Articoli di riviste sul tema "Reversible energy flows"
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1
Zhao, Yang, Chi-Chiu Ma, Lai-Ho Wong, GuanHua Chen, ZhiPing Xu, QuanShui Zheng, Qing Jiang e Allen T. Chwang. "Quasi-Reversible Energy Flows in Carbon-Nanotube Oscillators". Journal of Computational and Theoretical Nanoscience 3, n. 5 (1 ottobre 2006): 852–56. http://dx.doi.org/10.1166/jctn.2006.027.
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Devine, Sean. "Algorithmic Entropy and Landauer’s Principle Link Microscopic System Behaviour to the Thermodynamic Entropy". Entropy 20, n. 10 (17 ottobre 2018): 798. http://dx.doi.org/10.3390/e20100798.
Abstract (sommario):
Algorithmic information theory in conjunction with Landauer’s principle can quantify the cost of maintaining a reversible real-world computational system distant from equilibrium. As computational bits are conserved in an isolated reversible system, bit flows can be used to track the way a highly improbable configuration trends toward a highly probable equilibrium configuration. In an isolated reversible system, all microstates within a thermodynamic macrostate have the same algorithmic entropy. However, from a thermodynamic perspective, when these bits primarily specify stored energy states, corresponding to a fluctuation from the most probable set of states, they represent “potential entropy”. However, these bits become “realised entropy” when, under the second law of thermodynamics, they become bits specifying the momentum degrees of freedom. The distance of a fluctuation from equilibrium is identified as the number of computational bits that move from stored energy states to momentum states to define a highly probable or typical equilibrium state. When reversibility applies, from Landauer’s principle, it costs k B l n 2 T Joules to move a bit within the system from stored energy states to the momentum states.
3
Cartas-Fuentevilla, R., e A. Olvera-Santamaria. "Deforming the theory λϕ4 along the parameters and fields gradient flows". International Journal of Modern Physics A 30, n. 02 (20 gennaio 2015): 1550008. http://dx.doi.org/10.1142/s0217751x15500086.
Abstract (sommario):
Considering the action for the theory λϕ4 for a massive scalar bosonic field as an entropy functional on the space of coupling constants and on the space of fields, we determine the gradient flows for the scalar field, the mass and the self-interaction parameter. When the flow parameter is identified with the energy scale, we show that there exist phase transitions between unbroken exact symmetry scenarios and spontaneous symmetry breaking scenarios at increasingly high energies. Since a nonlinear heat equation drives the scalar field through a reaction-diffusion process, in general the flows are not reversible, mimicking the renormalization group flows of the c-theorem; the deformation of the field at increasingly high energies can be described as nonlinear traveling waves, or solitons associated to self-similar solutions.
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Salter, S. H., J. R. M. Taylor e N. J. Caldwell. "Power conversion mechanisms for wave energy". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 216, n. 1 (1 giugno 2002): 1–27. http://dx.doi.org/10.1243/147509002320382103.
Abstract (sommario):
It is easy to make a device that will respond vigorously to the action of sea waves. Indeed, it is quite hard to make one that will not. However, the conversion of the slow, random, reversing energy flows with very high extreme values into phase-locked synchronous electricity with power quality acceptable to a utility network is very much harder. This paper describes a range of different control strategies of varying degrees of sophistication and then describes possible conversion equipment for high-pressure oil and water and low-pressure air. Like many renewable energy sources, waves would benefit from some form of energy storage, particularly if they are to be used in weak island networks. Flywheels, gas accumulators, submerged oil/vacuum accumulators, thermal stores and reversible fuel cells are discussed, with emphasis on the coupling hardware. This leads on to a description of a new type of hydraulic machine with digital control which has been specially designed for high efficiency and flexible control of multiple erratic sources. An explanation of the rather low performance of air turbines in the random air flows caused by sea waves suggests the need for a variable-pitch version of the Wells turbine and the design of a reciprocating-flow wind-tunnel with recirculating energy recovery in which it could be tested.
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Devine, Sean. "Landauer’s Principle a Consequence of Bit Flows, Given Stirling’s Approximation". Entropy 23, n. 10 (30 settembre 2021): 1288. http://dx.doi.org/10.3390/e23101288.
Abstract (sommario):
According to Landauer’s principle, at least kBln2T Joules are needed to erase a bit that stores information in a thermodynamic system at temperature T. However, the arguments for the principle rely on a regime where the equipartition principle holds. This paper, by exploring a simple model of a thermodynamic system using algorithmic information theory, shows the energy cost of transferring a bit, or restoring the original state, is kBln2T Joules for a reversible system. The principle is a direct consequence of the statistics required to allocate energy between stored energy states and thermal states, and applies outside the validity of the equipartition principle. As the thermodynamic entropy of a system coincides with the algorithmic entropy of a typical state specifying the momentum degrees of freedom, it can quantify the thermodynamic requirements in terms of bit flows to maintain a system distant from the equilibrium set of states. The approach offers a simple conceptual understanding of entropy, while avoiding problems with the statistical mechanic’s approach to the second law of thermodynamics. Furthermore, the classical articulation of the principle can be used to derive the low temperature heat capacities, and is consistent with the quantum version of the principle.
6
Attou, A., e L. Bolle. "Integral formulation of balance equations for two-phase flow through a sudden enlargement Part 1: Basic approach". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 211, n. 5 (1 maggio 1997): 387–97. http://dx.doi.org/10.1243/0954406971522132.
Abstract (sommario):
A general expression of irreversible losses related to two-phase flows through a sudden enlargement is derived from basic balance equations (mass, momentum and energy). The need to take into account void fraction and quality changes is emphasized for some one-fluid flows. From a comparison with several experimental results, it is concluded that a void fraction decrease downstream of the enlargement must be considered in order to predict satisfactorily pressure variations on the basis of the momentum balance procedure. When expressed in the form of a fraction of reversible pressure recovery, dissipation losses appear to depend strongly on the quality. Their minimum value is observed for a larger quality value when the pressure of the system is increased.
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Peters, Michael H. "Nonequilibrium Entropy Conservation and the Transport Equations of Mass, Momentum, and Energy". Energies 14, n. 8 (14 aprile 2021): 2196. http://dx.doi.org/10.3390/en14082196.
Abstract (sommario):
Nonequilibrium statistical mechanics or molecular theory has put the transport equations of mass, momentum and energy on a firm or rigorous theoretical foundation that has played a critical role in their use and applications. Here, it is shown that those methods can be extended to nonequilibrium entropy conservation. As already known, the “closure” of the transport equations leads to the theory underlying the phenomenological laws, including Fick’s Law of Diffusion, Newton’s Law of Viscosity, and Fourier’s Law of Heat. In the case of entropy, closure leads to the relationship of entropy flux to heat as well as the Second Law or the necessity of positive entropy generation. It is further demonstrated how the complete set of transport equations, including entropy, can be simplified under physically restrictive assumptions, such as reversible flows and local equilibrium flows. This analysis, in general, yields a complete, rigorous set of transport equations for use in applications. Finally, it is also shown how this basis set of transport equations can be transformed to a new set of nonequilibrium thermodynamic functions, such as the nonequilibrium Gibbs’ transport equation derived here, which may have additional practical utility.
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Tiwari, Ravi Nath, Alberto Traverso e Federico Reggio. "Performance assessment of a reversible Tesla machine". E3S Web of Conferences 414 (2023): 03002. http://dx.doi.org/10.1051/e3sconf/202341403002.
Abstract (sommario):
It is well known that bladeless or Tesla turbomachinery, which was invented by Nikola Tesla in 1913, has several distinct features, such as reversibility of operation, which includes expander as well as compressor operation, just by reversing the rotational speed, provided that the statoric channels are purposely designed. Despite their potential application to a variety of fields, such as energy harvesting, automotive, light aircraft, and food processing, especially for low volumetric flows, Tesla machines have not found yet a specific market niche. In fact, at small size, it is estimated that the Tesla machinery does not change performance significantly, while conventional bladed machines are subject to significant efficiency reduction because of mechanical tolerances, thus matching the Tesla relatively low performance. Therefore, Tesla machines can become the fluid machinery of choice for small-size applications, thanks to their competitive performance at that size, simple construction, and reversible operation. A key objective of this paper is to numerically study Tesla devices in both expander and compressor modes with air as the working fluid. As a consequence of the high losses due to rotor and stator interactions, statorless (volute) configurations are investigated here, showing superior performance in both direct and indirect modes of operation. With reference to a laboratory prototype under construction, this paper presents the numerical design results, which predict the peak isentropic efficiencies of 63.5% and 57.5%, for the expander and compressor mode of operation, respectively. Actual prototype is expected to match those performance, apart from leakage and ventilation losses, not included in the numerical analysis.
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Jesudason, Christopher G. "Simulation Algorithm That Conserves Energy and Momentum for Molecular Dynamics of Systems Driven by Switching Potentials". Mathematical Problems in Engineering 2009 (2009): 1–14. http://dx.doi.org/10.1155/2009/215815.
Abstract (sommario):
Whenever there exists a crossover from one potential to another, computational problems are introduced in Molecular Dynamics (MD) simulation. These problem are overcome here by an algorithm, described in detail. The algorithm is applied to a 2-body particle potential for a hysteresis loop reaction model. Extreme temperature conditions were applied to test for algorithm effectiveness by monitoring global energy, pressure and temperature discrepancies in an equilibrium system. No net rate of energy and other flows within experimental error should be observed, in addition to invariance of temperature and pressure along the MD cell for the said system. It is found that all these conditions are met only when the algorithm is applied. It is concluded that the method can easily be extended to Nonequilibrium MD (NEMD) simulations and to reactive systems with reversible, non-hysteresis loops.
