Hasil untuk "Thermodynamics"

I. Prigogine

D. Brewer, C. Gorter, W. Halperin et al.

F. Morel

Zhenyu Zhang, M. Lagally

R. Brandenberger, C. Vafa

Lingen Chen, Chih Wu, F. Sun

C. R. Ferguson

G. Stephanopoulos, A. Aristidou, J. Nielsen

R. Criss

K. Birdi

J. E. Dunn, K. Rajagopal

J. Koski, V. Maisi, J. Pekola et al.

Significance A Maxwell demon makes use of information to convert thermal energy of a reservoir into work. A quantitative example is a thought experiment known as a Szilard engine, which uses one bit of information about the position of a thermalized molecule in a box to extract kBT ln 2 of work. The second law of thermodynamics remains valid because, according to Landauer principle, erasure of the information dissipates at least the same amount of heat. Here, we present an experimental realization of a Maxwell demon similar to a Szilard engine, in the form of a single electron box. We provide, to our knowledge, the first demonstration of extracting nearly kBT ln 2 of work for one bit of information. The most succinct manifestation of the second law of thermodynamics is the limitation imposed by the Landauer principle on the amount of heat a Maxwell demon (MD) can convert into free energy per single bit of information obtained in a measurement. We propose and realize an electronic MD based on a single-electron box operated as a Szilard engine, where kBT ln 2 of heat is extracted from the reservoir at temperature T per one bit of created information. The information is encoded in the position of an extra electron in the box.

R. Alicki, M. Fannes

Motivated by the recent interest in thermodynamics of micro- and mesoscopic quantum systems we study the maximal amount of work that can be reversibly extracted from a quantum system used to temporarily store energy. Guided by the notion of passivity of a quantum state we show that entangling unitary controls extract in general more work than independent ones. In the limit of a large number of copies one can reach the thermodynamical bound given by the variational principle for the free energy.

Antonio F. Miguel, Vinícius R. Pepe, Luiz A. O. Rocha

This study probabilistically assesses magma ascent by modeling dike propagation as a fully coupled fluid-flow, thermo-mechanical problem, explicitly accounting for the stochastic heterogeneity of the crustal host rock. We study felsic (rhyolite) lava flow and two distinct basaltic feeding regimes that correspond to the conditions necessary to produce the contrasting pāhoehoe and ʻaʻā surface morphologies. Basaltic dikes demonstrate high propagation efficiency to the surface (pāhoehoe-feeding regime 99.5%; ʻaʻā-feeding regime 97.5%), whereas rhyolite dikes have an 89% failure rate, attributed to significant friction. Both regimes represent distinct constructal approaches aimed at maximizing flow persistence. The pāhoehoe-feeding regime is a thermally regulated, stable design characterized by low-velocity, cooling-dominated dynamics. Its slow, persistent flow allows for significant conductive heating of the surrounding rock wall, creating an efficient, pre-heated thermal conduit. In contrast, the ʻaʻā-feeding regime is a mechanically dominated design governed by high-velocity, stochastic dynamics. This morphology is driven by forceful flow, and its thermal budget is supplemented by intense viscous dissipation (internal friction). Rhyolite magma flow fails upon losing constructal viability, driven by a coupled mechanical–thermal cascade. The sequence begins when a mechanical barrier halts the magma velocity, which triggers a freezing event and leads to permanent arrest.

Miguel Gonzalo Arenas-Quevedo, Jesús Gracia-Fadrique, José Luis López-Cervantes

Alireza Pourvahabi Anbari, Shima Rahmdel Delcheh, Muhammad Kashif et al.

Given the adverse effects of organic dyes from aqueous solutions on human physiology and the ecological system, establishing an effective system for their elimination is imperative. This study employs the in situ thermal (IST) method to synthesize nanocomposites comprising zeolitic imidazole frameworks, specifically Fe-ZIF-8 and Fe-ZIF-67. The investigation offers a comprehensive evaluation of the properties of these nano-adsorbents for the removal of malachite green (MG). The results indicate a significantly increased adsorption capacity of up to 495 and 552 mg g⁻¹ for Fe-ZIF-8 and Fe-ZIF-67, respectively. Furthermore, they demonstrate removal efficiencies of up to 90% and 95% for MG, respectively. Parameters associated with the adsorption process are derived from isotherms and removal kinetics, specifically the Freundlich model and the pseudo-second-order kinetics model, respectively. The enhanced adsorption capacity observed in Fe-ZIF-8 and Fe-ZIF-67 can be attributed to π–π stacking interactions, hydrogen bonding, and electrostatic attraction. After undergoing three cycles, both adsorbents consistently exhibit a high removal efficiency of approximately 85%, indicating notable structural integrity and outstanding potential for repeated use. The examined adsorbents display exceptional efficacy, favorable stability, and substantial specific surface area, underscoring their remarkable adsorption capabilities. The nanocomposites comprising Fe-ZIF-8 and Fe-ZIF-67 demonstrate considerable potential as highly favorable options for the elimination of MG and other cationic organic dyes from aqueous environments.

