Anis Shuib

A Review on the Viscous and Thermal Transport Properties of Nanofluids

In modern science and engineering nanofluids are playing a vital role in the application of heat transfer devices due to their effective properties. Addition of nanoparticles in the fluid can alter thermophysical properties of the nanofluid. Experimental and theoretical studies are essential to understand the change in fluid dynamics aspects of the fluid by the addition of nanoparticles. This paper presents a brief review on the viscous and thermal transport effects of nanofluids. The main emphasis is on the comparison of previous theoretical and experimental studies for thermophysical properties of nanofluids. These properties include density, viscosity, thermal conductivity and specific heat capacity of nanofluids.

Study the Release of Urea from Agrium® Coated Urea Using UV-Vis Spectrometer

Elucidating the release pattern of controlled release fertilizer (CRF) is important not just for manufactures but also for farmers because it assists them in making judgments of fertilizer effectiveness and nutrient planning. Investigation on the release pattern of different types of CRF both in the laboratory and in the crop-field is crucial in order to determine the effectiveness of fertilizer on plant growth. Consequently, the fertilizer application could be planned to meet the crop requirement. This paper presents a practical approach to analyze the release pattern using Agrium® coated urea. UV-Vis spectrometer is employed to analyze the amount of nitrogen released. The approach reduced analytical error by preventing sample dilution before measuring. According to laboratory results, UV-Vis spectrometer has shown a good potential to be used in studying the nutrient release behavior from CRF. A sigmoidal shape has been obtained from the release profile, and is corresponded with findings in other studies. The results satisfy the criteria for CRF specified by European Committee for Standardization. Collectively, this study demonstrated that the UV-Vis spectrometer is a promising equipment, which can be utilized in studying controlled release behavior.

Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m2/g and 0.17 cm2/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from sin...

Adsorptive Removal of Ni2+ from Aqueous Solution onto Rice Husk-Based Activated Carbon

The potential of rice husk-based activated carbon (RHAC) as an alternative low-cost adsorbent for the removal of Ni2+ from aqueous solution was studied. RHAC was prepared via chemical treatment using NaOH followed by the carbonization process. The textural properties of rice husk-based activated carbon, i.e. surface area (253 m2/g) and pore volume (0.17 cm2/g), were determined by N2 adsorption. The adsorption studies to remove Ni2+ from aqueous solution using RHAC were carried out at a fixed initial concentration of Ni2+ (150 ppm) with varying RHAC as a function of contact time at room temperature. The concentration of Ni2+ was determined by atomic absorption spectrophotometer (AAS). The maximum removal of Ni2+ was increased from 40% to 89% when the amount of RHAC was increased from 0.1 g to 0.5 g. The isotherm and kinetic analyses showed that equilibrium data of adsorption studies fitted well Langmuir, Freundlich and second order kinetic models.

The Potential of Thiosulfinates in Garlic Extract as Urease Bioinhibitor

Research on garlic or scientifically called as Alliumsativum L. has been conducted to ensure its inhibitory effects as potentially safe and biodegradable inhibitor. From previous research, thiosulfinates (TS) contained in garlic extract proved to inhibit platelets aggregation in medical applications. TS are obtained by extracting garlic cloves. In this study, the inhibitory effect is determined by analyzing ammonia (NH3) concentration in enzyme-containing solution and standard urea assay mixtures using UV-Vis spectrophotometer device. The Beer’s law is used to calculate the concentration with an aid of the curve value of standard NH3 calibration graph. Based on previous research, the NH3 concentration is predicted to decrease with amount of enzyme-containing solution and incubation time.

Thermodynamic Properties of Flufenamic Ionic Liquids

Active pharmaceutical ingredients-ionic liquids (APIs-ILs) in which, when compared to active pharmaceutical ingredients hydrochloride (APIs-HCl), exhibits better solubility, increased thermal stability and significant enhancement in the efficiency of APIs. Three novel flufenamic-ILs were synthesized and their density and viscosities were determined and reported as a function of temperature. From the experimental density data the crystal energy, molecular volume and standard entropy was estimated. The result showed that the density and viscosities decrease with increasing temperature in these four ionic liquids.

Numerical Simulation to Investigate the Effect of Non Newtonian Properties of Blood on Wall Shear Stress in Diseased Artery

Wall Shear Stress (WSS) in the artery is one of the indicators for brain artery disease progression. WSS is proportional to the viscosity and shear rate of the flowing fluid. In this study, WSS of cerebral artery with aneurysm was predicted using Computational Fluid Dynamics (CFD). The effect of non-Newtonian properties of blood will be studied by comparing Power law model with Newtonian model. Based on the results, maximum value of WSS is 150 Pa for Newtonian model and for Power Law model is 24 Pa. Newtonian model was found overpredicted the WSS resulted from Power Law.