In the present study, we report the results of the experiments conducted on the convective heat transfer of graphene nano-platelets dispersed in water-ethylene glycol. The graphene nano-suspension was employed as a coolant inside a micro-channel and heat-transfer coefficient (HTC) and pressure drop (PD) values of the system were reported at different operating conditions. The results demonstrated that the use of graphene nano-platelets can potentially augment the thermal conductivity of the working fluid by 32.1% (at wt. % = 0.3 at 60 °C). Likewise, GNP nano-suspension promoted the Brownian motion and thermophoresis effect, such that for the tests conducted within the mass fractions of 0.1%–0.3%, the HTC of the system was improved. However, a trade-off was identified between the PD value and the HTC. By assessing the thermal performance evaluation criteria (TPEC) of the system, it was identified that the thermal performance of the system increased by 21% despite a 12.1% augmentation in the PD value. Furthermore, with an increment in the fluid flow and heat-flux applied to the micro-channel, the HTC was augmented, showing the potential of the nano-suspension to be utilized in high heat-flux thermal applications.

Purpose: This study aims to model the nanofluid flow in microchannel heat sinks having the same length and hydraulic diameter but different cross-sections (circular, trapezoidal and square). Design/methodology/approach: The nanofluid is graphene nanoplatelets-silver/water, and the heat transfer in laminar flow was investigated. The range of coolant Reynolds number in this investigation was 200 ≤ Re ≤ 1000, and the concentrations of nano-sheets were from 0 to 0.1 vol. %. Findings: Results show that higher temperature leads to smaller Nusselt number, pressure drop and pumping power, and increasing solid nano-sheet volume fraction results in an expected increase in heat transfer. However, the influence of temperature on the friction factor is insignificant. In addition, by increasing the Reynolds number, the values of pressure drop, pumping power and Nusselt number augments, but friction factor diminishes. Research limitations/implications: Data extracted from a recent experimental work were used to obtain thermo-physical properties of nanofluids. Originality/value: The effects of temperature, microchannel cross-section shape, the volume concentration of nanoparticles and Reynolds number on thermal and hydraulics behavior of the nanofluid were investigated. Results are presented in terms of velocity, Nusselt number, pressure drop, friction loss and pumping power in various conditions. Validation of the model against previous papers showed satisfactory agreement.

Exhaust emissions from vessels have increasingly attracted attention in the continuously growing marine transport world trade market. The International Maritime Organization (IMO) has introduced a number of measures designed to reduce exhaust emissions from global shipping. As one of the busiest ports in the world, Qingdao port has been studied to propose possible support to the development of efficient emission reduction. In this study, a large amount data of emissions inventory in Qingdao port was used to predict its annual exhaust emissions, and hence, to help understand maritime pollution in Qingdao port. Bigdata analysis methodology was employed to perform accurate predictions on vessel emissions. The analysis results show that the emissions were dominated by container ships, oil tankers, and bulk cargo ships. The comparison between Qingdao port and other ports in emission control areas demonstrates the necessity of control measures for exhaust emissions. The adoption of shore power and efficient cargo handling seems to be a potential solution to reduce exhaust emissions. The findings of this study are meaningful for maritime safety administration to understand the current emission situation in Qingdao port, propose corresponding control measures, and perform pollution prevention.

With the development of science and technology, traffic perception, communication, information processing, artificial intelligence and the shipping information system have become important in supporting the realization of intelligent shipping transportation. Against this background, the Internet of Vessels (IoV) is proposed to integrate all these advanced technologies into a platform to meet the requirements of international and regional transportations. The purpose of this paper is to analyze how to benefit from the Internet of Vessels to improve the efficiency and safety of shipping, and promote the development of world transportation. In this paper, the IoV is introduced and its main architectures are outlined. Furthermore, the characteristics of the Internet of Vessels are described. Several important applications that illustrate the interaction of the Internet of Vessels’ components are proposed. Due to the development of the Internet of Vessels still being in its primary stage, challenges and prospects are identified and addressed. Finally, the main conclusions are drawn and future research priorities are provided for reference and as professional suggestions for future researchers in this field.