1,721,189 research outputs found
Realizzazione di una pressa “intelligente” per il controllo del ritorno elastico nel processo di piegatura
Full text linkThe hydraulic press brake for sheet metal bending has been designed for laboratory research and not for production aims; in particular, to perform accurate measurements of force during the operation of bending and then to validate and possibly to optimize the semi-empirical procedure created to solve the problem of springback. To understand the reasons for the design and implementation of a press brake is necessary to recall the problems that occur during the bending process. In particular, the springback phenomenon is seen in a negative way and one should try to reduce it as much as possible. This explains the use of the term " intelligent press brake" because it is necessary to create a system capable of acquiring all the information on the material being processed at an early stage of the process. The relevant data are then used as input to a prediction algorithm on the displacement to be imposed to the punch. The method used is semi-empirical method. The information relating to the properties of the material being processed is collected. Through the information of the material and the FEM simulations pre-loaded in the software of the press, the algorithm provides the value of the stroke of the punch needed to obtain the desired bending angle (considering also the elastic recovery). In the algorithm, the both linear and second degree interpolations are used. In the model, only the properties of the material have been included while it was not considered the effect of geometrical parameters, as the thickness sheet and the geometry of the tool (punch radius and die). The output parameters are the angle of springback and the properties of the material. The objective is therefore to improve the evaluation of the stroke of the punch considering the properties of the material through the direct measurement of load an
Assessment of Renewable Natural Gas Refueling Stations for Heavy-Duty Vehicles
No full textWith environmental concerns and limited natural resources, there is a need for cleaner sources of energy in the transportation sector. Renewable natural gas (RNG) is being considered as a potential fuel for heavy-duty applications due to its comparable usage to diesel and gasoline in vehicles. The idea of compressed RNG vehicles is being proposed especially because it will significantly reduce harmful emissions into the environment. This study examines the feasibility of implementing a nationwide network of compressed RNG refueling infrastructure in order to accommodate a conversion of long-haul, heavy-duty (LHHD) truck fleet from diesel fuel to RNG. Two methods, Constant Traffic and Variable Traffic, along with data about compressed RNG infrastructure and vehicles, were developed and used to predict fuelling requirements for LHHD truck fleet. Then, a detailed economic analysis was conducted on various test cases to estimate how different variables impact the final selling price of RNG. This provided insight with the understanding of what factors go into pricing RNG and if it can compete against diesel in the trucking market. Results disclosed that the cost to purchase RNG is the greatest factor in the final selling price of compressed RNG. Due to the variability in RNG production, however, there is no precise cost, which makes predictions challenging. However, results revealed that it is possible for compressed RNG to be competitive with diesel, with the mean compressed RNG price being 16.5% cheaper than diesel, before being taxed. Future studies should focus on the feasibility of the production of RNG and the associated costs. An in-depth analysis on operational and maintenance costs for compressed RNG refueling stations may also provide predictions that are more accurate. The methodology developed in this feasibility analysis may serve as a useful tool for future techno-economics of RNG refueling stations for other types of internal combustion engine (ICE) fleets or those powered with alternative green fuels
Control system algorithm for the prediction of sprinback in air bending
No full textThe phenomenon of springback, which is ruled by strain recovery after removal of forming loads, is of remarkable interest in air bending of metal sheets. In this process, the final angle is affected by a number of parameters related to both process geometry (sheet thickness, die and punch radii) and material properties (elastoplastic stress-strain law); because of this, punch stroke has to be calculated in a nontrivial way and a number of input parameters should be taken into account. In this work the study of total load as a function of displacement is used to collect information about material stress-strain law; using this approach, load data may be exploited to fine tune the mathematical description of the material and, finally, to improve springback prediction. A customized press brake able to measure both displacement and force during bending was fabricated for this purpose. The press brake is equipped with a control system algorithm able to collect material information directly during the initial stage of the bending process. These collected data are used to feed a model based on a FEM simulation and the model output is the final punch displacement suitable to obtained a specific bending angle after unloading. The program utilized for the simulation is Deform 2D. Preliminary tests were executed on metal sheets having thickness equal to 2.5 mm. Copyright © 2013 Trans Tech Publications Ltd
Smart Mobility for Green University Campus
No full textThe solution to integrate renewable energy sources and electric mobility can bring many economic benefits to the environment, both at the urban level and not alone, also it is one of the many roads for the future of mobility. The aim of this research describe a possible draft of green mobility sharing, based on power from renewable sources in order to feed a system of shared transport, in order to optimize traffic flows of vehicles, as well as the achievement of a zero impact of emissions to local towns, where the pollution is already high
