Proposal of a novel design for linear superconducting motor using 2G tape stacks

This paper presents a new design for a su- perconducting linear motor (SLM). This SLM uses stacks of second-generation (2G) superconducting tapes, which are responsible for replacing yttrium barium copper oxide bulks. The proposed SLM may operate as a synchronous motor or as a hysteresis motor, depending on the load force magnitude. A small-scale linear machine prototype with 2G stacks was constructed and tested to investigate the proposed SLM topology. The stator traveling magnetic field wave was represented by several Nd-Fe-B permanent magnets. A relative movement was produced between the stator and the stack, and the force was measured along the displacement. This system was also simulated by the finite element method, in order to calculate the induced currents in the stack and determine the electromagnetic force. The H-formulation was used to solve the problem, and a power law relation was applied to take into account the intrin- sically nonlinearity of the superconductor. The simulated and measured results were in accordance. Simulated re- sults were extrapolated, proving to be an interesting tool to scale up the motor in future projects. The proposed motor presented an estimated force density of almost 500 N/kg, which is much higher than any linear motor.This work was supported in part by the following agencies: CNPq/CAPES/INERGE, CNPq—Ci ˆ encias sem Fronteiras, FAPERJ, Catalan Government 2014- SGR-753, CONSOLIDER Excellence Network MAT2014-56063-C2-1-R and MAT2015-68994-REDC, Eurofusion EU COST ACTIONS MP1201/ MP1014/PPPT-WPMAG 2014, EUROTAPES FP7-NMP-Large-2011- 280432, FORTISSIMO FP7-2013-ICT-609029, and Spanish Govern- ment Agencies—Severo Ochoa Programme Centres of Excellence in R&D. (Corresponding author: Guilherme G. Sotelo.

Convolutional Goppa Codes

We define Convolutional Goppa Codes over algebraic curves and construct their corresponding dual codes. Examples over the projective line and over elliptic curves are described, obtaining in particular some Maximum-Distance Separable (MDS) convolutional codes.Comment: 8 pages, submitted to IEEE Trans. Inform. Theor

Identificación de productos de Triticum Aestivum en las pastas alimenticias. IV. Lipoproteínas solubles en éter de petróleo

Se ha establecido en trabajos anteriores (1-4) que, si bien el contenido en palmitato de sitosterol es un buen índice de la presencia de productos de Triticum aestivum en las pastas alimenticias, algunas variedades de dicha especie no podían ser detectadas debido a que su contenido en palmitato de sitosterol era similar al de las variedades de T. durum. La búsqueda de nuevas diferencias bioquímicas interespecíficas está justificada, no sólo por este hecho, sino también porque para obtener una buena aproximación en la determinación cuantitativa de productos de T. aestivum en las pastas alimenticias es necesario emplear más de un índice bioquímico, ya que todos ellos han de presentar cierta variabilidad intraespecífica

H-Formulation FEM Modeling of the Current Distribution in 2G HTS Tapes and Its Experimental Validation Using Hall Probe Mapping

One of the most widespread mathematical formulations applied to simulate the electromagnetic phenomena of coated conductor in the recent literature is the H one. However, the only validation of the model has been indirect by using measurements taken from the applications, as measurements of the energy losses in ac fields, forces developed in levitation systems or any other parameter related to a specific application. Direct validation of the calculation requires the observation of the local out of plane magnetic field over the surface of the sample and this is only accessible under magneto-optical observations and, in a larger scale and better dynamic range, by the Hall scanning microscopy. We propose here the experimental validation of the H-formulation by comparing the simulated results with measurements made by a Hall probe mapping in a second generation (2G) tape sample for several DC transported currents at 77 K. The paper presents a methodology to simulate the 2G tape by using only measured data obtained from a sample and its normalized J(B) experimental curves. Some boundary conditions that allow a faster convergence of the problem are investigated. Simulated results of the 2G tape modelled considering only the 1 μm HTS layer were compared with other that represent the most important layers of the coated conductor structure in the calculations. The simulated and measured results present a good agreement, proving that this model can calculate precisely the magnetic field and, hence, the current distribution in HTS samples.This work was supported in part by the followings grants: “Science Without Borders” from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); by the European Agency (EU) through the Factories of the Future Resources, Technology, Infrastructure and Services for Simulation and Modelling (FORTISSIMO) Project under Grant EU FP7-2013-ICT-609029, the European Development of Superconducting Tapes (EUROTAPES) Project under Grant EU-FP7 NMP-LA-2012- 280432, the European Consortium for the Development of Fusion Energy (EUROfusion, PPPT-WPMAG 2014), and EU COST ACTIONS MP1201 and MP1014; by the Spanish Ministry of Economy and Competitiveness through the “Severo Ochoa” Programme for Centres of Excellence in R&D under Grant SEV-2015-0496, CONSOLIDER Excellence Network under Grant MAT2015- 68994-REDC, COACHSUPENERGY project under Grant MAT2014-56063- C2-1-R, co-financed by the European Regional Development Fund; by the Catalan Government under Grant 2014-SGR-753 and Xarmae