Search results for "021108 energy"
showing 10 items of 80 documents
Investigating energy saving potential in a big shopping center through ventilation control
2019
Abstract This paper investigates energy saving measures for the ventilation system of large shopping centers. This kind of buildings is characterized by high yearly energy consumptions, because of the high level of operating hours and the frequent use of obsolete technologies. In the analyzed case studies, three big Do It Yourself (DIY) shops, located in Italy, are considered. Two different approaches are considered, they are aimed at reducing the annual energy consumption for the indoor air exchange of the sales area. The first considered retrofit solution consists in the installation of heat recovery exchangers, reducing the energy demand for the air thermal treatment without changing the…
Structural change in a Ricardian world economy: The role of extensive rent
2019
Abstract We study an implication of the Ricardian theory of differential extensive rent in a free trade regime. To this effect we develop a Ricardian two country two commodity open economy model. We assume that, unlike labour, land is heterogeneous both within and across countries and that the ratio of high to low quality land is different among the trading countries. By means of a numerical example we show that as the process of worldwide capital accumulation (and population growth) proceeds an industrial country may find it convenient to increase its domestic corn production and even reverse completely the pattern of its imports and exports.
Optimal design of flax fiber reinforced polymer composite as a lightweight component for automobiles from a life cycle assessment perspective
2019
The present study combines the generalized rule-of-mixture (ROM) model and the Ashby material selection method for the life cycle assessment (LCA) of flax fiber reinforced polymers (FRPs) and glass FRPs (GFRPs). The ROM model allows life cycle environmental impact predictions according to specific parameters of flax FRPs such as fiber format, volume fraction, manufacturing technique, and load-bearing capacity. The comparisons applied in this study are constructed on two common composite structures: mat panels and injection molded struts with equal stiffness and strength as the design criteria. On the one hand, the parametric LCA predicts that the equal strength design criterion for flax FRP…
Explainable Post-Occupancy Evaluation Using a Humanoid Robot
2020
The paper proposes a new methodological approach for evaluating the comfort condition using the concept of explainable post occupancy to make the user aware of the environmental state in which (s)he works. Such an approach was implemented on a humanoid robot with social capabilities that aims to enforce human engagement to follow recommendations. The humanoid robot helps the user to position the sensors correctly to acquire environmental measures corresponding to the temperature, humidity, noise level, and illuminance. The distribution of the last parameter due to its high variability is also retrieved by the simulation software Dialux. Using the post occupancy evaluation method, the robot …
A decentralized load control architecture for smart energy consumption in small islands
2020
Abstract In this paper we propose the adoption of Overgrid, a new decentralized load control architecture, for balancing the energy production variations introduced with the adoption of renewable sources, facilitating and improving the smart energy retrofit. The system is presented and applied for managing the aggregated daily load profile of a community of domestic end-users in the island of Lampedusa, Italy, exploiting the load profiles gathered in a real measurement campaign. The Overgrid Demand Response (DR) architecture is used for managing the residential flexible loads, estimating the aggregated power demand without any centralized server and creating a virtual “community” of smart b…
Covering the Gap for an Effective Energy and Environmental Design of Green Roofs: Contributions from Experimental and Modelling Researches
2021
AbstractGreen roofs are components of the building envelope that have become increasingly popular in urban contexts because other than providing numerous environmental benefits they are also capable of reducing building energy consumption, especially in summer. However, despite all these advantages, green roofs are still affected by some limitations. Specifically, there are some gaps affecting the energy modelling consisting in the absence of a proper database, information (growth stage, leaf area index, and coverage ratio) relative to the different green roof plant species, which technicians could use in case of lack of actual field data to perform energy analysis of buildings equipped wit…
A review on optimization and cost-optimal methodologies in low-energy buildings design and environmental considerations
2019
Abstract The topic of low-energy buildings received a widespread and growing interest in last years, thanks to energy saving policies of developed countries. The design of a low-energy building is addressed with energy saving measures and renewable energy generation, but the correct assessment of phenomena occurring in a building usually requires to perform dynamic simulations and to analyze multiple scenarios to attain the optimal solution. The optimality of a technical solution may be subject to contrasting constraints and objectives. For this reason, designers may employ mathematical optimization techniques, a non-familiar topic to most of building designers. In this paper, a review on o…
Computing Euclidean Steiner trees over segments
2020
In the classical Euclidean Steiner minimum tree (SMT) problem, we are given a set of points in the Euclidean plane and we are supposed to find the minimum length tree that connects all these points, allowing the addition of arbitrary additional points. We investigate the variant of the problem where the input is a set of line segments. We allow these segments to have length 0, i.e., they are points and hence we generalize the classical problem. Furthermore, they are allowed to intersect such that we can model polygonal input. As in the GeoSteiner approach of Juhl et al. (Math Program Comput 10(2):487–532, 2018) for the classical case, we use a two-phase approach where we construct a superse…
Impacts of roundabouts in suburban areas on congestion-specific vehicle speed profiles, pollutant and noise emissions: an empirical analysis
2019
Abstract Increasing concern about global warming and air quality has meant an increasing use of energetic and environmental indicators in roundabout design. This research compares different suburban roundabouts in terms of traffic performance, pollutant and noise emissions through an integrated empirical assessment. Field measurements were carried out with a light duty vehicle in single-lane (SL), compact two-lane (CTL) and multi-lane (ML) roundabouts using Portable Emission Measurements Systems, On-Board Diagnostic scan tool and Sound Level Meter, to measure real-world exhaust emissions, engine activity and acoustic data, respectively. Afterwards, predictive discrete choice models that cor…
Climate variability and agricultural production efficiency: evidence from Ethiopian farmers
2020
It is known that climate and weather variability have negative impacts on agricultural production efficiency. The aim of this study is to analyse the impact of climatic variables on farms’ efficiency in Ethiopia making use of nationally representative datasets from Living Standards Measurement Study–Integrated Surveys on Agriculture (LSMS-ISA) 2011/2012. By using the Stochastic Frontier Approach, we estimate simultaneously the farmers’ optimal production function and technical inefficiency equations, taking into account unobserved heterogeneity of farmers. Our main findings show that climate change variables have a positive effect on households’ efficiency but the impact depends on the diff…