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Bratianu, Constantin, e Ruxandra Bejinaru. "The Theory of Knowledge Fields: A Thermodynamics Approach". Systems 7, n. 2 (29 marzo 2019): 20. http://dx.doi.org/10.3390/systems7020020.
Abstract (sommario):
The emergence of knowledge economy and knowledge management revealed the need for reconsidering the concept of knowledge in a larger framework than that created by philosophers from ancient times. While the epistemology as a theory of knowledge and justification considers knowledge as a justified true belief, experts in knowledge management consider knowledge as a strategic resource. The new economic interpretation of knowledge as a strategic resource and a key contributor to achieving a competitive advantage generated a search of new metaphors to supply the attributes needed in constructing the new framework of understanding and operating with a working concept of knowledge in management. The most widespread knowledge metaphors are based on analogies with stocks, flows, and stock-and-flows. These metaphors induce, beyond some useful attributes, the Newtonian mechanics paradigm which is limited by the properties of linear spaces and reversible processes. The purpose of this paper is to show how we can enrich the theory of knowledge by introducing the concepts of knowledge fields and knowledge dynamics based on metaphorical thinking and the thermodynamics principles. The focus of our research is the energy metaphor which considers energy as a source semantic field. The main outcome of the present research is that knowledge can be considered as a field, which is manifesting in different forms like energy. This thermodynamics framework opens new directions for research in knowledge management, decision-making and leadership.
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VENAYAGAMOORTHY, SUBHAS K., e DEREK D. STRETCH. "On the turbulent Prandtl number in homogeneous stably stratified turbulence". Journal of Fluid Mechanics 644 (10 febbraio 2010): 359–69. http://dx.doi.org/10.1017/s002211200999293x.
Abstract (sommario):
In this paper, we derive a general relationship for the turbulent Prandtl number Prt for homogeneous stably stratified turbulence from the turbulent kinetic energy and scalar variance equations. A formulation for the turbulent Prandtl number, Prt, is developed in terms of a mixing length scale LM and an overturning length scale LE, the ratio of the mechanical (turbulent kinetic energy) decay time scale TL to scalar decay time scale Tρ and the gradient Richardson number Ri. We show that our formulation for Prt is appropriate even for non-stationary (developing) stratified flows, since it does not include the reversible contributions in both the turbulent kinetic energy production and buoyancy fluxes that drive the time variations in the flow. Our analysis of direct numerical simulation (DNS) data of homogeneous sheared turbulence shows that the ratio LM/LE ≈ 1 for weakly stratified flows. We show that in the limit of zero stratification, the turbulent Prandtl number is equal to the inverse of the ratio of the mechanical time scale to the scalar time scale, TL/Tρ. We use the stably stratified DNS data of Shih et al. (J. Fluid Mech., vol. 412, 2000, pp. 1–20; J. Fluid Mech., vol. 525, 2005, pp. 193–214) to propose a new parameterization for Prt in terms of the gradient Richardson number Ri. The formulation presented here provides a general framework for calculating Prt that will be useful for turbulence closure schemes in numerical models.
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Abanades, Stéphane. "A Review of Oxygen Carrier Materials and Related Thermochemical Redox Processes for Concentrating Solar Thermal Applications". Materials 16, n. 9 (7 maggio 2023): 3582. http://dx.doi.org/10.3390/ma16093582.
Abstract (sommario):
Redox materials have been investigated for various thermochemical processing applications including solar fuel production (hydrogen, syngas), ammonia synthesis, thermochemical energy storage, and air separation/oxygen pumping, while involving concentrated solar energy as the high-temperature process heat source for solid–gas reactions. Accordingly, these materials can be processed in two-step redox cycles for thermochemical fuel production from H2O and CO2 splitting. In such cycles, the metal oxide is first thermally reduced when heated under concentrated solar energy. Then, the reduced material is re-oxidized with either H2O or CO2 to produce H2 or CO. The mixture forms syngas that can be used for the synthesis of various hydrocarbon fuels. An alternative process involves redox systems of metal oxides/nitrides for ammonia synthesis from N2 and H2O based on chemical looping cycles. A metal nitride reacts with steam to form ammonia and the corresponding metal oxide. The latter is then recycled in a nitridation reaction with N2 and a reducer. In another process, redox systems can be processed in reversible endothermal/exothermal reactions for solar thermochemical energy storage at high temperature. The reduction corresponds to the heat charge while the reverse oxidation with air leads to the heat discharge for supplying process heat to a downstream process. Similar reversible redox reactions can finally be used for oxygen separation from air, which results in separate flows of O2 and N2 that can be both valorized, or thermochemical oxygen pumping to absorb residual oxygen. This review deals with the different redox materials involving stoichiometric or non-stoichiometric materials applied to solar fuel production (H2, syngas, ammonia), thermochemical energy storage, and thermochemical air separation or gas purification. The most relevant chemical looping reactions and the best performing materials acting as the oxygen carriers are identified and described, as well as the chemical reactors suitable for solar energy absorption, conversion, and storage.
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Anokhina, E. А., e А. V. Timoshenko. "SYNTHESIS OF THE THERMALLY COUPLED DISTILLATION SEQUENCES". Fine Chemical Technologies 12, n. 6 (28 dicembre 2017): 46–70. http://dx.doi.org/10.32362/2410-6593-2017-12-6-46-70.
Abstract (sommario):
Approaching a hypothetical thermodynamically reversible process is one of the main directions of energy saving in distillation. In practice, this is achieved by the use of systems with coupled thermal and material flows (STMP). Such systems have long been used in the separation of zeotropic mixtures. As follows from the analysis of literature data, they save energy costs by up to 30%. Recently, it has been revealed that the use of such systems is possible, expedient and energetically advantageous for separating the close-boiling and azeotropic mixtures by extractive distillation (ED). The article considers the main approaches to the synthesis of distillation schemes, including systems with STMP: 1) a method based on the construction of a "superstructure"; 2) a method based on the concept of thermodynamically equivalent configurations; 3) an evolutionary algorithm; 4) a method based on the transformation of distillation scheme graphs. As the analysis of the literature has shown, the first three methods are sufficiently well developed only for the synthesis of distillation schemes with STMP to separate zeotropic mixtures. There are a relatively small number of publications that consider the generation of ED schemes with STMP based on the concept of thermodynamically equivalent configurations for distillation of specific binary mixtures. The only current system approach to the synthesis of ED schemes with coupled thermal and material flows for multicomponent mixtures is the method of graphs (algorithm 4). At present, the first step has been taken to implement it in the form of a computer program. Thus, the article presents the current state of the problem of synthesizing highly effective, energy-saving distillation technologies, including extractive distillation, based on the analysis of publications over the past 20-25 years.
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Prudnikov, Nikita, Sergey Malakhov, Vsevolod Kulagin, Andrey Emelyanov, Sergey Chvalun, Vyacheslav Demin e Victor Erokhin. "Multi-Terminal Nonwoven Stochastic Memristive Devices Based on Polyamide-6 and Polyaniline for Neuromorphic Computing". Biomimetics 8, n. 2 (3 maggio 2023): 189. http://dx.doi.org/10.3390/biomimetics8020189.
Abstract (sommario):
Reservoir computing systems are promising for application in bio-inspired neuromorphic networks as they allow the considerable reduction of training energy and time costs as well as an overall system complexity. Conductive three-dimensional structures with the ability of reversible resistive switching are intensively developed to be applied in such systems. Nonwoven conductive materials, due to their stochasticity, flexibility and possibility of large-scale production, seem promising for this task. In this work, fabrication of a conductive 3D material by polyaniline synthesis on a polyamide-6 nonwoven matrix was shown. An organic stochastic device with a prospective to be used in reservoir computing systems with multiple inputs was created based on this material. The device demonstrates different responses (output current) when different combinations of voltage pulses are applied to the inputs. The approach is tested in handwritten digit image classification task in simulation with the overall accuracy exceeding 96%. This approach is beneficial for processing multiple data flows within a single reservoir device.
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Serkov, Aleksandr, Vitalii Breslavets, Juliya Breslavets, Igor Yakovenko e Irina Yatsenko. "INFLUENCE OF PULSE ELECTROMAGNETIC RADIATION ON PERFORMANCE OF ELECTRIC RADIO PRODUCTS". Системи управління, навігації та зв’язку. Збірник наукових праць 1, n. 75 (9 febbraio 2024): 201–5. http://dx.doi.org/10.26906/sunz.2024.1.201.
