We studied Zeta potentials of nanoparticles titanium dioxides （nTiO₂） in different concentration of NaNO₃ and phosphate (P) solutions. In addition, the effect of flow rate on the transport of nTiO₂ in P was investigated at pH＝6.5. Experimental results show that the Zeta potential of nTiO₂ is compressed with the increasing ion concentration (IC) of NaNO₃ at pH＝6.5. The negative charge increases with the augment of P. Therefore, the high P and low NaNO3 induce the stabilization of nTiO₂ aggregates. The transport experiments suggest that the rapid flow rate is favorable for the transportability of nTiO₂ and soluble phosphate. The breakthrough transport curves (BTCs) of nTiO₂ in sand columns can be fitted well with two-site kinetic attachment model. The modeling results suggest that the values of first-order attachment rate coefficients (k₂) and detachment rate coefficients (k_2d) on site 2 and first-order attachment rate coefficients (k₁) on site 1 are responsible to the attaching efficiency of nTiO₂ on sands and their transportability.

This paper reviews and compares the opportunities and challenges in terms of port and intermodal development in China and India—the two fast-growing economic giants in the world. The study analyzes the future direction of these two countries’ port-hinterland intermodal development from the sustainability perspective. Both China and India face some major opportunities and challenges in port-hinterland intermodal development. The proposal of the Silk Road Economic Belt and the 21st-century Maritime Silk Road, also known as the Belt and Road Initiative (BRI), offers plentiful opportunities for China. A challenge for China is that its development of dry ports is still in the infancy stage and thus it is unable to catch up with the pace of rapid economic growth. As compared with China, India focuses more on the social aspect to protect the welfare of its residents, which in turn jeopardizes India’s port-hinterland intermodal development in the economic sense. The biggest challenge for India is its social institution, which would take a long time to change. These in-depth comparative analyses not only give the future direction of port-hinterland intermodal development in China and India but also provide references for other countries with similar backgrounds.

The expansion of road networks, taken place during the last decades, was driven by technological progress and economic growth. The most innovative products of this trend—modern motorways and international road corridors—provide an excellent level of service, traffic safety and necessary information to travelers. However, despite this undeniable progress, major impediments and respective challenges to road authorities and operators still remain. The present paper analytically presents the main current challenges in the road engineering field, namely: a) financing new projects, b) alternative energy resources, especially renewable energy, c) serviceability, including maintenance of road infrastructure, traffic congestion and quality of the network, d) climate change hazards due to greenhouse gas emissions increase, e) environmental impacts, f) safety on roads, streets and motorways, and g) economy and cost-effectiveness. In each country and over each network, challenges and concerns may vary, but, in most cases, competent authorities, engaged in road development policies, have to deal with most of these issues. The optimization of the means to achieve the best results seems to be an enduring stake. In the present paper, the origin and the main features of these challenges are outlined as well as their tendency to get amplified or diminished under the actual evolving economic conditions worldwide, where growth alternates with crisis and social hardship. Moreover, responses, meant to provide solutions to the said challenges, are suggested, including research findings of Aristotle University and innovative technological achievements, to drive the transition to a more sustainable future.

The whole world is in a fuel crisis nearly approaching exhaustion, with climate change knocking at our doorsteps. In the fight against global warming, one of the principle components that demands technocratic attention is Transportation, not just as a significant contributor to atmospheric emissions but from a much broader perspective of environmental sustainability. 

From the traditional technocratic aspect of transport planning, our epiphany comes in the form of Land Use integrated sustainable transport policy in which Singapore has been a pioneer, and has led the way for both developed and developing nations in terms of mobility management. We intend to investigate Singapore’s Transport policy timeline delving into the past, present and future, with a case by case analysis for varying dimensions in the present scenario through selective benchmarking against contemporary cities like Hong Kong, London and New York. The discussions will include themes of modal split, land use policy, vehicular ownership, emission policy, parking policy, safety and road traffic management to name a few. A visualization of Singapore’s future in transportation particularly from the perspective of automated vehicles in conjunction with last mile solutions is also detailed.