Search results for "MAC"
showing 10 items of 24950 documents
Reinstatement of the Patagonian moss Ulota glabella Mitt. (Bryophyta, Orthotrichaceae)
2020
In 1842, J.D. Hooker collected a number of mosses on Hermite Island (Cape Horn region). From one of those gatherings, Hooker 141, four species of Ulota have been described: U. luteola, U. fuegiana, U. glabella, and U. eremitensis. The first two species are widely accepted, whereas the identity of the latter two has been recently discussed, and the names are now synonymized under U. fuegiana, the more widely distributed species in the Tierra del Fuego archipelago. Our studies, based on recent collections of Orthotrichaceae from Patagonia, show that specimens different from those of U. fuegiana and agreeing with the protologues of both U. glabella and U. eremitensis are common in Patagonia. C…
Exploring how social interactions influence regulators and innovators: The case of regulatory sandboxes
2020
Like incubators, regulatory sandboxes constitute a prominent mechanism to enable entrepreneurial activities that guide financial technology (FinTech) firms through regulatory frameworks in the financial industry. Because they are new, there is a lack of research on regulatory sandboxes; most studies have investigated legal aspects while overlooking the management perspective. To address this gap, this paper builds on incubation research studies to explore how social interactions within regulatory sandboxes influence the practices of regulators and regulatees, using social capital theory. An exploratory-abductive approach is adopted, using data collected from 16 semi-structured interviews. T…
A solar assisted seasonal borehole thermal energy system for a non-residential building in the Mediterranean area
2019
Abstract Solar heating and cooling systems are reliable and feasible solutions among renewable energy technologies. Indeed, solar thermal devices help reduce primary energy consumption and can reduce electricity demand, thus representing one of the best options for satisfying heating and/or cooling energy supply. The Borehole Thermal Energy Storage (BTES) represents one of the best promising option among the various storage technologies, because the size of the storage can be easily extended by drilling additional boreholes and simply connecting the pipes to the existing boreholes; the overall energy efficiency of this system is about 40–60%. In this paper, the authors present an applicatio…
Energy Policies and Sustainable Management of Energy Sources
2017
Sustainability of current energy policies and known mid-term policies are analised in their multiple facets. First an overview is given about the trend of global energy demand and energy production, analysing the share of energy sources and the geographic distribution of demand, on the basis of statistics and projections published by major agencies. The issue of sustainability of the energy cycle is finally addressed, with specific reference to systems with high share of renewable energy and storage capability, highlighting some promising energy sources and storage approaches.
Sea water desalination and energy consumption: A case study of wave energy converters (WEC) to desalination applications in sicily
2016
Recent studies about interactions among energy and water are considered as a new field of research. As almost all energy generation processes require significant amounts of water, and water requires energy for treatment and transport, so these two resources are inextricably linked. The main aim of this work is a presentation of the use of renewable energy for desalination plants in Sicily: in particular exploitation of wave energy into electrical energy necessary for water treatment. Desalination is the most energy intensive water treatment technology but it could be solution for many problems in water supply for areas with chronic debt of water. The aim of this work is a description of a s…
Aircraft wing rock oscillations suppression by simple adaptive control
2020
Abstract Roll angular motion of the modern aircraft operating in non-linear flight modes with a high angle of attack often demonstrates the limit cycle oscillations, which is commonly known as the wing rock phenomenon. Wing rock dynamics are represented by a substantially non-linear model, with parameters varying over a wide range, depending on the flight conditions (altitude, Mach number, payload mass, etc.) and angle of attack. A perspective approach of the wing rock suppression lies in the adaptation methods. In the present paper an application of the simple adaptive control approach with the Implicit Reference Model (IRM) is proposed and numerically studied. The IRM adaptive controller …
Adaptive Feedforward Control of a Pressure Compensated Differential Cylinder
2020
This paper presents the design, simulation and experimental verification of adaptive feedforward motion control for a hydraulic differential cylinder. The proposed solution is implemented on a hydraulic loader crane. Based on common adaptation methods, a typical electro-hydraulic motion control system has been extended with a novel adaptive feedforward controller that has two separate feedforward states, i.e, one for each direction of motion. Simulations show convergence of the feedforward states, as well as 23% reduction in root mean square (RMS) cylinder position error compared to a fixed gain feedforward controller. The experiments show an even more pronounced advantage of the proposed c…
Making Industrial Robots Smarter with Adaptive Reasoning and Autonomous Thinking for Real-Time Tasks in Dynamic Environments: A Case Study
2018
In order to extend the abilities of current robots in industrial applications towards more autonomous and flexible manufacturing, this work presents an integrated system comprising real-time sensing, path-planning and control of industrial robots to provide them with adaptive reasoning, autonomous thinking and environment interaction under dynamic and challenging conditions. The developed system consists of an intelligent motion planner for a 6 degrees-of-freedom robotic manipulator, which performs pick-and-place tasks according to an optimized path computed in real-time while avoiding a moving obstacle in the workspace. This moving obstacle is tracked by a sensing strategy based on ma-chin…
Analysis of Electrical Energy Demands in Friction Stir Welding of Aluminum Alloys
2017
Abstract Manufacturing processes, as used for discrete part manufacturing, are responsible for a substantial part of the environmental impact of products. Despite that, most of metalworking processes are still poorly documented in terms of environmental footprint. To be more specific, the scientific research has well covered conventional machining processes, concerning the other processes there is a lack of knowledge in terms of environmental load characterization instead. The present paper aims to contribute to fill this knowledge gap and an energetic analysis of Friction Stir welding (FSW) is presented. Following the CO2PE! methodological approach, power studies and a preliminary time stu…
Analysis of hybrid vehicle transmissions with any number of modes and planetary gearing: kinematics, power flows, mechanical power losses
2021
Abstract This paper is focused on upgrading a unified parametric model, available in the literature, that can perform both the analysis and the design of Power-Split Continuously Variable Transmissions (PS-CVTs), which are particularly promising to deploy in the hybrid electric powertrain. In particular, this work is focused on the analysis of PS-CVTs and proposes a new matrix approach for identifying the basic functional parameters underlying the model from the constructive layout of the transmission. This new method does not rely on a case-specific formulation, thus befits any power-split transmission, regardless of the number of planetary and ordinary gear sets and their constructive arr…