1,100 research outputs found
Industrial energy management systems in Italy: state of the art and perspective
Despite the economic crisis, the impact of industry sector Share on the total primary energy demand in Italy is still significant. The certification of companies according to the standard ISO 50001:2011 ("Energy management systems Requirements and guidelines for use"), can represent a key element in the achievement of objectives set in the 20-20-20 Climate-Energy Package.
This paper illustrates the state of implementation of ISO 50001 certifications in Italy, reporting on the results of a questionnaire carried out as a part of a master's thesis project at Sapienza, University of Rome in collaboration with FIRE (Italian Federation for the Rational Use of Energy) that included the major certification bodies, certified companies and consultants. The purpose is to outline the current situation, identify the perspectives and highlight the pros and cons related to the implementation of an Energy Management System (EnMS).
The big picture shows that Italy, one of the leading countries in energy efficiency policies, suffer from a significant delay in the implementation of the EnMS in industry with respect to Germany.
The results of the survey also show that the definition of energy performance indicators, as hell as the individuations of an energy baseline and a. monitoring plan constitute the requirements most critical to comply with for companies than for consultants. It also appears that more than 35% of companies already ISO 50001 certified have received benefits in terms of cumulative energy saving above 5%, and that the main reason why they have implemented an EnMS is related to the potential impact on increasing the competitiveness of the core business
Phase-tunable thermoelectricity in a Josephson junction
Superconducting tunnel junctions constitute the units of superconducting
quantum circuits and are massively used both for quantum sensing and quantum
computation. In previous works, we predicted the existence of a nonlinear
thermoelectric effect in a electron-hole symmetric system, namely, a thermally
biased tunnel junction between two different superconductors, where the
Josephson effect is suppressed. In this paper we investigate the impact of the
phase-coherent contributions on the thermoelectric effect, by tuning the size
of the Josephson coupling changing the flux of a direct-current Superconducting
Quantum Interference Device (dc-SQUID). For a suppressed Josephson coupling,
the system generates a finite average thermoelectric signal, combined to an
oscillation due to the standard ac Josephson phenomenology. At large Josephson
couplings, the thermoelectricity induces an oscillatory behaviour with zero
average value of the current/voltage with an amplitude and a frequency
associated to the Josephson coupling strength, and ultimately tuned by the
dc-SQUID magnetic flux. In conclusion, we demonstrate to be able to control the
dynamics of the spontaneous breaking of the electron-hole symmetry.
Furthermore, we compute how the flux applied to the dc-SQUID and the lumped
elements of the circuit determine the frequency of the thermoelectric signal
across the structure, and we envision a frequency modulation application
Phase-tunable temperature amplifier
Coherent caloritronics, the thermal counterpart of coherent electronics, has drawn growing attention since the discovery of heat interference in 2012. Thermal interferometers, diodes, transistors and nano-valves have been theoretically proposed and experimentally demonstrated by exploiting the quantum phase difference between two superconductors coupled through a Josephson junction. So far, the quantum-phase modulator has been realized in the form of a superconducting quantum interference device (SQUID) or a superconducting quantum interference proximity transistor (SQUIPT). Thence, an external magnetic field is necessary in order to manipulate the heat transport. Here, we theoretically propose the first on-chip fully thermal caloritronic device: the phase-tunable temperature amplifier (PTA). Taking advantage of a recently discovered thermoelectric effect in spin-split superconductors coupled to a spin-polarized system, we generate the magnetic flux controlling the transport through a temperature-biased SQUIPT by applying a temperature gradient. We simulate the behavior of the device and define a number of figures of merit in full analogy with voltage amplifiers. Notably, our architecture ensures almost infinite input thermal impedance, maximum gain of about 11 and efficiency reaching the 95%. This concept paves the way for applications in radiation sensing, thermal logics and quantum information
Phase-Tunable Thermal Logic: Computation with Heat
Boolean algebra, the branch of mathematics in which variables can assume only true or false values, is the theoretical basis of classical computation. The analogy between Boolean operations and electronic switching circuits, highlighted by Shannon in 1938, paved the way for modern computation based on electronic devices. The growth in the computational power of such devices, after an exciting exponential - Moore's trend - is nowadays blocked by heat dissipation due to computational tasks, which are very demanding due to the miniaturization of chips. Heat is often a detrimental form of energy which increases the system's entropy, decreasing the efficiency of logic operations. Here, we propose a physical system that is able to perform thermal-logic operations by reversing the old heat-disorder epitome into a heat-order paradigm. We lay the foundations of heat computation by encoding logic state variables in temperature and introducing the thermal counterparts of electronic logic gates. Exploiting quantum effects in thermally biased Josephson junctions (JJs), we propound a possible realization of a functionally complete logic. Our architecture ensures high operational stability and robustness, with switching frequencies reaching the GHz range
Blockchain acceptance and adoption in the tourism industry
Tourism has always been characterized by extensive innovativeness (from theme parks and cultural&gourmet tours till a deeper service integration). Today, digital solutions represent an opportunity to expand and innovate the range of services offered. Focusing on blockchain as an emerging technological solution, the paper investigates how expert and practitioners perceive the potentialities and limitations of its adoption in tourism.To capture the attitudes expressed in the field, we analyze the ongoing discussions on a major social network: Twitter.Through a social network analysis of the flow of tweetsconducted overthree months, we map the current perceptions towards blockchain. Specifically, we contribute to the literature on technology acceptance and adoption by intercepting the current perceptions in the tourism industry.This paper shows how experts and practitioners are envisioning the possibilities that blockchain shape future services in the tourism sector. Our study is based on an extensive literature review and a social network analysis of a Twitter-database. This allows us to investigate the current sentiment towards blockchain, and also to envision future directions of a promising and yet under analyzed technology
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