Md. Zuel Rana, Sharmin Akter, Abdul Barik et al.

In this research, the impacts of hydrostatic pressure over the structural, elastic, electrical, and optical characteristics of RbYO2 (Rubidium Yttrium Oxide) were extensively investigated utilizing density functional theory (DFT). This study explored the theoretical framework, providing valuable insights into the mechanical stability of RbYO2 under applied pressure. Our findings indicate that RbYO2 remains both dynamically and mechanically stable up to 80 GPa. Under ambient pressure, RbYO2 exhibits a ductile nature; however, it transitions to a brittle state as pressure increases. From our analysis, we noticed a gradual decrement in the band gap with increasing pressure, suggesting that RbYO2 holds significant potential for solar energy driven applications. The characteristics of the distinct orbitals of RbYO2 were determined through an analysis of the density of states (DOS) and partial density of states (PDOS). The computed band edge values of RbYO2 indicate that it possesses the right balance of oxidation and reduction potential necessary for breaking down contaminants. Furthermore, under pressure, there is a substantial enhancement in optical absorption efficiency. Introducing hydrostatic pressure proves to be a fruitful approach to reducing the band gap of RbYO2 and enhancing optical absorption across the visible light spectrum. We recorded remarkable absorption in both the near-visible and near-ultraviolet regions, highlighting the material's potential for water splitting in hydrogen generation and photo catalytic dye degradation. Based on our research, these findings may contribute significantly to further enhancing the efficiency of RbYO2, making it an appropriate candidate for advanced optoelectronic and photocatalytic applications.

V. Blickle, C. Bechinger

A. Ronzani, B. Karimi, J. Senior et al.

Quantum thermodynamics is emerging both as a topic of fundamental research and as a means to understand and potentially improve the performance of quantum devices1–10. A prominent platform for achieving the necessary manipulation of quantum states is superconducting circuit quantum electrodynamics (QED)11. In this platform, thermalization of a quantum system12–15 can be achieved by interfacing the circuit QED subsystem with a thermal reservoir of appropriate Hilbert dimensionality. Here we study heat transport through an assembly consisting of a superconducting qubit16 capacitively coupled between two nominally identical coplanar waveguide resonators, each equipped with a heat reservoir in the form of a normal-metal mesoscopic resistor termination. We report the observation of tunable photonic heat transport through the resonator–qubit–resonator assembly, showing that the reservoir-to-reservoir heat flux depends on the interplay between the qubit–resonator and the resonator–reservoir couplings, yielding qualitatively dissimilar results in different coupling regimes. Our quantum heat valve is relevant for the realization of quantum heat engines17 and refrigerators, which can be obtained, for example, by exploiting the time-domain dynamics and coherence of driven superconducting qubits18,19. This effort would ultimately bridge the gap between the fields of quantum information and thermodynamics of mesoscopic systems. The state of a superconducting circuit qubit governs the photonic heat flow through an integrated assembly, constituting a quantum heat valve that provides a testbed for exploring quantum thermodynamics in a circuit quantum electrodynamics setting.

N. Cottet, S. Jezouin, L. Bretheau et al.

Significance Maxwell’s demon plays a central role in thermodynamics of quantum information, yet a full experimental characterization is still missing in the quantum regime. Here we use superconducting circuits to realize a quantum Maxwell demon in which all thermodynamic quantities can be controlled and measured. Using power detection resolved at the single microwave photon level and unprecedented tomography techniques, we directly measure the extracted work while tracking the qubit and cavity entropies and energies. We are thus able to fully characterize the demon’s memory after the work extraction and show that it takes full part in the thermodynamic process. The experiment establishes superconducting circuits as a testbed well suited to perform quantum thermodynamics experiments. In apparent contradiction to the laws of thermodynamics, Maxwell’s demon is able to cyclically extract work from a system in contact with a thermal bath, exploiting the information about its microstate. The resolution of this paradox required the insight that an intimate relationship exists between information and thermodynamics. Here, we realize a Maxwell demon experiment that tracks the state of each constituent in both the classical and quantum regimes. The demon is a microwave cavity that encodes quantum information about a superconducting qubit and converts information into work by powering up a propagating microwave pulse by stimulated emission. Thanks to the high level of control of superconducting circuits, we directly measure the extracted work and quantify the entropy remaining in the demon’s memory. This experiment provides an enlightening illustration of the interplay of thermodynamics with quantum information.