Ballistic nanofriction

Sliding parts in nanosystems such as Nano ElectroMechanical Systems (NEMS) and nanomotors, increasingly involve large speeds, and rotations as well as translations of the moving surfaces; yet, the physics of high speed nanoscale friction is so far unexplored. Here, by simulating the motion of drifting and of kicked Au clusters on graphite - a workhorse system of experimental relevance -- we demonstrate and characterize a novel "ballistic" friction regime at high speed, separate from drift at low speed. The temperature dependence of the cluster slip distance and time, measuring friction, is opposite in these two regimes, consistent with theory. Crucial to both regimes is the interplay of rotations and translations, shown to be correlated in slow drift but anticorrelated in fast sliding. Despite these differences, we find the velocity dependence of ballistic friction to be, like drift, viscous

Hybrid (Gas and Geothermal) Greenhouse Simulations Aimed at Optimizing Investment and Operative Costs: A Case Study in NW Italy

Generally, greenhouses are high energy-consuming, sometimes accounting for 50% of the cost of greenhouse production. Geothermal energy plays a very important role in maintaining the desired temperature and reducing energy consumption. This work deals with a project of a hybrid heating plant (97% geothermal energy and 3% gas-condensing boiler) for the innovative Plant Phenotyping Greenhouse at the University Campus in Grugliasco (few km West of the city of Turin). The aim of the study is to testify to the energy efficiency of this kind of hybrid plant as well as its economic sustainability. Numerical simulations of a GRT were used to calibrate the system and verify that the software reasonably modeled the real case. They helped to correctly size the geothermal plant, also providing data about the thermal energy storage and production during on and off plant cycles. The results show a thermal power of 50.92 kW over 120 days of plant operation, in line with the expected energy needs to meet the base load demand. Long-term results further ensure a negligeable impact on the ground, with a thermal plume between 5 and 10 m from the plant, reducing substantially in a few months after switching off the plant

University of Turin performance in UI GreenMetric Energy and Climate Change

At the University of Turin (UniTo) the first attempt to reduce the ecological footprint dates back to 2006. In 2013 UniTo participated, for the first time, to the GreenMetric World University Rankings and it launched its most ambitious sustainable initiatives by publishing the first annual University Sustainability Report. Since 2013, several efforts have been made to reduce carbon emissions, to improve the energy efficiency of buildings, as well as for reducing water consumption, improving waste management, promoting sustainable mobility, and increasing ecological purchases. The most recent achievement was in 2016, when the University Green Office (UniToGO) was established. Concerning the energy management, UniTo may be considered as a “city within a city”: it counts about 70,000 students and 4,000 academic and administrative-technical staff studying and working in about 120 buildings, with an annual primary energy cost of over 10 M€. Thanks to UniToGO, UniTo adopted an Energy Plan with the aim to reduce primary energy consumption, to improve buildings energy efficiency and to increase the energy production from renewable energy. As a result, several actions relevant for GreenMetric were performed: the renovation of old chiller and substitution of new energy efficient LED, the implementation of Smart Building Systems (BEMS) for HVAC plants and the adoption of an OpenData policy for energy consumption, the increase of renewable energy production, mainly due to three cogeneration plants, and the adoption of a university policy in order to buy only renewable energy from the current Distribution System Operator. Moreover, UniTo took several efforts to improve or to design elements of green buildings in a partecipatory way. Finally, during 2017, the Environmental Sustainability Action Plan was set-up to plan future actions related to five sustainability fields: Energy, Food, Green Public Procurement, Mobility and Waste