Search results for "efficiency"
showing 10 items of 1430 documents
Synthesis and characterization of zinc carboxy–porphyrin complexes for dye sensitized solar cells
2018
Two zinc porphyrins, 2 and 8, have been synthesized. Porphyrin 8 displays better electronic communication between the dye and the TiO2 electrode. Photophysical measurements and electrochemistry experiments suggest that both porphyrins are very promising sensitizers for dye-sensitized solar cells (DSSCs). It was found that their molecular orbital energy levels favor electron injection and dye regeneration in DSSCs. Solar cells sensitized by 2 and 8 were fabricated, and it was found that they show power conversion efficiencies (PCEs) of 5.27% and 7.13%, respectively. Photovoltaic measurements (J–V curves) together with the incident photon-to-electron conversion efficiency spectra of the two c…
Innovative control logics for a rational utilization of electric loads and air-conditioning systems in a residential building
2015
The paper focuses on the evaluation of the impact on residential buildings of innovative control logics defined for a rational utilization of the electric loads and air-conditioning systems. The control logics are implementable thanks to a Decision Support and Energy Management Systems developed by the same authors and easily installable in new and still-existing houses. The paper shows how a significant reduction of the primary energy consumption can be obtained by controlling the air-conditioning units together with the other electric loads of the house. After having explained how the control logics operate, a simulation tool is described, developed for a preliminary evaluation of their e…
Experimental validation of the BAC factor method for lighting systems
2017
In the last few years, many buildings have been equipped with Building Automation and Control (BAC) systems. BAC systems can be used to achieve a significant reduction of the electrical consumption and to have all the well acknowledged benefits from the daylight (e.g. occupant comfort, health, well-being and productivity). For this reason, Standard EN 15232 "Energy performance of buildings — Impact of Building Automation, Controls and Building Management" puts into evidence the importance of the presence of BAC and Technical Building Management (TBM) systems, suggests a classification of these systems, explains their main functionalities and presents a simplified method to estimate their im…
Are the Best Available Technologies the only viable for energy interventions in historical buildings?
2014
Worth aged buildings represent among the existing buildings a special case when it comes to their energy refurbishment. Current available technologies for building components, characterized by high level of thermal performances, unfortunately, are also characterized, not rarely, by limited compatibility with the architectural integrity of the building. In other words, the so-called Best Available Technologies that are effectively adopted to optimize the energy performances of buildings, in the case of aged buildings to which a certain artistic, historic and/or architectural merit is recognized (heritage houses) could, actually, determine such kind of conflicts and therefore leading to the s…
Novel Energy Efficient Schemes for Wireless Sensor Networks Utilizing Mobile Sensors
2022
Wireless sensor networks (WSNs) facilitate many applications in different fields and are well-known in both academic and industrial areas. The networks mainly include sensors, networking parts and a data processing center to collect data for a variety of purposes. However, the energy consumption problem in the networks is always a critical problem that many researchers are looking for good solutions. In this paper, we propose a data collection method that uses mobile sensors attached with bigger energy storages to collect data from static sensors. In addition, we propose a hybrid energy harvesting scheme to harvest energy from ambient environments to support static sensors to prolong the ne…
The requirements and compliance of the Finnish act on energy efficiency in a large enterprise : a case study from the healthcare industry
2015
Energy management is becoming increasingly important for organizations due to legislative, environmental, and economic causes. The Act on Energy Efficiency came into force in Finland on 1st January 2015. One of the law’s obligations requires large enterprises to enhance and report their energy efficiency performance with an energy audit every four years. However, a large company can be exempted from the energy audit obligation in three ways under the Finnish law. The aim of this study is to discover the best solution for the target organization to meet the obligations posed by The Act on Energy Efficiency. The options considered in this study are: 1) performing energy audit as the law requi…
Energy rehabilitation of a nursery school in Sicily: winter and summer behaviours
2004
Following a previous work, concerning the energy audit of a nursery school belonging to the public building park of the town of Palermo, some further analyses have been conducted. These mainly refer to the environmental performances of the school that are assessed with regards to different interventions involving the envelope (the glazed part, particularly) and the surrounding spaces. The interventions are hierarchised by means of suitable indicators concerning energy, environment and economy issues. Finally a simple graph is proposed that visually summarises these indicators for each proposed action.
Performance evaluation of hybrid RO/MEE systems powered by a WTE plant
2008
Abstract The solid waste management is, in different contexts, a very critical issue. The use of landfills can no longer be considered a satisfactory environmental solution, therefore new methods have to be chosen and waste-to-energy (WTE) plants would provide an answer. Today's WTE plants are a far cry from their polluting predecessors. Using modern combustion and pollution control technology, WTE plants are able to retrieve considerable amounts of energy from waste combustion while minimizing emissions. As we know, is possible to recover thermal energy by combusting municipal solid waste (MSW) for electricity generation and district heating. However, with everincreasing population and rap…
Optimization on ports activation towards energy efficient data center networks
2018
Nowadays, Internet of thing including network support (i.e. checking social media, sending emails, video conferencing) requires smart and efficient data centers to support these services. Hence, data centers become more important and must be able to respond to ever changing service requirements and application demands. However, data centers are classified as one of the largest consumers of energy in the world. Existing topologies such as ScalNet improves the data center scalability while leading to enormous amounts of energy consumption. In this paper, we present a new energy efficient algorithm for ScalNet called Green ScalNet. The proposed topology strikes a compromise between maximizing …
ERCP : Energy-Efficient and Reliable-Aware Clustering Protocol for Wireless Sensor Networks
2022
Wireless Sensor Networks (WSNs) have been around for over a decade and have been used in many important applications. Energy and reliability are two of the major problems with these kinds of applications. Reliable data delivery is an important issue in WSNs because it is a key part of how well data are sent. At the same time, energy consumption in battery-based sensors is another challenge. Therefore, efficient clustering and routing are techniques that can be used to save sensors energy and guarantee reliable message delivery. With this in mind, this paper develops an energy-efficient and reliable clustering protocol (ERCP) for WSNs. First, an efficient clustering technique is proposed for…