Abstract (sommario):
The subject matter is the processes of analysis of the occurrence of reversible and irreversible failures of semiconductor devices under conditions of exposure to electromagnetic radiation. It is shown that the influence of pulsed electromagnetic radiation is accompanied by the emergence of currents in the conductive elements of products and the emergence of their internal fields. The mechanisms for the occurrence of instabilities of natural oscillations of semiconductor components of electrical and radio products, caused by their interaction with flows of charged particles, have been determined. The presence of instabilities of this kind has a significant impact on the spectral (operating) characteristics of electrical radio products. The results obtained in the work make it possible to assess the degree of influence of pulsed electromagnetic radiation on the operating (volt-ampere) characteristics of electrical radio products. The aim is a model of the mechanisms of the emergence and development of instabilities of natural oscillations of semiconductor structures, components of electrical radio products (communication equipment), in the presence of currents and voltages induced by pulsed electromagnetic radiation. The implementation of such a model is due to the possibility of transforming the energy of a flow of charged particles induced by external electromagnetic radiation into the energy of natural vibrations of a semiconductor structure, taking into account the properties of the structure itself (size, concentration of free carriers, permeability). The transformation of the energy of currents induced by electromagnetic radiation into natural vibrations of a semiconductor structure is determined by two effects (transition or Cherenkov radiation) depending on the location of the structure relative to the direction of the currents. The objectives are: the main electromagnetic effects affecting performance of electrical radio products (ERI) under exposure conditions external pulsed radiation and also indicates characteristic changes ERI parameters that determine their functional purpose, which are a consequence of these effects. The methods used are the method of successive approximations over a small parameter, which allows one to determine the spectrum of natural oscillations of a semiconductor device and the mode of their amplification (instability). The following results are obtained. The results of studies characterizing the malfunction of electrical radio products under conditions of exposure to third-party electromagnetic radiation are presented, as well as the main parameters characterizing the electromagnetic resistance of electronic devices to the effects of pulsed currents and voltages. The characteristic types of malfunctions of semiconductor devices (SCD), components of electronic components, in areas of irreversible and reversible failures, as well as the levels of intensities and currents of electric and magnetic fields affecting the SPD, separating the areas of reversible and irreversible failures, are given. Using the energy approach, a physical model of the occurrence of one of the types of reversible failures of the semiconductor element base (the appearance of S-shaped sections of currentvoltage characteristics) has been developed. This physical model makes it possible to determine the criteria for the electromagnetic resistance of a number of semiconductor devices to the effects of external pulsed radiation and also to obtain calculated ratios for assessing the degree of deviation of the operating characteristics of the PPP from the norm. Conclusion. Development of design relationships that determine the modes of amplification (generation) of oscillations of electrical radio products, making it possible to determine the degree of distortion of their current-voltage characteristics (reversible failures) and complete loss of performance (irreversible failures) depending on the parameters of external electromagnetic radiation. The results obtained in the work can be used in the development of amplifiers, generators and frequency converters operating in the millimeter and submillimeter range that are resistant to external electromagnetic radiation. Quantitative estimates of the criterion for reversible failures (instability increments) show that the amount of radiation energy lies within the sensitivity of modern submillimeter radiation receivers and is the cause of failures.
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Diebner, Hans H. "On the Entropy Flow between Parts of Multi-component Systems, Partial Entropies and the Implications for Observations". Zeitschrift für Naturforschung A 55, n. 3-4 (1 aprile 2000): 405–11. http://dx.doi.org/10.1515/zna-2000-3-406.
Abstract (sommario):
Abstract The concept of the time dependent instantaneously occupied phase space volume is applied to multi-component systems. It allows for the investigation of entropy flows betweeen the components of the system and the evaluation of partial entropies assigned to the subsystems. We give numerical examples by means of molecular dynamics simulations of a 100-particle gas. Using a symplectic exactly reversible algorithm, a consistent and reliable evalutation of energy and entropy exchanges as well as the intake of work is achieved. The entropy flow which is related to an information flow is linked to an observational situation. This yields a further indication for the necessity of an intrinsic observer for a better understanding of the physical world. In addition, it indicates the Gödelian structure of cognition in a most serious way because only “first-principle” assumptions are made. Thereby, the paradoxical situation which is created by Jaynes’ concept of an “anthropomorphic entropy” can be resolved by putting the anthropomorphic contents of thermodynamics down to an ontological basis. This is a straightforward extension of Szilard’s and Brillouin’s information theoretical treatment of cognition
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Kagdin, V. N., R. A. Maleyev, A. N. Zimin, S. M. Zuyev e D. R. Yakhutl'. "Starter-generator sets of modern vehicles". Izvestiya MGTU MAMI 15, n. 4 (15 dicembre 2021): 27–32. http://dx.doi.org/10.31992/2074-0530-2021-50-4-27-32.
Abstract (sommario):
This article describes the purpose and applications of the starter generator set. The modes of operation of a starter-generator set are considered both as a sequential excitation direct current electric motor, which rotates the shaft of an internal combustion engine, and as a generator, when an electric machine operates as a direct current source of independent excitation, supplying power to electric control circuits, electric motors of auxiliary electrical equipment, lighting and battery charging. Additional functions of a starter-generator set in the form of a start-stop system, regenerative braking, booster acceleration of a vehicle, damping of torsional moments of the shaft of an internal combustion engine and control of energy flows in the on-board network were studied.
The choice and substantiation of the optimal scheme, as well as the design of the starter-generator device, were carried out. The main technical and economic parameters of the starter-generator set were determined. The design of a starter-generator set was presented. This design is a reversible electric machine. A block diagram of a starter-generator set was developed.
Electrical machines used for starter-generator sets are considered. The design of an asynchronous machine with a squirrel-cage rotor, a synchronous machine with electromagnetic excitation, a valve machine with permanent magnets, a contactless machine, a synchronous machine with permanent magnets, and a valve machine with self-excitation are described. A review and analysis of electrical machines used in starter-generator sets of leading foreign companies is carried out.
The design of a reversible induction-dynamic machine is considered. The rotor rotates outside, and not inside the motor and is a short-circuited winding with a cast aluminum cage. The calculation of the main parameters of a reversible induction-dynamic machine was carried out both in the starting and in the generator modes. The calculation using a method similar to that of an induction motor was carried out.
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Stobart, R. K. "An availability approach to thermal energy recovery in vehicles". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 221, n. 9 (1 settembre 2007): 1107–24. http://dx.doi.org/10.1243/09544070jauto463.
Abstract (sommario):
Availability is a well-established and widely recognized way of describing the work-producing potential of energy systems. A first-law analysis is helpful in setting the energy context and ensuring that energy flows balance, but it is a second-law analysis based on availability that places an upper bound on the potential work output. In this analysis a new approach to thermal management intended for vehicle propulsion is examined and developed. Starting with a simple analysis of the chemical energy flow, a realistic heat exchange performance is introduced to establish a practical architecture. Within this framework, the availability analysis shows that effective thermal efficiencies of between 25 and 30 per cent are feasible. With a spark ignition engine operating at a high load condition, and the thermal recovery system at an operating pressure of 100 bar, the maximum efficiency possible with a steady flow work-producing device is 37 per cent (with fully reversible thermodynamic processes). In a water-based thermal recovery system, work could only reasonably be produced with heat transfer from a reservoir at the saturation temperature corresponding to the operating pressure. At 100 bar the maximum efficiency would be 33 per cent. In a different mode of operation, where heat is transferred incrementally to a thermal accumulator and work produced as required, the efficiency is 32 per cent at only 20 bar operating pressure. These efficiency values apply to work production to supplement a combustion engine at any operating condition. An analysis of a reciprocating expander as the work-producing device shows substantial flexibility in operation. Control of system operating pressure is shown to be of value in that periodic adjustments enhance the availability content of the thermal reservoir. The operating pressure of a fluid power system is related to the temperature of operation, and therefore the heat transfer processes. Choice of too high a pressure leads to reduced heat transfer, and ultimately a reduction in work output. There is an optimum condition that can be selected at design time and maintained during the running of the system.
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Ghalambaz, Mohammad, Seyed Abdollah Mansouri Mehryan, Kasra Ayoubi Ayoubloo, Ahmad Hajjar, Mohamad El Kadri, Obai Younis, Mohsen Saffari Pour e Christopher Hulme-Smith. "Thermal Energy Storage and Heat Transfer of Nano-Enhanced Phase Change Material (NePCM) in a Shell and Tube Thermal Energy Storage (TES) Unit with a Partial Layer of Eccentric Copper Foam". Molecules 26, n. 5 (9 marzo 2021): 1491. http://dx.doi.org/10.3390/molecules26051491.
Abstract (sommario):
Thermal energy storage units conventionally have the drawback of slow charging response. Thus, heat transfer enhancement techniques are required to reduce charging time. Using nanoadditives is a promising approach to enhance the heat transfer and energy storage response time of materials that store heat by undergoing a reversible phase change, so-called phase change materials. In the present study, a combination of such materials enhanced with the addition of nanometer-scale graphene oxide particles (called nano-enhanced phase change materials) and a layer of a copper foam is proposed to improve the thermal performance of a shell-and-tube latent heat thermal energy storage (LHTES) unit filled with capric acid. Both graphene oxide and copper nanoparticles were tested as the nanometer-scale additives. A geometrically nonuniform layer of copper foam was placed over the hot tube inside the unit. The metal foam layer can improve heat transfer with an increase of the composite thermal conductivity. However, it suppressed the natural convection flows and could reduce heat transfer in the molten regions. Thus, a metal foam layer with a nonuniform shape can maximize thermal conductivity in conduction-dominant regions and minimize its adverse impacts on natural convection flows. The heat transfer was modeled using partial differential equations for conservations of momentum and heat. The finite element method was used to solve the partial differential equations. A backward differential formula was used to control the accuracy and convergence of the solution automatically. Mesh adaptation was applied to increase the mesh resolution at the interface between phases and improve the quality and stability of the solution. The impact of the eccentricity and porosity of the metal foam layer and the volume fraction of nanoparticles on the energy storage and the thermal performance of the LHTES unit was addressed. The layer of the metal foam notably improves the response time of the LHTES unit, and a 10% eccentricity of the porous layer toward the bottom improved the response time of the LHTES unit by 50%. The presence of nanoadditives could reduce the response time (melting time) of the LHTES unit by 12%, and copper nanoparticles were slightly better than graphene oxide particles in terms of heat transfer enhancement. The design parameters of the eccentricity, porosity, and volume fraction of nanoparticles had minimal impact on the thermal energy storage capacity of the LHTES unit, while their impact on the melting time (response time) was significant. Thus, a combination of the enhancement method could practically reduce the thermal charging time of an LHTES unit without a significant increase in its size.
