Advances in Science and Technology Vol. 127

Abstract: Clinacanthus nutans consists with multiple medicinal properties. The plant is also known to be a source of biologically active compounds, particularly those with an antioxidant capacity. The phytochemical studies of C. nutans plant extract was mostly reported from its leaf part. Thus, the objectives of this study are to assess the phytochemical constituents and antioxidant activity of C. nutans leaf and stem. Methanol was used as solvent for the green extraction. Next, phytochemical screening, Fourier transform infrared (FTIR) analysis, total phenolic (TPC) and flavonoids contents (TFC), quercetin flavonoid compound analysis and in vitro antioxidant activity were performed on C. nutans leaf and stem. In comparison to stem extract, the leaf extract showed a more favorable appearance of metabolites. In FTIR analysis, both sample extracts revealed the presence of hydroxyl and carbonyl functional groups, which are important in antioxidant action. The TPC (228.06 mg GAE/g DW) and TFC (29.76 mg QE/g DW) values were higher in the leaf extract than the stem extract. Quercetin quantification in HPLC analysis revealed that the leaf extract (21.33 g/g) contained more quercetin than the stem extract (18.88 g/g). Between the extracts, leaf providing more antioxidant values of DPPH (15.50%) and FRAP (15.68 gFeSO₄/g) than stem. The greatest association was identified between TFC and FRAP reducing activity (r = 0.977, p<0.05) indicating that the flavonoid present in the extract contributed to C. nutans' antioxidant capacity.

Abstract: This study focuses on the performance and mechanical characteristics response of pure Canola oil and Canola oil with existence of Hyaluronic Acid. Numerous studies show that plant-based substances are infrequently used in synthetic synovial fluid. The sort of bio-fluid that derives from plant-based oil and can function as a synthetic synovial fluid is the focus of this work. Three samples of a bio-fluid made of Canola oil with three different concentrations of Hyaluronic Acid (HA) are 0 ml, 5 ml, and 10ml, respectively. The 500 mm x 500 mm x 4 mm Polylactic Acid (PLA) biomaterial disc was chosen in the pin on disc wear and friction test rig experiment in conjunction with a canola-based oil tested lubricant to simulate the mechanical principles on the knee. To obtain accurate findings for the wear rate and friction coefficient, the samples will be put through a tribology test. The experiment was conducted to measure the tribology of the stainless pin to observe the effect of coefficient of friction and wear rate on the pin. The reliable outcome may open up new avenues for future research on synthetic synovial fluid. On the other hand, this study is beneficial to medical technology for future treatment of any diseases related to synovial fluid and allows the manufacturer to improve understanding in the optimization of these lubricants in ensuring a long-term application in the human body.

Abstract: Steam batch sterilization is favorably utilized by conventional palm oil mills in Malaysia. However, there are some disadvantages to using steam batch sterilization, including the fact that it takes a long time to complete the sterilizing process, and a huge amount of wastewater is released as palm oil mill effluent (POME). Besides, extraction by fruit press expeller requires a large number of nuts or seeds to produce a high yield, which is relatively expensive. Therefore, this research aimed to investigate the capability of microwave sterilization and the Soxhlet extraction (solvent extraction) process as an alternative to the conventional method. The impact of various microwave power levels of 400, 600, and 800 W and water ratios of 0, 50, and 100 mL on oil yield and carotenoids value of microwave-sterilized oil palm mesocarp are also investigated. Microwave sterilization and Soxhlet extraction have been employed as a replacement for the conventional method of extracting a higher yield of palm oil mesocarp in order to fill the gap by the previous research, which applied two methods: microwave sterilization (power level) and extraction. Then, carotenoid value analysis with a UV spectrophotometer is utilized to examine the outcomes in order to demonstrate the efficacy of the method. As a result, a high oil yield and carotenoid value are produced, which is 59.31% at 800W with the absence of water (0 mL) and a carotenoid value of 757 ppm at 400W (0 mL), respectively. Meanwhile, other carotenoid values at different microwave power levels and water ratios are still within the acceptable range as per the commercial crude palm oil standard.

Abstract: The effects of Ga substitution at Mn site on electroresistance behaviour of La_0.85Ag_0.15MnO₃ compound prepared by solid-state reaction method were investigated. X-ray diffraction (XRD) measurement were recorded at room temperature and refined by employing Rietveld techniques. Ferromagnetic to paramagnetic transitions behaviour have been observed from ac susceptibility results. Resistivity-temperature curve with different applied currents of 1 mA and 5 mA showed metal-insulator, MI transition temperature, T_MI decreased with increased of the applied currents. The increased in applied current caused the maximum resistivity around T_MI to be decreased for both samples indicated increased in charge carrier density which resulting in drop of resistivity, hence, enhanced double exchange mechanism. The electroresistance (ER) effects have been investigated. The result showed that the ER effect increases when Ga is substituted.

