The influence of e-learning towards metacognitive enhancement in mathematical problem solving

This research aims to observe the influence of e-learning on metacognitive enhancement in mathematical problem-solving. The e-learning environment would encourage students to play more active roles in their learning. This research involves the students of Mechanical Engineering Department enrolled in the subject of Engineering Mathematics 4. It was found that the elearning method gives positive impacts on students' learning process. Therefore, it is suggested for educators to apply this method in their teaching. This is a suitable approach for students to be involved actively during their learning process. The lecturers should be more creative and innovative to vary their elearning to be lively, interesting, suitable, challenging while being in line with the students' cognitive development to provide comprehensible input

Taguchi Method for Development of Mass Flow Rate Correlation Using Hydrocarbon Refrigerant Mixture in Capillary Tube

The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM). The Taguchi method, a statistical experimental design approach, was employed. This approach explores the economic benefit that lies in studies of this nature, where only a small number of experiments are required and yet valid results are obtained. Considering the effects of the capillary tube geometry and the inlet condition of the tube, dimensionless parameters were chosen. The new correlation was also based on the Buckingham Pi theorem. This correlation predicts 86.67% of the present experimental data within a relative deviation of -10% to +10%. The predictions by this correlation were also compared with results in published literature

Synthesis and characterization of polyvinyl alcohol /polyaniline/functionalized multiwalled carbon nanotube compositeby gamma radiation method

The composite of functionalized multiwalled carbon nanotube (f-MWCNT), polyvinylalcohol (PVA) and polyaniline (PANI) were in-situ synthesized by gamma irradiation method. In order to make the free standing composite films, the mixture was cast onto a glass plate and dried before being exposed to irradiation. The formation and incorporation of PANI onto the surface of f-MWCNT were confirmed by field emission scanning electron microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Visible (UV-Vis) Spectrophotometer. It was found that in-situ polymerized PANI was coated onto the surface of f-MWCNT due to the increase of f-MWCNT diameter after irradiation and it is supported by the XRD spectra in which it shows that the intensity of main peak in PANI decreases upon irradiation. The increasing of absorption spectra intensity in the FTIR spectra indicates the polymerization of PANI is occurred. In addition, it was found that quinoid unit in composite film is richer as compared to unirradiated sample. This is supported by UV-Vis analysis that shows the benzenoid ring is excited in which the pi-pi* transition peak is shifted to the high wavenumber after irradiation. The calculated value for optical energy band gap decreases after irradiated at 50kGy by gammarays suggested that the resultant composite is more conductive as compared to unirradiated samples

Ergogenic, anti-diabetic and antioxidant attributes of selected Malaysian herbs: characterisation of flavonoids and correlation of functional activities

In the present work, aqueous ethanolic (60% ethanol) extracts from selected Malaysian herbs including Murraya koenigii L. Spreng, Lawsonia inermis L., Cosmos caudatus Kunth, Piper betle L., and P. sarmentosum Roxb. were evaluated for their ergogenic, anti-diabetic and antioxidant potentials. Results showed that the analysed herbs had ergogenic property and were able to activate 5'AMP-activated protein kinase (AMPK) in a concentration dependant manner. The highest AMPK activation was exhibited by M. koenigii extract which showed no significant (p > 0.05) difference with green tea (positive control). For anti-diabetic potential, the highest α-glucosidase inhibition was exhibited by M. koenigii extract with IC50 of 43.35 ± 7.5 μg/mL, which was higher than acarbose (positive control). The determinations of free radical scavenging activity and total phenolics content (TPC) indicated that the analysed herbs had good antioxidant activity. However, C. caudatus extract showed superior antioxidant activity with IC50 against free radical and TPC of 21.12 ± 3.20 μg/mL and 221.61 ± 7.49 mg GAE/g, respectively. RP-HPLC analysis established the presence of flavonoids in the herbs wherein L. inermis contained the highest flavonoid (catechin, epicatechin, naringin and rutin) content (668.87 mg/kg of extract). Correlations between the analyses were conducted, and revealed incoherent trends. Overall, M. koenigii was noted to be the most potent herb for enhancement of AMPK activity and α-glucosidase inhibition but exhibited moderate antioxidant activity. These results revealed that the selected herbs could be potential sources of natural ergogenic and anti-diabetic/antioxidant agents due to their rich profile of phenolics. Further analysis in vivo should be carried out to further elucidate the mechanism of actions of these herbs as ergogenic aids and anti-diabetic/antioxidant agents

Characterization of Mixed xWO3(1-x)Y2O3 Nanoparticle Thick Film for Gas Sensing Application

Microstructural, topology, inner morphology, and gas-sensitivity of mixed xWO3(1-x)Y2O3 nanoparticles (x = 1, 0.95, 0.9, 0.85, 0.8) thick-film semiconductor gas sensors were studied. The surface topography and inner morphological properties of the mixed powder and sensing film were characterized with X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Also, gas sensitivity properties of the printed films were evaluated in the presence of methane (CH4) and butane (C4H10) at up to 500 °C operating temperature of the sensor. The results show that the doping agent can modify some structural properties and gas sensitivity of the mixed powder

The analysis of grid independence study in continuous disperse of MQL delivery system

