1,721,060 research outputs found
Spreading of correlations in Markovian open quantum systems
Full text linkUnderstanding the spreading of quantum correlations in out-of-equilibrium many-body systems is one of the major challenges in physics. For isolated systems, a hydrodynamic theory explains the origin and spreading of entanglement via the propagation of quasiparticle pairs. However, when systems interact with their surrounding much less has been established. Here we show that the quasiparticle picture remains valid for open quantum systems: While information is still spread by quasiparticles, the environment modifies their correlation and introduces incoherent and mixing effects. For free fermions with gain/loss dissipation we provide formulas fully describing incoherent and quasiparticle contributions in the spreading of entropy and mutual information. Importantly, the latter is not affected by entanglement of the system with the external environment. The mutual information is exponentially damped at short times and eventually vanishes signaling the onset of a classical limit. The behavior of the logarithmic negativity is similar and this scenario is common to other dissipations. For weak dissipation, the presence of quasiparticles underlies remarkable scaling behaviors
Hydrodynamics of quantum entropies in Ising chains with linear dissipation
No full textWe study the dynamics of quantum information and of quantum correlations after a quantum quench, in transverse field Ising chains subject to generic linear dissipation. As we show, in the hydrodynamic limit of long times, large system sizes, and weak dissipation, entropy-related quantities - such as the von Neumann entropy, the Rényi entropies, and the associated mutual information - admit a simple description within the so-called quasiparticle picture. Specifically, we analytically derive a hydrodynamic formula, recently conjectured for generic noninteracting systems, which allows us to demonstrate a universal feature of the dynamics of correlations in such dissipative noninteracting system. For any possible dissipation, the mutual information grows up to a time scale that is proportional to the inverse dissipation rate, and then decreases, always vanishing in the long time limit. In passing, we provide analytic formulas describing the time-dependence of arbitrary functions of the fermionic covariance matrix, in the hydrodynamic limit
Noninteracting fermionic systems with localized losses: Exact results in the hydrodynamic limit
No full textWe investigate the interplay between unitary and nonunitary dynamics after a quantum quench in a noninteracting fermionic chain. In particular, we consider the effect of localized loss processes, for which fermions are added and removed incoherently at the center of the chain. We focus on the hydrodynamic limit of large distances from the localized losses and of long times, with their ratio being fixed. In this limit, the localized losses gives rise to an effective imaginary delta potential (nonunitary impurity), and the time-evolution of the local correlation functions admits a simple hydrodynamic description in terms of the fermionic occupations in the initial state and the reflection and transmission amplitudes of the impurity. We derive this hydrodynamic framework from the ab initio calculation of the microscopic dynamics. This allows us to analytically characterize the effect of losses for several theoretically relevant initial states, such as a uniform Fermi sea, homogeneous product states, or the inhomogeneous state obtained by joining two Fermi seas. In this latter setting, when both gain and loss processes are present, we observe the emergence of exotic nonequilibrium steady states with stepwise uniform density profiles. In all instances, for strong loss and gain rates the coherent dynamics of the system is arrested, which is a manifestation of the celebrated quantum Zeno effect
Life cycle costing approach for construction and demolition waste management chain: methodology of data collection and organization
No full textLCC analysis of construction and demolition waste management chain
No full textIn Italy, despite most of the mineral waste from construction and demolition (C&D)
activities is sent for recovery, we are still a long way from reaching the circular economy in the
building sector. Natural cave-generated aggregates are still favoured over recovered ones, implying
huge volumes of unsold recycled materials aside from the decrease of natural materials, whose supply
can be more restricted by time. In this work, the implementation of the Life Cycle Costing (LCC)
methodology will provide the basis for the political decision-makers' economic appraisal to stimulate
the market for recycled aggregates.. The LCC study assesses the preliminary, machinery acquisition,
operating, and disposal costs associated with the whole C&D value chain, from inert waste production
in demolition yards through the usage of recycled aggregates generated
Life cycle costing of construction and demolition waste management chain
No full textAccording to recent studies, in Italy, most of the mineral waste from construction and demolition (C&D)
activities is already sent for recovery, but the closure of the circle, necessary for the realization of the circular
economy, is not yet reached because there are still obstacles that prevent the widespread use of the secondary
resources produced in the recycling activities. In Italy, natural cave-generated aggregates are still preferred in
place of recovered ones and this implies large amounts of recycled materials that remain unsold, other than the
reduction of natural goods, of which availability can be more and more limited by time. This work deepens the
advantages of using recycled aggregates from the economic point of view, through the application of the Life
Cycle Costing (LCC) methodology.
The LCC analysis evaluates the preliminary, the machinery acquisition, the operating, and the disposal costs
relating to the entire C&D value chain, going from the generation of inert waste in demolition yards to the use of
the recycled aggregates produced. The results of this work will be the starting point for the proposal of incentive
mechanisms or reward criteria, whose implications are relevant to policymakers
LCA approach for the C&D waste management system in different countries of the world
Full text linkThe main problem with the recovery of construction and demolition (C&D) waste
is the huge amount of recycled aggregates that remain unsold, due, maybe, to
the lack of trust by sector operators. Carry on an environmental assessment
would be a useful method to reveal the advantages in the use of the secondary
resources. Through a literature review, this paper will analyze the application of
Life Cycle tools for evaluating circular strategies in C&D waste management to
compare different scenarios, hypotheses, and approaches adopted in life cycle
assessment (LCA). The comparison will be done between four scientific articles
from different countries (Italy, Spain, Denmark, and Brazil), in which an LCA
analysis regarding C&D waste management has been carried out
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