Abstract: This paper presents the performance of the three-dimensional progressive damage model using Puck failure criteria gradual degradation law to predict the structural responses, as well as the onset and propagation of failure due to different meshing techniques. The proposed damage model is performed using Abaqus explicit analysis. Three meshing strategies are analyzed using a solid element finite element model based on low-velocity impact loading. The structural responses are compared with experimental data taken from literature to measure the performance of such damage model. The results revealed that the models adopted here respond well to experimental data and demonstrate acceptable results in predicting the inter- and intra-laminar damage of the composite laminate.

Abstract: Groundwater has become one of the natural sources of water nowadays. Naturally, groundwater contains dissolving materials such as soils, rocks, and minerals, which later release constituents, including iron (Fe²⁺) and manganese (Mn). However, raw groundwater has been found to consist of a high concentration of such minerals, which exceed the Groundwater Quality Standard published by the Department of Environment Malaysia. Initially, the concentration of Fe²⁺ and Mn exceeding the limit mentioned in the standard; 1.0 and 0.2 mg/L, respectively, might affect the quality of the groundwater. Hence, such condition of water needs to be treated before it can be distributed to the user. This study presents the combination usage of alum and potassium permanganate (KMnO₄) in removing Fe²⁺ and Mn in the groundwater. The jar test was the main mechanism used in identifying the best optimum medium dosages (alum and KMnO₄) as well as the best contact time for both mediums to efficiently remove Fe²⁺ and Mn in groundwater. In this study, water samples were taken from Chicha Water Treatment Plant in Kelantan. It can be said that both alum and KMnO₄ managed to remove Fe²⁺ and Mn up to 35% and 45%, respectively when using alum dosage of 12 mg/L and KMnO₄ dosage of 1.5mg/L with a contact time of 40 minutes. In addition, both mediums also managed to remove other parameters such as colour, turbidity, cations, and pH.

Abstract: Fluoride removal is crucial in water sources because its existence is very harmful towards human and environment. With this concern, graphene oxide (GO) has been selected as an adsorbent due to its adsorptive characteristics. GO was modified with eggshell (GO/ES), a natural based of calcium precursor. The modification of the GO/ES adsorbent was done via ultra-sonification. The effects of each synthesis parameter toward fluoride removal were investigated and related to surface functional groups found in the modified GO/ES adsorbent. From the analysis, eggshell has been successfully decorated over GO structure, where GO-calcium bond was observed in the FTIR spectra. The interaction between GO and ES showed the increment of hydroxyl (O-H) and carboxyl (C-O) functional groups as increasing in ES amount. This resulted in increasing of fluoride removal, as high as 54.30 mg/g adsorption capacity. The effects of GO/ES ration, sonication temperature and synthesis time in tailoring the modified GO/ES adsorbent were also significant in the arrangement of these functional groups towards fluoride removal. Based on the results obtained, it can be concluded that modified GO/ES adsorbent, from natural calcium source is comparable with chemical based calcium source, where the same functional groups were observed from FTIR spectra.

Abstract: Lithium nickel cobalt manganese oxide, LiNi_1/3Co_1/3Mn_1/3O₂ (NMC 333) become a promising cathode material and attracted much attention to replace the LiCoO₂. The structure, particle size, and morphology are some of the factors that influence the performance of the NMC 333 materials were study in this work. The synthesis method of doped NMC 333 materials was done via combustion method and citric acid was used as a fuel. The final products of LiNi_0.3Mn_0.3Co_0.3Al_0.1O₂ and LiNi_0.3Mn_0.3Co_0.3Al_0.05Ti_0.05O₂ were denoted as 333A and 333AT, respectively. Based on the XRD results, all materials showed a pure, single phase and isostructural with hexagonal α-NaFeO₂. 333AT material show good cation ordering with RIR value of 1.25. It also shows the higher (003) peak intensity and smaller full widths at half maximum (FWHM) indicate this material has higher structural crystallinity and smaller crystallite size than 333A. Meanwhile, FESEM results revealed that all materials have morphology of polyhedral like shape and well-crystallized particles with smooth surfaces. Both materials clearly made up of micro-sized particles with the range particle size from 103 nm to 975 nm. 333A material display slightly larger crystallite size compared to the 333AT material. As a conclusion, doping technique will effect the structural and the morphology of materials.

Abstract: Soft soil consists of inherent properties where it is unstable in geotechnical condition with low shear strength. The present of soft soil is one of the problematic ground conditions that can pose great challenges in the related field. Moreover, soft soil is not suitable for being used in the construction of highways and buildings due to its undesirable characteristics such as high-water content, low shear strength, low bearing capacity and low permeability. Thus, soil improvement will be crucial in future geotechnical practice for designing structures in weak soil. The aim of this study is to investigate the effectiveness of the use of coconut shell ash (CSA) as an additive material to improve the strength of the soft soil. Preliminary tests were carried out on the soft soil sample for identification and classification purposes. Then, engineering tests were carried out such as compaction tests to determine the optimum moisture content (OMC) and maximum dry density (MDD), Un-confined Compression Test (UCT) to assess the unconfined compressive strength of the soft soil when mixed with 0, 5, 10, and 15% of CSA. Finally, this study resume that the coconut shell ash can act as a stabilizer that will lower the cost of treatment and will benefit the environment.