In the past few years, solid liquid extraction (SLE) has shown greater potential in extraction of rare earth elements (REE) compared to liquid-liquid extraction (LLE). The objective of this study is to analyse the extraction behaviour of dysprosium (Dy) using the extractant immobilised resin (EIR) in SLE. In this study, the synergist activity between ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C2mim][NTf2]) or 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2])) with conventional extractant of Aliquat 336 (A336) were investigated and the most effective synergist extractant (SE) was further immobilised onto resins (CR11, HP20 and SP207) to synthesise EIR. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect the concentration Dy before and after extraction. Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were used to characterise EIRs. From the study, [C2mim][NTf2] showed better compatibility with A336 since this SE (A336- [C2mim][NTf2]) gives higher extraction efficiency of Dy at 90% compared to A336- [C4mim][NTf2] with less than 11% efficiency. SLE using resins immobilised with A336- [C2mim][NTf2] proved that only EIR1 (CR11) can effectively extract Dy compared to EIR2 (HP20) and EIR3 (SP207). The porosity of CR11 was higher compared to other resins which made EIR1 very efficient in adsorbing Dy. Plus, using 0.1 g of EIR1, 100% of Dy was extracted from 5 mL of aqueous phase in SLE compared to 2 mL of aqueous phase in LLE. Conclusively, this research has the potential to improvise the conventional practise of LLE into SLE using EIR with reduction in the use of extractant.
Recently RESS method has been used by researchers to produce fine particles for pharmaceutical drug substances. Since RESS technology acknowledges a lot of benefits compare to conventional method of ginger extraction. Therefore, the objective of this research is to produce direct solid oil particles formation from ginger rhizome which contains valuable compounds by using RESS-CO2 process and to study the effect of pressure and temperature on extraction yield. RESS experiments were carried out at various extraction pressure of 3000, 4000, 5000, 6000 and 7000psi and at different extraction temperature of 40, 45, 50, 55, 60, 65 and 70°C, respectively for 40 minutes extraction time and constant flowrate (24ml/min).From the studies conducted, it was found that extraction pressure is an important factor that can affect particle size and extraction yield. By increasing the extraction pressure, the extraction yield was found to increase with increasing of pressure at constant temperature, but extraction yield was found to decrease with increasing temperature. The highest extraction yield is 2.41% obtained at extraction pressure of 6000psi and constant extraction temperature of 65°C.
Most of the previous researchers used conventional extraction technique such as steam distillation and solvent extraction method in Chromolaena Odorata extraction. Therefore, in this study a clean extraction method that is Supercritical Fluid Extraction (SFE) technology using supercritical carbon dioxide as a solvent (SC-CO2) was introduced for Chromolaena Odorata leaves extraction to produce oil of bioactive components. The objective of this research was to find the optimum pressure for the highest oil yield extracted. The extraction was conducted within a range of temperature (40, 45 and 50°C) and pressure (3000, 3500, 4000, 4500 and 5000psi), at a constant flowrate (24 ml/min) for 10, 20, 30, 40, 50 and 60 minutes of extraction time. From the studies, it was found that extraction pressure is an important factor that can affect the extraction yield where the oil yield increased as the pressure increased due to the increasing amount of CO2 consumed where it boost the density of the solvent to interact with the solute. The highest oil yield is 51.20% at pressure of 4000psi and temperature 50°C. Whereas at the highest pressure of 5000psi, the oil yield is the lowest. This shows that the extraction is not suitable at pressure 5000psi.
The objective of this study is to characterized chitin from Leucaena leucephala pods at different aging stages with hydrochloric acid HCl by using Fourier Transform Infrared (FTIR). Leucaena leucephala is chosen to be used in this study because it is abundantly and can be found easily along the road as it is widely spread in Malaysia and available throughout the year. Leucaena leucephala is not fully utilized yet and it could potential for new source for chitin. Results from FTIR shows that Amide I band in Leucaena leucephala before and after extraction range of 1650-1600cm-1 and is not divided into two peaks which make it appear close to a β-chitin. Beside, Amide I band of Leucaena leucephala before and after extraction is appearing wide (U-shaped) rather than sharp therefore the chitin from Leucaena leucephala is determined to be in the form of β- chitin.