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Zschunke, F., R. Rivas e P. O. Brunn. "Temperature Behavior of Magnetorheological Fluids". Applied Rheology 15, n. 2 (1 aprile 2005): 116–21. http://dx.doi.org/10.1515/arh-2005-0007.
Abstract (sommario):
AbstractMagnetorheological fluids (MRFs) show a high but reversible rise of the viscosity upon application of an external magnetic field. This effect can be utilized in controllable friction dampers where the MR fluid flows through a gap with a adjustable magnetic field. The change in the magnitude of the magnetic field leads to a change of the viscosity of the fluid which in turn effects the pressure drop in the system. So the damping force can be controlled by the magnitude of the external magnetic field. This energy dissipation leads to a rise of the damper temperature. For designing those dampers it is vital to know the influence of the geometry, which influences the magnetic field strength, as well as the flow properties and the temperature dependence of the magnetorheological effect. An approach to the solution of this problem is shown by using an Arrhenius relationship, where the fluid viscosity is a function of the shear rate, the magnetic field and the temperature. The aim of the here presented research is to show how the fluid behavior can be simply modeled for use in CFD codes to design dampers or other applications.
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Schmidt-Böcking, Horst Werner, Gerhard Luther, Michael Düren, Matthias Puchta, Tom Bender, Andreas Garg, Bernhard Ernst e Heinz Frobeen. "Renewable Electric Energy Storage Systems by Storage Spheres on the Seabed of Deep Lakes or Oceans". Energies 17, n. 1 (22 dicembre 2023): 73. http://dx.doi.org/10.3390/en17010073.
Abstract (sommario):
This paper describes a new underwater pumped storage hydropower concept (U.PSH) that can store electric energy by using the high water pressure on the seabed or in deep lakes to accomplish the energy transition from fossil to renewable sources. Conventional PSH basically consists of two storage reservoirs (upper and lower lake) at different topographical heights. It needs special topographic conditions, which are only limitedly available in mountain regions. Furthermore, due to the lack of acceptance and the environmental impact, new conventional PSH projects are very unlikely to be built in larger numbers in Europe in the near future. The presented solution solves these issues by placing the storage system on the seabed, thus having other geographical requirements. It operates as follows: in contrast to well-known conventional PSH plants, which use two separated water reservoirs of different heights, the U.PSH concept uses the static pressure of the water column in deep waters by installing a hollow concrete sphere in deep water. Storage of electricity is achieved by using a reversible pump in the hollow sphere. Upon opening a valve, water flows into the sphere, driving a turbine/generator, thereby discharging the storage device. In order to re-charge, the water is pumped out of the sphere against the pressure of the surrounding water. The power and energy, respectively, are proportional to the surrounding water pressure at the seabed. The amount of energy stored depends on the water depth and the volume of the spheres. The spheres need a cable connection to the shore or to a close-by floating transformer station (e.g., an offshore wind plant). No other connections such as pipes are needed. The functional principle of this energy storage technology, its state of the art, its storage capacity and the shape and size of the required spheres are discussed in this paper.
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Belliardi, Marco, Nerio Cereghetti, Paola Caputo e Simone Ferrari. "A Method to Analyze the Performance of Geocooling Systems with Borehole Heat Exchangers. Results in a Monitored Residential Building in Southern Alps". Energies 14, n. 21 (7 novembre 2021): 7407. http://dx.doi.org/10.3390/en14217407.
Abstract (sommario):
Geothermal heat is an increasingly adopted source for satisfying all thermal purposes in buildings by reversible heat pumps (HP). However, for residential buildings located in moderate climates, geocooling, that implies the use of geothermal source for cooling buildings without the operation of HP, is an efficient alternative for space cooling not yet explored enough. Geocooling allows two main benefits: to cool the buildings by high energy efficiencies improving summer comfort; to recharge the ground if space heating is provided by HP exploiting the geothermal source (GSHP). In these cases, geocooling allows to avoid the decreasing of the performances of the GSHP for space heating over the years. To explore these issues, a method has been developed and tested on a real case: a new residential building in Lugano (southern Switzerland) coupled with 13 borehole heat exchangers. The system provides space heating in winter by a GSHP and space cooling in summer by geocooling. During a 40 months monitoring campaign, data such as temperatures, heat flows and electricity consumptions were recorded to calibrate the model and verify the benefits of such configuration. Focusing on summer operation, the efficiency of the system, after the improvements implemented, is above 30, confirming, at least in similar contexts, the feasibility of geocooling. Achieved results provides knowledge for future installations, underlining the replication potential and the possible limits.
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Nadaždi, Ana, Aleksandra Parezanović, Zorana Petojević e Zorana Naunović. "Urban mining potential in Serbia: Case study of residential building material stock". Gradjevinski materijali i konstrukcije 65, n. 3 (2022): 85–91. http://dx.doi.org/10.5937/grmk2203085n.
Abstract (sommario):
As governments worldwide attempt to develop sustainable waste management strategies, massive amounts of waste have been accumulating. However, developing an effective waste management strategy requires a thorough understanding of waste types and quantites. The existing efforts to identify waste flows in the built environment are unsuitable for countries with non-reliable statistics as they mostly use location-specific parameters such as data on construction, renovation, demolition activity, and generation rates from the literature. The types and quantities of materials embedded are rarely considered. This study aims to fill the identified gap by estimating the quantities of different material types embedded in Serbian residential building stock. It will do so by calculating the volume and weights of building elements and their materials using information from a detailed building stock typology. The results show that the amounts of materials embedded vary significantly from district to district, ranging from 10 in Toplička District to 96.9 million tons in Belgrade. The mineral materials are the highest contributors to the material embedded, implying that future waste management strategies should focus on them. Apart from the formulation of location-specific circular economy and waste management strategies, these results may be useful for planning energy efficiency retrofitting activities, deconstruction and reversible design strategies.
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Pauluis, Olivier. "Sources and Sinks of Available Potential Energy in a Moist Atmosphere". Journal of the Atmospheric Sciences 64, n. 7 (1 luglio 2007): 2627–41. http://dx.doi.org/10.1175/jas3937.1.
Abstract (sommario):
Abstract Available potential energy (APE) is defined as the difference between the total static energy of the atmosphere and that of a reference state that minimizes the total static energy after a sequence of reversible adiabatic transformations. Determining the rate at which APE is generated in the atmosphere allows one to estimate the amount of kinetic energy that can be generated by atmosphere flows. Previous expressions for the sources and sinks of APE rely on a dry framework and are limited by the fact that they require prior knowledge of the distribution of latent heat release by atmospheric motion. In contrast, this paper uses a moist APE framework to derive a general formula for the sources and sinks of APE that can be equally applied to dry and moist circulations. Two key problems are addressed here. First, it is shown that any reorganization of the reference state due to diabatic heating or addition of water does not change its total static energy. This property makes it possible to determine the rate of change in APE even in the absence of an analytic formula for the reference state, as is the case in a moist atmosphere. Second, the effects of changing the total water content of an air parcel are also considered in order to evaluate the changes of APE due to precipitation, evaporation, and diffusion of water vapor. Based on these new findings, one can obtain the rate of change of APE from that of atmospheric entropy, water content, and pressure. This result is used to determine the sources and sinks of APE due to different processes such as external energy sources, frictional dissipation, diffusion of sensible heat and water vapor, surface evaporation, precipitation, and reevaporation. These sources and sinks are then discussed in the context of an idealized atmosphere in radiative–convective equilibrium. For a moist atmosphere, the production of APE by the surface energy flux is much larger than any observational or theoretical estimates of frictional dissipation, and, as is argued here, must be balanced by a comparable sink of APE due to the diffusion of water vapor from unstable to stable air parcels.
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Kaganovich, Boris M., Valery A. Stennikov, Maxim S. Zarodnyuk e Sergey V. Yakshin. "Conventional Hydraulic Circuits in an Analysis of Environmental Issues". E3S Web of Conferences 69 (2018): 02003. http://dx.doi.org/10.1051/e3sconf/20186902003.
Abstract (sommario):
The paper addresses the problems of conventional circuit modeling in an analysis of anthropogenic pollution of nature. A joint use of two types of models is proposed: 1) a model of conventional hydraulic circuits and 2) a model of extreme intermediate states developed by Melentiev Energy Systems Institute. The first model is used to calculate the distribution of pollutants in the atmosphere and their precipitation. The second model is intended for an analysis of the formation of pollutants and their transformations in branches as a result of chemical reactions and phase transitions. The analysis is based on the propositions of classical equilibrium thermodynamics. The applicability of the thermodynamic equilibrium and extremality principles and one-dimensional circuit models in the study of both reversible and irreversible processes are substantiated. Specific problems are analyzed. These are the determination of the yield of harmful substances in fuel combustion and processing, the distribution of pollutants in the atmosphere of large regions, the impact of hydro and wind power plants on the formation of harmful solutions in the air. The possibility of using a conventional graph (a thermodynamic tree) proposed by A.N. Gorban to analyze fuel technologies is demonstrated. The statement of the problem related to the assessment of the environmental compatibility of integrated energy systems is presented. The admissibility of the representation of the optimal distribution of flows in the integrated system as a sum of optimal distributions in its subsystems that differ from one another in physical-technical and economic nature is explained.
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Gavrilyuk, Sergey. "‘Uncertainty’ principle in two fluid–mechanics". ESAIM: Proceedings and Surveys 69 (2020): 47–55. http://dx.doi.org/10.1051/proc/202069047.
