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Experimental works on bubble column hydrodynamic are normally carried out on a laboratory scale less than 0.3 m with holes number less than 10. In this paper, we discuss several approaches to bubble column scale-up, relying on variables of parameters. Two spargers with different hole diameters (0.5 mm and 1.25 mm) and superficial gas velocities (0.0125 m/s and 0.0501 m/s) are used to determine the distribution of gas holdup and liquid flow pattern. An Insignificant level of bed heights is investigated for the efficiency of hydrodynamic performance. Computational Fluid Dynamic (CFD) is used as the realistic representation of the actual reactor. The flow of the gas-liquid interface is implemented using the VOF model using the finite volume method by tracking the volume fraction of each of the fluids throughout the domain. It is observed that the initial bed heights, superficial gas velocity, and hole diameter of the sparger influence the overall gas holdup. Although the difference in sparger hole diameter affects overall gas holdup, the results are weak relative to other operating conditions. The simulation work is then compared with experimental data to improve the accuracy in analyzing the hydrodynamics of multiphase system, as well as validated the multidimensional models.

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.

Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their &pi, &pi, interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/&minus, 4%) mg/g based on Langmuir isotherms.

Background: Polymeric inclusion complex has been used frequently as a drug delivery system due to controlled release, non-toxic properties and high bioavailability. Objective: The current study aims to improve drug release properties of orotic acid loaded with chitosan inclusion complex (OA/CS). Material and methods: The OA/CS inclusion complex were synthesized using freeze drying technique. The characterization of inclusion OA/CS was carried out using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), Differential Scanning Calorimetry (DSC), Zeta sizer, and Transmission Electron Microscopy (TEM). Results: The FTIR peaks of orotic acid have almost vanished in the OA/CS spectrum due to the restriction of OA vibration upon loading in CS cavity. The diffraction peaks of the OA/CS are completely diffused due to the amorphous state and the lack of crystallinity of inclusion complex. The DSC marked changes are indicative of the amorphous phase of solid dispersion, as well OA encapsulation into the nanocavity of CS. The size of OA/CS ranged between 58 nm and 200 nm and the zeta potential was 30 mV. In addition, transmission electron microscopy (TEM) showed that OA/CS sizes were ranged from 20 to 45 nm. Conclusion: Thus, this study indicates that OA/CS has promising future to further develop a carrier for drug delivery systems.

The present study aimed at the screening of parameters for electrocoagulation treatment of treated palm oil mill effluent using minimum-runs resolution IV design. The responses examined include: chemical oxygen demand removal (%), total suspended solids removal (%) and turbidity reduction (%), and the varied dependent factors comprise: electrical current density (mA/cm2), time (min), pH, electrolyte concentration (g/L), stirring speed (rpm), electrode spacing (mm) and electrode configuration (monopolar or dipolar). The statistical results revealed that the current density has a significant influence on the treatment performance at two-level interactions with pH, electrode spacing and electrode concentration and at three-level correlations with time and pH. Thus, the most important factors affecting the removal efficiency of the organic compounds were found to be pH, time, electrode spacing, electrolyte concentration and electrode configuration at a P value less than 0.05, respectively, in the descending order of significance. Therefore, the optimized electrocoagulation process could be reached with current density equal to 5 mA/cm2, electrolysis time of 5 min, electrode spacing of 5 mm and using monopolar electrode configuration. This combination provided the maximum ability of the process for chemical oxygen demand (68.84%), total suspended solids (93.27%) and turbidity reduction (92.88%) predictions, with the corresponding experimental values of 69.27, 97.59 and 96.91%, respectively.

Calculation work is carried out in the present project to study the effect of different parameters on hydrodynamics of gas-liquid flow by using CFD. The steady state and transient, three dimensional simulations are performed of the whole bubble column for various inlet gas and sparger designs. A standard k-ε is used to describe turbulence occurring in the continuous fluid. Results show he asymmetric recirculation stronger with an increase in the number of holes giving better mixing. The gas hold-up increased with superficial gas velocity but independent of the sparger design at high velocity. Comparison of simulation results with the previous experimental work data has provided a successful validation of the model.

