Siti Aslina Hussain

Expression and purification of the matrix protein of Nipah virus in baculovirus insect cell system.

Nipah virus (NiV) causes fatal respiratory illness and encephalitis in humans and animals. The matrix (M) protein of NiV plays an important role in the viral assembly and budding process. Thus, an access to the NiV M protein is vital to the design of viral antigens as diagnostic reagents. In this study, recombinant DNA technology was successfully adopted in the cloning and expression of NiV M protein. A recombinant expression cassette (baculovirus expression vector) was used to encode an N‐terminally His‐tagged NiV M protein in insect cells. A time‐course study demonstrated that the highest yield of recombinant M protein (400–500 μg) was expressed from 107 infected cells 3 days after infection. A single‐step purification method based on metal ion affinity chromatography was established to purify the NiV M protein, which successfully yielded a purity level of 95.67% and a purification factor of 3.39. The Western blotting and enzyme‐linked immunosorbent assay (ELISA) showed that the purified recombinant M protein (48 kDa) was antigenic and reacted strongly with the serum of a NiV infected pig.

Preparation and Quantification of Radioactive Particles for Tracking Hydrodynamic Behaviour in Multiphase Reactors

Radioactive Particle Tracking (RPT) technique has emerged as a potential and versatile technique, both in terms of richness of information and applicability to a variety of multiphase flow systems. RPT is not an off-the-shelf technique and thus has to be developed by the intended user. This paper is intended to present a simple method and procedure for preparing suitable radioactive particles tracer (Au-198 and Sc-46) irradiated simultaneously with neutrons using TRIGA Mark II research reactor. These present work focuses on the performance evaluation of encapsulated gold and scandium particle to be used as single radioactive particle tracer using qualitative and quantitative neutron activation analysis (NAA) and X-ray micro computed tomography (micro-CT) scanner installed at Malaysian Nuclear Agency.

Removal of Lactose from Highly Goat’s Milk Concentration through Ultrafiltration Membrane

Concentration of goat milk using cross-flow filtration unit with 10KDa molecular weight cut off (MCWO)-sized ultrafiltration membrane was examined under various operating conditions. The parameters to be optimized are trans-membrane pressure (TMP) and cross-flow velocity. Permeate flux is decreased with time due to fouling of the membrane. The localized membrane fouling may be reduced by increasing the feed flow rate and TMP to mitigate overall membrane fouling. By doing so, the transmission of lactose will also increase. The aim is to produce concentrated goat milk with minimal lactose content and thus high concentration of protein. Spray-drying method is used to convert the concentrated non-lactose milk obtained into milk powder. The milk powder then was characterized in terms of its surface particle, solubility, and nutritional content with the well-commercialized non-lactose milk. This project tackles understanding to minimize the deposition rates of particles on membrane by optimizing the involved parameters and be proved by comparing the yield obtained with well-commercialized non-lactose milk. Keywords: Goat’s milk, lactose intolerance, ultrafiltration, spray dry,membrane, concentration

Industrial radiotracer application in flow rate measurement and flowmeter calibration using 99mTc and 198Au nanoparticles radioisotope

The flow rate or fluid velocity measurement is important to maintain fluid flow quality performance in the systems. This study focuses on determination of volumetric flow rate measurement and to calibrate the conventional flowmeter using industrial radiotracer approach in quadrilateral gas-liquid bubble column reactor. In this work, two different radioisotopes which emit γ-ray have been chosen as radioactive tracer which is 99mTc produced from 99Mo/99mTc radioisotope generator and 198Au nanoparticle form neutron activation at research nuclear reactor TRIGA Mark II. Both radioisotopes representing liquid and solid tracer purposely designed for tracing liquid flow. The peak to peak radiotracer method known as pulse velocity method was applied to determine the volumetric flow rate. The radiation signals were monitored using 4 unit NaI scintillation detectors located at 4 different points nearby the inlet and outlet of the quadrilateral bubble column reactor process stream. The water volume inside the bubble column reactor was fixed at 0.04 m3 and liquid flow rates in this reactor were specified on installed flowmeter at different reference value which is 4 lpm, 8 lpm, and 12 lpm, respectively. The experimental result shows very good linearity and repeatability by following the theoretical equations with less uncertainty in volumetric flow rate measurement. The obtained results also validated the effectiveness of the proposed method for the installed flowmeter calibration efficiency.

