19672 research outputs found
Sort by
A Novel Sustainable Design to Develop Polypropylene and Unsaturated Polyester Resin Polymer Composites From Waste of Major Polluting Industries and Investigation on Their Physicomechanical and Wear Properties
No full textA novel concept of using Nutraceutical Industrial Coriander Seed Spent (NICSS) and Congo red (CR) dye adsorbed onto NICSS (CR-NICSS) as filler materials to fabricate polypropylene (PP) green thermoplastic composites and unsaturated polyester resin unsaturated polyester resin (USP)/CR-NICSS and USP/NICSS composites is presented. To maximize the adsorption of CR on NICSS and to study the influence of five parameters viz, process time, temperature, initial concentration of dye, adsorbent dosage and pH of the reaction mixture, we use a two-level fractional factorial design approach and analysis of variance to develop statistical model. The composites were evaluated for physico-mechanical and tribological properties and compared with the thermoplastic composites fabricated using NICSS. Flexural strength and flexural modulus of composites were improved by adding CR-NICSS and NICSS into PP matrix. The abrasive wear behavior, wear volume loss and specific wear rate as a function of abrading distance at 150, 300, 450, and 600 m and different loads of 23.54 and 33.54 N at 200 rpm were determined. The water absorption characteristics of thermoplastic composites were studied. The surface morphology of tensile fractured PP/CR-NICSS was examined under scanning electron microscope. The influence of water and thermal ageing on tensile strength and physical properties, such as density, surface hardness and effect of chemicals on USP/CR-NICSS and USP/NICSS are reported. POLYM. COMPOS., 40:1142–1157, 2019. © 2018 Society of Plastics Engineers. © 2018 Society of Plastics Engineer
The effect of high purity rice husk silica synthesised using solvent-thermal extraction method on the properties of natural rubber compounds
No full textThis work highlights the synthesis of high purity silica from rice husks and the effect of rice husk silica (RHS) loading on the mechanical, physical, and thermal properties of natural rubber (NR) compounds. The RHS was synthesised using the solvent-thermal extraction method, which was adopted from TAPPI T204 (2007) and TAPPI T264 (1997) standards with some modifications. The treatment successfully produced high purity RHS particles, with 99.9% SiO2 content between 100 to 300 nm in size. The high purity RHS was then incorporated in NR compounds at 2, 4, 6, 8, and 10 parts per hundred rubber (phr). Even without any surface modification, the high purity RHS-filled NR compounds showed tremendous improvements in strength-related properties at the optimum loading of 4 phr. In addition, the thermal stability of the NR compounds was remarkably improved with the addition of RHS. © 2018, BioResources
In-socket sensory system with an adaptive neuro-based fuzzy inference system for active transfemoral prosthetic legs
No full textAn in-socket sensory system enables the monitoring of transfemoral amputee movement for a microprocessor-controlled prosthetic leg. User movement recognition from an in-socket sensor allows a powered prosthetic leg to actively mimic healthy ambulation, thereby reducing an amputee's metabolic energy consumption. This study established an adaptive neurofuzzy inference system (ANFIS)-based control input framework from an in-socket sensor signal for gait phase classification to derive user intention as read by in-socket sensor arrays. Particular gait phase recognition was mapped with the cadence and torque control output of a knee joint actuator. The control input framework was validated with 30 experimental gait samples of the in-socket sensory signal of a transfemoral amputee walking at fluctuating speeds of 0 to 2 km · h- 1. The physical simulation of the controller presented a realistic simulation of the actuated knee joint in terms of a knee mechanism with 95% to 99% accuracy of knee cadence and 80% to 90% accuracy of torque compared with those of normal gait. The ANFIS system successfully detected the seven gait phases based on the amputee's in-socket sensor signals and assigned accurate knee joint torque and cadence values as output. © 2018 SPIE and IS&T
Subcritical water extraction of low methoxyl pectin from pomelo ( Citrus grandis (L.) Osbeck) peels
No full textLow methoxyl (LM) pectin was extracted from pomelo peels using subcritical water in a dynamic mode. The effects of pressure and temperature were analyzed through a face-centred central composite design. Extraction yield and the rate of extraction were found to be predominantly influenced by temperature. Optimization of the subcritical water extraction (SWE) yielded an optimized operating condition of 120 °C and 30 bar with a predicted pectin yield of 18.8%. The corresponding experimental yield was 19.6%, which is in close agreement with the predicted data. The pectin obtained from the optimized condition was further analyzed for its physicochemical properties. The kinetics of the SWE was also evaluated whereby the one-site kinetic desorption model was found to be in good agreement with experimental data (R2 > 0.94)
Foreign equity flows: Boon or bane to the liquidity of Malaysian stock market?