The mass loss of three wood species in Malaysia, Shorea laevis, Koompassia malaccensis, and Shorea parvifolia were measured against time and temperature at three different heating rates (5, 10 and 20 °C/min) in nitrogen environment, through thermogravimetry analysis (TGA) technique. This measurement revealed that the decomposition of these wood generally occurred in three stages, the dehydration stage, the active stage, and; the passive stage. The maximum decomposition peak in derivative thermogravimetric (DTG) analysis curve shifted towards higher temperature range with the expedition in heating rate. The kinetic decomposition parameters of the timbers were determined by adopting thermal kinetic method of Coats and Redfern. Principally, the density and moisture content of timber does not influence the kinetic parameters studied in this work. Overall, the thermal decomposition in the second-stage (active stage) was dominated by the hemicellulose and cellulose while the decomposition of lignin was apparent in the third-stage (passive stage) of pyrolysis. The higher activation energy in the second-stage indicates that more cellulose is contained in the sample. The activation energy of lignin is observed to be much lesser compared to the activation energy of the hemicellulose and cellulose for two species tested except for the Shorea parvifolia.

The most challenging issue faced by the petroleum industry in recent years was the water production during crude oil and gas extraction. This challenge has caused aggravated damages to treatment facilities by increasing the cost of production as water production increased over time. However, most of the water produced from oil and gas platforms is produced as water in oil emulsion. Treating emulsion has been experienced using techniques involve specific chemical methods. This study used the bottle test technique to investigate the performance of non-ionic demulsifiers, Propargyl Alcohol (PA) and Triethylene Glycol (TG), in breaking water in oil emulsion. Subsequently, a factorial design was applied for the characterisation of five variables, namely demulsifier dose, toluene concentration, pressure drop, temperature, and sitting time. Then, the significant factors were further analysed using Central Composite Design (CCD) based on the Response Surface Method (RSM). In particular, CCD was used to study the influence of demulsifier dose, toluene concentration, pressure drop, temperature, and sitting time on the response and to find the optimal condition to achieve maximum dehydration. Additionally, Analysis of Variance (ANOVA) was used to test the accuracy of the mathematical models established using CCD. The results show that demulsifier dose, temperature, and sitting time were the most significant parameters for breaking the emulsion, and that the optimal values for the input variables were successfully obtained using RSM.

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.

Achieving emulsion stability in the petroleum industry is a major challenge due to several problems encountered in the oil refining process, such as corrosion in equipment, high-pressure drops in pipelines, and catalyst poisoning in upstream facilities. Thus, several methods are applied for emulsion treatment and chemical treatment using surface-active agents, a fundamental method in the petroleum industry. The present work investigated the performance of a non-ionic surfactant in separating water in a crude oil emulsion via the bottle test technique. Then, a Fractional Factorial Design (2K&minus, 1) was used to characterise the effect of significant variables. In particular, a Pareto chart was employed and factors such as demulsifier dosage, toluene concentration, pressure, sitting time, and temperature were investigated. Accordingly, the parameters applied were further analysed using a Central Composite Design (CCD) based on the Response Surface Method (RSM). The experimental results based on analysis of Variance (ANOVA) show that demulsifier dosage, temperature, and sedimentation times were the main variables affecting the dehydration process, with the highest F-values being 564.74, 94.53 and 78.65 respectively. The increase in the surfactant dosage before critical concentration, temperature and sitting time leads to boosting dehydration efficiency. In addition, a mathematical model was established for the variables, with a coefficient of determination value of 0.9688. Finally, numerical optimisation was performed on the variables and the results show that the optimal values are 1000 ppm, 15.5 mL, &minus, 400 mmHg, 120 min, and 90 &deg, C, for demulsifier dosage, toluene concentration, pressure, sitting time, and temperature, respectively.

Radioactive particle tracking (RPT) is one of the non-invasive techniques for monitoring and investigating multiphase flow system. This technique have been widely utilized in the field of chemical process engineering for better understanding and optimizing process hydrodynamics especially in the multiphase reactor such as bubble column reactor. Due to opaque nature of industrial process systems, especially in the case of multiphase flows, noninvasive methods based on ionizing radiation have been considered for evaluating the hydrodynamic parameters. The feasibility study of radioactive particle tracking techniques in quadrilateral bubble column reactor has been successfully achieved. The radioactive particle tracking facility and data acquisition system has been developed and experimental calibration using single particle radioactive particle 46Sc to investigate dynamics behaviour of quadrilateral bubble column reactor is completed. The results indicated that there is back mixing behaviour in the bubble column process. The results also reported that the radioactive particle 46Sc is still in good condition and there is no radiation contamination problem arises while performing radioactive particle tracking techniques. The RPT technique was performed to reveal the instantaneous velocity and time-averaged liquid velocity in the current bubble column reactor.