Resonance Light-Scattering Enhancement Effect of the Y(III)–PUFX–Eosin System and its Fluorescence Study

Highly sensitive and rapid method for the determination of prulifloxacin (PUFX) has been developed on the basis of ion association reaction of PUFX, Y(III) and eosin Y (EY). In pH 6.5 BR buffer medium, PUFX reacts with Y(III) to form a 2:1 cationic chelate which further reacts with EY to form 2:1 ion-association complex. As a result, not only the spectra of absorption are changed, but quenching of fluorescence and significant enhancement of resonance Rayleigh scattering (RRS) is observed. Furthermore, a new RRS spectrum would appear, and the maximum RRS wavelength was located at about 375 nm. The fluorescence quenching (FQ) and enhanced RRS intensity were directly proportional to the PUFX concentration in the ranges of 1.5 – 7.6 μg mL–1 and 0.004 – 3.0 μg mL–1 with detection limits 8.5 ng mL–1 and 1.1 ng mL–1, respectively. The optimum conditions of RRS method and the effects of coexisting substances on the reaction were investigated. In addition the composition of ion-association complexes, the reaction mechanism, the energy transfer between absorption, fluorescence and RRS and reasons for RRS enhancement were discussed. The methods were applied to the determination of PUFX in pharmaceutical samples with satisfactory results.

Numerical study of fluid flow across multiple cosmo ball

The Cosmo ball mainly has its application as a filter media in an effluent treatment system. A very large surface area could be obtained for microbial attachment as the Cosmo ball has a design such that a surface for fluid interaction with the maximum microbial. This will greatly improve the degradation of organic matter in wastewater through the microbial activities. Cosmo ball is a media used in wastewater treatment in view to increase the surface area of contact and provide longer contact time for biological activities. It is usually placed as a media or as packing in the aeration tank, or in the activated sludge tank. It induces the growth of bacteria on its surface that will serve as a contact area for the wastewater and the microbial. The purpose of this simulation is to analyse the fluid flow pattern namely water around the Cosmo ball. By this means, the overall insights on the interaction of the fluid flow with the Cosmo ball surface can be visualised. The result shows that the fluid flows around the ball disperse inducing mixing in the overall system. There are some retention of flow has been observed that occurs in the ball. The retention of flow induces better microbial interaction to the fluid.

Preparation and quantification of radioactive particles for tracking hydrodynamic behavior in multiphase reactors.

Radioactive particle tracking (RPT) has emerged as a promising and versatile technique that can provide rich information about a variety of multiphase flow systems. However, RPT is not an off-the-shelf technique, and thus, users must customize RPT for their applications. This paper presents a simple procedure for preparing radioactive tracer particles created via irradiation with neutrons from the TRIGA Mark II research reactor. The present study focuses on the performance evaluation of encapsulated gold and scandium particles for applications as individual radioactive tracer particles using qualitative and quantitative neutron activation analysis (NAA) and an X-ray microcomputed tomography (X-ray Micro-CT) scanner installed at the Malaysian Nuclear Agency.

Numerical Study of Blood Flow Pressure Drop in Aorta Coronary Sinus Conduit

Numerical studies of the blood flow system of aorta coronary sinus conduit were carried out using ANSYS™ CFD simulation. The pressure inside the conduit was investigated to ensure a pressure drop from 80 to 15 mmHg. It was aimed to model a coronary sinus conduit in three-dimension using ANSYS™ CFD. The simulation involved pre-modeling, modeling and simulation stages where the model will undergo each section of program in ANSYS™ CFD such as design modeler, meshing, pre-processing, solver and post-processing. From the analysis of coronary sinus conduit, it is found that a narrow tube needs to be incorporated into the conduit produce. This is to induce a venturi effect to reduce the pressure of blood from 80 to 15 mmHg within a specific throat length. A model of 3 mm inlet and throat diameter of 1.13 mm throat diameter show the best result for pressure reduction from 80 to 15 mmHg. The model gives a uniform pressure drop along the throat section of the conduit.

