Institution
National University of Malaysia
Education•Kuala Lumpur, Malaysia•
About: National University of Malaysia is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Heat transfer. The organization has 26593 authors who have published 41270 publications receiving 552683 citations. The organization is also known as: NUM & Universiti Kebangsaan Malaysia.
Topics: Population, Heat transfer, Thin film, Membrane, Photovoltaic system
Papers published on a yearly basis
Papers
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TL;DR: This article found that the size of a classroom, personalities of the instructor and students and the perception of peers influenced the students to speak up in class, while many of them were still reluctant to participate in class.
99 citations
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TL;DR: In this article, a circular-hexagonal Fractal antenna is proposed for super wide band applications, which is made of iterations of a hexagonal slot inside a circular metallic patch with a transmission line and achieves a super wide bandwidth ranging from 2.18GHz to 44.5GHz with a bandwidth ratio of 20:4 : 1.
Abstract: In this paper, a novel circular-hexagonal Fractal antenna is investigated for super wide band applications. The proposed antenna is made of iterations of a hexagonal slot inside a circular metallic patch with a transmission line. A partial ground plane and asymmetrical patch toward the substrate are used for designing the antenna to achieve a super wide bandwidth ranging from 2.18GHz to 44.5GHz with a bandwidth ratio of 20:4 : 1. The impedance bandwidth and gain of the proposed antenna are much better than the recently reported super wideband antennas which make it appropriate for many wireless communications systems such as ISM, Wi-Fi, GPS, Bluetooth, WLAN and UWB. Details of the proposed antenna design are presented and discussed.
99 citations
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TL;DR: This single-step process could be a potential route for biodiesel production from high-acid value oil by simplifying the procedure and reducing costs.
Abstract: Solid acid catalyst was prepared from Kraft lignin by chemical activation with phosphoric acid, pyrolysis and sulfuric acid. This catalyst had high acid density as characterized by scanning electron microscope (SEM), energy-dispersive x-ray spectrometry (EDX) and Brunauer, Emmett, and Teller (BET) method analyses. It was further used to catalyze the esterification of oleic acid and one-step conversion of non-pretreated Jatropha oil to biodiesel. The effects of catalyst loading, reaction temperature and oil-to-methanol molar ratio, on the catalytic activity of the esterification were investigated. The highest catalytic activity was achieved with a 96.1% esterification rate, and the catalyst can be reused three times with little deactivation under optimized conditions. Biodiesel production from Jatropha oil was studied under such conditions. It was found that 96.3% biodiesel yield from non-pretreated Jatropha oil with high-acid value (12.7 mg KOH/g) could be achieved. The catalyst can be easily separated for reuse. This single-step process could be a potential route for biodiesel production from high-acid value oil by simplifying the procedure and reducing costs.
99 citations
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TL;DR: In this paper, a steady state energy analysis was performed on a photovoltaic thermal (PVT) collector with ∇-groove and the energy balance equation was obtained using the analytical and the matrix inversion methods.
99 citations
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TL;DR: In this paper, a dual-band antenna for radio frequency identification (RFID) reader applications covering free ISM bands of 2.37 GHz and 5.8 GHz is presented.
Abstract: A novel high-gain dual-band antenna for radio frequency identification (RFID) reader applications covering free ISM bands of 2.45 and 5.8 GHz is presented in this letter. The antenna is composed of a U-shaped copper strip with unequal arm, a printed rectangular ring, and the ground plane. A good impedance bandwidth of 120 MHz has been achieved from 2.37 to 2.49 GHz for the lower band, while the upper band covers 420 MHz (from 5.55 to 5.97 GHz). The U-shaped feeding strip excites the rectangular ring effectively by providing a good impedance matching with over 85% of total antenna efficiency in both the frequency bands and also 9.56 and 10.17 dBi gain in the lower and higher frequency band, respectively.
99 citations
Authors
Showing all 26827 results
Name | H-index | Papers | Citations |
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Jonathan E. Shaw | 114 | 629 | 108114 |
Sabu Thomas | 102 | 1554 | 51366 |
Biswajeet Pradhan | 98 | 735 | 32900 |
Haji Hassan Masjuki | 97 | 502 | 29653 |
Mika Sillanpää | 96 | 1019 | 44260 |
Choon Nam Ong | 86 | 444 | 25157 |
Keith R. Abrams | 86 | 355 | 30980 |
Kamaruzzaman Sopian | 84 | 989 | 25293 |
Benedikt M. Kessler | 82 | 385 | 24243 |
Michel Marre | 82 | 444 | 39052 |
Peter Willett | 76 | 479 | 29037 |
Peter F. M. Choong | 72 | 532 | 18185 |
Nidal Hilal | 72 | 395 | 21524 |
Margareta Nordin | 72 | 267 | 19578 |
Teuku Meurah Indra Mahlia | 70 | 339 | 17444 |