Computer technology has become a very important element in an advanced manufacturing system. The good and systematic data model for the exchange of manufacturing information between different stages of development of product life cycle is paramount to ensure the product is manufactured and delivered to the market successfully. As a result, ISO 10303, an international standard, or well known as Standard for Exchange of Product Model Data (STEP) is not just for providing a neutral data format within the heterogenous CAD systems, its functionality has extended to the whole life cycle of product. STEP Part 21 is the first implementation method from EXPRESS modelling language and implemented successfully as neutral product data to integrate heterogeneous CAD platform. However, this CAD STEP Part21 text file is hardly to be applied in manufacturing processes since it consists of purely geometrical and topological data. In this research, a nonprocedural approach is presented to translate the EXPRESS language model of STEP CAD data into a new product database system model. A new nonprocedural approach of data enrichment and automated machining feature recognition is proposed and implemented on this newly developed product database system and provide a solution for the interrelated tasks of automated machining feature recognition: (1) extraction of geometrical feature from STEP CAD model data of the part (2) formation of part representation suitable for form feature identification (3) matching of form features. This paper proves the validity of this newly developed product database system by translating STEP Part21 file from a commercial CAD system to database system format, data enrichment, performing automated machining feature recognition and lastly generating STEP standard data according to AP224 for supporting STEP based process planning and manufacturing applications.
Flipped Classroom enables instructors to spend more time for hands-on problem-solving instruction compared to the traditional pedagogical model which involves lectures. The purpose of this study is to determine the need for a problem-solving flipped classroom module to be designed for the STM3023: Internet of Things (IoT) subject offered at the Certificate level at Malaysian Community Colleges. A structured interview was conducted with 16 lecturers from 14 Community Colleges offering the subject to obtain their views on current teaching practices along with the challenges faced in the teaching and learning of IoT to entry level students. Participants were also asked about their readiness towards the flipped classroom following an orientation session on Flipped Classroom approach. The findings showed that lecturers mostly used traditional pedagogical models in the TVET settings such as lectures. Students usually followed instructions and merely replicate the hands-on tasks as demonstrated by their lecturers in class. It was also found that students were struggling with the subject due to their lack of competency in programming and grasping electrical and electronics concepts. Students were also found to be weak in mathematics and reasoning skills, thus making it a challenge to teach IoT to them. Therefore, a myriad of media, materials and application of real-world concepts may be required to aid lecturers to improve students’ achievement in the subject. The flipped classroom approach for teaching which gives more time for hands-on problem-solving instruction may be appropriate to support lecturers to overcome the challenges in teaching IoT.
Plywood is a wood product frequently utilized in building as part of concrete formwork systems. In the concreting process, plywood formwork needs to be strongly made to withstand the pressure subjected by the wet concrete as well as the impact. To reduce the dependency on solid timber as plywood, oil palm stem offers alternative materials. There are four main weaknesses of oil palm stem (OPS) as a material for plywood manufacturing; high variations in density and moisture content (MC), high water absorption and high surface roughness. Therefore, this study modified the drying and treatment process of OPS veneer. The veneer was predried by using roller presser for removing a large amount of water and later treated with medium molecular weight phenolformaldehyde (MMwPF) to bond together parenchyma tissue, cell wall, and a lumen for much uniform density and better surface bonding. The Charpy impact of OPS plywood developed in this study denoted as PTA was investigated. These properties were compared with the properties of another two types of commercial OPS plywood denoted as PTB and PTC which were manufactured using OPS veneer with tropical hardwood veneer for face and back veneer and control plywood denoted as PTD which was manufactured using 100% tropical hardwood veneer. The results showed that PTA has the highest mean value of energy and strength for both notched and unnotched Charpy impact.
The use of concrete for construction had become very common in developing countries. But concrete is not friendly environment because of it consumes huge quantities of natural materials and production of the cement, which is a major contributor to greenhouse gas emissions and global warming. The aim of this study is to investigate the Sustainable Green Concrete (SGC) which containing biomass aggregate; fly ash and Superplasticizer. Biomass aggregate and fly ash are waste industry products which are environmentally friendly. The study was carried out to identify the chemical properties of biomass aggregate, and to determine the chemical properties and optimum mix design of the Sustainable Green Concrete (SGC). A total of 90 cube samples were casted and compressive strength were tested at the age of 7, 14 and 28 days. The overall results showed that the workability and compressive strength were decreased with the increase of the replacement of natural aggregate with biomass aggregate. Besides that, the workability and compressive strength was increased with the incorporation with the replacement cement by fly ash. The SGC gained highest compressive strength for the concrete mixes of 39.3 N/mm2 with the optimum percentage used of SGC in producing concrete not exceeding 30% biomass aggregate and 6% of fly ash as a partial replacement with natural aggregate and cement respectively. The results obtained and observation made in this study suggested that biomass aggregate and fly ash are successfully used as partial replacement in producing SGC and can perform better strength development.