National University of 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.

Physical activity pattern and energy expenditure of Malaysian adults: findings from the Malaysian Adult Nutrition Survey (MANS).

Abstract: This paper aims to report the physical activity pattern and energy expenditure of adults aged 18 - 59 years in the Malaysian Adults Nutrition Survey (MANS) carried out between October 2002 and December 2003. The survey included 7349 adults representative of Peninsular Malaysia (Northern, Southern, Central and East Coast), as well as Sabah and Sarawak. A total of 6926 adults, comprising 3343 men and 3583 women, completed the physical activity section of the survey. Physical activity data was obtained using a physical activity questionnaire and 24-hour physical activity recall. Basal metabolic rate (BMR) was calculated from Ismail et al. (1998) predictive equations; total energy expenditure (TEE) was then estimated through factorial calculations based on time allocated and energy cost of various activities. Physical activity level (PAL) was calculated as the ratio of TEE to BMR. It was found that almost three-quarters of Malaysian adults traveled by passive modes of transportation. Only a third reported having ever-exercised, and an even smaller proportion of the population (14%) had adequate exercise. The population also spent the majority of their time (74% of the day) in sedentary activities, such as sleeping or lying down; doing light intensity activities (15% of the day), and doing moderate to vigorous intensity activities (10% of the day). Mean BMR and TEE was significantly higher amongst men than women, while mean PAL values were similar for men [1.6 (1.6 - 1.7)] and women [1.6 (1.6 - 1.6)]. More men (16%) were categorised as having active PAL compared to women (10%), while more women (43%) were categorised as having sedentary PAL compared to their male counterparts (37%). The present study provides the first in-depth report of the physical activity pattern, and national estimates of energy expenditure and physical activity levels of Malaysian adults, and concluded that Malaysian adults are generally sedentary. It is thus important that physical activity be further promoted and integrated into the lives of the population, preferably through various health promotion efforts as well as through the commitment of the authorities in providing a suitable environment for an active lifestyle.

Enhancing Morphology and Separation Performance of Polyamide 6,6 Membranes By Minimal Incorporation of Silver Decorated Graphene Oxide Nanoparticles.

Abstract: Nanomaterials can be incorporated in the synthesis of membrane to obtain mixed-matrix membrane with marked improvement in properties and performance. However, stability and dispersion of the nanomaterials in the membrane matrix, as well as the need to use high ratio of nanomaterials for obvious improvement of membrane properties, remain a major hurdle for commercialization. Hence, this study aims to investigate the improvement of polyamide 6,6 membrane properties with the incorporation of silver nanoparticles decorated on graphene oxide (Ag-GO) nanoplates and at the same time focus is given to the issues above. Graphene oxide nanoplates were synthesized using the modified Hummers' method and decorated with silver before embedded into the polyamide 6,6 matrix. Physicochemical characterizations were conducted on both nanoplates and the mixed-matrix Ag-GO polyamide 6,6 membrane. The issues of Ag agglomeration and leaching were not observed, which could be attributed to the decoration of Ag on GO that helped to disperse the nanomaterials and provided a better anchor point for the attachment of Ag nanoparticles. The synthesized membrane showed marked improvement regarding flux (135% increment) and antifouling (40% lower irreversible fouling), which could be ascribed to the more negative charge of membrane surface (-14 ± 6 to -31 ± 3.8 mV) and hydrophilicity (46% enhancement) of the membranes. With minimal embedment of Ag nanoparticles, the membrane showed superior antibacterial property where the E. coli bacteria could not form a single colony on the membrane surface. Overall, the decoration of Ag on GO nanoplates could be a promising approach to resolve the agglomeration and leaching issues as well as reduce the amount of precious Ag in the synthesis of Ag-GO polyamide 6,6 membrane.