Abstract (sommario):
Hamilton’s principle (or principle of stationary action) is one of the basic modelling tools in finite-degree-of-freedom mechanics. It states that the reversible motion of mechanical systems is completely determined by the corresponding Lagrangian which is the difference between kinetic and potential energy of our system. The governing equations are the Euler-Lagrange equations for Hamil- ton’s action. Hamilton’s principle can be naturally extended to both one-velocity and multi-velocity continuum mechanics (infinite-degree-of-freedom systems). In particular, the motion of multi–velocity continuum is described by a coupled system of ‘Newton’s laws’ (Euler-Lagrange equations) for each component. The introduction of dissipative terms compatible with the second law of thermodynamics and a natural restriction on the behaviour of potential energy (convexity) allows us to derive physically reasonable and mathematically well posed governing equations. I will consider a simplest example of two-velocity fluids where one of the phases is incompressible (for example, flow of dusty air, or flow of compressible bubbles in an incompressible fluid). A very surprising fact is that one can obtain different governing equations from the same Lagrangian. Different types of the governing equations are due to the choice of independent variables and the corresponding virtual motions. Even if the total momentum and total energy equations are the same, the equations for individual components differ from each other by the presence or absence of gyroscopic forces (also called ‘lift’ forces). These forces have no influence on the hyperbolicity of the governing equations, but can drastically change the distribution of density and velocity of components. To the best of my knowledge, such an uncertainty in obtaining the governing equations of multi- phase flows has never been the subject of discussion in a ‘multi-fluid’ community.
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Orro, Alfonso, Margarita Novales, Ángel Monteagudo, José-Benito Pérez-López e Miguel R. Bugarín. "Impact on City Bus Transit Services of the COVID–19 Lockdown and Return to the New Normal: The Case of A Coruña (Spain)". Sustainability 12, n. 17 (3 settembre 2020): 7206. http://dx.doi.org/10.3390/su12177206.
Abstract (sommario):
The COVID–19 pandemic led to restrictions on activities and mobility in many parts of the world. After the main peak of the crisis, restrictions were gradually removed, returning to a new normal situation. This process has impacted urban mobility. The limited information on the new normal situation shows changes that can be permanent or reversible. The impact on the diverse urban transport modes varies. This study analyzes the changes in transit ridership by line, the use of stops, the main origin–destination flows, changes in transit supply, operation time, and reliability of the city bus network of A Coruña. It is based on data from automatic vehicle location, bus stop boarding, and smart card use. Data from the first half of 2020 were compared to similar data in 2017–2019, defining suitable baselines for each analysis to avoid seasonal and day of week effects. The impact on transit ridership during the lockdown process was more significant than that on general traffic. In the new normal situation, the general traffic and the shared bike system recovered a higher percentage of their previous use than the bus system. These impacts are not uniform across the bus network.
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Indra, Ida Bagus Puspa, I. Made Anom Adiaksa e Gusti Ngurah Ardana. "EXPERIMENTAL STUDY OF THE EFFECT OF REACTOR TEMPERATURE RECONSTRUCTION ON FUEL CONSUMPTION AND DISTILLATE QUANTITY". Logic : Jurnal Rancang Bangun dan Teknologi 22, n. 2 (30 luglio 2022): 174–78. http://dx.doi.org/10.31940/logic.v22i2.174-178.
Abstract (sommario):
Temperature is a measure or degree of hotness or coldness of an object or system which is defined as a physical quantity that is divided between two or more objects that are in thermal equilibrium. The second law of thermodynamics states that there is no reversible process in which heat flows naturally from a high-temperature object to a low-temperature object, and not vice versa. Heat is energy that is transferred due to a temperature difference. This heat transfer always occurs and the process stops until thermal equilibrium occurs. In a high temperature distillation column, the distillate fluid will tend to be at the top and the bottom will tend to be cooler even though the heat treatment is carried out at the bottom. Thermal equilibrium is reached in a relatively long time because the distillation system is open. The addition of the pump aims to reconstruct the temperature so that it reaches thermal equilibrium more quickly. The process is carried out for 60 minutes using 25 liters of raw materials of the same quality and the temperature is set at 90 degrees Celsius. The average temperature difference in the reactor is 86.11%, the decrease in fuel consumption is 30.3%, and the increase in distillation quantity between the reactor without a pump compared to the reactor with a pump is 16.67%.
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Banwart, Steven A., Nikolaos P. Nikolaidis, Yong-Guan Zhu, Caroline L. Peacock e Donald L. Sparks. "Soil Functions: Connecting Earth's Critical Zone". Annual Review of Earth and Planetary Sciences 47, n. 1 (30 maggio 2019): 333–59. http://dx.doi.org/10.1146/annurev-earth-063016-020544.
Abstract (sommario):
Soil is the central interface of Earth's critical zone—the planetary surface layer extending from unaltered bedrock to the vegetation canopy—and is under intense pressure from human demand for biomass, water, and food resources. Soil functions are flows and transformations of mass, energy, and genetic information that connect soil to the wider critical zone, transmitting the impacts of human activity at the land surface and providing a control point for beneficial human intervention. Soil functions are manifest during bedrock weathering and, in fully developed soil profiles, correlate with the porosity architecture of soil structure and arise from the development of soil aggregates as fundamental ecological units. Advances in knowledge on the mechanistic processes of soil functions, their connection throughout the critical zone, and their quantitative representation in mathematical and computational models define research frontiers that address the major global challenges of critical zone resource provisioning for human benefit. ▪ Connecting the mechanisms of soil functions with critical zone processes defines integrating science to tackle challenges of climate change and food and water supply. ▪ Soil functions, which develop through formation of soil aggregates as fundamental eco-logical units, are manifest at the earliest stages of critical zone evolution. ▪ Global degradation of soil functions during the Anthropocene is reversible through positive human intervention in soil as a central control point in Earth's critical zone. ▪ Measurement and mathematical translation of soil functions and critical zone processes offer new computational approaches for basic and applied geosciences research.
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Nazeer, M., M. I. Khan, S. Kadry, Yuming Chu, F. Ahmad, W. Ali, M. Irfan e M. Shaheen. "Regular perturbation solution of Couette flow (non-Newtonian) between two parallel porous plates: a numerical analysis with irreversibility". Applied Mathematics and Mechanics 42, n. 1 (25 novembre 2020): 127–42. http://dx.doi.org/10.1007/s10483-021-2677-9.
Abstract (sommario):
AbstractThe unavailability of wasted energy due to the irreversibility in the process is called the entropy generation. An irreversible process is a process in which the entropy of the system is increased. The second law of thermodynamics is used to define whether the given system is reversible or irreversible. Here, our focus is how to reduce the entropy of the system and maximize the capability of the system. There are many methods for maximizing the capacity of heat transport. The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy. The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel. For this, we choose two different fluid models, namely, the plane and generalized Couette flows. The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid. The present analysis shows the effects of the fluid parameters on the velocity, the temperature, the entropy generation, and the Bejan number. The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method. To validate the perturbation solution, a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0. The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters. It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number. When ηi → 0 (i = 1, 2, 3), the Eyring-Powell fluid is transformed into a Newtonian fluid.
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Jimenez-Martín, Gonzalo, Xabier Judez, Mónica Aguado e Iñigo Garbayo. "Exploring Solid Oxide Electrolysis Cell Design for an Optimal Flow Distribution and Thermal Management". ECS Meeting Abstracts MA2023-01, n. 54 (28 agosto 2023): 167. http://dx.doi.org/10.1149/ma2023-0154167mtgabs.
Abstract (sommario):
Climate crisis and the subsequent increase of fossil fuels prices have encouraged the search for alternative and renewable energy sources. In this scenario, the use of hydrogen as green energy carrier is nowadays regarded as one of the keys to achieve the transition to a fully renewable energy system. Among the existent and commercial technologies to produce green hydrogen, solid oxide electrolysis (SOE) outstands due to their high efficiency and the possibility of operate in reversible mode, i.e on electrolysis mode to produce hydrogen and on fuel cell mode (SOFC) to generate power from stored hydrogen. However, large-scale commercialization of these devices is still to-be-realized, mainly hindered by their short life time caused by degradation problems. Apart from a correct materials selection and optimal microstructural design, uniform gas flow distribution along the cell is necessary. This is not only essential to reach higher performance but also to ensure good temperature distribution and minimize hotspots that would accelerate degradation. Therefore, cell design should be carefully optimized. For this purpose, replacing experimental cell design by computer modeling and simulation has been presented as a cost-effective alternative. In this sense, computational fluid dynamics (CFD) is a powerful tool that accurately predicts the behavior of the cells in diverse scenarios. CFD uses numerical analysis to solve the equations that define the behavior within the cells, including mass, species, momentum, energy and current conservation as well as electrochemical and heat transfer models that govern SOE behavior. In this work, strategies to optimize cell design and their implementation by means of ANSYS Fluent® commercial CFD software are presented. These strategies have been classified into two categories: i) modifying gas manifolds and ii) modifying internal gas channels. On one hand, the strategies related to manifold design include acting on the number of inlets, outlets and its type (i.e open to ambient or pipes). On the other hand, the strategies related to internal gas channels design involve using different interconnect plate geometric features such as rectangular or cylindrical ribs. By changing these cell features, significant improvements in flow distribution and minimized thermal gradients and pressure drop are observed. Simulations conclude that manifolds are the most influential cell feature in terms of flow, thermal and pressure drop distribution, obtaining that a simple modification in the number of inlets and outlets can conduct to normalized mass flows near to the unit, thermal gradients below 1 K/cm and a negligible pressure drop. Figure 1
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Yan, Aibin, Runqi Liu, Zhengfeng Huang, Patrick Girard e Xiaoqing Wen. "Designs of Level-Sensitive T Flip-Flops and Polar Encoders Based on Two XOR/XNOR Gates". Electronics 11, n. 10 (23 maggio 2022): 1658. http://dx.doi.org/10.3390/electronics11101658.