No full textThis paper examines the impact of gross foreign equity inflows on aggregate liquidity of the Malaysian stock market using newly assembled foreign trading data and the best performing bid-ask spread proxy. Employing vector autoregression, we discover a one-way causality from gross inflows to aggregate liquidity, and foreign investors erode liquidity of the Malaysian stock market. Additional analyses reveal that uncertainties in the U.S. markets negatively affect aggregate liquidity through the flows of foreign institutions, whose positive feedback trading destabilizes the local bourse. Despite the shocks, there is sufficient liquidity provision from local state-backed institutional funds and local proprietary day traders
Endoscopic Transsphenoidal Resection of Craniopharyngioma
No full textObjectives demonstrate, step-by-step, the technique and efficacy of endoscopic transsphenoidal approach in resection of a suprasellar craniopharyngioma. Design he video shows a step-by-step approach to the resection, covering the exposure, access, resection, and confirmation of resection and reconstruction. Setting The surgery was performed in the University of Malaya Medical Centre, a tertiary referral center in the capital of Malaysia. Participants Surgery was performed jointly by Professor Prepageran from the department of otorhinolaryngology and Professor Vicknes Waran from the division of neurosurgery. Both surgeons are from the University of Malaya. Video compilation, editing, and voice narration was done by Dr. Kong Yew Liew. Main Outcome Measures completeness of resection and avoidance of intra-A nd postoperative complications. Results based on intraoperative views and MRI findings, the tumor was completely resected with the patient suffering only transient diabetes insipidus. Conclusion central suprasellar tumors can be removed completely via an endoscopic transsphenoidal approach with minimal morbidity to the patient. The link to the video can be found at: Https://youtu.be/ZNIHfk12cYg
The Impact of Global Financial Crisis on IPO Underpricing in Malaysian Stock Market
No full textThis study examines the impact of the Global Financial Crisis (GFC) on Initial Public Offering (IPO) underpricing in the context of an emerging market from January 2006 to December 2011. Models consist of hierarchical and dummy variable regressions have been evaluated. Our results show, firstly, by comparison between the pre-GFC, GFC and post-GFC periods, it can be observed that IPOs initial returns (offer-to-close) are generally lower due to the crisis. Secondly, IPO underpricing provides an average of 17-25% of initial returns in the pre-GFC period, 1-3% during GFC period, and 3-7% in the post-GFC period. Thirdly, the financial crisis does not act as a moderator that worsens the relationship between underpricing of IPO and oversubscription ratio. Lastly, this study dispels the notion that investors should totally shun IPO during crisis period as there are still positive initial returns among the new issues. To the authors' knowledge, this is the first study on the impact of the GFC on IPO underpricing in Malaysia
Adaptive fuzzy exposure local contrast enhancement
No full textNumerous factors, such as illumination condition, can affect image quality. Local contrast enhancement is an approach for improving the local visibility detail of an image by increasing the contrast in local regions. Recently, researchers have shown an interest in solving the issue of non-uniform illumination. However, all the studies failed to improve the contrast of the non-uniform illumination and low-contrast images locally and regionally by individually focusing on each region and improving its contrast. The contrast of each region will be enhanced using a new local contrast enhancement technique called adaptive fuzzy exposure local contrast enhancement (AFELCE). The proposed AFELCE method is specifically designed to enhance the contrast by using specific algorithms for different regions. The proposed AFELCE technique successfully improves the contrast of 300 low-contrast and non-uniform illumination images taken from three different databases, namely, standard, underwater (UW), and microscopic human sperm (MHS) images. The proposed AFELCE method outperforms the state-of-the-art methods in terms of quality and quantity. Qualitatively, the proposed AFELCE method has successfully enhanced the contrast of the images by producing more uniform illumination images with high contrast than the other methods. Quantitatively, the proposed AFELCE method produces the highest average of entropy (E), measurement of enhancement (EME), and universal image quality index (UIQI) for the standard image database with the values of 7.582, 42.75, and 0.94, respectively. Similar results are obtained for the UW image database, where the proposed method produces the highest average of E, EME, and UIQI values with 7.124, 41.13, and 0.89, respectively. For the MHS image database, AFELCE produces the highest values for E and EME with the values of 7.602 and 42.51, respectively
Effect of trust and perceived reciprocal benefit on students' knowledge sharing via facebook and academic performance
No full textThis paper explored the effect of trust and perceived reciprocal benefit on students' knowledge sharing via Facebook and on students' academic performance and reputation. The research model was tested using 170 undergraduate students in Malaysia via structural equation modeling. The results show that trust and perceived reciprocal benefit are two strong predictors of knowledge sharing amongst students, which affects their academic performance and recognition. Students with high levels of altruism are more open to sharing knowledge without preconditions compared to those with lower levels of altruism. The findings of this research would help educational institutions use Facebook as a knowledge sharing platform and also convert their academic procedures to an e-learning environment with Facebook as its platform. Creating a virtual environment and facilitating knowledge sharing among students will encourage a more productive and constructive learning environment. Facebook groups are regarded as an online community that increase students' interaction, collaboration, and trust
Physicochemical property enhancement of biodiesel synthesis from hybrid feedstocks of waste cooking vegetable oil and Beauty leaf oil through optimized alkaline-catalysed transesterification
No full textRecycling waste cooking vegetable oils by reclaiming and using these oils as biodiesel feedstocks is one of the promising solutions to address global energy demands. However, producing these biodiesels poses a significant challenge because of their poor physicochemical properties due the high free fatty acid content and impurities present in the feedstock, which will reduce the biodiesel yields. Hence, this study implemented the following strategy in order to address this issue: (1) 70 vol% of waste cooking vegetable oil blended with 30 vol% of Calophyllum inophyllum oil named as WC70CI30 used to alter its properties, (2) a three-stage process (degumming, esterification, and transesterification) was conducted which reduces the free fatty acid content and presence of impurities, and (3) the transesterification process parameters (methanol/oil ratio, reaction temperature, reaction time, and catalyst concentration) were optimized using response surface methodology in order to increase the biodiesel conversion yield. The results show that the WC70CI30 biodiesel has favourable physicochemical properties, good cold flow properties, and high oxidation stability (22.4 h), which fulfil the fuel specifications stated in the ASTM D6751 and EN 14214 standards. It found that the WC70CI30 biodiesel has great potential as a diesel substitute without the need for antioxidants and pour point depressants