Universiti Teknologi Petronas

About: Universiti Teknologi Petronas is a education organization based out in Ipoh, Malaysia. It is known for research contribution in the topics: Adsorption & Ionic liquid. The organization has 6127 authors who have published 11284 publications receiving 119400 citations.

The Effect of Nanoparticles Crystallite Size on the Recovery Efficiency in Dielectric Nanofluid Flooding

Abstract: Application of nanotechnology in enhanced oil recovery (EOR) has been increasing in recent years. After secondary flooding, more than 60% of the original oil in place (OOIP) remains in the reservoir due to trapping of oil in the reservoir rock pores. One of the promising EOR methods is surfactant flooding, where substantial reduction in interfacial tension between oil and water could sufficiently displace oil from the reservoir. In this research, instability at the interfaces is created by dispersing 0.05 wt% ZnO nanoparticles in aqueous sodium dodecyl sulfate (SDS) solution during the core flooding experiment. The difference in the amount of particles adsorbed at the interface creates variation in the localized interfacial tension, thus induces fluid motion to reduce the stress. Four samples of different average crystallite size were used to study the effect of particle size on the spontaneous emulsification process which would in turn determine the recovery efficiency. From the study, ZnO nanofluid which consists of larger particles size gives 145% increase in the oil recovery as compared with the smaller ZnO nanoparticles. In contrast, 63% more oil was recovered by injecting Al2O3 nanofluid of smaller particles size as compared to the larger one. Formation of a cloudy solution was observed during the test which indicates the occurrence of an emulsification process. It can be concluded that ultralow Interfacial tension (IFT) value is not necessary to create spontaneous emulsification in dielectric nanofluid flooding.

An efficient defense method against UDP spoofed flooding traffic of denial of service (DoS) attacks in VANET

Abstract: Vehicular Ad hoc Networks (VANET) have emerged as a subset of the Mobile Ad hoc Network (MANET) application; it is considered to be a substantial approach to the Intelligent Transportation System (ITS). VANETs were introduced to support drivers and improve safety issues and driving comfort, as a step towards constructing a safer, cleaner and more intelligent environment. At the present time, vehicles are exposed to many security threats. One of them is the User Datagram Protocol (UDP)- based flooding which is a common form of Denial of Service (DoS) attacks, in which a malicious node forges a large number of fake identities, i.e.-, Internet Protocol (IP) spoofing addresses in order to disrupt the proper functions of the fair data transfer between two fast moving vehicles. Incorporating IP spoofing in the DoS attacks makes it even more difficult to defend against such attacks. In this paper, an efficient method is proposed to detect and defend against UDP flooding attacks under different IP spoofing types. The method makes use of a storage-efficient data structure and a Bloom filter based IPCHOCKREFERENCE detection method. This lightweight approach makes it relatively easy to deploy as its resource requirement is reasonably low. Simulation results consistently showed that the method is both efficient and effective in defending against UDP flooding attacks under different IP spoofing types. Specifically, the method outperformed others in achieving a higher detection rate yet with lower storage and computational costs.