Ultrafast single electron spin manipulation in 2D semiconductor quantum dots with optimally controlled time-dependent electric fields through spin-orbit coupling

We have studied theoretically the possibility of ultra-fast manipulation of a single electron spin in 2D semiconductor quantum dots, by means of high-frequency time-dependent electric fields. The electron spin degree of freedom is excited through spin-orbit coupling, and the procedure may be enhanced by the presence of a static magnetic field. We use quantum optimal control theory to tailor the temporal profile of the electric field in order to achieve the most effective manipulation. The scheme predicts significant control over spin operations in times of the order of picoseconds – an ultrafast time scale that permits to avoid the effects of decoherence if this scheme is to be used as a tool for quantum information processing

Graphical User Interface (GUI): ParamIni_LL_NRTL

33rd European Symposium on Computer Aided Process Engineering (ESCAPE33), June 18-21, 2023, Athens, Greece (Theme 8. Education and knowledge transfer: Poster 43,Board 107).In the present work, the NRTL model has been analyzed to obtain a good representation of the different ternary liquid-liquid equilibria that this thermodynamic model can reproduce satisfactorily. To do that, the main characteristics of different possible binary subsystems, ternary binodal curves (location in the composition diagram, size, tie-lines orientation, and plait point location), and LLLE tie triangles have been evaluated. With more than two hundred systems studied, the different behaviors have been parametrized to create, as the main objective of the present work, a database and a graphical user interface associated (ParamIni_LL_NRTL, Labarta et al. 2022. RUA: http://hdl.handle.net/10045/130017). This resource (publicly available for teaching and research uses) allows, given a set of ternary experimental LLE data to obtain by comparison with the elements of the database, a consistent set of initial NRTL parameters (taui,j, alfai,j) to start the corresponding correlation data procedure with enough guarantees.The authors gratefully acknowledge the financial support by the Ministry of Science and Innovation from Spain, under the project PID2021-124139NB-C21: SUS4Energy, 2022/00666/001 (AEI)

Improving some thermodynamic consistency tests for VLE data evaluation

Thermodynamics Conference 2013 (Statistical Mechanics and Thermodynamics Group of the Royal Society of Chemistry), The University of Manchester, 3-6 September 2013.The fundamental Gibbs-Duhem equation is the most widely referenced condition for consistency of the experimental VLE data, leading to a variety of thermodynamic consistency tests (TC tests). TC tests should be applied rigorously because deviations between the test results and VLE experimental data are usually attributed to the doubtful quality of the experimental data. Nevertheless, in many instances are the rough approximations involved in the applications of such TC tests the responsible of the bad results provided by a given experimental data set. In the present paper a method is suggested to calculate the term depending on the excess enthalpy (HE) that is rarely available and impedes rigorous calculation of the area test and the point (or differential) test in isobaric conditions. A relevant example of this problem is that the NIST algorithm uses the area test with the empirical Herington equation to estimate the term depending of HE, despite having been invalidated, and the point test is exclusively applied to isothermal and not to isobaric conditions. The comparison of the method proposed in this work with the standard procedures and data theoretically calculated demonstrates its capacity and validates experimental data sets otherwise improperly questioned.Financial support by means of the projects: MINECO. MAT2011-24991 and PROMETEO/2012/015

Techniques for Capturing Force Interactions in Reinforced Concrete Wall-Frame Systems Under Seismic Excitation

Estimating the lateral yielding strength of a multi-story reinforced concrete wall-frame structure is complex due to the interaction forces between the wall and the frame. The interaction force is perpetually changing corresponding with a time varying load, such as seismic excitation, and depending on material nonlinearities. This thesis is motivated by the ATC 78 project, which has an overall goal to develop simplified hand calculations, which consider nonlinearities and use probabilistic approaches, as a way to effectively and efficiently “rate” the seismic performance of reinforced concrete buildings on a unified rating system. In doing so, the new methodology will be able locate “killer buildings”, which were built before modern seismic building codes and may be particularly dangerous for building occupants and the public. The conclusions are used to develop a new engineering parameter β that can be used to relate simplified hand calculations to the actual strength of the structure

Analysis of the Zone Connecting Consecutive Sectors in Generalized Distillation Columns by Using the Ponchon-Savarit Method

Ponchon-Savarit is a classical graphical method for the design of binary distillation columns. This method is still widely used, mainly with didactical purposes, though it is also valid for preliminary calculations. Nevertheless, no complete description has been found in books and situations such as different thermal feed conditions, multiple feeds, possibilities to extract by-products or to add or remove heat, are not always considered. In this work we provide, a systematic analysis of the Ponchon-Savarit method by developing generalized equations for the operating lines or difference points, as well as a consistent analysis of what may happen in the zone between two consecutive trays of the corresponding sectors separated by a lateral stream of feed, product, or a heat removal or addition. The graphical interpretation of all situations shown allows a clarifying view of the different possibilities in the rectifying column and completes the existing literature about this method

Mapping Binary Liquid-Vapor or Liquid-Liquid-Vapor Equilibria Regions, including the Different Azeotropic Behaviours, as a Function of the NRTL Binary Parameters

13th Mediterranean Congress of Chemical Engineering (Sociedad Española de Química Industrial e Ingeniería Química, Fira Barcelona, Expoquimia), Barcelona, September 30-October 3, 2014As it is very well know, the synthesis and design of separation processes requires the use of models to represent the phase equilibrium data, which involves the previous correlation of experimental data to obtain the values of the corresponding parameters. In previous works, we have studied the capabilities and limitations of the classical GE models used in phase equilibrium data correlations, such as NRTL model, in representing the behaviour of different LV, LL and LLS equilibrium data. In the preset work, the relations between the binary parameters Aij of the NRTL model and the existence of different equilibrium regions (i.e.: LV, LL or LLV), as well as the different possible azeotropic behaviours are analyzed for different component systems. The Gibbs free enthalpy curve and the corresponding y-x and T-x,y diagrams along a matrix of Aij parameters has been studied within a range including the typical values observed in DECHEMA Chemistry Data Series

The understanding of the three-dimensional graphical behavior of the L-L-S phase equilibrium as a valuable tool to avoid spurious or incoherent experimental data

The complexity and variety of possible behaviors of the quaternary liquid-liquid, liquid-liquid-solid equilibrium at constant temperature are very high and, sometimes, are not well understood. It is not difficult to find references in literature where important misinterpretations and mistakes are committed as a consequence of applying a non-adequate experimental methodology and a lack of the spatial point of view. Thus, the objective of the present paper is to show several examples where special behaviors are selected to clarify some aspects concerning the experimental determination and graphical representation of liquid-liquid-solid equilibrium data, and emphasize the importance of the knowledge and consideration of the qualitative expected behavior of the system under study, obtained from the binaries.Universidad de Alicant

Geometrical aspects of the azeotropic liquid-liquid-vapour phase equilibria

The ternary isobaric liquid-liquid-vapour and liquid-vapour equilibrium can be very complex and may present a wide variety of three-dimensional representations, which sometimes are not very well understood. This paper presents several examples of possible complex spatial behaviours with different kind of azeotropes. These examples have been selected to clarify the expected projections deduced from the binaries and to help in the understanding of these type of equilibrium as well as in the experimental data determination and interpretation.Universidad de Alicant