Abstract (sommario):
Quantum-dot cellular automata is a novel nanotechnology that has the advantages of low energy dissipation, easy integration, and high computing speed. It is regarded as one of the powerful alternative technologies for the next generation of integrated circuits because of its unique implementation concept. In this paper, two XOR/XNOR gates are proposed. Level-sensitive T flip-flops, negative edge-trigger T flip-flops, two-to-one multiplexers, reversible gates, and (8, 4) polar encoders are implemented based on these two proposed logic gates. Simulation results show that, compared with the existing level-sensitive T flip-flops, the second proposed level-sensitive T flip-flop has fewer cells and lower energy dissipation; compared with the best (8, 4) polar encoder, the cell count and area of the second proposed (8, 4) polar encoder are decreased by 13.67% and 12.05%, respectively. The two XOR/XNOR gates have a stable output and low energy dissipation, which can be flexibly designed into complex quantum-dot cellular automata circuits.
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Esquivel-Sancho, Luis Miguel, Mauricio Muñoz-Arias, Hayden Phillips-Brenes e Roberto Pereira-Arroyo. "A Reversible Hydropump–Turbine System". Applied Sciences 12, n. 18 (9 settembre 2022): 9086. http://dx.doi.org/10.3390/app12189086.
Abstract (sommario):
Water-pumped storage systems have become an ideal alternative to regulate the intermittent power delivered by renewable energy sources. For small-scale operations, a type of centrifugal pump coupled to asynchronous machines represents an adequate solution due to their techno-economic feasibility in addition to their ability to operate as reversible systems. This work provides a novel port-Hamiltonian modelling approach to an integrated reversible hydropump–turbine system, that can be switched from motor pump to turbine-generator by employing a conventional hydraulic switch. Our modelling strategy provides a clear physical interpretation of the energy flow from the mechanical to electrical domains. Then, the model was built with multi-domain storing and dissipating elements and the interconnection of well-defined input–output port pairs. The system’s internal energy, i.e., Hamiltonian function, can be exploited for energy-shaping control strategies. The performance of our modelling approach is validated via numerical simulations.
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Serkov, А., V. Breslavets, Yu Breslavets e I. Yakovenko. "INFLUENCE OF ELECTROMAGNETIC RADIATION ON RESISTANCE OF SEMICONDUCTOR DEVICES". Системи управління, навігації та зв’язку. Збірник наукових праць 1, n. 71 (17 marzo 2023): 177–81. http://dx.doi.org/10.26906/sunz.2023.1.177.
Abstract (sommario):
The subject matter is the processes of analysis and mechanisms of appearance of instabilities of natural vibrations of semiconductor structures., due to their interaction with flows of charged particles under the influence of external electromagnetic radiation. It is shown that the influence of pulsed electromagnetic radiation is accompanied by the appearance of currents in the conductive elements of products that are capable of exciting natural oscillations of semiconductor components and are the cause of failures of radio products. The aim is to develop the theory of collisionless damping of surface polaritons in the classical approximation, as well as to study the mechanisms of collisionless damping of surface plasmons at the boundaries of semiconductor components of radio products under conditions when the temperature of carriers of conducting solids is much lower than the plasmon energy (quantum approximation). The objectives are: a kinetic equation describing the change in the number of surface plasmons as a result of their interaction with conduction electrons; obtaining its solution, which determine the decrement of oscillations and the power of spontaneous emission of particles. The methods used are: a method of successive approximations for solving the kinetic equations of the charged particle flux - semiconductor structure system within the framework of the quantum approach, when the interaction of waves and particles is in the nature of random collisions and is described by the method of secondary quantization of the system (representation of occupation numbers). The following results are obtained: Expressions are obtained for the decrements of surface plasmons in the presence of an infinitely high and infinitely small potential barrier at the interface between media. A kinetic equation is obtained that describes the change in the number surface plasmons as a result of their interaction with conduction electrons; his decisions are given, which determine oscillation decrement. Expressions are obtained for the decrements of surface plasmons at presence of infinitely high and infinitely small potential barrier at the interface between A physical model of the occurrence of reversible failures (effects induced by electromagnetic radiation currents per volt - ampere characteristics of semiconductor devices). The ranges of parameters of the external electromagnetic radiation at which this physical model is realized. Conclusion. Calculated relations are obtained that relate the parameters of semi-conductor structures: the concentration of free carriers, permittivity, carrier temperature with the value oscillation decrement in the classical and quantum approximations. The comparative analysis of quantitative estimates of the increments of oscillation instabilities carried out in the work makes it possible to solve the problems of optimizing the operating characteristics of active devices in the microwave range. The results of the work can be used in the development of microwave devices designed to amplify, generate and convert electromagnetic oscillations in the millimeter and submillimeter ranges.
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Vahabi, Mohsen, Pavel Lyakhov, Ali Newaz Bahar, Akira Otsuki e Khan A. Wahid. "Novel Reversible Comparator Design in Quantum Dot-Cellular Automata with Power Dissipation Analysis". Applied Sciences 12, n. 15 (4 agosto 2022): 7846. http://dx.doi.org/10.3390/app12157846.
Abstract (sommario):
In very large-scale integration (VLSI) circuits, a partial of energy lost leads to information loss in irreversible computing because, in conventional combinatorial circuits, each bit of information generates heat and power consumption, thus resulting in energy dissipation. When information is lost in conventional circuits, it will not be recoverable, as a result, the circuits are provided based on the reversible logic and according to reversible gates for data retrieval. Since comparators are one of the basic building blocks in digital logic design, in which they compare two numbers, the aim of this research is to design a 1-bit comparator building block based on reversible logic and implement it in the QCA with the minimum cell consumption, less occupied area, and lower latency, as well as to design it in a single layer. The proposed 1-bit reversible comparator is denser, cost-effective, and more efficient in quantum cost, power dissipation, and the main QCA parameters than that of previous works.
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Baktiyar, Moch Hanif, Anggita Adiningrum, Fatin Septianingsih e Bambang Poerwadi. "Utilization of Methylene Blue and Banana Peels as RFB Components (Redox Flow Battery)". Rekayasa Bahan Alam dan Energi Berkelanjutan 5, n. 1 (28 giugno 2021): 10–16. http://dx.doi.org/10.21776/ub.rbaet.2021.005.01.02.
Abstract (sommario):
RFB (Redox Flow Battery) is a secondary battery that provides energy conversion between chemistry and electricity through an alternating redox reaction by 2 pairs of electrons and protons. RFB with active ingredient Vanadium (VRB) is a type of RFB that is widely used and has problems such as the price of Vanadium is expensive, is toxic and the solvent (H2SO4) is corrosive. Therefore, an inexpensive and environmentally friendly organic electrolyte component emerged, namely Methylene Blue and banana peels. Methylene Blue has 2 electron-proton pairs which provide a reversible redox reaction and have the potential as an active ingredient in the RFB electrolyte. Banana peels have potential as an electrolyte solvent because they contain carbohydrates, citric acid and mineral electrolytes (potassium, sodium salt, phosphorus and magnesium) which support the electrolyte properties of banana peels. The stages of making electrolytes by fermentation of banana peel solution, addition of Methylene Blue and testing (galvanostatic and stress). The test results showed that Methylene Blue was able to provide the best performance (efficiency) on RFB and banana peels as an electrolyte in the battery was able to produce a voltage exceeding the VRB output voltage.
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Mukhopadhyay, Debarka, e Paramartha Dutta. "A study on energy optimized 4 dot 2 electron two dimensional quantum dot cellular automata logical reversible flip-flops". Microelectronics Journal 46, n. 6 (giugno 2015): 519–30. http://dx.doi.org/10.1016/j.mejo.2015.03.001.
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Judez, Xabier, Gonzalo Jimenez-Martín, Mónica Aguado e Iñigo Garbayo. "Approaches for Optimum Thermal Management of SOFC Cells: Fitting Operating Conditions & Smart Cell Design". ECS Meeting Abstracts MA2023-01, n. 54 (28 agosto 2023): 100. http://dx.doi.org/10.1149/ma2023-0154100mtgabs.
Abstract (sommario):
The thrust of green hydrogen as energy vector for the consolidation of a net-zero emitting global energy system implies the necessity of a fast development of high performing and highly efficient fuel cells and electrolyzers. Among the commercial choices, solid oxide cells can be considered as a better performing alternative compared to commercial proton exchange membrane and alkaline technologies. The benefits of this kind of technology arise from their higher operating temperatures of around 700-900 ºC, which results in improved kinetics and favored thermodynamics, allowing to reach unrivaled conversion efficiencies and reduced electricity consumption. Furthermore, this allows operating the cell reversibly in both fuel cell (SOFC) and electrolysis (SOE) modes. However, cell overheating and non-uniform temperature distribution can lead to an acceleration of degradation processes and cell cracking and sintering, which challenges long-term cell stability. In this sense, modeling at cell level enables to optimize operating conditions, improve cell design and predict and minimize such phenomena. Simulations allow mimicking the response of the cells and stacks at diverse operating scenarios and accelerates the optimization process minimizing experimental efforts; saving materials, time, and economical resources. We model SOFC/SOE cell behavior by means of Computational Fluid Dynamics (CFD), solving the mass, species, momentum, energy and current conservation equations, as well as electrochemical reaction models. In this work, a detailed methodology to guide design of the thermal management of SOFC by means of CFD and numerical optimization tools is proposed. These approaches combine acting both on operating conditions and cell geometry. Initially, we study the influence of inlet gas flows and describe a procedure to optimize the flows while maximizing the energetic outcome. Afterwards, we describe how numerical methods can allow fitting feed gas temperatures to avoid overheating. Finally, we go a step further by optimizing cell interconnect plate geometries to minimize internal temperature gradients. All in all, we demonstrate how CFD studies can accelerate SOFC cell design in order to maximize performance and extend lifespan. Figure 1
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Dongellini, Matteo, Christian Natale, Claudia Naldi, Eugenia Rossi di Schio, Paolo Valdiserri e Gian Luca Morini. "Energy and Environmental Performance Comparison of Heat Pump Systems Working with Alternative Refrigerants". Applied Sciences 13, n. 12 (17 giugno 2023): 7238. http://dx.doi.org/10.3390/app13127238.
