88 publications receiving 352 citations. Previous affiliations of Romisuhani Ahmad include Kerry General Hospital.

Effect of filler loading and coconut oil coupling agent on properties of low-density polyethylene and palm kernel shell eco-composites

Abstract: Palm kernel shell (PKS), a waste from the oil palm industry, has been utilized as filler in low-density polyethylene (LDPE) eco-composites in the present work. The effect of PKS content and coconut oil coupling agent (COCA) on tensile properties, water absorption, and morphological and thermal properties of LDPE/PKS eco-composites was investigated. The results show the increase of PKS content decreased the tensile strength and elongation at break, but increased the tensile modulus, crystallinity, and water absorption of ecocomposites. The presence of COCA as coupling agent improved the filler-matrix adhesion yield to increase the tensile strength, tensile modulus, crystallinity, and reduced water absorption of eco-composites. The better interfacial adhesion between PKS and LDPE with the addition of COCA was also evidenced by scanning electron microscopy studies. J. VINYL ADDIT. TECHNOL., 00:000–000, 2014. V C 2014 Society of Plastics Engineers

New approach for evaluation of the performance of spectral amplitude coding-optical code division multiple access system on high-speed data rate

Abstract: In this study, the authors proposed a new approach to evaluate the system performance of spectral amplitude codingoptical code division multiple access (SAC-OCDMA) systems. The system performance is evaluated based on a new code called the dynamic cyclic shift (DCS) code. The bit-error-rate (BER) performance of the DCS code on high-speed SAC-OCDMA systems has been analysed and reported in this study. The most remarkable trait of the newly developed DCS code is that the cross-correlation is variable between 1 and 0, and the phase induced intensity noise is low. In order to evaluate the performance of the DCS code in high-speed SAC-OCDMA system, the mathematical analysis has been extensively derived along with the simulation analysis at 10 Gbit/s, which is carried out by using 'Optisys TM ver.9 simulation software from Optiwave'. The results obtained for the DCS code were compared with those obtained from different coding schemes [e.g. random diagonal code and modified quadratic congruence code] for the same number of interfering users. It has been observed that the DCS code of BER equal to 10 -11 can support high data rate (5 Gbit/s) at 60 km transmission link.

Evaluation on the Mechanical Properties of Ground Granulated Blast Slag (GGBS) and Fly Ash Stabilized Soil via Geopolymer Process

Abstract: This study intended to address the problem of damaged (collapsed, cracked and decreased soil strength) road pavement structure built on clay soil due to clay soil properties such as low shear strength, high soil compressibility, low soil permeability, low soil strength, and high soil plasticity. Previous research reported that ground granulated blast slag (GGBS) and fly ash can be used for clay soil stabilizations, but the results of past research indicate that the road pavement construction standards remained unfulfilled, especially in terms of clay’s subgrade soil. Due to this reason, this study is carried out to further investigate soil stabilization using GGBS and fly ash-based geopolymer processes. This study investigates the effects of GGBS and ratios of fly ash (solid) to alkaline activator (liquid) of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, cured for 1 and 7 days. The molarity of sodium hydroxide (NaOH) and the ratio of sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) was fixed at 10 molar and 2.0 weight ratio. The mechanical properties of the soil stabilization based geopolymer process were tested using an unconfined compression test, while the characterization of soil stabilization was investigated using the plastic limit test, liquid limit test, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the highest strength obtained was 3.15 MPA with a GGBS to alkaline activator ratio of 1.5 and Na2SiO3 to NaOH ratio of 2.0 at 7 days curing time. These findings are useful in enhancing knowledge in the field of soil stabilization-based geopolymer, especially for applications in pavement construction. In addition, it can be used as a reference for academicians, civil engineers, and geotechnical engineers.

Statistical optics

Abstract: Course Description This is an advanced course in which we explore the field of Statistical Optics. Topics covered include such subjects as the statistical properties of natural (thermal) and laser light, spatial and temporal coherence, effects of partial coherence on optical imaging instruments, effects on imaging due to randomly inhomogeneous media, and a statistical treatment of the detection of light. Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.

Advanced progress in recycling municipal and construction solid wastes for manufacturing sustainable construction materials

Abstract: The sharply increasing solid waste generation has raised the environmental concerns worldwide which currently have been escalated to a worrying level. Intending to eliminate the negative environmental impacts of solid waste and meanwhile promote sustainability on the energy- and resource-intensive construction and building sector, considerable efforts have been devoted to recycling solid waste for the possible use in sustainable construction material products. This paper reviews the existing studies on recycling municipal and construction solid waste for the manufacture of geopolymer composites. Special attention is paid to the predominate performance of these geopolymer composite products. The principal findings of this work reveal that municipal and construction solid waste could be successfully incorporated into geopolymer composites in the forms of precursor, aggregate, additive, reinforcement fiber, or filling material. Additionally, the results indicate that although the inclusion of such waste might depress some of the attributes of geopolymer composites, proper proportion design and suitable treatment technique could alleviate these detrimental effects and further smooth the recycling progress. Finally, a brief discussion is provided to identify the important needs in the future research and development for promoting the utilization of solid waste materials in the forthcoming sustainable geopolymer industry. In summary, this work offers guidance for the better ecological choice to municipal and construction solid waste through developing waste materials into highly environmental-friendly construction materials.