Oil palm empty fruit bunches (EFB) is a plentiful agricultural waste in Malaysia, which can be further processed to increase its calorific value for fuel purposes and as a value-added product. Microwave pyrolysis is a promising technology that can convert the EFB into bio-oil, char and synthesis gas without cracking the EFB surface because of overheating. Computational fluid dynamics (ansysTM cfx 13.0, ANSYS, Inc. Southpointe, 275 Technology Drive, Canonsburg, PA 15317, U.S.A.) was used in a 3-D model to predict the temperature distribution of the EFB model in a microwave-heated reactor during the pyrolysis process. The parameters under investigation include heating source orientation, nitrogen gas flow rate, microwave power intensity and microwave absorber efficiency, which have an important role in pyrolysis optimisation. The results show that heating source orientation and nitrogen gas flow rate did not affect the EFB temperature profiles. However, microwave power intensity has a linear relationship with the EFB temperature at different microwave absorber efficiencies. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.

This paper describes the development of colloidal Au-SiO2 with core-shell structure nanoparticle radioactive tracers by neutron activation in nuclear reactor that produce Au-198 (T1/2=2.7 d) emitting gamma ray of 412 keV. Using conventional citrate-reduction method, gold nanoparticles were prepared from its corresponding metal salts in aqueous solution then coated with uniform shells of amorphous silica via a sol-gel reaction. The citrate-reduction-based method provides gold nanoparticles with higher concentration and narrow size distribution. By using transmission electron microscopy (TEM), the resultant of particle size and silica coatings could be varied from tens to several hundred of nanometers by controlling the catalyzer and precipitation time. Au-SiO2 core-shell nanostructure is good to prevent the particles from getting agglomerated resulting in a big mass. In addition, silica surface offer very good chances that make the hydrophobic and hydrophilic behavior on the gold nanoparticles. EDXRF spectrum has proven that Au-SiO2 core-shell nanoparticles sample consists purely of a gold and silica particles. This target material of radiotracer application used to investigate multiphase system in process industries without disturbing the system operation.

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.

Pollution has a negative influence on the environment and is necessary to eliminate from wastewater and aqueous solution. There are several adsorbents for removing the pollution, among them Graphene oxide and Chitosan are proper elements with great uptaking ability. In this investigation, graphene oxide surface was coated with chitosan paricles to remove the Cadmium (II) from aqueous solution. The impact of concentration, pH and time were studied to achieve the optimum conditions of adsorption. The adsorbent was analyzed by TEM, FT-IR, XRD, and SEM analysis. The outcomes presented that the adsorbent was prepared successfully. The concentration item was tested from 10 to 120 ppm. The pH and time items were studied from 3 to 8 value and from 5 to 140 minutes for eliminating cadmium (II) respectively. Freundlich and Langmuir's models was used and the pseudo-second-order was the best fitted kinetic model in this investigation. Conclusively, the maximum adsorption ability of the made adsorbent was achieved at 107.8 mg/g based on Langmuir isotherm.

Usage of a traversing beam gamma densitometer measurement for the phase fractions distribution of a mixture of water and kerosene was achieved experimentally in a horizontal pipe tube. The phase fractions distribution was determined with the beam being traversed in three directions for example 0, 45 and 90° of the vertical line passing through the axis of the pipe tube. Measurement was made at two positions spaced into 2.54 cm internal diameter along the 9.7 m pipe length (1.0 m and 7.72 m along the horizontal pipe tube) with two input water fractions of 0.4 and 0.6. The measurement was done in two-phase oil water experimental rig (TOWER) facility. This facility allows the two fluids to be fed to the test section before they separated throughout the coalescer and returned once again to the test line. The flow developed naturally from an initial stratified flow in which the oil and water were introduced separately at the top and the bottom of the test section, respectively. The flows were such that the liquids were fully inter-dispersed by the end of the test section. The phase fractions distribution was shown to be homogeneously mixed near to the outlet of the test section. The mean hold-up was found to depend on the mixture velocity.

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 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.