Abstract (sommario):
The European Parliament has imposed to reduce by 2030 whole HFC emissions by at least two-thirds with respect to 2014 levels. With the aim of contributing to determine the energy and environmental advantages of refrigerants alternative to R-410A, this paper reports the results of a numerical study focused on an HVAC system coupled to a residential building and based on a reversible electric heat pump. In particular, two heat pump typologies are considered: an air-source and a ground-source heat pump, both operating with the two refrigerants R-410A and R-454B. The environmental performance of the studied system is assessed by means of the TEWI (total equivalent warming impact) index. The adoption of R-454B involves a slight decrease (2–3%) in the overall annual energy performance of the system with respect to the use of R-410A. On the other hand, the working fluid R-454B guarantees a marked decrease in the TEWI indicator. Indeed, considering the current Italian emission factor of electricity taken from the grid, the total emissions over the entire heat pump operating life drop by about 25% and can decrease by up to 89% in perspective, following the current reduction trend of the emission factor.
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Shapoval, O., N. Chepurna e M. Kirichenko. "An analysis of effectiveness of air heat pump operation dependent on change of external air temperature". Ventilation, Illumination and Heat Gas Supply 37 (1 aprile 2021): 24–30. http://dx.doi.org/10.32347/2409-2606.2021.37.24-30.
Abstract (sommario):
Currently, air-to-water heat pumps are more widely used, which due to the high coefficient of performance reduce energy consumption and negative impact on the environment. They decrease the dependency on costs of energy resources. The work is devoted to solving the urgent problem of improving the efficiency of air heat pumps at low temperature of outdoor air in winter. One of the main problems of an air heat pump is the reduction of productivity when the outdoor air temperature decreases in winter. In this paper, the effectiveness of LG Therma V air-to-water heat pump to provide apartments with heating and hot water supply was analyzed. The heat pump is reversive, which can cool or heat a heat carrier. A four-way valve swithes the coolant flows between air exchangers. On the basis of the obtained results, plots of effectivness of the heat pump dependent on outdoor air temperature are built. It is shown that the effectiveness of the heat pump significantly depends not only on the outside temperature but also on the water temperature at the outlet of the heat pump. The use of heat pumps with a high coefficient of performance can significantly reduce energy costs. The most effective are low-temperature heating systems, in which the water temperature does not exceed 45 °C. The example is floor heating, which requires very low temperature of the floor surface – up to 30 °C. At outdoor air temperature not less than milnus 7 °C the heat pump is effective at higher temperature off heat carrier at output – up to 55 °C. To provide the uninterrupted heat supply, an additional air heater is included. It covers heat load during defrosting and very low outdoor air temperature. On the basis of the conducted researches, the directions of the further experimental and field researches are planned.
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Zhang, Ping, YiMin Xuan e Qiang Li. "A high-precision instrumentation of measuring thermal contact resistance using reversible heat flux". Experimental Thermal and Fluid Science 54 (aprile 2014): 204–11. http://dx.doi.org/10.1016/j.expthermflusci.2013.12.012.
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Zhang, Jingyu, Baolu Wang, Gang Li e Huilan Huang. "Thermal and electrical performances of PV/T system based on reversible thermochromic coating". Applied Thermal Engineering 234 (novembre 2023): 121358. http://dx.doi.org/10.1016/j.applthermaleng.2023.121358.
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Caruana, Roberta, Luca Marocco, Paolo Liberati e Manfredo Guilizzoni. "Experimental Analysis of the Effect of Limescale on the Wettability of Indirect Evaporative Cooling System Plates". Fluids 9, n. 3 (17 marzo 2024): 76. http://dx.doi.org/10.3390/fluids9030076.
Abstract (sommario):
Indirect evaporative cooling systems have attracted much interest in recent years as they guarantee good cooling effectiveness, with lower energy demand with respect to traditional systems, thus helping to address the issue of climate change. Many studies have shown that an increase in the wettability of recuperator plates results in an improvement in the system performance. However, if the water injected into the system comes from the city water supply, it will contain calcium carbonate residuals, which will form limescale layers on the plates, thus possibly changing their wetting behavior. Therefore, the wettability of three surfaces (an aluminum uncoated surface, AL, a standard epoxy coating, STD, and a hydrophilic lacquer, HPHI) was analyzed in the presence of limescale formations, and compared with that obtained in a previous study for corresponding clean surfaces. The results showed that the HPHI contact angle was reduced in the presence of limescale (median: 50°), that for STD was slightly increased (median: 81°), and that for AL was again reduced (median: 75°). Consequently, HPHI was confirmed to be the most wettable surface in both clean and limescale conditions. Finally, an analysis was undertaken evaluating the spreading factor and the reversible work of adhesion, which were in good agreement with the qualitative visual observations of the plates covered with limescale.
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Zhang, Wenying, Wenzhe Li e Pega Hrnjak. "Performance of an automotive reversible CO2 heat pump system during periodic frosting-defrosting cycles". Applied Thermal Engineering 236 (gennaio 2024): 121892. http://dx.doi.org/10.1016/j.applthermaleng.2023.121892.
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Dey, Shoroshi, Abhijit Das Sharma, Sandip Bysakh, Biswarup Satpati e Jayanta Mukhopadhyay. "Multicomponent Mixed Ionic and Electronic Conducting (MIEC) Air Electrodes and Their Heterointerface for Effective Application in Reversible Solid Oxide Cell (R-SOC): Efficacy of Stoichiometric and Off-Stoichiometric Compositions". ECS Meeting Abstracts MA2023-01, n. 54 (28 agosto 2023): 191. http://dx.doi.org/10.1149/ma2023-0154191mtgabs.
Abstract (sommario):
Reversible solid oxide cell (R-SOC) has triggered research interest from the past few years for its reversible applicability for power-to-fuel (P2F) in electrolyser cell (SOEC) to generate hydrogen by splitting of high temperature steam and fuel-to-power (F2P) in fuel cell (SOFC) mode of operation to produce power by oxidation of fuel with >80% conversion efficiency [1]. Primarily, R-SOC consists of a dense electrolyte conventionally yttria stabilized zirconia (YSZ), bridged between two porous electrodes, e.g., strontium doped lanthanum manganite (LSM) as air electrode and Nickel (Ni)-YSZ cermet as fuel electrode. Significant research has been devoted to carry out the long-term stability (≥ 2000 h) degradation in endurance test primarily due to major challenges like highly humid environment in the fuel electrode, microstructural flaws and polarization losses under high operational temperature. In this context, mixed ionic and electronically conducting (MIEC) oxide-based La-Sr-Co-Fe-O (LSCF) and Ba-Sr-Co-Fe-O (BSCF) air electrodes has drawn significant attention for the effective oxygen reduction (ORR) and oxygen evolution (OER) reaction in the context of SOFC and SOEC operational mode [2,3]. An attempt has been made in this present research work to establish the effect of off-stoichiometry in A-site lattice over the stoichiometric pristine compositions of La/Ba-Sr-Co-Fe-O (LSCF/BSCF)-based multicomponent MIEC-oxides and their associated heterostructure with optimised off-stoichiometric compositions that governs the electrochemical redox phenomena in conjunction with the functionally engineered Gd-doped ceria-based interlayer and buffer layer. Vacancy driven oxygen reduction (ORR) and oxide ion oxidation (OER) kinetics as a function of aliovalent charge compensation mechanism associated with the defect chemistry has also been investigated for these A-site non-stoichiometric compositions in the range of 1-0.92 for La/Ba(1-x)SrxCo1-yFeyO3-δ [x=0.4 and y=0.2]. A comparative study between the performance of the off-stoichiometric heterostructure synthesised using the optimised pristine compositions with that of the stoichiometric heterointerface has also been evaluated for their efficiency as catalyst for OER/ORR in reversible SOC mode of operation. The increasing trend of oxygen non-stoichiometry (δ) upon the transition from A-site stoichiometry to non-stoichiometric compositions reflected the formation of higher aliovalent cation of ‘Co’ to maintain the charge neutrality and thereby accelerates the associated oxygen redox kinetics. An optimum δ-value of 0.33 and 0.37 are found for LSCF and BSCF-compositions respectively having A-site non-stoichiometry of 0.94. Current density of 0.45 A.cm-2 at an applied voltage of 1.5 V @800℃ is obtained for stoichiometric composition of LSCF wherein 0.5 A.cm-2 is found for the off-stoichiometric batch corresponding to the hydrogen flux of 0.21Nl.h-1.cm-2. Such augmentation in performance may be related to the formation of higher lattice defect which eases the path for oxide ion oxidation. Formation of the interpenetrating heterointerface network at the air electrodes and electrode/electrolyte interfaces in the morphologically engineered cells having gradation in porosity has further been confirmed from Transmission Electron Microscopy (TEM) studies involving the high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and the STEM-EDS elemental spectrum mapping images of the cross-section of the sintered cells and clinically corelated with SOC performances. Orientation of the crystal lattice planes in the two types of grains across the heterojunction has also been determined from the High-Resolution Transmission Electron Microscopy (HRTEM) images. Further study to envisage the presumed hypothesis, based on the rate determining steps involving the defect lattice formation and probable mechanism for selective ORR/OER application, will also be described through hole and/or oxygen vacancy formalism using XPS and density functional theory (DFT) for such hetero-interpenetrating air electrodes. References: [1]. Y. Zhang et al. Int. J. Hydrog. Energy. 45 (2020) 5554. [2]. S. Dey et al. Int. J. Hydrog. Energy. 45 (2020) 3995-4007. [3] S. Dey et al. Ceram. Int. 48 (2022) 35799-35813.