Smart city by multi-agent systems
No full textThe current economic crisis, combined with growing citizen expectations, is placing increasing pressure on European cities to provide better and more efficient infrastructures and services, often for less cost. This trend has contributed to the growing popularity and use of the term `Smart City' [1]. The Smart City, represent a new way of thinking about urban space by shaping a model that integrates Green Energy Sources and Systems (GESSs), energy efficiency, sustainable mobility, protection of the environment and economic sustainability, that represent the goals for future developments. Smart cities are made by a high level of Information and Communication Technology-ICT- structures able to transmit energy, information flows multidirectional and connect a different sector that include mobility, energy, social, economy. Into Smart Cities transport systems are sustainable, smart grids are enhanced to ensure greater integration capabilities of production plants from renewable sources, public lighting is efficient, the buildings are equipped with sensors and devices aimed at rationalizing consumption energy and create greater awareness on the part of citizens, with the aim of improving the quality of life of people through a new governance of public administration capable of managing this innovation and cultural change. However, while wishing the transformation of cities in smart systems, have not defined models infrastructure, that allow different subsets to communicate and interact, in order to make the concrete realization of a smart city. The objective of this paper is to discuss a model of Smart City with a multi-agent systems and Internet of things, that provides intelligence to a city, as basic infrastructure for a definition of a model repeatable and exportable, so as advocated by the European Community, that is allocating considerable funds (Horizon 2020) for the creation of Smart City
Smart planning for ecoefficient cities
No full textCities are intensive centres of social activity and the central feature in the economical technology of civilizations. The cities directly express the energy resource framework and infrastructure available at any given time in history. Global acceleration in city formation and urban growth can be ascribed to a number of technological innovations, none more profound in their impact than the rise and spread of fossil fuel resources, products, systems, and tools. Much of the global environmental problems, and especially the fight against climate change, require proper management of energy, especially at the local level, through concrete actions that promote energy efficiency in buildings, the rational use of energy and the exploitation of renewable energy sources. The world energy economy has the largest influence on the decisions that people and governments make. Current global consumption rates are depleting the planets ability to sustain our way of life. Increased demand means increased prices in every sector of the world economy. Many alternative energy companies are creating new economies in order to facilitate a more sustainable energy market. Reduce greenhouse gas emissions by 20%, raise to 20% the share of energy produced from renewable sources and a 20% energy saving by 2020 all: this is in brief the contents of the so-called “climate-energy package 20-20-20” launched by the European Union. The goal is obviously to combat climate change and promote the use of renewable energy sources through binding targets for member countries. Who does not respect these constraints will face increasing costs to comply with the dictates of the Protocol, and it is on this aspect that the research is focusing in order to make more intelligent city. The system studied therefore wishes to combine different aspects of integration focusing on a building in the tertiary sector that meets these requirements
Analysis of sustainable and competitive energy system
No full textThe climate change is increasingly apparent and the need to be independent for the sourcing of energy sources has led to the establishment of the European Community financing schemes to support research and development of systems in place to decrease pollution and independence from fossil fuels. One way to catch up with greater conviction this scope is the production of energy at a large scale, using renewable sources. Now, the incentives are even a fundamental element for the development and competitiveness of these systems, but it is clear that if the policy guidelines will converge in the direction of Horizon 2020, the possibility of implementing such systems will become a model easily replicable and suitable. In this context, this work aims to show how a production system that exploits solar energy, through a plant collector, can be comparable in terms of cost with other energy sources. In particular, an estimate is made of an economic system with solar collectors for the production of electrical energy, starting with the year of production and on the basis of 25 years of life of the plant
The Exploitation of Vehicle-to-Grid Function for Power Quality Improvement in a Smart Grid
Full text linkSmart grids can be a good challenge for the near future if they are intelligently managed. Therefore, the exploitation of the energy resources distributed into a network is one of the most discussed themes in actual scientific literature, together with the attention paid to power quality (PQ) improvement. This paper aims to provide a possible solution to some common and dangerous PQ problems and voltage sags, considering the large diffusion of electric vehicles. A deep energy and power analysis to evaluate the feasibility of the vehicle-to-grid (V2G) function to compensate for PQ disturbances will be presented
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