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.

Advances in cellulose nanomaterials

Abstract: Research on nanocellulose has significantly increased over the past few decades, owing to the various attractive characteristics of this material, such as renewability, widespread availability, low density, excellent mechanical properties, economic value, biocompatibility, and biodegradability. Nanocellulose categorized into two main types, namely cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs). In this review, we present the recent advances made in the production of CNFs and CNCs. In addition to the conventional mechanical and chemical treatments used to prepare CNFs and CNCs, respectively, other promising techniques as well as pretreatment processes have been also proposed in recent times, in an effort to design an economically efficient and eco-friendly production route for nanocellulose. Further, while the hydrophilic nature of nanocellulose limits its use in polymeric matrices and in some industrial applications, the large number of hydroxyl groups on the surface of nanocellulose provides a suitable platform for various kinds of modification treatments. The various chemical and physical surface treatment procedures reported for nanocellulose have been reviewed in this paper. Finally, in this review, we summarize the life cycle assessment studies conducted so far on nanocellulose, which quantify the environmental impact of nanocellulose products. The current paper is a comprehensive review of the recent literature on nanostructured cellulose.

Photovoltaic/Thermal (PV/T) systems: Status and future prospects

Abstract: In the last four decades, greater attention has been paid to PV/T systems due to their advantages compared with PV or solar thermal systems alone. This paper aims to study various aspects of PV/T systems through the existing literature in order to highlight key points as future work in this field as well as illustrate different techniques used for such systems. In addition, PV/T systems are reviewed in terms of thermal and electrical side views. Furthermore, the analysis of solar thermal systems, various system applications such as air, water, air/water, phase change material PCM and Nanofluid systems are summarized. In light of most attempts to improve the PV/T system, more focus has been paid to the thermal rather than the electrical side. Furthermore, comparisons between PV/T systems in terms of performance parameters and efficiencies are presented. A critical review of many findings of previously conducted research is also discussed. It is found that the PV/T air heater system is promising for future preheating air applications. Moreover, it is suggested that the use of nanoparticles and water as base fluid improves the overall system efficiency. Furthermore, the PV side views require more attention in technical and cost terms. However, more research is essential to reduce the cost and, improve the effectiveness and technical design of such systems.