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Axiomatization and Measurement of Quasi-Hyperbolic Discounting
This article provides an axiomatic characterization of quasi-hyperbolic discounting and a more general class of semi-hyperbolic preferences. We impose consistency restrictions directly on the intertemporal trade-offs by relying on what we call “annuity compensations.” Our axiomatization leads naturally to an experimental design that disentangles discounting from the elasticity of intertemporal substitution. In a pilot experiment we use the partial identification approach to estimate bounds for the distributions of discount factors in the subject pool. Consistent with previous studies, we find evidence for both present and future bias.Economic
3D Real-Time Reconstruction using the Cloud
This work presents a 3D real-time reconstruction based on a visual SLAM (Simultaneous Localization and Mapping) approach using a RGBD camera. The proposed system aims to create a 3D model of an environment using a low-power computer and Amazon EC2 (Elastic Compute Cloud) server for computation offloading
A mathematical model for the optimization of the non-metallic mining supply chain in the mining district of Calamarí-Sucre (Colombia)
This article presents a mathematical model of the Supply chain of non-metallic mining. The model considers uncertainty scenarios in materials, elements for capacity planning in a multilevel chain and with multiple products. The mathematical model is collaborative and maximizes the profits of the actors in the supply chain. The model is implemented in Calamarí-Sucre mining district (Colombia). The scenario is applied to the extraction, processing, storage, and distribution of limestone. To solve the model, the GAMS software was used through libraries of relaxed mixed nonlinear programming - RMINLP and the DICOPT solver. The results indicate that the greatest benefits occur in a scenario of the high provision of raw materials. The equity in the economic benefits show a dynamics of vertical integration in the sector. The model applied to non-metallic mining complexes helps determine optimal strategies and decisions in different echelons
Biocatalytic Synthesis of Polyglycerol Polyricinoleate: A Comparison of Different Commercial Lipases
This paper describes the studies carried out to select the most suitable lipase as catalyst for the esterification of polyglycerol with polyricinoleic acid to yield polyglicerol polyricinoleate (PGPR), a value-added, bio-based food emulsifier. The enzymes assayed
were lipases from Rhizopus arrhizus, Rhizopus oryzae and Mucor javanicus, previously selected because of their suitable activity and moderate cost. First, the reaction was catalyzed by free lipases in a batch reactor and the influence of different operating conditions
(initial water content, amount of enzyme and temperature) on the progress of the reaction was studied. Next, the three lipases were immobilized by physical adsorption on the anion exchange resin, Lewatit MonoPlus MP 64, providing derivatives with a high activity and stability. Recovery of the immobilized derivative from the reaction medium was conducted with very good yields (≥ 99 %) and no loss of activity of the derivative with successive uses was proved. Finally, a high performance reactor, operating at low pressure and a dry atmosphere, was used to synthesise PGPR using the immobilized enzymes. Both Rhizopus arrhizus and Rhizopus oryzae lipases allowed the production of a PGPR which fulfils the “specific purity criteria on food additives other than colours and sweeteners” established by the Commission of the European Communities (AV ≤ 6 mg KOH/g), with an acid value of 4.91 and 5.31 mg KOH/g respectively
Tunable critical field in Rashba superconductor thin-films
The upper critical field in type II superconductors is limited by the Pauli
paramagnetic limit. In superconductors with strong Rashba spin-orbit coupling
this limit can be overcome by forming a helical state. Here we quantitatively
study the magnetic field-temperature phase diagram of finite-size
superconductors with Rashba spin-orbit coupling. We discuss the effect of
finite size and shape anisotropy. We demonstrate that the critical field is
controllable by intrinsic parameters such as spin-orbit coupling strength and
tunable parameters such as sample geometry and applied field direction. Our
study opens new avenues for the design of superconducting spin-valves.Comment: 5 pages, 4 figures, supplemental material
Reconfigurable Network for Quantum Transport Simulation
In 1981, Richard Feynman discussed the possibility of performing quantum
mechanical simulations of nature. Ever since, there has been an enormous
interest in using quantum mechanical systems, known as quantum simulators, to
mimic specific physical systems. Hitherto, these controllable systems have been
implemented on different platforms that rely on trapped atoms, superconducting
circuits and photonic arrays. Unfortunately, these platforms do not seem to
satisfy, at once, all desirable features of an universal simulator, namely
long-lived coherence, full control of system parameters, low losses, and
scalability. Here, we overcome these challenges and demonstrate robust
simulation of quantum transport phenomena using a state-of-art reconfigurable
electronic network. To test the robustness and precise control of our platform,
we explore the ballistic propagation of a single-excitation wavefunction in an
ordered lattice, and its localization due to disorder. We implement the
Su-Schrieffer-Heeger model to directly observe the emergence of
topologically-protected one-dimensional edge states. Furthermore, we present
the realization of the so-called perfect transport protocol, a key milestone
for the development of scalable quantum computing and communication. Finally,
we show the first simulation of the exciton dynamics in the B800 ring of the
purple bacteria LH2 complex. The high fidelity of our simulations together with
the low decoherence of our device make it a robust, versatile and promising
platform for the simulation of quantum transport phenomena
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