Simulation of cosmo balls in wastewater treatment

There are multiple ways to have wastewater treated. Being the common is the aeration tank where wastewater is captured in a tank for certain duration which known as Hydraulic Retention Time and it is then aerated. The aeration process pumps air into the wastewater by means of using surface aerator devices or using air diffusers which are install at the bottom of the tank. Cosmo ball serves as a packing medium in the aeration tank to allow microbial to growth on its surface. The air pumped into the wastewater provides the microbial with the oxygen need for oxidation of organic matter. Hence, the distribution of the oxygen around the Cosmo balls is crucial in determining the efficiency of the wastewater treatment plant. The purpose of this simulation is to have an insight on the flow distribution of the wastewater with and without the air across the Cosmo balls transient state. The Cosmo ball in bulk serves as the restriction to the flow. The multiphase flow show significant mixing in the system where the fine bubble serves as virtual mixer in the wastewater. In addition, the zone of the bubble retain in the system will improve the overall efficiency of the treatment plant. This is due to the fact that the bacteria will have sufficient contact time with the air bubble for oxidation process to occur. For a single Cosmo ball, it was found that the velocity distributed uniformly in the intermediate flow region while at the turbulence region the velocity is higher (Hussain et al., 2010). The lag in the individual Cosmo ball flow indicates that the hollow region in the balls can induce higher retention time for wastewater treatment. This is due to the nature of the chaotic flow regime inside the hollow region. The efficiency of the wastewater treatment plant greatly improves as well as to reduce the area needed for the treatment (Hussain et al., 2010). As can be seen in Figure 1(a), the air volume fraction is estimated at 0.1 due to great dispersion of the air bubble. For Figure l(b) and l(c) shows that air volume fraction is estimated at 0.15 and 0.20, respectively. This is due to less air bubble concentrate around the Cosmo balls in wastewater treatment tank. As a result, the higher the volume fraction the lower the concentration of air bubble distribute across the Cosmo ball as illustrated in Figure led), lee) and l(!) which is the volume fraction at 0.25, 0.30 and 0.35, respectively. This is significantly agreed due to air bubble unifonniy distributed across the Cosmo ball causing the microbial in the wastewater obtain oxygen unifonniy. This phenomenon is good in improving the wastewater treatment efficiency as most of the air volume fraction concentrate at about lower O.LIt is to be noted that most of the bubble will be trapped in either the internal volume of Cosmo ball or at the fin side of the Cosmo ball. This can greatly enhance the oxygen transfer rate to the wastewater as the bubble have enough retention time in the wastewater and exchange the required gas with the microbial on the surface of the Cosmo ball. This is agreed with the result found by Hussain et al., 2010. This is due to the bubble collision or break-up near to Cosmo ball surface and tank wall as shown in Figure 2. At high enough mixture velocity, the flow ultimately becomes mix (dispersion of air in water or water in air), but this is achieve only slowly. The effect of the high velocity show the tendency of the flow to mix and approach uniform distribution as the flow proceeds towards to the top of the tarue are the key of the result as depicted in Figure 2. The result proved that at higher velocity, the flow tendency to mix and distributed uniformly as found by Hussain et al., 2010. In general the streamline result illustrate the great complexity of liquid-gas disperse flow, reflecting to turbulence, gravitation, bubble break-up and coalesces which are occurring in the tank.

Numerical Method on Drug Release from Nanoparticles Using CFD

Nowadays, there are many ways to administer the huge variety of drugs that are on the market. A drug is a chemical substance, that when applied to a living creature, alters its body function. Many drugs are used daily, such as caffeine in coffee and aspirin for pain. A route of drug administration in pharmacology and toxicology is the path by which a drug is brought into contact with the body. The most critical issue is some drugs are not significantly absorbed into the bloodstream. There are thousands of questions on the drug diffusion in the bloodstream and the most common issue is how long will these micro particles drug be released from the tablet Thus, to identify the rate of the drug release and to control the drug release in our body is important, where to meet the target and not to become a waste. The Computational Fluid Dynamics method was used to investigate the drug design and diffusion profiles with time during the process of degradation and diffusion in water.