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Institution

University of Malaya

EducationKuala Lumpur, Malaysia
About: University of Malaya is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Fiber laser. The organization has 25087 authors who have published 51491 publications receiving 1036791 citations. The organization is also known as: UM & Universiti Malaya.


Papers
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Journal ArticleDOI
TL;DR: In this article, the effects of water on biodiesel production and refining were examined, and the quality of biodiesel was also examined, due to high contents of chemical oxygen demand, biological oxygen demand and higher pH values.
Abstract: Presence of water during biodiesel production and purification processes, storage and use in compression ignition (diesel) engines causes problems that cannot be ignored. These problems include: difficulties in biodiesel processing especially during alkali-catalyzed transesterification process, deterioration of biodiesel quality, decrease in heat of combustion, corrosion of fuel system components, and acceleration of hydrolytic reaction. Beside use of water during biodiesel purification results in wastewater discharges which causes environmental effects, due to high contents of chemical oxygen demand, biological oxygen demand, and higher pH values. Thus, this study critically analyzed and examined the effects of water on biodiesel production and the refining of crude biodiesel. Furthermore the effects of water on the quality of biodiesel were also examined.

244 citations

Journal ArticleDOI
TL;DR: In this paper, a carbon dioxide gas sensor from the room-temperature reduction of graphene oxide via hydrogen plasma was developed, where the hydrogen plasma contains radicals and atoms which give dissociation energies for oxygen functional groups, which is capable of reducing the graphene oxide.
Abstract: We report on the development of a carbon dioxide gas sensor from the room-temperature reduction of graphene oxide via hydrogen plasma. The hydrogen plasma contains radicals and atoms which give dissociation energies for oxygen functional groups, which is capable of reducing the graphene oxide. The sample morphology, degree of reduction, chemical bonding and gas sensing capability were systematically studied. The effective removal of oxygen functional groups at the edges and both basal planes while restoring C=C bonds has been observed by AFM, XPS and Raman analysis. The C/O ratio increased from 0.81 to 7.9 and the resistance decreased significantly from 33 kΩ to 1.6 kΩ after the reduction process. The fabricated rGO-F20 sensor shows the highest CO 2 gas sensing response of 71% and 15% at 1500 ppm in N 2 (37% RH) and air environment (68% RH), respectively. In addition, the sensor shows a good repeatability performance with the sensing and recovery time of about 4 min when exposed to 750 and 769 ppm CO 2 concentration. The repeatability performance was measured in air environment at 68% RH without external assisted recovery. This simple, room-temperature reduction process and sensing capability, low cost fabrication process of a graphene sensor could lead to the implementation of a practical indoor air quality monitor.

243 citations

Journal ArticleDOI
TL;DR: In this article, the potential of a relatively new data-driven method, namely the extreme learning machine (ELM) method, was explored for forecasting monthly stream-flow discharge rates in the Tigris River, Iraq.

243 citations

Journal ArticleDOI
TL;DR: In this article, the authors analyzed the ionic conductivity of the chitosan-NH 4 CF 3 SO 3 system over a wide range of frequency and at temperatures between 298 and 313 k. The temperature dependent conductivity data obeys Arrhenius relationship.
Abstract: Ionic conductivity for the chitosan-NH 4 CF 3 SO 3 system was conducted over a wide range of frequency and at temperatures between 298 and 313 K. Dielectric data were analyzed using complex permittivity e * and complex electrical modulus M * for the sample with the highest ionic conductivity at various temperatures. The temperature-dependent conductivity data obeys Arrhenius relationship. Jonschers universal power law was used to analyze AC conductivity of the sample. Hopping frequency was determined and activation energy of hopping is almost equal to the activation energy of conduction. The AC conductivity master curve was obtained for the highest conducting sample when scaled vertically by σ DC and horizontally by ω P .

242 citations

Journal ArticleDOI
TL;DR: Three types of biofunctionalizing surface treatments are applied and compared to have considerable effects on apatite forming ability, cell attachment, cell proliferation, and bone ingrowth of the studied biomaterials.

242 citations


Authors

Showing all 25327 results

NameH-indexPapersCitations
Diederick E. Grobbee1551051122748
Intae Yu134137289870
Ovsat Abdinov12986478489
Jyothsna Rani Komaragiri129109782258
Odette Benary12884474238
Paul M. Vanhoutte12786862177
Irene Vichou12676272520
Ian O. Ellis126105175435
Louisa Degenhardt126798139683
Matthew Jones125116196909
Andrius Juodagalvis118106967138
Martin Ravallion11557055380
R. St. Denis11292165326
Xiao-Ming Chen10859642229
A. Yurkewicz10651451537
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202391
2022418
20213,698
20203,646
20193,239
20183,203