Maximally Localized States in Quantum Mechanics with a Modified Commutation Relation to All Orders

We construct the states of maximal localization taking into account a modification of the commutation relation between position and momentum operators to all orders of the minimum length parameter. To first order, the algebra we use reproduces the one proposed by Kempft, Mangano and Mann. It is emphasized that a minimal length acts as a natural regulator for the theory, thus eliminating the otherwise ever appearing infinities. So, we use our results to calculate the first correction to the Casimir Effect due to the minimal length. We also discuss some of the physical consequences of the existence of a minimal length, culminating in a proposal to reformulate the very concept of "position measurement"

Real space mapping of topological invariants using artificial neural networks

Topological invariants allow to characterize Hamiltonians, predicting the existence of topologically protected in-gap modes. Those invariants can be computed by tracing the evolution of the occupied wavefunctions under twisted boundary conditions. However, those procedures do not allow to calculate a topological invariant by evaluating the system locally, and thus require information about the wavefunctions in the whole system. Here we show that artificial neural networks can be trained to identify the topological order by evaluating a local projection of the density matrix. We demonstrate this for two different models, a 1-D topological superconductor and a 2-D quantum anomalous Hall state, both with spatially modulated parameters. Our neural network correctly identifies the different topological domains in real space, predicting the location of in-gap states. By combining a neural network with a calculation of the electronic states that uses the Kernel Polynomial Method, we show that the local evaluation of the invariant can be carried out by evaluating a local quantity, in particular for systems without translational symmetry consisting of tens of thousands of atoms. Our results show that supervised learning is an efficient methodology to characterize the local topology of a system.Comment: 9 pages, 6 figure

Transthyretin familial amyloid polyneuropathy impact on health-related quality of life

info:eu-repo/semantics/publishedVersio

Thermoeconomic Simulation of Cascaded and Integrated Vapor Compression-Absorption Refrigeration Systems

The present work is composed by a comparative thermoeconomic analysisbetween two refrigeration systems: Vapor Compression CascadeRefrigeration System (VCCRS) and Integrated Refrigeration System byAbsorption and Vapor Compression (VCACRS). The thermoeconomicanalysis compares the systems under energy, exergy, economic andenvironmental aspects. The development of mathematical models for each ofthe systems is performed through the EES (Engineering Equation Solver)program. The optimized functions are exergy destruction and total cost rate(sum of cost rates of investment, operation, maintenance and enviromental)by minimizing these functions. The optimization method used is theweighted sum of the objectives, this can be achieved by assigning differentweights for each goal, then a new function that represents the linearrelationship between all the objectives is found. In present case the twoobjective functions are exergy destruction and total cost rate. Inmultiobjective optimization, the process of choosing among optimizedsolutions involves the definition of an equilibrium point, also called theideal point. In order to achieve a real solution of the minimum values ofthe described functions simultaneously one must determine which is thesmallest distance from the ideal point to the curve that defines theoptimized solutions. In the study the economical advantage of VCCRS inrelation to VCACRS was demonstrated. VCACRS has a cost 10.26% lowerthan VCCRS while VCCRS has a better exergetic efficiency, with itsdestruction of exergy 38.46% lower than VCACRS

Supergiant Barocaloric Effects in Acetoxy Silicone Rubber over a Wide Temperature Range: Great Potential for Solid-state Cooling

Solid-state cooling based on caloric effects is considered a viable alternative to replace the conventional vapor-compression refrigeration systems. Regarding barocaloric materials, recent results show that elastomers are promising candidates for cooling applications around room-temperature. In the present paper, we report supergiant barocaloric effects observed in acetoxy silicone rubber - a very popular, low-cost and environmentally friendly elastomer. Huge values of adiabatic temperature change and reversible isothermal entropy change were obtained upon moderate applied pressures and relatively low strains. These huge barocaloric changes are associated both to the polymer chains rearrangements induced by confined compression and to the first-order structural transition. The results are comparable to the best barocaloric materials reported so far, opening encouraging prospects for the application of elastomers in near future solid-state cooling devices.Comment: 19 pages, 7 figures, 2 table

The Power of Non-Determinism in Higher-Order Implicit Complexity

We investigate the power of non-determinism in purely functional programming languages with higher-order types. Specifically, we consider cons-free programs of varying data orders, equipped with explicit non-deterministic choice. Cons-freeness roughly means that data constructors cannot occur in function bodies and all manipulation of storage space thus has to happen indirectly using the call stack. While cons-free programs have previously been used by several authors to characterise complexity classes, the work on non-deterministic programs has almost exclusively considered programs of data order 0. Previous work has shown that adding explicit non-determinism to cons-free programs taking data of order 0 does not increase expressivity; we prove that this - dramatically - is not the case for higher data orders: adding non-determinism to programs with data order at least 1 allows for a characterisation of the entire class of elementary-time decidable sets. Finally we show how, even with non-deterministic choice, the original hierarchy of characterisations is restored by imposing different restrictions.Comment: pre-edition version of a paper accepted for publication at ESOP'1