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Daniarta, Sindu, Piotr Kolasiński e Attila R. Imre. "A Preliminary Design and Modeling Analysis of Two-Phase Volumetric Expanders for a Novel Reversible Organic Rankine-Based Cycle for Carnot Battery Technology". Applied Sciences 12, n. 7 (31 marzo 2022): 3557. http://dx.doi.org/10.3390/app12073557.
Abstract (sommario):
Carnot battery technology appears to be a promising solution to increase the development of power generation and offers a good solution for high-capacity, day-to-day energy storage. This technology may utilize the waste heat and store the electricity to recover it later. This article reports the preliminary analysis of a specially designed Carnot battery configuration employing a novel reversible Rankine-based thermodynamic cycle (RRTC). In this case, one volumetric expander is not only installed to generate power from a heat engine, but also to recover power during heat pump operating mode. The preliminary design and modeling results were obtained based on calculations taken from working fluid thermal properties of propane with some specific boundary conditions (i.e., secondary fluid hot temperature of 348.15 K, cooling temperature of 228.15 K, and waste heat temperature of 338.15 K). The results show that isentropic efficiency, pressure, and volumetric expansion ratio from both heat engine and heat pump operating modes are important parameters that must be taken into account when designing the two-phase expander for RRTC. The obtained results show that a designed two-phase volumetric expander in RRTC features a pressure ratio of 2.55 ± 1.15 and a volumetric ratio of 0.21 ± 0.105, and the Carnot battery may achieve the performance of 0.50–0.98.
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Nguyen, Thi Hai Quyen, Florian Eberheim, Sophie Göbel, Pascal Cop, Marius Eckert, Tim P. Schneider, Lukas Gümbel, Bernd M. Smarsly e Derck Schlettwein. "Enhancing the Spectroelectrochemical Performance of WO3 Films by Use of Structure-Directing Agents during Film Growth". Applied Sciences 12, n. 5 (23 febbraio 2022): 2327. http://dx.doi.org/10.3390/app12052327.
Abstract (sommario):
Thin, porous films of WO3 were fabricated by solution-based synthesis via spin-coating using polyethylene glycol (PEG), a block copolymer (PIB50-b-PEO45), or a combination of PEG and PIB50-b-PEO45 as structure-directing agents. The influence of the polymers on the composition and porosity of WO3 was investigated by microwave plasma atomic emission spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, X-ray diffraction, and gas sorption analysis. The electrochromic performance of the WO3 thin films was characterized with LiClO4 in propylene carbonate as electrolyte. To analyze the intercalation of the Li+ ions, time-of-flight secondary ion mass spectrometry, and X-ray photoelectron spectroscopy were performed on films in a pristine or reduced state. The use of PEG led to networks of micropores allowing fast reversible electrochromic switching with a high modulation of the optical transmittance and a high coloration efficiency. The use of PIB50-b-PEO45 provided isolated spherical mesopores leading to an electrochromic performance similar to compact WO3, only. Optimum characteristics were obtained in films which had been prepared in the presence of both, PEG and PIB50-b-PEO45, since WO3 films with mesopores were obtained that were interconnected by a microporous network and showed a clear progress in electrochromic switching beyond compact or microporous WO3.
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Berto, Silvia, Enrico Cagno, Enrico Prenesti, Giulia Aragona, Stefano Bertinetti, Agnese Giacomino, Paolo Inaudi, Mery Malandrino, Emanuele Terranova e Ornella Abollino. "Voltammetric Study for the Determination of Diclofenac in Aqueous Solutions Using Electro-Activated Carbon Electrodes". Applied Sciences 12, n. 16 (9 agosto 2022): 7983. http://dx.doi.org/10.3390/app12167983.
Abstract (sommario):
Diclofenac (DCF) is a nonsteroidal anti-inflammatory drug to treat pain and inflammatory diseases. The high consumption of the drug leads to a significant change in the ecosystem. With the aim of optimizing a fast screening analysis for DCF detection on many samples with a sensitive and cheap procedure, we considered electrochemical methods using carbon-based electrodes as sensors. The electrochemical behavior of the DCF was studied on glassy carbon electrodes (GCE) and on screen-printed carbon electrodes (SPCEs) from two different suppliers after an anodic activation. The surface of the SPCEs was analyzed by scanning electron microscope (SEM) and Energy Dispersive Spectrometry (EDS). On all the activated electrodes, the voltammetric procedure (Differential Pulse Voltammetry) for the determination of DCF was optimized by the Experimental Design method, and the linearity range of the response, as well as the calibration and limit parameters (limits of detection—LoD; limit of quantification—LoQ), were defined. Analyses on SPCEs were performed both by immersing the electrode in the solution and by deposing a drop of solution on the electrode. DCF signals are stabilized by the polishing process and enhanced by the anodic activation and acid pH. The electrochemical response of DCF is not reversible, and its by-products tend to be adsorbed on the surfaces, particularly on GCE. The lowest limit parameters were obtained using the GCE (LoD = 1.6 µg L−1) and the SPCE, having the smallest surface, immersed in solution (LoD = 7 µg L−1).
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Sajovic, Irena, Mateja Kert e Bojana Boh Podgornik. "Smart Textiles: A Review and Bibliometric Mapping". Applied Sciences 13, n. 18 (20 settembre 2023): 10489. http://dx.doi.org/10.3390/app131810489.
Abstract (sommario):
According to ISO/TR 23383, smart textiles reversibly interact with their environment and respond or adapt to changes in the environment. The present review and bibliometric analysis was performed on 5810 documents (1989–2022) from the Scopus database, using VOSviewer and Bibliometrix/Biblioshiny for science mapping. The results show that the field of smart textiles is highly interdisciplinary and dynamic, with an average growth rate of 22% and exponential growth in the last 10 years. Beeby, S.P., and Torah, R.N. have published the highest number of papers, while Wang, Z.L. has the highest number of citations. The leading journals are Sensors, ACS Applied Materials and Interfaces, and Textile Research Journal, while Advanced Materials has the highest number of citations. China is the country with the most publications and the most extensive cooperative relationships with other countries. Research on smart textiles is largely concerned with new materials and technologies, particularly in relation to electronic textiles. Recent research focuses on energy generation (triboelectric nanogenerators, thermoelectrics, Joule heating), conductive materials (MXenes, liquid metal, silver nanoparticles), sensors (strain sensors, self-powered sensors, gait analysis), speciality products (artificial muscles, soft robotics, EMI shielding), and advanced properties of smart textiles (self-powered, self-cleaning, washable, sustainable smart textiles).
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Dengaev, Aleksey V., Aydar A. Kayumov, Andrey A. Getalov, Firdavs A. Aliev, Gadel F. Baimukhametov, Boris V. Sargin, Alexander F. Maksimenko e Alexey V. Vakhin. "Chemical Viscosity Reduction of Heavy Oil by Multi-Frequency Ultrasonic Waves with the Main Harmonics of 20–60 kHz". Fluids 8, n. 4 (21 aprile 2023): 136. http://dx.doi.org/10.3390/fluids8040136.
Abstract (sommario):
Ultrasound technologies are well-known for their ability to intensify the heat and mass transfer processes. Hence, ultrasonic treatment processes are widely applied for the separation of oil–water emulsions, optimization of oil pumping processes, cleaning the bottomhole zone, etc. However, the main phenomenon under the positive influence of ultrasonic waves on such processes is the cavitation bubbles implosion on the water–oil boundary. It is well-known that ultrasound energy contributes to the reversible viscosity reduction in heavy oil systems. However, it is possible to exhibit chemical destruction of the weakest carbon–heteroatom bonds in the structure of the asphaltenes. This study investigates the influences of controllable ultrasound waves with frequency ranges of 20–60 kHz under the exposure time of 60 s on the rheology of a heavy crude oil sample produced from the Ashalcha reservoir (Tatarstan Republic, Russia). The specific feature of this study is the application of multi-frequency ultrasonic exposure with a wide spectrum of side harmonics with the frequency up to 400 kHz. The results of the Saturates, Aromatics, Resins and Asphaltenes (SARA) analysis method support the chemical consequences of ultrasonication of crude oil. The content of resins under the irradiation of ultrasound waves altered from 32.5 wt.% to 29.4 wt.%, while the number of aromatics hydrocarbons raised from 24.3 wt.% to 34.1 wt.%. The Gas Chromatography—Mass Spectroscopy (GC-MS) analytical analysis method was applied to qualitatively compare the composition of saturated and aromatics fractions between the initial and upgraded heavy crude oil in order to show the chemical destruction of asphaltene bonds after the ultrasonic treatment. It was demonstrated that ultrasound waves allowed chemical conversion of asphaltene fragments that led to irreversible viscosity reduction. The viscosity of the heavy oil sample under the favorable ultrasonic irradiation conditions reduced from 661.2 mPa·s to 178.8 mPa·s. This advantage can be used to develop enhanced oil recovery methods and partial upgrading processes in downstream conditions.