Search results for " EFFICIENCY"

Comparing the cost-efficiency of CoAP and HTTP in Web of Things applications

2014

Abstract Constrained Application Protocol (CoAP) has been introduced as a simpler alternative to the Hypertext Transfer Protocol (HTTP) for connecting constrained smart objects to the Web. The adoption of the protocol depends on its relative advantage, and the cost–benefit associated with the use of the protocol is a significant factor affecting a protocol adoption decision. This paper aims at deepening the understanding of the cost–benefits of CoAP and identifies the application scenarios where its use is likely to be economically justifiable. The paper analyzes the costs of using CoAP and HTTP in the Web of Things (WoT) applications, by identifying the components of the total cost of owne…

Effect of Ion Escape Velocity and Conversion Surface Material on H- Production

2011

According to generally accepted models surface production of negative ions depends on ion escape velocity and work function of the surface. We have conducted an experimental study addressing the role of the ion escape velocity on H− production. A converter‐type ion source at Los Alamos Neutron Science Center was employed for the experiment. The ion escape velocity was affected by varying the bias voltage of the converter electrode. It was observed that due to enhanced stripping of H− no direct gain of extracted beam current can be achieved by increasing the converter voltage. The conversion efficiency of H− was observed to vary with converter voltage and follow the existing theories in qual…

Does innovativeness reduce startup survival rates?

2015

There are two competing hypotheses explaining how innovativeness influences the survival of startups: On the one hand, innovativeness is argued to foster survival-enhancing attributes (e.g., market power and cost efficiency) and capabilities (e.g., absorptive capacity). On the other hand, an innovative startup faces (and bears the associated risks of) liabilities of newness and smallness that exceed those of its non-innovative counterparts. The available empirical literature addressing this theoretical tension mostly supports the former hypothesis; we suggest that this finding is, in part, driven by the common practice of employing an ex post measure that already embodies a degree of succes…

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

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…