Search results for "efficiency."

High-Performance Lead-Acid Batteries Enabled by Pb and PbO2 Nanostructured Electrodes: Effect of Operating Temperature

2021

Lead-acid batteries are now widely used for energy storage, as result of an established and reliable technology. In the last decade, several studies have been carried out to improve the performance of this type of batteries, with the main objective to replace the conventional plates with innovative electrodes with improved stability, increased capacity and a larger active surface. Such studies ultimately aim to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface and to guarantee a good electrical continuity during the repeated charge/discharge cycles. To achieve these objectives, our contribution focuses on the employment of nanostructured electr…

The thermal performances of historic masonry: In-situ measurements of thermal conductance on calcarenite stone walls in Palermo

2018

Abstract Rich literature explores materials and construction techniques of historic buildings, but limited information is available about the thermal and hygrometric features of their envelope. Nevertheless, accurate hygrothermal data are essential for identifying effective energy upgrade measures, which must be compatible with the conservation of the architectural heritage. In order to fill this gap, it is necessary to refer to local contexts, where the variety of historic buildings is limited and their material and construction features are comparable. This paper focuses on historic masonry walls and discusses the results of twenty in-situ measurements of thermal conductance, performed al…

The Recurrent Characteristics of Historic Buildings as a Support to Improve their Energy Performances: The Case Study of Palermo

2017

Abstract The analysis of the recurrent characteristics of the local historic architecture is useful to develop large-scale energy analyses, regulations and financial strategies, but also to support technical guidelines for an energy improvement balanced with conservation. For this purpose, a multi-scale methodology ranging from envelope components to the urban dimension is necessary. In the research here exposed, this approach is investigated by focusing on the historic architecture of Palermo. For this heritage, the collection of thermal and hygrometric data for envelope components is combined with the examination of representative constructions, based on building stock categorization. Int…

Calibration of a small anode germanium well detector

2017

SAGe kolokiteen kalibroinnit suoritettiin kolmelle näytegeometrialle. Kaksi geometrioista oli sylinterin muotoisia purkkeja, jotka mitattiin ilmaisimen päällä ja yksi koeputki, joka mitattiin kolon sisällä. Piikkitehokkuuskalibrointi tehtiin NPL:sta tilattujen sertifioitujen näytteiden avulla. Yksinuklidinäytteitä valmistettiin radioaktiivisista liuoksista totaalitehokkuuskalibrointia varten. Totaalitehokkuuskäyrä saatiin simuloimalla totaalitehokkuudet MCNP:llä ja sovittamalla malli vastaamaan kokeellisia tuloksia. Kalibraatiot tehtiin energiavälille 30 keV–1.9 MeV. Kalibroinnit olivat tarpeeksi luotettavia, että ilmaisinta voidaan käyttää akkreditoiduissa gammaspektrometrisissä mittauksis…

TRANSITION METAL OXIDES AS SELECTIVE CONTACTS FOR C-SI SOLAR CELLS

2021

Impacts des réseaux viaires sur les mobilités urbaines : quelques illustrations

2008

This research aims to find the impact of the network shape and structure on the urban mobilities, in order to fight against the automobile dependency and to include the externalities in the network design. Three examples illustrate this objective. The first one shows the influence of the network shape on the pedestrian urban flows. The second one emphasizes how sensitive to the network structure is the efficiency of a very flexible Demand Responsive Transport. The third example demonstrates that the network metric is favourable to the automobile and how it can be possible to apply an alternative metric, called the “slow metric” to reduce the urban sprawling and the automobile dependency.

STUDIES AND RESEARCHES CONCERNING THE POSSIBILITY OF USING HYDROGEN IN TURBO ENGINES

2014

The paper aims to study the main aspects related to using Hydrogen as fuel in thermal engines, the advantages and disadvantages of using it as fuel and the technical posibilities of adjusting it, Hydrogen used as supplement at the main fuel and Hydrogen used as working fluid. As a perspective, it can be considered using Hydrogen as thermical agent in a closed energetic flux with thermo- chemical compression of Hydrogen in a hybrid heat changer, based on the heat of burning products of thermical engines. The experiments made showed that using such a way of using the heat of burning products of turbo engines can assure the increase of power and efficiency of the whole instalation with 20 %, w…

Evaluation of biogas production and usage potential

2016

The aim of the research is the development of theoretical and methodical bases for determining the feasibility of plant raw materials growing for its further bioconversion into energy resources and tec hnological materials to maximize profit from business activities. Monograph, statistics, modelling and abstract logical methods have been used during the research. Directions of biogas usage have been examined. Biogas yields from different crops have been analyzed. It has been determined that high methane yields can be provided from root crops, grain crops, and several green forage plants. So, forage beet and maize can provide more than 5,500 m3 of biogas per hectare. Attention is paid to the…

Performance indicators to assess water & wastewater service criticalities and investments efficiency and effectiveness in the Italian regulatory cont…

2017

Energy Efficient Optimization for Wireless Virtualized Small Cell Networks With Large-Scale Multiple Antenna

2017

Wireless network virtualization is envisioned as a promising framework to provide efficient and customized services for next-generation wireless networks. In wireless virtualized networks (WVNs), limited radio resources are shared among different services providers for providing services to different users with heterogeneous demands. In this paper, we propose a resource allocation scheme for an orthogonal frequency division multiplexing-based WVN, where one small cell base station equipped with a large number of antennas serves the users with different service requirements. In particular, with the objective to obtain the energy efficiency in the uplink, a joint power, subcarrier, and antenn…