A sustainable cutting method of Minimum Quantity Lubricant (MQL) was introduced to promote lubrication effect and improve machinability. However, its performances are very dependent on the effectiveness of its mist to penetrate deep into the cutting zone. Optimizing the MQL system requires massive experimental work that increases cost and time. Therefore, this study conducts Computational Fluid Dynamic (CFD) analysis using ANSYS Fluent and focuses on the grid independence study in dispersed-continuous phase of MQL delivery system. The main aim is to identify the best mesh model that influences the accuracy of the CFD model. The analysis proposed two different unstructured grid cell elements of quadrilateral and triangular that were only applicable for 2-dimensional fluid flow in CFD. The unstructured grid was controlled with three different mesh quality factors such as Relevance Center, Smoothing, and Span Angle Center at coarse /low, medium, and fine /high. The results showed that the best mesh quality for quadrilateral was at 60,000 nodes number and coarse mesh, whereas the triangular was at 90,000 nodes number and coarse mesh. Both combinations resulted the most consistent and reliable result when compared with past studies. However, this study decided to choose quadrilateral cell element with 60,000 nodes number and coarse mesh as it is considered to be sufficient to provide accurate and reliable result as well as practical in terms of computational time for the MQL model in CFD analysis

Effect of nano-sized Co3O4 addition on the transport properties of YBa2Cu3O7−δ

The effect of nano-sized Co3O4 (10 - 30 nm) addition on YBa2Cu3O7−δ(Co3O4)x with x = 0 to 0.12 wt.% has been investigated by powder X-ray diffraction method, dc electrical resistance measurements and scanning electron microscopy. The Co3O4 particle size was larger than the coherence length but smaller than the penetration depth of the YBa2Cu3O7−δ superconductor. The onset transition temperature (T c onset) showed no significant changes for low Co3O4 addition (x ≤ 0.02 wt. %) and then decreased monotonically with the increase in Co3O4 content indicating a pair-breaking like mechanism in T c suppression for x = 0.03 to 0.12 wt. %. A sudden broadening of the superconducting-transition-width for x ≥ 0.11 wt. % was also observed. The transport properties were measured and related to the microstructure. Scanning electron micrographs showed homogeneous distribution of Co3O4 throughout the samples and the distance between particles was smaller than 1 μm but larger than the typical Abrikosov vortex lattice constant

Gait asymmetry assessment using muscle activity signal: a review of current methods

Gait asymmetry is a type of gait characteristics when there is difference in gait parameters statistically, measured bilaterally between left and right limbs. Gait asymmetry assessment is used to observe changes or deviation in gait due to pathological condition, effect of rehabilitation program or to give insight on effect of gait on stability and fall-risk. The assessments of gait asymmetry could be measured by using spatiotemporal, kinetics, kinematics parameters or by analysis of muscle activity signals obtained from surface electromyography (EMG). However, EMG-based assessment for gait asymmetry is not well explored compared to assessment using other gait parameters. This review aims to compare research designs, methods and procedure of previous studies that utilized EMG for gait asymmetry analysis. Therefore, any research in the future that involved gait asymmetry measurement could take note on and produce more reliable findings

Enhancing the decolorization of methylene blue using a low-cost super-absorbent aided by response surface methodology

The presence of organic dyes from industrial wastewater can cause pollution and exacerbate environmental problems; therefore, in the present work, activated carbon was synthesized from locally available oil palm trunk (OPT) biomass as a low-cost adsorbent to remove synthetic dye from aqueous media. The physical properties of the synthesized oil palm trunk activated carbon (OPTAC) were analyzed by SEM, FTIR-ATR, and XRD. The concurrent effects of the process variables (adsorbent dosage (g), methylene blue (MB) concentration (mg/L), and contact time (h)) on the MB removal percentage from aqueous solution were studied using a three-factor three-level Box–Behnken design (BBD) of response surface methodology (RSM), followed by the optimization of MB adsorption using OPTAC as the adsorbent. Based on the results of the analysis of variance (ANOVA) for the three parameters considered, adsorbent dosage (X1) is the most crucial parameter, with an F-value of 1857.43, followed by MB concentration (X2) and contact time (X3) with the F-values of 95.60 and 29.48, respectively. Furthermore, the highest MB removal efficiency of 97.9% was achieved at the optimum X1, X2, and X3 of 1.5 g, 200 mg/L, and 2 h, respectivel

Performance of Coated Carbide Tools when Turning Inconel Alloy 718 under Cryogenic Condition using RSM / N. Badroush ...[et al.]

This paper investigates the influence of cutting parameters on different responses variables and the performance of PVD coated carbide cutting tool when turning Inconel 718 under cryogenic condition. The factors and range of parameters investigated are; cutting speed (90-150 m/min), feed rate (0.05-0.2mm/rev) and depth of cut (0.25-0.75mm). The experimental runs were established using Box-Behnken design experiment. For the responses, 2 variables were evaluated which are surface roughness (Ra) of the machined surface and tool life (TL) of the insert. Analysis of Variance (ANOVA) was used to identify factors which significantly affect the response variables. From the analysis, the cutting speed and feed rate are the most significant factors affecting the TL followed by the depth of cut. While for the Ra, the interaction of feed rate and depth of cut are the most significant, followed by the depth of cut. The prediction Ra and TL models were developed with 95% of prediction interval between the predicted and actual experiments using the optimal parameters